1 /*
2 netutl.c -- some supporting network utility code
3 Copyright (C) 1998-2005 Ivo Timmermans
4 2000-2016 Guus Sliepen <guus@tinc-vpn.org>
5
6 This program is free software; you can redistribute it and/or modify
7 it under the terms of the GNU General Public License as published by
8 the Free Software Foundation; either version 2 of the License, or
9 (at your option) any later version.
10
11 This program is distributed in the hope that it will be useful,
12 but WITHOUT ANY WARRANTY; without even the implied warranty of
13 MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the
14 GNU General Public License for more details.
15
16 You should have received a copy of the GNU General Public License along
17 with this program; if not, write to the Free Software Foundation, Inc.,
18 51 Franklin Street, Fifth Floor, Boston, MA 02110-1301 USA.
19 */
20
21 #include "system.h"
22
23 #include "net.h"
24 #include "netutl.h"
25 #include "logger.h"
26 #include "utils.h"
27 #include "xalloc.h"
28
29 bool hostnames = false;
30
31 /*
32 Turn a string into a struct addrinfo.
33 Return NULL on failure.
34 */
str2addrinfo(const char * address,const char * service,int socktype)35 struct addrinfo *str2addrinfo(const char *address, const char *service, int socktype) {
36 struct addrinfo *ai = NULL, hint = {0};
37 int err;
38
39 hint.ai_family = addressfamily;
40 hint.ai_socktype = socktype;
41
42 #if HAVE_DECL_RES_INIT
43 // ensure glibc reloads /etc/resolv.conf.
44 res_init();
45 #endif
46 err = getaddrinfo(address, service, &hint, &ai);
47
48 if(err) {
49 logger(LOG_WARNING, "Error looking up %s port %s: %s", address,
50 service, gai_strerror(err));
51 return NULL;
52 }
53
54 return ai;
55 }
56
str2sockaddr(const char * address,const char * port)57 sockaddr_t str2sockaddr(const char *address, const char *port) {
58 struct addrinfo *ai = NULL, hint = {0};
59 sockaddr_t result;
60 int err;
61
62 hint.ai_family = AF_UNSPEC;
63 hint.ai_flags = AI_NUMERICHOST;
64 hint.ai_socktype = SOCK_STREAM;
65
66 err = getaddrinfo(address, port, &hint, &ai);
67
68 if(err || !ai) {
69 ifdebug(SCARY_THINGS)
70 logger(LOG_DEBUG, "Unknown type address %s port %s", address, port);
71 result.sa.sa_family = AF_UNKNOWN;
72 result.unknown.address = xstrdup(address);
73 result.unknown.port = xstrdup(port);
74 return result;
75 }
76
77 memcpy(&result, ai->ai_addr, ai->ai_addrlen);
78 freeaddrinfo(ai);
79
80 return result;
81 }
82
sockaddr2str(const sockaddr_t * sa,char ** addrstr,char ** portstr)83 void sockaddr2str(const sockaddr_t *sa, char **addrstr, char **portstr) {
84 char address[NI_MAXHOST];
85 char port[NI_MAXSERV];
86 char *scopeid;
87 int err;
88
89 if(sa->sa.sa_family == AF_UNKNOWN) {
90 if(addrstr) {
91 *addrstr = xstrdup(sa->unknown.address);
92 }
93
94 if(portstr) {
95 *portstr = xstrdup(sa->unknown.port);
96 }
97
98 return;
99 }
100
101 err = getnameinfo(&sa->sa, SALEN(sa->sa), address, sizeof(address), port, sizeof(port), NI_NUMERICHOST | NI_NUMERICSERV);
102
103 if(err) {
104 logger(LOG_ERR, "Error while translating addresses: %s",
105 gai_strerror(err));
106 abort();
107 }
108
109 scopeid = strchr(address, '%');
110
111 if(scopeid) {
112 *scopeid = '\0'; /* Descope. */
113 }
114
115 if(addrstr) {
116 *addrstr = xstrdup(address);
117 }
118
119 if(portstr) {
120 *portstr = xstrdup(port);
121 }
122 }
123
sockaddr2hostname(const sockaddr_t * sa)124 char *sockaddr2hostname(const sockaddr_t *sa) {
125 char *str;
126 char address[NI_MAXHOST] = "unknown";
127 char port[NI_MAXSERV] = "unknown";
128 int err;
129
130 if(sa->sa.sa_family == AF_UNKNOWN) {
131 xasprintf(&str, "%s port %s", sa->unknown.address, sa->unknown.port);
132 return str;
133 }
134
135 err = getnameinfo(&sa->sa, SALEN(sa->sa), address, sizeof(address), port, sizeof(port),
136 hostnames ? 0 : (NI_NUMERICHOST | NI_NUMERICSERV));
137
138 if(err) {
139 logger(LOG_ERR, "Error while looking up hostname: %s",
140 gai_strerror(err));
141 }
142
143 xasprintf(&str, "%s port %s", address, port);
144
145 return str;
146 }
147
sockaddrcmp_noport(const sockaddr_t * a,const sockaddr_t * b)148 int sockaddrcmp_noport(const sockaddr_t *a, const sockaddr_t *b) {
149 int result;
150
151 result = a->sa.sa_family - b->sa.sa_family;
152
153 if(result) {
154 return result;
155 }
156
157 switch(a->sa.sa_family) {
158 case AF_UNSPEC:
159 return 0;
160
161 case AF_UNKNOWN:
162 return strcmp(a->unknown.address, b->unknown.address);
163
164 case AF_INET:
165 return memcmp(&a->in.sin_addr, &b->in.sin_addr, sizeof(a->in.sin_addr));
166
167 case AF_INET6:
168 return memcmp(&a->in6.sin6_addr, &b->in6.sin6_addr, sizeof(a->in6.sin6_addr));
169
170 default:
171 logger(LOG_ERR, "sockaddrcmp() was called with unknown address family %d, exitting!",
172 a->sa.sa_family);
173 abort();
174 }
175 }
176
sockaddrcmp(const sockaddr_t * a,const sockaddr_t * b)177 int sockaddrcmp(const sockaddr_t *a, const sockaddr_t *b) {
178 int result;
179
180 result = a->sa.sa_family - b->sa.sa_family;
181
182 if(result) {
183 return result;
184 }
185
186 switch(a->sa.sa_family) {
187 case AF_UNSPEC:
188 return 0;
189
190 case AF_UNKNOWN:
191 result = strcmp(a->unknown.address, b->unknown.address);
192
193 if(result) {
194 return result;
195 }
196
197 return strcmp(a->unknown.port, b->unknown.port);
198
199 case AF_INET:
200 result = memcmp(&a->in.sin_addr, &b->in.sin_addr, sizeof(a->in.sin_addr));
201
202 if(result) {
203 return result;
204 }
205
206 return memcmp(&a->in.sin_port, &b->in.sin_port, sizeof(a->in.sin_port));
207
208 case AF_INET6:
209 result = memcmp(&a->in6.sin6_addr, &b->in6.sin6_addr, sizeof(a->in6.sin6_addr));
210
211 if(result) {
212 return result;
213 }
214
215 return memcmp(&a->in6.sin6_port, &b->in6.sin6_port, sizeof(a->in6.sin6_port));
216
217 default:
218 logger(LOG_ERR, "sockaddrcmp() was called with unknown address family %d, exitting!",
219 a->sa.sa_family);
220 abort();
221 }
222 }
223
sockaddrcpy(sockaddr_t * a,const sockaddr_t * b)224 void sockaddrcpy(sockaddr_t *a, const sockaddr_t *b) {
225 if(b->sa.sa_family != AF_UNKNOWN) {
226 *a = *b;
227 } else {
228 a->unknown.family = AF_UNKNOWN;
229 a->unknown.address = xstrdup(b->unknown.address);
230 a->unknown.port = xstrdup(b->unknown.port);
231 }
232 }
233
sockaddrfree(sockaddr_t * a)234 void sockaddrfree(sockaddr_t *a) {
235 if(a->sa.sa_family == AF_UNKNOWN) {
236 free(a->unknown.address);
237 free(a->unknown.port);
238 }
239 }
240
sockaddrunmap(sockaddr_t * sa)241 void sockaddrunmap(sockaddr_t *sa) {
242 if(sa->sa.sa_family == AF_INET6 && IN6_IS_ADDR_V4MAPPED(&sa->in6.sin6_addr)) {
243 sa->in.sin_addr.s_addr = ((uint32_t *) & sa->in6.sin6_addr)[3];
244 sa->in.sin_family = AF_INET;
245 }
246 }
247
sockaddr_setport(sockaddr_t * sa,const char * port)248 void sockaddr_setport(sockaddr_t *sa, const char *port) {
249 uint16_t portnum = htons(atoi(port));
250
251 if(!portnum) {
252 return;
253 }
254
255 switch(sa->sa.sa_family) {
256 case AF_INET:
257 sa->in.sin_port = portnum;
258 break;
259
260 case AF_INET6:
261 sa->in6.sin6_port = portnum;
262 break;
263
264 case AF_UNKNOWN:
265 free(sa->unknown.port);
266 sa->unknown.port = xstrdup(port);
267
268 default:
269 return;
270 }
271 }
272
273 /* Subnet mask handling */
274
maskcmp(const void * va,const void * vb,int masklen)275 int maskcmp(const void *va, const void *vb, int masklen) {
276 int i, m, result;
277 const char *a = va;
278 const char *b = vb;
279
280 for(m = masklen, i = 0; m >= 8; m -= 8, i++) {
281 result = a[i] - b[i];
282
283 if(result) {
284 return result;
285 }
286 }
287
288 if(m)
289 return (a[i] & (0x100 - (1 << (8 - m)))) -
290 (b[i] & (0x100 - (1 << (8 - m))));
291
292 return 0;
293 }
294
mask(void * va,int masklen,int len)295 void mask(void *va, int masklen, int len) {
296 int i;
297 char *a = va;
298
299 i = masklen / 8;
300 masklen %= 8;
301
302 if(masklen) {
303 a[i++] &= (0x100 - (1 << (8 - masklen)));
304 }
305
306 for(; i < len; i++) {
307 a[i] = 0;
308 }
309 }
310
maskcpy(void * va,const void * vb,int masklen,int len)311 void maskcpy(void *va, const void *vb, int masklen, int len) {
312 int i, m;
313 char *a = va;
314 const char *b = vb;
315
316 for(m = masklen, i = 0; m >= 8; m -= 8, i++) {
317 a[i] = b[i];
318 }
319
320 if(m) {
321 a[i] = b[i] & (0x100 - (1 << (8 - m)));
322 i++;
323 }
324
325 for(; i < len; i++) {
326 a[i] = 0;
327 }
328 }
329
maskcheck(const void * va,int masklen,int len)330 bool maskcheck(const void *va, int masklen, int len) {
331 int i;
332 const char *a = va;
333
334 i = masklen / 8;
335 masklen %= 8;
336
337 if(masklen && a[i++] & (0xff >> masklen)) {
338 return false;
339 }
340
341 for(; i < len; i++)
342 if(a[i] != 0) {
343 return false;
344 }
345
346 return true;
347 }
348