client_common.c: Trivial cosmetic cleanups.
[paraslash.git] / client_common.c
1 /*
2 * Copyright (C) 1997-2007 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 private_client_data *pcd = private_data;
37 RC4(&pcd->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 private_client_data *pcd = private_data;
49 RC4(&pcd->rc4_recv_key, len, indata, outdata);
50 }
51
52 /**
53 * Close the connection to para_server and free all resources.
54 *
55 * \param pcd Pointer to the client data.
56 *
57 * \sa client_open.
58 */
59 void client_close(struct private_client_data *pcd)
60 {
61 if (!pcd)
62 return;
63 if (pcd->fd >= 0) {
64 disable_crypt(pcd->fd);
65 close(pcd->fd);
66 }
67 free(pcd->user);
68 free(pcd->config_file);
69 free(pcd->key_file);
70 client_cmdline_parser_free(&pcd->conf);
71 free(pcd);
72 }
73
74 /* connect to para_server and register the client task */
75 static int client_connect(struct private_client_data *pcd)
76 {
77 int ret;
78
79 pcd->fd = -1;
80 ret = makesock(AF_UNSPEC, IPPROTO_TCP, 0, pcd->conf.hostname_arg,
81 pcd->conf.server_port_arg);
82 if (ret < 0)
83 return ret;
84 pcd->fd = ret;
85 pcd->status = CL_CONNECTED;
86 ret = mark_fd_nonblocking(pcd->fd);
87 if (ret < 0)
88 goto err_out;
89 pcd->task.pre_select = client_pre_select;
90 pcd->task.post_select = client_post_select;
91 pcd->task.private_data = pcd;
92 sprintf(pcd->task.status, "client");
93 register_task(&pcd->task);
94 return 1;
95 err_out:
96 close(pcd->fd);
97 pcd->fd = -1;
98 return ret;
99 }
100
101 /**
102 * Open connection to para_server.
103 *
104 * \param argc Usual argument count.
105 * \param argv Usual argument vector.
106 * \param pcd_ptr Points to dynamically allocated and initialized private client data
107 * upon successful return.
108 *
109 * Check the command line options given by \a argc and argv, set default values
110 * for user name and rsa key file, read further option from the config file.
111 * Finally, establish a connection to para_server.
112 *
113 * \return Standard.
114 */
115 int client_open(int argc, char *argv[], struct private_client_data **pcd_ptr)
116 {
117 char *home = para_homedir();
118 struct stat statbuf;
119 int ret;
120 struct private_client_data *pcd =
121 para_calloc(sizeof(struct private_client_data));
122
123 *pcd_ptr = pcd;
124 pcd->fd = -1;
125 ret = client_cmdline_parser(argc, argv, &pcd->conf);
126 HANDLE_VERSION_FLAG("client", pcd->conf);
127 ret = -E_CLIENT_SYNTAX;
128 if (!pcd->conf.inputs_num)
129 goto out;
130 pcd->user = pcd->conf.user_given?
131 para_strdup(pcd->conf.user_arg) : para_logname();
132
133 pcd->key_file = pcd->conf.key_file_given?
134 para_strdup(pcd->conf.key_file_arg) :
135 make_message("%s/.paraslash/key.%s", home, pcd->user);
136
137 pcd->config_file = pcd->conf.config_file_given?
138 para_strdup(pcd->conf.config_file_arg) :
139 make_message("%s/.paraslash/client.conf", home);
140 ret = stat(pcd->config_file, &statbuf);
141 if (ret && pcd->conf.config_file_given) {
142 ret = -E_NO_CONFIG;
143 goto out;
144 }
145 if (!ret) {
146 struct client_cmdline_parser_params params = {
147 .override = 0,
148 .initialize = 0,
149 .check_required = 0,
150 .check_ambiguity = 0
151 };
152 client_cmdline_parser_config_file(pcd->config_file,
153 &pcd->conf, &params);
154 }
155 ret = 1;
156 PARA_INFO_LOG("loglevel: %d\n", pcd->conf.loglevel_arg);
157 PARA_INFO_LOG("config_file: %s\n", pcd->config_file);
158 PARA_INFO_LOG("key_file: %s\n", pcd->key_file);
159 PARA_NOTICE_LOG("connecting %s:%d\n", pcd->conf.hostname_arg,
160 pcd->conf.server_port_arg);
161 ret = client_connect(pcd);
162 out:
163 free(home);
164 if (ret < 0) {
165 PARA_ERROR_LOG("%s\n", PARA_STRERROR(-ret));
166 client_close(pcd);
167 *pcd_ptr = NULL;
168 }
169 return ret;
170 }
171
172 /**
173 * The preselect hook for server commands.
174 *
175 * \param s Pointer to the scheduler.
176 * \param t Pointer to the task struct for this command.
177 *
178 * The task pointer must contain a pointer to the initialized client data
179 * structure as it is returned by client_open().
180 *
181 * This function checks the state of the connection and adds the file descriptor
182 * of the connection to the read or write fd set of \a s accordingly.
183 *
184 * \sa register_task() client_open(), struct sched, struct task.
185 */
186 void client_pre_select(struct sched *s, struct task *t)
187 {
188 struct private_client_data *pcd = t->private_data;
189
190 t->ret = 1;
191 pcd->check_r = 0;
192 pcd->check_w = 0;
193 if (pcd->fd < 0)
194 return;
195 switch (pcd->status) {
196 case CL_CONNECTED:
197 case CL_SENT_AUTH:
198 case CL_SENT_CH_RESPONSE:
199 case CL_SENT_COMMAND:
200 para_fd_set(pcd->fd, &s->rfds, &s->max_fileno);
201 pcd->check_r = 1;
202 return;
203
204 case CL_RECEIVED_WELCOME:
205 case CL_RECEIVED_CHALLENGE:
206 case CL_RECEIVED_PROCEED:
207 para_fd_set(pcd->fd, &s->wfds, &s->max_fileno);
208 pcd->check_w = 1;
209 return;
210
211 case CL_RECEIVING:
212 if (pcd->loaded < CLIENT_BUFSIZE - 1) {
213 para_fd_set(pcd->fd, &s->rfds, &s->max_fileno);
214 pcd->check_r = 1;
215 }
216 return;
217 case CL_SENDING:
218 if (*pcd->in_loaded) {
219 PARA_INFO_LOG("loaded: %zd\n", *pcd->in_loaded);
220 para_fd_set(pcd->fd, &s->wfds, &s->max_fileno);
221 pcd->check_w = 1;
222 } else {
223 if (*pcd->in_error) {
224 t->ret = *pcd->in_error;
225 s->timeout.tv_sec = 0;
226 s->timeout.tv_usec = 1;
227 }
228 }
229 return;
230 }
231 }
232
233 static ssize_t client_recv_buffer(struct private_client_data *pcd)
234 {
235 ssize_t ret = recv_buffer(pcd->fd, pcd->buf + pcd->loaded,
236 CLIENT_BUFSIZE - pcd->loaded);
237 if (!ret)
238 return -E_SERVER_EOF;
239 if (ret > 0)
240 pcd->loaded += ret;
241 return ret;
242
243 }
244
245 /**
246 * The post select hook for client commands.
247 *
248 * \param s Pointer to the scheduler.
249 * \param t Pointer to the task struct for this command.
250 *
251 * Depending on the current state of the connection and the status of the read
252 * and write fd sets of \a s, this function performs the necessary steps to
253 * authenticate the connection, to send the command given by \a t->private_data
254 * and to receive para_server's output, if any.
255 *
256 * \sa struct sched, struct task.
257 */
258 void client_post_select(struct sched *s, struct task *t)
259 {
260 struct private_client_data *pcd = t->private_data;
261
262 // PARA_INFO_LOG("status %d\n", pcd->status);
263 t->ret = 1;
264 if (pcd->fd < 0)
265 return;
266 if (!pcd->check_r && !pcd->check_w)
267 return;
268 if (pcd->check_r && !FD_ISSET(pcd->fd, &s->rfds))
269 return;
270 if (pcd->check_w && !FD_ISSET(pcd->fd, &s->wfds))
271 return;
272 switch (pcd->status) {
273 case CL_CONNECTED: /* receive welcome message */
274 t->ret = client_recv_buffer(pcd);
275 if (t->ret > 0)
276 pcd->status = CL_RECEIVED_WELCOME;
277 return;
278 case CL_RECEIVED_WELCOME: /* send auth command */
279 sprintf(pcd->buf, "auth %s%s", pcd->conf.plain_given?
280 "" : "rc4 ", pcd->user);
281 PARA_INFO_LOG("--> %s\n", pcd->buf);
282 t->ret = send_buffer(pcd->fd, pcd->buf);
283 if (t->ret >= 0)
284 pcd->status = CL_SENT_AUTH;
285 return;
286 case CL_SENT_AUTH: /* receive challenge number */
287 pcd->loaded = 0;
288 t->ret = client_recv_buffer(pcd);
289 if (t->ret < 0)
290 return;
291 if (t->ret != 64) {
292 t->ret = -E_INVALID_CHALLENGE;
293 PARA_ERROR_LOG("received the following: %s\n", pcd->buf);
294 return;
295 }
296 PARA_INFO_LOG("%s", "<-- [challenge]\n");
297 /* decrypt challenge number */
298 t->ret = para_decrypt_challenge(pcd->key_file, &pcd->challenge_nr,
299 (unsigned char *) pcd->buf, 64);
300 if (t->ret > 0)
301 pcd->status = CL_RECEIVED_CHALLENGE;
302 return;
303 case CL_RECEIVED_CHALLENGE: /* send decrypted challenge */
304 PARA_INFO_LOG("--> %lu\n", pcd->challenge_nr);
305 t->ret = send_va_buffer(pcd->fd, "%s%lu", CHALLENGE_RESPONSE_MSG,
306 pcd->challenge_nr);
307 if (t->ret > 0)
308 pcd->status = CL_SENT_CH_RESPONSE;
309 return;
310 case CL_SENT_CH_RESPONSE: /* read server response */
311 {
312 size_t bytes_received;
313 unsigned char rc4_buf[2 * RC4_KEY_LEN] = "";
314 pcd->loaded = 0;
315 t->ret = client_recv_buffer(pcd);
316 if (t->ret < 0)
317 return;
318 bytes_received = t->ret;
319 PARA_DEBUG_LOG("++++ server info ++++\n%s\n++++ end of server "
320 "info ++++\n", pcd->buf);
321 /* check if server has sent "Proceed" message */
322 t->ret = -E_CLIENT_AUTH;
323 if (!strstr(pcd->buf, PROCEED_MSG))
324 return;
325 t->ret = 1;
326 pcd->status = CL_RECEIVED_PROCEED;
327 if (bytes_received < PROCEED_MSG_LEN + 32)
328 return;
329 PARA_INFO_LOG("%s", "decrypting session key\n");
330 t->ret = para_decrypt_buffer(pcd->key_file, rc4_buf,
331 (unsigned char *)pcd->buf + PROCEED_MSG_LEN + 1,
332 bytes_received - PROCEED_MSG_LEN - 1);
333 if (t->ret < 0)
334 return;
335 RC4_set_key(&pcd->rc4_send_key, RC4_KEY_LEN, rc4_buf);
336 RC4_set_key(&pcd->rc4_recv_key, RC4_KEY_LEN, rc4_buf + RC4_KEY_LEN);
337 enable_crypt(pcd->fd, rc4_recv, rc4_send, pcd);
338 }
339 case CL_RECEIVED_PROCEED: /* concat args and send command */
340 {
341 int i;
342 char *command = NULL;
343 for (i = 0; i < pcd->conf.inputs_num; i++) {
344 char *tmp = command;
345 command = make_message("%s\n%s", command?
346 command : "", pcd->conf.inputs[i]);
347 free(tmp);
348 }
349 command = para_strcat(command, EOC_MSG "\n");
350 PARA_DEBUG_LOG("--> %s\n", command);
351 t->ret = send_buffer(pcd->fd, command);
352 free(command);
353 if (t->ret > 0)
354 pcd->status = CL_SENT_COMMAND;
355 return;
356 }
357 case CL_SENT_COMMAND:
358 pcd->loaded = 0;
359 t->ret = client_recv_buffer(pcd);
360 if (t->ret < 0)
361 return;
362 t->ret = -E_HANDSHAKE_COMPLETE;
363 if (strstr(pcd->buf, AWAITING_DATA_MSG))
364 pcd->status = CL_SENDING;
365 else
366 pcd->status = CL_RECEIVING;
367 return;
368 case CL_SENDING: /* FIXME: might block */
369 PARA_INFO_LOG("loaded: %zd\n", *pcd->in_loaded);
370 t->ret = send_bin_buffer(pcd->fd, pcd->inbuf, *pcd->in_loaded);
371 if (t->ret < 0)
372 return;
373 *pcd->in_loaded = 0;
374 return;
375 case CL_RECEIVING:
376 t->ret = client_recv_buffer(pcd);
377 return;
378 }
379 }