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                 "-O", "pxeconffile",
 223                 "-O", "pxepathprefix",
 224                 "-x", "0x5d:000a",
 225                 "-p", pidfile,
 226                 "-i", interface->name,
 227                 NULL,
 228         };
 229         snprintf(pidfile, sizeof(pidfile), "%s/udhcpc-%s.pid",
 230                         PIDFILE_BASE, interface->name);
 231
 232         process = process_create(interface);
 233
 234         process->path = pb_system_apps.udhcpc;
 235         process->argv = argv;
 236         process->exit_cb = udhcpc_process_exit;
 237         process->data = interface;
 238
 239         rc = process_run_async(process);
 240
 241         if (rc)
 242                 process_release(process);
 243         else
 244                 interface->udhcpc_process = process;
 245
 246         return;
 247 }
 248
 249 static void configure_interface_static(struct interface *interface,
 250                 const struct interface_config *config)
 251 {
 252         int rc;
 253
 254         rc = process_run_simple(interface, pb_system_apps.ip,
 255                         "address", "add", config->static_config.address,
 256                         "dev", interface->name, NULL);
 257
 258
 259         if (rc) {
 260                 pb_log("failed to add address %s to interface %s\n",
 261                                 config->static_config.address,
 262                                 interface->name);
 263                 return;
 264         }
 265
 266         /* we need the interface up before we can route through it */
 267         rc = interface_up(interface);
 268         if (rc)
 269                 return;
 270
 271         if (config->static_config.gateway)
 272                 rc = process_run_simple(interface, pb_system_apps.ip,
 273                                 "route", "add", "default",
 274                                 "via", config->static_config.gateway,
 275                                 NULL);
 276
 277         if (rc) {
 278                 pb_log("failed to add default route %s on interface %s\n",
 279                                 config->static_config.gateway,
 280                                 interface->name);
 281         }
 282
 283         return;
 284 }
 285
 286 static void configure_interface(struct network *network,
 287                 struct interface *interface, bool up, bool link)
 288 {
 289         const struct interface_config *config = NULL;
 290
 291         if (interface->state == IFSTATE_IGNORED)
 292                 return;
 293
 294         /* old interface? check that we're still up and running */
 295         if (interface->state == IFSTATE_CONFIGURED) {
 296                 if (!up)
 297                         interface->state = IFSTATE_NEW;
 298                 else if (!link)
 299                         interface->state = IFSTATE_UP_WAITING_LINK;
 300                 else
 301                         return;
 302         }
 303
 304         /* always up the lookback, no other handling required */
 305         if (!strcmp(interface->name, "lo")) {
 306                 if (interface->state == IFSTATE_NEW)
 307                         interface_up(interface);
 308                 interface->state = IFSTATE_CONFIGURED;
 309                 return;
 310         }
 311
 312         config = find_config_by_hwaddr(interface->hwaddr);
 313         if (config && config->ignore) {
 314                 pb_log("network: ignoring interface %s\n", interface->name);
 315                 interface->state = IFSTATE_IGNORED;
 316                 return;
 317         }
 318
 319         /* if we're in manual config mode, we need an interface configuration */
 320         if (network->manual_config && !config) {
 321                 interface->state = IFSTATE_IGNORED;
 322                 pb_log("network: skipping %s: manual config mode, "
 323                                 "but no config for this interface\n",
 324                                 interface->name);
 325                 return;
 326         }
 327
 328         /* new interface? bring up to the point so we can detect a link */
 329         if (interface->state == IFSTATE_NEW) {
 330                 if (!up) {
 331                         interface_up(interface);
 332                         pb_log("network: bringing up interface %s\n",
 333                                         interface->name);
 334                         return;
 335
 336                 } else if (!link) {
 337                         interface->state = IFSTATE_UP_WAITING_LINK;
 338                 }
 339         }
 340
 341         /* no link? wait for a notification */
 342         if (interface->state == IFSTATE_UP_WAITING_LINK && !link)
 343                 return;
 344
 345         pb_log("network: configuring interface %s\n", interface->name);
 346
 347         if (!config || config->method == CONFIG_METHOD_DHCP) {
 348                 configure_interface_dhcp(interface);
 349
 350         } else if (config->method == CONFIG_METHOD_STATIC) {
 351                 configure_interface_static(interface, config);
 352         }
 353 }
 354
 355 static int network_handle_nlmsg(struct network *network, struct nlmsghdr *nlmsg)
 356 {
 357         bool have_ifaddr, have_ifname;
 358         struct interface *interface;
 359         struct ifinfomsg *info;
 360         struct rtattr *attr;
 361         unsigned int mtu;
 362         uint8_t ifaddr[6];
 363         char ifname[IFNAMSIZ+1];
 364         int attrlen, type;
 365
 366
 367         /* we're only interested in NEWLINK messages */
 368         type = nlmsg->nlmsg_type;
 369         if (!(type == RTM_NEWLINK || type == RTM_DELLINK))
 370                 return 0;
 371
 372         info = NLMSG_DATA(nlmsg);
 373
 374         have_ifaddr = have_ifname = false;
 375         mtu = 1;
 376
 377         attrlen = nlmsg->nlmsg_len - sizeof(*info);
 378
 379         /* extract the interface name and hardware address attributes */
 380         for_each_rta(info + 1, attr, attrlen) {
 381                 void *data = RTA_DATA(attr);
 382
 383                 switch (attr->rta_type) {
 384                 case IFLA_ADDRESS:
 385                         memcpy(ifaddr, data, sizeof(ifaddr));
 386                         have_ifaddr = true;
 387                         break;
 388
 389                 case IFLA_IFNAME:
 390                         strncpy(ifname, data, IFNAMSIZ);
 391                         have_ifname = true;
 392                         break;
 393
 394                 case IFLA_MTU:
 395                         mtu = *(unsigned int *)data;
 396                         break;
 397                 }
 398         }
 399
 400         if (!have_ifaddr || !have_ifname)
 401                 return -1;
 402
 403         if (type == RTM_DELLINK || mtu == 0) {
 404                 interface = find_interface_by_ifindex(network, info->ifi_index);
 405                 if (!interface)
 406                         return 0;
 407                 pb_log("network: interface %s removed\n", interface->name);
 408                 remove_interface(network, interface);
 409                 return 0;
 410         }
 411
 412
 413         interface = find_interface_by_ifindex(network, info->ifi_index);
 414         if (!interface) {
 415                 interface = talloc_zero(network, struct interface);
 416                 interface->ifindex = info->ifi_index;
 417                 interface->state = IFSTATE_NEW;
 418                 memcpy(interface->hwaddr, ifaddr, sizeof(interface->hwaddr));
 419                 strncpy(interface->name, ifname, sizeof(interface->name) - 1);
 420                 add_interface(network, interface);
 421         }
 422
 423         /* notify the sysinfo code about changes to this interface */
 424         if (strcmp(interface->name, "lo"))
 425                 system_info_register_interface(
 426                                 sizeof(interface->hwaddr),
 427                                 interface->hwaddr, interface->name,
 428                                 info->ifi_flags & IFF_LOWER_UP);
 429
 430         configure_interface(network, interface,
 431                         info->ifi_flags & IFF_UP,
 432                         info->ifi_flags & IFF_LOWER_UP);
 433
 434         return 0;
 435 }
 436
 437 static int network_netlink_process(void *arg)
 438 {
 439         struct network *network = arg;
 440         struct nlmsghdr *nlmsg;
 441         struct msghdr msg;
 442         struct iovec iov;
 443         unsigned int len;
 444         int rc, flags;
 445
 446         memset(&msg, 0, sizeof(msg));
 447         msg.msg_iov = &iov;
 448         msg.msg_iovlen = 1;
 449
 450         flags = MSG_PEEK;
 451
 452 retry:
 453         iov.iov_len = network->netlink_buf_size;
 454         iov.iov_base = network->netlink_buf;
 455
 456         rc = recvmsg(network->netlink_sd, &msg, flags);
 457
 458         if (rc < 0) {
 459                 perror("netlink recv header");
 460                 return -1;
 461         }
 462
 463         len = rc;
 464
 465         /* if the netlink message was larger than our buffer, realloc
 466          * before reading again */
 467         if (len > network->netlink_buf_size || msg.msg_flags & MSG_TRUNC) {
 468                 network->netlink_buf_size *= 2;
 469                 network->netlink_buf = talloc_realloc(network,
 470                                         network->netlink_buf,
 471                                         char *,
 472                                         network->netlink_buf_size);
 473                 goto retry;
 474         }
 475
 476         /* otherwise, we're good to read the entire message without PEEK */
 477         if (flags == MSG_PEEK) {
 478                 flags = 0;
 479                 goto retry;
 480         }
 481
 482         for_each_nlmsg(network->netlink_buf, nlmsg, len)
 483                 network_handle_nlmsg(network, nlmsg);
 484
 485         return 0;
 486 }
 487
 488 static void network_init_dns(struct network *network)
 489 {
 490         const struct config *config;
 491         unsigned int i;
 492         int rc, len;
 493         bool modified;
 494         char *buf;
 495
 496         if (network->dry_run)
 497                 return;
 498
 499         config = config_get();
 500         if (!config || !config->network.n_dns_servers)
 501                 return;
 502
 503         rc = read_file(network, "/etc/resolv.conf", &buf, &len);
 504
 505         if (rc) {
 506                 buf = talloc_strdup(network, "");
 507                 len = 0;
 508         }
 509
 510         modified = false;
 511
 512         for (i = 0; i < config->network.n_dns_servers; i++) {
 513                 int dns_conf_len;
 514                 char *dns_conf;
 515
 516                 dns_conf = talloc_asprintf(network, "nameserver %s\n",
 517                                 config->network.dns_servers[i]);
 518
 519                 if (strstr(buf, dns_conf)) {
 520                         talloc_free(dns_conf);
 521                         continue;
 522                 }
 523
 524                 dns_conf_len = strlen(dns_conf);
 525                 buf = talloc_realloc(network, buf, char, len + dns_conf_len + 1);
 526                 memcpy(buf + len, dns_conf, dns_conf_len);
 527                 len += dns_conf_len;
 528                 buf[len - 1] = '\0';
 529                 modified = true;
 530
 531                 talloc_free(dns_conf);
 532         }
 533
 534         if (modified) {
 535                 rc = replace_file("/etc/resolv.conf", buf, len);
 536                 if (rc)
 537                         pb_log("error replacing resolv.conf: %s\n",
 538                                         strerror(errno));
 539         }
 540
 541         talloc_free(buf);
 542 }
 543
 544 struct network *network_init(struct device_handler *handler,
 545                 struct waitset *waitset, bool dry_run)
 546 {
 547         struct network *network;
 548         int rc;
 549
 550         network = talloc(handler, struct network);
 551         list_init(&network->interfaces);
 552         network->handler = handler;
 553         network->dry_run = dry_run;
 554         network->manual_config = config_get()->network.n_interfaces != 0;
 555
 556         network_init_dns(network);
 557
 558         rc = network_init_netlink(network);
 559         if (rc)
 560                 goto err;
 561
 562         network->waiter = waiter_register_io(waitset, network->netlink_sd,
 563                         WAIT_IN, network_netlink_process, network);
 564
 565         if (!network->waiter)
 566                 goto err;
 567
 568         rc = network_send_link_query(network);
 569         if (rc)
 570                 goto err;
 571
 572         return network;
 573
 574 err:
 575         network_shutdown(network);
 576         return NULL;
 577 }
 578
 579
 580 int network_shutdown(struct network *network)
 581 {
 582         struct interface *interface;
 583
 584         if (network->waiter)
 585                 waiter_remove(network->waiter);
 586
 587         list_for_each_entry(&network->interfaces, interface, list) {
 588                 if (interface->state == IFSTATE_IGNORED)
 589                         continue;
 590                 if (!strcmp(interface->name, "lo"))
 591                         continue;
 592                 interface_down(interface);
 593         }
 594
 595         close(network->netlink_sd);
 596         talloc_free(network);
 597         return 0;
 598 }