diff options
Diffstat (limited to 'net/rxrpc/ar-local.c')
| -rw-r--r-- | net/rxrpc/ar-local.c | 408 |
1 files changed, 408 insertions, 0 deletions
diff --git a/net/rxrpc/ar-local.c b/net/rxrpc/ar-local.c new file mode 100644 index 000000000..ca904ed54 --- /dev/null +++ b/net/rxrpc/ar-local.c @@ -0,0 +1,408 @@ +/* AF_RXRPC local endpoint management + * + * Copyright (C) 2007 Red Hat, Inc. All Rights Reserved. + * Written by David Howells (dhowells@redhat.com) + * + * This program is free software; you can redistribute it and/or + * modify it under the terms of the GNU General Public License + * as published by the Free Software Foundation; either version + * 2 of the License, or (at your option) any later version. + */ + +#include <linux/module.h> +#include <linux/net.h> +#include <linux/skbuff.h> +#include <linux/slab.h> +#include <linux/udp.h> +#include <linux/ip.h> +#include <net/sock.h> +#include <net/af_rxrpc.h> +#include <generated/utsrelease.h> +#include "ar-internal.h" + +static const char rxrpc_version_string[65] = "linux-" UTS_RELEASE " AF_RXRPC"; + +static LIST_HEAD(rxrpc_locals); +DEFINE_RWLOCK(rxrpc_local_lock); +static DECLARE_RWSEM(rxrpc_local_sem); +static DECLARE_WAIT_QUEUE_HEAD(rxrpc_local_wq); + +static void rxrpc_destroy_local(struct work_struct *work); +static void rxrpc_process_local_events(struct work_struct *work); + +/* + * allocate a new local + */ +static +struct rxrpc_local *rxrpc_alloc_local(struct sockaddr_rxrpc *srx) +{ + struct rxrpc_local *local; + + local = kzalloc(sizeof(struct rxrpc_local), GFP_KERNEL); + if (local) { + INIT_WORK(&local->destroyer, &rxrpc_destroy_local); + INIT_WORK(&local->acceptor, &rxrpc_accept_incoming_calls); + INIT_WORK(&local->rejecter, &rxrpc_reject_packets); + INIT_WORK(&local->event_processor, &rxrpc_process_local_events); + INIT_LIST_HEAD(&local->services); + INIT_LIST_HEAD(&local->link); + init_rwsem(&local->defrag_sem); + skb_queue_head_init(&local->accept_queue); + skb_queue_head_init(&local->reject_queue); + skb_queue_head_init(&local->event_queue); + spin_lock_init(&local->lock); + rwlock_init(&local->services_lock); + atomic_set(&local->usage, 1); + local->debug_id = atomic_inc_return(&rxrpc_debug_id); + memcpy(&local->srx, srx, sizeof(*srx)); + } + + _leave(" = %p", local); + return local; +} + +/* + * create the local socket + * - must be called with rxrpc_local_sem writelocked + */ +static int rxrpc_create_local(struct rxrpc_local *local) +{ + struct sock *sock; + int ret, opt; + + _enter("%p{%d}", local, local->srx.transport_type); + + /* create a socket to represent the local endpoint */ + ret = sock_create_kern(PF_INET, local->srx.transport_type, IPPROTO_UDP, + &local->socket); + if (ret < 0) { + _leave(" = %d [socket]", ret); + return ret; + } + + /* if a local address was supplied then bind it */ + if (local->srx.transport_len > sizeof(sa_family_t)) { + _debug("bind"); + ret = kernel_bind(local->socket, + (struct sockaddr *) &local->srx.transport, + local->srx.transport_len); + if (ret < 0) { + _debug("bind failed"); + goto error; + } + } + + /* we want to receive ICMP errors */ + opt = 1; + ret = kernel_setsockopt(local->socket, SOL_IP, IP_RECVERR, + (char *) &opt, sizeof(opt)); + if (ret < 0) { + _debug("setsockopt failed"); + goto error; + } + + /* we want to set the don't fragment bit */ + opt = IP_PMTUDISC_DO; + ret = kernel_setsockopt(local->socket, SOL_IP, IP_MTU_DISCOVER, + (char *) &opt, sizeof(opt)); + if (ret < 0) { + _debug("setsockopt failed"); + goto error; + } + + write_lock_bh(&rxrpc_local_lock); + list_add(&local->link, &rxrpc_locals); + write_unlock_bh(&rxrpc_local_lock); + + /* set the socket up */ + sock = local->socket->sk; + sock->sk_user_data = local; + sock->sk_data_ready = rxrpc_data_ready; + sock->sk_error_report = rxrpc_UDP_error_report; + _leave(" = 0"); + return 0; + +error: + kernel_sock_shutdown(local->socket, SHUT_RDWR); + local->socket->sk->sk_user_data = NULL; + sock_release(local->socket); + local->socket = NULL; + + _leave(" = %d", ret); + return ret; +} + +/* + * create a new local endpoint using the specified UDP address + */ +struct rxrpc_local *rxrpc_lookup_local(struct sockaddr_rxrpc *srx) +{ + struct rxrpc_local *local; + int ret; + + _enter("{%d,%u,%pI4+%hu}", + srx->transport_type, + srx->transport.family, + &srx->transport.sin.sin_addr, + ntohs(srx->transport.sin.sin_port)); + + down_write(&rxrpc_local_sem); + + /* see if we have a suitable local local endpoint already */ + read_lock_bh(&rxrpc_local_lock); + + list_for_each_entry(local, &rxrpc_locals, link) { + _debug("CMP {%d,%u,%pI4+%hu}", + local->srx.transport_type, + local->srx.transport.family, + &local->srx.transport.sin.sin_addr, + ntohs(local->srx.transport.sin.sin_port)); + + if (local->srx.transport_type != srx->transport_type || + local->srx.transport.family != srx->transport.family) + continue; + + switch (srx->transport.family) { + case AF_INET: + if (local->srx.transport.sin.sin_port != + srx->transport.sin.sin_port) + continue; + if (memcmp(&local->srx.transport.sin.sin_addr, + &srx->transport.sin.sin_addr, + sizeof(struct in_addr)) != 0) + continue; + goto found_local; + + default: + BUG(); + } + } + + read_unlock_bh(&rxrpc_local_lock); + + /* we didn't find one, so we need to create one */ + local = rxrpc_alloc_local(srx); + if (!local) { + up_write(&rxrpc_local_sem); + return ERR_PTR(-ENOMEM); + } + + ret = rxrpc_create_local(local); + if (ret < 0) { + up_write(&rxrpc_local_sem); + kfree(local); + _leave(" = %d", ret); + return ERR_PTR(ret); + } + + up_write(&rxrpc_local_sem); + + _net("LOCAL new %d {%d,%u,%pI4+%hu}", + local->debug_id, + local->srx.transport_type, + local->srx.transport.family, + &local->srx.transport.sin.sin_addr, + ntohs(local->srx.transport.sin.sin_port)); + + _leave(" = %p [new]", local); + return local; + +found_local: + rxrpc_get_local(local); + read_unlock_bh(&rxrpc_local_lock); + up_write(&rxrpc_local_sem); + + _net("LOCAL old %d {%d,%u,%pI4+%hu}", + local->debug_id, + local->srx.transport_type, + local->srx.transport.family, + &local->srx.transport.sin.sin_addr, + ntohs(local->srx.transport.sin.sin_port)); + + _leave(" = %p [reuse]", local); + return local; +} + +/* + * release a local endpoint + */ +void rxrpc_put_local(struct rxrpc_local *local) +{ + _enter("%p{u=%d}", local, atomic_read(&local->usage)); + + ASSERTCMP(atomic_read(&local->usage), >, 0); + + /* to prevent a race, the decrement and the dequeue must be effectively + * atomic */ + write_lock_bh(&rxrpc_local_lock); + if (unlikely(atomic_dec_and_test(&local->usage))) { + _debug("destroy local"); + rxrpc_queue_work(&local->destroyer); + } + write_unlock_bh(&rxrpc_local_lock); + _leave(""); +} + +/* + * destroy a local endpoint + */ +static void rxrpc_destroy_local(struct work_struct *work) +{ + struct rxrpc_local *local = + container_of(work, struct rxrpc_local, destroyer); + + _enter("%p{%d}", local, atomic_read(&local->usage)); + + down_write(&rxrpc_local_sem); + + write_lock_bh(&rxrpc_local_lock); + if (atomic_read(&local->usage) > 0) { + write_unlock_bh(&rxrpc_local_lock); + up_read(&rxrpc_local_sem); + _leave(" [resurrected]"); + return; + } + + list_del(&local->link); + local->socket->sk->sk_user_data = NULL; + write_unlock_bh(&rxrpc_local_lock); + + downgrade_write(&rxrpc_local_sem); + + ASSERT(list_empty(&local->services)); + ASSERT(!work_pending(&local->acceptor)); + ASSERT(!work_pending(&local->rejecter)); + ASSERT(!work_pending(&local->event_processor)); + + /* finish cleaning up the local descriptor */ + rxrpc_purge_queue(&local->accept_queue); + rxrpc_purge_queue(&local->reject_queue); + rxrpc_purge_queue(&local->event_queue); + kernel_sock_shutdown(local->socket, SHUT_RDWR); + sock_release(local->socket); + + up_read(&rxrpc_local_sem); + + _net("DESTROY LOCAL %d", local->debug_id); + kfree(local); + + if (list_empty(&rxrpc_locals)) + wake_up_all(&rxrpc_local_wq); + + _leave(""); +} + +/* + * preemptively destroy all local local endpoint rather than waiting for + * them to be destroyed + */ +void __exit rxrpc_destroy_all_locals(void) +{ + DECLARE_WAITQUEUE(myself,current); + + _enter(""); + + /* we simply have to wait for them to go away */ + if (!list_empty(&rxrpc_locals)) { + set_current_state(TASK_UNINTERRUPTIBLE); + add_wait_queue(&rxrpc_local_wq, &myself); + + while (!list_empty(&rxrpc_locals)) { + schedule(); + set_current_state(TASK_UNINTERRUPTIBLE); + } + + remove_wait_queue(&rxrpc_local_wq, &myself); + set_current_state(TASK_RUNNING); + } + + _leave(""); +} + +/* + * Reply to a version request + */ +static void rxrpc_send_version_request(struct rxrpc_local *local, + struct rxrpc_header *hdr, + struct sk_buff *skb) +{ + struct sockaddr_in sin; + struct msghdr msg; + struct kvec iov[2]; + size_t len; + int ret; + + _enter(""); + + sin.sin_family = AF_INET; + sin.sin_port = udp_hdr(skb)->source; + sin.sin_addr.s_addr = ip_hdr(skb)->saddr; + + msg.msg_name = &sin; + msg.msg_namelen = sizeof(sin); + msg.msg_control = NULL; + msg.msg_controllen = 0; + msg.msg_flags = 0; + + hdr->seq = 0; + hdr->serial = 0; + hdr->type = RXRPC_PACKET_TYPE_VERSION; + hdr->flags = RXRPC_LAST_PACKET | (~hdr->flags & RXRPC_CLIENT_INITIATED); + hdr->userStatus = 0; + hdr->_rsvd = 0; + + iov[0].iov_base = hdr; + iov[0].iov_len = sizeof(*hdr); + iov[1].iov_base = (char *)rxrpc_version_string; + iov[1].iov_len = sizeof(rxrpc_version_string); + + len = iov[0].iov_len + iov[1].iov_len; + + _proto("Tx VERSION (reply)"); + + ret = kernel_sendmsg(local->socket, &msg, iov, 2, len); + if (ret < 0) + _debug("sendmsg failed: %d", ret); + + _leave(""); +} + +/* + * Process event packets targetted at a local endpoint. + */ +static void rxrpc_process_local_events(struct work_struct *work) +{ + struct rxrpc_local *local = container_of(work, struct rxrpc_local, event_processor); + struct sk_buff *skb; + char v; + + _enter(""); + + atomic_inc(&local->usage); + + while ((skb = skb_dequeue(&local->event_queue))) { + struct rxrpc_skb_priv *sp = rxrpc_skb(skb); + + kdebug("{%d},{%u}", local->debug_id, sp->hdr.type); + + switch (sp->hdr.type) { + case RXRPC_PACKET_TYPE_VERSION: + if (skb_copy_bits(skb, 0, &v, 1) < 0) + return; + _proto("Rx VERSION { %02x }", v); + if (v == 0) + rxrpc_send_version_request(local, &sp->hdr, skb); + break; + + default: + /* Just ignore anything we don't understand */ + break; + } + + rxrpc_put_local(local); + rxrpc_free_skb(skb); + } + + rxrpc_put_local(local); + _leave(""); +} |