diff options
Diffstat (limited to 'net/rxrpc/call_accept.c')
| -rw-r--r-- | net/rxrpc/call_accept.c | 476 |
1 files changed, 476 insertions, 0 deletions
diff --git a/net/rxrpc/call_accept.c b/net/rxrpc/call_accept.c new file mode 100644 index 000000000000..0b2832141bd0 --- /dev/null +++ b/net/rxrpc/call_accept.c @@ -0,0 +1,476 @@ +/* incoming 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. + */ + +#define pr_fmt(fmt) KBUILD_MODNAME ": " fmt + +#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 <linux/gfp.h> +#include <net/sock.h> +#include <net/af_rxrpc.h> +#include <net/ip.h> +#include "ar-internal.h" + +/* + * generate a connection-level abort + */ +static int rxrpc_busy(struct rxrpc_local *local, struct sockaddr_rxrpc *srx, + struct rxrpc_wire_header *whdr) +{ + struct msghdr msg; + struct kvec iov[1]; + size_t len; + int ret; + + _enter("%d,,", local->debug_id); + + whdr->type = RXRPC_PACKET_TYPE_BUSY; + whdr->serial = htonl(1); + + msg.msg_name = &srx->transport.sin; + msg.msg_namelen = sizeof(srx->transport.sin); + msg.msg_control = NULL; + msg.msg_controllen = 0; + msg.msg_flags = 0; + + iov[0].iov_base = whdr; + iov[0].iov_len = sizeof(*whdr); + + len = iov[0].iov_len; + + _proto("Tx BUSY %%1"); + + ret = kernel_sendmsg(local->socket, &msg, iov, 1, len); + if (ret < 0) { + _leave(" = -EAGAIN [sendmsg failed: %d]", ret); + return -EAGAIN; + } + + _leave(" = 0"); + return 0; +} + +/* + * accept an incoming call that needs peer, transport and/or connection setting + * up + */ +static int rxrpc_accept_incoming_call(struct rxrpc_local *local, + struct rxrpc_sock *rx, + struct sk_buff *skb, + struct sockaddr_rxrpc *srx) +{ + struct rxrpc_connection *conn; + struct rxrpc_skb_priv *sp, *nsp; + struct rxrpc_call *call; + struct sk_buff *notification; + int ret; + + _enter(""); + + sp = rxrpc_skb(skb); + + /* get a notification message to send to the server app */ + notification = alloc_skb(0, GFP_NOFS); + if (!notification) { + _debug("no memory"); + ret = -ENOMEM; + goto error_nofree; + } + rxrpc_new_skb(notification); + notification->mark = RXRPC_SKB_MARK_NEW_CALL; + + conn = rxrpc_incoming_connection(local, srx, skb); + if (IS_ERR(conn)) { + _debug("no conn"); + ret = PTR_ERR(conn); + goto error; + } + + call = rxrpc_incoming_call(rx, conn, skb); + rxrpc_put_connection(conn); + if (IS_ERR(call)) { + _debug("no call"); + ret = PTR_ERR(call); + goto error; + } + + /* attach the call to the socket */ + read_lock_bh(&local->services_lock); + if (rx->sk.sk_state == RXRPC_CLOSE) + goto invalid_service; + + write_lock(&rx->call_lock); + if (!test_and_set_bit(RXRPC_CALL_INIT_ACCEPT, &call->flags)) { + rxrpc_get_call(call); + + spin_lock(&call->conn->state_lock); + if (sp->hdr.securityIndex > 0 && + call->conn->state == RXRPC_CONN_SERVICE_UNSECURED) { + _debug("await conn sec"); + list_add_tail(&call->accept_link, &rx->secureq); + call->conn->state = RXRPC_CONN_SERVICE_CHALLENGING; + set_bit(RXRPC_CONN_EV_CHALLENGE, &call->conn->events); + rxrpc_queue_conn(call->conn); + } else { + _debug("conn ready"); + call->state = RXRPC_CALL_SERVER_ACCEPTING; + list_add_tail(&call->accept_link, &rx->acceptq); + rxrpc_get_call(call); + nsp = rxrpc_skb(notification); + nsp->call = call; + + ASSERTCMP(atomic_read(&call->usage), >=, 3); + + _debug("notify"); + spin_lock(&call->lock); + ret = rxrpc_queue_rcv_skb(call, notification, true, + false); + spin_unlock(&call->lock); + notification = NULL; + BUG_ON(ret < 0); + } + spin_unlock(&call->conn->state_lock); + + _debug("queued"); + } + write_unlock(&rx->call_lock); + + _debug("process"); + rxrpc_fast_process_packet(call, skb); + + _debug("done"); + read_unlock_bh(&local->services_lock); + rxrpc_free_skb(notification); + rxrpc_put_call(call); + _leave(" = 0"); + return 0; + +invalid_service: + _debug("invalid"); + read_unlock_bh(&local->services_lock); + + read_lock_bh(&call->state_lock); + if (!test_bit(RXRPC_CALL_RELEASED, &call->flags) && + !test_and_set_bit(RXRPC_CALL_EV_RELEASE, &call->events)) { + rxrpc_get_call(call); + rxrpc_queue_call(call); + } + read_unlock_bh(&call->state_lock); + rxrpc_put_call(call); + ret = -ECONNREFUSED; +error: + rxrpc_free_skb(notification); +error_nofree: + _leave(" = %d", ret); + return ret; +} + +/* + * accept incoming calls that need peer, transport and/or connection setting up + * - the packets we get are all incoming client DATA packets that have seq == 1 + */ +void rxrpc_accept_incoming_calls(struct rxrpc_local *local) +{ + struct rxrpc_skb_priv *sp; + struct sockaddr_rxrpc srx; + struct rxrpc_sock *rx; + struct rxrpc_wire_header whdr; + struct sk_buff *skb; + int ret; + + _enter("%d", local->debug_id); + + skb = skb_dequeue(&local->accept_queue); + if (!skb) { + _leave("\n"); + return; + } + + _net("incoming call skb %p", skb); + + sp = rxrpc_skb(skb); + + /* Set up a response packet header in case we need it */ + whdr.epoch = htonl(sp->hdr.epoch); + whdr.cid = htonl(sp->hdr.cid); + whdr.callNumber = htonl(sp->hdr.callNumber); + whdr.seq = htonl(sp->hdr.seq); + whdr.serial = 0; + whdr.flags = 0; + whdr.type = 0; + whdr.userStatus = 0; + whdr.securityIndex = sp->hdr.securityIndex; + whdr._rsvd = 0; + whdr.serviceId = htons(sp->hdr.serviceId); + + if (rxrpc_extract_addr_from_skb(&srx, skb) < 0) + goto drop; + + /* get the socket providing the service */ + read_lock_bh(&local->services_lock); + list_for_each_entry(rx, &local->services, listen_link) { + if (rx->srx.srx_service == sp->hdr.serviceId && + rx->sk.sk_state != RXRPC_CLOSE) + goto found_service; + } + read_unlock_bh(&local->services_lock); + goto invalid_service; + +found_service: + _debug("found service %hd", rx->srx.srx_service); + if (sk_acceptq_is_full(&rx->sk)) + goto backlog_full; + sk_acceptq_added(&rx->sk); + sock_hold(&rx->sk); + read_unlock_bh(&local->services_lock); + + ret = rxrpc_accept_incoming_call(local, rx, skb, &srx); + if (ret < 0) + sk_acceptq_removed(&rx->sk); + sock_put(&rx->sk); + switch (ret) { + case -ECONNRESET: /* old calls are ignored */ + case -ECONNABORTED: /* aborted calls are reaborted or ignored */ + case 0: + return; + case -ECONNREFUSED: + goto invalid_service; + case -EBUSY: + goto busy; + case -EKEYREJECTED: + goto security_mismatch; + default: + BUG(); + } + +backlog_full: + read_unlock_bh(&local->services_lock); +busy: + rxrpc_busy(local, &srx, &whdr); + rxrpc_free_skb(skb); + return; + +drop: + rxrpc_free_skb(skb); + return; + +invalid_service: + skb->priority = RX_INVALID_OPERATION; + rxrpc_reject_packet(local, skb); + return; + + /* can't change connection security type mid-flow */ +security_mismatch: + skb->priority = RX_PROTOCOL_ERROR; + rxrpc_reject_packet(local, skb); + return; +} + +/* + * handle acceptance of a call by userspace + * - assign the user call ID to the call at the front of the queue + */ +struct rxrpc_call *rxrpc_accept_call(struct rxrpc_sock *rx, + unsigned long user_call_ID) +{ + struct rxrpc_call *call; + struct rb_node *parent, **pp; + int ret; + + _enter(",%lx", user_call_ID); + + ASSERT(!irqs_disabled()); + + write_lock(&rx->call_lock); + + ret = -ENODATA; + if (list_empty(&rx->acceptq)) + goto out; + + /* check the user ID isn't already in use */ + ret = -EBADSLT; + 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 out; + } + + /* dequeue the first call and check it's still valid */ + call = list_entry(rx->acceptq.next, struct rxrpc_call, accept_link); + list_del_init(&call->accept_link); + sk_acceptq_removed(&rx->sk); + + write_lock_bh(&call->state_lock); + switch (call->state) { + case RXRPC_CALL_SERVER_ACCEPTING: + call->state = RXRPC_CALL_SERVER_RECV_REQUEST; + break; + case RXRPC_CALL_REMOTELY_ABORTED: + case RXRPC_CALL_LOCALLY_ABORTED: + ret = -ECONNABORTED; + goto out_release; + case RXRPC_CALL_NETWORK_ERROR: + ret = call->conn->error; + goto out_release; + case RXRPC_CALL_DEAD: + ret = -ETIME; + goto out_discard; + default: + BUG(); + } + + /* formalise the acceptance */ + call->user_call_ID = user_call_ID; + rb_link_node(&call->sock_node, parent, pp); + rb_insert_color(&call->sock_node, &rx->calls); + if (test_and_set_bit(RXRPC_CALL_HAS_USERID, &call->flags)) + BUG(); + if (test_and_set_bit(RXRPC_CALL_EV_ACCEPTED, &call->events)) + BUG(); + rxrpc_queue_call(call); + + rxrpc_get_call(call); + write_unlock_bh(&call->state_lock); + write_unlock(&rx->call_lock); + _leave(" = %p{%d}", call, call->debug_id); + return call; + + /* if the call is already dying or dead, then we leave the socket's ref + * on it to be released by rxrpc_dead_call_expired() as induced by + * rxrpc_release_call() */ +out_release: + _debug("release %p", call); + if (!test_bit(RXRPC_CALL_RELEASED, &call->flags) && + !test_and_set_bit(RXRPC_CALL_EV_RELEASE, &call->events)) + rxrpc_queue_call(call); +out_discard: + write_unlock_bh(&call->state_lock); + _debug("discard %p", call); +out: + write_unlock(&rx->call_lock); + _leave(" = %d", ret); + return ERR_PTR(ret); +} + +/* + * Handle rejection of a call by userspace + * - reject the call at the front of the queue + */ +int rxrpc_reject_call(struct rxrpc_sock *rx) +{ + struct rxrpc_call *call; + int ret; + + _enter(""); + + ASSERT(!irqs_disabled()); + + write_lock(&rx->call_lock); + + ret = -ENODATA; + if (list_empty(&rx->acceptq)) + goto out; + + /* dequeue the first call and check it's still valid */ + call = list_entry(rx->acceptq.next, struct rxrpc_call, accept_link); + list_del_init(&call->accept_link); + sk_acceptq_removed(&rx->sk); + + write_lock_bh(&call->state_lock); + switch (call->state) { + case RXRPC_CALL_SERVER_ACCEPTING: + call->state = RXRPC_CALL_SERVER_BUSY; + if (test_and_set_bit(RXRPC_CALL_EV_REJECT_BUSY, &call->events)) + rxrpc_queue_call(call); + ret = 0; + goto out_release; + case RXRPC_CALL_REMOTELY_ABORTED: + case RXRPC_CALL_LOCALLY_ABORTED: + ret = -ECONNABORTED; + goto out_release; + case RXRPC_CALL_NETWORK_ERROR: + ret = call->conn->error; + goto out_release; + case RXRPC_CALL_DEAD: + ret = -ETIME; + goto out_discard; + default: + BUG(); + } + + /* if the call is already dying or dead, then we leave the socket's ref + * on it to be released by rxrpc_dead_call_expired() as induced by + * rxrpc_release_call() */ +out_release: + _debug("release %p", call); + if (!test_bit(RXRPC_CALL_RELEASED, &call->flags) && + !test_and_set_bit(RXRPC_CALL_EV_RELEASE, &call->events)) + rxrpc_queue_call(call); +out_discard: + write_unlock_bh(&call->state_lock); + _debug("discard %p", call); +out: + write_unlock(&rx->call_lock); + _leave(" = %d", ret); + return ret; +} + +/** + * rxrpc_kernel_accept_call - Allow a kernel service to accept an incoming call + * @sock: The socket on which the impending call is waiting + * @user_call_ID: The tag to attach to the call + * + * Allow a kernel service to accept an incoming call, assuming the incoming + * call is still valid. + */ +struct rxrpc_call *rxrpc_kernel_accept_call(struct socket *sock, + unsigned long user_call_ID) +{ + struct rxrpc_call *call; + + _enter(",%lx", user_call_ID); + call = rxrpc_accept_call(rxrpc_sk(sock->sk), user_call_ID); + _leave(" = %p", call); + return call; +} +EXPORT_SYMBOL(rxrpc_kernel_accept_call); + +/** + * rxrpc_kernel_reject_call - Allow a kernel service to reject an incoming call + * @sock: The socket on which the impending call is waiting + * + * Allow a kernel service to reject an incoming call with a BUSY message, + * assuming the incoming call is still valid. + */ +int rxrpc_kernel_reject_call(struct socket *sock) +{ + int ret; + + _enter(""); + ret = rxrpc_reject_call(rxrpc_sk(sock->sk)); + _leave(" = %d", ret); + return ret; +} +EXPORT_SYMBOL(rxrpc_kernel_reject_call); |