xref: /illumos-gate/usr/src/cmd/ipf/lib/common/ipft_tx.c (revision 9b4c7145)
1 /*
2  * Copyright (C) 1995-2001 by Darren Reed.
3  *
4  * See the IPFILTER.LICENCE file for details on licencing.
5  *
6  * Copyright 2006 Sun Microsystems, Inc.  All rights reserved.
7  * Use is subject to license terms.
8  */
9 
10 #pragma ident	"%Z%%M%	%I%	%E% SMI"
11 
12 #if !defined(lint)
13 static const char sccsid[] = "@(#)ipft_tx.c	1.7 6/5/96 (C) 1993 Darren Reed";
14 static const char rcsid[] = "@(#)$Id: ipft_tx.c,v 1.15.2.3 2005/06/18 02:41:34 darrenr Exp $";
15 #endif
16 
17 #include <ctype.h>
18 
19 #include "ipf.h"
20 #include "ipt.h"
21 
22 #ifndef linux
23 #include <netinet/ip_var.h>
24 #endif
25 #include <netinet/tcpip.h>
26 
27 
28 extern	int	opts;
29 
30 static	char	*tx_proto = "";
31 
32 static	int	text_open __P((char *)), text_close __P((void));
33 static	int	text_readip __P((char *, int, char **, int *));
34 static	int	parseline __P((char *, ip_t *, char **, int *));
35 
36 static	char	myflagset[] = "FSRPAUEC";
37 static	u_char	myflags[] = { TH_FIN, TH_SYN, TH_RST, TH_PUSH,
38 				TH_ACK, TH_URG, TH_ECN, TH_CWR };
39 
40 struct	ipread	iptext = { text_open, text_close, text_readip, R_DO_CKSUM };
41 static	FILE	*tfp = NULL;
42 static	int	tfd = -1;
43 
44 static	u_32_t	tx_hostnum __P((char *, int *));
45 static	u_short	tx_portnum __P((char *));
46 
47 
48 /*
49  * returns an ip address as a long var as a result of either a DNS lookup or
50  * straight inet_addr() call
51  */
tx_hostnum(host,resolved)52 static	u_32_t	tx_hostnum(host, resolved)
53 char	*host;
54 int	*resolved;
55 {
56 	i6addr_t ipa;
57 
58 	*resolved = 0;
59 	if (!strcasecmp("any", host))
60 		return 0L;
61 	if (ISDIGIT(*host))
62 		return inet_addr(host);
63 
64 	if (gethost(host, &ipa, 0) == -1) {
65 		*resolved = -1;
66 		fprintf(stderr, "can't resolve hostname: %s\n", host);
67 		return 0;
68 	}
69 	return ipa.in4_addr;
70 }
71 
72 
73 /*
74  * find the port number given by the name, either from getservbyname() or
75  * straight atoi()
76  */
tx_portnum(name)77 static	u_short	tx_portnum(name)
78 char	*name;
79 {
80 	struct	servent	*sp, *sp2;
81 	u_short	p1 = 0;
82 
83 	if (ISDIGIT(*name))
84 		return (u_short)atoi(name);
85 	if (!tx_proto)
86 		tx_proto = "tcp/udp";
87 	if (strcasecmp(tx_proto, "tcp/udp")) {
88 		sp = getservbyname(name, tx_proto);
89 		if (sp)
90 			return ntohs(sp->s_port);
91 		(void) fprintf(stderr, "unknown service \"%s\".\n", name);
92 		return 0;
93 	}
94 	sp = getservbyname(name, "tcp");
95 	if (sp)
96 		p1 = sp->s_port;
97 	sp2 = getservbyname(name, "udp");
98 	if (!sp || !sp2) {
99 		(void) fprintf(stderr, "unknown tcp/udp service \"%s\".\n",
100 			name);
101 		return 0;
102 	}
103 	if (p1 != sp2->s_port) {
104 		(void) fprintf(stderr, "%s %d/tcp is a different port to ",
105 			name, p1);
106 		(void) fprintf(stderr, "%s %d/udp\n", name, sp->s_port);
107 		return 0;
108 	}
109 	return ntohs(p1);
110 }
111 
112 
113 char	*tx_icmptypes[] = {
114 	"echorep", (char *)NULL, (char *)NULL, "unreach", "squench",
115 	"redir", (char *)NULL, (char *)NULL, "echo", "routerad",
116 	"routersol", "timex", "paramprob", "timest", "timestrep",
117 	"inforeq", "inforep", "maskreq", "maskrep", "END"
118 };
119 
text_open(fname)120 static	int	text_open(fname)
121 char	*fname;
122 {
123 	if (tfp && tfd != -1) {
124 		rewind(tfp);
125 		return tfd;
126 	}
127 
128 	if (!strcmp(fname, "-")) {
129 		tfd = 0;
130 		tfp = stdin;
131 	} else {
132 		tfd = open(fname, O_RDONLY);
133 		if (tfd != -1)
134 			tfp = fdopen(tfd, "r");
135 	}
136 	return tfd;
137 }
138 
139 
text_close()140 static	int	text_close()
141 {
142 	int	cfd = tfd;
143 
144 	tfd = -1;
145 	return close(cfd);
146 }
147 
148 
text_readip(buf,cnt,ifn,dir)149 static	int	text_readip(buf, cnt, ifn, dir)
150 char	*buf, **ifn;
151 int	cnt, *dir;
152 {
153 	register char *s;
154 	char	line[513];
155 
156 	*ifn = NULL;
157 	while (fgets(line, sizeof(line)-1, tfp)) {
158 		if ((s = strchr(line, '\n')))
159 			*s = '\0';
160 		if ((s = strchr(line, '\r')))
161 			*s = '\0';
162 		if ((s = strchr(line, '#')))
163 			*s = '\0';
164 		if (!*line)
165 			continue;
166 		if (!(opts & OPT_BRIEF))
167 			printf("input: %s\n", line);
168 		*ifn = NULL;
169 		*dir = 0;
170 		if (!parseline(line, (ip_t *)buf, ifn, dir))
171 #if 0
172 			return sizeof(ip_t) + sizeof(tcphdr_t);
173 #else
174 			return sizeof(ip_t);
175 #endif
176 	}
177 	return -1;
178 }
179 
parseline(line,ip,ifn,out)180 static	int	parseline(line, ip, ifn, out)
181 char	*line;
182 ip_t	*ip;
183 char	**ifn;
184 int	*out;
185 {
186 	tcphdr_t	th, *tcp = &th;
187 	struct	icmp	icmp, *ic = &icmp;
188 	char	*cps[20], **cpp, c, ipopts[68];
189 	int	i, r;
190 
191 	if (*ifn)
192 		free(*ifn);
193 	bzero((char *)ip, MAX(sizeof(*tcp), sizeof(*ic)) + sizeof(*ip));
194 	bzero((char *)tcp, sizeof(*tcp));
195 	bzero((char *)ic, sizeof(*ic));
196 	bzero(ipopts, sizeof(ipopts));
197 	IP_HL_A(ip, sizeof(*ip) >> 2);
198 	IP_V_A(ip, IPVERSION);
199 	for (i = 0, cps[0] = strtok(line, " \b\t\r\n"); cps[i] && i < 19; )
200 		cps[++i] = strtok(NULL, " \b\t\r\n");
201 
202 	cpp = cps;
203 	if (!*cpp)
204 		return 1;
205 
206 	c = **cpp;
207 	if (!ISALPHA(c) || (TOLOWER(c) != 'o' && TOLOWER(c) != 'i')) {
208 		fprintf(stderr, "bad direction \"%s\"\n", *cpp);
209 		return 1;
210 	}
211 	*out = (TOLOWER(c) == 'o') ? 1 : 0;
212 	cpp++;
213 	if (!*cpp)
214 		return 1;
215 
216 	if (!strcasecmp(*cpp, "on")) {
217 		cpp++;
218 		if (!*cpp)
219 			return 1;
220 		*ifn = strdup(*cpp++);
221 		if (!*cpp)
222 			return 1;
223 	}
224 
225 	c = **cpp;
226 	ip->ip_len = sizeof(ip_t);
227 	if (!strcasecmp(*cpp, "tcp") || !strcasecmp(*cpp, "udp") ||
228 	    !strcasecmp(*cpp, "icmp")) {
229 		if (c == 't') {
230 			ip->ip_p = IPPROTO_TCP;
231 			ip->ip_len += sizeof(struct tcphdr);
232 			tx_proto = "tcp";
233 		} else if (c == 'u') {
234 			ip->ip_p = IPPROTO_UDP;
235 			ip->ip_len += sizeof(struct udphdr);
236 			tx_proto = "udp";
237 		} else {
238 			ip->ip_p = IPPROTO_ICMP;
239 			ip->ip_len += ICMPERR_IPICMPHLEN;
240 			tx_proto = "icmp";
241 		}
242 		cpp++;
243 	} else if (ISDIGIT(**cpp) && !index(*cpp, '.')) {
244 		ip->ip_p = atoi(*cpp);
245 		cpp++;
246 	} else
247 		ip->ip_p = IPPROTO_IP;
248 
249 	if (!*cpp)
250 		return 1;
251 	if (ip->ip_p == IPPROTO_TCP || ip->ip_p == IPPROTO_UDP) {
252 		char	*last;
253 
254 		last = strchr(*cpp, ',');
255 		if (!last) {
256 			fprintf(stderr, "tcp/udp with no source port\n");
257 			return 1;
258 		}
259 		*last++ = '\0';
260 		tcp->th_sport = htons(tx_portnum(last));
261 		if (ip->ip_p == IPPROTO_TCP) {
262 			tcp->th_win = htons(4096);
263 			TCP_OFF_A(tcp, sizeof(*tcp) >> 2);
264 		}
265 	}
266 	ip->ip_src.s_addr = tx_hostnum(*cpp, &r);
267 	cpp++;
268 	if (!*cpp)
269 		return 1;
270 
271 	if (ip->ip_p == IPPROTO_TCP || ip->ip_p == IPPROTO_UDP) {
272 		char	*last;
273 
274 		last = strchr(*cpp, ',');
275 		if (!last) {
276 			fprintf(stderr, "tcp/udp with no destination port\n");
277 			return 1;
278 		}
279 		*last++ = '\0';
280 		tcp->th_dport = htons(tx_portnum(last));
281 	}
282 	ip->ip_dst.s_addr = tx_hostnum(*cpp, &r);
283 	cpp++;
284 	if (*cpp && ip->ip_p == IPPROTO_TCP) {
285 		char	*s, *t;
286 
287 		tcp->th_flags = 0;
288 		for (s = *cpp; *s; s++)
289 			if ((t  = strchr(myflagset, *s)))
290 				tcp->th_flags |= myflags[t - myflagset];
291 		if (tcp->th_flags)
292 			cpp++;
293 		if (tcp->th_flags == 0)
294 			abort();
295 		if (tcp->th_flags & TH_URG)
296 			tcp->th_urp = htons(1);
297 	} else if (*cpp && ip->ip_p == IPPROTO_ICMP) {
298 		extern	char	*tx_icmptypes[];
299 		char	**s, *t;
300 		int	i;
301 
302 		for (s = tx_icmptypes, i = 0; !*s || strcmp(*s, "END");
303 		     s++, i++)
304 			if (*s && !strncasecmp(*cpp, *s, strlen(*s))) {
305 				ic->icmp_type = i;
306 				if ((t = strchr(*cpp, ',')))
307 					ic->icmp_code = atoi(t+1);
308 				cpp++;
309 				break;
310 			}
311 	}
312 
313 	if (*cpp && !strcasecmp(*cpp, "opt")) {
314 		u_long	olen;
315 
316 		cpp++;
317 		olen = buildopts(*cpp, ipopts, (IP_HL(ip) - 5) << 2);
318 		if (olen) {
319 			bcopy(ipopts, (char *)(ip + 1), olen);
320 			IP_HL_A(ip, IP_HL(ip) + (olen >> 2));
321 		}
322 	}
323 	if (ip->ip_p == IPPROTO_TCP || ip->ip_p == IPPROTO_UDP)
324 		bcopy((char *)tcp, ((char *)ip) + (IP_HL(ip) << 2),
325 			sizeof(*tcp));
326 	else if (ip->ip_p == IPPROTO_ICMP)
327 		bcopy((char *)ic, ((char *)ip) + (IP_HL(ip) << 2),
328 			sizeof(*ic));
329 	ip->ip_len = htons(ip->ip_len);
330 	return 0;
331 }
332