deb3a26ded485f79855516fcd2c1c5f9772761b6
[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
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->buf);
68 free(ct->user);
69 free(ct->config_file);
70 free(ct->key_file);
71 client_cmdline_parser_free(&ct->conf);
72 free(ct);
73 }
74
75 /**
76 * The preselect hook for server commands.
77 *
78 * \param s Pointer to the scheduler.
79 * \param t Pointer to the task struct for this command.
80 *
81 * The task pointer must contain a pointer to the initialized client data
82 * structure as it is returned by client_open().
83 *
84 * This function checks the state of the connection and adds the file descriptor
85 * of the connection to the read or write fd set of \a s accordingly.
86 *
87 * \sa register_task() client_open(), struct sched, struct task.
88 */
89 static void client_pre_select(struct sched *s, struct task *t)
90 {
91 struct client_task *ct = container_of(t, struct client_task, task);
92
93 ct->check_r = 0;
94 ct->check_w = 0;
95 if (ct->fd < 0)
96 return;
97 switch (ct->status) {
98 case CL_CONNECTED:
99 case CL_SENT_AUTH:
100 case CL_SENT_CH_RESPONSE:
101 case CL_SENT_COMMAND:
102 para_fd_set(ct->fd, &s->rfds, &s->max_fileno);
103 ct->check_r = 1;
104 return;
105
106 case CL_RECEIVED_WELCOME:
107 case CL_RECEIVED_CHALLENGE:
108 case CL_RECEIVED_PROCEED:
109 para_fd_set(ct->fd, &s->wfds, &s->max_fileno);
110 ct->check_w = 1;
111 return;
112
113 case CL_RECEIVING:
114 if (ct->loaded < CLIENT_BUFSIZE - 1) {
115 para_fd_set(ct->fd, &s->rfds, &s->max_fileno);
116 ct->check_r = 1;
117 }
118 return;
119 case CL_SENDING:
120 if (!ct->in_loaded) /* stdin task not yet started */
121 return;
122 if (*ct->in_loaded) {
123 PARA_INFO_LOG("loaded: %zd\n", *ct->in_loaded);
124 para_fd_set(ct->fd, &s->wfds, &s->max_fileno);
125 ct->check_w = 1;
126 } else {
127 if (*ct->in_error) {
128 t->error = *ct->in_error;
129 s->timeout.tv_sec = 0;
130 s->timeout.tv_usec = 1;
131 }
132 }
133 return;
134 }
135 }
136
137 static ssize_t client_recv_buffer(struct client_task *ct)
138 {
139 ssize_t ret = recv_buffer(ct->fd, ct->buf + ct->loaded,
140 CLIENT_BUFSIZE - ct->loaded);
141 if (!ret)
142 return -E_SERVER_EOF;
143 if (ret > 0)
144 ct->loaded += ret;
145 return ret;
146
147 }
148
149 /**
150 * The post select hook for client commands.
151 *
152 * \param s Pointer to the scheduler.
153 * \param t Pointer to the task struct for this command.
154 *
155 * Depending on the current state of the connection and the status of the read
156 * and write fd sets of \a s, this function performs the necessary steps to
157 * authenticate the connection, to send the command given by \a t->private_data
158 * and to receive para_server's output, if any.
159 *
160 * \sa struct sched, struct task.
161 */
162 static void client_post_select(struct sched *s, struct task *t)
163 {
164 struct client_task *ct = container_of(t, struct client_task, task);
165
166 t->error = 0;
167 if (ct->fd < 0)
168 return;
169 if (!ct->check_r && !ct->check_w)
170 return;
171 if (ct->check_r && !FD_ISSET(ct->fd, &s->rfds))
172 return;
173 if (ct->check_w && !FD_ISSET(ct->fd, &s->wfds))
174 return;
175 switch (ct->status) {
176 case CL_CONNECTED: /* receive welcome message */
177 t->error = client_recv_buffer(ct);
178 if (t->error > 0)
179 ct->status = CL_RECEIVED_WELCOME;
180 return;
181 case CL_RECEIVED_WELCOME: /* send auth command */
182 sprintf(ct->buf, "auth rc4 %s", ct->user);
183 PARA_INFO_LOG("--> %s\n", ct->buf);
184 t->error = send_buffer(ct->fd, ct->buf);
185 if (t->error >= 0)
186 ct->status = CL_SENT_AUTH;
187 return;
188 case CL_SENT_AUTH: /* receive challenge number */
189 ct->loaded = 0;
190 t->error = client_recv_buffer(ct);
191 if (t->error < 0)
192 return;
193 if (t->error != 64) {
194 t->error = -E_INVALID_CHALLENGE;
195 PARA_ERROR_LOG("received the following: %s\n", ct->buf);
196 return;
197 }
198 PARA_INFO_LOG("<-- [challenge]\n");
199 /* decrypt challenge number */
200 t->error = para_decrypt_challenge(ct->key_file, &ct->challenge_nr,
201 (unsigned char *) ct->buf, 64);
202 if (t->error > 0)
203 ct->status = CL_RECEIVED_CHALLENGE;
204 return;
205 case CL_RECEIVED_CHALLENGE: /* send decrypted challenge */
206 PARA_INFO_LOG("--> %lu\n", ct->challenge_nr);
207 t->error = send_va_buffer(ct->fd, "%s%lu", CHALLENGE_RESPONSE_MSG,
208 ct->challenge_nr);
209 if (t->error > 0)
210 ct->status = CL_SENT_CH_RESPONSE;
211 return;
212 case CL_SENT_CH_RESPONSE: /* read server response */
213 {
214 size_t bytes_received;
215 unsigned char rc4_buf[2 * RC4_KEY_LEN] = "";
216 ct->loaded = 0;
217 t->error = client_recv_buffer(ct);
218 if (t->error < 0)
219 return;
220 bytes_received = t->error;
221 PARA_DEBUG_LOG("++++ server info ++++\n%s\n++++ end of server "
222 "info ++++\n", ct->buf);
223 /* check if server has sent "Proceed" message and the rc4 keys */
224 t->error = -E_CLIENT_AUTH;
225 if (bytes_received < PROCEED_MSG_LEN + 2 * RC4_KEY_LEN)
226 return;
227 if (!strstr(ct->buf, PROCEED_MSG))
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 ct->status = CL_RECEIVED_PROCEED;
239 return;
240 }
241 case CL_RECEIVED_PROCEED: /* concat args and send command */
242 {
243 int i;
244 char *command = NULL;
245 for (i = 0; i < ct->conf.inputs_num; i++) {
246 char *tmp = command;
247 command = make_message("%s\n%s", command?
248 command : "", ct->conf.inputs[i]);
249 free(tmp);
250 }
251 command = para_strcat(command, EOC_MSG "\n");
252 PARA_DEBUG_LOG("--> %s\n", command);
253 t->error = send_buffer(ct->fd, command);
254 free(command);
255 if (t->error > 0)
256 ct->status = CL_SENT_COMMAND;
257 return;
258 }
259 case CL_SENT_COMMAND:
260 ct->loaded = 0;
261 t->error = client_recv_buffer(ct);
262 if (t->error < 0)
263 return;
264 if (strstr(ct->buf, AWAITING_DATA_MSG))
265 ct->status = CL_SENDING;
266 else
267 ct->status = CL_RECEIVING;
268 return;
269 case CL_SENDING: /* FIXME: might block */
270 PARA_INFO_LOG("loaded: %zd\n", *ct->in_loaded);
271 t->error = send_bin_buffer(ct->fd, ct->inbuf, *ct->in_loaded);
272 if (t->error < 0)
273 return;
274 *ct->in_loaded = 0;
275 return;
276 case CL_RECEIVING:
277 t->error = client_recv_buffer(ct);
278 return;
279 }
280 }
281
282 /* connect to para_server and register the client task */
283 static int client_connect(struct client_task *ct)
284 {
285 int ret;
286
287 ct->fd = -1;
288 ret = makesock(AF_UNSPEC, IPPROTO_TCP, 0, ct->conf.hostname_arg,
289 ct->conf.server_port_arg);
290 if (ret < 0)
291 return ret;
292 ct->fd = ret;
293 ct->status = CL_CONNECTED;
294 ret = mark_fd_nonblocking(ct->fd);
295 if (ret < 0)
296 goto err_out;
297 ct->task.pre_select = client_pre_select;
298 ct->task.post_select = client_post_select;
299 sprintf(ct->task.status, "client");
300 register_task(&ct->task);
301 return 1;
302 err_out:
303 close(ct->fd);
304 ct->fd = -1;
305 return ret;
306 }
307
308 /**
309 * Open connection to para_server.
310 *
311 * \param argc Usual argument count.
312 * \param argv Usual argument vector.
313 * \param ct_ptr Points to dynamically allocated and initialized client task
314 * struct upon successful return.
315 * \param loglevel If not \p NULL, the number of the loglevel is stored here.
316 *
317 * Check the command line options given by \a argc and argv, set default values
318 * for user name and rsa key file, read further option from the config file.
319 * Finally, establish a connection to para_server.
320 *
321 * \return Standard.
322 */
323 int client_open(int argc, char *argv[], struct client_task **ct_ptr,
324 int *loglevel)
325 {
326 char *home = para_homedir();
327 int ret;
328 struct client_task *ct = para_calloc(sizeof(struct client_task));
329
330 ct->buf = para_malloc(CLIENT_BUFSIZE);
331 *ct_ptr = ct;
332 ct->fd = -1;
333 ret = -E_CLIENT_SYNTAX;
334 if (client_cmdline_parser(argc, argv, &ct->conf))
335 goto out;
336 HANDLE_VERSION_FLAG("client", ct->conf);
337 ret = -E_CLIENT_SYNTAX;
338 if (!ct->conf.inputs_num)
339 goto out;
340 ct->user = ct->conf.user_given?
341 para_strdup(ct->conf.user_arg) : para_logname();
342
343 ct->key_file = ct->conf.key_file_given?
344 para_strdup(ct->conf.key_file_arg) :
345 make_message("%s/.paraslash/key.%s", home, ct->user);
346
347 ct->config_file = ct->conf.config_file_given?
348 para_strdup(ct->conf.config_file_arg) :
349 make_message("%s/.paraslash/client.conf", home);
350 ret = file_exists(ct->config_file);
351 if (!ret && ct->conf.config_file_given) {
352 ret = -E_NO_CONFIG;
353 goto out;
354 }
355 if (ret) {
356 struct client_cmdline_parser_params params = {
357 .override = 0,
358 .initialize = 0,
359 .check_required = 0,
360 .check_ambiguity = 0,
361 .print_errors = 0
362 };
363 ret = -E_BAD_CONFIG;
364 if (client_cmdline_parser_config_file(ct->config_file,
365 &ct->conf, &params))
366 goto out;
367 }
368 if (loglevel)
369 *loglevel = get_loglevel_by_name(ct->conf.loglevel_arg);
370 PARA_INFO_LOG("loglevel: %s\n", ct->conf.loglevel_arg);
371 PARA_INFO_LOG("config_file: %s\n", ct->config_file);
372 PARA_INFO_LOG("key_file: %s\n", ct->key_file);
373 PARA_NOTICE_LOG("connecting %s:%d\n", ct->conf.hostname_arg,
374 ct->conf.server_port_arg);
375 ret = client_connect(ct);
376 out:
377 free(home);
378 if (ret < 0) {
379 PARA_ERROR_LOG("%s\n", para_strerror(-ret));
380 client_close(ct);
381 *ct_ptr = NULL;
382 }
383 return ret;
384 }