We need to zero out the checksum field before calculating the
checksum, of course. I have no idea how this passed the "icmp" test
set, looking into it.
Reported-by: Paul Holzinger <pholzing(a)redhat.com>
Fixes: 67ab6171729c ("Add csum_icmp4() helper for calculating ICMP checksums")
Signed-off-by: Stefano Brivio <sbrivio(a)redhat.com>
---
checksum.c | 7 +++++--
1 file changed, 5 insertions(+), 2 deletions(-)
diff --git a/checksum.c b/checksum.c
index 09d2c7c..c59869c 100644
--- a/checksum.c
+++ b/checksum.c
@@ -160,10 +160,13 @@ void csum_udp4(struct udphdr *udp4hr, in_addr_t saddr, in_addr_t
daddr,
*/
void csum_icmp4(struct icmphdr *icmp4hr, const void *payload, size_t len)
{
- /* Partial checksum for ICMP header alone */
- uint32_t psum = sum_16b(icmp4hr, sizeof(*icmp4hr));
+ uint32_t psum;
icmp4hr->checksum = 0;
+
+ /* Partial checksum for ICMP header alone */
+ psum = sum_16b(icmp4hr, sizeof(*icmp4hr));
+
icmp4hr->checksum = csum_unaligned(payload, len, psum);
}
--
2.35.1