From ac56a0b48da86fd1b4389632fb7c4c8a5d86eefa Mon Sep 17 00:00:00 2001 From: David Howells Date: Fri, 26 Aug 2022 15:39:28 +0100 Subject: rxrpc: Fix ICMP/ICMP6 error handling Because rxrpc pretends to be a tunnel on top of a UDP/UDP6 socket, allowing it to siphon off UDP packets early in the handling of received UDP packets thereby avoiding the packet going through the UDP receive queue, it doesn't get ICMP packets through the UDP ->sk_error_report() callback. In fact, it doesn't appear that there's any usable option for getting hold of ICMP packets. Fix this by adding a new UDP encap hook to distribute error messages for UDP tunnels. If the hook is set, then the tunnel driver will be able to see ICMP packets. The hook provides the offset into the packet of the UDP header of the original packet that caused the notification. An alternative would be to call the ->error_handler() hook - but that requires that the skbuff be cloned (as ip_icmp_error() or ipv6_cmp_error() do, though isn't really necessary or desirable in rxrpc's case is we want to parse them there and then, not queue them). Changes ======= ver #3) - Fixed an uninitialised variable. ver #2) - Fixed some missing CONFIG_AF_RXRPC_IPV6 conditionals. Fixes: 5271953cad31 ("rxrpc: Use the UDP encap_rcv hook") Signed-off-by: David Howells --- net/ipv4/udp.c | 2 ++ 1 file changed, 2 insertions(+) (limited to 'net/ipv4/udp.c') diff --git a/net/ipv4/udp.c b/net/ipv4/udp.c index 34eda973bbf1..cd72158e953a 100644 --- a/net/ipv4/udp.c +++ b/net/ipv4/udp.c @@ -783,6 +783,8 @@ int __udp4_lib_err(struct sk_buff *skb, u32 info, struct udp_table *udptable) */ if (tunnel) { /* ...not for tunnels though: we don't have a sending socket */ + if (udp_sk(sk)->encap_err_rcv) + udp_sk(sk)->encap_err_rcv(sk, skb, iph->ihl << 2); goto out; } if (!inet->recverr) { -- cgit v1.2.3-59-g8ed1b