client.c

   1 /* $Id: client.c,v 1.90 2009-12-04 22:14:47 tcunha Exp $ */
   2
   3 /*
   4  * Copyright (c) 2007 Nicholas Marriott <nicm@users.sourceforge.net>
   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/ioctl.h>
  21 #include <sys/socket.h>
  22 #include <sys/stat.h>
  23 #include <sys/un.h>
  24 #include <sys/wait.h>
  25
  26 #include <errno.h>
  27 #include <event.h>
  28 #include <fcntl.h>
  29 #include <pwd.h>
  30 #include <stdlib.h>
  31 #include <string.h>
  32 #include <syslog.h>
  33 #include <unistd.h>
  34
  35 #include "tmux.h"
  36
  37 struct imsgbuf  client_ibuf;
  38 struct event    client_event;
  39 const char     *client_exitmsg;
  40 int             client_exitval;
  41
  42 void            client_send_identify(int);
  43 void            client_send_environ(void);
  44 void            client_write_server(enum msgtype, void *, size_t);
  45 void            client_update_event(void);
  46 void            client_signal(int, short, void *);
  47 void            client_callback(int, short, void *);
  48 int             client_dispatch(void);
  49
  50 struct imsgbuf *
  51 client_init(char *path, int cmdflags, int flags)
  52 {
  53         struct sockaddr_un      sa;
  54         size_t                  size;
  55         int                     fd, mode;
  56 #ifdef HAVE_SETPROCTITLE
  57         char                    rpathbuf[MAXPATHLEN];
  58 #endif
  59
  60 #ifdef HAVE_SETPROCTITLE
  61         if (realpath(path, rpathbuf) == NULL)
  62                 strlcpy(rpathbuf, path, sizeof rpathbuf);
  63         setproctitle("client (%s)", rpathbuf);
  64 #endif
  65
  66         memset(&sa, 0, sizeof sa);
  67         sa.sun_family = AF_UNIX;
  68         size = strlcpy(sa.sun_path, path, sizeof sa.sun_path);
  69         if (size >= sizeof sa.sun_path) {
  70                 errno = ENAMETOOLONG;
  71                 goto not_found;
  72         }
  73
  74         if ((fd = socket(AF_UNIX, SOCK_STREAM, 0)) == -1)
  75                 fatal("socket failed");
  76
  77         if (connect(fd, (struct sockaddr *) &sa, SUN_LEN(&sa)) == -1) {
  78                 if (!(cmdflags & CMD_STARTSERVER))
  79                         goto not_found;
  80                 switch (errno) {
  81                 case ECONNREFUSED:
  82                         if (unlink(path) != 0)
  83                                 goto not_found;
  84                         /* FALLTHROUGH */
  85                 case ENOENT:
  86                         if ((fd = server_start(path)) == -1)
  87                                 goto start_failed;
  88                         goto server_started;
  89                 }
  90                 goto not_found;
  91         }
  92
  93 server_started:
  94         if ((mode = fcntl(fd, F_GETFL)) == -1)
  95                 fatal("fcntl failed");
  96         if (fcntl(fd, F_SETFL, mode|O_NONBLOCK) == -1)
  97                 fatal("fcntl failed");
  98         if (fcntl(fd, F_SETFD, FD_CLOEXEC) == -1)
  99                 fatal("fcntl failed");
 100         imsg_init(&client_ibuf, fd);
 101
 102         if (cmdflags & CMD_SENDENVIRON)
 103                 client_send_environ();
 104         if (isatty(STDIN_FILENO))
 105                 client_send_identify(flags);
 106
 107         return (&client_ibuf);
 108
 109 start_failed:
 110         log_warnx("server failed to start");
 111         return (NULL);
 112
 113 not_found:
 114         log_warn("server not found");
 115         return (NULL);
 116 }
 117
 118 void
 119 client_send_identify(int flags)
 120 {
 121         struct msg_identify_data        data;
 122         struct winsize                  ws;
 123         char                           *term;
 124         int                             fd;
 125
 126         if (ioctl(STDIN_FILENO, TIOCGWINSZ, &ws) == -1)
 127                 fatal("ioctl(TIOCGWINSZ)");
 128         data.flags = flags;
 129
 130         if (getcwd(data.cwd, sizeof data.cwd) == NULL)
 131                 *data.cwd = '\0';
 132
 133         term = getenv("TERM");
 134         if (term == NULL ||
 135             strlcpy(data.term, term, sizeof data.term) >= sizeof data.term)
 136                 *data.term = '\0';
 137
 138         if ((fd = dup(STDIN_FILENO)) == -1)
 139                 fatal("dup failed");
 140         imsg_compose(&client_ibuf,
 141             MSG_IDENTIFY, PROTOCOL_VERSION, -1, fd, &data, sizeof data);
 142 }
 143
 144 void
 145 client_send_environ(void)
 146 {
 147         struct msg_environ_data data;
 148         char                  **var;
 149
 150         for (var = environ; *var != NULL; var++) {
 151                 if (strlcpy(data.var, *var, sizeof data.var) >= sizeof data.var)
 152                         continue;
 153                 client_write_server(MSG_ENVIRON, &data, sizeof data);
 154         }
 155 }
 156
 157 void
 158 client_write_server(enum msgtype type, void *buf, size_t len)
 159 {
 160         imsg_compose(&client_ibuf, type, PROTOCOL_VERSION, -1, -1, buf, len);
 161 }
 162
 163 void
 164 client_update_event(void)
 165 {
 166         short   events;
 167
 168         event_del(&client_event);
 169         events = EV_READ;
 170         if (client_ibuf.w.queued > 0)
 171                 events |= EV_WRITE;
 172         event_set(&client_event, client_ibuf.fd, events, client_callback, NULL);
 173         event_add(&client_event, NULL);
 174 }
 175
 176 __dead void
 177 client_main(void)
 178 {
 179         struct event            ev_sigcont, ev_sigterm, ev_sigwinch;
 180         struct sigaction        sigact;
 181
 182         logfile("client");
 183
 184         /* Note: event_init() has already been called. */
 185
 186         /* Set up signals. */
 187         memset(&sigact, 0, sizeof sigact);
 188         sigemptyset(&sigact.sa_mask);
 189         sigact.sa_flags = SA_RESTART;
 190         sigact.sa_handler = SIG_IGN;
 191         if (sigaction(SIGINT, &sigact, NULL) != 0)
 192                 fatal("sigaction failed");
 193         if (sigaction(SIGPIPE, &sigact, NULL) != 0)
 194                 fatal("sigaction failed");
 195         if (sigaction(SIGUSR1, &sigact, NULL) != 0)
 196                 fatal("sigaction failed");
 197         if (sigaction(SIGUSR2, &sigact, NULL) != 0)
 198                 fatal("sigaction failed");
 199         if (sigaction(SIGTSTP, &sigact, NULL) != 0)
 200                 fatal("sigaction failed");
 201
 202         signal_set(&ev_sigcont, SIGCONT, client_signal, NULL);
 203         signal_add(&ev_sigcont, NULL);
 204         signal_set(&ev_sigterm, SIGTERM, client_signal, NULL);
 205         signal_add(&ev_sigterm, NULL);
 206         signal_set(&ev_sigwinch, SIGWINCH, client_signal, NULL);
 207         signal_add(&ev_sigwinch, NULL);
 208
 209         /*
 210          * imsg_read in the first client poll loop (before the terminal has
 211          * been initialised) may have read messages into the buffer after the
 212          * MSG_READY switched to here. Process anything outstanding now to
 213          * avoid hanging waiting for messages that have already arrived.
 214          */
 215         if (client_dispatch() != 0)
 216                 goto out;
 217
 218         /* Set the event and dispatch. */
 219         client_update_event();
 220         event_dispatch();
 221
 222 out:
 223         /* Print the exit message, if any, and exit. */
 224         if (client_exitmsg != NULL && !login_shell)
 225                 printf("[%s]\n", client_exitmsg);
 226         exit(client_exitval);
 227 }
 228
 229 /* ARGSUSED */
 230 void
 231 client_signal(int sig, unused short events, unused void *data)
 232 {
 233         struct sigaction        sigact;
 234
 235         switch (sig) {
 236         case SIGTERM:
 237                 client_exitmsg = "terminated";
 238                 client_exitval = 1;
 239                 client_write_server(MSG_EXITING, NULL, 0);
 240                 break;
 241         case SIGWINCH:
 242                 client_write_server(MSG_RESIZE, NULL, 0);
 243                 break;
 244         case SIGCONT:
 245                 memset(&sigact, 0, sizeof sigact);
 246                 sigemptyset(&sigact.sa_mask);
 247                 sigact.sa_flags = SA_RESTART;
 248                 sigact.sa_handler = SIG_IGN;
 249                 if (sigaction(SIGTSTP, &sigact, NULL) != 0)
 250                         fatal("sigaction failed");
 251                 client_write_server(MSG_WAKEUP, NULL, 0);
 252                 break;
 253         }
 254
 255         client_update_event();
 256 }
 257
 258 /* ARGSUSED */
 259 void
 260 client_callback(unused int fd, short events, unused void *data)
 261 {
 262         ssize_t n;
 263
 264         if (events & EV_READ) {
 265                 if ((n = imsg_read(&client_ibuf)) == -1 || n == 0)
 266                         goto lost_server;
 267                 if (client_dispatch() != 0) {
 268                         event_loopexit(NULL);
 269                         return;
 270                 }
 271         }
 272
 273         if (events & EV_WRITE) {
 274                 if (msgbuf_write(&client_ibuf.w) < 0)
 275                         goto lost_server;
 276         }
 277
 278         client_update_event();
 279         return;
 280
 281 lost_server:
 282         client_exitmsg = "lost server";
 283         client_exitval = 1;
 284         event_loopexit(NULL);
 285 }
 286
 287 int
 288 client_dispatch(void)
 289 {
 290         struct imsg             imsg;
 291         struct msg_lock_data    lockdata;
 292         struct sigaction        sigact;
 293         ssize_t                 n, datalen;
 294
 295         for (;;) {
 296                 if ((n = imsg_get(&client_ibuf, &imsg)) == -1)
 297                         fatalx("imsg_get failed");
 298                 if (n == 0)
 299                         return (0);
 300                 datalen = imsg.hdr.len - IMSG_HEADER_SIZE;
 301
 302                 log_debug("client got %d", imsg.hdr.type);
 303                 switch (imsg.hdr.type) {
 304                 case MSG_DETACH:
 305                         if (datalen != 0)
 306                                 fatalx("bad MSG_DETACH size");
 307
 308                         client_write_server(MSG_EXITING, NULL, 0);
 309                         client_exitmsg = "detached";
 310                         break;
 311                 case MSG_EXIT:
 312                         if (datalen != 0)
 313                                 fatalx("bad MSG_EXIT size");
 314
 315                         client_write_server(MSG_EXITING, NULL, 0);
 316                         client_exitmsg = "exited";
 317                         break;
 318                 case MSG_EXITED:
 319                         if (datalen != 0)
 320                                 fatalx("bad MSG_EXITED size");
 321
 322                         imsg_free(&imsg);
 323                         return (-1);
 324                 case MSG_SHUTDOWN:
 325                         if (datalen != 0)
 326                                 fatalx("bad MSG_SHUTDOWN size");
 327
 328                         client_write_server(MSG_EXITING, NULL, 0);
 329                         client_exitmsg = "server exited";
 330                         client_exitval = 1;
 331                         break;
 332                 case MSG_SUSPEND:
 333                         if (datalen != 0)
 334                                 fatalx("bad MSG_SUSPEND size");
 335
 336                         memset(&sigact, 0, sizeof sigact);
 337                         sigemptyset(&sigact.sa_mask);
 338                         sigact.sa_flags = SA_RESTART;
 339                         sigact.sa_handler = SIG_DFL;
 340                         if (sigaction(SIGTSTP, &sigact, NULL) != 0)
 341                                 fatal("sigaction failed");
 342                         kill(getpid(), SIGTSTP);
 343                         break;
 344                 case MSG_LOCK:
 345                         if (datalen != sizeof lockdata)
 346                                 fatalx("bad MSG_LOCK size");
 347                         memcpy(&lockdata, imsg.data, sizeof lockdata);
 348
 349                         lockdata.cmd[(sizeof lockdata.cmd) - 1] = '\0';
 350                         system(lockdata.cmd);
 351                         client_write_server(MSG_UNLOCK, NULL, 0);
 352                         break;
 353                 default:
 354                         fatalx("unexpected message");
 355                 }
 356
 357                 imsg_free(&imsg);
 358         }
 359 }