summaryrefslogtreecommitdiff
path: root/source3/lib/socket_wrapper.c
blob: cb3911c3582db0b7bfcd1334eaff6ec6171349a7 (plain)
1
2
3
4
5
6
7
8
9
10
11
12
13
14
15
16
17
18
19
20
21
22
23
24
25
26
27
28
29
30
31
32
33
34
35
36
37
38
39
40
41
42
43
44
45
46
47
48
49
50
51
52
53
54
55
56
57
58
59
60
61
62
63
64
65
66
67
68
69
70
71
72
73
74
75
76
77
78
79
80
81
82
83
84
85
86
87
88
89
90
91
92
93
94
95
96
97
98
99
100
101
102
103
104
105
106
107
108
109
110
111
112
113
114
115
116
117
118
119
120
121
122
123
124
125
126
127
128
129
130
131
132
133
134
135
136
137
138
139
140
141
142
143
144
145
146
147
148
149
150
151
152
153
154
155
156
157
158
159
160
161
162
163
164
165
166
167
168
169
170
171
172
173
174
175
176
177
178
179
180
181
182
183
184
185
186
187
188
189
190
191
192
193
194
195
196
197
198
199
200
201
202
203
204
205
206
207
208
209
210
211
212
213
214
215
216
217
218
219
220
221
222
223
224
225
226
227
228
229
230
231
232
233
234
235
236
237
238
239
240
241
242
243
244
245
246
247
248
249
250
251
252
253
254
255
256
257
258
259
260
261
262
263
264
265
266
267
268
269
270
271
272
273
274
275
276
277
278
279
280
281
282
283
284
285
286
287
288
289
290
291
292
293
294
295
296
297
298
299
300
301
302
303
304
305
306
307
308
309
310
311
312
313
314
315
316
317
318
319
320
321
322
323
324
325
326
327
328
329
330
331
332
333
334
335
336
337
338
339
340
341
342
343
344
345
346
347
348
349
350
351
352
353
354
355
356
357
358
359
360
361
362
363
364
365
366
367
368
369
370
371
372
373
374
375
376
377
378
379
380
381
382
383
384
385
386
387
388
389
390
391
392
393
394
395
396
397
398
399
400
401
402
403
404
405
406
407
408
409
410
411
412
413
414
415
416
417
418
419
420
421
422
423
424
425
426
427
428
429
430
431
432
433
434
435
436
437
438
439
440
441
442
443
444
445
446
447
448
449
450
451
452
453
454
455
456
457
458
459
460
461
462
463
464
465
466
467
/* 
   Socket wrapper library. Passes all socket communication over 
   unix domain sockets if the environment variable SOCKET_WRAPPER_DIR 
   is set.
   Copyright (C) Jelmer Vernooij 2005
   
   This program is free software; you can redistribute it and/or modify
   it under the terms of the GNU General Public License as published by
   the Free Software Foundation; either version 2 of the License, or
   (at your option) any later version.
   
   This program is distributed in the hope that it will be useful,
   but WITHOUT ANY WARRANTY; without even the implied warranty of
   MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
   GNU General Public License for more details.
   
   You should have received a copy of the GNU General Public License
   along with this program; if not, write to the Free Software
   Foundation, Inc., 675 Mass Ave, Cambridge, MA 02139, USA.
*/

#ifdef _SAMBA_BUILD_
#include "includes.h"
#include "system/network.h"
#else
#include <sys/types.h>
#include <sys/socket.h>
#include <errno.h>
#include <sys/un.h>
#include <netinet/in.h>
#include <netinet/tcp.h>
#include <stdlib.h>
#include <unistd.h>
#include <string.h>
#include <stdio.h>
#include "dlinklist.h"
#endif

/* LD_PRELOAD doesn't work yet, so REWRITE_CALLS is all we support
 * for now */
#define REWRITE_CALLS 

#ifdef REWRITE_CALLS
#define real_accept accept
#define real_connect connect
#define real_bind bind
#define real_getpeername getpeername
#define real_getsockname getsockname
#define real_getsockopt getsockopt
#define real_setsockopt setsockopt
#define real_recvfrom recvfrom
#define real_sendto sendto
#define real_socket socket
#define real_close close
#endif

static struct sockaddr *sockaddr_dup(const void *data, socklen_t len)
{
	struct sockaddr *ret = (struct sockaddr *)malloc(len);
	memcpy(ret, data, len);
	return ret;
}

struct socket_info
{
	int fd;

	int domain;
	int type;
	int protocol;
	int bound;

	char *path;
	char *tmp_path;

	struct sockaddr *myname;
	socklen_t myname_len;

	struct sockaddr *peername;
	socklen_t peername_len;

	struct socket_info *prev, *next;
};

static struct socket_info *sockets = NULL;

static int convert_un_in(const struct sockaddr_un *un, struct sockaddr_in *in, socklen_t *len)
{
	unsigned int prt;
	const char *p;
	int type;

	if ((*len) < sizeof(struct sockaddr_in)) {
		return 0;
	}

	in->sin_family = AF_INET;
	in->sin_port = 1025; /* Default to 1025 */
	p = strchr(un->sun_path, '/');
	if (p) p++; else p = un->sun_path;

	if (sscanf(p, "sock_ip_%d_%u", &type, &prt) == 2) {
		in->sin_port = htons(prt);
	}
	in->sin_addr.s_addr = htonl(INADDR_LOOPBACK);
	*len = sizeof(struct sockaddr_in);
	return 0;
}

static int convert_in_un(int type, const struct sockaddr_in *in, struct sockaddr_un *un)
{
	uint16_t prt = ntohs(in->sin_port);
	snprintf(un->sun_path, sizeof(un->sun_path), "%s/sock_ip_%d_%u", 
		 getenv("SOCKET_WRAPPER_DIR"), type, prt);
	return 0;
}

static struct socket_info *find_socket_info(int fd)
{
	struct socket_info *i;
	for (i = sockets; i; i = i->next) {
		if (i->fd == fd) 
			return i;
	}

	return NULL;
}

static int sockaddr_convert_to_un(const struct socket_info *si, const struct sockaddr *in_addr, socklen_t in_len, 
					 struct sockaddr_un *out_addr)
{
	if (!out_addr)
		return 0;

	out_addr->sun_family = AF_UNIX;

	switch (in_addr->sa_family) {
	case AF_INET:
		return convert_in_un(si->type, (const struct sockaddr_in *)in_addr, out_addr);
	case AF_UNIX:
		memcpy(out_addr, in_addr, sizeof(*out_addr));
		return 0;
	default:
		break;
	}
	
	errno = EAFNOSUPPORT;
	return -1;
}

static int sockaddr_convert_from_un(const struct socket_info *si, 
				    const struct sockaddr_un *in_addr, 
				    socklen_t un_addrlen,
				    int family,
				    struct sockaddr *out_addr,
				    socklen_t *out_len)
{
	if (out_addr == NULL || out_len == NULL) 
		return 0;

	if (un_addrlen == 0) {
		*out_len = 0;
		return 0;
	}

	switch (family) {
	case AF_INET:
		return convert_un_in(in_addr, (struct sockaddr_in *)out_addr, out_len);
	case AF_UNIX:
		memcpy(out_addr, in_addr, sizeof(*in_addr));
		*out_len = sizeof(*in_addr);
		return 0;
	default:
		break;
	}

	errno = EAFNOSUPPORT;
	return -1;
}

int swrap_socket(int domain, int type, int protocol)
{
	struct socket_info *si;
	int fd;

	if (!getenv("SOCKET_WRAPPER_DIR")) {
		return real_socket(domain, type, protocol);
	}
	
	fd = real_socket(AF_UNIX, type, 0);

	if (fd == -1) return -1;

	si = calloc(1, sizeof(struct socket_info));

	si->domain = domain;
	si->type = type;
	si->protocol = protocol;
	si->fd = fd;

	DLIST_ADD(sockets, si);

	return si->fd;
}

int swrap_accept(int s, struct sockaddr *addr, socklen_t *addrlen)
{
	struct socket_info *parent_si, *child_si;
	int fd;
	socklen_t un_addrlen = sizeof(struct sockaddr_un);
	struct sockaddr_un un_addr;
	int ret;

	parent_si = find_socket_info(s);
	if (!parent_si) {
		return real_accept(s, addr, addrlen);
	}

	ret = real_accept(s, (struct sockaddr *)&un_addr, &un_addrlen);
	if (ret == -1) return ret;

	fd = ret;

	ret = sockaddr_convert_from_un(parent_si, &un_addr, un_addrlen,
				       parent_si->domain, addr, addrlen);
	if (ret == -1) return ret;

	child_si = malloc(sizeof(struct socket_info));
	memset(child_si, 0, sizeof(*child_si));

	child_si->fd = fd;

	if (addr && addrlen) {
		child_si->myname_len = *addrlen;
		child_si->myname = sockaddr_dup(addr, *addrlen);
	}

	return fd;
}

int swrap_connect(int s, const struct sockaddr *serv_addr, socklen_t addrlen)
{
	int ret;
	struct sockaddr_un un_addr;
	struct socket_info *si = find_socket_info(s);

	if (!si) {
		return real_connect(s, serv_addr, addrlen);
	}

	/* only allow pseudo loopback connections */
	if (serv_addr->sa_family == AF_INET &&
		((const struct sockaddr_in *)serv_addr)->sin_addr.s_addr != 
	    htonl(INADDR_LOOPBACK)) {
		errno = ENETUNREACH;
		return -1;
	}

	ret = sockaddr_convert_to_un(si, (const struct sockaddr *)serv_addr, addrlen, &un_addr);
	if (ret == -1) return -1;

	ret = real_connect(s, (struct sockaddr *)&un_addr, 
			   sizeof(struct sockaddr_un));

	if (ret == 0) {
		si->peername_len = addrlen;
		si->peername = sockaddr_dup(serv_addr, addrlen);
	}

	return ret;
}

int swrap_bind(int s, const struct sockaddr *myaddr, socklen_t addrlen)
{
	int ret;
	struct sockaddr_un un_addr;
	struct socket_info *si = find_socket_info(s);

	if (!si) {
		return real_bind(s, myaddr, addrlen);
	}

	ret = sockaddr_convert_to_un(si, (const struct sockaddr *)myaddr, addrlen, &un_addr);
	if (ret == -1) return -1;

	unlink(un_addr.sun_path);

	ret = real_bind(s, (struct sockaddr *)&un_addr,
			sizeof(struct sockaddr_un));

	if (ret == 0) {
		si->myname_len = addrlen;
		si->myname = sockaddr_dup(myaddr, addrlen);
		si->bound = 1;
	}

	return ret;
}

int swrap_getpeername(int s, struct sockaddr *name, socklen_t *addrlen)
{
	struct socket_info *si = find_socket_info(s);

	if (!si) {
		return real_getpeername(s, name, addrlen);
	}

	if (!si->peername) 
	{
		errno = ENOTCONN;
		return -1;
	}

	memcpy(name, si->peername, si->peername_len);
	*addrlen = si->peername_len;

	return 0;
}

int swrap_getsockname(int s, struct sockaddr *name, socklen_t *addrlen)
{
	struct socket_info *si = find_socket_info(s);

	if (!si) {
		return real_getsockname(s, name, addrlen);
	}

	memcpy(name, si->myname, si->myname_len);
	*addrlen = si->myname_len;

	return 0;
}

int swrap_getsockopt(int s, int level, int optname, void *optval, socklen_t *optlen)
{
	struct socket_info *si = find_socket_info(s);

	if (!si) {
		return real_getsockopt(s, level, optname, optval, optlen);
	}

	if (level == SOL_SOCKET) {
		return real_getsockopt(s, level, optname, optval, optlen);
	} 

	switch (si->domain) {
	case AF_UNIX:
		return real_getsockopt(s, level, optname, optval, optlen);
	default:
		errno = ENOPROTOOPT;
		return -1;
	}
}

int swrap_setsockopt(int s, int  level,  int  optname,  const  void  *optval, socklen_t optlen)
{
	struct socket_info *si = find_socket_info(s);

	if (!si) {
		return real_setsockopt(s, level, optname, optval, optlen);
	}

	if (level == SOL_SOCKET) {
		return real_setsockopt(s, level, optname, optval, optlen);
	}

	switch (si->domain) {
	case AF_UNIX:
		return real_setsockopt(s, level, optname, optval, optlen);
	case AF_INET:
		/* Silence some warnings */
#ifdef TCP_NODELAY
		if (optname == TCP_NODELAY) 
			return 0;
#endif
	default:
		errno = ENOPROTOOPT;
		return -1;
	}
}

ssize_t swrap_recvfrom(int s, void *buf, size_t len, int flags, struct sockaddr *from, socklen_t *fromlen)
{
	struct sockaddr_un un_addr;
	socklen_t un_addrlen = sizeof(un_addr);
	int ret;
	struct socket_info *si = find_socket_info(s);

	if (!si) {
		return real_recvfrom(s, buf, len, flags, from, fromlen);
	}

	ret = real_recvfrom(s, buf, len, flags, (struct sockaddr *)&un_addr, &un_addrlen);
	if (ret == -1) 
		return ret;

	if (sockaddr_convert_from_un(si, &un_addr, un_addrlen,
				     si->domain, from, fromlen) == -1) {
		return -1;
	}
	
	return ret;
}

ssize_t swrap_sendto(int  s,  const  void *buf, size_t len, int flags, const struct sockaddr *to, socklen_t tolen)
{
	struct sockaddr_un un_addr;
	int ret;
	struct socket_info *si = find_socket_info(s);

	if (!si) {
		return real_sendto(s, buf, len, flags, to, tolen);
	}

	/* using sendto() on an unbound DGRAM socket would give the
	   recipient no way to reply, as unlike UDP, a unix domain socket
	   can't auto-assign emphemeral port numbers, so we need to assign
	   it here */
	if (si->bound == 0 && si->type == SOCK_DGRAM) {
		int i;

		un_addr.sun_family = AF_UNIX;

		for (i=0;i<1000;i++) {
			snprintf(un_addr.sun_path, sizeof(un_addr.sun_path), 
				 "%s/sock_ip_%u_%u", getenv("SOCKET_WRAPPER_DIR"), 
				 SOCK_DGRAM, i + 10000);
			if (bind(si->fd, (struct sockaddr *)&un_addr, 
				 sizeof(un_addr)) == 0) {
				si->tmp_path = strdup(un_addr.sun_path);
				si->bound = 1;
				break;
			}
		}
		if (i == 1000) {
			return -1;
		}
	}
	

	ret = sockaddr_convert_to_un(si, to, tolen, &un_addr);
	if (ret == -1) return -1;

	ret = real_sendto(s, buf, len, flags, (struct sockaddr *)&un_addr, sizeof(un_addr));

	return ret;
}

int swrap_close(int fd)
{
	struct socket_info *si = find_socket_info(fd);

	if (si) {
		DLIST_REMOVE(sockets, si);

		free(si->path);
		free(si->myname);
		free(si->peername);
		if (si->tmp_path) {
			unlink(si->tmp_path);
			free(si->tmp_path);
		}
		free(si);
	}

	return real_close(fd);
}