NEWS update.
[paraslash.git] / client_common.c
1 /*
2 * Copyright (C) 1997-2008 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 /**
75 * The preselect hook for server commands.
76 *
77 * \param s Pointer to the scheduler.
78 * \param t Pointer to the task struct for this command.
79 *
80 * The task pointer must contain a pointer to the initialized client data
81 * structure as it is returned by client_open().
82 *
83 * This function checks the state of the connection and adds the file descriptor
84 * of the connection to the read or write fd set of \a s accordingly.
85 *
86 * \sa register_task() client_open(), struct sched, struct task.
87 */
88 static void client_pre_select(struct sched *s, struct task *t)
89 {
90 struct private_client_data *pcd = t->private_data;
91
92 t->ret = 1;
93 pcd->check_r = 0;
94 pcd->check_w = 0;
95 if (pcd->fd < 0)
96 return;
97 switch (pcd->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(pcd->fd, &s->rfds, &s->max_fileno);
103 pcd->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(pcd->fd, &s->wfds, &s->max_fileno);
110 pcd->check_w = 1;
111 return;
112
113 case CL_RECEIVING:
114 if (pcd->loaded < CLIENT_BUFSIZE - 1) {
115 para_fd_set(pcd->fd, &s->rfds, &s->max_fileno);
116 pcd->check_r = 1;
117 }
118 return;
119 case CL_SENDING:
120 if (*pcd->in_loaded) {
121 PARA_INFO_LOG("loaded: %zd\n", *pcd->in_loaded);
122 para_fd_set(pcd->fd, &s->wfds, &s->max_fileno);
123 pcd->check_w = 1;
124 } else {
125 if (*pcd->in_error) {
126 t->ret = *pcd->in_error;
127 s->timeout.tv_sec = 0;
128 s->timeout.tv_usec = 1;
129 }
130 }
131 return;
132 }
133 }
134
135 static ssize_t client_recv_buffer(struct private_client_data *pcd)
136 {
137 ssize_t ret = recv_buffer(pcd->fd, pcd->buf + pcd->loaded,
138 CLIENT_BUFSIZE - pcd->loaded);
139 if (!ret)
140 return -E_SERVER_EOF;
141 if (ret > 0)
142 pcd->loaded += ret;
143 return ret;
144
145 }
146
147 /**
148 * The post select hook for client commands.
149 *
150 * \param s Pointer to the scheduler.
151 * \param t Pointer to the task struct for this command.
152 *
153 * Depending on the current state of the connection and the status of the read
154 * and write fd sets of \a s, this function performs the necessary steps to
155 * authenticate the connection, to send the command given by \a t->private_data
156 * and to receive para_server's output, if any.
157 *
158 * \sa struct sched, struct task.
159 */
160 static void client_post_select(struct sched *s, struct task *t)
161 {
162 struct private_client_data *pcd = t->private_data;
163
164 // PARA_INFO_LOG("status %d\n", pcd->status);
165 t->ret = 1;
166 if (pcd->fd < 0)
167 return;
168 if (!pcd->check_r && !pcd->check_w)
169 return;
170 if (pcd->check_r && !FD_ISSET(pcd->fd, &s->rfds))
171 return;
172 if (pcd->check_w && !FD_ISSET(pcd->fd, &s->wfds))
173 return;
174 switch (pcd->status) {
175 case CL_CONNECTED: /* receive welcome message */
176 t->ret = client_recv_buffer(pcd);
177 if (t->ret > 0)
178 pcd->status = CL_RECEIVED_WELCOME;
179 return;
180 case CL_RECEIVED_WELCOME: /* send auth command */
181 sprintf(pcd->buf, "auth %s%s", pcd->conf.plain_given?
182 "" : "rc4 ", pcd->user);
183 PARA_INFO_LOG("--> %s\n", pcd->buf);
184 t->ret = send_buffer(pcd->fd, pcd->buf);
185 if (t->ret >= 0)
186 pcd->status = CL_SENT_AUTH;
187 return;
188 case CL_SENT_AUTH: /* receive challenge number */
189 pcd->loaded = 0;
190 t->ret = client_recv_buffer(pcd);
191 if (t->ret < 0)
192 return;
193 if (t->ret != 64) {
194 t->ret = -E_INVALID_CHALLENGE;
195 PARA_ERROR_LOG("received the following: %s\n", pcd->buf);
196 return;
197 }
198 PARA_INFO_LOG("<-- [challenge]\n");
199 /* decrypt challenge number */
200 t->ret = para_decrypt_challenge(pcd->key_file, &pcd->challenge_nr,
201 (unsigned char *) pcd->buf, 64);
202 if (t->ret > 0)
203 pcd->status = CL_RECEIVED_CHALLENGE;
204 return;
205 case CL_RECEIVED_CHALLENGE: /* send decrypted challenge */
206 PARA_INFO_LOG("--> %lu\n", pcd->challenge_nr);
207 t->ret = send_va_buffer(pcd->fd, "%s%lu", CHALLENGE_RESPONSE_MSG,
208 pcd->challenge_nr);
209 if (t->ret > 0)
210 pcd->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 pcd->loaded = 0;
217 t->ret = client_recv_buffer(pcd);
218 if (t->ret < 0)
219 return;
220 bytes_received = t->ret;
221 PARA_DEBUG_LOG("++++ server info ++++\n%s\n++++ end of server "
222 "info ++++\n", pcd->buf);
223 /* check if server has sent "Proceed" message */
224 t->ret = -E_CLIENT_AUTH;
225 if (!strstr(pcd->buf, PROCEED_MSG))
226 return;
227 t->ret = 1;
228 pcd->status = CL_RECEIVED_PROCEED;
229 if (bytes_received < PROCEED_MSG_LEN + 32)
230 return;
231 PARA_INFO_LOG("decrypting session key\n");
232 t->ret = para_decrypt_buffer(pcd->key_file, rc4_buf,
233 (unsigned char *)pcd->buf + PROCEED_MSG_LEN + 1,
234 bytes_received - PROCEED_MSG_LEN - 1);
235 if (t->ret < 0)
236 return;
237 RC4_set_key(&pcd->rc4_send_key, RC4_KEY_LEN, rc4_buf);
238 RC4_set_key(&pcd->rc4_recv_key, RC4_KEY_LEN, rc4_buf + RC4_KEY_LEN);
239 enable_crypt(pcd->fd, rc4_recv, rc4_send, pcd);
240 }
241 case CL_RECEIVED_PROCEED: /* concat args and send command */
242 {
243 int i;
244 char *command = NULL;
245 for (i = 0; i < pcd->conf.inputs_num; i++) {
246 char *tmp = command;
247 command = make_message("%s\n%s", command?
248 command : "", pcd->conf.inputs[i]);
249 free(tmp);
250 }
251 command = para_strcat(command, EOC_MSG "\n");
252 PARA_DEBUG_LOG("--> %s\n", command);
253 t->ret = send_buffer(pcd->fd, command);
254 free(command);
255 if (t->ret > 0)
256 pcd->status = CL_SENT_COMMAND;
257 return;
258 }
259 case CL_SENT_COMMAND:
260 pcd->loaded = 0;
261 t->ret = client_recv_buffer(pcd);
262 if (t->ret < 0)
263 return;
264 t->ret = -E_HANDSHAKE_COMPLETE;
265 if (strstr(pcd->buf, AWAITING_DATA_MSG))
266 pcd->status = CL_SENDING;
267 else
268 pcd->status = CL_RECEIVING;
269 return;
270 case CL_SENDING: /* FIXME: might block */
271 PARA_INFO_LOG("loaded: %zd\n", *pcd->in_loaded);
272 t->ret = send_bin_buffer(pcd->fd, pcd->inbuf, *pcd->in_loaded);
273 if (t->ret < 0)
274 return;
275 *pcd->in_loaded = 0;
276 return;
277 case CL_RECEIVING:
278 t->ret = client_recv_buffer(pcd);
279 return;
280 }
281 }
282
283 /* connect to para_server and register the client task */
284 static int client_connect(struct private_client_data *pcd)
285 {
286 int ret;
287
288 pcd->fd = -1;
289 ret = makesock(AF_UNSPEC, IPPROTO_TCP, 0, pcd->conf.hostname_arg,
290 pcd->conf.server_port_arg);
291 if (ret < 0)
292 return ret;
293 pcd->fd = ret;
294 pcd->status = CL_CONNECTED;
295 ret = mark_fd_nonblocking(pcd->fd);
296 if (ret < 0)
297 goto err_out;
298 pcd->task.pre_select = client_pre_select;
299 pcd->task.post_select = client_post_select;
300 pcd->task.private_data = pcd;
301 sprintf(pcd->task.status, "client");
302 register_task(&pcd->task);
303 return 1;
304 err_out:
305 close(pcd->fd);
306 pcd->fd = -1;
307 return ret;
308 }
309
310 /**
311 * Open connection to para_server.
312 *
313 * \param argc Usual argument count.
314 * \param argv Usual argument vector.
315 * \param pcd_ptr Points to dynamically allocated and initialized private client data
316 * upon successful return.
317 *
318 * Check the command line options given by \a argc and argv, set default values
319 * for user name and rsa key file, read further option from the config file.
320 * Finally, establish a connection to para_server.
321 *
322 * \return Standard.
323 */
324 int client_open(int argc, char *argv[], struct private_client_data **pcd_ptr)
325 {
326 char *home = para_homedir();
327 struct stat statbuf;
328 int ret;
329 struct private_client_data *pcd =
330 para_calloc(sizeof(struct private_client_data));
331
332 *pcd_ptr = pcd;
333 pcd->fd = -1;
334 ret = client_cmdline_parser(argc, argv, &pcd->conf);
335 HANDLE_VERSION_FLAG("client", pcd->conf);
336 ret = -E_CLIENT_SYNTAX;
337 if (!pcd->conf.inputs_num)
338 goto out;
339 pcd->user = pcd->conf.user_given?
340 para_strdup(pcd->conf.user_arg) : para_logname();
341
342 pcd->key_file = pcd->conf.key_file_given?
343 para_strdup(pcd->conf.key_file_arg) :
344 make_message("%s/.paraslash/key.%s", home, pcd->user);
345
346 pcd->config_file = pcd->conf.config_file_given?
347 para_strdup(pcd->conf.config_file_arg) :
348 make_message("%s/.paraslash/client.conf", home);
349 ret = stat(pcd->config_file, &statbuf);
350 if (ret && pcd->conf.config_file_given) {
351 ret = -E_NO_CONFIG;
352 goto out;
353 }
354 if (!ret) {
355 struct client_cmdline_parser_params params = {
356 .override = 0,
357 .initialize = 0,
358 .check_required = 0,
359 .check_ambiguity = 0
360 };
361 client_cmdline_parser_config_file(pcd->config_file,
362 &pcd->conf, &params);
363 }
364 ret = 1;
365 PARA_INFO_LOG("loglevel: %d\n", pcd->conf.loglevel_arg);
366 PARA_INFO_LOG("config_file: %s\n", pcd->config_file);
367 PARA_INFO_LOG("key_file: %s\n", pcd->key_file);
368 PARA_NOTICE_LOG("connecting %s:%d\n", pcd->conf.hostname_arg,
369 pcd->conf.server_port_arg);
370 ret = client_connect(pcd);
371 out:
372 free(home);
373 if (ret < 0) {
374 PARA_ERROR_LOG("%s\n", para_strerror(-ret));
375 client_close(pcd);
376 *pcd_ptr = NULL;
377 }
378 return ret;
379 }
380