src/lxc/confile_utils.c

   1 /* liblxcapi
   2  *
   3  * Copyright © 2017 Christian Brauner <christian.brauner@ubuntu.com>.
   4  * Copyright © 2017 Canonical Ltd.
   5  *
   6  * This program is free software; you can redistribute it and/or modify
   7  * it under the terms of the GNU General Public License version 2, as
   8  * published by the Free Software Foundation.
   9  *
  10  * This program is distributed in the hope that it will be useful,
  11  * but WITHOUT ANY WARRANTY; without even the implied warranty of
  12  * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
  13  * GNU General Public License for more details.
  14  *
  15  * You should have received a copy of the GNU General Public License along
  16  * with this program; if not, write to the Free Software Foundation, Inc.,
  17  * 51 Franklin Street, Fifth Floor, Boston, MA 02110-1301 USA.
  18  */
  19
  20 #include "config.h"
  21
  22 #include <ctype.h>
  23 #include <stdio.h>
  24 #include <stdlib.h>
  25 #include <string.h>
  26 #include <arpa/inet.h>
  27
  28 #include "conf.h"
  29 #include "confile.h"
  30 #include "confile_utils.h"
  31 #include "error.h"
  32 #include "log.h"
  33 #include "list.h"
  34 #include "network.h"
  35 #include "parse.h"
  36 #include "utils.h"
  37
  38 lxc_log_define(lxc_confile_utils, lxc);
  39
  40 int parse_idmaps(const char *idmap, char *type, unsigned long *nsid,
  41                  unsigned long *hostid, unsigned long *range)
  42 {
  43         int ret = -1;
  44         unsigned long tmp_hostid, tmp_nsid, tmp_range;
  45         char tmp_type;
  46         char *window, *slide;
  47         char *dup = NULL;
  48
  49         /* Duplicate string. */
  50         dup = strdup(idmap);
  51         if (!dup)
  52                 goto on_error;
  53
  54         /* A prototypical idmap entry would be: "u 1000 1000000 65536" */
  55
  56         /* align */
  57         slide = window = dup;
  58         /* skip whitespace */
  59         slide += strspn(slide, " \t\r");
  60         if (slide != window && *slide == '\0')
  61                 goto on_error;
  62
  63         /* Validate type. */
  64         if (*slide != 'u' && *slide != 'g')
  65                 goto on_error;
  66         /* Assign type. */
  67         tmp_type = *slide;
  68
  69         /* move beyond type */
  70         slide++;
  71         /* align */
  72         window = slide;
  73         /* Validate that only whitespace follows. */
  74         slide += strspn(slide, " \t\r");
  75         /* There must be whitespace. */
  76         if (slide == window)
  77                 goto on_error;
  78
  79         /* Mark beginning of nsuid. */
  80         window = slide;
  81         /* Validate that non-whitespace follows. */
  82         slide += strcspn(slide, " \t\r");
  83         /* There must be non-whitespace. */
  84         if (slide == window || *slide == '\0')
  85                 goto on_error;
  86         /* Mark end of nsuid. */
  87         *slide = '\0';
  88
  89         /* Parse nsuid. */
  90         if (lxc_safe_ulong(window, &tmp_nsid) < 0)
  91                 goto on_error;
  92
  93         /* Move beyond \0. */
  94         slide++;
  95         /* align */
  96         window = slide;
  97         /* Validate that only whitespace follows. */
  98         slide += strspn(slide, " \t\r");
  99         /* If there was only one whitespace then we whiped it with our \0 above.
 100          * So only ensure that we're not at the end of the string.
 101          */
 102         if (*slide == '\0')
 103                 goto on_error;
 104
 105         /* Mark beginning of hostid. */
 106         window = slide;
 107         /* Validate that non-whitespace follows. */
 108         slide += strcspn(slide, " \t\r");
 109         /* There must be non-whitespace. */
 110         if (slide == window || *slide == '\0')
 111                 goto on_error;
 112         /* Mark end of nsuid. */
 113         *slide = '\0';
 114
 115         /* Parse hostid. */
 116         if (lxc_safe_ulong(window, &tmp_hostid) < 0)
 117                 goto on_error;
 118
 119         /* Move beyond \0. */
 120         slide++;
 121         /* align */
 122         window = slide;
 123         /* Validate that only whitespace follows. */
 124         slide += strspn(slide, " \t\r");
 125         /* If there was only one whitespace then we whiped it with our \0 above.
 126          * So only ensure that we're not at the end of the string.
 127          */
 128         if (*slide == '\0')
 129                 goto on_error;
 130
 131         /* Mark beginning of range. */
 132         window = slide;
 133         /* Validate that non-whitespace follows. */
 134         slide += strcspn(slide, " \t\r");
 135         /* There must be non-whitespace. */
 136         if (slide == window)
 137                 goto on_error;
 138
 139         /* The range is the last valid entry we expect. So make sure that there
 140          * is not trailing garbage and if there is, error out.
 141          */
 142         if (*(slide + strspn(slide, " \t\r\n")) != '\0')
 143                 goto on_error;
 144         /* Mark end of range. */
 145         *slide = '\0';
 146
 147         /* Parse range. */
 148         if (lxc_safe_ulong(window, &tmp_range) < 0)
 149                 goto on_error;
 150
 151         *type = tmp_type;
 152         *nsid = tmp_nsid;
 153         *hostid = tmp_hostid;
 154         *range = tmp_range;
 155
 156         /* Yay, we survived. */
 157         ret = 0;
 158
 159 on_error:
 160         free(dup);
 161
 162         return ret;
 163 }
 164
 165 bool lxc_config_value_empty(const char *value)
 166 {
 167         if (value && strlen(value) > 0)
 168                 return false;
 169
 170         return true;
 171 }
 172
 173 struct lxc_netdev *lxc_network_add(struct lxc_list *networks, int idx, bool tail)
 174 {
 175         struct lxc_list *newlist;
 176         struct lxc_netdev *netdev = NULL;
 177
 178         /* network does not exist */
 179         netdev = malloc(sizeof(*netdev));
 180         if (!netdev)
 181                 return NULL;
 182
 183         memset(netdev, 0, sizeof(*netdev));
 184         lxc_list_init(&netdev->ipv4);
 185         lxc_list_init(&netdev->ipv6);
 186
 187         /* give network a unique index */
 188         netdev->idx = idx;
 189
 190         /* prepare new list */
 191         newlist = malloc(sizeof(*newlist));
 192         if (!newlist) {
 193                 free(netdev);
 194                 return NULL;
 195         }
 196
 197         lxc_list_init(newlist);
 198         newlist->elem = netdev;
 199
 200         if (tail)
 201                 lxc_list_add_tail(networks, newlist);
 202         else
 203                 lxc_list_add(networks, newlist);
 204         return netdev;
 205 }
 206
 207 /* Takes care of finding the correct netdev struct in the networks list or
 208  * allocates a new one if it couldn't be found.
 209  */
 210 struct lxc_netdev *lxc_get_netdev_by_idx(struct lxc_conf *conf,
 211                                          unsigned int idx, bool allocate)
 212 {
 213         struct lxc_netdev *netdev = NULL;
 214         struct lxc_list *networks = &conf->network;
 215         struct lxc_list *insert = networks;
 216
 217         /* lookup network */
 218         if (!lxc_list_empty(networks)) {
 219                 lxc_list_for_each(insert, networks) {
 220                         netdev = insert->elem;
 221                         if (netdev->idx == idx)
 222                                 return netdev;
 223                         else if (netdev->idx > idx)
 224                                 break;
 225                 }
 226         }
 227
 228         if (!allocate)
 229                 return NULL;
 230
 231         return lxc_network_add(insert, idx, true);
 232 }
 233
 234 void lxc_log_configured_netdevs(const struct lxc_conf *conf)
 235 {
 236         struct lxc_netdev *netdev;
 237         struct lxc_list *it = (struct lxc_list *)&conf->network;;
 238
 239         if ((conf->loglevel != LXC_LOG_LEVEL_TRACE) &&
 240             (lxc_log_get_level() != LXC_LOG_LEVEL_TRACE))
 241                 return;
 242
 243         if (lxc_list_empty(it)) {
 244                 TRACE("container has no networks configured");
 245                 return;
 246         }
 247
 248         lxc_list_for_each(it, &conf->network) {
 249                 struct lxc_list *cur, *next;
 250                 struct lxc_inetdev *inet4dev;
 251                 struct lxc_inet6dev *inet6dev;
 252                 char bufinet4[INET_ADDRSTRLEN], bufinet6[INET6_ADDRSTRLEN];
 253
 254                 netdev = it->elem;
 255
 256                 TRACE("index: %zd", netdev->idx);
 257                 TRACE("ifindex: %d", netdev->ifindex);
 258                 switch (netdev->type) {
 259                 case LXC_NET_VETH:
 260                         TRACE("type: veth");
 261                         if (netdev->priv.veth_attr.pair[0] != '\0')
 262                                 TRACE("veth pair: %s",
 263                                       netdev->priv.veth_attr.pair);
 264                         if (netdev->priv.veth_attr.veth1[0] != '\0')
 265                                 TRACE("veth1 : %s",
 266                                       netdev->priv.veth_attr.veth1);
 267                         if (netdev->priv.veth_attr.ifindex > 0)
 268                                 TRACE("host side ifindex for veth device: %d",
 269                                       netdev->priv.veth_attr.ifindex);
 270                         break;
 271                 case LXC_NET_MACVLAN:
 272                         TRACE("type: macvlan");
 273                         if (netdev->priv.macvlan_attr.mode > 0) {
 274                                 char *macvlan_mode;
 275                                 macvlan_mode = lxc_macvlan_flag_to_mode(
 276                                     netdev->priv.macvlan_attr.mode);
 277                                 TRACE("macvlan mode: %s",
 278                                       macvlan_mode ? macvlan_mode
 279                                                    : "(invalid mode)");
 280                         }
 281                         break;
 282                 case LXC_NET_VLAN:
 283                         TRACE("type: vlan");
 284                         TRACE("vlan id: %d", netdev->priv.vlan_attr.vid);
 285                         break;
 286                 case LXC_NET_PHYS:
 287                         TRACE("type: phys");
 288                         if (netdev->priv.phys_attr.ifindex > 0) {
 289                                 TRACE("host side ifindex for phys device: %d",
 290                                       netdev->priv.phys_attr.ifindex);
 291                         }
 292                         break;
 293                 case LXC_NET_EMPTY:
 294                         TRACE("type: empty");
 295                         break;
 296                 case LXC_NET_NONE:
 297                         TRACE("type: none");
 298                         break;
 299                 default:
 300                         ERROR("invalid network type %d", netdev->type);
 301                         return;
 302                 }
 303
 304                 if (netdev->type != LXC_NET_EMPTY) {
 305                         TRACE("flags: %s",
 306                               netdev->flags == IFF_UP ? "up" : "none");
 307                         if (netdev->link[0] != '\0')
 308                                 TRACE("link: %s", netdev->link);
 309                         if (netdev->name[0] != '\0')
 310                                 TRACE("name: %s", netdev->name);
 311                         if (netdev->hwaddr)
 312                                 TRACE("hwaddr: %s", netdev->hwaddr);
 313                         if (netdev->mtu)
 314                                 TRACE("mtu: %s", netdev->mtu);
 315                         if (netdev->upscript)
 316                                 TRACE("upscript: %s", netdev->upscript);
 317                         if (netdev->downscript)
 318                                 TRACE("downscript: %s", netdev->downscript);
 319
 320                         TRACE("ipv4 gateway auto: %s",
 321                               netdev->ipv4_gateway_auto ? "true" : "false");
 322
 323                         if (netdev->ipv4_gateway) {
 324                                 inet_ntop(AF_INET, netdev->ipv4_gateway,
 325                                           bufinet4, sizeof(bufinet4));
 326                                 TRACE("ipv4 gateway: %s", bufinet4);
 327                         }
 328
 329                         lxc_list_for_each_safe(cur, &netdev->ipv4, next) {
 330                                 inet4dev = cur->elem;
 331                                 inet_ntop(AF_INET, &inet4dev->addr, bufinet4,
 332                                           sizeof(bufinet4));
 333                                 TRACE("ipv4 addr: %s", bufinet4);
 334                         }
 335
 336                         TRACE("ipv6 gateway auto: %s",
 337                               netdev->ipv6_gateway_auto ? "true" : "false");
 338                         if (netdev->ipv6_gateway) {
 339                                 inet_ntop(AF_INET6, netdev->ipv6_gateway,
 340                                           bufinet6, sizeof(bufinet6));
 341                                 TRACE("ipv6 gateway: %s", bufinet6);
 342                         }
 343                         lxc_list_for_each_safe(cur, &netdev->ipv6, next) {
 344                                 inet6dev = cur->elem;
 345                                 inet_ntop(AF_INET6, &inet6dev->addr, bufinet6,
 346                                           sizeof(bufinet6));
 347                                 TRACE("ipv6 addr: %s", bufinet6);
 348                         }
 349                 }
 350         }
 351 }
 352
 353 static void lxc_free_netdev(struct lxc_netdev *netdev)
 354 {
 355         struct lxc_list *cur, *next;
 356
 357         free(netdev->upscript);
 358         free(netdev->downscript);
 359         free(netdev->hwaddr);
 360         free(netdev->mtu);
 361
 362         free(netdev->ipv4_gateway);
 363         lxc_list_for_each_safe(cur, &netdev->ipv4, next) {
 364                 lxc_list_del(cur);
 365                 free(cur->elem);
 366                 free(cur);
 367         }
 368
 369         free(netdev->ipv6_gateway);
 370         lxc_list_for_each_safe(cur, &netdev->ipv6, next) {
 371                 lxc_list_del(cur);
 372                 free(cur->elem);
 373                 free(cur);
 374         }
 375
 376         free(netdev);
 377 }
 378
 379 bool lxc_remove_nic_by_idx(struct lxc_conf *conf, unsigned int idx)
 380 {
 381         struct lxc_list *cur, *next;
 382         struct lxc_netdev *netdev;
 383         bool found = false;
 384
 385         lxc_list_for_each_safe(cur, &conf->network, next) {
 386                 netdev = cur->elem;
 387                 if (netdev->idx != idx)
 388                         continue;
 389
 390                 lxc_list_del(cur);
 391                 found = true;
 392                 break;
 393         }
 394
 395         if (!found)
 396                 return false;
 397
 398         lxc_free_netdev(netdev);
 399         free(cur);
 400
 401         return true;
 402 }
 403
 404 void lxc_free_networks(struct lxc_list *networks)
 405 {
 406         struct lxc_list *cur, *next;
 407         struct lxc_netdev *netdev;
 408
 409         lxc_list_for_each_safe(cur, networks, next) {
 410                 netdev = cur->elem;
 411                 lxc_free_netdev(netdev);
 412                 free(cur);
 413         }
 414
 415         /* prevent segfaults */
 416         lxc_list_init(networks);
 417 }
 418
 419 static struct macvlan_mode {
 420         char *name;
 421         int mode;
 422 } macvlan_mode[] = {
 423     { "private",  MACVLAN_MODE_PRIVATE  },
 424     { "vepa",     MACVLAN_MODE_VEPA     },
 425     { "bridge",   MACVLAN_MODE_BRIDGE   },
 426     { "passthru", MACVLAN_MODE_PASSTHRU },
 427 };
 428
 429 int lxc_macvlan_mode_to_flag(int *mode, const char *value)
 430 {
 431         size_t i;
 432
 433         for (i = 0; i < sizeof(macvlan_mode) / sizeof(macvlan_mode[0]); i++) {
 434                 if (strcmp(macvlan_mode[i].name, value))
 435                         continue;
 436
 437                 *mode = macvlan_mode[i].mode;
 438                 return 0;
 439         }
 440
 441         return -1;
 442 }
 443
 444 char *lxc_macvlan_flag_to_mode(int mode)
 445 {
 446         size_t i;
 447
 448         for (i = 0; i < sizeof(macvlan_mode) / sizeof(macvlan_mode[0]); i++) {
 449                 if (macvlan_mode[i].mode == mode)
 450                         continue;
 451
 452                 return macvlan_mode[i].name;
 453         }
 454
 455         return NULL;
 456 }
 457
 458 int set_config_string_item(char **conf_item, const char *value)
 459 {
 460         char *new_value;
 461
 462         if (lxc_config_value_empty(value)) {
 463                 free(*conf_item);
 464                 *conf_item = NULL;
 465                 return 0;
 466         }
 467
 468         new_value = strdup(value);
 469         if (!new_value) {
 470                 SYSERROR("failed to duplicate string \"%s\"", value);
 471                 return -1;
 472         }
 473
 474         free(*conf_item);
 475         *conf_item = new_value;
 476         return 0;
 477 }
 478
 479 int set_config_string_item_max(char **conf_item, const char *value, size_t max)
 480 {
 481         if (strlen(value) >= max) {
 482                 ERROR("%s is too long (>= %lu)", value, (unsigned long)max);
 483                 return -1;
 484         }
 485
 486         return set_config_string_item(conf_item, value);
 487 }
 488
 489 int set_config_path_item(char **conf_item, const char *value)
 490 {
 491         return set_config_string_item_max(conf_item, value, PATH_MAX);
 492 }
 493
 494 int config_ip_prefix(struct in_addr *addr)
 495 {
 496         if (IN_CLASSA(addr->s_addr))
 497                 return 32 - IN_CLASSA_NSHIFT;
 498         if (IN_CLASSB(addr->s_addr))
 499                 return 32 - IN_CLASSB_NSHIFT;
 500         if (IN_CLASSC(addr->s_addr))
 501                 return 32 - IN_CLASSC_NSHIFT;
 502
 503         return 0;
 504 }
 505
 506 int network_ifname(char *valuep, const char *value)
 507 {
 508         if (strlen(value) >= IFNAMSIZ) {
 509                 ERROR("Network devie name \"%s\" is too long (>= %zu)", value,
 510                       (size_t)IFNAMSIZ);
 511         }
 512
 513         strcpy(valuep, value);
 514         return 0;
 515 }
 516
 517 int rand_complete_hwaddr(char *hwaddr)
 518 {
 519         const char hex[] = "0123456789abcdef";
 520         char *curs = hwaddr;
 521
 522 #ifndef HAVE_RAND_R
 523         randseed(true);
 524 #else
 525         unsigned int seed;
 526
 527         seed = randseed(false);
 528 #endif
 529         while (*curs != '\0' && *curs != '\n') {
 530                 if (*curs == 'x' || *curs == 'X') {
 531                         if (curs - hwaddr == 1) {
 532                                 /* ensure address is unicast */
 533 #ifdef HAVE_RAND_R
 534                                 *curs = hex[rand_r(&seed) & 0x0E];
 535                         } else {
 536                                 *curs = hex[rand_r(&seed) & 0x0F];
 537 #else
 538                                 *curs = hex[rand() & 0x0E];
 539                         } else {
 540                                 *curs = hex[rand() & 0x0F];
 541 #endif
 542                         }
 543                 }
 544                 curs++;
 545         }
 546         return 0;
 547 }
 548
 549 bool lxc_config_net_hwaddr(const char *line)
 550 {
 551         char *copy, *p;
 552
 553         if (strncmp(line, "lxc.net", 7) != 0)
 554                 return false;
 555         if (strncmp(line, "lxc.network.hwaddr", 18) == 0)
 556                 return true;
 557
 558         /* We have to dup the line, if line is something like
 559          * "lxc.net.[i].xxx = xxxxx ", we need to remove
 560          * '[i]' and compare its key with 'lxc.net.hwaddr'*/
 561         copy = strdup(line);
 562         if (!copy) {
 563                 SYSERROR("failed to allocate memory");
 564                 return false;
 565         }
 566         if (*(copy + 8) >= '0' && *(copy + 8) <= '9') {
 567                 p = strchr(copy + 8, '.');
 568                 if (!p) {
 569                         free(copy);
 570                         return false;
 571                 }
 572                 /* strlen("hwaddr") = 6 */
 573                 strncpy(copy + 8, p + 1, 6);
 574                 copy[8 + 6] = '\0';
 575         }
 576         if (strncmp(copy, "lxc.net.hwaddr", 14) == 0) {
 577                 free(copy);
 578                 return true;
 579         }
 580         free(copy);
 581
 582         /* We have to dup the line second time, if line is something like
 583          * "lxc.network.[i].xxx = xxxxx ", we need to remove
 584          * '[i]' and compare its key with 'lxc.network.hwaddr'*/
 585         copy = strdup(line);
 586         if (!copy) {
 587                 SYSERROR("failed to allocate memory");
 588                 return false;
 589         }
 590         if (*(copy + 12) >= '0' && *(copy + 12) <= '9') {
 591                 p = strchr(copy + 12, '.');
 592                 if (!p) {
 593                         free(copy);
 594                         return false;
 595                 }
 596                 /* strlen("hwaddr") = 6 */
 597                 strncpy(copy + 12, p + 1, 6);
 598                 copy[12 + 6] = '\0';
 599         }
 600         if (strncmp(copy, "lxc.network.hwaddr", 18) == 0) {
 601                 free(copy);
 602                 return true;
 603         }
 604
 605         free(copy);
 606         return false;
 607 }
 608
 609 /*
 610  * If we find a lxc.net.[i].hwaddr or lxc.network.hwaddr in the original config
 611  * file, we expand it in the unexpanded_config, so that after a save_config we
 612  * store the hwaddr for re-use.
 613  * This is only called when reading the config file, not when executing a
 614  * lxc.include.
 615  * 'x' and 'X' are substituted in-place.
 616  */
 617 void update_hwaddr(const char *line)
 618 {
 619         char *p;
 620
 621         line += lxc_char_left_gc(line, strlen(line));
 622         if (line[0] == '#')
 623                 return;
 624
 625         if (!lxc_config_net_hwaddr(line))
 626                 return;
 627
 628         /* Let config_net_hwaddr raise the error. */
 629         p = strchr(line, '=');
 630         if (!p)
 631                 return;
 632         p++;
 633
 634         while (isblank(*p))
 635                 p++;
 636
 637         if (!*p)
 638                 return;
 639
 640         rand_complete_hwaddr(p);
 641 }
 642
 643 bool new_hwaddr(char *hwaddr)
 644 {
 645         int ret;
 646
 647         (void)randseed(true);
 648
 649         ret = snprintf(hwaddr, 18, "00:16:3e:%02x:%02x:%02x", rand() % 255,
 650                        rand() % 255, rand() % 255);
 651         if (ret < 0 || ret >= 18) {
 652                 SYSERROR("Failed to call snprintf().");
 653                 return false;
 654         }
 655
 656         return true;
 657 }
 658
 659 int lxc_get_conf_str(char *retv, int inlen, const char *value)
 660 {
 661         if (!value)
 662                 return 0;
 663         if (retv && inlen >= strlen(value) + 1)
 664                 strncpy(retv, value, strlen(value) + 1);
 665
 666         return strlen(value);
 667 }
 668
 669 int lxc_get_conf_int(struct lxc_conf *c, char *retv, int inlen, int v)
 670 {
 671         if (!retv)
 672                 inlen = 0;
 673         else
 674                 memset(retv, 0, inlen);
 675
 676         return snprintf(retv, inlen, "%d", v);
 677 }
 678
 679 bool parse_limit_value(const char **value, unsigned long *res)
 680 {
 681         char *endptr = NULL;
 682
 683         if (strncmp(*value, "unlimited", sizeof("unlimited") - 1) == 0) {
 684                 *res = RLIM_INFINITY;
 685                 *value += sizeof("unlimited") - 1;
 686                 return true;
 687         }
 688
 689         errno = 0;
 690         *res = strtoul(*value, &endptr, 10);
 691         if (errno || !endptr)
 692                 return false;
 693         *value = endptr;
 694
 695         return true;
 696 }