xref: /freebsd/sbin/ifconfig/af_inet.c (revision 7ef62cebc2f965b0f640263e179276928885e33d)
1 /*-
2  * SPDX-License-Identifier: BSD-3-Clause
3  *
4  * Copyright (c) 1983, 1993
5  *	The Regents of the University of California.  All rights reserved.
6  *
7  * Redistribution and use in source and binary forms, with or without
8  * modification, are permitted provided that the following conditions
9  * are met:
10  * 1. Redistributions of source code must retain the above copyright
11  *    notice, this list of conditions and the following disclaimer.
12  * 2. Redistributions in binary form must reproduce the above copyright
13  *    notice, this list of conditions and the following disclaimer in the
14  *    documentation and/or other materials provided with the distribution.
15  * 3. Neither the name of the University nor the names of its contributors
16  *    may be used to endorse or promote products derived from this software
17  *    without specific prior written permission.
18  *
19  * THIS SOFTWARE IS PROVIDED BY THE REGENTS AND CONTRIBUTORS ``AS IS'' AND
20  * ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE
21  * IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE
22  * ARE DISCLAIMED.  IN NO EVENT SHALL THE REGENTS OR CONTRIBUTORS BE LIABLE
23  * FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL
24  * DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS
25  * OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION)
26  * HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT
27  * LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY
28  * OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF
29  * SUCH DAMAGE.
30  */
31 
32 #ifndef lint
33 static const char rcsid[] =
34   "$FreeBSD$";
35 #endif /* not lint */
36 
37 #include <sys/param.h>
38 #include <sys/ioctl.h>
39 #include <sys/socket.h>
40 #include <net/if.h>
41 
42 #include <ctype.h>
43 #include <err.h>
44 #include <stdio.h>
45 #include <stdlib.h>
46 #include <string.h>
47 #include <unistd.h>
48 #include <ifaddrs.h>
49 
50 #include <netinet/in.h>
51 #include <netinet/in_var.h>
52 #include <arpa/inet.h>
53 #include <netdb.h>
54 
55 #include "ifconfig.h"
56 #include "ifconfig_netlink.h"
57 
58 #ifdef WITHOUT_NETLINK
59 static struct in_aliasreq in_addreq;
60 static struct ifreq in_ridreq;
61 #else
62 struct in_px {
63 	struct in_addr		addr;
64 	int			plen;
65 	bool			addrset;
66 	bool			maskset;
67 };
68 struct in_pdata {
69 	struct in_px		addr;
70 	struct in_px		dst_addr;
71 	struct in_px		brd_addr;
72 	uint32_t		flags;
73 	uint32_t		vhid;
74 };
75 static struct in_pdata in_add, in_del;
76 #endif
77 
78 static char addr_buf[NI_MAXHOST];	/*for getnameinfo()*/
79 extern char *f_inet, *f_addr;
80 
81 static void
82 print_addr(struct sockaddr_in *sin)
83 {
84 	int error, n_flags;
85 
86 	if (f_addr != NULL && strcmp(f_addr, "fqdn") == 0)
87 		n_flags = 0;
88 	else if (f_addr != NULL && strcmp(f_addr, "host") == 0)
89 		n_flags = NI_NOFQDN;
90 	else
91 		n_flags = NI_NUMERICHOST;
92 
93 	error = getnameinfo((struct sockaddr *)sin, sin->sin_len, addr_buf,
94 			    sizeof(addr_buf), NULL, 0, n_flags);
95 
96 	if (error)
97 		inet_ntop(AF_INET, &sin->sin_addr, addr_buf, sizeof(addr_buf));
98 
99 	printf("\tinet %s", addr_buf);
100 }
101 
102 #ifdef WITHOUT_NETLINK
103 static void
104 in_status(if_ctx *ctx __unused, const struct ifaddrs *ifa)
105 {
106 	struct sockaddr_in *sin, null_sin = {};
107 
108 	sin = satosin(ifa->ifa_addr);
109 	if (sin == NULL)
110 		return;
111 
112 	print_addr(sin);
113 
114 	if (ifa->ifa_flags & IFF_POINTOPOINT) {
115 		sin = satosin(ifa->ifa_dstaddr);
116 		if (sin == NULL)
117 			sin = &null_sin;
118 		printf(" --> %s", inet_ntoa(sin->sin_addr));
119 	}
120 
121 	sin = satosin(ifa->ifa_netmask);
122 	if (sin == NULL)
123 		sin = &null_sin;
124 	if (f_inet != NULL && strcmp(f_inet, "cidr") == 0) {
125 		int cidr = 32;
126 		unsigned long smask;
127 
128 		smask = ntohl(sin->sin_addr.s_addr);
129 		while ((smask & 1) == 0) {
130 			smask = smask >> 1;
131 			cidr--;
132 			if (cidr == 0)
133 				break;
134 		}
135 		printf("/%d", cidr);
136 	} else if (f_inet != NULL && strcmp(f_inet, "dotted") == 0)
137 		printf(" netmask %s", inet_ntoa(sin->sin_addr));
138 	else
139 		printf(" netmask 0x%lx", (unsigned long)ntohl(sin->sin_addr.s_addr));
140 
141 	if (ifa->ifa_flags & IFF_BROADCAST) {
142 		sin = satosin(ifa->ifa_broadaddr);
143 		if (sin != NULL && sin->sin_addr.s_addr != 0)
144 			printf(" broadcast %s", inet_ntoa(sin->sin_addr));
145 	}
146 
147 	print_vhid(ifa);
148 
149 	putchar('\n');
150 }
151 
152 #else
153 static struct in_addr
154 get_mask(int plen)
155 {
156 	struct in_addr a;
157 
158 	a.s_addr = htonl(plen ? ~((1 << (32 - plen)) - 1) : 0);
159 
160 	return (a);
161 }
162 
163 static void
164 in_status_nl(if_ctx *ctx __unused, if_link_t *link, if_addr_t *ifa)
165 {
166 	struct sockaddr_in *sin = satosin(ifa->ifa_local);
167 	int plen = ifa->ifa_prefixlen;
168 
169 	print_addr(sin);
170 
171 	if (link->ifi_flags & IFF_POINTOPOINT) {
172 		struct sockaddr_in *dst = satosin(ifa->ifa_address);
173 
174 		printf(" --> %s", inet_ntoa(dst->sin_addr));
175 	}
176 	if (f_inet != NULL && strcmp(f_inet, "cidr") == 0) {
177 		printf("/%d", plen);
178 	} else if (f_inet != NULL && strcmp(f_inet, "dotted") == 0)
179 		printf(" netmask %s", inet_ntoa(get_mask(plen)));
180 	else
181 		printf(" netmask 0x%lx", (unsigned long)ntohl(get_mask(plen).s_addr));
182 
183 	if ((link->ifi_flags & IFF_BROADCAST) && plen != 0)  {
184 		struct sockaddr_in *brd = satosin(ifa->ifa_broadcast);
185 		if (brd != NULL)
186 			printf(" broadcast %s", inet_ntoa(brd->sin_addr));
187 	}
188 
189 	if (ifa->ifaf_vhid != 0)
190 		printf(" vhid %d", ifa->ifaf_vhid);
191 
192 	putchar('\n');
193 }
194 #endif
195 
196 
197 #ifdef WITHOUT_NETLINK
198 #define SIN(x) ((struct sockaddr_in *) &(x))
199 static struct sockaddr_in *sintab[] = {
200 	SIN(in_ridreq.ifr_addr), SIN(in_addreq.ifra_addr),
201 	SIN(in_addreq.ifra_mask), SIN(in_addreq.ifra_broadaddr)
202 };
203 
204 static void
205 in_copyaddr(if_ctx *ctx __unused, int to, int from)
206 {
207 	memcpy(sintab[to], sintab[from], sizeof(struct sockaddr_in));
208 }
209 
210 static void
211 in_getaddr(const char *s, int which)
212 {
213 	struct sockaddr_in *sin = sintab[which];
214 	struct hostent *hp;
215 	struct netent *np;
216 
217 	sin->sin_len = sizeof(*sin);
218 	sin->sin_family = AF_INET;
219 
220 	if (which == ADDR) {
221 		char *p = NULL;
222 
223 		if((p = strrchr(s, '/')) != NULL) {
224 			const char *errstr;
225 			/* address is `name/masklen' */
226 			int masklen = 0;
227 			struct sockaddr_in *min = sintab[MASK];
228 			*p = '\0';
229 			if (!isdigit(*(p + 1)))
230 				errstr = "invalid";
231 			else
232 				masklen = (int)strtonum(p + 1, 0, 32, &errstr);
233 			if (errstr != NULL) {
234 				*p = '/';
235 				errx(1, "%s: bad value (width %s)", s, errstr);
236 			}
237 			min->sin_family = AF_INET;
238 			min->sin_len = sizeof(*min);
239 			min->sin_addr.s_addr = htonl(~((1LL << (32 - masklen)) - 1) &
240 				              0xffffffff);
241 		}
242 	}
243 
244 	if (inet_aton(s, &sin->sin_addr))
245 		return;
246 	if ((hp = gethostbyname(s)) != NULL)
247 		bcopy(hp->h_addr, (char *)&sin->sin_addr,
248 		    MIN((size_t)hp->h_length, sizeof(sin->sin_addr)));
249 	else if ((np = getnetbyname(s)) != NULL)
250 		sin->sin_addr = inet_makeaddr(np->n_net, INADDR_ANY);
251 	else
252 		errx(1, "%s: bad value", s);
253 }
254 
255 #else
256 
257 static struct in_px *sintab_nl[] = {
258 	&in_del.addr,		/* RIDADDR */
259 	&in_add.addr,		/* ADDR */
260 	NULL,			/* MASK */
261 	&in_add.dst_addr,	/* DSTADDR*/
262 	&in_add.brd_addr,	/* BRDADDR*/
263 };
264 
265 static void
266 in_copyaddr(if_ctx *ctx __unused, int to, int from)
267 {
268 	sintab_nl[to]->addr = sintab_nl[from]->addr;
269 	sintab_nl[to]->addrset = sintab_nl[from]->addrset;
270 }
271 
272 static void
273 in_getip(const char *addr_str, struct in_addr *ip)
274 {
275 	struct hostent *hp;
276 	struct netent *np;
277 
278 	if (inet_aton(addr_str, ip))
279 		return;
280 	if ((hp = gethostbyname(addr_str)) != NULL)
281 		bcopy(hp->h_addr, (char *)ip,
282 		    MIN((size_t)hp->h_length, sizeof(ip)));
283 	else if ((np = getnetbyname(addr_str)) != NULL)
284 		*ip = inet_makeaddr(np->n_net, INADDR_ANY);
285 	else
286 		errx(1, "%s: bad value", addr_str);
287 }
288 
289 static void
290 in_getaddr(const char *s, int which)
291 {
292         struct in_px *px = sintab_nl[which];
293 
294 	if (which == MASK) {
295 		struct in_px *px_addr = sintab_nl[ADDR];
296 		struct in_addr mask = {};
297 
298 		in_getip(s, &mask);
299 		px_addr->plen = __bitcount32(mask.s_addr);
300 		px_addr->maskset = true;
301 		return;
302 	}
303 
304 	if (which == ADDR) {
305 		char *p = NULL;
306 
307 		if((p = strrchr(s, '/')) != NULL) {
308 			const char *errstr;
309 			/* address is `name/masklen' */
310 			int masklen;
311 			*p = '\0';
312 			if (!isdigit(*(p + 1)))
313 				errstr = "invalid";
314 			else
315 				masklen = (int)strtonum(p + 1, 0, 32, &errstr);
316 			if (errstr != NULL) {
317 				*p = '/';
318 				errx(1, "%s: bad value (width %s)", s, errstr);
319 			}
320 			px->plen = masklen;
321 			px->maskset = true;
322 		}
323 	}
324 
325 	in_getip(s, &px->addr);
326 	px->addrset = true;
327 }
328 
329 /*
330  * Deletes the first found IPv4 interface address for the interface.
331  *
332  * This function provides SIOCDIFADDR semantics missing in Netlink.
333  * When no valid IPv4 address is specified (sin_family or sin_len is wrong) to
334  * the SIOCDIFADDR call, it deletes the first found IPv4 address on the interface.
335  * 'ifconfig IFNAME inet addr/prefix' relies on that behavior, as it
336  *  executes empty SIOCDIFADDR before adding a new address.
337  */
338 static int
339 in_delete_first_nl(if_ctx *ctx)
340 {
341 	struct nlmsghdr *hdr;
342 	struct ifaddrmsg *ifahdr;
343 	uint32_t nlmsg_seq;
344 	struct in_addr addr;
345 	struct snl_writer nw = {};
346 	struct snl_errmsg_data e = {};
347 	struct snl_state *ss = ctx->io_ss;
348 	bool found = false;
349 
350 	uint32_t ifindex = if_nametoindex_nl(ss, ctx->ifname);
351 	if (ifindex == 0) {
352 		/* No interface with the desired name, nothing to delete */
353 		return (EADDRNOTAVAIL);
354 	}
355 
356 	snl_init_writer(ss, &nw);
357 	hdr = snl_create_msg_request(&nw, NL_RTM_GETADDR);
358 	hdr->nlmsg_flags |= NLM_F_DUMP;
359 	ifahdr = snl_reserve_msg_object(&nw, struct ifaddrmsg);
360 	ifahdr->ifa_family = AF_INET;
361 	ifahdr->ifa_index = ifindex;
362 
363 	if (!snl_finalize_msg(&nw) || !snl_send_message(ss, hdr))
364 		return (EINVAL);
365 
366 	nlmsg_seq = hdr->nlmsg_seq;
367 	while ((hdr = snl_read_reply_multi(ss, nlmsg_seq, &e)) != NULL) {
368 		struct snl_parsed_addr attrs = {};
369 		if (snl_parse_nlmsg(ss, hdr, &snl_rtm_addr_parser, &attrs)) {
370 			addr = satosin(attrs.ifa_local)->sin_addr;
371 			ifindex = attrs.ifa_index;
372 			found = true;
373 			break;
374 		} else
375 			return (EINVAL);
376 	}
377 	if (e.error != 0) {
378 		if (e.error_str != NULL)
379 			warnx("%s(): %s", __func__, e.error_str);
380 		return (e.error);
381 	}
382 
383 	if (!found)
384 		return (0);
385 
386 	/* Try to delete the found address */
387 	snl_init_writer(ss, &nw);
388 	hdr = snl_create_msg_request(&nw, NL_RTM_DELADDR);
389 	ifahdr = snl_reserve_msg_object(&nw, struct ifaddrmsg);
390 	ifahdr->ifa_family = AF_INET;
391 	ifahdr->ifa_index = ifindex;
392 	snl_add_msg_attr_ip4(&nw, IFA_LOCAL, &addr);
393 
394 	if (!snl_finalize_msg(&nw) || !snl_send_message(ss, hdr))
395 		return (EINVAL);
396 	memset(&e, 0, sizeof(e));
397 	snl_read_reply_code(ss, hdr->nlmsg_seq, &e);
398 	if (e.error_str != NULL)
399 		warnx("%s(): %s", __func__, e.error_str);
400 
401 	return (e.error);
402 }
403 
404 
405 static int
406 in_exec_nl(if_ctx *ctx, unsigned long action, void *data)
407 {
408 	struct in_pdata *pdata = (struct in_pdata *)data;
409 	struct snl_writer nw = {};
410 
411 	if (action == NL_RTM_DELADDR && !pdata->addr.addrset)
412 		return (in_delete_first_nl(ctx));
413 
414 	snl_init_writer(ctx->io_ss, &nw);
415 	struct nlmsghdr *hdr = snl_create_msg_request(&nw, action);
416 	struct ifaddrmsg *ifahdr = snl_reserve_msg_object(&nw, struct ifaddrmsg);
417 
418 	ifahdr->ifa_family = AF_INET;
419 	ifahdr->ifa_prefixlen = pdata->addr.plen;
420 	ifahdr->ifa_index = if_nametoindex_nl(ctx->io_ss, ctx->ifname);
421 
422 	snl_add_msg_attr_ip4(&nw, IFA_LOCAL, &pdata->addr.addr);
423 	if (action == NL_RTM_NEWADDR && pdata->dst_addr.addrset)
424 		snl_add_msg_attr_ip4(&nw, IFA_ADDRESS, &pdata->dst_addr.addr);
425 	if (action == NL_RTM_NEWADDR && pdata->brd_addr.addrset)
426 		snl_add_msg_attr_ip4(&nw, IFA_BROADCAST, &pdata->brd_addr.addr);
427 
428 	int off = snl_add_msg_attr_nested(&nw, IFA_FREEBSD);
429 	snl_add_msg_attr_u32(&nw, IFAF_FLAGS, pdata->flags);
430 	if (pdata->vhid != 0)
431 		snl_add_msg_attr_u32(&nw, IFAF_VHID, pdata->vhid);
432 	snl_end_attr_nested(&nw, off);
433 
434 	if (!snl_finalize_msg(&nw) || !snl_send_message(ctx->io_ss, hdr))
435 		return (0);
436 
437 	struct snl_errmsg_data e = {};
438 	snl_read_reply_code(ctx->io_ss, hdr->nlmsg_seq, &e);
439 	if (e.error_str != NULL)
440 		warnx("%s(): %s", __func__, e.error_str);
441 
442 	return (e.error);
443 }
444 
445 static void
446 in_setdefaultmask_nl(void)
447 {
448         struct in_px *px = sintab_nl[ADDR];
449 
450 	in_addr_t i = ntohl(px->addr.s_addr);
451 
452 	/*
453 	 * If netmask isn't supplied, use historical default.
454 	 * This is deprecated for interfaces other than loopback
455 	 * or point-to-point; warn in other cases.  In the future
456 	 * we should return an error rather than warning.
457 	 */
458 	if (IN_CLASSA(i))
459 		px->plen = IN_CLASSA_NSHIFT;
460 	else if (IN_CLASSB(i))
461 		px->plen = IN_CLASSB_NSHIFT;
462 	else
463 		px->plen = IN_CLASSC_NSHIFT;
464 	px->maskset = true;
465 }
466 #endif
467 
468 static void
469 warn_nomask(int ifflags)
470 {
471     if ((ifflags & (IFF_POINTOPOINT | IFF_LOOPBACK)) == 0) {
472 	warnx("WARNING: setting interface address without mask "
473 	    "is deprecated,\ndefault mask may not be correct.");
474     }
475 }
476 
477 static void
478 in_postproc(if_ctx *ctx __unused, int newaddr, int ifflags)
479 {
480 #ifdef WITHOUT_NETLINK
481 	if (sintab[ADDR]->sin_len != 0 && sintab[MASK]->sin_len == 0 && newaddr) {
482 		warn_nomask(ifflags);
483 	}
484 #else
485 	if (sintab_nl[ADDR]->addrset && !sintab_nl[ADDR]->maskset && newaddr) {
486 		warn_nomask(ifflags);
487 	    in_setdefaultmask_nl();
488 	}
489 #endif
490 }
491 
492 static void
493 in_status_tunnel(if_ctx *ctx)
494 {
495 	char src[NI_MAXHOST];
496 	char dst[NI_MAXHOST];
497 	struct ifreq ifr;
498 	const struct sockaddr *sa = (const struct sockaddr *) &ifr.ifr_addr;
499 
500 	memset(&ifr, 0, sizeof(ifr));
501 	strlcpy(ifr.ifr_name, ctx->ifname, IFNAMSIZ);
502 
503 	if (ioctl_ctx(ctx, SIOCGIFPSRCADDR, (caddr_t)&ifr) < 0)
504 		return;
505 	if (sa->sa_family != AF_INET)
506 		return;
507 	if (getnameinfo(sa, sa->sa_len, src, sizeof(src), 0, 0, NI_NUMERICHOST) != 0)
508 		src[0] = '\0';
509 
510 	if (ioctl_ctx(ctx, SIOCGIFPDSTADDR, (caddr_t)&ifr) < 0)
511 		return;
512 	if (sa->sa_family != AF_INET)
513 		return;
514 	if (getnameinfo(sa, sa->sa_len, dst, sizeof(dst), 0, 0, NI_NUMERICHOST) != 0)
515 		dst[0] = '\0';
516 
517 	printf("\ttunnel inet %s --> %s\n", src, dst);
518 }
519 
520 static void
521 in_set_tunnel(if_ctx *ctx, struct addrinfo *srcres, struct addrinfo *dstres)
522 {
523 	struct in_aliasreq addreq;
524 
525 	memset(&addreq, 0, sizeof(addreq));
526 	strlcpy(addreq.ifra_name, ctx->ifname, IFNAMSIZ);
527 	memcpy(&addreq.ifra_addr, srcres->ai_addr, srcres->ai_addr->sa_len);
528 	memcpy(&addreq.ifra_dstaddr, dstres->ai_addr, dstres->ai_addr->sa_len);
529 
530 	if (ioctl_ctx(ctx, SIOCSIFPHYADDR, &addreq) < 0)
531 		warn("SIOCSIFPHYADDR");
532 }
533 
534 static void
535 in_set_vhid(int vhid)
536 {
537 #ifdef WITHOUT_NETLINK
538 	in_addreq.ifra_vhid = vhid;
539 #else
540 	in_add.vhid = (uint32_t)vhid;
541 #endif
542 }
543 
544 static struct afswtch af_inet = {
545 	.af_name	= "inet",
546 	.af_af		= AF_INET,
547 #ifdef WITHOUT_NETLINK
548 	.af_status	= in_status,
549 #else
550 	.af_status	= in_status_nl,
551 #endif
552 	.af_getaddr	= in_getaddr,
553 	.af_copyaddr	= in_copyaddr,
554 	.af_postproc	= in_postproc,
555 	.af_status_tunnel = in_status_tunnel,
556 	.af_settunnel	= in_set_tunnel,
557 	.af_setvhid	= in_set_vhid,
558 #ifdef WITHOUT_NETLINK
559 	.af_difaddr	= SIOCDIFADDR,
560 	.af_aifaddr	= SIOCAIFADDR,
561 	.af_ridreq	= &in_ridreq,
562 	.af_addreq	= &in_addreq,
563 	.af_exec	= af_exec_ioctl,
564 #else
565 	.af_difaddr	= NL_RTM_DELADDR,
566 	.af_aifaddr	= NL_RTM_NEWADDR,
567 	.af_ridreq	= &in_del,
568 	.af_addreq	= &in_add,
569 	.af_exec	= in_exec_nl,
570 #endif
571 };
572 
573 static __constructor void
574 inet_ctor(void)
575 {
576 
577 #ifndef RESCUE
578 	if (!feature_present("inet"))
579 		return;
580 #endif
581 	af_register(&af_inet);
582 }
583