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osdl.org!shemmingeraba5acd2004-04-15 20:56:59 +00001/*
2 * arpd.c ARP helper daemon.
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#include <stdio.h>
13#include <syslog.h>
14#include <malloc.h>
15#include <string.h>
16#include <unistd.h>
17#include <stdlib.h>
18#include <netdb.h>
osdl.org!shemminger16efac52004-06-09 21:28:46 +000019#include <db_185.h>
osdl.org!shemmingeraba5acd2004-04-15 20:56:59 +000020#include <sys/ioctl.h>
21#include <sys/poll.h>
22#include <errno.h>
23#include <fcntl.h>
24#include <sys/uio.h>
25#include <sys/socket.h>
26#include <sys/time.h>
27#include <time.h>
28#include <signal.h>
29#include <linux/if.h>
osdl.net!shemminger17ce7fd2004-07-06 21:01:44 +000030#include <linux/if_ether.h>
osdl.org!shemmingeraba5acd2004-04-15 20:56:59 +000031#include <linux/if_arp.h>
32#include <netinet/in.h>
33#include <arpa/inet.h>
34#include <linux/if_packet.h>
35#include <linux/filter.h>
36
37#include "libnetlink.h"
38#include "utils.h"
Jiri Pirkodd502472014-05-15 15:10:20 +020039#include "rt_names.h"
osdl.org!shemmingeraba5acd2004-04-15 20:56:59 +000040
41int resolve_hosts;
42
43DB *dbase;
44char *dbname = "/var/lib/arpd/arpd.db";
45
Stephen Hemmingerae665a52006-12-05 10:10:22 -080046int ifnum;
osdl.org!shemmingeraba5acd2004-04-15 20:56:59 +000047int *ifvec;
48char **ifnames;
49
Stephen Hemmingeracd1e432016-03-21 11:56:36 -070050struct dbkey {
osdl.org!shemmingeraba5acd2004-04-15 20:56:59 +000051 __u32 iface;
52 __u32 addr;
53};
54
Stephen Hemmingeracd1e432016-03-21 11:56:36 -070055#define IS_NEG(x) (((__u8 *)(x))[0] == 0xFF)
Stephen Hemmingerae665a52006-12-05 10:10:22 -080056#define NEG_TIME(x) (((x)[2]<<24)|((x)[3]<<16)|((x)[4]<<8)|(x)[5])
Stephen Hemmingeracd1e432016-03-21 11:56:36 -070057#define NEG_AGE(x) ((__u32)time(NULL) - NEG_TIME((__u8 *)x))
osdl.org!shemmingeraba5acd2004-04-15 20:56:59 +000058#define NEG_VALID(x) (NEG_AGE(x) < negative_timeout)
Stephen Hemmingeracd1e432016-03-21 11:56:36 -070059#define NEG_CNT(x) (((__u8 *)(x))[1])
osdl.org!shemmingeraba5acd2004-04-15 20:56:59 +000060
61struct rtnl_handle rth;
62
63struct pollfd pset[2];
64int udp_sock = -1;
65
66volatile int do_exit;
67volatile int do_sync;
68volatile int do_stats;
69
70struct {
71 unsigned long arp_new;
72 unsigned long arp_change;
73
74 unsigned long app_recv;
75 unsigned long app_success;
76 unsigned long app_bad;
77 unsigned long app_neg;
78 unsigned long app_suppressed;
79
80 unsigned long kern_neg;
81 unsigned long kern_new;
82 unsigned long kern_change;
83
84 unsigned long probes_sent;
85 unsigned long probes_suppressed;
86} stats;
87
88int active_probing;
89int negative_timeout = 60;
90int no_kernel_broadcasts;
91int broadcast_rate = 1000;
92int broadcast_burst = 3000;
Stephen Hemminger0df7db32012-02-17 08:17:09 -080093int poll_timeout = 30000;
osdl.org!shemmingeraba5acd2004-04-15 20:56:59 +000094
Stephen Hemmingerd1f28cf2013-02-12 11:09:03 -080095static void usage(void)
osdl.org!shemmingeraba5acd2004-04-15 20:56:59 +000096{
97 fprintf(stderr,
Stephen Hemmingeracd1e432016-03-21 11:56:36 -070098 "Usage: arpd [ -lkh? ] [ -a N ] [ -b dbase ] [ -B number ] [ -f file ] [ -n time ] [-p interval ] [ -R rate ] [ interfaces ]\n");
osdl.org!shemmingeraba5acd2004-04-15 20:56:59 +000099 exit(1);
100}
101
Stephen Hemmingerd1f28cf2013-02-12 11:09:03 -0800102static int handle_if(int ifindex)
osdl.org!shemmingeraba5acd2004-04-15 20:56:59 +0000103{
104 int i;
105
106 if (ifnum == 0)
107 return 1;
108
Stephen Hemmingeracd1e432016-03-21 11:56:36 -0700109 for (i = 0; i < ifnum; i++)
osdl.org!shemmingeraba5acd2004-04-15 20:56:59 +0000110 if (ifvec[i] == ifindex)
111 return 1;
112 return 0;
113}
114
115int sysctl_adjusted;
116
Stephen Hemmingerd1f28cf2013-02-12 11:09:03 -0800117static void do_sysctl_adjustments(void)
osdl.org!shemmingeraba5acd2004-04-15 20:56:59 +0000118{
119 int i;
120
121 if (!ifnum)
122 return;
123
Stephen Hemmingeracd1e432016-03-21 11:56:36 -0700124 for (i = 0; i < ifnum; i++) {
osdl.org!shemmingeraba5acd2004-04-15 20:56:59 +0000125 char buf[128];
126 FILE *fp;
127
128 if (active_probing) {
129 sprintf(buf, "/proc/sys/net/ipv4/neigh/%s/mcast_solicit", ifnames[i]);
130 if ((fp = fopen(buf, "w")) != NULL) {
131 if (no_kernel_broadcasts)
132 strcpy(buf, "0\n");
133 else
Stephen Hemmingeracd1e432016-03-21 11:56:36 -0700134 sprintf(buf, "%d\n", active_probing >= 2 ? 1 : 3-active_probing);
osdl.org!shemmingeraba5acd2004-04-15 20:56:59 +0000135 fputs(buf, fp);
136 fclose(fp);
137 }
138 }
139
140 sprintf(buf, "/proc/sys/net/ipv4/neigh/%s/app_solicit", ifnames[i]);
141 if ((fp = fopen(buf, "w")) != NULL) {
Stephen Hemmingeracd1e432016-03-21 11:56:36 -0700142 sprintf(buf, "%d\n", active_probing <= 1 ? 1 : active_probing);
osdl.org!shemmingeraba5acd2004-04-15 20:56:59 +0000143 fputs(buf, fp);
144 fclose(fp);
145 }
146 }
147 sysctl_adjusted = 1;
148}
149
Stephen Hemmingerd1f28cf2013-02-12 11:09:03 -0800150static void undo_sysctl_adjustments(void)
osdl.org!shemmingeraba5acd2004-04-15 20:56:59 +0000151{
152 int i;
153
154 if (!sysctl_adjusted)
155 return;
156
Stephen Hemmingeracd1e432016-03-21 11:56:36 -0700157 for (i = 0; i < ifnum; i++) {
osdl.org!shemmingeraba5acd2004-04-15 20:56:59 +0000158 char buf[128];
159 FILE *fp;
160
161 if (active_probing) {
162 sprintf(buf, "/proc/sys/net/ipv4/neigh/%s/mcast_solicit", ifnames[i]);
163 if ((fp = fopen(buf, "w")) != NULL) {
164 strcpy(buf, "3\n");
165 fputs(buf, fp);
166 fclose(fp);
167 }
168 }
169 sprintf(buf, "/proc/sys/net/ipv4/neigh/%s/app_solicit", ifnames[i]);
170 if ((fp = fopen(buf, "w")) != NULL) {
171 strcpy(buf, "0\n");
172 fputs(buf, fp);
173 fclose(fp);
174 }
175 }
176 sysctl_adjusted = 0;
177}
178
179
Stephen Hemmingerd1f28cf2013-02-12 11:09:03 -0800180static int send_probe(int ifindex, __u32 addr)
osdl.org!shemmingeraba5acd2004-04-15 20:56:59 +0000181{
Phil Sutterd17b1362016-07-18 16:48:42 +0200182 struct ifreq ifr = { .ifr_ifindex = ifindex };
183 struct sockaddr_in dst = {
184 .sin_family = AF_INET,
185 .sin_port = htons(1025),
186 .sin_addr.s_addr = addr,
187 };
shemmingerf332d162005-07-05 22:37:15 +0000188 socklen_t len;
osdl.org!shemmingeraba5acd2004-04-15 20:56:59 +0000189 unsigned char buf[256];
Stephen Hemmingeracd1e432016-03-21 11:56:36 -0700190 struct arphdr *ah = (struct arphdr *)buf;
osdl.org!shemmingeraba5acd2004-04-15 20:56:59 +0000191 unsigned char *p = (unsigned char *)(ah+1);
Phil Sutterd17b1362016-07-18 16:48:42 +0200192 struct sockaddr_ll sll = {
193 .sll_family = AF_PACKET,
194 .sll_ifindex = ifindex,
195 .sll_protocol = htons(ETH_P_ARP),
196 };
osdl.org!shemmingeraba5acd2004-04-15 20:56:59 +0000197
osdl.org!shemmingeraba5acd2004-04-15 20:56:59 +0000198 if (ioctl(udp_sock, SIOCGIFNAME, &ifr))
199 return -1;
200 if (ioctl(udp_sock, SIOCGIFHWADDR, &ifr))
201 return -1;
202 if (ifr.ifr_hwaddr.sa_family != ARPHRD_ETHER)
203 return -1;
204 if (setsockopt(udp_sock, SOL_SOCKET, SO_BINDTODEVICE, ifr.ifr_name, strlen(ifr.ifr_name)+1) < 0)
205 return -1;
206
Stephen Hemmingeracd1e432016-03-21 11:56:36 -0700207 if (connect(udp_sock, (struct sockaddr *)&dst, sizeof(dst)) < 0)
osdl.org!shemmingeraba5acd2004-04-15 20:56:59 +0000208 return -1;
209 len = sizeof(dst);
Stephen Hemmingeracd1e432016-03-21 11:56:36 -0700210 if (getsockname(udp_sock, (struct sockaddr *)&dst, &len) < 0)
osdl.org!shemmingeraba5acd2004-04-15 20:56:59 +0000211 return -1;
212
213 ah->ar_hrd = htons(ifr.ifr_hwaddr.sa_family);
214 ah->ar_pro = htons(ETH_P_IP);
215 ah->ar_hln = 6;
216 ah->ar_pln = 4;
217 ah->ar_op = htons(ARPOP_REQUEST);
218
219 memcpy(p, ifr.ifr_hwaddr.sa_data, ah->ar_hln);
220 p += ah->ar_hln;
221
222 memcpy(p, &dst.sin_addr, 4);
Stephen Hemmingeracd1e432016-03-21 11:56:36 -0700223 p += 4;
osdl.org!shemmingeraba5acd2004-04-15 20:56:59 +0000224
osdl.org!shemmingeraba5acd2004-04-15 20:56:59 +0000225 memset(sll.sll_addr, 0xFF, sizeof(sll.sll_addr));
osdl.org!shemmingeraba5acd2004-04-15 20:56:59 +0000226 memcpy(p, &sll.sll_addr, ah->ar_hln);
Stephen Hemmingeracd1e432016-03-21 11:56:36 -0700227 p += ah->ar_hln;
osdl.org!shemmingeraba5acd2004-04-15 20:56:59 +0000228
229 memcpy(p, &addr, 4);
Stephen Hemmingeracd1e432016-03-21 11:56:36 -0700230 p += 4;
osdl.org!shemmingeraba5acd2004-04-15 20:56:59 +0000231
Stephen Hemmingeracd1e432016-03-21 11:56:36 -0700232 if (sendto(pset[0].fd, buf, p-buf, 0, (struct sockaddr *)&sll, sizeof(sll)) < 0)
osdl.org!shemmingeraba5acd2004-04-15 20:56:59 +0000233 return -1;
234 stats.probes_sent++;
235 return 0;
236}
237
238/* Be very tough on sending probes: 1 per second with burst of 3. */
239
Stephen Hemmingerd1f28cf2013-02-12 11:09:03 -0800240static int queue_active_probe(int ifindex, __u32 addr)
osdl.org!shemmingeraba5acd2004-04-15 20:56:59 +0000241{
242 static struct timeval prev;
243 static int buckets;
244 struct timeval now;
245
246 gettimeofday(&now, NULL);
247 if (prev.tv_sec) {
248 int diff = (now.tv_sec-prev.tv_sec)*1000+(now.tv_usec-prev.tv_usec)/1000;
Stephen Hemmingeracd1e432016-03-21 11:56:36 -0700249
osdl.org!shemmingeraba5acd2004-04-15 20:56:59 +0000250 buckets += diff;
251 } else {
252 buckets = broadcast_burst;
253 }
254 if (buckets > broadcast_burst)
255 buckets = broadcast_burst;
256 if (buckets >= broadcast_rate && !send_probe(ifindex, addr)) {
257 buckets -= broadcast_rate;
258 prev = now;
259 return 0;
260 }
261 stats.probes_suppressed++;
262 return -1;
263}
264
Stephen Hemmingerd1f28cf2013-02-12 11:09:03 -0800265static int respond_to_kernel(int ifindex, __u32 addr, char *lla, int llalen)
osdl.org!shemmingeraba5acd2004-04-15 20:56:59 +0000266{
267 struct {
Stephen Hemmingeracd1e432016-03-21 11:56:36 -0700268 struct nlmsghdr n;
269 struct ndmsg ndm;
270 char buf[256];
Phil Sutterd17b1362016-07-18 16:48:42 +0200271 } req = {
272 .n.nlmsg_len = NLMSG_LENGTH(sizeof(struct ndmsg)),
273 .n.nlmsg_flags = NLM_F_REQUEST,
274 .n.nlmsg_type = RTM_NEWNEIGH,
275 .ndm.ndm_family = AF_INET,
276 .ndm.ndm_state = NUD_STALE,
277 .ndm.ndm_ifindex = ifindex,
278 .ndm.ndm_type = RTN_UNICAST,
279 };
osdl.org!shemmingeraba5acd2004-04-15 20:56:59 +0000280
281 addattr_l(&req.n, sizeof(req), NDA_DST, &addr, 4);
282 addattr_l(&req.n, sizeof(req), NDA_LLADDR, lla, llalen);
Stephen Hemminger6cf83982011-12-23 10:40:04 -0800283 return rtnl_send(&rth, &req, req.n.nlmsg_len) <= 0;
osdl.org!shemmingeraba5acd2004-04-15 20:56:59 +0000284}
285
Stephen Hemmingerd1f28cf2013-02-12 11:09:03 -0800286static void prepare_neg_entry(__u8 *ndata, __u32 stamp)
osdl.org!shemmingeraba5acd2004-04-15 20:56:59 +0000287{
288 ndata[0] = 0xFF;
289 ndata[1] = 0;
290 ndata[2] = stamp>>24;
291 ndata[3] = stamp>>16;
292 ndata[4] = stamp>>8;
293 ndata[5] = stamp;
294}
295
296
Stephen Hemmingerd1f28cf2013-02-12 11:09:03 -0800297static int do_one_request(struct nlmsghdr *n)
osdl.org!shemmingeraba5acd2004-04-15 20:56:59 +0000298{
299 struct ndmsg *ndm = NLMSG_DATA(n);
300 int len = n->nlmsg_len;
Stephen Hemmingeracd1e432016-03-21 11:56:36 -0700301 struct rtattr *tb[NDA_MAX+1];
osdl.org!shemmingeraba5acd2004-04-15 20:56:59 +0000302 struct dbkey key;
303 DBT dbkey, dbdat;
304 int do_acct = 0;
305
306 if (n->nlmsg_type == NLMSG_DONE) {
307 dbase->sync(dbase, 0);
308
309 /* Now we have at least mirror of kernel db, so that
310 * may start real resolution.
311 */
312 do_sysctl_adjustments();
313 return 0;
314 }
315
316 if (n->nlmsg_type != RTM_GETNEIGH && n->nlmsg_type != RTM_NEWNEIGH)
317 return 0;
318
319 len -= NLMSG_LENGTH(sizeof(*ndm));
320 if (len < 0)
321 return -1;
322
323 if (ndm->ndm_family != AF_INET ||
324 (ifnum && !handle_if(ndm->ndm_ifindex)) ||
325 ndm->ndm_flags ||
326 ndm->ndm_type != RTN_UNICAST ||
327 !(ndm->ndm_state&~NUD_NOARP))
328 return 0;
329
osdl.org!shemmingeraba5acd2004-04-15 20:56:59 +0000330 parse_rtattr(tb, NDA_MAX, NDA_RTA(ndm), len);
331
332 if (!tb[NDA_DST])
333 return 0;
334
335 key.iface = ndm->ndm_ifindex;
336 memcpy(&key.addr, RTA_DATA(tb[NDA_DST]), 4);
337 dbkey.data = &key;
338 dbkey.size = sizeof(key);
339
340 if (dbase->get(dbase, &dbkey, &dbdat, 0) != 0) {
341 dbdat.data = 0;
342 dbdat.size = 0;
343 }
344
345 if (n->nlmsg_type == RTM_GETNEIGH) {
346 if (!(n->nlmsg_flags&NLM_F_REQUEST))
347 return 0;
348
349 if (!(ndm->ndm_state&(NUD_PROBE|NUD_INCOMPLETE))) {
350 stats.app_bad++;
351 return 0;
352 }
353
354 if (ndm->ndm_state&NUD_PROBE) {
355 /* If we get this, kernel still has some valid
356 * address, but unicast probing failed and host
357 * is either dead or changed its mac address.
358 * Kernel is going to initiate broadcast resolution.
359 * OK, we invalidate our information as well.
360 */
361 if (dbdat.data && !IS_NEG(dbdat.data))
362 stats.app_neg++;
363
364 dbase->del(dbase, &dbkey, 0);
365 } else {
366 /* If we get this kernel does not have any information.
367 * If we have something tell this to kernel. */
368 stats.app_recv++;
369 if (dbdat.data && !IS_NEG(dbdat.data)) {
370 stats.app_success++;
371 respond_to_kernel(key.iface, key.addr, dbdat.data, dbdat.size);
372 return 0;
373 }
374
375 /* Sheeit! We have nothing to tell. */
376 /* If we have recent negative entry, be silent. */
377 if (dbdat.data && NEG_VALID(dbdat.data)) {
378 if (NEG_CNT(dbdat.data) >= active_probing) {
379 stats.app_suppressed++;
380 return 0;
381 }
382 do_acct = 1;
383 }
384 }
385
386 if (active_probing &&
387 queue_active_probe(ndm->ndm_ifindex, key.addr) == 0 &&
388 do_acct) {
389 NEG_CNT(dbdat.data)++;
390 dbase->put(dbase, &dbkey, &dbdat, 0);
391 }
392 } else if (n->nlmsg_type == RTM_NEWNEIGH) {
393 if (n->nlmsg_flags&NLM_F_REQUEST)
394 return 0;
395
396 if (ndm->ndm_state&NUD_FAILED) {
397 /* Kernel was not able to resolve. Host is dead.
398 * Create negative entry if it is not present
399 * or renew it if it is too old. */
400 if (!dbdat.data ||
401 !IS_NEG(dbdat.data) ||
402 !NEG_VALID(dbdat.data)) {
403 __u8 ndata[6];
Stephen Hemmingeracd1e432016-03-21 11:56:36 -0700404
osdl.org!shemmingeraba5acd2004-04-15 20:56:59 +0000405 stats.kern_neg++;
406 prepare_neg_entry(ndata, time(NULL));
407 dbdat.data = ndata;
408 dbdat.size = sizeof(ndata);
409 dbase->put(dbase, &dbkey, &dbdat, 0);
410 }
411 } else if (tb[NDA_LLADDR]) {
412 if (dbdat.data && !IS_NEG(dbdat.data)) {
413 if (memcmp(RTA_DATA(tb[NDA_LLADDR]), dbdat.data, dbdat.size) == 0)
414 return 0;
415 stats.kern_change++;
416 } else {
417 stats.kern_new++;
418 }
419 dbdat.data = RTA_DATA(tb[NDA_LLADDR]);
420 dbdat.size = RTA_PAYLOAD(tb[NDA_LLADDR]);
421 dbase->put(dbase, &dbkey, &dbdat, 0);
422 }
423 }
424 return 0;
425}
426
Stephen Hemmingerd1f28cf2013-02-12 11:09:03 -0800427static void load_initial_table(void)
osdl.org!shemmingeraba5acd2004-04-15 20:56:59 +0000428{
Stephen Hemmingerd2468da2013-12-20 08:15:02 -0800429 if (rtnl_wilddump_request(&rth, AF_INET, RTM_GETNEIGH) < 0) {
430 perror("dump request failed");
431 exit(1);
432 }
Stephen Hemminger3d0b7432014-12-20 15:47:17 -0800433
osdl.org!shemmingeraba5acd2004-04-15 20:56:59 +0000434}
435
Stephen Hemmingerd1f28cf2013-02-12 11:09:03 -0800436static void get_kern_msg(void)
osdl.org!shemmingeraba5acd2004-04-15 20:56:59 +0000437{
438 int status;
439 struct nlmsghdr *h;
Phil Sutterd17b1362016-07-18 16:48:42 +0200440 struct sockaddr_nl nladdr = {};
osdl.org!shemmingeraba5acd2004-04-15 20:56:59 +0000441 struct iovec iov;
442 char buf[8192];
443 struct msghdr msg = {
Stephen Hemmingeracd1e432016-03-21 11:56:36 -0700444 (void *)&nladdr, sizeof(nladdr),
osdl.org!shemmingeraba5acd2004-04-15 20:56:59 +0000445 &iov, 1,
446 NULL, 0,
447 0
448 };
449
osdl.org!shemmingeraba5acd2004-04-15 20:56:59 +0000450 iov.iov_base = buf;
451 iov.iov_len = sizeof(buf);
452
453 status = recvmsg(rth.fd, &msg, MSG_DONTWAIT);
454
455 if (status <= 0)
456 return;
457
458 if (msg.msg_namelen != sizeof(nladdr))
459 return;
460
461 if (nladdr.nl_pid)
462 return;
463
Stephen Hemmingeracd1e432016-03-21 11:56:36 -0700464 for (h = (struct nlmsghdr *)buf; status >= sizeof(*h); ) {
osdl.org!shemmingeraba5acd2004-04-15 20:56:59 +0000465 int len = h->nlmsg_len;
466 int l = len - sizeof(*h);
467
468 if (l < 0 || len > status)
469 return;
470
471 if (do_one_request(h) < 0)
472 return;
473
474 status -= NLMSG_ALIGN(len);
Stephen Hemmingeracd1e432016-03-21 11:56:36 -0700475 h = (struct nlmsghdr *)((char *)h + NLMSG_ALIGN(len));
osdl.org!shemmingeraba5acd2004-04-15 20:56:59 +0000476 }
477}
478
479/* Receive gratuitous ARP messages and store them, that's all. */
Stephen Hemmingerd1f28cf2013-02-12 11:09:03 -0800480static void get_arp_pkt(void)
osdl.org!shemmingeraba5acd2004-04-15 20:56:59 +0000481{
482 unsigned char buf[1024];
483 struct sockaddr_ll sll;
shemmingerf332d162005-07-05 22:37:15 +0000484 socklen_t sll_len = sizeof(sll);
Stephen Hemmingeracd1e432016-03-21 11:56:36 -0700485 struct arphdr *a = (struct arphdr *)buf;
osdl.org!shemmingeraba5acd2004-04-15 20:56:59 +0000486 struct dbkey key;
487 DBT dbkey, dbdat;
488 int n;
489
Stephen Hemmingerae665a52006-12-05 10:10:22 -0800490 n = recvfrom(pset[0].fd, buf, sizeof(buf), MSG_DONTWAIT,
Stephen Hemmingeracd1e432016-03-21 11:56:36 -0700491 (struct sockaddr *)&sll, &sll_len);
osdl.org!shemmingeraba5acd2004-04-15 20:56:59 +0000492 if (n < 0) {
493 if (errno != EINTR && errno != EAGAIN)
494 syslog(LOG_ERR, "recvfrom: %m");
495 return;
496 }
497
498 if (ifnum && !handle_if(sll.sll_ifindex))
499 return;
500
501 /* Sanity checks */
502
503 if (n < sizeof(*a) ||
504 (a->ar_op != htons(ARPOP_REQUEST) &&
505 a->ar_op != htons(ARPOP_REPLY)) ||
506 a->ar_pln != 4 ||
507 a->ar_pro != htons(ETH_P_IP) ||
508 a->ar_hln != sll.sll_halen ||
509 sizeof(*a) + 2*4 + 2*a->ar_hln > n)
510 return;
511
512 key.iface = sll.sll_ifindex;
Stephen Hemmingeracd1e432016-03-21 11:56:36 -0700513 memcpy(&key.addr, (char *)(a+1) + a->ar_hln, 4);
osdl.org!shemmingeraba5acd2004-04-15 20:56:59 +0000514
Stephen Hemmingerae665a52006-12-05 10:10:22 -0800515 /* DAD message, ignore. */
osdl.org!shemmingeraba5acd2004-04-15 20:56:59 +0000516 if (key.addr == 0)
517 return;
518
519 dbkey.data = &key;
520 dbkey.size = sizeof(key);
521
522 if (dbase->get(dbase, &dbkey, &dbdat, 0) == 0 && !IS_NEG(dbdat.data)) {
523 if (memcmp(dbdat.data, a+1, dbdat.size) == 0)
524 return;
525 stats.arp_change++;
526 } else {
527 stats.arp_new++;
528 }
529
530 dbdat.data = a+1;
531 dbdat.size = a->ar_hln;
532 dbase->put(dbase, &dbkey, &dbdat, 0);
533}
534
Stephen Hemmingerd1f28cf2013-02-12 11:09:03 -0800535static void catch_signal(int sig, void (*handler)(int))
osdl.org!shemmingeraba5acd2004-04-15 20:56:59 +0000536{
Phil Sutterd17b1362016-07-18 16:48:42 +0200537 struct sigaction sa = { .sa_handler = handler };
osdl.org!shemmingeraba5acd2004-04-15 20:56:59 +0000538
osdl.org!shemmingeraba5acd2004-04-15 20:56:59 +0000539#ifdef SA_INTERRUPT
540 sa.sa_flags = SA_INTERRUPT;
Stephen Hemmingerae665a52006-12-05 10:10:22 -0800541#endif
osdl.org!shemmingeraba5acd2004-04-15 20:56:59 +0000542 sigaction(sig, &sa, NULL);
543}
544
545#include <setjmp.h>
546sigjmp_buf env;
547volatile int in_poll;
548
Stephen Hemmingerd1f28cf2013-02-12 11:09:03 -0800549static void sig_exit(int signo)
osdl.org!shemmingeraba5acd2004-04-15 20:56:59 +0000550{
551 do_exit = 1;
552 if (in_poll)
553 siglongjmp(env, 1);
554}
555
Stephen Hemmingerd1f28cf2013-02-12 11:09:03 -0800556static void sig_sync(int signo)
osdl.org!shemmingeraba5acd2004-04-15 20:56:59 +0000557{
558 do_sync = 1;
559 if (in_poll)
560 siglongjmp(env, 1);
561}
562
Stephen Hemmingerd1f28cf2013-02-12 11:09:03 -0800563static void sig_stats(int signo)
osdl.org!shemmingeraba5acd2004-04-15 20:56:59 +0000564{
565 do_sync = 1;
566 do_stats = 1;
567 if (in_poll)
568 siglongjmp(env, 1);
569}
570
Stephen Hemmingerd1f28cf2013-02-12 11:09:03 -0800571static void send_stats(void)
osdl.org!shemmingeraba5acd2004-04-15 20:56:59 +0000572{
573 syslog(LOG_INFO, "arp_rcv: n%lu c%lu app_rcv: tot %lu hits %lu bad %lu neg %lu sup %lu",
574 stats.arp_new, stats.arp_change,
575
576 stats.app_recv, stats.app_success,
577 stats.app_bad, stats.app_neg, stats.app_suppressed
578 );
579 syslog(LOG_INFO, "kern: n%lu c%lu neg %lu arp_send: %lu rlim %lu",
580 stats.kern_new, stats.kern_change, stats.kern_neg,
581
582 stats.probes_sent, stats.probes_suppressed
583 );
584 do_stats = 0;
585}
586
587
588int main(int argc, char **argv)
589{
590 int opt;
591 int do_list = 0;
592 char *do_load = NULL;
593
Stephen Hemminger0df7db32012-02-17 08:17:09 -0800594 while ((opt = getopt(argc, argv, "h?b:lf:a:n:p:kR:B:")) != EOF) {
osdl.org!shemmingeraba5acd2004-04-15 20:56:59 +0000595 switch (opt) {
Stephen Hemmingeracd1e432016-03-21 11:56:36 -0700596 case 'b':
osdl.org!shemmingeraba5acd2004-04-15 20:56:59 +0000597 dbname = optarg;
598 break;
599 case 'f':
600 if (do_load) {
601 fprintf(stderr, "Duplicate option -f\n");
602 usage();
603 }
604 do_load = optarg;
605 break;
606 case 'l':
607 do_list = 1;
608 break;
609 case 'a':
610 active_probing = atoi(optarg);
611 break;
612 case 'n':
613 negative_timeout = atoi(optarg);
614 break;
615 case 'k':
616 no_kernel_broadcasts = 1;
617 break;
Stephen Hemminger0df7db32012-02-17 08:17:09 -0800618 case 'p':
619 if ((poll_timeout = 1000 * strtod(optarg, NULL)) < 100) {
Stephen Hemmingeracd1e432016-03-21 11:56:36 -0700620 fprintf(stderr, "Invalid poll timeout\n");
Stephen Hemminger0df7db32012-02-17 08:17:09 -0800621 exit(-1);
622 }
623 break;
osdl.org!shemmingeraba5acd2004-04-15 20:56:59 +0000624 case 'R':
625 if ((broadcast_rate = atoi(optarg)) <= 0 ||
626 (broadcast_rate = 1000/broadcast_rate) <= 0) {
627 fprintf(stderr, "Invalid ARP rate\n");
628 exit(-1);
629 }
630 break;
631 case 'B':
632 if ((broadcast_burst = atoi(optarg)) <= 0 ||
633 (broadcast_burst = 1000*broadcast_burst) <= 0) {
634 fprintf(stderr, "Invalid ARP burst\n");
635 exit(-1);
636 }
637 break;
638 case 'h':
639 case '?':
640 default:
641 usage();
642 }
643 }
644 argc -= optind;
645 argv += optind;
646
647 if (argc > 0) {
648 ifnum = argc;
649 ifnames = argv;
650 ifvec = malloc(argc*sizeof(int));
651 if (!ifvec) {
652 perror("malloc");
653 exit(-1);
654 }
655 }
656
657 if ((udp_sock = socket(AF_INET, SOCK_DGRAM, 0)) < 0) {
658 perror("socket");
659 exit(-1);
660 }
661
Stephen Hemmingeracd1e432016-03-21 11:56:36 -0700662 if (ifnum) {
osdl.org!shemmingeraba5acd2004-04-15 20:56:59 +0000663 int i;
Phil Sutterd17b1362016-07-18 16:48:42 +0200664 struct ifreq ifr = {};
Stephen Hemmingeracd1e432016-03-21 11:56:36 -0700665
Stephen Hemmingeracd1e432016-03-21 11:56:36 -0700666 for (i = 0; i < ifnum; i++) {
osdl.org!shemmingeraba5acd2004-04-15 20:56:59 +0000667 strncpy(ifr.ifr_name, ifnames[i], IFNAMSIZ);
668 if (ioctl(udp_sock, SIOCGIFINDEX, &ifr)) {
669 perror("ioctl(SIOCGIFINDEX)");
Stephen Hemmingeracd1e432016-03-21 11:56:36 -0700670 exit(-1);
osdl.org!shemmingeraba5acd2004-04-15 20:56:59 +0000671 }
672 ifvec[i] = ifr.ifr_ifindex;
673 }
674 }
675
676 dbase = dbopen(dbname, O_CREAT|O_RDWR, 0644, DB_HASH, NULL);
677 if (dbase == NULL) {
678 perror("db_open");
679 exit(-1);
680 }
681
682 if (do_load) {
683 char buf[128];
684 FILE *fp;
685 struct dbkey k;
686 DBT dbkey, dbdat;
687
688 dbkey.data = &k;
689 dbkey.size = sizeof(k);
690
691 if (strcmp(do_load, "-") == 0 || strcmp(do_load, "--") == 0) {
692 fp = stdin;
693 } else if ((fp = fopen(do_load, "r")) == NULL) {
694 perror("fopen");
695 goto do_abort;
696 }
697
698 buf[sizeof(buf)-1] = 0;
Phil Sutter61170fd2015-11-28 01:00:05 +0100699 while (fgets(buf, sizeof(buf), fp)) {
osdl.org!shemmingeraba5acd2004-04-15 20:56:59 +0000700 __u8 b1[6];
701 char ipbuf[128];
702 char macbuf[128];
703
704 if (buf[0] == '#')
705 continue;
706
707 if (sscanf(buf, "%u%s%s", &k.iface, ipbuf, macbuf) != 3) {
708 fprintf(stderr, "Wrong format of input file \"%s\"\n", do_load);
709 goto do_abort;
710 }
711 if (strncmp(macbuf, "FAILED:", 7) == 0)
712 continue;
Stephen Hemmingeracd1e432016-03-21 11:56:36 -0700713 if (!inet_aton(ipbuf, (struct in_addr *)&k.addr)) {
osdl.org!shemmingeraba5acd2004-04-15 20:56:59 +0000714 fprintf(stderr, "Invalid IP address: \"%s\"\n", ipbuf);
715 goto do_abort;
716 }
shemmingerf332d162005-07-05 22:37:15 +0000717
Jiri Pirkodd502472014-05-15 15:10:20 +0200718 if (ll_addr_a2n((char *) b1, 6, macbuf) != 6)
osdl.org!shemmingeraba5acd2004-04-15 20:56:59 +0000719 goto do_abort;
720 dbdat.size = 6;
721
722 if (dbase->put(dbase, &dbkey, &dbdat, 0)) {
723 perror("hash->put");
724 goto do_abort;
725 }
726 }
727 dbase->sync(dbase, 0);
728 if (fp != stdin)
729 fclose(fp);
730 }
731
732 if (do_list) {
733 DBT dbkey, dbdat;
Stephen Hemmingeracd1e432016-03-21 11:56:36 -0700734
osdl.org!shemmingeraba5acd2004-04-15 20:56:59 +0000735 printf("%-8s %-15s %s\n", "#Ifindex", "IP", "MAC");
736 while (dbase->seq(dbase, &dbkey, &dbdat, R_NEXT) == 0) {
Stephen Hemmingerae665a52006-12-05 10:10:22 -0800737 struct dbkey *key = dbkey.data;
Stephen Hemmingeracd1e432016-03-21 11:56:36 -0700738
osdl.org!shemmingeraba5acd2004-04-15 20:56:59 +0000739 if (handle_if(key->iface)) {
740 if (!IS_NEG(dbdat.data)) {
shemmingerf332d162005-07-05 22:37:15 +0000741 char b1[18];
Stephen Hemmingeracd1e432016-03-21 11:56:36 -0700742
osdl.org!shemmingeraba5acd2004-04-15 20:56:59 +0000743 printf("%-8d %-15s %s\n",
744 key->iface,
Stephen Hemmingeracd1e432016-03-21 11:56:36 -0700745 inet_ntoa(*(struct in_addr *)&key->addr),
Jiri Pirkodd502472014-05-15 15:10:20 +0200746 ll_addr_n2a(dbdat.data, 6, ARPHRD_ETHER, b1, 18));
osdl.org!shemmingeraba5acd2004-04-15 20:56:59 +0000747 } else {
748 printf("%-8d %-15s FAILED: %dsec ago\n",
749 key->iface,
Stephen Hemmingeracd1e432016-03-21 11:56:36 -0700750 inet_ntoa(*(struct in_addr *)&key->addr),
osdl.org!shemmingeraba5acd2004-04-15 20:56:59 +0000751 NEG_AGE(dbdat.data));
752 }
753 }
754 }
755 }
756
757 if (do_load || do_list)
758 goto out;
759
760 pset[0].fd = socket(PF_PACKET, SOCK_DGRAM, 0);
761 if (pset[0].fd < 0) {
762 perror("socket");
763 exit(-1);
764 }
765
766 if (1) {
Phil Sutterd17b1362016-07-18 16:48:42 +0200767 struct sockaddr_ll sll = {
768 .sll_family = AF_PACKET,
769 .sll_protocol = htons(ETH_P_ARP),
770 .sll_ifindex = (ifnum == 1 ? ifvec[0] : 0),
771 };
Stephen Hemmingeracd1e432016-03-21 11:56:36 -0700772
Stephen Hemmingeracd1e432016-03-21 11:56:36 -0700773 if (bind(pset[0].fd, (struct sockaddr *)&sll, sizeof(sll)) < 0) {
osdl.org!shemmingeraba5acd2004-04-15 20:56:59 +0000774 perror("bind");
775 goto do_abort;
776 }
777 }
778
779 if (rtnl_open(&rth, RTMGRP_NEIGH) < 0) {
780 perror("rtnl_open");
781 goto do_abort;
782 }
783 pset[1].fd = rth.fd;
784
785 load_initial_table();
786
Mike Frysingera7a9ddb2009-11-06 06:04:39 -0500787 if (daemon(0, 0)) {
788 perror("arpd: daemon");
789 goto do_abort;
osdl.org!shemmingeraba5acd2004-04-15 20:56:59 +0000790 }
791
792 openlog("arpd", LOG_PID | LOG_CONS, LOG_DAEMON);
793 catch_signal(SIGINT, sig_exit);
794 catch_signal(SIGTERM, sig_exit);
795 catch_signal(SIGHUP, sig_sync);
796 catch_signal(SIGUSR1, sig_stats);
797
798#define EVENTS (POLLIN|POLLPRI|POLLERR|POLLHUP)
799 pset[0].events = EVENTS;
800 pset[0].revents = 0;
801 pset[1].events = EVENTS;
802 pset[1].revents = 0;
803
804 sigsetjmp(env, 1);
805
806 for (;;) {
807 in_poll = 1;
808
809 if (do_exit)
810 break;
811 if (do_sync) {
812 in_poll = 0;
813 dbase->sync(dbase, 0);
814 do_sync = 0;
815 in_poll = 1;
816 }
817 if (do_stats)
818 send_stats();
Stephen Hemminger0df7db32012-02-17 08:17:09 -0800819 if (poll(pset, 2, poll_timeout) > 0) {
osdl.org!shemmingeraba5acd2004-04-15 20:56:59 +0000820 in_poll = 0;
821 if (pset[0].revents&EVENTS)
822 get_arp_pkt();
823 if (pset[1].revents&EVENTS)
824 get_kern_msg();
825 } else {
826 do_sync = 1;
827 }
828 }
829
830 undo_sysctl_adjustments();
831out:
832 dbase->close(dbase);
833 exit(0);
834
835do_abort:
836 dbase->close(dbase);
837 exit(-1);
838}