ip/ipnetns.c

   1 /* SPDX-License-Identifier: GPL-2.0 */
   2 #define _ATFILE_SOURCE
   3 #include <sys/types.h>
   4 #include <sys/stat.h>
   5 #include <sys/wait.h>
   6 #include <sys/inotify.h>
   7 #include <sys/mount.h>
   8 #include <sys/syscall.h>
   9 #include <stdio.h>
  10 #include <string.h>
  11 #include <sched.h>
  12 #include <fcntl.h>
  13 #include <dirent.h>
  14 #include <errno.h>
  15 #include <unistd.h>
  16 #include <ctype.h>
  17 #include <linux/limits.h>
  18
  19 #include <linux/net_namespace.h>
  20
  21 #include "utils.h"
  22 #include "list.h"
  23 #include "ip_common.h"
  24 #include "namespace.h"
  25 #include "json_print.h"
  26
  27 static int usage(void)
  28 {
  29         fprintf(stderr, "Usage: ip netns list\n");
  30         fprintf(stderr, "       ip netns add NAME\n");
  31         fprintf(stderr, "       ip netns set NAME NETNSID\n");
  32         fprintf(stderr, "       ip [-all] netns delete [NAME]\n");
  33         fprintf(stderr, "       ip netns identify [PID]\n");
  34         fprintf(stderr, "       ip netns pids NAME\n");
  35         fprintf(stderr, "       ip [-all] netns exec [NAME] cmd ...\n");
  36         fprintf(stderr, "       ip netns monitor\n");
  37         fprintf(stderr, "       ip netns list-id\n");
  38         exit(-1);
  39 }
  40
  41 /* This socket is used to get nsid */
  42 static struct rtnl_handle rtnsh = { .fd = -1 };
  43
  44 static int have_rtnl_getnsid = -1;
  45
  46 static int ipnetns_accept_msg(const struct sockaddr_nl *who,
  47                               struct rtnl_ctrl_data *ctrl,
  48                               struct nlmsghdr *n, void *arg)
  49 {
  50         struct nlmsgerr *err = (struct nlmsgerr *)NLMSG_DATA(n);
  51
  52         if (n->nlmsg_type == NLMSG_ERROR &&
  53             (err->error == -EOPNOTSUPP || err->error == -EINVAL))
  54                 have_rtnl_getnsid = 0;
  55         else
  56                 have_rtnl_getnsid = 1;
  57         return -1;
  58 }
  59
  60 static int ipnetns_have_nsid(void)
  61 {
  62         struct {
  63                 struct nlmsghdr n;
  64                 struct rtgenmsg g;
  65                 char            buf[1024];
  66         } req = {
  67                 .n.nlmsg_len = NLMSG_LENGTH(sizeof(struct rtgenmsg)),
  68                 .n.nlmsg_flags = NLM_F_REQUEST,
  69                 .n.nlmsg_type = RTM_GETNSID,
  70                 .g.rtgen_family = AF_UNSPEC,
  71         };
  72         int fd;
  73
  74         if (have_rtnl_getnsid < 0) {
  75                 fd = open("/proc/self/ns/net", O_RDONLY);
  76                 if (fd < 0) {
  77                         have_rtnl_getnsid = 0;
  78                         return 0;
  79                 }
  80
  81                 addattr32(&req.n, 1024, NETNSA_FD, fd);
  82
  83                 if (rtnl_send(&rth, &req.n, req.n.nlmsg_len) < 0) {
  84                         perror("request send failed");
  85                         exit(1);
  86                 }
  87                 rtnl_listen(&rth, ipnetns_accept_msg, NULL);
  88                 close(fd);
  89         }
  90
  91         return have_rtnl_getnsid;
  92 }
  93
  94 int get_netnsid_from_name(const char *name)
  95 {
  96         struct {
  97                 struct nlmsghdr n;
  98                 struct rtgenmsg g;
  99                 char            buf[1024];
 100         } req = {
 101                 .n.nlmsg_len = NLMSG_LENGTH(sizeof(struct rtgenmsg)),
 102                 .n.nlmsg_flags = NLM_F_REQUEST,
 103                 .n.nlmsg_type = RTM_GETNSID,
 104                 .g.rtgen_family = AF_UNSPEC,
 105         };
 106         struct nlmsghdr *answer;
 107         struct rtattr *tb[NETNSA_MAX + 1];
 108         struct rtgenmsg *rthdr;
 109         int len, fd;
 110
 111         netns_nsid_socket_init();
 112
 113         fd = netns_get_fd(name);
 114         if (fd < 0)
 115                 return fd;
 116
 117         addattr32(&req.n, 1024, NETNSA_FD, fd);
 118         if (rtnl_talk(&rtnsh, &req.n, &answer) < 0) {
 119                 close(fd);
 120                 return -2;
 121         }
 122         close(fd);
 123
 124         /* Validate message and parse attributes */
 125         if (answer->nlmsg_type == NLMSG_ERROR)
 126                 goto err_out;
 127
 128         rthdr = NLMSG_DATA(answer);
 129         len = answer->nlmsg_len - NLMSG_SPACE(sizeof(*rthdr));
 130         if (len < 0)
 131                 goto err_out;
 132
 133         parse_rtattr(tb, NETNSA_MAX, NETNS_RTA(rthdr), len);
 134
 135         if (tb[NETNSA_NSID]) {
 136                 free(answer);
 137                 return rta_getattr_u32(tb[NETNSA_NSID]);
 138         }
 139
 140 err_out:
 141         free(answer);
 142         return -1;
 143 }
 144
 145 struct nsid_cache {
 146         struct hlist_node       nsid_hash;
 147         struct hlist_node       name_hash;
 148         int                     nsid;
 149         char                    name[0];
 150 };
 151
 152 #define NSIDMAP_SIZE            128
 153 #define NSID_HASH_NSID(nsid)    (nsid & (NSIDMAP_SIZE - 1))
 154 #define NSID_HASH_NAME(name)    (namehash(name) & (NSIDMAP_SIZE - 1))
 155
 156 static struct hlist_head        nsid_head[NSIDMAP_SIZE];
 157 static struct hlist_head        name_head[NSIDMAP_SIZE];
 158
 159 static struct nsid_cache *netns_map_get_by_nsid(int nsid)
 160 {
 161         uint32_t h = NSID_HASH_NSID(nsid);
 162         struct hlist_node *n;
 163
 164         hlist_for_each(n, &nsid_head[h]) {
 165                 struct nsid_cache *c = container_of(n, struct nsid_cache,
 166                                                     nsid_hash);
 167                 if (c->nsid == nsid)
 168                         return c;
 169         }
 170
 171         return NULL;
 172 }
 173
 174 char *get_name_from_nsid(int nsid)
 175 {
 176         struct nsid_cache *c;
 177
 178         netns_nsid_socket_init();
 179         netns_map_init();
 180
 181         c = netns_map_get_by_nsid(nsid);
 182         if (c)
 183                 return c->name;
 184
 185         return NULL;
 186 }
 187
 188 static int netns_map_add(int nsid, const char *name)
 189 {
 190         struct nsid_cache *c;
 191         uint32_t h;
 192
 193         if (netns_map_get_by_nsid(nsid) != NULL)
 194                 return -EEXIST;
 195
 196         c = malloc(sizeof(*c) + strlen(name) + 1);
 197         if (c == NULL) {
 198                 perror("malloc");
 199                 return -ENOMEM;
 200         }
 201         c->nsid = nsid;
 202         strcpy(c->name, name);
 203
 204         h = NSID_HASH_NSID(nsid);
 205         hlist_add_head(&c->nsid_hash, &nsid_head[h]);
 206
 207         h = NSID_HASH_NAME(name);
 208         hlist_add_head(&c->name_hash, &name_head[h]);
 209
 210         return 0;
 211 }
 212
 213 static void netns_map_del(struct nsid_cache *c)
 214 {
 215         hlist_del(&c->name_hash);
 216         hlist_del(&c->nsid_hash);
 217         free(c);
 218 }
 219
 220 void netns_nsid_socket_init(void)
 221 {
 222         if (rtnsh.fd > -1 || !ipnetns_have_nsid())
 223                 return;
 224
 225         if (rtnl_open(&rtnsh, 0) < 0) {
 226                 fprintf(stderr, "Cannot open rtnetlink\n");
 227                 exit(1);
 228         }
 229
 230 }
 231
 232 void netns_map_init(void)
 233 {
 234         static int initialized;
 235         struct dirent *entry;
 236         DIR *dir;
 237         int nsid;
 238
 239         if (initialized || !ipnetns_have_nsid())
 240                 return;
 241
 242         dir = opendir(NETNS_RUN_DIR);
 243         if (!dir)
 244                 return;
 245
 246         while ((entry = readdir(dir)) != NULL) {
 247                 if (strcmp(entry->d_name, ".") == 0)
 248                         continue;
 249                 if (strcmp(entry->d_name, "..") == 0)
 250                         continue;
 251                 nsid = get_netnsid_from_name(entry->d_name);
 252
 253                 if (nsid >= 0)
 254                         netns_map_add(nsid, entry->d_name);
 255         }
 256         closedir(dir);
 257         initialized = 1;
 258 }
 259
 260 static int netns_get_name(int nsid, char *name)
 261 {
 262         struct dirent *entry;
 263         DIR *dir;
 264         int id;
 265
 266         dir = opendir(NETNS_RUN_DIR);
 267         if (!dir)
 268                 return -ENOENT;
 269
 270         while ((entry = readdir(dir)) != NULL) {
 271                 if (strcmp(entry->d_name, ".") == 0)
 272                         continue;
 273                 if (strcmp(entry->d_name, "..") == 0)
 274                         continue;
 275                 id = get_netnsid_from_name(entry->d_name);
 276
 277                 if (nsid == id) {
 278                         strcpy(name, entry->d_name);
 279                         closedir(dir);
 280                         return 0;
 281                 }
 282         }
 283         closedir(dir);
 284         return -ENOENT;
 285 }
 286
 287 int print_nsid(const struct sockaddr_nl *who, struct nlmsghdr *n, void *arg)
 288 {
 289         struct rtgenmsg *rthdr = NLMSG_DATA(n);
 290         struct rtattr *tb[NETNSA_MAX+1];
 291         int len = n->nlmsg_len;
 292         FILE *fp = (FILE *)arg;
 293         struct nsid_cache *c;
 294         char name[NAME_MAX];
 295         int nsid;
 296
 297         if (n->nlmsg_type != RTM_NEWNSID && n->nlmsg_type != RTM_DELNSID)
 298                 return 0;
 299
 300         len -= NLMSG_SPACE(sizeof(*rthdr));
 301         if (len < 0) {
 302                 fprintf(stderr, "BUG: wrong nlmsg len %d in %s\n", len,
 303                         __func__);
 304                 return -1;
 305         }
 306
 307         parse_rtattr(tb, NETNSA_MAX, NETNS_RTA(rthdr), len);
 308         if (tb[NETNSA_NSID] == NULL) {
 309                 fprintf(stderr, "BUG: NETNSA_NSID is missing %s\n", __func__);
 310                 return -1;
 311         }
 312
 313         open_json_object(NULL);
 314         if (n->nlmsg_type == RTM_DELNSID)
 315                 print_bool(PRINT_ANY, "deleted", "Deleted ", true);
 316
 317         nsid = rta_getattr_u32(tb[NETNSA_NSID]);
 318         print_uint(PRINT_ANY, "nsid", "nsid %u ", nsid);
 319
 320         c = netns_map_get_by_nsid(nsid);
 321         if (c != NULL) {
 322                 print_string(PRINT_ANY, "name",
 323                              "(iproute2 netns name: %s)", c->name);
 324                 netns_map_del(c);
 325         }
 326
 327         /* During 'ip monitor nsid', no chance to have new nsid in cache. */
 328         if (c == NULL && n->nlmsg_type == RTM_NEWNSID)
 329                 if (netns_get_name(nsid, name) == 0) {
 330                         print_string(PRINT_ANY, "name",
 331                                      "(iproute2 netns name: %s)", name);
 332                         netns_map_add(nsid, name);
 333                 }
 334
 335         print_string(PRINT_FP, NULL, "\n", NULL);
 336         close_json_object();
 337         fflush(fp);
 338         return 0;
 339 }
 340
 341 static int netns_list_id(int argc, char **argv)
 342 {
 343         if (!ipnetns_have_nsid()) {
 344                 fprintf(stderr,
 345                         "RTM_GETNSID is not supported by the kernel.\n");
 346                 return -ENOTSUP;
 347         }
 348
 349         if (rtnl_nsiddump_req(&rth, AF_UNSPEC) < 0) {
 350                 perror("Cannot send dump request");
 351                 exit(1);
 352         }
 353
 354         new_json_obj(json);
 355         if (rtnl_dump_filter(&rth, print_nsid, stdout) < 0) {
 356                 delete_json_obj();
 357                 fprintf(stderr, "Dump terminated\n");
 358                 exit(1);
 359         }
 360         delete_json_obj();
 361         return 0;
 362 }
 363
 364 static int netns_list(int argc, char **argv)
 365 {
 366         struct dirent *entry;
 367         DIR *dir;
 368         int id;
 369
 370         dir = opendir(NETNS_RUN_DIR);
 371         if (!dir)
 372                 return 0;
 373
 374         new_json_obj(json);
 375         while ((entry = readdir(dir)) != NULL) {
 376                 if (strcmp(entry->d_name, ".") == 0)
 377                         continue;
 378                 if (strcmp(entry->d_name, "..") == 0)
 379                         continue;
 380
 381                 open_json_object(NULL);
 382                 print_string(PRINT_ANY, "name",
 383                              "%s", entry->d_name);
 384                 if (ipnetns_have_nsid()) {
 385                         id = get_netnsid_from_name(entry->d_name);
 386                         if (id >= 0)
 387                                 print_uint(PRINT_ANY, "id",
 388                                            " (id: %d)", id);
 389                 }
 390                 print_string(PRINT_FP, NULL, "\n", NULL);
 391                 close_json_object();
 392         }
 393         closedir(dir);
 394         delete_json_obj();
 395         return 0;
 396 }
 397
 398 static int on_netns_exec(char *nsname, void *arg)
 399 {
 400         char **argv = arg;
 401
 402         cmd_exec(argv[1], argv + 1, true);
 403         return 0;
 404 }
 405
 406 static int netns_exec(int argc, char **argv)
 407 {
 408         /* Setup the proper environment for apps that are not netns
 409          * aware, and execute a program in that environment.
 410          */
 411         const char *cmd;
 412
 413         if (argc < 1 && !do_all) {
 414                 fprintf(stderr, "No netns name specified\n");
 415                 return -1;
 416         }
 417         if ((argc < 2 && !do_all) || (argc < 1 && do_all)) {
 418                 fprintf(stderr, "No command specified\n");
 419                 return -1;
 420         }
 421
 422         if (do_all)
 423                 return do_each_netns(on_netns_exec, --argv, 1);
 424
 425         if (netns_switch(argv[0]))
 426                 return -1;
 427
 428         /* we just changed namespaces. clear any vrf association
 429          * with prior namespace before exec'ing command
 430          */
 431         vrf_reset();
 432
 433         /* ip must return the status of the child,
 434          * but do_cmd() will add a minus to this,
 435          * so let's add another one here to cancel it.
 436          */
 437         cmd = argv[1];
 438         return -cmd_exec(cmd, argv + 1, !!batch_mode);
 439 }
 440
 441 static int is_pid(const char *str)
 442 {
 443         int ch;
 444
 445         for (; (ch = *str); str++) {
 446                 if (!isdigit(ch))
 447                         return 0;
 448         }
 449         return 1;
 450 }
 451
 452 static int netns_pids(int argc, char **argv)
 453 {
 454         const char *name;
 455         char net_path[PATH_MAX];
 456         int netns;
 457         struct stat netst;
 458         DIR *dir;
 459         struct dirent *entry;
 460
 461         if (argc < 1) {
 462                 fprintf(stderr, "No netns name specified\n");
 463                 return -1;
 464         }
 465         if (argc > 1) {
 466                 fprintf(stderr, "extra arguments specified\n");
 467                 return -1;
 468         }
 469
 470         name = argv[0];
 471         snprintf(net_path, sizeof(net_path), "%s/%s", NETNS_RUN_DIR, name);
 472         netns = open(net_path, O_RDONLY);
 473         if (netns < 0) {
 474                 fprintf(stderr, "Cannot open network namespace: %s\n",
 475                         strerror(errno));
 476                 return -1;
 477         }
 478         if (fstat(netns, &netst) < 0) {
 479                 fprintf(stderr, "Stat of netns failed: %s\n",
 480                         strerror(errno));
 481                 return -1;
 482         }
 483         dir = opendir("/proc/");
 484         if (!dir) {
 485                 fprintf(stderr, "Open of /proc failed: %s\n",
 486                         strerror(errno));
 487                 return -1;
 488         }
 489         while ((entry = readdir(dir))) {
 490                 char pid_net_path[PATH_MAX];
 491                 struct stat st;
 492
 493                 if (!is_pid(entry->d_name))
 494                         continue;
 495                 snprintf(pid_net_path, sizeof(pid_net_path), "/proc/%s/ns/net",
 496                         entry->d_name);
 497                 if (stat(pid_net_path, &st) != 0)
 498                         continue;
 499                 if ((st.st_dev == netst.st_dev) &&
 500                     (st.st_ino == netst.st_ino)) {
 501                         printf("%s\n", entry->d_name);
 502                 }
 503         }
 504         closedir(dir);
 505         return 0;
 506
 507 }
 508
 509 int netns_identify_pid(const char *pidstr, char *name, int len)
 510 {
 511         char net_path[PATH_MAX];
 512         int netns;
 513         struct stat netst;
 514         DIR *dir;
 515         struct dirent *entry;
 516
 517         name[0] = '\0';
 518
 519         snprintf(net_path, sizeof(net_path), "/proc/%s/ns/net", pidstr);
 520         netns = open(net_path, O_RDONLY);
 521         if (netns < 0) {
 522                 fprintf(stderr, "Cannot open network namespace: %s\n",
 523                         strerror(errno));
 524                 return -1;
 525         }
 526         if (fstat(netns, &netst) < 0) {
 527                 fprintf(stderr, "Stat of netns failed: %s\n",
 528                         strerror(errno));
 529                 return -1;
 530         }
 531         dir = opendir(NETNS_RUN_DIR);
 532         if (!dir) {
 533                 /* Succeed treat a missing directory as an empty directory */
 534                 if (errno == ENOENT)
 535                         return 0;
 536
 537                 fprintf(stderr, "Failed to open directory %s:%s\n",
 538                         NETNS_RUN_DIR, strerror(errno));
 539                 return -1;
 540         }
 541
 542         while ((entry = readdir(dir))) {
 543                 char name_path[PATH_MAX];
 544                 struct stat st;
 545
 546                 if (strcmp(entry->d_name, ".") == 0)
 547                         continue;
 548                 if (strcmp(entry->d_name, "..") == 0)
 549                         continue;
 550
 551                 snprintf(name_path, sizeof(name_path), "%s/%s", NETNS_RUN_DIR,
 552                         entry->d_name);
 553
 554                 if (stat(name_path, &st) != 0)
 555                         continue;
 556
 557                 if ((st.st_dev == netst.st_dev) &&
 558                     (st.st_ino == netst.st_ino)) {
 559                         strlcpy(name, entry->d_name, len);
 560                 }
 561         }
 562         closedir(dir);
 563         return 0;
 564
 565 }
 566
 567 static int netns_identify(int argc, char **argv)
 568 {
 569         const char *pidstr;
 570         char name[256];
 571         int rc;
 572
 573         if (argc < 1) {
 574                 pidstr = "self";
 575         } else if (argc > 1) {
 576                 fprintf(stderr, "extra arguments specified\n");
 577                 return -1;
 578         } else {
 579                 pidstr = argv[0];
 580                 if (!is_pid(pidstr)) {
 581                         fprintf(stderr, "Specified string '%s' is not a pid\n",
 582                                         pidstr);
 583                         return -1;
 584                 }
 585         }
 586
 587         rc = netns_identify_pid(pidstr, name, sizeof(name));
 588         if (!rc)
 589                 printf("%s\n", name);
 590
 591         return rc;
 592 }
 593
 594 static int on_netns_del(char *nsname, void *arg)
 595 {
 596         char netns_path[PATH_MAX];
 597
 598         snprintf(netns_path, sizeof(netns_path), "%s/%s", NETNS_RUN_DIR, nsname);
 599         umount2(netns_path, MNT_DETACH);
 600         if (unlink(netns_path) < 0) {
 601                 fprintf(stderr, "Cannot remove namespace file \"%s\": %s\n",
 602                         netns_path, strerror(errno));
 603                 return -1;
 604         }
 605         return 0;
 606 }
 607
 608 static int netns_delete(int argc, char **argv)
 609 {
 610         if (argc < 1 && !do_all) {
 611                 fprintf(stderr, "No netns name specified\n");
 612                 return -1;
 613         }
 614
 615         if (do_all)
 616                 return netns_foreach(on_netns_del, NULL);
 617
 618         return on_netns_del(argv[0], NULL);
 619 }
 620
 621 static int create_netns_dir(void)
 622 {
 623         /* Create the base netns directory if it doesn't exist */
 624         if (mkdir(NETNS_RUN_DIR, S_IRWXU|S_IRGRP|S_IXGRP|S_IROTH|S_IXOTH)) {
 625                 if (errno != EEXIST) {
 626                         fprintf(stderr, "mkdir %s failed: %s\n",
 627                                 NETNS_RUN_DIR, strerror(errno));
 628                         return -1;
 629                 }
 630         }
 631
 632         return 0;
 633 }
 634
 635 static int netns_add(int argc, char **argv)
 636 {
 637         /* This function creates a new network namespace and
 638          * a new mount namespace and bind them into a well known
 639          * location in the filesystem based on the name provided.
 640          *
 641          * The mount namespace is created so that any necessary
 642          * userspace tweaks like remounting /sys, or bind mounting
 643          * a new /etc/resolv.conf can be shared between uers.
 644          */
 645         char netns_path[PATH_MAX];
 646         const char *name;
 647         int fd;
 648         int made_netns_run_dir_mount = 0;
 649
 650         if (argc < 1) {
 651                 fprintf(stderr, "No netns name specified\n");
 652                 return -1;
 653         }
 654         name = argv[0];
 655
 656         snprintf(netns_path, sizeof(netns_path), "%s/%s", NETNS_RUN_DIR, name);
 657
 658         if (create_netns_dir())
 659                 return -1;
 660
 661         /* Make it possible for network namespace mounts to propagate between
 662          * mount namespaces.  This makes it likely that a unmounting a network
 663          * namespace file in one namespace will unmount the network namespace
 664          * file in all namespaces allowing the network namespace to be freed
 665          * sooner.
 666          */
 667         while (mount("", NETNS_RUN_DIR, "none", MS_SHARED | MS_REC, NULL)) {
 668                 /* Fail unless we need to make the mount point */
 669                 if (errno != EINVAL || made_netns_run_dir_mount) {
 670                         fprintf(stderr, "mount --make-shared %s failed: %s\n",
 671                                 NETNS_RUN_DIR, strerror(errno));
 672                         return -1;
 673                 }
 674
 675                 /* Upgrade NETNS_RUN_DIR to a mount point */
 676                 if (mount(NETNS_RUN_DIR, NETNS_RUN_DIR, "none", MS_BIND | MS_REC, NULL)) {
 677                         fprintf(stderr, "mount --bind %s %s failed: %s\n",
 678                                 NETNS_RUN_DIR, NETNS_RUN_DIR, strerror(errno));
 679                         return -1;
 680                 }
 681                 made_netns_run_dir_mount = 1;
 682         }
 683
 684         /* Create the filesystem state */
 685         fd = open(netns_path, O_RDONLY|O_CREAT|O_EXCL, 0);
 686         if (fd < 0) {
 687                 fprintf(stderr, "Cannot create namespace file \"%s\": %s\n",
 688                         netns_path, strerror(errno));
 689                 return -1;
 690         }
 691         close(fd);
 692         if (unshare(CLONE_NEWNET) < 0) {
 693                 fprintf(stderr, "Failed to create a new network namespace \"%s\": %s\n",
 694                         name, strerror(errno));
 695                 goto out_delete;
 696         }
 697
 698         /* Bind the netns last so I can watch for it */
 699         if (mount("/proc/self/ns/net", netns_path, "none", MS_BIND, NULL) < 0) {
 700                 fprintf(stderr, "Bind /proc/self/ns/net -> %s failed: %s\n",
 701                         netns_path, strerror(errno));
 702                 goto out_delete;
 703         }
 704         return 0;
 705 out_delete:
 706         netns_delete(argc, argv);
 707         return -1;
 708 }
 709
 710 int set_netnsid_from_name(const char *name, int nsid)
 711 {
 712         struct {
 713                 struct nlmsghdr n;
 714                 struct rtgenmsg g;
 715                 char            buf[1024];
 716         } req = {
 717                 .n.nlmsg_len = NLMSG_LENGTH(sizeof(struct rtgenmsg)),
 718                 .n.nlmsg_flags = NLM_F_REQUEST,
 719                 .n.nlmsg_type = RTM_NEWNSID,
 720                 .g.rtgen_family = AF_UNSPEC,
 721         };
 722         int fd, err = 0;
 723
 724         netns_nsid_socket_init();
 725
 726         fd = netns_get_fd(name);
 727         if (fd < 0)
 728                 return fd;
 729
 730         addattr32(&req.n, 1024, NETNSA_FD, fd);
 731         addattr32(&req.n, 1024, NETNSA_NSID, nsid);
 732         if (rtnl_talk(&rth, &req.n, NULL) < 0)
 733                 err = -2;
 734
 735         close(fd);
 736         return err;
 737 }
 738
 739 static int netns_set(int argc, char **argv)
 740 {
 741         char netns_path[PATH_MAX];
 742         const char *name;
 743         unsigned int nsid;
 744         int netns;
 745
 746         if (argc < 1) {
 747                 fprintf(stderr, "No netns name specified\n");
 748                 return -1;
 749         }
 750         if (argc < 2) {
 751                 fprintf(stderr, "No nsid specified\n");
 752                 return -1;
 753         }
 754         name = argv[0];
 755         /* If a negative nsid is specified the kernel will select the nsid. */
 756         if (strcmp(argv[1], "auto") == 0)
 757                 nsid = -1;
 758         else if (get_unsigned(&nsid, argv[1], 0))
 759                 invarg("Invalid \"netnsid\" value\n", argv[1]);
 760
 761         snprintf(netns_path, sizeof(netns_path), "%s/%s", NETNS_RUN_DIR, name);
 762         netns = open(netns_path, O_RDONLY | O_CLOEXEC);
 763         if (netns < 0) {
 764                 fprintf(stderr, "Cannot open network namespace \"%s\": %s\n",
 765                         name, strerror(errno));
 766                 return -1;
 767         }
 768
 769         return set_netnsid_from_name(name, nsid);
 770 }
 771
 772 static int netns_monitor(int argc, char **argv)
 773 {
 774         char buf[4096];
 775         struct inotify_event *event;
 776         int fd;
 777
 778         fd = inotify_init();
 779         if (fd < 0) {
 780                 fprintf(stderr, "inotify_init failed: %s\n",
 781                         strerror(errno));
 782                 return -1;
 783         }
 784
 785         if (create_netns_dir())
 786                 return -1;
 787
 788         if (inotify_add_watch(fd, NETNS_RUN_DIR, IN_CREATE | IN_DELETE) < 0) {
 789                 fprintf(stderr, "inotify_add_watch failed: %s\n",
 790                         strerror(errno));
 791                 return -1;
 792         }
 793         for (;;) {
 794                 ssize_t len = read(fd, buf, sizeof(buf));
 795
 796                 if (len < 0) {
 797                         fprintf(stderr, "read failed: %s\n",
 798                                 strerror(errno));
 799                         return -1;
 800                 }
 801                 for (event = (struct inotify_event *)buf;
 802                      (char *)event < &buf[len];
 803                      event = (struct inotify_event *)((char *)event + sizeof(*event) + event->len)) {
 804                         if (event->mask & IN_CREATE)
 805                                 printf("add %s\n", event->name);
 806                         if (event->mask & IN_DELETE)
 807                                 printf("delete %s\n", event->name);
 808                 }
 809         }
 810         return 0;
 811 }
 812
 813 static int invalid_name(const char *name)
 814 {
 815         return !*name || strlen(name) > NAME_MAX ||
 816                 strchr(name, '/') || !strcmp(name, ".") || !strcmp(name, "..");
 817 }
 818
 819 int do_netns(int argc, char **argv)
 820 {
 821         netns_nsid_socket_init();
 822
 823         if (argc < 1) {
 824                 netns_map_init();
 825                 return netns_list(0, NULL);
 826         }
 827
 828         if (argc > 1 && invalid_name(argv[1])) {
 829                 fprintf(stderr, "Invalid netns name \"%s\"\n", argv[1]);
 830                 exit(-1);
 831         }
 832
 833         if ((matches(*argv, "list") == 0) || (matches(*argv, "show") == 0) ||
 834             (matches(*argv, "lst") == 0)) {
 835                 netns_map_init();
 836                 return netns_list(argc-1, argv+1);
 837         }
 838
 839         if ((matches(*argv, "list-id") == 0)) {
 840                 netns_map_init();
 841                 return netns_list_id(argc-1, argv+1);
 842         }
 843
 844         if (matches(*argv, "help") == 0)
 845                 return usage();
 846
 847         if (matches(*argv, "add") == 0)
 848                 return netns_add(argc-1, argv+1);
 849
 850         if (matches(*argv, "set") == 0)
 851                 return netns_set(argc-1, argv+1);
 852
 853         if (matches(*argv, "delete") == 0)
 854                 return netns_delete(argc-1, argv+1);
 855
 856         if (matches(*argv, "identify") == 0)
 857                 return netns_identify(argc-1, argv+1);
 858
 859         if (matches(*argv, "pids") == 0)
 860                 return netns_pids(argc-1, argv+1);
 861
 862         if (matches(*argv, "exec") == 0)
 863                 return netns_exec(argc-1, argv+1);
 864
 865         if (matches(*argv, "monitor") == 0)
 866                 return netns_monitor(argc-1, argv+1);
 867
 868         fprintf(stderr, "Command \"%s\" is unknown, try \"ip netns help\".\n", *argv);
 869         exit(-1);
 870 }