-/*-*- Mode: C; c-basic-offset: 8; indent-tabs-mode: nil -*-*/
-
+/* SPDX-License-Identifier: LGPL-2.1+ */
/***
This file is part of systemd.
along with systemd; If not, see <http://www.gnu.org/licenses/>.
***/
-#include <unistd.h>
#include <fcntl.h>
+#include <unistd.h>
#include "bus-container.h"
#include "bus-internal.h"
return bus_socket_start_auth(b);
}
-
-int bus_container_connect_kernel(sd_bus *b) {
- _cleanup_close_pair_ int pair[2] = { -1, -1 };
- _cleanup_close_ int pidnsfd = -1, mntnsfd = -1, usernsfd = -1, rootfd = -1;
- union {
- struct cmsghdr cmsghdr;
- uint8_t buf[CMSG_SPACE(sizeof(int))];
- } control = {};
- int error_buf = 0;
- struct iovec iov = {
- .iov_base = &error_buf,
- .iov_len = sizeof(error_buf),
- };
- struct msghdr mh = {
- .msg_control = &control,
- .msg_controllen = sizeof(control),
- .msg_iov = &iov,
- .msg_iovlen = 1,
- };
- struct cmsghdr *cmsg;
- pid_t child;
- siginfo_t si;
- int r, fd = -1;
- ssize_t n;
-
- assert(b);
- assert(b->input_fd < 0);
- assert(b->output_fd < 0);
- assert(b->nspid > 0 || b->machine);
-
- if (b->nspid <= 0) {
- r = container_get_leader(b->machine, &b->nspid);
- if (r < 0)
- return r;
- }
-
- r = namespace_open(b->nspid, &pidnsfd, &mntnsfd, NULL, &usernsfd, &rootfd);
- if (r < 0)
- return r;
-
- if (socketpair(AF_UNIX, SOCK_SEQPACKET, 0, pair) < 0)
- return -errno;
-
- child = fork();
- if (child < 0)
- return -errno;
-
- if (child == 0) {
- pid_t grandchild;
-
- pair[0] = safe_close(pair[0]);
-
- r = namespace_enter(pidnsfd, mntnsfd, -1, usernsfd, rootfd);
- if (r < 0)
- _exit(EXIT_FAILURE);
-
- /* We just changed PID namespace, however it will only
- * take effect on the children we now fork. Hence,
- * let's fork another time, and connect from this
- * grandchild, so that kdbus only sees the credentials
- * of this process which comes from within the
- * container, and not outside of it */
-
- grandchild = fork();
- if (grandchild < 0)
- _exit(EXIT_FAILURE);
-
- if (grandchild == 0) {
- fd = open(b->kernel, O_RDWR|O_NOCTTY|O_CLOEXEC);
- if (fd < 0) {
- /* Try to send error up */
- error_buf = errno;
- (void) write(pair[1], &error_buf, sizeof(error_buf));
- _exit(EXIT_FAILURE);
- }
-
- r = send_one_fd(pair[1], fd, 0);
- if (r < 0)
- _exit(EXIT_FAILURE);
-
- _exit(EXIT_SUCCESS);
- }
-
- r = wait_for_terminate(grandchild, &si);
- if (r < 0)
- _exit(EXIT_FAILURE);
-
- if (si.si_code != CLD_EXITED)
- _exit(EXIT_FAILURE);
-
- _exit(si.si_status);
- }
-
- pair[1] = safe_close(pair[1]);
-
- r = wait_for_terminate(child, &si);
- if (r < 0)
- return r;
-
- n = recvmsg(pair[0], &mh, MSG_NOSIGNAL|MSG_CMSG_CLOEXEC);
- if (n < 0)
- return -errno;
-
- CMSG_FOREACH(cmsg, &mh) {
- if (cmsg->cmsg_level == SOL_SOCKET && cmsg->cmsg_type == SCM_RIGHTS) {
- int *fds;
- unsigned n_fds;
-
- assert(fd < 0);
-
- fds = (int*) CMSG_DATA(cmsg);
- n_fds = (cmsg->cmsg_len - CMSG_LEN(0)) / sizeof(int);
-
- if (n_fds != 1) {
- close_many(fds, n_fds);
- return -EIO;
- }
-
- fd = fds[0];
- }
- }
-
- /* If there's an fd passed, we are good. */
- if (fd >= 0) {
- b->input_fd = b->output_fd = fd;
- return bus_kernel_take_fd(b);
- }
-
- /* If there's an error passed, use it */
- if (n == sizeof(error_buf) && error_buf > 0)
- return -error_buf;
-
- /* Otherwise, we have no clue */
- return -EIO;
-}