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Commit 5e457896 authored by Lorenzo Colitti's avatar Lorenzo Colitti Committed by David S. Miller
Browse files

net: ipv6: Fix ping to link-local addresses. 

ping_v6_sendmsg does not set flowi6_oif in response to
sin6_scope_id or sk_bound_dev_if, so it is not possible to use
these APIs to ping an IPv6 address on a different interface.
Instead, it sets flowi6_iif, which is incorrect but harmless.

Stop setting flowi6_iif, and support various ways of setting oif
in the same priority order used by udpv6_sendmsg.

Tested: https://android-review.googlesource.com/#/c/254470/


Signed-off-by: default avatarLorenzo Colitti <lorenzo@google.com>
Signed-off-by: default avatarDavid S. Miller <davem@davemloft.net>
parent 12311959

net/ipv6/ping.c

+17 −16
Original line number Diff line number Diff line
@@ -55,7 +55,7 @@ static int ping_v6_sendmsg(struct sock *sk, struct msghdr *msg, size_t len) 
	struct icmp6hdr user_icmph;

	int addr_type;

	struct in6_addr *daddr;

	int iif = 0;

	int oif = 0;

	struct flowi6 fl6;

	int err;

	struct dst_entry *dst;
@@ -78,25 +78,30 @@ static int ping_v6_sendmsg(struct sock *sk, struct msghdr *msg, size_t len) 
		if (u->sin6_family != AF_INET6) {

			return -EAFNOSUPPORT;

		}

		if (sk->sk_bound_dev_if &&

		    sk->sk_bound_dev_if != u->sin6_scope_id) {

			return -EINVAL;

		}

		daddr = &(u->sin6_addr);

		iif = u->sin6_scope_id;

		if (__ipv6_addr_needs_scope_id(ipv6_addr_type(daddr)))

			oif = u->sin6_scope_id;

	} else {

		if (sk->sk_state != TCP_ESTABLISHED)

			return -EDESTADDRREQ;

		daddr = &sk->sk_v6_daddr;

	}



	if (!iif)

		iif = sk->sk_bound_dev_if;

	if (!oif)

		oif = sk->sk_bound_dev_if;



	if (!oif)

		oif = np->sticky_pktinfo.ipi6_ifindex;



	if (!oif && ipv6_addr_is_multicast(daddr))

		oif = np->mcast_oif;

	else if (!oif)

		oif = np->ucast_oif;



	addr_type = ipv6_addr_type(daddr);

	if (__ipv6_addr_needs_scope_id(addr_type) && !iif)

		return -EINVAL;

	if (addr_type & IPV6_ADDR_MAPPED)

	if ((__ipv6_addr_needs_scope_id(addr_type) && !oif) ||

	    (addr_type & IPV6_ADDR_MAPPED) ||

	    (oif && sk->sk_bound_dev_if && oif != sk->sk_bound_dev_if))

		return -EINVAL;



	/* TODO: use ip6_datagram_send_ctl to get options from cmsg */
@@ -106,16 +111,12 @@ static int ping_v6_sendmsg(struct sock *sk, struct msghdr *msg, size_t len) 
	fl6.flowi6_proto = IPPROTO_ICMPV6;

	fl6.saddr = np->saddr;

	fl6.daddr = *daddr;

	fl6.flowi6_oif = oif;

	fl6.flowi6_mark = sk->sk_mark;

	fl6.fl6_icmp_type = user_icmph.icmp6_type;

	fl6.fl6_icmp_code = user_icmph.icmp6_code;

	security_sk_classify_flow(sk, flowi6_to_flowi(&fl6));



	if (!fl6.flowi6_oif && ipv6_addr_is_multicast(&fl6.daddr))

		fl6.flowi6_oif = np->mcast_oif;

	else if (!fl6.flowi6_oif)

		fl6.flowi6_oif = np->ucast_oif;



	ipc6.tclass = np->tclass;

	fl6.flowlabel = ip6_make_flowinfo(ipc6.tclass, fl6.flowlabel);