xref: /freebsd/sbin/ifconfig/ifconfig_netlink.c (revision 95eb4b873b6a8b527c5bd78d7191975dfca38998) 
1 /*-
2  * SPDX-License-Identifier: BSD-2-Clause-FreeBSD
3  *
4  * Copyright (c) 2022 Alexander V. Chernikov <melifaro@FreeBSD.org>
5  *
6  * Redistribution and use in source and binary forms, with or without
7  * modification, are permitted provided that the following conditions
8  * are met:
9  * 1. Redistributions of source code must retain the above copyright
10  *    notice, this list of conditions and the following disclaimer.
11  * 2. Redistributions in binary form must reproduce the above copyright
12  *    notice, this list of conditions and the following disclaimer in the
13  *    documentation and/or other materials provided with the distribution.
14  *
15  * THIS SOFTWARE IS PROVIDED BY THE AUTHOR AND CONTRIBUTORS ``AS IS'' AND
16  * ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE
17  * IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE
18  * ARE DISCLAIMED. IN NO EVENT SHALL THE AUTHOR OR CONTRIBUTORS BE LIABLE
19  * FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL
20  * DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS
21  * OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION)
22  * HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT
23  * LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY
24  * OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF
25  * SUCH DAMAGE.
26  */
27 
28 #include <stdio.h>
29 #include <stdlib.h>
30 #include <string.h>
31 #include <stdbool.h>
32 #include <err.h>
33 #include <errno.h>
34 #include <netdb.h>
35 
36 #include <sys/bitcount.h>
37 #include <sys/param.h>
38 #include <sys/linker.h>
39 #include <sys/module.h>
40 #include <sys/socket.h>
41 #include <sys/sysctl.h>
42 #include <sys/time.h>
43 #include <sys/types.h>
44 
45 #include <netinet/in.h>
46 #include <arpa/inet.h>
47 
48 #include <net/ethernet.h>
49 #include <net/if.h>
50 #include <net/if_dl.h>
51 #include <net/if_strings.h>
52 #include <net/if_types.h>
53 #include "ifconfig.h"
54 #include "ifconfig_netlink.h"
55 
56 static const char	*IFFBITS[] = {
57 	"UP",			/* 00:0x1 IFF_UP*/
58 	"BROADCAST",		/* 01:0x2 IFF_BROADCAST*/
59 	"DEBUG",		/* 02:0x4 IFF_DEBUG*/
60 	"LOOPBACK",		/* 03:0x8 IFF_LOOPBACK*/
61 	"POINTOPOINT",		/* 04:0x10 IFF_POINTOPOINT*/
62 	"NEEDSEPOCH",		/* 05:0x20 IFF_NEEDSEPOCH*/
63 	"RUNNING",		/* 06:0x40 IFF_DRV_RUNNING*/
64 	"NOARP",		/* 07:0x80 IFF_NOARP*/
65 	"PROMISC",		/* 08:0x100 IFF_PROMISC*/
66 	"ALLMULTI",		/* 09:0x200 IFF_ALLMULTI*/
67 	"DRV_OACTIVE",		/* 10:0x400 IFF_DRV_OACTIVE*/
68 	"SIMPLEX",		/* 11:0x800 IFF_SIMPLEX*/
69 	"LINK0",		/* 12:0x1000 IFF_LINK0*/
70 	"LINK1",		/* 13:0x2000 IFF_LINK1*/
71 	"LINK2",		/* 14:0x4000 IFF_LINK2*/
72 	"MULTICAST",		/* 15:0x8000 IFF_MULTICAST*/
73 	"CANTCONFIG",		/* 16:0x10000 IFF_CANTCONFIG*/
74 	"PPROMISC",		/* 17:0x20000 IFF_PPROMISC*/
75 	"MONITOR",		/* 18:0x40000 IFF_MONITOR*/
76 	"STATICARP",		/* 19:0x80000 IFF_STATICARP*/
77 	"STICKYARP",		/* 20:0x100000 IFF_STICKYARP*/
78 	"DYING",		/* 21:0x200000 IFF_DYING*/
79 	"RENAMING",		/* 22:0x400000 IFF_RENAMING*/
80 	"NOGROUP",		/* 23:0x800000 IFF_NOGROUP*/
81 	"LOWER_UP",		/* 24:0x1000000 IFF_NETLINK_1*/
82 };
83 
84 static void
85 nl_init_socket(struct snl_state *ss)
86 {
87 	if (snl_init(ss, NETLINK_ROUTE))
88 		return;
89 
90 	if (modfind("netlink") == -1 && errno == ENOENT) {
91 		/* Try to load */
92 		if (kldload("netlink") == -1)
93 			err(1, "netlink is not loaded and load attempt failed");
94 		if (snl_init(ss, NETLINK_ROUTE))
95 			return;
96 	}
97 
98 	err(1, "unable to open netlink socket");
99 }
100 
101 int
102 ifconfig_nl(if_ctx *ctx, int iscreate,
103     const struct afswtch *uafp)
104 {
105 	struct snl_state ss = {};
106 
107 	nl_init_socket(&ss);
108 	ctx->io_ss = &ss;
109 
110 	int error = ifconfig_ioctl(ctx, iscreate, uafp);
111 
112 	snl_free(&ss);
113 	ctx->io_ss = NULL;
114 
115 	return (error);
116 }
117 
118 struct ifa {
119 	struct ifa		*next;
120 	uint32_t		idx;
121 	struct snl_parsed_addr	addr;
122 };
123 
124 struct iface {
125 	struct snl_parsed_link	link;
126 	struct ifa		*ifa;
127 	uint32_t		ifa_count;
128 	uint32_t		idx;
129 };
130 
131 struct ifmap {
132 	uint32_t		size;
133 	uint32_t		count;
134 	struct iface		**ifaces;
135 };
136 
137 /*
138  * Returns ifmap ifindex->snl_parsed_link.
139  * Memory is allocated using snl temporary buffers
140  */
141 static struct ifmap *
142 prepare_ifmap(struct snl_state *ss)
143 {
144 	struct snl_writer nw = {};
145 
146 	snl_init_writer(ss, &nw);
147 	struct nlmsghdr *hdr = snl_create_msg_request(&nw, RTM_GETLINK);
148 	hdr->nlmsg_flags |= NLM_F_DUMP;
149 	snl_reserve_msg_object(&nw, struct ifinfomsg);
150 
151 	if (! (hdr = snl_finalize_msg(&nw)) || !snl_send_message(ss, hdr))
152 		return (NULL);
153 
154 	uint32_t nlmsg_seq = hdr->nlmsg_seq;
155 	struct ifmap *ifmap = snl_allocz(ss, sizeof(*ifmap));
156 	struct snl_errmsg_data e = {};
157 
158 	while ((hdr = snl_read_reply_multi(ss, nlmsg_seq, &e)) != NULL) {
159 		struct iface *iface = snl_allocz(ss, sizeof(*iface));
160 
161 		if (!snl_parse_nlmsg(ss, hdr, &snl_rtm_link_parser, &iface->link))
162 			continue;
163 		if (iface->link.ifi_index >= ifmap->size) {
164 			size_t new_size = MAX(ifmap->size, 32);
165 
166 			while (new_size <= iface->link.ifi_index + 1)
167 				new_size *= 2;
168 
169 			struct iface **ifaces= snl_allocz(ss, new_size * sizeof(void *));
170 			memcpy(ifaces, ifmap->ifaces, ifmap->size * sizeof(void *));
171 			ifmap->ifaces = ifaces;
172 			ifmap->size = new_size;
173 		}
174 		ifmap->ifaces[iface->link.ifi_index] = iface;
175 		ifmap->count++;
176 		iface->idx = ifmap->count;
177 	}
178 	return (ifmap);
179 }
180 
181 uint32_t
182 if_nametoindex_nl(struct snl_state *ss, const char *ifname)
183 {
184 	struct snl_writer nw = {};
185 	struct snl_parsed_link_simple link = {};
186 
187 	snl_init_writer(ss, &nw);
188 	struct nlmsghdr *hdr = snl_create_msg_request(&nw, RTM_GETLINK);
189 	snl_reserve_msg_object(&nw, struct ifinfomsg);
190 	snl_add_msg_attr_string(&nw, IFLA_IFNAME, ifname);
191 
192 	if (! (hdr = snl_finalize_msg(&nw)) || !snl_send_message(ss, hdr))
193 		return (0);
194 
195 	hdr = snl_read_reply(ss, hdr->nlmsg_seq);
196 	if (hdr->nlmsg_type != NL_RTM_NEWLINK)
197 		return (0);
198 	if (!snl_parse_nlmsg(ss, hdr, &snl_rtm_link_parser_simple, &link))
199 		return (0);
200 
201 	return (link.ifi_index);
202 }
203 
204 ifType
205 convert_iftype(ifType iftype)
206 {
207 	switch (iftype) {
208 	case IFT_IEEE8023ADLAG:
209 		return (IFT_ETHER);
210 	case IFT_INFINIBANDLAG:
211 		return (IFT_INFINIBAND);
212 	default:
213 		return (iftype);
214 	}
215 }
216 
217 static void
218 prepare_ifaddrs(struct snl_state *ss, struct ifmap *ifmap)
219 {
220 	struct snl_writer nw = {};
221 
222 	snl_init_writer(ss, &nw);
223 	struct nlmsghdr *hdr = snl_create_msg_request(&nw, RTM_GETADDR);
224 	hdr->nlmsg_flags |= NLM_F_DUMP;
225 	snl_reserve_msg_object(&nw, struct ifaddrmsg);
226 
227 	if (! (hdr = snl_finalize_msg(&nw)) || !snl_send_message(ss, hdr))
228 		return;
229 
230 	uint32_t nlmsg_seq = hdr->nlmsg_seq;
231 	struct snl_errmsg_data e = {};
232 	uint32_t count = 0;
233 
234 	while ((hdr = snl_read_reply_multi(ss, nlmsg_seq, &e)) != NULL) {
235 		struct ifa *ifa = snl_allocz(ss, sizeof(*ifa));
236 
237 		if (!snl_parse_nlmsg(ss, hdr, &snl_rtm_addr_parser, &ifa->addr))
238 			continue;
239 
240 		const uint32_t ifindex = ifa->addr.ifa_index;
241 		if (ifindex >= ifmap->size || ifmap->ifaces[ifindex] == NULL)
242 			continue;
243 		struct iface *iface = ifmap->ifaces[ifindex];
244 		ifa->next = iface->ifa;
245 		ifa->idx = ++count;
246 		iface->ifa = ifa;
247 		iface->ifa_count++;
248 	}
249 }
250 
251 static bool
252 match_iface(struct ifconfig_args *args, struct iface *iface)
253 {
254 	if_link_t *link = &iface->link;
255 
256 	if (args->ifname != NULL && strcmp(args->ifname, link->ifla_ifname))
257 		return (false);
258 
259 	if (!match_if_flags(args, link->ifi_flags))
260 		return (false);
261 
262 	if (!group_member(link->ifla_ifname, args->matchgroup, args->nogroup))
263 		return (false);
264 
265 	if (args->afp == NULL)
266 		return (true);
267 
268 	if (!strcmp(args->afp->af_name, "ether")) {
269 		if (link->ifla_address == NULL)
270 			return (false);
271 
272 		struct sockaddr_dl sdl = {
273 			.sdl_len = sizeof(struct sockaddr_dl),
274 			.sdl_family = AF_LINK,
275 			.sdl_type = convert_iftype(link->ifi_type),
276 			.sdl_alen = NLA_DATA_LEN(link->ifla_address),
277 		};
278 		return (match_ether(&sdl));
279 	} else if (args->afp->af_af == AF_LINK)
280 		/*
281 		 * The rtnetlink(4) RTM_GETADDR does not list link level
282 		 * addresses, so latter cycle won't match anything.  Short
283 		 * circuit on RTM_GETLINK has provided us an address.
284 		 */
285 		return (link->ifla_address != NULL);
286 
287 	for (struct ifa *ifa = iface->ifa; ifa != NULL; ifa = ifa->next) {
288 		if (args->afp->af_af == ifa->addr.ifa_family)
289 			return (true);
290 	}
291 
292 	return (false);
293 }
294 
295 /* Sort according to the kernel-provided order */
296 static int
297 cmp_iface(const void *_a, const void *_b)
298 {
299 	const struct iface *a = *((const void * const *)_a);
300 	const struct iface *b = *((const void * const *)_b);
301 
302 	return ((a->idx > b->idx) * 2 - 1);
303 }
304 
305 static int
306 cmp_ifaddr(const void *_a, const void *_b)
307 {
308 	const struct ifa *a = *((const void * const *)_a);
309 	const struct ifa *b = *((const void * const *)_b);
310 
311 	if (a->addr.ifa_family != b->addr.ifa_family)
312 		return ((a->addr.ifa_family > b->addr.ifa_family) * 2 - 1);
313 	return ((a->idx > b->idx) * 2 - 1);
314 }
315 
316 static void
317 sort_iface_ifaddrs(struct snl_state *ss, struct iface *iface)
318 {
319 	if (iface->ifa_count == 0)
320 		return;
321 
322 	struct ifa **sorted_ifaddrs = snl_allocz(ss, iface->ifa_count * sizeof(void *));
323 	struct ifa *ifa = iface->ifa;
324 
325 	for (uint32_t i = 0; i < iface->ifa_count; i++) {
326 		struct ifa *ifa_next = ifa->next;
327 
328 		sorted_ifaddrs[i] = ifa;
329 		ifa->next = NULL;
330 		ifa = ifa_next;
331 	}
332 	qsort(sorted_ifaddrs, iface->ifa_count, sizeof(void *), cmp_ifaddr);
333 	ifa = sorted_ifaddrs[0];
334 	iface->ifa = ifa;
335 	for (uint32_t i = 1; i < iface->ifa_count; i++) {
336 		ifa->next = sorted_ifaddrs[i];
337 		ifa = sorted_ifaddrs[i];
338 	}
339 }
340 
341 static void
342 print_ifcaps(if_ctx *ctx, if_link_t *link)
343 {
344 	uint32_t sz_u32 = roundup2(link->iflaf_caps.nla_bitset_size, 32) / 32;
345 
346 	if (sz_u32 > 0) {
347 		uint32_t *caps = link->iflaf_caps.nla_bitset_value;
348 
349 		printf("\toptions=%x", caps[0]);
350 		print_bits("IFCAPS", caps, sz_u32, ifcap_bit_names, nitems(ifcap_bit_names));
351 		putchar('\n');
352 	}
353 
354 	if (ctx->args->supmedia && sz_u32 > 0) {
355 		uint32_t *caps = link->iflaf_caps.nla_bitset_mask;
356 
357 		printf("\tcapabilities=%x", caps[0]);
358 		print_bits("IFCAPS", caps, sz_u32, ifcap_bit_names, nitems(ifcap_bit_names));
359 		putchar('\n');
360 	}
361 }
362 
363 static void
364 status_nl(if_ctx *ctx, struct iface *iface)
365 {
366 	if_link_t *link = &iface->link;
367 	struct ifconfig_args *args = ctx->args;
368 	char *drivername = NULL;
369 
370 	printf("%s: ", link->ifla_ifname);
371 
372 	printf("flags=%x", link->ifi_flags);
373 	print_bits("IFF", &link->ifi_flags, 1, IFFBITS, nitems(IFFBITS));
374 
375 	print_metric(ctx);
376 	printf(" mtu %d\n", link->ifla_mtu);
377 
378 	if (link->ifla_ifalias != NULL)
379 		printf("\tdescription: %s\n", link->ifla_ifalias);
380 
381 	print_ifcaps(ctx, link);
382 	tunnel_status(ctx);
383 
384 	if (args->allfamilies | (args->afp != NULL && args->afp->af_af == AF_LINK)) {
385 		/* Start with link-level */
386 		const struct afswtch *p = af_getbyfamily(AF_LINK);
387 		if (p != NULL && link->ifla_address != NULL)
388 			p->af_status(ctx, link, NULL);
389 	}
390 
391 	sort_iface_ifaddrs(ctx->io_ss, iface);
392 
393 	for (struct ifa *ifa = iface->ifa; ifa != NULL; ifa = ifa->next) {
394 		if (args->allfamilies) {
395 			const struct afswtch *p = af_getbyfamily(ifa->addr.ifa_family);
396 
397 			if (p != NULL)
398 				p->af_status(ctx, link, &ifa->addr);
399 		} else if (args->afp->af_af == ifa->addr.ifa_family) {
400 			const struct afswtch *p = args->afp;
401 
402 			p->af_status(ctx, link, &ifa->addr);
403 		}
404 	}
405 
406 	/* TODO: convert to netlink */
407 	if (args->allfamilies)
408 		af_other_status(ctx);
409 	else if (args->afp->af_other_status != NULL)
410 		args->afp->af_other_status(ctx);
411 
412 	print_ifstatus(ctx);
413 	if (args->drivername || args->verbose) {
414 		if (ifconfig_get_orig_name(lifh, link->ifla_ifname,
415 		    &drivername) != 0) {
416 			if (ifconfig_err_errtype(lifh) == OTHER)
417 				fprintf(stderr, "get original name: %s\n",
418 				    strerror(ifconfig_err_errno(lifh)));
419 			else
420 				fprintf(stderr,
421 				    "get original name: error type %d\n",
422 				    ifconfig_err_errtype(lifh));
423 			exit_code = 1;
424 		}
425 		if (drivername != NULL)
426 			printf("\tdrivername: %s\n", drivername);
427 		free(drivername);
428 	}
429 	if (args->verbose > 0)
430 		sfp_status(ctx);
431 }
432 
433 static int
434 get_local_socket(void)
435 {
436 	int s = socket(AF_LOCAL, SOCK_DGRAM, 0);
437 
438 	if (s < 0)
439 		err(1, "socket(family %u,SOCK_DGRAM)", AF_LOCAL);
440 	return (s);
441 }
442 
443 void
444 list_interfaces_nl(struct ifconfig_args *args)
445 {
446 	struct snl_state ss = {};
447 	struct ifconfig_context _ctx = {
448 		.args = args,
449 		.io_s = get_local_socket(),
450 		.io_ss = &ss,
451 	};
452 	struct ifconfig_context *ctx = &_ctx;
453 
454 	nl_init_socket(&ss);
455 
456 	struct ifmap *ifmap = prepare_ifmap(&ss);
457 	struct iface **sorted_ifaces = snl_allocz(&ss, ifmap->count * sizeof(void *));
458 	for (uint32_t i = 0, num = 0; i < ifmap->size; i++) {
459 		if (ifmap->ifaces[i] != NULL) {
460 			sorted_ifaces[num++] = ifmap->ifaces[i];
461 			if (num == ifmap->count)
462 				break;
463 		}
464 	}
465 	qsort(sorted_ifaces, ifmap->count, sizeof(void *), cmp_iface);
466 	prepare_ifaddrs(&ss, ifmap);
467 
468 	for (uint32_t i = 0, num = 0; i < ifmap->count; i++) {
469 		struct iface *iface = sorted_ifaces[i];
470 
471 		if (!match_iface(args, iface))
472 			continue;
473 
474 		ctx->ifname = iface->link.ifla_ifname;
475 
476 		if (args->namesonly) {
477 			if (num++ != 0)
478 				printf(" ");
479 			fputs(iface->link.ifla_ifname, stdout);
480 		} else if (args->argc == 0)
481 			status_nl(ctx, iface);
482 		else
483 			ifconfig_ioctl(ctx, 0, args->afp);
484 	}
485 	if (args->namesonly)
486 		printf("\n");
487 
488 	close(ctx->io_s);
489 	snl_free(&ss);
490 }
491 
492