util: reset signals when we fork off agents

[elogind.git] / src / shared / util.c

diff --git a/src/shared/util.c b/src/shared/util.c
index a54e8799530d4e2e3b40161ef1c618c14b6109a7..98c07163da28e8e871ef976392300c67f8d94bbe 100644 (file)
--- a/src/shared/util.c
+++ b/src/shared/util.c
@@ -937,7 +937,7 @@ int readlink_and_canonicalize(const char *p, char **r) {
 }
 
 int reset_all_signal_handlers(void) {
-        int sig;
+        int sig, r = 0;
 
         for (sig = 1; sig < _NSIG; sig++) {
                 struct sigaction sa = {
@@ -945,16 +945,29 @@ int reset_all_signal_handlers(void) {
                         .sa_flags = SA_RESTART,
                 };
 
+                /* These two cannot be caught... */
                 if (sig == SIGKILL || sig == SIGSTOP)
                         continue;
 
                 /* On Linux the first two RT signals are reserved by
                  * glibc, and sigaction() will return EINVAL for them. */
                 if ((sigaction(sig, &sa, NULL) < 0))
-                        if (errno != EINVAL)
-                                return -errno;
+                        if (errno != EINVAL && r == 0)
+                                r = -errno;
         }
 
+        return r;
+}
+
+int reset_signal_mask(void) {
+        sigset_t ss;
+
+        if (sigemptyset(&ss) < 0)
+                return -errno;
+
+        if (sigprocmask(SIG_SETMASK, &ss, NULL) < 0)
+                return -errno;
+
         return 0;
 }
 
@@ -5130,6 +5143,12 @@ int fork_agent(pid_t *pid, const int except[], unsigned n_except, const char *pa
         /* Don't leak fds to the agent */
         close_all_fds(except, n_except);
 
+        /* Make sure we actually can kill the agent, if we need to, in
+         * case somebody invoked us from a shell script that trapped
+         * SIGTERM or so... */
+        reset_all_signal_handlers();
+        reset_signal_mask();
+
         stdout_is_tty = isatty(STDOUT_FILENO);
         stderr_is_tty = isatty(STDERR_FILENO);
 
@@ -7137,3 +7156,24 @@ int unquote_many_words(const char **p, ...) {
 
         return c;
 }
+
+int free_and_strdup(char **p, const char *s) {
+        char *t;
+
+        assert(p);
+
+        /* Replaces a string pointer with an strdup()ed new string,
+         * possibly freeing the old one. */
+
+        if (s) {
+                t = strdup(s);
+                if (!t)
+                        return -ENOMEM;
+        } else
+                t = NULL;
+
+        free(*p);
+        *p = t;
+
+        return 0;
+}