net/ipv4/igmp.c

350 	struct sk_buff *skb;
362 		skb = alloc_skb(size + hlen + tlen,
364 		if (skb)
370 	skb->priority = TC_PRIO_CONTROL;
376 		kfree_skb(skb);
380 	skb_dst_set(skb, &rt->dst);
381 	skb->dev = dev;
383 	skb_reserve(skb, hlen);
384 	skb_tailroom_reserve(skb, mtu, tlen);
386 	skb_reset_network_header(skb);
387 	pip = ip_hdr(skb);
388 	skb_put(skb, sizeof(struct iphdr) + 4);
403 	ip_select_ident(net, skb, NULL);
409 	skb->transport_header = skb->network_header + sizeof(struct iphdr) + 4;
410 	skb_put(skb, sizeof(*pig));
411 	pig = igmpv3_report_hdr(skb);
417 	return skb;
420 static int igmpv3_sendpack(struct sk_buff *skb)
422 	struct igmphdr *pig = igmp_hdr(skb);
423 	const int igmplen = skb_tail_pointer(skb) - skb_transport_header(skb);
425 	pig->csum = ip_compute_csum(igmp_hdr(skb), igmplen);
427 	return ip_local_out(dev_net(skb_dst(skb)->dev), skb->sk, skb);
435 static struct sk_buff *add_grhead(struct sk_buff *skb, struct ip_mc_list *pmc,
442 	if (!skb) {
443 		skb = igmpv3_newpack(dev, mtu);
444 		if (!skb)
447 	pgr = skb_put(skb, sizeof(struct igmpv3_grec));
452 	pih = igmpv3_report_hdr(skb);
455 	return skb;
458 #define AVAILABLE(skb)	((skb) ? skb_availroom(skb) : 0)
460 static struct sk_buff *add_grec(struct sk_buff *skb, struct ip_mc_list *pmc,
472 		return skb;
475 		return skb;
479 		return skb;
493 	pih = skb ? igmpv3_report_hdr(skb) : NULL;
498 		    AVAILABLE(skb) < grec_size(pmc, type, gdeleted, sdeleted)) {
499 			if (skb)
500 				igmpv3_sendpack(skb);
501 			skb = igmpv3_newpack(dev, mtu);
529 		if (AVAILABLE(skb) < sizeof(__be32) +
535 			if (skb)
536 				igmpv3_sendpack(skb);
537 			skb = igmpv3_newpack(dev, mtu);
542 			skb = add_grhead(skb, pmc, type, &pgr, mtu);
545 		if (!skb)
547 		psrc = skb_put(skb, sizeof(__be32));
570 			return skb;
573 			if (skb && AVAILABLE(skb) < sizeof(struct igmpv3_grec)) {
574 				igmpv3_sendpack(skb);
575 				skb = NULL; /* add_grhead will get a new one */
577 			skb = add_grhead(skb, pmc, type, &pgr, mtu);
585 	return skb;
590 	struct sk_buff *skb = NULL;
607 			skb = add_grec(skb, pmc, type, 0, 0);
617 		skb = add_grec(skb, pmc, type, 0, 0);
620 	if (!skb)
622 	return igmpv3_sendpack(skb);
656 	struct sk_buff *skb = NULL;
669 			skb = add_grec(skb, pmc, type, 1, 0);
670 			skb = add_grec(skb, pmc, dtype, 1, 1);
675 				skb = add_grec(skb, pmc, type, 1, 0);
705 		skb = add_grec(skb, pmc, type, 0, 0);
706 		skb = add_grec(skb, pmc, dtype, 0, 1);	/* deleted sources */
714 			skb = add_grec(skb, pmc, type, 0, 0);
721 	if (!skb)
723 	(void) igmpv3_sendpack(skb);
729 	struct sk_buff *skb;
760 	skb = alloc_skb(IGMP_SIZE + hlen + tlen, GFP_ATOMIC);
761 	if (!skb) {
765 	skb->priority = TC_PRIO_CONTROL;
767 	skb_dst_set(skb, &rt->dst);
769 	skb_reserve(skb, hlen);
771 	skb_reset_network_header(skb);
772 	iph = ip_hdr(skb);
773 	skb_put(skb, sizeof(struct iphdr) + 4);
783 	ip_select_ident(net, skb, NULL);
789 	ih = skb_put(skb, sizeof(struct igmphdr));
796 	return ip_local_out(net, skb->sk, skb);
944 static bool igmp_heard_query(struct in_device *in_dev, struct sk_buff *skb,
947 	struct igmphdr 		*ih = igmp_hdr(skb);
948 	struct igmpv3_query *ih3 = igmpv3_query_hdr(skb);
995 		if (!pskb_may_pull(skb, sizeof(struct igmpv3_query)))
998 		ih3 = igmpv3_query_hdr(skb);
1000 			if (!pskb_may_pull(skb, sizeof(struct igmpv3_query)
1003 			ih3 = igmpv3_query_hdr(skb);
1072 int igmp_rcv(struct sk_buff *skb)
1076 	struct net_device *dev = skb->dev;
1078 	int len = skb->len;
1082 		dev = dev_get_by_index_rcu(dev_net(dev), IPCB(skb)->iif);
1091 	if (!pskb_may_pull(skb, sizeof(struct igmphdr)))
1094 	if (skb_checksum_simple_validate(skb))
1097 	ih = igmp_hdr(skb);
1100 		dropped = igmp_heard_query(in_dev, skb, len);
1105 		if (rt_is_output_route(skb_rtable(skb)))
1108 		if (skb->pkt_type == PACKET_MULTICAST ||
1109 		    skb->pkt_type == PACKET_BROADCAST)
1114 		return pim_rcv_v1(skb);
1129 		kfree_skb(skb);
1131 		consume_skb(skb);
1497 static int ip_mc_check_iphdr(struct sk_buff *skb)
1501 	unsigned int offset = skb_network_offset(skb) + sizeof(*iph);
1503 	if (!pskb_may_pull(skb, offset))
1506 	iph = ip_hdr(skb);
1508 	if (iph->version != 4 || ip_hdrlen(skb) < sizeof(*iph))
1511 	offset += ip_hdrlen(skb) - sizeof(*iph);
1513 	if (!pskb_may_pull(skb, offset))
1516 	iph = ip_hdr(skb);
1521 	len = skb_network_offset(skb) + ntohs(iph->tot_len);
1522 	if (skb->len < len || len < offset)
1525 	skb_set_transport_header(skb, offset);
1530 static int ip_mc_check_igmp_reportv3(struct sk_buff *skb)
1532 	unsigned int len = skb_transport_offset(skb);
1536 	return ip_mc_may_pull(skb, len) ? 0 : -EINVAL;
1539 static int ip_mc_check_igmp_query(struct sk_buff *skb)
1541 	unsigned int transport_len = ip_transport_len(skb);
1550 		len = skb_transport_offset(skb) + sizeof(struct igmpv3_query);
1551 		if (!ip_mc_may_pull(skb, len))
1558 	if (!igmp_hdr(skb)->group &&
1559 	    ip_hdr(skb)->daddr != htonl(INADDR_ALLHOSTS_GROUP))
1565 static int ip_mc_check_igmp_msg(struct sk_buff *skb)
1567 	switch (igmp_hdr(skb)->type) {
1573 		return ip_mc_check_igmp_reportv3(skb);
1575 		return ip_mc_check_igmp_query(skb);
1581 static __sum16 ip_mc_validate_checksum(struct sk_buff *skb)
1583 	return skb_checksum_simple_validate(skb);
1586 static int ip_mc_check_igmp_csum(struct sk_buff *skb)
1588 	unsigned int len = skb_transport_offset(skb) + sizeof(struct igmphdr);
1589 	unsigned int transport_len = ip_transport_len(skb);
1592 	if (!ip_mc_may_pull(skb, len))
1595 	skb_chk = skb_checksum_trimmed(skb, transport_len,
1600 	if (skb_chk != skb)
1608  * @skb: the skb to validate
1611  * skb transport header accordingly and returns zero.
1618  * Caller needs to set the skb network header and free any returned skb if it
1619  * differs from the provided skb.
1621 int ip_mc_check_igmp(struct sk_buff *skb)
1623 	int ret = ip_mc_check_iphdr(skb);
1628 	if (ip_hdr(skb)->protocol != IPPROTO_IGMP)
1631 	ret = ip_mc_check_igmp_csum(skb);
1635 	return ip_mc_check_igmp_msg(skb);