-const char parsers_rcs[] = "$Id: parsers.c,v 1.80 2006/12/29 19:08:22 fabiankeil Exp $";
+const char parsers_rcs[] = "$Id: parsers.c,v 1.81 2006/12/31 22:21:33 fabiankeil Exp $";
/*********************************************************************
*
* File : $Source: /cvsroot/ijbswa/current/parsers.c,v $
*
* Revisions :
* $Log: parsers.c,v $
+ * Revision 1.81 2006/12/31 22:21:33 fabiankeil
+ * Skip empty filter files in filter_header()
+ * but don't ignore the ones that come afterwards.
+ * Fixes BR 1619208, this time for real.
+ *
* Revision 1.80 2006/12/29 19:08:22 fabiankeil
* Reverted parts of my last commit
* to keep error handling working.
#include <string.h>
#include <time.h>
+#ifdef FEATURE_ZLIB
+#include <zlib.h>
+#endif
+
#if !defined(_WIN32) && !defined(__OS2__)
#include <unistd.h>
#endif
const struct parsers server_patterns_light[] = {
{ "Content-Length:", 15, server_content_length },
{ "Transfer-Encoding:", 18, server_transfer_coding },
+#ifdef FEATURE_ZLIB
+ { "Content-Encoding:", 17, server_content_encoding },
+#endif /* def FEATURE_ZLIB */
{ NULL, 0, NULL }
};
}
+#ifdef FEATURE_ZLIB
+/*********************************************************************
+ *
+ * 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 */
+ size_t bufsize; /* allocated size of the new buffer */
+ 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 */
+
+ bufsize = csp->iob->size;
+ skip_size = (size_t)(csp->iob->cur - csp->iob->buf);
+
+ if (bufsize < 10)
+ {
+ /*
+ * This is to protect the parsing of gzipped data,
+ * but it should(?) be valid for deflated data also.
+ */
+ log_error (LOG_LEVEL_ERROR, "Buffer too small decompressing iob");
+ return JB_ERR_COMPRESS;
+ }
+
+ 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 ((*csp->iob->cur++ != (char)0x1f)
+ || (*csp->iob->cur++ != (char)0x8b)
+ || (*csp->iob->cur++ != Z_DEFLATED))
+ {
+ log_error (LOG_LEVEL_ERROR, "Invalid gzip header when decompressing");
+ return JB_ERR_COMPRESS;
+ }
+ else
+ {
+ int flags = *csp->iob->cur++;
+ /*
+ * XXX: These magic numbers should be replaced
+ * with macros to give a better idea what they do.
+ */
+ if (flags & 0xe0)
+ {
+ /* The gzip header has reserved bits set; bail out. */
+ log_error (LOG_LEVEL_ERROR, "Invalid gzip header when decompressing");
+ return JB_ERR_COMPRESS;
+ }
+ csp->iob->cur += 6;
+
+ /* Skip extra fields if necessary. */
+ if (flags & 0x04)
+ {
+ /*
+ * Skip a given number of bytes, specified
+ * as a 16-bit little-endian value.
+ */
+ csp->iob->cur += *csp->iob->cur++ + (*csp->iob->cur++ << 8);
+ }
+
+ /* Skip the filename if necessary. */
+ if (flags & 0x08)
+ {
+ /* A null-terminated string follows. */
+ while (*csp->iob->cur++);
+ }
+
+ /* Skip the comment if necessary. */
+ if (flags & 0x10)
+ {
+ while (*csp->iob->cur++);
+ }
+
+ /* Skip the CRC if necessary. */
+ if (flags & 0x02)
+ {
+ csp->iob->cur += 2;
+ }
+ }
+ }
+ else if (csp->content_type & CT_DEFLATE)
+ {
+ log_error (LOG_LEVEL_INFO, "Decompressing deflated iob: %d", *csp->iob->cur);
+ /*
+ * 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 *)csp->iob->cur;
+ zstr.avail_in = (unsigned long)(csp->iob->eod - csp->iob->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 = 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 zlib wants more data then there's a problem, because
+ * the complete compressed file should have been buffered.
+ */
+ if (0 == zstr.avail_in)
+ {
+ log_error(LOG_LEVEL_ERROR, "Unexpected end of compressed iob");
+ return JB_ERR_COMPRESS;
+ }
+
+ /*
+ * If we tried the limit and still didn't have enough
+ * memory, just give up.
+ */
+ if (bufsize == csp->config->buffer_limit)
+ {
+ log_error(LOG_LEVEL_ERROR, "Buffer limit reached while decompressing iob");
+ 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);
+ 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 += 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));
+ assert(zstr.avail_out > 0);
+
+ buf = tmpbuf;
+ }
+ }
+
+ inflateEnd(&zstr);
+ if (status != Z_STREAM_END)
+ {
+ /* We failed to decompress the stream. */
+ log_error(LOG_LEVEL_ERROR,
+ "Error in 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))
+ {
+ char t = csp->iob->cur[100];
+ csp->iob->cur[100] = '\0';
+ /*
+ * XXX: The debug level should be lowered
+ * before the next stable release.
+ */
+ log_error(LOG_LEVEL_INFO, "Sucessfully decompressed: %s", csp->iob->cur);
+ csp->iob->cur[100] = t;
+ return JB_ERR_OK;
+ }
+ else
+ {
+ /* It seems that zlib did something weird. */
+ log_error(LOG_LEVEL_ERROR,
+ "Unexpected error decompressing the buffer (iob): %d==%d, %d>%d, %d<%d",
+ csp->iob->cur, csp->iob->buf + skip_size, csp->iob->eod, csp->iob->buf,
+ csp->iob->eod, csp->iob->buf + csp->iob->size);
+ return JB_ERR_COMPRESS;
+ }
+
+}
+#endif /* defined(FEATURE_ZLIB) */
+
+
/*********************************************************************
*
* Function : get_header
*/
if (strncmpic(csp->http->cmd, "HEAD", 4))
{
- /*XXX: Code duplication*/
+ /*XXX: Code duplication */
for (v = pats; (err == JB_ERR_OK) && (v->str != NULL) ; v++)
{
for (p = csp->headers->first; (err == JB_ERR_OK) && (p != NULL) ; p = p->next)
newval = csp->action->string[ACTION_STRING_CONTENT_TYPE];
- if (csp->content_type != CT_TABOO)
+ assert(!csp->content_type || (csp->content_type == CT_TABOO));
+
+ if (!(csp->content_type & CT_TABOO))
{
if ((strstr(*header, " text/") && !strstr(*header, "plain"))
- || strstr(*header, "xml")
- || strstr(*header, "application/x-javascript"))
- csp->content_type = CT_TEXT;
+ || strstr(*header, "xml")
+ || strstr(*header, "application/x-javascript"))
+ {
+ csp->content_type |= CT_TEXT;
+ }
else if (strstr(*header, " image/gif"))
- csp->content_type = CT_GIF;
+ {
+ csp->content_type |= CT_GIF;
+ }
else if (strstr(*header, " image/jpeg"))
- csp->content_type = CT_JPEG;
+ {
+ csp->content_type |= CT_JPEG;
+ }
else
+ {
csp->content_type = 0;
+ }
}
/*
* Are we enabling text mode by force?
*/
if (csp->action->flags & ACTION_FORCE_TEXT_MODE)
{
- /*
- * Do we really have to?
- */
- if (csp->content_type == CT_TEXT)
+ /*
+ * Do we really have to?
+ */
+ if (csp->content_type & CT_TEXT)
{
log_error(LOG_LEVEL_HEADER, "Text mode is already enabled.");
}
else
{
- csp->content_type = CT_TEXT;
+ csp->content_type |= CT_TEXT;
log_error(LOG_LEVEL_HEADER, "Text mode enabled by force. Take cover!");
}
}
*/
if (csp->action->flags & ACTION_CONTENT_TYPE_OVERWRITE)
{
- /*
- * Make sure the user doesn't accidently
- * change the content type of binary documents.
- */
- if (csp->content_type == CT_TEXT)
- {
- freez(*header);
- *header = strdup("Content-Type: ");
- string_append(header, newval);
-
- if (header == NULL)
- {
- log_error(LOG_LEVEL_HEADER, "Insufficient memory. Conten-Type crunched without replacement!");
- 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 text. "
- "Enable force-text-mode if you know what you're doing.", *header);
- }
+ /*
+ * Make sure the user doesn't accidently
+ * change the content type of binary documents.
+ */
+ if (csp->content_type & CT_TEXT)
+ {
+ freez(*header);
+ *header = strdup("Content-Type: ");
+ string_append(header, newval);
+
+ if (header == NULL)
+ {
+ log_error(LOG_LEVEL_HEADER,
+ "Insufficient memory. Content-Type crunched without replacement!");
+ 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 text. "
+ "Enable force-text-mode if you know what you're doing.", *header);
+ }
}
return JB_ERR_OK;
}
*/
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;
}
/*
* If the body was modified, it has been de-chunked first
- * and the header must be removed.
+ * 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)
{
*
* Function : server_content_encoding
*
- * Description : Prohibit filtering (CT_TABOO) if content encoding compresses
+ * Description : This function is run twice for each request,
+ * unless FEATURE_ZLIB and filtering are disabled.
+ *
+ * The first run is used to check if the content
+ * is compressed, if FEATURE_ZLIB is disabled
+ * filtering is then disabled as well, if FEATURE_ZLIB
+ * is enabled the content is marked for decompression.
+ *
+ * The second run is used to remove the Content-Encoding
+ * header if the decompression was successful.
*
* Parameters :
* 1 : csp = Current client state (buffers, headers, etc...)
*********************************************************************/
jb_err server_content_encoding(struct client_state *csp, char **header)
{
- /*
- * Turn off pcrs and gif filtering if body compressed
- */
+#ifdef FEATURE_ZLIB
+ /* XXX: Why would we modify the content if it was taboo? */
+ if ((csp->flags & CSP_FLAG_MODIFIED) && !(csp->content_type & CT_TABOO))
+ {
+ /*
+ * 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);
+ }
+ 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, "compress"))
+ {
+ /*
+ * We can't decompress this; therefore we can't filter
+ * it either.
+ */
+ csp->content_type |= CT_TABOO;
+ }
+#else /* !defined(FEATURE_ZLIB) */
if (strstr(*header, "gzip") || strstr(*header, "compress") || strstr(*header, "deflate"))
{
- csp->content_type = CT_TABOO;
+ /*
+ * Body is compressed, turn off pcrs and gif filtering.
+ */
+ csp->content_type |= CT_TABOO;
}
+#endif /* !defined(FEATURE_ZLIB) */
return JB_ERR_OK;
projects / privoxy.git / blobdiff