b1eaa78b2db7563b699c6993509e738b12f665a8
[paraslash.git] / client_common.c
1 /*
2 * Copyright (C) 1997-2009 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 #include <openssl/rc4.h>
12
13 #include "para.h"
14 #include "error.h"
15 #include "list.h"
16 #include "sched.h"
17 #include "client.cmdline.h"
18 #include "crypt.h"
19 #include "rc4.h"
20 #include "net.h"
21 #include "fd.h"
22 #include "string.h"
23 #include "client.cmdline.h"
24 #include "client.h"
25
26 /**
27 * Close the connection to para_server and free all resources.
28 *
29 * \param ct Pointer to the client data.
30 *
31 * \sa client_open.
32 */
33 void client_close(struct client_task *ct)
34 {
35 if (!ct)
36 return;
37 if (ct->rc4c.fd >= 0)
38 close(ct->rc4c.fd);
39 free(ct->buf);
40 free(ct->user);
41 free(ct->config_file);
42 free(ct->key_file);
43 client_cmdline_parser_free(&ct->conf);
44 free(ct);
45 }
46
47 /**
48 * The preselect hook for server commands.
49 *
50 * \param s Pointer to the scheduler.
51 * \param t Pointer to the task struct for this command.
52 *
53 * The task pointer must contain a pointer to the initialized client data
54 * structure as it is returned by client_open().
55 *
56 * This function checks the state of the connection and adds the file descriptor
57 * of the connection to the read or write fd set of \a s accordingly.
58 *
59 * \sa register_task() client_open(), struct sched, struct task.
60 */
61 static void client_pre_select(struct sched *s, struct task *t)
62 {
63 struct client_task *ct = container_of(t, struct client_task, task);
64
65 ct->check_r = 0;
66 ct->check_w = 0;
67 if (ct->rc4c.fd < 0)
68 return;
69 switch (ct->status) {
70 case CL_CONNECTED:
71 case CL_SENT_AUTH:
72 case CL_SENT_CH_RESPONSE:
73 case CL_SENT_COMMAND:
74 para_fd_set(ct->rc4c.fd, &s->rfds, &s->max_fileno);
75 ct->check_r = 1;
76 return;
77
78 case CL_RECEIVED_WELCOME:
79 case CL_RECEIVED_CHALLENGE:
80 case CL_RECEIVED_PROCEED:
81 para_fd_set(ct->rc4c.fd, &s->wfds, &s->max_fileno);
82 ct->check_w = 1;
83 return;
84
85 case CL_RECEIVING:
86 if (ct->loaded < CLIENT_BUFSIZE - 1) {
87 para_fd_set(ct->rc4c.fd, &s->rfds, &s->max_fileno);
88 ct->check_r = 1;
89 }
90 return;
91 case CL_SENDING:
92 if (!ct->in_loaded) /* stdin task not yet started */
93 return;
94 if (*ct->in_loaded) {
95 PARA_INFO_LOG("loaded: %zd\n", *ct->in_loaded);
96 para_fd_set(ct->rc4c.fd, &s->wfds, &s->max_fileno);
97 ct->check_w = 1;
98 } else {
99 if (*ct->in_error) {
100 t->error = *ct->in_error;
101 s->timeout.tv_sec = 0;
102 s->timeout.tv_usec = 1;
103 }
104 }
105 return;
106 }
107 }
108
109 static ssize_t client_recv_buffer(struct client_task *ct)
110 {
111 ssize_t ret;
112
113 if (ct->status < CL_RECEIVED_PROCEED)
114 ret = recv_buffer(ct->rc4c.fd, ct->buf + ct->loaded,
115 CLIENT_BUFSIZE - ct->loaded);
116 else
117 ret = rc4_recv_buffer(&ct->rc4c, ct->buf + ct->loaded,
118 CLIENT_BUFSIZE - ct->loaded);
119 if (!ret)
120 return -E_SERVER_EOF;
121 if (ret > 0)
122 ct->loaded += ret;
123 return ret;
124
125 }
126
127 /**
128 * The post select hook for client commands.
129 *
130 * \param s Pointer to the scheduler.
131 * \param t Pointer to the task struct for this command.
132 *
133 * Depending on the current state of the connection and the status of the read
134 * and write fd sets of \a s, this function performs the necessary steps to
135 * authenticate the connection, to send the command given by \a t->private_data
136 * and to receive para_server's output, if any.
137 *
138 * \sa struct sched, struct task.
139 */
140 static void client_post_select(struct sched *s, struct task *t)
141 {
142 struct client_task *ct = container_of(t, struct client_task, task);
143
144 t->error = 0;
145 if (ct->rc4c.fd < 0)
146 return;
147 if (!ct->check_r && !ct->check_w)
148 return;
149 if (ct->check_r && !FD_ISSET(ct->rc4c.fd, &s->rfds))
150 return;
151 if (ct->check_w && !FD_ISSET(ct->rc4c.fd, &s->wfds))
152 return;
153 switch (ct->status) {
154 case CL_CONNECTED: /* receive welcome message */
155 t->error = client_recv_buffer(ct);
156 if (t->error > 0)
157 ct->status = CL_RECEIVED_WELCOME;
158 return;
159 case CL_RECEIVED_WELCOME: /* send auth command */
160 sprintf(ct->buf, "auth rc4 %s", ct->user);
161 PARA_INFO_LOG("--> %s\n", ct->buf);
162 t->error = send_buffer(ct->rc4c.fd, ct->buf);
163 if (t->error >= 0)
164 ct->status = CL_SENT_AUTH;
165 return;
166 case CL_SENT_AUTH: /* receive challenge number */
167 ct->loaded = 0;
168 t->error = client_recv_buffer(ct);
169 if (t->error < 0)
170 return;
171 if (t->error != 64) {
172 t->error = -E_INVALID_CHALLENGE;
173 PARA_ERROR_LOG("received the following: %s\n", ct->buf);
174 return;
175 }
176 PARA_INFO_LOG("<-- [challenge]\n");
177 /* decrypt challenge number */
178 t->error = para_decrypt_challenge(ct->key_file, &ct->challenge_nr,
179 (unsigned char *) ct->buf, 64);
180 if (t->error > 0)
181 ct->status = CL_RECEIVED_CHALLENGE;
182 return;
183 case CL_RECEIVED_CHALLENGE: /* send decrypted challenge */
184 PARA_INFO_LOG("--> %lu\n", ct->challenge_nr);
185 t->error = send_va_buffer(ct->rc4c.fd, "%s%lu", CHALLENGE_RESPONSE_MSG,
186 ct->challenge_nr);
187 if (t->error > 0)
188 ct->status = CL_SENT_CH_RESPONSE;
189 return;
190 case CL_SENT_CH_RESPONSE: /* read server response */
191 {
192 size_t bytes_received;
193 unsigned char rc4_buf[2 * RC4_KEY_LEN] = "";
194 ct->loaded = 0;
195 t->error = client_recv_buffer(ct);
196 if (t->error < 0)
197 return;
198 bytes_received = t->error;
199 PARA_DEBUG_LOG("++++ server info ++++\n%s\n++++ end of server "
200 "info ++++\n", ct->buf);
201 /* check if server has sent "Proceed" message and the rc4 keys */
202 t->error = -E_CLIENT_AUTH;
203 if (bytes_received < PROCEED_MSG_LEN + 2 * RC4_KEY_LEN)
204 return;
205 if (!strstr(ct->buf, PROCEED_MSG))
206 return;
207 PARA_INFO_LOG("decrypting session key\n");
208 t->error = para_decrypt_buffer(ct->key_file, rc4_buf,
209 (unsigned char *)ct->buf + PROCEED_MSG_LEN + 1,
210 bytes_received - PROCEED_MSG_LEN - 1);
211 if (t->error < 0)
212 return;
213 RC4_set_key(&ct->rc4c.send_key, RC4_KEY_LEN, rc4_buf);
214 RC4_set_key(&ct->rc4c.recv_key, RC4_KEY_LEN, rc4_buf + RC4_KEY_LEN);
215 ct->status = CL_RECEIVED_PROCEED;
216 return;
217 }
218 case CL_RECEIVED_PROCEED: /* concat args and send command */
219 {
220 int i;
221 char *command = NULL;
222 for (i = 0; i < ct->conf.inputs_num; i++) {
223 char *tmp = command;
224 command = make_message("%s\n%s", command?
225 command : "", ct->conf.inputs[i]);
226 free(tmp);
227 }
228 command = para_strcat(command, EOC_MSG "\n");
229 PARA_DEBUG_LOG("--> %s\n", command);
230 t->error = rc4_send_buffer(&ct->rc4c, command);
231 free(command);
232 if (t->error > 0)
233 ct->status = CL_SENT_COMMAND;
234 return;
235 }
236 case CL_SENT_COMMAND:
237 ct->loaded = 0;
238 t->error = client_recv_buffer(ct);
239 if (t->error < 0)
240 return;
241 if (strstr(ct->buf, AWAITING_DATA_MSG))
242 ct->status = CL_SENDING;
243 else
244 ct->status = CL_RECEIVING;
245 return;
246 case CL_SENDING: /* FIXME: might block */
247 PARA_INFO_LOG("loaded: %zd\n", *ct->in_loaded);
248 t->error = rc4_send_bin_buffer(&ct->rc4c, ct->inbuf, *ct->in_loaded);
249 if (t->error < 0)
250 return;
251 *ct->in_loaded = 0;
252 return;
253 case CL_RECEIVING:
254 t->error = client_recv_buffer(ct);
255 return;
256 }
257 }
258
259 /* connect to para_server and register the client task */
260 static int client_connect(struct client_task *ct)
261 {
262 int ret;
263
264 ct->rc4c.fd = -1;
265 ret = makesock(AF_UNSPEC, IPPROTO_TCP, 0, ct->conf.hostname_arg,
266 ct->conf.server_port_arg);
267 if (ret < 0)
268 return ret;
269 ct->rc4c.fd = ret;
270 ct->status = CL_CONNECTED;
271 ret = mark_fd_nonblocking(ct->rc4c.fd);
272 if (ret < 0)
273 goto err_out;
274 ct->task.pre_select = client_pre_select;
275 ct->task.post_select = client_post_select;
276 sprintf(ct->task.status, "client");
277 register_task(&ct->task);
278 return 1;
279 err_out:
280 close(ct->rc4c.fd);
281 ct->rc4c.fd = -1;
282 return ret;
283 }
284
285 /**
286 * Open connection to para_server.
287 *
288 * \param argc Usual argument count.
289 * \param argv Usual argument vector.
290 * \param ct_ptr Points to dynamically allocated and initialized client task
291 * struct upon successful return.
292 * \param loglevel If not \p NULL, the number of the loglevel is stored here.
293 *
294 * Check the command line options given by \a argc and argv, set default values
295 * for user name and rsa key file, read further option from the config file.
296 * Finally, establish a connection to para_server.
297 *
298 * \return Standard.
299 */
300 int client_open(int argc, char *argv[], struct client_task **ct_ptr,
301 int *loglevel)
302 {
303 char *home = para_homedir();
304 int ret;
305 struct client_task *ct = para_calloc(sizeof(struct client_task));
306
307 ct->buf = para_malloc(CLIENT_BUFSIZE);
308 *ct_ptr = ct;
309 ct->rc4c.fd = -1;
310 ret = -E_CLIENT_SYNTAX;
311 if (client_cmdline_parser(argc, argv, &ct->conf))
312 goto out;
313 HANDLE_VERSION_FLAG("client", ct->conf);
314 ret = -E_CLIENT_SYNTAX;
315 if (!ct->conf.inputs_num)
316 goto out;
317 ct->user = ct->conf.user_given?
318 para_strdup(ct->conf.user_arg) : para_logname();
319
320 ct->key_file = ct->conf.key_file_given?
321 para_strdup(ct->conf.key_file_arg) :
322 make_message("%s/.paraslash/key.%s", home, ct->user);
323
324 ct->config_file = ct->conf.config_file_given?
325 para_strdup(ct->conf.config_file_arg) :
326 make_message("%s/.paraslash/client.conf", home);
327 ret = file_exists(ct->config_file);
328 if (!ret && ct->conf.config_file_given) {
329 ret = -E_NO_CONFIG;
330 goto out;
331 }
332 if (ret) {
333 struct client_cmdline_parser_params params = {
334 .override = 0,
335 .initialize = 0,
336 .check_required = 0,
337 .check_ambiguity = 0,
338 .print_errors = 0
339 };
340 ret = -E_BAD_CONFIG;
341 if (client_cmdline_parser_config_file(ct->config_file,
342 &ct->conf, &params))
343 goto out;
344 }
345 if (loglevel)
346 *loglevel = get_loglevel_by_name(ct->conf.loglevel_arg);
347 PARA_INFO_LOG("loglevel: %s\n", ct->conf.loglevel_arg);
348 PARA_INFO_LOG("config_file: %s\n", ct->config_file);
349 PARA_INFO_LOG("key_file: %s\n", ct->key_file);
350 PARA_NOTICE_LOG("connecting %s:%d\n", ct->conf.hostname_arg,
351 ct->conf.server_port_arg);
352 ret = client_connect(ct);
353 out:
354 free(home);
355 if (ret < 0) {
356 PARA_ERROR_LOG("%s\n", para_strerror(-ret));
357 client_close(ct);
358 *ct_ptr = NULL;
359 }
360 return ret;
361 }