From b89bb75386acbe81692fd339ea5b6512abb5a5a5 Mon Sep 17 00:00:00 2001
From: Marcelo Magallon <marcelo.magallon@grafana.com>
Date: Mon, 23 May 2022 08:54:11 -0600
Subject: [PATCH] Report whether or not the TTL value was read (#205)
In IPv6 a hop limit of 0 is valid, so the TTL the code is reporting is
actually a valid value in that case.
Initialize ttl to -1, so that in the case of not getting a TTL value
from the control message, we can let the rest of the code whether the
reported value was actually 0 or whether it couldn't be read.
Signed-off-by: Marcelo E. Magallon <marcelo.magallon@grafana.com>
---
packetconn.go | 4 ++--
1 file changed, 2 insertions(+), 2 deletions(-)
diff --git a/packetconn.go b/packetconn.go
index 38e17e3..6a972f5 100644
--- a/packetconn.go
+++ b/packetconn.go
@@ -65,7 +65,7 @@ func (c *icmpv4Conn) SetFlagTTL() error {
}
func (c *icmpv4Conn) ReadFrom(b []byte) (int, int, net.Addr, error) {
- var ttl int
+ ttl := -1
n, cm, src, err := c.c.IPv4PacketConn().ReadFrom(b)
if cm != nil {
ttl = cm.TTL
@@ -90,7 +90,7 @@ func (c *icmpV6Conn) SetFlagTTL() error {
}
func (c *icmpV6Conn) ReadFrom(b []byte) (int, int, net.Addr, error) {
- var ttl int
+ ttl := -1
n, cm, src, err := c.c.IPv6PacketConn().ReadFrom(b)
if cm != nil {
ttl = cm.HopLimit