7c93b91722649a2a5386db892d444702025b07bd
[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 pointer that holds the encrypted data after return
31 * \param private_data pointer to the private client data containing
32 * the rc4 key
33 * */
34 static void rc4_send(unsigned long len, const unsigned char *indata,
35 unsigned char *outdata, void *private_data)
36 {
37 struct private_client_data *pcd = private_data;
38 RC4(&pcd->rc4_send_key, len, indata, outdata);
39 }
40
41 /*
42 * rc4 decrypt received data
43 *
44 * \param len the number of bytes to decrypt
45 * \param indata pointer to the input data of length \a len
46 * \param outdata pointer that holds the decrypted data after return
47 * \param private_data pointer to the private client data containing
48 * the rc4 key
49 * */
50 static void rc4_recv(unsigned long len, const unsigned char *indata,
51 unsigned char *outdata, void *private_data)
52 {
53 struct private_client_data *pcd = private_data;
54 RC4(&pcd->rc4_recv_key, len, indata, outdata);
55 }
56
57 /**
58 * close the connection to para_server and free all resources
59 *
60 * \param pcd pointer to the client data
61 *
62 * \sa client_open.
63 * */
64 void client_close(struct private_client_data *pcd)
65 {
66 if (!pcd)
67 return;
68 if (pcd->fd >= 0) {
69 disable_crypt(pcd->fd);
70 close(pcd->fd);
71 }
72 free(pcd->user);
73 free(pcd->config_file);
74 free(pcd->key_file);
75 client_cmdline_parser_free(&pcd->conf);
76 free(pcd);
77 }
78
79 static int client_connect(struct private_client_data *pcd)
80 {
81 int ret;
82 struct hostent *he;
83 struct sockaddr_in their_addr;
84
85 pcd->fd = -1;
86 ret = get_host_info(pcd->conf.hostname_arg, &he);
87 if (ret < 0)
88 return ret;
89 /* get new socket */
90 ret = get_stream_socket(AF_INET);
91 if (ret < 0)
92 return ret;
93 pcd->fd = ret;
94 /* init their_addr */
95 init_sockaddr(&their_addr, pcd->conf.server_port_arg, he);
96 ret = PARA_CONNECT(pcd->fd, &their_addr);
97 if (ret < 0)
98 goto err_out;
99 pcd->status = CL_CONNECTED;
100 ret = mark_fd_nonblock(pcd->fd);
101 if (ret < 0)
102 goto err_out;
103 pcd->task.pre_select = client_pre_select;
104 pcd->task.post_select = client_post_select;
105 pcd->task.private_data = pcd;
106 sprintf(pcd->task.status, "client");
107 register_task(&pcd->task);
108 return 1;
109 err_out:
110 close(pcd->fd);
111 pcd->fd = -1;
112 return ret;
113 }
114
115 /**
116 * open connection to para_server
117 *
118 * \param argc usual argument count
119 * \param argv usual argument vector
120 * \param pcd_ptr points to dynamically allocated and initialized private client data
121 * upon successful return
122 *
123 * Check the command line options given by \a argc and argv, set default values
124 * for user name and rsa key file, read further option from the config file.
125 * Finally, establish a connection to para_server.
126 *
127 * \return Positive on success, negative on errors.
128 */
129 int client_open(int argc, char *argv[], struct private_client_data **pcd_ptr)
130 {
131 char *home = para_homedir();
132 struct stat statbuf;
133 int ret;
134 struct private_client_data *pcd =
135 para_calloc(sizeof(struct private_client_data));
136
137 *pcd_ptr = pcd;
138 pcd->fd = -1;
139 ret = client_cmdline_parser(argc, argv, &pcd->conf);
140 HANDLE_VERSION_FLAG("client", pcd->conf);
141 ret = -E_CLIENT_SYNTAX;
142 if (!pcd->conf.inputs_num)
143 goto out;
144 pcd->user = pcd->conf.user_given?
145 para_strdup(pcd->conf.user_arg) : para_logname();
146
147 pcd->key_file = pcd->conf.key_file_given?
148 para_strdup(pcd->conf.key_file_arg) :
149 make_message("%s/.paraslash/key.%s", home, pcd->user);
150
151 pcd->config_file = pcd->conf.config_file_given?
152 para_strdup(pcd->conf.config_file_arg) :
153 make_message("%s/.paraslash/client.conf", home);
154 ret = stat(pcd->config_file, &statbuf);
155 if (ret && pcd->conf.config_file_given) {
156 ret = -E_NO_CONFIG;
157 goto out;
158 }
159 if (!ret) {
160 struct client_cmdline_parser_params params = {
161 .override = 0,
162 .initialize = 0,
163 .check_required = 0,
164 .check_ambiguity = 0
165 };
166 client_cmdline_parser_config_file(pcd->config_file,
167 &pcd->conf, &params);
168 }
169 ret = 1;
170 PARA_INFO_LOG("loglevel: %d\n", pcd->conf.loglevel_arg);
171 PARA_INFO_LOG("config_file: %s\n", pcd->config_file);
172 PARA_INFO_LOG("key_file: %s\n", pcd->key_file);
173 PARA_NOTICE_LOG("connecting %s:%d\n", pcd->conf.hostname_arg,
174 pcd->conf.server_port_arg);
175 ret = client_connect(pcd);
176 out:
177 free(home);
178 if (ret < 0) {
179 PARA_ERROR_LOG("%s\n", PARA_STRERROR(-ret));
180 client_close(pcd);
181 *pcd_ptr = NULL;
182 }
183 return ret;
184 }
185
186 /**
187 * the preselect hook for server commands
188 *
189 * \param s pointer to the scheduler
190 * \param t pointer to the task struct for this command
191 *
192 * The task pointer must contain a pointer to the initialized client data
193 * structure as it is returned by client_open().
194 *
195 * This function checks the state of the connection and adds the file descriptor
196 * of the connection to the read or write fd set of \a s accordingly.
197 *
198 * \sa register_task() client_open(), struct sched, struct task
199 */
200 void client_pre_select(struct sched *s, struct task *t)
201 {
202 struct private_client_data *pcd = t->private_data;
203
204 t->ret = 1;
205 pcd->check_r = 0;
206 pcd->check_w = 0;
207 if (pcd->fd < 0)
208 return;
209 switch (pcd->status) {
210 case CL_CONNECTED:
211 case CL_SENT_AUTH:
212 case CL_SENT_CH_RESPONSE:
213 case CL_SENT_COMMAND:
214 para_fd_set(pcd->fd, &s->rfds, &s->max_fileno);
215 pcd->check_r = 1;
216 return;
217
218 case CL_RECEIVED_WELCOME:
219 case CL_RECEIVED_CHALLENGE:
220 case CL_RECEIVED_PROCEED:
221 para_fd_set(pcd->fd, &s->wfds, &s->max_fileno);
222 pcd->check_w = 1;
223 return;
224
225 case CL_RECEIVING:
226 if (pcd->loaded < CLIENT_BUFSIZE - 1) {
227 para_fd_set(pcd->fd, &s->rfds, &s->max_fileno);
228 pcd->check_r = 1;
229 }
230 return;
231 case CL_SENDING:
232 if (*pcd->in_loaded) {
233 PARA_INFO_LOG("loaded: %zd\n", *pcd->in_loaded);
234 para_fd_set(pcd->fd, &s->wfds, &s->max_fileno);
235 pcd->check_w = 1;
236 } else {
237 if (*pcd->in_eof) {
238 t->ret = -E_INPUT_EOF;
239 s->timeout.tv_sec = 0;
240 s->timeout.tv_usec = 1;
241 }
242 }
243 return;
244 }
245 }
246
247 static ssize_t client_recv_buffer(struct private_client_data *pcd)
248 {
249 ssize_t ret = recv_buffer(pcd->fd, pcd->buf + pcd->loaded,
250 CLIENT_BUFSIZE - pcd->loaded);
251 if (!ret)
252 return -E_SERVER_EOF;
253 if (ret > 0)
254 pcd->loaded += ret;
255 return ret;
256
257 }
258
259 /**
260 * the post select hook for client commands
261 *
262 * \param s pointer to the scheduler
263 * \param t pointer to the task struct for this command
264 *
265 * Depending on the current state of the connection and the status of the read
266 * and write fd sets of \a s, this function performs the neccessary steps to
267 * authenticate the connection, to send the commmand given by \a
268 * t->private_data and to receive para_server's output, if any.
269 *
270 * \sa struct sched, struct task
271 */
272 void client_post_select(struct sched *s, struct task *t)
273 {
274 struct private_client_data *pcd = t->private_data;
275
276 // PARA_INFO_LOG("status %d\n", pcd->status);
277 t->ret = 1;
278 if (pcd->fd < 0)
279 return;
280 if (!pcd->check_r && !pcd->check_w)
281 return;
282 if (pcd->check_r && !FD_ISSET(pcd->fd, &s->rfds))
283 return;
284 if (pcd->check_w && !FD_ISSET(pcd->fd, &s->wfds))
285 return;
286 switch (pcd->status) {
287 case CL_CONNECTED: /* receive welcome message */
288 t->ret = client_recv_buffer(pcd);
289 if (t->ret > 0)
290 pcd->status = CL_RECEIVED_WELCOME;
291 return;
292 case CL_RECEIVED_WELCOME: /* send auth command */
293 sprintf(pcd->buf, "auth %s%s", pcd->conf.plain_given?
294 "" : "rc4 ", pcd->user);
295 PARA_INFO_LOG("--> %s\n", pcd->buf);
296 t->ret = send_buffer(pcd->fd, pcd->buf);
297 if (t->ret >= 0)
298 pcd->status = CL_SENT_AUTH;
299 return;
300 case CL_SENT_AUTH: /* receive challenge number */
301 pcd->loaded = 0;
302 t->ret = client_recv_buffer(pcd);
303 if (t->ret < 0)
304 return;
305 if (t->ret != 64) {
306 t->ret = -E_INVALID_CHALLENGE;
307 PARA_ERROR_LOG("received the following: %s\n", pcd->buf);
308 return;
309 }
310 PARA_INFO_LOG("%s", "<-- [challenge]\n");
311 /* decrypt challenge number */
312 t->ret = para_decrypt_challenge(pcd->key_file, &pcd->challenge_nr,
313 (unsigned char *) pcd->buf, 64);
314 if (t->ret > 0)
315 pcd->status = CL_RECEIVED_CHALLENGE;
316 return;
317 case CL_RECEIVED_CHALLENGE: /* send decrypted challenge */
318 PARA_INFO_LOG("--> %lu\n", pcd->challenge_nr);
319 t->ret = send_va_buffer(pcd->fd, "%s%lu", CHALLENGE_RESPONSE_MSG,
320 pcd->challenge_nr);
321 if (t->ret > 0)
322 pcd->status = CL_SENT_CH_RESPONSE;
323 return;
324 case CL_SENT_CH_RESPONSE: /* read server response */
325 {
326 size_t bytes_received;
327 unsigned char rc4_buf[2 * RC4_KEY_LEN] = "";
328 pcd->loaded = 0;
329 t->ret = client_recv_buffer(pcd);
330 if (t->ret < 0)
331 return;
332 bytes_received = t->ret;
333 PARA_DEBUG_LOG("++++ server info ++++\n%s\n++++ end of server "
334 "info ++++\n", pcd->buf);
335 /* check if server has sent "Proceed" message */
336 t->ret = -E_CLIENT_AUTH;
337 if (!strstr(pcd->buf, PROCEED_MSG))
338 return;
339 t->ret = 1;
340 pcd->status = CL_RECEIVED_PROCEED;
341 if (bytes_received < PROCEED_MSG_LEN + 32)
342 return;
343 PARA_INFO_LOG("%s", "decrypting session key\n");
344 t->ret = para_decrypt_buffer(pcd->key_file, rc4_buf,
345 (unsigned char *)pcd->buf + PROCEED_MSG_LEN + 1,
346 bytes_received - PROCEED_MSG_LEN - 1);
347 if (t->ret < 0)
348 return;
349 RC4_set_key(&pcd->rc4_send_key, RC4_KEY_LEN, rc4_buf);
350 RC4_set_key(&pcd->rc4_recv_key, RC4_KEY_LEN, rc4_buf + RC4_KEY_LEN);
351 enable_crypt(pcd->fd, rc4_recv, rc4_send, pcd);
352 }
353 case CL_RECEIVED_PROCEED: /* concat args and send command */
354 {
355 int i;
356 char *command = NULL;
357 for (i = 0; i < pcd->conf.inputs_num; i++) {
358 char *tmp = command;
359 command = make_message("%s\n%s", command?
360 command : "", pcd->conf.inputs[i]);
361 free(tmp);
362 }
363 command = para_strcat(command, EOC_MSG "\n");
364 PARA_DEBUG_LOG("--> %s\n", command);
365 t->ret = send_buffer(pcd->fd, command);
366 free(command);
367 if (t->ret > 0)
368 pcd->status = CL_SENT_COMMAND;
369 return;
370 }
371 case CL_SENT_COMMAND:
372 pcd->loaded = 0;
373 t->ret = client_recv_buffer(pcd);
374 if (t->ret < 0)
375 return;
376 t->ret = -E_HANDSHAKE_COMPLETE;
377 if (strstr(pcd->buf, AWAITING_DATA_MSG))
378 pcd->status = CL_SENDING;
379 else
380 pcd->status = CL_RECEIVING;
381 return;
382 case CL_SENDING: /* FIXME: might block */
383 PARA_INFO_LOG("loaded: %zd\n", *pcd->in_loaded);
384 t->ret = send_bin_buffer(pcd->fd, pcd->inbuf, *pcd->in_loaded);
385 if (t->ret < 0)
386 return;
387 *pcd->in_loaded = 0; /* FIXME: short writes */
388 return;
389 case CL_RECEIVING:
390 t->ret = client_recv_buffer(pcd);
391 return;
392 }
393 }