/* RxRPC individual remote procedure call handling * * 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/circ_buf.h> #include <net/sock.h> #include <net/af_rxrpc.h> #include "ar-internal.h" const char *const rxrpc_call_states[] = { [RXRPC_CALL_CLIENT_SEND_REQUEST] = "ClSndReq", [RXRPC_CALL_CLIENT_AWAIT_REPLY] = "ClAwtRpl", [RXRPC_CALL_CLIENT_RECV_REPLY] = "ClRcvRpl", [RXRPC_CALL_CLIENT_FINAL_ACK] = "ClFnlACK", [RXRPC_CALL_SERVER_SECURING] = "SvSecure", [RXRPC_CALL_SERVER_ACCEPTING] = "SvAccept", [RXRPC_CALL_SERVER_RECV_REQUEST] = "SvRcvReq", [RXRPC_CALL_SERVER_ACK_REQUEST] = "SvAckReq", [RXRPC_CALL_SERVER_SEND_REPLY] = "SvSndRpl", [RXRPC_CALL_SERVER_AWAIT_ACK] = "SvAwtACK", [RXRPC_CALL_COMPLETE] = "Complete", [RXRPC_CALL_SERVER_BUSY] = "SvBusy ", [RXRPC_CALL_REMOTELY_ABORTED] = "RmtAbort", [RXRPC_CALL_LOCALLY_ABORTED] = "LocAbort", [RXRPC_CALL_NETWORK_ERROR] = "NetError", [RXRPC_CALL_DEAD] = "Dead ", }; struct kmem_cache *rxrpc_call_jar; LIST_HEAD(rxrpc_calls); DEFINE_RWLOCK(rxrpc_call_lock); static unsigned rxrpc_call_max_lifetime = 60; static unsigned rxrpc_dead_call_timeout = 2; static void rxrpc_destroy_call(struct work_struct *work); static void rxrpc_call_life_expired(unsigned long _call); static void rxrpc_dead_call_expired(unsigned long _call); static void rxrpc_ack_time_expired(unsigned long _call); static void rxrpc_resend_time_expired(unsigned long _call); /* * allocate a new call */ static struct rxrpc_call *rxrpc_alloc_call(gfp_t gfp) { struct rxrpc_call *call; call = kmem_cache_zalloc(rxrpc_call_jar, gfp); if (!call) return NULL; call->acks_winsz = 16; call->acks_window = kmalloc(call->acks_winsz * sizeof(unsigned long), gfp); if (!call->acks_window) { kmem_cache_free(rxrpc_call_jar, call); return NULL; } setup_timer(&call->lifetimer, &rxrpc_call_life_expired, (unsigned long) call); setup_timer(&call->deadspan, &rxrpc_dead_call_expired, (unsigned long) call); setup_timer(&call->ack_timer, &rxrpc_ack_time_expired, (unsigned long) call); setup_timer(&call->resend_timer, &rxrpc_resend_time_expired, (unsigned long) call); INIT_WORK(&call->destroyer, &rxrpc_destroy_call); INIT_WORK(&call->processor, &rxrpc_process_call); INIT_LIST_HEAD(&call->accept_link); skb_queue_head_init(&call->rx_queue); skb_queue_head_init(&call->rx_oos_queue); init_waitqueue_head(&call->tx_waitq); spin_lock_init(&call->lock); rwlock_init(&call->state_lock); atomic_set(&call->usage, 1); call->debug_id = atomic_inc_return(&rxrpc_debug_id); call->state = RXRPC_CALL_CLIENT_SEND_REQUEST; memset(&call->sock_node, 0xed, sizeof(call->sock_node)); call->rx_data_expect = 1; call->rx_data_eaten = 0; call->rx_first_oos = 0; call->ackr_win_top = call->rx_data_eaten + 1 + RXRPC_MAXACKS; call->creation_jif = jiffies; return call; } /* * allocate a new client call and attempt to get a connection slot for it */ static struct rxrpc_call *rxrpc_alloc_client_call( struct rxrpc_sock *rx, struct rxrpc_transport *trans, struct rxrpc_conn_bundle *bundle, gfp_t gfp) { struct rxrpc_call *call; int ret; _enter(""); ASSERT(rx != NULL); ASSERT(trans != NULL); ASSERT(bundle != NULL); call = rxrpc_alloc_call(gfp); if (!call) return ERR_PTR(-ENOMEM); sock_hold(&rx->sk); call->socket = rx; call->rx_data_post = 1; ret = rxrpc_connect_call(rx, trans, bundle, call, gfp); if (ret < 0) { kmem_cache_free(rxrpc_call_jar, call); return ERR_PTR(ret); } spin_lock(&call->conn->trans->peer->lock); list_add(&call->error_link, &call->conn->trans->peer->error_targets); spin_unlock(&call->conn->trans->peer->lock); call->lifetimer.expires = jiffies + rxrpc_call_max_lifetime * HZ; add_timer(&call->lifetimer); _leave(" = %p", call); return call; } /* * set up a call for the given data * - called in process context with IRQs enabled */ struct rxrpc_call *rxrpc_get_client_call(struct rxrpc_sock *rx, struct rxrpc_transport *trans, struct rxrpc_conn_bundle *bundle, unsigned long user_call_ID, int create, gfp_t gfp) { struct rxrpc_call *call, *candidate; struct rb_node *p, *parent, **pp; _enter("%p,%d,%d,%lx,%d", rx, trans ? trans->debug_id : -1, bundle ? bundle->debug_id : -1, user_call_ID, create); /* search the extant calls first for one that matches the specified * user ID */ read_lock(&rx->call_lock); p = rx->calls.rb_node; while (p) { call = rb_entry(p, struct rxrpc_call, sock_node); if (user_call_ID < call->user_call_ID) p = p->rb_left; else if (user_call_ID > call->user_call_ID) p = p->rb_right; else goto found_extant_call; } read_unlock(&rx->call_lock); if (!create || !trans) return ERR_PTR(-EBADSLT); /* not yet present - create a candidate for a new record and then * redo the search */ candidate = rxrpc_alloc_client_call(rx, trans, bundle, gfp); if (IS_ERR(candidate)) { _leave(" = %ld", PTR_ERR(candidate)); return candidate; } candidate->user_call_ID = user_call_ID; __set_bit(RXRPC_CALL_HAS_USERID, &candidate->flags); write_lock(&rx->call_lock); pp = &rx->calls.rb_node; parent = NULL; while (*pp) { parent = *pp; call = rb_entry(parent, struct rxrpc_call, sock_node); if (user_call_ID < call->user_call_ID) pp = &(*pp)->rb_left; else if (user_call_ID > call->user_call_ID) pp = &(*pp)->rb_right; else goto found_extant_second; } /* second search also failed; add the new call */ call = candidate; candidate = NULL; rxrpc_get_call(call); rb_link_node(&call->sock_node, parent, pp); rb_insert_color(&call->sock_node, &rx->calls); write_unlock(&rx->call_lock); write_lock_bh(&rxrpc_call_lock); list_add_tail(&call->link, &rxrpc_calls); write_unlock_bh(&rxrpc_call_lock); _net("CALL new %d on CONN %d", call->debug_id, call->conn->debug_id); _leave(" = %p [new]", call); return call; /* we found the call in the list immediately */ found_extant_call: rxrpc_get_call(call); read_unlock(&rx->call_lock); _leave(" = %p [extant %d]", call, atomic_read(&call->usage)); return call; /* we found the call on the second time through the list */ found_extant_second: rxrpc_get_call(call); write_unlock(&rx->call_lock); rxrpc_put_call(candidate); _leave(" = %p [second %d]", call, atomic_read(&call->usage)); return call; } /* * set up an incoming call * - called in process context with IRQs enabled */ struct rxrpc_call *rxrpc_incoming_call(struct rxrpc_sock *rx, struct rxrpc_connection *conn, struct rxrpc_header *hdr, gfp_t gfp) { struct rxrpc_call *call, *candidate; struct rb_node **p, *parent; __be32 call_id; _enter(",%d,,%x", conn->debug_id, gfp); ASSERT(rx != NULL); candidate = rxrpc_alloc_call(gfp); if (!candidate) return ERR_PTR(-EBUSY); candidate->socket = rx; candidate->conn = conn; candidate->cid = hdr->cid; candidate->call_id = hdr->callNumber; candidate->channel = ntohl(hdr->cid) & RXRPC_CHANNELMASK; candidate->rx_data_post = 0; candidate->state = RXRPC_CALL_SERVER_ACCEPTING; if (conn->security_ix > 0) candidate->state = RXRPC_CALL_SERVER_SECURING; write_lock_bh(&conn->lock); /* set the channel for this call */ call = conn->channels[candidate->channel]; _debug("channel[%u] is %p", candidate->channel, call); if (call && call->call_id == hdr->callNumber) { /* already set; must've been a duplicate packet */ _debug("extant call [%d]", call->state); ASSERTCMP(call->conn, ==, conn); read_lock(&call->state_lock); switch (call->state) { case RXRPC_CALL_LOCALLY_ABORTED: if (!test_and_set_bit(RXRPC_CALL_ABORT, &call->events)) rxrpc_queue_call(call); case RXRPC_CALL_REMOTELY_ABORTED: read_unlock(&call->state_lock); goto aborted_call; default: rxrpc_get_call(call); read_unlock(&call->state_lock); goto extant_call; } } if (call) { /* it seems the channel is still in use from the previous call * - ditch the old binding if its call is now complete */ _debug("CALL: %u { %s }", call->debug_id, rxrpc_call_states[call->state]); if (call->state >= RXRPC_CALL_COMPLETE) { conn->channels[call->channel] = NULL; } else { write_unlock_bh(&conn->lock); kmem_cache_free(rxrpc_call_jar, candidate); _leave(" = -EBUSY"); return ERR_PTR(-EBUSY); } } /* check the call number isn't duplicate */ _debug("check dup"); call_id = hdr->callNumber; p = &conn->calls.rb_node; parent = NULL; while (*p) { parent = *p; call = rb_entry(parent, struct rxrpc_call, conn_node); if (call_id < call->call_id) p = &(*p)->rb_left; else if (call_id > call->call_id) p = &(*p)->rb_right; else goto old_call; } /* make the call available */ _debug("new call"); call = candidate; candidate = NULL; rb_link_node(&call->conn_node, parent, p); rb_insert_color(&call->conn_node, &conn->calls); conn->channels[call->channel] = call; sock_hold(&rx->sk); atomic_inc(&conn->usage); write_unlock_bh(&conn->lock); spin_lock(&conn->trans->peer->lock); list_add(&call->error_link, &conn->trans->peer->error_targets); spin_unlock(&conn->trans->peer->lock); write_lock_bh(&rxrpc_call_lock); list_add_tail(&call->link, &rxrpc_calls); write_unlock_bh(&rxrpc_call_lock); _net("CALL incoming %d on CONN %d", call->debug_id, call->conn->debug_id); call->lifetimer.expires = jiffies + rxrpc_call_max_lifetime * HZ; add_timer(&call->lifetimer); _leave(" = %p {%d} [new]", call, call->debug_id); return call; extant_call: write_unlock_bh(&conn->lock); kmem_cache_free(rxrpc_call_jar, candidate); _leave(" = %p {%d} [extant]", call, call ? call->debug_id : -1); return call; aborted_call: write_unlock_bh(&conn->lock); kmem_cache_free(rxrpc_call_jar, candidate); _leave(" = -ECONNABORTED"); return ERR_PTR(-ECONNABORTED); old_call: write_unlock_bh(&conn->lock); kmem_cache_free(rxrpc_call_jar, candidate); _leave(" = -ECONNRESET [old]"); return ERR_PTR(-ECONNRESET); } /* * find an extant server call * - called in process context with IRQs enabled */ struct rxrpc_call *rxrpc_find_server_call(struct rxrpc_sock *rx, unsigned long user_call_ID) { struct rxrpc_call *call; struct rb_node *p; _enter("%p,%lx", rx, user_call_ID); /* search the extant calls for one that matches the specified user * ID */ read_lock(&rx->call_lock); p = rx->calls.rb_node; while (p) { call = rb_entry(p, struct rxrpc_call, sock_node); if (user_call_ID < call->user_call_ID) p = p->rb_left; else if (user_call_ID > call->user_call_ID) p = p->rb_right; else goto found_extant_call; } read_unlock(&rx->call_lock); _leave(" = NULL"); return NULL; /* we found the call in the list immediately */ found_extant_call: rxrpc_get_call(call); read_unlock(&rx->call_lock); _leave(" = %p [%d]", call, atomic_read(&call->usage)); return call; } /* * detach a call from a socket and set up for release */ void rxrpc_release_call(struct rxrpc_call *call) { struct rxrpc_connection *conn = call->conn; struct rxrpc_sock *rx = call->socket; _enter("{%d,%d,%d,%d}", call->debug_id, atomic_read(&call->usage), atomic_read(&call->ackr_not_idle), call->rx_first_oos); spin_lock_bh(&call->lock); if (test_and_set_bit(RXRPC_CALL_RELEASED, &call->flags)) BUG(); spin_unlock_bh(&call->lock); /* dissociate from the socket * - the socket's ref on the call is passed to the death timer */ _debug("RELEASE CALL %p (%d CONN %p)", call, call->debug_id, conn); write_lock_bh(&rx->call_lock); if (!list_empty(&call->accept_link)) { _debug("unlinking once-pending call %p { e=%lx f=%lx }", call, call->events, call->flags); ASSERT(!test_bit(RXRPC_CALL_HAS_USERID, &call->flags)); list_del_init(&call->accept_link); sk_acceptq_removed(&rx->sk); } else if (test_bit(RXRPC_CALL_HAS_USERID, &call->flags)) { rb_erase(&call->sock_node, &rx->calls); memset(&call->sock_node, 0xdd, sizeof(call->sock_node)); clear_bit(RXRPC_CALL_HAS_USERID, &call->flags); } write_unlock_bh(&rx->call_lock); /* free up the channel for reuse */ spin_lock(&conn->trans->client_lock); write_lock_bh(&conn->lock); write_lock(&call->state_lock); if (conn->channels[call->channel] == call) conn->channels[call->channel] = NULL; if (conn->out_clientflag && conn->bundle) { conn->avail_calls++; switch (conn->avail_calls) { case 1: list_move_tail(&conn->bundle_link, &conn->bundle->avail_conns); case 2 ... RXRPC_MAXCALLS - 1: ASSERT(conn->channels[0] == NULL || conn->channels[1] == NULL || conn->channels[2] == NULL || conn->channels[3] == NULL); break; case RXRPC_MAXCALLS: list_move_tail(&conn->bundle_link, &conn->bundle->unused_conns); ASSERT(conn->channels[0] == NULL && conn->channels[1] == NULL && conn->channels[2] == NULL && conn->channels[3] == NULL); break; default: printk(KERN_ERR "RxRPC: conn->avail_calls=%d\n", conn->avail_calls); BUG(); } } spin_unlock(&conn->trans->client_lock); if (call->state < RXRPC_CALL_COMPLETE && call->state != RXRPC_CALL_CLIENT_FINAL_ACK) { _debug("+++ ABORTING STATE %d +++\n", call->state); call->state = RXRPC_CALL_LOCALLY_ABORTED; call->abort_code = RX_CALL_DEAD; set_bit(RXRPC_CALL_ABORT, &call->events); rxrpc_queue_call(call); } write_unlock(&call->state_lock); write_unlock_bh(&conn->lock); /* clean up the Rx queue */ if (!skb_queue_empty(&call->rx_queue) || !skb_queue_empty(&call->rx_oos_queue)) { struct rxrpc_skb_priv *sp; struct sk_buff *skb; _debug("purge Rx queues"); spin_lock_bh(&call->lock); while ((skb = skb_dequeue(&call->rx_queue)) || (skb = skb_dequeue(&call->rx_oos_queue))) { sp = rxrpc_skb(skb); if (sp->call) { ASSERTCMP(sp->call, ==, call); rxrpc_put_call(call); sp->call = NULL; } skb->destructor = NULL; spin_unlock_bh(&call->lock); _debug("- zap %s %%%u #%u", rxrpc_pkts[sp->hdr.type], ntohl(sp->hdr.serial), ntohl(sp->hdr.seq)); rxrpc_free_skb(skb); spin_lock_bh(&call->lock); } spin_unlock_bh(&call->lock); ASSERTCMP(call->state, !=, RXRPC_CALL_COMPLETE); } del_timer_sync(&call->resend_timer); del_timer_sync(&call->ack_timer); del_timer_sync(&call->lifetimer); call->deadspan.expires = jiffies + rxrpc_dead_call_timeout * HZ; add_timer(&call->deadspan); _leave(""); } /* * handle a dead call being ready for reaping */ static void rxrpc_dead_call_expired(unsigned long _call) { struct rxrpc_call *call = (struct rxrpc_call *) _call; _enter("{%d}", call->debug_id); write_lock_bh(&call->state_lock); call->state = RXRPC_CALL_DEAD; write_unlock_bh(&call->state_lock); rxrpc_put_call(call); } /* * mark a call as to be released, aborting it if it's still in progress * - called with softirqs disabled */ static void rxrpc_mark_call_released(struct rxrpc_call *call) { bool sched; write_lock(&call->state_lock); if (call->state < RXRPC_CALL_DEAD) { sched = false; if (call->state < RXRPC_CALL_COMPLETE) { _debug("abort call %p", call); call->state = RXRPC_CALL_LOCALLY_ABORTED; call->abort_code = RX_CALL_DEAD; if (!test_and_set_bit(RXRPC_CALL_ABORT, &call->events)) sched = true; } if (!test_and_set_bit(RXRPC_CALL_RELEASE, &call->events)) sched = true; if (sched) rxrpc_queue_call(call); } write_unlock(&call->state_lock); } /* * release all the calls associated with a socket */ void rxrpc_release_calls_on_socket(struct rxrpc_sock *rx) { struct rxrpc_call *call; struct rb_node *p; _enter("%p", rx); read_lock_bh(&rx->call_lock); /* mark all the calls as no longer wanting incoming packets */ for (p = rb_first(&rx->calls); p; p = rb_next(p)) { call = rb_entry(p, struct rxrpc_call, sock_node); rxrpc_mark_call_released(call); } /* kill the not-yet-accepted incoming calls */ list_for_each_entry(call, &rx->secureq, accept_link) { rxrpc_mark_call_released(call); } list_for_each_entry(call, &rx->acceptq, accept_link) { rxrpc_mark_call_released(call); } read_unlock_bh(&rx->call_lock); _leave(""); } /* * release a call */ void __rxrpc_put_call(struct rxrpc_call *call) { ASSERT(call != NULL); _enter("%p{u=%d}", call, atomic_read(&call->usage)); ASSERTCMP(atomic_read(&call->usage), >, 0); if (atomic_dec_and_test(&call->usage)) { _debug("call %d dead", call->debug_id); ASSERTCMP(call->state, ==, RXRPC_CALL_DEAD); rxrpc_queue_work(&call->destroyer); } _leave(""); } /* * clean up a call */ static void rxrpc_cleanup_call(struct rxrpc_call *call) { _net("DESTROY CALL %d", call->debug_id); ASSERT(call->socket); memset(&call->sock_node, 0xcd, sizeof(call->sock_node)); del_timer_sync(&call->lifetimer); del_timer_sync(&call->deadspan); del_timer_sync(&call->ack_timer); del_timer_sync(&call->resend_timer); ASSERT(test_bit(RXRPC_CALL_RELEASED, &call->flags)); ASSERTCMP(call->events, ==, 0); if (work_pending(&call->processor)) { _debug("defer destroy"); rxrpc_queue_work(&call->destroyer); return; } if (call->conn) { spin_lock(&call->conn->trans->peer->lock); list_del(&call->error_link); spin_unlock(&call->conn->trans->peer->lock); write_lock_bh(&call->conn->lock); rb_erase(&call->conn_node, &call->conn->calls); write_unlock_bh(&call->conn->lock); rxrpc_put_connection(call->conn); } if (call->acks_window) { _debug("kill Tx window %d", CIRC_CNT(call->acks_head, call->acks_tail, call->acks_winsz)); smp_mb(); while (CIRC_CNT(call->acks_head, call->acks_tail, call->acks_winsz) > 0) { struct rxrpc_skb_priv *sp; unsigned long _skb; _skb = call->acks_window[call->acks_tail] & ~1; sp = rxrpc_skb((struct sk_buff *) _skb); _debug("+++ clear Tx %u", ntohl(sp->hdr.seq)); rxrpc_free_skb((struct sk_buff *) _skb); call->acks_tail = (call->acks_tail + 1) & (call->acks_winsz - 1); } kfree(call->acks_window); } rxrpc_free_skb(call->tx_pending); rxrpc_purge_queue(&call->rx_queue); ASSERT(skb_queue_empty(&call->rx_oos_queue)); sock_put(&call->socket->sk); kmem_cache_free(rxrpc_call_jar, call); } /* * destroy a call */ static void rxrpc_destroy_call(struct work_struct *work) { struct rxrpc_call *call = container_of(work, struct rxrpc_call, destroyer); _enter("%p{%d,%d,%p}", call, atomic_read(&call->usage), call->channel, call->conn); ASSERTCMP(call->state, ==, RXRPC_CALL_DEAD); write_lock_bh(&rxrpc_call_lock); list_del_init(&call->link); write_unlock_bh(&rxrpc_call_lock); rxrpc_cleanup_call(call); _leave(""); } /* * preemptively destroy all the call records from a transport endpoint rather * than waiting for them to time out */ void __exit rxrpc_destroy_all_calls(void) { struct rxrpc_call *call; _enter(""); write_lock_bh(&rxrpc_call_lock); while (!list_empty(&rxrpc_calls)) { call = list_entry(rxrpc_calls.next, struct rxrpc_call, link); _debug("Zapping call %p", call); list_del_init(&call->link); switch (atomic_read(&call->usage)) { case 0: ASSERTCMP(call->state, ==, RXRPC_CALL_DEAD); break; case 1: if (del_timer_sync(&call->deadspan) != 0 && call->state != RXRPC_CALL_DEAD) rxrpc_dead_call_expired((unsigned long) call); if (call->state != RXRPC_CALL_DEAD) break; default: printk(KERN_ERR "RXRPC:" " Call %p still in use (%d,%d,%s,%lx,%lx)!\n", call, atomic_read(&call->usage), atomic_read(&call->ackr_not_idle), rxrpc_call_states[call->state], call->flags, call->events); if (!skb_queue_empty(&call->rx_queue)) printk(KERN_ERR"RXRPC: Rx queue occupied\n"); if (!skb_queue_empty(&call->rx_oos_queue)) printk(KERN_ERR"RXRPC: OOS queue occupied\n"); break; } write_unlock_bh(&rxrpc_call_lock); cond_resched(); write_lock_bh(&rxrpc_call_lock); } write_unlock_bh(&rxrpc_call_lock); _leave(""); } /* * handle call lifetime being exceeded */ static void rxrpc_call_life_expired(unsigned long _call) { struct rxrpc_call *call = (struct rxrpc_call *) _call; if (call->state >= RXRPC_CALL_COMPLETE) return; _enter("{%d}", call->debug_id); read_lock_bh(&call->state_lock); if (call->state < RXRPC_CALL_COMPLETE) { set_bit(RXRPC_CALL_LIFE_TIMER, &call->events); rxrpc_queue_call(call); } read_unlock_bh(&call->state_lock); } /* * handle resend timer expiry */ static void rxrpc_resend_time_expired(unsigned long _call) { struct rxrpc_call *call = (struct rxrpc_call *) _call; _enter("{%d}", call->debug_id); if (call->state >= RXRPC_CALL_COMPLETE) return; read_lock_bh(&call->state_lock); clear_bit(RXRPC_CALL_RUN_RTIMER, &call->flags); if (call->state < RXRPC_CALL_COMPLETE && !test_and_set_bit(RXRPC_CALL_RESEND_TIMER, &call->events)) rxrpc_queue_call(call); read_unlock_bh(&call->state_lock); } /* * handle ACK timer expiry */ static void rxrpc_ack_time_expired(unsigned long _call) { struct rxrpc_call *call = (struct rxrpc_call *) _call; _enter("{%d}", call->debug_id); if (call->state >= RXRPC_CALL_COMPLETE) return; read_lock_bh(&call->state_lock); if (call->state < RXRPC_CALL_COMPLETE && !test_and_set_bit(RXRPC_CALL_ACK, &call->events)) rxrpc_queue_call(call); read_unlock_bh(&call->state_lock); }