ping_v6_sendmsg never sets flowi6_oif, so it is not possible to ping an IPv6 address on a different interface. Instead, it sets flowi6_iif, which is incorrect but harmless. Also, it returns an error if a passed-in scope ID doesn't match sk_bound_dev_if.
Get rid of the error, 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: Lorenzo Colitti <lore...@google.com> --- net/ipv6/ping.c | 29 +++++++++++++++-------------- 1 file changed, 15 insertions(+), 14 deletions(-) diff --git a/net/ipv6/ping.c b/net/ipv6/ping.c index fed40d1..eabf1ea 100644 --- a/net/ipv6/ping.c +++ b/net/ipv6/ping.c @@ -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; @@ -78,23 +78,28 @@ 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)) + fl6.flowi6_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) + if (__ipv6_addr_needs_scope_id(addr_type) && !oif) return -EINVAL; if (addr_type & IPV6_ADDR_MAPPED) return -EINVAL; @@ -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); -- 2.8.0.rc3.226.g39d4020
