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 static void
proc_signal_cb(int signo,__unused short events,void * arg)104 proc_signal_cb(int signo, __unused short events, void *arg)
105 {
106 struct tmuxproc *tp = arg;
107
108 tp->signalcb(signo);
109 }
110
111 static int
peer_check_version(struct tmuxpeer * peer,struct imsg * imsg)112 peer_check_version(struct tmuxpeer *peer, struct imsg *imsg)
113 {
114 int version;
115
116 version = imsg->hdr.peerid & 0xff;
117 if (imsg->hdr.type != MSG_VERSION && version != PROTOCOL_VERSION) {
118 log_debug("peer %p bad version %d", peer, version);
119
120 proc_send(peer, MSG_VERSION, -1, NULL, 0);
121 peer->flags |= PEER_BAD;
122
123 return (-1);
124 }
125 return (0);
126 }
127
128 static void
proc_update_event(struct tmuxpeer * peer)129 proc_update_event(struct tmuxpeer *peer)
130 {
131 short events;
132
133 event_del(&peer->event);
134
135 events = EV_READ;
136 if (peer->ibuf.w.queued > 0)
137 events |= EV_WRITE;
138 event_set(&peer->event, peer->ibuf.fd, events, proc_event_cb, peer);
139
140 event_add(&peer->event, NULL);
141 }
142
143 int
proc_send(struct tmuxpeer * peer,enum msgtype type,int fd,const void * buf,size_t len)144 proc_send(struct tmuxpeer *peer, enum msgtype type, int fd, const void *buf,
145 size_t len)
146 {
147 struct imsgbuf *ibuf = &peer->ibuf;
148 void *vp = (void *)buf;
149 int retval;
150
151 if (peer->flags & PEER_BAD)
152 return (-1);
153 log_debug("sending message %d to peer %p (%zu bytes)", type, peer, len);
154
155 retval = imsg_compose(ibuf, type, PROTOCOL_VERSION, -1, fd, vp, len);
156 if (retval != 1)
157 return (-1);
158 proc_update_event(peer);
159 return (0);
160 }
161
162 int
proc_send_s(struct tmuxpeer * peer,enum msgtype type,const char * s)163 proc_send_s(struct tmuxpeer *peer, enum msgtype type, const char *s)
164 {
165 return (proc_send(peer, type, -1, s, strlen(s) + 1));
166 }
167
168 struct tmuxproc *
proc_start(const char * name,struct event_base * base,int forkflag,void (* signalcb)(int))169 proc_start(const char *name, struct event_base *base, int forkflag,
170 void (*signalcb)(int))
171 {
172 struct tmuxproc *tp;
173 struct utsname u;
174
175 if (forkflag) {
176 switch (fork()) {
177 case -1:
178 fatal("fork failed");
179 case 0:
180 break;
181 default:
182 return (NULL);
183 }
184 if (daemon(1, 0) != 0)
185 fatal("daemon failed");
186
187 clear_signals(0);
188 if (event_reinit(base) != 0)
189 fatalx("event_reinit failed");
190 }
191
192 log_open(name);
193
194 setproctitle("%s (%s)", name, socket_path);
195
196 if (uname(&u) < 0)
197 memset(&u, 0, sizeof u);
198
199 log_debug("%s started (%ld): socket %s, protocol %d", name,
200 (long)getpid(), socket_path, PROTOCOL_VERSION);
201 log_debug("on %s %s %s; libevent %s (%s)", u.sysname, u.release,
202 u.version, event_get_version(), event_get_method());
203
204 tp = xcalloc(1, sizeof *tp);
205 tp->name = xstrdup(name);
206
207 tp->signalcb = signalcb;
208 set_signals(proc_signal_cb, tp);
209
210 return (tp);
211 }
212
213 void
proc_loop(struct tmuxproc * tp,int (* loopcb)(void))214 proc_loop(struct tmuxproc *tp, int (*loopcb)(void))
215 {
216 log_debug("%s loop enter", tp->name);
217 do
218 event_loop(EVLOOP_ONCE);
219 while (!tp->exit && (loopcb == NULL || !loopcb ()));
220 log_debug("%s loop exit", tp->name);
221 }
222
223 void
proc_exit(struct tmuxproc * tp)224 proc_exit(struct tmuxproc *tp)
225 {
226 tp->exit = 1;
227 }
228
229 struct tmuxpeer *
proc_add_peer(struct tmuxproc * tp,int fd,void (* dispatchcb)(struct imsg *,void *),void * arg)230 proc_add_peer(struct tmuxproc *tp, int fd,
231 void (*dispatchcb)(struct imsg *, void *), void *arg)
232 {
233 struct tmuxpeer *peer;
234
235 peer = xcalloc(1, sizeof *peer);
236 peer->parent = tp;
237
238 peer->dispatchcb = dispatchcb;
239 peer->arg = arg;
240
241 imsg_init(&peer->ibuf, fd);
242 event_set(&peer->event, fd, EV_READ, proc_event_cb, peer);
243
244 log_debug("add peer %p: %d (%p)", peer, fd, arg);
245
246 proc_update_event(peer);
247 return (peer);
248 }
249
250 void
proc_remove_peer(struct tmuxpeer * peer)251 proc_remove_peer(struct tmuxpeer *peer)
252 {
253 log_debug("remove peer %p", peer);
254
255 event_del(&peer->event);
256 imsg_clear(&peer->ibuf);
257
258 close(peer->ibuf.fd);
259 free(peer);
260 }
261
262 void
proc_kill_peer(struct tmuxpeer * peer)263 proc_kill_peer(struct tmuxpeer *peer)
264 {
265 peer->flags |= PEER_BAD;
266 }
267