From 5125deb3148e6711a6855de8430c4958ed77eaa1 Mon Sep 17 00:00:00 2001
From: tilghman <tilghman@f38db490-d61c-443f-a65b-d21fe96a405b>
Date: Mon, 11 Dec 2006 00:33:59 +0000
Subject: When doing a fork() and exec(), two problems existed (Issue 8086): 1)
 Ignored signals stayed ignored after the exec(). 2) Signals could possibly
 fire between the fork() and exec(), causing Asterisk signal handlers within
 the child to execute, which caused nasty race conditions.

git-svn-id: http://svn.digium.com/svn/asterisk/branches/1.2@48374 f38db490-d61c-443f-a65b-d21fe96a405b
---
 apps/app_externalivr.c | 12 +++++++++++-
 apps/app_festival.c    | 11 +++++++++--
 apps/app_ices.c        | 18 +++++++++++++++---
 apps/app_mp3.c         | 16 +++++++++++++---
 apps/app_nbscat.c      | 16 +++++++++++++---
 apps/app_zapras.c      | 18 +++++++++++++-----
 6 files changed, 74 insertions(+), 17 deletions(-)

(limited to 'apps')

diff --git a/apps/app_externalivr.c b/apps/app_externalivr.c
index fc5f34082..068463cec 100644
--- a/apps/app_externalivr.c
+++ b/apps/app_externalivr.c
@@ -31,6 +31,7 @@
 #include <string.h>
 #include <unistd.h>
 #include <errno.h>
+#include <signal.h>
 
 #include "asterisk.h"
 
@@ -258,9 +259,13 @@ static int app_exec(struct ast_channel *chan, void *data)
 	FILE *child_commands = NULL;
 	FILE *child_errors = NULL;
 	FILE *child_events = NULL;
+	sigset_t fullset, oldset;
 
 	LOCAL_USER_ADD(u);
-	
+
+	sigfillset(&fullset);
+	pthread_sigmask(SIG_BLOCK, &fullset, &oldset);
+
 	AST_LIST_HEAD_INIT(&u->playlist);
 	AST_LIST_HEAD_INIT(&u->finishlist);
 	u->abort_current_sound = 0;
@@ -314,6 +319,9 @@ static int app_exec(struct ast_channel *chan, void *data)
 		/* child process */
 		int i;
 
+		signal(SIGPIPE, SIG_DFL);
+		pthread_sigmask(SIG_UNBLOCK, &fullset, NULL);
+
 		if (option_highpriority)
 			ast_set_priority(0);
 
@@ -337,6 +345,8 @@ static int app_exec(struct ast_channel *chan, void *data)
 		int waitfds[2] = { child_errors_fd, child_commands_fd };
 		struct ast_channel *rchan;
 
+		pthread_sigmask(SIG_SETMASK, &oldset, NULL);
+
 		close(child_stdin[0]);
 		child_stdin[0] = 0;
 		close(child_stdout[1]);
diff --git a/apps/app_festival.c b/apps/app_festival.c
index 7c69dc8b9..33f54aaf3 100644
--- a/apps/app_festival.c
+++ b/apps/app_festival.c
@@ -127,19 +127,26 @@ static int send_waveform_to_fd(char *waveform, int length, int fd) {
 #ifdef __PPC__ 
 	char c;
 #endif
+	sigset_t fullset, oldset;
+
+	sigfillset(&fullset);
+	pthread_sigmask(SIG_BLOCK, &fullset, &oldset);
 
         res = fork();
         if (res < 0)
                 ast_log(LOG_WARNING, "Fork failed\n");
-        if (res)
+        if (res) {
+		pthread_sigmask(SIG_SETMASK, &oldset, NULL);
                 return res;
+	}
         for (x=0;x<256;x++) {
                 if (x != fd)
                         close(x);
         }
 	if (option_highpriority)
 		ast_set_priority(0);
-
+	signal(SIGPIPE, SIG_DFL);
+	pthread_sigmask(SIG_UNBLOCK, &fullset, NULL);
 /*IAS */
 #ifdef __PPC__  
 	for( x=0; x<length; x+=2)
diff --git a/apps/app_ices.c b/apps/app_ices.c
index b6b5ad3f7..5a9b9412d 100644
--- a/apps/app_ices.c
+++ b/apps/app_ices.c
@@ -68,15 +68,27 @@ static int icesencode(char *filename, int fd)
 {
 	int res;
 	int x;
+	sigset_t fullset, oldset;
+
+	sigfillset(&fullset);
+	pthread_sigmask(SIG_BLOCK, &fullset, &oldset);
+
 	res = fork();
 	if (res < 0) 
 		ast_log(LOG_WARNING, "Fork failed\n");
-	if (res)
+	if (res) {
+		pthread_sigmask(SIG_SETMASK, &oldset, NULL);
 		return res;
+	}
+
+	/* Stop ignoring PIPE */
+	signal(SIGPIPE, SIG_DFL);
+	pthread_sigmask(SIG_UNBLOCK, &fullset, NULL);
+
 	if (option_highpriority)
 		ast_set_priority(0);
 	dup2(fd, STDIN_FILENO);
-	for (x=STDERR_FILENO + 1;x<256;x++) {
+	for (x=STDERR_FILENO + 1;x<1024;x++) {
 		if ((x != STDIN_FILENO) && (x != STDOUT_FILENO))
 			close(x);
 	}
@@ -87,7 +99,7 @@ static int icesencode(char *filename, int fd)
 	/* As a last-ditch effort, try to use PATH */
 	execlp("ices", "ices", filename, (char *)NULL);
 	ast_log(LOG_WARNING, "Execute of ices failed\n");
-	return -1;
+	_exit(0);
 }
 
 static int ices_exec(struct ast_channel *chan, void *data)
diff --git a/apps/app_mp3.c b/apps/app_mp3.c
index 31fc32096..1cba886bb 100644
--- a/apps/app_mp3.c
+++ b/apps/app_mp3.c
@@ -67,15 +67,25 @@ static int mp3play(char *filename, int fd)
 {
 	int res;
 	int x;
+	sigset_t fullset, oldset;
+
+	sigfillset(&fullset);
+	pthread_sigmask(SIG_BLOCK, &fullset, &oldset);
+
 	res = fork();
 	if (res < 0) 
 		ast_log(LOG_WARNING, "Fork failed\n");
-	if (res)
+	if (res) {
+		pthread_sigmask(SIG_SETMASK, &oldset, NULL);
 		return res;
+	}
 	if (option_highpriority)
 		ast_set_priority(0);
+	signal(SIGPIPE, SIG_DFL);
+	pthread_sigmask(SIG_UNBLOCK, &fullset, NULL);
+
 	dup2(fd, STDOUT_FILENO);
-	for (x=0;x<256;x++) {
+	for (x=STDERR_FILENO + 1;x<256;x++) {
 		if (x != STDOUT_FILENO)
 			close(x);
 	}
@@ -97,7 +107,7 @@ static int mp3play(char *filename, int fd)
 	    execlp("mpg123", "mpg123", "-q", "-s", "-f", "8192", "--mono", "-r", "8000", filename, (char *)NULL);
 	}
 	ast_log(LOG_WARNING, "Execute of mpg123 failed\n");
-	return -1;
+	_exit(0);
 }
 
 static int timed_read(int fd, void *data, int datalen, int timeout)
diff --git a/apps/app_nbscat.c b/apps/app_nbscat.c
index adc232373..004bde77b 100644
--- a/apps/app_nbscat.c
+++ b/apps/app_nbscat.c
@@ -71,16 +71,26 @@ static int NBScatplay(int fd)
 {
 	int res;
 	int x;
+	sigset_t fullset, oldset;
+
+	sigfillset(&fullset);
+	pthread_sigmask(SIG_BLOCK, &fullset, &oldset);
+
 	res = fork();
 	if (res < 0) 
 		ast_log(LOG_WARNING, "Fork failed\n");
-	if (res)
+	if (res) {
+		pthread_sigmask(SIG_SETMASK, &oldset, NULL);
 		return res;
+	}
+	signal(SIGPIPE, SIG_DFL);
+	pthread_sigmask(SIG_UNBLOCK, &fullset, NULL);
+
 	if (option_highpriority)
 		ast_set_priority(0);
 
 	dup2(fd, STDOUT_FILENO);
-	for (x=0;x<256;x++) {
+	for (x = STDERR_FILENO + 1; x < 1024; x++) {
 		if (x != STDOUT_FILENO)
 			close(x);
 	}
@@ -88,7 +98,7 @@ static int NBScatplay(int fd)
 	execl(NBSCAT, "nbscat8k", "-d", (char *)NULL);
 	execl(LOCAL_NBSCAT, "nbscat8k", "-d", (char *)NULL);
 	ast_log(LOG_WARNING, "Execute of nbscat8k failed\n");
-	return -1;
+	_exit(0);
 }
 
 static int timed_read(int fd, void *data, int datalen)
diff --git a/apps/app_zapras.c b/apps/app_zapras.c
index cf770f2b7..91336f5e4 100644
--- a/apps/app_zapras.c
+++ b/apps/app_zapras.c
@@ -87,11 +87,23 @@ static pid_t spawn_ras(struct ast_channel *chan, char *args)
 	char *argv[PPP_MAX_ARGS];
 	int argc = 0;
 	char *stringp=NULL;
+	sigset_t fullset, oldset;
+
+	sigfillset(&fullset);
+	pthread_sigmask(SIG_BLOCK, &fullset, &oldset);
 
 	/* Start by forking */
 	pid = fork();
-	if (pid)
+	if (pid) {
+		pthread_sigmask(SIG_SETMASK, &oldset, NULL);
 		return pid;
+	}
+
+	/* Restore original signal handlers */
+	for (x=0;x<NSIG;x++)
+		signal(x, SIG_DFL);
+
+	pthread_sigmask(SIG_UNBLOCK, &fullset, NULL);
 
 	/* Execute RAS on File handles */
 	dup2(chan->fds[0], STDIN_FILENO);
@@ -104,10 +116,6 @@ static pid_t spawn_ras(struct ast_channel *chan, char *args)
 	for (x=STDERR_FILENO + 1;x<1024;x++) 
 		close(x);
 
-	/* Restore original signal handlers */
-	for (x=0;x<NSIG;x++)
-		signal(x, SIG_DFL);
-
 	/* Reset all arguments */
 	memset(argv, 0, sizeof(argv));
 
-- 
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