unregister_task(): Set error status to E_TASK_UNREGISTERED
[paraslash.git] / client_common.c
1 /*
2 * Copyright (C) 1997-2008 Andre Noll <maan@systemlinux.org>
3 *
4 * Licensed under the GPL v2. For licencing details see COPYING.
5 */
6
7 /** \file client_common.c Common functions of para_client and para_audiod. */
8
9 #include <sys/types.h>
10 #include <dirent.h>
11
12 #include "para.h"
13 #include "error.h"
14 #include "list.h"
15 #include "sched.h"
16 #include "client.cmdline.h"
17 #include "crypt.h"
18 #include "rc4.h"
19 #include "net.h"
20 #include "fd.h"
21 #include "string.h"
22 #include "client.cmdline.h"
23 #include "client.h"
24
25 /*
26 * Rc4-encrypt data before sending.
27 *
28 * \param len The number of bytes to encrypt.
29 * \param indata Pointer to the input data of length \a len to be encrypted.
30 * \param outdata Result-pointer that holds the encrypted data.
31 * \param private_data Contains the rc4 key.
32 */
33 static void rc4_send(unsigned long len, const unsigned char *indata,
34 unsigned char *outdata, void *private_data)
35 {
36 struct client_task *ct = private_data;
37 RC4(&ct->rc4_send_key, len, indata, outdata);
38 }
39
40 /*
41 * Rc4-decrypt received data.
42 *
43 * Parameters are identical to those of rc4_send.
44 */
45 static void rc4_recv(unsigned long len, const unsigned char *indata,
46 unsigned char *outdata, void *private_data)
47 {
48 struct client_task *ct = private_data;
49 RC4(&ct->rc4_recv_key, len, indata, outdata);
50 }
51
52 /**
53 * Close the connection to para_server and free all resources.
54 *
55 * \param ct Pointer to the client data.
56 *
57 * \sa client_open.
58 */
59 void client_close(struct client_task *ct)
60 {
61 if (!ct)
62 return;
63 if (ct->fd >= 0) {
64 disable_crypt(ct->fd);
65 close(ct->fd);
66 }
67 free(ct->user);
68 free(ct->config_file);
69 free(ct->key_file);
70 client_cmdline_parser_free(&ct->conf);
71 free(ct);
72 }
73
74 /**
75 * The preselect hook for server commands.
76 *
77 * \param s Pointer to the scheduler.
78 * \param t Pointer to the task struct for this command.
79 *
80 * The task pointer must contain a pointer to the initialized client data
81 * structure as it is returned by client_open().
82 *
83 * This function checks the state of the connection and adds the file descriptor
84 * of the connection to the read or write fd set of \a s accordingly.
85 *
86 * \sa register_task() client_open(), struct sched, struct task.
87 */
88 static void client_pre_select(struct sched *s, struct task *t)
89 {
90 struct client_task *ct = container_of(t, struct client_task, task);
91
92 ct->check_r = 0;
93 ct->check_w = 0;
94 if (ct->fd < 0)
95 return;
96 switch (ct->status) {
97 case CL_CONNECTED:
98 case CL_SENT_AUTH:
99 case CL_SENT_CH_RESPONSE:
100 case CL_SENT_COMMAND:
101 para_fd_set(ct->fd, &s->rfds, &s->max_fileno);
102 ct->check_r = 1;
103 return;
104
105 case CL_RECEIVED_WELCOME:
106 case CL_RECEIVED_CHALLENGE:
107 case CL_RECEIVED_PROCEED:
108 para_fd_set(ct->fd, &s->wfds, &s->max_fileno);
109 ct->check_w = 1;
110 return;
111
112 case CL_RECEIVING:
113 if (ct->loaded < CLIENT_BUFSIZE - 1) {
114 para_fd_set(ct->fd, &s->rfds, &s->max_fileno);
115 ct->check_r = 1;
116 }
117 return;
118 case CL_SENDING:
119 if (*ct->in_loaded) {
120 PARA_INFO_LOG("loaded: %zd\n", *ct->in_loaded);
121 para_fd_set(ct->fd, &s->wfds, &s->max_fileno);
122 ct->check_w = 1;
123 } else {
124 if (*ct->in_error) {
125 t->error = *ct->in_error;
126 s->timeout.tv_sec = 0;
127 s->timeout.tv_usec = 1;
128 }
129 }
130 return;
131 }
132 }
133
134 static ssize_t client_recv_buffer(struct client_task *ct)
135 {
136 ssize_t ret = recv_buffer(ct->fd, ct->buf + ct->loaded,
137 CLIENT_BUFSIZE - ct->loaded);
138 if (!ret)
139 return -E_SERVER_EOF;
140 if (ret > 0)
141 ct->loaded += ret;
142 return ret;
143
144 }
145
146 /**
147 * The post select hook for client commands.
148 *
149 * \param s Pointer to the scheduler.
150 * \param t Pointer to the task struct for this command.
151 *
152 * Depending on the current state of the connection and the status of the read
153 * and write fd sets of \a s, this function performs the necessary steps to
154 * authenticate the connection, to send the command given by \a t->private_data
155 * and to receive para_server's output, if any.
156 *
157 * \sa struct sched, struct task.
158 */
159 static void client_post_select(struct sched *s, struct task *t)
160 {
161 struct client_task *ct = container_of(t, struct client_task, task);
162
163 t->error = 0;
164 if (ct->fd < 0)
165 return;
166 if (!ct->check_r && !ct->check_w)
167 return;
168 if (ct->check_r && !FD_ISSET(ct->fd, &s->rfds))
169 return;
170 if (ct->check_w && !FD_ISSET(ct->fd, &s->wfds))
171 return;
172 switch (ct->status) {
173 case CL_CONNECTED: /* receive welcome message */
174 t->error = client_recv_buffer(ct);
175 if (t->error > 0)
176 ct->status = CL_RECEIVED_WELCOME;
177 return;
178 case CL_RECEIVED_WELCOME: /* send auth command */
179 sprintf(ct->buf, "auth %s%s", ct->conf.plain_given?
180 "" : "rc4 ", ct->user);
181 PARA_INFO_LOG("--> %s\n", ct->buf);
182 t->error = send_buffer(ct->fd, ct->buf);
183 if (t->error >= 0)
184 ct->status = CL_SENT_AUTH;
185 return;
186 case CL_SENT_AUTH: /* receive challenge number */
187 ct->loaded = 0;
188 t->error = client_recv_buffer(ct);
189 if (t->error < 0)
190 return;
191 if (t->error != 64) {
192 t->error = -E_INVALID_CHALLENGE;
193 PARA_ERROR_LOG("received the following: %s\n", ct->buf);
194 return;
195 }
196 PARA_INFO_LOG("<-- [challenge]\n");
197 /* decrypt challenge number */
198 t->error = para_decrypt_challenge(ct->key_file, &ct->challenge_nr,
199 (unsigned char *) ct->buf, 64);
200 if (t->error > 0)
201 ct->status = CL_RECEIVED_CHALLENGE;
202 return;
203 case CL_RECEIVED_CHALLENGE: /* send decrypted challenge */
204 PARA_INFO_LOG("--> %lu\n", ct->challenge_nr);
205 t->error = send_va_buffer(ct->fd, "%s%lu", CHALLENGE_RESPONSE_MSG,
206 ct->challenge_nr);
207 if (t->error > 0)
208 ct->status = CL_SENT_CH_RESPONSE;
209 return;
210 case CL_SENT_CH_RESPONSE: /* read server response */
211 {
212 size_t bytes_received;
213 unsigned char rc4_buf[2 * RC4_KEY_LEN] = "";
214 ct->loaded = 0;
215 t->error = client_recv_buffer(ct);
216 if (t->error < 0)
217 return;
218 bytes_received = t->error;
219 PARA_DEBUG_LOG("++++ server info ++++\n%s\n++++ end of server "
220 "info ++++\n", ct->buf);
221 /* check if server has sent "Proceed" message */
222 t->error = -E_CLIENT_AUTH;
223 if (!strstr(ct->buf, PROCEED_MSG))
224 return;
225 t->error = 0;
226 ct->status = CL_RECEIVED_PROCEED;
227 if (bytes_received < PROCEED_MSG_LEN + 32)
228 return;
229 PARA_INFO_LOG("decrypting session key\n");
230 t->error = para_decrypt_buffer(ct->key_file, rc4_buf,
231 (unsigned char *)ct->buf + PROCEED_MSG_LEN + 1,
232 bytes_received - PROCEED_MSG_LEN - 1);
233 if (t->error < 0)
234 return;
235 RC4_set_key(&ct->rc4_send_key, RC4_KEY_LEN, rc4_buf);
236 RC4_set_key(&ct->rc4_recv_key, RC4_KEY_LEN, rc4_buf + RC4_KEY_LEN);
237 enable_crypt(ct->fd, rc4_recv, rc4_send, ct);
238 }
239 case CL_RECEIVED_PROCEED: /* concat args and send command */
240 {
241 int i;
242 char *command = NULL;
243 for (i = 0; i < ct->conf.inputs_num; i++) {
244 char *tmp = command;
245 command = make_message("%s\n%s", command?
246 command : "", ct->conf.inputs[i]);
247 free(tmp);
248 }
249 command = para_strcat(command, EOC_MSG "\n");
250 PARA_DEBUG_LOG("--> %s\n", command);
251 t->error = send_buffer(ct->fd, command);
252 free(command);
253 if (t->error > 0)
254 ct->status = CL_SENT_COMMAND;
255 return;
256 }
257 case CL_SENT_COMMAND:
258 ct->loaded = 0;
259 t->error = client_recv_buffer(ct);
260 if (t->error < 0)
261 return;
262 if (strstr(ct->buf, AWAITING_DATA_MSG))
263 ct->status = CL_SENDING;
264 else
265 ct->status = CL_RECEIVING;
266 return;
267 case CL_SENDING: /* FIXME: might block */
268 PARA_INFO_LOG("loaded: %zd\n", *ct->in_loaded);
269 t->error = send_bin_buffer(ct->fd, ct->inbuf, *ct->in_loaded);
270 if (t->error < 0)
271 return;
272 *ct->in_loaded = 0;
273 return;
274 case CL_RECEIVING:
275 t->error = client_recv_buffer(ct);
276 return;
277 }
278 }
279
280 /* connect to para_server and register the client task */
281 static int client_connect(struct client_task *ct)
282 {
283 int ret;
284
285 ct->fd = -1;
286 ret = makesock(AF_UNSPEC, IPPROTO_TCP, 0, ct->conf.hostname_arg,
287 ct->conf.server_port_arg);
288 if (ret < 0)
289 return ret;
290 ct->fd = ret;
291 ct->status = CL_CONNECTED;
292 ret = mark_fd_nonblocking(ct->fd);
293 if (ret < 0)
294 goto err_out;
295 ct->task.pre_select = client_pre_select;
296 ct->task.post_select = client_post_select;
297 sprintf(ct->task.status, "client");
298 register_task(&ct->task);
299 return 1;
300 err_out:
301 close(ct->fd);
302 ct->fd = -1;
303 return ret;
304 }
305
306 /**
307 * Open connection to para_server.
308 *
309 * \param argc Usual argument count.
310 * \param argv Usual argument vector.
311 * \param ct_ptr Points to dynamically allocated and initialized client task
312 * struct upon successful return.
313 *
314 * Check the command line options given by \a argc and argv, set default values
315 * for user name and rsa key file, read further option from the config file.
316 * Finally, establish a connection to para_server.
317 *
318 * \return Standard.
319 */
320 int client_open(int argc, char *argv[], struct client_task **ct_ptr)
321 {
322 char *home = para_homedir();
323 struct stat statbuf;
324 int ret;
325 struct client_task *ct = para_calloc(sizeof(struct client_task));
326
327 *ct_ptr = ct;
328 ct->fd = -1;
329 ret = client_cmdline_parser(argc, argv, &ct->conf);
330 HANDLE_VERSION_FLAG("client", ct->conf);
331 ret = -E_CLIENT_SYNTAX;
332 if (!ct->conf.inputs_num)
333 goto out;
334 ct->user = ct->conf.user_given?
335 para_strdup(ct->conf.user_arg) : para_logname();
336
337 ct->key_file = ct->conf.key_file_given?
338 para_strdup(ct->conf.key_file_arg) :
339 make_message("%s/.paraslash/key.%s", home, ct->user);
340
341 ct->config_file = ct->conf.config_file_given?
342 para_strdup(ct->conf.config_file_arg) :
343 make_message("%s/.paraslash/client.conf", home);
344 ret = stat(ct->config_file, &statbuf);
345 if (ret && ct->conf.config_file_given) {
346 ret = -E_NO_CONFIG;
347 goto out;
348 }
349 if (!ret) {
350 struct client_cmdline_parser_params params = {
351 .override = 0,
352 .initialize = 0,
353 .check_required = 0,
354 .check_ambiguity = 0
355 };
356 client_cmdline_parser_config_file(ct->config_file,
357 &ct->conf, &params);
358 }
359 ret = 1;
360 PARA_INFO_LOG("loglevel: %d\n", ct->conf.loglevel_arg);
361 PARA_INFO_LOG("config_file: %s\n", ct->config_file);
362 PARA_INFO_LOG("key_file: %s\n", ct->key_file);
363 PARA_NOTICE_LOG("connecting %s:%d\n", ct->conf.hostname_arg,
364 ct->conf.server_port_arg);
365 ret = client_connect(ct);
366 out:
367 free(home);
368 if (ret < 0) {
369 PARA_ERROR_LOG("%s\n", para_strerror(-ret));
370 client_close(ct);
371 *ct_ptr = NULL;
372 }
373 return ret;
374 }
375