]>
Commit | Line | Data |
---|---|---|
1 | /* | |
2 | * ll_map.c | |
3 | * | |
4 | * This program is free software; you can redistribute it and/or | |
5 | * modify it under the terms of the GNU General Public License | |
6 | * as published by the Free Software Foundation; either version | |
7 | * 2 of the License, or (at your option) any later version. | |
8 | * | |
9 | * Authors: Alexey Kuznetsov, <kuznet@ms2.inr.ac.ru> | |
10 | * | |
11 | */ | |
12 | ||
13 | #include <stdio.h> | |
14 | #include <stdlib.h> | |
15 | #include <unistd.h> | |
16 | #include <fcntl.h> | |
17 | #include <sys/socket.h> | |
18 | #include <netinet/in.h> | |
19 | #include <string.h> | |
20 | #include <net/if.h> | |
21 | ||
22 | #include "libnetlink.h" | |
23 | #include "ll_map.h" | |
24 | #include "list.h" | |
25 | #include "utils.h" | |
26 | ||
27 | struct ll_cache { | |
28 | struct hlist_node idx_hash; | |
29 | struct hlist_node name_hash; | |
30 | unsigned flags; | |
31 | unsigned index; | |
32 | unsigned short type; | |
33 | struct list_head altnames_list; | |
34 | char name[]; | |
35 | }; | |
36 | ||
37 | #define IDXMAP_SIZE 1024 | |
38 | static struct hlist_head idx_head[IDXMAP_SIZE]; | |
39 | static struct hlist_head name_head[IDXMAP_SIZE]; | |
40 | ||
41 | static struct ll_cache *ll_get_by_index(unsigned index) | |
42 | { | |
43 | struct hlist_node *n; | |
44 | unsigned h = index & (IDXMAP_SIZE - 1); | |
45 | ||
46 | hlist_for_each(n, &idx_head[h]) { | |
47 | struct ll_cache *im | |
48 | = container_of(n, struct ll_cache, idx_hash); | |
49 | if (im->index == index) | |
50 | return im; | |
51 | } | |
52 | ||
53 | return NULL; | |
54 | } | |
55 | ||
56 | unsigned namehash(const char *str) | |
57 | { | |
58 | unsigned hash = 5381; | |
59 | ||
60 | while (*str) | |
61 | hash = ((hash << 5) + hash) + *str++; /* hash * 33 + c */ | |
62 | ||
63 | return hash; | |
64 | } | |
65 | ||
66 | static struct ll_cache *ll_get_by_name(const char *name) | |
67 | { | |
68 | struct hlist_node *n; | |
69 | unsigned h = namehash(name) & (IDXMAP_SIZE - 1); | |
70 | ||
71 | hlist_for_each(n, &name_head[h]) { | |
72 | struct ll_cache *im | |
73 | = container_of(n, struct ll_cache, name_hash); | |
74 | ||
75 | if (strcmp(im->name, name) == 0) | |
76 | return im; | |
77 | } | |
78 | ||
79 | return NULL; | |
80 | } | |
81 | ||
82 | static struct ll_cache *ll_entry_create(struct ifinfomsg *ifi, | |
83 | const char *ifname, | |
84 | struct ll_cache *parent_im) | |
85 | { | |
86 | struct ll_cache *im; | |
87 | unsigned int h; | |
88 | ||
89 | im = malloc(sizeof(*im) + strlen(ifname) + 1); | |
90 | if (!im) | |
91 | return NULL; | |
92 | im->index = ifi->ifi_index; | |
93 | strcpy(im->name, ifname); | |
94 | im->type = ifi->ifi_type; | |
95 | im->flags = ifi->ifi_flags; | |
96 | ||
97 | if (parent_im) { | |
98 | list_add_tail(&im->altnames_list, &parent_im->altnames_list); | |
99 | } else { | |
100 | /* This is parent, insert to index hash. */ | |
101 | h = ifi->ifi_index & (IDXMAP_SIZE - 1); | |
102 | hlist_add_head(&im->idx_hash, &idx_head[h]); | |
103 | INIT_LIST_HEAD(&im->altnames_list); | |
104 | } | |
105 | ||
106 | h = namehash(ifname) & (IDXMAP_SIZE - 1); | |
107 | hlist_add_head(&im->name_hash, &name_head[h]); | |
108 | return im; | |
109 | } | |
110 | ||
111 | static void ll_entry_destroy(struct ll_cache *im, bool im_is_parent) | |
112 | { | |
113 | hlist_del(&im->name_hash); | |
114 | if (im_is_parent) | |
115 | hlist_del(&im->idx_hash); | |
116 | else | |
117 | list_del(&im->altnames_list); | |
118 | free(im); | |
119 | } | |
120 | ||
121 | static void ll_entry_update(struct ll_cache *im, struct ifinfomsg *ifi, | |
122 | const char *ifname) | |
123 | { | |
124 | unsigned int h; | |
125 | ||
126 | im->flags = ifi->ifi_flags; | |
127 | if (!strcmp(im->name, ifname)) | |
128 | return; | |
129 | hlist_del(&im->name_hash); | |
130 | h = namehash(ifname) & (IDXMAP_SIZE - 1); | |
131 | hlist_add_head(&im->name_hash, &name_head[h]); | |
132 | } | |
133 | ||
134 | static void ll_altname_entries_create(struct ll_cache *parent_im, | |
135 | struct ifinfomsg *ifi, struct rtattr **tb) | |
136 | { | |
137 | struct rtattr *i, *proplist = tb[IFLA_PROP_LIST]; | |
138 | int rem; | |
139 | ||
140 | if (!proplist) | |
141 | return; | |
142 | rem = RTA_PAYLOAD(proplist); | |
143 | for (i = RTA_DATA(proplist); RTA_OK(i, rem); | |
144 | i = RTA_NEXT(i, rem)) { | |
145 | if (i->rta_type != IFLA_ALT_IFNAME) | |
146 | continue; | |
147 | ll_entry_create(ifi, rta_getattr_str(i), parent_im); | |
148 | } | |
149 | } | |
150 | ||
151 | static void ll_altname_entries_destroy(struct ll_cache *parent_im) | |
152 | { | |
153 | struct ll_cache *im, *tmp; | |
154 | ||
155 | list_for_each_entry_safe(im, tmp, &parent_im->altnames_list, | |
156 | altnames_list) | |
157 | ll_entry_destroy(im, false); | |
158 | } | |
159 | ||
160 | static void ll_altname_entries_update(struct ll_cache *parent_im, | |
161 | struct ifinfomsg *ifi, struct rtattr **tb) | |
162 | { | |
163 | struct rtattr *i, *proplist = tb[IFLA_PROP_LIST]; | |
164 | struct ll_cache *im; | |
165 | int rem; | |
166 | ||
167 | if (!proplist) { | |
168 | ll_altname_entries_destroy(parent_im); | |
169 | return; | |
170 | } | |
171 | ||
172 | /* Simply compare the altname list with the cached one | |
173 | * and if it does not fit 1:1, recreate the cached list | |
174 | * from scratch. | |
175 | */ | |
176 | im = list_first_entry(&parent_im->altnames_list, typeof(*im), | |
177 | altnames_list); | |
178 | rem = RTA_PAYLOAD(proplist); | |
179 | for (i = RTA_DATA(proplist); RTA_OK(i, rem); | |
180 | i = RTA_NEXT(i, rem)) { | |
181 | if (i->rta_type != IFLA_ALT_IFNAME) | |
182 | continue; | |
183 | if (!im || strcmp(rta_getattr_str(i), im->name)) | |
184 | goto recreate_altname_entries; | |
185 | im = list_next_entry(im, altnames_list); | |
186 | } | |
187 | if (list_next_entry(im, altnames_list)) | |
188 | goto recreate_altname_entries; | |
189 | return; | |
190 | ||
191 | recreate_altname_entries: | |
192 | ll_altname_entries_destroy(parent_im); | |
193 | ll_altname_entries_create(parent_im, ifi, tb); | |
194 | } | |
195 | ||
196 | static void ll_entries_create(struct ifinfomsg *ifi, struct rtattr **tb) | |
197 | { | |
198 | struct ll_cache *parent_im; | |
199 | ||
200 | if (!tb[IFLA_IFNAME]) | |
201 | return; | |
202 | parent_im = ll_entry_create(ifi, rta_getattr_str(tb[IFLA_IFNAME]), | |
203 | NULL); | |
204 | if (!parent_im) | |
205 | return; | |
206 | ll_altname_entries_create(parent_im, ifi, tb); | |
207 | } | |
208 | ||
209 | static void ll_entries_destroy(struct ll_cache *parent_im) | |
210 | { | |
211 | ll_altname_entries_destroy(parent_im); | |
212 | ll_entry_destroy(parent_im, true); | |
213 | } | |
214 | ||
215 | static void ll_entries_update(struct ll_cache *parent_im, | |
216 | struct ifinfomsg *ifi, struct rtattr **tb) | |
217 | { | |
218 | if (tb[IFLA_IFNAME]) | |
219 | ll_entry_update(parent_im, ifi, | |
220 | rta_getattr_str(tb[IFLA_IFNAME])); | |
221 | ll_altname_entries_update(parent_im, ifi, tb); | |
222 | } | |
223 | ||
224 | int ll_remember_index(struct nlmsghdr *n, void *arg) | |
225 | { | |
226 | struct ifinfomsg *ifi = NLMSG_DATA(n); | |
227 | struct ll_cache *im; | |
228 | struct rtattr *tb[IFLA_MAX+1]; | |
229 | ||
230 | if (n->nlmsg_type != RTM_NEWLINK && n->nlmsg_type != RTM_DELLINK) | |
231 | return 0; | |
232 | ||
233 | if (n->nlmsg_len < NLMSG_LENGTH(sizeof(*ifi))) | |
234 | return -1; | |
235 | ||
236 | im = ll_get_by_index(ifi->ifi_index); | |
237 | if (n->nlmsg_type == RTM_DELLINK) { | |
238 | if (im) | |
239 | ll_entries_destroy(im); | |
240 | return 0; | |
241 | } | |
242 | ||
243 | parse_rtattr_flags(tb, IFLA_MAX, IFLA_RTA(ifi), | |
244 | IFLA_PAYLOAD(n), NLA_F_NESTED); | |
245 | if (im) | |
246 | ll_entries_update(im, ifi, tb); | |
247 | else | |
248 | ll_entries_create(ifi, tb); | |
249 | return 0; | |
250 | } | |
251 | ||
252 | const char *ll_idx_n2a(unsigned int idx) | |
253 | { | |
254 | static char buf[IFNAMSIZ]; | |
255 | ||
256 | snprintf(buf, sizeof(buf), "if%u", idx); | |
257 | return buf; | |
258 | } | |
259 | ||
260 | static unsigned int ll_idx_a2n(const char *name) | |
261 | { | |
262 | unsigned int idx; | |
263 | ||
264 | if (sscanf(name, "if%u", &idx) != 1) | |
265 | return 0; | |
266 | return idx; | |
267 | } | |
268 | ||
269 | static int ll_link_get(const char *name, int index) | |
270 | { | |
271 | struct { | |
272 | struct nlmsghdr n; | |
273 | struct ifinfomsg ifm; | |
274 | char buf[1024]; | |
275 | } req = { | |
276 | .n.nlmsg_len = NLMSG_LENGTH(sizeof(struct ifinfomsg)), | |
277 | .n.nlmsg_flags = NLM_F_REQUEST, | |
278 | .n.nlmsg_type = RTM_GETLINK, | |
279 | .ifm.ifi_index = index, | |
280 | }; | |
281 | __u32 filt_mask = RTEXT_FILTER_VF | RTEXT_FILTER_SKIP_STATS; | |
282 | struct rtnl_handle rth = {}; | |
283 | struct nlmsghdr *answer; | |
284 | int rc = 0; | |
285 | ||
286 | if (rtnl_open(&rth, 0) < 0) | |
287 | return 0; | |
288 | ||
289 | addattr32(&req.n, sizeof(req), IFLA_EXT_MASK, filt_mask); | |
290 | if (name) | |
291 | addattr_l(&req.n, sizeof(req), | |
292 | !check_ifname(name) ? IFLA_IFNAME : IFLA_ALT_IFNAME, | |
293 | name, strlen(name) + 1); | |
294 | ||
295 | if (rtnl_talk_suppress_rtnl_errmsg(&rth, &req.n, &answer) < 0) | |
296 | goto out; | |
297 | ||
298 | /* add entry to cache */ | |
299 | rc = ll_remember_index(answer, NULL); | |
300 | if (!rc) { | |
301 | struct ifinfomsg *ifm = NLMSG_DATA(answer); | |
302 | ||
303 | rc = ifm->ifi_index; | |
304 | } | |
305 | ||
306 | free(answer); | |
307 | out: | |
308 | rtnl_close(&rth); | |
309 | return rc; | |
310 | } | |
311 | ||
312 | const char *ll_index_to_name(unsigned int idx) | |
313 | { | |
314 | static char buf[IFNAMSIZ]; | |
315 | const struct ll_cache *im; | |
316 | ||
317 | if (idx == 0) | |
318 | return "*"; | |
319 | ||
320 | im = ll_get_by_index(idx); | |
321 | if (im) | |
322 | return im->name; | |
323 | ||
324 | if (ll_link_get(NULL, idx) == idx) { | |
325 | im = ll_get_by_index(idx); | |
326 | if (im) | |
327 | return im->name; | |
328 | } | |
329 | ||
330 | if (if_indextoname(idx, buf) == NULL) | |
331 | snprintf(buf, IFNAMSIZ, "if%u", idx); | |
332 | ||
333 | return buf; | |
334 | } | |
335 | ||
336 | int ll_index_to_type(unsigned idx) | |
337 | { | |
338 | const struct ll_cache *im; | |
339 | ||
340 | if (idx == 0) | |
341 | return -1; | |
342 | ||
343 | im = ll_get_by_index(idx); | |
344 | return im ? im->type : -1; | |
345 | } | |
346 | ||
347 | int ll_index_to_flags(unsigned idx) | |
348 | { | |
349 | const struct ll_cache *im; | |
350 | ||
351 | if (idx == 0) | |
352 | return 0; | |
353 | ||
354 | im = ll_get_by_index(idx); | |
355 | return im ? im->flags : -1; | |
356 | } | |
357 | ||
358 | unsigned ll_name_to_index(const char *name) | |
359 | { | |
360 | const struct ll_cache *im; | |
361 | unsigned idx; | |
362 | ||
363 | if (name == NULL) | |
364 | return 0; | |
365 | ||
366 | im = ll_get_by_name(name); | |
367 | if (im) | |
368 | return im->index; | |
369 | ||
370 | idx = ll_link_get(name, 0); | |
371 | if (idx == 0) | |
372 | idx = if_nametoindex(name); | |
373 | if (idx == 0) | |
374 | idx = ll_idx_a2n(name); | |
375 | return idx; | |
376 | } | |
377 | ||
378 | void ll_drop_by_index(unsigned index) | |
379 | { | |
380 | struct ll_cache *im; | |
381 | ||
382 | im = ll_get_by_index(index); | |
383 | if (!im) | |
384 | return; | |
385 | ||
386 | hlist_del(&im->idx_hash); | |
387 | hlist_del(&im->name_hash); | |
388 | ||
389 | free(im); | |
390 | } | |
391 | ||
392 | void ll_init_map(struct rtnl_handle *rth) | |
393 | { | |
394 | static int initialized; | |
395 | ||
396 | if (initialized) | |
397 | return; | |
398 | ||
399 | if (rtnl_linkdump_req(rth, AF_UNSPEC) < 0) { | |
400 | perror("Cannot send dump request"); | |
401 | exit(1); | |
402 | } | |
403 | ||
404 | if (rtnl_dump_filter(rth, ll_remember_index, NULL) < 0) { | |
405 | fprintf(stderr, "Dump terminated\n"); | |
406 | exit(1); | |
407 | } | |
408 | ||
409 | initialized = 1; | |
410 | } |