Merged revisions 48374 via svnmerge from

https://origsvn.digium.com/svn/asterisk/branches/1.2

........
r48374 | tilghman | 2006-12-10 18:33:59 -0600 (Sun, 10 Dec 2006) | 5 lines

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: https://origsvn.digium.com/svn/asterisk/branches/1.4@48375 65c4cc65-6c06-0410-ace0-fbb531ad65f3

diff --git a/apps/app_externalivr.c b/apps/app_externalivr.c
index a42dd95512f1d5e36e3922ad9c95a3949710a4b3..461e7483c112fc2b7fc2df427d41cd76265d0d05 100644 (file)
--- a/apps/app_externalivr.c
+++ b/apps/app_externalivr.c
@@ -40,6 +40,7 @@ ASTERISK_FILE_VERSION(__FILE__, "$Revision$")
 #include <string.h>
 #include <unistd.h>
 #include <errno.h>
+#include <signal.h>
 
 #include "asterisk/lock.h"
 #include "asterisk/file.h"
@@ -261,9 +262,13 @@ static int app_exec(struct ast_channel *chan, void *data)
                .finishlist = AST_LIST_HEAD_INIT_VALUE,
        };
        struct ivr_localuser *u = &foo;
+       sigset_t fullset, oldset;
 
        lu = ast_module_user_add(chan);
-       
+
+       sigfillset(&fullset);
+       pthread_sigmask(SIG_BLOCK, &fullset, &oldset);
+
        u->abort_current_sound = 0;
        u->chan = chan;
        
@@ -312,6 +317,9 @@ 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 (ast_opt_high_priority)
                        ast_set_priority(0);
 
@@ -335,6 +343,8 @@ 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 6e7a4ffd49de857da49940c19d800effdd2e7502..126dde29d5f83b49f532b767be729de12257fe33 100644 (file)
--- a/apps/app_festival.c
+++ b/apps/app_festival.c
@@ -130,19 +130,26 @@ 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 (ast_opt_high_priority)
                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 c44b931364522258150a614c1e0854ca2bf6e9b7..8c6d5e7e5691bc3f3df7f491f22aa6ba09560c92 100644 (file)
--- a/apps/app_ices.c
+++ b/apps/app_ices.c
@@ -65,15 +65,27 @@ 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 (ast_opt_high_priority)
                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);
        }
@@ -84,7 +96,7 @@ 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 667de67ad0e401fbad00a70ad50612d6533dd0d5..55d50f01190d64cc6d3aef6f89490ff62f93906a 100644 (file)
--- a/apps/app_mp3.c
+++ b/apps/app_mp3.c
@@ -64,15 +64,25 @@ 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 (ast_opt_high_priority)
                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);
        }
@@ -94,7 +104,7 @@ 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 34658434660f12f5d5c126ad395f877c61373baa..5f3000404c9a8608cc31d572afcccbab43aa8072 100644 (file)
--- a/apps/app_nbscat.c
+++ b/apps/app_nbscat.c
@@ -68,16 +68,26 @@ 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 (ast_opt_high_priority)
                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);
        }
@@ -85,7 +95,7 @@ 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 de682f72c44d7ac03a7dbdfe46c64f243e6c4e2f..c3ccf30d917da16f24975acde006722b65b3e002 100644 (file)
--- a/apps/app_zapras.c
+++ b/apps/app_zapras.c
@@ -82,11 +82,23 @@ 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);
@@ -99,10 +111,6 @@ 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));
 

diff --git a/res/res_agi.c b/res/res_agi.c
index ecac92282a9bad00102557ecf403a085e27d9cd7..a8417587f3947fee16baf4764d6cad266d1f6342 100644 (file)
--- a/res/res_agi.c
+++ b/res/res_agi.c
@@ -240,7 +240,7 @@ static enum agi_result launch_script(char *script, char *argv[], int *fds, int *
        int audio[2];
        int x;
        int res;
-       sigset_t signal_set;
+       sigset_t signal_set, old_set;
        
        if (!strncasecmp(script, "agi://", 6))
                return launch_netscript(script, argv, fds, efd, opid);
@@ -282,11 +282,14 @@ static enum agi_result launch_script(char *script, char *argv[], int *fds, int *
                        return AGI_RESULT_FAILURE;
                }
        }
-       ast_replace_sigchld();
+
+       /* Block SIGHUP during the fork - prevents a race */
+       sigfillset(&signal_set);
+       pthread_sigmask(SIG_BLOCK, &signal_set, &old_set);
        pid = fork();
        if (pid < 0) {
                ast_log(LOG_WARNING, "Failed to fork(): %s\n", strerror(errno));
-               ast_unreplace_sigchld();
+               pthread_sigmask(SIG_SETMASK, &old_set, NULL);
                return AGI_RESULT_FAILURE;
        }
        if (!pid) {
@@ -314,9 +317,18 @@ static enum agi_result launch_script(char *script, char *argv[], int *fds, int *
                } else {
                        close(STDERR_FILENO + 1);
                }
-               
+
+               /* Before we unblock our signals, return our trapped signals back to the defaults */
+               signal(SIGHUP, SIG_DFL);
+               signal(SIGCHLD, SIG_DFL);
+               signal(SIGINT, SIG_DFL);
+               signal(SIGURG, SIG_DFL);
+               signal(SIGTERM, SIG_DFL);
+               signal(SIGPIPE, SIG_DFL);
+               signal(SIGXFSZ, SIG_DFL);
+
                /* unblock important signal handlers */
-               if (sigfillset(&signal_set) || pthread_sigmask(SIG_UNBLOCK, &signal_set, NULL)) {
+               if (pthread_sigmask(SIG_UNBLOCK, &signal_set, NULL)) {
                        ast_log(LOG_WARNING, "unable to unblock signals for AGI script: %s\n", strerror(errno));
                        _exit(1);
                }
@@ -332,6 +344,7 @@ static enum agi_result launch_script(char *script, char *argv[], int *fds, int *
                fflush(stdout);
                _exit(1);
        }
+       pthread_sigmask(SIG_SETMASK, &old_set, NULL);
        if (option_verbose > 2) 
                ast_verbose(VERBOSE_PREFIX_3 "Launched AGI Script %s\n", script);
        fds[0] = toast[0];
@@ -348,7 +361,6 @@ static enum agi_result launch_script(char *script, char *argv[], int *fds, int *
 
        *opid = pid;
        return AGI_RESULT_SUCCESS;
-               
 }
 
 static void setup_env(struct ast_channel *chan, char *request, int fd, int enhanced)

diff --git a/res/res_musiconhold.c b/res/res_musiconhold.c
index 267cbc92bf41e27fa78a85f0caec3d097d6dd0af..328b099afee15ba0614c8423b0ee03882b4d38eb 100644 (file)
--- a/res/res_musiconhold.c
+++ b/res/res_musiconhold.c
@@ -340,6 +340,7 @@ static int spawn_mp3(struct mohclass *class)
        int argc = 0;
        DIR *dir = NULL;
        struct dirent *de;
+       sigset_t signal_set, old_set;
 
        
        if (!strcasecmp(class->dir, "nodir")) {
@@ -424,6 +425,11 @@ static int spawn_mp3(struct mohclass *class)
        if (time(NULL) - class->start < respawn_time) {
                sleep(respawn_time - (time(NULL) - class->start));
        }
+
+       /* Block signals during the fork() */
+       sigfillset(&signal_set);
+       pthread_sigmask(SIG_BLOCK, &signal_set, &old_set);
+
        time(&class->start);
        class->pid = fork();
        if (class->pid < 0) {
@@ -438,6 +444,10 @@ static int spawn_mp3(struct mohclass *class)
                if (ast_opt_high_priority)
                        ast_set_priority(0);
 
+               /* Reset ignored signals back to default */
+               signal(SIGPIPE, SIG_DFL);
+               pthread_sigmask(SIG_UNBLOCK, &signal_set, NULL);
+
                close(fds[0]);
                /* Stdout goes to pipe */
                dup2(fds[1], STDOUT_FILENO);
@@ -464,6 +474,7 @@ static int spawn_mp3(struct mohclass *class)
                _exit(1);
        } else {
                /* Parent */
+               pthread_sigmask(SIG_SETMASK, &old_set, NULL);
                close(fds[1]);
        }
        return fds[0];