xref: /freebsd/sbin/ifconfig/ifconfig_netlink.c (revision b1b17432aa1be670564161232d110461a5dde4ce)
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 #define _WANT_IFCAP_BIT_NAMES
29 
30 #include <stdio.h>
31 #include <stdlib.h>
32 #include <string.h>
33 #include <stdbool.h>
34 #include <err.h>
35 #include <errno.h>
36 #include <netdb.h>
37 
38 #include <sys/bitcount.h>
39 #include <sys/param.h>
40 #include <sys/linker.h>
41 #include <sys/module.h>
42 #include <sys/socket.h>
43 #include <sys/sysctl.h>
44 #include <sys/time.h>
45 #include <sys/types.h>
46 
47 #include <netinet/in.h>
48 #include <arpa/inet.h>
49 
50 #include <net/ethernet.h>
51 #include <net/if.h>
52 #include <net/if_dl.h>
53 #include <net/if_strings.h>
54 #include <net/if_types.h>
55 #include "ifconfig.h"
56 #include "ifconfig_netlink.h"
57 
58 static const char	*IFFBITS[] = {
59 	"UP",			/* 00:0x1 IFF_UP*/
60 	"BROADCAST",		/* 01:0x2 IFF_BROADCAST*/
61 	"DEBUG",		/* 02:0x4 IFF_DEBUG*/
62 	"LOOPBACK",		/* 03:0x8 IFF_LOOPBACK*/
63 	"POINTOPOINT",		/* 04:0x10 IFF_POINTOPOINT*/
64 	"NEEDSEPOCH",		/* 05:0x20 IFF_NEEDSEPOCH*/
65 	"RUNNING",		/* 06:0x40 IFF_DRV_RUNNING*/
66 	"NOARP",		/* 07:0x80 IFF_NOARP*/
67 	"PROMISC",		/* 08:0x100 IFF_PROMISC*/
68 	"ALLMULTI",		/* 09:0x200 IFF_ALLMULTI*/
69 	"DRV_OACTIVE",		/* 10:0x400 IFF_DRV_OACTIVE*/
70 	"SIMPLEX",		/* 11:0x800 IFF_SIMPLEX*/
71 	"LINK0",		/* 12:0x1000 IFF_LINK0*/
72 	"LINK1",		/* 13:0x2000 IFF_LINK1*/
73 	"LINK2",		/* 14:0x4000 IFF_LINK2*/
74 	"MULTICAST",		/* 15:0x8000 IFF_MULTICAST*/
75 	"CANTCONFIG",		/* 16:0x10000 IFF_CANTCONFIG*/
76 	"PPROMISC",		/* 17:0x20000 IFF_PPROMISC*/
77 	"MONITOR",		/* 18:0x40000 IFF_MONITOR*/
78 	"STATICARP",		/* 19:0x80000 IFF_STATICARP*/
79 	"STICKYARP",		/* 20:0x100000 IFF_STICKYARP*/
80 	"DYING",		/* 21:0x200000 IFF_DYING*/
81 	"RENAMING",		/* 22:0x400000 IFF_RENAMING*/
82 	"PALLMULTI",		/* 23:0x800000 IFF_PALLMULTI*/
83 	"LOWER_UP",		/* 24:0x1000000 IFF_NETLINK_1*/
84 };
85 
86 static void
nl_init_socket(struct snl_state * ss)87 nl_init_socket(struct snl_state *ss)
88 {
89 	if (snl_init(ss, NETLINK_ROUTE))
90 		return;
91 
92 	if (modfind("netlink") == -1 && errno == ENOENT) {
93 		/* Try to load */
94 		if (kldload("netlink") == -1)
95 			err(1, "netlink is not loaded and load attempt failed");
96 		if (snl_init(ss, NETLINK_ROUTE))
97 			return;
98 	}
99 
100 	err(1, "unable to open netlink socket");
101 }
102 
103 int
ifconfig_nl(if_ctx * ctx,int iscreate,const struct afswtch * uafp)104 ifconfig_nl(if_ctx *ctx, int iscreate,
105     const struct afswtch *uafp)
106 {
107 	struct snl_state ss = {};
108 
109 	nl_init_socket(&ss);
110 	ctx->io_ss = &ss;
111 
112 	int error = ifconfig_ioctl(ctx, iscreate, uafp);
113 
114 	snl_free(&ss);
115 	ctx->io_ss = NULL;
116 
117 	return (error);
118 }
119 
120 struct ifa {
121 	struct ifa		*next;
122 	uint32_t		idx;
123 	struct snl_parsed_addr	addr;
124 };
125 
126 struct iface {
127 	struct snl_parsed_link	link;
128 	struct ifa		*ifa;
129 	uint32_t		ifa_count;
130 	uint32_t		idx;
131 };
132 
133 struct ifmap {
134 	uint32_t		size;
135 	uint32_t		count;
136 	struct iface		**ifaces;
137 };
138 
139 /*
140  * Returns ifmap ifindex->snl_parsed_link.
141  * Memory is allocated using snl temporary buffers
142  */
143 static struct ifmap *
prepare_ifmap(struct snl_state * ss,const char * ifname)144 prepare_ifmap(struct snl_state *ss, const char *ifname)
145 {
146 	struct snl_writer nw = {};
147 
148 	snl_init_writer(ss, &nw);
149 	struct nlmsghdr *hdr = snl_create_msg_request(&nw, RTM_GETLINK);
150 	hdr->nlmsg_flags |= NLM_F_DUMP;
151 	snl_reserve_msg_object(&nw, struct ifinfomsg);
152        if (ifname != NULL)
153                snl_add_msg_attr_string(&nw, IFLA_IFNAME, ifname);
154 
155 	if (! (hdr = snl_finalize_msg(&nw)) || !snl_send_message(ss, hdr))
156 		return (NULL);
157 
158 	uint32_t nlmsg_seq = hdr->nlmsg_seq;
159 	struct ifmap *ifmap = snl_allocz(ss, sizeof(*ifmap));
160 	struct snl_errmsg_data e = {};
161 
162 	while ((hdr = snl_read_reply_multi(ss, nlmsg_seq, &e)) != NULL) {
163 		struct iface *iface = snl_allocz(ss, sizeof(*iface));
164 
165 		if (!snl_parse_nlmsg(ss, hdr, &snl_rtm_link_parser, &iface->link))
166 			continue;
167 		if (iface->link.ifi_index >= ifmap->size) {
168 			size_t new_size = MAX(ifmap->size, 32);
169 
170 			while (new_size <= iface->link.ifi_index + 1)
171 				new_size *= 2;
172 
173 			struct iface **ifaces= snl_allocz(ss, new_size * sizeof(void *));
174 			memcpy(ifaces, ifmap->ifaces, ifmap->size * sizeof(void *));
175 			ifmap->ifaces = ifaces;
176 			ifmap->size = new_size;
177 		}
178 		ifmap->ifaces[iface->link.ifi_index] = iface;
179 		ifmap->count++;
180 		iface->idx = ifmap->count;
181 	}
182 	return (ifmap);
183 }
184 
185 uint32_t
if_nametoindex_nl(struct snl_state * ss,const char * ifname)186 if_nametoindex_nl(struct snl_state *ss, const char *ifname)
187 {
188 	struct snl_writer nw = {};
189 	struct snl_parsed_link_simple link = {};
190 
191 	snl_init_writer(ss, &nw);
192 	struct nlmsghdr *hdr = snl_create_msg_request(&nw, RTM_GETLINK);
193 	snl_reserve_msg_object(&nw, struct ifinfomsg);
194 	snl_add_msg_attr_string(&nw, IFLA_IFNAME, ifname);
195 
196 	if (! (hdr = snl_finalize_msg(&nw)) || !snl_send_message(ss, hdr))
197 		return (0);
198 
199 	hdr = snl_read_reply(ss, hdr->nlmsg_seq);
200 	if (hdr->nlmsg_type != NL_RTM_NEWLINK)
201 		return (0);
202 	if (!snl_parse_nlmsg(ss, hdr, &snl_rtm_link_parser_simple, &link))
203 		return (0);
204 
205 	return (link.ifi_index);
206 }
207 
208 ifType
convert_iftype(ifType iftype)209 convert_iftype(ifType iftype)
210 {
211 	switch (iftype) {
212 	case IFT_IEEE8023ADLAG:
213 		return (IFT_ETHER);
214 	case IFT_INFINIBANDLAG:
215 		return (IFT_INFINIBAND);
216 	default:
217 		return (iftype);
218 	}
219 }
220 
221 static void
prepare_ifaddrs(struct snl_state * ss,struct ifmap * ifmap)222 prepare_ifaddrs(struct snl_state *ss, struct ifmap *ifmap)
223 {
224 	struct snl_writer nw = {};
225 
226 	snl_init_writer(ss, &nw);
227 	struct nlmsghdr *hdr = snl_create_msg_request(&nw, RTM_GETADDR);
228 	hdr->nlmsg_flags |= NLM_F_DUMP;
229 	snl_reserve_msg_object(&nw, struct ifaddrmsg);
230 
231 	if (! (hdr = snl_finalize_msg(&nw)) || !snl_send_message(ss, hdr))
232 		return;
233 
234 	uint32_t nlmsg_seq = hdr->nlmsg_seq;
235 	struct snl_errmsg_data e = {};
236 	uint32_t count = 0;
237 
238 	while ((hdr = snl_read_reply_multi(ss, nlmsg_seq, &e)) != NULL) {
239 		struct ifa *ifa = snl_allocz(ss, sizeof(*ifa));
240 
241 		if (!snl_parse_nlmsg(ss, hdr, &snl_rtm_addr_parser, &ifa->addr))
242 			continue;
243 
244 		const uint32_t ifindex = ifa->addr.ifa_index;
245 		if (ifindex >= ifmap->size || ifmap->ifaces[ifindex] == NULL)
246 			continue;
247 		struct iface *iface = ifmap->ifaces[ifindex];
248 		ifa->next = iface->ifa;
249 		ifa->idx = ++count;
250 		iface->ifa = ifa;
251 		iface->ifa_count++;
252 	}
253 }
254 
255 static bool
match_iface(struct ifconfig_args * args,struct iface * iface)256 match_iface(struct ifconfig_args *args, struct iface *iface)
257 {
258 	if_link_t *link = &iface->link;
259 
260 	if (args->ifname != NULL && strcmp(args->ifname, link->ifla_ifname))
261 		return (false);
262 
263 	if (!match_if_flags(args, link->ifi_flags))
264 		return (false);
265 
266 	if (!group_member(link->ifla_ifname, args->matchgroup, args->nogroup))
267 		return (false);
268 
269 	if (args->afp == NULL)
270 		return (true);
271 
272 	if (!strcmp(args->afp->af_name, "ether")) {
273 		if (link->ifla_address == NULL)
274 			return (false);
275 
276 		struct sockaddr_dl sdl = {
277 			.sdl_len = sizeof(struct sockaddr_dl),
278 			.sdl_family = AF_LINK,
279 			.sdl_type = convert_iftype(link->ifi_type),
280 			.sdl_alen = NLA_DATA_LEN(link->ifla_address),
281 		};
282 		return (match_ether(&sdl));
283 	} else if (args->afp->af_af == AF_LINK)
284 		/*
285 		 * The rtnetlink(4) RTM_GETADDR does not list link level
286 		 * addresses, so latter cycle won't match anything.  Short
287 		 * circuit on RTM_GETLINK has provided us an address.
288 		 */
289 		return (link->ifla_address != NULL);
290 
291 	for (struct ifa *ifa = iface->ifa; ifa != NULL; ifa = ifa->next) {
292 		if (args->afp->af_af == ifa->addr.ifa_family)
293 			return (true);
294 	}
295 
296 	return (false);
297 }
298 
299 /* Sort according to the kernel-provided order */
300 static int
cmp_iface(const void * _a,const void * _b)301 cmp_iface(const void *_a, const void *_b)
302 {
303 	const struct iface *a = *((const void * const *)_a);
304 	const struct iface *b = *((const void * const *)_b);
305 
306 	return ((a->idx > b->idx) * 2 - 1);
307 }
308 
309 static int
cmp_ifaddr(const void * _a,const void * _b)310 cmp_ifaddr(const void *_a, const void *_b)
311 {
312 	const struct ifa *a = *((const void * const *)_a);
313 	const struct ifa *b = *((const void * const *)_b);
314 
315 	if (a->addr.ifa_family != b->addr.ifa_family)
316 		return ((a->addr.ifa_family > b->addr.ifa_family) * 2 - 1);
317 	return ((a->idx > b->idx) * 2 - 1);
318 }
319 
320 static void
sort_iface_ifaddrs(struct snl_state * ss,struct iface * iface)321 sort_iface_ifaddrs(struct snl_state *ss, struct iface *iface)
322 {
323 	if (iface->ifa_count == 0)
324 		return;
325 
326 	struct ifa **sorted_ifaddrs = snl_allocz(ss, iface->ifa_count * sizeof(void *));
327 	struct ifa *ifa = iface->ifa;
328 
329 	for (uint32_t i = 0; i < iface->ifa_count; i++) {
330 		struct ifa *ifa_next = ifa->next;
331 
332 		sorted_ifaddrs[i] = ifa;
333 		ifa->next = NULL;
334 		ifa = ifa_next;
335 	}
336 	qsort(sorted_ifaddrs, iface->ifa_count, sizeof(void *), cmp_ifaddr);
337 	ifa = sorted_ifaddrs[0];
338 	iface->ifa = ifa;
339 	for (uint32_t i = 1; i < iface->ifa_count; i++) {
340 		ifa->next = sorted_ifaddrs[i];
341 		ifa = sorted_ifaddrs[i];
342 	}
343 }
344 
345 static void
print_ifcaps(if_ctx * ctx,if_link_t * link)346 print_ifcaps(if_ctx *ctx, if_link_t *link)
347 {
348 	uint32_t sz_u32 = roundup2(link->iflaf_caps.nla_bitset_size, 32) / 32;
349 
350 	if (sz_u32 > 0) {
351 		uint32_t *caps = link->iflaf_caps.nla_bitset_value;
352 
353 		printf("\toptions=%x", caps[0]);
354 		print_bits("IFCAPS", caps, sz_u32, ifcap_bit_names, nitems(ifcap_bit_names));
355 		putchar('\n');
356 	}
357 
358 	if (ctx->args->supmedia && sz_u32 > 0) {
359 		uint32_t *caps = link->iflaf_caps.nla_bitset_mask;
360 
361 		printf("\tcapabilities=%x", caps[0]);
362 		print_bits("IFCAPS", caps, sz_u32, ifcap_bit_names, nitems(ifcap_bit_names));
363 		putchar('\n');
364 	}
365 }
366 
367 static void
status_nl(if_ctx * ctx,struct iface * iface)368 status_nl(if_ctx *ctx, struct iface *iface)
369 {
370 	if_link_t *link = &iface->link;
371 	struct ifconfig_args *args = ctx->args;
372 	char *drivername = NULL;
373 
374 	printf("%s: ", link->ifla_ifname);
375 
376 	printf("flags=%x", link->ifi_flags);
377 	print_bits("IFF", &link->ifi_flags, 1, IFFBITS, nitems(IFFBITS));
378 
379 	print_metric(ctx);
380 	printf(" mtu %d\n", link->ifla_mtu);
381 
382 	if (link->ifla_ifalias != NULL)
383 		printf("\tdescription: %s\n", link->ifla_ifalias);
384 
385 	print_ifcaps(ctx, link);
386 	tunnel_status(ctx);
387 
388 	if (args->allfamilies | (args->afp != NULL && args->afp->af_af == AF_LINK)) {
389 		/* Start with link-level */
390 		const struct afswtch *p = af_getbyfamily(AF_LINK);
391 		if (p != NULL && link->ifla_address != NULL)
392 			p->af_status(ctx, link, NULL);
393 	}
394 
395 	sort_iface_ifaddrs(ctx->io_ss, iface);
396 
397 	for (struct ifa *ifa = iface->ifa; ifa != NULL; ifa = ifa->next) {
398 		if (args->allfamilies) {
399 			const struct afswtch *p = af_getbyfamily(ifa->addr.ifa_family);
400 
401 			if (p != NULL)
402 				p->af_status(ctx, link, &ifa->addr);
403 		} else if (args->afp->af_af == ifa->addr.ifa_family) {
404 			const struct afswtch *p = args->afp;
405 
406 			p->af_status(ctx, link, &ifa->addr);
407 		}
408 	}
409 
410 	/* TODO: convert to netlink */
411 	if (args->allfamilies)
412 		af_other_status(ctx);
413 	else if (args->afp->af_other_status != NULL)
414 		args->afp->af_other_status(ctx);
415 
416 	print_ifstatus(ctx);
417 	if (args->drivername || args->verbose) {
418 		if (ifconfig_get_orig_name(lifh, link->ifla_ifname,
419 		    &drivername) != 0) {
420 			if (ifconfig_err_errtype(lifh) == OTHER)
421 				fprintf(stderr, "get original name: %s\n",
422 				    strerror(ifconfig_err_errno(lifh)));
423 			else
424 				fprintf(stderr,
425 				    "get original name: error type %d\n",
426 				    ifconfig_err_errtype(lifh));
427 			exit_code = 1;
428 		}
429 		if (drivername != NULL)
430 			printf("\tdrivername: %s\n", drivername);
431 		free(drivername);
432 	}
433 	if (args->verbose > 0)
434 		sfp_status(ctx);
435 }
436 
437 static int
get_local_socket(void)438 get_local_socket(void)
439 {
440 	int s = socket(AF_LOCAL, SOCK_DGRAM, 0);
441 
442 	if (s < 0)
443 		err(1, "socket(family %u,SOCK_DGRAM)", AF_LOCAL);
444 	return (s);
445 }
446 
447 void
list_interfaces_nl(struct ifconfig_args * args)448 list_interfaces_nl(struct ifconfig_args *args)
449 {
450 	struct snl_state ss = {};
451 	struct ifconfig_context _ctx = {
452 		.args = args,
453 		.io_s = get_local_socket(),
454 		.io_ss = &ss,
455 	};
456 	struct ifconfig_context *ctx = &_ctx;
457 
458 	nl_init_socket(&ss);
459 
460        struct ifmap *ifmap = prepare_ifmap(&ss, args->ifname);
461 	struct iface **sorted_ifaces = snl_allocz(&ss, ifmap->count * sizeof(void *));
462 	for (uint32_t i = 0, num = 0; i < ifmap->size; i++) {
463 		if (ifmap->ifaces[i] != NULL) {
464 			sorted_ifaces[num++] = ifmap->ifaces[i];
465 			if (num == ifmap->count)
466 				break;
467 		}
468 	}
469 	qsort(sorted_ifaces, ifmap->count, sizeof(void *), cmp_iface);
470 	prepare_ifaddrs(&ss, ifmap);
471 
472 	for (uint32_t i = 0, num = 0; i < ifmap->count; i++) {
473 		struct iface *iface = sorted_ifaces[i];
474 
475 		if (!match_iface(args, iface))
476 			continue;
477 
478 		ctx->ifname = iface->link.ifla_ifname;
479 
480 		if (args->namesonly) {
481 			if (num++ != 0)
482 				printf(" ");
483 			fputs(iface->link.ifla_ifname, stdout);
484 		} else if (args->argc == 0)
485 			status_nl(ctx, iface);
486 		else
487 			ifconfig_ioctl(ctx, 0, args->afp);
488 	}
489 	if (args->namesonly)
490 		printf("\n");
491 
492 	close(ctx->io_s);
493 	snl_free(&ss);
494 }
495 
496