1 /*
2 * Copyright (c) 2005 Evgeniy Polyakov <johnpol@2ka.mxt.ru>
3 *
4 *
5 * This program is free software; you can redistribute it and/or modify
6 * it under the terms of the GNU General Public License as published by
7 * the Free Software Foundation; either version 2 of the License, or
8 * (at your option) any later version.
9 *
10 * This program is distributed in the hope that it will be useful,
11 * but WITHOUT ANY WARRANTY; without even the implied warranty of
12 * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the
13 * GNU General Public License for more details.
14 *
15 * You should have received a copy of the GNU General Public License
16 * along with this program; if not, write to the Free Software
17 * Foundation, Inc., 59 Temple Place, Suite 330, Boston, MA 02111-1307 USA
18 */
19
20 #include <sys/types.h>
21 #include <sys/socket.h>
22 #include <sys/poll.h>
23 #include <sys/time.h>
24
25 #include <arpa/inet.h>
26
27 #include <ctype.h>
28 #include <errno.h>
29 #include <stdio.h>
30 #include <stdlib.h>
31 #include <string.h>
32 #include <stdarg.h>
33 #include <time.h>
34 #include <unistd.h>
35
36 #include <netinet/ip.h>
37 #include <netinet/tcp.h>
38
39 #include <linux/connector.h>
40 #include <linux/types.h>
41 #include <linux/netlink.h>
42 #include <linux/rtnetlink.h>
43 #include <linux/unistd.h>
44
45 #include <libnfnetlink/libnfnetlink.h>
46
47 #include <linux/netfilter/nfnetlink.h>
48 #include <linux/netfilter/xt_osf.h>
49
50 #define OPTDEL ','
51 #define OSFPDEL ':'
52 #define MAXOPTSTRLEN 128
53
54 #ifndef NIPQUAD
55 #define NIPQUAD(addr) \
56 ((unsigned char *)&addr)[0], \
57 ((unsigned char *)&addr)[1], \
58 ((unsigned char *)&addr)[2], \
59 ((unsigned char *)&addr)[3]
60 #endif
61
62 static struct nfnl_handle *nfnlh;
63 static struct nfnl_subsys_handle *nfnlssh;
64
65 static struct xt_osf_opt IANA_opts[] = {
66 { .kind = 0, .length = 1,},
67 { .kind=1, .length=1,},
68 { .kind=2, .length=4,},
69 { .kind=3, .length=3,},
70 { .kind=4, .length=2,},
71 { .kind=5, .length=1,}, /* SACK length is not defined */
72 { .kind=6, .length=6,},
73 { .kind=7, .length=6,},
74 { .kind=8, .length=10,},
75 { .kind=9, .length=2,},
76 { .kind=10, .length=3,},
77 { .kind=11, .length=1,}, /* CC: Suppose 1 */
78 { .kind=12, .length=1,}, /* the same */
79 { .kind=13, .length=1,}, /* and here too */
80 { .kind=14, .length=3,},
81 { .kind=15, .length=1,}, /* TCP Alternate Checksum Data. Length is not defined */
82 { .kind=16, .length=1,},
83 { .kind=17, .length=1,},
84 { .kind=18, .length=3,},
85 { .kind=19, .length=18,},
86 { .kind=20, .length=1,},
87 { .kind=21, .length=1,},
88 { .kind=22, .length=1,},
89 { .kind=23, .length=1,},
90 { .kind=24, .length=1,},
91 { .kind=25, .length=1,},
92 { .kind=26, .length=1,},
93 };
94
95 static FILE *osf_log_stream;
96
uloga(const char * f,...)97 static void uloga(const char *f, ...)
98 {
99 va_list ap;
100
101 if (!osf_log_stream)
102 osf_log_stream = stdout;
103
104 va_start(ap, f);
105 vfprintf(osf_log_stream, f, ap);
106 va_end(ap);
107
108 fflush(osf_log_stream);
109 }
110
ulog(const char * f,...)111 static void ulog(const char *f, ...)
112 {
113 char str[64];
114 struct tm tm;
115 struct timeval tv;
116 va_list ap;
117
118 if (!osf_log_stream)
119 osf_log_stream = stdout;
120
121 gettimeofday(&tv, NULL);
122 localtime_r((time_t *)&tv.tv_sec, &tm);
123 strftime(str, sizeof(str), "%F %R:%S", &tm);
124
125 fprintf(osf_log_stream, "%s.%lu %ld ", str, tv.tv_usec, syscall(__NR_gettid));
126
127 va_start(ap, f);
128 vfprintf(osf_log_stream, f, ap);
129 va_end(ap);
130
131 fflush(osf_log_stream);
132 }
133
134 #define ulog_err(f, a...) uloga(f ": %s [%d].\n", ##a, strerror(errno), errno)
135
xt_osf_strchr(char * ptr,char c)136 static char *xt_osf_strchr(char *ptr, char c)
137 {
138 char *tmp;
139
140 tmp = strchr(ptr, c);
141 if (tmp)
142 *tmp = '\0';
143
144 while (tmp && tmp + 1 && isspace(*(tmp + 1)))
145 tmp++;
146
147 return tmp;
148 }
149
xt_osf_parse_opt(struct xt_osf_opt * opt,__u16 * optnum,char * obuf,int olen)150 static void xt_osf_parse_opt(struct xt_osf_opt *opt, __u16 *optnum, char *obuf, int olen)
151 {
152 int i, op;
153 char *ptr, wc;
154 unsigned long val;
155
156 ptr = &obuf[0];
157 i = 0;
158 while (ptr != NULL && i < olen && *ptr != 0) {
159 val = 0;
160 op = 0;
161 wc = OSF_WSS_PLAIN;
162 switch (obuf[i]) {
163 case 'N':
164 op = OSFOPT_NOP;
165 ptr = xt_osf_strchr(&obuf[i], OPTDEL);
166 if (ptr) {
167 *ptr = '\0';
168 ptr++;
169 i += (int)(ptr - &obuf[i]);
170 } else
171 i++;
172 break;
173 case 'S':
174 op = OSFOPT_SACKP;
175 ptr = xt_osf_strchr(&obuf[i], OPTDEL);
176 if (ptr) {
177 *ptr = '\0';
178 ptr++;
179 i += (int)(ptr - &obuf[i]);
180 } else
181 i++;
182 break;
183 case 'T':
184 op = OSFOPT_TS;
185 ptr = xt_osf_strchr(&obuf[i], OPTDEL);
186 if (ptr) {
187 *ptr = '\0';
188 ptr++;
189 i += (int)(ptr - &obuf[i]);
190 } else
191 i++;
192 break;
193 case 'W':
194 op = OSFOPT_WSO;
195 ptr = xt_osf_strchr(&obuf[i], OPTDEL);
196 if (ptr) {
197 switch (obuf[i + 1]) {
198 case '%':
199 wc = OSF_WSS_MODULO;
200 break;
201 case 'S':
202 wc = OSF_WSS_MSS;
203 break;
204 case 'T':
205 wc = OSF_WSS_MTU;
206 break;
207 default:
208 wc = OSF_WSS_PLAIN;
209 break;
210 }
211
212 *ptr = '\0';
213 ptr++;
214 if (wc)
215 val = strtoul(&obuf[i + 2], NULL, 10);
216 else
217 val = strtoul(&obuf[i + 1], NULL, 10);
218 i += (int)(ptr - &obuf[i]);
219
220 } else
221 i++;
222 break;
223 case 'M':
224 op = OSFOPT_MSS;
225 ptr = xt_osf_strchr(&obuf[i], OPTDEL);
226 if (ptr) {
227 if (obuf[i + 1] == '%')
228 wc = OSF_WSS_MODULO;
229 *ptr = '\0';
230 ptr++;
231 if (wc)
232 val = strtoul(&obuf[i + 2], NULL, 10);
233 else
234 val = strtoul(&obuf[i + 1], NULL, 10);
235 i += (int)(ptr - &obuf[i]);
236 } else
237 i++;
238 break;
239 case 'E':
240 op = OSFOPT_EOL;
241 ptr = xt_osf_strchr(&obuf[i], OPTDEL);
242 if (ptr) {
243 *ptr = '\0';
244 ptr++;
245 i += (int)(ptr - &obuf[i]);
246 } else
247 i++;
248 break;
249 default:
250 op = OSFOPT_EMPTY;
251 ptr = xt_osf_strchr(&obuf[i], OPTDEL);
252 if (ptr) {
253 ptr++;
254 i += (int)(ptr - &obuf[i]);
255 } else
256 i++;
257 break;
258 }
259
260 if (op != OSFOPT_EMPTY) {
261 opt[*optnum].kind = IANA_opts[op].kind;
262 opt[*optnum].length = IANA_opts[op].length;
263 opt[*optnum].wc.wc = wc;
264 opt[*optnum].wc.val = val;
265 (*optnum)++;
266 }
267 }
268 }
269
osf_load_line(char * buffer,int len,int del)270 static int osf_load_line(char *buffer, int len, int del)
271 {
272 int i, cnt = 0;
273 char obuf[MAXOPTSTRLEN];
274 struct xt_osf_user_finger f;
275 char *pbeg, *pend;
276 char buf[NFNL_HEADER_LEN + NFA_LENGTH(sizeof(struct xt_osf_user_finger))];
277 struct nlmsghdr *nmh = (struct nlmsghdr *) buf;
278
279 memset(&f, 0, sizeof(struct xt_osf_user_finger));
280
281 ulog("Loading '%s'.\n", buffer);
282
283 for (i = 0; i < len && buffer[i] != '\0'; ++i) {
284 if (buffer[i] == ':')
285 cnt++;
286 }
287
288 if (cnt != 8) {
289 ulog("Wrong input line '%s': cnt: %d, must be 8, i: %d, must be %d.\n", buffer, cnt, i, len);
290 return -EINVAL;
291 }
292
293 memset(obuf, 0, sizeof(obuf));
294
295 pbeg = buffer;
296 pend = xt_osf_strchr(pbeg, OSFPDEL);
297 if (pend) {
298 *pend = '\0';
299 if (pbeg[0] == 'S') {
300 f.wss.wc = OSF_WSS_MSS;
301 if (pbeg[1] == '%')
302 f.wss.val = strtoul(&pbeg[2], NULL, 10);
303 else if (pbeg[1] == '*')
304 f.wss.val = 0;
305 else
306 f.wss.val = strtoul(&pbeg[1], NULL, 10);
307 } else if (pbeg[0] == 'T') {
308 f.wss.wc = OSF_WSS_MTU;
309 if (pbeg[1] == '%')
310 f.wss.val = strtoul(&pbeg[2], NULL, 10);
311 else if (pbeg[1] == '*')
312 f.wss.val = 0;
313 else
314 f.wss.val = strtoul(&pbeg[1], NULL, 10);
315 } else if (pbeg[0] == '%') {
316 f.wss.wc = OSF_WSS_MODULO;
317 f.wss.val = strtoul(&pbeg[1], NULL, 10);
318 } else if (isdigit(pbeg[0])) {
319 f.wss.wc = OSF_WSS_PLAIN;
320 f.wss.val = strtoul(&pbeg[0], NULL, 10);
321 }
322
323 pbeg = pend + 1;
324 }
325 pend = xt_osf_strchr(pbeg, OSFPDEL);
326 if (pend) {
327 *pend = '\0';
328 f.ttl = strtoul(pbeg, NULL, 10);
329 pbeg = pend + 1;
330 }
331 pend = xt_osf_strchr(pbeg, OSFPDEL);
332 if (pend) {
333 *pend = '\0';
334 f.df = strtoul(pbeg, NULL, 10);
335 pbeg = pend + 1;
336 }
337 pend = xt_osf_strchr(pbeg, OSFPDEL);
338 if (pend) {
339 *pend = '\0';
340 f.ss = strtoul(pbeg, NULL, 10);
341 pbeg = pend + 1;
342 }
343
344 pend = xt_osf_strchr(pbeg, OSFPDEL);
345 if (pend) {
346 *pend = '\0';
347 cnt = snprintf(obuf, sizeof(obuf), "%s,", pbeg);
348 pbeg = pend + 1;
349 }
350
351 pend = xt_osf_strchr(pbeg, OSFPDEL);
352 if (pend) {
353 *pend = '\0';
354 if (pbeg[0] == '@' || pbeg[0] == '*')
355 cnt = snprintf(f.genre, sizeof(f.genre), "%s", pbeg + 1);
356 else
357 cnt = snprintf(f.genre, sizeof(f.genre), "%s", pbeg);
358 pbeg = pend + 1;
359 }
360
361 pend = xt_osf_strchr(pbeg, OSFPDEL);
362 if (pend) {
363 *pend = '\0';
364 cnt = snprintf(f.version, sizeof(f.version), "%s", pbeg);
365 pbeg = pend + 1;
366 }
367
368 pend = xt_osf_strchr(pbeg, OSFPDEL);
369 if (pend) {
370 *pend = '\0';
371 cnt =
372 snprintf(f.subtype, sizeof(f.subtype), "%s", pbeg);
373 pbeg = pend + 1;
374 }
375
376 xt_osf_parse_opt(f.opt, &f.opt_num, obuf, sizeof(obuf));
377
378 memset(buf, 0, sizeof(buf));
379
380 if (del)
381 nfnl_fill_hdr(nfnlssh, nmh, 0, AF_UNSPEC, 0, OSF_MSG_REMOVE, NLM_F_REQUEST);
382 else
383 nfnl_fill_hdr(nfnlssh, nmh, 0, AF_UNSPEC, 0, OSF_MSG_ADD, NLM_F_REQUEST | NLM_F_CREATE);
384
385 nfnl_addattr_l(nmh, sizeof(buf), OSF_ATTR_FINGER, &f, sizeof(struct xt_osf_user_finger));
386
387 return nfnl_talk(nfnlh, nmh, 0, 0, NULL, NULL, NULL);
388 }
389
osf_load_entries(char * path,int del)390 static int osf_load_entries(char *path, int del)
391 {
392 FILE *inf;
393 int err = 0;
394 char buf[1024];
395
396 inf = fopen(path, "r");
397 if (!inf) {
398 ulog_err("Failed to open file '%s'", path);
399 return -1;
400 }
401
402 while(fgets(buf, sizeof(buf), inf)) {
403 int len;
404
405 if (buf[0] == '#' || buf[0] == '\n' || buf[0] == '\r')
406 continue;
407
408 len = strlen(buf) - 1;
409
410 if (len <= 0)
411 continue;
412
413 buf[len] = '\0';
414
415 err = osf_load_line(buf, len, del);
416 if (err)
417 break;
418
419 memset(buf, 0, sizeof(buf));
420 }
421
422 fclose(inf);
423 return err;
424 }
425
main(int argc,char * argv[])426 int main(int argc, char *argv[])
427 {
428 int ch, del = 0, err;
429 char *fingerprints = NULL;
430
431 while ((ch = getopt(argc, argv, "f:dh")) != -1) {
432 switch (ch) {
433 case 'f':
434 fingerprints = optarg;
435 break;
436 case 'd':
437 del = 1;
438 break;
439 default:
440 fprintf(stderr,
441 "Usage: %s -f fingerprints -d <del rules> -h\n",
442 argv[0]);
443 return -1;
444 }
445 }
446
447 if (!fingerprints) {
448 err = -ENOENT;
449 goto err_out_exit;
450 }
451
452 nfnlh = nfnl_open();
453 if (!nfnlh) {
454 err = -EINVAL;
455 ulog_err("Failed to create nfnl handler");
456 goto err_out_exit;
457 }
458
459 #ifndef NFNL_SUBSYS_OSF
460 #define NFNL_SUBSYS_OSF 5
461 #endif
462
463 nfnlssh = nfnl_subsys_open(nfnlh, NFNL_SUBSYS_OSF, OSF_MSG_MAX, 0);
464 if (!nfnlssh) {
465 err = -EINVAL;
466 ulog_err("Faied to create nfnl subsystem");
467 goto err_out_close;
468 }
469
470 err = osf_load_entries(fingerprints, del);
471 if (err)
472 goto err_out_close_subsys;
473
474 nfnl_subsys_close(nfnlssh);
475 nfnl_close(nfnlh);
476
477 return 0;
478
479 err_out_close_subsys:
480 nfnl_subsys_close(nfnlssh);
481 err_out_close:
482 nfnl_close(nfnlh);
483 err_out_exit:
484 return err;
485 }
486