/* Maintain an RxRPC server socket to do AFS communications through * * 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/slab.h> #include <net/sock.h> #include <net/af_rxrpc.h> #include <rxrpc/packet.h> #include "internal.h" #include "afs_cm.h" static struct socket *afs_socket; /* my RxRPC socket */ static struct workqueue_struct *afs_async_calls; static atomic_t afs_outstanding_calls; static atomic_t afs_outstanding_skbs; static void afs_wake_up_call_waiter(struct afs_call *); static int afs_wait_for_call_to_complete(struct afs_call *); static void afs_wake_up_async_call(struct afs_call *); static int afs_dont_wait_for_call_to_complete(struct afs_call *); static void afs_process_async_call(struct work_struct *); static void afs_rx_interceptor(struct sock *, unsigned long, struct sk_buff *); static int afs_deliver_cm_op_id(struct afs_call *, struct sk_buff *, bool); /* synchronous call management */ const struct afs_wait_mode afs_sync_call = { .rx_wakeup = afs_wake_up_call_waiter, .wait = afs_wait_for_call_to_complete, }; /* asynchronous call management */ const struct afs_wait_mode afs_async_call = { .rx_wakeup = afs_wake_up_async_call, .wait = afs_dont_wait_for_call_to_complete, }; /* asynchronous incoming call management */ static const struct afs_wait_mode afs_async_incoming_call = { .rx_wakeup = afs_wake_up_async_call, }; /* asynchronous incoming call initial processing */ static const struct afs_call_type afs_RXCMxxxx = { .name = "CB.xxxx", .deliver = afs_deliver_cm_op_id, .abort_to_error = afs_abort_to_error, }; static void afs_collect_incoming_call(struct work_struct *); static struct sk_buff_head afs_incoming_calls; static DECLARE_WORK(afs_collect_incoming_call_work, afs_collect_incoming_call); /* * open an RxRPC socket and bind it to be a server for callback notifications * - the socket is left in blocking mode and non-blocking ops use MSG_DONTWAIT */ int afs_open_socket(void) { struct sockaddr_rxrpc srx; struct socket *socket; int ret; _enter(""); skb_queue_head_init(&afs_incoming_calls); afs_async_calls = create_singlethread_workqueue("kafsd"); if (!afs_async_calls) { _leave(" = -ENOMEM [wq]"); return -ENOMEM; } ret = sock_create_kern(AF_RXRPC, SOCK_DGRAM, PF_INET, &socket); if (ret < 0) { destroy_workqueue(afs_async_calls); _leave(" = %d [socket]", ret); return ret; } socket->sk->sk_allocation = GFP_NOFS; /* bind the callback manager's address to make this a server socket */ srx.srx_family = AF_RXRPC; srx.srx_service = CM_SERVICE; srx.transport_type = SOCK_DGRAM; srx.transport_len = sizeof(srx.transport.sin); srx.transport.sin.sin_family = AF_INET; srx.transport.sin.sin_port = htons(AFS_CM_PORT); memset(&srx.transport.sin.sin_addr, 0, sizeof(srx.transport.sin.sin_addr)); ret = kernel_bind(socket, (struct sockaddr *) &srx, sizeof(srx)); if (ret < 0) { sock_release(socket); destroy_workqueue(afs_async_calls); _leave(" = %d [bind]", ret); return ret; } rxrpc_kernel_intercept_rx_messages(socket, afs_rx_interceptor); afs_socket = socket; _leave(" = 0"); return 0; } /* * close the RxRPC socket AFS was using */ void afs_close_socket(void) { _enter(""); sock_release(afs_socket); _debug("dework"); destroy_workqueue(afs_async_calls); ASSERTCMP(atomic_read(&afs_outstanding_skbs), ==, 0); ASSERTCMP(atomic_read(&afs_outstanding_calls), ==, 0); _leave(""); } /* * note that the data in a socket buffer is now delivered and that the buffer * should be freed */ static void afs_data_delivered(struct sk_buff *skb) { if (!skb) { _debug("DLVR NULL [%d]", atomic_read(&afs_outstanding_skbs)); dump_stack(); } else { _debug("DLVR %p{%u} [%d]", skb, skb->mark, atomic_read(&afs_outstanding_skbs)); if (atomic_dec_return(&afs_outstanding_skbs) == -1) BUG(); rxrpc_kernel_data_delivered(skb); } } /* * free a socket buffer */ static void afs_free_skb(struct sk_buff *skb) { if (!skb) { _debug("FREE NULL [%d]", atomic_read(&afs_outstanding_skbs)); dump_stack(); } else { _debug("FREE %p{%u} [%d]", skb, skb->mark, atomic_read(&afs_outstanding_skbs)); if (atomic_dec_return(&afs_outstanding_skbs) == -1) BUG(); rxrpc_kernel_free_skb(skb); } } /* * free a call */ static void afs_free_call(struct afs_call *call) { _debug("DONE %p{%s} [%d]", call, call->type->name, atomic_read(&afs_outstanding_calls)); if (atomic_dec_return(&afs_outstanding_calls) == -1) BUG(); ASSERTCMP(call->rxcall, ==, NULL); ASSERT(!work_pending(&call->async_work)); ASSERT(skb_queue_empty(&call->rx_queue)); ASSERT(call->type->name != NULL); kfree(call->request); kfree(call); } /* * allocate a call with flat request and reply buffers */ struct afs_call *afs_alloc_flat_call(const struct afs_call_type *type, size_t request_size, size_t reply_size) { struct afs_call *call; call = kzalloc(sizeof(*call), GFP_NOFS); if (!call) goto nomem_call; _debug("CALL %p{%s} [%d]", call, type->name, atomic_read(&afs_outstanding_calls)); atomic_inc(&afs_outstanding_calls); call->type = type; call->request_size = request_size; call->reply_max = reply_size; if (request_size) { call->request = kmalloc(request_size, GFP_NOFS); if (!call->request) goto nomem_free; } if (reply_size) { call->buffer = kmalloc(reply_size, GFP_NOFS); if (!call->buffer) goto nomem_free; } init_waitqueue_head(&call->waitq); skb_queue_head_init(&call->rx_queue); return call; nomem_free: afs_free_call(call); nomem_call: return NULL; } /* * clean up a call with flat buffer */ void afs_flat_call_destructor(struct afs_call *call) { _enter(""); kfree(call->request); call->request = NULL; kfree(call->buffer); call->buffer = NULL; } /* * attach the data from a bunch of pages on an inode to a call */ static int afs_send_pages(struct afs_call *call, struct msghdr *msg, struct kvec *iov) { struct page *pages[8]; unsigned count, n, loop, offset, to; pgoff_t first = call->first, last = call->last; int ret; _enter(""); offset = call->first_offset; call->first_offset = 0; do { _debug("attach %lx-%lx", first, last); count = last - first + 1; if (count > ARRAY_SIZE(pages)) count = ARRAY_SIZE(pages); n = find_get_pages_contig(call->mapping, first, count, pages); ASSERTCMP(n, ==, count); loop = 0; do { msg->msg_flags = 0; to = PAGE_SIZE; if (first + loop >= last) to = call->last_to; else msg->msg_flags = MSG_MORE; iov->iov_base = kmap(pages[loop]) + offset; iov->iov_len = to - offset; offset = 0; _debug("- range %u-%u%s", offset, to, msg->msg_flags ? " [more]" : ""); msg->msg_iov = (struct iovec *) iov; msg->msg_iovlen = 1; /* have to change the state *before* sending the last * packet as RxRPC might give us the reply before it * returns from sending the request */ if (first + loop >= last) call->state = AFS_CALL_AWAIT_REPLY; ret = rxrpc_kernel_send_data(call->rxcall, msg, to - offset); kunmap(pages[loop]); if (ret < 0) break; } while (++loop < count); first += count; for (loop = 0; loop < count; loop++) put_page(pages[loop]); if (ret < 0) break; } while (first <= last); _leave(" = %d", ret); return ret; } /* * initiate a call */ int afs_make_call(struct in_addr *addr, struct afs_call *call, gfp_t gfp, const struct afs_wait_mode *wait_mode) { struct sockaddr_rxrpc srx; struct rxrpc_call *rxcall; struct msghdr msg; struct kvec iov[1]; int ret; _enter("%x,{%d},", addr->s_addr, ntohs(call->port)); ASSERT(call->type != NULL); ASSERT(call->type->name != NULL); _debug("____MAKE %p{%s,%x} [%d]____", call, call->type->name, key_serial(call->key), atomic_read(&afs_outstanding_calls)); call->wait_mode = wait_mode; INIT_WORK(&call->async_work, afs_process_async_call); memset(&srx, 0, sizeof(srx)); srx.srx_family = AF_RXRPC; srx.srx_service = call->service_id; srx.transport_type = SOCK_DGRAM; srx.transport_len = sizeof(srx.transport.sin); srx.transport.sin.sin_family = AF_INET; srx.transport.sin.sin_port = call->port; memcpy(&srx.transport.sin.sin_addr, addr, 4); /* create a call */ rxcall = rxrpc_kernel_begin_call(afs_socket, &srx, call->key, (unsigned long) call, gfp); call->key = NULL; if (IS_ERR(rxcall)) { ret = PTR_ERR(rxcall); goto error_kill_call; } call->rxcall = rxcall; /* send the request */ iov[0].iov_base = call->request; iov[0].iov_len = call->request_size; msg.msg_name = NULL; msg.msg_namelen = 0; msg.msg_iov = (struct iovec *) iov; msg.msg_iovlen = 1; msg.msg_control = NULL; msg.msg_controllen = 0; msg.msg_flags = (call->send_pages ? MSG_MORE : 0); /* have to change the state *before* sending the last packet as RxRPC * might give us the reply before it returns from sending the * request */ if (!call->send_pages) call->state = AFS_CALL_AWAIT_REPLY; ret = rxrpc_kernel_send_data(rxcall, &msg, call->request_size); if (ret < 0) goto error_do_abort; if (call->send_pages) { ret = afs_send_pages(call, &msg, iov); if (ret < 0) goto error_do_abort; } /* at this point, an async call may no longer exist as it may have * already completed */ return wait_mode->wait(call); error_do_abort: rxrpc_kernel_abort_call(rxcall, RX_USER_ABORT); rxrpc_kernel_end_call(rxcall); call->rxcall = NULL; error_kill_call: call->type->destructor(call); afs_free_call(call); _leave(" = %d", ret); return ret; } /* * handles intercepted messages that were arriving in the socket's Rx queue * - called with the socket receive queue lock held to ensure message ordering * - called with softirqs disabled */ static void afs_rx_interceptor(struct sock *sk, unsigned long user_call_ID, struct sk_buff *skb) { struct afs_call *call = (struct afs_call *) user_call_ID; _enter("%p,,%u", call, skb->mark); _debug("ICPT %p{%u} [%d]", skb, skb->mark, atomic_read(&afs_outstanding_skbs)); ASSERTCMP(sk, ==, afs_socket->sk); atomic_inc(&afs_outstanding_skbs); if (!call) { /* its an incoming call for our callback service */ skb_queue_tail(&afs_incoming_calls, skb); queue_work(afs_wq, &afs_collect_incoming_call_work); } else { /* route the messages directly to the appropriate call */ skb_queue_tail(&call->rx_queue, skb); call->wait_mode->rx_wakeup(call); } _leave(""); } /* * deliver messages to a call */ static void afs_deliver_to_call(struct afs_call *call) { struct sk_buff *skb; bool last; u32 abort_code; int ret; _enter(""); while ((call->state == AFS_CALL_AWAIT_REPLY || call->state == AFS_CALL_AWAIT_OP_ID || call->state == AFS_CALL_AWAIT_REQUEST || call->state == AFS_CALL_AWAIT_ACK) && (skb = skb_dequeue(&call->rx_queue))) { switch (skb->mark) { case RXRPC_SKB_MARK_DATA: _debug("Rcv DATA"); last = rxrpc_kernel_is_data_last(skb); ret = call->type->deliver(call, skb, last); switch (ret) { case 0: if (last && call->state == AFS_CALL_AWAIT_REPLY) call->state = AFS_CALL_COMPLETE; break; case -ENOTCONN: abort_code = RX_CALL_DEAD; goto do_abort; case -ENOTSUPP: abort_code = RX_INVALID_OPERATION; goto do_abort; default: abort_code = RXGEN_CC_UNMARSHAL; if (call->state != AFS_CALL_AWAIT_REPLY) abort_code = RXGEN_SS_UNMARSHAL; do_abort: rxrpc_kernel_abort_call(call->rxcall, abort_code); call->error = ret; call->state = AFS_CALL_ERROR; break; } afs_data_delivered(skb); skb = NULL; continue; case RXRPC_SKB_MARK_FINAL_ACK: _debug("Rcv ACK"); call->state = AFS_CALL_COMPLETE; break; case RXRPC_SKB_MARK_BUSY: _debug("Rcv BUSY"); call->error = -EBUSY; call->state = AFS_CALL_BUSY; break; case RXRPC_SKB_MARK_REMOTE_ABORT: abort_code = rxrpc_kernel_get_abort_code(skb); call->error = call->type->abort_to_error(abort_code); call->state = AFS_CALL_ABORTED; _debug("Rcv ABORT %u -> %d", abort_code, call->error); break; case RXRPC_SKB_MARK_NET_ERROR: call->error = -rxrpc_kernel_get_error_number(skb); call->state = AFS_CALL_ERROR; _debug("Rcv NET ERROR %d", call->error); break; case RXRPC_SKB_MARK_LOCAL_ERROR: call->error = -rxrpc_kernel_get_error_number(skb); call->state = AFS_CALL_ERROR; _debug("Rcv LOCAL ERROR %d", call->error); break; default: BUG(); break; } afs_free_skb(skb); } /* make sure the queue is empty if the call is done with (we might have * aborted the call early because of an unmarshalling error) */ if (call->state >= AFS_CALL_COMPLETE) { while ((skb = skb_dequeue(&call->rx_queue))) afs_free_skb(skb); if (call->incoming) { rxrpc_kernel_end_call(call->rxcall); call->rxcall = NULL; call->type->destructor(call); afs_free_call(call); } } _leave(""); } /* * wait synchronously for a call to complete */ static int afs_wait_for_call_to_complete(struct afs_call *call) { struct sk_buff *skb; int ret; DECLARE_WAITQUEUE(myself, current); _enter(""); add_wait_queue(&call->waitq, &myself); for (;;) { set_current_state(TASK_INTERRUPTIBLE); /* deliver any messages that are in the queue */ if (!skb_queue_empty(&call->rx_queue)) { __set_current_state(TASK_RUNNING); afs_deliver_to_call(call); continue; } ret = call->error; if (call->state >= AFS_CALL_COMPLETE) break; ret = -EINTR; if (signal_pending(current)) break; schedule(); } remove_wait_queue(&call->waitq, &myself); __set_current_state(TASK_RUNNING); /* kill the call */ if (call->state < AFS_CALL_COMPLETE) { _debug("call incomplete"); rxrpc_kernel_abort_call(call->rxcall, RX_CALL_DEAD); while ((skb = skb_dequeue(&call->rx_queue))) afs_free_skb(skb); } _debug("call complete"); rxrpc_kernel_end_call(call->rxcall); call->rxcall = NULL; call->type->destructor(call); afs_free_call(call); _leave(" = %d", ret); return ret; } /* * wake up a waiting call */ static void afs_wake_up_call_waiter(struct afs_call *call) { wake_up(&call->waitq); } /* * wake up an asynchronous call */ static void afs_wake_up_async_call(struct afs_call *call) { _enter(""); queue_work(afs_async_calls, &call->async_work); } /* * put a call into asynchronous mode * - mustn't touch the call descriptor as the call my have completed by the * time we get here */ static int afs_dont_wait_for_call_to_complete(struct afs_call *call) { _enter(""); return -EINPROGRESS; } /* * delete an asynchronous call */ static void afs_delete_async_call(struct work_struct *work) { struct afs_call *call = container_of(work, struct afs_call, async_work); _enter(""); afs_free_call(call); _leave(""); } /* * perform processing on an asynchronous call * - on a multiple-thread workqueue this work item may try to run on several * CPUs at the same time */ static void afs_process_async_call(struct work_struct *work) { struct afs_call *call = container_of(work, struct afs_call, async_work); _enter(""); if (!skb_queue_empty(&call->rx_queue)) afs_deliver_to_call(call); if (call->state >= AFS_CALL_COMPLETE && call->wait_mode) { if (call->wait_mode->async_complete) call->wait_mode->async_complete(call->reply, call->error); call->reply = NULL; /* kill the call */ rxrpc_kernel_end_call(call->rxcall); call->rxcall = NULL; if (call->type->destructor) call->type->destructor(call); /* we can't just delete the call because the work item may be * queued */ PREPARE_WORK(&call->async_work, afs_delete_async_call); queue_work(afs_async_calls, &call->async_work); } _leave(""); } /* * empty a socket buffer into a flat reply buffer */ void afs_transfer_reply(struct afs_call *call, struct sk_buff *skb) { size_t len = skb->len; if (skb_copy_bits(skb, 0, call->buffer + call->reply_size, len) < 0) BUG(); call->reply_size += len; } /* * accept the backlog of incoming calls */ static void afs_collect_incoming_call(struct work_struct *work) { struct rxrpc_call *rxcall; struct afs_call *call = NULL; struct sk_buff *skb; while ((skb = skb_dequeue(&afs_incoming_calls))) { _debug("new call"); /* don't need the notification */ afs_free_skb(skb); if (!call) { call = kzalloc(sizeof(struct afs_call), GFP_KERNEL); if (!call) { rxrpc_kernel_reject_call(afs_socket); return; } INIT_WORK(&call->async_work, afs_process_async_call); call->wait_mode = &afs_async_incoming_call; call->type = &afs_RXCMxxxx; init_waitqueue_head(&call->waitq); skb_queue_head_init(&call->rx_queue); call->state = AFS_CALL_AWAIT_OP_ID; _debug("CALL %p{%s} [%d]", call, call->type->name, atomic_read(&afs_outstanding_calls)); atomic_inc(&afs_outstanding_calls); } rxcall = rxrpc_kernel_accept_call(afs_socket, (unsigned long) call); if (!IS_ERR(rxcall)) { call->rxcall = rxcall; call = NULL; } } if (call) afs_free_call(call); } /* * grab the operation ID from an incoming cache manager call */ static int afs_deliver_cm_op_id(struct afs_call *call, struct sk_buff *skb, bool last) { size_t len = skb->len; void *oibuf = (void *) &call->operation_ID; _enter("{%u},{%zu},%d", call->offset, len, last); ASSERTCMP(call->offset, <, 4); /* the operation ID forms the first four bytes of the request data */ len = min_t(size_t, len, 4 - call->offset); if (skb_copy_bits(skb, 0, oibuf + call->offset, len) < 0) BUG(); if (!pskb_pull(skb, len)) BUG(); call->offset += len; if (call->offset < 4) { if (last) { _leave(" = -EBADMSG [op ID short]"); return -EBADMSG; } _leave(" = 0 [incomplete]"); return 0; } call->state = AFS_CALL_AWAIT_REQUEST; /* ask the cache manager to route the call (it'll change the call type * if successful) */ if (!afs_cm_incoming_call(call)) return -ENOTSUPP; /* pass responsibility for the remainer of this message off to the * cache manager op */ return call->type->deliver(call, skb, last); } /* * send an empty reply */ void afs_send_empty_reply(struct afs_call *call) { struct msghdr msg; struct iovec iov[1]; _enter(""); iov[0].iov_base = NULL; iov[0].iov_len = 0; msg.msg_name = NULL; msg.msg_namelen = 0; msg.msg_iov = iov; msg.msg_iovlen = 0; msg.msg_control = NULL; msg.msg_controllen = 0; msg.msg_flags = 0; call->state = AFS_CALL_AWAIT_ACK; switch (rxrpc_kernel_send_data(call->rxcall, &msg, 0)) { case 0: _leave(" [replied]"); return; case -ENOMEM: _debug("oom"); rxrpc_kernel_abort_call(call->rxcall, RX_USER_ABORT); default: rxrpc_kernel_end_call(call->rxcall); call->rxcall = NULL; call->type->destructor(call); afs_free_call(call); _leave(" [error]"); return; } } /* * send a simple reply */ void afs_send_simple_reply(struct afs_call *call, const void *buf, size_t len) { struct msghdr msg; struct iovec iov[1]; int n; _enter(""); iov[0].iov_base = (void *) buf; iov[0].iov_len = len; msg.msg_name = NULL; msg.msg_namelen = 0; msg.msg_iov = iov; msg.msg_iovlen = 1; msg.msg_control = NULL; msg.msg_controllen = 0; msg.msg_flags = 0; call->state = AFS_CALL_AWAIT_ACK; n = rxrpc_kernel_send_data(call->rxcall, &msg, len); if (n >= 0) { _leave(" [replied]"); return; } if (n == -ENOMEM) { _debug("oom"); rxrpc_kernel_abort_call(call->rxcall, RX_USER_ABORT); } rxrpc_kernel_end_call(call->rxcall); call->rxcall = NULL; call->type->destructor(call); afs_free_call(call); _leave(" [error]"); } /* * extract a piece of data from the received data socket buffers */ int afs_extract_data(struct afs_call *call, struct sk_buff *skb, bool last, void *buf, size_t count) { size_t len = skb->len; _enter("{%u},{%zu},%d,,%zu", call->offset, len, last, count); ASSERTCMP(call->offset, <, count); len = min_t(size_t, len, count - call->offset); if (skb_copy_bits(skb, 0, buf + call->offset, len) < 0 || !pskb_pull(skb, len)) BUG(); call->offset += len; if (call->offset < count) { if (last) { _leave(" = -EBADMSG [%d < %zu]", call->offset, count); return -EBADMSG; } _leave(" = -EAGAIN"); return -EAGAIN; } return 0; }