From 935d855b47978395b1b007da83a2493ead709ebb Mon Sep 17 00:00:00 2001
From: Miroslav Lichvar <mlichvar@redhat.com>
Date: Wed, 5 Apr 2017 11:20:22 +0200
Subject: [PATCH] util: indicate truncated Unix socket path in
 UTI_SockaddrToString()

Specify the maximum length of the path in the snprintf() format to avoid
a new gcc warning (-Wformat-truncation). If the path doesn't fit in the
buffer, indicate with the '>' symbol that it was truncated. The function
is used only for debug messages.
---
 test/unit/util.c | 17 ++++++++++++++++-
 util.c           |  8 ++++++--
 2 files changed, 22 insertions(+), 3 deletions(-)

diff --git a/test/unit/util.c b/test/unit/util.c
index 5cd9badd..43f6214e 100644
--- a/test/unit/util.c
+++ b/test/unit/util.c
@@ -4,10 +4,11 @@
 void test_unit(void) {
   NTP_int64 ntp_ts, ntp_fuzz;
   struct timespec ts, ts2;
+  struct sockaddr_un sun;
   double x, y;
   Float f;
   int i, j, c;
-  char buf[16];
+  char buf[16], *s;
 
   for (i = -31; i < 31; i++) {
     x = pow(2.0, i);
@@ -145,4 +146,18 @@ void test_unit(void) {
       c++;
   }
   TEST_CHECK(c > 46000 && c < 48000);
+
+  for (i = 1; i < 2 * BUFFER_LENGTH; i++) {
+    sun.sun_family = AF_UNIX;
+    for (j = 0; j + 1 < i && j + 1 < sizeof (sun.sun_path); j++)
+      sun.sun_path[j] = 'A' + j % 26;
+    sun.sun_path[j] = '\0';
+    s = UTI_SockaddrToString((struct sockaddr *)&sun);
+    if (i <= BUFFER_LENGTH) {
+      TEST_CHECK(!strcmp(s, sun.sun_path));
+    } else {
+      TEST_CHECK(!strncmp(s, sun.sun_path, BUFFER_LENGTH - 2));
+      TEST_CHECK(s[BUFFER_LENGTH - 2] == '>');
+    }
+  }
 }
diff --git a/util.c b/util.c
index a7610c5b..c336e36f 100644
--- a/util.c
+++ b/util.c
@@ -558,7 +558,7 @@ char *UTI_SockaddrToString(struct sockaddr *sa)
 {
   unsigned short port;
   IPAddr ip;
-  char *result;
+  char *result, *sun_path;
 
   result = NEXT_BUFFER;
 
@@ -571,7 +571,11 @@ char *UTI_SockaddrToString(struct sockaddr *sa)
       snprintf(result, BUFFER_LENGTH, "%s:%hu", UTI_IPToString(&ip), port);
       break;
     case AF_UNIX:
-      snprintf(result, BUFFER_LENGTH, "%s", ((struct sockaddr_un *)sa)->sun_path);
+      sun_path = ((struct sockaddr_un *)sa)->sun_path;
+      snprintf(result, BUFFER_LENGTH, "%.*s", BUFFER_LENGTH - 1, sun_path);
+      /* Indicate truncated path */
+      if (strlen(sun_path) >= BUFFER_LENGTH)
+        result[BUFFER_LENGTH - 2] = '>';
       break;
     default:
       snprintf(result, BUFFER_LENGTH, "[UNKNOWN]");
-- 
2.47.3