lib: when running as a daemon, only redirect sdtin, stdout, sdterr to null when a...

     Also write memstat to stderr when stderr is not a tty
     and allow for --log stdout

Signed-off-by: Lou Berger <lberger@labn.net>

diff --git a/lib/libfrr.c b/lib/libfrr.c
index 07e2eafec59cc449b271c2fec74ab7104c1dd14d..e8900572694ae813393339160a9a05f228449ae9 100644 (file)
--- a/lib/libfrr.c
+++ b/lib/libfrr.c
@@ -130,6 +130,7 @@ static const struct optspec os_always = {
        "      --limit-fds    Limit number of fds supported\n",
        lo_always};
 
+static bool logging_to_stdout = false; /* set when --log stdout specified */
 
 static const struct option lo_cfg[] = {
        {"config_file", required_argument, NULL, 'f'},
@@ -738,6 +739,11 @@ struct event_loop *frr_init(void)
        while ((log_arg = log_args_pop(di->early_logging))) {
                command_setup_early_logging(log_arg->target,
                                            di->early_loglevel);
+               /* this is a bit of a hack,
+                  but need to notice when
+                  the target is stdout */
+               if (strcmp(log_arg->target, "stdout") == 0)
+                       logging_to_stdout = true;
                XFREE(MTYPE_TMP, log_arg);
        }
 
@@ -1088,9 +1094,15 @@ static void frr_terminal_close(int isexit)
                             "%s: failed to open /dev/null: %s", __func__,
                             safe_strerror(errno));
        } else {
-               dup2(nullfd, 0);
-               dup2(nullfd, 1);
-               dup2(nullfd, 2);
+               int fd;
+               /*
+                * only redirect stdin, stdout, stderr to null when a tty also
+                * don't redirect when stdout is set with --log stdout
+                */
+               for (fd = 2; fd >= 0; fd--)
+                       if (isatty(fd) &&
+                           (fd != STDOUT_FILENO || !logging_to_stdout))
+                               dup2(nullfd, fd);
                close(nullfd);
        }
 }
@@ -1168,9 +1180,16 @@ void frr_run(struct event_loop *master)
                                     "%s: failed to open /dev/null: %s",
                                     __func__, safe_strerror(errno));
                } else {
-                       dup2(nullfd, 0);
-                       dup2(nullfd, 1);
-                       dup2(nullfd, 2);
+                       int fd;
+                       /*
+                        * only redirect stdin, stdout, stderr to null when a
+                        * tty also don't redirect when stdout is set with --log
+                        * stdout
+                        */
+                       for (fd = 2; fd >= 0; fd--)
+                               if (isatty(fd) &&
+                                   (fd != STDOUT_FILENO || !logging_to_stdout))
+                                       dup2(nullfd, fd);
                        close(nullfd);
                }
 
@@ -1194,7 +1213,7 @@ void frr_fini(void)
 {
        FILE *fp;
        char filename[128];
-       int have_leftovers;
+       int have_leftovers = 0;
 
        hook_call(frr_fini);
 
@@ -1220,16 +1239,15 @@ void frr_fini(void)
        /* frrmod_init -> nothing needed / hooks */
        rcu_shutdown();
 
-       if (!debug_memstats_at_exit)
-               return;
-
-       have_leftovers = log_memstats(stderr, di->name);
+       /* also log memstats to stderr when stderr goes to a file*/
+       if (debug_memstats_at_exit || !isatty(STDERR_FILENO))
+               have_leftovers = log_memstats(stderr, di->name);
 
        /* in case we decide at runtime that we want exit-memstats for
-        * a daemon, but it has no stderr because it's daemonized
+        * a daemon
         * (only do this if we actually have something to print though)
         */
-       if (!have_leftovers)
+       if (!debug_memstats_at_exit || !have_leftovers)
                return;
 
        snprintf(filename, sizeof(filename), "/tmp/frr-memstats-%s-%llu-%llu",