tmux/server.c
2015-10-22 12:01:09 +01:00

477 lines
9.8 KiB
C

/* $OpenBSD$ */
/*
* Copyright (c) 2007 Nicholas Marriott <nicm@users.sourceforge.net>
*
* Permission to use, copy, modify, and distribute this software for any
* purpose with or without fee is hereby granted, provided that the above
* copyright notice and this permission notice appear in all copies.
*
* THE SOFTWARE IS PROVIDED "AS IS" AND THE AUTHOR DISCLAIMS ALL WARRANTIES
* WITH REGARD TO THIS SOFTWARE INCLUDING ALL IMPLIED WARRANTIES OF
* MERCHANTABILITY AND FITNESS. IN NO EVENT SHALL THE AUTHOR BE LIABLE FOR
* ANY SPECIAL, DIRECT, INDIRECT, OR CONSEQUENTIAL DAMAGES OR ANY DAMAGES
* WHATSOEVER RESULTING FROM LOSS OF MIND, USE, DATA OR PROFITS, WHETHER
* IN AN ACTION OF CONTRACT, NEGLIGENCE OR OTHER TORTIOUS ACTION, ARISING
* OUT OF OR IN CONNECTION WITH THE USE OR PERFORMANCE OF THIS SOFTWARE.
*/
#include <sys/types.h>
#include <sys/ioctl.h>
#include <sys/socket.h>
#include <sys/stat.h>
#include <sys/un.h>
#include <sys/wait.h>
#include <errno.h>
#include <event.h>
#include <fcntl.h>
#include <signal.h>
#include <stdio.h>
#include <stdlib.h>
#include <string.h>
#include <termios.h>
#include <time.h>
#include <unistd.h>
#include "tmux.h"
/*
* Main server functions.
*/
struct clients clients;
int server_fd;
int server_exit;
struct event server_ev_accept;
struct session *marked_session;
struct winlink *marked_winlink;
struct window *marked_window;
struct window_pane *marked_window_pane;
struct layout_cell *marked_layout_cell;
int server_create_socket(void);
void server_loop(void);
int server_should_exit(void);
void server_send_exit(void);
void server_accept_callback(int, short, void *);
void server_signal_callback(int, short, void *);
void server_child_signal(void);
void server_child_exited(pid_t, int);
void server_child_stopped(pid_t, int);
/* Set marked pane. */
void
server_set_marked(struct session *s, struct winlink *wl, struct window_pane *wp)
{
marked_session = s;
marked_winlink = wl;
marked_window = wl->window;
marked_window_pane = wp;
marked_layout_cell = wp->layout_cell;
}
/* Clear marked pane. */
void
server_clear_marked(void)
{
marked_session = NULL;
marked_winlink = NULL;
marked_window = NULL;
marked_window_pane = NULL;
marked_layout_cell = NULL;
}
/* Is this the marked pane? */
int
server_is_marked(struct session *s, struct winlink *wl, struct window_pane *wp)
{
if (s == NULL || wl == NULL || wp == NULL)
return (0);
if (marked_session != s || marked_winlink != wl)
return (0);
if (marked_window_pane != wp)
return (0);
return (server_check_marked());
}
/* Check if the marked pane is still valid. */
int
server_check_marked(void)
{
struct winlink *wl;
if (marked_window_pane == NULL)
return (0);
if (marked_layout_cell != marked_window_pane->layout_cell)
return (0);
if (!session_alive(marked_session))
return (0);
RB_FOREACH(wl, winlinks, &marked_session->windows) {
if (wl->window == marked_window && wl == marked_winlink)
break;
}
if (wl == NULL)
return (0);
if (!window_has_pane(marked_window, marked_window_pane))
return (0);
return (window_pane_visible(marked_window_pane));
}
/* Create server socket. */
int
server_create_socket(void)
{
struct sockaddr_un sa;
size_t size;
mode_t mask;
int fd;
memset(&sa, 0, sizeof sa);
sa.sun_family = AF_UNIX;
size = strlcpy(sa.sun_path, socket_path, sizeof sa.sun_path);
if (size >= sizeof sa.sun_path) {
errno = ENAMETOOLONG;
return (-1);
}
unlink(sa.sun_path);
if ((fd = socket(AF_UNIX, SOCK_STREAM, 0)) == -1)
return (-1);
mask = umask(S_IXUSR|S_IXGRP|S_IRWXO);
if (bind(fd, (struct sockaddr *) &sa, sizeof(sa)) == -1)
return (-1);
umask(mask);
if (listen(fd, 16) == -1)
return (-1);
setblocking(fd, 0);
return (fd);
}
/* Fork new server. */
int
server_start(struct event_base *base, int lockfd, char *lockfile)
{
int pair[2];
/* The first client is special and gets a socketpair; create it. */
if (socketpair(AF_UNIX, SOCK_STREAM, PF_UNSPEC, pair) != 0)
fatal("socketpair failed");
log_debug("starting server");
switch (fork()) {
case -1:
fatal("fork failed");
case 0:
break;
default:
close(pair[1]);
return (pair[0]);
}
close(pair[0]);
/*
* Must daemonise before loading configuration as the PID changes so
* $TMUX would be wrong for sessions created in the config file.
*/
if (daemon(1, 0) != 0)
fatal("daemon failed");
/* event_init() was called in our parent, need to reinit. */
clear_signals(0);
if (event_reinit(base) != 0)
fatal("event_reinit failed");
logfile("server");
log_debug("server started, pid %ld", (long) getpid());
RB_INIT(&windows);
RB_INIT(&all_window_panes);
TAILQ_INIT(&clients);
RB_INIT(&sessions);
TAILQ_INIT(&session_groups);
mode_key_init_trees();
key_bindings_init();
utf8_build();
start_time = time(NULL);
log_debug("socket path %s", socket_path);
#ifdef HAVE_SETPROCTITLE
setproctitle("server (%s)", socket_path);
#endif
server_fd = server_create_socket();
if (server_fd == -1)
fatal("couldn't create socket");
server_update_socket();
server_client_create(pair[1]);
unlink(lockfile);
free(lockfile);
close(lockfd);
start_cfg();
status_prompt_load_history();
server_add_accept(0);
set_signals(server_signal_callback);
server_loop();
status_prompt_save_history();
exit(0);
}
/* Main server loop. */
void
server_loop(void)
{
while (!server_should_exit()) {
log_debug("event dispatch enter");
event_loop(EVLOOP_ONCE);
log_debug("event dispatch exit");
server_client_loop();
}
}
/* Check if the server should exit (no more clients or sessions). */
int
server_should_exit(void)
{
struct client *c;
if (!options_get_number(&global_options, "exit-unattached")) {
if (!RB_EMPTY(&sessions))
return (0);
}
TAILQ_FOREACH(c, &clients, entry) {
if (c->session != NULL)
return (0);
}
/*
* No attached clients therefore want to exit - flush any waiting
* clients but don't actually exit until they've gone.
*/
cmd_wait_for_flush();
if (!TAILQ_EMPTY(&clients))
return (0);
return (1);
}
/* Exit the server by killing all clients and windows. */
void
server_send_exit(void)
{
struct client *c, *c1;
struct session *s, *s1;
cmd_wait_for_flush();
TAILQ_FOREACH_SAFE(c, &clients, entry, c1) {
if (c->flags & (CLIENT_BAD|CLIENT_SUSPENDED))
server_client_lost(c);
else
server_write_client(c, MSG_EXIT, NULL, 0);
c->session = NULL;
}
RB_FOREACH_SAFE(s, sessions, &sessions, s1)
session_destroy(s);
}
/* Update socket execute permissions based on whether sessions are attached. */
void
server_update_socket(void)
{
struct session *s;
static int last = -1;
int n, mode;
struct stat sb;
n = 0;
RB_FOREACH(s, sessions, &sessions) {
if (!(s->flags & SESSION_UNATTACHED)) {
n++;
break;
}
}
if (n != last) {
last = n;
if (stat(socket_path, &sb) != 0)
return;
mode = sb.st_mode;
if (n != 0) {
if (mode & S_IRUSR)
mode |= S_IXUSR;
if (mode & S_IRGRP)
mode |= S_IXGRP;
if (mode & S_IROTH)
mode |= S_IXOTH;
} else
mode &= ~(S_IXUSR|S_IXGRP|S_IXOTH);
chmod(socket_path, mode);
}
}
/* Callback for server socket. */
void
server_accept_callback(int fd, short events, unused void *data)
{
struct sockaddr_storage sa;
socklen_t slen = sizeof sa;
int newfd;
server_add_accept(0);
if (!(events & EV_READ))
return;
newfd = accept(fd, (struct sockaddr *) &sa, &slen);
if (newfd == -1) {
if (errno == EAGAIN || errno == EINTR || errno == ECONNABORTED)
return;
if (errno == ENFILE || errno == EMFILE) {
/* Delete and don't try again for 1 second. */
server_add_accept(1);
return;
}
fatal("accept failed");
}
if (server_exit) {
close(newfd);
return;
}
server_client_create(newfd);
}
/*
* Add accept event. If timeout is nonzero, add as a timeout instead of a read
* event - used to backoff when running out of file descriptors.
*/
void
server_add_accept(int timeout)
{
struct timeval tv = { timeout, 0 };
if (event_initialized(&server_ev_accept))
event_del(&server_ev_accept);
if (timeout == 0) {
event_set(&server_ev_accept,
server_fd, EV_READ, server_accept_callback, NULL);
event_add(&server_ev_accept, NULL);
} else {
event_set(&server_ev_accept,
server_fd, EV_TIMEOUT, server_accept_callback, NULL);
event_add(&server_ev_accept, &tv);
}
}
/* Signal handler. */
void
server_signal_callback(int sig, unused short events, unused void *data)
{
int fd;
switch (sig) {
case SIGTERM:
server_exit = 1;
server_send_exit();
break;
case SIGCHLD:
server_child_signal();
break;
case SIGUSR1:
event_del(&server_ev_accept);
fd = server_create_socket();
if (fd != -1) {
close(server_fd);
server_fd = fd;
server_update_socket();
}
server_add_accept(0);
break;
}
}
/* Handle SIGCHLD. */
void
server_child_signal(void)
{
int status;
pid_t pid;
for (;;) {
switch (pid = waitpid(WAIT_ANY, &status, WNOHANG|WUNTRACED)) {
case -1:
if (errno == ECHILD)
return;
fatal("waitpid failed");
case 0:
return;
}
if (WIFSTOPPED(status))
server_child_stopped(pid, status);
else if (WIFEXITED(status) || WIFSIGNALED(status))
server_child_exited(pid, status);
}
}
/* Handle exited children. */
void
server_child_exited(pid_t pid, int status)
{
struct window *w, *w1;
struct window_pane *wp;
struct job *job;
RB_FOREACH_SAFE(w, windows, &windows, w1) {
TAILQ_FOREACH(wp, &w->panes, entry) {
if (wp->pid == pid) {
wp->status = status;
server_destroy_pane(wp);
break;
}
}
}
LIST_FOREACH(job, &all_jobs, lentry) {
if (pid == job->pid) {
job_died(job, status); /* might free job */
break;
}
}
}
/* Handle stopped children. */
void
server_child_stopped(pid_t pid, int status)
{
struct window *w;
struct window_pane *wp;
if (WSTOPSIG(status) == SIGTTIN || WSTOPSIG(status) == SIGTTOU)
return;
RB_FOREACH(w, windows, &windows) {
TAILQ_FOREACH(wp, &w->panes, entry) {
if (wp->pid == pid) {
if (killpg(pid, SIGCONT) != 0)
kill(pid, SIGCONT);
}
}
}
}