| /* |
| * Copyright (C) 2014-2017, Travelping GmbH <info@travelping.com> |
| * |
| * This program is free software: you can redistribute it and/or modify |
| * it under the terms of the GNU Affero General Public License as |
| * published by the Free Software Foundation, either version 3 of the |
| * License, or (at your option) any later version. |
| * |
| * This program 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 Affero General Public License for more details. |
| * |
| * You should have received a copy of the GNU Affero General Public License |
| * along with this program. If not, see <http://www.gnu.org/licenses/>. |
| * |
| */ |
| |
| #if defined(__linux__) |
| |
| #ifdef HAVE_CONFIG_H |
| # include "config.h" |
| #endif |
| |
| #ifndef _GNU_SOURCE |
| # define _GNU_SOURCE |
| #endif |
| |
| #include <errno.h> |
| #include <stdio.h> |
| #include <stdlib.h> |
| #include <unistd.h> |
| #include <sched.h> |
| #include <signal.h> |
| #include <sys/types.h> |
| #include <sys/stat.h> |
| #include <sys/socket.h> |
| #include <sys/mount.h> |
| #include <sys/param.h> |
| #include <fcntl.h> |
| #include <errno.h> |
| |
| #include "netns.h" |
| |
| #define NETNS_PATH "/var/run/netns" |
| |
| static int default_nsfd; |
| |
| int switch_ns(int nsfd, sigset_t *oldmask) |
| { |
| sigset_t intmask; |
| |
| sigfillset(&intmask); |
| sigprocmask(SIG_BLOCK, &intmask, oldmask); |
| |
| return setns(nsfd, CLONE_NEWNET); |
| } |
| |
| void restore_ns(sigset_t *oldmask) |
| { |
| setns(default_nsfd, CLONE_NEWNET); |
| |
| sigprocmask(SIG_SETMASK, oldmask, NULL); |
| } |
| |
| int open_ns(int nsfd, const char *pathname, int flags) |
| { |
| sigset_t intmask, oldmask; |
| int fd; |
| int errsv; |
| |
| sigfillset(&intmask); |
| sigprocmask(SIG_BLOCK, &intmask, &oldmask); |
| |
| setns(nsfd, CLONE_NEWNET); |
| fd = open(pathname, flags); |
| errsv = errno; |
| setns(default_nsfd, CLONE_NEWNET); |
| |
| sigprocmask(SIG_SETMASK, &oldmask, NULL); |
| |
| errno = errsv; |
| return fd; |
| } |
| |
| int socket_ns(int nsfd, int domain, int type, int protocol) |
| { |
| sigset_t intmask, oldmask; |
| int sk; |
| int errsv; |
| |
| sigfillset(&intmask); |
| sigprocmask(SIG_BLOCK, &intmask, &oldmask); |
| |
| setns(nsfd, CLONE_NEWNET); |
| sk = socket(domain, type, protocol); |
| errsv = errno; |
| setns(default_nsfd, CLONE_NEWNET); |
| |
| sigprocmask(SIG_SETMASK, &oldmask, NULL); |
| |
| errno = errsv; |
| return sk; |
| } |
| |
| void init_netns() |
| { |
| if ((default_nsfd = open("/proc/self/ns/net", O_RDONLY)) < 0) { |
| perror("init_netns"); |
| exit(EXIT_FAILURE); |
| } |
| } |
| |
| int get_nsfd(const char *name) |
| { |
| int r; |
| sigset_t intmask, oldmask; |
| char path[MAXPATHLEN] = NETNS_PATH; |
| |
| r = mkdir(path, S_IRWXU|S_IRGRP|S_IXGRP|S_IROTH|S_IXOTH); |
| if (r < 0 && errno != EEXIST) |
| return r; |
| |
| snprintf(path, sizeof(path), "%s/%s", NETNS_PATH, name); |
| r = open(path, O_RDONLY|O_CREAT|O_EXCL, 0); |
| if (r < 0) { |
| if (errno == EEXIST) |
| return open(path, O_RDONLY); |
| |
| return r; |
| } |
| close(r); |
| |
| sigfillset(&intmask); |
| sigprocmask(SIG_BLOCK, &intmask, &oldmask); |
| |
| unshare(CLONE_NEWNET); |
| mount("/proc/self/ns/net", path, "none", MS_BIND, NULL); |
| |
| setns(default_nsfd, CLONE_NEWNET); |
| |
| sigprocmask(SIG_SETMASK, &oldmask, NULL); |
| |
| return open(path, O_RDONLY); |
| } |
| |
| #endif |