From 8a2045620e13d66ba8f271dc8378f7bd0830aaae Mon Sep 17 00:00:00 2001 From: Karel Zak Date: Thu, 26 Nov 2015 14:09:45 +0100 Subject: lsns: new command Signed-off-by: Karel Zak --- sys-utils/lsns.c | 572 +++++++++++++++++++++++++++++++++++++++++++++++++++++++ 1 file changed, 572 insertions(+) create mode 100644 sys-utils/lsns.c (limited to 'sys-utils/lsns.c') diff --git a/sys-utils/lsns.c b/sys-utils/lsns.c new file mode 100644 index 000000000..6bc651292 --- /dev/null +++ b/sys-utils/lsns.c @@ -0,0 +1,572 @@ +/* + * lsns(8) - list system namespaces + * + * Copyright (C) 2015 Karel Zak + * + * 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 +#include +#include +#include +#include +#include +#include +#include +#include + +#include + +#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 print process namespace\n"), out); + fputs(_(" -n, --noheadings don't print headings\n"), out); + fputs(_(" -o, --output 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; +} -- cgit v1.2.3-55-g7522