xref: /openbsd-src/sbin/pfctl/pfctl_osfp.c (revision ae711728d410d2bb41f3a563f2e2ebdede715edc)
1 /*	$OpenBSD: pfctl_osfp.c,v 1.27 2020/01/15 11:52:50 sashan 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 <netinet/in.h>
24 #include <netinet/ip.h>
25 #include <netinet/ip6.h>
26 #include <net/if.h>
27 #include <net/pfvar.h>
28 
29 #include <ctype.h>
30 #include <err.h>
31 #include <errno.h>
32 #include <stdio.h>
33 #include <stdlib.h>
34 #include <string.h>
35 
36 #include "pfctl_parser.h"
37 #include "pfctl.h"
38 
39 #define MAXIMUM(a, b)	(((a) > (b)) ? (a) : (b))
40 
41 /* #define OSFP_DEBUG	1 */
42 #ifdef OSFP_DEBUG
43 # define DEBUG(fp, str, v...) \
44 	fprintf(stderr, "%s:%s:%s " str "\n", (fp)->fp_os.fp_class_nm, \
45 	    (fp)->fp_os.fp_version_nm, (fp)->fp_os.fp_subtype_nm , ## v);
46 #else
47 # define DEBUG(fp, str, v...) ((void)0)
48 #endif
49 
50 
51 struct name_entry;
52 LIST_HEAD(name_list, name_entry);
53 struct name_entry {
54 	LIST_ENTRY(name_entry)	nm_entry;
55 	int			nm_num;
56 	char			nm_name[PF_OSFP_LEN];
57 
58 	struct name_list	nm_sublist;
59 	int			nm_sublist_num;
60 };
61 struct name_list classes = LIST_HEAD_INITIALIZER(&classes);
62 int class_count;
63 int fingerprint_count;
64 
65 void			 add_fingerprint(int, int, struct pf_osfp_ioctl *);
66 struct name_entry	*fingerprint_name_entry(struct name_list *, char *);
67 void			 pfctl_flush_my_fingerprints(struct name_list *);
68 char			*get_field(char **, size_t *, int *);
69 int			 get_int(char **, size_t *, int *, int *, const char *,
70 			     int, int, const char *, int);
71 int			 get_str(char **, size_t *, char **, const char *, int,
72 			     const char *, int);
73 int			 get_tcpopts(const char *, int, const char *,
74 			    pf_tcpopts_t *, int *, int *, int *, int *, int *,
75 			    int *);
76 void			 import_fingerprint(struct pf_osfp_ioctl *);
77 #ifdef OSFP_DEBUG
78 const char		*print_ioctl(struct pf_osfp_ioctl *);
79 #endif
80 void			 print_name_list(int, struct name_list *, const char *);
81 void			 sort_name_list(int, struct name_list *);
82 struct name_entry	*lookup_name_list(struct name_list *, const char *);
83 
84 /* Load fingerprints from a file */
85 int
pfctl_file_fingerprints(int dev,int opts,const char * fp_filename)86 pfctl_file_fingerprints(int dev, int opts, const char *fp_filename)
87 {
88 	FILE *in;
89 	char *line;
90 	size_t len;
91 	int i, lineno = 0;
92 	int window, w_mod, ttl, df, psize, p_mod, mss, mss_mod, wscale,
93 	    wscale_mod, optcnt, ts0;
94 	pf_tcpopts_t packed_tcpopts;
95 	char *class, *version, *subtype, *desc, *tcpopts;
96 	struct pf_osfp_ioctl fp;
97 
98 	pfctl_flush_my_fingerprints(&classes);
99 
100 	if ((in = pfctl_fopen(fp_filename, "r")) == NULL) {
101 		warn("%s", fp_filename);
102 		return (1);
103 	}
104 	class = version = subtype = desc = tcpopts = NULL;
105 
106 	if ((opts & PF_OPT_NOACTION) == 0)
107 		pfctl_clear_fingerprints(dev, opts);
108 
109 	while ((line = fgetln(in, &len)) != NULL) {
110 		lineno++;
111 		free(class);
112 		free(version);
113 		free(subtype);
114 		free(desc);
115 		free(tcpopts);
116 		class = version = subtype = desc = tcpopts = NULL;
117 		memset(&fp, 0, sizeof(fp));
118 
119 		/* Chop off comment */
120 		for (i = 0; i < len; i++)
121 			if (line[i] == '#') {
122 				len = i;
123 				break;
124 			}
125 		/* Chop off whitespace */
126 		while (len > 0 && isspace((unsigned char)line[len - 1]))
127 			len--;
128 		while (len > 0 && isspace((unsigned char)line[0])) {
129 			len--;
130 			line++;
131 		}
132 		if (len == 0)
133 			continue;
134 
135 #define T_DC	0x01	/* Allow don't care */
136 #define T_MSS	0x02	/* Allow MSS multiple */
137 #define T_MTU	0x04	/* Allow MTU multiple */
138 #define T_MOD	0x08	/* Allow modulus */
139 
140 #define GET_INT(v, mod, n, ty, mx) \
141 	get_int(&line, &len, &v, mod, n, ty, mx, fp_filename, lineno)
142 #define GET_STR(v, n, mn) \
143 	get_str(&line, &len, &v, n, mn, fp_filename, lineno)
144 
145 		if (GET_INT(window, &w_mod, "window size", T_DC|T_MSS|T_MTU|
146 		    T_MOD, 0xffff) ||
147 		    GET_INT(ttl, NULL, "ttl", 0, 0xff) ||
148 		    GET_INT(df, NULL, "don't fragment frag", 0, 1) ||
149 		    GET_INT(psize, &p_mod, "overall packet size", T_MOD|T_DC,
150 		    8192) ||
151 		    GET_STR(tcpopts, "TCP Options", 1) ||
152 		    GET_STR(class, "OS class", 1) ||
153 		    GET_STR(version, "OS version", 0) ||
154 		    GET_STR(subtype, "OS subtype", 0) ||
155 		    GET_STR(desc, "OS description", 2))
156 			continue;
157 		if (get_tcpopts(fp_filename, lineno, tcpopts, &packed_tcpopts,
158 		    &optcnt, &mss, &mss_mod, &wscale, &wscale_mod, &ts0))
159 			continue;
160 		if (len != 0) {
161 			fprintf(stderr, "%s:%d excess field\n", fp_filename,
162 			    lineno);
163 			continue;
164 		}
165 
166 		fp.fp_ttl = ttl;
167 		if (df)
168 			fp.fp_flags |= PF_OSFP_DF;
169 		switch (w_mod) {
170 		case 0:
171 			break;
172 		case T_DC:
173 			fp.fp_flags |= PF_OSFP_WSIZE_DC;
174 			break;
175 		case T_MSS:
176 			fp.fp_flags |= PF_OSFP_WSIZE_MSS;
177 			break;
178 		case T_MTU:
179 			fp.fp_flags |= PF_OSFP_WSIZE_MTU;
180 			break;
181 		case T_MOD:
182 			fp.fp_flags |= PF_OSFP_WSIZE_MOD;
183 			break;
184 		}
185 		fp.fp_wsize = window;
186 
187 		switch (p_mod) {
188 		case T_DC:
189 			fp.fp_flags |= PF_OSFP_PSIZE_DC;
190 			break;
191 		case T_MOD:
192 			fp.fp_flags |= PF_OSFP_PSIZE_MOD;
193 		}
194 		fp.fp_psize = psize;
195 
196 
197 		switch (wscale_mod) {
198 		case T_DC:
199 			fp.fp_flags |= PF_OSFP_WSCALE_DC;
200 			break;
201 		case T_MOD:
202 			fp.fp_flags |= PF_OSFP_WSCALE_MOD;
203 		}
204 		fp.fp_wscale = wscale;
205 
206 		switch (mss_mod) {
207 		case T_DC:
208 			fp.fp_flags |= PF_OSFP_MSS_DC;
209 			break;
210 		case T_MOD:
211 			fp.fp_flags |= PF_OSFP_MSS_MOD;
212 			break;
213 		}
214 		fp.fp_mss = mss;
215 
216 		fp.fp_tcpopts = packed_tcpopts;
217 		fp.fp_optcnt = optcnt;
218 		if (ts0)
219 			fp.fp_flags |= PF_OSFP_TS0;
220 
221 		if (class[0] == '@')
222 			fp.fp_os.fp_enflags |= PF_OSFP_GENERIC;
223 		if (class[0] == '*')
224 			fp.fp_os.fp_enflags |= PF_OSFP_NODETAIL;
225 
226 		if (class[0] == '@' || class[0] == '*')
227 			strlcpy(fp.fp_os.fp_class_nm, class + 1,
228 			    sizeof(fp.fp_os.fp_class_nm));
229 		else
230 			strlcpy(fp.fp_os.fp_class_nm, class,
231 			    sizeof(fp.fp_os.fp_class_nm));
232 		strlcpy(fp.fp_os.fp_version_nm, version,
233 		    sizeof(fp.fp_os.fp_version_nm));
234 		strlcpy(fp.fp_os.fp_subtype_nm, subtype,
235 		    sizeof(fp.fp_os.fp_subtype_nm));
236 
237 		add_fingerprint(dev, opts, &fp);
238 
239 		fp.fp_flags |= (PF_OSFP_DF | PF_OSFP_INET6);
240 		fp.fp_psize += sizeof(struct ip6_hdr) - sizeof(struct ip);
241 		add_fingerprint(dev, opts, &fp);
242 	}
243 
244 	free(class);
245 	free(version);
246 	free(subtype);
247 	free(desc);
248 	free(tcpopts);
249 
250 	fclose(in);
251 
252 	if (opts & PF_OPT_VERBOSE2)
253 		printf("Loaded %d passive OS fingerprints\n",
254 		    fingerprint_count);
255 	return (0);
256 }
257 
258 /* flush the kernel's fingerprints */
259 void
pfctl_clear_fingerprints(int dev,int opts)260 pfctl_clear_fingerprints(int dev, int opts)
261 {
262 	if (ioctl(dev, DIOCOSFPFLUSH) == -1)
263 		pfctl_err(opts, 1, "DIOCOSFPFLUSH");
264 }
265 
266 /* flush pfctl's view of the fingerprints */
267 void
pfctl_flush_my_fingerprints(struct name_list * list)268 pfctl_flush_my_fingerprints(struct name_list *list)
269 {
270 	struct name_entry *nm;
271 
272 	while ((nm = LIST_FIRST(list)) != NULL) {
273 		LIST_REMOVE(nm, nm_entry);
274 		pfctl_flush_my_fingerprints(&nm->nm_sublist);
275 		free(nm);
276 	}
277 	fingerprint_count = 0;
278 	class_count = 0;
279 }
280 
281 /* Fetch the active fingerprints from the kernel */
282 int
pfctl_load_fingerprints(int dev,int opts)283 pfctl_load_fingerprints(int dev, int opts)
284 {
285 	struct pf_osfp_ioctl io;
286 	int i;
287 
288 	pfctl_flush_my_fingerprints(&classes);
289 
290 	for (i = 0; i >= 0; i++) {
291 		memset(&io, 0, sizeof(io));
292 		io.fp_getnum = i;
293 		if (ioctl(dev, DIOCOSFPGET, &io) == -1) {
294 			if (errno == EBUSY)
295 				break;
296 			warn("DIOCOSFPGET");
297 			return (1);
298 		}
299 		import_fingerprint(&io);
300 	}
301 	return (0);
302 }
303 
304 /* List the fingerprints */
305 void
pfctl_show_fingerprints(int opts)306 pfctl_show_fingerprints(int opts)
307 {
308 	if (LIST_FIRST(&classes) != NULL) {
309 		if (opts & PF_OPT_SHOWALL) {
310 			pfctl_print_title("OS FINGERPRINTS:");
311 			printf("%u fingerprints loaded\n", fingerprint_count);
312 		} else {
313 			printf("Class\tVersion\tSubtype(subversion)\n");
314 			printf("-----\t-------\t-------------------\n");
315 			sort_name_list(opts, &classes);
316 			print_name_list(opts, &classes, "");
317 		}
318 	}
319 }
320 
321 /* Lookup a fingerprint */
322 pf_osfp_t
pfctl_get_fingerprint(const char * name)323 pfctl_get_fingerprint(const char *name)
324 {
325 	struct name_entry *nm, *class_nm, *version_nm, *subtype_nm;
326 	pf_osfp_t ret = PF_OSFP_NOMATCH;
327 	int class, version, subtype;
328 	int unp_class, unp_version, unp_subtype;
329 	int wr_len, version_len, subtype_len;
330 	char *ptr, *wr_name;
331 
332 	if (strcasecmp(name, "unknown") == 0)
333 		return (PF_OSFP_UNKNOWN);
334 
335 	/* Try most likely no version and no subtype */
336 	if ((nm = lookup_name_list(&classes, name))) {
337 		class = nm->nm_num;
338 		version = PF_OSFP_ANY;
339 		subtype = PF_OSFP_ANY;
340 		goto found;
341 	} else {
342 
343 		/* Chop it up into class/version/subtype */
344 
345 		if ((wr_name = strdup(name)) == NULL)
346 			err(1, "malloc");
347 		if ((ptr = strchr(wr_name, ' ')) == NULL) {
348 			free(wr_name);
349 			return (PF_OSFP_NOMATCH);
350 		}
351 		*ptr++ = '\0';
352 
353 		/* The class is easy to find since it is delimited by a space */
354 		if ((class_nm = lookup_name_list(&classes, wr_name)) == NULL) {
355 			free(wr_name);
356 			return (PF_OSFP_NOMATCH);
357 		}
358 		class = class_nm->nm_num;
359 
360 		/* Try no subtype */
361 		if ((version_nm = lookup_name_list(&class_nm->nm_sublist, ptr)))
362 		{
363 			version = version_nm->nm_num;
364 			subtype = PF_OSFP_ANY;
365 			free(wr_name);
366 			goto found;
367 		}
368 
369 
370 		/*
371 		 * There must be a version and a subtype.
372 		 * We'll do some fuzzy matching to pick up things like:
373 		 *   Linux 2.2.14 (version=2.2 subtype=14)
374 		 *   FreeBSD 4.0-STABLE (version=4.0 subtype=STABLE)
375 		 *   Windows 2000 SP2	(version=2000 subtype=SP2)
376 		 */
377 #define CONNECTOR(x)	((x) == '.' || (x) == ' ' || (x) == '\t' || (x) == '-')
378 		wr_len = strlen(ptr);
379 		LIST_FOREACH(version_nm, &class_nm->nm_sublist, nm_entry) {
380 			version_len = strlen(version_nm->nm_name);
381 			if (wr_len < version_len + 2 ||
382 			    !CONNECTOR(ptr[version_len]))
383 				continue;
384 			/* first part of the string must be version */
385 			if (strncasecmp(ptr, version_nm->nm_name,
386 			    version_len))
387 				continue;
388 
389 			LIST_FOREACH(subtype_nm, &version_nm->nm_sublist,
390 			    nm_entry) {
391 				subtype_len = strlen(subtype_nm->nm_name);
392 				if (wr_len != version_len + subtype_len + 1)
393 					continue;
394 
395 				/* last part of the string must be subtype */
396 				if (strcasecmp(&ptr[version_len+1],
397 				    subtype_nm->nm_name) != 0)
398 					continue;
399 
400 				/* Found it!! */
401 				version = version_nm->nm_num;
402 				subtype = subtype_nm->nm_num;
403 				free(wr_name);
404 				goto found;
405 			}
406 		}
407 
408 		free(wr_name);
409 		return (PF_OSFP_NOMATCH);
410 	}
411 
412 found:
413 	PF_OSFP_PACK(ret, class, version, subtype);
414 	if (ret != PF_OSFP_NOMATCH) {
415 		PF_OSFP_UNPACK(ret, unp_class, unp_version, unp_subtype);
416 		if (class != unp_class) {
417 			fprintf(stderr, "warning: fingerprint table overflowed "
418 			    "classes\n");
419 			return (PF_OSFP_NOMATCH);
420 		}
421 		if (version != unp_version) {
422 			fprintf(stderr, "warning: fingerprint table overflowed "
423 			    "versions\n");
424 			return (PF_OSFP_NOMATCH);
425 		}
426 		if (subtype != unp_subtype) {
427 			fprintf(stderr, "warning: fingerprint table overflowed "
428 			    "subtypes\n");
429 			return (PF_OSFP_NOMATCH);
430 		}
431 	}
432 	if (ret == PF_OSFP_ANY) {
433 		/* should never happen */
434 		fprintf(stderr, "warning: fingerprint packed to 'any'\n");
435 		return (PF_OSFP_NOMATCH);
436 	}
437 
438 	return (ret);
439 }
440 
441 /* Lookup a fingerprint name by ID */
442 char *
pfctl_lookup_fingerprint(pf_osfp_t fp,char * buf,size_t len)443 pfctl_lookup_fingerprint(pf_osfp_t fp, char *buf, size_t len)
444 {
445 	int class, version, subtype;
446 	struct name_list *list;
447 	struct name_entry *nm;
448 
449 	char *class_name, *version_name, *subtype_name;
450 	class_name = version_name = subtype_name = NULL;
451 
452 	if (fp == PF_OSFP_UNKNOWN) {
453 		strlcpy(buf, "unknown", len);
454 		return (buf);
455 	}
456 	if (fp == PF_OSFP_ANY) {
457 		strlcpy(buf, "any", len);
458 		return (buf);
459 	}
460 
461 	PF_OSFP_UNPACK(fp, class, version, subtype);
462 	if (class >= (1 << _FP_CLASS_BITS) ||
463 	    version >= (1 << _FP_VERSION_BITS) ||
464 	    subtype >= (1 << _FP_SUBTYPE_BITS)) {
465 		warnx("PF_OSFP_UNPACK(0x%x) failed!!", fp);
466 		strlcpy(buf, "nomatch", len);
467 		return (buf);
468 	}
469 
470 	LIST_FOREACH(nm, &classes, nm_entry) {
471 		if (nm->nm_num == class) {
472 			class_name = nm->nm_name;
473 			if (version == PF_OSFP_ANY)
474 				goto found;
475 			list = &nm->nm_sublist;
476 			LIST_FOREACH(nm, list, nm_entry) {
477 				if (nm->nm_num == version) {
478 					version_name = nm->nm_name;
479 					if (subtype == PF_OSFP_ANY)
480 						goto found;
481 					list = &nm->nm_sublist;
482 					LIST_FOREACH(nm, list, nm_entry) {
483 						if (nm->nm_num == subtype) {
484 							subtype_name =
485 							    nm->nm_name;
486 							goto found;
487 						}
488 					} /* foreach subtype */
489 					strlcpy(buf, "nomatch", len);
490 					return (buf);
491 				}
492 			} /* foreach version */
493 			strlcpy(buf, "nomatch", len);
494 			return (buf);
495 		}
496 	} /* foreach class */
497 
498 	strlcpy(buf, "nomatch", len);
499 	return (buf);
500 
501 found:
502 	snprintf(buf, len, "%s", class_name);
503 	if (version_name) {
504 		strlcat(buf, " ", len);
505 		strlcat(buf, version_name, len);
506 		if (subtype_name) {
507 			if (strchr(version_name, ' '))
508 				strlcat(buf, " ", len);
509 			else if (strchr(version_name, '.') &&
510 			    isdigit((unsigned char)*subtype_name))
511 				strlcat(buf, ".", len);
512 			else
513 				strlcat(buf, " ", len);
514 			strlcat(buf, subtype_name, len);
515 		}
516 	}
517 	return (buf);
518 }
519 
520 /* lookup a name in a list */
521 struct name_entry *
lookup_name_list(struct name_list * list,const char * name)522 lookup_name_list(struct name_list *list, const char *name)
523 {
524 	struct name_entry *nm;
525 	LIST_FOREACH(nm, list, nm_entry)
526 		if (strcasecmp(name, nm->nm_name) == 0)
527 			return (nm);
528 
529 	return (NULL);
530 }
531 
532 
533 void
add_fingerprint(int dev,int opts,struct pf_osfp_ioctl * fp)534 add_fingerprint(int dev, int opts, struct pf_osfp_ioctl *fp)
535 {
536 	struct pf_osfp_ioctl fptmp;
537 	struct name_entry *nm_class, *nm_version, *nm_subtype;
538 	int class, version, subtype;
539 
540 /* We expand #-# or #.#-#.# version/subtypes into multiple fingerprints */
541 #define EXPAND(field) do {						\
542 	int _dot = -1, _start = -1, _end = -1, _i = 0;			\
543 	/* pick major version out of #.# */				\
544 	if (isdigit((unsigned char)fp->field[_i]) &&			\
545 	    fp->field[_i+1] == '.') {					\
546 		_dot = fp->field[_i] - '0';				\
547 		_i += 2;						\
548 	}								\
549 	if (isdigit((unsigned char)fp->field[_i]))			\
550 		_start = fp->field[_i++] - '0';				\
551 	else								\
552 		break;							\
553 	if (isdigit((unsigned char)fp->field[_i]))			\
554 		_start = (_start * 10) + fp->field[_i++] - '0';		\
555 	if (fp->field[_i++] != '-')					\
556 		break;							\
557 	if (isdigit((unsigned char)fp->field[_i]) &&			\
558 	    fp->field[_i+1] == '.' && fp->field[_i] - '0' == _dot)	\
559 		_i += 2;						\
560 	else if (_dot != -1)						\
561 		break;							\
562 	if (isdigit((unsigned char)fp->field[_i]))			\
563 		_end = fp->field[_i++] - '0';				\
564 	else								\
565 		break;							\
566 	if (isdigit((unsigned char)fp->field[_i]))			\
567 		_end = (_end * 10) + fp->field[_i++] - '0';		\
568 	if (isdigit((unsigned char)fp->field[_i]))			\
569 		_end = (_end * 10) + fp->field[_i++] - '0';		\
570 	if (fp->field[_i] != '\0')					\
571 		break;							\
572 	memcpy(&fptmp, fp, sizeof(fptmp));				\
573 	for (;_start <= _end; _start++) {				\
574 		memset(fptmp.field, 0, sizeof(fptmp.field));		\
575 		fptmp.fp_os.fp_enflags |= PF_OSFP_EXPANDED;		\
576 		if (_dot == -1)						\
577 			snprintf(fptmp.field, sizeof(fptmp.field),	\
578 			    "%d", _start);				\
579 		    else						\
580 			snprintf(fptmp.field, sizeof(fptmp.field),	\
581 			    "%d.%d", _dot, _start);			\
582 		add_fingerprint(dev, opts, &fptmp);			\
583 	}								\
584 } while(0)
585 
586 	/* We allow "#-#" as a version or subtype and we'll expand it */
587 	EXPAND(fp_os.fp_version_nm);
588 	EXPAND(fp_os.fp_subtype_nm);
589 
590 	if (strcasecmp(fp->fp_os.fp_class_nm, "nomatch") == 0)
591 		errx(1, "fingerprint class \"nomatch\" is reserved");
592 
593 	version = PF_OSFP_ANY;
594 	subtype = PF_OSFP_ANY;
595 
596 	nm_class = fingerprint_name_entry(&classes, fp->fp_os.fp_class_nm);
597 	if (nm_class->nm_num == 0)
598 		nm_class->nm_num = ++class_count;
599 	class = nm_class->nm_num;
600 
601 	nm_version = fingerprint_name_entry(&nm_class->nm_sublist,
602 	    fp->fp_os.fp_version_nm);
603 	if (nm_version) {
604 		if (nm_version->nm_num == 0)
605 			nm_version->nm_num = ++nm_class->nm_sublist_num;
606 		version = nm_version->nm_num;
607 		nm_subtype = fingerprint_name_entry(&nm_version->nm_sublist,
608 		    fp->fp_os.fp_subtype_nm);
609 		if (nm_subtype) {
610 			if (nm_subtype->nm_num == 0)
611 				nm_subtype->nm_num =
612 				    ++nm_version->nm_sublist_num;
613 			subtype = nm_subtype->nm_num;
614 		}
615 	}
616 
617 
618 	DEBUG(fp, "\tsignature %d:%d:%d %s", class, version, subtype,
619 	    print_ioctl(fp));
620 
621 	PF_OSFP_PACK(fp->fp_os.fp_os, class, version, subtype);
622 	fingerprint_count++;
623 
624 #ifdef FAKE_PF_KERNEL
625 	/* Linked to the sys/net/pf_osfp.c.  Call pf_osfp_add() */
626 	if ((errno = pf_osfp_add(fp)))
627 #else
628 	if ((opts & PF_OPT_NOACTION) == 0 && ioctl(dev, DIOCOSFPADD, fp) == -1)
629 #endif /* FAKE_PF_KERNEL */
630 	{
631 		if (errno == EEXIST) {
632 			warn("Duplicate signature for %s %s %s",
633 				fp->fp_os.fp_class_nm,
634 				fp->fp_os.fp_version_nm,
635 				fp->fp_os.fp_subtype_nm);
636 
637 		} else {
638 			err(1, "DIOCOSFPADD");
639 		}
640 	}
641 }
642 
643 /* import a fingerprint from the kernel */
644 void
import_fingerprint(struct pf_osfp_ioctl * fp)645 import_fingerprint(struct pf_osfp_ioctl *fp)
646 {
647 	struct name_entry *nm_class, *nm_version, *nm_subtype;
648 	int class, version, subtype;
649 
650 	PF_OSFP_UNPACK(fp->fp_os.fp_os, class, version, subtype);
651 
652 	nm_class = fingerprint_name_entry(&classes, fp->fp_os.fp_class_nm);
653 	if (nm_class->nm_num == 0) {
654 		nm_class->nm_num = class;
655 		class_count = MAXIMUM(class_count, class);
656 	}
657 
658 	nm_version = fingerprint_name_entry(&nm_class->nm_sublist,
659 	    fp->fp_os.fp_version_nm);
660 	if (nm_version) {
661 		if (nm_version->nm_num == 0) {
662 			nm_version->nm_num = version;
663 			nm_class->nm_sublist_num = MAXIMUM(nm_class->nm_sublist_num,
664 			    version);
665 		}
666 		nm_subtype = fingerprint_name_entry(&nm_version->nm_sublist,
667 		    fp->fp_os.fp_subtype_nm);
668 		if (nm_subtype) {
669 			if (nm_subtype->nm_num == 0) {
670 				nm_subtype->nm_num = subtype;
671 				nm_version->nm_sublist_num =
672 				    MAXIMUM(nm_version->nm_sublist_num, subtype);
673 			}
674 		}
675 	}
676 
677 
678 	fingerprint_count++;
679 	DEBUG(fp, "import signature %d:%d:%d", class, version, subtype);
680 }
681 
682 /* Find an entry for a fingerprints class/version/subtype */
683 struct name_entry *
fingerprint_name_entry(struct name_list * list,char * name)684 fingerprint_name_entry(struct name_list *list, char *name)
685 {
686 	struct name_entry *nm_entry;
687 
688 	if (name == NULL || strlen(name) == 0)
689 		return (NULL);
690 
691 	LIST_FOREACH(nm_entry, list, nm_entry) {
692 		if (strcasecmp(nm_entry->nm_name, name) == 0) {
693 			/* We'll move this to the front of the list later */
694 			LIST_REMOVE(nm_entry, nm_entry);
695 			break;
696 		}
697 	}
698 	if (nm_entry == NULL) {
699 		nm_entry = calloc(1, sizeof(*nm_entry));
700 		if (nm_entry == NULL)
701 			err(1, "calloc");
702 		LIST_INIT(&nm_entry->nm_sublist);
703 		strlcpy(nm_entry->nm_name, name, sizeof(nm_entry->nm_name));
704 	}
705 	LIST_INSERT_HEAD(list, nm_entry, nm_entry);
706 	return (nm_entry);
707 }
708 
709 
710 void
print_name_list(int opts,struct name_list * nml,const char * prefix)711 print_name_list(int opts, struct name_list *nml, const char *prefix)
712 {
713 	char newprefix[32];
714 	struct name_entry *nm;
715 
716 	LIST_FOREACH(nm, nml, nm_entry) {
717 		snprintf(newprefix, sizeof(newprefix), "%s%s\t", prefix,
718 		    nm->nm_name);
719 		printf("%s\n", newprefix);
720 		print_name_list(opts, &nm->nm_sublist, newprefix);
721 	}
722 }
723 
724 void
sort_name_list(int opts,struct name_list * nml)725 sort_name_list(int opts, struct name_list *nml)
726 {
727 	struct name_list new;
728 	struct name_entry *nm, *nmsearch, *nmlast;
729 
730 	/* yes yes, it's a very slow sort.  so sue me */
731 
732 	LIST_INIT(&new);
733 
734 	while ((nm = LIST_FIRST(nml)) != NULL) {
735 		LIST_REMOVE(nm, nm_entry);
736 		nmlast = NULL;
737 		LIST_FOREACH(nmsearch, &new, nm_entry) {
738 			if (strcasecmp(nmsearch->nm_name, nm->nm_name) > 0) {
739 				LIST_INSERT_BEFORE(nmsearch, nm, nm_entry);
740 				break;
741 			}
742 			nmlast = nmsearch;
743 		}
744 		if (nmsearch == NULL) {
745 			if (nmlast)
746 				LIST_INSERT_AFTER(nmlast, nm, nm_entry);
747 			else
748 				LIST_INSERT_HEAD(&new, nm, nm_entry);
749 		}
750 
751 		sort_name_list(opts, &nm->nm_sublist);
752 	}
753 	nmlast = NULL;
754 	while ((nm = LIST_FIRST(&new)) != NULL) {
755 		LIST_REMOVE(nm, nm_entry);
756 		if (nmlast == NULL)
757 			LIST_INSERT_HEAD(nml, nm, nm_entry);
758 		else
759 			LIST_INSERT_AFTER(nmlast, nm, nm_entry);
760 		nmlast = nm;
761 	}
762 }
763 
764 /* parse the next integer in a formatted config file line */
765 int
get_int(char ** line,size_t * len,int * var,int * mod,const char * name,int flags,int max,const char * filename,int lineno)766 get_int(char **line, size_t *len, int *var, int *mod,
767     const char *name, int flags, int max, const char *filename, int lineno)
768 {
769 	int fieldlen, i;
770 	char *field;
771 	long val = 0;
772 
773 	if (mod)
774 		*mod = 0;
775 	*var = 0;
776 
777 	field = get_field(line, len, &fieldlen);
778 	if (field == NULL)
779 		return (1);
780 	if (fieldlen == 0) {
781 		fprintf(stderr, "%s:%d empty %s\n", filename, lineno, name);
782 		return (1);
783 	}
784 
785 	i = 0;
786 	if ((*field == '%' || *field == 'S' || *field == 'T' || *field == '*')
787 	    && fieldlen >= 1) {
788 		switch (*field) {
789 		case 'S':
790 			if (mod && (flags & T_MSS))
791 				*mod = T_MSS;
792 			if (fieldlen == 1)
793 				return (0);
794 			break;
795 		case 'T':
796 			if (mod && (flags & T_MTU))
797 				*mod = T_MTU;
798 			if (fieldlen == 1)
799 				return (0);
800 			break;
801 		case '*':
802 			if (fieldlen != 1) {
803 				fprintf(stderr, "%s:%d long '%c' %s\n",
804 				    filename, lineno, *field, name);
805 				return (1);
806 			}
807 			if (mod && (flags & T_DC)) {
808 				*mod = T_DC;
809 				return (0);
810 			}
811 		case '%':
812 			if (mod && (flags & T_MOD))
813 				*mod = T_MOD;
814 			if (fieldlen == 1) {
815 				fprintf(stderr, "%s:%d modulus %s must have a "
816 				    "value\n", filename, lineno, name);
817 				return (1);
818 			}
819 			break;
820 		}
821 		if (mod == NULL || *mod == 0) {
822 			fprintf(stderr, "%s:%d does not allow %c' %s\n",
823 			    filename, lineno, *field, name);
824 			return (1);
825 		}
826 		i++;
827 	}
828 
829 	for (; i < fieldlen; i++) {
830 		if (field[i] < '0' || field[i] > '9') {
831 			fprintf(stderr, "%s:%d non-digit character in %s\n",
832 			    filename, lineno, name);
833 			return (1);
834 		}
835 		val = val * 10 + field[i] - '0';
836 		if (val < 0) {
837 			fprintf(stderr, "%s:%d %s overflowed\n", filename,
838 			    lineno, name);
839 			return (1);
840 		}
841 	}
842 
843 	if (val > max) {
844 		fprintf(stderr, "%s:%d %s value %ld > %d\n", filename, lineno,
845 		    name, val, max);
846 		return (1);
847 	}
848 	*var = (int)val;
849 
850 	return (0);
851 }
852 
853 /* parse the next string in a formatted config file line */
854 int
get_str(char ** line,size_t * len,char ** v,const char * name,int minlen,const char * filename,int lineno)855 get_str(char **line, size_t *len, char **v, const char *name, int minlen,
856     const char *filename, int lineno)
857 {
858 	int fieldlen;
859 	char *ptr;
860 
861 	ptr = get_field(line, len, &fieldlen);
862 	if (ptr == NULL)
863 		return (1);
864 	if (fieldlen < minlen) {
865 		fprintf(stderr, "%s:%d too short %s\n", filename, lineno, name);
866 		return (1);
867 	}
868 	if ((*v = malloc(fieldlen + 1)) == NULL) {
869 		perror("malloc()");
870 		return (1);
871 	}
872 	memcpy(*v, ptr, fieldlen);
873 	(*v)[fieldlen] = '\0';
874 
875 	return (0);
876 }
877 
878 /* Parse out the TCP opts */
879 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)880 get_tcpopts(const char *filename, int lineno, const char *tcpopts,
881     pf_tcpopts_t *packed, int *optcnt, int *mss, int *mss_mod, int *wscale,
882     int *wscale_mod, int *ts0)
883 {
884 	int i, opt;
885 
886 	*packed = 0;
887 	*optcnt = 0;
888 	*wscale = 0;
889 	*wscale_mod = T_DC;
890 	*mss = 0;
891 	*mss_mod = T_DC;
892 	*ts0 = 0;
893 	if (strcmp(tcpopts, ".") == 0)
894 		return (0);
895 
896 	for (i = 0; tcpopts[i] && *optcnt < PF_OSFP_MAX_OPTS;) {
897 		switch ((opt = toupper((unsigned char)tcpopts[i++]))) {
898 		case 'N':	/* FALLTHROUGH */
899 		case 'S':
900 			*packed = (*packed << PF_OSFP_TCPOPT_BITS) |
901 			    (opt == 'N' ? PF_OSFP_TCPOPT_NOP :
902 			    PF_OSFP_TCPOPT_SACK);
903 			break;
904 		case 'W':	/* FALLTHROUGH */
905 		case 'M': {
906 			int *this_mod, *this;
907 
908 			if (opt == 'W') {
909 				this = wscale;
910 				this_mod = wscale_mod;
911 			} else {
912 				this = mss;
913 				this_mod = mss_mod;
914 			}
915 			*this = 0;
916 			*this_mod = 0;
917 
918 			*packed = (*packed << PF_OSFP_TCPOPT_BITS) |
919 			    (opt == 'W' ? PF_OSFP_TCPOPT_WSCALE :
920 			    PF_OSFP_TCPOPT_MSS);
921 			if (tcpopts[i] == '*' && (tcpopts[i + 1] == '\0' ||
922 			    tcpopts[i + 1] == ',')) {
923 				*this_mod = T_DC;
924 				i++;
925 				break;
926 			}
927 
928 			if (tcpopts[i] == '%') {
929 				*this_mod = T_MOD;
930 				i++;
931 			}
932 			do {
933 				if (!isdigit((unsigned char)tcpopts[i])) {
934 					fprintf(stderr, "%s:%d unknown "
935 					    "character '%c' in %c TCP opt\n",
936 					    filename, lineno, tcpopts[i], opt);
937 					return (1);
938 				}
939 				*this = (*this * 10) + tcpopts[i++] - '0';
940 			} while(tcpopts[i] != ',' && tcpopts[i] != '\0');
941 			break;
942 		}
943 		case 'T':
944 			if (tcpopts[i] == '0') {
945 				*ts0 = 1;
946 				i++;
947 			}
948 			*packed = (*packed << PF_OSFP_TCPOPT_BITS) |
949 			    PF_OSFP_TCPOPT_TS;
950 			break;
951 		}
952 		(*optcnt) ++;
953 		if (tcpopts[i] == '\0')
954 			break;
955 		if (tcpopts[i] != ',') {
956 			fprintf(stderr, "%s:%d unknown option to %c TCP opt\n",
957 			    filename, lineno, opt);
958 			return (1);
959 		}
960 		i++;
961 	}
962 
963 	return (0);
964 }
965 
966 /* rip the next field out of a formatted config file line */
967 char *
get_field(char ** line,size_t * len,int * fieldlen)968 get_field(char **line, size_t *len, int *fieldlen)
969 {
970 	char *ret, *ptr = *line;
971 	size_t plen = *len;
972 
973 
974 	while (plen && isspace((unsigned char)*ptr)) {
975 		plen--;
976 		ptr++;
977 	}
978 	ret = ptr;
979 	*fieldlen = 0;
980 
981 	for (; plen > 0 && *ptr != ':'; plen--, ptr++)
982 		(*fieldlen)++;
983 	if (plen) {
984 		*line = ptr + 1;
985 		*len = plen - 1;
986 	} else {
987 		*len = 0;
988 	}
989 	while (*fieldlen && isspace((unsigned char)ret[*fieldlen - 1]))
990 		(*fieldlen)--;
991 	return (ret);
992 }
993 
994 
995 #ifdef OSFP_DEBUG
996 const char *
print_ioctl(struct pf_osfp_ioctl * fp)997 print_ioctl(struct pf_osfp_ioctl *fp)
998 {
999 	static char buf[1024];
1000 	char tmp[32];
1001 	int i, opt;
1002 
1003 	*buf = '\0';
1004 	if (fp->fp_flags & PF_OSFP_WSIZE_DC)
1005 		strlcat(buf, "*", sizeof(buf));
1006 	else if (fp->fp_flags & PF_OSFP_WSIZE_MSS)
1007 		strlcat(buf, "S", sizeof(buf));
1008 	else if (fp->fp_flags & PF_OSFP_WSIZE_MTU)
1009 		strlcat(buf, "T", sizeof(buf));
1010 	else {
1011 		if (fp->fp_flags & PF_OSFP_WSIZE_MOD)
1012 			strlcat(buf, "%", sizeof(buf));
1013 		snprintf(tmp, sizeof(tmp), "%d", fp->fp_wsize);
1014 		strlcat(buf, tmp, sizeof(buf));
1015 	}
1016 	strlcat(buf, ":", sizeof(buf));
1017 
1018 	snprintf(tmp, sizeof(tmp), "%d", fp->fp_ttl);
1019 	strlcat(buf, tmp, sizeof(buf));
1020 	strlcat(buf, ":", sizeof(buf));
1021 
1022 	if (fp->fp_flags & PF_OSFP_DF)
1023 		strlcat(buf, "1", sizeof(buf));
1024 	else
1025 		strlcat(buf, "0", sizeof(buf));
1026 	strlcat(buf, ":", sizeof(buf));
1027 
1028 	if (fp->fp_flags & PF_OSFP_PSIZE_DC)
1029 		strlcat(buf, "*", sizeof(buf));
1030 	else {
1031 		if (fp->fp_flags & PF_OSFP_PSIZE_MOD)
1032 			strlcat(buf, "%", sizeof(buf));
1033 		snprintf(tmp, sizeof(tmp), "%d", fp->fp_psize);
1034 		strlcat(buf, tmp, sizeof(buf));
1035 	}
1036 	strlcat(buf, ":", sizeof(buf));
1037 
1038 	if (fp->fp_optcnt == 0)
1039 		strlcat(buf, ".", sizeof(buf));
1040 	for (i = fp->fp_optcnt - 1; i >= 0; i--) {
1041 		opt = fp->fp_tcpopts >> (i * PF_OSFP_TCPOPT_BITS);
1042 		opt &= (1 << PF_OSFP_TCPOPT_BITS) - 1;
1043 		switch (opt) {
1044 		case PF_OSFP_TCPOPT_NOP:
1045 			strlcat(buf, "N", sizeof(buf));
1046 			break;
1047 		case PF_OSFP_TCPOPT_SACK:
1048 			strlcat(buf, "S", sizeof(buf));
1049 			break;
1050 		case PF_OSFP_TCPOPT_TS:
1051 			strlcat(buf, "T", sizeof(buf));
1052 			if (fp->fp_flags & PF_OSFP_TS0)
1053 				strlcat(buf, "0", sizeof(buf));
1054 			break;
1055 		case PF_OSFP_TCPOPT_MSS:
1056 			strlcat(buf, "M", sizeof(buf));
1057 			if (fp->fp_flags & PF_OSFP_MSS_DC)
1058 				strlcat(buf, "*", sizeof(buf));
1059 			else {
1060 				if (fp->fp_flags & PF_OSFP_MSS_MOD)
1061 					strlcat(buf, "%", sizeof(buf));
1062 				snprintf(tmp, sizeof(tmp), "%d", fp->fp_mss);
1063 				strlcat(buf, tmp, sizeof(buf));
1064 			}
1065 			break;
1066 		case PF_OSFP_TCPOPT_WSCALE:
1067 			strlcat(buf, "W", sizeof(buf));
1068 			if (fp->fp_flags & PF_OSFP_WSCALE_DC)
1069 				strlcat(buf, "*", sizeof(buf));
1070 			else {
1071 				if (fp->fp_flags & PF_OSFP_WSCALE_MOD)
1072 					strlcat(buf, "%", sizeof(buf));
1073 				snprintf(tmp, sizeof(tmp), "%d", fp->fp_wscale);
1074 				strlcat(buf, tmp, sizeof(buf));
1075 			}
1076 			break;
1077 		}
1078 
1079 		if (i != 0)
1080 			strlcat(buf, ",", sizeof(buf));
1081 	}
1082 	strlcat(buf, ":", sizeof(buf));
1083 
1084 	strlcat(buf, fp->fp_os.fp_class_nm, sizeof(buf));
1085 	strlcat(buf, ":", sizeof(buf));
1086 	strlcat(buf, fp->fp_os.fp_version_nm, sizeof(buf));
1087 	strlcat(buf, ":", sizeof(buf));
1088 	strlcat(buf, fp->fp_os.fp_subtype_nm, sizeof(buf));
1089 	strlcat(buf, ":", sizeof(buf));
1090 
1091 	snprintf(tmp, sizeof(tmp), "TcpOpts %d 0x%llx", fp->fp_optcnt,
1092 	    (long long int)fp->fp_tcpopts);
1093 	strlcat(buf, tmp, sizeof(buf));
1094 
1095 	return (buf);
1096 }
1097 #endif
1098