Commit 73372783 authored Oct 11, 2024 by Ibe Van de Veire Committed by Henrik Brix Andersen Oct 22, 2024

net: ip: igmp: Fix wrong header length

The header length of the net ip packet was calculated using only the
net_pkt_ip_hdr_len function. The correct header length should be
calculated by adding net_pkt_ip_hdr_len and net_pkt_ipv4_opts_len. This
resulted in an incorrect IGMP version type in case of IGMPv2 message
(when IGMPv3 was enabled). The IGMP message was not parsed correctly and
therefore dropped.

Signed-off-by: Ibe Van de Veire <ibe.vandeveire@basalte.be>
(cherry picked from commit f852c123)

parent 6937dabf

subsys/net/ip/igmp.c

+2 −1

Changes for subsys/net/ip/igmp.c: 2 added lines, 1 removed line.
Original line number	Diff line number	Diff line
		@@ -425,7 +425,8 @@ enum net_verdict net_ipv4_igmp_input(struct net_pkt pkt, struct net_ipv4_hdr i
		struct net_ipv4_igmp_v2_query *igmpv2_hdr;
		enum igmp_version version;
		int ret;
		int igmp_buf_len = pkt->buffer->len - net_pkt_ip_hdr_len(pkt);
		int igmp_buf_len =
		pkt->buffer->len - (net_pkt_ip_hdr_len(pkt) + net_pkt_ipv4_opts_len(pkt));

		/* Detect IGMP type (RFC 3376 ch 7.1) */
		if (igmp_buf_len == 8) {

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