blob: 6020c89d9228846b6478e03dacd7860e7beb01ce [file] [log] [blame]
Linus Torvalds1da177e2005-04-16 15:20:36 -07001/* krxsecd.c: Rx security daemon
2 *
3 * Copyright (C) 2002 Red Hat, Inc. All Rights Reserved.
4 * Written by David Howells (dhowells@redhat.com)
5 *
6 * This program is free software; you can redistribute it and/or
7 * modify it under the terms of the GNU General Public License
8 * as published by the Free Software Foundation; either version
9 * 2 of the License, or (at your option) any later version.
10 *
11 * This daemon deals with:
12 * - consulting the application as to whether inbound peers and calls should be authorised
13 * - generating security challenges for inbound connections
14 * - responding to security challenges on outbound connections
15 */
16
17#include <linux/module.h>
18#include <linux/sched.h>
19#include <linux/completion.h>
20#include <linux/spinlock.h>
21#include <linux/init.h>
22#include <rxrpc/krxsecd.h>
23#include <rxrpc/transport.h>
24#include <rxrpc/connection.h>
25#include <rxrpc/message.h>
26#include <rxrpc/peer.h>
27#include <rxrpc/call.h>
28#include <linux/udp.h>
29#include <linux/ip.h>
30#include <net/sock.h>
31#include "internal.h"
32
33static DECLARE_WAIT_QUEUE_HEAD(rxrpc_krxsecd_sleepq);
34static DECLARE_COMPLETION(rxrpc_krxsecd_dead);
35static volatile int rxrpc_krxsecd_die;
36
37static atomic_t rxrpc_krxsecd_qcount;
38
39/* queue of unprocessed inbound messages with seqno #1 and
40 * RXRPC_CLIENT_INITIATED flag set */
41static LIST_HEAD(rxrpc_krxsecd_initmsgq);
42static DEFINE_SPINLOCK(rxrpc_krxsecd_initmsgq_lock);
43
44static void rxrpc_krxsecd_process_incoming_call(struct rxrpc_message *msg);
45
46/*****************************************************************************/
47/*
48 * Rx security daemon
49 */
50static int rxrpc_krxsecd(void *arg)
51{
52 DECLARE_WAITQUEUE(krxsecd, current);
53
54 int die;
55
56 printk("Started krxsecd %d\n", current->pid);
57
58 daemonize("krxsecd");
59
60 /* loop around waiting for work to do */
61 do {
62 /* wait for work or to be told to exit */
63 _debug("### Begin Wait");
64 if (!atomic_read(&rxrpc_krxsecd_qcount)) {
65 set_current_state(TASK_INTERRUPTIBLE);
66
67 add_wait_queue(&rxrpc_krxsecd_sleepq, &krxsecd);
68
69 for (;;) {
70 set_current_state(TASK_INTERRUPTIBLE);
71 if (atomic_read(&rxrpc_krxsecd_qcount) ||
72 rxrpc_krxsecd_die ||
73 signal_pending(current))
74 break;
75
76 schedule();
77 }
78
79 remove_wait_queue(&rxrpc_krxsecd_sleepq, &krxsecd);
80 set_current_state(TASK_RUNNING);
81 }
82 die = rxrpc_krxsecd_die;
83 _debug("### End Wait");
84
85 /* see if there're incoming calls in need of authenticating */
86 _debug("### Begin Inbound Calls");
87
88 if (!list_empty(&rxrpc_krxsecd_initmsgq)) {
89 struct rxrpc_message *msg = NULL;
90
91 spin_lock(&rxrpc_krxsecd_initmsgq_lock);
92
93 if (!list_empty(&rxrpc_krxsecd_initmsgq)) {
94 msg = list_entry(rxrpc_krxsecd_initmsgq.next,
95 struct rxrpc_message, link);
96 list_del_init(&msg->link);
97 atomic_dec(&rxrpc_krxsecd_qcount);
98 }
99
100 spin_unlock(&rxrpc_krxsecd_initmsgq_lock);
101
102 if (msg) {
103 rxrpc_krxsecd_process_incoming_call(msg);
104 rxrpc_put_message(msg);
105 }
106 }
107
108 _debug("### End Inbound Calls");
109
110 try_to_freeze(PF_FREEZE);
111
112 /* discard pending signals */
113 rxrpc_discard_my_signals();
114
115 } while (!die);
116
117 /* and that's all */
118 complete_and_exit(&rxrpc_krxsecd_dead, 0);
119
120} /* end rxrpc_krxsecd() */
121
122/*****************************************************************************/
123/*
124 * start up a krxsecd daemon
125 */
126int __init rxrpc_krxsecd_init(void)
127{
128 return kernel_thread(rxrpc_krxsecd, NULL, 0);
129
130} /* end rxrpc_krxsecd_init() */
131
132/*****************************************************************************/
133/*
134 * kill the krxsecd daemon and wait for it to complete
135 */
136void rxrpc_krxsecd_kill(void)
137{
138 rxrpc_krxsecd_die = 1;
139 wake_up_all(&rxrpc_krxsecd_sleepq);
140 wait_for_completion(&rxrpc_krxsecd_dead);
141
142} /* end rxrpc_krxsecd_kill() */
143
144/*****************************************************************************/
145/*
146 * clear all pending incoming calls for the specified transport
147 */
148void rxrpc_krxsecd_clear_transport(struct rxrpc_transport *trans)
149{
150 LIST_HEAD(tmp);
151
152 struct rxrpc_message *msg;
153 struct list_head *_p, *_n;
154
155 _enter("%p",trans);
156
157 /* move all the messages for this transport onto a temp list */
158 spin_lock(&rxrpc_krxsecd_initmsgq_lock);
159
160 list_for_each_safe(_p, _n, &rxrpc_krxsecd_initmsgq) {
161 msg = list_entry(_p, struct rxrpc_message, link);
162 if (msg->trans == trans) {
163 list_del(&msg->link);
164 list_add_tail(&msg->link, &tmp);
165 atomic_dec(&rxrpc_krxsecd_qcount);
166 }
167 }
168
169 spin_unlock(&rxrpc_krxsecd_initmsgq_lock);
170
171 /* zap all messages on the temp list */
172 while (!list_empty(&tmp)) {
173 msg = list_entry(tmp.next, struct rxrpc_message, link);
174 list_del_init(&msg->link);
175 rxrpc_put_message(msg);
176 }
177
178 _leave("");
179} /* end rxrpc_krxsecd_clear_transport() */
180
181/*****************************************************************************/
182/*
183 * queue a message on the incoming calls list
184 */
185void rxrpc_krxsecd_queue_incoming_call(struct rxrpc_message *msg)
186{
187 _enter("%p", msg);
188
189 /* queue for processing by krxsecd */
190 spin_lock(&rxrpc_krxsecd_initmsgq_lock);
191
192 if (!rxrpc_krxsecd_die) {
193 rxrpc_get_message(msg);
194 list_add_tail(&msg->link, &rxrpc_krxsecd_initmsgq);
195 atomic_inc(&rxrpc_krxsecd_qcount);
196 }
197
198 spin_unlock(&rxrpc_krxsecd_initmsgq_lock);
199
200 wake_up(&rxrpc_krxsecd_sleepq);
201
202 _leave("");
203} /* end rxrpc_krxsecd_queue_incoming_call() */
204
205/*****************************************************************************/
206/*
207 * process the initial message of an incoming call
208 */
209void rxrpc_krxsecd_process_incoming_call(struct rxrpc_message *msg)
210{
211 struct rxrpc_transport *trans = msg->trans;
212 struct rxrpc_service *srv;
213 struct rxrpc_call *call;
214 struct list_head *_p;
215 unsigned short sid;
216 int ret;
217
218 _enter("%p{tr=%p}", msg, trans);
219
220 ret = rxrpc_incoming_call(msg->conn, msg, &call);
221 if (ret < 0)
222 goto out;
223
224 /* find the matching service on the transport */
225 sid = ntohs(msg->hdr.serviceId);
226 srv = NULL;
227
228 spin_lock(&trans->lock);
229 list_for_each(_p, &trans->services) {
230 srv = list_entry(_p, struct rxrpc_service, link);
231 if (srv->service_id == sid && try_module_get(srv->owner)) {
232 /* found a match (made sure it won't vanish) */
233 _debug("found service '%s'", srv->name);
234 call->owner = srv->owner;
235 break;
236 }
237 }
238 spin_unlock(&trans->lock);
239
240 /* report the new connection
241 * - the func must inc the call's usage count to keep it
242 */
243 ret = -ENOENT;
244 if (_p != &trans->services) {
245 /* attempt to accept the call */
246 call->conn->service = srv;
247 call->app_attn_func = srv->attn_func;
248 call->app_error_func = srv->error_func;
249 call->app_aemap_func = srv->aemap_func;
250
251 ret = srv->new_call(call);
252
253 /* send an abort if an error occurred */
254 if (ret < 0) {
255 rxrpc_call_abort(call, ret);
256 }
257 else {
258 /* formally receive and ACK the new packet */
259 ret = rxrpc_conn_receive_call_packet(call->conn,
260 call, msg);
261 }
262 }
263
264 rxrpc_put_call(call);
265 out:
266 if (ret < 0)
267 rxrpc_trans_immediate_abort(trans, msg, ret);
268
269 _leave(" (%d)", ret);
270} /* end rxrpc_krxsecd_process_incoming_call() */