src/vip6-autod.c

   1 /*
   2  * $Id: vip6-autod.c,v 1.3 2007/07/26 23:08:00 dhozac Exp $
   3  * Copyright (c) 2007 The Trustees of Princeton University
   4  * Author: Daniel Hokka Zakrisson <daniel@hozac.com>
   5  *
   6  * Licensed under the terms of the GNU General Public License
   7  * version 2 or later.
   8  */
   9
  10 #ifdef HAVE_CONFIG_H
  11 #  include <config.h>
  12 #endif
  13
  14 #include <stdio.h>
  15 #include <stdlib.h>
  16 #include <unistd.h>
  17 #include <stdint.h>
  18 #include <string.h>
  19 #include <time.h>
  20 #include <sys/types.h>
  21 #include <sys/socket.h>
  22 #include <sys/ioctl.h>
  23 #include <arpa/inet.h>
  24 #include <dirent.h>
  25 #include <ctype.h>
  26 #include <errno.h>
  27 #include <signal.h>
  28 #include <syslog.h>
  29
  30 #include <asm/types.h>
  31 /* not defined for gcc -ansi */
  32 typedef uint64_t __u64;
  33 typedef int64_t __s64;
  34 #include <netlink/netlink.h>
  35 #include <netlink/route/addr.h>
  36
  37 #include <vserver.h>
  38 #include "pathconfig.h"
  39
  40 #define HAS_ADDRESS     0x01
  41 #define HAS_PREFIX      0x02
  42 struct nid_list {
  43         nid_t nid;
  44         struct nid_list *next;
  45 };
  46 struct prefix_list {
  47         struct prefix_list *prev;
  48         struct prefix_list *next;
  49         uint32_t mask;
  50         int ifindex;
  51         struct {
  52                 struct in6_addr addr;
  53                 int prefix_len;
  54                 time_t valid_until;
  55         } prefix;
  56         struct {
  57                 struct in6_addr addr;
  58                 int prefix_len;
  59                 time_t valid_until;
  60         } address;
  61         struct nid_list *nids;
  62 };
  63
  64 struct nl_handle *handle;
  65
  66 /* from linux/include/net/ipv6.h */
  67 static inline int ipv6_prefix_equal(struct in6_addr *prefix,
  68                                     struct in6_addr *addr, int prefixlen)
  69 {
  70         uint32_t *a1 = prefix->s6_addr32, *a2 = addr->s6_addr32;
  71         unsigned pdw, pbi;
  72
  73         /* check complete u32 in prefix */
  74         pdw = prefixlen >> 5;
  75         if (pdw && memcmp(a1, a2, pdw << 2))
  76                 return 0;
  77
  78         /* check incomplete u32 in prefix */
  79         pbi = prefixlen & 0x1f;
  80         if (pbi && ((a1[pdw] ^ a2[pdw]) & htonl((0xffffffff) << (32 - pbi))))
  81                 return 0;
  82
  83         return 1;
  84 }
  85
  86 static int add_address_to_interface(int ifindex, struct in6_addr *address, int prefix)
  87 {
  88         int err = -1;
  89         struct rtnl_addr *rta;
  90         struct nl_addr *nl;
  91
  92         nl = nl_addr_build(AF_INET6, address, sizeof(struct in6_addr));
  93         rta = rtnl_addr_alloc();
  94
  95         rtnl_addr_set_family(rta, AF_INET6);
  96         rtnl_addr_set_ifindex(rta, ifindex);
  97         rtnl_addr_set_local(rta, nl);
  98         rtnl_addr_set_prefixlen(rta, prefix);
  99
 100         if (rtnl_addr_add(handle, rta, NLM_F_REPLACE) != -1 || errno == EEXIST)
 101                 err = 0;
 102
 103         rtnl_addr_free(rta);
 104         nl_addr_destroy(nl);
 105         return err;
 106 }
 107
 108 static int add_nid_to_list(struct prefix_list *i, nid_t nid)
 109 {
 110         struct nid_list *n;
 111         n = calloc(1, sizeof(struct nid_list));
 112         if (!n)
 113                 return -1;
 114         n->nid = nid;
 115         n->next = i->nids;
 116         i->nids = n;
 117         return 0;
 118 }
 119
 120 static void cleanup_prefix(struct prefix_list *i)
 121 {
 122         struct nid_list *n;
 123
 124         for (n = i->nids; n; n = n->next) {
 125                 struct rtnl_addr *rta;
 126                 struct nl_addr *nl;
 127                 struct in6_addr a;
 128
 129                 memcpy(&a, &i->address.addr, sizeof(a));
 130                 rta = rtnl_addr_alloc();
 131                 nl = nl_addr_build(AF_INET6, &a, sizeof(a));
 132
 133                 rtnl_addr_set_family(rta, AF_INET6);
 134                 rtnl_addr_set_ifindex(rta, i->ifindex);
 135                 rtnl_addr_set_local(rta, nl);
 136                 rtnl_addr_set_prefixlen(rta, i->address.prefix_len);
 137
 138                 /* ignore errors */
 139                 rtnl_addr_delete(handle, rta, 0);
 140
 141                 nl_addr_destroy(nl);
 142                 rtnl_addr_free(rta);
 143         }
 144 }
 145
 146 static void do_slices_autoconf(struct prefix_list *head)
 147 {
 148         DIR *dp;
 149         struct dirent *de;
 150         nid_t nid;
 151         struct vc_net_nx addr;
 152         struct prefix_list *i;
 153
 154         if ((dp = opendir("/proc/virtnet")) == NULL)
 155                 return;
 156         while ((de = readdir(dp)) != NULL) {
 157                 if (!isdigit(de->d_name[0]))
 158                         continue;
 159
 160                 nid = strtoul(de->d_name, NULL, 10);
 161                 addr.type = vcNET_IPV6A;
 162                 addr.count = 0;
 163                 if (vc_net_remove(nid, &addr) == -1) {
 164                         syslog(LOG_ERR, "vc_net_remove: %s", strerror(errno));
 165                         continue;
 166                 }
 167
 168                 for (i = head->next; i;) {
 169                         /* expired */
 170                         if (i->mask & HAS_PREFIX && i->prefix.valid_until < time(NULL)) {
 171                                 struct prefix_list *tmp;
 172                                 char buf[64];
 173
 174                                 inet_ntop(AF_INET6, &i->address.addr, buf, sizeof(buf));
 175                                 syslog(LOG_NOTICE, "Address %s timed out", buf);
 176
 177                                 if (i->next)
 178                                         i->next->prev = i->prev;
 179                                 if (i->prev)
 180                                         i->prev->next = i->next;
 181                                 tmp = i->next;
 182
 183                                 cleanup_prefix(i);
 184
 185                                 free(i);
 186                                 i = tmp;
 187                                 continue;
 188                         }
 189                         if (i->mask != (HAS_ADDRESS|HAS_PREFIX))
 190                                 goto next;
 191
 192                         addr.count = 1;
 193                         addr.mask[0] = i->prefix.prefix_len;
 194                         memcpy(addr.ip, &i->address.addr, sizeof(struct in6_addr));
 195                         addr.ip[2] = htonl((ntohl(addr.ip[2]) & 0xffffff00) | ((nid & 0x7f00) >> 7));
 196                         addr.ip[3] = htonl((ntohl(addr.ip[3]) & 0x00ffffff) | ((nid & 0xff) << 25));
 197                         if (vc_net_add(nid, &addr) == -1) {
 198                                 syslog(LOG_ERR, "vc_net_add: %s", strerror(errno));
 199                                 exit(1);
 200                         }
 201                         if (add_address_to_interface(i->ifindex, (struct in6_addr *) addr.ip, i->prefix.prefix_len) == -1) {
 202                                 syslog(LOG_ERR, "add_address_to_interface: %s", strerror(errno));
 203                                 exit(1);
 204                         }
 205                         if (add_nid_to_list(i, nid) == -1) {
 206                                 syslog(LOG_ERR, "add_nid_to_list: %s", strerror(errno));
 207                                 exit(1);
 208                         }
 209 next:
 210                         i = i->next;
 211                 }
 212         }
 213         closedir(dp);
 214 }
 215
 216 static int add_prefix(struct prefix_list *head, struct prefixmsg *msg,
 217                       struct in6_addr *prefix, struct prefix_cacheinfo *cache)
 218 {
 219         struct prefix_list *i = head;
 220         if (!msg || !prefix || !cache)
 221                 return -1;
 222         /* XXX IF_PREFIX_AUTOCONF == 0x02 */
 223         if (!(msg->prefix_flags & 0x02))
 224                 return -1;
 225
 226         do {
 227                 if (i->next != NULL)
 228                         i = i->next;
 229                 if (ipv6_prefix_equal(prefix, &i->prefix.addr, msg->prefix_len) ||
 230                     ipv6_prefix_equal(prefix, &i->address.addr, msg->prefix_len)) {
 231                         i->mask |= HAS_PREFIX;
 232                         i->ifindex = msg->prefix_ifindex;
 233                         memcpy(&i->prefix.addr, prefix, sizeof(*prefix));
 234                         i->prefix.prefix_len = msg->prefix_len;
 235                         i->prefix.valid_until = time(NULL) + cache->preferred_time;
 236                         return 0;
 237                 }
 238         } while (i->next);
 239
 240         i->next = calloc(1, sizeof(*i));
 241         if (!i->next)
 242                 return -1;
 243         i->next->prev = i;
 244         i = i->next;
 245         i->mask = HAS_PREFIX;
 246         memcpy(&i->prefix.addr, prefix, sizeof(*prefix));
 247         i->prefix.prefix_len = msg->prefix_len;
 248         i->prefix.valid_until = time(NULL) + cache->preferred_time;
 249
 250         return 1;
 251 }
 252
 253 static inline int add_address(struct prefix_list *head, struct ifaddrmsg *msg,
 254                               struct in6_addr *address, struct ifa_cacheinfo *cache)
 255 {
 256         struct prefix_list *i = head;
 257         if (!msg || !address || !cache)
 258                 return -1;
 259
 260         if (address->s6_addr[11] != 0xFF || address->s6_addr[12] != 0xFE)
 261                 return -1;
 262
 263         do {
 264                 if (i->next != NULL)
 265                         i = i->next;
 266                 if (ipv6_prefix_equal(address, &i->prefix.addr, msg->ifa_prefixlen) ||
 267                     ipv6_prefix_equal(address, &i->address.addr, msg->ifa_prefixlen)) {
 268                         i->mask |= HAS_ADDRESS;
 269                         memcpy(&i->address.addr, address, sizeof(*address));
 270                         i->address.prefix_len = msg->ifa_prefixlen;
 271                         i->address.valid_until = time(NULL) + cache->ifa_prefered;
 272                         return 0;
 273                 }
 274         } while (i->next);
 275
 276         i->next = calloc(1, sizeof(*i));
 277         if (!i->next)
 278                 return -1;
 279         i->next->prev = i;
 280         i = i->next;
 281         i->mask = HAS_ADDRESS;
 282         memcpy(&i->address.addr, address, sizeof(*address));
 283         i->address.prefix_len = msg->ifa_prefixlen;
 284         i->address.valid_until = time(NULL) + cache->ifa_prefered;
 285
 286         return 1;
 287 }
 288
 289 static struct nla_policy addr_policy[IFA_MAX+1] = {
 290         [IFA_ADDRESS]   = { .minlen = sizeof(struct in6_addr) },
 291         [IFA_LABEL]     = { .type = NLA_STRING,
 292                             .maxlen = IFNAMSIZ },
 293         [IFA_CACHEINFO] = { .minlen = sizeof(struct ifa_cacheinfo) },
 294 };
 295 static struct nla_policy prefix_policy[PREFIX_MAX+1] = {
 296         [PREFIX_ADDRESS]   = { .minlen = sizeof(struct in6_addr) },
 297         [PREFIX_CACHEINFO] = { .minlen = sizeof(struct prefix_cacheinfo) },
 298 };
 299 int handle_valid_msg(struct nl_msg *msg, void *arg)
 300 {
 301         struct nlmsghdr *nlh = nlmsg_hdr(msg);
 302         int ret = -1;
 303         char *payload;
 304         struct sockaddr_nl *source = nlmsg_get_src(msg);
 305
 306         payload = nlmsg_data(nlh);
 307         if (source->nl_groups == RTMGRP_IPV6_PREFIX) {
 308                 struct prefixmsg *prefixmsg;
 309                 struct in6_addr *prefix = NULL;
 310                 struct prefix_cacheinfo *cacheinfo = NULL;
 311                 struct nlattr *tb[PREFIX_MAX+1];
 312
 313                 if (nlmsg_parse(nlh, sizeof(struct prefixmsg), tb, PREFIX_MAX, prefix_policy) < 0) {
 314                         syslog(LOG_ERR, "Failed to parse prefixmsg");
 315                         return -1;
 316                 }
 317
 318                 prefixmsg = (struct prefixmsg *) payload;
 319                 if (tb[PREFIX_ADDRESS])
 320                         prefix = nl_data_get(nla_get_data(tb[PREFIX_ADDRESS]));
 321                 if (tb[PREFIX_CACHEINFO])
 322                         cacheinfo = nl_data_get(nla_get_data(tb[PREFIX_CACHEINFO]));
 323                 ret = add_prefix(arg, prefixmsg, prefix, cacheinfo);
 324         }
 325         else if (source->nl_groups == RTMGRP_IPV6_IFADDR) {
 326                 struct ifaddrmsg *ifaddrmsg;
 327                 struct in6_addr *address = NULL;
 328                 struct ifa_cacheinfo *cacheinfo = NULL;
 329                 struct nlattr *tb[IFA_MAX+1];
 330
 331                 if (nlmsg_parse(nlh, sizeof(struct ifaddrmsg), tb, IFA_MAX, addr_policy) < 0) {
 332                         syslog(LOG_ERR, "Failed to parse ifaddrmsg");
 333                         return -1;
 334                 }
 335
 336                 ifaddrmsg = (struct ifaddrmsg *) payload;
 337                 if (tb[IFA_ADDRESS])
 338                         address = nl_data_get(nla_get_data(tb[IFA_ADDRESS]));
 339                 if (tb[IFA_CACHEINFO])
 340                         cacheinfo = nl_data_get(nla_get_data(tb[IFA_CACHEINFO]));
 341                 ret = add_address(arg, ifaddrmsg, address, cacheinfo);
 342         }
 343         if (ret >= 0)
 344                 do_slices_autoconf(arg);
 345
 346         return 0;
 347 }
 348
 349 int handle_error_msg(struct sockaddr_nl *source, struct nlmsgerr *err,
 350                      void *arg)
 351 {
 352         syslog(LOG_ERR, "%s", strerror(err->error));
 353         return 0;
 354 }
 355
 356 int handle_no_op(struct nl_msg *msg, void *arg)
 357 {
 358         return 0;
 359 }
 360
 361 /* only for access in the signal handler */
 362 struct prefix_list head;
 363 void signal_handler(int signal)
 364 {
 365         switch (signal) {
 366         case SIGUSR1:
 367                 do_slices_autoconf(&head);
 368                 break;
 369         }
 370 }
 371
 372 static int write_pidfile(const char *filename)
 373 {
 374         FILE *fp;
 375         fp = fopen(filename, "w");
 376         if (!fp)
 377                 return -1;
 378         fprintf(fp, "%d\n", getpid());
 379         fclose(fp);
 380         return 0;
 381 }
 382
 383 int main(int argc, char *argv[])
 384 {
 385         struct nl_cb *cbs;
 386         head.prev = head.next = NULL;
 387
 388         openlog("vip6-autod", LOG_PERROR, LOG_DAEMON);
 389
 390         handle = nl_handle_alloc_nondefault(NL_CB_VERBOSE);
 391         cbs = nl_handle_get_cb(handle);
 392         nl_cb_set(cbs, NL_CB_VALID, NL_CB_CUSTOM, handle_valid_msg, &head);
 393         nl_cb_set(cbs, NL_CB_SEQ_CHECK, NL_CB_CUSTOM, handle_no_op, NULL);
 394         nl_cb_err(cbs, NL_CB_CUSTOM, handle_error_msg, &head);
 395         nl_disable_sequence_check(handle);
 396
 397         nl_join_groups(handle, RTMGRP_IPV6_PREFIX|RTMGRP_IPV6_IFADDR);
 398         if (nl_connect(handle, NETLINK_ROUTE) == -1) {
 399                 syslog(LOG_CRIT, "nl_connect: %s", strerror(errno));
 400                 exit(1);
 401         }
 402
 403         if (daemon(0, 0) == -1)
 404                 return -1;
 405
 406         /* XXX .. here is a hack */
 407         write_pidfile(DEFAULT_PKGSTATEDIR "/../vip6-autod.pid");
 408
 409         signal(SIGUSR1, signal_handler);
 410
 411         while (nl_recvmsgs(handle, cbs) > 0);
 412
 413         nl_close(handle);
 414         closelog();
 415         return 0;
 416 }