Move valid_fd_012() from string.c to fd.c.
[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 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->user);
68 free(ct->config_file);
69 free(ct->key_file);
70 client_cmdline_parser_free(&ct->conf);
71 free(ct);
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 client_task *ct = container_of(t, struct client_task, task);
91
92 ct->check_r = 0;
93 ct->check_w = 0;
94 if (ct->fd < 0)
95 return;
96 switch (ct->status) {
97 case CL_CONNECTED:
98 case CL_SENT_AUTH:
99 case CL_SENT_CH_RESPONSE:
100 case CL_SENT_COMMAND:
101 para_fd_set(ct->fd, &s->rfds, &s->max_fileno);
102 ct->check_r = 1;
103 return;
104
105 case CL_RECEIVED_WELCOME:
106 case CL_RECEIVED_CHALLENGE:
107 case CL_RECEIVED_PROCEED:
108 para_fd_set(ct->fd, &s->wfds, &s->max_fileno);
109 ct->check_w = 1;
110 return;
111
112 case CL_RECEIVING:
113 if (ct->loaded < CLIENT_BUFSIZE - 1) {
114 para_fd_set(ct->fd, &s->rfds, &s->max_fileno);
115 ct->check_r = 1;
116 }
117 return;
118 case CL_SENDING:
119 if (!ct->in_loaded) /* stdin task not yet started */
120 return;
121 if (*ct->in_loaded) {
122 PARA_INFO_LOG("loaded: %zd\n", *ct->in_loaded);
123 para_fd_set(ct->fd, &s->wfds, &s->max_fileno);
124 ct->check_w = 1;
125 } else {
126 if (*ct->in_error) {
127 t->error = *ct->in_error;
128 s->timeout.tv_sec = 0;
129 s->timeout.tv_usec = 1;
130 }
131 }
132 return;
133 }
134 }
135
136 static ssize_t client_recv_buffer(struct client_task *ct)
137 {
138 ssize_t ret = recv_buffer(ct->fd, ct->buf + ct->loaded,
139 CLIENT_BUFSIZE - ct->loaded);
140 if (!ret)
141 return -E_SERVER_EOF;
142 if (ret > 0)
143 ct->loaded += ret;
144 return ret;
145
146 }
147
148 /**
149 * The post select hook for client commands.
150 *
151 * \param s Pointer to the scheduler.
152 * \param t Pointer to the task struct for this command.
153 *
154 * Depending on the current state of the connection and the status of the read
155 * and write fd sets of \a s, this function performs the necessary steps to
156 * authenticate the connection, to send the command given by \a t->private_data
157 * and to receive para_server's output, if any.
158 *
159 * \sa struct sched, struct task.
160 */
161 static void client_post_select(struct sched *s, struct task *t)
162 {
163 struct client_task *ct = container_of(t, struct client_task, task);
164
165 t->error = 0;
166 if (ct->fd < 0)
167 return;
168 if (!ct->check_r && !ct->check_w)
169 return;
170 if (ct->check_r && !FD_ISSET(ct->fd, &s->rfds))
171 return;
172 if (ct->check_w && !FD_ISSET(ct->fd, &s->wfds))
173 return;
174 switch (ct->status) {
175 case CL_CONNECTED: /* receive welcome message */
176 t->error = client_recv_buffer(ct);
177 if (t->error > 0)
178 ct->status = CL_RECEIVED_WELCOME;
179 return;
180 case CL_RECEIVED_WELCOME: /* send auth command */
181 sprintf(ct->buf, "auth %s%s", ct->conf.plain_given?
182 "" : "rc4 ", 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 */
224 t->error = -E_CLIENT_AUTH;
225 if (!strstr(ct->buf, PROCEED_MSG))
226 return;
227 t->error = 0;
228 ct->status = CL_RECEIVED_PROCEED;
229 if (bytes_received < PROCEED_MSG_LEN + 32)
230 return;
231 PARA_INFO_LOG("decrypting session key\n");
232 t->error = para_decrypt_buffer(ct->key_file, rc4_buf,
233 (unsigned char *)ct->buf + PROCEED_MSG_LEN + 1,
234 bytes_received - PROCEED_MSG_LEN - 1);
235 if (t->error < 0)
236 return;
237 RC4_set_key(&ct->rc4_send_key, RC4_KEY_LEN, rc4_buf);
238 RC4_set_key(&ct->rc4_recv_key, RC4_KEY_LEN, rc4_buf + RC4_KEY_LEN);
239 enable_crypt(ct->fd, rc4_recv, rc4_send, ct);
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 *
316 * Check the command line options given by \a argc and argv, set default values
317 * for user name and rsa key file, read further option from the config file.
318 * Finally, establish a connection to para_server.
319 *
320 * \return Standard.
321 */
322 int client_open(int argc, char *argv[], struct client_task **ct_ptr)
323 {
324 char *home = para_homedir();
325 struct stat statbuf;
326 int ret;
327 struct client_task *ct = para_calloc(sizeof(struct client_task));
328
329 *ct_ptr = ct;
330 ct->fd = -1;
331 ret = client_cmdline_parser(argc, argv, &ct->conf);
332 HANDLE_VERSION_FLAG("client", ct->conf);
333 ret = -E_CLIENT_SYNTAX;
334 if (!ct->conf.inputs_num)
335 goto out;
336 ct->user = ct->conf.user_given?
337 para_strdup(ct->conf.user_arg) : para_logname();
338
339 ct->key_file = ct->conf.key_file_given?
340 para_strdup(ct->conf.key_file_arg) :
341 make_message("%s/.paraslash/key.%s", home, ct->user);
342
343 ct->config_file = ct->conf.config_file_given?
344 para_strdup(ct->conf.config_file_arg) :
345 make_message("%s/.paraslash/client.conf", home);
346 ret = stat(ct->config_file, &statbuf);
347 if (ret && ct->conf.config_file_given) {
348 ret = -E_NO_CONFIG;
349 goto out;
350 }
351 if (!ret) {
352 struct client_cmdline_parser_params params = {
353 .override = 0,
354 .initialize = 0,
355 .check_required = 0,
356 .check_ambiguity = 0
357 };
358 client_cmdline_parser_config_file(ct->config_file,
359 &ct->conf, &params);
360 }
361 ret = 1;
362 PARA_INFO_LOG("loglevel: %d\n", ct->conf.loglevel_arg);
363 PARA_INFO_LOG("config_file: %s\n", ct->config_file);
364 PARA_INFO_LOG("key_file: %s\n", ct->key_file);
365 PARA_NOTICE_LOG("connecting %s:%d\n", ct->conf.hostname_arg,
366 ct->conf.server_port_arg);
367 ret = client_connect(ct);
368 out:
369 free(home);
370 if (ret < 0) {
371 PARA_ERROR_LOG("%s\n", para_strerror(-ret));
372 client_close(ct);
373 *ct_ptr = NULL;
374 }
375 return ret;
376 }
377