-const char filters_rcs[] = "$Id: filters.c,v 1.69 2006/12/08 12:39:13 fabiankeil Exp $";
+const char filters_rcs[] = "$Id: filters.c,v 1.103 2008/03/06 16:33:45 fabiankeil Exp $";
/*********************************************************************
*
* File : $Source: /cvsroot/ijbswa/current/filters.c,v $
* `jpeg_inspect_response', `execute_single_pcrs_command',
* `rewrite_url', `get_last_url'
*
- * Copyright : Written by and Copyright (C) 2001, 2004-2006 the SourceForge
+ * Copyright : Written by and Copyright (C) 2001, 2004-2008 the SourceForge
* Privoxy team. http://www.privoxy.org/
*
* Based on the Internet Junkbuster originally written
*
* Revisions :
* $Log: filters.c,v $
+ * Revision 1.103 2008/03/06 16:33:45 fabiankeil
+ * If limit-connect isn't used, don't limit CONNECT requests to port 443.
+ *
+ * Revision 1.102 2008/03/01 14:00:44 fabiankeil
+ * Let the block action take the reason for the block
+ * as argument and show it on the "blocked" page.
+ *
+ * Revision 1.101 2008/02/23 16:57:12 fabiankeil
+ * Rename url_actions() to get_url_actions() and let it
+ * use the standard parameter ordering.
+ *
+ * Revision 1.100 2008/02/23 16:33:43 fabiankeil
+ * Let forward_url() use the standard parameter ordering
+ * and mark its second parameter immutable.
+ *
+ * Revision 1.99 2008/02/03 13:57:58 fabiankeil
+ * Add SOCKS5 support for forward-override{}.
+ *
+ * Revision 1.98 2008/01/04 17:43:45 fabiankeil
+ * Improve the warning messages that get logged if the action files
+ * "enable" filters but no filters of that type have been loaded.
+ *
+ * Revision 1.97 2007/11/30 15:37:03 fabiankeil
+ * Use freez instead of free.
+ *
+ * Revision 1.96 2007/10/19 16:53:28 fabiankeil
+ * Add helper function to check if any content filters are enabled.
+ *
+ * Revision 1.95 2007/10/17 19:31:20 fabiankeil
+ * Omitting the zero chunk that ends the chunk transfer encoding seems
+ * to be the new black. Log the problem and continue filtering anyway.
+ *
+ * Revision 1.94 2007/09/29 13:20:20 fabiankeil
+ * Remove two redundant and one useless log messages.
+ *
+ * Revision 1.93 2007/09/29 10:21:16 fabiankeil
+ * - Move get_filter_function() from jcc.c to filters.c
+ * so the filter functions can be static.
+ * - Don't bother filtering body-less responses.
+ *
+ * Revision 1.92 2007/09/28 16:38:55 fabiankeil
+ * - Execute content filters through execute_content_filter().
+ * - Add prepare_for_filtering() so filter functions don't have to
+ * care about de-chunking and decompression. As a side effect this enables
+ * decompression for gif_deanimate_response() and jpeg_inspect_response().
+ * - Change remove_chunked_transfer_coding()'s return type to jb_err.
+ * Some clowns feel like chunking empty responses in which case
+ * (size == 0) is valid but previously would be interpreted as error.
+ *
+ * Revision 1.91 2007/09/02 15:31:20 fabiankeil
+ * Move match_portlist() from filter.c to urlmatch.c.
+ * It's used for url matching, not for filtering.
+ *
+ * Revision 1.90 2007/09/02 12:44:17 fabiankeil
+ * Remove newline at the end of a log_error() message.
+ *
+ * Revision 1.89 2007/08/05 13:42:23 fabiankeil
+ * #1763173 from Stefan Huehner: declare some more functions static.
+ *
+ * Revision 1.88 2007/06/01 16:41:11 fabiankeil
+ * Add forward-override{} to change the forwarding settings through
+ * action sections. This is mainly interesting to forward different
+ * clients differently (for example based on User-Agent or request
+ * origin).
+ *
+ * Revision 1.87 2007/04/30 15:53:10 fabiankeil
+ * Make sure filters with dynamic jobs actually use them.
+ *
+ * Revision 1.86 2007/04/30 15:03:28 fabiankeil
+ * - Introduce dynamic pcrs jobs that can resolve variables.
+ * - Don't run redirect functions more than once,
+ * unless they are activated more than once.
+ *
+ * Revision 1.85 2007/03/21 12:24:47 fabiankeil
+ * - Log the content size after decompression in decompress_iob()
+ * instead of pcrs_filter_response().
+ *
+ * Revision 1.84 2007/03/20 15:16:34 fabiankeil
+ * Use dedicated header filter actions instead of abusing "filter".
+ * Replace "filter-client-headers" and "filter-client-headers"
+ * with "server-header-filter" and "client-header-filter".
+ *
+ * Revision 1.83 2007/03/17 15:20:05 fabiankeil
+ * New config option: enforce-blocks.
+ *
+ * Revision 1.82 2007/03/13 11:28:43 fabiankeil
+ * - Fix port handling in acl_addr() and use a temporary acl spec
+ * copy so error messages don't contain a truncated version.
+ * - Log size of iob before and after decompression.
+ *
+ * Revision 1.81 2007/03/05 14:40:53 fabiankeil
+ * - Cosmetical changes for LOG_LEVEL_RE_FILTER messages.
+ * - Hide the "Go there anyway" link for blocked CONNECT
+ * requests where going there anyway doesn't work anyway.
+ *
+ * Revision 1.80 2007/02/07 10:55:20 fabiankeil
+ * - Save the reason for generating http_responses.
+ * - Block (+block) with status code 403 instead of 404.
+ * - Use a different kludge to remember a failed decompression.
+ *
+ * Revision 1.79 2007/01/31 16:21:38 fabiankeil
+ * Search for Max-Forwards headers case-insensitive,
+ * don't generate the "501 unsupported" message for invalid
+ * Max-Forwards values and don't increase negative ones.
+ *
+ * Revision 1.78 2007/01/28 13:41:18 fabiankeil
+ * - Add HEAD support to finish_http_response.
+ * - Add error favicon to internal HTML error messages.
+ *
+ * Revision 1.77 2007/01/12 15:36:44 fabiankeil
+ * Mark *csp as immutable for is_untrusted_url()
+ * and is_imageurl(). Closes FR 1237736.
+ *
+ * Revision 1.76 2007/01/01 19:36:37 fabiankeil
+ * Integrate a modified version of Wil Mahan's
+ * zlib patch (PR #895531).
+ *
+ * Revision 1.75 2006/12/29 18:30:46 fabiankeil
+ * Fixed gcc43 conversion warnings,
+ * changed sprintf calls to snprintf.
+ *
+ * Revision 1.74 2006/12/24 17:37:38 fabiankeil
+ * Adjust comment in pcrs_filter_response()
+ * to recent pcrs changes. Hohoho.
+ *
+ * Revision 1.73 2006/12/23 16:01:02 fabiankeil
+ * Don't crash if pcre returns an error code
+ * that pcrs didn't expect. Fixes BR 1621173.
+ *
+ * Revision 1.72 2006/12/22 18:52:53 fabiankeil
+ * Modified is_untrusted_url to complain in case of
+ * write errors and to give a reason when adding new
+ * entries to the trustfile. Closes FR 1097611.
+ *
+ * Revision 1.71 2006/12/22 14:24:52 fabiankeil
+ * Skip empty filter files in pcrs_filter_response,
+ * but don't ignore the ones that come afterwards.
+ * Fixes parts of BR 1619208.
+ *
+ * Revision 1.70 2006/12/09 13:33:15 fabiankeil
+ * Added some sanity checks for get_last_url().
+ * Fixed possible segfault caused by my last commit.
+ *
* Revision 1.69 2006/12/08 12:39:13 fabiankeil
* Let get_last_url() catch https URLs as well.
*
#include "list.h"
#include "deanimate.h"
#include "urlmatch.h"
+#include "loaders.h"
#ifdef _WIN32
#include "win32.h"
*/
#define ijb_isdigit(__X) isdigit((int)(unsigned char)(__X))
+static jb_err remove_chunked_transfer_coding(char *buffer, size_t *size);
+static jb_err prepare_for_filtering(struct client_state *csp);
#ifdef FEATURE_ACL
/*********************************************************************
* Returns : 0 => Ok, everything else is an error.
*
*********************************************************************/
-int acl_addr(char *aspec, struct access_control_addr *aca)
+int acl_addr(const char *aspec, struct access_control_addr *aca)
{
- int i, masklength, port;
+ int i, masklength;
+ long port;
char *p;
+ char *acl_spec = NULL;
masklength = 32;
port = 0;
- if ((p = strchr(aspec, '/')) != NULL)
+ /*
+ * Use a temporary acl spec copy so we can log
+ * the unmodified original in case of parse errors.
+ */
+ acl_spec = strdup(aspec);
+ if (acl_spec == NULL)
{
- *p++ = '\0';
+ /* XXX: This will be logged as parse error. */
+ return(-1);
+ }
+ if ((p = strchr(acl_spec, '/')) != NULL)
+ {
+ *p++ = '\0';
if (ijb_isdigit(*p) == 0)
{
+ freez(acl_spec);
return(-1);
}
masklength = atoi(p);
if ((masklength < 0) || (masklength > 32))
{
+ freez(acl_spec);
return(-1);
}
- if ((p = strchr(aspec, ':')) != NULL)
+ if ((p = strchr(acl_spec, ':')) != NULL)
{
+ char *endptr;
+
*p++ = '\0';
+ port = strtol(p, &endptr, 10);
- if (ijb_isdigit(*p) == 0)
+ if (port <= 0 || port > 65535 || *endptr != '\0')
{
+ freez(acl_spec);
return(-1);
}
- port = atoi(p);
}
- aca->port = port;
+ aca->port = (unsigned long)port;
- aca->addr = ntohl(resolve_hostname_to_ip(aspec));
+ aca->addr = ntohl(resolve_hostname_to_ip(acl_spec));
+ freez(acl_spec);
if (aca->addr == INADDR_NONE)
{
+ /* XXX: This will be logged as parse error. */
return(-1);
}
/*********************************************************************
*
- * Function : match_portlist
+ * Function : connect_port_is_forbidden
*
- * Description : Check if a given number is covered by a comma
- * separated list of numbers and ranges (a,b-c,d,..)
+ * Description : Check to see if CONNECT requests to the destination
+ * port of this request are forbidden. The check is
+ * independend of the actual request method.
*
* Parameters :
- * 1 : portlist = String with list
- * 2 : port = port to check
+ * 1 : csp = Current client state (buffers, headers, etc...)
*
- * Returns : 0 => no match
- * 1 => match
+ * Returns : True if yes, false otherwise.
*
*********************************************************************/
-int match_portlist(const char *portlist, int port)
+int connect_port_is_forbidden(const struct client_state *csp)
{
- char *min, *max, *next, *portlist_copy;
-
- min = next = portlist_copy = strdup(portlist);
-
- /*
- * Zero-terminate first item and remember offset for next
- */
- if (NULL != (next = strchr(portlist_copy, (int) ',')))
- {
- *next++ = '\0';
- }
-
- /*
- * Loop through all items, checking for match
- */
- while(min)
- {
- if (NULL == (max = strchr(min, (int) '-')))
- {
- /*
- * No dash, check for equality
- */
- if (port == atoi(min))
- {
- free(portlist_copy);
- return(1);
- }
- }
- else
- {
- /*
- * This is a range, so check if between min and max,
- * or, if max was omitted, between min and 65K
- */
- *max++ = '\0';
- if(port >= atoi(min) && port <= (atoi(max) ? atoi(max) : 65535))
- {
- free(portlist_copy);
- return(1);
- }
-
- }
-
- /*
- * Jump to next item
- */
- min = next;
-
- /*
- * Zero-terminate next item and remember offset for n+1
- */
- if ((NULL != next) && (NULL != (next = strchr(next, (int) ','))))
- {
- *next++ = '\0';
- }
- }
-
- free(portlist_copy);
- return 0;
-
+ return ((csp->action->flags & ACTION_LIMIT_CONNECT) &&
+ !match_portlist(csp->action->string[ACTION_STRING_LIMIT_CONNECT],
+ csp->http->port));
}
return cgi_error_memory();
}
}
-
}
else
#endif /* def FEATURE_IMAGE_BLOCKING */
}
else
{
- rsp->status = strdup("404 Request for blocked URL");
+ rsp->status = strdup("403 Request for blocked URL");
}
if (rsp->status == NULL)
#ifdef FEATURE_FORCE_LOAD
err = map(exports, "force-prefix", 1, FORCE_PREFIX, 1);
- if (csp->http->ssl != 0)
+ /*
+ * Export the force conditional block killer if
+ *
+ * - Privoxy was compiled without FEATURE_FORCE_LOAD, or
+ * - Privoxy is configured to enforce blocks, or
+ * - it's a CONNECT request and enforcing wouldn't work anyway.
+ */
+ if ((csp->config->feature_flags & RUNTIME_FEATURE_ENFORCE_BLOCKS)
+ || (0 == strcmpic(csp->http->gpc, "connect")))
#endif /* ndef FEATURE_FORCE_LOAD */
{
err = map_block_killer(exports, "force-support");
if (!err) err = map(exports, "hostport", 1, html_encode(csp->http->hostport), 0);
if (!err) err = map(exports, "path", 1, html_encode(csp->http->path), 0);
if (!err) err = map(exports, "path-ue", 1, url_encode(csp->http->path), 0);
-
+ if (!err)
+ {
+ const char *block_reason;
+ if (csp->action->string[ACTION_STRING_BLOCK] != NULL)
+ {
+ block_reason = csp->action->string[ACTION_STRING_BLOCK];
+ }
+ else
+ {
+ assert(connect_port_is_forbidden(csp));
+ block_reason = "Forbidden CONNECT port.";
+ }
+ err = map(exports, "block-reason", 1, html_encode(block_reason), 0);
+ }
if (err)
{
free_map(exports);
return cgi_error_memory();
}
}
+ rsp->reason = RSP_REASON_BLOCKED;
- return finish_http_response(rsp);
+ return finish_http_response(csp, rsp);
}
p = strdup("");
for (tl = csp->config->trust_list; (t = *tl) != NULL ; tl++)
{
- sprintf(buf, "<li>%s</li>\n", t->spec);
+ snprintf(buf, sizeof(buf), "<li>%s</li>\n", t->spec);
string_append(&p, buf);
}
err = map(exports, "trusted-referrers", 1, p, 0);
p = strdup("");
for (l = csp->config->trust_info->first; l ; l = l->next)
{
- sprintf(buf, "<li> <a href=\"%s\">%s</a><br>\n",l->str, l->str);
+ snprintf(buf, sizeof(buf), "<li> <a href=\"%s\">%s</a><br>\n", l->str, l->str);
string_append(&p, buf);
}
err = map(exports, "trust-info", 1, p, 0);
}
/*
- * Export the force prefix or the force conditional block killer
+ * Export the force conditional block killer if
+ *
+ * - Privoxy was compiled without FEATURE_FORCE_LOAD, or
+ * - Privoxy is configured to enforce blocks, or
+ * - it's a CONNECT request and enforcing wouldn't work anyway.
*/
#ifdef FEATURE_FORCE_LOAD
- err = map(exports, "force-prefix", 1, FORCE_PREFIX, 1);
+ if ((csp->config->feature_flags & RUNTIME_FEATURE_ENFORCE_BLOCKS)
+ || (0 == strcmpic(csp->http->gpc, "connect")))
+ {
+ err = map_block_killer(exports, "force-support");
+ }
+ else
+ {
+ err = map(exports, "force-prefix", 1, FORCE_PREFIX, 1);
+ }
#else /* ifndef FEATURE_FORCE_LOAD */
err = map_block_killer(exports, "force-support");
#endif /* ndef FEATURE_FORCE_LOAD */
free_http_response(rsp);
return cgi_error_memory();
}
+ rsp->reason = RSP_REASON_UNTRUSTED;
- return finish_http_response(rsp);
+ return finish_http_response(csp, rsp);
}
#endif /* def FEATURE_TRUST */
+
/*********************************************************************
*
- * Function : execute_single_pcrs_command
+ * Function : compile_dynamic_pcrs_job_list
*
- * Description : Apply single pcrs command to the subject.
- * The subject itself is left untouched, memory for the result
- * is malloc()ed and it is the caller's responsibility to free
- * the result when it's no longer needed.
+ * Description : Compiles a dynamic pcrs job list (one with variables
+ * resolved at request time)
*
* Parameters :
- * 1 : subject = the subject (== original) string
- * 2 : pcrs_command = the pcrs command as string (s@foo@bar@)
- * 3 : hits = int* for returning the number of modifications
+ * 1 : csp = Current client state (buffers, headers, etc...)
+ * 2 : b = The filter list to compile
*
* Returns : NULL in case of errors, otherwise the
- * result of the pcrs command.
+ * pcrs job list.
*
*********************************************************************/
-char *execute_single_pcrs_command(char *subject, const char *pcrs_command, int *hits)
+pcrs_job *compile_dynamic_pcrs_job_list(const struct client_state *csp, const struct re_filterfile_spec *b)
{
- int error;
- size_t size;
- char *result = NULL;
- pcrs_job *job;
-
- assert(subject);
- assert(pcrs_command);
-
- *hits = 0;
- size = strlen(subject);
+ struct list_entry *pattern;
+ pcrs_job *job_list = NULL;
+ pcrs_job *dummy = NULL;
+ pcrs_job *lastjob = NULL;
+ int error = 0;
- if (NULL == (job = pcrs_compile_command(pcrs_command, &error)))
- {
- log_error(LOG_LEVEL_ERROR, "Failed to compile pcrs command \"%s\". Error: %d.",
- pcrs_command, error);
- }
- else if ((*hits = pcrs_execute(job, subject, size, &result, &size)) < 0)
+ const struct pcrs_variable variables[] =
{
- log_error(LOG_LEVEL_ERROR, "Failed to execute pcrs command: %s", pcrs_strerror(*hits));
- *hits = 0;
- freez(result);
- }
+ {"url", csp->http->url, 1},
+ {"path", csp->http->path, 1},
+ {"host", csp->http->host, 1},
+ {"origin", csp->ip_addr_str, 1},
+ {NULL, NULL, 1}
+ };
- if (job)
+ for (pattern = b->patterns->first; pattern != NULL; pattern = pattern->next)
{
- job = pcrs_free_job(job);
- }
+ assert(pattern->str != NULL);
- return result;
+ dummy = pcrs_compile_dynamic_command(pattern->str, variables, &error);
+ if (NULL == dummy)
+ {
+ assert(error < 0);
+ log_error(LOG_LEVEL_ERROR,
+ "Adding filter job \'%s\' to dynamic filter %s failed: %s",
+ pattern->str, b->name, pcrs_strerror(error));
+ continue;
+ }
+ else
+ {
+ if (error == PCRS_WARN_TRUNCATION)
+ {
+ log_error(LOG_LEVEL_ERROR,
+ "At least one of the variables in \'%s\' had to "
+ "be truncated before compilation", pattern->str);
+ }
+ if (job_list == NULL)
+ {
+ job_list = dummy;
+ }
+ else
+ {
+ lastjob->next = dummy;
+ }
+ lastjob = dummy;
+ }
+ }
+ return job_list;
}
+
/*********************************************************************
*
* Function : rewrite_url
assert(old_url);
assert(pcrs_command);
- new_url = execute_single_pcrs_command(old_url, pcrs_command, &hits);
+ new_url = pcrs_execute_single_command(old_url, pcrs_command, &hits);
if (hits == 0)
{
log_error(LOG_LEVEL_REDIRECTS,
"pcrs command \"%s\" didn't change \"%s\".",
- pcrs_command, old_url, new_url);
+ pcrs_command, old_url);
+ freez(new_url);
+ }
+ else if (hits < 0)
+ {
+ log_error(LOG_LEVEL_REDIRECTS,
+ "executing pcrs command \"%s\" to rewrite %s failed: %s",
+ pcrs_command, old_url, pcrs_strerror(hits));
freez(new_url);
}
else if (strncmpic(new_url, "http://", 7) && strncmpic(new_url, "https://", 8))
* If it exists, use the previously rewritten URL as input
* otherwise just use the old path.
*/
- old_url = new_url ? new_url : strdup(csp->http->path);
+ old_url = (new_url != NULL) ? new_url : strdup(csp->http->path);
new_url = get_last_url(old_url, redirect_mode);
freez(old_url);
}
+
+ /*
+ * Disable redirect checkers, so that they
+ * will be only run more than once if the user
+ * also enables them through tags.
+ *
+ * From a performance point of view
+ * it doesn't matter, but the duplicated
+ * log messages are annoying.
+ */
+ csp->action->flags &= ~ACTION_FAST_REDIRECTS;
#endif /* def FEATURE_FAST_REDIRECTS */
+ csp->action->flags &= ~ACTION_REDIRECT;
/* Did any redirect action trigger? */
if (new_url)
free_http_response(rsp);
return cgi_error_memory();
}
+ rsp->reason = RSP_REASON_REDIRECTED;
freez(new_url);
- return finish_http_response(rsp);
+
+ return finish_http_response(csp, rsp);
}
}
* otherwise
*
*********************************************************************/
-int is_imageurl(struct client_state *csp)
+int is_imageurl(const struct client_state *csp)
{
#ifdef FEATURE_IMAGE_DETECT_MSIE
char *tmp;
* Returns : 0 => trusted, 1 => untrusted
*
*********************************************************************/
-int is_untrusted_url(struct client_state *csp)
+int is_untrusted_url(const struct client_state *csp)
{
struct file_list *fl;
struct block_spec *b;
{
/* if the URL's referrer is from a trusted referrer, then
* add the target spec to the trustfile as an unblocked
- * domain and return NULL (which means it's OK).
+ * domain and return 0 (which means it's OK).
*/
FILE *fp;
string_join(&new_entry, path);
}
+ /*
+ * Give a reason for generating this entry.
+ */
+ string_append(&new_entry, " # Trusted referrer was: ");
+ string_append(&new_entry, referer);
+
if (new_entry != NULL)
{
- fprintf(fp, "%s\n", new_entry);
- free(new_entry);
+ if (-1 == fprintf(fp, "%s\n", new_entry))
+ {
+ log_error(LOG_LEVEL_ERROR, "Failed to append \'%s\' to trustfile \'%s\': %E",
+ new_entry, csp->config->trustfile);
+ }
+ freez(new_entry);
}
else
{
fclose(fp);
}
+ else
+ {
+ log_error(LOG_LEVEL_ERROR, "Failed to append new entry for \'%s\' to trustfile \'%s\': %E",
+ csp->http->hostport, csp->config->trustfile);
+ }
return 0;
}
}
+
return 1;
}
#endif /* def FEATURE_TRUST */
* Function : pcrs_filter_response
*
* Description : Execute all text substitutions from all applying
- * +filter actions on the text buffer that's been accumulated
- * in csp->iob->buf. If this changes the contents, set
- * csp->content_length to the modified size and raise the
- * CSP_FLAG_MODIFIED flag.
+ * +filter actions on the text buffer that's been
+ * accumulated in csp->iob->buf.
*
* Parameters :
* 1 : csp = Current client state (buffers, headers, etc...)
* or NULL if there were no hits or something went wrong
*
*********************************************************************/
-char *pcrs_filter_response(struct client_state *csp)
+static char *pcrs_filter_response(struct client_state *csp)
{
int hits=0;
size_t size, prev_size;
- char *old = csp->iob->cur, *new = NULL;
+ char *old = NULL;
+ char *new = NULL;
pcrs_job *job;
struct file_list *fl;
{
return(NULL);
}
- size = csp->iob->eod - csp->iob->cur;
/*
* Need to check the set of re_filterfiles...
if (0 == found_filters)
{
- log_error(LOG_LEVEL_ERROR, "Unable to get current state of regexp filtering.");
- return(NULL);
+ log_error(LOG_LEVEL_ERROR, "Inconsistent configuration: "
+ "content filtering enabled, but no content filters available.");
+ return(NULL);
}
- /*
- * If the body has a "chunked" transfer-encoding,
- * get rid of it first, adjusting size and iob->eod
- */
- if (csp->flags & CSP_FLAG_CHUNKED)
- {
- log_error(LOG_LEVEL_RE_FILTER, "Need to de-chunk first");
- if (0 == (size = remove_chunked_transfer_coding(csp->iob->cur, size)))
- {
- return(NULL);
- }
- csp->iob->eod = csp->iob->cur + size;
- csp->flags |= CSP_FLAG_MODIFIED;
- }
+ size = (size_t)(csp->iob->eod - csp->iob->cur);
+ old = csp->iob->cur;
for (i = 0; i < MAX_AF_FILES; i++)
{
fl = csp->rlist[i];
if ((NULL == fl) || (NULL == fl->f))
- break;
+ {
+ /*
+ * Either there are no filter files
+ * left, or this filter file just
+ * contains no valid filters.
+ *
+ * Continue to be sure we don't miss
+ * valid filter files that are chained
+ * after empty or invalid ones.
+ */
+ continue;
+ }
/*
* For all applying +filter actions, look if a filter by that
* name exists and if yes, execute it's pcrs_joblist on the
*/
for (b = fl->f; b; b = b->next)
{
+ if (b->type != FT_CONTENT_FILTER)
+ {
+ /* Skip header filters */
+ continue;
+ }
+
for (filtername = csp->action->multi[ACTION_MULTI_FILTER]->first;
filtername ; filtername = filtername->next)
{
if (strcmp(b->name, filtername->str) == 0)
{
- int current_hits = 0;
+ int current_hits = 0; /* Number of hits caused by this filter */
+ int job_number = 0; /* Which job we're currently executing */
+ int job_hits = 0; /* How many hits the current job caused */
+ pcrs_job *joblist = b->joblist;
+
+ if (b->dynamic) joblist = compile_dynamic_pcrs_job_list(csp, b);
- if ( NULL == b->joblist )
+ if (NULL == joblist)
{
log_error(LOG_LEVEL_RE_FILTER, "Filter %s has empty joblist. Nothing to do.", b->name);
continue;
prev_size = size;
/* Apply all jobs from the joblist */
- for (job = b->joblist; NULL != job; job = job->next)
+ for (job = joblist; NULL != job; job = job->next)
{
- current_hits += pcrs_execute(job, old, size, &new, &size);
- if (old != csp->iob->cur) free(old);
- old=new;
+ job_number++;
+ job_hits = pcrs_execute(job, old, size, &new, &size);
+
+ if (job_hits >= 0)
+ {
+ /*
+ * That went well. Continue filtering
+ * and use the result of this job as
+ * input for the next one.
+ */
+ current_hits += job_hits;
+ if (old != csp->iob->cur)
+ {
+ freez(old);
+ }
+ old = new;
+ }
+ else
+ {
+ /*
+ * This job caused an unexpected error. Inform the user
+ * and skip the rest of the jobs in this filter. We could
+ * continue with the next job, but usually the jobs
+ * depend on each other or are similar enough to
+ * fail for the same reason.
+ *
+ * At the moment our pcrs expects the error codes of pcre 3.4,
+ * but newer pcre versions can return additional error codes.
+ * As a result pcrs_strerror()'s error message might be
+ * "Unknown error ...", therefore we print the numerical value
+ * as well.
+ *
+ * XXX: Is this important enough for LOG_LEVEL_ERROR or
+ * should we use LOG_LEVEL_RE_FILTER instead?
+ */
+ log_error(LOG_LEVEL_ERROR, "Skipped filter \'%s\' after job number %u: %s (%d)",
+ b->name, job_number, pcrs_strerror(job_hits), job_hits);
+ break;
+ }
}
- log_error(LOG_LEVEL_RE_FILTER, "re_filtering %s%s (size %d) with filter %s produced %d hits (new size %d).",
- csp->http->hostport, csp->http->path, prev_size, b->name, current_hits, size);
+ if (b->dynamic) pcrs_free_joblist(joblist);
+
+ log_error(LOG_LEVEL_RE_FILTER,
+ "filtering %s%s (size %d) with \'%s\' produced %d hits (new size %d).",
+ csp->http->hostport, csp->http->path, prev_size, b->name, current_hits, size);
hits += current_hits;
}
*/
if (!hits)
{
- free(new);
+ freez(new);
return(NULL);
}
* or NULL in case something went wrong.
*
*********************************************************************/
-char *gif_deanimate_response(struct client_state *csp)
+static char *gif_deanimate_response(struct client_state *csp)
{
struct binbuffer *in, *out;
char *p;
- size_t size = csp->iob->eod - csp->iob->cur;
+ size_t size;
- /*
- * If the body has a "chunked" transfer-encoding,
- * get rid of it first, adjusting size and iob->eod
- */
- if (csp->flags & CSP_FLAG_CHUNKED)
- {
- log_error(LOG_LEVEL_DEANIMATE, "Need to de-chunk first");
- if (0 == (size = remove_chunked_transfer_coding(csp->iob->cur, size)))
- {
- return(NULL);
- }
- csp->iob->eod = csp->iob->cur + size;
- csp->flags |= CSP_FLAG_MODIFIED;
- }
+ size = (size_t)(csp->iob->eod - csp->iob->cur);
if ( (NULL == (in = (struct binbuffer *)zalloc(sizeof *in )))
|| (NULL == (out = (struct binbuffer *)zalloc(sizeof *out))) )
if (gif_deanimate(in, out, strncmp("last", csp->action->string[ACTION_STRING_DEANIMATE], 4)))
{
log_error(LOG_LEVEL_DEANIMATE, "failed! (gif parsing)");
- free(in);
+ freez(in);
buf_free(out);
return(NULL);
}
csp->content_length = out->offset;
csp->flags |= CSP_FLAG_MODIFIED;
p = out->buffer;
- free(in);
- free(out);
+ freez(in);
+ freez(out);
return(p);
}
* or NULL in case something went wrong.
*
*********************************************************************/
-char *jpeg_inspect_response(struct client_state *csp)
+static char *jpeg_inspect_response(struct client_state *csp)
{
- struct binbuffer *in = NULL, *out = NULL;
+ struct binbuffer *in = NULL;
+ struct binbuffer *out = NULL;
char *p = NULL;
- size_t size = csp->iob->eod - csp->iob->cur;
+ size_t size;
- /*
- * If the body has a "chunked" transfer-encoding,
- * get rid of it first, adjusting size and iob->eod
- */
- if (csp->flags & CSP_FLAG_CHUNKED)
- {
- log_error(LOG_LEVEL_DEANIMATE, "Need to de-chunk first");
- if (0 == (size = remove_chunked_transfer_coding(csp->iob->cur, size)))
- {
- return(NULL);
- }
- csp->iob->eod = csp->iob->cur + size;
- csp->flags |= CSP_FLAG_MODIFIED;
- }
+ size = (size_t)(csp->iob->eod - csp->iob->cur);
if (NULL == (in = (struct binbuffer *)zalloc(sizeof *in )))
{
if (jpeg_inspect(in, out))
{
log_error(LOG_LEVEL_DEANIMATE, "failed! (jpeg parsing)");
- free(in);
+ freez(in);
buf_free(out);
return(NULL);
csp->content_length = out->offset;
csp->flags |= CSP_FLAG_MODIFIED;
p = out->buffer;
- free(in);
- free(out);
+ freez(in);
+ freez(out);
return(p);
}
}
+/*********************************************************************
+ *
+ * Function : get_filter_function
+ *
+ * Description : Decides which content filter function has
+ * to be applied (if any).
+ *
+ * XXX: Doesn't handle filter_popups()
+ * because of the different prototype. Probably
+ * we should ditch filter_popups() anyway, it's
+ * even less reliable than popup blocking based
+ * on pcrs filters.
+ *
+ * Parameters :
+ * 1 : csp = Current client state (buffers, headers, etc...)
+ *
+ * Returns : The content filter function to run, or
+ * NULL if no content filter is active
+ *
+ *********************************************************************/
+filter_function_ptr get_filter_function(struct client_state *csp)
+{
+ filter_function_ptr filter_function = NULL;
+
+ /*
+ * 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)
+ {
+ log_error(LOG_LEVEL_HEADER, "Text mode is already enabled.");
+ }
+ else
+ {
+ csp->content_type |= CT_TEXT;
+ log_error(LOG_LEVEL_HEADER, "Text mode enabled by force. Take cover!");
+ }
+ }
+
+ if (!(csp->content_type & CT_DECLARED))
+ {
+ /*
+ * The server didn't bother to declare a MIME-Type.
+ * Assume it's text that can be filtered.
+ *
+ * This also regulary happens with 304 responses,
+ * therefore logging anything here would cause
+ * too much noise.
+ */
+ csp->content_type |= CT_TEXT;
+ }
+
+ /*
+ * Choose the applying filter function based on
+ * the content type and action settings.
+ */
+ if ((csp->content_type & CT_TEXT) &&
+ (csp->rlist != NULL) &&
+ (!list_is_empty(csp->action->multi[ACTION_MULTI_FILTER])))
+ {
+ filter_function = pcrs_filter_response;
+ }
+ else if ((csp->content_type & CT_GIF) &&
+ (csp->action->flags & ACTION_DEANIMATE))
+ {
+ filter_function = gif_deanimate_response;
+ }
+ else if ((csp->content_type & CT_JPEG) &&
+ (csp->action->flags & ACTION_JPEG_INSPECT))
+ {
+ filter_function = jpeg_inspect_response;
+ }
+
+ return filter_function;
+}
+
+
/*********************************************************************
*
* Function : remove_chunked_transfer_coding
*
* Parameters :
* 1 : buffer = Pointer to the text buffer
- * 2 : size = Number of bytes to be processed
+ * 2 : size = In: Number of bytes to be processed,
+ * Out: Number of bytes after de-chunking.
+ * (undefined in case of errors)
*
- * Returns : The new size, i.e. the number of bytes from buffer which
- * are occupied by the stripped body, or 0 in case something
- * went wrong
+ * Returns : JB_ERR_OK for success,
+ * JB_ERR_PARSE otherwise
*
*********************************************************************/
-int remove_chunked_transfer_coding(char *buffer, const size_t size)
+static jb_err remove_chunked_transfer_coding(char *buffer, size_t *size)
{
size_t newsize = 0;
unsigned int chunksize = 0;
if (sscanf(buffer, "%x", &chunksize) != 1)
{
log_error(LOG_LEVEL_ERROR, "Invalid first chunksize while stripping \"chunked\" transfer coding");
- return(0);
+ return JB_ERR_PARSE;
}
while (chunksize > 0)
if (NULL == (from_p = strstr(from_p, "\r\n")))
{
log_error(LOG_LEVEL_ERROR, "Parse error while stripping \"chunked\" transfer coding");
- return(0);
+ return JB_ERR_PARSE;
}
- if ((newsize += chunksize) >= size)
+ if ((newsize += chunksize) >= *size)
{
log_error(LOG_LEVEL_ERROR, "Chunksize exceeds buffer in \"chunked\" transfer coding");
- return(0);
+ return JB_ERR_PARSE;
}
from_p += 2;
if (sscanf(from_p, "%x", &chunksize) != 1)
{
- log_error(LOG_LEVEL_ERROR, "Parse error while stripping \"chunked\" transfer coding");
- return(0);
+ log_error(LOG_LEVEL_INFO, "Invalid \"chunked\" transfer encoding detected and ignored.");
+ break;
+ }
+ }
+
+ /* XXX: Should get its own loglevel. */
+ log_error(LOG_LEVEL_RE_FILTER, "De-chunking successful. Shrunk from %d to %d", *size, newsize);
+
+ *size = newsize;
+
+ return JB_ERR_OK;
+
+}
+
+
+/*********************************************************************
+ *
+ * Function : prepare_for_filtering
+ *
+ * Description : If necessary, de-chunks and decompresses
+ * the content so it can get filterd.
+ *
+ * Parameters :
+ * 1 : csp = Current client state (buffers, headers, etc...)
+ *
+ * Returns : JB_ERR_OK for success,
+ * JB_ERR_PARSE otherwise
+ *
+ *********************************************************************/
+static jb_err prepare_for_filtering(struct client_state *csp)
+{
+ jb_err err = JB_ERR_OK;
+
+ /*
+ * If the body has a "chunked" transfer-encoding,
+ * get rid of it, adjusting size and iob->eod
+ */
+ if (csp->flags & CSP_FLAG_CHUNKED)
+ {
+ size_t size = (size_t)(csp->iob->eod - csp->iob->cur);
+
+ log_error(LOG_LEVEL_RE_FILTER, "Need to de-chunk first");
+ err = remove_chunked_transfer_coding(csp->iob->cur, &size);
+ if (JB_ERR_OK == err)
+ {
+ csp->iob->eod = csp->iob->cur + size;
+ csp->flags |= CSP_FLAG_MODIFIED;
+ }
+ else
+ {
+ return JB_ERR_PARSE;
+ }
+ }
+
+#ifdef FEATURE_ZLIB
+ /*
+ * If the body has a supported transfer-encoding,
+ * decompress it, adjusting size and iob->eod.
+ */
+ if (csp->content_type & (CT_GZIP|CT_DEFLATE))
+ {
+ if (0 == csp->iob->eod - csp->iob->cur)
+ {
+ /* Nothing left after de-chunking. */
+ return JB_ERR_OK;
+ }
+
+ err = decompress_iob(csp);
+
+ if (JB_ERR_OK == err)
+ {
+ csp->flags |= CSP_FLAG_MODIFIED;
+ csp->content_type &= ~CT_TABOO;
+ }
+ else
+ {
+ /*
+ * Unset CT_GZIP and CT_DEFLATE to remember not
+ * to modify the Content-Encoding header later.
+ */
+ csp->content_type &= ~CT_GZIP;
+ csp->content_type &= ~CT_DEFLATE;
}
}
+#endif
+
+ return err;
+}
+
+
+/*********************************************************************
+ *
+ * Function : execute_content_filter
+ *
+ * Description : Executes a given content filter.
+ *
+ * Parameters :
+ * 1 : csp = Current client state (buffers, headers, etc...)
+ * 2 : content_filter = The filter function to execute
+ *
+ * Returns : Pointer to the modified buffer, or
+ * NULL if filtering failed or wasn't necessary.
+ *
+ *********************************************************************/
+char *execute_content_filter(struct client_state *csp, filter_function_ptr content_filter)
+{
+ if (0 == csp->iob->eod - csp->iob->cur)
+ {
+ /*
+ * No content (probably status code 301, 302 ...),
+ * no filtering necessary.
+ */
+ return NULL;
+ }
- /* FIXME: Should this get its own loglevel? */
- log_error(LOG_LEVEL_RE_FILTER, "De-chunking successful. Shrunk from %d to %d\n", size, newsize);
- return(newsize);
+ if (JB_ERR_OK != prepare_for_filtering(csp))
+ {
+ /*
+ * failed to de-chunk or decompress.
+ */
+ return NULL;
+ }
+ if (0 == csp->iob->eod - csp->iob->cur)
+ {
+ /*
+ * Clown alarm: chunked and/or compressed nothing delivered.
+ */
+ return NULL;
+ }
+
+ return ((*content_filter)(csp));
}
/*********************************************************************
*
- * Function : url_actions
+ * Function : get_url_actions
*
* Description : Gets the actions for this URL.
*
* Parameters :
- * 1 : http = http_request request for blocked URLs
- * 2 : csp = Current client state (buffers, headers, etc...)
+ * 1 : csp = Current client state (buffers, headers, etc...)
+ * 2 : http = http_request request for blocked URLs
*
* Returns : N/A
*
*********************************************************************/
-void url_actions(struct http_request *http,
- struct client_state *csp)
+void get_url_actions(struct client_state *csp, struct http_request *http)
{
struct file_list *fl;
struct url_actions *b;
}
+/*********************************************************************
+ *
+ * Function : get_forward_override_settings
+ *
+ * Description : Returns forward settings as specified with the
+ * forward-override{} action. forward-override accepts
+ * forward lines similar to the one used in the
+ * configuration file, but without the URL pattern.
+ *
+ * For example:
+ *
+ * forward / .
+ *
+ * in the configuration file can be replaced with
+ * the action section:
+ *
+ * {+forward-override{forward .}}
+ * /
+ *
+ * Parameters :
+ * 1 : csp = Current client state (buffers, headers, etc...)
+ *
+ * Returns : Pointer to forwarding structure in case of success.
+ * Invalid syntax is fatal.
+ *
+ *********************************************************************/
+const static struct forward_spec *get_forward_override_settings(struct client_state *csp)
+{
+ const char *forward_override_line = csp->action->string[ACTION_STRING_FORWARD_OVERRIDE];
+ char forward_settings[BUFFER_SIZE];
+ char *http_parent = NULL;
+ /* variable names were chosen for consistency reasons. */
+ struct forward_spec *fwd = NULL;
+ int vec_count;
+ char *vec[3];
+
+ assert(csp->action->flags & ACTION_FORWARD_OVERRIDE);
+ /* Should be enforced by load_one_actions_file() */
+ assert(strlen(forward_override_line) < sizeof(forward_settings) - 1);
+
+ /* Create a copy ssplit can modify */
+ strlcpy(forward_settings, forward_override_line, sizeof(forward_settings));
+
+ if (NULL != csp->fwd)
+ {
+ /*
+ * XXX: Currently necessary to prevent memory
+ * leaks when the show-url-info cgi page is visited.
+ */
+ unload_forward_spec(csp->fwd);
+ }
+
+ /*
+ * allocate a new forward node, valid only for
+ * the lifetime of this request. Save its location
+ * in csp as well, so sweep() can free it later on.
+ */
+ fwd = csp->fwd = zalloc(sizeof(*fwd));
+ if (NULL == fwd)
+ {
+ log_error(LOG_LEVEL_FATAL,
+ "can't allocate memory for forward-override{%s}", forward_override_line);
+ /* Never get here - LOG_LEVEL_FATAL causes program exit */
+ }
+
+ vec_count = ssplit(forward_settings, " \t", vec, SZ(vec), 1, 1);
+ if ((vec_count == 2) && !strcasecmp(vec[0], "forward"))
+ {
+ fwd->type = SOCKS_NONE;
+
+ /* Parse the parent HTTP proxy host:port */
+ http_parent = vec[1];
+
+ }
+ else if (vec_count == 3)
+ {
+ char *socks_proxy = NULL;
+
+ if (!strcasecmp(vec[0], "forward-socks4"))
+ {
+ fwd->type = SOCKS_4;
+ socks_proxy = vec[1];
+ }
+ else if (!strcasecmp(vec[0], "forward-socks4a"))
+ {
+ fwd->type = SOCKS_4A;
+ socks_proxy = vec[1];
+ }
+ else if (!strcasecmp(vec[0], "forward-socks5"))
+ {
+ fwd->type = SOCKS_5;
+ socks_proxy = vec[1];
+ }
+
+ if (NULL != socks_proxy)
+ {
+ /* Parse the SOCKS proxy host[:port] */
+ fwd->gateway_host = strdup(socks_proxy);
+
+ if (NULL != (socks_proxy = strchr(fwd->gateway_host, ':')))
+ {
+ *socks_proxy++ = '\0';
+ fwd->gateway_port = strtol(socks_proxy, NULL, 0);
+ }
+
+ if (fwd->gateway_port <= 0)
+ {
+ fwd->gateway_port = 1080;
+ }
+
+ http_parent = vec[2];
+ }
+ }
+
+ if (NULL == http_parent)
+ {
+ log_error(LOG_LEVEL_FATAL,
+ "Invalid forward-override syntax in: %s", forward_override_line);
+ /* Never get here - LOG_LEVEL_FATAL causes program exit */
+ }
+
+ /* Parse http forwarding settings */
+ if (strcmp(http_parent, ".") != 0)
+ {
+ fwd->forward_host = strdup(http_parent);
+
+ if (NULL != (http_parent = strchr(fwd->forward_host, ':')))
+ {
+ *http_parent++ = '\0';
+ fwd->forward_port = strtol(http_parent, NULL, 0);
+ }
+
+ if (fwd->forward_port <= 0)
+ {
+ fwd->forward_port = 8000;
+ }
+ }
+
+ assert (NULL != fwd);
+
+ log_error(LOG_LEVEL_CONNECT,
+ "Overriding forwarding settings based on \'%s\'", forward_override_line);
+
+ return fwd;
+}
+
+
/*********************************************************************
*
* Function : forward_url
* Description : Should we forward this to another proxy?
*
* Parameters :
- * 1 : http = http_request request for current URL
- * 2 : csp = Current client state (buffers, headers, etc...)
+ * 1 : csp = Current client state (buffers, headers, etc...)
+ * 2 : http = http_request request for current URL
*
* Returns : Pointer to forwarding information.
*
*********************************************************************/
-const struct forward_spec * forward_url(struct http_request *http,
- struct client_state *csp)
+const struct forward_spec *forward_url(struct client_state *csp,
+ const struct http_request *http)
{
static const struct forward_spec fwd_default[1] = { FORWARD_SPEC_INITIALIZER };
struct forward_spec *fwd = csp->config->forward;
+ if (csp->action->flags & ACTION_FORWARD_OVERRIDE)
+ {
+ return get_forward_override_settings(csp);
+ }
+
if (fwd == NULL)
{
return fwd_default;
{
for (p = csp->headers->first; (p != NULL) ; p = p->next)
{
- if (!strncmp("Max-Forwards:", p->str, 13)
- && (*(p->str+13) != '\0') && (atoi(p->str+13) == 0))
+ if (!strncmpic("Max-Forwards:", p->str, 13))
{
- /* FIXME: We could handle at least TRACE here,
- but that would require a verbatim copy of
- the request which we don't have anymore */
+ unsigned int max_forwards;
- log_error(LOG_LEVEL_HEADER, "Found Max-Forwards:0 in OPTIONS or TRACE request -- Returning 501");
-
- /* Get mem for response or fail*/
- if (NULL == (rsp = alloc_http_response()))
+ /*
+ * If it's a Max-Forwards value of zero,
+ * we have to intercept the request.
+ */
+ if (1 == sscanf(p->str+12, ": %u", &max_forwards) && max_forwards == 0)
{
- return cgi_error_memory();
- }
+ /*
+ * FIXME: We could handle at least TRACE here,
+ * but that would require a verbatim copy of
+ * the request which we don't have anymore
+ */
+ log_error(LOG_LEVEL_HEADER,
+ "Detected header \'%s\' in OPTIONS or TRACE request. Returning 501.",
+ p->str);
+
+ /* Get mem for response or fail*/
+ if (NULL == (rsp = alloc_http_response()))
+ {
+ return cgi_error_memory();
+ }
- if (NULL == (rsp->status = strdup("501 Not Implemented")))
- {
- free_http_response(rsp);
- return cgi_error_memory();
- }
+ if (NULL == (rsp->status = strdup("501 Not Implemented")))
+ {
+ free_http_response(rsp);
+ return cgi_error_memory();
+ }
+
+ rsp->is_static = 1;
+ rsp->reason = RSP_REASON_UNSUPPORTED;
- rsp->is_static = 1;
- return(finish_http_response(rsp));
+ return(finish_http_response(csp, rsp));
+ }
}
}
}
}
+/*********************************************************************
+ *
+ * Function : content_filters_enabled
+ *
+ * Description : Checks whether there are any content filters
+ * enabled for the current request.
+ *
+ * Parameters :
+ * 1 : csp = Current client state (buffers, headers, etc...)
+ *
+ * Returns : TRUE for yes, FALSE otherwise
+ *
+ *********************************************************************/
+inline int content_filters_enabled(const struct client_state *csp)
+{
+ return (((csp->rlist != NULL) &&
+ (!list_is_empty(csp->action->multi[ACTION_MULTI_FILTER]))) ||
+ (csp->action->flags & (ACTION_DEANIMATE|ACTION_JPEG_INSPECT)));
+}
+
/*
Local Variables:
tab-width: 3
projects / privoxy.git / blobdiff