From: Renato Westphal <renato@opensourcerouting.org>
Date: Wed, 20 Sep 2017 03:02:01 +0000 (-0300)
Subject: zebra: fix logging of MPLS labels
X-Git-Tag: frr-4.0-dev~224^2~3
X-Git-Url: https://git.puffer.fish/?a=commitdiff_plain;h=9a62e84b5b6379ff3419da8f52728b95f31bacf3;p=matthieu%2Ffrr.git

zebra: fix logging of MPLS labels

* use %u instead of %d, we don't want to print negative labels;
* increase the size of label_buf to accommodate the worst case scenarios;
* use strlcat() instead of strcat() as a security best practice.

Signed-off-by: Renato Westphal <renato@opensourcerouting.org>
---

diff --git a/zebra/rt_netlink.c b/zebra/rt_netlink.c
index a939dde8d5..3b2d22fa95 100644
--- a/zebra/rt_netlink.c
+++ b/zebra/rt_netlink.c
@@ -845,7 +845,7 @@ static void _netlink_route_build_singlepath(const char *routedesc, int bytelen,
 {
 	struct nexthop_label *nh_label;
 	mpls_lse_t out_lse[MPLS_MAX_LABELS];
-	char label_buf[100];
+	char label_buf[256];
 
 	/*
 	 * label_buf is *only* currently used within debugging.
@@ -876,12 +876,13 @@ static void _netlink_route_build_singlepath(const char *routedesc, int bytelen,
 							     0, 0, bos);
 				if (IS_ZEBRA_DEBUG_KERNEL) {
 					if (!num_labels)
-						sprintf(label_buf, "label %d",
+						sprintf(label_buf, "label %u",
 							nh_label->label[i]);
 					else {
-						sprintf(label_buf1, "/%d",
+						sprintf(label_buf1, "/%u",
 							nh_label->label[i]);
-						strcat(label_buf, label_buf1);
+						strlcat(label_buf, label_buf1,
+							sizeof(label_buf));
 					}
 				}
 				num_labels++;
@@ -1044,7 +1045,7 @@ static void _netlink_route_build_multipath(const char *routedesc, int bytelen,
 {
 	struct nexthop_label *nh_label;
 	mpls_lse_t out_lse[MPLS_MAX_LABELS];
-	char label_buf[100];
+	char label_buf[256];
 
 	rtnh->rtnh_len = sizeof(*rtnh);
 	rtnh->rtnh_flags = 0;
@@ -1080,12 +1081,13 @@ static void _netlink_route_build_multipath(const char *routedesc, int bytelen,
 							     0, 0, bos);
 				if (IS_ZEBRA_DEBUG_KERNEL) {
 					if (!num_labels)
-						sprintf(label_buf, "label %d",
+						sprintf(label_buf, "label %u",
 							nh_label->label[i]);
 					else {
-						sprintf(label_buf1, "/%d",
+						sprintf(label_buf1, "/%u",
 							nh_label->label[i]);
-						strcat(label_buf, label_buf1);
+						strlcat(label_buf, label_buf1,
+							sizeof(label_buf));
 					}
 				}
 				num_labels++;