diff options
Diffstat (limited to '')
| -rw-r--r-- | net/rxrpc/peer_object.c | 528 |
1 files changed, 528 insertions, 0 deletions
diff --git a/net/rxrpc/peer_object.c b/net/rxrpc/peer_object.c new file mode 100644 index 000000000..26d2ae9ba --- /dev/null +++ b/net/rxrpc/peer_object.c @@ -0,0 +1,528 @@ +// SPDX-License-Identifier: GPL-2.0-or-later +/* RxRPC remote transport endpoint record management + * + * Copyright (C) 2007, 2016 Red Hat, Inc. All Rights Reserved. + * Written by David Howells (dhowells@redhat.com) + */ + +#define pr_fmt(fmt) KBUILD_MODNAME ": " fmt + +#include <linux/module.h> +#include <linux/net.h> +#include <linux/skbuff.h> +#include <linux/udp.h> +#include <linux/in.h> +#include <linux/in6.h> +#include <linux/slab.h> +#include <linux/hashtable.h> +#include <net/sock.h> +#include <net/af_rxrpc.h> +#include <net/ip.h> +#include <net/route.h> +#include <net/ip6_route.h> +#include "ar-internal.h" + +/* + * Hash a peer key. + */ +static unsigned long rxrpc_peer_hash_key(struct rxrpc_local *local, + const struct sockaddr_rxrpc *srx) +{ + const u16 *p; + unsigned int i, size; + unsigned long hash_key; + + _enter(""); + + hash_key = (unsigned long)local / __alignof__(*local); + hash_key += srx->transport_type; + hash_key += srx->transport_len; + hash_key += srx->transport.family; + + switch (srx->transport.family) { + case AF_INET: + hash_key += (u16 __force)srx->transport.sin.sin_port; + size = sizeof(srx->transport.sin.sin_addr); + p = (u16 *)&srx->transport.sin.sin_addr; + break; +#ifdef CONFIG_AF_RXRPC_IPV6 + case AF_INET6: + hash_key += (u16 __force)srx->transport.sin.sin_port; + size = sizeof(srx->transport.sin6.sin6_addr); + p = (u16 *)&srx->transport.sin6.sin6_addr; + break; +#endif + default: + WARN(1, "AF_RXRPC: Unsupported transport address family\n"); + return 0; + } + + /* Step through the peer address in 16-bit portions for speed */ + for (i = 0; i < size; i += sizeof(*p), p++) + hash_key += *p; + + _leave(" 0x%lx", hash_key); + return hash_key; +} + +/* + * Compare a peer to a key. Return -ve, 0 or +ve to indicate less than, same + * or greater than. + * + * Unfortunately, the primitives in linux/hashtable.h don't allow for sorted + * buckets and mid-bucket insertion, so we don't make full use of this + * information at this point. + */ +static long rxrpc_peer_cmp_key(const struct rxrpc_peer *peer, + struct rxrpc_local *local, + const struct sockaddr_rxrpc *srx, + unsigned long hash_key) +{ + long diff; + + diff = ((peer->hash_key - hash_key) ?: + ((unsigned long)peer->local - (unsigned long)local) ?: + (peer->srx.transport_type - srx->transport_type) ?: + (peer->srx.transport_len - srx->transport_len) ?: + (peer->srx.transport.family - srx->transport.family)); + if (diff != 0) + return diff; + + switch (srx->transport.family) { + case AF_INET: + return ((u16 __force)peer->srx.transport.sin.sin_port - + (u16 __force)srx->transport.sin.sin_port) ?: + memcmp(&peer->srx.transport.sin.sin_addr, + &srx->transport.sin.sin_addr, + sizeof(struct in_addr)); +#ifdef CONFIG_AF_RXRPC_IPV6 + case AF_INET6: + return ((u16 __force)peer->srx.transport.sin6.sin6_port - + (u16 __force)srx->transport.sin6.sin6_port) ?: + memcmp(&peer->srx.transport.sin6.sin6_addr, + &srx->transport.sin6.sin6_addr, + sizeof(struct in6_addr)); +#endif + default: + BUG(); + } +} + +/* + * Look up a remote transport endpoint for the specified address using RCU. + */ +static struct rxrpc_peer *__rxrpc_lookup_peer_rcu( + struct rxrpc_local *local, + const struct sockaddr_rxrpc *srx, + unsigned long hash_key) +{ + struct rxrpc_peer *peer; + struct rxrpc_net *rxnet = local->rxnet; + + hash_for_each_possible_rcu(rxnet->peer_hash, peer, hash_link, hash_key) { + if (rxrpc_peer_cmp_key(peer, local, srx, hash_key) == 0 && + refcount_read(&peer->ref) > 0) + return peer; + } + + return NULL; +} + +/* + * Look up a remote transport endpoint for the specified address using RCU. + */ +struct rxrpc_peer *rxrpc_lookup_peer_rcu(struct rxrpc_local *local, + const struct sockaddr_rxrpc *srx) +{ + struct rxrpc_peer *peer; + unsigned long hash_key = rxrpc_peer_hash_key(local, srx); + + peer = __rxrpc_lookup_peer_rcu(local, srx, hash_key); + if (peer) { + _net("PEER %d {%pISp}", peer->debug_id, &peer->srx.transport); + _leave(" = %p {u=%d}", peer, refcount_read(&peer->ref)); + } + return peer; +} + +/* + * assess the MTU size for the network interface through which this peer is + * reached + */ +static void rxrpc_assess_MTU_size(struct rxrpc_sock *rx, + struct rxrpc_peer *peer) +{ + struct net *net = sock_net(&rx->sk); + struct dst_entry *dst; + struct rtable *rt; + struct flowi fl; + struct flowi4 *fl4 = &fl.u.ip4; +#ifdef CONFIG_AF_RXRPC_IPV6 + struct flowi6 *fl6 = &fl.u.ip6; +#endif + + peer->if_mtu = 1500; + + memset(&fl, 0, sizeof(fl)); + switch (peer->srx.transport.family) { + case AF_INET: + rt = ip_route_output_ports( + net, fl4, NULL, + peer->srx.transport.sin.sin_addr.s_addr, 0, + htons(7000), htons(7001), IPPROTO_UDP, 0, 0); + if (IS_ERR(rt)) { + _leave(" [route err %ld]", PTR_ERR(rt)); + return; + } + dst = &rt->dst; + break; + +#ifdef CONFIG_AF_RXRPC_IPV6 + case AF_INET6: + fl6->flowi6_iif = LOOPBACK_IFINDEX; + fl6->flowi6_scope = RT_SCOPE_UNIVERSE; + fl6->flowi6_proto = IPPROTO_UDP; + memcpy(&fl6->daddr, &peer->srx.transport.sin6.sin6_addr, + sizeof(struct in6_addr)); + fl6->fl6_dport = htons(7001); + fl6->fl6_sport = htons(7000); + dst = ip6_route_output(net, NULL, fl6); + if (dst->error) { + _leave(" [route err %d]", dst->error); + return; + } + break; +#endif + + default: + BUG(); + } + + peer->if_mtu = dst_mtu(dst); + dst_release(dst); + + _leave(" [if_mtu %u]", peer->if_mtu); +} + +/* + * Allocate a peer. + */ +struct rxrpc_peer *rxrpc_alloc_peer(struct rxrpc_local *local, gfp_t gfp) +{ + const void *here = __builtin_return_address(0); + struct rxrpc_peer *peer; + + _enter(""); + + peer = kzalloc(sizeof(struct rxrpc_peer), gfp); + if (peer) { + refcount_set(&peer->ref, 1); + peer->local = rxrpc_get_local(local); + INIT_HLIST_HEAD(&peer->error_targets); + peer->service_conns = RB_ROOT; + seqlock_init(&peer->service_conn_lock); + spin_lock_init(&peer->lock); + spin_lock_init(&peer->rtt_input_lock); + peer->debug_id = atomic_inc_return(&rxrpc_debug_id); + + rxrpc_peer_init_rtt(peer); + + if (RXRPC_TX_SMSS > 2190) + peer->cong_cwnd = 2; + else if (RXRPC_TX_SMSS > 1095) + peer->cong_cwnd = 3; + else + peer->cong_cwnd = 4; + trace_rxrpc_peer(peer->debug_id, rxrpc_peer_new, 1, here); + } + + _leave(" = %p", peer); + return peer; +} + +/* + * Initialise peer record. + */ +static void rxrpc_init_peer(struct rxrpc_sock *rx, struct rxrpc_peer *peer, + unsigned long hash_key) +{ + peer->hash_key = hash_key; + rxrpc_assess_MTU_size(rx, peer); + peer->mtu = peer->if_mtu; + peer->rtt_last_req = ktime_get_real(); + + switch (peer->srx.transport.family) { + case AF_INET: + peer->hdrsize = sizeof(struct iphdr); + break; +#ifdef CONFIG_AF_RXRPC_IPV6 + case AF_INET6: + peer->hdrsize = sizeof(struct ipv6hdr); + break; +#endif + default: + BUG(); + } + + switch (peer->srx.transport_type) { + case SOCK_DGRAM: + peer->hdrsize += sizeof(struct udphdr); + break; + default: + BUG(); + } + + peer->hdrsize += sizeof(struct rxrpc_wire_header); + peer->maxdata = peer->mtu - peer->hdrsize; +} + +/* + * Set up a new peer. + */ +static struct rxrpc_peer *rxrpc_create_peer(struct rxrpc_sock *rx, + struct rxrpc_local *local, + struct sockaddr_rxrpc *srx, + unsigned long hash_key, + gfp_t gfp) +{ + struct rxrpc_peer *peer; + + _enter(""); + + peer = rxrpc_alloc_peer(local, gfp); + if (peer) { + memcpy(&peer->srx, srx, sizeof(*srx)); + rxrpc_init_peer(rx, peer, hash_key); + } + + _leave(" = %p", peer); + return peer; +} + +static void rxrpc_free_peer(struct rxrpc_peer *peer) +{ + rxrpc_put_local(peer->local); + kfree_rcu(peer, rcu); +} + +/* + * Set up a new incoming peer. There shouldn't be any other matching peers + * since we've already done a search in the list from the non-reentrant context + * (the data_ready handler) that is the only place we can add new peers. + */ +void rxrpc_new_incoming_peer(struct rxrpc_sock *rx, struct rxrpc_local *local, + struct rxrpc_peer *peer) +{ + struct rxrpc_net *rxnet = local->rxnet; + unsigned long hash_key; + + hash_key = rxrpc_peer_hash_key(local, &peer->srx); + rxrpc_init_peer(rx, peer, hash_key); + + spin_lock(&rxnet->peer_hash_lock); + hash_add_rcu(rxnet->peer_hash, &peer->hash_link, hash_key); + list_add_tail(&peer->keepalive_link, &rxnet->peer_keepalive_new); + spin_unlock(&rxnet->peer_hash_lock); +} + +/* + * obtain a remote transport endpoint for the specified address + */ +struct rxrpc_peer *rxrpc_lookup_peer(struct rxrpc_sock *rx, + struct rxrpc_local *local, + struct sockaddr_rxrpc *srx, gfp_t gfp) +{ + struct rxrpc_peer *peer, *candidate; + struct rxrpc_net *rxnet = local->rxnet; + unsigned long hash_key = rxrpc_peer_hash_key(local, srx); + + _enter("{%pISp}", &srx->transport); + + /* search the peer list first */ + rcu_read_lock(); + peer = __rxrpc_lookup_peer_rcu(local, srx, hash_key); + if (peer && !rxrpc_get_peer_maybe(peer)) + peer = NULL; + rcu_read_unlock(); + + if (!peer) { + /* The peer is not yet present in hash - create a candidate + * for a new record and then redo the search. + */ + candidate = rxrpc_create_peer(rx, local, srx, hash_key, gfp); + if (!candidate) { + _leave(" = NULL [nomem]"); + return NULL; + } + + spin_lock_bh(&rxnet->peer_hash_lock); + + /* Need to check that we aren't racing with someone else */ + peer = __rxrpc_lookup_peer_rcu(local, srx, hash_key); + if (peer && !rxrpc_get_peer_maybe(peer)) + peer = NULL; + if (!peer) { + hash_add_rcu(rxnet->peer_hash, + &candidate->hash_link, hash_key); + list_add_tail(&candidate->keepalive_link, + &rxnet->peer_keepalive_new); + } + + spin_unlock_bh(&rxnet->peer_hash_lock); + + if (peer) + rxrpc_free_peer(candidate); + else + peer = candidate; + } + + _net("PEER %d {%pISp}", peer->debug_id, &peer->srx.transport); + + _leave(" = %p {u=%d}", peer, refcount_read(&peer->ref)); + return peer; +} + +/* + * Get a ref on a peer record. + */ +struct rxrpc_peer *rxrpc_get_peer(struct rxrpc_peer *peer) +{ + const void *here = __builtin_return_address(0); + int r; + + __refcount_inc(&peer->ref, &r); + trace_rxrpc_peer(peer->debug_id, rxrpc_peer_got, r + 1, here); + return peer; +} + +/* + * Get a ref on a peer record unless its usage has already reached 0. + */ +struct rxrpc_peer *rxrpc_get_peer_maybe(struct rxrpc_peer *peer) +{ + const void *here = __builtin_return_address(0); + int r; + + if (peer) { + if (__refcount_inc_not_zero(&peer->ref, &r)) + trace_rxrpc_peer(peer->debug_id, rxrpc_peer_got, r + 1, here); + else + peer = NULL; + } + return peer; +} + +/* + * Discard a peer record. + */ +static void __rxrpc_put_peer(struct rxrpc_peer *peer) +{ + struct rxrpc_net *rxnet = peer->local->rxnet; + + ASSERT(hlist_empty(&peer->error_targets)); + + spin_lock_bh(&rxnet->peer_hash_lock); + hash_del_rcu(&peer->hash_link); + list_del_init(&peer->keepalive_link); + spin_unlock_bh(&rxnet->peer_hash_lock); + + rxrpc_free_peer(peer); +} + +/* + * Drop a ref on a peer record. + */ +void rxrpc_put_peer(struct rxrpc_peer *peer) +{ + const void *here = __builtin_return_address(0); + unsigned int debug_id; + bool dead; + int r; + + if (peer) { + debug_id = peer->debug_id; + dead = __refcount_dec_and_test(&peer->ref, &r); + trace_rxrpc_peer(debug_id, rxrpc_peer_put, r - 1, here); + if (dead) + __rxrpc_put_peer(peer); + } +} + +/* + * Drop a ref on a peer record where the caller already holds the + * peer_hash_lock. + */ +void rxrpc_put_peer_locked(struct rxrpc_peer *peer) +{ + const void *here = __builtin_return_address(0); + unsigned int debug_id = peer->debug_id; + bool dead; + int r; + + dead = __refcount_dec_and_test(&peer->ref, &r); + trace_rxrpc_peer(debug_id, rxrpc_peer_put, r - 1, here); + if (dead) { + hash_del_rcu(&peer->hash_link); + list_del_init(&peer->keepalive_link); + rxrpc_free_peer(peer); + } +} + +/* + * Make sure all peer records have been discarded. + */ +void rxrpc_destroy_all_peers(struct rxrpc_net *rxnet) +{ + struct rxrpc_peer *peer; + int i; + + for (i = 0; i < HASH_SIZE(rxnet->peer_hash); i++) { + if (hlist_empty(&rxnet->peer_hash[i])) + continue; + + hlist_for_each_entry(peer, &rxnet->peer_hash[i], hash_link) { + pr_err("Leaked peer %u {%u} %pISp\n", + peer->debug_id, + refcount_read(&peer->ref), + &peer->srx.transport); + } + } +} + +/** + * rxrpc_kernel_get_peer - Get the peer address of a call + * @sock: The socket on which the call is in progress. + * @call: The call to query + * @_srx: Where to place the result + * + * Get the address of the remote peer in a call. + */ +void rxrpc_kernel_get_peer(struct socket *sock, struct rxrpc_call *call, + struct sockaddr_rxrpc *_srx) +{ + *_srx = call->peer->srx; +} +EXPORT_SYMBOL(rxrpc_kernel_get_peer); + +/** + * rxrpc_kernel_get_srtt - Get a call's peer smoothed RTT + * @sock: The socket on which the call is in progress. + * @call: The call to query + * @_srtt: Where to store the SRTT value. + * + * Get the call's peer smoothed RTT in uS. + */ +bool rxrpc_kernel_get_srtt(struct socket *sock, struct rxrpc_call *call, + u32 *_srtt) +{ + struct rxrpc_peer *peer = call->peer; + + if (peer->rtt_count == 0) { + *_srtt = 1000000; /* 1S */ + return false; + } + + *_srtt = call->peer->srtt_us >> 3; + return true; +} +EXPORT_SYMBOL(rxrpc_kernel_get_srtt); |