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-rw-r--r--modules/loggers/mod_log_forensic.c289
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diff --git a/modules/loggers/mod_log_forensic.c b/modules/loggers/mod_log_forensic.c
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+/* Licensed to the Apache Software Foundation (ASF) under one or more
+ * contributor license agreements. See the NOTICE file distributed with
+ * this work for additional information regarding copyright ownership.
+ * The ASF licenses this file to You under the Apache License, Version 2.0
+ * (the "License"); 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
+ *
+ * Unless required by applicable law or agreed to in writing, software
+ * distributed under the License is distributed on an "AS IS" BASIS,
+ * WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
+ * See the License for the specific language governing permissions and
+ * limitations under the License.
+ */
+
+/*
+ * See also support/check_forensic.
+ * Relate the forensic log to the transfer log by including
+ * %{forensic-id}n in the custom log format, for example:
+ * CustomLog logs/custom "%h %l %u %t \"%r\" %>s %b %{forensic-id}n"
+ *
+ * Credit is due to Tina Bird <tbird precision-guesswork.com>, whose
+ * idea this module was.
+ *
+ * Ben Laurie 29/12/2003
+ */
+
+#include "httpd.h"
+#include "http_config.h"
+#include "http_log.h"
+#include "apr_strings.h"
+#include "apr_atomic.h"
+#include "http_protocol.h"
+#include "test_char.h"
+#if APR_HAVE_UNISTD_H
+#include <unistd.h>
+#endif
+
+module AP_MODULE_DECLARE_DATA log_forensic_module;
+
+typedef struct fcfg {
+ const char *logname;
+ apr_file_t *fd;
+} fcfg;
+
+static apr_uint32_t next_id;
+
+static void *make_forensic_log_scfg(apr_pool_t *p, server_rec *s)
+{
+ fcfg *cfg = apr_pcalloc(p, sizeof *cfg);
+
+ cfg->logname = NULL;
+ cfg->fd = NULL;
+
+ return cfg;
+}
+
+static void *merge_forensic_log_scfg(apr_pool_t *p, void *parent, void *new)
+{
+ fcfg *cfg = apr_pcalloc(p, sizeof *cfg);
+ fcfg *pc = parent;
+ fcfg *nc = new;
+
+ cfg->logname = apr_pstrdup(p, nc->logname ? nc->logname : pc->logname);
+ cfg->fd = NULL;
+
+ return cfg;
+}
+
+static int open_log(server_rec *s, apr_pool_t *p)
+{
+ fcfg *cfg = ap_get_module_config(s->module_config, &log_forensic_module);
+
+ if (!cfg->logname || cfg->fd)
+ return 1;
+
+ if (*cfg->logname == '|') {
+ piped_log *pl;
+ const char *pname = ap_server_root_relative(p, cfg->logname + 1);
+
+ pl = ap_open_piped_log(p, pname);
+ if (pl == NULL) {
+ ap_log_error(APLOG_MARK, APLOG_ERR, 0, s, APLOGNO(00650)
+ "couldn't spawn forensic log pipe %s", cfg->logname);
+ return 0;
+ }
+ cfg->fd = ap_piped_log_write_fd(pl);
+ }
+ else {
+ const char *fname = ap_server_root_relative(p, cfg->logname);
+ apr_status_t rv;
+
+ if ((rv = apr_file_open(&cfg->fd, fname,
+ APR_WRITE | APR_APPEND | APR_CREATE,
+ APR_OS_DEFAULT, p)) != APR_SUCCESS) {
+ ap_log_error(APLOG_MARK, APLOG_ERR, rv, s, APLOGNO(00651)
+ "could not open forensic log file %s.", fname);
+ return 0;
+ }
+ }
+
+ return 1;
+}
+
+static int log_init(apr_pool_t *pc, apr_pool_t *p, apr_pool_t *pt,
+ server_rec *s)
+{
+ for ( ; s ; s = s->next) {
+ if (!open_log(s, p)) {
+ return HTTP_INTERNAL_SERVER_ERROR;
+ }
+ }
+
+ return OK;
+}
+
+
+/* e is the first _invalid_ location in q
+ N.B. returns the terminating NUL.
+ */
+static char *log_escape(char *q, const char *e, const char *p)
+{
+ for ( ; *p ; ++p) {
+ ap_assert(q < e);
+ if (TEST_CHAR(*p, T_ESCAPE_FORENSIC)) {
+ ap_assert(q+2 < e);
+ *q++ = '%';
+ ap_bin2hex(p, 1, q);
+ q += 2;
+ }
+ else
+ *q++ = *p;
+ }
+ ap_assert(q < e);
+ *q = '\0';
+
+ return q;
+}
+
+typedef struct hlog {
+ char *log;
+ char *pos;
+ char *end;
+ apr_pool_t *p;
+ apr_size_t count;
+} hlog;
+
+static apr_size_t count_string(const char *p)
+{
+ apr_size_t n;
+
+ for (n = 0 ; *p ; ++p, ++n)
+ if (TEST_CHAR(*p, T_ESCAPE_FORENSIC))
+ n += 2;
+ return n;
+}
+
+static int count_headers(void *h_, const char *key, const char *value)
+{
+ hlog *h = h_;
+
+ h->count += count_string(key)+count_string(value)+2;
+
+ return 1;
+}
+
+static int log_headers(void *h_, const char *key, const char *value)
+{
+ hlog *h = h_;
+
+ /* note that we don't have to check h->pos here, coz its been done
+ for us by log_escape */
+ *h->pos++ = '|';
+ h->pos = log_escape(h->pos, h->end, key);
+ *h->pos++ = ':';
+ h->pos = log_escape(h->pos, h->end, value);
+
+ return 1;
+}
+
+static int log_before(request_rec *r)
+{
+ fcfg *cfg = ap_get_module_config(r->server->module_config,
+ &log_forensic_module);
+ const char *id;
+ hlog h;
+ apr_size_t n;
+ apr_status_t rv;
+
+ if (!cfg->fd || r->prev) {
+ return DECLINED;
+ }
+
+ if (!(id = apr_table_get(r->subprocess_env, "UNIQUE_ID"))) {
+ /* we make the assumption that we can't go through all the PIDs in
+ under 1 second */
+ id = apr_psprintf(r->pool, "%" APR_PID_T_FMT ":%lx:%x", getpid(),
+ time(NULL), apr_atomic_inc32(&next_id));
+ }
+ ap_set_module_config(r->request_config, &log_forensic_module, (char *)id);
+
+ h.p = r->pool;
+ h.count = 0;
+
+ apr_table_do(count_headers, &h, r->headers_in, NULL);
+
+ h.count += 1+strlen(id)+1+count_string(r->the_request)+1+1;
+ h.log = apr_palloc(r->pool, h.count);
+ h.pos = h.log;
+ h.end = h.log+h.count;
+
+ *h.pos++ = '+';
+ strcpy(h.pos, id);
+ h.pos += strlen(h.pos);
+ *h.pos++ = '|';
+ h.pos = log_escape(h.pos, h.end, r->the_request);
+
+ apr_table_do(log_headers, &h, r->headers_in, NULL);
+
+ ap_assert(h.pos < h.end);
+ *h.pos++ = '\n';
+
+ n = h.count-1;
+ rv = apr_file_write(cfg->fd, h.log, &n);
+ ap_assert(rv == APR_SUCCESS && n == h.count-1);
+
+ apr_table_setn(r->notes, "forensic-id", id);
+
+ return OK;
+}
+
+static int log_after(request_rec *r)
+{
+ fcfg *cfg = ap_get_module_config(r->server->module_config,
+ &log_forensic_module);
+ const char *id = ap_get_module_config(r->request_config,
+ &log_forensic_module);
+ char *s;
+ apr_size_t l, n;
+ apr_status_t rv;
+
+ if (!cfg->fd || id == NULL) {
+ return DECLINED;
+ }
+
+ s = apr_pstrcat(r->pool, "-", id, "\n", NULL);
+ l = n = strlen(s);
+ rv = apr_file_write(cfg->fd, s, &n);
+ ap_assert(rv == APR_SUCCESS && n == l);
+
+ return OK;
+}
+
+static const char *set_forensic_log(cmd_parms *cmd, void *dummy, const char *fn)
+{
+ fcfg *cfg = ap_get_module_config(cmd->server->module_config,
+ &log_forensic_module);
+
+ cfg->logname = fn;
+ return NULL;
+}
+
+static const command_rec forensic_log_cmds[] =
+{
+ AP_INIT_TAKE1("ForensicLog", set_forensic_log, NULL, RSRC_CONF,
+ "the filename of the forensic log"),
+ { NULL }
+};
+
+static void register_hooks(apr_pool_t *p)
+{
+ static const char * const pre[] = { "mod_unique_id.c", NULL };
+
+ ap_hook_open_logs(log_init,NULL,NULL,APR_HOOK_MIDDLE);
+ ap_hook_post_read_request(log_before,pre,NULL,APR_HOOK_REALLY_FIRST);
+ ap_hook_log_transaction(log_after,NULL,NULL,APR_HOOK_REALLY_LAST);
+}
+
+AP_DECLARE_MODULE(log_forensic) =
+{
+ STANDARD20_MODULE_STUFF,
+ NULL, /* create per-dir config */
+ NULL, /* merge per-dir config */
+ make_forensic_log_scfg, /* server config */
+ merge_forensic_log_scfg, /* merge server config */
+ forensic_log_cmds, /* command apr_table_t */
+ register_hooks /* register hooks */
+};