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1 | /* | |
2 | * NS functions. | |
3 | * Copyright (C) 2014 6WIND S.A. | |
4 | * | |
5 | * This file is part of GNU Zebra. | |
6 | * | |
7 | * GNU Zebra is free software; you can redistribute it and/or modify | |
8 | * it under the terms of the GNU General Public License as published | |
9 | * by the Free Software Foundation; either version 2, or (at your | |
10 | * option) any later version. | |
11 | * | |
12 | * GNU Zebra is distributed in the hope that it will be useful, but | |
13 | * WITHOUT ANY WARRANTY; without even the implied warranty of | |
14 | * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the GNU | |
15 | * General Public License for more details. | |
16 | * | |
17 | * You should have received a copy of the GNU General Public License along | |
18 | * with this program; see the file COPYING; if not, write to the Free Software | |
19 | * Foundation, Inc., 51 Franklin St, Fifth Floor, Boston, MA 02110-1301 USA | |
20 | */ | |
21 | ||
22 | #include <zebra.h> | |
23 | ||
24 | #ifdef HAVE_NETNS | |
25 | #undef _GNU_SOURCE | |
26 | #define _GNU_SOURCE | |
27 | ||
28 | #include <sched.h> | |
29 | #endif | |
30 | ||
31 | /* for basename */ | |
32 | #include <libgen.h> | |
33 | ||
34 | #include "if.h" | |
35 | #include "ns.h" | |
36 | #include "log.h" | |
37 | #include "memory.h" | |
38 | #include "command.h" | |
39 | #include "vty.h" | |
40 | #include "vrf.h" | |
41 | #include "lib_errors.h" | |
42 | ||
43 | DEFINE_MTYPE_STATIC(LIB, NS, "NetNS Context") | |
44 | DEFINE_MTYPE_STATIC(LIB, NS_NAME, "NetNS Name") | |
45 | ||
46 | /* default NS ID value used when VRF backend is not NETNS */ | |
47 | #define NS_DEFAULT_INTERNAL 0 | |
48 | ||
49 | static inline int ns_compare(const struct ns *ns, const struct ns *ns2); | |
50 | static struct ns *ns_lookup_name_internal(const char *name); | |
51 | ||
52 | RB_GENERATE(ns_head, ns, entry, ns_compare) | |
53 | ||
54 | struct ns_head ns_tree = RB_INITIALIZER(&ns_tree); | |
55 | ||
56 | static struct ns *default_ns; | |
57 | static int ns_current_ns_fd; | |
58 | static int ns_default_ns_fd; | |
59 | ||
60 | static int ns_debug; | |
61 | ||
62 | struct ns_map_nsid { | |
63 | RB_ENTRY(ns_map_nsid) id_entry; | |
64 | ns_id_t ns_id_external; | |
65 | ns_id_t ns_id; | |
66 | }; | |
67 | ||
68 | static inline int ns_map_compare(const struct ns_map_nsid *a, | |
69 | const struct ns_map_nsid *b) | |
70 | { | |
71 | return (a->ns_id - b->ns_id); | |
72 | } | |
73 | ||
74 | RB_HEAD(ns_map_nsid_head, ns_map_nsid); | |
75 | RB_PROTOTYPE(ns_map_nsid_head, ns_map_nsid, id_entry, ns_map_compare); | |
76 | RB_GENERATE(ns_map_nsid_head, ns_map_nsid, id_entry, ns_map_compare); | |
77 | struct ns_map_nsid_head ns_map_nsid_list = RB_INITIALIZER(&ns_map_nsid_list); | |
78 | ||
79 | static ns_id_t ns_id_external_numbering; | |
80 | ||
81 | ||
82 | #ifndef CLONE_NEWNET | |
83 | #define CLONE_NEWNET 0x40000000 | |
84 | /* New network namespace (lo, device, names sockets, etc) */ | |
85 | #endif | |
86 | ||
87 | #ifndef HAVE_SETNS | |
88 | static inline int setns(int fd, int nstype) | |
89 | { | |
90 | #ifdef __NR_setns | |
91 | return syscall(__NR_setns, fd, nstype); | |
92 | #else | |
93 | errno = EINVAL; | |
94 | return -1; | |
95 | #endif | |
96 | } | |
97 | #endif /* !HAVE_SETNS */ | |
98 | ||
99 | #ifdef HAVE_NETNS | |
100 | static int have_netns_enabled = -1; | |
101 | #endif /* HAVE_NETNS */ | |
102 | ||
103 | /* default NS ID value used when VRF backend is not NETNS */ | |
104 | #define NS_DEFAULT_INTERNAL 0 | |
105 | ||
106 | static int have_netns(void) | |
107 | { | |
108 | #ifdef HAVE_NETNS | |
109 | if (have_netns_enabled < 0) { | |
110 | int fd = open(NS_DEFAULT_NAME, O_RDONLY); | |
111 | ||
112 | if (fd < 0) | |
113 | have_netns_enabled = 0; | |
114 | else { | |
115 | have_netns_enabled = 1; | |
116 | close(fd); | |
117 | } | |
118 | } | |
119 | return have_netns_enabled; | |
120 | #else | |
121 | return 0; | |
122 | #endif | |
123 | } | |
124 | ||
125 | /* Holding NS hooks */ | |
126 | struct ns_master { | |
127 | int (*ns_new_hook)(struct ns *ns); | |
128 | int (*ns_delete_hook)(struct ns *ns); | |
129 | int (*ns_enable_hook)(struct ns *ns); | |
130 | int (*ns_disable_hook)(struct ns *ns); | |
131 | } ns_master = { | |
132 | 0, | |
133 | }; | |
134 | ||
135 | static int ns_is_enabled(struct ns *ns); | |
136 | ||
137 | static inline int ns_compare(const struct ns *a, const struct ns *b) | |
138 | { | |
139 | return (a->ns_id - b->ns_id); | |
140 | } | |
141 | ||
142 | /* Look up a NS by identifier. */ | |
143 | static struct ns *ns_lookup_internal(ns_id_t ns_id) | |
144 | { | |
145 | struct ns ns; | |
146 | ||
147 | ns.ns_id = ns_id; | |
148 | return RB_FIND(ns_head, &ns_tree, &ns); | |
149 | } | |
150 | ||
151 | /* Look up a NS by name */ | |
152 | static struct ns *ns_lookup_name_internal(const char *name) | |
153 | { | |
154 | struct ns *ns = NULL; | |
155 | ||
156 | RB_FOREACH (ns, ns_head, &ns_tree) { | |
157 | if (ns->name != NULL) { | |
158 | if (strcmp(name, ns->name) == 0) | |
159 | return ns; | |
160 | } | |
161 | } | |
162 | return NULL; | |
163 | } | |
164 | ||
165 | static struct ns *ns_get_created_internal(struct ns *ns, char *name, | |
166 | ns_id_t ns_id) | |
167 | { | |
168 | int created = 0; | |
169 | /* | |
170 | * Initialize interfaces. | |
171 | */ | |
172 | if (!ns && !name && ns_id != NS_UNKNOWN) | |
173 | ns = ns_lookup_internal(ns_id); | |
174 | if (!ns && name) | |
175 | ns = ns_lookup_name_internal(name); | |
176 | if (!ns) { | |
177 | ns = XCALLOC(MTYPE_NS, sizeof(struct ns)); | |
178 | ns->ns_id = ns_id; | |
179 | if (name) | |
180 | ns->name = XSTRDUP(MTYPE_NS_NAME, name); | |
181 | ns->fd = -1; | |
182 | RB_INSERT(ns_head, &ns_tree, ns); | |
183 | created = 1; | |
184 | } | |
185 | if (ns_id != ns->ns_id) { | |
186 | RB_REMOVE(ns_head, &ns_tree, ns); | |
187 | ns->ns_id = ns_id; | |
188 | RB_INSERT(ns_head, &ns_tree, ns); | |
189 | } | |
190 | if (!created) | |
191 | return ns; | |
192 | if (ns_debug) { | |
193 | if (ns->ns_id != NS_UNKNOWN) | |
194 | zlog_info("NS %u is created.", ns->ns_id); | |
195 | else | |
196 | zlog_info("NS %s is created.", ns->name); | |
197 | } | |
198 | if (ns_master.ns_new_hook) | |
199 | (*ns_master.ns_new_hook)(ns); | |
200 | return ns; | |
201 | } | |
202 | ||
203 | /* | |
204 | * Enable a NS - that is, let the NS be ready to use. | |
205 | * The NS_ENABLE_HOOK callback will be called to inform | |
206 | * that they can allocate resources in this NS. | |
207 | * | |
208 | * RETURN: 1 - enabled successfully; otherwise, 0. | |
209 | */ | |
210 | static int ns_enable_internal(struct ns *ns, void (*func)(ns_id_t, void *)) | |
211 | { | |
212 | if (!ns_is_enabled(ns)) { | |
213 | if (have_netns()) { | |
214 | ns->fd = open(ns->name, O_RDONLY); | |
215 | } else { | |
216 | ns->fd = -2; | |
217 | /* Remember ns_enable_hook has been called */ | |
218 | errno = -ENOTSUP; | |
219 | } | |
220 | ||
221 | if (!ns_is_enabled(ns)) { | |
222 | flog_err_sys(EC_LIB_SYSTEM_CALL, | |
223 | "Can not enable NS %u: %s!", ns->ns_id, | |
224 | safe_strerror(errno)); | |
225 | return 0; | |
226 | } | |
227 | ||
228 | /* Non default NS. leave */ | |
229 | if (ns->ns_id == NS_UNKNOWN) { | |
230 | flog_err(EC_LIB_NS, | |
231 | "Can not enable NS %s %u: Invalid NSID", | |
232 | ns->name, ns->ns_id); | |
233 | return 0; | |
234 | } | |
235 | if (func) | |
236 | func(ns->ns_id, (void *)ns->vrf_ctxt); | |
237 | if (ns_debug) { | |
238 | if (have_netns()) | |
239 | zlog_info("NS %u is associated with NETNS %s.", | |
240 | ns->ns_id, ns->name); | |
241 | zlog_info("NS %u is enabled.", ns->ns_id); | |
242 | } | |
243 | /* zebra first receives NS enable event, | |
244 | * then VRF enable event | |
245 | */ | |
246 | if (ns_master.ns_enable_hook) | |
247 | (*ns_master.ns_enable_hook)(ns); | |
248 | } | |
249 | ||
250 | return 1; | |
251 | } | |
252 | ||
253 | /* | |
254 | * Check whether the NS is enabled - that is, whether the NS | |
255 | * is ready to allocate resources. Currently there's only one | |
256 | * type of resource: socket. | |
257 | */ | |
258 | static int ns_is_enabled(struct ns *ns) | |
259 | { | |
260 | if (have_netns()) | |
261 | return ns && ns->fd >= 0; | |
262 | else | |
263 | return ns && ns->fd == -2 && ns->ns_id == NS_DEFAULT; | |
264 | } | |
265 | ||
266 | /* | |
267 | * Disable a NS - that is, let the NS be unusable. | |
268 | * The NS_DELETE_HOOK callback will be called to inform | |
269 | * that they must release the resources in the NS. | |
270 | */ | |
271 | static void ns_disable_internal(struct ns *ns) | |
272 | { | |
273 | if (ns_is_enabled(ns)) { | |
274 | if (ns_debug) | |
275 | zlog_info("NS %u is to be disabled.", ns->ns_id); | |
276 | ||
277 | if (ns_master.ns_disable_hook) | |
278 | (*ns_master.ns_disable_hook)(ns); | |
279 | ||
280 | if (have_netns()) | |
281 | close(ns->fd); | |
282 | ||
283 | ns->fd = -1; | |
284 | } | |
285 | } | |
286 | ||
287 | /* VRF list existance check by name. */ | |
288 | static struct ns_map_nsid *ns_map_nsid_lookup_by_nsid(ns_id_t ns_id) | |
289 | { | |
290 | struct ns_map_nsid ns_map; | |
291 | ||
292 | ns_map.ns_id = ns_id; | |
293 | return RB_FIND(ns_map_nsid_head, &ns_map_nsid_list, &ns_map); | |
294 | } | |
295 | ||
296 | ns_id_t ns_map_nsid_with_external(ns_id_t ns_id, bool map) | |
297 | { | |
298 | struct ns_map_nsid *ns_map; | |
299 | vrf_id_t ns_id_external; | |
300 | ||
301 | ns_map = ns_map_nsid_lookup_by_nsid(ns_id); | |
302 | if (ns_map && !map) { | |
303 | ns_id_external = ns_map->ns_id_external; | |
304 | RB_REMOVE(ns_map_nsid_head, &ns_map_nsid_list, ns_map); | |
305 | return ns_id_external; | |
306 | } | |
307 | if (ns_map) | |
308 | return ns_map->ns_id_external; | |
309 | ns_map = XCALLOC(MTYPE_NS, sizeof(struct ns_map_nsid)); | |
310 | /* increase vrf_id | |
311 | * default vrf is the first one : 0 | |
312 | */ | |
313 | ns_map->ns_id_external = ns_id_external_numbering++; | |
314 | ns_map->ns_id = ns_id; | |
315 | RB_INSERT(ns_map_nsid_head, &ns_map_nsid_list, ns_map); | |
316 | return ns_map->ns_id_external; | |
317 | } | |
318 | ||
319 | struct ns *ns_get_created(struct ns *ns, char *name, ns_id_t ns_id) | |
320 | { | |
321 | return ns_get_created_internal(ns, name, ns_id); | |
322 | } | |
323 | ||
324 | int ns_have_netns(void) | |
325 | { | |
326 | return have_netns(); | |
327 | } | |
328 | ||
329 | /* Delete a NS. This is called in ns_terminate(). */ | |
330 | void ns_delete(struct ns *ns) | |
331 | { | |
332 | if (ns_debug) | |
333 | zlog_info("NS %u is to be deleted.", ns->ns_id); | |
334 | ||
335 | ns_disable(ns); | |
336 | ||
337 | if (ns_master.ns_delete_hook) | |
338 | (*ns_master.ns_delete_hook)(ns); | |
339 | ||
340 | /* | |
341 | * I'm not entirely sure if the vrf->iflist | |
342 | * needs to be moved into here or not. | |
343 | */ | |
344 | // if_terminate (&ns->iflist); | |
345 | ||
346 | RB_REMOVE(ns_head, &ns_tree, ns); | |
347 | if (ns->name) | |
348 | XFREE(MTYPE_NS_NAME, ns->name); | |
349 | ||
350 | XFREE(MTYPE_NS, ns); | |
351 | } | |
352 | ||
353 | /* Look up the data pointer of the specified VRF. */ | |
354 | void *ns_info_lookup(ns_id_t ns_id) | |
355 | { | |
356 | struct ns *ns = ns_lookup_internal(ns_id); | |
357 | ||
358 | return ns ? ns->info : NULL; | |
359 | } | |
360 | ||
361 | /* Look up a NS by name */ | |
362 | struct ns *ns_lookup_name(const char *name) | |
363 | { | |
364 | return ns_lookup_name_internal(name); | |
365 | } | |
366 | ||
367 | int ns_enable(struct ns *ns, void (*func)(ns_id_t, void *)) | |
368 | { | |
369 | return ns_enable_internal(ns, func); | |
370 | } | |
371 | ||
372 | void ns_disable(struct ns *ns) | |
373 | { | |
374 | return ns_disable_internal(ns); | |
375 | } | |
376 | ||
377 | struct ns *ns_lookup(ns_id_t ns_id) | |
378 | { | |
379 | return ns_lookup_internal(ns_id); | |
380 | } | |
381 | ||
382 | void ns_walk_func(int (*func)(struct ns *)) | |
383 | { | |
384 | struct ns *ns = NULL; | |
385 | ||
386 | RB_FOREACH (ns, ns_head, &ns_tree) | |
387 | func(ns); | |
388 | } | |
389 | ||
390 | const char *ns_get_name(struct ns *ns) | |
391 | { | |
392 | if (!ns) | |
393 | return NULL; | |
394 | return ns->name; | |
395 | } | |
396 | ||
397 | /* Add a NS hook. Please add hooks before calling ns_init(). */ | |
398 | void ns_add_hook(int type, int (*func)(struct ns *)) | |
399 | { | |
400 | switch (type) { | |
401 | case NS_NEW_HOOK: | |
402 | ns_master.ns_new_hook = func; | |
403 | break; | |
404 | case NS_DELETE_HOOK: | |
405 | ns_master.ns_delete_hook = func; | |
406 | break; | |
407 | case NS_ENABLE_HOOK: | |
408 | ns_master.ns_enable_hook = func; | |
409 | break; | |
410 | case NS_DISABLE_HOOK: | |
411 | ns_master.ns_disable_hook = func; | |
412 | break; | |
413 | default: | |
414 | break; | |
415 | } | |
416 | } | |
417 | ||
418 | /* | |
419 | * NS realization with NETNS | |
420 | */ | |
421 | ||
422 | char *ns_netns_pathname(struct vty *vty, const char *name) | |
423 | { | |
424 | static char pathname[PATH_MAX]; | |
425 | char *result; | |
426 | char *check_base; | |
427 | ||
428 | if (name[0] == '/') /* absolute pathname */ | |
429 | result = realpath(name, pathname); | |
430 | else { | |
431 | /* relevant pathname */ | |
432 | char tmp_name[PATH_MAX]; | |
433 | ||
434 | snprintf(tmp_name, PATH_MAX, "%s/%s", NS_RUN_DIR, name); | |
435 | result = realpath(tmp_name, pathname); | |
436 | } | |
437 | ||
438 | if (!result) { | |
439 | if (vty) | |
440 | vty_out(vty, "Invalid pathname for %s: %s\n", | |
441 | pathname, | |
442 | safe_strerror(errno)); | |
443 | else | |
444 | flog_warn(EC_LIB_LINUX_NS, | |
445 | "Invalid pathname for %s: %s", pathname, | |
446 | safe_strerror(errno)); | |
447 | return NULL; | |
448 | } | |
449 | check_base = basename(pathname); | |
450 | if (check_base != NULL && strlen(check_base) + 1 > NS_NAMSIZ) { | |
451 | if (vty) | |
452 | vty_out(vty, "NS name (%s) invalid: too long (>%d)\n", | |
453 | check_base, NS_NAMSIZ - 1); | |
454 | else | |
455 | flog_warn(EC_LIB_LINUX_NS, | |
456 | "NS name (%s) invalid: too long (>%d)", | |
457 | check_base, NS_NAMSIZ - 1); | |
458 | return NULL; | |
459 | } | |
460 | return pathname; | |
461 | } | |
462 | ||
463 | void ns_init(void) | |
464 | { | |
465 | static int ns_initialised; | |
466 | ||
467 | ns_debug = 0; | |
468 | /* silently return as initialisation done */ | |
469 | if (ns_initialised == 1) | |
470 | return; | |
471 | errno = 0; | |
472 | if (have_netns()) | |
473 | ns_default_ns_fd = open(NS_DEFAULT_NAME, O_RDONLY); | |
474 | else { | |
475 | ns_default_ns_fd = -1; | |
476 | default_ns = NULL; | |
477 | } | |
478 | ns_current_ns_fd = -1; | |
479 | ns_initialised = 1; | |
480 | } | |
481 | ||
482 | /* Initialize NS module. */ | |
483 | void ns_init_management(ns_id_t default_ns_id, ns_id_t internal_ns) | |
484 | { | |
485 | int fd; | |
486 | ||
487 | ns_init(); | |
488 | default_ns = ns_get_created_internal(NULL, NULL, default_ns_id); | |
489 | if (!default_ns) { | |
490 | flog_err(EC_LIB_NS, "%s: failed to create the default NS!", | |
491 | __func__); | |
492 | exit(1); | |
493 | } | |
494 | if (have_netns()) { | |
495 | fd = open(NS_DEFAULT_NAME, O_RDONLY); | |
496 | default_ns->fd = fd; | |
497 | } | |
498 | default_ns->internal_ns_id = internal_ns; | |
499 | ||
500 | /* Set the default NS name. */ | |
501 | default_ns->name = XSTRDUP(MTYPE_NS_NAME, NS_DEFAULT_NAME); | |
502 | if (ns_debug) | |
503 | zlog_info("%s: default NSID is %u", __func__, | |
504 | default_ns->ns_id); | |
505 | ||
506 | /* Enable the default NS. */ | |
507 | if (!ns_enable(default_ns, NULL)) { | |
508 | flog_err(EC_LIB_NS, "%s: failed to enable the default NS!", | |
509 | __func__); | |
510 | exit(1); | |
511 | } | |
512 | } | |
513 | ||
514 | /* Terminate NS module. */ | |
515 | void ns_terminate(void) | |
516 | { | |
517 | struct ns *ns; | |
518 | ||
519 | while (!RB_EMPTY(ns_head, &ns_tree)) { | |
520 | ns = RB_ROOT(ns_head, &ns_tree); | |
521 | ||
522 | ns_delete(ns); | |
523 | } | |
524 | } | |
525 | ||
526 | int ns_switch_to_netns(const char *name) | |
527 | { | |
528 | int ret; | |
529 | int fd; | |
530 | ||
531 | if (name == NULL) | |
532 | return -1; | |
533 | if (ns_default_ns_fd == -1) | |
534 | return -1; | |
535 | fd = open(name, O_RDONLY); | |
536 | if (fd == -1) { | |
537 | errno = EINVAL; | |
538 | return -1; | |
539 | } | |
540 | ret = setns(fd, CLONE_NEWNET); | |
541 | ns_current_ns_fd = fd; | |
542 | close(fd); | |
543 | return ret; | |
544 | } | |
545 | ||
546 | /* returns 1 if switch() was not called before | |
547 | * return status of setns() otherwise | |
548 | */ | |
549 | int ns_switchback_to_initial(void) | |
550 | { | |
551 | if (ns_current_ns_fd != -1 && ns_default_ns_fd != -1) { | |
552 | int ret; | |
553 | ||
554 | ret = setns(ns_default_ns_fd, CLONE_NEWNET); | |
555 | ns_current_ns_fd = -1; | |
556 | return ret; | |
557 | } | |
558 | /* silently ignore if setns() is not called */ | |
559 | return 1; | |
560 | } | |
561 | ||
562 | /* Create a socket for the NS. */ | |
563 | int ns_socket(int domain, int type, int protocol, ns_id_t ns_id) | |
564 | { | |
565 | struct ns *ns = ns_lookup(ns_id); | |
566 | int ret; | |
567 | ||
568 | if (!ns || !ns_is_enabled(ns)) { | |
569 | errno = EINVAL; | |
570 | return -1; | |
571 | } | |
572 | if (have_netns()) { | |
573 | ret = (ns_id != NS_DEFAULT) ? setns(ns->fd, CLONE_NEWNET) : 0; | |
574 | if (ret >= 0) { | |
575 | ret = socket(domain, type, protocol); | |
576 | if (ns_id != NS_DEFAULT) { | |
577 | setns(ns_lookup(NS_DEFAULT)->fd, CLONE_NEWNET); | |
578 | ns_current_ns_fd = ns_id; | |
579 | } | |
580 | } | |
581 | } else | |
582 | ret = socket(domain, type, protocol); | |
583 | ||
584 | return ret; | |
585 | } | |
586 | ||
587 | ns_id_t ns_get_default_id(void) | |
588 | { | |
589 | if (default_ns) | |
590 | return default_ns->ns_id; | |
591 | return NS_DEFAULT_INTERNAL; | |
592 | } |