diff options
Diffstat (limited to 'net/rxrpc/peer_event.c')
| -rw-r--r-- | net/rxrpc/peer_event.c | 636 |
1 files changed, 636 insertions, 0 deletions
diff --git a/net/rxrpc/peer_event.c b/net/rxrpc/peer_event.c new file mode 100644 index 000000000..32561e956 --- /dev/null +++ b/net/rxrpc/peer_event.c @@ -0,0 +1,636 @@ +// SPDX-License-Identifier: GPL-2.0-or-later +/* Peer event handling, typically ICMP messages. + * + * Copyright (C) 2007 Red Hat, Inc. All Rights Reserved. + * Written by David Howells (dhowells@redhat.com) + */ + +#include <linux/module.h> +#include <linux/net.h> +#include <linux/skbuff.h> +#include <linux/errqueue.h> +#include <linux/udp.h> +#include <linux/in.h> +#include <linux/in6.h> +#include <linux/icmp.h> +#include <net/sock.h> +#include <net/af_rxrpc.h> +#include <net/ip.h> +#include <net/icmp.h> +#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, + unsigned int udp_offset, + unsigned int *info, + struct sockaddr_rxrpc *srx) +{ + struct iphdr *ip, *ip0 = ip_hdr(skb); + struct icmphdr *icmp = icmp_hdr(skb); + struct udphdr *udp = (struct udphdr *)(skb->data + udp_offset); + + _enter("%u,%u,%u", ip0->protocol, icmp->type, icmp->code); + + switch (icmp->type) { + case ICMP_DEST_UNREACH: + *info = ntohs(icmp->un.frag.mtu); + fallthrough; + 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->dest; + 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->dest; + 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, + unsigned int udp_offset, + unsigned int *info, + struct sockaddr_rxrpc *srx) +{ + struct icmp6hdr *icmp = icmp6_hdr(skb); + struct ipv6hdr *ip, *ip0 = ipv6_hdr(skb); + struct udphdr *udp = (struct udphdr *)(skb->data + udp_offset); + + _enter("%u,%u,%u", ip0->nexthdr, icmp->icmp6_type, icmp->icmp6_code); + + switch (icmp->icmp6_type) { + case ICMPV6_DEST_UNREACH: + *info = ntohl(icmp->icmp6_mtu); + fallthrough; + 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->dest; + 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->dest; + 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, + unsigned int udp_offset) +{ + struct sock_extended_err ee; + struct sockaddr_rxrpc srx; + struct rxrpc_local *local; + struct rxrpc_peer *peer; + unsigned int info = 0; + int err; + 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, udp_offset, + &info, &srx); + break; +#ifdef CONFIG_AF_RXRPC_IPV6 + case 6: + peer = rxrpc_lookup_peer_icmp6_rcu(local, skb, udp_offset, + &info, &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: + switch (type) { + case ICMP_DEST_UNREACH: + switch (code) { + case ICMP_FRAG_NEEDED: + rxrpc_adjust_mtu(peer, info); + rcu_read_unlock(); + rxrpc_put_peer(peer); + return; + default: + break; + } + + err = EHOSTUNREACH; + if (code <= NR_ICMP_UNREACH) { + /* Might want to do something different with + * non-fatal errors + */ + //harderr = icmp_err_convert[code].fatal; + err = icmp_err_convert[code].errno; + } + break; + + case ICMP_TIME_EXCEEDED: + err = EHOSTUNREACH; + break; + default: + err = EPROTO; + break; + } + + 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: + switch (type) { + case ICMPV6_PKT_TOOBIG: + rxrpc_adjust_mtu(peer, info); + rcu_read_unlock(); + rxrpc_put_peer(peer); + return; + } + + icmpv6_err_convert(type, code, &err); + + 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. + */ +static struct rxrpc_peer *rxrpc_lookup_peer_local_rcu(struct rxrpc_local *local, + const struct sk_buff *skb, + struct sockaddr_rxrpc *srx) +{ + struct sock_exterr_skb *serr = SKB_EXT_ERR(skb); + + _enter(""); + + 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; + + switch (srx->transport.family) { + case AF_INET: + srx->transport_len = sizeof(srx->transport.sin); + srx->transport.family = AF_INET; + srx->transport.sin.sin_port = serr->port; + switch (serr->ee.ee_origin) { + case SO_EE_ORIGIN_ICMP: + _net("Rx ICMP"); + memcpy(&srx->transport.sin.sin_addr, + skb_network_header(skb) + serr->addr_offset, + sizeof(struct in_addr)); + break; + case SO_EE_ORIGIN_ICMP6: + _net("Rx ICMP6 on v4 sock"); + memcpy(&srx->transport.sin.sin_addr, + skb_network_header(skb) + serr->addr_offset + 12, + sizeof(struct in_addr)); + break; + default: + memcpy(&srx->transport.sin.sin_addr, &ip_hdr(skb)->saddr, + sizeof(struct in_addr)); + break; + } + break; + +#ifdef CONFIG_AF_RXRPC_IPV6 + case AF_INET6: + switch (serr->ee.ee_origin) { + case SO_EE_ORIGIN_ICMP6: + _net("Rx ICMP6"); + srx->transport.sin6.sin6_port = serr->port; + memcpy(&srx->transport.sin6.sin6_addr, + skb_network_header(skb) + serr->addr_offset, + sizeof(struct in6_addr)); + break; + case SO_EE_ORIGIN_ICMP: + _net("Rx ICMP on v6 sock"); + srx->transport_len = sizeof(srx->transport.sin); + srx->transport.family = AF_INET; + srx->transport.sin.sin_port = serr->port; + memcpy(&srx->transport.sin.sin_addr, + skb_network_header(skb) + serr->addr_offset, + sizeof(struct in_addr)); + break; + default: + memcpy(&srx->transport.sin6.sin6_addr, + &ipv6_hdr(skb)->saddr, + sizeof(struct in6_addr)); + break; + } + break; +#endif + + default: + BUG(); + } + + return rxrpc_lookup_peer_rcu(local, srx); +} + +/* + * Handle an MTU/fragmentation problem. + */ +static void rxrpc_adjust_mtu(struct rxrpc_peer *peer, unsigned int mtu) +{ + _net("Rx ICMP Fragmentation Needed (%d)", mtu); + + /* wind down the local interface MTU */ + if (mtu > 0 && peer->if_mtu == 65535 && mtu < peer->if_mtu) { + peer->if_mtu = mtu; + _net("I/F MTU %u", mtu); + } + + if (mtu == 0) { + /* they didn't give us a size, estimate one */ + mtu = peer->if_mtu; + if (mtu > 1500) { + mtu >>= 1; + if (mtu < 1500) + mtu = 1500; + } else { + mtu -= 100; + if (mtu < peer->hdrsize) + mtu = peer->hdrsize + 4; + } + } + + if (mtu < peer->mtu) { + spin_lock_bh(&peer->lock); + peer->mtu = mtu; + peer->maxdata = peer->mtu - peer->hdrsize; + spin_unlock_bh(&peer->lock); + _net("Net MTU %u (maxdata %u)", + peer->mtu, peer->maxdata); + } +} + +/* + * Handle an error received on the local endpoint. + */ +void rxrpc_error_report(struct sock *sk) +{ + struct sock_exterr_skb *serr; + struct sockaddr_rxrpc srx; + struct rxrpc_local *local; + struct rxrpc_peer *peer = NULL; + struct sk_buff *skb; + + rcu_read_lock(); + local = rcu_dereference_sk_user_data(sk); + if (unlikely(!local)) { + rcu_read_unlock(); + return; + } + _enter("%p{%d}", sk, local->debug_id); + + /* Clear the outstanding error value on the socket so that it doesn't + * cause kernel_sendmsg() to return it later. + */ + sock_error(sk); + + skb = sock_dequeue_err_skb(sk); + if (!skb) { + rcu_read_unlock(); + _leave("UDP socket errqueue empty"); + return; + } + 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); + } + } + + rcu_read_unlock(); + rxrpc_free_skb(skb, rxrpc_skb_freed); + rxrpc_put_peer(peer); + _leave(""); +} + +/* + * Map an error report to error codes on the peer record. + */ +static void rxrpc_store_error(struct rxrpc_peer *peer, + struct sock_exterr_skb *serr) +{ + enum rxrpc_call_completion compl = RXRPC_CALL_NETWORK_ERROR; + struct sock_extended_err *ee; + int err; + + _enter(""); + + ee = &serr->ee; + + err = ee->ee_errno; + + switch (ee->ee_origin) { + case SO_EE_ORIGIN_ICMP: + switch (ee->ee_type) { + case ICMP_DEST_UNREACH: + switch (ee->ee_code) { + case ICMP_NET_UNREACH: + _net("Rx Received ICMP Network Unreachable"); + break; + case ICMP_HOST_UNREACH: + _net("Rx Received ICMP Host Unreachable"); + break; + case ICMP_PORT_UNREACH: + _net("Rx Received ICMP Port Unreachable"); + break; + case ICMP_NET_UNKNOWN: + _net("Rx Received ICMP Unknown Network"); + break; + case ICMP_HOST_UNKNOWN: + _net("Rx Received ICMP Unknown Host"); + break; + default: + _net("Rx Received ICMP DestUnreach code=%u", + ee->ee_code); + break; + } + break; + + case ICMP_TIME_EXCEEDED: + _net("Rx Received ICMP TTL Exceeded"); + break; + + default: + _proto("Rx Received ICMP error { type=%u code=%u }", + ee->ee_type, ee->ee_code); + break; + } + break; + + case SO_EE_ORIGIN_NONE: + case SO_EE_ORIGIN_LOCAL: + _proto("Rx Received local error { error=%d }", err); + compl = RXRPC_CALL_LOCAL_ERROR; + break; + + case SO_EE_ORIGIN_ICMP6: + if (err == EACCES) + err = EHOSTUNREACH; + fallthrough; + default: + _proto("Rx Received error report { orig=%u }", ee->ee_origin); + break; + } + + rxrpc_distribute_error(peer, err, compl); +} + +/* + * Distribute an error that occurred on a peer. + */ +static void rxrpc_distribute_error(struct rxrpc_peer *peer, int error, + enum rxrpc_call_completion compl) +{ + struct rxrpc_call *call; + + hlist_for_each_entry_rcu(call, &peer->error_targets, error_link) { + rxrpc_see_call(call); + rxrpc_set_call_completion(call, compl, 0, -error); + } +} + +/* + * Perform keep-alive pings. + */ +static void rxrpc_peer_keepalive_dispatch(struct rxrpc_net *rxnet, + struct list_head *collector, + time64_t base, + u8 cursor) +{ + struct rxrpc_peer *peer; + const u8 mask = ARRAY_SIZE(rxnet->peer_keepalive) - 1; + time64_t keepalive_at; + int slot; + + spin_lock_bh(&rxnet->peer_hash_lock); + + while (!list_empty(collector)) { + peer = list_entry(collector->next, + struct rxrpc_peer, keepalive_link); + + list_del_init(&peer->keepalive_link); + if (!rxrpc_get_peer_maybe(peer)) + continue; + + if (__rxrpc_use_local(peer->local)) { + spin_unlock_bh(&rxnet->peer_hash_lock); + + keepalive_at = peer->last_tx_at + RXRPC_KEEPALIVE_TIME; + slot = keepalive_at - base; + _debug("%02x peer %u t=%d {%pISp}", + cursor, peer->debug_id, slot, &peer->srx.transport); + + if (keepalive_at <= base || + keepalive_at > base + RXRPC_KEEPALIVE_TIME) { + rxrpc_send_keepalive(peer); + slot = RXRPC_KEEPALIVE_TIME; + } + + /* A transmission to this peer occurred since last we + * examined it so put it into the appropriate future + * bucket. + */ + slot += cursor; + slot &= mask; + spin_lock_bh(&rxnet->peer_hash_lock); + list_add_tail(&peer->keepalive_link, + &rxnet->peer_keepalive[slot & mask]); + rxrpc_unuse_local(peer->local); + } + rxrpc_put_peer_locked(peer); + } + + spin_unlock_bh(&rxnet->peer_hash_lock); +} + +/* + * Perform keep-alive pings with VERSION packets to keep any NAT alive. + */ +void rxrpc_peer_keepalive_worker(struct work_struct *work) +{ + struct rxrpc_net *rxnet = + container_of(work, struct rxrpc_net, peer_keepalive_work); + const u8 mask = ARRAY_SIZE(rxnet->peer_keepalive) - 1; + time64_t base, now, delay; + u8 cursor, stop; + LIST_HEAD(collector); + + now = ktime_get_seconds(); + base = rxnet->peer_keepalive_base; + cursor = rxnet->peer_keepalive_cursor; + _enter("%lld,%u", base - now, cursor); + + if (!rxnet->live) + return; + + /* Remove to a temporary list all the peers that are currently lodged + * in expired buckets plus all new peers. + * + * Everything in the bucket at the cursor is processed this + * second; the bucket at cursor + 1 goes at now + 1s and so + * on... + */ + spin_lock_bh(&rxnet->peer_hash_lock); + list_splice_init(&rxnet->peer_keepalive_new, &collector); + + stop = cursor + ARRAY_SIZE(rxnet->peer_keepalive); + while (base <= now && (s8)(cursor - stop) < 0) { + list_splice_tail_init(&rxnet->peer_keepalive[cursor & mask], + &collector); + base++; + cursor++; + } + + base = now; + spin_unlock_bh(&rxnet->peer_hash_lock); + + rxnet->peer_keepalive_base = base; + rxnet->peer_keepalive_cursor = cursor; + rxrpc_peer_keepalive_dispatch(rxnet, &collector, base, cursor); + ASSERT(list_empty(&collector)); + + /* Schedule the timer for the next occupied timeslot. */ + cursor = rxnet->peer_keepalive_cursor; + stop = cursor + RXRPC_KEEPALIVE_TIME - 1; + for (; (s8)(cursor - stop) < 0; cursor++) { + if (!list_empty(&rxnet->peer_keepalive[cursor & mask])) + break; + base++; + } + + now = ktime_get_seconds(); + delay = base - now; + if (delay < 1) + delay = 1; + delay *= HZ; + if (rxnet->live) + timer_reduce(&rxnet->peer_keepalive_timer, jiffies + delay); + + _leave(""); +} |