xref: /netbsd/dist/pf/sbin/pfctl/pfctl_osfp.c (revision f88c7923)
1 /*	$NetBSD: pfctl_osfp.c,v 1.8 2019/02/03 10:48:47 mrg Exp $	*/
2 /*	$OpenBSD: pfctl_osfp.c,v 1.15 2006/12/13 05:10:15 itojun Exp $ */
3 
4 /*
5  * Copyright (c) 2003 Mike Frantzen <frantzen@openbsd.org>
6  *
7  * Permission to use, copy, modify, and distribute this software for any
8  * purpose with or without fee is hereby granted, provided that the above
9  * copyright notice and this permission notice appear in all copies.
10  *
11  * THE SOFTWARE IS PROVIDED "AS IS" AND THE AUTHOR DISCLAIMS ALL WARRANTIES
12  * WITH REGARD TO THIS SOFTWARE INCLUDING ALL IMPLIED WARRANTIES OF
13  * MERCHANTABILITY AND FITNESS. IN NO EVENT SHALL THE AUTHOR BE LIABLE FOR
14  * ANY SPECIAL, DIRECT, INDIRECT, OR CONSEQUENTIAL DAMAGES OR ANY DAMAGES
15  * WHATSOEVER RESULTING FROM LOSS OF USE, DATA OR PROFITS, WHETHER IN AN
16  * ACTION OF CONTRACT, NEGLIGENCE OR OTHER TORTIOUS ACTION, ARISING OUT OF
17  * OR IN CONNECTION WITH THE USE OR PERFORMANCE OF THIS SOFTWARE.
18  */
19 
20 #include <sys/types.h>
21 #include <sys/ioctl.h>
22 #include <sys/socket.h>
23 
24 #include <net/if.h>
25 #include <net/pfvar.h>
26 
27 #include <netinet/in_systm.h>
28 #include <netinet/ip.h>
29 #include <netinet/ip6.h>
30 
31 #include <ctype.h>
32 #include <err.h>
33 #include <errno.h>
34 #include <stdio.h>
35 #include <stdlib.h>
36 #include <string.h>
37 
38 #include "pfctl_parser.h"
39 #include "pfctl.h"
40 
41 #ifndef MIN
42 # define MIN(a,b)	(((a) < (b)) ? (a) : (b))
43 #endif /* MIN */
44 #ifndef MAX
45 # define MAX(a,b)	(((a) > (b)) ? (a) : (b))
46 #endif /* MAX */
47 
48 
49 #if 0
50 # define DEBUG(fp, str, v...) \
51 	fprintf(stderr, "%s:%s:%s " str "\n", (fp)->fp_os.fp_class_nm, \
52 	    (fp)->fp_os.fp_version_nm, (fp)->fp_os.fp_subtype_nm , ## v);
53 #else
54 # define DEBUG(fp, str, v...) ((void)0)
55 #endif
56 
57 
58 struct name_entry;
59 LIST_HEAD(name_list, name_entry);
60 struct name_entry {
61 	LIST_ENTRY(name_entry)	nm_entry;
62 	int			nm_num;
63 	char			nm_name[PF_OSFP_LEN];
64 
65 	struct name_list	nm_sublist;
66 	int			nm_sublist_num;
67 };
68 struct name_list classes = LIST_HEAD_INITIALIZER(&classes);
69 int class_count;
70 int fingerprint_count;
71 
72 void			 add_fingerprint(int, int, struct pf_osfp_ioctl *);
73 struct name_entry	*fingerprint_name_entry(struct name_list *, char *);
74 void			 pfctl_flush_my_fingerprints(struct name_list *);
75 char			*get_field(char **, size_t *, int *);
76 int			 get_int(char **, size_t *, int *, int *, const char *,
77 			     int, int, const char *, int);
78 int			 get_str(char **, size_t *, char **, const char *, int,
79 			     const char *, int);
80 int			 get_tcpopts(const char *, int, const char *,
81 			    pf_tcpopts_t *, int *, int *, int *, int *, int *,
82 			    int *);
83 void			 import_fingerprint(struct pf_osfp_ioctl *);
84 const char		*print_ioctl(struct pf_osfp_ioctl *);
85 void			 print_name_list(int, struct name_list *, const char *);
86 void			 sort_name_list(int, struct name_list *);
87 struct name_entry	*lookup_name_list(struct name_list *, const char *);
88 
89 /* Load fingerprints from a file */
90 int
pfctl_file_fingerprints(int dev,int opts,const char * fp_filename)91 pfctl_file_fingerprints(int dev, int opts, const char *fp_filename)
92 {
93 	FILE *in;
94 	char *line;
95 	size_t len;
96 	int i, lineno = 0;
97 	int window, w_mod, ttl, df, psize, p_mod, mss, mss_mod, wscale,
98 	    wscale_mod, optcnt, ts0;
99 	pf_tcpopts_t packed_tcpopts;
100 	char *class, *version, *subtype, *desc, *tcpopts;
101 	struct pf_osfp_ioctl fp;
102 
103 	pfctl_flush_my_fingerprints(&classes);
104 
105 	if ((in = pfctl_fopen(fp_filename, "r")) == NULL) {
106 		warn("%s", fp_filename);
107 		return (1);
108 	}
109 	class = version = subtype = desc = tcpopts = NULL;
110 
111 	if ((opts & PF_OPT_NOACTION) == 0)
112 		pfctl_clear_fingerprints(dev, opts);
113 
114 	while ((line = fgetln(in, &len)) != NULL) {
115 		lineno++;
116 		if (class)
117 			free(class);
118 		if (version)
119 			free(version);
120 		if (subtype)
121 			free(subtype);
122 		if (desc)
123 			free(desc);
124 		if (tcpopts)
125 			free(tcpopts);
126 		class = version = subtype = desc = tcpopts = NULL;
127 		memset(&fp, 0, sizeof(fp));
128 
129 		/* Chop off comment */
130 		for (i = 0; i < len; i++)
131 			if (line[i] == '#') {
132 				len = i;
133 				break;
134 			}
135 		/* Chop off whitespace */
136 		while (len > 0 && isspace((unsigned char)line[len - 1]))
137 			len--;
138 		while (len > 0 && isspace((unsigned char)line[0])) {
139 			len--;
140 			line++;
141 		}
142 		if (len == 0)
143 			continue;
144 
145 #define T_DC	0x01	/* Allow don't care */
146 #define T_MSS	0x02	/* Allow MSS multiple */
147 #define T_MTU	0x04	/* Allow MTU multiple */
148 #define T_MOD	0x08	/* Allow modulus */
149 
150 #define GET_INT(v, mod, n, ty, mx) \
151 	get_int(&line, &len, &v, mod, n, ty, mx, fp_filename, lineno)
152 #define GET_STR(v, n, mn) \
153 	get_str(&line, &len, &v, n, mn, fp_filename, lineno)
154 
155 		if (GET_INT(window, &w_mod, "window size", T_DC|T_MSS|T_MTU|
156 		    T_MOD, 0xffff) ||
157 		    GET_INT(ttl, NULL, "ttl", 0, 0xff) ||
158 		    GET_INT(df, NULL, "don't fragment frag", 0, 1) ||
159 		    GET_INT(psize, &p_mod, "overall packet size", T_MOD|T_DC,
160 		    8192) ||
161 		    GET_STR(tcpopts, "TCP Options", 1) ||
162 		    GET_STR(class, "OS class", 1) ||
163 		    GET_STR(version, "OS version", 0) ||
164 		    GET_STR(subtype, "OS subtype", 0) ||
165 		    GET_STR(desc, "OS description", 2))
166 			continue;
167 		if (get_tcpopts(fp_filename, lineno, tcpopts, &packed_tcpopts,
168 		    &optcnt, &mss, &mss_mod, &wscale, &wscale_mod, &ts0))
169 			continue;
170 		if (len != 0) {
171 			fprintf(stderr, "%s:%d excess field\n", fp_filename,
172 			    lineno);
173 			continue;
174 		}
175 
176 		fp.fp_ttl = ttl;
177 		if (df)
178 			fp.fp_flags |= PF_OSFP_DF;
179 		switch (w_mod) {
180 		case 0:
181 			break;
182 		case T_DC:
183 			fp.fp_flags |= PF_OSFP_WSIZE_DC;
184 			break;
185 		case T_MSS:
186 			fp.fp_flags |= PF_OSFP_WSIZE_MSS;
187 			break;
188 		case T_MTU:
189 			fp.fp_flags |= PF_OSFP_WSIZE_MTU;
190 			break;
191 		case T_MOD:
192 			fp.fp_flags |= PF_OSFP_WSIZE_MOD;
193 			break;
194 		}
195 		fp.fp_wsize = window;
196 
197 		switch (p_mod) {
198 		case T_DC:
199 			fp.fp_flags |= PF_OSFP_PSIZE_DC;
200 			break;
201 		case T_MOD:
202 			fp.fp_flags |= PF_OSFP_PSIZE_MOD;
203 		}
204 		fp.fp_psize = psize;
205 
206 
207 		switch (wscale_mod) {
208 		case T_DC:
209 			fp.fp_flags |= PF_OSFP_WSCALE_DC;
210 			break;
211 		case T_MOD:
212 			fp.fp_flags |= PF_OSFP_WSCALE_MOD;
213 		}
214 		fp.fp_wscale = wscale;
215 
216 		switch (mss_mod) {
217 		case T_DC:
218 			fp.fp_flags |= PF_OSFP_MSS_DC;
219 			break;
220 		case T_MOD:
221 			fp.fp_flags |= PF_OSFP_MSS_MOD;
222 			break;
223 		}
224 		fp.fp_mss = mss;
225 
226 		fp.fp_tcpopts = packed_tcpopts;
227 		fp.fp_optcnt = optcnt;
228 		if (ts0)
229 			fp.fp_flags |= PF_OSFP_TS0;
230 
231 		if (class[0] == '@')
232 			fp.fp_os.fp_enflags |= PF_OSFP_GENERIC;
233 		if (class[0] == '*')
234 			fp.fp_os.fp_enflags |= PF_OSFP_NODETAIL;
235 
236 		if (class[0] == '@' || class[0] == '*')
237 			strlcpy(fp.fp_os.fp_class_nm, class + 1,
238 			    sizeof(fp.fp_os.fp_class_nm));
239 		else
240 			strlcpy(fp.fp_os.fp_class_nm, class,
241 			    sizeof(fp.fp_os.fp_class_nm));
242 		strlcpy(fp.fp_os.fp_version_nm, version,
243 		    sizeof(fp.fp_os.fp_version_nm));
244 		strlcpy(fp.fp_os.fp_subtype_nm, subtype,
245 		    sizeof(fp.fp_os.fp_subtype_nm));
246 
247 		add_fingerprint(dev, opts, &fp);
248 
249 		fp.fp_flags |= (PF_OSFP_DF | PF_OSFP_INET6);
250 		fp.fp_psize += sizeof(struct ip6_hdr) - sizeof(struct ip);
251 		add_fingerprint(dev, opts, &fp);
252 	}
253 
254 	if (class)
255 		free(class);
256 	if (version)
257 		free(version);
258 	if (subtype)
259 		free(subtype);
260 	if (desc)
261 		free(desc);
262 	if (tcpopts)
263 		free(tcpopts);
264 
265 	fclose(in);
266 
267 	if (opts & PF_OPT_VERBOSE2)
268 		printf("Loaded %d passive OS fingerprints\n",
269 		    fingerprint_count);
270 	return (0);
271 }
272 
273 /* flush the kernel's fingerprints */
274 void
pfctl_clear_fingerprints(int dev,int opts)275 pfctl_clear_fingerprints(int dev, int opts)
276 {
277 	if (ioctl(dev, DIOCOSFPFLUSH))
278 		err(1, "DIOCOSFPFLUSH");
279 }
280 
281 /* flush pfctl's view of the fingerprints */
282 void
pfctl_flush_my_fingerprints(struct name_list * list)283 pfctl_flush_my_fingerprints(struct name_list *list)
284 {
285 	struct name_entry *nm;
286 
287 	while ((nm = LIST_FIRST(list)) != NULL) {
288 		LIST_REMOVE(nm, nm_entry);
289 		pfctl_flush_my_fingerprints(&nm->nm_sublist);
290 		free(nm);
291 	}
292 	fingerprint_count = 0;
293 	class_count = 0;
294 }
295 
296 /* Fetch the active fingerprints from the kernel */
297 int
pfctl_load_fingerprints(int dev,int opts)298 pfctl_load_fingerprints(int dev, int opts)
299 {
300 	struct pf_osfp_ioctl io;
301 	int i;
302 
303 	pfctl_flush_my_fingerprints(&classes);
304 
305 	for (i = 0; i >= 0; i++) {
306 		memset(&io, 0, sizeof(io));
307 		io.fp_getnum = i;
308 		if (ioctl(dev, DIOCOSFPGET, &io)) {
309 			if (errno == EBUSY)
310 				break;
311 			warn("DIOCOSFPGET");
312 			return (1);
313 		}
314 		import_fingerprint(&io);
315 	}
316 	return (0);
317 }
318 
319 /* List the fingerprints */
320 void
pfctl_show_fingerprints(int opts)321 pfctl_show_fingerprints(int opts)
322 {
323 	if (LIST_FIRST(&classes) != NULL) {
324 		if (opts & PF_OPT_SHOWALL) {
325 			pfctl_print_title("OS FINGERPRINTS:");
326 			printf("%u fingerprints loaded\n", fingerprint_count);
327 		} else {
328 			printf("Class\tVersion\tSubtype(subversion)\n");
329 			printf("-----\t-------\t-------------------\n");
330 			sort_name_list(opts, &classes);
331 			print_name_list(opts, &classes, "");
332 		}
333 	}
334 }
335 
336 /* Lookup a fingerprint */
337 pf_osfp_t
pfctl_get_fingerprint(const char * name)338 pfctl_get_fingerprint(const char *name)
339 {
340 	struct name_entry *nm, *class_nm, *version_nm, *subtype_nm;
341 	pf_osfp_t ret = PF_OSFP_NOMATCH;
342 	int class, version, subtype;
343 	int unp_class, unp_version, unp_subtype;
344 	int wr_len, version_len, subtype_len;
345 	char *ptr, *wr_name;
346 
347 	if (strcasecmp(name, "unknown") == 0)
348 		return (PF_OSFP_UNKNOWN);
349 
350 	/* Try most likely no version and no subtype */
351 	if ((nm = lookup_name_list(&classes, name))) {
352 		class = nm->nm_num;
353 		version = PF_OSFP_ANY;
354 		subtype = PF_OSFP_ANY;
355 		goto found;
356 	} else {
357 
358 		/* Chop it up into class/version/subtype */
359 
360 		if ((wr_name = strdup(name)) == NULL)
361 			err(1, "malloc");
362 		if ((ptr = strchr(wr_name, ' ')) == NULL) {
363 			free(wr_name);
364 			return (PF_OSFP_NOMATCH);
365 		}
366 		*ptr++ = '\0';
367 
368 		/* The class is easy to find since it is delimited by a space */
369 		if ((class_nm = lookup_name_list(&classes, wr_name)) == NULL) {
370 			free(wr_name);
371 			return (PF_OSFP_NOMATCH);
372 		}
373 		class = class_nm->nm_num;
374 
375 		/* Try no subtype */
376 		if ((version_nm = lookup_name_list(&class_nm->nm_sublist, ptr)))
377 		{
378 			version = version_nm->nm_num;
379 			subtype = PF_OSFP_ANY;
380 			free(wr_name);
381 			goto found;
382 		}
383 
384 
385 		/*
386 		 * There must be a version and a subtype.
387 		 * We'll do some fuzzy matching to pick up things like:
388 		 *   Linux 2.2.14 (version=2.2 subtype=14)
389 		 *   FreeBSD 4.0-STABLE (version=4.0 subtype=STABLE)
390 		 *   Windows 2000 SP2	(version=2000 subtype=SP2)
391 		 */
392 #define CONNECTOR(x)	((x) == '.' || (x) == ' ' || (x) == '\t' || (x) == '-')
393 		wr_len = strlen(ptr);
394 		LIST_FOREACH(version_nm, &class_nm->nm_sublist, nm_entry) {
395 			version_len = strlen(version_nm->nm_name);
396 			if (wr_len < version_len + 2 ||
397 			    !CONNECTOR(ptr[version_len]))
398 				continue;
399 			/* first part of the string must be version */
400 			if (strncasecmp(ptr, version_nm->nm_name,
401 			    version_len))
402 				continue;
403 
404 			LIST_FOREACH(subtype_nm, &version_nm->nm_sublist,
405 			    nm_entry) {
406 				subtype_len = strlen(subtype_nm->nm_name);
407 				if (wr_len != version_len + subtype_len + 1)
408 					continue;
409 
410 				/* last part of the string must be subtype */
411 				if (strcasecmp(&ptr[version_len+1],
412 				    subtype_nm->nm_name) != 0)
413 					continue;
414 
415 				/* Found it!! */
416 				version = version_nm->nm_num;
417 				subtype = subtype_nm->nm_num;
418 				free(wr_name);
419 				goto found;
420 			}
421 		}
422 
423 		free(wr_name);
424 		return (PF_OSFP_NOMATCH);
425 	}
426 
427 found:
428 	PF_OSFP_PACK(ret, class, version, subtype);
429 	if (ret != PF_OSFP_NOMATCH) {
430 		PF_OSFP_UNPACK(ret, unp_class, unp_version, unp_subtype);
431 		if (class != unp_class) {
432 			fprintf(stderr, "warning: fingerprint table overflowed "
433 			    "classes\n");
434 			return (PF_OSFP_NOMATCH);
435 		}
436 		if (version != unp_version) {
437 			fprintf(stderr, "warning: fingerprint table overflowed "
438 			    "versions\n");
439 			return (PF_OSFP_NOMATCH);
440 		}
441 		if (subtype != unp_subtype) {
442 			fprintf(stderr, "warning: fingerprint table overflowed "
443 			    "subtypes\n");
444 			return (PF_OSFP_NOMATCH);
445 		}
446 	}
447 	if (ret == PF_OSFP_ANY) {
448 		/* should never happen */
449 		fprintf(stderr, "warning: fingerprint packed to 'any'\n");
450 		return (PF_OSFP_NOMATCH);
451 	}
452 
453 	return (ret);
454 }
455 
456 /* Lookup a fingerprint name by ID */
457 char *
pfctl_lookup_fingerprint(pf_osfp_t fp,char * buf,size_t len)458 pfctl_lookup_fingerprint(pf_osfp_t fp, char *buf, size_t len)
459 {
460 	int class, version, subtype;
461 	struct name_list *list;
462 	struct name_entry *nm;
463 
464 	char *class_name, *version_name, *subtype_name;
465 	class_name = version_name = subtype_name = NULL;
466 
467 	if (fp == PF_OSFP_UNKNOWN) {
468 		strlcpy(buf, "unknown", len);
469 		return (buf);
470 	}
471 	if (fp == PF_OSFP_ANY) {
472 		strlcpy(buf, "any", len);
473 		return (buf);
474 	}
475 
476 	PF_OSFP_UNPACK(fp, class, version, subtype);
477 	if (class >= (1 << _FP_CLASS_BITS) ||
478 	    version >= (1 << _FP_VERSION_BITS) ||
479 	    subtype >= (1 << _FP_SUBTYPE_BITS)) {
480 		warnx("PF_OSFP_UNPACK(0x%x) failed!!", fp);
481 		strlcpy(buf, "nomatch", len);
482 		return (buf);
483 	}
484 
485 	LIST_FOREACH(nm, &classes, nm_entry) {
486 		if (nm->nm_num == class) {
487 			class_name = nm->nm_name;
488 			if (version == PF_OSFP_ANY)
489 				goto found;
490 			list = &nm->nm_sublist;
491 			LIST_FOREACH(nm, list, nm_entry) {
492 				if (nm->nm_num == version) {
493 					version_name = nm->nm_name;
494 					if (subtype == PF_OSFP_ANY)
495 						goto found;
496 					list = &nm->nm_sublist;
497 					LIST_FOREACH(nm, list, nm_entry) {
498 						if (nm->nm_num == subtype) {
499 							subtype_name =
500 							    nm->nm_name;
501 							goto found;
502 						}
503 					} /* foreach subtype */
504 					strlcpy(buf, "nomatch", len);
505 					return (buf);
506 				}
507 			} /* foreach version */
508 			strlcpy(buf, "nomatch", len);
509 			return (buf);
510 		}
511 	} /* foreach class */
512 
513 	strlcpy(buf, "nomatch", len);
514 	return (buf);
515 
516 found:
517 	snprintf(buf, len, "%s", class_name);
518 	if (version_name) {
519 		strlcat(buf, " ", len);
520 		strlcat(buf, version_name, len);
521 		if (subtype_name) {
522 			if (strchr(version_name, ' '))
523 				strlcat(buf, " ", len);
524 			else if (strchr(version_name, '.') &&
525 			    isdigit((unsigned char)*subtype_name))
526 				strlcat(buf, ".", len);
527 			else
528 				strlcat(buf, " ", len);
529 			strlcat(buf, subtype_name, len);
530 		}
531 	}
532 	return (buf);
533 }
534 
535 /* lookup a name in a list */
536 struct name_entry *
lookup_name_list(struct name_list * list,const char * name)537 lookup_name_list(struct name_list *list, const char *name)
538 {
539 	struct name_entry *nm;
540 	LIST_FOREACH(nm, list, nm_entry)
541 		if (strcasecmp(name, nm->nm_name) == 0)
542 			return (nm);
543 
544 	return (NULL);
545 }
546 
547 
548 void
add_fingerprint(int dev,int opts,struct pf_osfp_ioctl * fp)549 add_fingerprint(int dev, int opts, struct pf_osfp_ioctl *fp)
550 {
551 	struct pf_osfp_ioctl fptmp;
552 	struct name_entry *nm_class, *nm_version, *nm_subtype;
553 	int class, version, subtype;
554 
555 /* We expand #-# or #.#-#.# version/subtypes into multiple fingerprints */
556 #define EXPAND(field) do {						\
557 	int _dot = -1, _start = -1, _end = -1, _i = 0;			\
558 	/* pick major version out of #.# */				\
559 	if (isdigit((unsigned char)fp->field[_i]) && fp->field[_i+1] == '.') { \
560 		_dot = fp->field[_i] - '0';				\
561 		_i += 2;						\
562 	}								\
563 	if (isdigit((unsigned char)fp->field[_i]))			\
564 		_start = fp->field[_i++] - '0';				\
565 	else								\
566 		break;							\
567 	if (isdigit((unsigned char)fp->field[_i]))			\
568 		_start = (_start * 10) + fp->field[_i++] - '0';		\
569 	if (fp->field[_i++] != '-')					\
570 		break;							\
571 	if (isdigit((unsigned char)fp->field[_i]) && fp->field[_i+1] == '.' && \
572 	    fp->field[_i] - '0' == _dot)				\
573 		_i += 2;						\
574 	else if (_dot != -1)						\
575 		break;							\
576 	if (isdigit((unsigned char)fp->field[_i]))			\
577 		_end = fp->field[_i++] - '0';				\
578 	else								\
579 		break;							\
580 	if (isdigit((unsigned char)fp->field[_i]))			\
581 		_end = (_end * 10) + fp->field[_i++] - '0';		\
582 	if (isdigit((unsigned char)fp->field[_i]))			\
583 		_end = (_end * 10) + fp->field[_i++] - '0';		\
584 	if (fp->field[_i] != '\0')					\
585 		break;							\
586 	memcpy(&fptmp, fp, sizeof(fptmp));				\
587 	for (;_start <= _end; _start++) {				\
588 		memset(fptmp.field, 0, sizeof(fptmp.field));		\
589 		fptmp.fp_os.fp_enflags |= PF_OSFP_EXPANDED;		\
590 		if (_dot == -1)						\
591 			snprintf(fptmp.field, sizeof(fptmp.field),	\
592 			    "%d", _start);				\
593 		    else						\
594 			snprintf(fptmp.field, sizeof(fptmp.field),	\
595 			    "%d.%d", _dot, _start);			\
596 		add_fingerprint(dev, opts, &fptmp);			\
597 	}								\
598 } while(0)
599 
600 	/* We allow "#-#" as a version or subtype and we'll expand it */
601 	EXPAND(fp_os.fp_version_nm);
602 	EXPAND(fp_os.fp_subtype_nm);
603 
604 	if (strcasecmp(fp->fp_os.fp_class_nm, "nomatch") == 0)
605 		errx(1, "fingerprint class \"nomatch\" is reserved");
606 
607 	version = PF_OSFP_ANY;
608 	subtype = PF_OSFP_ANY;
609 
610 	nm_class = fingerprint_name_entry(&classes, fp->fp_os.fp_class_nm);
611 	if (nm_class->nm_num == 0)
612 		nm_class->nm_num = ++class_count;
613 	class = nm_class->nm_num;
614 
615 	nm_version = fingerprint_name_entry(&nm_class->nm_sublist,
616 	    fp->fp_os.fp_version_nm);
617 	if (nm_version) {
618 		if (nm_version->nm_num == 0)
619 			nm_version->nm_num = ++nm_class->nm_sublist_num;
620 		version = nm_version->nm_num;
621 		nm_subtype = fingerprint_name_entry(&nm_version->nm_sublist,
622 		    fp->fp_os.fp_subtype_nm);
623 		if (nm_subtype) {
624 			if (nm_subtype->nm_num == 0)
625 				nm_subtype->nm_num =
626 				    ++nm_version->nm_sublist_num;
627 			subtype = nm_subtype->nm_num;
628 		}
629 	}
630 
631 
632 	DEBUG(fp, "\tsignature %d:%d:%d %s", class, version, subtype,
633 	    print_ioctl(fp));
634 
635 	PF_OSFP_PACK(fp->fp_os.fp_os, class, version, subtype);
636 	fingerprint_count++;
637 
638 #ifdef FAKE_PF_KERNEL
639 	/* Linked to the sys/net/pf_osfp.c.  Call pf_osfp_add() */
640 	if ((errno = pf_osfp_add(fp)))
641 #else
642 	if ((opts & PF_OPT_NOACTION) == 0 && ioctl(dev, DIOCOSFPADD, fp))
643 #endif /* FAKE_PF_KERNEL */
644 	{
645 		if (errno == EEXIST) {
646 			warn("Duplicate signature for %s %s %s",
647 				fp->fp_os.fp_class_nm,
648 				fp->fp_os.fp_version_nm,
649 				fp->fp_os.fp_subtype_nm);
650 
651 		} else {
652 			err(1, "DIOCOSFPADD");
653 		}
654 	}
655 }
656 
657 /* import a fingerprint from the kernel */
658 void
import_fingerprint(struct pf_osfp_ioctl * fp)659 import_fingerprint(struct pf_osfp_ioctl *fp)
660 {
661 	struct name_entry *nm_class, *nm_version, *nm_subtype;
662 	int class, version, subtype;
663 
664 	PF_OSFP_UNPACK(fp->fp_os.fp_os, class, version, subtype);
665 
666 	nm_class = fingerprint_name_entry(&classes, fp->fp_os.fp_class_nm);
667 	if (nm_class->nm_num == 0) {
668 		nm_class->nm_num = class;
669 		class_count = MAX(class_count, class);
670 	}
671 
672 	nm_version = fingerprint_name_entry(&nm_class->nm_sublist,
673 	    fp->fp_os.fp_version_nm);
674 	if (nm_version) {
675 		if (nm_version->nm_num == 0) {
676 			nm_version->nm_num = version;
677 			nm_class->nm_sublist_num = MAX(nm_class->nm_sublist_num,
678 			    version);
679 		}
680 		nm_subtype = fingerprint_name_entry(&nm_version->nm_sublist,
681 		    fp->fp_os.fp_subtype_nm);
682 		if (nm_subtype) {
683 			if (nm_subtype->nm_num == 0) {
684 				nm_subtype->nm_num = subtype;
685 				nm_version->nm_sublist_num =
686 				    MAX(nm_version->nm_sublist_num, subtype);
687 			}
688 		}
689 	}
690 
691 
692 	fingerprint_count++;
693 	DEBUG(fp, "import signature %d:%d:%d", class, version, subtype);
694 }
695 
696 /* Find an entry for a fingerprints class/version/subtype */
697 struct name_entry *
fingerprint_name_entry(struct name_list * list,char * name)698 fingerprint_name_entry(struct name_list *list, char *name)
699 {
700 	struct name_entry *nm_entry;
701 
702 	if (name == NULL || strlen(name) == 0)
703 		return (NULL);
704 
705 	LIST_FOREACH(nm_entry, list, nm_entry) {
706 		if (strcasecmp(nm_entry->nm_name, name) == 0) {
707 			/* We'll move this to the front of the list later */
708 			LIST_REMOVE(nm_entry, nm_entry);
709 			break;
710 		}
711 	}
712 	if (nm_entry == NULL) {
713 		nm_entry = calloc(1, sizeof(*nm_entry));
714 		if (nm_entry == NULL)
715 			err(1, "calloc");
716 		LIST_INIT(&nm_entry->nm_sublist);
717 		strlcpy(nm_entry->nm_name, name, sizeof(nm_entry->nm_name));
718 	}
719 	LIST_INSERT_HEAD(list, nm_entry, nm_entry);
720 	return (nm_entry);
721 }
722 
723 
724 void
print_name_list(int opts,struct name_list * nml,const char * prefix)725 print_name_list(int opts, struct name_list *nml, const char *prefix)
726 {
727 	char newprefix[33];
728 	struct name_entry *nm;
729 
730 	LIST_FOREACH(nm, nml, nm_entry) {
731 		snprintf(newprefix, sizeof(newprefix), "%s%s\t", prefix,
732 		    nm->nm_name);
733 		printf("%s\n", newprefix);
734 		print_name_list(opts, &nm->nm_sublist, newprefix);
735 	}
736 }
737 
738 void
sort_name_list(int opts,struct name_list * nml)739 sort_name_list(int opts, struct name_list *nml)
740 {
741 	struct name_list new;
742 	struct name_entry *nm, *nmsearch, *nmlast;
743 
744 	/* yes yes, it's a very slow sort.  so sue me */
745 
746 	LIST_INIT(&new);
747 
748 	while ((nm = LIST_FIRST(nml)) != NULL) {
749 		LIST_REMOVE(nm, nm_entry);
750 		nmlast = NULL;
751 		LIST_FOREACH(nmsearch, &new, nm_entry) {
752 			if (strcasecmp(nmsearch->nm_name, nm->nm_name) > 0) {
753 				LIST_INSERT_BEFORE(nmsearch, nm, nm_entry);
754 				break;
755 			}
756 			nmlast = nmsearch;
757 		}
758 		if (nmsearch == NULL) {
759 			if (nmlast)
760 				LIST_INSERT_AFTER(nmlast, nm, nm_entry);
761 			else
762 				LIST_INSERT_HEAD(&new, nm, nm_entry);
763 		}
764 
765 		sort_name_list(opts, &nm->nm_sublist);
766 	}
767 	nmlast = NULL;
768 	while ((nm = LIST_FIRST(&new)) != NULL) {
769 		LIST_REMOVE(nm, nm_entry);
770 		if (nmlast == NULL)
771 			LIST_INSERT_HEAD(nml, nm, nm_entry);
772 		else
773 			LIST_INSERT_AFTER(nmlast, nm, nm_entry);
774 		nmlast = nm;
775 	}
776 }
777 
778 /* parse the next integer in a formatted config file line */
779 int
get_int(char ** line,size_t * len,int * var,int * mod,const char * name,int flags,int max,const char * filename,int lineno)780 get_int(char **line, size_t *len, int *var, int *mod,
781     const char *name, int flags, int max, const char *filename, int lineno)
782 {
783 	int fieldlen, i;
784 	char *field;
785 	long val = 0;
786 
787 	if (mod)
788 		*mod = 0;
789 	*var = 0;
790 
791 	field = get_field(line, len, &fieldlen);
792 	if (field == NULL)
793 		return (1);
794 	if (fieldlen == 0) {
795 		fprintf(stderr, "%s:%d empty %s\n", filename, lineno, name);
796 		return (1);
797 	}
798 
799 	i = 0;
800 	if ((*field == '%' || *field == 'S' || *field == 'T' || *field == '*')
801 	    && fieldlen >= 1) {
802 		switch (*field) {
803 		case 'S':
804 			if (mod && (flags & T_MSS))
805 				*mod = T_MSS;
806 			if (fieldlen == 1)
807 				return (0);
808 			break;
809 		case 'T':
810 			if (mod && (flags & T_MTU))
811 				*mod = T_MTU;
812 			if (fieldlen == 1)
813 				return (0);
814 			break;
815 		case '*':
816 			if (fieldlen != 1) {
817 				fprintf(stderr, "%s:%d long '%c' %s\n",
818 				    filename, lineno, *field, name);
819 				return (1);
820 			}
821 			if (mod && (flags & T_DC)) {
822 				*mod = T_DC;
823 				return (0);
824 			}
825 		case '%':
826 			if (mod && (flags & T_MOD))
827 				*mod = T_MOD;
828 			if (fieldlen == 1) {
829 				fprintf(stderr, "%s:%d modulus %s must have a "
830 				    "value\n", filename, lineno, name);
831 				return (1);
832 			}
833 			break;
834 		}
835 		if (mod == NULL || *mod == 0) {
836 			fprintf(stderr, "%s:%d does not allow %c' %s\n",
837 			    filename, lineno, *field, name);
838 			return (1);
839 		}
840 		i++;
841 	}
842 
843 	for (; i < fieldlen; i++) {
844 		if (field[i] < '0' || field[i] > '9') {
845 			fprintf(stderr, "%s:%d non-digit character in %s\n",
846 			    filename, lineno, name);
847 			return (1);
848 		}
849 		val = val * 10 + field[i] - '0';
850 		if (val < 0) {
851 			fprintf(stderr, "%s:%d %s overflowed\n", filename,
852 			    lineno, name);
853 			return (1);
854 		}
855 	}
856 
857 	if (val > max) {
858 		fprintf(stderr, "%s:%d %s value %ld > %d\n", filename, lineno,
859 		    name, val, max);
860 		return (1);
861 	}
862 	*var = (int)val;
863 
864 	return (0);
865 }
866 
867 /* parse the next string in a formatted config file line */
868 int
get_str(char ** line,size_t * len,char ** v,const char * name,int minlen,const char * filename,int lineno)869 get_str(char **line, size_t *len, char **v, const char *name, int minlen,
870     const char *filename, int lineno)
871 {
872 	int fieldlen;
873 	char *ptr;
874 
875 	ptr = get_field(line, len, &fieldlen);
876 	if (ptr == NULL)
877 		return (1);
878 	if (fieldlen < minlen) {
879 		fprintf(stderr, "%s:%d too short %s\n", filename, lineno, name);
880 		return (1);
881 	}
882 	if ((*v = malloc(fieldlen + 1)) == NULL) {
883 		perror("malloc()");
884 		return (1);
885 	}
886 	memcpy(*v, ptr, fieldlen);
887 	(*v)[fieldlen] = '\0';
888 
889 	return (0);
890 }
891 
892 /* Parse out the TCP opts */
893 int
get_tcpopts(const char * filename,int lineno,const char * tcpopts,pf_tcpopts_t * packed,int * optcnt,int * mss,int * mss_mod,int * wscale,int * wscale_mod,int * ts0)894 get_tcpopts(const char *filename, int lineno, const char *tcpopts,
895     pf_tcpopts_t *packed, int *optcnt, int *mss, int *mss_mod, int *wscale,
896     int *wscale_mod, int *ts0)
897 {
898 	int i, opt;
899 
900 	*packed = 0;
901 	*optcnt = 0;
902 	*wscale = 0;
903 	*wscale_mod = T_DC;
904 	*mss = 0;
905 	*mss_mod = T_DC;
906 	*ts0 = 0;
907 	if (strcmp(tcpopts, ".") == 0)
908 		return (0);
909 
910 	for (i = 0; tcpopts[i] && *optcnt < PF_OSFP_MAX_OPTS;) {
911 		switch ((opt = toupper((unsigned char)tcpopts[i++]))) {
912 		case 'N':	/* FALLTHROUGH */
913 		case 'S':
914 			*packed = (*packed << PF_OSFP_TCPOPT_BITS) |
915 			    (opt == 'N' ? PF_OSFP_TCPOPT_NOP :
916 			    PF_OSFP_TCPOPT_SACK);
917 			break;
918 		case 'W':	/* FALLTHROUGH */
919 		case 'M': {
920 			int *this_mod, *this;
921 
922 			if (opt == 'W') {
923 				this = wscale;
924 				this_mod = wscale_mod;
925 			} else {
926 				this = mss;
927 				this_mod = mss_mod;
928 			}
929 			*this = 0;
930 			*this_mod = 0;
931 
932 			*packed = (*packed << PF_OSFP_TCPOPT_BITS) |
933 			    (opt == 'W' ? PF_OSFP_TCPOPT_WSCALE :
934 			    PF_OSFP_TCPOPT_MSS);
935 			if (tcpopts[i] == '*' && (tcpopts[i + 1] == '\0' ||
936 			    tcpopts[i + 1] == ',')) {
937 				*this_mod = T_DC;
938 				i++;
939 				break;
940 			}
941 
942 			if (tcpopts[i] == '%') {
943 				*this_mod = T_MOD;
944 				i++;
945 			}
946 			do {
947 				if (!isdigit((unsigned char)tcpopts[i])) {
948 					fprintf(stderr, "%s:%d unknown "
949 					    "character '%c' in %c TCP opt\n",
950 					    filename, lineno, tcpopts[i], opt);
951 					return (1);
952 				}
953 				*this = (*this * 10) + tcpopts[i++] - '0';
954 			} while(tcpopts[i] != ',' && tcpopts[i] != '\0');
955 			break;
956 		}
957 		case 'T':
958 			if (tcpopts[i] == '0') {
959 				*ts0 = 1;
960 				i++;
961 			}
962 			*packed = (*packed << PF_OSFP_TCPOPT_BITS) |
963 			    PF_OSFP_TCPOPT_TS;
964 			break;
965 		}
966 		(*optcnt) ++;
967 		if (tcpopts[i] == '\0')
968 			break;
969 		if (tcpopts[i] != ',') {
970 			fprintf(stderr, "%s:%d unknown option to %c TCP opt\n",
971 			    filename, lineno, opt);
972 			return (1);
973 		}
974 		i++;
975 	}
976 
977 	return (0);
978 }
979 
980 /* rip the next field ouf of a formatted config file line */
981 char *
get_field(char ** line,size_t * len,int * fieldlen)982 get_field(char **line, size_t *len, int *fieldlen)
983 {
984 	char *ret, *ptr = *line;
985 	size_t plen = *len;
986 
987 
988 	while (plen && isspace((unsigned char)*ptr)) {
989 		plen--;
990 		ptr++;
991 	}
992 	ret = ptr;
993 	*fieldlen = 0;
994 
995 	for (; plen > 0 && *ptr != ':'; plen--, ptr++)
996 		(*fieldlen)++;
997 	if (plen) {
998 		*line = ptr + 1;
999 		*len = plen - 1;
1000 	} else {
1001 		*len = 0;
1002 	}
1003 	while (*fieldlen && isspace((unsigned char)ret[*fieldlen - 1]))
1004 		(*fieldlen)--;
1005 	return (ret);
1006 }
1007 
1008 
1009 const char *
print_ioctl(struct pf_osfp_ioctl * fp)1010 print_ioctl(struct pf_osfp_ioctl *fp)
1011 {
1012 	static char buf[1024];
1013 	char tmp[32];
1014 	int i, opt;
1015 
1016 	*buf = '\0';
1017 	if (fp->fp_flags & PF_OSFP_WSIZE_DC)
1018 		strlcat(buf, "*", sizeof(buf));
1019 	else if (fp->fp_flags & PF_OSFP_WSIZE_MSS)
1020 		strlcat(buf, "S", sizeof(buf));
1021 	else if (fp->fp_flags & PF_OSFP_WSIZE_MTU)
1022 		strlcat(buf, "T", sizeof(buf));
1023 	else {
1024 		if (fp->fp_flags & PF_OSFP_WSIZE_MOD)
1025 			strlcat(buf, "%", sizeof(buf));
1026 		snprintf(tmp, sizeof(tmp), "%d", fp->fp_wsize);
1027 		strlcat(buf, tmp, sizeof(buf));
1028 	}
1029 	strlcat(buf, ":", sizeof(buf));
1030 
1031 	snprintf(tmp, sizeof(tmp), "%d", fp->fp_ttl);
1032 	strlcat(buf, tmp, sizeof(buf));
1033 	strlcat(buf, ":", sizeof(buf));
1034 
1035 	if (fp->fp_flags & PF_OSFP_DF)
1036 		strlcat(buf, "1", sizeof(buf));
1037 	else
1038 		strlcat(buf, "0", sizeof(buf));
1039 	strlcat(buf, ":", sizeof(buf));
1040 
1041 	if (fp->fp_flags & PF_OSFP_PSIZE_DC)
1042 		strlcat(buf, "*", sizeof(buf));
1043 	else {
1044 		if (fp->fp_flags & PF_OSFP_PSIZE_MOD)
1045 			strlcat(buf, "%", sizeof(buf));
1046 		snprintf(tmp, sizeof(tmp), "%d", fp->fp_psize);
1047 		strlcat(buf, tmp, sizeof(buf));
1048 	}
1049 	strlcat(buf, ":", sizeof(buf));
1050 
1051 	if (fp->fp_optcnt == 0)
1052 		strlcat(buf, ".", sizeof(buf));
1053 	for (i = fp->fp_optcnt - 1; i >= 0; i--) {
1054 		opt = fp->fp_tcpopts >> (i * PF_OSFP_TCPOPT_BITS);
1055 		opt &= (1 << PF_OSFP_TCPOPT_BITS) - 1;
1056 		switch (opt) {
1057 		case PF_OSFP_TCPOPT_NOP:
1058 			strlcat(buf, "N", sizeof(buf));
1059 			break;
1060 		case PF_OSFP_TCPOPT_SACK:
1061 			strlcat(buf, "S", sizeof(buf));
1062 			break;
1063 		case PF_OSFP_TCPOPT_TS:
1064 			strlcat(buf, "T", sizeof(buf));
1065 			if (fp->fp_flags & PF_OSFP_TS0)
1066 				strlcat(buf, "0", sizeof(buf));
1067 			break;
1068 		case PF_OSFP_TCPOPT_MSS:
1069 			strlcat(buf, "M", sizeof(buf));
1070 			if (fp->fp_flags & PF_OSFP_MSS_DC)
1071 				strlcat(buf, "*", sizeof(buf));
1072 			else {
1073 				if (fp->fp_flags & PF_OSFP_MSS_MOD)
1074 					strlcat(buf, "%", sizeof(buf));
1075 				snprintf(tmp, sizeof(tmp), "%d", fp->fp_mss);
1076 				strlcat(buf, tmp, sizeof(buf));
1077 			}
1078 			break;
1079 		case PF_OSFP_TCPOPT_WSCALE:
1080 			strlcat(buf, "W", sizeof(buf));
1081 			if (fp->fp_flags & PF_OSFP_WSCALE_DC)
1082 				strlcat(buf, "*", sizeof(buf));
1083 			else {
1084 				if (fp->fp_flags & PF_OSFP_WSCALE_MOD)
1085 					strlcat(buf, "%", sizeof(buf));
1086 				snprintf(tmp, sizeof(tmp), "%d", fp->fp_wscale);
1087 				strlcat(buf, tmp, sizeof(buf));
1088 			}
1089 			break;
1090 		}
1091 
1092 		if (i != 0)
1093 			strlcat(buf, ",", sizeof(buf));
1094 	}
1095 	strlcat(buf, ":", sizeof(buf));
1096 
1097 	strlcat(buf, fp->fp_os.fp_class_nm, sizeof(buf));
1098 	strlcat(buf, ":", sizeof(buf));
1099 	strlcat(buf, fp->fp_os.fp_version_nm, sizeof(buf));
1100 	strlcat(buf, ":", sizeof(buf));
1101 	strlcat(buf, fp->fp_os.fp_subtype_nm, sizeof(buf));
1102 	strlcat(buf, ":", sizeof(buf));
1103 
1104 	snprintf(tmp, sizeof(tmp), "TcpOpts %d 0x%llx", fp->fp_optcnt,
1105 	    (long long int)fp->fp_tcpopts);
1106 	strlcat(buf, tmp, sizeof(buf));
1107 
1108 	return (buf);
1109 }
1110