xref: /openbsd-src/usr.sbin/tcpdump/pfctl_osfp.c (revision 5b859c19fe53bbea08f5c342e0a4470e99f883e1)
1 /*	$OpenBSD: pfctl_osfp.c,v 1.9 2014/08/14 12:44:44 mpi Exp $ */
2 
3 /*
4  * Copyright (c) 2003 Mike Frantzen <frantzen@openbsd.org>
5  *
6  * Permission to use, copy, modify, and distribute this software for any
7  * purpose with or without fee is hereby granted, provided that the above
8  * copyright notice and this permission notice appear in all copies.
9  *
10  * THE SOFTWARE IS PROVIDED "AS IS" AND THE AUTHOR DISCLAIMS ALL WARRANTIES
11  * WITH REGARD TO THIS SOFTWARE INCLUDING ALL IMPLIED WARRANTIES OF
12  * MERCHANTABILITY AND FITNESS. IN NO EVENT SHALL THE AUTHOR BE LIABLE FOR
13  * ANY SPECIAL, DIRECT, INDIRECT, OR CONSEQUENTIAL DAMAGES OR ANY DAMAGES
14  * WHATSOEVER RESULTING FROM LOSS OF USE, DATA OR PROFITS, WHETHER IN AN
15  * ACTION OF CONTRACT, NEGLIGENCE OR OTHER TORTIOUS ACTION, ARISING OUT OF
16  * OR IN CONNECTION WITH THE USE OR PERFORMANCE OF THIS SOFTWARE.
17  */
18 
19 #include <sys/types.h>
20 #include <sys/ioctl.h>
21 #include <sys/socket.h>
22 
23 #include <net/if.h>
24 #include <net/pfvar.h>
25 
26 #include <ctype.h>
27 #include <err.h>
28 #include <errno.h>
29 #include <stdio.h>
30 #include <stdlib.h>
31 #include <string.h>
32 
33 #include <netinet/ip.h>
34 #include <netinet/ip6.h>
35 
36 #include "privsep.h"
37 #include "pfctl_parser.h"
38 
39 #ifndef MIN
40 # define MIN(a,b)	(((a) < (b)) ? (a) : (b))
41 #endif /* MIN */
42 #ifndef MAX
43 # define MAX(a,b)	(((a) > (b)) ? (a) : (b))
44 #endif /* MAX */
45 
46 
47 #if 0
48 # define DEBUG(fp, str, v...) \
49 	fprintf(stderr, "%s:%s:%s " str "\n", (fp)->fp_os.fp_class_nm, \
50 	    (fp)->fp_os.fp_version_nm, (fp)->fp_os.fp_subtype_nm , ## v);
51 #else
52 # define DEBUG(fp, str, v...) ((void)0)
53 #endif
54 
55 
56 struct name_entry;
57 LIST_HEAD(name_list, name_entry);
58 struct name_entry {
59 	LIST_ENTRY(name_entry)	nm_entry;
60 	int			nm_num;
61 	char			nm_name[PF_OSFP_LEN];
62 
63 	struct name_list	nm_sublist;
64 	int			nm_sublist_num;
65 };
66 struct name_list classes = LIST_HEAD_INITIALIZER(&classes);
67 int class_count;
68 int fingerprint_count;
69 
70 void			 add_fingerprint(int, int, struct pf_osfp_ioctl *);
71 struct name_entry	*fingerprint_name_entry(struct name_list *, char *);
72 void			 pfctl_flush_my_fingerprints(struct name_list *);
73 char			*get_field(u_char **, size_t *, int *);
74 int			 get_int(u_char **, size_t *, int *, int *, const char *,
75 			     int, int, const char *, int);
76 int			 get_str(u_char **, size_t *, char **, const char *, int,
77 			     const char *, int);
78 int			 get_tcpopts(const char *, int, const u_char *,
79 			    pf_tcpopts_t *, int *, int *, int *, int *, int *,
80 			    int *);
81 void			 import_fingerprint(struct pf_osfp_ioctl *);
82 const char		*print_ioctl(struct pf_osfp_ioctl *);
83 void			 print_name_list(int, struct name_list *, const char *);
84 void			 sort_name_list(int, struct name_list *);
85 struct name_entry	*lookup_name_list(struct name_list *, const char *);
86 
87 /* XXX arbitrary */
88 #define MAX_FP_LINE 1024
89 
90 /* Load fingerprints from a file */
91 int
92 pfctl_file_fingerprints(int dev, int opts, const char *fp_filename)
93 {
94 	u_char buf[MAX_FP_LINE];
95 	u_char *line;
96 	size_t len;
97 	int i, lineno = 0;
98 	int window, w_mod, ttl, df, psize, p_mod, mss, mss_mod, wscale,
99 	    wscale_mod, optcnt, ts0;
100 	pf_tcpopts_t packed_tcpopts;
101 	char *class, *version, *subtype, *desc, *tcpopts;
102 	struct pf_osfp_ioctl fp;
103 
104 	pfctl_flush_my_fingerprints(&classes);
105 	class = version = subtype = desc = tcpopts = NULL;
106 
107 	if ((opts & PF_OPT_NOACTION) == 0)
108 		pfctl_clear_fingerprints(dev, opts);
109 
110 	priv_getlines(FTAB_PFOSFP);
111 	while ((len = priv_getline(buf, sizeof(buf))) > 0) {
112 		buf[len -1] = '\n';
113 		line = buf;
114 		lineno++;
115 		if (class)
116 			free(class);
117 		if (version)
118 			free(version);
119 		if (subtype)
120 			free(subtype);
121 		if (desc)
122 			free(desc);
123 		if (tcpopts)
124 			free(tcpopts);
125 		class = version = subtype = desc = tcpopts = NULL;
126 		memset(&fp, 0, sizeof(fp));
127 
128 		/* Chop off comment */
129 		for (i = 0; i < len; i++)
130 			if (line[i] == '#') {
131 				len = i;
132 				break;
133 			}
134 		/* Chop off whitespace */
135 		while (len > 0 && isspace(line[len - 1]))
136 			len--;
137 		while (len > 0 && isspace(line[0])) {
138 			len--;
139 			line++;
140 		}
141 		if (len == 0)
142 			continue;
143 
144 #define T_DC	0x01	/* Allow don't care */
145 #define T_MSS	0x02	/* Allow MSS multiple */
146 #define T_MTU	0x04	/* Allow MTU multiple */
147 #define T_MOD	0x08	/* Allow modulus */
148 
149 #define GET_INT(v, mod, n, ty, mx) \
150 	get_int(&line, &len, &v, mod, n, ty, mx, fp_filename, lineno)
151 #define GET_STR(v, n, mn) \
152 	get_str(&line, &len, &v, n, mn, fp_filename, lineno)
153 
154 		if (GET_INT(window, &w_mod, "window size", T_DC|T_MSS|T_MTU|
155 		    T_MOD, 0xffff) ||
156 		    GET_INT(ttl, NULL, "ttl", 0, 0xff) ||
157 		    GET_INT(df, NULL, "don't fragment frag", 0, 1) ||
158 		    GET_INT(psize, &p_mod, "overall packet size", T_MOD|T_DC,
159 		    8192) ||
160 		    GET_STR(tcpopts, "TCP Options", 1) ||
161 		    GET_STR(class, "OS class", 1) ||
162 		    GET_STR(version, "OS version", 0) ||
163 		    GET_STR(subtype, "OS subtype", 0) ||
164 		    GET_STR(desc, "OS description", 2))
165 			continue;
166 		if (get_tcpopts(fp_filename, lineno, tcpopts, &packed_tcpopts,
167 		    &optcnt, &mss, &mss_mod, &wscale, &wscale_mod, &ts0))
168 			continue;
169 		if (len != 0) {
170 			fprintf(stderr, "%s:%d excess field\n", fp_filename,
171 			    lineno);
172 			continue;
173 		}
174 
175 		fp.fp_ttl = ttl;
176 		if (df)
177 			fp.fp_flags |= PF_OSFP_DF;
178 		switch (w_mod) {
179 		case 0:
180 			break;
181 		case T_DC:
182 			fp.fp_flags |= PF_OSFP_WSIZE_DC;
183 			break;
184 		case T_MSS:
185 			fp.fp_flags |= PF_OSFP_WSIZE_MSS;
186 			break;
187 		case T_MTU:
188 			fp.fp_flags |= PF_OSFP_WSIZE_MTU;
189 			break;
190 		case T_MOD:
191 			fp.fp_flags |= PF_OSFP_WSIZE_MOD;
192 			break;
193 		}
194 		fp.fp_wsize = window;
195 
196 		switch (p_mod) {
197 		case T_DC:
198 			fp.fp_flags |= PF_OSFP_PSIZE_DC;
199 			break;
200 		case T_MOD:
201 			fp.fp_flags |= PF_OSFP_PSIZE_MOD;
202 		}
203 		fp.fp_psize = psize;
204 
205 
206 		switch (wscale_mod) {
207 		case T_DC:
208 			fp.fp_flags |= PF_OSFP_WSCALE_DC;
209 			break;
210 		case T_MOD:
211 			fp.fp_flags |= PF_OSFP_WSCALE_MOD;
212 		}
213 		fp.fp_wscale = wscale;
214 
215 		switch (mss_mod) {
216 		case T_DC:
217 			fp.fp_flags |= PF_OSFP_MSS_DC;
218 			break;
219 		case T_MOD:
220 			fp.fp_flags |= PF_OSFP_MSS_MOD;
221 			break;
222 		}
223 		fp.fp_mss = mss;
224 
225 		fp.fp_tcpopts = packed_tcpopts;
226 		fp.fp_optcnt = optcnt;
227 		if (ts0)
228 			fp.fp_flags |= PF_OSFP_TS0;
229 
230 		if (class[0] == '@')
231 			fp.fp_os.fp_enflags |= PF_OSFP_GENERIC;
232 		if (class[0] == '*')
233 			fp.fp_os.fp_enflags |= PF_OSFP_NODETAIL;
234 
235 		if (class[0] == '@' || class[0] == '*')
236 			strlcpy(fp.fp_os.fp_class_nm, class + 1,
237 			    sizeof(fp.fp_os.fp_class_nm));
238 		else
239 			strlcpy(fp.fp_os.fp_class_nm, class,
240 			    sizeof(fp.fp_os.fp_class_nm));
241 		strlcpy(fp.fp_os.fp_version_nm, version,
242 		    sizeof(fp.fp_os.fp_version_nm));
243 		strlcpy(fp.fp_os.fp_subtype_nm, subtype,
244 		    sizeof(fp.fp_os.fp_subtype_nm));
245 
246 		add_fingerprint(dev, opts, &fp);
247 
248 		fp.fp_flags |= (PF_OSFP_DF | PF_OSFP_INET6);
249 		fp.fp_psize += sizeof(struct ip6_hdr) - sizeof(struct ip);
250 		add_fingerprint(dev, opts, &fp);
251 	}
252 
253 	if (class)
254 		free(class);
255 	if (version)
256 		free(version);
257 	if (subtype)
258 		free(subtype);
259 	if (desc)
260 		free(desc);
261 
262 	if (opts & PF_OPT_VERBOSE2)
263 		printf("Loaded %d passive OS fingerprints\n",
264 		    fingerprint_count);
265 	return (0);
266 }
267 
268 /* flush the kernel's fingerprints */
269 void
270 pfctl_clear_fingerprints(int dev, int opts)
271 {
272 	if (ioctl(dev, DIOCOSFPFLUSH))
273 		err(1, "DIOCOSFPFLUSH");
274 }
275 
276 /* flush pfctl's view of the fingerprints */
277 void
278 pfctl_flush_my_fingerprints(struct name_list *list)
279 {
280 	struct name_entry *nm;
281 
282 	while ((nm = LIST_FIRST(list)) != NULL) {
283 		LIST_REMOVE(nm, nm_entry);
284 		pfctl_flush_my_fingerprints(&nm->nm_sublist);
285 		fingerprint_count--;
286 		free(nm);
287 	}
288 	class_count = 0;
289 }
290 
291 /* Fetch the active fingerprints from the kernel */
292 int
293 pfctl_load_fingerprints(int dev, int opts)
294 {
295 	struct pf_osfp_ioctl io;
296 	int i;
297 
298 	pfctl_flush_my_fingerprints(&classes);
299 
300 	for (i = 0; i >= 0; i++) {
301 		memset(&io, 0, sizeof(io));
302 		io.fp_getnum = i;
303 		if (ioctl(dev, DIOCOSFPGET, &io)) {
304 			if (errno == EBUSY)
305 				break;
306 			warn("DIOCOSFPGET");
307 			return (1);
308 		}
309 		import_fingerprint(&io);
310 	}
311 	return (0);
312 }
313 
314 /* List the fingerprints */
315 void
316 pfctl_show_fingerprints(int opts)
317 {
318 	printf("Passive OS Fingerprints:\n");
319 	printf("\tClass\tVersion\tSubtype(subversion)\n");
320 	printf("\t-----\t-------\t-------------------\n");
321 	sort_name_list(opts, &classes);
322 	print_name_list(opts, &classes, "\t");
323 }
324 
325 /* Lookup a fingerprint */
326 pf_osfp_t
327 pfctl_get_fingerprint(const char *name)
328 {
329 	struct name_entry *nm, *class_nm, *version_nm, *subtype_nm;
330 	pf_osfp_t ret = PF_OSFP_NOMATCH;
331 	int class, version, subtype;
332 	int unp_class, unp_version, unp_subtype;
333 	int wr_len, version_len, subtype_len;
334 	char *ptr, *wr_name;
335 
336 	if (strcasecmp(name, "unknown") == 0)
337 		return (PF_OSFP_UNKNOWN);
338 
339 	/* Try most likely no version and no subtype */
340 	if ((nm = lookup_name_list(&classes, name))) {
341 		class = nm->nm_num;
342 		version = PF_OSFP_ANY;
343 		subtype = PF_OSFP_ANY;
344 		goto found;
345 	} else {
346 
347 		/* Chop it up into class/version/subtype */
348 
349 		if ((wr_name = strdup(name)) == NULL)
350 			err(1, "malloc");
351 		if ((ptr = strchr(wr_name, ' ')) == NULL) {
352 			free(wr_name);
353 			return (PF_OSFP_NOMATCH);
354 		}
355 		*ptr++ = '\0';
356 
357 		/* The class is easy to find since it is delimited by a space */
358 		if ((class_nm = lookup_name_list(&classes, wr_name)) == NULL) {
359 			free(wr_name);
360 			return (PF_OSFP_NOMATCH);
361 		}
362 		class = class_nm->nm_num;
363 
364 		/* Try no subtype */
365 		if ((version_nm = lookup_name_list(&class_nm->nm_sublist, ptr)))
366 		{
367 			version = version_nm->nm_num;
368 			subtype = PF_OSFP_ANY;
369 			free(wr_name);
370 			goto found;
371 		}
372 
373 
374 		/*
375 		 * There must be a version and a subtype.
376 		 * We'll do some fuzzy matching to pick up things like:
377 		 *   Linux 2.2.14 (version=2.2 subtype=14)
378 		 *   FreeBSD 4.0-STABLE (version=4.0 subtype=STABLE)
379 		 *   Windows 2000 SP2	(version=2000 subtype=SP2)
380 		 */
381 #define CONNECTOR(x)	((x) == '.' || (x) == ' ' || (x) == '\t' || (x) == '-')
382 		wr_len = strlen(ptr);
383 		LIST_FOREACH(version_nm, &class_nm->nm_sublist, nm_entry) {
384 			version_len = strlen(version_nm->nm_name);
385 			if (wr_len < version_len + 2 ||
386 			    !CONNECTOR(ptr[version_len]))
387 				continue;
388 			/* first part of the string must be version */
389 			if (strncasecmp(ptr, version_nm->nm_name,
390 			    version_len))
391 				continue;
392 
393 			LIST_FOREACH(subtype_nm, &version_nm->nm_sublist,
394 			    nm_entry) {
395 				subtype_len = strlen(subtype_nm->nm_name);
396 				if (wr_len != version_len + subtype_len + 1)
397 					continue;
398 
399 				/* last part of the string must be subtype */
400 				if (strcasecmp(&ptr[version_len+1],
401 				    subtype_nm->nm_name) != 0)
402 					continue;
403 
404 				/* Found it!! */
405 				version = version_nm->nm_num;
406 				subtype = subtype_nm->nm_num;
407 				free(wr_name);
408 				goto found;
409 			}
410 		}
411 
412 		free(wr_name);
413 		return (PF_OSFP_NOMATCH);
414 	}
415 
416 found:
417 	PF_OSFP_PACK(ret, class, version, subtype);
418 	if (ret != PF_OSFP_NOMATCH) {
419 		PF_OSFP_UNPACK(ret, unp_class, unp_version, unp_subtype);
420 		if (class != unp_class) {
421 			fprintf(stderr, "warning: fingerprint table overflowed "
422 			    "classes\n");
423 			return (PF_OSFP_NOMATCH);
424 		}
425 		if (version != unp_version) {
426 			fprintf(stderr, "warning: fingerprint table overflowed "
427 			    "versions\n");
428 			return (PF_OSFP_NOMATCH);
429 		}
430 		if (subtype != unp_subtype) {
431 			fprintf(stderr, "warning: fingerprint table overflowed "
432 			    "subtypes\n");
433 			return (PF_OSFP_NOMATCH);
434 		}
435 	}
436 	if (ret == PF_OSFP_ANY) {
437 		/* should never happen */
438 		fprintf(stderr, "warning: fingerprint packed to 'any'\n");
439 		return (PF_OSFP_NOMATCH);
440 	}
441 
442 	return (ret);
443 }
444 
445 /* Lookup a fingerprint name by ID */
446 char *
447 pfctl_lookup_fingerprint(pf_osfp_t fp, char *buf, size_t len)
448 {
449 	int class, version, subtype;
450 	struct name_list *list;
451 	struct name_entry *nm;
452 
453 	u_char *class_name, *version_name, *subtype_name;
454 	class_name = version_name = subtype_name = NULL;
455 
456 	if (fp == PF_OSFP_UNKNOWN) {
457 		strlcpy(buf, "unknown", len);
458 		return (buf);
459 	}
460 	if (fp == PF_OSFP_ANY) {
461 		strlcpy(buf, "any", len);
462 		return (buf);
463 	}
464 
465 	PF_OSFP_UNPACK(fp, class, version, subtype);
466 	if (class >= (1 << _FP_CLASS_BITS) ||
467 	    version >= (1 << _FP_VERSION_BITS) ||
468 	    subtype >= (1 << _FP_SUBTYPE_BITS)) {
469 		warnx("PF_OSFP_UNPACK(0x%x) failed!!", fp);
470 		strlcpy(buf, "nomatch", len);
471 		return (buf);
472 	}
473 
474 	LIST_FOREACH(nm, &classes, nm_entry) {
475 		if (nm->nm_num == class) {
476 			class_name = nm->nm_name;
477 			if (version == PF_OSFP_ANY)
478 				goto found;
479 			list = &nm->nm_sublist;
480 			LIST_FOREACH(nm, list, nm_entry) {
481 				if (nm->nm_num == version) {
482 					version_name = nm->nm_name;
483 					if (subtype == PF_OSFP_ANY)
484 						goto found;
485 					list = &nm->nm_sublist;
486 					LIST_FOREACH(nm, list, nm_entry) {
487 						if (nm->nm_num == subtype) {
488 							subtype_name =
489 							    nm->nm_name;
490 							goto found;
491 						}
492 					} /* foreach subtype */
493 					strlcpy(buf, "nomatch", len);
494 					return (buf);
495 				}
496 			} /* foreach version */
497 			strlcpy(buf, "nomatch", len);
498 			return (buf);
499 		}
500 	} /* foreach class */
501 
502 	strlcpy(buf, "nomatch", len);
503 	return (buf);
504 
505 found:
506 	snprintf(buf, len, "%s", class_name);
507 	if (version_name) {
508 		strlcat(buf, " ", len);
509 		strlcat(buf, version_name, len);
510 		if (subtype_name) {
511 			if (strchr(version_name, ' '))
512 				strlcat(buf, " ", len);
513 			else if (strchr(version_name, '.') &&
514 			    isdigit(*subtype_name))
515 				strlcat(buf, ".", len);
516 			else
517 				strlcat(buf, " ", len);
518 			strlcat(buf, subtype_name, len);
519 		}
520 	}
521 	return (buf);
522 }
523 
524 /* lookup a name in a list */
525 struct name_entry *
526 lookup_name_list(struct name_list *list, const char *name)
527 {
528 	struct name_entry *nm;
529 	LIST_FOREACH(nm, list, nm_entry)
530 		if (strcasecmp(name, nm->nm_name) == 0)
531 			return (nm);
532 
533 	return (NULL);
534 }
535 
536 
537 void
538 add_fingerprint(int dev, int opts, struct pf_osfp_ioctl *fp)
539 {
540 	struct pf_osfp_ioctl fptmp;
541 	struct name_entry *nm_class, *nm_version, *nm_subtype;
542 	int class, version, subtype;
543 
544 /* We expand #-# or #.#-#.# version/subtypes into multiple fingerprints */
545 #define EXPAND(field) do {						\
546 	int _dot = -1, _start = -1, _end = -1, _i = 0;			\
547 	/* pick major version out of #.# */				\
548 	if (isdigit(fp->field[_i]) && fp->field[_i+1] == '.') {		\
549 		_dot = fp->field[_i] - '0';				\
550 		_i += 2;						\
551 	}								\
552 	if (isdigit(fp->field[_i]))					\
553 		_start = fp->field[_i++] - '0';				\
554 	else								\
555 		break;							\
556 	if (isdigit(fp->field[_i]))					\
557 		_start = (_start * 10) + fp->field[_i++] - '0';		\
558 	if (fp->field[_i++] != '-')					\
559 		break;							\
560 	if (isdigit(fp->field[_i]) && fp->field[_i+1] == '.' &&		\
561 	    fp->field[_i] - '0' == _dot)				\
562 		_i += 2;						\
563 	else if (_dot != -1)						\
564 		break;							\
565 	if (isdigit(fp->field[_i]))					\
566 		_end = fp->field[_i++] - '0';				\
567 	else								\
568 		break;							\
569 	if (isdigit(fp->field[_i]))					\
570 		_end = (_end * 10) + fp->field[_i++] - '0';		\
571 	if (isdigit(fp->field[_i]))					\
572 		_end = (_end * 10) + fp->field[_i++] - '0';		\
573 	if (fp->field[_i] != '\0')					\
574 		break;							\
575 	memcpy(&fptmp, fp, sizeof(fptmp));				\
576 	for (;_start <= _end; _start++) {				\
577 		memset(fptmp.field, 0, sizeof(fptmp.field));		\
578 		fptmp.fp_os.fp_enflags |= PF_OSFP_EXPANDED;		\
579 		if (_dot == -1)						\
580 			snprintf(fptmp.field, sizeof(fptmp.field),	\
581 			    "%d", _start);				\
582 		    else						\
583 			snprintf(fptmp.field, sizeof(fptmp.field),	\
584 			    "%d.%d", _dot, _start);			\
585 		add_fingerprint(dev, opts, &fptmp);			\
586 	}								\
587 } while(0)
588 
589 	/* We allow "#-#" as a version or subtype and we'll expand it */
590 	EXPAND(fp_os.fp_version_nm);
591 	EXPAND(fp_os.fp_subtype_nm);
592 
593 	if (strcasecmp(fp->fp_os.fp_class_nm, "nomatch") == 0)
594 		errx(1, "fingerprint class \"nomatch\" is reserved");
595 
596 	version = PF_OSFP_ANY;
597 	subtype = PF_OSFP_ANY;
598 
599 	nm_class = fingerprint_name_entry(&classes, fp->fp_os.fp_class_nm);
600 	if (nm_class->nm_num == 0)
601 		nm_class->nm_num = ++class_count;
602 	class = nm_class->nm_num;
603 
604 	nm_version = fingerprint_name_entry(&nm_class->nm_sublist,
605 	    fp->fp_os.fp_version_nm);
606 	if (nm_version) {
607 		if (nm_version->nm_num == 0)
608 			nm_version->nm_num = ++nm_class->nm_sublist_num;
609 		version = nm_version->nm_num;
610 		nm_subtype = fingerprint_name_entry(&nm_version->nm_sublist,
611 		    fp->fp_os.fp_subtype_nm);
612 		if (nm_subtype) {
613 			if (nm_subtype->nm_num == 0)
614 				nm_subtype->nm_num =
615 				    ++nm_version->nm_sublist_num;
616 			subtype = nm_subtype->nm_num;
617 		}
618 	}
619 
620 
621 	DEBUG(fp, "\tsignature %d:%d:%d %s", class, version, subtype,
622 	    print_ioctl(fp));
623 
624 	PF_OSFP_PACK(fp->fp_os.fp_os, class, version, subtype);
625 	fingerprint_count++;
626 
627 #ifdef FAKE_PF_KERNEL
628 	/* Linked to the sys/net/pf_osfp.c.  Call pf_osfp_add() */
629 	if ((errno = pf_osfp_add(fp)))
630 #else
631 	if ((opts & PF_OPT_NOACTION) == 0 && ioctl(dev, DIOCOSFPADD, fp))
632 #endif /* FAKE_PF_KERNEL */
633 	{
634 		if (errno == EEXIST) {
635 			warn("Duplicate signature for %s %s %s",
636 				fp->fp_os.fp_class_nm,
637 				fp->fp_os.fp_version_nm,
638 				fp->fp_os.fp_subtype_nm);
639 
640 		} else {
641 			err(1, "DIOCOSFPADD");
642 		}
643 	}
644 }
645 
646 /* import a fingerprint from the kernel */
647 void
648 import_fingerprint(struct pf_osfp_ioctl *fp)
649 {
650 	struct name_entry *nm_class, *nm_version, *nm_subtype;
651 	int class, version, subtype;
652 
653 	PF_OSFP_UNPACK(fp->fp_os.fp_os, class, version, subtype);
654 
655 	nm_class = fingerprint_name_entry(&classes, fp->fp_os.fp_class_nm);
656 	if (nm_class->nm_num == 0) {
657 		nm_class->nm_num = class;
658 		class_count = MAX(class_count, class);
659 	}
660 
661 	nm_version = fingerprint_name_entry(&nm_class->nm_sublist,
662 	    fp->fp_os.fp_version_nm);
663 	if (nm_version) {
664 		if (nm_version->nm_num == 0) {
665 			nm_version->nm_num = version;
666 			nm_class->nm_sublist_num = MAX(nm_class->nm_sublist_num,
667 			    version);
668 		}
669 		nm_subtype = fingerprint_name_entry(&nm_version->nm_sublist,
670 		    fp->fp_os.fp_subtype_nm);
671 		if (nm_subtype) {
672 			if (nm_subtype->nm_num == 0) {
673 				nm_subtype->nm_num = subtype;
674 				nm_version->nm_sublist_num =
675 				    MAX(nm_version->nm_sublist_num, subtype);
676 			}
677 		}
678 	}
679 
680 
681 	fingerprint_count++;
682 	DEBUG(fp, "import signature %d:%d:%d", class, version, subtype);
683 }
684 
685 /* Find an entry for a fingerprints class/version/subtype */
686 struct name_entry *
687 fingerprint_name_entry(struct name_list *list, char *name)
688 {
689 	struct name_entry *nm_entry;
690 
691 	if (name == NULL || strlen(name) == 0)
692 		return (NULL);
693 
694 	LIST_FOREACH(nm_entry, list, nm_entry) {
695 		if (strcasecmp(nm_entry->nm_name, name) == 0) {
696 			/* We'll move this to the front of the list later */
697 			LIST_REMOVE(nm_entry, nm_entry);
698 			break;
699 		}
700 	}
701 	if (nm_entry == NULL) {
702 		nm_entry = calloc(1, sizeof(*nm_entry));
703 		if (nm_entry == NULL)
704 			err(1, "calloc");
705 		LIST_INIT(&nm_entry->nm_sublist);
706 		strlcpy(nm_entry->nm_name, name, sizeof(nm_entry->nm_name));
707 	}
708 	LIST_INSERT_HEAD(list, nm_entry, nm_entry);
709 	return (nm_entry);
710 }
711 
712 
713 void
714 print_name_list(int opts, struct name_list *nml, const char *prefix)
715 {
716 	char newprefix[32];
717 	struct name_entry *nm;
718 
719 	LIST_FOREACH(nm, nml, nm_entry) {
720 		snprintf(newprefix, sizeof(newprefix), "%s%s\t", prefix,
721 		    nm->nm_name);
722 		printf("%s\n", newprefix);
723 		print_name_list(opts, &nm->nm_sublist, newprefix);
724 	}
725 }
726 
727 void
728 sort_name_list(int opts, struct name_list *nml)
729 {
730 	struct name_list new;
731 	struct name_entry *nm, *nmsearch, *nmlast;
732 
733 	/* yes yes, it's a very slow sort.  so sue me */
734 
735 	LIST_INIT(&new);
736 
737 	while ((nm = LIST_FIRST(nml)) != NULL) {
738 		LIST_REMOVE(nm, nm_entry);
739 		nmlast = NULL;
740 		LIST_FOREACH(nmsearch, &new, nm_entry) {
741 			if (strcasecmp(nmsearch->nm_name, nm->nm_name) > 0) {
742 				LIST_INSERT_BEFORE(nmsearch, nm, nm_entry);
743 				break;
744 			}
745 			nmlast = nmsearch;
746 		}
747 		if (nmsearch == NULL) {
748 			if (nmlast)
749 				LIST_INSERT_AFTER(nmlast, nm, nm_entry);
750 			else
751 				LIST_INSERT_HEAD(&new, nm, nm_entry);
752 		}
753 
754 		sort_name_list(opts, &nm->nm_sublist);
755 	}
756 	nmlast = NULL;
757 	while ((nm = LIST_FIRST(&new)) != NULL) {
758 		LIST_REMOVE(nm, nm_entry);
759 		if (nmlast == NULL)
760 			LIST_INSERT_HEAD(nml, nm, nm_entry);
761 		else
762 			LIST_INSERT_AFTER(nmlast, nm, nm_entry);
763 		nmlast = nm;
764 	}
765 	return;
766 }
767 
768 /* parse the next integer in a formatted config file line */
769 int
770 get_int(u_char **line, size_t *len, int *var, int *mod,
771     const char *name, int flags, int max, const char *filename, int lineno)
772 {
773 	int fieldlen, i;
774 	u_char *field;
775 	long val = 0;
776 
777 	if (mod)
778 		*mod = 0;
779 	*var = 0;
780 
781 	field = get_field(line, len, &fieldlen);
782 	if (field == NULL)
783 		return (1);
784 	if (fieldlen == 0) {
785 		fprintf(stderr, "%s:%d empty %s\n", filename, lineno, name);
786 		return (1);
787 	}
788 
789 	i = 0;
790 	if ((*field == '%' || *field == 'S' || *field == 'T' || *field == '*')
791 	    && fieldlen >= 1) {
792 		switch (*field) {
793 		case 'S':
794 			if (mod && (flags & T_MSS))
795 				*mod = T_MSS;
796 			if (fieldlen == 1)
797 				return (0);
798 			break;
799 		case 'T':
800 			if (mod && (flags & T_MTU))
801 				*mod = T_MTU;
802 			if (fieldlen == 1)
803 				return (0);
804 			break;
805 		case '*':
806 			if (fieldlen != 1) {
807 				fprintf(stderr, "%s:%d long '%c' %s\n",
808 				    filename, lineno, *field, name);
809 				return (1);
810 			}
811 			if (mod && (flags & T_DC)) {
812 				*mod = T_DC;
813 				return (0);
814 			}
815 		case '%':
816 			if (mod && (flags & T_MOD))
817 				*mod = T_MOD;
818 			if (fieldlen == 1) {
819 				fprintf(stderr, "%s:%d modulus %s must have a "
820 				    "value\n", filename, lineno, name);
821 				return (1);
822 			}
823 			break;
824 		}
825 		if (mod == NULL || *mod == 0) {
826 			fprintf(stderr, "%s:%d does not allow %c' %s\n",
827 			    filename, lineno, *field, name);
828 			return (1);
829 		}
830 		i++;
831 	}
832 
833 	for (; i < fieldlen; i++) {
834 		if (field[i] < '0'  || field[i] > '9') {
835 			fprintf(stderr, "%s:%d non-digit character in %s\n",
836 			    filename, lineno, name);
837 			return (1);
838 		}
839 		val = val * 10 + field[i] - '0';
840 		if (val < 0) {
841 			fprintf(stderr, "%s:%d %s overflowed\n", filename,
842 			    lineno, name);
843 			return (1);
844 		}
845 	}
846 
847 	if (val > max) {
848 		fprintf(stderr, "%s:%d %s value %ld > %d\n", filename, lineno,
849 		    name, val, max);
850 		return (1);
851 	}
852 	*var = (int)val;
853 
854 	return (0);
855 }
856 
857 /* parse the next string in a formatted config file line */
858 int
859 get_str(u_char **line, size_t *len, char **v, const char *name, int minlen,
860     const char *filename, int lineno)
861 {
862 	int fieldlen;
863 	char *ptr;
864 
865 	ptr = get_field(line, len, &fieldlen);
866 	if (ptr == NULL)
867 		return (1);
868 	if (fieldlen < minlen) {
869 		fprintf(stderr, "%s:%d too short %s\n", filename, lineno, name);
870 		return (1);
871 	}
872 	if ((*v = malloc(fieldlen + 1)) == NULL) {
873 		perror("malloc()");
874 		return (1);
875 	}
876 	memcpy(*v, ptr, fieldlen);
877 	(*v)[fieldlen] = '\0';
878 
879 	return (0);
880 }
881 
882 /* Parse out the TCP opts */
883 int
884 get_tcpopts(const char *filename, int lineno, const u_char *tcpopts,
885     pf_tcpopts_t *packed, int *optcnt, int *mss, int *mss_mod, int *wscale,
886     int *wscale_mod, int *ts0)
887 {
888 	int i, opt;
889 
890 	*packed = 0;
891 	*optcnt = 0;
892 	*wscale = 0;
893 	*wscale_mod = T_DC;
894 	*mss = 0;
895 	*mss_mod = T_DC;
896 	*ts0 = 0;
897 	if (strcmp(tcpopts, ".") == 0)
898 		return (0);
899 
900 	for (i = 0; tcpopts[i] && *optcnt < PF_OSFP_MAX_OPTS;) {
901 		switch ((opt = toupper(tcpopts[i++]))) {
902 		case 'N':	/* FALLTHROUGH */
903 		case 'S':
904 			*packed = (*packed << PF_OSFP_TCPOPT_BITS) |
905 			    (opt == 'N' ? PF_OSFP_TCPOPT_NOP :
906 			    PF_OSFP_TCPOPT_SACK);
907 			break;
908 		case 'W':	/* FALLTHROUGH */
909 		case 'M': {
910 			int *this_mod, *this;
911 
912 			if (opt == 'W') {
913 				this = wscale;
914 				this_mod = wscale_mod;
915 			} else {
916 				this = mss;
917 				this_mod = mss_mod;
918 			}
919 			*this = 0;
920 			*this_mod = 0;
921 
922 			*packed = (*packed << PF_OSFP_TCPOPT_BITS) |
923 			    (opt == 'W' ? PF_OSFP_TCPOPT_WSCALE :
924 			    PF_OSFP_TCPOPT_MSS);
925 			if (tcpopts[i] == '*' && (tcpopts[i + 1] == '\0' ||
926 			    tcpopts[i + 1] == ',')) {
927 				*this_mod = T_DC;
928 				i++;
929 				break;
930 			}
931 
932 			if (tcpopts[i] == '%') {
933 				*this_mod = T_MOD;
934 				i++;
935 			}
936 			do {
937 				if (!isdigit(tcpopts[i])) {
938 					fprintf(stderr, "%s:%d unknown "
939 					    "character '%c' in %c TCP opt\n",
940 					    filename, lineno, tcpopts[i], opt);
941 					return (1);
942 				}
943 				*this = (*this * 10) + tcpopts[i++] - '0';
944 			} while(tcpopts[i] != ',' && tcpopts[i] != '\0');
945 			break;
946 		}
947 		case 'T':
948 			if (tcpopts[i] == '0') {
949 				*ts0 = 1;
950 				i++;
951 			}
952 			*packed = (*packed << PF_OSFP_TCPOPT_BITS) |
953 			    PF_OSFP_TCPOPT_TS;
954 			break;
955 		}
956 		(*optcnt) ++;
957 		if (tcpopts[i] == '\0')
958 			break;
959 		if (tcpopts[i] != ',') {
960 			fprintf(stderr, "%s:%d unknown option to %c TCP opt\n",
961 			    filename, lineno, opt);
962 			return (1);
963 		}
964 		i++;
965 	}
966 
967 	return (0);
968 }
969 
970 /* rip the next field ouf of a formatted config file line */
971 char *
972 get_field(u_char **line, size_t *len, int *fieldlen)
973 {
974 	char *ret, *ptr = *line;
975 	size_t plen = *len;
976 
977 
978 	while (plen && isspace((unsigned char)*ptr)) {
979 		plen--;
980 		ptr++;
981 	}
982 	ret = ptr;
983 	*fieldlen = 0;
984 
985 	for (; plen > 0 && *ptr != ':'; plen--, ptr++)
986 		(*fieldlen)++;
987 	if (plen) {
988 		*line = ptr + 1;
989 		*len = plen - 1;
990 	} else {
991 		*len = 0;
992 	}
993 	while (*fieldlen && isspace((unsigned char)ret[*fieldlen - 1]))
994 		(*fieldlen)--;
995 	return (ret);
996 }
997 
998 
999 const char *
1000 print_ioctl(struct pf_osfp_ioctl *fp)
1001 {
1002 	static char buf[1024];
1003 	char tmp[32];
1004 	int i, opt;
1005 
1006 	*buf = '\0';
1007 	if (fp->fp_flags & PF_OSFP_WSIZE_DC)
1008 		strlcat(buf, "*", sizeof(buf));
1009 	else if (fp->fp_flags & PF_OSFP_WSIZE_MSS)
1010 		strlcat(buf, "S", sizeof(buf));
1011 	else if (fp->fp_flags & PF_OSFP_WSIZE_MTU)
1012 		strlcat(buf, "T", sizeof(buf));
1013 	else {
1014 		if (fp->fp_flags & PF_OSFP_WSIZE_MOD)
1015 			strlcat(buf, "%", sizeof(buf));
1016 		snprintf(tmp, sizeof(tmp), "%d", fp->fp_wsize);
1017 		strlcat(buf, tmp, sizeof(buf));
1018 	}
1019 	strlcat(buf, ":", sizeof(buf));
1020 
1021 	snprintf(tmp, sizeof(tmp), "%d", fp->fp_ttl);
1022 	strlcat(buf, tmp, sizeof(buf));
1023 	strlcat(buf, ":", sizeof(buf));
1024 
1025 	if (fp->fp_flags & PF_OSFP_DF)
1026 		strlcat(buf, "1", sizeof(buf));
1027 	else
1028 		strlcat(buf, "0", sizeof(buf));
1029 	strlcat(buf, ":", sizeof(buf));
1030 
1031 	if (fp->fp_flags & PF_OSFP_PSIZE_DC)
1032 		strlcat(buf, "*", sizeof(buf));
1033 	else {
1034 		if (fp->fp_flags & PF_OSFP_PSIZE_MOD)
1035 			strlcat(buf, "%", sizeof(buf));
1036 		snprintf(tmp, sizeof(tmp), "%d", fp->fp_psize);
1037 		strlcat(buf, tmp, sizeof(buf));
1038 	}
1039 	strlcat(buf, ":", sizeof(buf));
1040 
1041 	if (fp->fp_optcnt == 0)
1042 		strlcat(buf, ".", sizeof(buf));
1043 	for (i = fp->fp_optcnt - 1; i >= 0; i--) {
1044 		opt = fp->fp_tcpopts >> (i * PF_OSFP_TCPOPT_BITS);
1045 		opt &= (1 << PF_OSFP_TCPOPT_BITS) - 1;
1046 		switch (opt) {
1047 		case PF_OSFP_TCPOPT_NOP:
1048 			strlcat(buf, "N", sizeof(buf));
1049 			break;
1050 		case PF_OSFP_TCPOPT_SACK:
1051 			strlcat(buf, "S", sizeof(buf));
1052 			break;
1053 		case PF_OSFP_TCPOPT_TS:
1054 			strlcat(buf, "T", sizeof(buf));
1055 			if (fp->fp_flags & PF_OSFP_TS0)
1056 				strlcat(buf, "0", sizeof(buf));
1057 			break;
1058 		case PF_OSFP_TCPOPT_MSS:
1059 			strlcat(buf, "M", sizeof(buf));
1060 			if (fp->fp_flags & PF_OSFP_MSS_DC)
1061 				strlcat(buf, "*", sizeof(buf));
1062 			else {
1063 				if (fp->fp_flags & PF_OSFP_MSS_MOD)
1064 					strlcat(buf, "%", sizeof(buf));
1065 				snprintf(tmp, sizeof(tmp), "%d", fp->fp_mss);
1066 				strlcat(buf, tmp, sizeof(buf));
1067 			}
1068 			break;
1069 		case PF_OSFP_TCPOPT_WSCALE:
1070 			strlcat(buf, "W", sizeof(buf));
1071 			if (fp->fp_flags & PF_OSFP_WSCALE_DC)
1072 				strlcat(buf, "*", sizeof(buf));
1073 			else {
1074 				if (fp->fp_flags & PF_OSFP_WSCALE_MOD)
1075 					strlcat(buf, "%", sizeof(buf));
1076 				snprintf(tmp, sizeof(tmp), "%d", fp->fp_wscale);
1077 				strlcat(buf, tmp, sizeof(buf));
1078 			}
1079 			break;
1080 		}
1081 
1082 		if (i != 0)
1083 			strlcat(buf, ",", sizeof(buf));
1084 	}
1085 	strlcat(buf, ":", sizeof(buf));
1086 
1087 	strlcat(buf, fp->fp_os.fp_class_nm, sizeof(buf));
1088 	strlcat(buf, ":", sizeof(buf));
1089 	strlcat(buf, fp->fp_os.fp_version_nm, sizeof(buf));
1090 	strlcat(buf, ":", sizeof(buf));
1091 	strlcat(buf, fp->fp_os.fp_subtype_nm, sizeof(buf));
1092 	strlcat(buf, ":", sizeof(buf));
1093 
1094 	snprintf(tmp, sizeof(tmp), "TcpOpts %d 0x%llx", fp->fp_optcnt,
1095 	    (long long int)fp->fp_tcpopts);
1096 	strlcat(buf, tmp, sizeof(buf));
1097 
1098 	return (buf);
1099 }
1100