sys-utils/lsns.c

   1 /*
   2  * lsns(8) - list system namespaces
   3  *
   4  * Copyright (C) 2015 Karel Zak <kzak@redhat.com>
   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 as published by
   8  * the Free Software Foundation; either version 2 of the License, or
   9  * (at your option) any later version.
  10  *
  11  * This program is distributed in the hope that it would be useful,
  12  * but WITHOUT ANY WARRANTY; without even the implied warranty of
  13  * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
  14  * GNU General Public License for more details.
  15  *
  16  * You should have received a copy of the GNU General Public License
  17  * along with this program; if not, write to the Free Software Foundation,
  18  * Inc., 59 Temple Place, Suite 330, Boston, MA  02111-1307  USA
  19  */
  20 #include <stdio.h>
  21 #include <string.h>
  22 #include <getopt.h>
  23 #include <stdlib.h>
  24 #include <assert.h>
  25 #include <dirent.h>
  26 #include <unistd.h>
  27 #include <sys/stat.h>
  28 #include <sys/types.h>
  29 #include <wchar.h>
  30 #include <libsmartcols.h>
  31 #include <libmount.h>
  32
  33 #ifdef HAVE_LINUX_NET_NAMESPACE_H
  34 #include <stdbool.h>
  35 #include <sys/socket.h>
  36 #include <linux/netlink.h>
  37 #include <linux/rtnetlink.h>
  38 #include <linux/net_namespace.h>
  39 #endif
  40
  41 #include "pathnames.h"
  42 #include "nls.h"
  43 #include "xalloc.h"
  44 #include "c.h"
  45 #include "list.h"
  46 #include "closestream.h"
  47 #include "optutils.h"
  48 #include "procutils.h"
  49 #include "strutils.h"
  50 #include "namespace.h"
  51 #include "path.h"
  52 #include "idcache.h"
  53
  54 #include "debug.h"
  55
  56 static UL_DEBUG_DEFINE_MASK(lsns);
  57 UL_DEBUG_DEFINE_MASKNAMES(lsns) = UL_DEBUG_EMPTY_MASKNAMES;
  58
  59 #define LSNS_DEBUG_INIT         (1 << 1)
  60 #define LSNS_DEBUG_PROC         (1 << 2)
  61 #define LSNS_DEBUG_NS           (1 << 3)
  62 #define LSNS_DEBUG_ALL          0xFFFF
  63
  64 #define LSNS_NETNS_UNUSABLE -2
  65
  66 #define DBG(m, x)       __UL_DBG(lsns, LSNS_DEBUG_, m, x)
  67 #define ON_DBG(m, x)    __UL_DBG_CALL(lsns, LSNS_DEBUG_, m, x)
  68
  69 static struct idcache *uid_cache = NULL;
  70
  71 /* column IDs */
  72 enum {
  73         COL_NS = 0,
  74         COL_TYPE,
  75         COL_PATH,
  76         COL_NPROCS,
  77         COL_PID,
  78         COL_PPID,
  79         COL_COMMAND,
  80         COL_UID,
  81         COL_USER,
  82         COL_NETNSID,
  83         COL_NSFS,
  84 };
  85
  86 /* column names */
  87 struct colinfo {
  88         const char *name; /* header */
  89         double     whint; /* width hint (N < 1 is in percent of termwidth) */
  90         int        flags; /* SCOLS_FL_* */
  91         const char *help;
  92 };
  93
  94 /* columns descriptions */
  95 static const struct colinfo infos[] = {
  96         [COL_NS]      = { "NS",     10, SCOLS_FL_RIGHT, N_("namespace identifier (inode number)") },
  97         [COL_TYPE]    = { "TYPE",    5, 0, N_("kind of namespace") },
  98         [COL_PATH]    = { "PATH",    0, 0, N_("path to the namespace")},
  99         [COL_NPROCS]  = { "NPROCS",  5, SCOLS_FL_RIGHT, N_("number of processes in the namespace") },
 100         [COL_PID]     = { "PID",     5, SCOLS_FL_RIGHT, N_("lowest PID in the namespace") },
 101         [COL_PPID]    = { "PPID",    5, SCOLS_FL_RIGHT, N_("PPID of the PID") },
 102         [COL_COMMAND] = { "COMMAND", 0, SCOLS_FL_TRUNC, N_("command line of the PID")},
 103         [COL_UID]     = { "UID",     0, SCOLS_FL_RIGHT, N_("UID of the PID")},
 104         [COL_USER]    = { "USER",    0, 0, N_("username of the PID")},
 105         [COL_NETNSID] = { "NETNSID", 0, SCOLS_FL_RIGHT, N_("namespace ID as used by network subsystem")},
 106         [COL_NSFS]    = { "NSFS",    0, SCOLS_FL_WRAP, N_("nsfs mountpoint (usually used network subsystem)")}
 107 };
 108
 109 static int columns[ARRAY_SIZE(infos) * 2];
 110 static size_t ncolumns;
 111
 112 enum {
 113         LSNS_ID_MNT = 0,
 114         LSNS_ID_NET,
 115         LSNS_ID_PID,
 116         LSNS_ID_UTS,
 117         LSNS_ID_IPC,
 118         LSNS_ID_USER,
 119         LSNS_ID_CGROUP
 120 };
 121
 122 static char *ns_names[] = {
 123         [LSNS_ID_MNT] = "mnt",
 124         [LSNS_ID_NET] = "net",
 125         [LSNS_ID_PID] = "pid",
 126         [LSNS_ID_UTS] = "uts",
 127         [LSNS_ID_IPC] = "ipc",
 128         [LSNS_ID_USER] = "user",
 129         [LSNS_ID_CGROUP] = "cgroup"
 130 };
 131
 132 struct lsns_namespace {
 133         ino_t id;
 134         int type;                       /* LSNS_* */
 135         int nprocs;
 136         int netnsid;
 137
 138         struct lsns_process *proc;
 139
 140         struct list_head namespaces;    /* lsns->processes member */
 141         struct list_head processes;     /* head of lsns_process *siblings */
 142 };
 143
 144 struct lsns_process {
 145         pid_t pid;              /* process PID */
 146         pid_t ppid;             /* parent's PID */
 147         pid_t tpid;             /* thread group */
 148         char state;
 149         uid_t uid;
 150
 151         ino_t            ns_ids[ARRAY_SIZE(ns_names)];
 152         struct list_head ns_siblings[ARRAY_SIZE(ns_names)];
 153
 154         struct list_head processes;     /* list of processes */
 155
 156         struct libscols_line *outline;
 157         struct lsns_process *parent;
 158
 159         int netnsid;
 160 };
 161
 162 struct lsns {
 163         struct list_head processes;
 164         struct list_head namespaces;
 165
 166         pid_t   fltr_pid;       /* filter out by PID */
 167         ino_t   fltr_ns;        /* filter out by namespace */
 168         int     fltr_types[ARRAY_SIZE(ns_names)];
 169         int     fltr_ntypes;
 170
 171         unsigned int raw        : 1,
 172                      json       : 1,
 173                      tree       : 1,
 174                      list       : 1,
 175                      no_trunc   : 1,
 176                      no_headings: 1,
 177                      no_wrap    : 1;
 178
 179         struct libmnt_table *tab;
 180 };
 181
 182 struct netnsid_cache {
 183         ino_t ino;
 184         int   id;
 185         struct list_head netnsids;
 186 };
 187
 188 static struct list_head netnsids_cache;
 189
 190 static int netlink_fd = -1;
 191
 192 static void lsns_init_debug(void)
 193 {
 194         __UL_INIT_DEBUG(lsns, LSNS_DEBUG_, 0, LSNS_DEBUG);
 195 }
 196
 197 static int ns_name2type(const char *name)
 198 {
 199         size_t i;
 200
 201         for (i = 0; i < ARRAY_SIZE(ns_names); i++) {
 202                 if (strcmp(ns_names[i], name) == 0)
 203                         return i;
 204         }
 205         return -1;
 206 }
 207
 208 static int column_name_to_id(const char *name, size_t namesz)
 209 {
 210         size_t i;
 211
 212         assert(name);
 213
 214         for (i = 0; i < ARRAY_SIZE(infos); i++) {
 215                 const char *cn = infos[i].name;
 216
 217                 if (!strncasecmp(name, cn, namesz) && !*(cn + namesz))
 218                         return i;
 219         }
 220         warnx(_("unknown column: %s"), name);
 221         return -1;
 222 }
 223
 224 static int has_column(int id)
 225 {
 226         size_t i;
 227
 228         for (i = 0; i < ncolumns; i++) {
 229                 if (columns[i] == id)
 230                         return 1;
 231         }
 232         return 0;
 233 }
 234
 235 static inline int get_column_id(int num)
 236 {
 237         assert(num >= 0);
 238         assert((size_t) num < ncolumns);
 239         assert(columns[num] < (int) ARRAY_SIZE(infos));
 240
 241         return columns[num];
 242 }
 243
 244 static inline const struct colinfo *get_column_info(unsigned num)
 245 {
 246         return &infos[ get_column_id(num) ];
 247 }
 248
 249 static int get_ns_ino(int dir, const char *nsname, ino_t *ino)
 250 {
 251         struct stat st;
 252         char path[16];
 253
 254         snprintf(path, sizeof(path), "ns/%s", nsname);
 255
 256         if (fstatat(dir, path, &st, 0) != 0)
 257                 return -errno;
 258         *ino = st.st_ino;
 259         return 0;
 260 }
 261
 262 static int parse_proc_stat(FILE *fp, pid_t *pid, char *state, pid_t *ppid)
 263 {
 264         char *line = NULL, *p;
 265         size_t len = 0;
 266         int rc;
 267
 268         if (getline(&line, &len, fp) < 0) {
 269                 rc = -errno;
 270                 goto error;
 271         }
 272
 273         p = strrchr(line, ')');
 274         if (p == NULL ||
 275             sscanf(line, "%d (", pid) != 1 ||
 276             sscanf(p, ") %c %d*[^\n]", state, ppid) != 2) {
 277                 rc = -EINVAL;
 278                 goto error;
 279         }
 280         rc = 0;
 281
 282 error:
 283         free(line);
 284         return rc;
 285 }
 286
 287 #ifdef HAVE_LINUX_NET_NAMESPACE_H
 288 static int netnsid_cache_find(ino_t netino, int *netnsid)
 289 {
 290         struct list_head *p;
 291
 292         list_for_each(p, &netnsids_cache) {
 293                 struct netnsid_cache *e = list_entry(p,
 294                                                      struct netnsid_cache,
 295                                                      netnsids);
 296                 if (e->ino == netino) {
 297                         *netnsid = e->id;
 298                         return 1;
 299                 }
 300         }
 301
 302         return 0;
 303 }
 304
 305 static void netnsid_cache_add(ino_t netino, int netnsid)
 306 {
 307         struct netnsid_cache *e;
 308
 309         e = xcalloc(1, sizeof(*e));
 310         e->ino = netino;
 311         e->id  = netnsid;
 312         INIT_LIST_HEAD(&e->netnsids);
 313         list_add(&e->netnsids, &netnsids_cache);
 314 }
 315
 316 static int get_netnsid_via_netlink_send_request(int target_fd)
 317 {
 318         unsigned char req[NLMSG_SPACE(sizeof(struct rtgenmsg))
 319                           + RTA_SPACE(sizeof(int32_t))];
 320
 321         struct nlmsghdr *nlh = (struct nlmsghdr *)req;
 322         struct rtgenmsg *rt = NLMSG_DATA(req);
 323         struct rtattr *rta = (struct rtattr *)
 324                 (req + NLMSG_SPACE(sizeof(struct rtgenmsg)));
 325         int32_t *fd = RTA_DATA(rta);
 326
 327         nlh->nlmsg_len = sizeof(req);
 328         nlh->nlmsg_flags = NLM_F_REQUEST;
 329         nlh->nlmsg_type = RTM_GETNSID;
 330         rt->rtgen_family = AF_UNSPEC;
 331         rta->rta_type = NETNSA_FD;
 332         rta->rta_len = RTA_SPACE(sizeof(int32_t));
 333         *fd = target_fd;
 334
 335         if (send(netlink_fd, req, sizeof(req), 0) < 0)
 336                 return -1;
 337         return 0;
 338 }
 339
 340 static int get_netnsid_via_netlink_recv_response(int *netnsid)
 341 {
 342         unsigned char res[NLMSG_SPACE(sizeof(struct rtgenmsg))
 343                           + ((RTA_SPACE(sizeof(int32_t))
 344                               < RTA_SPACE(sizeof(struct nlmsgerr)))
 345                              ? RTA_SPACE(sizeof(struct nlmsgerr))
 346                              : RTA_SPACE(sizeof(int32_t)))];
 347         int reslen, rtalen;
 348
 349         struct nlmsghdr *nlh;
 350         struct rtattr *rta;
 351
 352         reslen = recv(netlink_fd, res, sizeof(res), 0);
 353         if (reslen < 0)
 354                 return -1;
 355
 356         nlh = (struct nlmsghdr *)res;
 357         if (!(NLMSG_OK(nlh, reslen)
 358               && nlh->nlmsg_type == RTM_NEWNSID))
 359                 return -1;
 360
 361         rtalen = NLMSG_PAYLOAD(nlh, sizeof(struct rtgenmsg));
 362         rta = (struct rtattr *)(res + NLMSG_SPACE(sizeof(struct rtgenmsg)));
 363         if (!(RTA_OK(rta, rtalen)
 364               && rta->rta_type == NETNSA_NSID))
 365                 return -1;
 366
 367         *netnsid = *(int *)RTA_DATA(rta);
 368
 369         return 0;
 370 }
 371
 372 static int get_netnsid_via_netlink(int dir, const char *path)
 373 {
 374         int netnsid;
 375         int target_fd;
 376
 377         if (netlink_fd < 0)
 378                 return LSNS_NETNS_UNUSABLE;
 379
 380         target_fd = openat(dir, path, O_RDONLY);
 381         if (target_fd < 0)
 382                 return LSNS_NETNS_UNUSABLE;
 383
 384         if (get_netnsid_via_netlink_send_request(target_fd) < 0) {
 385                 netnsid = LSNS_NETNS_UNUSABLE;
 386                 goto out;
 387         }
 388
 389         if (get_netnsid_via_netlink_recv_response(&netnsid) < 0) {
 390                 netnsid = LSNS_NETNS_UNUSABLE;
 391                 goto out;
 392         }
 393
 394  out:
 395         close(target_fd);
 396         return netnsid;
 397 }
 398
 399 static int get_netnsid(int dir, ino_t netino)
 400 {
 401         int netnsid;
 402
 403         if (!netnsid_cache_find(netino, &netnsid)) {
 404                 netnsid = get_netnsid_via_netlink(dir, "ns/net");
 405                 netnsid_cache_add(netino, netnsid);
 406         }
 407
 408         return netnsid;
 409 }
 410 #else
 411 static int get_netnsid(int dir __attribute__((__unused__)),
 412                        ino_t netino __attribute__((__unused__)))
 413 {
 414         return LSNS_NETNS_UNUSABLE;
 415 }
 416 #endif /* HAVE_LINUX_NET_NAMESPACE_H */
 417
 418 static int read_process(struct lsns *ls, pid_t pid)
 419 {
 420         struct lsns_process *p = NULL;
 421         char buf[BUFSIZ];
 422         DIR *dir;
 423         int rc = 0, fd;
 424         FILE *f = NULL;
 425         size_t i;
 426         struct stat st;
 427
 428         DBG(PROC, ul_debug("reading %d", (int) pid));
 429
 430         snprintf(buf, sizeof(buf), "/proc/%d", pid);
 431         dir = opendir(buf);
 432         if (!dir)
 433                 return -errno;
 434
 435         p = xcalloc(1, sizeof(*p));
 436         if (!p) {
 437                 rc = -ENOMEM;
 438                 goto done;
 439         }
 440         p->netnsid = LSNS_NETNS_UNUSABLE;
 441
 442         if (fstat(dirfd(dir), &st) == 0) {
 443                 p->uid = st.st_uid;
 444                 add_uid(uid_cache, st.st_uid);
 445         }
 446
 447         fd = openat(dirfd(dir), "stat", O_RDONLY);
 448         if (fd < 0) {
 449                 rc = -errno;
 450                 goto done;
 451         }
 452         if (!(f = fdopen(fd, "r"))) {
 453                 rc = -errno;
 454                 goto done;
 455         }
 456         rc = parse_proc_stat(f, &p->pid, &p->state, &p->ppid);
 457         if (rc < 0)
 458                 goto done;
 459         rc = 0;
 460
 461         for (i = 0; i < ARRAY_SIZE(p->ns_ids); i++) {
 462                 INIT_LIST_HEAD(&p->ns_siblings[i]);
 463
 464                 if (!ls->fltr_types[i])
 465                         continue;
 466
 467                 rc = get_ns_ino(dirfd(dir), ns_names[i], &p->ns_ids[i]);
 468                 if (rc && rc != -EACCES && rc != -ENOENT)
 469                         goto done;
 470                 if (i == LSNS_ID_NET)
 471                         p->netnsid = get_netnsid(dirfd(dir), p->ns_ids[i]);
 472                 rc = 0;
 473         }
 474
 475         INIT_LIST_HEAD(&p->processes);
 476
 477         DBG(PROC, ul_debugobj(p, "new pid=%d", p->pid));
 478         list_add_tail(&p->processes, &ls->processes);
 479 done:
 480         if (f)
 481                 fclose(f);
 482         closedir(dir);
 483         if (rc)
 484                 free(p);
 485         return rc;
 486 }
 487
 488 static int read_processes(struct lsns *ls)
 489 {
 490         struct proc_processes *proc = NULL;
 491         pid_t pid;
 492         int rc = 0;
 493
 494         DBG(PROC, ul_debug("opening /proc"));
 495
 496         if (!(proc = proc_open_processes())) {
 497                 rc = -errno;
 498                 goto done;
 499         }
 500
 501         while (proc_next_pid(proc, &pid) == 0) {
 502                 rc = read_process(ls, pid);
 503                 if (rc && rc != -EACCES && rc != -ENOENT)
 504                         break;
 505                 rc = 0;
 506         }
 507 done:
 508         DBG(PROC, ul_debug("closing /proc"));
 509         proc_close_processes(proc);
 510         return rc;
 511 }
 512
 513 static struct lsns_namespace *get_namespace(struct lsns *ls, ino_t ino)
 514 {
 515         struct list_head *p;
 516
 517         list_for_each(p, &ls->namespaces) {
 518                 struct lsns_namespace *ns = list_entry(p, struct lsns_namespace, namespaces);
 519
 520                 if (ns->id == ino)
 521                         return ns;
 522         }
 523         return NULL;
 524 }
 525
 526 static int namespace_has_process(struct lsns_namespace *ns, pid_t pid)
 527 {
 528         struct list_head *p;
 529
 530         list_for_each(p, &ns->processes) {
 531                 struct lsns_process *proc = list_entry(p, struct lsns_process, ns_siblings[ns->type]);
 532
 533                 if (proc->pid == pid)
 534                         return 1;
 535         }
 536         return 0;
 537 }
 538
 539 static struct lsns_namespace *add_namespace(struct lsns *ls, int type, ino_t ino)
 540 {
 541         struct lsns_namespace *ns = xcalloc(1, sizeof(*ns));
 542
 543         if (!ns)
 544                 return NULL;
 545
 546         DBG(NS, ul_debugobj(ns, "new %s[%ju]", ns_names[type], (uintmax_t)ino));
 547
 548         INIT_LIST_HEAD(&ns->processes);
 549         INIT_LIST_HEAD(&ns->namespaces);
 550
 551         ns->type = type;
 552         ns->id = ino;
 553
 554         list_add_tail(&ns->namespaces, &ls->namespaces);
 555         return ns;
 556 }
 557
 558 static int add_process_to_namespace(struct lsns *ls, struct lsns_namespace *ns, struct lsns_process *proc)
 559 {
 560         struct list_head *p;
 561
 562         DBG(NS, ul_debugobj(ns, "add process [%p] pid=%d to %s[%ju]",
 563                 proc, proc->pid, ns_names[ns->type], (uintmax_t)ns->id));
 564
 565         list_for_each(p, &ls->processes) {
 566                 struct lsns_process *xproc = list_entry(p, struct lsns_process, processes);
 567
 568                 if (xproc->pid == proc->ppid)           /* my parent */
 569                         proc->parent = xproc;
 570                 else if (xproc->ppid == proc->pid)      /* my child */
 571                         xproc->parent = proc;
 572         }
 573
 574         list_add_tail(&proc->ns_siblings[ns->type], &ns->processes);
 575         ns->nprocs++;
 576
 577         if (!ns->proc || ns->proc->pid > proc->pid)
 578                 ns->proc = proc;
 579
 580         return 0;
 581 }
 582
 583 static int cmp_namespaces(struct list_head *a, struct list_head *b,
 584                           __attribute__((__unused__)) void *data)
 585 {
 586         struct lsns_namespace *xa = list_entry(a, struct lsns_namespace, namespaces),
 587                               *xb = list_entry(b, struct lsns_namespace, namespaces);
 588
 589         return cmp_numbers(xa->id, xb->id);
 590 }
 591
 592 static int netnsid_xasputs(char **str, int netnsid)
 593 {
 594         if (netnsid >= 0)
 595                 return xasprintf(str, "%d", netnsid);
 596 #ifdef NETNSA_NSID_NOT_ASSIGNED
 597         else if (netnsid == NETNSA_NSID_NOT_ASSIGNED)
 598                 return xasprintf(str, "%s", "unassigned");
 599 #endif
 600         else
 601                 return 0;
 602 }
 603
 604 static int read_namespaces(struct lsns *ls)
 605 {
 606         struct list_head *p;
 607
 608         DBG(NS, ul_debug("reading namespace"));
 609
 610         list_for_each(p, &ls->processes) {
 611                 size_t i;
 612                 struct lsns_namespace *ns;
 613                 struct lsns_process *proc = list_entry(p, struct lsns_process, processes);
 614
 615                 for (i = 0; i < ARRAY_SIZE(proc->ns_ids); i++) {
 616                         if (proc->ns_ids[i] == 0)
 617                                 continue;
 618                         if (!(ns = get_namespace(ls, proc->ns_ids[i]))) {
 619                                 ns = add_namespace(ls, i, proc->ns_ids[i]);
 620                                 if (!ns)
 621                                         return -ENOMEM;
 622                         }
 623                         add_process_to_namespace(ls, ns, proc);
 624                 }
 625         }
 626
 627         list_sort(&ls->namespaces, cmp_namespaces, NULL);
 628
 629         return 0;
 630 }
 631
 632 static int is_nsfs_root(struct libmnt_fs *fs, void *data)
 633 {
 634         if (!mnt_fs_match_fstype(fs, "nsfs") || !mnt_fs_get_root(fs))
 635                 return 0;
 636
 637         return (strcmp(mnt_fs_get_root(fs), (char *)data) == 0);
 638 }
 639
 640 static int is_path_included(const char *path_set, const char *elt,
 641                               const char sep)
 642 {
 643         size_t elt_len;
 644         size_t path_set_len;
 645         char *tmp;
 646
 647
 648         tmp = strstr(path_set, elt);
 649         if (!tmp)
 650                 return 0;
 651
 652         elt_len = strlen(elt);
 653         path_set_len = strlen(path_set);
 654
 655         /* path_set includes only elt or
 656          * path_set includes elt as the first element.
 657          */
 658         if (tmp == path_set
 659             && ((path_set_len == elt_len)
 660                 || (path_set[elt_len] == sep)))
 661                 return 1;
 662
 663         /* path_set includes elt at the middle
 664          * or as the last element.
 665          */
 666         if ((*(tmp - 1) == sep)
 667             && ((*(tmp + elt_len) == sep)
 668                 || (*(tmp + elt_len) == '\0')))
 669                 return 1;
 670
 671         return 0;
 672 }
 673
 674 static int nsfs_xasputs(char **str,
 675                         struct lsns_namespace *ns,
 676                         struct libmnt_table *tab,
 677                         char sep)
 678 {
 679         struct libmnt_iter *itr = mnt_new_iter(MNT_ITER_FORWARD);
 680         char *expected_root;
 681         struct libmnt_fs *fs = NULL;
 682
 683         xasprintf(&expected_root, "%s:[%ju]", ns_names[ns->type], (uintmax_t)ns->id);
 684         *str = NULL;
 685
 686         while (mnt_table_find_next_fs(tab, itr, is_nsfs_root,
 687                                       expected_root, &fs) == 0) {
 688
 689                 const char *tgt = mnt_fs_get_target(fs);
 690
 691                 if (!*str)
 692                         xasprintf(str, "%s", tgt);
 693
 694                 else if (!is_path_included(*str, tgt, sep)) {
 695                         char *tmp = NULL;
 696
 697                         xasprintf(&tmp, "%s%c%s", *str, sep, tgt);
 698                         free(*str);
 699                         *str = tmp;
 700                 }
 701         }
 702         free(expected_root);
 703         mnt_free_iter(itr);
 704
 705         return 1;
 706 }
 707 static void add_scols_line(struct lsns *ls, struct libscols_table *table,
 708                            struct lsns_namespace *ns, struct lsns_process *proc)
 709 {
 710         size_t i;
 711         struct libscols_line *line;
 712
 713         assert(ns);
 714         assert(table);
 715
 716         line = scols_table_new_line(table,
 717                         ls->tree && proc->parent ? proc->parent->outline : NULL);
 718         if (!line) {
 719                 warn(_("failed to add line to output"));
 720                 return;
 721         }
 722
 723         for (i = 0; i < ncolumns; i++) {
 724                 char *str = NULL;
 725
 726                 switch (get_column_id(i)) {
 727                 case COL_NS:
 728                         xasprintf(&str, "%ju", (uintmax_t)ns->id);
 729                         break;
 730                 case COL_PID:
 731                         xasprintf(&str, "%d", (int) proc->pid);
 732                         break;
 733                 case COL_PPID:
 734                         xasprintf(&str, "%d", (int) proc->ppid);
 735                         break;
 736                 case COL_TYPE:
 737                         xasprintf(&str, "%s", ns_names[ns->type]);
 738                         break;
 739                 case COL_NPROCS:
 740                         xasprintf(&str, "%d", ns->nprocs);
 741                         break;
 742                 case COL_COMMAND:
 743                         str = proc_get_command(proc->pid);
 744                         if (!str)
 745                                 str = proc_get_command_name(proc->pid);
 746                         break;
 747                 case COL_PATH:
 748                         xasprintf(&str, "/proc/%d/ns/%s", (int) proc->pid, ns_names[ns->type]);
 749                         break;
 750                 case COL_UID:
 751                         xasprintf(&str, "%d", (int) proc->uid);
 752                         break;
 753                 case COL_USER:
 754                         xasprintf(&str, "%s", get_id(uid_cache, proc->uid)->name);
 755                         break;
 756                 case COL_NETNSID:
 757                         if (ns->type == LSNS_ID_NET)
 758                                 netnsid_xasputs(&str, proc->netnsid);
 759                         break;
 760                 case COL_NSFS:
 761                         nsfs_xasputs(&str, ns, ls->tab, ls->no_wrap ? ',' : '\n');
 762                         break;
 763                 default:
 764                         break;
 765                 }
 766
 767                 if (str && scols_line_refer_data(line, i, str) != 0)
 768                         err_oom();
 769         }
 770
 771         proc->outline = line;
 772 }
 773
 774 static struct libscols_table *init_scols_table(struct lsns *ls)
 775 {
 776         struct libscols_table *tab;
 777         size_t i;
 778
 779         tab = scols_new_table();
 780         if (!tab) {
 781                 warn(_("failed to initialize output table"));
 782                 return NULL;
 783         }
 784
 785         scols_table_enable_raw(tab, ls->raw);
 786         scols_table_enable_json(tab, ls->json);
 787         scols_table_enable_noheadings(tab, ls->no_headings);
 788
 789         if (ls->json)
 790                 scols_table_set_name(tab, "namespaces");
 791
 792         for (i = 0; i < ncolumns; i++) {
 793                 const struct colinfo *col = get_column_info(i);
 794                 int flags = col->flags;
 795                 struct libscols_column *cl;
 796
 797                 if (ls->no_trunc)
 798                        flags &= ~SCOLS_FL_TRUNC;
 799                 if (ls->tree && get_column_id(i) == COL_COMMAND)
 800                         flags |= SCOLS_FL_TREE;
 801                 if (ls->no_wrap)
 802                         flags &= ~SCOLS_FL_WRAP;
 803
 804                 cl = scols_table_new_column(tab, col->name, col->whint, flags);
 805                 if (cl == NULL) {
 806                         warnx(_("failed to initialize output column"));
 807                         goto err;
 808                 }
 809                 if (!ls->no_wrap && get_column_id(i) == COL_NSFS) {
 810                         scols_column_set_wrapfunc(cl,
 811                                                   scols_wrapnl_chunksize,
 812                                                   scols_wrapnl_nextchunk,
 813                                                   NULL);
 814                         scols_column_set_safechars(cl, "\n");
 815                 }
 816         }
 817
 818         return tab;
 819 err:
 820         scols_unref_table(tab);
 821         return NULL;
 822 }
 823
 824 static int show_namespaces(struct lsns *ls)
 825 {
 826         struct libscols_table *tab;
 827         struct list_head *p;
 828         int rc = 0;
 829
 830         tab = init_scols_table(ls);
 831         if (!tab)
 832                 return -ENOMEM;
 833
 834         list_for_each(p, &ls->namespaces) {
 835                 struct lsns_namespace *ns = list_entry(p, struct lsns_namespace, namespaces);
 836
 837                 if (ls->fltr_pid != 0 && !namespace_has_process(ns, ls->fltr_pid))
 838                         continue;
 839
 840                 add_scols_line(ls, tab, ns, ns->proc);
 841         }
 842
 843         scols_print_table(tab);
 844         scols_unref_table(tab);
 845         return rc;
 846 }
 847
 848 static void show_process(struct lsns *ls, struct libscols_table *tab,
 849                          struct lsns_process *proc, struct lsns_namespace *ns)
 850 {
 851         /*
 852          * create a tree from parent->child relation, but only if the parent is
 853          * within the same namespace
 854          */
 855         if (ls->tree
 856             && proc->parent
 857             && !proc->parent->outline
 858             && proc->parent->ns_ids[ns->type] == proc->ns_ids[ns->type])
 859                 show_process(ls, tab, proc->parent, ns);
 860
 861         add_scols_line(ls, tab, ns, proc);
 862 }
 863
 864
 865 static int show_namespace_processes(struct lsns *ls, struct lsns_namespace *ns)
 866 {
 867         struct libscols_table *tab;
 868         struct list_head *p;
 869
 870         tab = init_scols_table(ls);
 871         if (!tab)
 872                 return -ENOMEM;
 873
 874         list_for_each(p, &ns->processes) {
 875                 struct lsns_process *proc = list_entry(p, struct lsns_process, ns_siblings[ns->type]);
 876
 877                 if (!proc->outline)
 878                         show_process(ls, tab, proc, ns);
 879         }
 880
 881
 882         scols_print_table(tab);
 883         scols_unref_table(tab);
 884         return 0;
 885 }
 886
 887 static void __attribute__((__noreturn__)) usage(void)
 888 {
 889         FILE *out = stdout;
 890         size_t i;
 891
 892         fputs(USAGE_HEADER, out);
 893
 894         fprintf(out,
 895                 _(" %s [options] [<namespace>]\n"), program_invocation_short_name);
 896
 897         fputs(USAGE_SEPARATOR, out);
 898         fputs(_("List system namespaces.\n"), out);
 899
 900         fputs(USAGE_OPTIONS, out);
 901         fputs(_(" -J, --json             use JSON output format\n"), out);
 902         fputs(_(" -l, --list             use list format output\n"), out);
 903         fputs(_(" -n, --noheadings       don't print headings\n"), out);
 904         fputs(_(" -o, --output <list>    define which output columns to use\n"), out);
 905         fputs(_(" -p, --task <pid>       print process namespaces\n"), out);
 906         fputs(_(" -r, --raw              use the raw output format\n"), out);
 907         fputs(_(" -u, --notruncate       don't truncate text in columns\n"), out);
 908         fputs(_(" -W, --nowrap           don't use multi-line representation\n"), out);
 909         fputs(_(" -t, --type <name>      namespace type (mnt, net, ipc, user, pid, uts, cgroup)\n"), out);
 910
 911         fputs(USAGE_SEPARATOR, out);
 912         printf(USAGE_HELP_OPTIONS(24));
 913
 914         fputs(USAGE_COLUMNS, out);
 915         for (i = 0; i < ARRAY_SIZE(infos); i++)
 916                 fprintf(out, " %11s  %s\n", infos[i].name, _(infos[i].help));
 917
 918         printf(USAGE_MAN_TAIL("lsns(8)"));
 919
 920         exit(EXIT_SUCCESS);
 921 }
 922
 923
 924 int main(int argc, char *argv[])
 925 {
 926         struct lsns ls;
 927         int c;
 928         int r = 0;
 929         char *outarg = NULL;
 930         static const struct option long_opts[] = {
 931                 { "json",       no_argument,       NULL, 'J' },
 932                 { "task",       required_argument, NULL, 'p' },
 933                 { "help",       no_argument,       NULL, 'h' },
 934                 { "output",     required_argument, NULL, 'o' },
 935                 { "notruncate", no_argument,       NULL, 'u' },
 936                 { "version",    no_argument,       NULL, 'V' },
 937                 { "noheadings", no_argument,       NULL, 'n' },
 938                 { "nowrap",     no_argument,       NULL, 'W' },
 939                 { "list",       no_argument,       NULL, 'l' },
 940                 { "raw",        no_argument,       NULL, 'r' },
 941                 { "type",       required_argument, NULL, 't' },
 942                 { NULL, 0, NULL, 0 }
 943         };
 944
 945         static const ul_excl_t excl[] = {       /* rows and cols in ASCII order */
 946                 { 'J','r' },
 947                 { 0 }
 948         };
 949         int excl_st[ARRAY_SIZE(excl)] = UL_EXCL_STATUS_INIT;
 950         int is_net = 0;
 951
 952         setlocale(LC_ALL, "");
 953         bindtextdomain(PACKAGE, LOCALEDIR);
 954         textdomain(PACKAGE);
 955         atexit(close_stdout);
 956
 957         lsns_init_debug();
 958         memset(&ls, 0, sizeof(ls));
 959
 960         INIT_LIST_HEAD(&ls.processes);
 961         INIT_LIST_HEAD(&ls.namespaces);
 962         INIT_LIST_HEAD(&netnsids_cache);
 963
 964         while ((c = getopt_long(argc, argv,
 965                                 "Jlp:o:nruhVt:W", long_opts, NULL)) != -1) {
 966
 967                 err_exclusive_options(c, long_opts, excl, excl_st);
 968
 969                 switch(c) {
 970                 case 'J':
 971                         ls.json = 1;
 972                         break;
 973                 case 'l':
 974                         ls.list = 1;
 975                         break;
 976                 case 'o':
 977                         outarg = optarg;
 978                         break;
 979                 case 'V':
 980                         printf(UTIL_LINUX_VERSION);
 981                         return EXIT_SUCCESS;
 982                 case 'p':
 983                         ls.fltr_pid = strtos32_or_err(optarg, _("invalid PID argument"));
 984                         break;
 985                 case 'h':
 986                         usage();
 987                 case 'n':
 988                         ls.no_headings = 1;
 989                         break;
 990                 case 'r':
 991                         ls.no_wrap = ls.raw = 1;
 992                         break;
 993                 case 'u':
 994                         ls.no_trunc = 1;
 995                         break;
 996                 case 't':
 997                 {
 998                         int type = ns_name2type(optarg);
 999                         if (type < 0)
1000                                 errx(EXIT_FAILURE, _("unknown namespace type: %s"), optarg);
1001                         ls.fltr_types[type] = 1;
1002                         ls.fltr_ntypes++;
1003                         if (type == LSNS_ID_NET)
1004                                 is_net = 1;
1005                         break;
1006                 }
1007                 case 'W':
1008                         ls.no_wrap = 1;
1009                         break;
1010                 default:
1011                         errtryhelp(EXIT_FAILURE);
1012                 }
1013         }
1014
1015         if (!ls.fltr_ntypes) {
1016                 size_t i;
1017
1018                 for (i = 0; i < ARRAY_SIZE(ns_names); i++)
1019                         ls.fltr_types[i] = 1;
1020         }
1021
1022         if (optind < argc) {
1023                 if (ls.fltr_pid)
1024                         errx(EXIT_FAILURE, _("--task is mutually exclusive with <namespace>"));
1025                 ls.fltr_ns = strtou64_or_err(argv[optind], _("invalid namespace argument"));
1026                 ls.tree = ls.list ? 0 : 1;
1027
1028                 if (!ncolumns) {
1029                         columns[ncolumns++] = COL_PID;
1030                         columns[ncolumns++] = COL_PPID;
1031                         columns[ncolumns++] = COL_USER;
1032                         columns[ncolumns++] = COL_COMMAND;
1033                 }
1034         }
1035
1036         if (!ncolumns) {
1037                 columns[ncolumns++] = COL_NS;
1038                 columns[ncolumns++] = COL_TYPE;
1039                 columns[ncolumns++] = COL_NPROCS;
1040                 columns[ncolumns++] = COL_PID;
1041                 columns[ncolumns++] = COL_USER;
1042                 if (is_net) {
1043                         columns[ncolumns++] = COL_NETNSID;
1044                         columns[ncolumns++] = COL_NSFS;
1045                 }
1046                 columns[ncolumns++] = COL_COMMAND;
1047         }
1048
1049         if (outarg && string_add_to_idarray(outarg, columns, ARRAY_SIZE(columns),
1050                                   &ncolumns, column_name_to_id) < 0)
1051                 return EXIT_FAILURE;
1052
1053         scols_init_debug(0);
1054
1055         uid_cache = new_idcache();
1056         if (!uid_cache)
1057                 err(EXIT_FAILURE, _("failed to allocate UID cache"));
1058
1059 #ifdef HAVE_LINUX_NET_NAMESPACE_H
1060         if (has_column(COL_NETNSID))
1061                 netlink_fd = socket(AF_NETLINK, SOCK_RAW, NETLINK_ROUTE);
1062 #endif
1063         if (has_column(COL_NSFS)) {
1064                 ls.tab = mnt_new_table_from_file(_PATH_PROC_MOUNTINFO);
1065                 if (!ls.tab)
1066                         err(MNT_EX_FAIL, _("failed to parse %s"), _PATH_PROC_MOUNTINFO);
1067         }
1068
1069         r = read_processes(&ls);
1070         if (!r)
1071                 r = read_namespaces(&ls);
1072         if (!r) {
1073                 if (ls.fltr_ns) {
1074                         struct lsns_namespace *ns = get_namespace(&ls, ls.fltr_ns);
1075
1076                         if (!ns)
1077                                 errx(EXIT_FAILURE, _("not found namespace: %ju"), (uintmax_t) ls.fltr_ns);
1078                         r = show_namespace_processes(&ls, ns);
1079                 } else
1080                         r = show_namespaces(&ls);
1081         }
1082
1083         mnt_free_table(ls.tab);
1084         if (netlink_fd >= 0)
1085                 close(netlink_fd);
1086         free_idcache(uid_cache);
1087         return r == 0 ? EXIT_SUCCESS : EXIT_FAILURE;
1088 }