git.ozlabs.org Git - petitboot/blob - discover/network.c

   1
   2 #include <stdbool.h>
   3 #include <stdint.h>
   4 #include <string.h>
   5 #include <stdlib.h>
   6 #include <errno.h>
   7 #include <sys/socket.h>
   8 #include <linux/if.h>
   9 #include <linux/netlink.h>
  10 #include <linux/rtnetlink.h>
  11
  12 #include <log/log.h>
  13 #include <list/list.h>
  14 #include <types/types.h>
  15 #include <talloc/talloc.h>
  16 #include <waiter/waiter.h>
  17 #include <pb-config/pb-config.h>
  18 #include <process/process.h>
  19 #include <system/system.h>
  20
  21 #include "file.h"
  22 #include "network.h"
  23 #include "sysinfo.h"
  24 #include "device-handler.h"
  25
  26 #define HWADDR_SIZE     6
  27 #define PIDFILE_BASE    (LOCAL_STATE_DIR "/petitboot/")
  28 #define INITIAL_BUFSIZE 4096
  29
  30 #define for_each_nlmsg(buf, nlmsg, len) \
  31         for (nlmsg = (struct nlmsghdr *)buf; \
  32                 NLMSG_OK(nlmsg, len) && nlmsg->nlmsg_type != NLMSG_DONE; \
  33                 nlmsg = NLMSG_NEXT(nlmsg, len))
  34
  35 #define for_each_rta(buf, rta, attrlen) \
  36         for (rta = (struct rtattr *)(buf); RTA_OK(rta, attrlen); \
  37                         rta = RTA_NEXT(rta, attrlen))
  38
  39
  40 struct interface {
  41         int     ifindex;
  42         char    name[IFNAMSIZ];
  43         uint8_t hwaddr[HWADDR_SIZE];
  44
  45         enum {
  46                 IFSTATE_NEW,
  47                 IFSTATE_UP_WAITING_LINK,
  48                 IFSTATE_CONFIGURED,
  49                 IFSTATE_IGNORED,
  50         } state;
  51
  52         struct list_item list;
  53         struct process *udhcpc_process;
  54         struct discover_device *dev;
  55 };
  56
  57 struct network {
  58         struct list             interfaces;
  59         struct device_handler   *handler;
  60         struct waiter           *waiter;
  61         int                     netlink_sd;
  62         void                    *netlink_buf;
  63         unsigned int            netlink_buf_size;
  64         bool                    manual_config;
  65         bool                    dry_run;
  66 };
  67
  68 static const struct interface_config *find_config_by_hwaddr(
  69                 uint8_t *hwaddr)
  70 {
  71         const struct config *config;
  72         unsigned int i;
  73
  74         config = config_get();
  75         if (!config)
  76                 return NULL;
  77
  78         for (i = 0; i < config->network.n_interfaces; i++) {
  79                 struct interface_config *ifconf = config->network.interfaces[i];
  80
  81                 if (!memcmp(ifconf->hwaddr, hwaddr, HWADDR_SIZE))
  82                         return ifconf;
  83         }
  84
  85         return NULL;
  86 }
  87
  88 static struct interface *find_interface_by_ifindex(struct network *network,
  89                 int ifindex)
  90 {
  91         struct interface *interface;
  92
  93         list_for_each_entry(&network->interfaces, interface, list)
  94                 if (interface->ifindex == ifindex)
  95                         return interface;
  96
  97         return NULL;
  98 }
  99
 100 static int network_init_netlink(struct network *network)
 101 {
 102         struct sockaddr_nl addr;
 103         int rc;
 104
 105         memset(&addr, 0, sizeof(addr));
 106         addr.nl_family = AF_NETLINK;
 107         addr.nl_groups = RTMGRP_LINK;
 108
 109         network->netlink_sd = socket(AF_NETLINK, SOCK_DGRAM, NETLINK_ROUTE);
 110         if (network->netlink_sd < 0) {
 111                 perror("socket(AF_NETLINK)");
 112                 return -1;
 113         }
 114
 115         rc = bind(network->netlink_sd, (struct sockaddr *)&addr, sizeof(addr));
 116         if (rc) {
 117                 perror("bind(sockaddr_nl)");
 118                 close(network->netlink_sd);
 119                 return -1;
 120         }
 121
 122         network->netlink_buf_size = INITIAL_BUFSIZE;
 123         network->netlink_buf = talloc_array(network, char,
 124                                 network->netlink_buf_size);
 125
 126         return 0;
 127 }
 128
 129 static int network_send_link_query(struct network *network)
 130 {
 131         int rc;
 132         struct {
 133                 struct nlmsghdr nlmsg;
 134                 struct rtgenmsg rtmsg;
 135         } msg;
 136
 137         memset(&msg, 0, sizeof(msg));
 138
 139         msg.nlmsg.nlmsg_len = sizeof(msg);
 140         msg.nlmsg.nlmsg_type = RTM_GETLINK;
 141         msg.nlmsg.nlmsg_flags = NLM_F_REQUEST | NLM_F_ROOT;
 142         msg.nlmsg.nlmsg_seq = 0;
 143         msg.nlmsg.nlmsg_pid = 0;
 144         msg.rtmsg.rtgen_family = AF_UNSPEC;
 145
 146         rc = send(network->netlink_sd, &msg, sizeof(msg), MSG_NOSIGNAL);
 147         if (rc != sizeof(msg))
 148                 return -1;
 149
 150         return 0;
 151 }
 152
 153 static void add_interface(struct network *network,
 154                 struct interface *interface)
 155 {
 156         list_add(&network->interfaces, &interface->list);
 157         interface->dev = discover_device_create(network->handler,
 158                                         interface->name);
 159         interface->dev->device->type = DEVICE_TYPE_NETWORK;
 160         device_handler_add_device(network->handler, interface->dev);
 161 }
 162
 163 static void remove_interface(struct network *network,
 164                 struct interface *interface)
 165 {
 166         device_handler_remove(network->handler, interface->dev);
 167         list_remove(&interface->list);
 168         talloc_free(interface);
 169 }
 170
 171 static int interface_change(struct interface *interface, bool up)
 172 {
 173         const char *statestr = up ? "up" : "down";
 174         int rc;
 175
 176         if (!up && interface->udhcpc_process) {
 177                 /* we don't care about the callback from here */
 178                 interface->udhcpc_process->exit_cb = NULL;
 179                 interface->udhcpc_process->data = NULL;
 180                 process_stop_async(interface->udhcpc_process);
 181                 process_release(interface->udhcpc_process);
 182         }
 183
 184         rc = process_run_simple(interface, pb_system_apps.ip,
 185                         "link", "set", interface->name, statestr, NULL);
 186         if (rc) {
 187                 pb_log("failed to bring interface %s %s\n", interface->name,
 188                                 statestr);
 189                 return -1;
 190         }
 191         return 0;
 192 }
 193
 194 static int interface_up(struct interface *interface)
 195 {
 196         return interface_change(interface, true);
 197 }
 198
 199 static int interface_down(struct interface *interface)
 200 {
 201         return interface_change(interface, false);
 202 }
 203
 204 static void udhcpc_process_exit(struct process *process)
 205 {
 206         struct interface *interface = process->data;
 207         pb_debug("udhcp client [pid %d] for interface %s exited, rc %d\n",
 208                         process->pid, interface->name, process->exit_status);
 209         interface->udhcpc_process = NULL;
 210         process_release(process);
 211 }
 212
 213 static void configure_interface_dhcp(struct interface *interface)
 214 {
 215         struct process *process;
 216         char pidfile[256];
 217         int rc;
 218         const char *argv[] = {
 219                 pb_system_apps.udhcpc,
 220                 "-R",
 221                 "-n",
 222                 "-p", pidfile,
 223                 "-i", interface->name,
 224                 NULL,
 225         };
 226         snprintf(pidfile, sizeof(pidfile), "%s/udhcpc-%s.pid",
 227                         PIDFILE_BASE, interface->name);
 228
 229         process = process_create(interface);
 230
 231         process->path = pb_system_apps.udhcpc;
 232         process->argv = argv;
 233         process->exit_cb = udhcpc_process_exit;
 234         process->data = interface;
 235
 236         rc = process_run_async(process);
 237
 238         if (rc)
 239                 process_release(process);
 240         else
 241                 interface->udhcpc_process = process;
 242
 243         return;
 244 }
 245
 246 static void configure_interface_static(struct interface *interface,
 247                 const struct interface_config *config)
 248 {
 249         int rc;
 250
 251         rc = process_run_simple(interface, pb_system_apps.ip,
 252                         "address", "add", config->static_config.address,
 253                         "dev", interface->name, NULL);
 254
 255
 256         if (rc) {
 257                 pb_log("failed to add address %s to interface %s\n",
 258                                 config->static_config.address,
 259                                 interface->name);
 260                 return;
 261         }
 262
 263         /* we need the interface up before we can route through it */
 264         rc = interface_up(interface);
 265         if (rc)
 266                 return;
 267
 268         if (config->static_config.gateway)
 269                 rc = process_run_simple(interface, pb_system_apps.ip,
 270                                 "route", "add", "default",
 271                                 "via", config->static_config.gateway,
 272                                 NULL);
 273
 274         if (rc) {
 275                 pb_log("failed to add default route %s on interface %s\n",
 276                                 config->static_config.gateway,
 277                                 interface->name);
 278         }
 279
 280         return;
 281 }
 282
 283 static void configure_interface(struct network *network,
 284                 struct interface *interface, bool up, bool link)
 285 {
 286         const struct interface_config *config = NULL;
 287
 288         if (interface->state == IFSTATE_IGNORED)
 289                 return;
 290
 291         /* old interface? check that we're still up and running */
 292         if (interface->state == IFSTATE_CONFIGURED) {
 293                 if (!up)
 294                         interface->state = IFSTATE_NEW;
 295                 else if (!link)
 296                         interface->state = IFSTATE_UP_WAITING_LINK;
 297                 else
 298                         return;
 299         }
 300
 301         /* always up the lookback, no other handling required */
 302         if (!strcmp(interface->name, "lo")) {
 303                 if (interface->state == IFSTATE_NEW)
 304                         interface_up(interface);
 305                 interface->state = IFSTATE_CONFIGURED;
 306                 return;
 307         }
 308
 309         config = find_config_by_hwaddr(interface->hwaddr);
 310         if (config && config->ignore) {
 311                 pb_log("network: ignoring interface %s\n", interface->name);
 312                 interface->state = IFSTATE_IGNORED;
 313                 return;
 314         }
 315
 316         /* if we're in manual config mode, we need an interface configuration */
 317         if (network->manual_config && !config) {
 318                 interface->state = IFSTATE_IGNORED;
 319                 pb_log("network: skipping %s: manual config mode, "
 320                                 "but no config for this interface\n",
 321                                 interface->name);
 322                 return;
 323         }
 324
 325         /* new interface? bring up to the point so we can detect a link */
 326         if (interface->state == IFSTATE_NEW) {
 327                 if (!up) {
 328                         interface_up(interface);
 329                         pb_log("network: bringing up interface %s\n",
 330                                         interface->name);
 331                         return;
 332
 333                 } else if (!link) {
 334                         interface->state = IFSTATE_UP_WAITING_LINK;
 335                 }
 336         }
 337
 338         /* no link? wait for a notification */
 339         if (interface->state == IFSTATE_UP_WAITING_LINK && !link)
 340                 return;
 341
 342         pb_log("network: configuring interface %s\n", interface->name);
 343
 344         if (!config || config->method == CONFIG_METHOD_DHCP) {
 345                 configure_interface_dhcp(interface);
 346
 347         } else if (config->method == CONFIG_METHOD_STATIC) {
 348                 configure_interface_static(interface, config);
 349         }
 350 }
 351
 352 static int network_handle_nlmsg(struct network *network, struct nlmsghdr *nlmsg)
 353 {
 354         bool have_ifaddr, have_ifname;
 355         struct interface *interface;
 356         struct ifinfomsg *info;
 357         struct rtattr *attr;
 358         unsigned int mtu;
 359         uint8_t ifaddr[6];
 360         char ifname[IFNAMSIZ+1];
 361         int attrlen, type;
 362
 363
 364         /* we're only interested in NEWLINK messages */
 365         type = nlmsg->nlmsg_type;
 366         if (!(type == RTM_NEWLINK || type == RTM_DELLINK))
 367                 return 0;
 368
 369         info = NLMSG_DATA(nlmsg);
 370
 371         have_ifaddr = have_ifname = false;
 372         mtu = 1;
 373
 374         attrlen = nlmsg->nlmsg_len - sizeof(*info);
 375
 376         /* extract the interface name and hardware address attributes */
 377         for_each_rta(info + 1, attr, attrlen) {
 378                 void *data = RTA_DATA(attr);
 379
 380                 switch (attr->rta_type) {
 381                 case IFLA_ADDRESS:
 382                         memcpy(ifaddr, data, sizeof(ifaddr));
 383                         have_ifaddr = true;
 384                         break;
 385
 386                 case IFLA_IFNAME:
 387                         strncpy(ifname, data, IFNAMSIZ);
 388                         have_ifname = true;
 389                         break;
 390
 391                 case IFLA_MTU:
 392                         mtu = *(unsigned int *)data;
 393                         break;
 394                 }
 395         }
 396
 397         if (!have_ifaddr || !have_ifname)
 398                 return -1;
 399
 400         if (type == RTM_DELLINK || mtu == 0) {
 401                 interface = find_interface_by_ifindex(network, info->ifi_index);
 402                 if (!interface)
 403                         return 0;
 404                 pb_log("network: interface %s removed\n", interface->name);
 405                 remove_interface(network, interface);
 406                 return 0;
 407         }
 408
 409
 410         interface = find_interface_by_ifindex(network, info->ifi_index);
 411         if (!interface) {
 412                 interface = talloc_zero(network, struct interface);
 413                 interface->ifindex = info->ifi_index;
 414                 interface->state = IFSTATE_NEW;
 415                 memcpy(interface->hwaddr, ifaddr, sizeof(interface->hwaddr));
 416                 strncpy(interface->name, ifname, sizeof(interface->name) - 1);
 417                 add_interface(network, interface);
 418
 419                 /* tell the sysinfo code about this interface */
 420                 if (strcmp(interface->name, "lo"))
 421                         system_info_register_interface(
 422                                         sizeof(interface->hwaddr),
 423                                         interface->hwaddr, interface->name);
 424         }
 425
 426         configure_interface(network, interface,
 427                         info->ifi_flags & IFF_UP,
 428                         info->ifi_flags & IFF_LOWER_UP);
 429
 430         return 0;
 431 }
 432
 433 static int network_netlink_process(void *arg)
 434 {
 435         struct network *network = arg;
 436         struct nlmsghdr *nlmsg;
 437         struct msghdr msg;
 438         struct iovec iov;
 439         unsigned int len;
 440         int rc, flags;
 441
 442         memset(&msg, 0, sizeof(msg));
 443         msg.msg_iov = &iov;
 444         msg.msg_iovlen = 1;
 445
 446         flags = MSG_PEEK;
 447
 448 retry:
 449         iov.iov_len = network->netlink_buf_size;
 450         iov.iov_base = network->netlink_buf;
 451
 452         rc = recvmsg(network->netlink_sd, &msg, flags);
 453
 454         if (rc < 0) {
 455                 perror("netlink recv header");
 456                 return -1;
 457         }
 458
 459         len = rc;
 460
 461         /* if the netlink message was larger than our buffer, realloc
 462          * before reading again */
 463         if (len > network->netlink_buf_size || msg.msg_flags & MSG_TRUNC) {
 464                 network->netlink_buf_size *= 2;
 465                 network->netlink_buf = talloc_realloc(network,
 466                                         network->netlink_buf,
 467                                         char *,
 468                                         network->netlink_buf_size);
 469                 goto retry;
 470         }
 471
 472         /* otherwise, we're good to read the entire message without PEEK */
 473         if (flags == MSG_PEEK) {
 474                 flags = 0;
 475                 goto retry;
 476         }
 477
 478         for_each_nlmsg(network->netlink_buf, nlmsg, len)
 479                 network_handle_nlmsg(network, nlmsg);
 480
 481         return 0;
 482 }
 483
 484 static void network_init_dns(struct network *network)
 485 {
 486         const struct config *config;
 487         unsigned int i;
 488         int rc, len;
 489         bool modified;
 490         char *buf;
 491
 492         if (network->dry_run)
 493                 return;
 494
 495         config = config_get();
 496         if (!config || !config->network.n_dns_servers)
 497                 return;
 498
 499         rc = read_file(network, "/etc/resolv.conf", &buf, &len);
 500
 501         if (rc) {
 502                 buf = talloc_strdup(network, "");
 503                 len = 0;
 504         }
 505
 506         modified = false;
 507
 508         for (i = 0; i < config->network.n_dns_servers; i++) {
 509                 int dns_conf_len;
 510                 char *dns_conf;
 511
 512                 dns_conf = talloc_asprintf(network, "nameserver %s\n",
 513                                 config->network.dns_servers[i]);
 514
 515                 if (strstr(buf, dns_conf)) {
 516                         talloc_free(dns_conf);
 517                         continue;
 518                 }
 519
 520                 dns_conf_len = strlen(dns_conf);
 521                 buf = talloc_realloc(network, buf, char, len + dns_conf_len + 1);
 522                 memcpy(buf + len, dns_conf, dns_conf_len);
 523                 len += dns_conf_len;
 524                 buf[len - 1] = '\0';
 525                 modified = true;
 526
 527                 talloc_free(dns_conf);
 528         }
 529
 530         if (modified) {
 531                 rc = replace_file("/etc/resolv.conf", buf, len);
 532                 if (rc)
 533                         pb_log("error replacing resolv.conf: %s\n",
 534                                         strerror(errno));
 535         }
 536
 537         talloc_free(buf);
 538 }
 539
 540 struct network *network_init(struct device_handler *handler,
 541                 struct waitset *waitset, bool dry_run)
 542 {
 543         struct network *network;
 544         int rc;
 545
 546         network = talloc(handler, struct network);
 547         list_init(&network->interfaces);
 548         network->handler = handler;
 549         network->manual_config = false;
 550         network->dry_run = dry_run;
 551
 552         network_init_dns(network);
 553
 554         rc = network_init_netlink(network);
 555         if (rc)
 556                 goto err;
 557
 558         network->waiter = waiter_register_io(waitset, network->netlink_sd,
 559                         WAIT_IN, network_netlink_process, network);
 560
 561         if (!network->waiter)
 562                 goto err;
 563
 564         rc = network_send_link_query(network);
 565         if (rc)
 566                 goto err;
 567
 568         return network;
 569
 570 err:
 571         network_shutdown(network);
 572         return NULL;
 573 }
 574
 575
 576 int network_shutdown(struct network *network)
 577 {
 578         struct interface *interface;
 579
 580         if (network->waiter)
 581                 waiter_remove(network->waiter);
 582
 583         list_for_each_entry(&network->interfaces, interface, list)
 584                 interface_down(interface);
 585
 586         close(network->netlink_sd);
 587         talloc_free(network);
 588         return 0;
 589 }