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718e3744 | 1 | /* Kernel communication using netlink interface. |
2 | * Copyright (C) 1999 Kunihiro Ishiguro | |
3 | * | |
4 | * This file is part of GNU Zebra. | |
5 | * | |
6 | * GNU Zebra is free software; you can redistribute it and/or modify it | |
7 | * under the terms of the GNU General Public License as published by the | |
8 | * Free Software Foundation; either version 2, or (at your option) any | |
9 | * later version. | |
10 | * | |
11 | * GNU Zebra is distributed in the hope that it will be useful, but | |
12 | * WITHOUT ANY WARRANTY; without even the implied warranty of | |
13 | * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the GNU | |
14 | * General Public License for more details. | |
15 | * | |
896014f4 DL |
16 | * You should have received a copy of the GNU General Public License along |
17 | * with this program; see the file COPYING; if not, write to the Free Software | |
18 | * Foundation, Inc., 51 Franklin St, Fifth Floor, Boston, MA 02110-1301 USA | |
718e3744 | 19 | */ |
1fdc9eae | 20 | |
21 | #include <zebra.h> | |
22 | ||
ddfeb486 DL |
23 | #ifdef HAVE_NETLINK |
24 | ||
1fdc9eae | 25 | #include "linklist.h" |
26 | #include "if.h" | |
27 | #include "log.h" | |
28 | #include "prefix.h" | |
29 | #include "connected.h" | |
30 | #include "table.h" | |
31 | #include "memory.h" | |
32 | #include "zebra_memory.h" | |
33 | #include "rib.h" | |
34 | #include "thread.h" | |
35 | #include "privs.h" | |
36 | #include "nexthop.h" | |
37 | #include "vrf.h" | |
38 | #include "mpls.h" | |
39 | ||
40 | #include "zebra/zserv.h" | |
41 | #include "zebra/zebra_ns.h" | |
42 | #include "zebra/zebra_vrf.h" | |
43 | #include "zebra/debug.h" | |
44 | #include "zebra/kernel_netlink.h" | |
45 | #include "zebra/rt_netlink.h" | |
46 | #include "zebra/if_netlink.h" | |
47 | ||
48 | #ifndef SO_RCVBUFFORCE | |
49 | #define SO_RCVBUFFORCE (33) | |
50 | #endif | |
51 | ||
52 | /* Hack for GNU libc version 2. */ | |
53 | #ifndef MSG_TRUNC | |
54 | #define MSG_TRUNC 0x20 | |
55 | #endif /* MSG_TRUNC */ | |
56 | ||
57 | #ifndef NLMSG_TAIL | |
d62a17ae | 58 | #define NLMSG_TAIL(nmsg) \ |
59 | ((struct rtattr *)(((u_char *)(nmsg)) + NLMSG_ALIGN((nmsg)->nlmsg_len))) | |
1fdc9eae | 60 | #endif |
61 | ||
62 | #ifndef RTA_TAIL | |
d62a17ae | 63 | #define RTA_TAIL(rta) \ |
64 | ((struct rtattr *)(((u_char *)(rta)) + RTA_ALIGN((rta)->rta_len))) | |
1fdc9eae | 65 | #endif |
66 | ||
f909c673 DS |
67 | #ifndef RTNL_FAMILY_IP6MR |
68 | #define RTNL_FAMILY_IP6MR 129 | |
69 | #endif | |
70 | ||
71 | #ifndef RTPROT_MROUTED | |
72 | #define RTPROT_MROUTED 17 | |
73 | #endif | |
74 | ||
d62a17ae | 75 | static const struct message nlmsg_str[] = {{RTM_NEWROUTE, "RTM_NEWROUTE"}, |
76 | {RTM_DELROUTE, "RTM_DELROUTE"}, | |
77 | {RTM_GETROUTE, "RTM_GETROUTE"}, | |
78 | {RTM_NEWLINK, "RTM_NEWLINK"}, | |
79 | {RTM_DELLINK, "RTM_DELLINK"}, | |
80 | {RTM_GETLINK, "RTM_GETLINK"}, | |
81 | {RTM_NEWADDR, "RTM_NEWADDR"}, | |
82 | {RTM_DELADDR, "RTM_DELADDR"}, | |
83 | {RTM_GETADDR, "RTM_GETADDR"}, | |
84 | {RTM_NEWNEIGH, "RTM_NEWNEIGH"}, | |
85 | {RTM_DELNEIGH, "RTM_DELNEIGH"}, | |
86 | {RTM_GETNEIGH, "RTM_GETNEIGH"}, | |
87 | {0}}; | |
1fdc9eae | 88 | |
89 | static const struct message rtproto_str[] = { | |
d62a17ae | 90 | {RTPROT_REDIRECT, "redirect"}, |
91 | {RTPROT_KERNEL, "kernel"}, | |
92 | {RTPROT_BOOT, "boot"}, | |
93 | {RTPROT_STATIC, "static"}, | |
94 | {RTPROT_GATED, "GateD"}, | |
95 | {RTPROT_RA, "router advertisement"}, | |
96 | {RTPROT_MRT, "MRT"}, | |
97 | {RTPROT_ZEBRA, "Zebra"}, | |
1fdc9eae | 98 | #ifdef RTPROT_BIRD |
d62a17ae | 99 | {RTPROT_BIRD, "BIRD"}, |
1fdc9eae | 100 | #endif /* RTPROT_BIRD */ |
d62a17ae | 101 | {RTPROT_MROUTED, "mroute"}, |
102 | {RTPROT_BGP, "BGP"}, | |
103 | {RTPROT_OSPF, "OSPF"}, | |
104 | {RTPROT_ISIS, "IS-IS"}, | |
105 | {RTPROT_RIP, "RIP"}, | |
106 | {RTPROT_RIPNG, "RIPNG"}, | |
107 | {0}}; | |
108 | ||
109 | static const struct message family_str[] = {{AF_INET, "ipv4"}, | |
110 | {AF_INET6, "ipv6"}, | |
111 | {AF_BRIDGE, "bridge"}, | |
112 | {RTNL_FAMILY_IPMR, "ipv4MR"}, | |
113 | {RTNL_FAMILY_IP6MR, "ipv6MR"}, | |
114 | {0}}; | |
115 | ||
116 | static const struct message rttype_str[] = {{RTN_UNICAST, "unicast"}, | |
117 | {RTN_MULTICAST, "multicast"}, | |
118 | {0}}; | |
b339bde7 | 119 | |
1fdc9eae | 120 | extern struct thread_master *master; |
121 | extern u_int32_t nl_rcvbufsize; | |
122 | ||
123 | extern struct zebra_privs_t zserv_privs; | |
124 | ||
d62a17ae | 125 | int netlink_talk_filter(struct sockaddr_nl *snl, struct nlmsghdr *h, |
126 | ns_id_t ns_id, int startup) | |
1fdc9eae | 127 | { |
d62a17ae | 128 | zlog_warn("netlink_talk: ignoring message type 0x%04x NS %u", |
129 | h->nlmsg_type, ns_id); | |
130 | return 0; | |
1fdc9eae | 131 | } |
132 | ||
d62a17ae | 133 | static int netlink_recvbuf(struct nlsock *nl, uint32_t newsize) |
1fdc9eae | 134 | { |
d62a17ae | 135 | u_int32_t oldsize; |
136 | socklen_t newlen = sizeof(newsize); | |
137 | socklen_t oldlen = sizeof(oldsize); | |
138 | int ret; | |
139 | ||
140 | ret = getsockopt(nl->sock, SOL_SOCKET, SO_RCVBUF, &oldsize, &oldlen); | |
141 | if (ret < 0) { | |
142 | zlog_err("Can't get %s receive buffer size: %s", nl->name, | |
143 | safe_strerror(errno)); | |
144 | return -1; | |
145 | } | |
146 | ||
147 | /* Try force option (linux >= 2.6.14) and fall back to normal set */ | |
148 | if (zserv_privs.change(ZPRIVS_RAISE)) | |
149 | zlog_err("routing_socket: Can't raise privileges"); | |
150 | ret = setsockopt(nl->sock, SOL_SOCKET, SO_RCVBUFFORCE, &nl_rcvbufsize, | |
151 | sizeof(nl_rcvbufsize)); | |
152 | if (zserv_privs.change(ZPRIVS_LOWER)) | |
153 | zlog_err("routing_socket: Can't lower privileges"); | |
154 | if (ret < 0) | |
155 | ret = setsockopt(nl->sock, SOL_SOCKET, SO_RCVBUF, | |
156 | &nl_rcvbufsize, sizeof(nl_rcvbufsize)); | |
157 | if (ret < 0) { | |
158 | zlog_err("Can't set %s receive buffer size: %s", nl->name, | |
159 | safe_strerror(errno)); | |
160 | return -1; | |
161 | } | |
162 | ||
163 | ret = getsockopt(nl->sock, SOL_SOCKET, SO_RCVBUF, &newsize, &newlen); | |
164 | if (ret < 0) { | |
165 | zlog_err("Can't get %s receive buffer size: %s", nl->name, | |
166 | safe_strerror(errno)); | |
167 | return -1; | |
168 | } | |
169 | ||
170 | zlog_info("Setting netlink socket receive buffer size: %u -> %u", | |
171 | oldsize, newsize); | |
172 | return 0; | |
1fdc9eae | 173 | } |
174 | ||
175 | /* Make socket for Linux netlink interface. */ | |
d62a17ae | 176 | static int netlink_socket(struct nlsock *nl, unsigned long groups, |
177 | ns_id_t ns_id) | |
1fdc9eae | 178 | { |
d62a17ae | 179 | int ret; |
180 | struct sockaddr_nl snl; | |
181 | int sock; | |
182 | int namelen; | |
183 | int save_errno; | |
184 | ||
185 | if (zserv_privs.change(ZPRIVS_RAISE)) { | |
186 | zlog_err("Can't raise privileges"); | |
187 | return -1; | |
188 | } | |
189 | ||
190 | sock = socket(AF_NETLINK, SOCK_RAW, NETLINK_ROUTE); | |
191 | if (sock < 0) { | |
192 | zlog_err("Can't open %s socket: %s", nl->name, | |
193 | safe_strerror(errno)); | |
194 | return -1; | |
195 | } | |
196 | ||
197 | memset(&snl, 0, sizeof snl); | |
198 | snl.nl_family = AF_NETLINK; | |
199 | snl.nl_groups = groups; | |
200 | ||
201 | /* Bind the socket to the netlink structure for anything. */ | |
202 | ret = bind(sock, (struct sockaddr *)&snl, sizeof snl); | |
203 | save_errno = errno; | |
204 | if (zserv_privs.change(ZPRIVS_LOWER)) | |
205 | zlog_err("Can't lower privileges"); | |
206 | ||
207 | if (ret < 0) { | |
208 | zlog_err("Can't bind %s socket to group 0x%x: %s", nl->name, | |
209 | snl.nl_groups, safe_strerror(save_errno)); | |
210 | close(sock); | |
211 | return -1; | |
212 | } | |
213 | ||
214 | /* multiple netlink sockets will have different nl_pid */ | |
215 | namelen = sizeof snl; | |
216 | ret = getsockname(sock, (struct sockaddr *)&snl, (socklen_t *)&namelen); | |
217 | if (ret < 0 || namelen != sizeof snl) { | |
218 | zlog_err("Can't get %s socket name: %s", nl->name, | |
219 | safe_strerror(errno)); | |
220 | close(sock); | |
221 | return -1; | |
222 | } | |
223 | ||
224 | nl->snl = snl; | |
225 | nl->sock = sock; | |
226 | return ret; | |
1fdc9eae | 227 | } |
228 | ||
d62a17ae | 229 | static int netlink_information_fetch(struct sockaddr_nl *snl, |
230 | struct nlmsghdr *h, ns_id_t ns_id, | |
231 | int startup) | |
1fdc9eae | 232 | { |
d62a17ae | 233 | /* JF: Ignore messages that aren't from the kernel */ |
234 | if (snl->nl_pid != 0) { | |
235 | zlog_err("Ignoring message from pid %u", snl->nl_pid); | |
236 | return 0; | |
237 | } | |
238 | ||
239 | switch (h->nlmsg_type) { | |
240 | case RTM_NEWROUTE: | |
241 | return netlink_route_change(snl, h, ns_id, startup); | |
242 | break; | |
243 | case RTM_DELROUTE: | |
244 | return netlink_route_change(snl, h, ns_id, startup); | |
245 | break; | |
246 | case RTM_NEWLINK: | |
247 | return netlink_link_change(snl, h, ns_id, startup); | |
248 | break; | |
249 | case RTM_DELLINK: | |
250 | return netlink_link_change(snl, h, ns_id, startup); | |
251 | break; | |
252 | case RTM_NEWADDR: | |
253 | return netlink_interface_addr(snl, h, ns_id, startup); | |
254 | break; | |
255 | case RTM_DELADDR: | |
256 | return netlink_interface_addr(snl, h, ns_id, startup); | |
257 | break; | |
258 | case RTM_NEWNEIGH: | |
259 | return netlink_neigh_change(snl, h, ns_id); | |
260 | break; | |
261 | case RTM_DELNEIGH: | |
262 | return netlink_neigh_change(snl, h, ns_id); | |
263 | break; | |
264 | default: | |
265 | zlog_warn("Unknown netlink nlmsg_type %d vrf %u\n", | |
266 | h->nlmsg_type, ns_id); | |
267 | break; | |
268 | } | |
269 | return 0; | |
1fdc9eae | 270 | } |
271 | ||
d62a17ae | 272 | static int kernel_read(struct thread *thread) |
1fdc9eae | 273 | { |
d62a17ae | 274 | struct zebra_ns *zns = (struct zebra_ns *)THREAD_ARG(thread); |
275 | netlink_parse_info(netlink_information_fetch, &zns->netlink, zns, 5, 0); | |
276 | zns->t_netlink = NULL; | |
277 | thread_add_read(zebrad.master, kernel_read, zns, zns->netlink.sock, | |
278 | &zns->t_netlink); | |
1fdc9eae | 279 | |
d62a17ae | 280 | return 0; |
1fdc9eae | 281 | } |
282 | ||
283 | /* Filter out messages from self that occur on listener socket, | |
284 | * caused by our actions on the command socket | |
285 | */ | |
d62a17ae | 286 | static void netlink_install_filter(int sock, __u32 pid) |
1fdc9eae | 287 | { |
d62a17ae | 288 | struct sock_filter filter[] = { |
289 | /* 0: ldh [4] */ | |
290 | BPF_STMT(BPF_LD | BPF_ABS | BPF_H, | |
291 | offsetof(struct nlmsghdr, nlmsg_type)), | |
292 | /* 1: jeq 0x18 jt 5 jf next */ | |
293 | BPF_JUMP(BPF_JMP | BPF_JEQ | BPF_K, htons(RTM_NEWROUTE), 3, 0), | |
294 | /* 2: jeq 0x19 jt 5 jf next */ | |
295 | BPF_JUMP(BPF_JMP | BPF_JEQ | BPF_K, htons(RTM_DELROUTE), 2, 0), | |
296 | /* 3: jeq 0x19 jt 5 jf next */ | |
297 | BPF_JUMP(BPF_JMP | BPF_JEQ | BPF_K, htons(RTM_NEWNEIGH), 1, 0), | |
298 | /* 4: jeq 0x19 jt 5 jf 8 */ | |
299 | BPF_JUMP(BPF_JMP | BPF_JEQ | BPF_K, htons(RTM_DELNEIGH), 0, 3), | |
300 | /* 5: ldw [12] */ | |
301 | BPF_STMT(BPF_LD | BPF_ABS | BPF_W, | |
302 | offsetof(struct nlmsghdr, nlmsg_pid)), | |
303 | /* 6: jeq XX jt 7 jf 8 */ | |
304 | BPF_JUMP(BPF_JMP | BPF_JEQ | BPF_K, htonl(pid), 0, 1), | |
305 | /* 7: ret 0 (skip) */ | |
306 | BPF_STMT(BPF_RET | BPF_K, 0), | |
307 | /* 8: ret 0xffff (keep) */ | |
308 | BPF_STMT(BPF_RET | BPF_K, 0xffff), | |
309 | }; | |
310 | ||
311 | struct sock_fprog prog = { | |
9d303b37 | 312 | .len = array_size(filter), .filter = filter, |
d62a17ae | 313 | }; |
314 | ||
315 | if (setsockopt(sock, SOL_SOCKET, SO_ATTACH_FILTER, &prog, sizeof(prog)) | |
316 | < 0) | |
317 | zlog_warn("Can't install socket filter: %s\n", | |
318 | safe_strerror(errno)); | |
1fdc9eae | 319 | } |
320 | ||
d62a17ae | 321 | void netlink_parse_rtattr(struct rtattr **tb, int max, struct rtattr *rta, |
322 | int len) | |
1fdc9eae | 323 | { |
d62a17ae | 324 | while (RTA_OK(rta, len)) { |
325 | if (rta->rta_type <= max) | |
326 | tb[rta->rta_type] = rta; | |
327 | rta = RTA_NEXT(rta, len); | |
328 | } | |
1fdc9eae | 329 | } |
330 | ||
d62a17ae | 331 | int addattr_l(struct nlmsghdr *n, unsigned int maxlen, int type, void *data, |
332 | unsigned int alen) | |
1fdc9eae | 333 | { |
d62a17ae | 334 | int len; |
335 | struct rtattr *rta; | |
1fdc9eae | 336 | |
d62a17ae | 337 | len = RTA_LENGTH(alen); |
1fdc9eae | 338 | |
d62a17ae | 339 | if (NLMSG_ALIGN(n->nlmsg_len) + RTA_ALIGN(len) > maxlen) |
340 | return -1; | |
1fdc9eae | 341 | |
d62a17ae | 342 | rta = (struct rtattr *)(((char *)n) + NLMSG_ALIGN(n->nlmsg_len)); |
343 | rta->rta_type = type; | |
344 | rta->rta_len = len; | |
4b2792b5 | 345 | |
d62a17ae | 346 | if (data) |
347 | memcpy(RTA_DATA(rta), data, alen); | |
348 | else | |
349 | assert(alen == 0); | |
4b2792b5 | 350 | |
d62a17ae | 351 | n->nlmsg_len = NLMSG_ALIGN(n->nlmsg_len) + RTA_ALIGN(len); |
1fdc9eae | 352 | |
d62a17ae | 353 | return 0; |
1fdc9eae | 354 | } |
355 | ||
d62a17ae | 356 | int rta_addattr_l(struct rtattr *rta, unsigned int maxlen, int type, void *data, |
357 | unsigned int alen) | |
1fdc9eae | 358 | { |
d62a17ae | 359 | unsigned int len; |
360 | struct rtattr *subrta; | |
1fdc9eae | 361 | |
d62a17ae | 362 | len = RTA_LENGTH(alen); |
1fdc9eae | 363 | |
d62a17ae | 364 | if (RTA_ALIGN(rta->rta_len) + RTA_ALIGN(len) > maxlen) |
365 | return -1; | |
1fdc9eae | 366 | |
d62a17ae | 367 | subrta = (struct rtattr *)(((char *)rta) + RTA_ALIGN(rta->rta_len)); |
368 | subrta->rta_type = type; | |
369 | subrta->rta_len = len; | |
4b2792b5 | 370 | |
d62a17ae | 371 | if (data) |
372 | memcpy(RTA_DATA(subrta), data, alen); | |
373 | else | |
374 | assert(alen == 0); | |
4b2792b5 | 375 | |
d62a17ae | 376 | rta->rta_len = NLMSG_ALIGN(rta->rta_len) + RTA_ALIGN(len); |
1fdc9eae | 377 | |
d62a17ae | 378 | return 0; |
1fdc9eae | 379 | } |
380 | ||
d62a17ae | 381 | int addattr16(struct nlmsghdr *n, unsigned int maxlen, int type, u_int16_t data) |
bbc16902 | 382 | { |
d62a17ae | 383 | return addattr_l(n, maxlen, type, &data, sizeof(u_int16_t)); |
bbc16902 | 384 | } |
385 | ||
d62a17ae | 386 | int addattr32(struct nlmsghdr *n, unsigned int maxlen, int type, int data) |
1fdc9eae | 387 | { |
d62a17ae | 388 | return addattr_l(n, maxlen, type, &data, sizeof(u_int32_t)); |
1fdc9eae | 389 | } |
390 | ||
d62a17ae | 391 | struct rtattr *addattr_nest(struct nlmsghdr *n, int maxlen, int type) |
1fdc9eae | 392 | { |
d62a17ae | 393 | struct rtattr *nest = NLMSG_TAIL(n); |
1fdc9eae | 394 | |
d62a17ae | 395 | addattr_l(n, maxlen, type, NULL, 0); |
396 | return nest; | |
1fdc9eae | 397 | } |
398 | ||
d62a17ae | 399 | int addattr_nest_end(struct nlmsghdr *n, struct rtattr *nest) |
1fdc9eae | 400 | { |
d62a17ae | 401 | nest->rta_len = (u_char *)NLMSG_TAIL(n) - (u_char *)nest; |
402 | return n->nlmsg_len; | |
1fdc9eae | 403 | } |
404 | ||
d62a17ae | 405 | struct rtattr *rta_nest(struct rtattr *rta, int maxlen, int type) |
1fdc9eae | 406 | { |
d62a17ae | 407 | struct rtattr *nest = RTA_TAIL(rta); |
1fdc9eae | 408 | |
d62a17ae | 409 | rta_addattr_l(rta, maxlen, type, NULL, 0); |
410 | return nest; | |
1fdc9eae | 411 | } |
412 | ||
d62a17ae | 413 | int rta_nest_end(struct rtattr *rta, struct rtattr *nest) |
1fdc9eae | 414 | { |
d62a17ae | 415 | nest->rta_len = (u_char *)RTA_TAIL(rta) - (u_char *)nest; |
416 | return rta->rta_len; | |
1fdc9eae | 417 | } |
418 | ||
d62a17ae | 419 | const char *nl_msg_type_to_str(uint16_t msg_type) |
1fdc9eae | 420 | { |
d62a17ae | 421 | return lookup_msg(nlmsg_str, msg_type, ""); |
1fdc9eae | 422 | } |
423 | ||
d62a17ae | 424 | const char *nl_rtproto_to_str(u_char rtproto) |
1fdc9eae | 425 | { |
d62a17ae | 426 | return lookup_msg(rtproto_str, rtproto, ""); |
1fdc9eae | 427 | } |
b339bde7 | 428 | |
d62a17ae | 429 | const char *nl_family_to_str(u_char family) |
b339bde7 | 430 | { |
d62a17ae | 431 | return lookup_msg(family_str, family, ""); |
b339bde7 DS |
432 | } |
433 | ||
d62a17ae | 434 | const char *nl_rttype_to_str(u_char rttype) |
b339bde7 | 435 | { |
d62a17ae | 436 | return lookup_msg(rttype_str, rttype, ""); |
b339bde7 DS |
437 | } |
438 | ||
936ebf0a DS |
439 | /* |
440 | * netlink_parse_info | |
441 | * | |
442 | * Receive message from netlink interface and pass those information | |
443 | * to the given function. | |
444 | * | |
445 | * filter -> Function to call to read the results | |
446 | * nl -> netlink socket information | |
447 | * zns -> The zebra namespace data | |
448 | * count -> How many we should read in, 0 means as much as possible | |
449 | * startup -> Are we reading in under startup conditions? passed to | |
450 | * the filter. | |
451 | */ | |
d62a17ae | 452 | int netlink_parse_info(int (*filter)(struct sockaddr_nl *, struct nlmsghdr *, |
453 | ns_id_t, int), | |
454 | struct nlsock *nl, struct zebra_ns *zns, int count, | |
455 | int startup) | |
1fdc9eae | 456 | { |
d62a17ae | 457 | int status; |
458 | int ret = 0; | |
459 | int error; | |
460 | int read_in = 0; | |
461 | ||
462 | while (1) { | |
463 | char buf[NL_PKT_BUF_SIZE]; | |
464 | struct iovec iov = {.iov_base = buf, .iov_len = sizeof buf}; | |
465 | struct sockaddr_nl snl; | |
466 | struct msghdr msg = {.msg_name = (void *)&snl, | |
467 | .msg_namelen = sizeof snl, | |
468 | .msg_iov = &iov, | |
469 | .msg_iovlen = 1}; | |
470 | struct nlmsghdr *h; | |
471 | ||
472 | if (count && read_in >= count) | |
473 | return 0; | |
474 | ||
475 | status = recvmsg(nl->sock, &msg, 0); | |
476 | if (status < 0) { | |
477 | if (errno == EINTR) | |
478 | continue; | |
479 | if (errno == EWOULDBLOCK || errno == EAGAIN) | |
480 | break; | |
481 | zlog_err("%s recvmsg overrun: %s", nl->name, | |
482 | safe_strerror(errno)); | |
483 | /* | |
484 | * In this case we are screwed. | |
485 | * There is no good way to | |
486 | * recover zebra at this point. | |
487 | */ | |
488 | exit(-1); | |
489 | continue; | |
1fdc9eae | 490 | } |
491 | ||
d62a17ae | 492 | if (status == 0) { |
493 | zlog_err("%s EOF", nl->name); | |
494 | return -1; | |
495 | } | |
496 | ||
497 | if (msg.msg_namelen != sizeof snl) { | |
498 | zlog_err("%s sender address length error: length %d", | |
499 | nl->name, msg.msg_namelen); | |
500 | return -1; | |
501 | } | |
502 | ||
503 | if (IS_ZEBRA_DEBUG_KERNEL_MSGDUMP_RECV) { | |
504 | zlog_debug("%s: << netlink message dump [recv]", | |
505 | __func__); | |
506 | zlog_hexdump(buf, status); | |
507 | } | |
508 | ||
509 | read_in++; | |
510 | for (h = (struct nlmsghdr *)buf; | |
511 | NLMSG_OK(h, (unsigned int)status); | |
512 | h = NLMSG_NEXT(h, status)) { | |
513 | /* Finish of reading. */ | |
514 | if (h->nlmsg_type == NLMSG_DONE) | |
515 | return ret; | |
516 | ||
517 | /* Error handling. */ | |
518 | if (h->nlmsg_type == NLMSG_ERROR) { | |
519 | struct nlmsgerr *err = | |
520 | (struct nlmsgerr *)NLMSG_DATA(h); | |
521 | int errnum = err->error; | |
522 | int msg_type = err->msg.nlmsg_type; | |
523 | ||
524 | /* If the error field is zero, then this is an | |
525 | * ACK */ | |
526 | if (err->error == 0) { | |
527 | if (IS_ZEBRA_DEBUG_KERNEL) { | |
528 | zlog_debug( | |
529 | "%s: %s ACK: type=%s(%u), seq=%u, pid=%u", | |
530 | __FUNCTION__, nl->name, | |
531 | nl_msg_type_to_str( | |
532 | err->msg.nlmsg_type), | |
533 | err->msg.nlmsg_type, | |
534 | err->msg.nlmsg_seq, | |
535 | err->msg.nlmsg_pid); | |
536 | } | |
537 | ||
538 | /* return if not a multipart message, | |
539 | * otherwise continue */ | |
540 | if (!(h->nlmsg_flags & NLM_F_MULTI)) | |
541 | return 0; | |
542 | continue; | |
543 | } | |
544 | ||
545 | if (h->nlmsg_len | |
546 | < NLMSG_LENGTH(sizeof(struct nlmsgerr))) { | |
547 | zlog_err("%s error: message truncated", | |
548 | nl->name); | |
549 | return -1; | |
550 | } | |
551 | ||
552 | /* Deal with errors that occur because of races | |
553 | * in link handling */ | |
554 | if (nl == &zns->netlink_cmd | |
555 | && ((msg_type == RTM_DELROUTE | |
556 | && (-errnum == ENODEV | |
557 | || -errnum == ESRCH)) | |
558 | || (msg_type == RTM_NEWROUTE | |
559 | && (-errnum == ENETDOWN | |
560 | || -errnum == EEXIST)))) { | |
561 | if (IS_ZEBRA_DEBUG_KERNEL) | |
562 | zlog_debug( | |
563 | "%s: error: %s type=%s(%u), seq=%u, pid=%u", | |
564 | nl->name, | |
565 | safe_strerror(-errnum), | |
566 | nl_msg_type_to_str( | |
567 | msg_type), | |
568 | msg_type, | |
569 | err->msg.nlmsg_seq, | |
570 | err->msg.nlmsg_pid); | |
571 | return 0; | |
572 | } | |
573 | ||
574 | /* We see RTM_DELNEIGH when shutting down an | |
575 | * interface with an IPv4 | |
576 | * link-local. The kernel should have already | |
577 | * deleted the neighbor | |
578 | * so do not log these as an error. | |
579 | */ | |
580 | if (msg_type == RTM_DELNEIGH | |
581 | || (nl == &zns->netlink_cmd | |
582 | && msg_type == RTM_NEWROUTE | |
583 | && (-errnum == ESRCH | |
584 | || -errnum == ENETUNREACH))) { | |
585 | /* This is known to happen in some | |
586 | * situations, don't log | |
587 | * as error. | |
588 | */ | |
589 | if (IS_ZEBRA_DEBUG_KERNEL) | |
590 | zlog_debug( | |
591 | "%s error: %s, type=%s(%u), seq=%u, pid=%u", | |
592 | nl->name, | |
593 | safe_strerror(-errnum), | |
594 | nl_msg_type_to_str( | |
595 | msg_type), | |
596 | msg_type, | |
597 | err->msg.nlmsg_seq, | |
598 | err->msg.nlmsg_pid); | |
599 | } else | |
600 | zlog_err( | |
601 | "%s error: %s, type=%s(%u), seq=%u, pid=%u", | |
602 | nl->name, | |
603 | safe_strerror(-errnum), | |
604 | nl_msg_type_to_str(msg_type), | |
605 | msg_type, err->msg.nlmsg_seq, | |
606 | err->msg.nlmsg_pid); | |
607 | ||
608 | return -1; | |
609 | } | |
610 | ||
611 | /* OK we got netlink message. */ | |
612 | if (IS_ZEBRA_DEBUG_KERNEL) | |
613 | zlog_debug( | |
614 | "netlink_parse_info: %s type %s(%u), len=%d, seq=%u, pid=%u", | |
615 | nl->name, | |
616 | nl_msg_type_to_str(h->nlmsg_type), | |
617 | h->nlmsg_type, h->nlmsg_len, | |
618 | h->nlmsg_seq, h->nlmsg_pid); | |
619 | ||
620 | /* skip unsolicited messages originating from command | |
621 | * socket | |
622 | * linux sets the originators port-id for {NEW|DEL}ADDR | |
623 | * messages, | |
624 | * so this has to be checked here. */ | |
625 | if (nl != &zns->netlink_cmd | |
626 | && h->nlmsg_pid == zns->netlink_cmd.snl.nl_pid | |
627 | && (h->nlmsg_type != RTM_NEWADDR | |
628 | && h->nlmsg_type != RTM_DELADDR)) { | |
629 | if (IS_ZEBRA_DEBUG_KERNEL) | |
630 | zlog_debug( | |
631 | "netlink_parse_info: %s packet comes from %s", | |
632 | zns->netlink_cmd.name, | |
633 | nl->name); | |
634 | continue; | |
635 | } | |
636 | ||
637 | error = (*filter)(&snl, h, zns->ns_id, startup); | |
638 | if (error < 0) { | |
639 | zlog_err("%s filter function error", nl->name); | |
640 | ret = error; | |
641 | } | |
642 | } | |
643 | ||
644 | /* After error care. */ | |
645 | if (msg.msg_flags & MSG_TRUNC) { | |
646 | zlog_err("%s error: message truncated", nl->name); | |
647 | continue; | |
648 | } | |
649 | if (status) { | |
650 | zlog_err("%s error: data remnant size %d", nl->name, | |
651 | status); | |
652 | return -1; | |
653 | } | |
654 | } | |
655 | return ret; | |
1fdc9eae | 656 | } |
657 | ||
936ebf0a DS |
658 | /* |
659 | * netlink_talk | |
660 | * | |
661 | * sendmsg() to netlink socket then recvmsg(). | |
662 | * Calls netlink_parse_info to parse returned data | |
663 | * | |
664 | * filter -> The filter to read final results from kernel | |
665 | * nlmsghdr -> The data to send to the kernel | |
666 | * nl -> The netlink socket information | |
667 | * zns -> The zebra namespace information | |
668 | * startup -> Are we reading in under startup conditions | |
669 | * This is passed through eventually to filter. | |
670 | */ | |
d62a17ae | 671 | int netlink_talk(int (*filter)(struct sockaddr_nl *, struct nlmsghdr *, ns_id_t, |
672 | int startup), | |
673 | struct nlmsghdr *n, struct nlsock *nl, struct zebra_ns *zns, | |
674 | int startup) | |
1fdc9eae | 675 | { |
d62a17ae | 676 | int status; |
677 | struct sockaddr_nl snl; | |
678 | struct iovec iov = {.iov_base = (void *)n, .iov_len = n->nlmsg_len}; | |
679 | struct msghdr msg = { | |
680 | .msg_name = (void *)&snl, | |
681 | .msg_namelen = sizeof snl, | |
682 | .msg_iov = &iov, | |
683 | .msg_iovlen = 1, | |
684 | }; | |
685 | int save_errno; | |
686 | ||
687 | memset(&snl, 0, sizeof snl); | |
688 | snl.nl_family = AF_NETLINK; | |
689 | ||
690 | n->nlmsg_seq = ++nl->seq; | |
691 | n->nlmsg_pid = nl->snl.nl_pid; | |
692 | ||
693 | /* Request an acknowledgement by setting NLM_F_ACK */ | |
694 | n->nlmsg_flags |= NLM_F_ACK; | |
695 | ||
696 | if (IS_ZEBRA_DEBUG_KERNEL) | |
697 | zlog_debug( | |
698 | "netlink_talk: %s type %s(%u), len=%d seq=%u flags 0x%x", | |
699 | nl->name, nl_msg_type_to_str(n->nlmsg_type), | |
700 | n->nlmsg_type, n->nlmsg_len, n->nlmsg_seq, | |
701 | n->nlmsg_flags); | |
702 | ||
703 | /* Send message to netlink interface. */ | |
704 | if (zserv_privs.change(ZPRIVS_RAISE)) | |
705 | zlog_err("Can't raise privileges"); | |
706 | status = sendmsg(nl->sock, &msg, 0); | |
707 | save_errno = errno; | |
708 | if (zserv_privs.change(ZPRIVS_LOWER)) | |
709 | zlog_err("Can't lower privileges"); | |
710 | ||
711 | if (IS_ZEBRA_DEBUG_KERNEL_MSGDUMP_SEND) { | |
712 | zlog_debug("%s: >> netlink message dump [sent]", __func__); | |
713 | zlog_hexdump(n, n->nlmsg_len); | |
714 | } | |
715 | ||
716 | if (status < 0) { | |
717 | zlog_err("netlink_talk sendmsg() error: %s", | |
718 | safe_strerror(save_errno)); | |
719 | return -1; | |
720 | } | |
721 | ||
722 | ||
723 | /* | |
724 | * Get reply from netlink socket. | |
725 | * The reply should either be an acknowlegement or an error. | |
726 | */ | |
727 | return netlink_parse_info(filter, nl, zns, 0, startup); | |
1fdc9eae | 728 | } |
729 | ||
289602d7 | 730 | /* Issue request message to kernel via netlink socket. GET messages |
731 | * are issued through this interface. | |
732 | */ | |
d62a17ae | 733 | int netlink_request(struct nlsock *nl, struct nlmsghdr *n) |
1fdc9eae | 734 | { |
d62a17ae | 735 | int ret; |
736 | struct sockaddr_nl snl; | |
737 | int save_errno; | |
738 | ||
739 | /* Check netlink socket. */ | |
740 | if (nl->sock < 0) { | |
741 | zlog_err("%s socket isn't active.", nl->name); | |
742 | return -1; | |
743 | } | |
744 | ||
745 | /* Fill common fields for all requests. */ | |
746 | n->nlmsg_flags = NLM_F_ROOT | NLM_F_MATCH | NLM_F_REQUEST; | |
747 | n->nlmsg_pid = nl->snl.nl_pid; | |
748 | n->nlmsg_seq = ++nl->seq; | |
749 | ||
750 | memset(&snl, 0, sizeof snl); | |
751 | snl.nl_family = AF_NETLINK; | |
752 | ||
753 | /* Raise capabilities and send message, then lower capabilities. */ | |
754 | if (zserv_privs.change(ZPRIVS_RAISE)) { | |
755 | zlog_err("Can't raise privileges"); | |
756 | return -1; | |
757 | } | |
758 | ||
759 | ret = sendto(nl->sock, (void *)n, n->nlmsg_len, 0, | |
760 | (struct sockaddr *)&snl, sizeof snl); | |
761 | save_errno = errno; | |
762 | ||
763 | if (zserv_privs.change(ZPRIVS_LOWER)) | |
764 | zlog_err("Can't lower privileges"); | |
765 | ||
766 | if (ret < 0) { | |
767 | zlog_err("%s sendto failed: %s", nl->name, | |
768 | safe_strerror(save_errno)); | |
769 | return -1; | |
770 | } | |
771 | ||
772 | return 0; | |
1fdc9eae | 773 | } |
774 | ||
775 | /* Exported interface function. This function simply calls | |
776 | netlink_socket (). */ | |
d62a17ae | 777 | void kernel_init(struct zebra_ns *zns) |
1fdc9eae | 778 | { |
d62a17ae | 779 | unsigned long groups; |
780 | ||
781 | /* Initialize netlink sockets */ | |
782 | groups = RTMGRP_LINK | RTMGRP_IPV4_ROUTE | RTMGRP_IPV4_IFADDR | |
783 | | RTMGRP_IPV6_ROUTE | RTMGRP_IPV6_IFADDR | RTMGRP_IPV4_MROUTE | |
784 | | RTMGRP_NEIGH; | |
785 | ||
786 | snprintf(zns->netlink.name, sizeof(zns->netlink.name), | |
787 | "netlink-listen (NS %u)", zns->ns_id); | |
788 | zns->netlink.sock = -1; | |
789 | netlink_socket(&zns->netlink, groups, zns->ns_id); | |
790 | ||
791 | snprintf(zns->netlink_cmd.name, sizeof(zns->netlink_cmd.name), | |
792 | "netlink-cmd (NS %u)", zns->ns_id); | |
793 | zns->netlink_cmd.sock = -1; | |
794 | netlink_socket(&zns->netlink_cmd, 0, zns->ns_id); | |
795 | ||
796 | /* Register kernel socket. */ | |
797 | if (zns->netlink.sock > 0) { | |
798 | /* Only want non-blocking on the netlink event socket */ | |
799 | if (fcntl(zns->netlink.sock, F_SETFL, O_NONBLOCK) < 0) | |
800 | zlog_err("Can't set %s socket flags: %s", | |
801 | zns->netlink.name, safe_strerror(errno)); | |
802 | ||
803 | /* Set receive buffer size if it's set from command line */ | |
804 | if (nl_rcvbufsize) | |
805 | netlink_recvbuf(&zns->netlink, nl_rcvbufsize); | |
806 | ||
807 | netlink_install_filter(zns->netlink.sock, | |
808 | zns->netlink_cmd.snl.nl_pid); | |
809 | zns->t_netlink = NULL; | |
810 | thread_add_read(zebrad.master, kernel_read, zns, | |
811 | zns->netlink.sock, &zns->t_netlink); | |
812 | } | |
813 | ||
814 | rt_netlink_init(); | |
1fdc9eae | 815 | } |
816 | ||
d62a17ae | 817 | void kernel_terminate(struct zebra_ns *zns) |
1fdc9eae | 818 | { |
d62a17ae | 819 | THREAD_READ_OFF(zns->t_netlink); |
820 | ||
821 | if (zns->netlink.sock >= 0) { | |
822 | close(zns->netlink.sock); | |
823 | zns->netlink.sock = -1; | |
824 | } | |
825 | ||
826 | if (zns->netlink_cmd.sock >= 0) { | |
827 | close(zns->netlink_cmd.sock); | |
828 | zns->netlink_cmd.sock = -1; | |
829 | } | |
1fdc9eae | 830 | } |
ddfeb486 DL |
831 | |
832 | #endif /* HAVE_NETLINK */ |