1 /*
2  *
3  * Copyright (c) 2004 Scott Ullrich <GeekGod@GeekGod.com>
4  * Portions Copyright (c) 2004 Chris Pressey <cpressey@catseye.mine.nu>
5  *
6  * Copyright (c) 2004 The DragonFly Project.
7  * All rights reserved.
8  *
9  * This code is derived from software contributed to The DragonFly Project
10  * by Scott Ullrich and Chris Pressey (see above for e-mail addresses).
11  *
12  * Redistribution and use in source and binary forms, with or without
13  * modification, are permitted provided that the following conditions
14  * are met:
15  *
16  * 1. Redistributions of source code must retain the above copyright
17  *    notice, this list of conditions and the following disclaimer.
18  *
19  * 2. Redistributions in binary form must reproduce the above copyright
20  *    notice, this list of conditions and the following disclaimer in
21  *    the documentation and/or other materials provided with the
22  *    distribution.
23  *
24  * 3. Neither the name of The DragonFly Project nor the names of its
25  *    contributors may be used to endorse or promote products derived
26  *    from this software without specific, prior written permission.
27  *
28  * THIS SOFTWARE IS PROVIDED BY THE COPYRIGHT HOLDERS AND CONTRIBUTORS
29  * ``AS IS'' AND ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT
30  * LIMITED TO, THE IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS
31  * FOR A PARTICULAR PURPOSE ARE DISCLAIMED.  IN NO EVENT SHALL THE
32  * COPYRIGHT HOLDERS, CONTRIBUTORS OR VOICES IN THE AUTHOR'S HEAD
33  * BE LIABLE FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY
34  * OR CONSEQUENTIAL DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT
35  * OF SUBSTITUTE GOODS OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR
36  * BUSINESS INTERRUPTION) HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY,
37  * WHETHER IN CONTRACT, STRICT LIABILITY, OR TORT (INCLUDING NEGLIGENCE
38  * OR OTHERWISE) ARISING IN ANY WAY OUT OF THE USE OF THIS SOFTWARE,
39  * EVEN IF ADVISED OF THE POSSIBILITY OF SUCH DAMAGE.
40  * COPYRIGHT HOLDERS OR CONTRIBUTORS BE LIABLE FOR ANY DIRECT, INDIRECT,
41  * INCIDENTAL, SPECIAL, EXEMPLARY OR CONSEQUENTIAL DAMAGES (INCLUDING,
42  * BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS OR SERVICES;
43  * LOSS OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION) HOWEVER CAUSED
44  * AND ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT LIABILITY,
45  * OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY OUT
46  * OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF
47  * SUCH DAMAGE.
48  */
49 
50 /*
51  * conn_tcp.c
52  * $Id: conn_tcp.c,v 1.16 2005/02/06 19:53:19 cpressey Exp $
53  */
54 
55 #include "system.h"
56 #ifdef HAS_TCP
57 
58 #include <sys/types.h>
59 #include <sys/stat.h>
60 #include <sys/time.h>
61 #include <sys/errno.h>
62 #include <sys/types.h>
63 #include <sys/socket.h>
64 #include <netinet/in.h>
65 #include <arpa/inet.h>
66 
67 #include <err.h>
68 #include <errno.h>
69 #include <stdarg.h>
70 #include <stdio.h>
71 #include <stdlib.h>
72 #include <string.h>
73 #include <unistd.h>
74 
75 #include <libaura/buffer.h>
76 
77 #define	NEEDS_DFUI_STRUCTURE_DEFINITIONS
78 #include "dfui.h"
79 #undef	NEEDS_DFUI_STRUCTURE_DEFINITIONS
80 #include "encoding.h"
81 #include "conn_tcp.h"
82 #include "dump.h"
83 
84 /***** BACKEND ******/
85 
86 /** High Level **/
87 
88 /*
89  * Connect to the frontend.
90  */
91 dfui_err_t
92 dfui_tcp_be_start(struct dfui_connection *c)
93 {
94 	struct sockaddr_in servaddr;
95 	int server_port;
96 	int tru = 1;
97 
98 	server_port = atoi(c->rendezvous);
99 
100 	/*
101 	 * Create the tcp socket
102 	 */
103 	errno = 0;
104 	if ((T_TCP(c)->listen_sd = socket(AF_INET, SOCK_STREAM, 0)) == -1)
105 		return(DFUI_FAILURE);
106 	dfui_debug("LISTEN_SOCKET<<%d>>\n", T_TCP(c)->listen_sd);
107 
108 	if (setsockopt(T_TCP(c)->listen_sd, SOL_SOCKET, SO_REUSEADDR,
109 	    &tru, sizeof(tru)) == -1) {
110 		return(DFUI_FAILURE);
111 	}
112 
113 	bzero(&servaddr, sizeof(servaddr));
114 	servaddr.sin_family = AF_INET;
115 	servaddr.sin_port = htons(server_port);
116 	switch(inet_pton(AF_INET, "127.0.0.1", &servaddr.sin_addr)) {
117 	case 0:
118 		warnx("inet_pton(): address not parseable");
119 		return(DFUI_FAILURE);
120 	case 1:
121 		break;
122 	default:
123 		warn("inet_pton()");
124 		return(DFUI_FAILURE);
125 	}
126 
127 	if (bind(T_TCP(c)->listen_sd, (struct sockaddr *)&servaddr, sizeof(servaddr)) == -1) {
128 		warn("bind()");
129 		return(DFUI_FAILURE);
130 	}
131 	dfui_debug("BOUND_ON<<%d>>\n", T_TCP(c)->listen_sd);
132 	if (listen(T_TCP(c)->listen_sd, 0) == -1)
133 		return(DFUI_FAILURE);
134 	dfui_debug("LISTENING_ON<<%d>>\n", T_TCP(c)->listen_sd);
135 	/* at this point we should be listening on the rendezvous port */
136 	return(DFUI_SUCCESS);
137 }
138 
139 /*
140  * Tell the frontend that we're done and disconnect from it.
141  */
142 dfui_err_t
143 dfui_tcp_be_stop(struct dfui_connection *c)
144 {
145 	if (dfui_tcp_be_ll_exchange(c, DFUI_BE_MSG_STOP, "")) {
146 		close(T_TCP(c)->listen_sd);
147 		close(T_TCP(c)->connected_sd);
148 		fclose(T_TCP(c)->stream);
149 		return(DFUI_SUCCESS);
150 	} else
151 		return(DFUI_FAILURE);
152 }
153 
154 /** Low Level **/
155 
156 /*
157  * Exchange a message with the frontend.  This involves two receive()/reply()
158  * cycles: one to provide our message, one to get a reply from the frontend.
159  *
160  * Note that this does not immediately send the message to the frontend -
161  * it can't, because we're a service and it's a client.  What it does is
162  * keep the message handy and wait for a frontend request to come in.  It
163  * then replies to that request with our message.
164  *
165  * The protocol looks something like the following, using the PRESENT and
166  * SUBMIT exchange as an example:
167  *
168  * frontend (client) | backend (service)
169  * ------------------+------------------
170  *
171  *                                     [stage 1]
172  * READY            -->                ll_receive()
173  *                 <--  PRESENT(form)  ll_reply()
174  *
175  *                                     [stage 2]
176  * SUBMIT(form)     -->                ll_receive()
177  *                 <--  READY          ll_reply()
178  *
179  * Each of those exchanges is a pair of calls, on our end, to
180  * dfui_tcp_be_ll_receive() and dfui_npipe_be_ll_reply().
181  *
182  * The set of messages that the client can pass us is determined by
183  * the conversation state:
184  *
185  *   o  In stage 1, only READY and ABORT are meaningful.
186  *   o  After a PRESENT, the messages SUBMIT and ABORT are meaningul
187  *      in stage 2.
188  *   o  During a PROG_*, the messages CONTINUE, CANCEL, and ABORT
189  *      are meaningful in stage 2.
190  *
191  * If the frontend sends us with READY in stage 2, we assume it has
192  * fallen out of sync, so we send the same initial reply again, going
193  * back to stage 1 as it were.
194  *
195  * After this call, the message is available in c->ebuf.
196  */
197 dfui_err_t
198 dfui_tcp_be_ll_exchange(struct dfui_connection *c, char msgtype, const char *msg)
199 {
200 	char *fmsg;
201 
202 	/*
203 	 * Construct our message to send.
204 	 */
205 
206 	fmsg = malloc(strlen(msg) + 2);
207 	fmsg[0] = msgtype;
208 	strcpy(fmsg + 1, msg);
209 
210 	/*
211 	 * Get the frontend's message.
212 	 */
213 
214 	dfui_tcp_be_ll_receive(c);
215 
216 	/*
217 	 * Frontend message should have been either READY or ABORT.
218 	 * If ABORT, we get out of here pronto.
219 	 */
220 
221 	if (aura_buffer_buf(c->ebuf)[0] == DFUI_FE_MSG_ABORT) {
222 		free(fmsg);
223 		return(DFUI_FAILURE);
224 	}
225 
226 	/* XXX if (!READY) ??? */
227 
228 	do {
229 		dfui_tcp_be_ll_reply(c, fmsg);
230 
231 		/*
232 		 * Here, the frontend has picked up our request and is
233 		 * processing it.  We have to wait for the response.
234 		 */
235 
236 		dfui_tcp_be_ll_receive(c);
237 
238 		/*
239 		 * Did we get READY from this?
240 		 * If so, loop!
241 		 */
242 
243 	} while (aura_buffer_buf(c->ebuf)[0] == DFUI_FE_MSG_READY);
244 
245 	fmsg[0] = DFUI_BE_MSG_READY;
246 	fmsg[1] = '\0';
247 	dfui_tcp_be_ll_reply(c, fmsg);
248 
249 	free(fmsg);
250 	return(DFUI_SUCCESS);
251 }
252 
253 /*
254  * Receive a message from the frontend.
255  * This call is synchronous.
256  * After this call, the NUL-terminated message is available in
257  * c->ebuf.
258  */
259 dfui_err_t
260 dfui_tcp_be_ll_receive(struct dfui_connection *c)
261 {
262 	int length;
263 	char *buf;
264 
265 	top:
266 
267 	if (!T_TCP(c)->is_connected) {
268 	dfui_debug("NOT_CONNECTED,ACCEPTING_ON<<%d>>\n", T_TCP(c)->listen_sd);
269 		T_TCP(c)->connected_sd = accept(T_TCP(c)->listen_sd, NULL, NULL);
270 		dfui_debug("ACCEPTED<<%d>>\n", T_TCP(c)->connected_sd);
271 		T_TCP(c)->stream = fdopen(T_TCP(c)->connected_sd, "r+");
272 		T_TCP(c)->is_connected = 1;
273 	} else {
274 		dfui_debug("ALREADY_CONNECTED<<>>\n");
275 	}
276 
277 	dfui_debug("WAITING<<>>\n");
278 
279 	if (read_data(T_TCP(c)->stream, (char *)&length, sizeof(length)) == -1) {
280 		dfui_debug("LOST_THEM<<>>\n");
281 		fclose(T_TCP(c)->stream);
282 		T_TCP(c)->is_connected = 0;
283 		goto top;
284 	}
285 
286 	buf = malloc(length + 1);
287 	if (read_data(T_TCP(c)->stream, buf, length) == -1) {
288 		dfui_debug("LOST_THEM<<>>\n");
289 		fclose(T_TCP(c)->stream);
290 		T_TCP(c)->is_connected = 0;
291 		goto top;
292 	}
293 
294 	aura_buffer_set(c->ebuf, buf, length);
295 	free(buf);
296 
297 	dfui_debug("RECEIVED<<%s>>\n", aura_buffer_buf(c->ebuf));
298 
299 	return(DFUI_SUCCESS);
300 }
301 
302 /*
303  * Send a NUL-terminated reply to the frontend.
304  */
305 dfui_err_t
306 dfui_tcp_be_ll_reply(struct dfui_connection *c, const char *fmsg)
307 {
308 	int length;
309 
310 	dfui_debug("SEND<<%s>>\n", fmsg);
311 	length = strlen(fmsg);
312 	write_data(T_TCP(c)->stream, (char *)&length, sizeof(length));
313 	write_data(T_TCP(c)->stream, fmsg, length);
314 
315 	return(DFUI_SUCCESS);
316 }
317 
318 /******** FRONTEND ********/
319 
320 /** High Level **/
321 
322 dfui_err_t
323 dfui_tcp_fe_connect(struct dfui_connection *c)
324 {
325         struct sockaddr_in servaddr;
326         int server_port;
327 	int connected = 0;
328 
329         server_port = atoi(c->rendezvous);
330 
331         /*
332          * Create the tcp socket
333          */
334 	while (!connected) {
335 		errno = 0;
336 		if ((T_TCP(c)->connected_sd = socket(AF_INET, SOCK_STREAM, 0)) == -1) {
337 			return(DFUI_FAILURE);
338 		}
339 
340 		dfui_debug("CLIENT_SOCKET<<%d>>\n", T_TCP(c)->connected_sd);
341 		bzero(&servaddr, sizeof(servaddr));
342 		servaddr.sin_family = AF_INET;
343 		servaddr.sin_port = htons(server_port);
344 		inet_pton(AF_INET, "127.0.0.1", &servaddr.sin_addr);
345 
346 		if (connect(T_TCP(c)->connected_sd, (struct sockaddr *)&servaddr,
347 		    sizeof(servaddr)) == 0) {
348 			dfui_debug("CONNECTED<<>>\n");
349 			connected = 1;
350 		} else {
351 			dfui_debug("NO_CONNECT<<>>\n");
352 			close(T_TCP(c)->connected_sd);
353 			sleep(1);
354 		}
355 	}
356 
357         /* at this point we should be connected */
358 
359 	T_TCP(c)->stream = fdopen(T_TCP(c)->connected_sd, "r+");
360 
361         return(DFUI_SUCCESS);
362 }
363 
364 dfui_err_t
365 dfui_tcp_fe_disconnect(struct dfui_connection *c)
366 {
367 	close(T_TCP(c)->connected_sd);
368 	return(DFUI_SUCCESS);
369 }
370 
371 /** Low Level **/
372 
373 /*
374  * Ask for, and subsequently receieve, a message from the backend.
375  * msgtype should be one of the DFUI_FE_MSG_* constants.
376  * This call is synchronous.
377  * After this call, the null-terminated, encoded message is
378  * available in T_TCP(c)->buf.
379  */
380 dfui_err_t
381 dfui_tcp_fe_ll_request(struct dfui_connection *c, char msgtype, const char *msg)
382 {
383 	char *fmsg, *buf;
384 	int length, result;
385 
386 	/*
387 	 * First, assert that the connection is open.
388 	 */
389 
390 	if (c == NULL || T_TCP(c)->connected_sd == -1)
391 		return(DFUI_FAILURE);
392 
393 	/*
394 	 * Construct a message.
395 	 */
396 
397 	fmsg = malloc(strlen(msg) + 2);
398 	fmsg[0] = msgtype;
399 	strcpy(fmsg + 1, msg);
400 	dfui_debug("SEND<<%s>>\n", fmsg);
401 
402 	/*
403 	 * Send a NUL-terminated message to the backend.
404 	 */
405 
406         length = strlen(fmsg);
407         result = write_data(T_TCP(c)->stream, (char *)&length, sizeof(length));
408 	dfui_debug("result<<%d>>\n", result);
409 	result = write_data(T_TCP(c)->stream, (char *)fmsg, length);
410 	dfui_debug("result<<%d>>\n", result);
411 
412 	/*
413 	 * Receive a reply from the backend.
414 	 * If our message was a READY, this should be a message like PRESENT.
415 	 * Otherwise it should simply be a READY.
416 	 */
417 
418 	dfui_debug("WAITING<<>>\n");
419         result = read_data(T_TCP(c)->stream, (char *)&length, sizeof(length));
420 	dfui_debug("result<<%d>>\n", result);
421         buf = malloc(length + 1);
422         result = read_data(T_TCP(c)->stream, buf, length);
423 	dfui_debug("result<<%d>>\n", result);
424         aura_buffer_set(c->ebuf, buf, length);
425         free(buf);
426 
427 	dfui_debug("RECV<<%s>>\n", aura_buffer_buf(c->ebuf));
428 
429 	free(fmsg);
430 
431 	return(DFUI_SUCCESS);
432 }
433 
434 int
435 read_data(FILE *f, char *buf, int n)
436 {
437 	int bcount;	/* counts bytes read */
438 	int br;		/* bytes read this pass */
439 
440 	bcount = 0;
441 	br = 0;
442 	while (bcount < n) {
443 		if ((br = fread(buf, 1, n - bcount, f)) > 0) {
444 			dfui_debug("READ_BYTES<<%d>>\n", br);
445 			bcount += br;
446 			buf += br;
447 		} else if (br <= 0) {
448 			dfui_debug("read_data_error<<%d>>\n", br);
449 			return(-1);
450 		}
451 	}
452 	return(bcount);
453 }
454 
455 int
456 write_data(FILE *f, const char *buf, int n)
457 {
458         int bcount;	/* counts bytes written */
459         int bw;		/* bytes written this pass */
460 
461         bcount = 0;
462         bw = 0;
463         while (bcount < n) {
464                 if ((bw = fwrite(buf, 1, n - bcount, f)) > 0) {
465 			dfui_debug("WROTE_BYTES<<%d>>\n", bw);
466                         bcount += bw;
467                         buf += bw;
468                 } else if (bw <= 0) {
469 			dfui_debug("write_data_error<<%d>>\n", bw);
470 			return(-1);
471 		}
472         }
473         return(bcount);
474 }
475 
476 #endif /* HAS_TCP */
477