1 /* SPDX-License-Identifier: LGPL-2.1-or-later */
2
3 #include <fcntl.h>
4 #include <unistd.h>
5
6 #include "bus-container.h"
7 #include "bus-internal.h"
8 #include "bus-socket.h"
9 #include "fd-util.h"
10 #include "namespace-util.h"
11 #include "process-util.h"
12 #include "string-util.h"
13 #include "util.h"
14
bus_container_connect_socket(sd_bus * b)15 int bus_container_connect_socket(sd_bus *b) {
16 _cleanup_close_pair_ int pair[2] = { -1, -1 };
17 _cleanup_close_ int pidnsfd = -1, mntnsfd = -1, usernsfd = -1, rootfd = -1;
18 int r, error_buf = 0;
19 pid_t child;
20 ssize_t n;
21
22 assert(b);
23 assert(b->input_fd < 0);
24 assert(b->output_fd < 0);
25 assert(b->nspid > 0 || b->machine);
26
27 if (b->nspid <= 0) {
28 log_debug("sd-bus: connecting bus%s%s to machine %s...",
29 b->description ? " " : "", strempty(b->description), b->machine);
30
31 r = container_get_leader(b->machine, &b->nspid);
32 if (r < 0)
33 return r;
34 } else
35 log_debug("sd-bus: connecting bus%s%s to namespace of PID "PID_FMT"...",
36 b->description ? " " : "", strempty(b->description), b->nspid);
37
38 r = namespace_open(b->nspid, &pidnsfd, &mntnsfd, NULL, &usernsfd, &rootfd);
39 if (r < 0)
40 return log_debug_errno(r, "Failed to open namespace of PID "PID_FMT": %m", b->nspid);
41
42 b->input_fd = socket(b->sockaddr.sa.sa_family, SOCK_STREAM|SOCK_CLOEXEC|SOCK_NONBLOCK, 0);
43 if (b->input_fd < 0)
44 return log_debug_errno(errno, "Failed to create a socket: %m");
45
46 b->input_fd = fd_move_above_stdio(b->input_fd);
47
48 b->output_fd = b->input_fd;
49
50 bus_socket_setup(b);
51
52 if (socketpair(AF_UNIX, SOCK_SEQPACKET|SOCK_CLOEXEC, 0, pair) < 0)
53 return log_debug_errno(errno, "Failed to create a socket pair: %m");
54
55 r = namespace_fork("(sd-buscntrns)", "(sd-buscntr)", NULL, 0, FORK_RESET_SIGNALS|FORK_DEATHSIG,
56 pidnsfd, mntnsfd, -1, usernsfd, rootfd, &child);
57 if (r < 0)
58 return log_debug_errno(r, "Failed to create namespace for (sd-buscntr): %m");
59 if (r == 0) {
60 pair[0] = safe_close(pair[0]);
61
62 r = connect(b->input_fd, &b->sockaddr.sa, b->sockaddr_size);
63 if (r < 0) {
64 /* Try to send error up */
65 error_buf = errno;
66 (void) write(pair[1], &error_buf, sizeof(error_buf));
67 _exit(EXIT_FAILURE);
68 }
69
70 _exit(EXIT_SUCCESS);
71 }
72
73 pair[1] = safe_close(pair[1]);
74
75 r = wait_for_terminate_and_check("(sd-buscntrns)", child, 0);
76 if (r < 0)
77 return r;
78 bool nonzero_exit_status = r != EXIT_SUCCESS;
79
80 n = read(pair[0], &error_buf, sizeof(error_buf));
81 if (n < 0)
82 return log_debug_errno(errno, "Failed to read error status from (sd-buscntr): %m");
83
84 if (n > 0) {
85 if (n != sizeof(error_buf))
86 return log_debug_errno(SYNTHETIC_ERRNO(EIO),
87 "Read error status of unexpected length %zd from (sd-buscntr): %m", n);
88
89 if (error_buf < 0)
90 return log_debug_errno(SYNTHETIC_ERRNO(EBADMSG),
91 "Got unexpected error status from (sd-buscntr): %m");
92
93 if (error_buf == EINPROGRESS)
94 return 1;
95
96 if (error_buf > 0)
97 return log_debug_errno(error_buf, "(sd-buscntr) failed to connect to D-Bus socket: %m");
98 }
99
100 if (nonzero_exit_status)
101 return -EPROTO;
102
103 return bus_socket_start_auth(b);
104 }
105