Standardized routines for forking processes (keeps all the specialized code in one place).

git-svn-id: https://origsvn.digium.com/svn/asterisk/trunk@114188 65c4cc65-6c06-0410-ace0-fbb531ad65f3

3 files changed, 113 insertions, 5 deletions

diff --git a/main/app.c b/main/app.c
index ee72d1078..05cdf1748 100644
--- a/main/app.c
+++ b/main/app.c
@@ -32,6 +32,7 @@ ASTERISK_FILE_VERSION(__FILE__, "$Revision$")
 #endif
 #include <regex.h>
 #include <sys/file.h> /* added this to allow to compile, sorry! */
+#include <signal.h>
 
 #include "asterisk/paths.h"	/* use ast_config_AST_DATA_DIR */
 #include "asterisk/channel.h"
@@ -1759,3 +1760,65 @@ int ast_get_encoded_char(const char *stream, char *result, size_t *consumed)
 	return 0;
 }
 
+void ast_close_fds_above_n(int n)
+{
+	int x, null;
+	null = open("/dev/null", O_RDONLY);
+	for (x = n + 1; x <= (null >= 8192 ? null : 8192); x++) {
+		if (x != null) {
+			/* Side effect of dup2 is that it closes any existing fd without error.
+			 * This prevents valgrind and other debugging tools from sending up
+			 * false error reports. */
+			dup2(null, x);
+			close(x);
+		}
+	}
+	close(null);
+}
+
+int ast_safe_fork(int stop_reaper)
+{
+	sigset_t signal_set, old_set;
+	int pid;
+
+	/* Don't let the default signal handler for children reap our status */
+	if (stop_reaper) {
+		ast_replace_sigchld();
+	}
+
+	sigfillset(&signal_set);
+	pthread_sigmask(SIG_BLOCK, &signal_set, &old_set);
+
+	pid = fork();
+
+	if (pid != 0) {
+		/* Fork failed or parent */
+		pthread_sigmask(SIG_SETMASK, &old_set, NULL);
+		return pid;
+	} else {
+		/* Child */
+
+		/* 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 (pthread_sigmask(SIG_UNBLOCK, &signal_set, NULL)) {
+			ast_log(LOG_WARNING, "unable to unblock signals for AGI script: %s\n", strerror(errno));
+			_exit(1);
+		}
+
+		return pid;
+	}
+}
+
+void ast_safe_fork_cleanup(void)
+{
+	ast_unreplace_sigchld();
+}
+
diff --git a/main/asterisk.c b/main/asterisk.c
index f08a4d020..99df3ef45 100644
--- a/main/asterisk.c
+++ b/main/asterisk.c
@@ -848,9 +848,6 @@ void ast_unreplace_sigchld(void)
 int ast_safe_system(const char *s)
 {
 	pid_t pid;
-#ifdef HAVE_WORKING_FORK
-	int x;
-#endif
 	int res;
 	struct rusage rusage;
 	int status;
@@ -869,8 +866,7 @@ int ast_safe_system(const char *s)
 		if (ast_opt_high_priority)
 			ast_set_priority(0);
 		/* Close file descriptors and launch system command */
-		for (x = STDERR_FILENO + 1; x < 4096; x++)
-			close(x);
+		ast_close_fds_above_n(STDERR_FILENO);
 #endif
 		execl("/bin/sh", "/bin/sh", "-c", s, (char *) NULL);
 		_exit(1);
diff --git a/main/logger.c b/main/logger.c
index b7c517fa7..dce2097d9 100644
--- a/main/logger.c
+++ b/main/logger.c
@@ -413,6 +413,55 @@ static void init_logger_chain(int reload, int locked)
 	ast_config_destroy(cfg);
 }
 
+void ast_child_verbose(int level, const char *fmt, ...)
+{
+	char *msg = NULL, *emsg = NULL, *sptr, *eptr;
+	va_list ap, aq;
+	int size;
+
+	/* Don't bother, if the level isn't that high */
+	if (option_verbose < level) {
+		return;
+	}
+
+	va_start(ap, fmt);
+	va_copy(aq, ap);
+	if ((size = vsnprintf(msg, 0, fmt, ap)) < 0) {
+		va_end(ap);
+		va_end(aq);
+		return;
+	}
+	va_end(ap);
+
+	if (!(msg = ast_malloc(size + 1))) {
+		va_end(aq);
+		return;
+	}
+
+	vsnprintf(msg, size + 1, fmt, aq);
+	va_end(aq);
+
+	if (!(emsg = ast_malloc(size * 2 + 1))) {
+		ast_free(msg);
+		return;
+	}
+
+	for (sptr = msg, eptr = emsg; ; sptr++) {
+		if (*sptr == '"') {
+			*eptr++ = '\\';
+		}
+		*eptr++ = *sptr;
+		if (*sptr == '\0') {
+			break;
+		}
+	}
+	ast_free(msg);
+
+	fprintf(stdout, "verbose \"%s\" %d\n", emsg, level);
+	fflush(stdout);
+	ast_free(emsg);
+}
+
 void ast_queue_log(const char *queuename, const char *callid, const char *agent, const char *event, const char *fmt, ...)
 {
 	va_list ap;