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