Commit c8715a8e authored by Paul Davey's avatar Paul Davey Committed by David S. Miller
Browse files

ipmr: Add high byte of VIF ID to igmpmsg 



Use the unused3 byte in struct igmpmsg to hold the high 8 bits of the
VIF ID.

If using more than 255 IPv4 multicast interfaces it is necessary to have
access to a VIF ID for cache reports that is wider than 8 bits, the VIF
ID present in the igmpmsg reports sent to mroute_sk was only 8 bits wide
in the igmpmsg header.  Adding the high 8 bits of the 16 bit VIF ID in
the unused byte allows use of more than 255 IPv4 multicast interfaces.

Signed-off-by: default avatarPaul Davey <paul.davey@alliedtelesis.co.nz>
Signed-off-by: default avatarDavid S. Miller <davem@davemloft.net>
parent 501cb008

include/uapi/linux/mroute.h

+2 −2
Original line number Diff line number Diff line
@@ -113,8 +113,8 @@ struct igmpmsg { 
	__u32 unused1,unused2;

	unsigned char im_msgtype;		/* What is this */

	unsigned char im_mbz;			/* Must be zero */

	unsigned char im_vif;			/* Interface (this ought to be a vifi_t!) */

	unsigned char unused3;

	unsigned char im_vif;			/* Low 8 bits of Interface */

	unsigned char im_vif_hi;		/* High 8 bits of Interface */

	struct in_addr im_src,im_dst;

};

net/ipv4/ipmr.c

+6 −2
Original line number Diff line number Diff line
@@ -1038,10 +1038,13 @@ static int ipmr_cache_report(struct mr_table *mrt, 
		memcpy(msg, skb_network_header(pkt), sizeof(struct iphdr));

		msg->im_msgtype = assert;

		msg->im_mbz = 0;

		if (assert == IGMPMSG_WRVIFWHOLE)

		if (assert == IGMPMSG_WRVIFWHOLE) {

			msg->im_vif = vifi;

		else

			msg->im_vif_hi = vifi >> 8;

		} else {

			msg->im_vif = mrt->mroute_reg_vif_num;

			msg->im_vif_hi = mrt->mroute_reg_vif_num >> 8;

		}

		ip_hdr(skb)->ihl = sizeof(struct iphdr) >> 2;

		ip_hdr(skb)->tot_len = htons(ntohs(ip_hdr(pkt)->tot_len) +

					     sizeof(struct iphdr));
@@ -1054,6 +1057,7 @@ static int ipmr_cache_report(struct mr_table *mrt, 
		ip_hdr(skb)->protocol = 0;

		msg = (struct igmpmsg *)skb_network_header(skb);

		msg->im_vif = vifi;

		msg->im_vif_hi = vifi >> 8;

		skb_dst_set(skb, dst_clone(skb_dst(pkt)));

		/* Add our header */

		igmp = skb_put(skb, sizeof(struct igmphdr));

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