lsns: new command

Signed-off-by: Karel Zak <kzak@redhat.com>
pull/238/head
Karel Zak 7 years ago
parent 0e756daeb6
commit 8a2045620e
  1. 5
      configure.ac
  2. 9
      sys-utils/Makemodule.am
  3. 572
      sys-utils/lsns.c

@ -1405,6 +1405,11 @@ UL_REQUIRES_LINUX([lsipc])
UL_REQUIRES_BUILD([lsipc], [libsmartcols])
AM_CONDITIONAL([BUILD_LSIPC], [test "x$build_lsipc" = xyes])
UL_BUILD_INIT([lsns], [check])
UL_REQUIRES_LINUX([lsns])
UL_REQUIRES_BUILD([lsns], [libsmartcols])
AM_CONDITIONAL([BUILD_LSNS], [test "x$build_lsns" = xyes])
UL_BUILD_INIT([renice], [yes])
AM_CONDITIONAL([BUILD_RENICE], [test "x$build_renice" = xyes])

@ -226,6 +226,15 @@ prlimit_CFLAGS = $(AM_CFLAGS) -I$(ul_libsmartcols_incdir)
endif
if BUILD_LSNS
usrbin_exec_PROGRAMS += lsns
#dist_man_MANS += sys-utils/lsns.1
lsns_SOURCES = sys-utils/lsns.c
lsns_LDADD = $(LDADD) libcommon.la libsmartcols.la
lsns_CFLAGS = $(AM_CFLAGS) -I$(ul_libsmartcols_incdir)
endif
if BUILD_MOUNT
#
# The original mount is in mount/ directory

@ -0,0 +1,572 @@
/*
* 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 <libsmartcols.h>
#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 "path.h"
#include "debug.h"
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 DBG(m, x) __UL_DBG(lsns, LSNS_DEBUG_, m, x)
#define ON_DBG(m, x) __UL_DBG_CALL(lsns, LSNS_DEBUG_, m, x)
/* column IDs */
enum {
COL_NS = 0,
COL_TYPE,
COL_PATH,
COL_NPROCS,
COL_PID,
COL_COMMAND
};
/* 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;
};
/* columns descriptions */
static struct colinfo infos[] = {
[COL_NS] = { "NS", 10, SCOLS_FL_RIGHT, N_("command of the process holding the lock") },
[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") },
[COL_PID] = { "PID", 5, SCOLS_FL_RIGHT, N_("lowers PID in the namespace") },
[COL_COMMAND] = { "COMMAND", 0, SCOLS_FL_TRUNC, N_("command line of the PID")}
};
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
};
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"
};
struct lsns_namespace {
ino_t id;
int type; /* LSNS_* */
int nprocs;
pid_t pid;
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;
ino_t ns_ids[ARRAY_SIZE(ns_names)];
struct list_head ns_siblings[ARRAY_SIZE(ns_names)];
struct list_head branch; /* head of children list */
struct list_head children; /* list of children */
struct list_head processes; /* list of processes */
};
struct lsns {
struct list_head processes;
struct list_head namespaces;
pid_t pid;
unsigned int raw : 1,
json : 1,
no_headings: 1;
};
static void lsns_init_debug(void)
{
__UL_INIT_DEBUG(lsns, LSNS_DEBUG_, 0, LSNS_DEBUG);
}
static void disable_columns_truncate(void)
{
size_t i;
for (i = 0; i < ARRAY_SIZE(infos); i++)
infos[i].flags &= ~SCOLS_FL_TRUNC;
}
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 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 struct colinfo *get_column_info(unsigned num)
{
return &infos[ get_column_id(num) ];
}
static ino_t 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 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;
DBG(PROC, ul_debug("reading %d", (int) pid));
snprintf(buf, sizeof(buf), "/proc/%d", pid);
dir = opendir(buf);
if (!dir)
return -errno;
p = calloc(1, sizeof(*p));
if (!p) {
rc = -ENOMEM;
goto done;
}
fd = openat(dirfd(dir), "stat", O_RDONLY);
if (fd < 0) {
rc = -errno;
goto done;
}
if (!(f = fdopen(fd, "r"))) {
rc = -errno;
goto done;
}
rc = fscanf(f, "%d %*s %c %d*[^\n]", &p->pid, &p->state, &p->ppid);
if (rc != 3) {
rc = -errno;
goto done;
}
rc = 0;
for (i = 0; i < ARRAY_SIZE(p->ns_ids); i++) {
INIT_LIST_HEAD(&p->ns_siblings[i]);
rc = get_ns_ino(dirfd(dir), ns_names[i], &p->ns_ids[i]);
if (rc && rc != -EACCES)
goto done;
rc = 0;
}
INIT_LIST_HEAD(&p->processes);
INIT_LIST_HEAD(&p->branch);
INIT_LIST_HEAD(&p->children);
DBG(PROC, ul_debug("add %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;
if (ls->pid) {
rc = read_process(ls, ls->pid);
goto done;
}
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)
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, int type, 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 && ns->type == type)
return ns;
}
return NULL;
}
static struct lsns_namespace *add_namespace(struct lsns *ls, int type, ino_t ino)
{
struct lsns_namespace *ns = calloc(1, sizeof(*ns));
if (!ns)
return NULL;
DBG(NS, ul_debug("add %s[%lu]", ns_names[type], 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_namespace *ns, struct lsns_process *proc)
{
DBG(NS, ul_debug("add process %d to %s[%lu]", proc->pid, ns_names[ns->type], ns->id));
list_add_tail(&proc->ns_siblings[ns->type], &ns->processes);
ns->nprocs++;
if (ns->pid == 0 || ns->pid > proc->pid)
ns->pid = proc->pid;
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, i, proc->ns_ids[i]))) {
ns = add_namespace(ls, i, proc->ns_ids[i]);
if (!ns)
return -ENOMEM;
}
add_process_to_namespace(ns, proc);
}
}
return 0;
}
static void add_scols_line(struct libscols_table *table, struct lsns_namespace *ns)
{
size_t i;
struct libscols_line *line;
assert(ns);
assert(table);
line = scols_table_new_line(table, 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, "%lu", ns->id);
break;
case COL_PID:
xasprintf(&str, "%d", (int) ns->pid);
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(ns->pid);
if (!str)
str = proc_get_command_name(ns->pid);
break;
case COL_PATH:
break;
default:
break;
}
if (str)
scols_line_set_data(line, i, str);
}
}
static int show_namespaces(struct lsns *ls)
{
struct libscols_table *tab;
struct list_head *p;
size_t i;
int rc = 0;
tab = scols_new_table();
if (!tab) {
warn(_("failed to initialize output table"));
return -ENOMEM;
}
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++) {
struct colinfo *col = get_column_info(i);
if (!scols_table_new_column(tab, col->name, col->whint, col->flags)) {
warnx(_("failed to initialize output column"));
rc = -errno;
goto done;
}
}
list_for_each(p, &ls->namespaces) {
struct lsns_namespace *ns = list_entry(p, struct lsns_namespace, namespaces);
add_scols_line(tab, ns);
}
scols_print_table(tab);
done:
scols_unref_table(tab);
return rc;
}
static void __attribute__ ((__noreturn__)) usage(FILE * out)
{
size_t i;
fputs(USAGE_HEADER, out);
fprintf(out,
_(" %s [options]\n"), program_invocation_short_name);
fputs(USAGE_SEPARATOR, out);
fputs(_("List local system locks.\n"), out);
fputs(USAGE_OPTIONS, out);
fputs(_(" -J, --json use JSON output format\n"), out);
fputs(_(" -p, --task <pid> print process namespace\n"), out);
fputs(_(" -n, --noheadings don't print headings\n"), out);
fputs(_(" -o, --output <list> define which output columns to use\n"), out);
fputs(_(" -r, --raw use the raw output format\n"), out);
fputs(_(" -u, --notruncate don't truncate text in columns\n"), out);
fputs(USAGE_SEPARATOR, out);
fputs(USAGE_HELP, out);
fputs(USAGE_VERSION, out);
fputs(_("\nAvailable columns (for --output):\n"), out);
for (i = 0; i < ARRAY_SIZE(infos); i++)
fprintf(out, " %11s %s\n", infos[i].name, _(infos[i].help));
fprintf(out, USAGE_MAN_TAIL("lslocks(8)"));
exit(out == stderr ? EXIT_FAILURE : EXIT_SUCCESS);
}
int main(int argc, char *argv[])
{
struct lsns ls;
int c;
int r = 0;
char *outarg = NULL;
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' },
{ "notruncate", no_argument, NULL, 'u' },
{ "version", no_argument, NULL, 'V' },
{ "noheadings", no_argument, NULL, 'n' },
{ "raw", no_argument, NULL, 'r' },
{ 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;
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);
while ((c = getopt_long(argc, argv,
"Jp:o:nruhV", long_opts, NULL)) != -1) {
err_exclusive_options(c, long_opts, excl, excl_st);
switch(c) {
case 'J':
ls.json = 1;
break;
case 'o':
outarg = optarg;
break;
case 'V':
printf(UTIL_LINUX_VERSION);
return EXIT_SUCCESS;
case 'p':
ls.pid = strtos32_or_err(optarg, _("invalid PID argument"));
break;
case 'h':
usage(stdout);
case 'n':
ls.no_headings = 1;
break;
case 'r':
ls.raw = 1;
break;
case 'u':
disable_columns_truncate();
break;
case '?':
default:
usage(stderr);
}
}
if (!ncolumns) {
/* default columns */
columns[ncolumns++] = COL_NS;
columns[ncolumns++] = COL_TYPE;
columns[ncolumns++] = COL_NPROCS;
columns[ncolumns++] = COL_PID;
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);
r = read_processes(&ls);
if (!r)
r = read_namespaces(&ls);
if (!r)
r = show_namespaces(&ls);
return r == 0 ? EXIT_SUCCESS : EXIT_FAILURE;
}
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