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/* $Id: client.c,v 1.102 2011/03/19 23:27:35 tcunha Exp $ */
/*
* 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/socket.h>
#include <sys/stat.h>
#include <sys/un.h>
#include <sys/wait.h>
#include <errno.h>
#include <event.h>
#include <fcntl.h>
#include <pwd.h>
#include <stdlib.h>
#include <string.h>
#include <unistd.h>
#include "tmux.h"
struct imsgbuf client_ibuf;
struct event client_event;
const char *client_exitmsg;
int client_exitval;
enum msgtype client_exittype;
int client_attached;
int client_connect(char *, int);
void client_send_identify(int);
void client_send_environ(void);
void client_write_server(enum msgtype, void *, size_t);
void client_update_event(void);
void client_signal(int, short, void *);
void client_callback(int, short, void *);
int client_dispatch_attached(void);
int client_dispatch_wait(void *);
/* Connect client to server. */
int
client_connect(char *path, int start_server)
{
struct sockaddr_un sa;
size_t size;
int fd;
memset(&sa, 0, sizeof sa);
sa.sun_family = AF_UNIX;
size = strlcpy(sa.sun_path, path, sizeof sa.sun_path);
if (size >= sizeof sa.sun_path) {
errno = ENAMETOOLONG;
return (-1);
}
if ((fd = socket(AF_UNIX, SOCK_STREAM, 0)) == -1)
fatal("socket failed");
if (connect(fd, (struct sockaddr *) &sa, SUN_LEN(&sa)) == -1) {
if (!start_server)
goto failed;
switch (errno) {
case ECONNREFUSED:
if (unlink(path) != 0)
goto failed;
/* FALLTHROUGH */
case ENOENT:
if ((fd = server_start()) == -1)
goto failed;
break;
default:
goto failed;
}
}
setblocking(fd, 0);
return (fd);
failed:
close(fd);
return (-1);
}
/* Client main loop. */
int
client_main(int argc, char **argv, int flags)
{
struct cmd *cmd;
struct cmd_list *cmdlist;
struct msg_command_data cmddata;
int cmdflags, fd;
pid_t ppid;
enum msgtype msg;
char *cause;
/* Set up the initial command. */
cmdflags = 0;
if (shell_cmd != NULL) {
msg = MSG_SHELL;
cmdflags = CMD_STARTSERVER;
} else if (argc == 0) {
msg = MSG_COMMAND;
cmdflags = CMD_STARTSERVER|CMD_SENDENVIRON|CMD_CANTNEST;
} else {
msg = MSG_COMMAND;
/*
* It sucks parsing the command string twice (in client and
* later in server) but it is necessary to get the start server
* flag.
*/
if ((cmdlist = cmd_list_parse(argc, argv, &cause)) == NULL) {
log_warnx("%s", cause);
return (1);
}
cmdflags &= ~CMD_STARTSERVER;
TAILQ_FOREACH(cmd, &cmdlist->list, qentry) {
if (cmd->entry->flags & CMD_STARTSERVER)
cmdflags |= CMD_STARTSERVER;
if (cmd->entry->flags & CMD_SENDENVIRON)
cmdflags |= CMD_SENDENVIRON;
if (cmd->entry->flags & CMD_CANTNEST)
cmdflags |= CMD_CANTNEST;
}
cmd_list_free(cmdlist);
}
/*
* Check if this could be a nested session, if the command can't nest:
* if the socket path matches $TMUX, this is probably the same server.
*/
if (shell_cmd == NULL && environ_path != NULL &&
cmdflags & CMD_CANTNEST && strcmp(socket_path, environ_path) == 0) {
log_warnx("sessions should be nested with care. "
"unset $TMUX to force.");
return (1);
}
/* Initialise the client socket and start the server. */
fd = client_connect(socket_path, cmdflags & CMD_STARTSERVER);
if (fd == -1) {
log_warn("failed to connect to server");
return (1);
}
/* Set process title, log and signals now this is the client. */
#ifdef HAVE_SETPROCTITLE
setproctitle("client (%s)", socket_path);
#endif
logfile("client");
/* Create imsg. */
imsg_init(&client_ibuf, fd);
event_set(&client_event, fd, EV_READ, client_callback, shell_cmd);
/* Establish signal handlers. */
set_signals(client_signal);
/* Send initial environment. */
if (cmdflags & CMD_SENDENVIRON)
client_send_environ();
client_send_identify(flags);
/* Send first command. */
if (msg == MSG_COMMAND) {
/* Fill in command line arguments. */
cmddata.pid = environ_pid;
cmddata.idx = environ_idx;
/* Prepare command for server. */
cmddata.argc = argc;
if (cmd_pack_argv(
argc, argv, cmddata.argv, sizeof cmddata.argv) != 0) {
log_warnx("command too long");
return (1);
}
client_write_server(msg, &cmddata, sizeof cmddata);
} else if (msg == MSG_SHELL)
client_write_server(msg, NULL, 0);
/* Set the event and dispatch. */
client_update_event();
event_dispatch();
/* Print the exit message, if any, and exit. */
if (client_attached) {
if (client_exitmsg != NULL && !login_shell)
printf("[%s]\n", client_exitmsg);
ppid = getppid();
if (client_exittype == MSG_DETACHKILL && ppid > 1)
kill(ppid, SIGHUP);
}
return (client_exitval);
}
/* Send identify message to server with the file descriptors. */
void
client_send_identify(int flags)
{
struct msg_identify_data data;
char *term;
int fd;
data.flags = flags;
if (getcwd(data.cwd, sizeof data.cwd) == NULL)
*data.cwd = '\0';
term = getenv("TERM");
if (term == NULL ||
strlcpy(data.term, term, sizeof data.term) >= sizeof data.term)
*data.term = '\0';
if ((fd = dup(STDIN_FILENO)) == -1)
fatal("dup failed");
imsg_compose(&client_ibuf,
MSG_IDENTIFY, PROTOCOL_VERSION, -1, fd, &data, sizeof data);
if ((fd = dup(STDOUT_FILENO)) == -1)
fatal("dup failed");
imsg_compose(&client_ibuf,
MSG_STDOUT, PROTOCOL_VERSION, -1, fd, NULL, 0);
if ((fd = dup(STDERR_FILENO)) == -1)
fatal("dup failed");
imsg_compose(&client_ibuf,
MSG_STDERR, PROTOCOL_VERSION, -1, fd, NULL, 0);
}
/* Forward entire environment to server. */
void
client_send_environ(void)
{
struct msg_environ_data data;
char **var;
for (var = environ; *var != NULL; var++) {
if (strlcpy(data.var, *var, sizeof data.var) >= sizeof data.var)
continue;
client_write_server(MSG_ENVIRON, &data, sizeof data);
}
}
/* Write a message to the server without a file descriptor. */
void
client_write_server(enum msgtype type, void *buf, size_t len)
{
imsg_compose(&client_ibuf, type, PROTOCOL_VERSION, -1, -1, buf, len);
}
/* Update client event based on whether it needs to read or read and write. */
void
client_update_event(void)
{
short events;
event_del(&client_event);
events = EV_READ;
if (client_ibuf.w.queued > 0)
events |= EV_WRITE;
event_set(
&client_event, client_ibuf.fd, events, client_callback, shell_cmd);
event_add(&client_event, NULL);
}
/* Callback to handle signals in the client. */
/* ARGSUSED */
void
client_signal(int sig, unused short events, unused void *data)
{
struct sigaction sigact;
int status;
if (!client_attached) {
switch (sig) {
case SIGCHLD:
waitpid(WAIT_ANY, &status, WNOHANG);
break;
case SIGTERM:
event_loopexit(NULL);
break;
}
} else {
switch (sig) {
case SIGHUP:
client_exitmsg = "lost tty";
client_exitval = 1;
client_write_server(MSG_EXITING, NULL, 0);
break;
case SIGTERM:
client_exitmsg = "terminated";
client_exitval = 1;
client_write_server(MSG_EXITING, NULL, 0);
break;
case SIGWINCH:
client_write_server(MSG_RESIZE, NULL, 0);
break;
case SIGCONT:
memset(&sigact, 0, sizeof sigact);
sigemptyset(&sigact.sa_mask);
sigact.sa_flags = SA_RESTART;
sigact.sa_handler = SIG_IGN;
if (sigaction(SIGTSTP, &sigact, NULL) != 0)
fatal("sigaction failed");
client_write_server(MSG_WAKEUP, NULL, 0);
break;
}
}
client_update_event();
}
/* Callback for client imsg read events. */
/* ARGSUSED */
void
client_callback(unused int fd, short events, void *data)
{
ssize_t n;
int retval;
if (events & EV_READ) {
if ((n = imsg_read(&client_ibuf)) == -1 || n == 0)
goto lost_server;
if (client_attached)
retval = client_dispatch_attached();
else
retval = client_dispatch_wait(data);
if (retval != 0) {
event_loopexit(NULL);
return;
}
}
if (events & EV_WRITE) {
if (msgbuf_write(&client_ibuf.w) < 0)
goto lost_server;
}
client_update_event();
return;
lost_server:
client_exitmsg = "lost server";
client_exitval = 1;
event_loopexit(NULL);
}
/* Dispatch imsgs when in wait state (before MSG_READY). */
int
client_dispatch_wait(void *data)
{
struct imsg imsg;
ssize_t n, datalen;
struct msg_shell_data shelldata;
struct msg_exit_data exitdata;
const char *shellcmd = data;
if ((n = imsg_read(&client_ibuf)) == -1 || n == 0)
fatalx("imsg_read failed");
for (;;) {
if ((n = imsg_get(&client_ibuf, &imsg)) == -1)
fatalx("imsg_get failed");
if (n == 0)
return (0);
datalen = imsg.hdr.len - IMSG_HEADER_SIZE;
switch (imsg.hdr.type) {
case MSG_EXIT:
case MSG_SHUTDOWN:
if (datalen != sizeof exitdata) {
if (datalen != 0)
fatalx("bad MSG_EXIT size");
} else {
memcpy(&exitdata, imsg.data, sizeof exitdata);
client_exitval = exitdata.retcode;
}
imsg_free(&imsg);
return (-1);
case MSG_READY:
if (datalen != 0)
fatalx("bad MSG_READY size");
client_attached = 1;
break;
case MSG_VERSION:
if (datalen != 0)
fatalx("bad MSG_VERSION size");
log_warnx("protocol version mismatch (client %u, "
"server %u)", PROTOCOL_VERSION, imsg.hdr.peerid);
client_exitval = 1;
imsg_free(&imsg);
return (-1);
case MSG_SHELL:
if (datalen != sizeof shelldata)
fatalx("bad MSG_SHELL size");
memcpy(&shelldata, imsg.data, sizeof shelldata);
shelldata.shell[(sizeof shelldata.shell) - 1] = '\0';
clear_signals(0);
shell_exec(shelldata.shell, shellcmd);
/* NOTREACHED */
default:
fatalx("unexpected message");
}
imsg_free(&imsg);
}
}
/* Dispatch imsgs in attached state (after MSG_READY). */
/* ARGSUSED */
int
client_dispatch_attached(void)
{
struct imsg imsg;
struct msg_lock_data lockdata;
struct sigaction sigact;
ssize_t n, datalen;
for (;;) {
if ((n = imsg_get(&client_ibuf, &imsg)) == -1)
fatalx("imsg_get failed");
if (n == 0)
return (0);
datalen = imsg.hdr.len - IMSG_HEADER_SIZE;
log_debug("client got %d", imsg.hdr.type);
switch (imsg.hdr.type) {
case MSG_DETACHKILL:
case MSG_DETACH:
if (datalen != 0)
fatalx("bad MSG_DETACH size");
client_exittype = imsg.hdr.type;
if (imsg.hdr.type == MSG_DETACHKILL)
client_exitmsg = "detached and SIGHUP";
else
client_exitmsg = "detached";
client_write_server(MSG_EXITING, NULL, 0);
break;
case MSG_EXIT:
if (datalen != 0 &&
datalen != sizeof (struct msg_exit_data))
fatalx("bad MSG_EXIT size");
client_write_server(MSG_EXITING, NULL, 0);
client_exitmsg = "exited";
break;
case MSG_EXITED:
if (datalen != 0)
fatalx("bad MSG_EXITED size");
imsg_free(&imsg);
return (-1);
case MSG_SHUTDOWN:
if (datalen != 0)
fatalx("bad MSG_SHUTDOWN size");
client_write_server(MSG_EXITING, NULL, 0);
client_exitmsg = "server exited";
client_exitval = 1;
break;
case MSG_SUSPEND:
if (datalen != 0)
fatalx("bad MSG_SUSPEND size");
memset(&sigact, 0, sizeof sigact);
sigemptyset(&sigact.sa_mask);
sigact.sa_flags = SA_RESTART;
sigact.sa_handler = SIG_DFL;
if (sigaction(SIGTSTP, &sigact, NULL) != 0)
fatal("sigaction failed");
kill(getpid(), SIGTSTP);
break;
case MSG_LOCK:
if (datalen != sizeof lockdata)
fatalx("bad MSG_LOCK size");
memcpy(&lockdata, imsg.data, sizeof lockdata);
lockdata.cmd[(sizeof lockdata.cmd) - 1] = '\0';
system(lockdata.cmd);
client_write_server(MSG_UNLOCK, NULL, 0);
break;
default:
fatalx("unexpected message");
}
imsg_free(&imsg);
}
}