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- /*********************************************************************
- *
- * File : $Source: /cvsroot/ijbswa/current/parsers.c,v $
- *
- * Purpose : Declares functions to parse/crunch headers and pages.
- *
- * Copyright : Written by and Copyright (C) 2001-2020 the
- * Privoxy team. https://www.privoxy.org/
- *
- * Based on the Internet Junkbuster originally written
- * by and Copyright (C) 1997 Anonymous Coders and
- * Junkbusters Corporation. http://www.junkbusters.com
- *
- * This program is free software; you can redistribute it
- * and/or modify it under the terms of the GNU General
- * Public License as published by the Free Software
- * Foundation; either version 2 of the License, or (at
- * your option) any later version.
- *
- * This program is distributed in the hope that it will
- * be useful, but WITHOUT ANY WARRANTY; without even the
- * implied warranty of MERCHANTABILITY or FITNESS FOR A
- * PARTICULAR PURPOSE. See the GNU General Public
- * License for more details.
- *
- * The GNU General Public License should be included with
- * this file. If not, you can view it at
- * http://www.gnu.org/copyleft/gpl.html
- * or write to the Free Software Foundation, Inc., 59
- * Temple Place - Suite 330, Boston, MA 02111-1307, USA.
- *
- *********************************************************************/
- #include "config.h"
- #ifndef _WIN32
- #include <stdio.h>
- #include <sys/types.h>
- #endif
- #include <stdlib.h>
- #include <ctype.h>
- #include <assert.h>
- #include <string.h>
- #ifdef __GLIBC__
- /*
- * Convince GNU's libc to provide a strptime prototype.
- */
- #define __USE_XOPEN
- #endif /*__GLIBC__ */
- #include <time.h>
- #ifdef FEATURE_ZLIB
- #include <zlib.h>
- #define GZIP_IDENTIFIER_1 0x1f
- #define GZIP_IDENTIFIER_2 0x8b
- #define GZIP_FLAG_CHECKSUM 0x02
- #define GZIP_FLAG_EXTRA_FIELDS 0x04
- #define GZIP_FLAG_FILE_NAME 0x08
- #define GZIP_FLAG_COMMENT 0x10
- #define GZIP_FLAG_RESERVED_BITS 0xe0
- #endif
- #ifdef FEATURE_BROTLI
- #include <brotli/decode.h>
- #endif
- #if !defined(_WIN32)
- #include <unistd.h>
- #endif
- #include "project.h"
- #ifdef FEATURE_PTHREAD
- #include "jcc.h"
- /* jcc.h is for mutex semapores only */
- #endif /* def FEATURE_PTHREAD */
- #include "list.h"
- #include "parsers.h"
- #include "ssplit.h"
- #include "errlog.h"
- #include "jbsockets.h"
- #include "miscutil.h"
- #include "list.h"
- #include "actions.h"
- #include "filters.h"
- #ifdef FEATURE_HTTPS_INSPECTION
- #include "ssl.h"
- #endif
- #ifndef HAVE_STRPTIME
- #include "strptime.h"
- #endif
- static char *get_header_line(struct iob *iob);
- static jb_err scan_headers(struct client_state *csp);
- static jb_err header_tagger(struct client_state *csp, char *header);
- static jb_err parse_header_time(const char *header_time, time_t *result);
- static jb_err parse_time_header(const char *header, time_t *result);
- static jb_err crumble (struct client_state *csp, char **header);
- static jb_err filter_header (struct client_state *csp, char **header);
- static jb_err client_connection (struct client_state *csp, char **header);
- static jb_err client_referrer (struct client_state *csp, char **header);
- static jb_err client_uagent (struct client_state *csp, char **header);
- static jb_err client_ua (struct client_state *csp, char **header);
- static jb_err client_from (struct client_state *csp, char **header);
- static jb_err client_send_cookie (struct client_state *csp, char **header);
- static jb_err client_x_forwarded (struct client_state *csp, char **header);
- static jb_err client_accept_encoding (struct client_state *csp, char **header);
- static jb_err client_te (struct client_state *csp, char **header);
- static jb_err client_max_forwards (struct client_state *csp, char **header);
- static jb_err client_host (struct client_state *csp, char **header);
- static jb_err client_if_modified_since (struct client_state *csp, char **header);
- static jb_err client_accept_language (struct client_state *csp, char **header);
- static jb_err client_if_none_match (struct client_state *csp, char **header);
- static jb_err crunch_client_header (struct client_state *csp, char **header);
- static jb_err client_x_filter (struct client_state *csp, char **header);
- static jb_err client_range (struct client_state *csp, char **header);
- static jb_err client_expect (struct client_state *csp, char **header);
- static jb_err server_set_cookie (struct client_state *csp, char **header);
- static jb_err server_connection (struct client_state *csp, char **header);
- static jb_err server_content_type (struct client_state *csp, char **header);
- static jb_err server_adjust_content_length(struct client_state *csp, char **header);
- static jb_err server_content_md5 (struct client_state *csp, char **header);
- static jb_err server_content_encoding (struct client_state *csp, char **header);
- static jb_err server_transfer_coding (struct client_state *csp, char **header);
- static jb_err server_http (struct client_state *csp, char **header);
- static jb_err crunch_server_header (struct client_state *csp, char **header);
- static jb_err server_last_modified (struct client_state *csp, char **header);
- static jb_err server_content_disposition(struct client_state *csp, char **header);
- #ifdef FEATURE_ZLIB
- static jb_err server_adjust_content_encoding(struct client_state *csp, char **header);
- #endif
- #ifdef FEATURE_CONNECTION_KEEP_ALIVE
- static jb_err server_save_content_length(struct client_state *csp, char **header);
- static jb_err server_keep_alive(struct client_state *csp, char **header);
- static jb_err server_proxy_connection(struct client_state *csp, char **header);
- static jb_err client_keep_alive(struct client_state *csp, char **header);
- static jb_err client_proxy_connection(struct client_state *csp, char **header);
- #endif /* def FEATURE_CONNECTION_KEEP_ALIVE */
- static jb_err client_save_content_length(struct client_state *csp, char **header);
- static jb_err client_host_adder (struct client_state *csp);
- static jb_err client_xtra_adder (struct client_state *csp);
- static jb_err client_x_forwarded_for_adder(struct client_state *csp);
- static jb_err client_connection_header_adder(struct client_state *csp);
- static jb_err server_connection_adder(struct client_state *csp);
- #ifdef FEATURE_CONNECTION_KEEP_ALIVE
- static jb_err server_proxy_connection_adder(struct client_state *csp);
- #endif /* def FEATURE_CONNECTION_KEEP_ALIVE */
- static jb_err proxy_authentication(struct client_state *csp, char **header);
- static jb_err create_forged_referrer(char **header, const char *hostport);
- static jb_err create_fake_referrer(char **header, const char *fake_referrer);
- static jb_err handle_conditional_hide_referrer_parameter(char **header,
- const char *host, const int parameter_conditional_block);
- static void create_content_length_header(unsigned long long content_length,
- char *header, size_t buffer_length);
- /*
- * List of functions to run on a list of headers.
- */
- struct parsers
- {
- /** The header prefix to match */
- const char *str;
- /** The length of the prefix to match */
- const size_t len;
- /** The function to apply to this line */
- const parser_func_ptr parser;
- };
- static const struct parsers client_patterns[] = {
- { "referer:", 8, client_referrer },
- { "user-agent:", 11, client_uagent },
- { "ua-", 3, client_ua },
- { "from:", 5, client_from },
- { "cookie:", 7, client_send_cookie },
- { "x-forwarded-for:", 16, client_x_forwarded },
- { "Accept-Encoding:", 16, client_accept_encoding },
- { "TE:", 3, client_te },
- { "Host:", 5, client_host },
- { "if-modified-since:", 18, client_if_modified_since },
- { "Content-Length:", 15, client_save_content_length },
- #ifdef FEATURE_CONNECTION_KEEP_ALIVE
- { "Keep-Alive:", 11, client_keep_alive },
- { "Proxy-Connection:", 17, client_proxy_connection },
- #else
- { "Keep-Alive:", 11, crumble },
- { "Proxy-Connection:", 17, crumble },
- #endif
- { "connection:", 11, client_connection },
- { "max-forwards:", 13, client_max_forwards },
- { "Accept-Language:", 16, client_accept_language },
- { "if-none-match:", 14, client_if_none_match },
- { "Range:", 6, client_range },
- { "Request-Range:", 14, client_range },
- { "If-Range:", 9, client_range },
- { "X-Filter:", 9, client_x_filter },
- { "Proxy-Authorization:", 20, proxy_authentication },
- #if 0
- { "Transfer-Encoding:", 18, client_transfer_encoding },
- #endif
- { "Expect:", 7, client_expect },
- { "*", 0, crunch_client_header },
- { "*", 0, filter_header },
- { NULL, 0, NULL }
- };
- static const struct parsers server_patterns[] = {
- { "HTTP/", 5, server_http },
- { "set-cookie:", 11, server_set_cookie },
- { "connection:", 11, server_connection },
- { "Content-Type:", 13, server_content_type },
- { "Content-MD5:", 12, server_content_md5 },
- { "Content-Encoding:", 17, server_content_encoding },
- #ifdef FEATURE_CONNECTION_KEEP_ALIVE
- { "Content-Length:", 15, server_save_content_length },
- { "Keep-Alive:", 11, server_keep_alive },
- { "Proxy-Connection:", 17, server_proxy_connection },
- #else
- { "Keep-Alive:", 11, crumble },
- #endif /* def FEATURE_CONNECTION_KEEP_ALIVE */
- { "Transfer-Encoding:", 18, server_transfer_coding },
- { "content-disposition:", 20, server_content_disposition },
- { "Last-Modified:", 14, server_last_modified },
- { "Proxy-Authenticate:", 19, proxy_authentication },
- { "*", 0, crunch_server_header },
- { "*", 0, filter_header },
- { NULL, 0, NULL }
- };
- static const add_header_func_ptr add_client_headers[] = {
- client_host_adder,
- client_x_forwarded_for_adder,
- client_xtra_adder,
- client_connection_header_adder,
- NULL
- };
- static const add_header_func_ptr add_server_headers[] = {
- server_connection_adder,
- #ifdef FEATURE_CONNECTION_KEEP_ALIVE
- server_proxy_connection_adder,
- #endif /* def FEATURE_CONNECTION_KEEP_ALIVE */
- NULL
- };
- /*********************************************************************
- *
- * Function : flush_iob
- *
- * Description : Write any pending "buffered" content.
- *
- * Parameters :
- * 1 : fd = file descriptor of the socket to read
- * 2 : iob = The I/O buffer to flush, usually csp->iob.
- * 3 : delay = Number of milliseconds to delay the writes
- *
- * Returns : On success, the number of bytes written are returned (zero
- * indicates nothing was written). On error, -1 is returned,
- * and errno is set appropriately. If count is zero and the
- * file descriptor refers to a regular file, 0 will be
- * returned without causing any other effect. For a special
- * file, the results are not portable.
- *
- *********************************************************************/
- long flush_iob(jb_socket fd, struct iob *iob, unsigned int delay)
- {
- long len = iob->eod - iob->cur;
- if (len <= 0)
- {
- return(0);
- }
- if (write_socket_delayed(fd, iob->cur, (size_t)len, delay))
- {
- return(-1);
- }
- iob->eod = iob->cur = iob->buf;
- return(len);
- }
- /*********************************************************************
- *
- * Function : add_to_iob
- *
- * Description : Add content to the buffer, expanding the
- * buffer if necessary.
- *
- * Parameters :
- * 1 : iob = Destination buffer.
- * 2 : buffer_limit = Limit to which the destination may grow
- * 3 : src = holds the content to be added
- * 4 : n = number of bytes to be added
- *
- * Returns : JB_ERR_OK on success, JB_ERR_MEMORY if out-of-memory
- * or buffer limit reached.
- *
- *********************************************************************/
- jb_err add_to_iob(struct iob *iob, const size_t buffer_limit, char *src, long n)
- {
- size_t used, offset, need;
- char *p;
- if (n <= 0) return JB_ERR_OK;
- used = (size_t)(iob->eod - iob->buf);
- offset = (size_t)(iob->cur - iob->buf);
- need = used + (size_t)n + 1;
- /*
- * If the buffer can't hold the new data, extend it first.
- * Use the next power of two if possible, else use the actual need.
- */
- if (need > buffer_limit)
- {
- log_error(LOG_LEVEL_INFO,
- "Buffer limit reached while extending the buffer (iob). Needed: %lu. Limit: %lu",
- need, buffer_limit);
- return JB_ERR_MEMORY;
- }
- if (need > iob->size)
- {
- size_t want = iob->size ? iob->size : 512;
- while (want <= need)
- {
- want *= 2;
- }
- if (want <= buffer_limit && NULL != (p = (char *)realloc(iob->buf, want)))
- {
- iob->size = want;
- }
- else if (NULL != (p = (char *)realloc(iob->buf, need)))
- {
- iob->size = need;
- }
- else
- {
- log_error(LOG_LEVEL_ERROR, "Extending the buffer (iob) failed: %E");
- return JB_ERR_MEMORY;
- }
- /* Update the iob pointers */
- iob->cur = p + offset;
- iob->eod = p + used;
- iob->buf = p;
- }
- /* copy the new data into the iob buffer */
- memcpy(iob->eod, src, (size_t)n);
- /* point to the end of the data */
- iob->eod += n;
- /* null terminate == cheap insurance */
- *iob->eod = '\0';
- return JB_ERR_OK;
- }
- /*********************************************************************
- *
- * Function : clear_iob
- *
- * Description : Frees the memory allocated for an I/O buffer and
- * resets the structure.
- *
- * Parameters :
- * 1 : iob = I/O buffer to clear.
- *
- * Returns : N/A
- *
- *********************************************************************/
- void clear_iob(struct iob *iob)
- {
- free(iob->buf);
- memset(iob, '\0', sizeof(*iob));
- }
- #ifdef FEATURE_ZLIB
- #ifdef FEATURE_BROTLI
- /*********************************************************************
- *
- * Function : decompress_iob_with_brotli
- *
- * Description : Decompress buffered page using Brotli.
- *
- * Parameters :
- * 1 : csp = Current client state (buffers, headers, etc...)
- *
- * Returns : JB_ERR_OK on success,
- * JB_ERR_MEMORY if out-of-memory limit reached, and
- * JB_ERR_COMPRESS if error decompressing buffer.
- *
- *********************************************************************/
- static jb_err decompress_iob_with_brotli(struct client_state *csp)
- {
- BrotliDecoderResult result;
- char *decoded_buffer;
- size_t decoded_size;
- size_t decoded_buffer_size;
- size_t encoded_size;
- enum { MAX_COMPRESSION_FACTOR = 15 };
- encoded_size = (size_t)(csp->iob->eod - csp->iob->cur);
- /*
- * The BrotliDecoderDecompress() api is a bit unfortunate
- * and requires the caller to reserve enough memory for
- * the decompressed content. Hopefully reserving
- * MAX_COMPRESSION_FACTOR times the original size is
- * sufficient. If not, BrotliDecoderDecompress() will fail.
- */
- decoded_buffer_size = encoded_size * MAX_COMPRESSION_FACTOR;
- if (decoded_buffer_size > csp->config->buffer_limit)
- {
- log_error(LOG_LEVEL_ERROR,
- "Buffer limit reached before decompressing iob with Brotli");
- return JB_ERR_MEMORY;
- }
- decoded_buffer = malloc(decoded_buffer_size);
- if (decoded_buffer == NULL)
- {
- log_error(LOG_LEVEL_ERROR,
- "Failed to allocate %lu bytes for Brotli decompression",
- decoded_buffer_size);
- return JB_ERR_MEMORY;
- }
- decoded_size = decoded_buffer_size;
- result = BrotliDecoderDecompress(encoded_size,
- (const uint8_t *)csp->iob->cur, &decoded_size,
- (uint8_t *)decoded_buffer);
- if (result == BROTLI_DECODER_RESULT_SUCCESS)
- {
- /*
- * Update the iob, since the decompression was successful.
- */
- freez(csp->iob->buf);
- csp->iob->buf = decoded_buffer;
- csp->iob->cur = csp->iob->buf;
- csp->iob->eod = csp->iob->cur + decoded_size;
- csp->iob->size = decoded_buffer_size;
- log_error(LOG_LEVEL_RE_FILTER,
- "Decompression successful. Old size: %lu, new size: %lu.",
- encoded_size, decoded_size);
- return JB_ERR_OK;
- }
- else
- {
- log_error(LOG_LEVEL_ERROR, "Failed to decompress buffer with Brotli");
- freez(decoded_buffer);
- return JB_ERR_COMPRESS;
- }
- }
- #endif
- /*********************************************************************
- *
- * Function : decompress_iob
- *
- * Description : Decompress buffered page, expanding the
- * buffer as necessary. csp->iob->cur
- * should point to the the beginning of the
- * compressed data block.
- *
- * Parameters :
- * 1 : csp = Current client state (buffers, headers, etc...)
- *
- * Returns : JB_ERR_OK on success,
- * JB_ERR_MEMORY if out-of-memory limit reached, and
- * JB_ERR_COMPRESS if error decompressing buffer.
- *
- *********************************************************************/
- jb_err decompress_iob(struct client_state *csp)
- {
- char *buf; /* new, uncompressed buffer */
- char *cur; /* Current iob position (to keep the original
- * iob->cur unmodified if we return early) */
- size_t bufsize; /* allocated size of the new buffer */
- size_t old_size; /* Content size before decompression */
- size_t skip_size; /* Number of bytes at the beginning of the iob
- that we should NOT decompress. */
- int status; /* return status of the inflate() call */
- z_stream zstr; /* used by calls to zlib */
- #ifdef FUZZ
- assert(csp->iob->cur - csp->iob->buf >= 0);
- assert(csp->iob->eod - csp->iob->cur >= 0);
- #else
- assert(csp->iob->cur - csp->iob->buf > 0);
- assert(csp->iob->eod - csp->iob->cur > 0);
- #endif
- bufsize = csp->iob->size;
- skip_size = (size_t)(csp->iob->cur - csp->iob->buf);
- old_size = (size_t)(csp->iob->eod - csp->iob->cur);
- cur = csp->iob->cur;
- if (bufsize < (size_t)10)
- {
- /*
- * This is to protect the parsing of gzipped data,
- * but it should(?) be valid for deflated data also.
- */
- log_error(LOG_LEVEL_ERROR,
- "Insufficient data to start decompression. Bytes in buffer: %ld",
- csp->iob->eod - csp->iob->cur);
- return JB_ERR_COMPRESS;
- }
- #ifdef FEATURE_BROTLI
- if (csp->content_type & CT_BROTLI)
- {
- return decompress_iob_with_brotli(csp);
- }
- #endif
- if (csp->content_type & CT_GZIP)
- {
- /*
- * Our task is slightly complicated by the facts that data
- * compressed by gzip does not include a zlib header, and
- * that there is no easily accessible interface in zlib to
- * handle a gzip header. We strip off the gzip header by
- * hand, and later inform zlib not to expect a header.
- */
- /*
- * Strip off the gzip header. Please see RFC 1952 for more
- * explanation of the appropriate fields.
- */
- if (((*cur++ & 0xff) != GZIP_IDENTIFIER_1)
- || ((*cur++ & 0xff) != GZIP_IDENTIFIER_2)
- || (*cur++ != Z_DEFLATED))
- {
- log_error(LOG_LEVEL_ERROR, "Invalid gzip header when decompressing");
- return JB_ERR_COMPRESS;
- }
- else
- {
- int flags = *cur++;
- if (flags & GZIP_FLAG_RESERVED_BITS)
- {
- /* The gzip header has reserved bits set; bail out. */
- log_error(LOG_LEVEL_ERROR, "Invalid gzip header flags when decompressing");
- return JB_ERR_COMPRESS;
- }
- /*
- * Skip mtime (4 bytes), extra flags (1 byte)
- * and OS type (1 byte).
- */
- cur += 6;
- /* Skip extra fields if necessary. */
- if (flags & GZIP_FLAG_EXTRA_FIELDS)
- {
- /*
- * Skip a given number of bytes, specified
- * as a 16-bit little-endian value.
- *
- * XXX: this code is untested and should probably be removed.
- */
- int skip_bytes;
- skip_bytes = *cur++;
- skip_bytes += *cur++ << 8;
- /*
- * The number of bytes to skip should be positive
- * and we'd like to stay in the buffer.
- */
- if ((skip_bytes < 0) || (skip_bytes >= (csp->iob->eod - cur)))
- {
- log_error(LOG_LEVEL_ERROR,
- "Unreasonable amount of bytes to skip (%d). Stopping decompression",
- skip_bytes);
- return JB_ERR_COMPRESS;
- }
- log_error(LOG_LEVEL_INFO,
- "Skipping %d bytes for gzip compression. Does this sound right?",
- skip_bytes);
- cur += skip_bytes;
- }
- /* Skip the filename if necessary. */
- if (flags & GZIP_FLAG_FILE_NAME)
- {
- /* A null-terminated string is supposed to follow. */
- while (*cur++ && (cur < csp->iob->eod));
- }
- /* Skip the comment if necessary. */
- if (flags & GZIP_FLAG_COMMENT)
- {
- /* A null-terminated string is supposed to follow. */
- while (*cur++ && (cur < csp->iob->eod));
- }
- /* Skip the CRC if necessary. */
- if (flags & GZIP_FLAG_CHECKSUM)
- {
- cur += 2;
- }
- if (cur >= csp->iob->eod)
- {
- /*
- * If the current position pointer reached or passed
- * the buffer end, we were obviously tricked to skip
- * too much.
- */
- log_error(LOG_LEVEL_ERROR,
- "Malformed gzip header detected. Aborting decompression.");
- return JB_ERR_COMPRESS;
- }
- }
- }
- else if (csp->content_type & CT_DEFLATE)
- {
- /*
- * In theory (that is, according to RFC 1950), deflate-compressed
- * data should begin with a two-byte zlib header and have an
- * adler32 checksum at the end. It seems that in practice only
- * the raw compressed data is sent. Note that this means that
- * we are not RFC 1950-compliant here, but the advantage is that
- * this actually works. :)
- *
- * We add a dummy null byte to tell zlib where the data ends,
- * and later inform it not to expect a header.
- *
- * Fortunately, add_to_iob() has thoughtfully null-terminated
- * the buffer; we can just increment the end pointer to include
- * the dummy byte.
- */
- csp->iob->eod++;
- }
- else
- {
- log_error(LOG_LEVEL_ERROR,
- "Unable to determine compression format for decompression");
- return JB_ERR_COMPRESS;
- }
- /* Set up the fields required by zlib. */
- zstr.next_in = (Bytef *)cur;
- zstr.avail_in = (unsigned int)(csp->iob->eod - cur);
- zstr.zalloc = Z_NULL;
- zstr.zfree = Z_NULL;
- zstr.opaque = Z_NULL;
- /*
- * Passing -MAX_WBITS to inflateInit2 tells the library
- * that there is no zlib header.
- */
- if (inflateInit2(&zstr, -MAX_WBITS) != Z_OK)
- {
- log_error(LOG_LEVEL_ERROR, "Error initializing decompression");
- return JB_ERR_COMPRESS;
- }
- /*
- * Next, we allocate new storage for the inflated data.
- * We don't modify the existing iob yet, so in case there
- * is error in decompression we can recover gracefully.
- */
- buf = zalloc(bufsize);
- if (NULL == buf)
- {
- log_error(LOG_LEVEL_ERROR, "Out of memory decompressing iob");
- return JB_ERR_MEMORY;
- }
- assert(bufsize >= skip_size);
- memcpy(buf, csp->iob->buf, skip_size);
- zstr.avail_out = (uInt)(bufsize - skip_size);
- zstr.next_out = (Bytef *)buf + skip_size;
- /* Try to decompress the whole stream in one shot. */
- while (Z_BUF_ERROR == (status = inflate(&zstr, Z_FINISH)))
- {
- /* We need to allocate more memory for the output buffer. */
- char *tmpbuf; /* used for realloc'ing the buffer */
- size_t oldbufsize = bufsize; /* keep track of the old bufsize */
- if (0 == zstr.avail_in)
- {
- /*
- * If zlib wants more data then there's a problem, because
- * the complete compressed file should have been buffered.
- */
- log_error(LOG_LEVEL_ERROR,
- "Unexpected end of compressed iob. Using what we got so far.");
- break;
- }
- /*
- * If we reached the buffer limit and still didn't have enough
- * memory, just give up. Due to the ceiling enforced by the next
- * if block we could actually check for equality here, but as it
- * can be easily mistaken for a bug we don't.
- */
- if (bufsize >= csp->config->buffer_limit)
- {
- log_error(LOG_LEVEL_ERROR, "Buffer limit reached while decompressing iob");
- freez(buf);
- inflateEnd(&zstr);
- return JB_ERR_MEMORY;
- }
- /* Try doubling the buffer size each time. */
- bufsize *= 2;
- /* Don't exceed the buffer limit. */
- if (bufsize > csp->config->buffer_limit)
- {
- bufsize = csp->config->buffer_limit;
- }
- /* Try to allocate the new buffer. */
- tmpbuf = realloc(buf, bufsize);
- if (NULL == tmpbuf)
- {
- log_error(LOG_LEVEL_ERROR, "Out of memory decompressing iob");
- freez(buf);
- inflateEnd(&zstr);
- return JB_ERR_MEMORY;
- }
- else
- {
- char *oldnext_out = (char *)zstr.next_out;
- /*
- * Update the fields for inflate() to use the new
- * buffer, which may be in a location different from
- * the old one.
- */
- zstr.avail_out += (uInt)(bufsize - oldbufsize);
- zstr.next_out = (Bytef *)tmpbuf + bufsize - zstr.avail_out;
- /*
- * Compare with an uglier method of calculating these values
- * that doesn't require the extra oldbufsize variable.
- */
- assert(zstr.avail_out == tmpbuf + bufsize - (char *)zstr.next_out);
- assert((char *)zstr.next_out == tmpbuf + ((char *)oldnext_out - buf));
- buf = tmpbuf;
- }
- }
- if (Z_STREAM_ERROR == inflateEnd(&zstr))
- {
- log_error(LOG_LEVEL_ERROR,
- "Inconsistent stream state after decompression: %s", zstr.msg);
- /*
- * XXX: Intentionally no return.
- *
- * According to zlib.h, Z_STREAM_ERROR is returned
- * "if the stream state was inconsistent".
- *
- * I assume in this case inflate()'s status
- * would also be something different than Z_STREAM_END
- * so this check should be redundant, but lets see.
- */
- }
- if ((status != Z_STREAM_END) && (0 != zstr.avail_in))
- {
- /*
- * We failed to decompress the stream and it's
- * not simply because of missing data.
- */
- log_error(LOG_LEVEL_ERROR,
- "Unexpected error while decompressing to the buffer (iob): %s",
- zstr.msg);
- return JB_ERR_COMPRESS;
- }
- /*
- * Finally, we can actually update the iob, since the
- * decompression was successful. First, free the old
- * buffer.
- */
- freez(csp->iob->buf);
- /* Now, update the iob to use the new buffer. */
- csp->iob->buf = buf;
- csp->iob->cur = csp->iob->buf + skip_size;
- csp->iob->eod = (char *)zstr.next_out;
- csp->iob->size = bufsize;
- /*
- * Make sure the new uncompressed iob obeys some minimal
- * consistency conditions.
- */
- if ((csp->iob->buf <= csp->iob->cur)
- && (csp->iob->cur <= csp->iob->eod)
- && (csp->iob->eod <= csp->iob->buf + csp->iob->size))
- {
- const size_t new_size = (size_t)(csp->iob->eod - csp->iob->cur);
- if (new_size > (size_t)0)
- {
- log_error(LOG_LEVEL_RE_FILTER,
- "Decompression successful. Old size: %lu, new size: %lu.",
- old_size, new_size);
- }
- else
- {
- /* zlib thinks this is OK, so let's do the same. */
- log_error(LOG_LEVEL_RE_FILTER,
- "Decompression didn't result in any content.");
- }
- }
- else
- {
- /* It seems that zlib did something weird. */
- log_error(LOG_LEVEL_ERROR, "Inconsistent buffer after decompression");
- return JB_ERR_COMPRESS;
- }
- return JB_ERR_OK;
- }
- #endif /* defined(FEATURE_ZLIB) */
- /*********************************************************************
- *
- * Function : normalize_lws
- *
- * Description : Reduces unquoted linear whitespace in headers to
- * a single space in accordance with RFC 7230 3.2.4.
- * This simplifies parsing and filtering later on.
- *
- * Parameters :
- * 1 : header = A header with linear whitespace to reduce.
- *
- * Returns : N/A
- *
- *********************************************************************/
- static void normalize_lws(char *header)
- {
- char *p = header;
- while (*p != '\0')
- {
- if (privoxy_isspace(*p) && privoxy_isspace(*(p+1)))
- {
- char *q = p+1;
- while (privoxy_isspace(*q))
- {
- q++;
- }
- log_error(LOG_LEVEL_HEADER, "Reducing whitespace in '%s'", header);
- string_move(p+1, q);
- }
- if (*p == '\t')
- {
- log_error(LOG_LEVEL_HEADER,
- "Converting tab to space in '%s'", header);
- *p = ' ';
- }
- else if (*p == '"')
- {
- char *end_of_token = strstr(p+1, "\"");
- if (NULL != end_of_token)
- {
- /* Don't mess with quoted text. */
- p = end_of_token;
- }
- else
- {
- log_error(LOG_LEVEL_HEADER,
- "Ignoring single quote in '%s'", header);
- }
- }
- p++;
- }
- p = strchr(header, ':');
- if ((p != NULL) && (p != header) && privoxy_isspace(*(p-1)))
- {
- /*
- * There's still space before the colon.
- * We don't want it.
- */
- string_move(p-1, p);
- }
- }
- /*********************************************************************
- *
- * Function : get_header
- *
- * Description : This (odd) routine will parse the csp->iob
- * to get the next complete header.
- *
- * Parameters :
- * 1 : iob = The I/O buffer to parse, usually csp->iob.
- *
- * Returns : Any one of the following:
- *
- * 1) a pointer to a dynamically allocated string that contains a header line
- * 2) NULL indicating that the end of the header was reached
- * 3) "" indicating that the end of the iob was reached before finding
- * a complete header line.
- *
- *********************************************************************/
- char *get_header(struct iob *iob)
- {
- char *header;
- header = get_header_line(iob);
- if ((header == NULL) || (*header == '\0'))
- {
- /*
- * No complete header read yet, tell the client.
- */
- return header;
- }
- while ((iob->cur[0] == ' ') || (iob->cur[0] == '\t'))
- {
- /*
- * Header spans multiple lines, append the next one.
- */
- char *continued_header;
- continued_header = get_header_line(iob);
- if ((continued_header == NULL) || (*continued_header == '\0'))
- {
- /*
- * No complete header read yet, return what we got.
- * XXX: Should "unread" header instead.
- */
- log_error(LOG_LEVEL_INFO,
- "Failed to read a multi-line header properly: '%s'",
- header);
- break;
- }
- if (JB_ERR_OK != string_join(&header, continued_header))
- {
- log_error(LOG_LEVEL_FATAL,
- "Out of memory while appending multiple headers.");
- }
- else
- {
- /* XXX: remove before next stable release. */
- log_error(LOG_LEVEL_HEADER,
- "Merged multiple header lines to: '%s'",
- header);
- }
- }
- normalize_lws(header);
- return header;
- }
- /*********************************************************************
- *
- * Function : get_header_line
- *
- * Description : This (odd) routine will parse the csp->iob
- * to get the next header line.
- *
- * Parameters :
- * 1 : iob = The I/O buffer to parse, usually csp->iob.
- *
- * Returns : Any one of the following:
- *
- * 1) a pointer to a dynamically allocated string that contains a header line
- * 2) NULL indicating that the end of the header was reached
- * 3) "" indicating that the end of the iob was reached before finding
- * a complete header line.
- *
- *********************************************************************/
- static char *get_header_line(struct iob *iob)
- {
- char *p, *q, *ret;
- if ((iob->cur == NULL)
- || ((p = strchr(iob->cur, '\n')) == NULL))
- {
- return(""); /* couldn't find a complete header */
- }
- *p = '\0';
- ret = strdup(iob->cur);
- if (ret == NULL)
- {
- /* FIXME No way to handle error properly */
- log_error(LOG_LEVEL_FATAL, "Out of memory in get_header_line()");
- }
- assert(ret != NULL);
- iob->cur = p+1;
- if ((q = strchr(ret, '\r')) != NULL) *q = '\0';
- /* is this a blank line (i.e. the end of the header) ? */
- if (*ret == '\0')
- {
- freez(ret);
- return NULL;
- }
- return ret;
- }
- /*********************************************************************
- *
- * Function : get_header_value
- *
- * Description : Get the value of a given header from a chained list
- * of header lines or return NULL if no such header is
- * present in the list.
- *
- * Parameters :
- * 1 : header_list = pointer to list
- * 2 : header_name = string with name of header to look for.
- * Trailing colon required, capitalization
- * doesn't matter.
- *
- * Returns : NULL if not found, else value of header
- *
- *********************************************************************/
- char *get_header_value(const struct list *header_list, const char *header_name)
- {
- struct list_entry *cur_entry;
- char *ret = NULL;
- size_t length = 0;
- assert(header_list);
- assert(header_name);
- length = strlen(header_name);
- for (cur_entry = header_list->first; cur_entry ; cur_entry = cur_entry->next)
- {
- if (cur_entry->str)
- {
- if (!strncmpic(cur_entry->str, header_name, length))
- {
- /*
- * Found: return pointer to start of value
- */
- ret = cur_entry->str + length;
- while (*ret && privoxy_isspace(*ret)) ret++;
- return ret;
- }
- }
- }
- /*
- * Not found
- */
- return NULL;
- }
- /*********************************************************************
- *
- * Function : scan_headers
- *
- * Description : Scans headers, applies tags and updates action bits.
- *
- * Parameters :
- * 1 : csp = Current client state (buffers, headers, etc...)
- *
- * Returns : JB_ERR_OK
- *
- *********************************************************************/
- static jb_err scan_headers(struct client_state *csp)
- {
- struct list_entry *h; /* Header */
- jb_err err = JB_ERR_OK;
- for (h = csp->headers->first; (err == JB_ERR_OK) && (h != NULL) ; h = h->next)
- {
- /* Header crunch()ed in previous run? -> ignore */
- if (h->str == NULL) continue;
- log_error(LOG_LEVEL_HEADER, "scan: %s", h->str);
- err = header_tagger(csp, h->str);
- }
- return err;
- }
- /*********************************************************************
- *
- * Function : enforce_header_order
- *
- * Description : Enforces a given header order.
- *
- * Parameters :
- * 1 : headers = List of headers to order.
- * 2 : ordered_headers = List of ordered header names.
- *
- * Returns : N/A
- *
- *********************************************************************/
- static void enforce_header_order(struct list *headers, const struct list *ordered_headers)
- {
- struct list_entry *sorted_header;
- struct list new_headers[1];
- struct list_entry *header;
- init_list(new_headers);
- /* The request line is always the first "header" */
- assert(NULL != headers->first->str);
- enlist(new_headers, headers->first->str);
- freez(headers->first->str)
- /* Enlist the specified headers in the given order */
- for (sorted_header = ordered_headers->first; sorted_header != NULL;
- sorted_header = sorted_header->next)
- {
- const size_t sorted_header_length = strlen(sorted_header->str);
- for (header = headers->first; header != NULL; header = header->next)
- {
- /* Header enlisted in previous run? -> ignore */
- if (header->str == NULL) continue;
- if (0 == strncmpic(sorted_header->str, header->str, sorted_header_length)
- && (header->str[sorted_header_length] == ':'))
- {
- log_error(LOG_LEVEL_HEADER, "Enlisting sorted header %s", header->str);
- if (JB_ERR_OK != enlist(new_headers, header->str))
- {
- log_error(LOG_LEVEL_HEADER, "Failed to enlist %s", header->str);
- }
- freez(header->str);
- }
- }
- }
- /* Enlist the rest of the headers behind the ordered ones */
- for (header = headers->first; header != NULL; header = header->next)
- {
- /* Header enlisted in previous run? -> ignore */
- if (header->str == NULL) continue;
- log_error(LOG_LEVEL_HEADER,
- "Enlisting left-over header %s", header->str);
- if (JB_ERR_OK != enlist(new_headers, header->str))
- {
- log_error(LOG_LEVEL_HEADER, "Failed to enlist %s", header->str);
- }
- freez(header->str);
- }
- list_remove_all(headers);
- list_duplicate(headers, new_headers);
- list_remove_all(new_headers);
- return;
- }
- /*********************************************************************
- *
- * Function : sed
- *
- * Description : add, delete or modify lines in the HTTP header streams.
- * On entry, it receives a linked list of headers space
- * that was allocated dynamically (both the list nodes
- * and the header contents).
- *
- * As a side effect it frees the space used by the original
- * header lines.
- *
- * Parameters :
- * 1 : csp = Current client state (buffers, headers, etc...)
- * 2 : filter_server_headers = Boolean to switch between
- * server and header filtering.
- *
- * Returns : JB_ERR_OK in case off success, or
- * JB_ERR_MEMORY on some out-of-memory errors, or
- * JB_ERR_PARSE in case of fatal parse errors.
- *
- *********************************************************************/
- jb_err sed(struct client_state *csp, int filter_server_headers)
- {
- /* XXX: use more descriptive names. */
- struct list_entry *p;
- const struct parsers *v;
- const add_header_func_ptr *f;
- jb_err err = JB_ERR_OK;
- scan_headers(csp);
- if (filter_server_headers)
- {
- v = server_patterns;
- f = add_server_headers;
- check_negative_tag_patterns(csp, PATTERN_SPEC_NO_RESPONSE_TAG_PATTERN);
- }
- else
- {
- v = client_patterns;
- f = add_client_headers;
- check_negative_tag_patterns(csp, PATTERN_SPEC_NO_REQUEST_TAG_PATTERN);
- }
- while (v->str != NULL)
- {
- for (p = csp->headers->first; p != NULL; p = p->next)
- {
- /* Header crunch()ed in previous run? -> ignore */
- if (p->str == NULL) continue;
- /* Does the current parser handle this header? */
- if ((strncmpic(p->str, v->str, v->len) == 0) ||
- (v->len == CHECK_EVERY_HEADER_REMAINING))
- {
- err = v->parser(csp, &(p->str));
- if (err != JB_ERR_OK)
- {
- return err;
- }
- }
- }
- v++;
- }
- /* place additional headers on the csp->headers list */
- while ((err == JB_ERR_OK) && (*f))
- {
- err = (*f)(csp);
- f++;
- }
- if (!filter_server_headers && !list_is_empty(csp->config->ordered_client_headers))
- {
- enforce_header_order(csp->headers, csp->config->ordered_client_headers);
- }
- return err;
- }
- #ifdef FEATURE_HTTPS_INSPECTION
- /*********************************************************************
- *
- * Function : sed_https
- *
- * Description : add, delete or modify lines in the HTTPS client
- * header streams. Wrapper around sed().
- *
- * Parameters :
- * 1 : csp = Current client state (buffers, headers, etc...)
- *
- * Returns : JB_ERR_OK in case off success, or
- * JB_ERR_MEMORY on some out-of-memory errors, or
- * JB_ERR_PARSE in case of fatal parse errors.
- *
- *********************************************************************/
- jb_err sed_https(struct client_state *csp)
- {
- jb_err err;
- struct list headers;
- /*
- * Temporarily replace csp->headers with csp->https_headers
- * to trick sed() into filtering the https headers.
- */
- headers.first = csp->headers->first;
- headers.last = csp->headers->last;
- csp->headers->first = csp->https_headers->first;
- csp->headers->last = csp->https_headers->last;
- /*
- * Start with fresh tags. Already existing tags may
- * be set again. This is necessary to overrule
- * URL-based patterns.
- */
- destroy_list(csp->tags);
- /*
- * We want client header filters and taggers
- * so temporarily remove the flag.
- */
- csp->flags &= ~CSP_FLAG_CLIENT_HEADER_PARSING_DONE;
- err = sed(csp, FILTER_CLIENT_HEADERS);
- csp->flags |= CSP_FLAG_CLIENT_HEADER_PARSING_DONE;
- /*
- * Update the last header which may have changed
- * due to header additions,
- */
- csp->https_headers->last = csp->headers->last;
- csp->headers->first = headers.first;
- csp->headers->last = headers.last;
- return err;
- }
- #endif /* def FEATURE_HTTPS_INSPECTION */
- /*********************************************************************
- *
- * Function : update_server_headers
- *
- * Description : Updates server headers after the body has been modified.
- *
- * Parameters :
- * 1 : csp = Current client state (buffers, headers, etc...)
- *
- * Returns : JB_ERR_OK in case off success, or
- * JB_ERR_MEMORY on out-of-memory error.
- *
- *********************************************************************/
- jb_err update_server_headers(struct client_state *csp)
- {
- jb_err err = JB_ERR_OK;
- static const struct parsers server_patterns_light[] = {
- { "Content-Length:", 15, server_adjust_content_length },
- { "Transfer-Encoding:", 18, server_transfer_coding },
- #ifdef FEATURE_ZLIB
- { "Content-Encoding:", 17, server_adjust_content_encoding },
- #endif /* def FEATURE_ZLIB */
- { NULL, 0, NULL }
- };
- if (strncmpic(csp->http->cmd, "HEAD", 4))
- {
- const struct parsers *v;
- struct list_entry *p;
- for (v = server_patterns_light; (err == JB_ERR_OK) && (v->str != NULL); v++)
- {
- for (p = csp->headers->first; (err == JB_ERR_OK) && (p != NULL); p = p->next)
- {
- /* Header crunch()ed in previous run? -> ignore */
- if (p->str == NULL) continue;
- /* Does the current parser handle this header? */
- if (strncmpic(p->str, v->str, v->len) == 0)
- {
- err = v->parser(csp, (char **)&(p->str));
- }
- }
- }
- }
- #ifdef FEATURE_CONNECTION_KEEP_ALIVE
- if ((JB_ERR_OK == err)
- && (csp->flags & CSP_FLAG_MODIFIED)
- && (csp->flags & CSP_FLAG_CLIENT_CONNECTION_KEEP_ALIVE)
- && !(csp->flags & CSP_FLAG_SERVER_CONTENT_LENGTH_SET))
- {
- char header[50];
- create_content_length_header(csp->content_length, header, sizeof(header));
- err = enlist(csp->headers, header);
- if (JB_ERR_OK == err)
- {
- log_error(LOG_LEVEL_HEADER,
- "Content modified with no Content-Length header set. "
- "Created: %s.", header);
- csp->flags |= CSP_FLAG_SERVER_CONTENT_LENGTH_SET;
- }
- }
- #endif /* def FEATURE_CONNECTION_KEEP_ALIVE */
- #ifdef FEATURE_COMPRESSION
- if ((JB_ERR_OK == err)
- && (csp->flags & CSP_FLAG_BUFFERED_CONTENT_DEFLATED))
- {
- err = enlist_unique_header(csp->headers, "Content-Encoding", "deflate");
- if (JB_ERR_OK == err)
- {
- log_error(LOG_LEVEL_HEADER, "Added header: Content-Encoding: deflate");
- }
- }
- #endif
- return err;
- }
- /*********************************************************************
- *
- * Function : header_tagger
- *
- * Description : Executes all text substitutions from applying
- * tag actions and saves the result as tag.
- *
- * XXX: Shares enough code with filter_header() and
- * pcrs_filter_response() to warrant some helper functions.
- *
- * Parameters :
- * 1 : csp = Current client state (buffers, headers, etc...)
- * 2 : header = Header that is used as tagger input
- *
- * Returns : JB_ERR_OK on success and always succeeds
- *
- *********************************************************************/
- static jb_err header_tagger(struct client_state *csp, char *header)
- {
- enum filter_type wanted_filter_type;
- int multi_action_index;
- pcrs_job *job;
- struct re_filterfile_spec *b;
- struct list_entry *tag_name;
- const size_t header_length = strlen(header);
- if (csp->flags & CSP_FLAG_CLIENT_HEADER_PARSING_DONE)
- {
- wanted_filter_type = FT_SERVER_HEADER_TAGGER;
- multi_action_index = ACTION_MULTI_SERVER_HEADER_TAGGER;
- }
- else
- {
- wanted_filter_type = FT_CLIENT_HEADER_TAGGER;
- multi_action_index = ACTION_MULTI_CLIENT_HEADER_TAGGER;
- }
- if (list_is_empty(csp->action->multi[multi_action_index])
- || filters_available(csp) == FALSE)
- {
- /* Return early if no taggers apply or if none are available. */
- return JB_ERR_OK;
- }
- /* Execute all applying taggers */
- for (tag_name = csp->action->multi[multi_action_index]->first;
- NULL != tag_name; tag_name = tag_name->next)
- {
- char *modified_tag = NULL;
- char *tag = header;
- size_t size = header_length;
- pcrs_job *joblist;
- b = get_filter(csp, tag_name->str, wanted_filter_type);
- if (b == NULL)
- {
- continue;
- }
- joblist = b->joblist;
- if (b->dynamic) joblist = compile_dynamic_pcrs_job_list(csp, b);
- if (NULL == joblist)
- {
- log_error(LOG_LEVEL_RE_FILTER,
- "Tagger %s has empty joblist. Nothing to do.", b->name);
- continue;
- }
- /* execute their pcrs_joblist on the header. */
- for (job = joblist; NULL != job; job = job->next)
- {
- const int hits = pcrs_execute(job, tag, size, &modified_tag, &size);
- if (0 < hits)
- {
- /* Success, continue with the modified version. */
- if (tag != header)
- {
- freez(tag);
- }
- tag = modified_tag;
- }
- else
- {
- /* Tagger doesn't match */
- if (0 > hits)
- {
- /* Regex failure, log it but continue anyway. */
- assert(NULL != header);
- log_error(LOG_LEVEL_ERROR,
- "Problems with tagger \'%s\' and header \'%s\': %s",
- b->name, header, pcrs_strerror(hits));
- }
- freez(modified_tag);
- }
- }
- if (b->dynamic) pcrs_free_joblist(joblist);
- /* If this tagger matched */
- if (tag != header)
- {
- if (0 == size)
- {
- /*
- * There is no technical limitation which makes
- * it impossible to use empty tags, but I assume
- * no one would do it intentionally.
- */
- freez(tag);
- log_error(LOG_LEVEL_INFO,
- "Tagger \'%s\' created an empty tag. Ignored.", b->name);
- continue;
- }
- if (!list_contains_item(csp->tags, tag))
- {
- if (JB_ERR_OK != enlist(csp->tags, tag))
- {
- log_error(LOG_LEVEL_ERROR,
- "Insufficient memory to add tag \'%s\', "
- "based on tagger \'%s\' and header \'%s\'",
- tag, b->name, header);
- }
- else
- {
- char *action_message;
- /*
- * update the action bits right away, to make
- * tagging based on tags set by earlier taggers
- * of the same kind possible.
- */
- if (update_action_bits_for_tag(csp, tag))
- {
- action_message = "Action bits updated accordingly.";
- }
- else
- {
- action_message = "No action bits update necessary.";
- }
- log_error(LOG_LEVEL_HEADER,
- "Tagger \'%s\' added tag \'%s\'. %s",
- b->name, tag, action_message);
- }
- }
- else
- {
- /* XXX: Is this log-worthy? */
- log_error(LOG_LEVEL_HEADER,
- "Tagger \'%s\' didn't add tag \'%s\'. Tag already present",
- b->name, tag);
- }
- freez(tag);
- }
- }
- return JB_ERR_OK;
- }
- /* here begins the family of parser functions that reformat header lines */
- /*********************************************************************
- *
- * Function : filter_header
- *
- * Description : Executes all text substitutions from all applying
- * +(server|client)-header-filter actions on the header.
- * Most of the code was copied from pcrs_filter_response,
- * including the rather short variable names
- *
- * Parameters :
- * 1 : csp = Current client state (buffers, headers, etc...)
- * 2 : header = On input, pointer to header to modify.
- * On output, pointer to the modified header, or NULL
- * to remove the header. This function frees the
- * original string if necessary.
- *
- * Returns : JB_ERR_OK on success and always succeeds
- *
- *********************************************************************/
- static jb_err filter_header(struct client_state *csp, char **header)
- {
- int hits=0;
- int matches;
- size_t size = strlen(*header);
- char *newheader = NULL;
- pcrs_job *job;
- struct re_filterfile_spec *b;
- struct list_entry *filtername;
- enum filter_type wanted_filter_type;
- int multi_action_index;
- if (csp->flags & CSP_FLAG_NO_FILTERING)
- {
- return JB_ERR_OK;
- }
- if (csp->flags & CSP_FLAG_CLIENT_HEADER_PARSING_DONE)
- {
- wanted_filter_type = FT_SERVER_HEADER_FILTER;
- multi_action_index = ACTION_MULTI_SERVER_HEADER_FILTER;
- }
- else
- {
- wanted_filter_type = FT_CLIENT_HEADER_FILTER;
- multi_action_index = ACTION_MULTI_CLIENT_HEADER_FILTER;
- }
- if (list_is_empty(csp->action->multi[multi_action_index])
- || filters_available(csp) == FALSE)
- {
- /* Return early if no filters apply or if none are available. */
- return JB_ERR_OK;
- }
- /* Execute all applying header filters */
- for (filtername = csp->action->multi[multi_action_index]->first;
- filtername != NULL; filtername = filtername->next)
- {
- int current_hits = 0;
- pcrs_job *joblist;
- b = get_filter(csp, filtername->str, wanted_filter_type);
- if (b == NULL)
- {
- continue;
- }
- joblist = b->joblist;
- if (b->dynamic) joblist = compile_dynamic_pcrs_job_list(csp, b);
- if (NULL == joblist)
- {
- log_error(LOG_LEVEL_RE_FILTER, "Filter %s has empty joblist. Nothing to do.", b->name);
- continue;
- }
- log_error(LOG_LEVEL_RE_FILTER, "filtering \'%s\' (size %lu) with \'%s\' ...",
- *header, size, b->name);
- /* Apply all jobs from the joblist */
- for (job = joblist; NULL != job; job = job->next)
- {
- matches = pcrs_execute(job, *header, size, &newheader, &size);
- if (0 < matches)
- {
- current_hits += matches;
- log_error(LOG_LEVEL_HEADER, "Transforming \"%s\" to \"%s\"", *header, newheader);
- freez(*header);
- *header = newheader;
- }
- else if (0 == matches)
- {
- /* Filter doesn't change header */
- freez(newheader);
- }
- else
- {
- /* RegEx failure */
- log_error(LOG_LEVEL_ERROR, "Filtering \'%s\' with \'%s\' didn't work out: %s",
- *header, b->name, pcrs_strerror(matches));
- if (newheader != NULL)
- {
- log_error(LOG_LEVEL_ERROR, "Freeing what's left: %s", newheader);
- freez(newheader);
- }
- }
- }
- if (b->dynamic) pcrs_free_joblist(joblist);
- log_error(LOG_LEVEL_RE_FILTER,
- "... produced %d hits (new size %lu).", current_hits, size);
- hits += current_hits;
- }
- /*
- * Additionally checking for hits is important because if
- * the continue hack is triggered, server headers can
- * arrive empty to separate multiple heads from each other.
- */
- if ((0 == size) && hits)
- {
- log_error(LOG_LEVEL_HEADER, "Removing empty header %s", *header);
- freez(*header);
- }
- return JB_ERR_OK;
- }
- /*********************************************************************
- *
- * Function : server_connection
- *
- * Description : Makes sure a proper "Connection:" header is
- * set and signals connection_header_adder to
- * do nothing.
- *
- * Parameters :
- * 1 : csp = Current client state (buffers, headers, etc...)
- * 2 : header = On input, pointer to header to modify.
- * On output, pointer to the modified header, or NULL
- * to remove the header. This function frees the
- * original string if necessary.
- *
- * Returns : JB_ERR_OK on success.
- *
- *********************************************************************/
- static jb_err server_connection(struct client_state *csp, char **header)
- {
- if (!strcmpic(*header, "Connection: keep-alive")
- #ifdef FEATURE_CONNECTION_KEEP_ALIVE
- && !(csp->flags & CSP_FLAG_SERVER_SOCKET_TAINTED)
- #endif
- )
- {
- #ifdef FEATURE_CONNECTION_KEEP_ALIVE
- if ((csp->config->feature_flags & RUNTIME_FEATURE_CONNECTION_KEEP_ALIVE))
- {
- csp->flags |= CSP_FLAG_SERVER_CONNECTION_KEEP_ALIVE;
- }
- if ((csp->flags & CSP_FLAG_CLIENT_CONNECTION_KEEP_ALIVE))
- {
- log_error(LOG_LEVEL_HEADER,
- "Keeping the server header '%s' around.", *header);
- }
- else
- #endif /* FEATURE_CONNECTION_KEEP_ALIVE */
- {
- char *old_header = *header;
- *header = strdup_or_die("Connection: close");
- log_error(LOG_LEVEL_HEADER, "Replaced: \'%s\' with \'%s\'", old_header, *header);
- freez(old_header);
- }
- }
- /* Signal server_connection_adder() to return early. */
- csp->flags |= CSP_FLAG_SERVER_CONNECTION_HEADER_SET;
- return JB_ERR_OK;
- }
- #ifdef FEATURE_CONNECTION_KEEP_ALIVE
- /*********************************************************************
- *
- * Function : server_keep_alive
- *
- * Description : Stores the server's keep alive timeout.
- *
- * Parameters :
- * 1 : csp = Current client state (buffers, headers, etc...)
- * 2 : header = On input, pointer to header to modify.
- * On output, pointer to the modified header, or NULL
- * to remove the header. This function frees the
- * original string if necessary.
- *
- * Returns : JB_ERR_OK.
- *
- *********************************************************************/
- static jb_err server_keep_alive(struct client_state *csp, char **header)
- {
- unsigned int keep_alive_timeout;
- const char *timeout_position = strstr(*header, "timeout=");
- if ((NULL == timeout_position)
- || (1 != sscanf(timeout_position, "timeout=%u", &keep_alive_timeout)))
- {
- log_error(LOG_LEVEL_ERROR, "Couldn't parse: %s", *header);
- }
- else
- {
- if (keep_alive_timeout < csp->server_connection.keep_alive_timeout)
- {
- log_error(LOG_LEVEL_HEADER,
- "Reducing keep-alive timeout from %u to %u.",
- csp->server_connection.keep_alive_timeout, keep_alive_timeout);
- csp->server_connection.keep_alive_timeout = keep_alive_timeout;
- }
- else
- {
- /* XXX: Is this log worthy? */
- log_error(LOG_LEVEL_HEADER,
- "Server keep-alive timeout is %u. Sticking with %u.",
- keep_alive_timeout, csp->server_connection.keep_alive_timeout);
- }
- csp->flags |= CSP_FLAG_SERVER_KEEP_ALIVE_TIMEOUT_SET;
- }
- freez(*header);
- return JB_ERR_OK;
- }
- /*********************************************************************
- *
- * Function : server_proxy_connection
- *
- * Description : Figures out whether or not we should add a
- * Proxy-Connection header.
- *
- * Parameters :
- * 1 : csp = Current client state (buffers, headers, etc...)
- * 2 : header = On input, pointer to header to modify.
- * On output, pointer to the modified header, or NULL
- * to remove the header. This function frees the
- * original string if necessary.
- *
- * Returns : JB_ERR_OK.
- *
- *********************************************************************/
- static jb_err server_proxy_connection(struct client_state *csp, char **header)
- {
- csp->flags |= CSP_FLAG_SERVER_PROXY_CONNECTION_HEADER_SET;
- return JB_ERR_OK;
- }
- #endif /* def FEATURE_CONNECTION_KEEP_ALIVE */
- /*********************************************************************
- *
- * Function : proxy_authentication
- *
- * Description : Removes headers that are relevant for proxy
- * authentication unless forwarding them has
- * been explicitly requested.
- *
- * Parameters :
- * 1 : csp = Current client state (buffers, headers, etc...)
- * 2 : header = On input, pointer to header to modify.
- * On output, pointer to the modified header, or NULL
- * to remove the header. This function frees the
- * original string if necessary.
- *
- * Returns : JB_ERR_OK.
- *
- *********************************************************************/
- static jb_err proxy_authentication(struct client_state *csp, char **header)
- {
- if ((csp->config->feature_flags &
- RUNTIME_FEATURE_FORWARD_PROXY_AUTHENTICATION_HEADERS) == 0) {
- log_error(LOG_LEVEL_HEADER,
- "Forwarding proxy authentication headers is disabled. Crunching: %s", *header);
- freez(*header);
- }
- return JB_ERR_OK;
- }
- #ifdef FEATURE_CONNECTION_KEEP_ALIVE
- /*********************************************************************
- *
- * Function : client_keep_alive
- *
- * Description : Stores the client's keep alive timeout.
- *
- * Parameters :
- * 1 : csp = Current client state (buffers, headers, etc...)
- * 2 : header = On input, pointer to header to modify.
- * On output, pointer to the modified header, or NULL
- * to remove the header. This function frees the
- * original string if necessary.
- *
- * Returns : JB_ERR_OK.
- *
- *********************************************************************/
- static jb_err client_keep_alive(struct client_state *csp, char **header)
- {
- unsigned int keep_alive_timeout;
- char *timeout_position;
- if (!(csp->config->feature_flags & RUNTIME_FEATURE_CONNECTION_KEEP_ALIVE))
- {
- log_error(LOG_LEVEL_HEADER,
- "keep-alive support is disabled. Crunching: %s.", *header);
- freez(*header);
- return JB_ERR_OK;
- }
- /* Check for parameter-less format "Keep-Alive: 100" */
- timeout_position = strstr(*header, ": ");
- if ((NULL == timeout_position)
- || (1 != sscanf(timeout_position, ": %u", &keep_alive_timeout)))
- {
- /* Assume parameter format "Keep-Alive: timeout=100" */
- timeout_position = strstr(*header, "timeout=");
- if ((NULL == timeout_position)
- || (1 != sscanf(timeout_position, "timeout=%u", &keep_alive_timeout)))
- {
- log_error(LOG_LEVEL_HEADER,
- "Couldn't parse: '%s'. Using default timeout %u",
- *header, csp->config->keep_alive_timeout);
- freez(*header);
- return JB_ERR_OK;
- }
- }
- if (keep_alive_timeout < csp->config->keep_alive_timeout)
- {
- log_error(LOG_LEVEL_HEADER,
- "Reducing keep-alive timeout from %u to %u.",
- csp->config->keep_alive_timeout, keep_alive_timeout);
- csp->server_connection.keep_alive_timeout = keep_alive_timeout;
- }
- else
- {
- /* XXX: Is this log worthy? */
- log_error(LOG_LEVEL_HEADER,
- "Client keep-alive timeout is %u. Sticking with %u.",
- keep_alive_timeout, csp->config->keep_alive_timeout);
- freez(*header);
- }
- return JB_ERR_OK;
- }
- #endif /* def FEATURE_CONNECTION_KEEP_ALIVE */
- /*********************************************************************
- *
- * Function : get_content_length
- *
- * Description : Gets the content length specified in a
- * Content-Length header.
- *
- * Parameters :
- * 1 : header_value = The Content-Length header value.
- * 2 : length = Storage to return the value.
- *
- * Returns : JB_ERR_OK on success, or
- * JB_ERR_PARSE if no value is recognized.
- *
- *********************************************************************/
- static jb_err get_content_length(const char *header_value, unsigned long long *length)
- {
- #ifdef _WIN32
- #if SIZEOF_LONG_LONG < 8
- #error sizeof(unsigned long long) too small
- #endif
- if (1 != sscanf(header_value, "%I64u", length))
- #else
- if (1 != sscanf(header_value, "%llu", length))
- #endif
- {
- return JB_ERR_PARSE;
- }
- return JB_ERR_OK;
- }
- /*********************************************************************
- *
- * Function : client_save_content_length
- *
- * Description : Save the Content-Length sent by the client.
- *
- * Parameters :
- * 1 : csp = Current client state (buffers, headers, etc...)
- * 2 : header = On input, pointer to header to modify.
- * On output, pointer to the modified header, or NULL
- * to remove the header. This function frees the
- * original string if necessary.
- *
- * Returns : JB_ERR_OK on success, or
- * JB_ERR_MEMORY on out-of-memory error.
- *
- *********************************************************************/
- static jb_err client_save_content_length(struct client_state *csp, char **header)
- {
- unsigned long long content_length = 0;
- const char *header_value;
- assert(*(*header+14) == ':');
- header_value = *header + 15;
- if (JB_ERR_OK != get_content_length(header_value, &content_length))
- {
- log_error(LOG_LEVEL_ERROR, "Crunching invalid header: %s", *header);
- freez(*header);
- }
- else
- {
- csp->expected_client_content_length = content_length;
- }
- return JB_ERR_OK;
- }
- /*********************************************************************
- *
- * Function : client_connection
- *
- * Description : Makes sure a proper "Connection:" header is
- * set and signals connection_header_adder
- * to do nothing.
- *
- * Parameters :
- * 1 : csp = Current client state (buffers, headers, etc...)
- * 2 : header = On input, pointer to header to modify.
- * On output, pointer to the modified header, or NULL
- * to remove the header. This function frees the
- * original string if necessary.
- *
- * Returns : JB_ERR_OK on success.
- *
- *********************************************************************/
- static jb_err client_connection(struct client_state *csp, char **header)
- {
- static const char connection_close[] = "Connection: close";
- if (!strcmpic(*header, connection_close))
- {
- #ifdef FEATURE_CONNECTION_KEEP_ALIVE
- if ((csp->config->feature_flags & RUNTIME_FEATURE_CONNECTION_SHARING)
- && !(csp->flags & CSP_FLAG_SERVER_SOCKET_TAINTED)
- #ifdef FEATURE_HTTPS_INSPECTION
- && !client_use_ssl(csp)
- #endif
- )
- {
- if (!strcmpic(csp->http->version, "HTTP/1.1"))
- {
- log_error(LOG_LEVEL_HEADER,
- "Removing \'%s\' to imply keep-alive.", *header);
- freez(*header);
- /*
- * While we imply keep-alive to the server,
- * we have to remember that the client didn't.
- */
- csp->flags &= ~CSP_FLAG_CLIENT_CONNECTION_KEEP_ALIVE;
- }
- else
- {
- char *old_header = *header;
- *header = strdup_or_die("Connection: keep-alive");
- log_error(LOG_LEVEL_HEADER,
- "Replaced: \'%s\' with \'%s\'", old_header, *header);
- freez(old_header);
- }
- }
- else
- {
- log_error(LOG_LEVEL_HEADER,
- "Keeping the client header '%s' around. "
- "The connection will not be kept alive.",
- *header);
- csp->flags &= ~CSP_FLAG_CLIENT_CONNECTION_KEEP_ALIVE;
- }
- }
- else if ((csp->config->feature_flags & RUNTIME_FEATURE_CONNECTION_KEEP_ALIVE)
- && !(csp->flags & CSP_FLAG_SERVER_SOCKET_TAINTED))
- {
- log_error(LOG_LEVEL_HEADER,
- "Keeping the client header '%s' around. "
- "The server connection will be kept alive if possible.",
- *header);
- csp->flags |= CSP_FLAG_CLIENT_CONNECTION_KEEP_ALIVE;
- #endif /* def FEATURE_CONNECTION_KEEP_ALIVE */
- }
- else
- {
- char *old_header = *header;
- *header = strdup_or_die(connection_close);
- log_error(LOG_LEVEL_HEADER,
- "Replaced: \'%s\' with \'%s\'", old_header, *header);
- freez(old_header);
- }
- /* Signal client_connection_header_adder() to return early. */
- csp->flags |= CSP_FLAG_CLIENT_CONNECTION_HEADER_SET;
- return JB_ERR_OK;
- }
- #ifdef FEATURE_CONNECTION_KEEP_ALIVE
- /*********************************************************************
- *
- * Function : client_proxy_connection
- *
- * Description : Sets the CLIENT_CONNECTION_KEEP_ALIVE flag when
- * appropriate and removes the Proxy-Connection
- * header.
- *
- * Parameters :
- * 1 : csp = Current client state (buffers, headers, etc...)
- * 2 : header = On input, pointer to header to modify.
- * On output, pointer to the modified header, or NULL
- * to remove the header. This function frees the
- * original string if necessary.
- *
- * Returns : JB_ERR_OK
- *
- *********************************************************************/
- static jb_err client_proxy_connection(struct client_state *csp, char **header)
- {
- if (0 == (csp->flags & CSP_FLAG_CLIENT_CONNECTION_KEEP_ALIVE)
- && (csp->http->ssl == 0)
- && (NULL == strstr(*header, "close")))
- {
- log_error(LOG_LEVEL_HEADER,
- "The client connection can be kept alive due to: %s", *header);
- csp->flags |= CSP_FLAG_CLIENT_CONNECTION_KEEP_ALIVE;
- }
- crumble(csp, header);
- return JB_ERR_OK;
- }
- #endif /* def FEATURE_CONNECTION_KEEP_ALIVE */
- /*********************************************************************
- *
- * Function : client_transfer_encoding
- *
- * Description : Raise the CSP_FLAG_CHUNKED_CLIENT_BODY flag if
- * the request body is "chunked"
- *
- * XXX: Currently not called through sed() as we
- * need the flag earlier on. Should be fixed.
- *
- * Parameters :
- * 1 : csp = Current client state (buffers, headers, etc...)
- * 2 : header = On input, pointer to header to modify.
- * On output, pointer to the modified header, or NULL
- * to remove the header. This function frees the
- * original string if necessary.
- *
- * Returns : JB_ERR_OK on success, or
- *
- *********************************************************************/
- jb_err client_transfer_encoding(struct client_state *csp, char **header)
- {
- if (strstr(*header, "chunked"))
- {
- csp->flags |= CSP_FLAG_CHUNKED_CLIENT_BODY;
- log_error(LOG_LEVEL_HEADER, "Expecting chunked client body");
- }
- return JB_ERR_OK;
- }
- /*********************************************************************
- *
- * Function : client_expect
- *
- * Description : Raise the CSP_FLAG_UNSUPPORTED_CLIENT_EXPECTATION
- * if the Expect header value is unsupported.
- *
- * Rejecting unsupported expectations is a RFC 7231 5.1.1
- * MAY and a RFC 2616 (obsolete) MUST.
- *
- * Parameters :
- * 1 : csp = Current client state (buffers, headers, etc...)
- * 2 : header = On input, pointer to header to modify.
- * On output, pointer to the modified header, or NULL
- * to remove the header. This function frees the
- * original string if necessary.
- *
- * Returns : JB_ERR_OK on success, or
- *
- *********************************************************************/
- jb_err client_expect(struct client_state *csp, char **header)
- {
- if (0 != strcmpic(*header, "Expect: 100-continue"))
- {
- csp->flags |= CSP_FLAG_UNSUPPORTED_CLIENT_EXPECTATION;
- log_error(LOG_LEVEL_HEADER,
- "Unsupported client expectaction: %s", *header);
- }
- return JB_ERR_OK;
- }
- /*********************************************************************
- *
- * Function : crumble
- *
- * Description : This is called if a header matches a pattern to "crunch"
- *
- * Parameters :
- * 1 : csp = Current client state (buffers, headers, etc...)
- * 2 : header = On input, pointer to header to modify.
- * On output, pointer to the modified header, or NULL
- * to remove the header. This function frees the
- * original string if necessary.
- *
- * Returns : JB_ERR_OK on success, or
- * JB_ERR_MEMORY on out-of-memory error.
- *
- *********************************************************************/
- static jb_err crumble(struct client_state *csp, char **header)
- {
- (void)csp;
- log_error(LOG_LEVEL_HEADER, "crumble crunched: %s!", *header);
- freez(*header);
- return JB_ERR_OK;
- }
- /*********************************************************************
- *
- * Function : crunch_server_header
- *
- * Description : Crunch server header if it matches a string supplied by the
- * user. Called from `sed'.
- *
- * Parameters :
- * 1 : csp = Current client state (buffers, headers, etc...)
- * 2 : header = On input, pointer to header to modify.
- * On output, pointer to the modified header, or NULL
- * to remove the header. This function frees the
- * original string if necessary.
- *
- * Returns : JB_ERR_OK on success and always succeeds
- *
- *********************************************************************/
- static jb_err crunch_server_header(struct client_state *csp, char **header)
- {
- const char *crunch_pattern;
- /* Do we feel like crunching? */
- if ((csp->action->flags & ACTION_CRUNCH_SERVER_HEADER))
- {
- crunch_pattern = csp->action->string[ACTION_STRING_SERVER_HEADER];
- /* Is the current header the lucky one? */
- if (strstr(*header, crunch_pattern))
- {
- log_error(LOG_LEVEL_HEADER, "Crunching server header: %s (contains: %s)", *header, crunch_pattern);
- freez(*header);
- }
- }
- return JB_ERR_OK;
- }
- /*********************************************************************
- *
- * Function : server_content_type
- *
- * Description : Set the content-type for filterable types (text/.*,
- * .*xml.*, .*script.* and image/gif) unless filtering has been
- * forbidden (CT_TABOO) while parsing earlier headers.
- * NOTE: Since text/plain is commonly used by web servers
- * for files whose correct type is unknown, we don't
- * set CT_TEXT for it.
- *
- * Parameters :
- * 1 : csp = Current client state (buffers, headers, etc...)
- * 2 : header = On input, pointer to header to modify.
- * On output, pointer to the modified header, or NULL
- * to remove the header. This function frees the
- * original string if necessary.
- *
- * Returns : JB_ERR_OK on success, or
- * JB_ERR_MEMORY on out-of-memory error.
- *
- *********************************************************************/
- static jb_err server_content_type(struct client_state *csp, char **header)
- {
- /* Remove header if it isn't the first Content-Type header */
- if ((csp->content_type & CT_DECLARED))
- {
- if (content_filters_enabled(csp->action))
- {
- /*
- * Making sure the client interprets the content the same way
- * Privoxy did is only relevant if Privoxy modified it.
- *
- * Checking for this is "hard" as it's not yet known when
- * this function is called, thus go shopping and and just
- * check if Privoxy could filter it.
- *
- * The main thing is that we don't mess with the headers
- * unless the user signalled that it's acceptable.
- */
- log_error(LOG_LEVEL_HEADER,
- "Multiple Content-Type headers detected. "
- "Removing and ignoring: %s",
- *header);
- freez(*header);
- }
- return JB_ERR_OK;
- }
- /*
- * Signal that the Content-Type has been set.
- */
- csp->content_type |= CT_DECLARED;
- if (!(csp->content_type & CT_TABOO))
- {
- /*
- * XXX: The assumption that text/plain is a sign of
- * binary data seems to be somewhat unreasonable nowadays
- * and should be dropped after 3.0.8 is out.
- */
- if ((strstr(*header, "text/") && !strstr(*header, "plain"))
- || strstr(*header, "xml")
- || strstr(*header, "script"))
- {
- csp->content_type |= CT_TEXT;
- }
- else if (strstr(*header, "image/gif"))
- {
- csp->content_type |= CT_GIF;
- }
- }
- /*
- * Are we messing with the content type?
- */
- if (csp->action->flags & ACTION_CONTENT_TYPE_OVERWRITE)
- {
- /*
- * Make sure the user doesn't accidentally
- * change the content type of binary documents.
- */
- if ((csp->content_type & CT_TEXT) || (csp->action->flags & ACTION_FORCE_TEXT_MODE))
- {
- jb_err err;
- freez(*header);
- *header = strdup_or_die("Content-Type: ");
- err = string_append(header, csp->action->string[ACTION_STRING_CONTENT_TYPE]);
- if (JB_ERR_OK != err)
- {
- log_error(LOG_LEVEL_HEADER, "Insufficient memory to replace Content-Type!");
- return JB_ERR_MEMORY;
- }
- log_error(LOG_LEVEL_HEADER, "Modified: %s!", *header);
- }
- else
- {
- log_error(LOG_LEVEL_HEADER, "%s not replaced. "
- "It doesn't look like a content type that should be filtered. "
- "Enable force-text-mode if you know what you're doing.", *header);
- }
- }
- return JB_ERR_OK;
- }
- /*********************************************************************
- *
- * Function : server_transfer_coding
- *
- * Description : - Prohibit filtering (CT_TABOO) if transfer coding compresses
- * - Raise the CSP_FLAG_CHUNKED flag if coding is "chunked"
- * - Remove header if body was chunked but has been
- * de-chunked for filtering.
- *
- * Parameters :
- * 1 : csp = Current client state (buffers, headers, etc...)
- * 2 : header = On input, pointer to header to modify.
- * On output, pointer to the modified header, or NULL
- * to remove the header. This function frees the
- * original string if necessary.
- *
- * Returns : JB_ERR_OK on success, or
- * JB_ERR_MEMORY on out-of-memory error.
- *
- *********************************************************************/
- static jb_err server_transfer_coding(struct client_state *csp, char **header)
- {
- /*
- * Turn off pcrs and gif filtering if body compressed
- */
- if (strstr(*header, "gzip") || strstr(*header, "compress") || strstr(*header, "deflate"))
- {
- #ifdef FEATURE_ZLIB
- /*
- * XXX: Added to test if we could use CT_GZIP and CT_DEFLATE here.
- */
- log_error(LOG_LEVEL_INFO, "Marking content type for %s as CT_TABOO because of %s.",
- csp->http->cmd, *header);
- #endif /* def FEATURE_ZLIB */
- csp->content_type = CT_TABOO;
- }
- /*
- * Raise flag if body chunked
- */
- if (strstr(*header, "chunked"))
- {
- csp->flags |= CSP_FLAG_CHUNKED;
- /*
- * If the body was modified, it has been de-chunked first
- * and the header must be removed.
- *
- * FIXME: If there is more than one transfer encoding,
- * only the "chunked" part should be removed here.
- */
- if (csp->flags & CSP_FLAG_MODIFIED)
- {
- log_error(LOG_LEVEL_HEADER, "Removing: %s", *header);
- freez(*header);
- }
- }
- return JB_ERR_OK;
- }
- /*********************************************************************
- *
- * Function : server_content_encoding
- *
- * Description : Used to check if the content is compressed, and if
- * FEATURE_ZLIB is disabled, filtering is disabled as
- * well.
- *
- * If FEATURE_ZLIB is enabled and the compression type
- * supported, the content is marked for decompression.
- *
- * XXX: Doesn't properly deal with multiple or with
- * unsupported but unknown encodings.
- * Is case-sensitive but shouldn't be.
- *
- * Parameters :
- * 1 : csp = Current client state (buffers, headers, etc...)
- * 2 : header = On input, pointer to header to modify.
- * On output, pointer to the modified header, or NULL
- * to remove the header. This function frees the
- * original string if necessary.
- *
- * Returns : JB_ERR_OK on success, or
- * JB_ERR_MEMORY on out-of-memory error.
- *
- *********************************************************************/
- static jb_err server_content_encoding(struct client_state *csp, char **header)
- {
- #ifdef FEATURE_ZLIB
- if (strstr(*header, "sdch"))
- {
- /*
- * Shared Dictionary Compression over HTTP isn't supported,
- * filtering it anyway is pretty much guaranteed to mess up
- * the encoding.
- */
- csp->content_type |= CT_TABOO;
- /*
- * Log a warning if the user expects the content to be filtered.
- */
- if (content_filters_enabled(csp->action))
- {
- log_error(LOG_LEVEL_INFO,
- "SDCH-compressed content detected, content filtering disabled. "
- "Consider suppressing SDCH offers made by the client.");
- }
- }
- else if (strstr(*header, "gzip"))
- {
- /* Mark for gzip decompression */
- csp->content_type |= CT_GZIP;
- }
- else if (strstr(*header, "deflate"))
- {
- /* Mark for zlib decompression */
- csp->content_type |= CT_DEFLATE;
- }
- else if (strstr(*header, "br"))
- {
- #ifdef FEATURE_BROTLI
- /* Mark for Brotli decompression */
- csp->content_type |= CT_BROTLI;
- #else
- csp->content_type |= CT_TABOO;
- #endif
- }
- else if (strstr(*header, "compress"))
- {
- /*
- * We can't decompress this; therefore we can't filter
- * it either.
- */
- csp->content_type |= CT_TABOO;
- }
- #else /* !defined(FEATURE_ZLIB) */
- /*
- * XXX: Using a black list here isn't the right approach.
- *
- * In case of SDCH, building with zlib support isn't
- * going to help.
- */
- if (strstr(*header, "gzip") ||
- strstr(*header, "compress") ||
- strstr(*header, "deflate") ||
- strstr(*header, "sdch"))
- {
- /*
- * Body is compressed, turn off pcrs and gif filtering.
- */
- csp->content_type |= CT_TABOO;
- /*
- * Log a warning if the user expects the content to be filtered.
- */
- if (content_filters_enabled(csp->action))
- {
- log_error(LOG_LEVEL_INFO,
- "Compressed content detected, content filtering disabled. "
- "Consider recompiling Privoxy with zlib support or "
- "enable the prevent-compression action.");
- }
- }
- #endif /* defined(FEATURE_ZLIB) */
- return JB_ERR_OK;
- }
- #ifdef FEATURE_ZLIB
- /*********************************************************************
- *
- * Function : server_adjust_content_encoding
- *
- * Description : Remove the Content-Encoding header if the
- * decompression was successful and the content
- * has been modified.
- *
- * Parameters :
- * 1 : csp = Current client state (buffers, headers, etc...)
- * 2 : header = On input, pointer to header to modify.
- * On output, pointer to the modified header, or NULL
- * to remove the header. This function frees the
- * original string if necessary.
- *
- * Returns : JB_ERR_OK on success, or
- * JB_ERR_MEMORY on out-of-memory error.
- *
- *********************************************************************/
- static jb_err server_adjust_content_encoding(struct client_state *csp, char **header)
- {
- if ((csp->flags & CSP_FLAG_MODIFIED)
- && ((csp->content_type & (CT_GZIP | CT_DEFLATE))
- #ifdef FEATURE_BROTLI
- || (csp->content_type & CT_BROTLI)
- #endif
- )
- )
- {
- /*
- * We successfully decompressed the content,
- * and have to clean the header now, so the
- * client no longer expects compressed data.
- *
- * XXX: There is a difference between cleaning
- * and removing it completely.
- */
- log_error(LOG_LEVEL_HEADER, "Crunching: %s", *header);
- freez(*header);
- }
- return JB_ERR_OK;
- }
- #endif /* defined(FEATURE_ZLIB) */
- /*********************************************************************
- *
- * Function : server_adjust_content_length
- *
- * Description : Adjust Content-Length header if we modified
- * the body.
- *
- * Parameters :
- * 1 : csp = Current client state (buffers, headers, etc...)
- * 2 : header = On input, pointer to header to modify.
- * On output, pointer to the modified header, or NULL
- * to remove the header. This function frees the
- * original string if necessary.
- *
- * Returns : JB_ERR_OK on success, or
- * JB_ERR_MEMORY on out-of-memory error.
- *
- *********************************************************************/
- static jb_err server_adjust_content_length(struct client_state *csp, char **header)
- {
- /* Regenerate header if the content was modified. */
- if (csp->flags & CSP_FLAG_MODIFIED)
- {
- const size_t header_length = 50;
- freez(*header);
- *header = malloc(header_length);
- if (*header == NULL)
- {
- return JB_ERR_MEMORY;
- }
- create_content_length_header(csp->content_length, *header, header_length);
- log_error(LOG_LEVEL_HEADER,
- "Adjusted Content-Length to %llu", csp->content_length);
- }
- return JB_ERR_OK;
- }
- #ifdef FEATURE_CONNECTION_KEEP_ALIVE
- /*********************************************************************
- *
- * Function : server_save_content_length
- *
- * Description : Save the Content-Length sent by the server.
- *
- * Parameters :
- * 1 : csp = Current client state (buffers, headers, etc...)
- * 2 : header = On input, pointer to header to modify.
- * On output, pointer to the modified header, or NULL
- * to remove the header. This function frees the
- * original string if necessary.
- *
- * Returns : JB_ERR_OK on success, or
- * JB_ERR_MEMORY on out-of-memory error.
- *
- *********************************************************************/
- static jb_err server_save_content_length(struct client_state *csp, char **header)
- {
- unsigned long long content_length = 0;
- const char *header_value;
- assert(*(*header+14) == ':');
- header_value = *header + 15;
- if (JB_ERR_OK != get_content_length(header_value, &content_length))
- {
- log_error(LOG_LEVEL_ERROR, "Crunching invalid header: %s", *header);
- freez(*header);
- }
- else
- {
- csp->expected_content_length = content_length;
- csp->flags |= CSP_FLAG_SERVER_CONTENT_LENGTH_SET;
- csp->flags |= CSP_FLAG_CONTENT_LENGTH_SET;
- }
- return JB_ERR_OK;
- }
- #endif /* def FEATURE_CONNECTION_KEEP_ALIVE */
- /*********************************************************************
- *
- * Function : server_content_md5
- *
- * Description : Crumble any Content-MD5 headers if the document was
- * modified. FIXME: Should we re-compute instead?
- *
- * Parameters :
- * 1 : csp = Current client state (buffers, headers, etc...)
- * 2 : header = On input, pointer to header to modify.
- * On output, pointer to the modified header, or NULL
- * to remove the header. This function frees the
- * original string if necessary.
- *
- * Returns : JB_ERR_OK on success, or
- * JB_ERR_MEMORY on out-of-memory error.
- *
- *********************************************************************/
- static jb_err server_content_md5(struct client_state *csp, char **header)
- {
- if (csp->flags & CSP_FLAG_MODIFIED)
- {
- log_error(LOG_LEVEL_HEADER, "Crunching Content-MD5");
- freez(*header);
- }
- return JB_ERR_OK;
- }
- /*********************************************************************
- *
- * Function : server_content_disposition
- *
- * Description : If enabled, blocks or modifies the "Content-Disposition" header.
- * Called from `sed'.
- *
- * Parameters :
- * 1 : csp = Current client state (buffers, headers, etc...)
- * 2 : header = On input, pointer to header to modify.
- * On output, pointer to the modified header, or NULL
- * to remove the header. This function frees the
- * original string if necessary.
- *
- * Returns : JB_ERR_OK on success, or
- * JB_ERR_MEMORY on out-of-memory error.
- *
- *********************************************************************/
- static jb_err server_content_disposition(struct client_state *csp, char **header)
- {
- const char *newval;
- /*
- * Are we messing with the Content-Disposition header?
- */
- if ((csp->action->flags & ACTION_HIDE_CONTENT_DISPOSITION) == 0)
- {
- /* Me tinks not */
- return JB_ERR_OK;
- }
- newval = csp->action->string[ACTION_STRING_CONTENT_DISPOSITION];
- if ((newval == NULL) || (0 == strcmpic(newval, "block")))
- {
- /*
- * Blocking content-disposition header
- */
- log_error(LOG_LEVEL_HEADER, "Crunching %s!", *header);
- freez(*header);
- return JB_ERR_OK;
- }
- else
- {
- /*
- * Replacing Content-Disposition header
- */
- freez(*header);
- *header = strdup("Content-Disposition: ");
- string_append(header, newval);
- if (*header != NULL)
- {
- log_error(LOG_LEVEL_HEADER,
- "Content-Disposition header crunched and replaced with: %s", *header);
- }
- }
- return (*header == NULL) ? JB_ERR_MEMORY : JB_ERR_OK;
- }
- /*********************************************************************
- *
- * Function : server_last_modified
- *
- * Description : Changes Last-Modified header to the actual date
- * to help hide-if-modified-since.
- * Called from `sed'.
- *
- * Parameters :
- * 1 : csp = Current client state (buffers, headers, etc...)
- * 2 : header = On input, pointer to header to modify.
- * On output, pointer to the modified header, or NULL
- * to remove the header. This function frees the
- * original string if necessary.
- *
- * Returns : JB_ERR_OK on success, or
- * JB_ERR_MEMORY on out-of-memory error.
- *
- *********************************************************************/
- static jb_err server_last_modified(struct client_state *csp, char **header)
- {
- const char *newval;
- time_t last_modified;
- char newheader[50];
- /*
- * Are we messing with the Last-Modified header?
- */
- if ((csp->action->flags & ACTION_OVERWRITE_LAST_MODIFIED) == 0)
- {
- /*Nope*/
- return JB_ERR_OK;
- }
- newval = csp->action->string[ACTION_STRING_LAST_MODIFIED];
- if (0 == strcmpic(newval, "block"))
- {
- /*
- * Blocking Last-Modified header. Useless but why not.
- */
- log_error(LOG_LEVEL_HEADER, "Crunching %s!", *header);
- freez(*header);
- return JB_ERR_OK;
- }
- else if (0 == strcmpic(newval, "reset-to-request-time"))
- {
- /*
- * Setting Last-Modified Header to now.
- */
- char buf[30];
- get_http_time(0, buf, sizeof(buf));
- freez(*header);
- *header = strdup("Last-Modified: ");
- string_append(header, buf);
- if (*header == NULL)
- {
- log_error(LOG_LEVEL_HEADER, "Insufficient memory. Last-Modified header got lost, boohoo.");
- }
- else
- {
- log_error(LOG_LEVEL_HEADER, "Reset to present time: %s", *header);
- }
- }
- else if (0 == strcmpic(newval, "randomize"))
- {
- log_error(LOG_LEVEL_HEADER, "Randomizing: %s", *header);
- if (JB_ERR_OK != parse_time_header(*header, &last_modified))
- {
- log_error(LOG_LEVEL_HEADER,
- "Couldn't parse time in %s (crunching!)", *header);
- freez(*header);
- }
- else
- {
- time_t now;
- struct tm *timeptr = NULL;
- long int rtime;
- struct tm gmt;
- now = time(NULL);
- rtime = (long int)difftime(now, last_modified);
- if (rtime)
- {
- long int days, hours, minutes, seconds;
- const int negative_delta = (rtime < 0);
- if (negative_delta)
- {
- rtime *= -1;
- log_error(LOG_LEVEL_HEADER, "Server time in the future.");
- }
- rtime = pick_from_range(rtime);
- if (negative_delta)
- {
- rtime *= -1;
- }
- last_modified += rtime;
- timeptr = privoxy_gmtime_r(&last_modified, &gmt);
- if ((NULL == timeptr) || !strftime(newheader,
- sizeof(newheader), "%a, %d %b %Y %H:%M:%S GMT", timeptr))
- {
- log_error(LOG_LEVEL_ERROR,
- "Randomizing '%s' failed. Crunching the header without replacement.",
- *header);
- freez(*header);
- return JB_ERR_OK;
- }
- freez(*header);
- *header = strdup("Last-Modified: ");
- string_append(header, newheader);
- if (*header == NULL)
- {
- log_error(LOG_LEVEL_ERROR, "Insufficient memory, header crunched without replacement.");
- return JB_ERR_MEMORY;
- }
- days = rtime / (3600 * 24);
- hours = rtime / 3600 % 24;
- minutes = rtime / 60 % 60;
- seconds = rtime % 60;
- log_error(LOG_LEVEL_HEADER,
- "Randomized: %s (added %ld da%s %ld hou%s %ld minut%s %ld second%s",
- *header, days, (days == 1) ? "y" : "ys", hours, (hours == 1) ? "r" : "rs",
- minutes, (minutes == 1) ? "e" : "es", seconds, (seconds == 1) ? ")" : "s)");
- }
- else
- {
- log_error(LOG_LEVEL_HEADER, "Randomized ... or not. No time difference to work with.");
- }
- }
- }
- return JB_ERR_OK;
- }
- /*********************************************************************
- *
- * Function : client_accept_encoding
- *
- * Description : Rewrite the client's Accept-Encoding header so that
- * if doesn't allow compression, if the action applies.
- * Note: For HTTP/1.0 the absence of the header is enough.
- *
- * Parameters :
- * 1 : csp = Current client state (buffers, headers, etc...)
- * 2 : header = On input, pointer to header to modify.
- * On output, pointer to the modified header, or NULL
- * to remove the header. This function frees the
- * original string if necessary.
- *
- * Returns : JB_ERR_OK on success, or
- * JB_ERR_MEMORY on out-of-memory error.
- *
- *********************************************************************/
- static jb_err client_accept_encoding(struct client_state *csp, char **header)
- {
- #ifdef FEATURE_COMPRESSION
- if ((csp->config->feature_flags & RUNTIME_FEATURE_COMPRESSION)
- && strstr(*header, "deflate"))
- {
- csp->flags |= CSP_FLAG_CLIENT_SUPPORTS_DEFLATE;
- }
- #endif
- if ((csp->action->flags & ACTION_NO_COMPRESSION) != 0)
- {
- log_error(LOG_LEVEL_HEADER, "Suppressed offer to compress content");
- freez(*header);
- }
- return JB_ERR_OK;
- }
- /*********************************************************************
- *
- * Function : client_te
- *
- * Description : Rewrite the client's TE header so that
- * if doesn't allow compression, if the action applies.
- *
- * Parameters :
- * 1 : csp = Current client state (buffers, headers, etc...)
- * 2 : header = On input, pointer to header to modify.
- * On output, pointer to the modified header, or NULL
- * to remove the header. This function frees the
- * original string if necessary.
- *
- * Returns : JB_ERR_OK on success, or
- * JB_ERR_MEMORY on out-of-memory error.
- *
- *********************************************************************/
- static jb_err client_te(struct client_state *csp, char **header)
- {
- if ((csp->action->flags & ACTION_NO_COMPRESSION) != 0)
- {
- freez(*header);
- log_error(LOG_LEVEL_HEADER, "Suppressed offer to compress transfer");
- }
- return JB_ERR_OK;
- }
- /*********************************************************************
- *
- * Function : client_referrer
- *
- * Description : Handle the "referer" config setting properly.
- * Called from `sed'.
- *
- * Parameters :
- * 1 : csp = Current client state (buffers, headers, etc...)
- * 2 : header = On input, pointer to header to modify.
- * On output, pointer to the modified header, or NULL
- * to remove the header. This function frees the
- * original string if necessary.
- *
- * Returns : JB_ERR_OK on success, or
- * JB_ERR_MEMORY on out-of-memory error.
- *
- *********************************************************************/
- static jb_err client_referrer(struct client_state *csp, char **header)
- {
- const char *parameter;
- /* booleans for parameters we have to check multiple times */
- int parameter_conditional_block;
- int parameter_conditional_forge;
- #ifdef FEATURE_FORCE_LOAD
- /*
- * Since the referrer can include the prefix even
- * if the request itself is non-forced, we must
- * clean it unconditionally.
- *
- * XXX: strclean is too broad
- */
- strclean(*header, FORCE_PREFIX);
- #endif /* def FEATURE_FORCE_LOAD */
- if ((csp->action->flags & ACTION_HIDE_REFERER) == 0)
- {
- /* Nothing left to do */
- return JB_ERR_OK;
- }
- parameter = csp->action->string[ACTION_STRING_REFERER];
- assert(parameter != NULL);
- parameter_conditional_block = (0 == strcmpic(parameter, "conditional-block"));
- parameter_conditional_forge = (0 == strcmpic(parameter, "conditional-forge"));
- if (!parameter_conditional_block && !parameter_conditional_forge)
- {
- /*
- * As conditional-block and conditional-forge are the only
- * parameters that rely on the original referrer, we can
- * remove it now for all the others.
- */
- freez(*header);
- }
- if (0 == strcmpic(parameter, "block"))
- {
- log_error(LOG_LEVEL_HEADER, "Referer crunched!");
- return JB_ERR_OK;
- }
- else if (parameter_conditional_block || parameter_conditional_forge)
- {
- return handle_conditional_hide_referrer_parameter(header,
- csp->http->hostport, parameter_conditional_block);
- }
- else if (0 == strcmpic(parameter, "forge"))
- {
- return create_forged_referrer(header, csp->http->hostport);
- }
- else
- {
- /* interpret parameter as user-supplied referer to fake */
- return create_fake_referrer(header, parameter);
- }
- }
- /*********************************************************************
- *
- * Function : client_accept_language
- *
- * Description : Handle the "Accept-Language" config setting properly.
- * Called from `sed'.
- *
- * Parameters :
- * 1 : csp = Current client state (buffers, headers, etc...)
- * 2 : header = On input, pointer to header to modify.
- * On output, pointer to the modified header, or NULL
- * to remove the header. This function frees the
- * original string if necessary.
- *
- * Returns : JB_ERR_OK on success, or
- * JB_ERR_MEMORY on out-of-memory error.
- *
- *********************************************************************/
- static jb_err client_accept_language(struct client_state *csp, char **header)
- {
- const char *newval;
- /*
- * Are we messing with the Accept-Language?
- */
- if ((csp->action->flags & ACTION_HIDE_ACCEPT_LANGUAGE) == 0)
- {
- /*I don't think so*/
- return JB_ERR_OK;
- }
- newval = csp->action->string[ACTION_STRING_LANGUAGE];
- if ((newval == NULL) || (0 == strcmpic(newval, "block")))
- {
- /*
- * Blocking Accept-Language header
- */
- log_error(LOG_LEVEL_HEADER, "Crunching Accept-Language!");
- freez(*header);
- return JB_ERR_OK;
- }
- else
- {
- /*
- * Replacing Accept-Language header
- */
- freez(*header);
- *header = strdup("Accept-Language: ");
- string_append(header, newval);
- if (*header == NULL)
- {
- log_error(LOG_LEVEL_ERROR,
- "Insufficient memory. Accept-Language header crunched without replacement.");
- }
- else
- {
- log_error(LOG_LEVEL_HEADER,
- "Accept-Language header crunched and replaced with: %s", *header);
- }
- }
- return (*header == NULL) ? JB_ERR_MEMORY : JB_ERR_OK;
- }
- /*********************************************************************
- *
- * Function : crunch_client_header
- *
- * Description : Crunch client header if it matches a string supplied by the
- * user. Called from `sed'.
- *
- * Parameters :
- * 1 : csp = Current client state (buffers, headers, etc...)
- * 2 : header = On input, pointer to header to modify.
- * On output, pointer to the modified header, or NULL
- * to remove the header. This function frees the
- * original string if necessary.
- *
- * Returns : JB_ERR_OK on success and always succeeds
- *
- *********************************************************************/
- static jb_err crunch_client_header(struct client_state *csp, char **header)
- {
- const char *crunch_pattern;
- /* Do we feel like crunching? */
- if ((csp->action->flags & ACTION_CRUNCH_CLIENT_HEADER))
- {
- crunch_pattern = csp->action->string[ACTION_STRING_CLIENT_HEADER];
- /* Is the current header the lucky one? */
- if (strstr(*header, crunch_pattern))
- {
- log_error(LOG_LEVEL_HEADER, "Crunching client header: %s (contains: %s)", *header, crunch_pattern);
- freez(*header);
- }
- }
- return JB_ERR_OK;
- }
- /*********************************************************************
- *
- * Function : client_uagent
- *
- * Description : Handle the "user-agent" config setting properly
- * and remember its original value to enable browser
- * bug workarounds. Called from `sed'.
- *
- * Parameters :
- * 1 : csp = Current client state (buffers, headers, etc...)
- * 2 : header = On input, pointer to header to modify.
- * On output, pointer to the modified header, or NULL
- * to remove the header. This function frees the
- * original string if necessary.
- *
- * Returns : JB_ERR_OK on success, or
- * JB_ERR_MEMORY on out-of-memory error.
- *
- *********************************************************************/
- static jb_err client_uagent(struct client_state *csp, char **header)
- {
- const char *newval;
- if ((csp->action->flags & ACTION_HIDE_USER_AGENT) == 0)
- {
- return JB_ERR_OK;
- }
- newval = csp->action->string[ACTION_STRING_USER_AGENT];
- if (newval == NULL)
- {
- return JB_ERR_OK;
- }
- freez(*header);
- *header = strdup("User-Agent: ");
- string_append(header, newval);
- log_error(LOG_LEVEL_HEADER, "Modified: %s", *header);
- return (*header == NULL) ? JB_ERR_MEMORY : JB_ERR_OK;
- }
- /*********************************************************************
- *
- * Function : client_ua
- *
- * Description : Handle "ua-" headers properly. Called from `sed'.
- *
- * Parameters :
- * 1 : csp = Current client state (buffers, headers, etc...)
- * 2 : header = On input, pointer to header to modify.
- * On output, pointer to the modified header, or NULL
- * to remove the header. This function frees the
- * original string if necessary.
- *
- * Returns : JB_ERR_OK on success, or
- * JB_ERR_MEMORY on out-of-memory error.
- *
- *********************************************************************/
- static jb_err client_ua(struct client_state *csp, char **header)
- {
- if ((csp->action->flags & ACTION_HIDE_USER_AGENT) != 0)
- {
- log_error(LOG_LEVEL_HEADER, "crunched User-Agent!");
- freez(*header);
- }
- return JB_ERR_OK;
- }
- /*********************************************************************
- *
- * Function : client_from
- *
- * Description : Handle the "from" config setting properly.
- * Called from `sed'.
- *
- * Parameters :
- * 1 : csp = Current client state (buffers, headers, etc...)
- * 2 : header = On input, pointer to header to modify.
- * On output, pointer to the modified header, or NULL
- * to remove the header. This function frees the
- * original string if necessary.
- *
- * Returns : JB_ERR_OK on success, or
- * JB_ERR_MEMORY on out-of-memory error.
- *
- *********************************************************************/
- static jb_err client_from(struct client_state *csp, char **header)
- {
- const char *newval;
- if ((csp->action->flags & ACTION_HIDE_FROM) == 0)
- {
- return JB_ERR_OK;
- }
- freez(*header);
- newval = csp->action->string[ACTION_STRING_FROM];
- /*
- * Are we blocking the e-mail address?
- */
- if ((newval == NULL) || (0 == strcmpic(newval, "block")))
- {
- log_error(LOG_LEVEL_HEADER, "crunched From!");
- return JB_ERR_OK;
- }
- log_error(LOG_LEVEL_HEADER, " modified");
- *header = strdup("From: ");
- string_append(header, newval);
- return (*header == NULL) ? JB_ERR_MEMORY : JB_ERR_OK;
- }
- /*********************************************************************
- *
- * Function : client_send_cookie
- *
- * Description : Crunches the "cookie" header if necessary.
- * Called from `sed'.
- *
- * XXX: Stupid name, doesn't send squat.
- *
- * Parameters :
- * 1 : csp = Current client state (buffers, headers, etc...)
- * 2 : header = On input, pointer to header to modify.
- * On output, pointer to the modified header, or NULL
- * to remove the header. This function frees the
- * original string if necessary.
- *
- * Returns : JB_ERR_OK on success, or
- * JB_ERR_MEMORY on out-of-memory error.
- *
- *********************************************************************/
- static jb_err client_send_cookie(struct client_state *csp, char **header)
- {
- if (csp->action->flags & ACTION_CRUNCH_OUTGOING_COOKIES)
- {
- log_error(LOG_LEVEL_HEADER, "Crunched outgoing cookie: %s", *header);
- freez(*header);
- }
- return JB_ERR_OK;
- }
- /*********************************************************************
- *
- * Function : client_x_forwarded
- *
- * Description : Handle the "x-forwarded-for" config setting properly,
- * also used in the add_client_headers list. Called from `sed'.
- *
- * Parameters :
- * 1 : csp = Current client state (buffers, headers, etc...)
- * 2 : header = On input, pointer to header to modify.
- * On output, pointer to the modified header, or NULL
- * to remove the header. This function frees the
- * original string if necessary.
- *
- * Returns : JB_ERR_OK on success, or
- * JB_ERR_MEMORY on out-of-memory error.
- *
- *********************************************************************/
- jb_err client_x_forwarded(struct client_state *csp, char **header)
- {
- if (0 != (csp->action->flags & ACTION_CHANGE_X_FORWARDED_FOR))
- {
- const char *parameter = csp->action->string[ACTION_STRING_CHANGE_X_FORWARDED_FOR];
- if (0 == strcmpic(parameter, "block"))
- {
- freez(*header);
- log_error(LOG_LEVEL_HEADER, "crunched x-forwarded-for!");
- }
- else if (0 == strcmpic(parameter, "add"))
- {
- string_append(header, ", ");
- string_append(header, csp->ip_addr_str);
- if (*header == NULL)
- {
- return JB_ERR_MEMORY;
- }
- log_error(LOG_LEVEL_HEADER,
- "Appended client IP address to %s", *header);
- csp->flags |= CSP_FLAG_X_FORWARDED_FOR_APPENDED;
- }
- else
- {
- log_error(LOG_LEVEL_FATAL,
- "Invalid change-x-forwarded-for parameter: '%s'", parameter);
- }
- }
- return JB_ERR_OK;
- }
- /*********************************************************************
- *
- * Function : client_max_forwards
- *
- * Description : If the HTTP method is OPTIONS or TRACE, subtract one
- * from the value of the Max-Forwards header field.
- *
- * Parameters :
- * 1 : csp = Current client state (buffers, headers, etc...)
- * 2 : header = On input, pointer to header to modify.
- * On output, pointer to the modified header, or NULL
- * to remove the header. This function frees the
- * original string if necessary.
- *
- * Returns : JB_ERR_OK on success, or
- * JB_ERR_MEMORY on out-of-memory error.
- *
- *********************************************************************/
- static jb_err client_max_forwards(struct client_state *csp, char **header)
- {
- int max_forwards;
- if ((0 == strcmpic(csp->http->gpc, "trace")) ||
- (0 == strcmpic(csp->http->gpc, "options")))
- {
- assert(*(*header+12) == ':');
- if (1 == sscanf(*header+12, ": %d", &max_forwards))
- {
- if (max_forwards > 0)
- {
- snprintf(*header, strlen(*header)+1, "Max-Forwards: %d", --max_forwards);
- log_error(LOG_LEVEL_HEADER,
- "Max-Forwards value for %s request reduced to %d.",
- csp->http->gpc, max_forwards);
- }
- else if (max_forwards < 0)
- {
- log_error(LOG_LEVEL_ERROR, "Crunching invalid header: %s", *header);
- freez(*header);
- }
- }
- else
- {
- log_error(LOG_LEVEL_ERROR, "Crunching invalid header: %s", *header);
- freez(*header);
- }
- }
- return JB_ERR_OK;
- }
- /*********************************************************************
- *
- * Function : client_host
- *
- * Description : If the request URI did not contain host and
- * port information, parse and evaluate the Host
- * header field.
- *
- * Parameters :
- * 1 : csp = Current client state (buffers, headers, etc...)
- * 2 : header = On input, pointer to header to modify.
- * On output, pointer to the modified header, or NULL
- * to remove the header. This function frees the
- * original string if necessary.
- *
- * Returns : JB_ERR_OK on success, or
- * JB_ERR_MEMORY on out-of-memory error.
- *
- *********************************************************************/
- static jb_err client_host(struct client_state *csp, char **header)
- {
- char *p, *q;
- if (strlen(*header) < 7)
- {
- log_error(LOG_LEVEL_HEADER, "Removing empty Host header");
- freez(*header);
- return JB_ERR_OK;
- }
- if (!csp->http->hostport || (*csp->http->hostport == '*') ||
- *csp->http->hostport == ' ' || *csp->http->hostport == '\0')
- {
- p = strdup_or_die((*header)+6);
- chomp(p);
- q = strdup_or_die(p);
- freez(csp->http->hostport);
- csp->http->hostport = p;
- freez(csp->http->host);
- csp->http->host = q;
- q = strchr(csp->http->host, ':');
- if (q != NULL)
- {
- /* Terminate hostname and evaluate port string */
- *q++ = '\0';
- csp->http->port = atoi(q);
- }
- else
- {
- csp->http->port = csp->http->ssl ? 443 : 80;
- }
- log_error(LOG_LEVEL_HEADER, "New host and port from Host field: %s = %s:%d",
- csp->http->hostport, csp->http->host, csp->http->port);
- }
- /* Signal client_host_adder() to return right away */
- csp->flags |= CSP_FLAG_HOST_HEADER_IS_SET;
- return JB_ERR_OK;
- }
- /*********************************************************************
- *
- * Function : client_if_modified_since
- *
- * Description : Remove or modify the If-Modified-Since header.
- *
- * Parameters :
- * 1 : csp = Current client state (buffers, headers, etc...)
- * 2 : header = On input, pointer to header to modify.
- * On output, pointer to the modified header, or NULL
- * to remove the header. This function frees the
- * original string if necessary.
- *
- * Returns : JB_ERR_OK on success, or
- * JB_ERR_MEMORY on out-of-memory error.
- *
- *********************************************************************/
- static jb_err client_if_modified_since(struct client_state *csp, char **header)
- {
- char newheader[50];
- struct tm gmt;
- struct tm *timeptr = NULL;
- time_t tm = 0;
- const char *newval;
- char * endptr;
- if (0 == strcmpic(*header, "If-Modified-Since: Wed, 08 Jun 1955 12:00:00 GMT"))
- {
- /*
- * The client got an error message because of a temporary problem,
- * the problem is gone and the client now tries to revalidate our
- * error message on the real server. The revalidation would always
- * end with the transmission of the whole document and there is
- * no need to expose the bogus If-Modified-Since header.
- */
- log_error(LOG_LEVEL_HEADER, "Crunching useless If-Modified-Since header.");
- freez(*header);
- }
- else if (csp->action->flags & ACTION_HIDE_IF_MODIFIED_SINCE)
- {
- newval = csp->action->string[ACTION_STRING_IF_MODIFIED_SINCE];
- if ((0 == strcmpic(newval, "block")))
- {
- log_error(LOG_LEVEL_HEADER, "Crunching %s", *header);
- freez(*header);
- }
- else /* add random value */
- {
- if (JB_ERR_OK != parse_time_header(*header, &tm))
- {
- log_error(LOG_LEVEL_HEADER,
- "Couldn't parse time in %s (crunching!)", *header);
- freez(*header);
- }
- else
- {
- long int hours, minutes, seconds;
- long int rtime = strtol(newval, &endptr, 0);
- const int negative_range = (rtime < 0);
- if (rtime)
- {
- log_error(LOG_LEVEL_HEADER, "Randomizing: %s (random range: %ld minut%s)",
- *header, rtime, (rtime == 1 || rtime == -1) ? "e": "es");
- if (negative_range)
- {
- rtime *= -1;
- }
- rtime *= 60;
- rtime = pick_from_range(rtime);
- }
- else
- {
- log_error(LOG_LEVEL_ERROR,
- "Random range is 0. Assuming time transformation test.");
- }
- tm += rtime * (negative_range ? -1 : 1);
- timeptr = privoxy_gmtime_r(&tm, &gmt);
- if ((NULL == timeptr) || !strftime(newheader,
- sizeof(newheader), "%a, %d %b %Y %H:%M:%S GMT", timeptr))
- {
- log_error(LOG_LEVEL_ERROR,
- "Randomizing '%s' failed. Crunching the header without replacement.",
- *header);
- freez(*header);
- return JB_ERR_OK;
- }
- freez(*header);
- *header = strdup("If-Modified-Since: ");
- string_append(header, newheader);
- if (*header == NULL)
- {
- log_error(LOG_LEVEL_HEADER, "Insufficient memory, header crunched without replacement.");
- return JB_ERR_MEMORY;
- }
- hours = rtime / 3600;
- minutes = rtime / 60 % 60;
- seconds = rtime % 60;
- log_error(LOG_LEVEL_HEADER,
- "Randomized: %s (%s %ld hou%s %ld minut%s %ld second%s",
- *header, (negative_range) ? "subtracted" : "added", hours,
- (hours == 1) ? "r" : "rs", minutes, (minutes == 1) ? "e" : "es",
- seconds, (seconds == 1) ? ")" : "s)");
- }
- }
- }
- return JB_ERR_OK;
- }
- /*********************************************************************
- *
- * Function : client_if_none_match
- *
- * Description : Remove the If-None-Match header.
- *
- * Parameters :
- * 1 : csp = Current client state (buffers, headers, etc...)
- * 2 : header = On input, pointer to header to modify.
- * On output, pointer to the modified header, or NULL
- * to remove the header. This function frees the
- * original string if necessary.
- *
- * Returns : JB_ERR_OK on success, or
- * JB_ERR_MEMORY on out-of-memory error.
- *
- *********************************************************************/
- static jb_err client_if_none_match(struct client_state *csp, char **header)
- {
- if (csp->action->flags & ACTION_CRUNCH_IF_NONE_MATCH)
- {
- log_error(LOG_LEVEL_HEADER, "Crunching %s", *header);
- freez(*header);
- }
- return JB_ERR_OK;
- }
- /*********************************************************************
- *
- * Function : client_x_filter
- *
- * Description : Disables filtering if the client set "X-Filter: No".
- * Called from `sed'.
- *
- * Parameters :
- * 1 : csp = Current client state (buffers, headers, etc...)
- * 2 : header = On input, pointer to header to modify.
- * On output, pointer to the modified header, or NULL
- * to remove the header. This function frees the
- * original string if necessary.
- *
- * Returns : JB_ERR_OK on success
- *
- *********************************************************************/
- jb_err client_x_filter(struct client_state *csp, char **header)
- {
- if (0 == strcmpic(*header, "X-Filter: No"))
- {
- if (!(csp->config->feature_flags & RUNTIME_FEATURE_HTTP_TOGGLE))
- {
- log_error(LOG_LEVEL_INFO, "Ignored the client's request to fetch without filtering.");
- }
- else
- {
- if (csp->action->flags & ACTION_FORCE_TEXT_MODE)
- {
- log_error(LOG_LEVEL_HEADER,
- "force-text-mode overruled the client's request to fetch without filtering!");
- }
- else
- {
- csp->content_type = CT_TABOO; /* XXX: This hack shouldn't be necessary */
- csp->flags |= CSP_FLAG_NO_FILTERING;
- log_error(LOG_LEVEL_HEADER, "Accepted the client's request to fetch without filtering.");
- }
- log_error(LOG_LEVEL_HEADER, "Crunching %s", *header);
- freez(*header);
- }
- }
- return JB_ERR_OK;
- }
- /*********************************************************************
- *
- * Function : client_range
- *
- * Description : Removes Range, Request-Range and If-Range headers if
- * content filtering is enabled and the range doesn't
- * start at byte 0.
- *
- * If the client's version of the document has been
- * altered by Privoxy, the server could interpret the
- * range differently than the client intended in which
- * case the user could end up with corrupted content.
- *
- * If the range starts at byte 0 this isn't an issue
- * so the header can pass. Partial requests like this
- * are used to render preview images for videos without
- * downloading the whole video.
- *
- * While HTTP doesn't require that range requests are
- * honoured and the client could simply abort the download
- * after receiving a sufficient amount of data, various
- * clients don't handle complete responses to range
- * requests gracefully and emit misleading error messages
- * instead.
- *
- * Parameters :
- * 1 : csp = Current client state (buffers, headers, etc...)
- * 2 : header = On input, pointer to header to modify.
- * On output, pointer to the modified header, or NULL
- * to remove the header. This function frees the
- * original string if necessary.
- *
- * Returns : JB_ERR_OK
- *
- *********************************************************************/
- static jb_err client_range(struct client_state *csp, char **header)
- {
- if (content_filters_enabled(csp->action)
- && (0 != strncmpic(strstr(*header, ":"), ": bytes=0-", 10)))
- {
- log_error(LOG_LEVEL_HEADER, "Content filtering is enabled."
- " Crunching: \'%s\' to prevent range-mismatch problems.", *header);
- freez(*header);
- }
- return JB_ERR_OK;
- }
- /* the following functions add headers directly to the header list */
- /*********************************************************************
- *
- * Function : client_host_adder
- *
- * Description : Adds the Host: header field if it is missing.
- * Called from `sed'.
- *
- * Parameters :
- * 1 : csp = Current client state (buffers, headers, etc...)
- *
- * Returns : JB_ERR_OK on success, or
- * JB_ERR_MEMORY on out-of-memory error.
- *
- *********************************************************************/
- static jb_err client_host_adder(struct client_state *csp)
- {
- char *p;
- jb_err err;
- if (csp->flags & CSP_FLAG_HOST_HEADER_IS_SET)
- {
- /* Header already set by the client, nothing to do. */
- return JB_ERR_OK;
- }
- if (!csp->http->hostport || !*(csp->http->hostport))
- {
- log_error(LOG_LEVEL_ERROR, "Destination host unknown.");
- return JB_ERR_PARSE;
- }
- /*
- * remove 'user:pass@' from 'proto://user:pass@host'
- */
- if ((p = strchr( csp->http->hostport, '@')) != NULL)
- {
- p++;
- }
- else
- {
- p = csp->http->hostport;
- }
- /* XXX: Just add it, we already made sure that it will be unique */
- log_error(LOG_LEVEL_HEADER, "addh-unique: Host: %s", p);
- err = enlist_unique_header(csp->headers, "Host", p);
- return err;
- }
- /*********************************************************************
- *
- * Function : client_xtra_adder
- *
- * Description : Used in the add_client_headers list. Called from `sed'.
- *
- * Parameters :
- * 1 : csp = Current client state (buffers, headers, etc...)
- *
- * Returns : JB_ERR_OK on success, or
- * JB_ERR_MEMORY on out-of-memory error.
- *
- *********************************************************************/
- static jb_err client_xtra_adder(struct client_state *csp)
- {
- struct list_entry *lst;
- jb_err err;
- for (lst = csp->action->multi[ACTION_MULTI_ADD_HEADER]->first;
- lst ; lst = lst->next)
- {
- log_error(LOG_LEVEL_HEADER, "addh: %s", lst->str);
- err = enlist(csp->headers, lst->str);
- if (err)
- {
- return err;
- }
- }
- return JB_ERR_OK;
- }
- /*********************************************************************
- *
- * Function : client_x_forwarded_for_adder
- *
- * Description : Used in the add_client_headers list. Called from `sed'.
- *
- * Parameters :
- * 1 : csp = Current client state (buffers, headers, etc...)
- *
- * Returns : JB_ERR_OK on success, or
- * JB_ERR_MEMORY on out-of-memory error.
- *
- *********************************************************************/
- static jb_err client_x_forwarded_for_adder(struct client_state *csp)
- {
- char *header = NULL;
- jb_err err;
- if (!((csp->action->flags & ACTION_CHANGE_X_FORWARDED_FOR)
- && (0 == strcmpic(csp->action->string[ACTION_STRING_CHANGE_X_FORWARDED_FOR], "add")))
- || (csp->flags & CSP_FLAG_X_FORWARDED_FOR_APPENDED))
- {
- /*
- * If we aren't adding X-Forwarded-For headers,
- * or we already appended an existing X-Forwarded-For
- * header, there's nothing left to do here.
- */
- return JB_ERR_OK;
- }
- header = strdup("X-Forwarded-For: ");
- string_append(&header, csp->ip_addr_str);
- if (header == NULL)
- {
- return JB_ERR_MEMORY;
- }
- log_error(LOG_LEVEL_HEADER, "addh: %s", header);
- err = enlist(csp->headers, header);
- freez(header);
- return err;
- }
- /*********************************************************************
- *
- * Function : server_connection_adder
- *
- * Description : Adds an appropriate "Connection:" header to csp->headers
- * unless the header was already present. Called from `sed'.
- *
- * Parameters :
- * 1 : csp = Current client state (buffers, headers, etc...)
- *
- * Returns : JB_ERR_OK on success, or
- * JB_ERR_MEMORY on out-of-memory error.
- *
- *********************************************************************/
- static jb_err server_connection_adder(struct client_state *csp)
- {
- const unsigned int flags = csp->flags;
- const char *response_status_line = csp->headers->first->str;
- static const char connection_close[] = "Connection: close";
- if ((flags & CSP_FLAG_CLIENT_HEADER_PARSING_DONE)
- && (flags & CSP_FLAG_SERVER_CONNECTION_HEADER_SET))
- {
- return JB_ERR_OK;
- }
- /*
- * XXX: if we downgraded the response, this check will fail.
- */
- if ((csp->config->feature_flags &
- RUNTIME_FEATURE_CONNECTION_KEEP_ALIVE)
- && (NULL != response_status_line)
- && !strncmpic(response_status_line, "HTTP/1.1", 8)
- #ifdef FEATURE_CONNECTION_KEEP_ALIVE
- && !(csp->flags & CSP_FLAG_SERVER_SOCKET_TAINTED)
- #endif
- )
- {
- log_error(LOG_LEVEL_HEADER, "A HTTP/1.1 response "
- "without Connection header implies keep-alive.");
- csp->flags |= CSP_FLAG_SERVER_CONNECTION_KEEP_ALIVE;
- return JB_ERR_OK;
- }
- log_error(LOG_LEVEL_HEADER, "Adding: %s", connection_close);
- return enlist(csp->headers, connection_close);
- }
- #ifdef FEATURE_CONNECTION_KEEP_ALIVE
- /*********************************************************************
- *
- * Function : server_proxy_connection_adder
- *
- * Description : Adds a "Proxy-Connection: keep-alive" header to
- * csp->headers when appropriate.
- *
- * Parameters :
- * 1 : csp = Current client state (buffers, headers, etc...)
- *
- * Returns : JB_ERR_OK on success, or
- * JB_ERR_MEMORY on out-of-memory error.
- *
- *********************************************************************/
- static jb_err server_proxy_connection_adder(struct client_state *csp)
- {
- static const char proxy_connection_header[] = "Proxy-Connection: keep-alive";
- jb_err err = JB_ERR_OK;
- if ((csp->flags & CSP_FLAG_CLIENT_CONNECTION_KEEP_ALIVE)
- && !(csp->flags & CSP_FLAG_SERVER_SOCKET_TAINTED)
- && !(csp->flags & CSP_FLAG_SERVER_PROXY_CONNECTION_HEADER_SET)
- && ((csp->flags & CSP_FLAG_SERVER_CONTENT_LENGTH_SET)
- || (csp->flags & CSP_FLAG_CHUNKED))
- #ifdef FEATURE_HTTPS_INSPECTION
- && !client_use_ssl(csp)
- && !csp->http->ssl
- #endif
- )
- {
- log_error(LOG_LEVEL_HEADER, "Adding: %s", proxy_connection_header);
- err = enlist(csp->headers, proxy_connection_header);
- }
- return err;
- }
- #endif /* FEATURE_CONNECTION_KEEP_ALIVE */
- /*********************************************************************
- *
- * Function : client_connection_header_adder
- *
- * Description : Adds a proper "Connection:" header to csp->headers
- * unless the header was already present or it's a
- * CONNECT request. Called from `sed'.
- *
- * Parameters :
- * 1 : csp = Current client state (buffers, headers, etc...)
- *
- * Returns : JB_ERR_OK on success, or
- * JB_ERR_MEMORY on out-of-memory error.
- *
- *********************************************************************/
- static jb_err client_connection_header_adder(struct client_state *csp)
- {
- static const char connection_close[] = "Connection: close";
- if (!(csp->flags & CSP_FLAG_CLIENT_HEADER_PARSING_DONE)
- && (csp->flags & CSP_FLAG_CLIENT_CONNECTION_HEADER_SET))
- {
- return JB_ERR_OK;
- }
- /*
- * In case of CONNECT requests "Connection: close" is implied,
- * but actually setting the header has been reported to cause
- * problems with some forwarding proxies that close the
- * connection prematurely.
- */
- if (csp->http->ssl != 0)
- {
- return JB_ERR_OK;
- }
- #ifdef FEATURE_CONNECTION_KEEP_ALIVE
- if ((csp->config->feature_flags & RUNTIME_FEATURE_CONNECTION_KEEP_ALIVE)
- && !(csp->flags & CSP_FLAG_SERVER_SOCKET_TAINTED)
- && !strcmpic(csp->http->version, "HTTP/1.1"))
- {
- csp->flags |= CSP_FLAG_CLIENT_CONNECTION_KEEP_ALIVE;
- return JB_ERR_OK;
- }
- #endif /* FEATURE_CONNECTION_KEEP_ALIVE */
- log_error(LOG_LEVEL_HEADER, "Adding: %s", connection_close);
- return enlist(csp->headers, connection_close);
- }
- /*********************************************************************
- *
- * Function : server_http
- *
- * Description : - Save the HTTP Status into csp->http->status
- * - Set CT_TABOO to prevent filtering if the answer
- * is a partial range (HTTP status 206)
- * - Rewrite HTTP/1.1 answers to HTTP/1.0 if +downgrade
- * action applies.
- * - Normalize the HTTP-version.
- *
- * Parameters :
- * 1 : csp = Current client state (buffers, headers, etc...)
- * 2 : header = On input, pointer to header to modify.
- * On output, pointer to the modified header, or NULL
- * to remove the header. This function frees the
- * original string if necessary.
- *
- * Returns : JB_ERR_OK on success, or
- * JB_ERR_PARSE on fatal parse errors.
- *
- *********************************************************************/
- static jb_err server_http(struct client_state *csp, char **header)
- {
- char *reason_phrase = NULL;
- char *new_response_line;
- char *p;
- size_t length;
- unsigned int major_version;
- unsigned int minor_version;
- /* Get the reason phrase which start after the second whitespace */
- p = strchr(*header, ' ');
- if (NULL != p)
- {
- p++;
- reason_phrase = strchr(p, ' ');
- }
- if (reason_phrase != NULL)
- {
- reason_phrase++;
- }
- else
- {
- log_error(LOG_LEVEL_ERROR,
- "Response line lacks reason phrase: %s", *header);
- reason_phrase="";
- }
- if (3 != sscanf(*header, "HTTP/%u.%u %d", &major_version,
- &minor_version, &(csp->http->status)))
- {
- log_error(LOG_LEVEL_ERROR,
- "Failed to parse the response line: %s", *header);
- return JB_ERR_PARSE;
- }
- if (csp->http->status == 101 ||
- csp->http->status == 206)
- {
- csp->content_type = CT_TABOO;
- }
- if (major_version != 1 || (minor_version != 0 && minor_version != 1))
- {
- /*
- * According to RFC 7230 2.6 intermediaries MUST send
- * their own HTTP-version in forwarded messages.
- */
- log_error(LOG_LEVEL_ERROR,
- "Unsupported HTTP version. Downgrading to 1.1.");
- major_version = 1;
- minor_version = 1;
- }
- if (((csp->action->flags & ACTION_DOWNGRADE) != 0) && (minor_version == 1))
- {
- log_error(LOG_LEVEL_HEADER, "Downgrading answer to HTTP/1.0");
- minor_version = 0;
- }
- /* Rebuild response line. */
- length = sizeof("HTTP/1.1 200 ") + strlen(reason_phrase) + 1;
- new_response_line = malloc_or_die(length);
- snprintf(new_response_line, length, "HTTP/%u.%u %d %s",
- major_version, minor_version, csp->http->status, reason_phrase);
- if (0 != strcmp(*header, new_response_line))
- {
- log_error(LOG_LEVEL_HEADER, "Response line '%s' changed to '%s'",
- *header, new_response_line);
- }
- freez(*header);
- *header = new_response_line;
- return JB_ERR_OK;
- }
- /*********************************************************************
- *
- * Function : add_cooky_expiry_date
- *
- * Description : Adds a cookie expiry date to a string.
- *
- * Parameters :
- * 1 : cookie = On input, pointer to cookie to modify.
- * On output, pointer to the modified header.
- * The original string is freed.
- * 2 : lifetime = Seconds the cookie should be valid
- *
- * Returns : N/A
- *
- *********************************************************************/
- static void add_cookie_expiry_date(char **cookie, time_t lifetime)
- {
- char tmp[50];
- struct tm *timeptr = NULL;
- time_t expiry_date = time(NULL) + lifetime;
- struct tm gmt;
- timeptr = privoxy_gmtime_r(&expiry_date, &gmt);
- if (NULL == timeptr)
- {
- log_error(LOG_LEVEL_FATAL,
- "Failed to get the time in add_cooky_expiry_date()");
- }
- strftime(tmp, sizeof(tmp), "; expires=%a, %d-%b-%Y %H:%M:%S GMT", timeptr);
- if (JB_ERR_OK != string_append(cookie, tmp))
- {
- log_error(LOG_LEVEL_FATAL, "Out of memory in add_cooky_expiry()");
- }
- }
- /*********************************************************************
- *
- * Function : server_set_cookie
- *
- * Description : Handle the server "cookie" header properly.
- * Crunch, accept or rewrite it to a session cookie.
- * Called from `sed'.
- *
- * Parameters :
- * 1 : csp = Current client state (buffers, headers, etc...)
- * 2 : header = On input, pointer to header to modify.
- * On output, pointer to the modified header, or NULL
- * to remove the header. This function frees the
- * original string if necessary.
- *
- * Returns : JB_ERR_OK on success, or
- * JB_ERR_MEMORY on out-of-memory error.
- *
- *********************************************************************/
- static jb_err server_set_cookie(struct client_state *csp, char **header)
- {
- if ((csp->action->flags & ACTION_CRUNCH_INCOMING_COOKIES) != 0)
- {
- log_error(LOG_LEVEL_HEADER, "Crunching incoming cookie: %s", *header);
- freez(*header);
- }
- else if ((0 != (csp->action->flags & ACTION_SESSION_COOKIES_ONLY))
- || (0 != (csp->action->flags & ACTION_LIMIT_COOKIE_LIFETIME)))
- {
- time_t now;
- time_t cookie_time;
- long cookie_lifetime = 0;
- enum
- {
- NO_EXPIRY_DATE_SPECIFIED,
- EXPIRY_DATE_ACCEPTABLE,
- EXPIRY_DATE_UNACCEPTABLE
- } expiry_date_status = NO_EXPIRY_DATE_SPECIFIED;
- /* A variable to store the tag we're working on */
- char *cur_tag;
- /* Skip "Set-Cookie:" (11 characters) in header */
- cur_tag = *header + 11;
- /* skip whitespace between "Set-Cookie:" and value */
- while (*cur_tag && privoxy_isspace(*cur_tag))
- {
- cur_tag++;
- }
- time(&now);
- if ((csp->action->flags & ACTION_LIMIT_COOKIE_LIFETIME) != 0)
- {
- const char *param = csp->action->string[ACTION_STRING_LIMIT_COOKIE_LIFETIME];
- cookie_lifetime = strtol(param, NULL, 0);
- if (cookie_lifetime < 0)
- {
- log_error(LOG_LEVEL_FATAL, "Invalid cookie lifetime limit: %s", param);
- }
- cookie_lifetime *= 60;
- }
- /* Loop through each tag in the cookie */
- while (*cur_tag)
- {
- /* Find next tag */
- char *next_tag = strchr(cur_tag, ';');
- if (next_tag != NULL)
- {
- /* Skip the ';' character itself */
- next_tag++;
- /* skip whitespace ";" and start of tag */
- while (*next_tag && privoxy_isspace(*next_tag))
- {
- next_tag++;
- }
- }
- else
- {
- /* "Next tag" is the end of the string */
- next_tag = cur_tag + strlen(cur_tag);
- }
- /*
- * Check the expiration date to see
- * if the cookie is still valid, if yes,
- * rewrite it to a session cookie.
- */
- if ((strncmpic(cur_tag, "expires=", 8) == 0) && *(cur_tag + 8))
- {
- char *expiration_date = cur_tag + 8; /* Skip "[Ee]xpires=" */
- if ((expiration_date[0] == '"')
- && (expiration_date[1] != '\0'))
- {
- /*
- * Skip quotation mark. RFC 2109 10.1.2 seems to hint
- * that the expiration date isn't supposed to be quoted,
- * but some servers do it anyway.
- */
- expiration_date++;
- }
- /* Did we detect the date properly? */
- if (JB_ERR_OK != parse_header_time(expiration_date, &cookie_time))
- {
- /*
- * Nope, treat it as if it was still valid.
- *
- * XXX: Should we remove the whole cookie instead?
- */
- log_error(LOG_LEVEL_ERROR,
- "Can't parse \'%s\', send by %s. Unsupported time format?", cur_tag, csp->http->url);
- string_move(cur_tag, next_tag);
- expiry_date_status = EXPIRY_DATE_UNACCEPTABLE;
- }
- else
- {
- /*
- * Yes. Check if the cookie is still valid.
- *
- * If the cookie is already expired it's probably
- * a delete cookie and even if it isn't, the browser
- * will discard it anyway.
- */
- /*
- * XXX: timegm() isn't available on some AmigaOS
- * versions and our replacement doesn't work.
- *
- * Our options are to either:
- *
- * - disable session-cookies-only completely if timegm
- * is missing,
- *
- * - to simply remove all expired tags, like it has
- * been done until Privoxy 3.0.6 and to live with
- * the consequence that it can cause login/logout
- * problems on servers that don't validate their
- * input properly, or
- *
- * - to replace it with mktime in which
- * case there is a slight chance of valid cookies
- * passing as already expired.
- *
- * This is the way it's currently done and it's not
- * as bad as it sounds. If the missing GMT offset is
- * enough to change the result of the expiration check
- * the cookie will be only valid for a few hours
- * anyway, which in many cases will be shorter
- * than a browser session.
- */
- if (cookie_time < now)
- {
- log_error(LOG_LEVEL_HEADER,
- "Cookie \'%s\' is already expired and can pass unmodified.", *header);
- /* Just in case some clown sets more then one expiration date */
- cur_tag = next_tag;
- expiry_date_status = EXPIRY_DATE_ACCEPTABLE;
- }
- else if ((cookie_lifetime != 0) && (cookie_time < (now + cookie_lifetime)))
- {
- log_error(LOG_LEVEL_HEADER, "Cookie \'%s\' can pass unmodified. "
- "Its lifetime is below the limit.", *header);
- /* Just in case some clown sets more then one expiration date */
- cur_tag = next_tag;
- expiry_date_status = EXPIRY_DATE_ACCEPTABLE;
- }
- else
- {
- /*
- * Still valid, delete expiration date by copying
- * the rest of the string over it.
- */
- string_move(cur_tag, next_tag);
- /* That changed the header, need to issue a log message */
- expiry_date_status = EXPIRY_DATE_UNACCEPTABLE;
- /*
- * Note that the next tag has now been moved to *cur_tag,
- * so we do not need to update the cur_tag pointer.
- */
- }
- }
- }
- else
- {
- /* Move on to next cookie tag */
- cur_tag = next_tag;
- }
- }
- if (expiry_date_status != EXPIRY_DATE_ACCEPTABLE)
- {
- assert(NULL != *header);
- if (cookie_lifetime != 0)
- {
- add_cookie_expiry_date(header, cookie_lifetime);
- log_error(LOG_LEVEL_HEADER, "Cookie rewritten to: %s", *header);
- }
- else if (expiry_date_status != NO_EXPIRY_DATE_SPECIFIED)
- {
- log_error(LOG_LEVEL_HEADER,
- "Cookie rewritten to a temporary one: %s", *header);
- }
- }
- }
- return JB_ERR_OK;
- }
- #ifdef FEATURE_FORCE_LOAD
- /*********************************************************************
- *
- * Function : strclean
- *
- * Description : In-Situ-Eliminate all occurrences of substring in
- * string
- *
- * Parameters :
- * 1 : string = string to clean
- * 2 : substring = substring to eliminate
- *
- * Returns : Number of eliminations
- *
- *********************************************************************/
- int strclean(char *string, const char *substring)
- {
- int hits = 0;
- size_t len;
- char *pos, *p;
- len = strlen(substring);
- while((pos = strstr(string, substring)) != NULL)
- {
- p = pos + len;
- do
- {
- *(p - len) = *p;
- }
- while (*p++ != '\0');
- hits++;
- }
- return(hits);
- }
- #endif /* def FEATURE_FORCE_LOAD */
- /*********************************************************************
- *
- * Function : parse_header_time
- *
- * Description : Parses time formats used in HTTP header strings
- * to get the numerical respresentation.
- *
- * Parameters :
- * 1 : header_time = HTTP header time as string.
- * 2 : result = storage for header_time in seconds
- *
- * Returns : JB_ERR_OK if the time format was recognized, or
- * JB_ERR_PARSE otherwise.
- *
- *********************************************************************/
- static jb_err parse_header_time(const char *header_time, time_t *result)
- {
- struct tm gmt;
- /*
- * Checking for two-digit years first in an
- * attempt to work around GNU libc's strptime()
- * reporting negative year values when using %Y.
- */
- static const char time_formats[][22] = {
- /* Tue, 02-Jun-37 20:00:00 */
- "%a, %d-%b-%y %H:%M:%S",
- /* Tue, 02 Jun 2037 20:00:00 */
- "%a, %d %b %Y %H:%M:%S",
- /* Tue, 02-Jun-2037 20:00:00 */
- "%a, %d-%b-%Y %H:%M:%S",
- /* Tuesday, 02-Jun-2037 20:00:00 */
- "%A, %d-%b-%Y %H:%M:%S",
- /* Tuesday Jun 02 20:00:00 2037 */
- "%A %b %d %H:%M:%S %Y"
- };
- unsigned int i;
- for (i = 0; i < SZ(time_formats); i++)
- {
- /*
- * Zero out gmt to prevent time zone offsets.
- * Documented to be required for GNU libc.
- */
- memset(&gmt, 0, sizeof(gmt));
- if (NULL != strptime(header_time, time_formats[i], &gmt))
- {
- /* Sanity check for GNU libc. */
- if (gmt.tm_year < 0)
- {
- log_error(LOG_LEVEL_HEADER,
- "Failed to parse '%s' using '%s'. Moving on.",
- header_time, time_formats[i]);
- continue;
- }
- *result = timegm(&gmt);
- #ifdef FEATURE_STRPTIME_SANITY_CHECKS
- /*
- * Verify that parsing the date recreated from the first
- * parse operation gets the previous result. If it doesn't,
- * either strptime() or strftime() are malfunctioning.
- *
- * We could string-compare the recreated date with the original
- * header date, but this leads to false positives as strptime()
- * may let %a accept all day formats while strftime() will only
- * create one.
- */
- {
- char recreated_date[100];
- struct tm *tm;
- struct tm storage;
- time_t result2;
- tm = privoxy_gmtime_r(result, &storage);
- if (!strftime(recreated_date, sizeof(recreated_date),
- time_formats[i], tm))
- {
- log_error(LOG_LEVEL_ERROR, "Failed to recreate date '%s' with '%s'.",
- header_time, time_formats[i]);
- continue;
- }
- memset(&gmt, 0, sizeof(gmt));
- if (NULL == strptime(recreated_date, time_formats[i], &gmt))
- {
- log_error(LOG_LEVEL_ERROR,
- "Failed to parse '%s' generated with '%s' to recreate '%s'.",
- recreated_date, time_formats[i], header_time);
- continue;
- }
- result2 = timegm(&gmt);
- if (*result != result2)
- {
- log_error(LOG_LEVEL_ERROR, "strftime() and strptime() disagree. "
- "Format: '%s'. In: '%s', out: '%s'. %ld != %ld. Rejecting.",
- time_formats[i], header_time, recreated_date, *result, result2);
- continue;
- }
- }
- #endif
- return JB_ERR_OK;
- }
- }
- return JB_ERR_PARSE;
- }
- /*********************************************************************
- *
- * Function : parse_time_header
- *
- * Description : Parses the time in an HTTP time header to get
- * the numerical respresentation.
- *
- * Parameters :
- * 1 : header = HTTP header with a time value
- * 2 : result = storage for header_time in seconds
- *
- * Returns : JB_ERR_OK if the time format was recognized, or
- * JB_ERR_PARSE otherwise.
- *
- *********************************************************************/
- static jb_err parse_time_header(const char *header, time_t *result)
- {
- const char *header_time;
- header_time = strchr(header, ':');
- /*
- * Currently this can't happen as all callers are called
- * through sed() which requires a header name followed by
- * a colon.
- */
- assert(header_time != NULL);
- header_time++;
- if (*header_time == ' ')
- {
- header_time++;
- }
- return parse_header_time(header_time, result);
- }
- /*********************************************************************
- *
- * Function : get_destination_from_headers
- *
- * Description : Parse the "Host:" header to get the request's destination.
- * Only needed if the client's request was forcefully
- * redirected into Privoxy.
- *
- * Code mainly copied from client_host() which is currently
- * run too late for this purpose.
- *
- * Parameters :
- * 1 : headers = List of headers (one of them hopefully being
- * the "Host:" header)
- * 2 : http = storage for the result (host, port and hostport).
- *
- * Returns : JB_ERR_MEMORY (or terminates) in case of memory problems,
- * JB_ERR_PARSE if the host header couldn't be found,
- * JB_ERR_OK otherwise.
- *
- *********************************************************************/
- jb_err get_destination_from_headers(const struct list *headers, struct http_request *http)
- {
- char *q;
- char *p;
- char *host;
- host = get_header_value(headers, "Host:");
- if (NULL == host)
- {
- log_error(LOG_LEVEL_ERROR, "No \"Host:\" header found.");
- return JB_ERR_PARSE;
- }
- p = string_tolower(host);
- if (p == NULL)
- {
- return JB_ERR_MEMORY;
- }
- chomp(p);
- q = strdup_or_die(p);
- freez(http->hostport);
- http->hostport = p;
- freez(http->host);
- http->host = q;
- q = strchr(http->host, ':');
- if (q != NULL)
- {
- /* Terminate hostname and evaluate port string */
- *q++ = '\0';
- http->port = atoi(q);
- }
- else
- {
- http->port = 80;
- }
- /* Rebuild request URL */
- freez(http->url);
- http->url = strdup("http://");
- string_append(&http->url, http->hostport);
- string_append(&http->url, http->path);
- if (http->url == NULL)
- {
- return JB_ERR_MEMORY;
- }
- log_error(LOG_LEVEL_HEADER,
- "Destination extracted from \"Host\" header. New request URL: %s",
- http->url);
- /*
- * Regenerate request line in "proxy format"
- * to make rewrites more convenient.
- */
- assert(http->cmd != NULL);
- freez(http->cmd);
- http->cmd = strdup_or_die(http->gpc);
- string_append(&http->cmd, " ");
- string_append(&http->cmd, http->url);
- string_append(&http->cmd, " ");
- string_append(&http->cmd, http->version);
- if (http->cmd == NULL)
- {
- return JB_ERR_MEMORY;
- }
- return JB_ERR_OK;
- }
- #ifdef FEATURE_HTTPS_INSPECTION
- /*********************************************************************
- *
- * Function : get_destination_from_https_headers
- *
- * Description : Parse the previously encrypted "Host:" header to
- * get the request's destination.
- *
- * Parameters :
- * 1 : headers = List of headers (one of them hopefully being
- * the "Host:" header)
- * 2 : http = storage for the result (host, port and hostport).
- *
- * Returns : JB_ERR_MEMORY (or terminates) in case of memory problems,
- * JB_ERR_PARSE if the host header couldn't be found,
- * JB_ERR_OK otherwise.
- *
- *********************************************************************/
- jb_err get_destination_from_https_headers(const struct list *headers, struct http_request *http)
- {
- char *q;
- char *p;
- char *host;
- host = get_header_value(headers, "Host:");
- if (NULL == host)
- {
- log_error(LOG_LEVEL_ERROR, "No \"Host:\" header found.");
- return JB_ERR_PARSE;
- }
- p = string_tolower(host);
- if (p == NULL)
- {
- return JB_ERR_MEMORY;
- }
- chomp(p);
- q = strdup_or_die(p);
- freez(http->hostport);
- http->hostport = p;
- freez(http->host);
- http->host = q;
- q = strchr(http->host, ':');
- if (q != NULL)
- {
- /* Terminate hostname and evaluate port string */
- *q++ = '\0';
- http->port = atoi(q);
- }
- else
- {
- http->port = 443;
- }
- /* Rebuild request URL */
- freez(http->url);
- http->url = strdup_or_die(http->path);
- log_error(LOG_LEVEL_HEADER,
- "Destination extracted from \"Host\" header. New request URL: %s",
- http->url);
- /*
- * Regenerate request line in "proxy format"
- * to make rewrites more convenient.
- */
- assert(http->cmd != NULL);
- freez(http->cmd);
- http->cmd = strdup_or_die(http->gpc);
- string_append(&http->cmd, " ");
- string_append(&http->cmd, http->url);
- string_append(&http->cmd, " ");
- string_append(&http->cmd, http->version);
- if (http->cmd == NULL)
- {
- return JB_ERR_MEMORY;
- }
- return JB_ERR_OK;
- }
- #endif /* def FEATURE_HTTPS_INSPECTION */
- /*********************************************************************
- *
- * Function : create_forged_referrer
- *
- * Description : Helper for client_referrer to forge a referer as
- * 'http://hostname[:port]/' to fool stupid
- * checks for in-site links
- *
- * Parameters :
- * 1 : header = Pointer to header pointer
- * 2 : hostport = Host and optionally port as string
- *
- * Returns : JB_ERR_OK in case of success, or
- * JB_ERR_MEMORY in case of memory problems.
- *
- *********************************************************************/
- static jb_err create_forged_referrer(char **header, const char *hostport)
- {
- assert(NULL == *header);
- *header = strdup("Referer: http://");
- string_append(header, hostport);
- string_append(header, "/");
- if (NULL == *header)
- {
- return JB_ERR_MEMORY;
- }
- log_error(LOG_LEVEL_HEADER, "Referer forged to: %s", *header);
- return JB_ERR_OK;
- }
- /*********************************************************************
- *
- * Function : create_fake_referrer
- *
- * Description : Helper for client_referrer to create a fake referrer
- * based on a string supplied by the user.
- *
- * Parameters :
- * 1 : header = Pointer to header pointer
- * 2 : hosthost = Referrer to fake
- *
- * Returns : JB_ERR_OK in case of success, or
- * JB_ERR_MEMORY in case of memory problems.
- *
- *********************************************************************/
- static jb_err create_fake_referrer(char **header, const char *fake_referrer)
- {
- assert(NULL == *header);
- if ((0 != strncmpic(fake_referrer, "http://", 7)) && (0 != strncmpic(fake_referrer, "https://", 8)))
- {
- log_error(LOG_LEVEL_HEADER,
- "Parameter: +hide-referrer{%s} is a bad idea, but I don't care.", fake_referrer);
- }
- *header = strdup("Referer: ");
- string_append(header, fake_referrer);
- if (NULL == *header)
- {
- return JB_ERR_MEMORY;
- }
- log_error(LOG_LEVEL_HEADER, "Referer replaced with: %s", *header);
- return JB_ERR_OK;
- }
- /*********************************************************************
- *
- * Function : handle_conditional_hide_referrer_parameter
- *
- * Description : Helper for client_referrer to crunch or forge
- * the referrer header if the host has changed.
- *
- * Parameters :
- * 1 : header = Pointer to header pointer
- * 2 : host = The target host (may include the port)
- * 3 : parameter_conditional_block = Boolean to signal
- * if we're in conditional-block mode. If not set,
- * we're in conditional-forge mode.
- *
- * Returns : JB_ERR_OK in case of success, or
- * JB_ERR_MEMORY in case of memory problems.
- *
- *********************************************************************/
- static jb_err handle_conditional_hide_referrer_parameter(char **header,
- const char *host, const int parameter_conditional_block)
- {
- char *referer = strdup_or_die(*header);
- const size_t hostlength = strlen(host);
- const char *referer_url = NULL;
- /* referer begins with 'Referer: http[s]://' */
- if ((hostlength+17) < strlen(referer))
- {
- /*
- * Shorten referer to make sure the referer is blocked
- * if www.example.org/www.example.com-shall-see-the-referer/
- * links to www.example.com/
- */
- referer[hostlength+17] = '\0';
- }
- referer_url = strstr(referer, "http://");
- if ((NULL == referer_url) || (NULL == strstr(referer_url, host)))
- {
- /* Host has changed, Referer is invalid or a https URL. */
- if (parameter_conditional_block)
- {
- log_error(LOG_LEVEL_HEADER, "New host is: %s. Crunching %s!", host, *header);
- freez(*header);
- }
- else
- {
- freez(*header);
- freez(referer);
- return create_forged_referrer(header, host);
- }
- }
- freez(referer);
- return JB_ERR_OK;
- }
- /*********************************************************************
- *
- * Function : create_content_length_header
- *
- * Description : Creates a Content-Length header.
- *
- * Parameters :
- * 1 : content_length = The content length to be used in the header.
- * 2 : header = Allocated space to safe the header.
- * 3 : buffer_length = The length of the allocated space.
- *
- * Returns : void
- *
- *********************************************************************/
- static void create_content_length_header(unsigned long long content_length,
- char *header, size_t buffer_length)
- {
- #ifdef _WIN32
- #if SIZEOF_LONG_LONG < 8
- #error sizeof(unsigned long long) too small
- #endif
- snprintf(header, buffer_length, "Content-Length: %I64u", content_length);
- #else
- snprintf(header, buffer_length, "Content-Length: %llu", content_length);
- #endif
- }
- /*********************************************************************
- *
- * Function : get_expected_content_length
- *
- * Description : Figures out the content length from a list of headers.
- *
- * Parameters :
- * 1 : headers = List of headers
- *
- * Returns : Number of bytes to expect
- *
- *********************************************************************/
- unsigned long long get_expected_content_length(struct list *headers)
- {
- const char *content_length_header;
- unsigned long long content_length = 0;
- content_length_header = get_header_value(headers, "Content-Length:");
- if (content_length_header != NULL)
- {
- if (JB_ERR_OK != get_content_length(content_length_header, &content_length))
- {
- log_error(LOG_LEVEL_ERROR,
- "Failed to get the Content-Length in %s", content_length_header);
- /* XXX: The header will be removed later on */
- return 0;
- }
- }
- return content_length;
- }
- /*
- Local Variables:
- tab-width: 3
- end:
- */
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