Resolves: RHEL-85950 - FRR doesn't send logs to stdout when running as a daemon

0012-print-log-to-stdout.patch

@@ -0,0 +1,108 @@
+From 4d28aea95851dc14b3987b004f457d7a4a1535f8 Mon Sep 17 00:00:00 2001
+From: Lou Berger <lberger@labn.net>
+Date: Sun, 2 Oct 2022 15:56:07 +0000
+Subject: [PATCH] lib: when running as a daemon, only redirect sdtin, stdout,
+ sdterr to null when a tty.
+
+     Also write memstat to stderr when stderr is not a tty
+     and allow for --log stdout
+
+Signed-off-by: Lou Berger <lberger@labn.net>
+---
+ lib/libfrr.c | 44 +++++++++++++++++++++++++++++++-------------
+ 1 file changed, 31 insertions(+), 13 deletions(-)
+
+diff --git a/lib/libfrr.c b/lib/libfrr.c
+index 07e2eafec59c..e8900572694a 100644
+--- 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",

frr.spec

@@ -7,7 +7,7 @@
 
 Name: frr
 Version: 8.5.3
-Release: 7%{?checkout}%{?dist}
+Release: 8%{?checkout}%{?dist}
 Summary: Routing daemon
 License: GPLv2+
 URL: http://www.frrouting.org
@@ -74,6 +74,7 @@ Patch0008: 0008-CVE-2023-46753.patch
 Patch0009: 0009-bfd-bgp-shutdown-notification.patch
 Patch0010: 0010-bgp-bfd-drop-connection.patch
 Patch0011: 0011-bgp-graceful-restart-noop.patch
+Patch0012: 0012-print-log-to-stdout.patch
 
 %description
 FRRouting is free software that manages TCP/IP based routing protocols. It takes
@@ -279,6 +280,9 @@ make check PYTHON=%{__python3}
 %endif
 
 %changelog
+* Thu Apr 03 2025 Michal Ruprich <mruprich@redhat.com> - 8.5.3-8
+- Resolves: RHEL-85950 - FRR doesn't send logs to stdout when running as a daemon
+
 * Fri Feb 14 2025 Michal Ruprich <mruprich@redhat.com> - 8.5.3-7
 - Resolves: RHEL-68432 - FRR gives false warning when Graceful Restart enabled