/* krxsecd.c: Rx security daemon * * Copyright (C) 2002 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. * * This daemon deals with: * - consulting the application as to whether inbound peers and calls should be authorised * - generating security challenges for inbound connections * - responding to security challenges on outbound connections */ #include <linux/module.h> #include <linux/sched.h> #include <linux/completion.h> #include <linux/spinlock.h> #include <linux/init.h> #include <rxrpc/krxsecd.h> #include <rxrpc/transport.h> #include <rxrpc/connection.h> #include <rxrpc/message.h> #include <rxrpc/peer.h> #include <rxrpc/call.h> #include <linux/udp.h> #include <linux/ip.h> #include <linux/freezer.h> #include <net/sock.h> #include "internal.h" static DECLARE_WAIT_QUEUE_HEAD(rxrpc_krxsecd_sleepq); static DECLARE_COMPLETION(rxrpc_krxsecd_dead); static volatile int rxrpc_krxsecd_die; static atomic_t rxrpc_krxsecd_qcount; /* queue of unprocessed inbound messages with seqno #1 and * RXRPC_CLIENT_INITIATED flag set */ static LIST_HEAD(rxrpc_krxsecd_initmsgq); static DEFINE_SPINLOCK(rxrpc_krxsecd_initmsgq_lock); static void rxrpc_krxsecd_process_incoming_call(struct rxrpc_message *msg); /*****************************************************************************/ /* * Rx security daemon */ static int rxrpc_krxsecd(void *arg) { DECLARE_WAITQUEUE(krxsecd, current); int die; printk("Started krxsecd %d\n", current->pid); daemonize("krxsecd"); /* loop around waiting for work to do */ do { /* wait for work or to be told to exit */ _debug("### Begin Wait"); if (!atomic_read(&rxrpc_krxsecd_qcount)) { set_current_state(TASK_INTERRUPTIBLE); add_wait_queue(&rxrpc_krxsecd_sleepq, &krxsecd); for (;;) { set_current_state(TASK_INTERRUPTIBLE); if (atomic_read(&rxrpc_krxsecd_qcount) || rxrpc_krxsecd_die || signal_pending(current)) break; schedule(); } remove_wait_queue(&rxrpc_krxsecd_sleepq, &krxsecd); set_current_state(TASK_RUNNING); } die = rxrpc_krxsecd_die; _debug("### End Wait"); /* see if there're incoming calls in need of authenticating */ _debug("### Begin Inbound Calls"); if (!list_empty(&rxrpc_krxsecd_initmsgq)) { struct rxrpc_message *msg = NULL; spin_lock(&rxrpc_krxsecd_initmsgq_lock); if (!list_empty(&rxrpc_krxsecd_initmsgq)) { msg = list_entry(rxrpc_krxsecd_initmsgq.next, struct rxrpc_message, link); list_del_init(&msg->link); atomic_dec(&rxrpc_krxsecd_qcount); } spin_unlock(&rxrpc_krxsecd_initmsgq_lock); if (msg) { rxrpc_krxsecd_process_incoming_call(msg); rxrpc_put_message(msg); } } _debug("### End Inbound Calls"); try_to_freeze(); /* discard pending signals */ rxrpc_discard_my_signals(); } while (!die); /* and that's all */ complete_and_exit(&rxrpc_krxsecd_dead, 0); } /* end rxrpc_krxsecd() */ /*****************************************************************************/ /* * start up a krxsecd daemon */ int __init rxrpc_krxsecd_init(void) { return kernel_thread(rxrpc_krxsecd, NULL, 0); } /* end rxrpc_krxsecd_init() */ /*****************************************************************************/ /* * kill the krxsecd daemon and wait for it to complete */ void rxrpc_krxsecd_kill(void) { rxrpc_krxsecd_die = 1; wake_up_all(&rxrpc_krxsecd_sleepq); wait_for_completion(&rxrpc_krxsecd_dead); } /* end rxrpc_krxsecd_kill() */ /*****************************************************************************/ /* * clear all pending incoming calls for the specified transport */ void rxrpc_krxsecd_clear_transport(struct rxrpc_transport *trans) { LIST_HEAD(tmp); struct rxrpc_message *msg; struct list_head *_p, *_n; _enter("%p",trans); /* move all the messages for this transport onto a temp list */ spin_lock(&rxrpc_krxsecd_initmsgq_lock); list_for_each_safe(_p, _n, &rxrpc_krxsecd_initmsgq) { msg = list_entry(_p, struct rxrpc_message, link); if (msg->trans == trans) { list_move_tail(&msg->link, &tmp); atomic_dec(&rxrpc_krxsecd_qcount); } } spin_unlock(&rxrpc_krxsecd_initmsgq_lock); /* zap all messages on the temp list */ while (!list_empty(&tmp)) { msg = list_entry(tmp.next, struct rxrpc_message, link); list_del_init(&msg->link); rxrpc_put_message(msg); } _leave(""); } /* end rxrpc_krxsecd_clear_transport() */ /*****************************************************************************/ /* * queue a message on the incoming calls list */ void rxrpc_krxsecd_queue_incoming_call(struct rxrpc_message *msg) { _enter("%p", msg); /* queue for processing by krxsecd */ spin_lock(&rxrpc_krxsecd_initmsgq_lock); if (!rxrpc_krxsecd_die) { rxrpc_get_message(msg); list_add_tail(&msg->link, &rxrpc_krxsecd_initmsgq); atomic_inc(&rxrpc_krxsecd_qcount); } spin_unlock(&rxrpc_krxsecd_initmsgq_lock); wake_up(&rxrpc_krxsecd_sleepq); _leave(""); } /* end rxrpc_krxsecd_queue_incoming_call() */ /*****************************************************************************/ /* * process the initial message of an incoming call */ void rxrpc_krxsecd_process_incoming_call(struct rxrpc_message *msg) { struct rxrpc_transport *trans = msg->trans; struct rxrpc_service *srv; struct rxrpc_call *call; struct list_head *_p; unsigned short sid; int ret; _enter("%p{tr=%p}", msg, trans); ret = rxrpc_incoming_call(msg->conn, msg, &call); if (ret < 0) goto out; /* find the matching service on the transport */ sid = ntohs(msg->hdr.serviceId); srv = NULL; spin_lock(&trans->lock); list_for_each(_p, &trans->services) { srv = list_entry(_p, struct rxrpc_service, link); if (srv->service_id == sid && try_module_get(srv->owner)) { /* found a match (made sure it won't vanish) */ _debug("found service '%s'", srv->name); call->owner = srv->owner; break; } } spin_unlock(&trans->lock); /* report the new connection * - the func must inc the call's usage count to keep it */ ret = -ENOENT; if (_p != &trans->services) { /* attempt to accept the call */ call->conn->service = srv; call->app_attn_func = srv->attn_func; call->app_error_func = srv->error_func; call->app_aemap_func = srv->aemap_func; ret = srv->new_call(call); /* send an abort if an error occurred */ if (ret < 0) { rxrpc_call_abort(call, ret); } else { /* formally receive and ACK the new packet */ ret = rxrpc_conn_receive_call_packet(call->conn, call, msg); } } rxrpc_put_call(call); out: if (ret < 0) rxrpc_trans_immediate_abort(trans, msg, ret); _leave(" (%d)", ret); } /* end rxrpc_krxsecd_process_incoming_call() */