/apache2/apache2_util.c
C | 392 lines | 241 code | 74 blank | 77 comment | 91 complexity | c131880623192f8f217d9d134d749d13 MD5 | raw file
- /*
- * ModSecurity for Apache 2.x, http://www.modsecurity.org/
- * Copyright (c) 2004-2011 Trustwave Holdings, Inc. (http://www.trustwave.com/)
- *
- * You may not use this file except in compliance with
- * the License. You may obtain a copy of the License at
- *
- * http://www.apache.org/licenses/LICENSE-2.0
- *
- * If any of the files related to licensing are missing or if you have any
- * other questions related to licensing please contact Trustwave Holdings, Inc.
- * directly using the email address security@modsecurity.org.
- */
- #include "modsecurity.h"
- #include "apache2.h"
- #include "http_core.h"
- #include "util_script.h"
- /**
- * Sends a brigade with an error bucket down the filter chain.
- */
- apr_status_t send_error_bucket(modsec_rec *msr, ap_filter_t *f, int status) {
- apr_bucket_brigade *brigade = NULL;
- apr_bucket *bucket = NULL;
- /* Set the status line explicitly for the error document */
- f->r->status_line = ap_get_status_line(status);
- brigade = apr_brigade_create(f->r->pool, f->r->connection->bucket_alloc);
- if (brigade == NULL) return APR_EGENERAL;
- bucket = ap_bucket_error_create(status, NULL, f->r->pool, f->r->connection->bucket_alloc);
- if (bucket == NULL) return APR_EGENERAL;
- APR_BRIGADE_INSERT_TAIL(brigade, bucket);
- bucket = apr_bucket_eos_create(f->r->connection->bucket_alloc);
- if (bucket == NULL) return APR_EGENERAL;
- APR_BRIGADE_INSERT_TAIL(brigade, bucket);
- ap_pass_brigade(f->next, brigade);
- /* NOTE:
- * It may not matter what we do from the filter as it may be too
- * late to even generate an error (already sent to client). Nick Kew
- * recommends to return APR_EGENERAL in hopes that the handler in control
- * will notice and do The Right Thing. So, that is what we do now.
- */
- return APR_EGENERAL;
- }
- /**
- * Execute system command. First line of the output will be returned in
- * the "output" parameter.
- */
- int apache2_exec(modsec_rec *msr, const char *command, const char **argv, char **output) {
- apr_procattr_t *procattr = NULL;
- apr_proc_t *procnew = NULL;
- apr_status_t rc = APR_SUCCESS;
- const char *const *env = NULL;
- apr_file_t *script_out = NULL;
- request_rec *r = msr->r;
- if (argv == NULL) {
- argv = apr_pcalloc(r->pool, 3 * sizeof(char *));
- argv[0] = command;
- argv[1] = NULL;
- }
- ap_add_cgi_vars(r);
- ap_add_common_vars(r);
- /* PHP hack, getting around its silly security checks. */
- apr_table_add(r->subprocess_env, "PATH_TRANSLATED", command);
- apr_table_add(r->subprocess_env, "REDIRECT_STATUS", "302");
- env = (const char * const *)ap_create_environment(r->pool, r->subprocess_env);
- if (env == NULL) {
- msr_log(msr, 1, "Exec: Unable to create environment.");
- return -1;
- }
- procnew = apr_pcalloc(r->pool, sizeof(*procnew));
- if (procnew == NULL) {
- msr_log(msr, 1, "Exec: Unable to allocate %lu bytes.", (unsigned long)sizeof(*procnew));
- return -1;
- }
- apr_procattr_create(&procattr, r->pool);
- if (procattr == NULL) {
- msr_log(msr, 1, "Exec: Unable to create procattr.");
- return -1;
- }
- apr_procattr_io_set(procattr, APR_NO_PIPE, APR_FULL_BLOCK, APR_NO_PIPE);
- apr_procattr_cmdtype_set(procattr, APR_SHELLCMD);
- if (msr->txcfg->debuglog_level >= 9) {
- msr_log(msr, 9, "Exec: %s", log_escape_nq(r->pool, command));
- }
- rc = apr_proc_create(procnew, command, argv, env, procattr, r->pool);
- if (rc != APR_SUCCESS) {
- msr_log(msr, 1, "Exec: Execution failed: %s (%s)", log_escape_nq(r->pool, command),
- get_apr_error(r->pool, rc));
- return -1;
- }
- apr_pool_note_subprocess(r->pool, procnew, APR_KILL_AFTER_TIMEOUT);
- script_out = procnew->out;
- if (!script_out) {
- msr_log(msr, 1, "Exec: Failed to get script output pipe.");
- return -1;
- }
- apr_file_pipe_timeout_set(script_out, r->server->timeout);
- /* Now read from the pipe. */
- {
- char buf[260] = "";
- char *p = buf;
- apr_size_t nbytes = 255;
- apr_status_t rc2;
- rc2 = apr_file_read(script_out, buf, &nbytes);
- if (rc2 == APR_SUCCESS) {
- buf[nbytes] = 0;
- /* if there is more than one line ignore them */
- while(*p != 0) {
- if (*p == 0x0a) *p = 0;
- p++;
- }
- if (msr->txcfg->debuglog_level >= 4) {
- msr_log(msr, 4, "Exec: First line from script output: \"%s\"",
- log_escape(r->pool, buf));
- }
- if (output != NULL) *output = apr_pstrdup(r->pool, buf);
- /* Soak up the remaining data. */
- nbytes = 255;
- while(apr_file_read(script_out, buf, &nbytes) == APR_SUCCESS) nbytes = 255;
- } else {
- msr_log(msr, 1, "Exec: Execution failed while reading output: %s (%s)",
- log_escape_nq(r->pool, command),
- get_apr_error(r->pool, rc2));
- return -1;
- }
- }
- apr_proc_wait(procnew, NULL, NULL, APR_WAIT);
- return 1;
- }
- /**
- * Returns a new string that contains the error
- * message for the given return code.
- */
- char *get_apr_error(apr_pool_t *p, apr_status_t rc) {
- char *text = apr_pcalloc(p, 201);
- if (text == NULL) return NULL;
- apr_strerror(rc, text, 200);
- return text;
- }
- /**
- * Retrieve named environment variable.
- */
- char *get_env_var(request_rec *r, char *name) {
- char *result = (char *)apr_table_get(r->notes, name);
- if (result == NULL) {
- result = (char *)apr_table_get(r->subprocess_env, name);
- }
- if (result == NULL) {
- result = getenv(name);
- }
- return result;
- }
- /**
- * Extended internal log helper function. Use msr_log instead. If fixup is
- * true, the message will be stripped of any trailing newline and any
- * required bytes will be escaped.
- */
- static void internal_log_ex(request_rec *r, directory_config *dcfg, modsec_rec *msr,
- int level, int fixup, const char *text, va_list ap)
- {
- apr_size_t nbytes, nbytes_written;
- apr_file_t *debuglog_fd = NULL;
- int filter_debug_level = 0;
- char str1[1024] = "";
- char str2[1256] = "";
- /* Find the logging FD and determine the logging level from configuration. */
- if (dcfg != NULL) {
- if ((dcfg->debuglog_fd != NULL)&&(dcfg->debuglog_fd != NOT_SET_P)) {
- debuglog_fd = dcfg->debuglog_fd;
- }
- if (dcfg->debuglog_level != NOT_SET) {
- filter_debug_level = dcfg->debuglog_level;
- }
- }
- /* Return immediately if we don't have where to write
- * or if the log level of the message is higher than
- * wanted in the log.
- */
- if ((level > 3)&&( (debuglog_fd == NULL) || (level > filter_debug_level) )) return;
- /* Construct the message. */
- apr_vsnprintf(str1, sizeof(str1), text, ap);
- if (fixup) {
- int len = strlen(str1);
- /* Strip line ending. */
- if (len && str1[len - 1] == '\n') {
- str1[len - 1] = '\0';
- }
- if (len > 1 && str1[len - 2] == '\r') {
- str1[len - 2] = '\0';
- }
- }
- /* Construct the log entry. */
- apr_snprintf(str2, sizeof(str2),
- "[%s] [%s/sid#%pp][rid#%pp][%s][%d] %s\n",
- current_logtime(msr->mp), ap_get_server_name(r), (r->server),
- r, ((r->uri == NULL) ? "" : log_escape_nq(msr->mp, r->uri)),
- level, (fixup ? log_escape_nq(msr->mp, str1) : str1));
- /* Write to the debug log. */
- if ((debuglog_fd != NULL)&&(level <= filter_debug_level)) {
- nbytes = strlen(str2);
- apr_file_write_full(debuglog_fd, str2, nbytes, &nbytes_written);
- }
- /* Send message levels 1-3 to the Apache error log and
- * add it to the message list in the audit log. */
- if (level <= 3) {
- char *unique_id = (char *)get_env_var(r, "UNIQUE_ID");
- char *hostname = (char *)msr->hostname;
- if (unique_id != NULL) {
- unique_id = apr_psprintf(msr->mp, " [unique_id \"%s\"]",
- log_escape(msr->mp, unique_id));
- }
- else unique_id = "";
- if (hostname != NULL) {
- hostname = apr_psprintf(msr->mp, " [hostname \"%s\"]",
- log_escape(msr->mp, hostname));
- }
- else hostname = "";
- #if AP_SERVER_MAJORVERSION_NUMBER > 1 && AP_SERVER_MINORVERSION_NUMBER > 2
- ap_log_error(APLOG_MARK, APLOG_ERR | APLOG_NOERRNO, 0, r->server,
- "[client %s] ModSecurity: %s%s [uri \"%s\"]%s", r->useragent_ip ? r->useragent_ip : r->connection->client_ip, str1,
- hostname, log_escape(msr->mp, r->uri), unique_id);
- #else
- ap_log_error(APLOG_MARK, APLOG_ERR | APLOG_NOERRNO, 0, r->server,
- "[client %s] ModSecurity: %s%s [uri \"%s\"]%s", r->connection->remote_ip, str1,
- hostname, log_escape(msr->mp, r->uri), unique_id);
- #endif
- /* Add this message to the list. */
- if (msr != NULL) {
- /* Force relevency if this is an alert */
- msr->is_relevant++;
- *(const char **)apr_array_push(msr->alerts) = apr_pstrdup(msr->mp, str1);
- }
- }
- return;
- }
- /**
- * Logs one message at the given level to the debug log (and to the
- * Apache error log if the message is important enough.
- */
- void msr_log(modsec_rec *msr, int level, const char *text, ...) {
- va_list ap;
- va_start(ap, text);
- internal_log_ex(msr->r, msr->txcfg, msr, level, 0, text, ap);
- va_end(ap);
- }
- /**
- * Logs one message at level 3 to the debug log and to the
- * Apache error log. This is intended for error callbacks.
- */
- void msr_log_error(modsec_rec *msr, const char *text, ...) {
- va_list ap;
- va_start(ap, text);
- internal_log_ex(msr->r, msr->txcfg, msr, 3, 1, text, ap);
- va_end(ap);
- }
- /**
- * Logs one message at level 4 to the debug log and to the
- * Apache error log. This is intended for warning callbacks.
- *
- * The 'text' will first be escaped.
- */
- void msr_log_warn(modsec_rec *msr, const char *text, ...) {
- va_list ap;
- va_start(ap, text);
- internal_log_ex(msr->r, msr->txcfg, msr, 4, 1, text, ap);
- va_end(ap);
- }
- /**
- * Converts an Apache error log message into one line of text.
- */
- char *format_error_log_message(apr_pool_t *mp, error_message_t *em) {
- char *s_file = "", *s_line = "", *s_level = "";
- char *s_status = "", *s_message = "";
- char *msg = NULL;
- if (em == NULL) return NULL;
- if (em->file != NULL) {
- s_file = apr_psprintf(mp, "[file \"%s\"] ",
- log_escape(mp, (char *)em->file));
- if (s_file == NULL) return NULL;
- }
- if (em->line > 0) {
- s_line = apr_psprintf(mp, "[line %d] ", em->line);
- if (s_line == NULL) return NULL;
- }
- s_level = apr_psprintf(mp, "[level %d] ", em->level);
- if (s_level == NULL) return NULL;
- if (em->status != 0) {
- s_status = apr_psprintf(mp, "[status %d] ", em->status);
- if (s_status == NULL) return NULL;
- }
- if (em->message != NULL) {
- s_message = log_escape_nq(mp, em->message);
- if (s_message == NULL) return NULL;
- }
- msg = apr_psprintf(mp, "%s%s%s%s%s", s_file, s_line, s_level, s_status, s_message);
- if (msg == NULL) return NULL;
- return msg;
- }
- /**
- * Determines the reponse protocol Apache will use (or has used)
- * to respond to the given request.
- */
- const char *get_response_protocol(request_rec *r) {
- int proto_num = r->proto_num;
- if (r->assbackwards) {
- return NULL;
- }
- if (proto_num > HTTP_VERSION(1,0)
- && apr_table_get(r->subprocess_env, "downgrade-1.0"))
- {
- proto_num = HTTP_VERSION(1,0);
- }
- if (proto_num == HTTP_VERSION(1,0)
- && apr_table_get(r->subprocess_env, "force-response-1.0"))
- {
- return "HTTP/1.0";
- }
- return AP_SERVER_PROTOCOL;
- }