git: 1d712c05370d - main - traceroute6: Properly calculate UDP checksum

[Mark Johnston]

The branch main has been updated by markj:

URL: https://cgit.FreeBSD.org/src/commit/?id=1d712c05370dca8cbf81d1ecd9acd606fdcacaf4

commit 1d712c05370dca8cbf81d1ecd9acd606fdcacaf4
Author:     Zhenlei Huang <zlei.huang at gmail.com>
AuthorDate: 2021-05-03 16:46:19 +0000
Commit:     Mark Johnston <markj at FreeBSD.org>
CommitDate: 2021-05-03 17:24:30 +0000

    traceroute6: Properly calculate UDP checksum
    
    The revision D25604 capsicumize traceroute6. For UDP the send socket was
    changed from SOCK_DGRAM to SOCK_RAW and thus the UDP checksum need be
    calculated by application itself other than the kernel.
    
    outpacket is filled with zeros by line 707, thus the first round the UDP
    checksum is correct. But subsequent rounds outudp->uh_sum will be left
    with garbage.
    
    PR:             255507
    Reviewed by:    ae, markj, tuexen
    MFC after:      3 days
    Differential Revision:  https://reviews.freebsd.org/D30042
---
 usr.sbin/traceroute6/traceroute6.c | 1 +
 1 file changed, 1 insertion(+)

diff --git a/usr.sbin/traceroute6/traceroute6.c b/usr.sbin/traceroute6/traceroute6.c
index 8449a9861302..a071c084ad07 100644
--- a/usr.sbin/traceroute6/traceroute6.c
+++ b/usr.sbin/traceroute6/traceroute6.c
@@ -1118,6 +1118,7 @@ send_probe(int seq, u_long hops)
 		outudp->uh_sport = htons(ident);
 		outudp->uh_dport = htons(port+seq);
 		outudp->uh_ulen = htons(datalen);
+		outudp->uh_sum = 0;
 		outudp->uh_sum = udp_cksum(&Src, &Dst, outpacket, datalen);
 		break;
 	case IPPROTO_NONE: