1 /* $OpenBSD$ */
2
3 /*
4 * Copyright (c) 2022 Nicholas Marriott <nicholas.marriott@gmail.com>
5 *
6 * Permission to use, copy, modify, and distribute this software for any
7 * purpose with or without fee is hereby granted, provided that the above
8 * copyright notice and this permission notice appear in all copies.
9 *
10 * THE SOFTWARE IS PROVIDED "AS IS" AND THE AUTHOR DISCLAIMS ALL WARRANTIES
11 * WITH REGARD TO THIS SOFTWARE INCLUDING ALL IMPLIED WARRANTIES OF
12 * MERCHANTABILITY AND FITNESS. IN NO EVENT SHALL THE AUTHOR BE LIABLE FOR
13 * ANY SPECIAL, DIRECT, INDIRECT, OR CONSEQUENTIAL DAMAGES OR ANY DAMAGES
14 * WHATSOEVER RESULTING FROM LOSS OF MIND, USE, DATA OR PROFITS, WHETHER
15 * IN AN ACTION OF CONTRACT, NEGLIGENCE OR OTHER TORTIOUS ACTION, ARISING
16 * OUT OF OR IN CONNECTION WITH THE USE OR PERFORMANCE OF THIS SOFTWARE.
17 */
18
19 #include <sys/types.h>
20 #include <sys/un.h>
21
22 #include <systemd/sd-bus.h>
23 #include <systemd/sd-daemon.h>
24 #include <systemd/sd-login.h>
25 #include <systemd/sd-id128.h>
26
27 #include <stdlib.h>
28 #include <string.h>
29 #include <unistd.h>
30
31 #include "tmux.h"
32
33 int
systemd_activated(void)34 systemd_activated(void)
35 {
36 return (sd_listen_fds(0) >= 1);
37 }
38
39 int
systemd_create_socket(int flags,char ** cause)40 systemd_create_socket(int flags, char **cause)
41 {
42 int fds;
43 int fd;
44 struct sockaddr_un sa;
45 socklen_t addrlen = sizeof sa;
46
47 fds = sd_listen_fds(0);
48 if (fds > 1) { /* too many file descriptors */
49 errno = E2BIG;
50 goto fail;
51 }
52
53 if (fds == 1) { /* socket-activated */
54 fd = SD_LISTEN_FDS_START;
55 if (!sd_is_socket_unix(fd, SOCK_STREAM, 1, NULL, 0)) {
56 errno = EPFNOSUPPORT;
57 goto fail;
58 }
59 if (getsockname(fd, (struct sockaddr *)&sa, &addrlen) == -1)
60 goto fail;
61 socket_path = xstrdup(sa.sun_path);
62 return (fd);
63 }
64
65 return (server_create_socket(flags, cause));
66
67 fail:
68 if (cause != NULL)
69 xasprintf(cause, "systemd socket error (%s)", strerror(errno));
70 return (-1);
71 }
72
73 int
systemd_move_pid_to_new_cgroup(pid_t pid,char ** cause)74 systemd_move_pid_to_new_cgroup(pid_t pid, char **cause)
75 {
76 sd_bus_error error = SD_BUS_ERROR_NULL;
77 sd_bus_message *m = NULL, *reply = NULL;
78 sd_bus *bus = NULL;
79 char *name, *desc, *slice;
80 sd_id128_t uuid;
81 int r;
82 pid_t parent_pid;
83
84 /* Connect to the session bus. */
85 r = sd_bus_default_user(&bus);
86 if (r < 0) {
87 xasprintf(cause, "failed to connect to session bus: %s",
88 strerror(-r));
89 goto finish;
90 }
91
92 /* Start building the method call. */
93 r = sd_bus_message_new_method_call(bus, &m,
94 "org.freedesktop.systemd1",
95 "/org/freedesktop/systemd1",
96 "org.freedesktop.systemd1.Manager",
97 "StartTransientUnit");
98 if (r < 0) {
99 xasprintf(cause, "failed to create bus message: %s",
100 strerror(-r));
101 goto finish;
102 }
103
104 /* Generate a unique name for the new scope, to avoid collisions. */
105 r = sd_id128_randomize(&uuid);
106 if (r < 0) {
107 xasprintf(cause, "failed to generate uuid: %s", strerror(-r));
108 goto finish;
109 }
110 xasprintf(&name, "tmux-spawn-" SD_ID128_UUID_FORMAT_STR ".scope",
111 SD_ID128_FORMAT_VAL(uuid));
112 r = sd_bus_message_append(m, "s", name);
113 free(name);
114 if (r < 0) {
115 xasprintf(cause, "failed to append to bus message: %s",
116 strerror(-r));
117 goto finish;
118 }
119
120 /* Mode: fail if there's a queued unit with the same name. */
121 r = sd_bus_message_append(m, "s", "fail");
122 if (r < 0) {
123 xasprintf(cause, "failed to append to bus message: %s",
124 strerror(-r));
125 goto finish;
126 }
127
128 /* Start properties array. */
129 r = sd_bus_message_open_container(m, 'a', "(sv)");
130 if (r < 0) {
131 xasprintf(cause, "failed to start properties array: %s",
132 strerror(-r));
133 goto finish;
134 }
135
136 parent_pid = getpid();
137 xasprintf(&desc, "tmux child pane %ld launched by process %ld",
138 (long)pid, (long)parent_pid);
139 r = sd_bus_message_append(m, "(sv)", "Description", "s", desc);
140 free(desc);
141 if (r < 0) {
142 xasprintf(cause, "failed to append to properties: %s",
143 strerror(-r));
144 goto finish;
145 }
146
147 /*
148 * Make sure that the session shells are terminated with SIGHUP since
149 * bash and friends tend to ignore SIGTERM.
150 */
151 r = sd_bus_message_append(m, "(sv)", "SendSIGHUP", "b", 1);
152 if (r < 0) {
153 xasprintf(cause, "failed to append to properties: %s",
154 strerror(-r));
155 goto finish;
156 }
157
158 /*
159 * Inherit the slice from the parent process, or default to
160 * "app-tmux.slice" if that fails.
161 */
162 r = sd_pid_get_user_slice(parent_pid, &slice);
163 if (r < 0) {
164 slice = xstrdup("app-tmux.slice");
165 }
166 r = sd_bus_message_append(m, "(sv)", "Slice", "s", slice);
167 free(slice);
168 if (r < 0) {
169 xasprintf(cause, "failed to append to properties: %s",
170 strerror(-r));
171 goto finish;
172 }
173
174 /* PIDs to add to the scope: length - 1 array of uint32_t. */
175 r = sd_bus_message_append(m, "(sv)", "PIDs", "au", 1, pid);
176 if (r < 0) {
177 xasprintf(cause, "failed to append to properties: %s",
178 strerror(-r));
179 goto finish;
180 }
181
182 /* Clean up the scope even if it fails. */
183 r = sd_bus_message_append(m, "(sv)", "CollectMode", "s",
184 "inactive-or-failed");
185 if (r < 0) {
186 xasprintf(cause, "failed to append to properties: %s",
187 strerror(-r));
188 goto finish;
189 }
190
191 /* End properties array. */
192 r = sd_bus_message_close_container(m);
193 if (r < 0) {
194 xasprintf(cause, "failed to end properties array: %s",
195 strerror(-r));
196 goto finish;
197 }
198
199 /* aux is currently unused and should be passed an empty array. */
200 r = sd_bus_message_append(m, "a(sa(sv))", 0);
201 if (r < 0) {
202 xasprintf(cause, "failed to append to bus message: %s",
203 strerror(-r));
204 goto finish;
205 }
206
207 /* Call the method with a timeout of 1 second = 1e6 us. */
208 r = sd_bus_call(bus, m, 1000000, &error, &reply);
209 if (r < 0) {
210 if (error.message != NULL) {
211 /* We have a specific error message from sd-bus. */
212 xasprintf(cause, "StartTransientUnit call failed: %s",
213 error.message);
214 } else {
215 xasprintf(cause, "StartTransientUnit call failed: %s",
216 strerror(-r));
217 }
218 goto finish;
219 }
220
221 finish:
222 sd_bus_error_free(&error);
223 sd_bus_message_unref(m);
224 sd_bus_message_unref(reply);
225 sd_bus_unref(bus);
226
227 return (r);
228 }
229