From 7d8758598f49d5569018064f8824164a6a08eca7 Mon Sep 17 00:00:00 2001
From: Jan Kneschke <jan@kneschke.de>
Date: Tue, 22 Nov 2005 11:21:35 +0000
Subject: [PATCH] - init FAM after fdevent-backend is up - open + fstat instead
 of stat + open for speed reasons - only init FAM if requested by config

git-svn-id: svn://svn.lighttpd.net/lighttpd/branches/lighttpd-merge-1.4.x@872 152afb58-edef-0310-8abb-c4023f1b3aa9
---
 src/server.c     | 44 +++++++++++++++++++++++++-------------------
 src/stat_cache.c | 37 ++++++++++++++++++++++---------------
 2 files changed, 47 insertions(+), 34 deletions(-)

diff --git a/src/server.c b/src/server.c
index d3c26587..66c5ef26 100644
--- a/src/server.c
+++ b/src/server.c
@@ -763,24 +763,6 @@ int main (int argc, char **argv) {
 	getitimer(ITIMER_REAL, &interval);
 #endif
 
-	/* might fail if user is using fam (not gamin) and famd isn't running */
-	if (NULL == (srv->stat_cache = stat_cache_init())) {
-#if defined(HAVE_FAM_H) && !defined(HAVE_FAMNOEXISTS)
-		log_error_write(srv, __FILE__, __LINE__, "s",
-			"FAMOpen2() failed.  Is famd running?");
-		return -1;
-#else
-		SEGFAULT();
-#endif
-	}
-
-#ifdef HAVE_FAM_H
-	/* setup FAM */
-	srv->stat_cache->fam_fcce_ndx = -1;
-	fdevent_register(srv->ev, FAMCONNECTION_GETFD(srv->stat_cache->fam), stat_cache_handle_fdevent, NULL);
-	fdevent_event_add(srv->ev, &(srv->stat_cache->fam_fcce_ndx), FAMCONNECTION_GETFD(srv->stat_cache->fam), FDEVENT_IN);
-#endif
-
 #ifdef HAVE_FORK	
 	/* start watcher and workers */
 	num_childs = srv->srvconf.max_worker;
@@ -828,7 +810,31 @@ int main (int argc, char **argv) {
 		
 		return -1;
 	}
-	
+
+	/* might fail if user is using fam (not gamin) and famd isn't running */
+	if (NULL == (srv->stat_cache = stat_cache_init())) {
+		log_error_write(srv, __FILE__, __LINE__, "s",
+			"stat-cache could not be setup, dieing.");
+		return -1;
+	}
+
+#ifdef HAVE_FAM_H
+	/* setup FAM */
+	if (srv->srvconf.stat_cache_engine == STAT_CACHE_ENGINE_FAM) {
+		if (0 != FAMOpen2(srv->stat_cache->fam, "lighttpd")) {
+			return -1;
+		}
+#ifdef HAVE_FAMNOEXISTS
+		FAMNoExists(srv->stat_cache->fam);
+#endif
+
+		srv->stat_cache->fam_fcce_ndx = -1;
+		fdevent_register(srv->ev, FAMCONNECTION_GETFD(srv->stat_cache->fam), stat_cache_handle_fdevent, NULL);
+		fdevent_event_add(srv->ev, &(srv->stat_cache->fam_fcce_ndx), FAMCONNECTION_GETFD(srv->stat_cache->fam), FDEVENT_IN);
+	}
+#endif
+
+
 	/* get the current number of FDs */
 	srv->cur_fds = open("/dev/null", O_RDONLY);
 	close(srv->cur_fds);
diff --git a/src/stat_cache.c b/src/stat_cache.c
index 5b9950a9..f12202e2 100644
--- a/src/stat_cache.c
+++ b/src/stat_cache.c
@@ -111,13 +111,6 @@ stat_cache *stat_cache_init(void) {
 	fc->dir_name = buffer_init();
 #ifdef HAVE_FAM_H
 	fc->fam = calloc(1, sizeof(*fc->fam));
-
-	if (0 != FAMOpen2(fc->fam, "lighttpd")) {
-		return NULL;
-	}
-#ifdef HAVE_FAMNOEXISTS
-	FAMNoExists(fc->fam);
-#endif
 #endif
 
 #ifdef DEBUG_STAT_CACHE	
@@ -354,6 +347,7 @@ handler_t stat_cache_get_entry(server *srv, connection *con, buffer *name, stat_
 	stat_cache *sc;
 	struct stat st;
 	size_t k;
+	int fd;
 #ifdef DEBUG_STAT_CACHE	
 	size_t i;
 #endif
@@ -452,20 +446,18 @@ handler_t stat_cache_get_entry(server *srv, connection *con, buffer *name, stat_
 		}
 	}
 #endif
-	if (-1 == (con->conf.follow_symlink ? stat(name->ptr, &st) : lstat(name->ptr, &st))) {
-		/* stat() failed, ENOENT, ... and so on */
+	/* try to open the file */
+	if (-1 == (fd = open(name->ptr, O_RDONLY))) {
 		return HANDLER_ERROR;
 	}
 
-	if (S_ISREG(st.st_mode)) {
-		int fd;
-		/* see if we can open the file for reading */
-		if (-1 == (fd = open(name->ptr, O_RDONLY))) {
-			return HANDLER_ERROR;
-		}
+	if (-1 == fstat(fd, &st)) {
 		close(fd);
+		return HANDLER_ERROR;
 	}
 
+	close(fd);
+
 	if (NULL == sce) {
 		int osize = 0;
 		       
@@ -498,6 +490,21 @@ handler_t stat_cache_get_entry(server *srv, connection *con, buffer *name, stat_
 	sce->st = st;
 	sce->stat_ts = srv->cur_ts;
 
+	/* catch the obvious symlinks 
+	 *
+	 * this is not a secure check as we still have a race-condition between
+	 * the stat() and the open. We can only solve this by 
+	 * 1. open() the file
+	 * 2. fstat() the fd
+	 *
+	 * and keeping the file open for the rest of the time. But this can
+	 * only be done at network level.
+	 * 
+	 * */
+	if (S_ISLNK(st.st_mode) && !con->conf.follow_symlink) {
+		return HANDLER_ERROR;
+	}
+
 	if (S_ISREG(st.st_mode)) {	
 		/* determine mimetype */
 		buffer_reset(sce->content_type);