daemon: replace atoi() with strtoul_ui() and strtol_i()

Replace atoi() with strtoul_ui() for --timeout and --init-timeout
(non-negative integers) and with strtol_i() for --max-connections
(signed integers). This improves error handling and input validation
by detecting invalid values and providing clear error messages.
Update tests to ensure these arguments are properly validated.

Signed-off-by: Usman Akinyemi <usmanakinyemi202@gmail.com>
Signed-off-by: Taylor Blau <me@ttaylorr.com>

2 files changed, 33 insertions, 4 deletions

diff --git a/daemon.c b/daemon.c
index cb946e3c95..a40e435c63 100644
--- a/daemon.c
+++ b/daemon.c
@@ -4,6 +4,7 @@
 #include "abspath.h"
 #include "config.h"
 #include "environment.h"
+#include "gettext.h"
 #include "path.h"
 #include "pkt-line.h"
 #include "protocol.h"
@@ -1308,17 +1309,20 @@ int cmd_main(int argc, const char **argv)
 			continue;
 		}
 		if (skip_prefix(arg, "--timeout=", &v)) {
-			timeout = atoi(v);
+			if (strtoul_ui(v, 10, &timeout))
+				die(_("invalid timeout '%s', expecting a non-negative integer"), v);
 			continue;
 		}
 		if (skip_prefix(arg, "--init-timeout=", &v)) {
-			init_timeout = atoi(v);
+			if (strtoul_ui(v, 10, &init_timeout))
+				die(_("invalid init-timeout '%s', expecting a non-negative integer"), v);
 			continue;
 		}
 		if (skip_prefix(arg, "--max-connections=", &v)) {
-			max_connections = atoi(v);
+			if (strtol_i(v, 10, &max_connections))
+				die(_("invalid max-connections '%s', expecting an integer"), v);
 			if (max_connections < 0)
-				max_connections = 0;	        /* unlimited */
+				max_connections = 0;  /* unlimited */
 			continue;
 		}
 		if (!strcmp(arg, "--strict-paths")) {
diff --git a/t/t5570-git-daemon.sh b/t/t5570-git-daemon.sh
index c5f08b6799..e3df7d8641 100755
--- a/t/t5570-git-daemon.sh
+++ b/t/t5570-git-daemon.sh
@@ -8,6 +8,31 @@ TEST_PASSES_SANITIZE_LEAK=true
 . ./test-lib.sh
 
 . "$TEST_DIRECTORY"/lib-git-daemon.sh
+
+test_expect_success 'daemon rejects invalid --init-timeout values' '
+	for arg in "3a" "-3"
+	do
+		test_must_fail git daemon --init-timeout="$arg" 2>err &&
+		test_grep "fatal: invalid init-timeout ${SQ}$arg${SQ}, expecting a non-negative integer" err ||
+		return 1
+	done
+'
+
+test_expect_success 'daemon rejects invalid --timeout values' '
+	for arg in "3a" "-3"
+	do
+		test_must_fail git daemon --timeout="$arg" 2>err &&
+		test_grep "fatal: invalid timeout ${SQ}$arg${SQ}, expecting a non-negative integer" err ||
+		return 1
+	done
+'
+
+test_expect_success 'daemon rejects invalid --max-connections values' '
+	arg='3a' &&
+	test_must_fail git daemon --max-connections=3a 2>err &&
+	test_grep "fatal: invalid max-connections ${SQ}$arg${SQ}, expecting an integer" err
+'
+
 start_git_daemon
 
 check_verbose_connect () {