1/*	$FreeBSD$	*/
2
3/*
4 * Copyright (C) 2001-2004 by Darren Reed.
5 *
6 * See the IPFILTER.LICENCE file for details on licencing.
7 */
8%{
9#include "ipf.h"
10#include <syslog.h>
11#undef	OPT_NAT
12#undef	OPT_VERBOSE
13#include "ipmon_l.h"
14#include "ipmon.h"
15
16#define	YYDEBUG	1
17
18extern	void	yyerror __P((char *));
19extern	int	yyparse __P((void));
20extern	int	yylex __P((void));
21extern	int	yydebug;
22extern	FILE	*yyin;
23extern	int	yylineNum;
24
25typedef	struct	opt	{
26	struct	opt	*o_next;
27	int		o_line;
28	int		o_type;
29	int		o_num;
30	char		*o_str;
31	struct in_addr	o_ip;
32} opt_t;
33
34static	void	build_action __P((struct opt *));
35static	opt_t	*new_opt __P((int));
36static	void	free_action __P((ipmon_action_t *));
37
38static	ipmon_action_t	*alist = NULL;
39%}
40
41%union	{
42	char	*str;
43	u_32_t	num;
44	struct in_addr	addr;
45	struct opt	*opt;
46	union	i6addr	ip6;
47}
48
49%token	<num>	YY_NUMBER YY_HEX
50%token	<str>	YY_STR
51%token	<ip6>	YY_IPV6
52%token	YY_COMMENT
53%token	YY_CMP_EQ YY_CMP_NE YY_CMP_LE YY_CMP_GE YY_CMP_LT YY_CMP_GT
54%token	YY_RANGE_OUT YY_RANGE_IN
55
56%token	IPM_MATCH IPM_BODY IPM_COMMENT IPM_DIRECTION IPM_DSTIP IPM_DSTPORT
57%token	IPM_EVERY IPM_EXECUTE IPM_GROUP IPM_INTERFACE IPM_IN IPM_NO IPM_OUT
58%token	IPM_PACKET IPM_PACKETS IPM_POOL IPM_PROTOCOL IPM_RESULT IPM_RULE
59%token	IPM_SECOND IPM_SECONDS IPM_SRCIP IPM_SRCPORT IPM_LOGTAG IPM_WITH
60%token	IPM_DO IPM_SAVE IPM_SYSLOG IPM_NOTHING IPM_RAW IPM_TYPE IPM_NAT
61%token	IPM_STATE IPM_NATTAG IPM_IPF
62%type	<addr> ipv4
63%type	<opt> direction dstip dstport every execute group interface
64%type	<opt> protocol result rule srcip srcport logtag matching
65%type	<opt> matchopt nattag type doopt doing save syslog nothing
66%type	<num> saveopts saveopt typeopt
67
68%%
69file:	line
70	| assign
71	| file line
72	| file assign
73	;
74
75line:	IPM_MATCH '{' matching '}' IPM_DO '{' doing '}' ';'
76					{ build_action($3); resetlexer(); }
77	| IPM_COMMENT
78	| YY_COMMENT
79	;
80
81assign:	YY_STR assigning YY_STR ';'		{ set_variable($1, $3);
82						  resetlexer();
83						  free($1);
84						  free($3);
85						  yyvarnext = 0;
86						}
87	;
88
89assigning:
90	'='					{ yyvarnext = 1; }
91	;
92
93matching:
94	matchopt				{ $$ = $1; }
95	| matchopt ',' matching			{ $1->o_next = $3; $$ = $1; }
96	;
97
98matchopt:
99	direction				{ $$ = $1; }
100	| dstip					{ $$ = $1; }
101	| dstport				{ $$ = $1; }
102	| every					{ $$ = $1; }
103	| group					{ $$ = $1; }
104	| interface				{ $$ = $1; }
105	| protocol				{ $$ = $1; }
106	| result				{ $$ = $1; }
107	| rule					{ $$ = $1; }
108	| srcip					{ $$ = $1; }
109	| srcport				{ $$ = $1; }
110	| logtag				{ $$ = $1; }
111	| nattag				{ $$ = $1; }
112	| type					{ $$ = $1; }
113	;
114
115doing:
116	doopt					{ $$ = $1; }
117	| doopt ',' doing			{ $1->o_next = $3; $$ = $1; }
118	;
119
120doopt:
121	execute					{ $$ = $1; }
122	| save					{ $$ = $1; }
123	| syslog				{ $$ = $1; }
124	| nothing				{ $$ = $1; }
125	;
126
127direction:
128	IPM_DIRECTION '=' IPM_IN		{ $$ = new_opt(IPM_DIRECTION);
129						  $$->o_num = IPM_IN; }
130	| IPM_DIRECTION '=' IPM_OUT		{ $$ = new_opt(IPM_DIRECTION);
131						  $$->o_num = IPM_OUT; }
132	;
133
134dstip:	IPM_DSTIP '=' ipv4 '/' YY_NUMBER	{ $$ = new_opt(IPM_DSTIP);
135						  $$->o_ip = $3;
136						  $$->o_num = $5; }
137	;
138
139dstport:
140	IPM_DSTPORT '=' YY_NUMBER		{ $$ = new_opt(IPM_DSTPORT);
141						  $$->o_num = $3; }
142	| IPM_DSTPORT '=' YY_STR		{ $$ = new_opt(IPM_DSTPORT);
143						  $$->o_str = $3; }
144	;
145
146every:	IPM_EVERY IPM_SECOND			{ $$ = new_opt(IPM_SECOND);
147						  $$->o_num = 1; }
148	| IPM_EVERY YY_NUMBER IPM_SECONDS	{ $$ = new_opt(IPM_SECOND);
149						  $$->o_num = $2; }
150	| IPM_EVERY IPM_PACKET			{ $$ = new_opt(IPM_PACKET);
151						  $$->o_num = 1; }
152	| IPM_EVERY YY_NUMBER IPM_PACKETS	{ $$ = new_opt(IPM_PACKET);
153						  $$->o_num = $2; }
154	;
155
156group:	IPM_GROUP '=' YY_NUMBER			{ $$ = new_opt(IPM_GROUP);
157						  $$->o_num = $3; }
158	| IPM_GROUP '=' YY_STR			{ $$ = new_opt(IPM_GROUP);
159						  $$->o_str = $3; }
160	;
161
162interface:
163	IPM_INTERFACE '=' YY_STR		{ $$ = new_opt(IPM_INTERFACE);
164						  $$->o_str = $3; }
165	;
166
167logtag:	IPM_LOGTAG '=' YY_NUMBER		{ $$ = new_opt(IPM_LOGTAG);
168						  $$->o_num = $3; }
169	;
170
171nattag:	IPM_NATTAG '=' YY_STR			{ $$ = new_opt(IPM_NATTAG);
172						  $$->o_str = $3; }
173	;
174
175protocol:
176	IPM_PROTOCOL '=' YY_NUMBER		{ $$ = new_opt(IPM_PROTOCOL);
177						  $$->o_num = $3; }
178	| IPM_PROTOCOL '=' YY_STR		{ $$ = new_opt(IPM_PROTOCOL);
179						  $$->o_num = getproto($3);
180						  free($3);
181						}
182	;
183
184result:	IPM_RESULT '=' YY_STR			{ $$ = new_opt(IPM_RESULT);
185						  $$->o_str = $3; }
186	;
187
188rule:	IPM_RULE '=' YY_NUMBER			{ $$ = new_opt(IPM_RULE);
189						  $$->o_num = YY_NUMBER; }
190	;
191
192srcip:	IPM_SRCIP '=' ipv4 '/' YY_NUMBER	{ $$ = new_opt(IPM_SRCIP);
193						  $$->o_ip = $3;
194						  $$->o_num = $5; }
195	;
196
197srcport:
198	IPM_SRCPORT '=' YY_NUMBER		{ $$ = new_opt(IPM_SRCPORT);
199						  $$->o_num = $3; }
200	| IPM_SRCPORT '=' YY_STR		{ $$ = new_opt(IPM_SRCPORT);
201						  $$->o_str = $3; }
202	;
203
204type:	IPM_TYPE '=' typeopt			{ $$ = new_opt(IPM_TYPE);
205						  $$->o_num = $3; }
206	;
207
208typeopt:
209	IPM_IPF					{ $$ = IPL_MAGIC; }
210	| IPM_NAT				{ $$ = IPL_MAGIC_NAT; }
211	| IPM_STATE				{ $$ = IPL_MAGIC_STATE; }
212	;
213
214execute:
215	IPM_EXECUTE YY_STR			{ $$ = new_opt(IPM_EXECUTE);
216						  $$->o_str = $2; }
217	;
218
219save:	IPM_SAVE saveopts YY_STR		{ $$ = new_opt(IPM_SAVE);
220						  $$->o_num = $2;
221						  $$->o_str = $3; }
222	;
223
224saveopts:					{ $$ = 0; }
225	| saveopt				{ $$ = $1; }
226	| saveopt ',' saveopts			{ $$ = $1 | $3; }
227	;
228
229saveopt:
230	IPM_RAW					{ $$ = IPMDO_SAVERAW; }
231	;
232
233syslog:	IPM_SYSLOG				{ $$ = new_opt(IPM_SYSLOG); }
234	;
235
236nothing:
237	IPM_NOTHING				{ $$ = 0; }
238	;
239
240ipv4:   YY_NUMBER '.' YY_NUMBER '.' YY_NUMBER '.' YY_NUMBER
241		{ if ($1 > 255 || $3 > 255 || $5 > 255 || $7 > 255) {
242			yyerror("Invalid octet string for IP address");
243			return 0;
244		  }
245		  $$.s_addr = ($1 << 24) | ($3 << 16) | ($5 << 8) | $7;
246		  $$.s_addr = htonl($$.s_addr);
247		}
248%%
249static	struct	wordtab	yywords[] = {
250	{ "body",	IPM_BODY },
251	{ "direction",	IPM_DIRECTION },
252	{ "do",		IPM_DO },
253	{ "dstip",	IPM_DSTIP },
254	{ "dstport",	IPM_DSTPORT },
255	{ "every",	IPM_EVERY },
256	{ "execute",	IPM_EXECUTE },
257	{ "group",	IPM_GROUP },
258	{ "in",		IPM_IN },
259	{ "interface",	IPM_INTERFACE },
260	{ "ipf",	IPM_IPF },
261	{ "logtag",	IPM_LOGTAG },
262	{ "match",	IPM_MATCH },
263	{ "nat",	IPM_NAT },
264	{ "nattag",	IPM_NATTAG },
265	{ "no",		IPM_NO },
266	{ "nothing",	IPM_NOTHING },
267	{ "out",	IPM_OUT },
268	{ "packet",	IPM_PACKET },
269	{ "packets",	IPM_PACKETS },
270	{ "protocol",	IPM_PROTOCOL },
271	{ "result",	IPM_RESULT },
272	{ "rule",	IPM_RULE },
273	{ "save",	IPM_SAVE },
274	{ "second",	IPM_SECOND },
275	{ "seconds",	IPM_SECONDS },
276	{ "srcip",	IPM_SRCIP },
277	{ "srcport",	IPM_SRCPORT },
278	{ "state",	IPM_STATE },
279	{ "syslog",	IPM_SYSLOG },
280	{ "with",	IPM_WITH },
281	{ NULL,		0 }
282};
283
284static int macflags[17][2] = {
285	{ IPM_DIRECTION,	IPMAC_DIRECTION	},
286	{ IPM_DSTIP,		IPMAC_DSTIP	},
287	{ IPM_DSTPORT,		IPMAC_DSTPORT	},
288	{ IPM_GROUP,		IPMAC_GROUP	},
289	{ IPM_INTERFACE,	IPMAC_INTERFACE	},
290	{ IPM_LOGTAG,		IPMAC_LOGTAG 	},
291	{ IPM_NATTAG,		IPMAC_NATTAG 	},
292	{ IPM_PACKET,		IPMAC_EVERY	},
293	{ IPM_PROTOCOL,		IPMAC_PROTOCOL	},
294	{ IPM_RESULT,		IPMAC_RESULT	},
295	{ IPM_RULE,		IPMAC_RULE	},
296	{ IPM_SECOND,		IPMAC_EVERY	},
297	{ IPM_SRCIP,		IPMAC_SRCIP	},
298	{ IPM_SRCPORT,		IPMAC_SRCPORT	},
299	{ IPM_TYPE,		IPMAC_TYPE 	},
300	{ IPM_WITH,		IPMAC_WITH 	},
301	{ 0, 0 }
302};
303
304static opt_t *new_opt(type)
305int type;
306{
307	opt_t *o;
308
309	o = (opt_t *)malloc(sizeof(*o));
310	o->o_type = type;
311	o->o_line = yylineNum;
312	o->o_num = 0;
313	o->o_str = (char *)0;
314	o->o_next = NULL;
315	return o;
316}
317
318static void build_action(olist)
319opt_t *olist;
320{
321	ipmon_action_t *a;
322	opt_t *o;
323	char c;
324	int i;
325
326	a = (ipmon_action_t *)calloc(1, sizeof(*a));
327	if (a == NULL)
328		return;
329	while ((o = olist) != NULL) {
330		/*
331		 * Check to see if the same comparator is being used more than
332		 * once per matching statement.
333		 */
334		for (i = 0; macflags[i][0]; i++)
335			if (macflags[i][0] == o->o_type)
336				break;
337		if (macflags[i][1] & a->ac_mflag) {
338			fprintf(stderr, "%s redfined on line %d\n",
339				yykeytostr(o->o_type), yylineNum);
340			if (o->o_str != NULL)
341				free(o->o_str);
342			olist = o->o_next;
343			free(o);
344			continue;
345		}
346
347		a->ac_mflag |= macflags[i][1];
348
349		switch (o->o_type)
350		{
351		case IPM_DIRECTION :
352			a->ac_direction = o->o_num;
353			break;
354		case IPM_DSTIP :
355			a->ac_dip = o->o_ip.s_addr;
356			a->ac_dmsk = htonl(0xffffffff << (32 - o->o_num));
357			break;
358		case IPM_DSTPORT :
359			a->ac_dport = htons(o->o_num);
360			break;
361		case IPM_EXECUTE :
362			a->ac_exec = o->o_str;
363			c = *o->o_str;
364			if (c== '"'|| c == '\'') {
365				if (o->o_str[strlen(o->o_str) - 1] == c) {
366					a->ac_run = strdup(o->o_str + 1);
367					a->ac_run[strlen(a->ac_run) - 1] ='\0';
368				} else
369					a->ac_run = o->o_str;
370			} else
371				a->ac_run = o->o_str;
372			o->o_str = NULL;
373			break;
374		case IPM_INTERFACE :
375			a->ac_iface = o->o_str;
376			o->o_str = NULL;
377			break;
378		case IPM_GROUP :
379			if (o->o_str != NULL)
380				strncpy(a->ac_group, o->o_str, FR_GROUPLEN);
381			else
382				sprintf(a->ac_group, "%d", o->o_num);
383			break;
384		case IPM_LOGTAG :
385			a->ac_logtag = o->o_num;
386			break;
387		case IPM_NATTAG :
388			strncpy(a->ac_nattag, o->o_str, sizeof(a->ac_nattag));
389			break;
390		case IPM_PACKET :
391			a->ac_packet = o->o_num;
392			break;
393		case IPM_PROTOCOL :
394			a->ac_proto = o->o_num;
395			break;
396		case IPM_RULE :
397			a->ac_rule = o->o_num;
398			break;
399		case IPM_RESULT :
400			if (!strcasecmp(o->o_str, "pass"))
401				a->ac_result = IPMR_PASS;
402			else if (!strcasecmp(o->o_str, "block"))
403				a->ac_result = IPMR_BLOCK;
404			else if (!strcasecmp(o->o_str, "nomatch"))
405				a->ac_result = IPMR_NOMATCH;
406			else if (!strcasecmp(o->o_str, "log"))
407				a->ac_result = IPMR_LOG;
408			break;
409		case IPM_SECOND :
410			a->ac_second = o->o_num;
411			break;
412		case IPM_SRCIP :
413			a->ac_sip = o->o_ip.s_addr;
414			a->ac_smsk = htonl(0xffffffff << (32 - o->o_num));
415			break;
416		case IPM_SRCPORT :
417			a->ac_sport = htons(o->o_num);
418			break;
419		case IPM_SAVE :
420			if (a->ac_savefile != NULL) {
421				fprintf(stderr, "%s redfined on line %d\n",
422					yykeytostr(o->o_type), yylineNum);
423				break;
424			}
425			a->ac_savefile = strdup(o->o_str);
426			a->ac_savefp = fopen(o->o_str, "a");
427			a->ac_dflag |= o->o_num & IPMDO_SAVERAW;
428			break;
429		case IPM_SYSLOG :
430			if (a->ac_syslog != 0) {
431				fprintf(stderr, "%s redfined on line %d\n",
432					yykeytostr(o->o_type), yylineNum);
433				break;
434			}
435			a->ac_syslog = 1;
436			break;
437		case IPM_TYPE :
438			a->ac_type = o->o_num;
439			break;
440		case IPM_WITH :
441			break;
442		default :
443			break;
444		}
445
446		olist = o->o_next;
447		if (o->o_str != NULL)
448			free(o->o_str);
449		free(o);
450	}
451	a->ac_next = alist;
452	alist = a;
453}
454
455
456int check_action(buf, log, opts, lvl)
457char *buf, *log;
458int opts, lvl;
459{
460	ipmon_action_t *a;
461	struct timeval tv;
462	ipflog_t *ipf;
463	tcphdr_t *tcp;
464	iplog_t *ipl;
465	int matched;
466	u_long t1;
467	ip_t *ip;
468
469	matched = 0;
470	ipl = (iplog_t *)buf;
471	ipf = (ipflog_t *)(ipl +1);
472	ip = (ip_t *)(ipf + 1);
473	tcp = (tcphdr_t *)((char *)ip + (IP_HL(ip) << 2));
474
475	for (a = alist; a != NULL; a = a->ac_next) {
476		if ((a->ac_mflag & IPMAC_DIRECTION) != 0) {
477			if (a->ac_direction == IPM_IN) {
478				if ((ipf->fl_flags & FR_INQUE) == 0)
479					continue;
480			} else if (a->ac_direction == IPM_OUT) {
481				if ((ipf->fl_flags & FR_OUTQUE) == 0)
482					continue;
483			}
484		}
485
486		if ((a->ac_type != 0) && (a->ac_type != ipl->ipl_magic))
487			continue;
488
489		if ((a->ac_mflag & IPMAC_EVERY) != 0) {
490			gettimeofday(&tv, NULL);
491			t1 = tv.tv_sec - a->ac_lastsec;
492			if (tv.tv_usec <= a->ac_lastusec)
493				t1--;
494			if (a->ac_second != 0) {
495				if (t1 < a->ac_second)
496					continue;
497				a->ac_lastsec = tv.tv_sec;
498				a->ac_lastusec = tv.tv_usec;
499			}
500
501			if (a->ac_packet != 0) {
502				if (a->ac_pktcnt == 0)
503					a->ac_pktcnt++;
504				else if (a->ac_pktcnt == a->ac_packet) {
505					a->ac_pktcnt = 0;
506					continue;
507				} else {
508					a->ac_pktcnt++;
509					continue;
510				}
511			}
512		}
513
514		if ((a->ac_mflag & IPMAC_DSTIP) != 0) {
515			if ((ip->ip_dst.s_addr & a->ac_dmsk) != a->ac_dip)
516				continue;
517		}
518
519		if ((a->ac_mflag & IPMAC_DSTPORT) != 0) {
520			if (ip->ip_p != IPPROTO_UDP && ip->ip_p != IPPROTO_TCP)
521				continue;
522			if (tcp->th_dport != a->ac_dport)
523				continue;
524		}
525
526		if ((a->ac_mflag & IPMAC_GROUP) != 0) {
527			if (strncmp(a->ac_group, ipf->fl_group,
528				    FR_GROUPLEN) != 0)
529				continue;
530		}
531
532		if ((a->ac_mflag & IPMAC_INTERFACE) != 0) {
533			if (strcmp(a->ac_iface, ipf->fl_ifname))
534				continue;
535		}
536
537		if ((a->ac_mflag & IPMAC_PROTOCOL) != 0) {
538			if (a->ac_proto != ip->ip_p)
539				continue;
540		}
541
542		if ((a->ac_mflag & IPMAC_RESULT) != 0) {
543			if ((ipf->fl_flags & FF_LOGNOMATCH) != 0) {
544				if (a->ac_result != IPMR_NOMATCH)
545					continue;
546			} else if (FR_ISPASS(ipf->fl_flags)) {
547				if (a->ac_result != IPMR_PASS)
548					continue;
549			} else if (FR_ISBLOCK(ipf->fl_flags)) {
550				if (a->ac_result != IPMR_BLOCK)
551					continue;
552			} else {	/* Log only */
553				if (a->ac_result != IPMR_LOG)
554					continue;
555			}
556		}
557
558		if ((a->ac_mflag & IPMAC_RULE) != 0) {
559			if (a->ac_rule != ipf->fl_rule)
560				continue;
561		}
562
563		if ((a->ac_mflag & IPMAC_SRCIP) != 0) {
564			if ((ip->ip_src.s_addr & a->ac_smsk) != a->ac_sip)
565				continue;
566		}
567
568		if ((a->ac_mflag & IPMAC_SRCPORT) != 0) {
569			if (ip->ip_p != IPPROTO_UDP && ip->ip_p != IPPROTO_TCP)
570				continue;
571			if (tcp->th_sport != a->ac_sport)
572				continue;
573		}
574
575		if ((a->ac_mflag & IPMAC_LOGTAG) != 0) {
576			if (a->ac_logtag != ipf->fl_logtag)
577				continue;
578		}
579
580		if ((a->ac_mflag & IPMAC_NATTAG) != 0) {
581			if (strncmp(a->ac_nattag, ipf->fl_nattag.ipt_tag,
582				    IPFTAG_LEN) != 0)
583				continue;
584		}
585
586		matched = 1;
587
588		/*
589		 * It matched so now execute the command
590		 */
591		if (a->ac_syslog != 0) {
592			syslog(lvl, "%s", log);
593		}
594
595		if (a->ac_savefp != NULL) {
596			if (a->ac_dflag & IPMDO_SAVERAW)
597				fwrite(ipl, 1, ipl->ipl_dsize, a->ac_savefp);
598			else
599				fputs(log, a->ac_savefp);
600		}
601
602		if (a->ac_exec != NULL) {
603			switch (fork())
604			{
605			case 0 :
606			{
607				FILE *pi;
608
609				pi = popen(a->ac_run, "w");
610				if (pi != NULL) {
611					fprintf(pi, "%s\n", log);
612					if ((opts & OPT_HEXHDR) != 0) {
613						dumphex(pi, 0, buf,
614							sizeof(*ipl) +
615							sizeof(*ipf));
616					}
617					if ((opts & OPT_HEXBODY) != 0) {
618						dumphex(pi, 0, (char *)ip,
619							ipf->fl_hlen +
620							ipf->fl_plen);
621					}
622					pclose(pi);
623				}
624				exit(1);
625			}
626			case -1 :
627				break;
628			default :
629				break;
630			}
631		}
632	}
633
634	return matched;
635}
636
637
638static void free_action(a)
639ipmon_action_t *a;
640{
641	if (a->ac_savefile != NULL) {
642		free(a->ac_savefile);
643		a->ac_savefile = NULL;
644	}
645	if (a->ac_savefp != NULL) {
646		fclose(a->ac_savefp);
647		a->ac_savefp = NULL;
648	}
649	if (a->ac_exec != NULL) {
650		free(a->ac_exec);
651		if (a->ac_run == a->ac_exec)
652			a->ac_run = NULL;
653		a->ac_exec = NULL;
654	}
655	if (a->ac_run != NULL) {
656		free(a->ac_run);
657		a->ac_run = NULL;
658	}
659	if (a->ac_iface != NULL) {
660		free(a->ac_iface);
661		a->ac_iface = NULL;
662	}
663	a->ac_next = NULL;
664	free(a);
665}
666
667
668int load_config(file)
669char *file;
670{
671	ipmon_action_t *a;
672	FILE *fp;
673	char *s;
674
675	s = getenv("YYDEBUG");
676	if (s != NULL)
677		yydebug = atoi(s);
678	else
679		yydebug = 0;
680
681	while ((a = alist) != NULL) {
682		alist = a->ac_next;
683		free_action(a);
684	}
685
686	yylineNum = 1;
687
688	(void) yysettab(yywords);
689
690	fp = fopen(file, "r");
691	if (!fp) {
692		perror("load_config:fopen:");
693		return -1;
694	}
695	yyin = fp;
696	while (!feof(fp))
697		yyparse();
698	fclose(fp);
699	return 0;
700}
701