replace para_connect() by PARA_CONNECT.
[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 "para.h"
10 #include "error.h"
11 #include "list.h"
12 #include "sched.h"
13 #include "client.cmdline.h"
14 #include "crypt.h"
15 #include "rc4.h"
16 #include "net.h"
17 #include "fd.h"
18 #include "string.h"
19 #include "client.cmdline.h"
20 #include "client.h"
21
22 /*
23 * rc4 encrypt data before sending
24 *
25 * \param len the number of bytes to encrypt
26 * \param indata pointer to the input data of length \a len to be encrypted
27 * \param outdata pointer that holds the encrypted data after return
28 * \param private_data pointer to the private client data containing
29 * the rc4 key
30 * */
31 static void rc4_send(unsigned long len, const unsigned char *indata,
32 unsigned char *outdata, void *private_data)
33 {
34 struct private_client_data *pcd = private_data;
35 RC4(&pcd->rc4_send_key, len, indata, outdata);
36 }
37
38 /*
39 * rc4 decrypt received data
40 *
41 * \param len the number of bytes to decrypt
42 * \param indata pointer to the input data of length \a len
43 * \param outdata pointer that holds the decrypted data after return
44 * \param private_data pointer to the private client data containing
45 * the rc4 key
46 * */
47 static void rc4_recv(unsigned long len, const unsigned char *indata,
48 unsigned char *outdata, void *private_data)
49 {
50 struct private_client_data *pcd = private_data;
51 RC4(&pcd->rc4_recv_key, len, indata, outdata);
52 }
53
54 /**
55 * close the connection to para_server and free all resources
56 *
57 * \param pcd pointer to the client data
58 *
59 * \sa client_open.
60 * */
61 void client_close(struct private_client_data *pcd)
62 {
63 if (!pcd)
64 return;
65 if (pcd->fd >= 0) {
66 disable_crypt(pcd->fd);
67 close(pcd->fd);
68 }
69 free(pcd->user);
70 free(pcd->config_file);
71 free(pcd->key_file);
72 client_cmdline_parser_free(&pcd->conf);
73 free(pcd);
74 }
75
76 static int client_connect(struct private_client_data *pcd)
77 {
78 int ret;
79 struct hostent *he;
80 struct sockaddr_in their_addr;
81
82 pcd->fd = -1;
83 ret = get_host_info(pcd->conf.hostname_arg, &he);
84 if (ret < 0)
85 return ret;
86 /* get new socket */
87 ret = get_stream_socket(AF_INET);
88 if (ret < 0)
89 return ret;
90 pcd->fd = ret;
91 /* init their_addr */
92 init_sockaddr(&their_addr, pcd->conf.server_port_arg, he);
93 ret = PARA_CONNECT(pcd->fd, &their_addr);
94 if (ret < 0)
95 goto err_out;
96 pcd->status = CL_CONNECTED;
97 ret = mark_fd_nonblock(pcd->fd);
98 if (ret < 0)
99 goto err_out;
100 pcd->task.pre_select = client_pre_select;
101 pcd->task.post_select = client_post_select;
102 pcd->task.private_data = pcd;
103 sprintf(pcd->task.status, "client");
104 register_task(&pcd->task);
105 return 1;
106 err_out:
107 close(pcd->fd);
108 pcd->fd = -1;
109 return ret;
110 }
111
112 /**
113 * open connection to para_server
114 *
115 * \param argc usual argument count
116 * \param argv usual argument vector
117 * \param pcd_ptr points to dynamically allocated and initialized private client data
118 * upon successful return
119 *
120 * Check the command line options given by \a argc and argv, set default values
121 * for user name and rsa key file, read further option from the config file.
122 * Finally, establish a connection to para_server.
123 *
124 * \return Positive on success, negative on errors.
125 */
126 int client_open(int argc, char *argv[], struct private_client_data **pcd_ptr)
127 {
128 char *home = para_homedir();
129 struct stat statbuf;
130 int ret;
131 struct private_client_data *pcd =
132 para_calloc(sizeof(struct private_client_data));
133
134 *pcd_ptr = pcd;
135 pcd->fd = -1;
136 ret = client_cmdline_parser(argc, argv, &pcd->conf);
137 HANDLE_VERSION_FLAG("client", pcd->conf);
138 ret = -E_CLIENT_SYNTAX;
139 if (!pcd->conf.inputs_num)
140 goto out;
141 pcd->user = pcd->conf.user_given?
142 para_strdup(pcd->conf.user_arg) : para_logname();
143
144 pcd->key_file = pcd->conf.key_file_given?
145 para_strdup(pcd->conf.key_file_arg) :
146 make_message("%s/.paraslash/key.%s", home, pcd->user);
147
148 pcd->config_file = pcd->conf.config_file_given?
149 para_strdup(pcd->conf.config_file_arg) :
150 make_message("%s/.paraslash/client.conf", home);
151 ret = stat(pcd->config_file, &statbuf);
152 if (ret && pcd->conf.config_file_given) {
153 ret = -E_NO_CONFIG;
154 goto out;
155 }
156 if (!ret) {
157 struct client_cmdline_parser_params params = {
158 .override = 0,
159 .initialize = 0,
160 .check_required = 0,
161 .check_ambiguity = 0
162 };
163 client_cmdline_parser_config_file(pcd->config_file,
164 &pcd->conf, &params);
165 }
166 ret = 1;
167 PARA_INFO_LOG("loglevel: %d\n", pcd->conf.loglevel_arg);
168 PARA_INFO_LOG("config_file: %s\n", pcd->config_file);
169 PARA_INFO_LOG("key_file: %s\n", pcd->key_file);
170 PARA_NOTICE_LOG("connecting %s:%d\n", pcd->conf.hostname_arg,
171 pcd->conf.server_port_arg);
172 ret = client_connect(pcd);
173 out:
174 free(home);
175 if (ret < 0) {
176 PARA_ERROR_LOG("%s\n", PARA_STRERROR(-ret));
177 client_close(pcd);
178 *pcd_ptr = NULL;
179 }
180 return ret;
181 }
182
183 /**
184 * the preselect hook for server commands
185 *
186 * \param s pointer to the scheduler
187 * \param t pointer to the task struct for this command
188 *
189 * The task pointer must contain a pointer to the initialized client data
190 * structure as it is returned by client_open().
191 *
192 * This function checks the state of the connection and adds the file descriptor
193 * of the connection to the read or write fd set of \a s accordingly.
194 *
195 * \sa register_task() client_open(), struct sched, struct task
196 */
197 void client_pre_select(struct sched *s, struct task *t)
198 {
199 struct private_client_data *pcd = t->private_data;
200
201 t->ret = 1;
202 pcd->check_r = 0;
203 pcd->check_w = 0;
204 if (pcd->fd < 0)
205 return;
206 switch (pcd->status) {
207 case CL_CONNECTED:
208 case CL_SENT_AUTH:
209 case CL_SENT_CH_RESPONSE:
210 case CL_SENT_COMMAND:
211 para_fd_set(pcd->fd, &s->rfds, &s->max_fileno);
212 pcd->check_r = 1;
213 return;
214
215 case CL_RECEIVED_WELCOME:
216 case CL_RECEIVED_CHALLENGE:
217 case CL_RECEIVED_PROCEED:
218 para_fd_set(pcd->fd, &s->wfds, &s->max_fileno);
219 pcd->check_w = 1;
220 return;
221
222 case CL_RECEIVING:
223 if (pcd->loaded < CLIENT_BUFSIZE - 1) {
224 para_fd_set(pcd->fd, &s->rfds, &s->max_fileno);
225 pcd->check_r = 1;
226 }
227 return;
228 case CL_SENDING:
229 if (*pcd->in_loaded) {
230 PARA_INFO_LOG("loaded: %zd\n", *pcd->in_loaded);
231 para_fd_set(pcd->fd, &s->wfds, &s->max_fileno);
232 pcd->check_w = 1;
233 } else {
234 if (*pcd->in_eof) {
235 t->ret = -E_INPUT_EOF;
236 s->timeout.tv_sec = 0;
237 s->timeout.tv_usec = 1;
238 }
239 }
240 return;
241 }
242 }
243
244 static ssize_t client_recv_buffer(struct private_client_data *pcd)
245 {
246 ssize_t ret = recv_buffer(pcd->fd, pcd->buf + pcd->loaded,
247 CLIENT_BUFSIZE - pcd->loaded);
248 if (!ret)
249 return -E_SERVER_EOF;
250 if (ret > 0)
251 pcd->loaded += ret;
252 return ret;
253
254 }
255
256 /**
257 * the post select hook for client commands
258 *
259 * \param s pointer to the scheduler
260 * \param t pointer to the task struct for this command
261 *
262 * Depending on the current state of the connection and the status of the read
263 * and write fd sets of \a s, this function performs the neccessary steps to
264 * authenticate the connection, to send the commmand given by \a
265 * t->private_data and to receive para_server's output, if any.
266 *
267 * \sa struct sched, struct task
268 */
269 void client_post_select(struct sched *s, struct task *t)
270 {
271 struct private_client_data *pcd = t->private_data;
272
273 // PARA_INFO_LOG("status %d\n", pcd->status);
274 t->ret = 1;
275 if (pcd->fd < 0)
276 return;
277 if (!pcd->check_r && !pcd->check_w)
278 return;
279 if (pcd->check_r && !FD_ISSET(pcd->fd, &s->rfds))
280 return;
281 if (pcd->check_w && !FD_ISSET(pcd->fd, &s->wfds))
282 return;
283 switch (pcd->status) {
284 case CL_CONNECTED: /* receive welcome message */
285 t->ret = client_recv_buffer(pcd);
286 if (t->ret > 0)
287 pcd->status = CL_RECEIVED_WELCOME;
288 return;
289 case CL_RECEIVED_WELCOME: /* send auth command */
290 sprintf(pcd->buf, "auth %s%s", pcd->conf.plain_given?
291 "" : "rc4 ", pcd->user);
292 PARA_INFO_LOG("--> %s\n", pcd->buf);
293 t->ret = send_buffer(pcd->fd, pcd->buf);
294 if (t->ret >= 0)
295 pcd->status = CL_SENT_AUTH;
296 return;
297 case CL_SENT_AUTH: /* receive challenge number */
298 pcd->loaded = 0;
299 t->ret = client_recv_buffer(pcd);
300 if (t->ret < 0)
301 return;
302 if (t->ret != 64) {
303 t->ret = -E_INVALID_CHALLENGE;
304 PARA_ERROR_LOG("received the following: %s\n", pcd->buf);
305 return;
306 }
307 PARA_INFO_LOG("%s", "<-- [challenge]\n");
308 /* decrypt challenge number */
309 t->ret = para_decrypt_challenge(pcd->key_file, &pcd->challenge_nr,
310 (unsigned char *) pcd->buf, 64);
311 if (t->ret > 0)
312 pcd->status = CL_RECEIVED_CHALLENGE;
313 return;
314 case CL_RECEIVED_CHALLENGE: /* send decrypted challenge */
315 PARA_INFO_LOG("--> %lu\n", pcd->challenge_nr);
316 t->ret = send_va_buffer(pcd->fd, "%s%lu", CHALLENGE_RESPONSE_MSG,
317 pcd->challenge_nr);
318 if (t->ret > 0)
319 pcd->status = CL_SENT_CH_RESPONSE;
320 return;
321 case CL_SENT_CH_RESPONSE: /* read server response */
322 {
323 size_t bytes_received;
324 unsigned char rc4_buf[2 * RC4_KEY_LEN] = "";
325 pcd->loaded = 0;
326 t->ret = client_recv_buffer(pcd);
327 if (t->ret < 0)
328 return;
329 bytes_received = t->ret;
330 PARA_DEBUG_LOG("++++ server info ++++\n%s\n++++ end of server "
331 "info ++++\n", pcd->buf);
332 /* check if server has sent "Proceed" message */
333 t->ret = -E_CLIENT_AUTH;
334 if (!strstr(pcd->buf, PROCEED_MSG))
335 return;
336 t->ret = 1;
337 pcd->status = CL_RECEIVED_PROCEED;
338 if (bytes_received < PROCEED_MSG_LEN + 32)
339 return;
340 PARA_INFO_LOG("%s", "decrypting session key\n");
341 t->ret = para_decrypt_buffer(pcd->key_file, rc4_buf,
342 (unsigned char *)pcd->buf + PROCEED_MSG_LEN + 1,
343 bytes_received - PROCEED_MSG_LEN - 1);
344 if (t->ret < 0)
345 return;
346 RC4_set_key(&pcd->rc4_send_key, RC4_KEY_LEN, rc4_buf);
347 RC4_set_key(&pcd->rc4_recv_key, RC4_KEY_LEN, rc4_buf + RC4_KEY_LEN);
348 enable_crypt(pcd->fd, rc4_recv, rc4_send, pcd);
349 }
350 case CL_RECEIVED_PROCEED: /* concat args and send command */
351 {
352 int i;
353 char *command = NULL;
354 for (i = 0; i < pcd->conf.inputs_num; i++) {
355 char *tmp = command;
356 command = make_message("%s\n%s", command?
357 command : "", pcd->conf.inputs[i]);
358 free(tmp);
359 }
360 command = para_strcat(command, EOC_MSG "\n");
361 PARA_DEBUG_LOG("--> %s\n", command);
362 t->ret = send_buffer(pcd->fd, command);
363 free(command);
364 if (t->ret > 0)
365 pcd->status = CL_SENT_COMMAND;
366 return;
367 }
368 case CL_SENT_COMMAND:
369 pcd->loaded = 0;
370 t->ret = client_recv_buffer(pcd);
371 if (t->ret < 0)
372 return;
373 t->ret = -E_HANDSHAKE_COMPLETE;
374 if (strstr(pcd->buf, AWAITING_DATA_MSG))
375 pcd->status = CL_SENDING;
376 else
377 pcd->status = CL_RECEIVING;
378 return;
379 case CL_SENDING: /* FIXME: might block */
380 PARA_INFO_LOG("loaded: %zd\n", *pcd->in_loaded);
381 t->ret = send_bin_buffer(pcd->fd, pcd->inbuf, *pcd->in_loaded);
382 if (t->ret < 0)
383 return;
384 *pcd->in_loaded = 0; /* FIXME: short writes */
385 return;
386 case CL_RECEIVING:
387 t->ret = client_recv_buffer(pcd);
388 return;
389 }
390 }