+/*
+ * Copyright (C) 2019 Michael Jeanson <mjeanson@efficios.com>
+ *
+ * This library is free software; you can redistribute it and/or modify it
+ * under the terms of the GNU Lesser General Public License as published by the
+ * Free Software Foundation; version 2.1 of the License.
+ *
+ * This library is distributed in the hope that it will be useful, but WITHOUT
+ * ANY WARRANTY; without even the implied warranty of MERCHANTABILITY or
+ * FITNESS FOR A PARTICULAR PURPOSE. See the GNU Lesser General Public License
+ * for more details.
+ *
+ * You should have received a copy of the GNU Lesser General Public License
+ * along with this library; if not, write to the Free Software Foundation,
+ * Inc., 51 Franklin Street, Fifth Floor, Boston, MA 02110-1301 USA
+ */
+
+#ifndef _GNU_SOURCE
+#define _GNU_SOURCE
+#endif
+
+#include <popt.h>
+#include <sched.h>
+#include <stdarg.h>
+#include <stdio.h>
+#include <stdlib.h>
+#include <string.h>
+#include <sys/stat.h>
+#include <sys/types.h>
+#include <unistd.h>
+
+#include <common/compat/tid.h>
+
+#include "signal-helper.h"
+#include "utils.h"
+
+#define LTTNG_PROC_NS_PATH_MAX 40
+
+static int debug = 0;
+static char *ns_opt = NULL;
+static char *before_unshare_wait_file_path = NULL;
+static char *after_unshare_wait_file_path = NULL;
+static char *after_unshare_signal_file_path = NULL;
+
+static struct poptOption opts[] = {
+ /* longName, shortName, argInfo, argPtr, value, descrip, argDesc */
+ { "debug", 'd', POPT_ARG_NONE, &debug, 0, "Enable debug output", NULL },
+ { "ns", 'n', POPT_ARG_STRING, &ns_opt, 0, "Namespace short identifier", NULL },
+ { "before", 'b', POPT_ARG_STRING, &before_unshare_wait_file_path, 0, "Wait for file before unshare", NULL },
+ { "after", 'a', POPT_ARG_STRING, &after_unshare_wait_file_path, 0, "Wait for file after unshare", NULL },
+ { "signal", 's', POPT_ARG_STRING, &after_unshare_signal_file_path, 0, "Create signal file after unshare", NULL },
+ POPT_AUTOHELP
+ { NULL, 0, 0, NULL, 0 }
+};
+
+static void debug_printf(const char *format, ...)
+{
+ va_list args;
+ va_start(args, format);
+
+ if (debug) {
+ vfprintf(stderr, format, args);
+ }
+
+ va_end(args);
+}
+
+static int get_ns_inum(const char *ns, ino_t *ns_inum)
+{
+ int ret = 0;
+ struct stat sb;
+ char proc_ns_path[LTTNG_PROC_NS_PATH_MAX];
+
+ /*
+ * /proc/thread-self was introduced in kernel v3.17
+ */
+ if (snprintf(proc_ns_path, LTTNG_PROC_NS_PATH_MAX,
+ "/proc/thread-self/ns/%s", ns) >= 0) {
+ if (stat(proc_ns_path, &sb) == 0) {
+ *ns_inum = sb.st_ino;
+ } else {
+ ret = -1;
+ }
+ goto end;
+ }
+
+ if (snprintf(proc_ns_path, LTTNG_PROC_NS_PATH_MAX,
+ "/proc/self/task/%d/%s/net", lttng_gettid(), ns) >= 0) {
+ if (stat(proc_ns_path, &sb) == 0) {
+ *ns_inum = sb.st_ino;
+ } else {
+ ret = -1;
+ }
+ goto end;
+ }
+end:
+ return ret;
+}
+
+static int do_the_needful(int ns_flag, const char *ns_str)
+{
+ int ret = 0;
+ ino_t ns1, ns2;
+
+ ret = get_ns_inum(ns_str, &ns1);
+ if (ret) {
+ debug_printf("Failed to get ns inode number for namespace %s",
+ ns_str);
+ ret = -1;
+ goto end;
+ }
+ debug_printf("Initial %s ns inode number: %lu\n", ns_str, ns1);
+
+ /* Wait on synchronization before unshare. */
+ if (before_unshare_wait_file_path) {
+ ret = wait_on_file(before_unshare_wait_file_path);
+ if (ret != 0) {
+ goto end;
+ }
+ }
+
+ ret = unshare(ns_flag);
+ if (ret == -1) {
+ perror("Failed to unshare namespace");
+ goto end;
+ }
+
+ ret = get_ns_inum(ns_str, &ns2);
+ if (ret) {
+ debug_printf("Failed to get ns inode number for namespace %s",
+ ns_str);
+ ret = -1;
+ goto end;
+ }
+ debug_printf("Post unshare %s ns inode number: %lu\n", ns_str, ns2);
+
+ /* Signal that the unshare call is completed. */
+ if (after_unshare_signal_file_path) {
+ ret = create_file(after_unshare_signal_file_path);
+ if (ret != 0) {
+ goto end;
+ }
+ }
+
+ /* Wait on synchronization after unshare. */
+ if (after_unshare_wait_file_path) {
+ ret = wait_on_file(after_unshare_wait_file_path);
+ if (ret != 0) {
+ goto end;
+ }
+ }
+
+end:
+ return ret;
+}
+
+int main(int argc, const char **argv)
+{
+ int opt;
+ int ret = EXIT_SUCCESS;
+ poptContext pc;
+
+ pc = poptGetContext(NULL, argc, argv, opts, 0);
+ poptReadDefaultConfig(pc, 0);
+
+ if (argc < 2) {
+ poptPrintHelp(pc, stderr, 0);
+ ret = EXIT_FAILURE;
+ goto end;
+ }
+
+ while ((opt = poptGetNextOpt(pc)) >= 0) {
+ switch (opt) {
+ default:
+ poptPrintUsage(pc, stderr, 0);
+ ret = EXIT_FAILURE;
+ goto end;
+ }
+ }
+
+ if (opt < -1) {
+ /* an error occurred during option processing */
+ poptPrintUsage(pc, stderr, 0);
+ fprintf(stderr, "%s: %s\n",
+ poptBadOption(pc, POPT_BADOPTION_NOALIAS),
+ poptStrerror(opt));
+ ret = EXIT_FAILURE;
+ goto end;
+ }
+
+ if (ns_opt == NULL) {
+ poptPrintUsage(pc, stderr, 0);
+ ret = EXIT_FAILURE;
+ goto end;
+ }
+
+ if (set_signal_handler()) {
+ ret = EXIT_FAILURE;
+ goto end;
+ }
+
+ if (strncmp(ns_opt, "cgroup", 3) == 0) {
+ ret = do_the_needful(CLONE_NEWCGROUP, "cgroup");
+ } else if (strncmp(ns_opt, "ipc", 3) == 0) {
+ ret = do_the_needful(CLONE_NEWIPC, "ipc");
+ } else if (strncmp(ns_opt, "mnt", 3) == 0) {
+ ret = do_the_needful(CLONE_NEWNS, "mnt");
+ } else if (strncmp(ns_opt, "net", 3) == 0) {
+ ret = do_the_needful(CLONE_NEWNET, "net");
+ } else if (strncmp(ns_opt, "pid", 3) == 0) {
+ ret = do_the_needful(CLONE_NEWPID, "pid");
+ } else if (strncmp(ns_opt, "user", 3) == 0) {
+ /*
+ * Will always fail, requires a single threaded application,
+ * which can't happen with UST.
+ */
+ ret = do_the_needful(CLONE_NEWUSER, "user");
+ } else if (strncmp(ns_opt, "uts", 3) == 0) {
+ ret = do_the_needful(CLONE_NEWUTS, "uts");
+ } else {
+ printf("invalid ns id\n");
+ ret = EXIT_FAILURE;
+ goto end;
+ }
+ ret = ret ? EXIT_FAILURE : EXIT_SUCCESS;
+end:
+ poptFreeContext(pc);
+ return ret;
+}
projects / lttng-tools.git / commitdiff
