Systemd/src/libsystemd-bus/bus-container.c
Lennart Poettering b6741478e7 journal: add ability to browse journals of running OS containers
This adds the new library call sd_journal_open_container() and a new
"-M" switch to journalctl. Particular care is taken that journalctl's
"-b" switch resolves to the current boot ID of the container, not the
host.
2013-12-11 22:04:03 +01:00

128 lines
3.4 KiB
C

/*-*- Mode: C; c-basic-offset: 8; indent-tabs-mode: nil -*-*/
/***
This file is part of systemd.
Copyright 2013 Lennart Poettering
systemd 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; either version 2.1 of the License, or
(at your option) any later version.
systemd 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 systemd; If not, see <http://www.gnu.org/licenses/>.
***/
#include <unistd.h>
#include <fcntl.h>
#include "util.h"
#include "fileio.h"
#include "bus-internal.h"
#include "bus-socket.h"
#include "bus-container.h"
int bus_container_connect(sd_bus *b) {
_cleanup_free_ char *s = NULL, *ns = NULL, *root = NULL, *class = NULL;
_cleanup_close_ int nsfd = -1, rootfd = -1;
char *p;
siginfo_t si;
pid_t leader, child;
int r;
assert(b);
assert(b->input_fd < 0);
assert(b->output_fd < 0);
p = strappenda("/run/systemd/machines/", b->machine);
r = parse_env_file(p, NEWLINE, "LEADER", &s, "CLASS", &class, NULL);
if (r == -ENOENT)
return -EHOSTDOWN;
if (r < 0)
return r;
if (!s)
return -EIO;
if (!streq_ptr(class, "container"))
return -EIO;
r = parse_pid(s, &leader);
if (r < 0)
return r;
if (leader <= 1)
return -EIO;
r = asprintf(&ns, "/proc/%lu/ns/mnt", (unsigned long) leader);
if (r < 0)
return -ENOMEM;
nsfd = open(ns, O_RDONLY|O_NOCTTY|O_CLOEXEC);
if (nsfd < 0)
return -errno;
r = asprintf(&root, "/proc/%lu/root", (unsigned long) leader);
if (r < 0)
return -ENOMEM;
rootfd = open(root, O_RDONLY|O_NOCTTY|O_CLOEXEC|O_DIRECTORY);
if (rootfd < 0)
return -errno;
b->input_fd = socket(b->sockaddr.sa.sa_family, SOCK_STREAM|SOCK_CLOEXEC|SOCK_NONBLOCK, 0);
if (b->input_fd < 0)
return -errno;
b->output_fd = b->input_fd;
r = bus_socket_setup(b);
if (r < 0)
return r;
child = fork();
if (child < 0)
return -errno;
if (child == 0) {
r = setns(nsfd, CLONE_NEWNS);
if (r < 0)
_exit(255);
if (fchdir(rootfd) < 0)
_exit(255);
if (chroot(".") < 0)
_exit(255);
r = connect(b->input_fd, &b->sockaddr.sa, b->sockaddr_size);
if (r < 0) {
if (errno == EINPROGRESS)
_exit(1);
_exit(255);
}
_exit(0);
}
r = wait_for_terminate(child, &si);
if (r < 0)
return r;
if (si.si_code != CLD_EXITED)
return -EIO;
if (si.si_status == 1)
return 1;
if (si.si_status != 0)
return -EIO;
return bus_socket_start_auth(b);
}