From b6c66c4324e7dd66a06a6a034204ae7d4e95c28c Mon Sep 17 00:00:00 2001 From: David Howells Date: Wed, 12 Oct 2022 09:51:12 +0100 Subject: [PATCH] rxrpc: Use the core ICMP/ICMP6 parsers Make rxrpc_encap_rcv_err() pass the ICMP/ICMP6 skbuff to ip_icmp_error() or ipv6_icmp_error() as appropriate to do the parsing rather than trying to do it in rxrpc. This pushes an error report onto the UDP socket's error queue and calls ->sk_error_report() from which point rxrpc can pick it up. It would be preferable to steal the packet directly from ip*_icmp_error() rather than letting it get queued, but this is probably good enough. Also note that __udp4_lib_err() calls sk_error_report() twice in some cases. Signed-off-by: David Howells cc: Marc Dionne cc: linux-afs@lists.infradead.org --- net/rxrpc/ar-internal.h | 1 - net/rxrpc/local_object.c | 13 +++ net/rxrpc/peer_event.c | 247 +++++---------------------------------- 3 files changed, 43 insertions(+), 218 deletions(-) diff --git a/net/rxrpc/ar-internal.h b/net/rxrpc/ar-internal.h index 51270b2e49c3..ba0ee5d1c723 100644 --- a/net/rxrpc/ar-internal.h +++ b/net/rxrpc/ar-internal.h @@ -998,7 +998,6 @@ void rxrpc_send_keepalive(struct rxrpc_peer *); /* * peer_event.c */ -void rxrpc_encap_err_rcv(struct sock *, struct sk_buff *, int, __be16, u32, u8 *); void rxrpc_error_report(struct sock *); void rxrpc_peer_keepalive_worker(struct work_struct *); diff --git a/net/rxrpc/local_object.c b/net/rxrpc/local_object.c index 38ea98ff426b..e95e75e785fb 100644 --- a/net/rxrpc/local_object.c +++ b/net/rxrpc/local_object.c @@ -23,6 +23,19 @@ static void rxrpc_local_processor(struct work_struct *); static void rxrpc_local_rcu(struct rcu_head *); +/* + * Handle an ICMP/ICMP6 error turning up at the tunnel. Push it through the + * usual mechanism so that it gets parsed and presented through the UDP + * socket's error_report(). + */ +static void rxrpc_encap_err_rcv(struct sock *sk, struct sk_buff *skb, int err, + __be16 port, u32 info, u8 *payload) +{ + if (ip_hdr(skb)->version == IPVERSION) + return ip_icmp_error(sk, skb, err, port, info, payload); + return ipv6_icmp_error(sk, skb, err, port, info, payload); +} + /* * Compare a local to an address. Return -ve, 0 or +ve to indicate less than, * same or greater than. diff --git a/net/rxrpc/peer_event.c b/net/rxrpc/peer_event.c index d7d6d7aff985..cda3890657a9 100644 --- a/net/rxrpc/peer_event.c +++ b/net/rxrpc/peer_event.c @@ -16,220 +16,12 @@ #include #include #include -#include #include "ar-internal.h" -static void rxrpc_adjust_mtu(struct rxrpc_peer *, unsigned int); static void rxrpc_store_error(struct rxrpc_peer *, struct sock_exterr_skb *); static void rxrpc_distribute_error(struct rxrpc_peer *, int, enum rxrpc_call_completion); -/* - * Find the peer associated with an ICMPv4 packet. - */ -static struct rxrpc_peer *rxrpc_lookup_peer_icmp_rcu(struct rxrpc_local *local, - struct sk_buff *skb, - __be16 udp_port, - struct sockaddr_rxrpc *srx) -{ - struct iphdr *ip, *ip0 = ip_hdr(skb); - struct icmphdr *icmp = icmp_hdr(skb); - - _enter("%u,%u,%u", ip0->protocol, icmp->type, icmp->code); - - switch (icmp->type) { - case ICMP_DEST_UNREACH: - case ICMP_TIME_EXCEEDED: - case ICMP_PARAMETERPROB: - ip = (struct iphdr *)((void *)icmp + 8); - break; - default: - return NULL; - } - - memset(srx, 0, sizeof(*srx)); - srx->transport_type = local->srx.transport_type; - srx->transport_len = local->srx.transport_len; - srx->transport.family = local->srx.transport.family; - - /* Can we see an ICMP4 packet on an ICMP6 listening socket? and vice - * versa? - */ - switch (srx->transport.family) { - case AF_INET: - srx->transport_len = sizeof(srx->transport.sin); - srx->transport.family = AF_INET; - srx->transport.sin.sin_port = udp_port; - memcpy(&srx->transport.sin.sin_addr, &ip->daddr, - sizeof(struct in_addr)); - break; - -#ifdef CONFIG_AF_RXRPC_IPV6 - case AF_INET6: - srx->transport_len = sizeof(srx->transport.sin); - srx->transport.family = AF_INET; - srx->transport.sin.sin_port = udp_port; - memcpy(&srx->transport.sin.sin_addr, &ip->daddr, - sizeof(struct in_addr)); - break; -#endif - - default: - WARN_ON_ONCE(1); - return NULL; - } - - _net("ICMP {%pISp}", &srx->transport); - return rxrpc_lookup_peer_rcu(local, srx); -} - -#ifdef CONFIG_AF_RXRPC_IPV6 -/* - * Find the peer associated with an ICMPv6 packet. - */ -static struct rxrpc_peer *rxrpc_lookup_peer_icmp6_rcu(struct rxrpc_local *local, - struct sk_buff *skb, - __be16 udp_port, - struct sockaddr_rxrpc *srx) -{ - struct icmp6hdr *icmp = icmp6_hdr(skb); - struct ipv6hdr *ip, *ip0 = ipv6_hdr(skb); - - _enter("%u,%u,%u", ip0->nexthdr, icmp->icmp6_type, icmp->icmp6_code); - - switch (icmp->icmp6_type) { - case ICMPV6_DEST_UNREACH: - case ICMPV6_PKT_TOOBIG: - case ICMPV6_TIME_EXCEED: - case ICMPV6_PARAMPROB: - ip = (struct ipv6hdr *)((void *)icmp + 8); - break; - default: - return NULL; - } - - memset(srx, 0, sizeof(*srx)); - srx->transport_type = local->srx.transport_type; - srx->transport_len = local->srx.transport_len; - srx->transport.family = local->srx.transport.family; - - /* Can we see an ICMP4 packet on an ICMP6 listening socket? and vice - * versa? - */ - switch (srx->transport.family) { - case AF_INET: - _net("Rx ICMP6 on v4 sock"); - srx->transport_len = sizeof(srx->transport.sin); - srx->transport.family = AF_INET; - srx->transport.sin.sin_port = udp_port; - memcpy(&srx->transport.sin.sin_addr, - &ip->daddr.s6_addr32[3], sizeof(struct in_addr)); - break; - case AF_INET6: - _net("Rx ICMP6"); - srx->transport.sin.sin_port = udp_port; - memcpy(&srx->transport.sin6.sin6_addr, &ip->daddr, - sizeof(struct in6_addr)); - break; - default: - WARN_ON_ONCE(1); - return NULL; - } - - _net("ICMP {%pISp}", &srx->transport); - return rxrpc_lookup_peer_rcu(local, srx); -} -#endif /* CONFIG_AF_RXRPC_IPV6 */ - -/* - * Handle an error received on the local endpoint as a tunnel. - */ -void rxrpc_encap_err_rcv(struct sock *sk, struct sk_buff *skb, int err, - __be16 port, u32 info, u8 *payload) -{ - struct sock_extended_err ee; - struct sockaddr_rxrpc srx; - struct rxrpc_local *local; - struct rxrpc_peer *peer; - u8 version = ip_hdr(skb)->version; - u8 type = icmp_hdr(skb)->type; - u8 code = icmp_hdr(skb)->code; - - rcu_read_lock(); - local = rcu_dereference_sk_user_data(sk); - if (unlikely(!local)) { - rcu_read_unlock(); - return; - } - - rxrpc_new_skb(skb, rxrpc_skb_received); - - switch (ip_hdr(skb)->version) { - case IPVERSION: - peer = rxrpc_lookup_peer_icmp_rcu(local, skb, port, &srx); - break; -#ifdef CONFIG_AF_RXRPC_IPV6 - case 6: - peer = rxrpc_lookup_peer_icmp6_rcu(local, skb, port, &srx); - break; -#endif - default: - rcu_read_unlock(); - return; - } - - if (peer && !rxrpc_get_peer_maybe(peer)) - peer = NULL; - if (!peer) { - rcu_read_unlock(); - return; - } - - memset(&ee, 0, sizeof(ee)); - - switch (version) { - case IPVERSION: - if (type == ICMP_DEST_UNREACH && - code == ICMP_FRAG_NEEDED) { - rxrpc_adjust_mtu(peer, info); - rcu_read_unlock(); - rxrpc_put_peer(peer); - return; - } - - ee.ee_origin = SO_EE_ORIGIN_ICMP; - ee.ee_type = type; - ee.ee_code = code; - ee.ee_errno = err; - break; - -#ifdef CONFIG_AF_RXRPC_IPV6 - case 6: - if (type == ICMPV6_PKT_TOOBIG) { - rxrpc_adjust_mtu(peer, info); - rcu_read_unlock(); - rxrpc_put_peer(peer); - return; - } - - if (err == EACCES) - err = EHOSTUNREACH; - - ee.ee_origin = SO_EE_ORIGIN_ICMP6; - ee.ee_type = type; - ee.ee_code = code; - ee.ee_errno = err; - break; -#endif - } - - trace_rxrpc_rx_icmp(peer, &ee, &srx); - - rxrpc_distribute_error(peer, err, RXRPC_CALL_NETWORK_ERROR); - rcu_read_unlock(); - rxrpc_put_peer(peer); -} - /* * Find the peer associated with a local error. */ @@ -246,6 +38,9 @@ static struct rxrpc_peer *rxrpc_lookup_peer_local_rcu(struct rxrpc_local *local, srx->transport_len = local->srx.transport_len; srx->transport.family = local->srx.transport.family; + /* Can we see an ICMP4 packet on an ICMP6 listening socket? and vice + * versa? + */ switch (srx->transport.family) { case AF_INET: srx->transport_len = sizeof(srx->transport.sin); @@ -375,20 +170,38 @@ void rxrpc_error_report(struct sock *sk) } rxrpc_new_skb(skb, rxrpc_skb_received); serr = SKB_EXT_ERR(skb); - - if (serr->ee.ee_origin == SO_EE_ORIGIN_LOCAL) { - peer = rxrpc_lookup_peer_local_rcu(local, skb, &srx); - if (peer && !rxrpc_get_peer_maybe(peer)) - peer = NULL; - if (peer) { - trace_rxrpc_rx_icmp(peer, &serr->ee, &srx); - rxrpc_store_error(peer, serr); - } + if (!skb->len && serr->ee.ee_origin == SO_EE_ORIGIN_TIMESTAMPING) { + _leave("UDP empty message"); + rcu_read_unlock(); + rxrpc_free_skb(skb, rxrpc_skb_freed); + return; } + peer = rxrpc_lookup_peer_local_rcu(local, skb, &srx); + if (peer && !rxrpc_get_peer_maybe(peer)) + peer = NULL; + if (!peer) { + rcu_read_unlock(); + rxrpc_free_skb(skb, rxrpc_skb_freed); + _leave(" [no peer]"); + return; + } + + trace_rxrpc_rx_icmp(peer, &serr->ee, &srx); + + if ((serr->ee.ee_origin == SO_EE_ORIGIN_ICMP && + serr->ee.ee_type == ICMP_DEST_UNREACH && + serr->ee.ee_code == ICMP_FRAG_NEEDED)) { + rxrpc_adjust_mtu(peer, serr->ee.ee_info); + goto out; + } + + rxrpc_store_error(peer, serr); +out: rcu_read_unlock(); rxrpc_free_skb(skb, rxrpc_skb_freed); rxrpc_put_peer(peer); + _leave(""); }