Adding upstream version 2.33.1.upstream/2.33.1upstream

Signed-off-by: Daniel Baumann <daniel.baumann@progress-linux.org>

1 files changed, 1100 insertions, 0 deletions

diff --git a/sys-utils/lsns.c b/sys-utils/lsns.c
new file mode 100644
index 0000000..38ea2e0
--- /dev/null
+++ b/sys-utils/lsns.c
@@ -0,0 +1,1100 @@
+/*
+ * lsns(8) - list system namespaces
+ *
+ * Copyright (C) 2015 Karel Zak <kzak@redhat.com>
+ *
+ * This program is free software; you can redistribute it and/or modify
+ * it under the terms of the GNU General Public License as published by
+ * the Free Software Foundation; either version 2 of the License, or
+ * (at your option) any later version.
+ *
+ * This program is distributed in the hope that it would be useful,
+ * but WITHOUT ANY WARRANTY; without even the implied warranty of
+ * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
+ * GNU General Public License for more details.
+ *
+ * You should have received a copy of the GNU General Public License
+ * along with this program; if not, write to the Free Software Foundation,
+ * Inc., 59 Temple Place, Suite 330, Boston, MA  02111-1307  USA
+ */
+#include <stdio.h>
+#include <string.h>
+#include <getopt.h>
+#include <stdlib.h>
+#include <assert.h>
+#include <dirent.h>
+#include <unistd.h>
+#include <sys/stat.h>
+#include <sys/types.h>
+#include <wchar.h>
+#include <libsmartcols.h>
+#include <libmount.h>
+
+#ifdef HAVE_LINUX_NET_NAMESPACE_H
+#include <stdbool.h>
+#include <sys/socket.h>
+#include <linux/netlink.h>
+#include <linux/rtnetlink.h>
+#include <linux/net_namespace.h>
+#endif
+
+#include "pathnames.h"
+#include "nls.h"
+#include "xalloc.h"
+#include "c.h"
+#include "list.h"
+#include "closestream.h"
+#include "optutils.h"
+#include "procutils.h"
+#include "strutils.h"
+#include "namespace.h"
+#include "idcache.h"
+
+#include "debug.h"
+
+static UL_DEBUG_DEFINE_MASK(lsns);
+UL_DEBUG_DEFINE_MASKNAMES(lsns) = UL_DEBUG_EMPTY_MASKNAMES;
+
+#define LSNS_DEBUG_INIT		(1 << 1)
+#define LSNS_DEBUG_PROC		(1 << 2)
+#define LSNS_DEBUG_NS		(1 << 3)
+#define LSNS_DEBUG_ALL		0xFFFF
+
+#define LSNS_NETNS_UNUSABLE -2
+
+#define DBG(m, x)       __UL_DBG(lsns, LSNS_DEBUG_, m, x)
+#define ON_DBG(m, x)    __UL_DBG_CALL(lsns, LSNS_DEBUG_, m, x)
+
+#define UL_DEBUG_CURRENT_MASK	UL_DEBUG_MASK(lsns)
+#include "debugobj.h"
+
+static struct idcache *uid_cache = NULL;
+
+/* column IDs */
+enum {
+	COL_NS = 0,
+	COL_TYPE,
+	COL_PATH,
+	COL_NPROCS,
+	COL_PID,
+	COL_PPID,
+	COL_COMMAND,
+	COL_UID,
+	COL_USER,
+	COL_NETNSID,
+	COL_NSFS,
+};
+
+/* column names */
+struct colinfo {
+	const char *name; /* header */
+	double	   whint; /* width hint (N < 1 is in percent of termwidth) */
+	int	   flags; /* SCOLS_FL_* */
+	const char *help;
+	int        json_type;
+};
+
+/* columns descriptions */
+static const struct colinfo infos[] = {
+	[COL_NS]      = { "NS",     10, SCOLS_FL_RIGHT, N_("namespace identifier (inode number)"), SCOLS_JSON_NUMBER },
+	[COL_TYPE]    = { "TYPE",    5, 0, N_("kind of namespace") },
+	[COL_PATH]    = { "PATH",    0, 0, N_("path to the namespace")},
+	[COL_NPROCS]  = { "NPROCS",  5, SCOLS_FL_RIGHT, N_("number of processes in the namespace"), SCOLS_JSON_NUMBER },
+	[COL_PID]     = { "PID",     5, SCOLS_FL_RIGHT, N_("lowest PID in the namespace"), SCOLS_JSON_NUMBER },
+	[COL_PPID]    = { "PPID",    5, SCOLS_FL_RIGHT, N_("PPID of the PID"), SCOLS_JSON_NUMBER },
+	[COL_COMMAND] = { "COMMAND", 0, SCOLS_FL_TRUNC, N_("command line of the PID")},
+	[COL_UID]     = { "UID",     0, SCOLS_FL_RIGHT, N_("UID of the PID"), SCOLS_JSON_NUMBER},
+	[COL_USER]    = { "USER",    0, 0, N_("username of the PID")},
+	[COL_NETNSID] = { "NETNSID", 0, SCOLS_FL_RIGHT, N_("namespace ID as used by network subsystem")},
+	[COL_NSFS]    = { "NSFS",    0, SCOLS_FL_WRAP, N_("nsfs mountpoint (usually used network subsystem)")}
+};
+
+static int columns[ARRAY_SIZE(infos) * 2];
+static size_t ncolumns;
+
+enum {
+	LSNS_ID_MNT = 0,
+	LSNS_ID_NET,
+	LSNS_ID_PID,
+	LSNS_ID_UTS,
+	LSNS_ID_IPC,
+	LSNS_ID_USER,
+	LSNS_ID_CGROUP
+};
+
+static char *ns_names[] = {
+	[LSNS_ID_MNT] = "mnt",
+	[LSNS_ID_NET] = "net",
+	[LSNS_ID_PID] = "pid",
+	[LSNS_ID_UTS] = "uts",
+	[LSNS_ID_IPC] = "ipc",
+	[LSNS_ID_USER] = "user",
+	[LSNS_ID_CGROUP] = "cgroup"
+};
+
+struct lsns_namespace {
+	ino_t id;
+	int type;			/* LSNS_* */
+	int nprocs;
+	int netnsid;
+
+	struct lsns_process *proc;
+
+	struct list_head namespaces;	/* lsns->processes member */
+	struct list_head processes;	/* head of lsns_process *siblings */
+};
+
+struct lsns_process {
+	pid_t pid;		/* process PID */
+	pid_t ppid;		/* parent's PID */
+	pid_t tpid;		/* thread group */
+	char state;
+	uid_t uid;
+
+	ino_t            ns_ids[ARRAY_SIZE(ns_names)];
+	struct list_head ns_siblings[ARRAY_SIZE(ns_names)];
+
+	struct list_head processes;	/* list of processes */
+
+	struct libscols_line *outline;
+	struct lsns_process *parent;
+
+	int netnsid;
+};
+
+struct lsns {
+	struct list_head processes;
+	struct list_head namespaces;
+
+	pid_t	fltr_pid;	/* filter out by PID */
+	ino_t	fltr_ns;	/* filter out by namespace */
+	int	fltr_types[ARRAY_SIZE(ns_names)];
+	int	fltr_ntypes;
+
+	unsigned int raw	: 1,
+		     json	: 1,
+		     tree	: 1,
+		     list	: 1,
+		     no_trunc	: 1,
+		     no_headings: 1,
+		     no_wrap    : 1;
+
+	struct libmnt_table *tab;
+};
+
+struct netnsid_cache {
+	ino_t ino;
+	int   id;
+	struct list_head netnsids;
+};
+
+static struct list_head netnsids_cache;
+
+static int netlink_fd = -1;
+
+static void lsns_init_debug(void)
+{
+	__UL_INIT_DEBUG_FROM_ENV(lsns, LSNS_DEBUG_, 0, LSNS_DEBUG);
+}
+
+static int ns_name2type(const char *name)
+{
+	size_t i;
+
+	for (i = 0; i < ARRAY_SIZE(ns_names); i++) {
+		if (strcmp(ns_names[i], name) == 0)
+			return i;
+	}
+	return -1;
+}
+
+static int column_name_to_id(const char *name, size_t namesz)
+{
+	size_t i;
+
+	assert(name);
+
+	for (i = 0; i < ARRAY_SIZE(infos); i++) {
+		const char *cn = infos[i].name;
+
+		if (!strncasecmp(name, cn, namesz) && !*(cn + namesz))
+			return i;
+	}
+	warnx(_("unknown column: %s"), name);
+	return -1;
+}
+
+static int has_column(int id)
+{
+	size_t i;
+
+	for (i = 0; i < ncolumns; i++) {
+		if (columns[i] == id)
+			return 1;
+	}
+	return 0;
+}
+
+static inline int get_column_id(int num)
+{
+	assert(num >= 0);
+	assert((size_t) num < ncolumns);
+	assert(columns[num] < (int) ARRAY_SIZE(infos));
+
+	return columns[num];
+}
+
+static inline const struct colinfo *get_column_info(unsigned num)
+{
+	return &infos[ get_column_id(num) ];
+}
+
+static int get_ns_ino(int dir, const char *nsname, ino_t *ino)
+{
+	struct stat st;
+	char path[16];
+
+	snprintf(path, sizeof(path), "ns/%s", nsname);
+
+	if (fstatat(dir, path, &st, 0) != 0)
+		return -errno;
+	*ino = st.st_ino;
+	return 0;
+}
+
+static int parse_proc_stat(FILE *fp, pid_t *pid, char *state, pid_t *ppid)
+{
+	char *line = NULL, *p;
+	size_t len = 0;
+	int rc;
+
+	if (getline(&line, &len, fp) < 0) {
+		rc = -errno;
+		goto error;
+	}
+
+	p = strrchr(line, ')');
+	if (p == NULL ||
+	    sscanf(line, "%d (", pid) != 1 ||
+	    sscanf(p, ") %c %d*[^\n]", state, ppid) != 2) {
+		rc = -EINVAL;
+		goto error;
+	}
+	rc = 0;
+
+error:
+	free(line);
+	return rc;
+}
+
+#ifdef HAVE_LINUX_NET_NAMESPACE_H
+static int netnsid_cache_find(ino_t netino, int *netnsid)
+{
+	struct list_head *p;
+
+	list_for_each(p, &netnsids_cache) {
+		struct netnsid_cache *e = list_entry(p,
+						     struct netnsid_cache,
+						     netnsids);
+		if (e->ino == netino) {
+			*netnsid = e->id;
+			return 1;
+		}
+	}
+
+	return 0;
+}
+
+static void netnsid_cache_add(ino_t netino, int netnsid)
+{
+	struct netnsid_cache *e;
+
+	e = xcalloc(1, sizeof(*e));
+	e->ino = netino;
+	e->id  = netnsid;
+	INIT_LIST_HEAD(&e->netnsids);
+	list_add(&e->netnsids, &netnsids_cache);
+}
+
+static int get_netnsid_via_netlink_send_request(int target_fd)
+{
+	unsigned char req[NLMSG_SPACE(sizeof(struct rtgenmsg))
+			  + RTA_SPACE(sizeof(int32_t))];
+
+	struct nlmsghdr *nlh = (struct nlmsghdr *)req;
+	struct rtgenmsg *rt = NLMSG_DATA(req);
+	struct rtattr *rta = (struct rtattr *)
+		(req + NLMSG_SPACE(sizeof(struct rtgenmsg)));
+	int32_t *fd = RTA_DATA(rta);
+
+	nlh->nlmsg_len = sizeof(req);
+	nlh->nlmsg_flags = NLM_F_REQUEST;
+	nlh->nlmsg_type = RTM_GETNSID;
+	rt->rtgen_family = AF_UNSPEC;
+	rta->rta_type = NETNSA_FD;
+	rta->rta_len = RTA_SPACE(sizeof(int32_t));
+	*fd = target_fd;
+
+	if (send(netlink_fd, req, sizeof(req), 0) < 0)
+		return -1;
+	return 0;
+}
+
+static int get_netnsid_via_netlink_recv_response(int *netnsid)
+{
+	unsigned char res[NLMSG_SPACE(sizeof(struct rtgenmsg))
+			  + ((RTA_SPACE(sizeof(int32_t))
+			      < RTA_SPACE(sizeof(struct nlmsgerr)))
+			     ? RTA_SPACE(sizeof(struct nlmsgerr))
+			     : RTA_SPACE(sizeof(int32_t)))];
+	int rtalen;
+	ssize_t reslen;
+
+	struct nlmsghdr *nlh;
+	struct rtattr *rta;
+
+	reslen = recv(netlink_fd, res, sizeof(res), 0);
+	if (reslen < 0)
+		return -1;
+
+	nlh = (struct nlmsghdr *)res;
+	if (!(NLMSG_OK(nlh, (size_t)reslen)
+	      && nlh->nlmsg_type == RTM_NEWNSID))
+		return -1;
+
+	rtalen = NLMSG_PAYLOAD(nlh, sizeof(struct rtgenmsg));
+	rta = (struct rtattr *)(res + NLMSG_SPACE(sizeof(struct rtgenmsg)));
+	if (!(RTA_OK(rta, rtalen)
+	      && rta->rta_type == NETNSA_NSID))
+		return -1;
+
+	*netnsid = *(int *)RTA_DATA(rta);
+
+	return 0;
+}
+
+static int get_netnsid_via_netlink(int dir, const char *path)
+{
+	int netnsid;
+	int target_fd;
+
+	if (netlink_fd < 0)
+		return LSNS_NETNS_UNUSABLE;
+
+	target_fd = openat(dir, path, O_RDONLY);
+	if (target_fd < 0)
+		return LSNS_NETNS_UNUSABLE;
+
+	if (get_netnsid_via_netlink_send_request(target_fd) < 0) {
+		netnsid = LSNS_NETNS_UNUSABLE;
+		goto out;
+	}
+
+	if (get_netnsid_via_netlink_recv_response(&netnsid) < 0) {
+		netnsid = LSNS_NETNS_UNUSABLE;
+		goto out;
+	}
+
+ out:
+	close(target_fd);
+	return netnsid;
+}
+
+static int get_netnsid(int dir, ino_t netino)
+{
+	int netnsid;
+
+	if (!netnsid_cache_find(netino, &netnsid)) {
+		netnsid = get_netnsid_via_netlink(dir, "ns/net");
+		netnsid_cache_add(netino, netnsid);
+	}
+
+	return netnsid;
+}
+#else
+static int get_netnsid(int dir __attribute__((__unused__)),
+		       ino_t netino __attribute__((__unused__)))
+{
+	return LSNS_NETNS_UNUSABLE;
+}
+#endif /* HAVE_LINUX_NET_NAMESPACE_H */
+
+static int read_process(struct lsns *ls, pid_t pid)
+{
+	struct lsns_process *p = NULL;
+	char buf[BUFSIZ];
+	DIR *dir;
+	int rc = 0, fd;
+	FILE *f = NULL;
+	size_t i;
+	struct stat st;
+
+	DBG(PROC, ul_debug("reading %d", (int) pid));
+
+	snprintf(buf, sizeof(buf), "/proc/%d", pid);
+	dir = opendir(buf);
+	if (!dir)
+		return -errno;
+
+	p = xcalloc(1, sizeof(*p));
+	p->netnsid = LSNS_NETNS_UNUSABLE;
+
+	if (fstat(dirfd(dir), &st) == 0) {
+		p->uid = st.st_uid;
+		add_uid(uid_cache, st.st_uid);
+	}
+
+	fd = openat(dirfd(dir), "stat", O_RDONLY);
+	if (fd < 0) {
+		rc = -errno;
+		goto done;
+	}
+	if (!(f = fdopen(fd, "r"))) {
+		rc = -errno;
+		goto done;
+	}
+	rc = parse_proc_stat(f, &p->pid, &p->state, &p->ppid);
+	if (rc < 0)
+		goto done;
+	rc = 0;
+
+	for (i = 0; i < ARRAY_SIZE(p->ns_ids); i++) {
+		INIT_LIST_HEAD(&p->ns_siblings[i]);
+
+		if (!ls->fltr_types[i])
+			continue;
+
+		rc = get_ns_ino(dirfd(dir), ns_names[i], &p->ns_ids[i]);
+		if (rc && rc != -EACCES && rc != -ENOENT)
+			goto done;
+		if (i == LSNS_ID_NET)
+			p->netnsid = get_netnsid(dirfd(dir), p->ns_ids[i]);
+		rc = 0;
+	}
+
+	INIT_LIST_HEAD(&p->processes);
+
+	DBG(PROC, ul_debugobj(p, "new pid=%d", p->pid));
+	list_add_tail(&p->processes, &ls->processes);
+done:
+	if (f)
+		fclose(f);
+	closedir(dir);
+	if (rc)
+		free(p);
+	return rc;
+}
+
+static int read_processes(struct lsns *ls)
+{
+	struct proc_processes *proc = NULL;
+	pid_t pid;
+	int rc = 0;
+
+	DBG(PROC, ul_debug("opening /proc"));
+
+	if (!(proc = proc_open_processes())) {
+		rc = -errno;
+		goto done;
+	}
+
+	while (proc_next_pid(proc, &pid) == 0) {
+		rc = read_process(ls, pid);
+		if (rc && rc != -EACCES && rc != -ENOENT)
+			break;
+		rc = 0;
+	}
+done:
+	DBG(PROC, ul_debug("closing /proc"));
+	proc_close_processes(proc);
+	return rc;
+}
+
+static struct lsns_namespace *get_namespace(struct lsns *ls, ino_t ino)
+{
+	struct list_head *p;
+
+	list_for_each(p, &ls->namespaces) {
+		struct lsns_namespace *ns = list_entry(p, struct lsns_namespace, namespaces);
+
+		if (ns->id == ino)
+			return ns;
+	}
+	return NULL;
+}
+
+static int namespace_has_process(struct lsns_namespace *ns, pid_t pid)
+{
+	struct list_head *p;
+
+	list_for_each(p, &ns->processes) {
+		struct lsns_process *proc = list_entry(p, struct lsns_process, ns_siblings[ns->type]);
+
+		if (proc->pid == pid)
+			return 1;
+	}
+	return 0;
+}
+
+static struct lsns_namespace *add_namespace(struct lsns *ls, int type, ino_t ino)
+{
+	struct lsns_namespace *ns = xcalloc(1, sizeof(*ns));
+
+	if (!ns)
+		return NULL;
+
+	DBG(NS, ul_debugobj(ns, "new %s[%ju]", ns_names[type], (uintmax_t)ino));
+
+	INIT_LIST_HEAD(&ns->processes);
+	INIT_LIST_HEAD(&ns->namespaces);
+
+	ns->type = type;
+	ns->id = ino;
+
+	list_add_tail(&ns->namespaces, &ls->namespaces);
+	return ns;
+}
+
+static int add_process_to_namespace(struct lsns *ls, struct lsns_namespace *ns, struct lsns_process *proc)
+{
+	struct list_head *p;
+
+	DBG(NS, ul_debugobj(ns, "add process [%p] pid=%d to %s[%ju]",
+		proc, proc->pid, ns_names[ns->type], (uintmax_t)ns->id));
+
+	list_for_each(p, &ls->processes) {
+		struct lsns_process *xproc = list_entry(p, struct lsns_process, processes);
+
+		if (xproc->pid == proc->ppid)		/* my parent */
+			proc->parent = xproc;
+		else if (xproc->ppid == proc->pid)	/* my child */
+			xproc->parent = proc;
+	}
+
+	list_add_tail(&proc->ns_siblings[ns->type], &ns->processes);
+	ns->nprocs++;
+
+	if (!ns->proc || ns->proc->pid > proc->pid)
+		ns->proc = proc;
+
+	return 0;
+}
+
+static int cmp_namespaces(struct list_head *a, struct list_head *b,
+			  __attribute__((__unused__)) void *data)
+{
+	struct lsns_namespace *xa = list_entry(a, struct lsns_namespace, namespaces),
+			      *xb = list_entry(b, struct lsns_namespace, namespaces);
+
+	return cmp_numbers(xa->id, xb->id);
+}
+
+static int netnsid_xasputs(char **str, int netnsid)
+{
+	if (netnsid >= 0)
+		return xasprintf(str, "%d", netnsid);
+#ifdef NETNSA_NSID_NOT_ASSIGNED
+	else if (netnsid == NETNSA_NSID_NOT_ASSIGNED)
+		return xasprintf(str, "%s", "unassigned");
+#endif
+	else
+		return 0;
+}
+
+static int read_namespaces(struct lsns *ls)
+{
+	struct list_head *p;
+
+	DBG(NS, ul_debug("reading namespace"));
+
+	list_for_each(p, &ls->processes) {
+		size_t i;
+		struct lsns_namespace *ns;
+		struct lsns_process *proc = list_entry(p, struct lsns_process, processes);
+
+		for (i = 0; i < ARRAY_SIZE(proc->ns_ids); i++) {
+			if (proc->ns_ids[i] == 0)
+				continue;
+			if (!(ns = get_namespace(ls, proc->ns_ids[i]))) {
+				ns = add_namespace(ls, i, proc->ns_ids[i]);
+				if (!ns)
+					return -ENOMEM;
+			}
+			add_process_to_namespace(ls, ns, proc);
+		}
+	}
+
+	list_sort(&ls->namespaces, cmp_namespaces, NULL);
+
+	return 0;
+}
+
+static int is_nsfs_root(struct libmnt_fs *fs, void *data)
+{
+	if (!mnt_fs_match_fstype(fs, "nsfs") || !mnt_fs_get_root(fs))
+		return 0;
+
+	return (strcmp(mnt_fs_get_root(fs), (char *)data) == 0);
+}
+
+static int is_path_included(const char *path_set, const char *elt,
+			      const char sep)
+{
+	size_t elt_len;
+	size_t path_set_len;
+	char *tmp;
+
+
+	tmp = strstr(path_set, elt);
+	if (!tmp)
+		return 0;
+
+	elt_len = strlen(elt);
+	path_set_len = strlen(path_set);
+
+	/* path_set includes only elt or
+	 * path_set includes elt as the first element.
+	 */
+	if (tmp == path_set
+	    && ((path_set_len == elt_len)
+		|| (path_set[elt_len] == sep)))
+		return 1;
+
+	/* path_set includes elt at the middle
+	 * or as the last element.
+	 */
+	if ((*(tmp - 1) == sep)
+	    && ((*(tmp + elt_len) == sep)
+		|| (*(tmp + elt_len) == '\0')))
+		return 1;
+
+	return 0;
+}
+
+static int nsfs_xasputs(char **str,
+			struct lsns_namespace *ns,
+			struct libmnt_table *tab,
+			char sep)
+{
+	struct libmnt_iter *itr = mnt_new_iter(MNT_ITER_FORWARD);
+	char *expected_root;
+	struct libmnt_fs *fs = NULL;
+
+	xasprintf(&expected_root, "%s:[%ju]", ns_names[ns->type], (uintmax_t)ns->id);
+	*str = NULL;
+
+	while (mnt_table_find_next_fs(tab, itr, is_nsfs_root,
+				      expected_root, &fs) == 0) {
+
+		const char *tgt = mnt_fs_get_target(fs);
+
+		if (!*str)
+			xasprintf(str, "%s", tgt);
+
+		else if (!is_path_included(*str, tgt, sep)) {
+			char *tmp = NULL;
+
+			xasprintf(&tmp, "%s%c%s", *str, sep, tgt);
+			free(*str);
+			*str = tmp;
+		}
+	}
+	free(expected_root);
+	mnt_free_iter(itr);
+
+	return 1;
+}
+static void add_scols_line(struct lsns *ls, struct libscols_table *table,
+			   struct lsns_namespace *ns, struct lsns_process *proc)
+{
+	size_t i;
+	struct libscols_line *line;
+
+	assert(ns);
+	assert(table);
+
+	line = scols_table_new_line(table,
+			ls->tree && proc->parent ? proc->parent->outline : NULL);
+	if (!line) {
+		warn(_("failed to add line to output"));
+		return;
+	}
+
+	for (i = 0; i < ncolumns; i++) {
+		char *str = NULL;
+
+		switch (get_column_id(i)) {
+		case COL_NS:
+			xasprintf(&str, "%ju", (uintmax_t)ns->id);
+			break;
+		case COL_PID:
+			xasprintf(&str, "%d", (int) proc->pid);
+			break;
+		case COL_PPID:
+			xasprintf(&str, "%d", (int) proc->ppid);
+			break;
+		case COL_TYPE:
+			xasprintf(&str, "%s", ns_names[ns->type]);
+			break;
+		case COL_NPROCS:
+			xasprintf(&str, "%d", ns->nprocs);
+			break;
+		case COL_COMMAND:
+			str = proc_get_command(proc->pid);
+			if (!str)
+				str = proc_get_command_name(proc->pid);
+			break;
+		case COL_PATH:
+			xasprintf(&str, "/proc/%d/ns/%s", (int) proc->pid, ns_names[ns->type]);
+			break;
+		case COL_UID:
+			xasprintf(&str, "%d", (int) proc->uid);
+			break;
+		case COL_USER:
+			xasprintf(&str, "%s", get_id(uid_cache, proc->uid)->name);
+			break;
+		case COL_NETNSID:
+			if (ns->type == LSNS_ID_NET)
+				netnsid_xasputs(&str, proc->netnsid);
+			break;
+		case COL_NSFS:
+			nsfs_xasputs(&str, ns, ls->tab, ls->no_wrap ? ',' : '\n');
+			break;
+		default:
+			break;
+		}
+
+		if (str && scols_line_refer_data(line, i, str) != 0)
+			err_oom();
+	}
+
+	proc->outline = line;
+}
+
+static struct libscols_table *init_scols_table(struct lsns *ls)
+{
+	struct libscols_table *tab;
+	size_t i;
+
+	tab = scols_new_table();
+	if (!tab) {
+		warn(_("failed to initialize output table"));
+		return NULL;
+	}
+
+	scols_table_enable_raw(tab, ls->raw);
+	scols_table_enable_json(tab, ls->json);
+	scols_table_enable_noheadings(tab, ls->no_headings);
+
+	if (ls->json)
+		scols_table_set_name(tab, "namespaces");
+
+	for (i = 0; i < ncolumns; i++) {
+		const struct colinfo *col = get_column_info(i);
+		int flags = col->flags;
+		struct libscols_column *cl;
+
+		if (ls->no_trunc)
+		       flags &= ~SCOLS_FL_TRUNC;
+		if (ls->tree && get_column_id(i) == COL_COMMAND)
+			flags |= SCOLS_FL_TREE;
+		if (ls->no_wrap)
+			flags &= ~SCOLS_FL_WRAP;
+
+		cl = scols_table_new_column(tab, col->name, col->whint, flags);
+		if (cl == NULL) {
+			warnx(_("failed to initialize output column"));
+			goto err;
+		}
+		if (ls->json)
+			scols_column_set_json_type(cl, col->json_type);
+
+		if (!ls->no_wrap && get_column_id(i) == COL_NSFS) {
+			scols_column_set_wrapfunc(cl,
+						  scols_wrapnl_chunksize,
+						  scols_wrapnl_nextchunk,
+						  NULL);
+			scols_column_set_safechars(cl, "\n");
+		}
+	}
+
+	return tab;
+err:
+	scols_unref_table(tab);
+	return NULL;
+}
+
+static int show_namespaces(struct lsns *ls)
+{
+	struct libscols_table *tab;
+	struct list_head *p;
+	int rc = 0;
+
+	tab = init_scols_table(ls);
+	if (!tab)
+		return -ENOMEM;
+
+	list_for_each(p, &ls->namespaces) {
+		struct lsns_namespace *ns = list_entry(p, struct lsns_namespace, namespaces);
+
+		if (ls->fltr_pid != 0 && !namespace_has_process(ns, ls->fltr_pid))
+			continue;
+
+		add_scols_line(ls, tab, ns, ns->proc);
+	}
+
+	scols_print_table(tab);
+	scols_unref_table(tab);
+	return rc;
+}
+
+static void show_process(struct lsns *ls, struct libscols_table *tab,
+			 struct lsns_process *proc, struct lsns_namespace *ns)
+{
+	/*
+	 * create a tree from parent->child relation, but only if the parent is
+	 * within the same namespace
+	 */
+	if (ls->tree
+	    && proc->parent
+	    && !proc->parent->outline
+	    && proc->parent->ns_ids[ns->type] == proc->ns_ids[ns->type])
+		show_process(ls, tab, proc->parent, ns);
+
+	add_scols_line(ls, tab, ns, proc);
+}
+
+
+static int show_namespace_processes(struct lsns *ls, struct lsns_namespace *ns)
+{
+	struct libscols_table *tab;
+	struct list_head *p;
+
+	tab = init_scols_table(ls);
+	if (!tab)
+		return -ENOMEM;
+
+	list_for_each(p, &ns->processes) {
+		struct lsns_process *proc = list_entry(p, struct lsns_process, ns_siblings[ns->type]);
+
+		if (!proc->outline)
+			show_process(ls, tab, proc, ns);
+	}
+
+
+	scols_print_table(tab);
+	scols_unref_table(tab);
+	return 0;
+}
+
+static void __attribute__((__noreturn__)) usage(void)
+{
+	FILE *out = stdout;
+	size_t i;
+
+	fputs(USAGE_HEADER, out);
+
+	fprintf(out,
+		_(" %s [options] [<namespace>]\n"), program_invocation_short_name);
+
+	fputs(USAGE_SEPARATOR, out);
+	fputs(_("List system namespaces.\n"), out);
+
+	fputs(USAGE_OPTIONS, out);
+	fputs(_(" -J, --json             use JSON output format\n"), out);
+	fputs(_(" -l, --list             use list format output\n"), out);
+	fputs(_(" -n, --noheadings       don't print headings\n"), out);
+	fputs(_(" -o, --output <list>    define which output columns to use\n"), out);
+	fputs(_("     --output-all       output all columns\n"), out);
+	fputs(_(" -p, --task <pid>       print process namespaces\n"), out);
+	fputs(_(" -r, --raw              use the raw output format\n"), out);
+	fputs(_(" -u, --notruncate       don't truncate text in columns\n"), out);
+	fputs(_(" -W, --nowrap           don't use multi-line representation\n"), out);
+	fputs(_(" -t, --type <name>      namespace type (mnt, net, ipc, user, pid, uts, cgroup)\n"), out);
+
+	fputs(USAGE_SEPARATOR, out);
+	printf(USAGE_HELP_OPTIONS(24));
+
+	fputs(USAGE_COLUMNS, out);
+	for (i = 0; i < ARRAY_SIZE(infos); i++)
+		fprintf(out, " %11s  %s\n", infos[i].name, _(infos[i].help));
+
+	printf(USAGE_MAN_TAIL("lsns(8)"));
+
+	exit(EXIT_SUCCESS);
+}
+
+
+int main(int argc, char *argv[])
+{
+	struct lsns ls;
+	int c;
+	int r = 0;
+	char *outarg = NULL;
+	enum {
+		OPT_OUTPUT_ALL = CHAR_MAX + 1
+	};
+	static const struct option long_opts[] = {
+		{ "json",       no_argument,       NULL, 'J' },
+		{ "task",       required_argument, NULL, 'p' },
+		{ "help",	no_argument,       NULL, 'h' },
+		{ "output",     required_argument, NULL, 'o' },
+		{ "output-all", no_argument,       NULL, OPT_OUTPUT_ALL },
+		{ "notruncate", no_argument,       NULL, 'u' },
+		{ "version",    no_argument,       NULL, 'V' },
+		{ "noheadings", no_argument,       NULL, 'n' },
+		{ "nowrap",     no_argument,       NULL, 'W' },
+		{ "list",       no_argument,       NULL, 'l' },
+		{ "raw",        no_argument,       NULL, 'r' },
+		{ "type",       required_argument, NULL, 't' },
+		{ NULL, 0, NULL, 0 }
+	};
+
+	static const ul_excl_t excl[] = {	/* rows and cols in ASCII order */
+		{ 'J','r' },
+		{ 0 }
+	};
+	int excl_st[ARRAY_SIZE(excl)] = UL_EXCL_STATUS_INIT;
+	int is_net = 0;
+
+	setlocale(LC_ALL, "");
+	bindtextdomain(PACKAGE, LOCALEDIR);
+	textdomain(PACKAGE);
+	atexit(close_stdout);
+
+	lsns_init_debug();
+	memset(&ls, 0, sizeof(ls));
+
+	INIT_LIST_HEAD(&ls.processes);
+	INIT_LIST_HEAD(&ls.namespaces);
+	INIT_LIST_HEAD(&netnsids_cache);
+
+	while ((c = getopt_long(argc, argv,
+				"Jlp:o:nruhVt:W", long_opts, NULL)) != -1) {
+
+		err_exclusive_options(c, long_opts, excl, excl_st);
+
+		switch(c) {
+		case 'J':
+			ls.json = 1;
+			break;
+		case 'l':
+			ls.list = 1;
+			break;
+		case 'o':
+			outarg = optarg;
+			break;
+		case OPT_OUTPUT_ALL:
+			for (ncolumns = 0; ncolumns < ARRAY_SIZE(infos); ncolumns++)
+				columns[ncolumns] = ncolumns;
+			break;
+		case 'V':
+			printf(UTIL_LINUX_VERSION);
+			return EXIT_SUCCESS;
+		case 'p':
+			ls.fltr_pid = strtos32_or_err(optarg, _("invalid PID argument"));
+			break;
+		case 'h':
+			usage();
+		case 'n':
+			ls.no_headings = 1;
+			break;
+		case 'r':
+			ls.no_wrap = ls.raw = 1;
+			break;
+		case 'u':
+			ls.no_trunc = 1;
+			break;
+		case 't':
+		{
+			int type = ns_name2type(optarg);
+			if (type < 0)
+				errx(EXIT_FAILURE, _("unknown namespace type: %s"), optarg);
+			ls.fltr_types[type] = 1;
+			ls.fltr_ntypes++;
+			if (type == LSNS_ID_NET)
+				is_net = 1;
+			break;
+		}
+		case 'W':
+			ls.no_wrap = 1;
+			break;
+		default:
+			errtryhelp(EXIT_FAILURE);
+		}
+	}
+
+	if (!ls.fltr_ntypes) {
+		size_t i;
+
+		for (i = 0; i < ARRAY_SIZE(ns_names); i++)
+			ls.fltr_types[i] = 1;
+	}
+
+	if (optind < argc) {
+		if (ls.fltr_pid)
+			errx(EXIT_FAILURE, _("--task is mutually exclusive with <namespace>"));
+		ls.fltr_ns = strtou64_or_err(argv[optind], _("invalid namespace argument"));
+		ls.tree = ls.list ? 0 : 1;
+
+		if (!ncolumns) {
+			columns[ncolumns++] = COL_PID;
+			columns[ncolumns++] = COL_PPID;
+			columns[ncolumns++] = COL_USER;
+			columns[ncolumns++] = COL_COMMAND;
+		}
+	}
+
+	if (!ncolumns) {
+		columns[ncolumns++] = COL_NS;
+		columns[ncolumns++] = COL_TYPE;
+		columns[ncolumns++] = COL_NPROCS;
+		columns[ncolumns++] = COL_PID;
+		columns[ncolumns++] = COL_USER;
+		if (is_net) {
+			columns[ncolumns++] = COL_NETNSID;
+			columns[ncolumns++] = COL_NSFS;
+		}
+		columns[ncolumns++] = COL_COMMAND;
+	}
+
+	if (outarg && string_add_to_idarray(outarg, columns, ARRAY_SIZE(columns),
+				  &ncolumns, column_name_to_id) < 0)
+		return EXIT_FAILURE;
+
+	scols_init_debug(0);
+
+	uid_cache = new_idcache();
+	if (!uid_cache)
+		err(EXIT_FAILURE, _("failed to allocate UID cache"));
+
+#ifdef HAVE_LINUX_NET_NAMESPACE_H
+	if (has_column(COL_NETNSID))
+		netlink_fd = socket(AF_NETLINK, SOCK_RAW, NETLINK_ROUTE);
+#endif
+	if (has_column(COL_NSFS)) {
+		ls.tab = mnt_new_table_from_file(_PATH_PROC_MOUNTINFO);
+		if (!ls.tab)
+			err(MNT_EX_FAIL, _("failed to parse %s"), _PATH_PROC_MOUNTINFO);
+	}
+
+	r = read_processes(&ls);
+	if (!r)
+		r = read_namespaces(&ls);
+	if (!r) {
+		if (ls.fltr_ns) {
+			struct lsns_namespace *ns = get_namespace(&ls, ls.fltr_ns);
+
+			if (!ns)
+				errx(EXIT_FAILURE, _("not found namespace: %ju"), (uintmax_t) ls.fltr_ns);
+			r = show_namespace_processes(&ls, ns);
+		} else
+			r = show_namespaces(&ls);
+	}
+
+	mnt_free_table(ls.tab);
+	if (netlink_fd >= 0)
+		close(netlink_fd);
+	free_idcache(uid_cache);
+	return r == 0 ? EXIT_SUCCESS : EXIT_FAILURE;
+}