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