[Backport v3.6-branch] net: ip: igmp: Fix IGMP determination

subsys/net/ip/igmp.c

@@ -22,18 +22,15 @@ LOG_MODULE_DECLARE(net_ipv4, CONFIG_NET_IPV4_LOG_LEVEL);
 #include "connection.h"
 #include "ipv4.h"
 #include "net_stats.h"
+#include "igmp.h"
 
 /* Timeout for various buffer allocations in this file. */
 #define PKT_WAIT_TIME K_MSEC(50)
 
 #define IPV4_OPT_HDR_ROUTER_ALERT_LEN 4
 
-#define IGMPV3_MODE_IS_INCLUDE        0x01
-#define IGMPV3_MODE_IS_EXCLUDE        0x02
-#define IGMPV3_CHANGE_TO_INCLUDE_MODE 0x03
-#define IGMPV3_CHANGE_TO_EXCLUDE_MODE 0x04
-#define IGMPV3_ALLOW_NEW_SOURCES      0x05
-#define IGMPV3_BLOCK_OLD_SOURCES      0x06
+#define IGMPV2_PAYLOAD_MIN_LEN 8
+#define IGMPV3_PAYLOAD_MIN_LEN 12
 
 static const struct in_addr all_systems = { { { 224, 0, 0, 1 } } };
 #if defined(CONFIG_NET_IPV4_IGMPV3)
@@ -417,28 +414,29 @@ static int send_igmp_v3_report(struct net_if *iface, struct net_ipv4_igmp_v3_que
 
 enum net_verdict net_ipv4_igmp_input(struct net_pkt *pkt, struct net_ipv4_hdr *ip_hdr)
 {
-#if defined(CONFIG_NET_IPV4_IGMPV3)
-	NET_PKT_DATA_ACCESS_CONTIGUOUS_DEFINE(igmpv3_access, struct net_ipv4_igmp_v3_query);
-	struct net_ipv4_igmp_v3_query *igmpv3_hdr;
-#endif
+	int ret;
 	NET_PKT_DATA_ACCESS_CONTIGUOUS_DEFINE(igmpv2_access, struct net_ipv4_igmp_v2_query);
+
 	struct net_ipv4_igmp_v2_query *igmpv2_hdr;
+	int igmp_buf_len =
+		pkt->buffer->len - (net_pkt_ip_hdr_len(pkt) + net_pkt_ipv4_opts_len(pkt));
+#if defined(CONFIG_NET_IPV4_IGMPV3)
+	struct net_ipv4_igmp_v3_query *igmpv3_hdr;
 	enum igmp_version version;
-	int ret;
-	int igmp_buf_len = pkt->buffer->len - net_pkt_ip_hdr_len(pkt);
+
+	NET_PKT_DATA_ACCESS_CONTIGUOUS_DEFINE(igmpv3_access, struct net_ipv4_igmp_v3_query);
 
 	/* Detect IGMP type (RFC 3376 ch 7.1) */
-	if (igmp_buf_len == 8) {
+	if (igmp_buf_len == IGMPV2_PAYLOAD_MIN_LEN) {
 		/* IGMPv1/2 detected */
 		version = IGMPV2;
-	} else if (igmp_buf_len >= 12) {
+	} else if (igmp_buf_len >= IGMPV3_PAYLOAD_MIN_LEN) {
 		/* IGMPv3 detected */
 		version = IGMPV3;
-#if !defined(CONFIG_NET_IPV4_IGMPV3)
-		NET_DBG("DROP: %sv3 msg received but %s support is disabled", "IGMP", "IGMP");
-		return NET_DROP;
-#endif
 	} else {
+#else
+	if (igmp_buf_len < IGMPV2_PAYLOAD_MIN_LEN) {
+#endif
 		NET_DBG("DROP: unsupported payload length");
 		return NET_DROP;
 	}

subsys/net/ip/igmp.h

@@ -0,0 +1,23 @@
+/**
+ * @file
+ * @brief IGMP definitions
+ * This is not to be included by the application.
+ */
+
+/*
+ * Copyright (c) 2024 Basalte bv
+ *
+ * SPDX-License-Identifier: Apache-2.0
+ */
+
+#ifndef __IGMP_H
+#define __IGMP_H
+
+#define IGMPV3_MODE_IS_INCLUDE        0x01
+#define IGMPV3_MODE_IS_EXCLUDE        0x02
+#define IGMPV3_CHANGE_TO_INCLUDE_MODE 0x03
+#define IGMPV3_CHANGE_TO_EXCLUDE_MODE 0x04
+#define IGMPV3_ALLOW_NEW_SOURCES      0x05
+#define IGMPV3_BLOCK_OLD_SOURCES      0x06
+
+#endif /* __IGMP_H */

tests/net/igmp/src/main.c

@@ -32,6 +32,7 @@ LOG_MODULE_REGISTER(net_test, CONFIG_NET_IPV4_LOG_LEVEL);
 #include <zephyr/random/random.h>
 
 #include "ipv4.h"
+#include "igmp.h"
 
 #define THREAD_SLEEP 50 /* ms */
 
@@ -98,37 +99,87 @@ static void net_test_iface_init(struct net_if *iface)
 			     NET_LINK_ETHERNET);
 }
 
+#if defined(CONFIG_NET_IPV4_IGMPV3)
+static struct net_ipv4_igmp_v3_report *get_igmp_hdr(struct net_pkt *pkt)
+#else
 static struct net_ipv4_igmp_v2_query *get_igmp_hdr(struct net_pkt *pkt)
+#endif
 {
 	net_pkt_cursor_init(pkt);
 
 	net_pkt_skip(pkt, net_pkt_ip_hdr_len(pkt) +
 		     net_pkt_ipv4_opts_len(pkt));
 
+#if defined(CONFIG_NET_IPV4_IGMPV3)
+	return (struct net_ipv4_igmp_v3_report *)net_pkt_cursor_get_pos(pkt);
+#else
 	return (struct net_ipv4_igmp_v2_query *)net_pkt_cursor_get_pos(pkt);
+#endif
 }
 
+#if defined(CONFIG_NET_IPV4_IGMPV3)
+static struct net_ipv4_igmp_v3_group_record *get_igmp_group_record(struct net_pkt *pkt)
+{
+	net_pkt_cursor_init(pkt);
+
+	net_pkt_skip(pkt, net_pkt_ip_hdr_len(pkt) + net_pkt_ipv4_opts_len(pkt));
+	net_pkt_skip(pkt, sizeof(struct net_ipv4_igmp_v3_report));
+
+	return (struct net_ipv4_igmp_v3_group_record *)net_pkt_cursor_get_pos(pkt);
+}
+#endif
+
 static int tester_send(const struct device *dev, struct net_pkt *pkt)
 {
-	struct net_ipv4_igmp_v2_query *igmp;
+#if defined(CONFIG_NET_IPV4_IGMPV3)
+	struct net_ipv4_igmp_v3_report *igmp_header;
+	struct net_ipv4_igmp_v3_group_record *igmp_group_record;
+#else
+	struct net_ipv4_igmp_v2_query *igmp_header;
+#endif
 
 	if (!pkt->buffer) {
 		TC_ERROR("No data to send!\n");
 		return -ENODATA;
 	}
 
-	igmp = get_igmp_hdr(pkt);
+	igmp_header = get_igmp_hdr(pkt);
 
-	if (igmp->type == NET_IPV4_IGMP_QUERY) {
+	if (igmp_header->type == NET_IPV4_IGMP_QUERY) {
 		NET_DBG("Received query....");
 		is_query_received = true;
 		k_sem_give(&wait_data);
-	} else if (igmp->type == NET_IPV4_IGMP_REPORT_V2) {
+	} else if (igmp_header->type == NET_IPV4_IGMP_REPORT_V2) {
 		NET_DBG("Received v2 report....");
+		zassert_false(IS_ENABLED(CONFIG_NET_IPV4_IGMPV3),
+			      "Wrong IGMP report received (IGMPv2)");
 		is_join_msg_ok = true;
 		is_report_sent = true;
 		k_sem_give(&wait_data);
-	} else if (igmp->type == NET_IPV4_IGMP_LEAVE) {
+	} else if (igmp_header->type == NET_IPV4_IGMP_REPORT_V3) {
+		NET_DBG("Received v3 report....");
+		zassert_true(IS_ENABLED(CONFIG_NET_IPV4_IGMPV3),
+			     "Wrong IGMP report received (IGMPv3)");
+
+#if defined(CONFIG_NET_IPV4_IGMPV3)
+		zassert_true(ntohs(igmp_header->groups_len) == 1,
+			     "Invalid group length of IGMPv3 report (%d)", igmp_header->groups_len);
+
+		igmp_group_record = get_igmp_group_record(pkt);
+		zassert_true(igmp_group_record->sources_len == 0,
+			     "Invalid sources length of IGMPv3 group record");
+
+		if (igmp_group_record->type == IGMPV3_CHANGE_TO_EXCLUDE_MODE) {
+			is_join_msg_ok = true;
+		} else if (igmp_group_record->type == IGMPV3_CHANGE_TO_INCLUDE_MODE) {
+			is_leave_msg_ok = true;
+		}
+#else
+		is_join_msg_ok = true;
+#endif
+		is_report_sent = true;
+		k_sem_give(&wait_data);
+	} else if (igmp_header->type == NET_IPV4_IGMP_LEAVE) {
 		NET_DBG("Received leave....");
 		is_leave_msg_ok = true;
 		k_sem_give(&wait_data);

tests/net/igmp/testcase.yaml

@@ -11,3 +11,11 @@ tests:
   net.igmp.preempt:
     extra_configs:
       - CONFIG_NET_TC_THREAD_PREEMPTIVE=y
+  net.igmpv3:
+    extra_configs:
+      - CONFIG_NET_TC_THREAD_COOPERATIVE=y
+      - CONFIG_NET_IPV4_IGMPV3=y
+  net.igmpv3.preempt:
+    extra_configs:
+      - CONFIG_NET_TC_THREAD_PREEMPTIVE=y
+      - CONFIG_NET_IPV4_IGMPV3=y