Lose the CAP_NET_ADMIN at every fork, instead of at startup. Otherwise, if

Asterisk runs as a non-root user and the administrator does a 'restart now',
Asterisk loses the ability to set QOS on packets.
(closes issue #14004)
 Reported by: nemo
 Patches: 
       20090105__bug14004.diff.txt uploaded by Corydon76 (license 14)
 Tested by: Corydon76


git-svn-id: http://svn.digium.com/svn/asterisk/branches/1.4@172438 f38db490-d61c-443f-a65b-d21fe96a405b

1 files changed, 28 insertions, 9 deletions

diff --git a/apps/app_festival.c b/apps/app_festival.c
index ab05824f5..5650d983b 100644
--- a/apps/app_festival.c
+++ b/apps/app_festival.c
@@ -25,6 +25,10 @@
  * \ingroup applications
  */
 
+/*** MODULEINFO
+	<depend>working_fork</depend>
+ ***/
+
 #include "asterisk.h"
 
 ASTERISK_FILE_VERSION(__FILE__, "$Revision$")
@@ -46,6 +50,9 @@ ASTERISK_FILE_VERSION(__FILE__, "$Revision$")
 #include <fcntl.h>
 #include <ctype.h>
 #include <errno.h>
+#ifdef HAVE_CAP
+#include <sys/capability.h>
+#endif /* HAVE_CAP */
 
 #include "asterisk/file.h"
 #include "asterisk/logger.h"
@@ -132,21 +139,33 @@ static int send_waveform_to_fd(char *waveform, int length, int fd) {
 	char c;
 #endif
 	sigset_t fullset, oldset;
+#ifdef HAVE_CAP
+	cap_t cap;
+#endif
 
 	sigfillset(&fullset);
 	pthread_sigmask(SIG_BLOCK, &fullset, &oldset);
 
-        res = fork();
-        if (res < 0)
-                ast_log(LOG_WARNING, "Fork failed\n");
-        if (res) {
+	res = fork();
+	if (res < 0)
+		ast_log(LOG_WARNING, "Fork failed\n");
+	if (res) {
 		pthread_sigmask(SIG_SETMASK, &oldset, NULL);
-                return res;
+		return res;
+	}
+#ifdef HAVE_CAP
+	cap = cap_from_text("cap_net_admin-eip");
+
+	if (cap_set_proc(cap)) {
+		/* Careful with order! Logging cannot happen after we close FDs */
+		ast_log(LOG_WARNING, "Unable to remove capabilities.\n");
+	}
+	cap_free(cap);
+#endif
+	for (x=0;x<256;x++) {
+		if (x != fd)
+			close(x);
 	}
-        for (x=0;x<256;x++) {
-                if (x != fd)
-                        close(x);
-        }
 	if (ast_opt_high_priority)
 		ast_set_priority(0);
 	signal(SIGPIPE, SIG_DFL);