1 /* $NetBSD: wire.c,v 1.1.1.3 2015/01/17 16:34:18 christos Exp $ */
2
3 /*
4 * Copyright (c) 1997-2014 Erez Zadok
5 * Copyright (c) 1990 Jan-Simon Pendry
6 * Copyright (c) 1990 Imperial College of Science, Technology & Medicine
7 * Copyright (c) 1990 The Regents of the University of California.
8 * All rights reserved.
9 *
10 * This code is derived from software contributed to Berkeley by
11 * Jan-Simon Pendry at Imperial College, London.
12 *
13 * Redistribution and use in source and binary forms, with or without
14 * modification, are permitted provided that the following conditions
15 * are met:
16 * 1. Redistributions of source code must retain the above copyright
17 * notice, this list of conditions and the following disclaimer.
18 * 2. Redistributions in binary form must reproduce the above copyright
19 * notice, this list of conditions and the following disclaimer in the
20 * documentation and/or other materials provided with the distribution.
21 * 3. Neither the name of the University nor the names of its contributors
22 * may be used to endorse or promote products derived from this software
23 * without specific prior written permission.
24 *
25 * THIS SOFTWARE IS PROVIDED BY THE REGENTS AND CONTRIBUTORS ``AS IS'' AND
26 * ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE
27 * IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE
28 * ARE DISCLAIMED. IN NO EVENT SHALL THE REGENTS OR CONTRIBUTORS BE LIABLE
29 * FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL
30 * DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS
31 * OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION)
32 * HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT
33 * LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY
34 * OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF
35 * SUCH DAMAGE.
36 *
37 *
38 * File: am-utils/libamu/wire.c
39 *
40 */
41
42 /*
43 * This function returns the subnet (address&netmask) for the primary network
44 * interface. If the resulting address has an entry in the hosts file, the
45 * corresponding name is returned, otherwise the address is returned in
46 * standard internet format.
47 * As a side-effect, a list of local IP/net address is recorded for use
48 * by the islocalnet() function.
49 *
50 * Derived from original by Paul Anderson (23/4/90)
51 * Updates from Dirk Grunwald (11/11/91)
52 */
53
54 #ifdef HAVE_CONFIG_H
55 # include <config.h>
56 #endif /* HAVE_CONFIG_H */
57 #include <am_defs.h>
58 #include <amu.h>
59
60
61 #ifdef HAVE_IFADDRS_H
62 #include <ifaddrs.h>
63 #endif /* HAVE_IFADDRS_H */
64
65 #ifdef HAVE_IRS_H
66 # include <irs.h>
67 #endif /* HAVE_IRS_H */
68
69 /*
70 * List of locally connected networks
71 */
72 typedef struct addrlist addrlist;
73 struct addrlist {
74 addrlist *ip_next;
75 u_long ip_addr; /* address of network */
76 u_long ip_mask;
77 char *ip_net_num; /* number of network */
78 char *ip_net_name; /* name of network */
79 };
80 static addrlist *localnets = NULL;
81
82 #if defined(IFF_LOCAL_LOOPBACK) && !defined(IFF_LOOPBACK)
83 # define IFF_LOOPBACK IFF_LOCAL_LOOPBACK
84 #endif /* defined(IFF_LOCAL_LOOPBACK) && !defined(IFF_LOOPBACK) */
85
86 #define C(x) ((x) & 0xff)
87 #define GFBUFLEN 1024
88 #define S2IN(s) (((struct sockaddr_in *)(s))->sin_addr.s_addr)
89
90
91 /* return malloc'ed buffer. caller must free it */
92 char *
print_wires(void)93 print_wires(void)
94 {
95 addrlist *al;
96 char s[256];
97 int i;
98 char *buf;
99 int bufcount = 0;
100 int buf_size = 1024;
101
102 buf = SALLOC(buf_size); /* initial allocation (may grow!) */
103 if (!buf)
104 return NULL;
105
106 if (!localnets) {
107 xstrlcpy(buf, "No networks\n", buf_size);
108 return buf;
109 }
110 /* check if there's more than one network */
111 if (!localnets->ip_next) {
112 /* use buf_size for sizeof(buf) because of the realloc() below */
113 xsnprintf(buf, buf_size,
114 "Network: wire=\"%s\" (netnumber=%s).\n",
115 localnets->ip_net_name, localnets->ip_net_num);
116 return buf;
117 }
118 buf[0] = '\0'; /* null out buffer before appending */
119 for (i = 1, al = localnets; al; al = al->ip_next, i++) {
120 xsnprintf(s, sizeof(s), "Network %d: wire=\"%s\" (netnumber=%s).\n",
121 i, al->ip_net_name, al->ip_net_num);
122 bufcount += strlen(s);
123 if (bufcount > buf_size) {
124 buf_size *= 2;
125 buf = xrealloc(buf, buf_size);
126 }
127 xstrlcat(buf, s, buf_size);
128 }
129 return buf;
130 }
131
132
133 static struct addrlist *
getwire_lookup(u_long address,u_long netmask,int ishost)134 getwire_lookup(u_long address, u_long netmask, int ishost)
135 {
136 struct addrlist *al;
137 u_long subnet;
138 char netNumberBuf[64];
139 char buf[GFBUFLEN], *s;
140 #ifdef HAVE_IRS_H
141 struct nwent *np;
142 #else /* not HAVE_IRS_H */
143 struct netent *np;
144 #endif /* not HAVE_IRS_H */
145
146 /*
147 * Add interface to local network singly linked list
148 */
149 al = ALLOC(struct addrlist);
150 al->ip_addr = address;
151 al->ip_mask = netmask;
152 al->ip_net_name = NO_SUBNET; /* fill in a bit later */
153 al->ip_net_num = "0.0.0.0"; /* fill in a bit later */
154 al->ip_next = NULL;
155
156 subnet = ntohl(address) & ntohl(netmask);
157
158 if (ishost)
159 np = NULL;
160 else {
161 #ifdef HAVE_IRS_H
162 u_long mask = ntohl(netmask);
163 static struct irs_acc *irs_gen;
164 static struct irs_nw *irs_nw;
165 u_long net;
166 int maskbits;
167 u_char addr[4];
168
169 if (irs_gen == NULL)
170 #ifdef irs_irp_acc
171 /*
172 * bsdi4 added another argument to this function, without changing
173 * its name. The irs_irp_acc is the one (hacky) distinguishing
174 * feature found in <irs.h> that can differentiate between bsdi3 and
175 * bsdi4.
176 */
177 irs_gen = irs_gen_acc("", NULL);
178 #else /* not irs_irp_acc */
179 irs_gen = irs_gen_acc("");
180 #endif /* not irs_irp_acc */
181 if (irs_gen && irs_nw == NULL)
182 irs_nw = (*irs_gen->nw_map)(irs_gen);
183 net = ntohl(address) & (mask = ntohl(netmask));
184 addr[0] = (0xFF000000 & net) >> 24;
185 addr[1] = (0x00FF0000 & net) >> 16;
186 addr[2] = (0x0000FF00 & net) >> 8;
187 addr[3] = (0x000000FF & net);
188 for (maskbits = 32; !(mask & 1); mask >>= 1)
189 maskbits--;
190 np = (*irs_nw->byaddr)(irs_nw, addr, maskbits, AF_INET);
191 #else /* not HAVE_IRS_H */
192 np = getnetbyaddr(subnet, AF_INET);
193 /*
194 * Some systems (IRIX 6.4) cannot getnetbyaddr on networks such as
195 * "128.59.16.0". Instead, they need to look for the short form of
196 * the network, "128.59.16". So if the first getnetbyaddr failed, we
197 * shift the subnet way from zeros and try again.
198 */
199 if (!np) {
200 u_long short_subnet = subnet;
201 while (short_subnet && (short_subnet & 0x000000ff) == 0)
202 short_subnet >>= 8;
203 np = getnetbyaddr(short_subnet, AF_INET);
204 if (np)
205 plog(XLOG_WARNING, "getnetbyaddr failed on 0x%x, succeeded on 0x%x",
206 (u_int) subnet, (u_int) short_subnet);
207 }
208 #endif /* not HAVE_IRS_H */
209 }
210
211 if ((subnet & 0xffffff) == 0) {
212 xsnprintf(netNumberBuf, sizeof(netNumberBuf), "%lu", C(subnet >> 24));
213 } else if ((subnet & 0xffff) == 0) {
214 xsnprintf(netNumberBuf, sizeof(netNumberBuf), "%lu.%lu",
215 C(subnet >> 24), C(subnet >> 16));
216 } else if ((subnet & 0xff) == 0) {
217 xsnprintf(netNumberBuf, sizeof(netNumberBuf), "%lu.%lu.%lu",
218 C(subnet >> 24), C(subnet >> 16),
219 C(subnet >> 8));
220 } else {
221 xsnprintf(netNumberBuf, sizeof(netNumberBuf), "%lu.%lu.%lu.%lu",
222 C(subnet >> 24), C(subnet >> 16),
223 C(subnet >> 8), C(subnet));
224 }
225
226 /* fill in network number (string) */
227 al->ip_net_num = xstrdup(netNumberBuf);
228
229 if (np != NULL)
230 s = np->n_name;
231 else {
232 struct hostent *hp;
233
234 subnet = address & netmask;
235 hp = gethostbyaddr((char *) &subnet, 4, AF_INET);
236 if (hp != NULL)
237 s = (char *) hp->h_name;
238 else
239 s = inet_dquad(buf, sizeof(buf), subnet);
240 }
241
242 /* fill in network name (string) */
243 al->ip_net_name = xstrdup(s);
244 /* Let's be cautious here about buffer overflows -Ion */
245 if (strlen(s) > MAXHOSTNAMELEN) {
246 al->ip_net_name[MAXHOSTNAMELEN] = '\0';
247 plog(XLOG_WARNING, "Long hostname %s truncated to %d characters",
248 s, MAXHOSTNAMELEN);
249 }
250
251 return (al);
252 }
253
254
255 /*
256 * Make a dotted quad from a 32bit IP address
257 * addr is in network byte order.
258 * sizeof(buf) needs to be at least 16.
259 */
260 char *
inet_dquad(char * buf,size_t l,u_long addr)261 inet_dquad(char *buf, size_t l, u_long addr)
262 {
263 addr = ntohl(addr);
264 xsnprintf(buf, l, "%ld.%ld.%ld.%ld",
265 ((addr >> 24) & 0xff),
266 ((addr >> 16) & 0xff),
267 ((addr >> 8) & 0xff),
268 ((addr >> 0) & 0xff));
269 return buf;
270 }
271
272
273 /*
274 * Determine whether a network is on a local network
275 * (addr) is in network byte order.
276 */
277 int
islocalnet(u_long addr)278 islocalnet(u_long addr)
279 {
280 addrlist *al;
281
282 for (al = localnets; al; al = al->ip_next)
283 if (((addr ^ al->ip_addr) & al->ip_mask) == 0)
284 return TRUE;
285
286 #ifdef DEBUG
287 {
288 char buf[16];
289 plog(XLOG_INFO, "%s is on a remote network",
290 inet_dquad(buf, sizeof(buf), addr));
291 }
292 #endif /* DEBUG */
293
294 return FALSE;
295 }
296
297
298 /*
299 * Determine whether a network name is one of the local networks
300 * of a host.
301 */
302 int
is_network_member(const char * net)303 is_network_member(const char *net)
304 {
305 addrlist *al;
306
307 /*
308 * If the network name string does not contain a '/', use old behavior.
309 * If it does contain a '/' then interpret the string as a network/netmask
310 * pair. If "netmask" doesn't exist, use the interface's own netmask.
311 * Also support fully explicit netmasks such as 255.255.255.0 as well as
312 * bit-length netmask such as /24 (hex formats such 0xffffff00 work too).
313 */
314 if (strchr(net, '/') == NULL) {
315 for (al = localnets; al; al = al->ip_next)
316 if (STREQ(net, al->ip_net_name) || STREQ(net, al->ip_net_num))
317 return TRUE;
318 } else {
319 char *netstr = xstrdup(net), *maskstr;
320 u_long netnum, masknum = 0;
321 maskstr = strchr(netstr, '/');
322 if (maskstr == NULL) {
323 plog(XLOG_ERROR, "%s: netstr %s does not have a `/'", __func__, netstr);
324 XFREE(netstr);
325 return FALSE;
326 }
327 maskstr[0] = '\0'; /* null terminate netstr */
328 maskstr++;
329 if (*maskstr == '\0') /* if empty string, make it NULL */
330 maskstr = NULL;
331 /* check if netmask uses a dotted-quad or bit-length, or not defined at all */
332 if (maskstr) {
333 if (strchr(maskstr, '.')) {
334 /* XXX: inet_addr is obsolste, convert to inet_aton() */
335 masknum = inet_addr(maskstr);
336 if (masknum == INADDR_NONE) /* can be invalid (-1) or all-1s */
337 masknum = 0xffffffff;
338 } else if (NSTRCEQ(maskstr, "0x", 2)) {
339 masknum = strtoul(maskstr, NULL, 16);
340 } else {
341 int bits = atoi(maskstr);
342 if (bits < 0)
343 bits = 0;
344 if (bits > 32)
345 bits = 32;
346 masknum = 0xffffffff << (32-bits);
347 }
348 }
349 netnum = inet_addr(netstr); /* not checking return value, b/c -1 (0xffffffff) is valid */
350 XFREE(netstr); /* netstr not needed any longer */
351
352 /* now check against each local interface */
353 for (al = localnets; al; al = al->ip_next) {
354 if ((al->ip_addr & (maskstr ? masknum : al->ip_mask)) == netnum)
355 return TRUE;
356 }
357 }
358
359 return FALSE;
360 }
361
362
363 /*
364 * Determine whether a IP address (netnum) is one of the local interfaces,
365 * returns TRUE/FALSE.
366 * Does not include the loopback interface: caller needs to check that.
367 */
368 int
is_interface_local(u_long netnum)369 is_interface_local(u_long netnum)
370 {
371 addrlist *al;
372
373 for (al = localnets; al; al = al->ip_next) {
374 if (al->ip_addr == netnum)
375 return TRUE;
376 }
377 return FALSE;
378 }
379
380
381 #ifdef HAVE_GETIFADDRS
382 void
getwire(char ** name1,char ** number1)383 getwire(char **name1, char **number1)
384 {
385 addrlist *al = NULL, *tail = NULL;
386 struct ifaddrs *ifaddrs, *ifap;
387 #ifndef HAVE_STRUCT_IFADDRS_IFA_NEXT
388 int count = 0, i;
389 #endif /* not HAVE_STRUCT_IFADDRS_IFA_NEXT */
390
391 ifaddrs = NULL;
392 #ifdef HAVE_STRUCT_IFADDRS_IFA_NEXT
393 if (getifaddrs(&ifaddrs) < 0)
394 goto out;
395
396 for (ifap = ifaddrs; ifap != NULL; ifap = ifap->ifa_next) {
397 #else /* not HAVE_STRUCT_IFADDRS_IFA_NEXT */
398 if (getifaddrs(&ifaddrs, &count) < 0)
399 goto out;
400
401 for (i = 0,ifap = ifaddrs; i < count; ifap++, i++) {
402 #endif /* HAVE_STRUCT_IFADDRS_IFA_NEXT */
403
404 if (!ifap || !ifap->ifa_addr || ifap->ifa_addr->sa_family != AF_INET)
405 continue;
406
407 /*
408 * If the interface is the loopback, or it's not running,
409 * then ignore it.
410 */
411 if (S2IN(ifap->ifa_addr) == htonl(INADDR_LOOPBACK))
412 continue;
413 if ((ifap->ifa_flags & IFF_RUNNING) == 0)
414 continue;
415
416 if ((ifap->ifa_flags & IFF_POINTOPOINT) == 0)
417 al = getwire_lookup(S2IN(ifap->ifa_addr), S2IN(ifap->ifa_netmask), 0);
418 else
419 al = getwire_lookup(S2IN(ifap->ifa_dstaddr), 0xffffffff, 1);
420
421 /* append to the end of the list */
422 if (!localnets || tail == NULL) {
423 localnets = tail = al;
424 tail->ip_next = NULL;
425 } else {
426 tail->ip_next = al;
427 tail = al;
428 }
429 }
430
431 out:
432 if (ifaddrs)
433 XFREE(ifaddrs);
434
435 if (localnets) {
436 *name1 = localnets->ip_net_name;
437 *number1 = localnets->ip_net_num;
438 } else {
439 *name1 = NO_SUBNET;
440 *number1 = "0.0.0.0";
441 }
442 }
443
444 #else /* not HAVE_GETIFADDRS */
445
446 #if defined(HAVE_STRUCT_IFREQ_IFR_ADDR) && defined(HAVE_STRUCT_SOCKADDR_SA_LEN)
447 # define SIZE(ifr) (MAX((ifr)->ifr_addr.sa_len, sizeof((ifr)->ifr_addr)) + sizeof(ifr->ifr_name))
448 #else /* not defined(HAVE_STRUCT_IFREQ_IFR_ADDR) && defined(HAVE_STRUCT_SOCKADDR_SA_LEN) */
449 # define SIZE(ifr) sizeof(struct ifreq)
450 #endif /* not defined(HAVE_STRUCT_IFREQ_IFR_ADDR) && defined(HAVE_STRUCT_SOCKADDR_SA_LEN) */
451
452 #define clist (ifc.ifc_ifcu.ifcu_req)
453 #define count (ifc.ifc_len/sizeof(struct ifreq))
454
455
456 void
457 getwire(char **name1, char **number1)
458 {
459 struct ifconf ifc;
460 struct ifreq *ifr, ifrpool;
461 caddr_t cp, cplim;
462 int fd = -1;
463 u_long address;
464 addrlist *al = NULL, *tail = NULL;
465 char buf[GFBUFLEN];
466
467 #ifndef SIOCGIFFLAGS
468 /* if cannot get interface flags, return nothing */
469 plog(XLOG_ERROR, "getwire unable to get interface flags");
470 localnets = NULL;
471 return;
472 #endif /* not SIOCGIFFLAGS */
473
474 /*
475 * Get suitable socket
476 */
477 if ((fd = socket(AF_INET, SOCK_DGRAM, 0)) < 0)
478 goto out;
479
480 /*
481 * Fill in ifconf details
482 */
483 memset(&buf[0], 0, GFBUFLEN);
484 ifc.ifc_len = sizeof(buf);
485 ifc.ifc_buf = buf;
486
487 /*
488 * Get network interface configurations
489 */
490 if (ioctl(fd, SIOCGIFCONF, (caddr_t) & ifc) < 0)
491 goto out;
492
493 /*
494 * Upper bound on array
495 */
496 cplim = buf + ifc.ifc_len;
497
498 /*
499 * This is some magic to cope with both "traditional" and the
500 * new 4.4BSD-style struct sockaddrs. The new structure has
501 * variable length and a size field to support longer addresses.
502 * AF_LINK is a new definition for 4.4BSD.
503 */
504
505 /*
506 * Scan the list looking for a suitable interface
507 */
508 for (cp = buf; cp < cplim; /* increment in the loop body */) {
509 memcpy(&ifrpool, cp, sizeof(ifrpool));
510 ifr = &ifrpool;
511 cp += SIZE(ifr);
512
513 if (ifr->ifr_addr.sa_family != AF_INET)
514 continue;
515
516 address = ((struct sockaddr_in *) &ifr->ifr_addr)->sin_addr.s_addr;
517
518 /*
519 * Get interface flags
520 */
521 if (ioctl(fd, SIOCGIFFLAGS, (caddr_t) ifr) < 0)
522 continue;
523
524 /*
525 * If the interface is the loopback, or it's not running,
526 * then ignore it.
527 */
528 if (address == htonl(INADDR_LOOPBACK))
529 continue;
530 /*
531 * Fix for 0.0.0.0 loopback on SunOS 3.X which defines IFF_ROUTE
532 * instead of IFF_LOOPBACK.
533 */
534 #ifdef IFF_ROUTE
535 if (ifr->ifr_flags == (IFF_UP|IFF_RUNNING))
536 continue;
537 #endif /* IFF_ROUTE */
538
539 /* if the interface is not UP or not RUNNING, skip it */
540 if ((ifr->ifr_flags & IFF_RUNNING) == 0 ||
541 (ifr->ifr_flags & IFF_UP) == 0)
542 continue;
543
544 if ((ifr->ifr_flags & IFF_POINTOPOINT) == 0) {
545 /*
546 * Get the netmask of this interface
547 */
548 if (ioctl(fd, SIOCGIFNETMASK, (caddr_t) ifr) < 0)
549 continue;
550
551 al = getwire_lookup(address, S2IN(&ifr->ifr_addr), 0);
552 } else
553 al = getwire_lookup(address, 0xffffffff, 1);
554
555 /* append to the end of the list */
556 if (!localnets) {
557 localnets = tail = al;
558 tail->ip_next = NULL;
559 } else {
560 tail->ip_next = al;
561 tail = al;
562 }
563 }
564
565 out:
566 if (fd >= 0)
567 close(fd);
568 if (localnets) {
569 *name1 = localnets->ip_net_name;
570 *number1 = localnets->ip_net_num;
571 } else {
572 *name1 = NO_SUBNET;
573 *number1 = "0.0.0.0";
574 }
575 }
576 #endif /* not HAVE_GETIFADDRS */
577