1 /* $OpenBSD$ */
2
3 /*
4 * Copyright (c) 2015 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/uio.h>
21 #include <sys/utsname.h>
22
23 #include <errno.h>
24 #include <event.h>
25 #include <stdlib.h>
26 #include <string.h>
27 #include <unistd.h>
28
29 #include "tmux.h"
30
31 struct tmuxproc {
32 const char *name;
33 int exit;
34
35 void (*signalcb)(int);
36 };
37
38 struct tmuxpeer {
39 struct tmuxproc *parent;
40
41 struct imsgbuf ibuf;
42 struct event event;
43
44 int flags;
45 #define PEER_BAD 0x1
46
47 void (*dispatchcb)(struct imsg *, void *);
48 void *arg;
49 };
50
51 static int peer_check_version(struct tmuxpeer *, struct imsg *);
52 static void proc_update_event(struct tmuxpeer *);
53
54 static void
proc_event_cb(__unused int fd,short events,void * arg)55 proc_event_cb(__unused int fd, short events, void *arg)
56 {
57 struct tmuxpeer *peer = arg;
58 ssize_t n;
59 struct imsg imsg;
60
61 if (!(peer->flags & PEER_BAD) && (events & EV_READ)) {
62 if (((n = imsg_read(&peer->ibuf)) == -1 && errno != EAGAIN) ||
63 n == 0) {
64 peer->dispatchcb(NULL, peer->arg);
65 return;
66 }
67 for (;;) {
68 if ((n = imsg_get(&peer->ibuf, &imsg)) == -1) {
69 peer->dispatchcb(NULL, peer->arg);
70 return;
71 }
72 if (n == 0)
73 break;
74 log_debug("peer %p message %d", peer, imsg.hdr.type);
75
76 if (peer_check_version(peer, &imsg) != 0) {
77 if (imsg.fd != -1)
78 close(imsg.fd);
79 imsg_free(&imsg);
80 break;
81 }
82
83 peer->dispatchcb(&imsg, peer->arg);
84 imsg_free(&imsg);
85 }
86 }
87
88 if (events & EV_WRITE) {
89 if (msgbuf_write(&peer->ibuf.w) <= 0 && errno != EAGAIN) {
90 peer->dispatchcb(NULL, peer->arg);
91 return;
92 }
93 }
94
95 if ((peer->flags & PEER_BAD) && peer->ibuf.w.queued == 0) {
96 peer->dispatchcb(NULL, peer->arg);
97 return;
98 }
99
100 proc_update_event(peer);
101 }
102
103 #ifndef TMATE
104 static void
proc_signal_cb(int signo,__unused short events,void * arg)105 proc_signal_cb(int signo, __unused short events, void *arg)
106 {
107 struct tmuxproc *tp = arg;
108
109 tp->signalcb(signo);
110 }
111 #endif
112
113 static int
peer_check_version(struct tmuxpeer * peer,struct imsg * imsg)114 peer_check_version(struct tmuxpeer *peer, struct imsg *imsg)
115 {
116 int version;
117
118 version = imsg->hdr.peerid & 0xff;
119 if (imsg->hdr.type != MSG_VERSION && version != PROTOCOL_VERSION) {
120 log_debug("peer %p bad version %d", peer, version);
121
122 proc_send(peer, MSG_VERSION, -1, NULL, 0);
123 peer->flags |= PEER_BAD;
124
125 return (-1);
126 }
127 return (0);
128 }
129
130 static void
proc_update_event(struct tmuxpeer * peer)131 proc_update_event(struct tmuxpeer *peer)
132 {
133 short events;
134
135 event_del(&peer->event);
136
137 events = EV_READ;
138 if (peer->ibuf.w.queued > 0)
139 events |= EV_WRITE;
140 event_set(&peer->event, peer->ibuf.fd, events, proc_event_cb, peer);
141
142 event_add(&peer->event, NULL);
143 }
144
145 int
proc_send(struct tmuxpeer * peer,enum msgtype type,int fd,const void * buf,size_t len)146 proc_send(struct tmuxpeer *peer, enum msgtype type, int fd, const void *buf,
147 size_t len)
148 {
149 struct imsgbuf *ibuf = &peer->ibuf;
150 void *vp = (void *)buf;
151 int retval;
152
153 if (peer->flags & PEER_BAD)
154 return (-1);
155 log_debug("sending message %d to peer %p (%zu bytes)", type, peer, len);
156
157 retval = imsg_compose(ibuf, type, PROTOCOL_VERSION, -1, fd, vp, len);
158 if (retval != 1)
159 return (-1);
160 proc_update_event(peer);
161 return (0);
162 }
163
164 int
proc_send_s(struct tmuxpeer * peer,enum msgtype type,const char * s)165 proc_send_s(struct tmuxpeer *peer, enum msgtype type, const char *s)
166 {
167 return (proc_send(peer, type, -1, s, strlen(s) + 1));
168 }
169
170 struct tmuxproc *
proc_start(const char * name,struct event_base * base,int forkflag,void (* signalcb)(int))171 proc_start(const char *name, struct event_base *base, int forkflag,
172 void (*signalcb)(int))
173 {
174 struct tmuxproc *tp;
175 struct utsname u;
176
177 #ifdef TMATE
178 if (forkflag)
179 fatal("can't fork");
180 #else
181 if (forkflag) {
182 switch (fork()) {
183 case -1:
184 fatal("fork failed");
185 case 0:
186 break;
187 default:
188 return (NULL);
189 }
190 if (daemon(1, 0) != 0)
191 fatal("daemon failed");
192
193 clear_signals(0);
194 if (event_reinit(base) != 0)
195 fatalx("event_reinit failed");
196 }
197 log_open(name);
198 #endif
199
200 #ifdef HAVE_SETPROCTITLE
201 setproctitle("%s (%s)", name, socket_path);
202 #endif
203
204 if (uname(&u) < 0)
205 memset(&u, 0, sizeof u);
206
207 log_debug("%s started (%ld): socket %s, protocol %d", name,
208 (long)getpid(), socket_path, PROTOCOL_VERSION);
209 log_debug("on %s %s %s; libevent %s (%s)", u.sysname, u.release,
210 u.version, event_get_version(), event_get_method());
211
212 tp = xcalloc(1, sizeof *tp);
213 tp->name = xstrdup(name);
214
215 #ifndef TMATE
216 tp->signalcb = signalcb;
217 set_signals(proc_signal_cb, tp);
218 #endif
219
220 return (tp);
221 }
222
223 void
proc_loop(struct tmuxproc * tp,int (* loopcb)(void))224 proc_loop(struct tmuxproc *tp, int (*loopcb)(void))
225 {
226 log_debug("%s loop enter", tp->name);
227 do
228 event_loop(EVLOOP_ONCE);
229 while (!tp->exit && (loopcb == NULL || !loopcb ()));
230
231 #ifdef TMATE
232 /* flush data on sockets */
233 event_loop(EVLOOP_ONCE | EVLOOP_NONBLOCK);
234 #endif
235
236 log_debug("%s loop exit", tp->name);
237 }
238
239 void
proc_exit(struct tmuxproc * tp)240 proc_exit(struct tmuxproc *tp)
241 {
242 tp->exit = 1;
243 }
244
245 struct tmuxpeer *
proc_add_peer(struct tmuxproc * tp,int fd,void (* dispatchcb)(struct imsg *,void *),void * arg)246 proc_add_peer(struct tmuxproc *tp, int fd,
247 void (*dispatchcb)(struct imsg *, void *), void *arg)
248 {
249 struct tmuxpeer *peer;
250
251 peer = xcalloc(1, sizeof *peer);
252 peer->parent = tp;
253
254 peer->dispatchcb = dispatchcb;
255 peer->arg = arg;
256
257 imsg_init(&peer->ibuf, fd);
258 event_set(&peer->event, fd, EV_READ, proc_event_cb, peer);
259
260 log_debug("add peer %p: %d (%p)", peer, fd, arg);
261
262 proc_update_event(peer);
263 return (peer);
264 }
265
266 void
proc_remove_peer(struct tmuxpeer * peer)267 proc_remove_peer(struct tmuxpeer *peer)
268 {
269 log_debug("remove peer %p", peer);
270
271 event_del(&peer->event);
272 imsg_clear(&peer->ibuf);
273
274 close(peer->ibuf.fd);
275 free(peer);
276 }
277
278 void
proc_kill_peer(struct tmuxpeer * peer)279 proc_kill_peer(struct tmuxpeer *peer)
280 {
281 peer->flags |= PEER_BAD;
282 }
283