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GCC Code Coverage Report

Directory:	./		Exec	Total	Coverage
File:	usr.bin/tmux/client.c	Lines:	0	326	0.0 %
Date:	2016-12-06	Branches:	0	204	0.0 %


/* $OpenBSD: client.c,v 1.113 2016/01/19 15:59:12 nicm Exp $ */

/*
 * Copyright (c) 2007 Nicholas Marriott <nicholas.marriott@gmail.com>
 *
 * 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/file.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 <imsg.h>
#include <signal.h>
#include <stdlib.h>
#include <string.h>
#include <unistd.h>

#include "tmux.h"

struct tmuxproc	*client_proc;
struct tmuxpeer	*client_peer;
int		 client_flags;
struct event	 client_stdin;
enum {
	CLIENT_EXIT_NONE,
	CLIENT_EXIT_DETACHED,
	CLIENT_EXIT_DETACHED_HUP,
	CLIENT_EXIT_LOST_TTY,
	CLIENT_EXIT_TERMINATED,
	CLIENT_EXIT_LOST_SERVER,
	CLIENT_EXIT_EXITED,
	CLIENT_EXIT_SERVER_EXITED,
} client_exitreason = CLIENT_EXIT_NONE;
int		 client_exitval;
enum msgtype	 client_exittype;
const char	*client_exitsession;
int		 client_attached;

__dead void	client_exec(const char *,const char *);
int		client_get_lock(char *);
int		client_connect(struct event_base *, const char *, int);
void		client_send_identify(const char *, const char *);
void		client_stdin_callback(int, short, void *);
void		client_write(int, const char *, size_t);
void		client_signal(int);
void		client_dispatch(struct imsg *, void *);
void		client_dispatch_attached(struct imsg *);
void		client_dispatch_wait(struct imsg *, const char *);
const char     *client_exit_message(void);

/*
 * Get server create lock. If already held then server start is happening in
 * another client, so block until the lock is released and return -2 to
 * retry. Return -1 on failure to continue and start the server anyway.
 */
int
client_get_lock(char *lockfile)
{
	int lockfd;

	log_debug("lock file is %s", lockfile);

	if ((lockfd = open(lockfile, O_WRONLY|O_CREAT, 0600)) == -1) {
		log_debug("open failed: %s", strerror(errno));
		return (-1);
	}

	if (flock(lockfd, LOCK_EX|LOCK_NB) == -1) {
		log_debug("flock failed: %s", strerror(errno));
		if (errno != EAGAIN)
			return (lockfd);
		while (flock(lockfd, LOCK_EX) == -1 && errno == EINTR)
			/* nothing */;
		close(lockfd);
		return (-2);
	}
	log_debug("flock succeeded");

	return (lockfd);
}

/* Connect client to server. */
int
client_connect(struct event_base *base, const char *path, int start_server)
{
	struct sockaddr_un	sa;
	size_t			size;
	int			fd, lockfd = -1, locked = 0;
	char		       *lockfile = NULL;

	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);
	}
	log_debug("socket is %s", path);

retry:
	if ((fd = socket(AF_UNIX, SOCK_STREAM, 0)) == -1)
		return (-1);

	log_debug("trying connect");
	if (connect(fd, (struct sockaddr *)&sa, sizeof sa) == -1) {
		log_debug("connect failed: %s", strerror(errno));
		if (errno != ECONNREFUSED && errno != ENOENT)
			goto failed;
		if (!start_server)
			goto failed;
		close(fd);

		if (!locked) {
			xasprintf(&lockfile, "%s.lock", path);
			if ((lockfd = client_get_lock(lockfile)) < 0) {
				log_debug("didn't get lock (%d)", lockfd);

				free(lockfile);
				lockfile = NULL;

				if (lockfd == -2)
					goto retry;
			}
			log_debug("got lock (%d)", lockfd);

			/*
			 * Always retry at least once, even if we got the lock,
			 * because another client could have taken the lock,
			 * started the server and released the lock between our
			 * connect() and flock().
			 */
			locked = 1;
			goto retry;
		}

		if (lockfd >= 0 && unlink(path) != 0 && errno != ENOENT) {
			free(lockfile);
			close(lockfd);
			return (-1);
		}
		fd = server_start(base, lockfd, lockfile);
	}

	if (locked && lockfd >= 0) {
		free(lockfile);
		close(lockfd);
	}
	setblocking(fd, 0);
	return (fd);

failed:
	if (locked) {
		free(lockfile);
		close(lockfd);
	}
	close(fd);
	return (-1);
}

/* Get exit string from reason number. */
const char *
client_exit_message(void)
{
	static char msg[256];

	switch (client_exitreason) {
	case CLIENT_EXIT_NONE:
		break;
	case CLIENT_EXIT_DETACHED:
		if (client_exitsession != NULL) {
			xsnprintf(msg, sizeof msg, "detached "
			    "(from session %s)", client_exitsession);
			return (msg);
		}
		return ("detached");
	case CLIENT_EXIT_DETACHED_HUP:
		if (client_exitsession != NULL) {
			xsnprintf(msg, sizeof msg, "detached and SIGHUP "
			    "(from session %s)", client_exitsession);
			return (msg);
		}
		return ("detached and SIGHUP");
	case CLIENT_EXIT_LOST_TTY:
		return ("lost tty");
	case CLIENT_EXIT_TERMINATED:
		return ("terminated");
	case CLIENT_EXIT_LOST_SERVER:
		return ("lost server");
	case CLIENT_EXIT_EXITED:
		return ("exited");
	case CLIENT_EXIT_SERVER_EXITED:
		return ("server exited");
	}
	return ("unknown reason");
}

/* Client main loop. */
int
client_main(struct event_base *base, int argc, char **argv, int flags,
    const char *shellcmd)
{
	struct cmd		*cmd;
	struct cmd_list		*cmdlist;
	struct msg_command_data	*data;
	int			 cmdflags, fd, i;
	const char		*ttynam, *cwd;
	pid_t			 ppid;
	enum msgtype		 msg;
	char			*cause, path[PATH_MAX];
	struct termios		 tio, saved_tio;
	size_t			 size;

	/* Ignore SIGCHLD now or daemon() in the server will leave a zombie. */
	signal(SIGCHLD, SIG_IGN);

	/* Save the flags. */
	client_flags = flags;

	/* Set up the initial command. */
	cmdflags = 0;
	if (shellcmd != NULL) {
		msg = MSG_SHELL;
		cmdflags = CMD_STARTSERVER;
	} else if (argc == 0) {
		msg = MSG_COMMAND;
		cmdflags = CMD_STARTSERVER;
	} 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.
		 */
		cmdlist = cmd_list_parse(argc, argv, NULL, 0, &cause);
		if (cmdlist == NULL) {
			fprintf(stderr, "%s\n", cause);
			return (1);
		}
		cmdflags &= ~CMD_STARTSERVER;
		TAILQ_FOREACH(cmd, &cmdlist->list, qentry) {
			if (cmd->entry->flags & CMD_STARTSERVER)
				cmdflags |= CMD_STARTSERVER;
		}
		cmd_list_free(cmdlist);
	}

	/* Create client process structure (starts logging). */
	client_proc = proc_start("client", base, 0, client_signal);

	/* Initialize the client socket and start the server. */
	fd = client_connect(base, socket_path, cmdflags & CMD_STARTSERVER);
	if (fd == -1) {
		if (errno == ECONNREFUSED) {
			fprintf(stderr, "no server running on %s\n",
			    socket_path);
		} else {
			fprintf(stderr, "error connecting to %s (%s)\n",
			    socket_path, strerror(errno));
		}
		return (1);
	}
	client_peer = proc_add_peer(client_proc, fd, client_dispatch,
	    (void *)shellcmd);

	/* Save these before pledge(). */
	if ((cwd = getcwd(path, sizeof path)) == NULL) {
		if ((cwd = find_home()) == NULL)
			cwd = "/";
	}
	if ((ttynam = ttyname(STDIN_FILENO)) == NULL)
		ttynam = "";

	/*
	 * Drop privileges for client. "proc exec" is needed for -c and for
	 * locking (which uses system(3)).
	 *
	 * "tty" is needed to restore termios(4) and also for some reason -CC
	 * does not work properly without it (input is not recognised).
	 *
	 * "sendfd" is dropped later in client_dispatch_wait().
	 */
	if (pledge("stdio unix sendfd proc exec tty wpath cpath rpath", NULL) != 0)
		fatal("pledge failed");

	/* Free stuff that is not used in the client. */
	options_free(global_options);
	options_free(global_s_options);
	options_free(global_w_options);
	environ_free(global_environ);

	/* Create stdin handler. */
	setblocking(STDIN_FILENO, 0);
	event_set(&client_stdin, STDIN_FILENO, EV_READ|EV_PERSIST,
	    client_stdin_callback, NULL);
	if (client_flags & CLIENT_CONTROLCONTROL) {
		if (tcgetattr(STDIN_FILENO, &saved_tio) != 0)
			fatal("tcgetattr failed");
		cfmakeraw(&tio);
		tio.c_iflag = ICRNL|IXANY;
		tio.c_oflag = OPOST|ONLCR;
		tio.c_lflag = NOKERNINFO;
		tio.c_cflag = CREAD|CS8|HUPCL;
		tio.c_cc[VMIN] = 1;
		tio.c_cc[VTIME] = 0;
		cfsetispeed(&tio, cfgetispeed(&saved_tio));
		cfsetospeed(&tio, cfgetospeed(&saved_tio));
		tcsetattr(STDIN_FILENO, TCSANOW, &tio);
	}

	/* Send identify messages. */
	client_send_identify(ttynam, cwd);

	/* Send first command. */
	if (msg == MSG_COMMAND) {
		/* How big is the command? */
		size = 0;
		for (i = 0; i < argc; i++)
			size += strlen(argv[i]) + 1;
		data = xmalloc((sizeof *data) + size);

		/* Prepare command for server. */
		data->argc = argc;
		if (cmd_pack_argv(argc, argv, (char *)(data + 1), size) != 0) {
			fprintf(stderr, "command too long\n");
			free(data);
			return (1);
		}
		size += sizeof *data;

		/* Send the command. */
		if (proc_send(client_peer, msg, -1, data, size) != 0) {
			fprintf(stderr, "failed to send command\n");
			free(data);
			return (1);
		}
		free(data);
	} else if (msg == MSG_SHELL)
		proc_send(client_peer, msg, -1, NULL, 0);

	/* Start main loop. */
	proc_loop(client_proc, NULL);

	/* Print the exit message, if any, and exit. */
	if (client_attached) {
		if (client_exitreason != CLIENT_EXIT_NONE)
			printf("[%s]\n", client_exit_message());

		ppid = getppid();
		if (client_exittype == MSG_DETACHKILL && ppid > 1)
			kill(ppid, SIGHUP);
	} else if (client_flags & CLIENT_CONTROLCONTROL) {
		if (client_exitreason != CLIENT_EXIT_NONE)
			printf("%%exit %s\n", client_exit_message());
		else
			printf("%%exit\n");
		printf("\033\\");
		tcsetattr(STDOUT_FILENO, TCSAFLUSH, &saved_tio);
	} else if (client_exitreason != CLIENT_EXIT_NONE)
		fprintf(stderr, "%s\n", client_exit_message());
	setblocking(STDIN_FILENO, 1);
	return (client_exitval);
}

/* Send identify messages to server. */
void
client_send_identify(const char *ttynam, const char *cwd)
{
	const char	 *s;
	char		**ss;
	size_t		  sslen;
	int		  fd, flags = client_flags;
	pid_t		  pid;

	proc_send(client_peer, MSG_IDENTIFY_FLAGS, -1, &flags, sizeof flags);

	if ((s = getenv("TERM")) == NULL)
		s = "";
	proc_send(client_peer, MSG_IDENTIFY_TERM, -1, s, strlen(s) + 1);

	proc_send(client_peer, MSG_IDENTIFY_TTYNAME, -1, ttynam,
	    strlen(ttynam) + 1);
	proc_send(client_peer, MSG_IDENTIFY_CWD, -1, cwd, strlen(cwd) + 1);

	if ((fd = dup(STDIN_FILENO)) == -1)
		fatal("dup failed");
	proc_send(client_peer, MSG_IDENTIFY_STDIN, fd, NULL, 0);

	pid = getpid();
	proc_send(client_peer, MSG_IDENTIFY_CLIENTPID, -1, &pid, sizeof pid);

	for (ss = environ; *ss != NULL; ss++) {
		sslen = strlen(*ss) + 1;
		if (sslen > MAX_IMSGSIZE - IMSG_HEADER_SIZE)
			continue;
		proc_send(client_peer, MSG_IDENTIFY_ENVIRON, -1, *ss, sslen);
	}

	proc_send(client_peer, MSG_IDENTIFY_DONE, -1, NULL, 0);
}

/* Callback for client stdin read events. */
void
client_stdin_callback(__unused int fd, __unused short events,
    __unused void *arg)
{
	struct msg_stdin_data	data;

	data.size = read(STDIN_FILENO, data.data, sizeof data.data);
	if (data.size < 0 && (errno == EINTR || errno == EAGAIN))
		return;

	proc_send(client_peer, MSG_STDIN, -1, &data, sizeof data);
	if (data.size <= 0)
		event_del(&client_stdin);
}

/* Force write to file descriptor. */
void
client_write(int fd, const char *data, size_t size)
{
	ssize_t	used;

	while (size != 0) {
		used = write(fd, data, size);
		if (used == -1) {
			if (errno == EINTR || errno == EAGAIN)
				continue;
			break;
		}
		data += used;
		size -= used;
	}
}

/* Run command in shell; used for -c. */
__dead void
client_exec(const char *shell, const char *shellcmd)
{
	const char	*name, *ptr;
	char		*argv0;

	log_debug("shell %s, command %s", shell, shellcmd);

	ptr = strrchr(shell, '/');
	if (ptr != NULL && *(ptr + 1) != '\0')
		name = ptr + 1;
	else
		name = shell;
	if (client_flags & CLIENT_LOGIN)
		xasprintf(&argv0, "-%s", name);
	else
		xasprintf(&argv0, "%s", name);
	setenv("SHELL", shell, 1);

	setblocking(STDIN_FILENO, 1);
	setblocking(STDOUT_FILENO, 1);
	setblocking(STDERR_FILENO, 1);
	closefrom(STDERR_FILENO + 1);

	execl(shell, argv0, "-c", shellcmd, (char *) NULL);
	fatal("execl failed");
}

/* Callback to handle signals in the client. */
void
client_signal(int sig)
{
	struct sigaction sigact;
	int		 status;

	if (sig == SIGCHLD)
		waitpid(WAIT_ANY, &status, WNOHANG);
	else if (!client_attached) {
		if (sig == SIGTERM)
			proc_exit(client_proc);
	} else {
		switch (sig) {
		case SIGHUP:
			client_exitreason = CLIENT_EXIT_LOST_TTY;
			client_exitval = 1;
			proc_send(client_peer, MSG_EXITING, -1, NULL, 0);
			break;
		case SIGTERM:
			client_exitreason = CLIENT_EXIT_TERMINATED;
			client_exitval = 1;
			proc_send(client_peer, MSG_EXITING, -1, NULL, 0);
			break;
		case SIGWINCH:
			proc_send(client_peer, MSG_RESIZE, -1, 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");
			proc_send(client_peer, MSG_WAKEUP, -1, NULL, 0);
			break;
		}
	}
}

/* Callback for client read events. */
void
client_dispatch(struct imsg *imsg, void *arg)
{
	if (imsg == NULL) {
		client_exitreason = CLIENT_EXIT_LOST_SERVER;
		client_exitval = 1;
		proc_exit(client_proc);
		return;
	}

	if (client_attached)
		client_dispatch_attached(imsg);
	else
		client_dispatch_wait(imsg, arg);
}

/* Dispatch imsgs when in wait state (before MSG_READY). */
void
client_dispatch_wait(struct imsg *imsg, const char *shellcmd)
{
	char			*data;
	ssize_t			 datalen;
	struct msg_stdout_data	 stdoutdata;
	struct msg_stderr_data	 stderrdata;
	int			 retval;
	static int		 pledge_applied;

	/*
	 * "sendfd" is no longer required once all of the identify messages
	 * have been sent. We know the server won't send us anything until that
	 * point (because we don't ask it to), so we can drop "sendfd" once we
	 * get the first message from the server.
	 */
	if (!pledge_applied) {
		if (pledge("stdio unix proc exec tty wpath cpath rpath", NULL) != 0)
			fatal("pledge failed");
		pledge_applied = 1;
	};

	data = imsg->data;
	datalen = imsg->hdr.len - IMSG_HEADER_SIZE;

	switch (imsg->hdr.type) {
	case MSG_EXIT:
	case MSG_SHUTDOWN:
		if (datalen != sizeof retval && datalen != 0)
			fatalx("bad MSG_EXIT size");
		if (datalen == sizeof retval) {
			memcpy(&retval, data, sizeof retval);
			client_exitval = retval;
		}
		proc_exit(client_proc);
		break;
	case MSG_READY:
		if (datalen != 0)
			fatalx("bad MSG_READY size");

		event_del(&client_stdin);
		client_attached = 1;
		proc_send(client_peer, MSG_RESIZE, -1, NULL, 0);
		break;
	case MSG_STDIN:
		if (datalen != 0)
			fatalx("bad MSG_STDIN size");

		event_add(&client_stdin, NULL);
		break;
	case MSG_STDOUT:
		if (datalen != sizeof stdoutdata)
			fatalx("bad MSG_STDOUT size");
		memcpy(&stdoutdata, data, sizeof stdoutdata);

		client_write(STDOUT_FILENO, stdoutdata.data,
		    stdoutdata.size);
		break;
	case MSG_STDERR:
		if (datalen != sizeof stderrdata)
			fatalx("bad MSG_STDERR size");
		memcpy(&stderrdata, data, sizeof stderrdata);

		client_write(STDERR_FILENO, stderrdata.data,
		    stderrdata.size);
		break;
	case MSG_VERSION:
		if (datalen != 0)
			fatalx("bad MSG_VERSION size");

		fprintf(stderr, "protocol version mismatch "
		    "(client %d, server %u)\n", PROTOCOL_VERSION,
		    imsg->hdr.peerid & 0xff);
		client_exitval = 1;
		proc_exit(client_proc);
		break;
	case MSG_SHELL:
		if (datalen == 0 || data[datalen - 1] != '\0')
			fatalx("bad MSG_SHELL string");

		clear_signals(0);
		client_exec(data, shellcmd);
		/* NOTREACHED */
	case MSG_DETACH:
	case MSG_DETACHKILL:
		proc_send(client_peer, MSG_EXITING, -1, NULL, 0);
		break;
	case MSG_EXITED:
		proc_exit(client_proc);
		break;
	}
}

/* Dispatch imsgs in attached state (after MSG_READY). */
void
client_dispatch_attached(struct imsg *imsg)
{
	struct sigaction	 sigact;
	char			*data;
	ssize_t			 datalen;

	data = imsg->data;
	datalen = imsg->hdr.len - IMSG_HEADER_SIZE;

	switch (imsg->hdr.type) {
	case MSG_DETACH:
	case MSG_DETACHKILL:
		if (datalen == 0 || data[datalen - 1] != '\0')
			fatalx("bad MSG_DETACH string");

		client_exitsession = xstrdup(data);
		client_exittype = imsg->hdr.type;
		if (imsg->hdr.type == MSG_DETACHKILL)
			client_exitreason = CLIENT_EXIT_DETACHED_HUP;
		else
			client_exitreason = CLIENT_EXIT_DETACHED;
		proc_send(client_peer, MSG_EXITING, -1, NULL, 0);
		break;
	case MSG_EXIT:
		if (datalen != 0 && datalen != sizeof (int))
			fatalx("bad MSG_EXIT size");

		proc_send(client_peer, MSG_EXITING, -1, NULL, 0);
		client_exitreason = CLIENT_EXIT_EXITED;
		break;
	case MSG_EXITED:
		if (datalen != 0)
			fatalx("bad MSG_EXITED size");

		proc_exit(client_proc);
		break;
	case MSG_SHUTDOWN:
		if (datalen != 0)
			fatalx("bad MSG_SHUTDOWN size");

		proc_send(client_peer, MSG_EXITING, -1, NULL, 0);
		client_exitreason = CLIENT_EXIT_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 == 0 || data[datalen - 1] != '\0')
			fatalx("bad MSG_LOCK string");

		system(data);
		proc_send(client_peer, MSG_UNLOCK, -1, NULL, 0);
		break;
	}
}


Generated by: GCOVR (Version 3.3)

Line	Branch	Exec	Source
1			/* $OpenBSD: client.c,v 1.113 2016/01/19 15:59:12 nicm Exp $ */
2
3			/*
4			* Copyright (c) 2007 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/file.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 <imsg.h>
30			#include <signal.h>
31			#include <stdlib.h>
32			#include <string.h>
33			#include <unistd.h>
34
35			#include "tmux.h"
36
37			struct tmuxproc *client_proc;
38			struct tmuxpeer *client_peer;
39			int client_flags;
40			struct event client_stdin;
41			enum {
42			CLIENT_EXIT_NONE,
43			CLIENT_EXIT_DETACHED,
44			CLIENT_EXIT_DETACHED_HUP,
45			CLIENT_EXIT_LOST_TTY,
46			CLIENT_EXIT_TERMINATED,
47			CLIENT_EXIT_LOST_SERVER,
48			CLIENT_EXIT_EXITED,
49			CLIENT_EXIT_SERVER_EXITED,
50			} client_exitreason = CLIENT_EXIT_NONE;
51			int client_exitval;
52			enum msgtype client_exittype;
53			const char *client_exitsession;
54			int client_attached;
55
56			__dead void client_exec(const char ,const char );
57			int client_get_lock(char *);
58			int client_connect(struct event_base , const char , int);
59			void client_send_identify(const char , const char );
60			void client_stdin_callback(int, short, void *);
61			void client_write(int, const char *, size_t);
62			void client_signal(int);
63			void client_dispatch(struct imsg , void );
64			void client_dispatch_attached(struct imsg *);
65			void client_dispatch_wait(struct imsg , const char );
66			const char *client_exit_message(void);
67
68			/*
69			* Get server create lock. If already held then server start is happening in
70			* another client, so block until the lock is released and return -2 to
71			* retry. Return -1 on failure to continue and start the server anyway.
72			*/
73			int
74			client_get_lock(char *lockfile)
75			{
76			int lockfd;
77
78			log_debug("lock file is %s", lockfile);
79
80			if ((lockfd = open(lockfile, O_WRONLY\|O_CREAT, 0600)) == -1) {
81			log_debug("open failed: %s", strerror(errno));
82			return (-1);
83			}
84
85			if (flock(lockfd, LOCK_EX\|LOCK_NB) == -1) {
86			log_debug("flock failed: %s", strerror(errno));
87			if (errno != EAGAIN)
88			return (lockfd);
89			while (flock(lockfd, LOCK_EX) == -1 && errno == EINTR)
90			/* nothing */;
91			close(lockfd);
92			return (-2);
93			}
94			log_debug("flock succeeded");
95
96			return (lockfd);
97			}
98
99			/* Connect client to server. */
100			int
101			client_connect(struct event_base base, const char path, int start_server)
102			{
103			struct sockaddr_un sa;
104			size_t size;
105			int fd, lockfd = -1, locked = 0;
106			char *lockfile = NULL;
107
108			memset(&sa, 0, sizeof sa);
109			sa.sun_family = AF_UNIX;
110			size = strlcpy(sa.sun_path, path, sizeof sa.sun_path);
111			if (size >= sizeof sa.sun_path) {
112			errno = ENAMETOOLONG;
113			return (-1);
114			}
115			log_debug("socket is %s", path);
116
117			retry:
118			if ((fd = socket(AF_UNIX, SOCK_STREAM, 0)) == -1)
119			return (-1);
120
121			log_debug("trying connect");
122			if (connect(fd, (struct sockaddr *)&sa, sizeof sa) == -1) {
123			log_debug("connect failed: %s", strerror(errno));
124			if (errno != ECONNREFUSED && errno != ENOENT)
125			goto failed;
126			if (!start_server)
127			goto failed;
128			close(fd);
129
130			if (!locked) {
131			xasprintf(&lockfile, "%s.lock", path);
132			if ((lockfd = client_get_lock(lockfile)) < 0) {
133			log_debug("didn't get lock (%d)", lockfd);
134
135			free(lockfile);
136			lockfile = NULL;
137
138			if (lockfd == -2)
139			goto retry;
140			}
141			log_debug("got lock (%d)", lockfd);
142
143			/*
144			* Always retry at least once, even if we got the lock,
145			* because another client could have taken the lock,
146			* started the server and released the lock between our
147			* connect() and flock().
148			*/
149			locked = 1;
150			goto retry;
151			}
152
153			if (lockfd >= 0 && unlink(path) != 0 && errno != ENOENT) {
154			free(lockfile);
155			close(lockfd);
156			return (-1);
157			}
158			fd = server_start(base, lockfd, lockfile);
159			}
160
161			if (locked && lockfd >= 0) {
162			free(lockfile);
163			close(lockfd);
164			}
165			setblocking(fd, 0);
166			return (fd);
167
168			failed:
169			if (locked) {
170			free(lockfile);
171			close(lockfd);
172			}
173			close(fd);
174			return (-1);
175			}
176
177			/* Get exit string from reason number. */
178			const char *
179			client_exit_message(void)
180			{
181			static char msg[256];
182
183			switch (client_exitreason) {
184			case CLIENT_EXIT_NONE:
185			break;
186			case CLIENT_EXIT_DETACHED:
187			if (client_exitsession != NULL) {
188			xsnprintf(msg, sizeof msg, "detached "
189			"(from session %s)", client_exitsession);
190			return (msg);
191			}
192			return ("detached");
193			case CLIENT_EXIT_DETACHED_HUP:
194			if (client_exitsession != NULL) {
195			xsnprintf(msg, sizeof msg, "detached and SIGHUP "
196			"(from session %s)", client_exitsession);
197			return (msg);
198			}
199			return ("detached and SIGHUP");
200			case CLIENT_EXIT_LOST_TTY:
201			return ("lost tty");
202			case CLIENT_EXIT_TERMINATED:
203			return ("terminated");
204			case CLIENT_EXIT_LOST_SERVER:
205			return ("lost server");
206			case CLIENT_EXIT_EXITED:
207			return ("exited");
208			case CLIENT_EXIT_SERVER_EXITED:
209			return ("server exited");
210			}
211			return ("unknown reason");
212			}
213
214			/* Client main loop. */
215			int
216			client_main(struct event_base base, int argc, char *argv, int flags,
217			const char *shellcmd)
218			{
219			struct cmd *cmd;
220			struct cmd_list *cmdlist;
221			struct msg_command_data *data;
222			int cmdflags, fd, i;
223			const char ttynam, cwd;
224			pid_t ppid;
225			enum msgtype msg;
226			char *cause, path[PATH_MAX];
227			struct termios tio, saved_tio;
228			size_t size;
229
230			/* Ignore SIGCHLD now or daemon() in the server will leave a zombie. */
231			signal(SIGCHLD, SIG_IGN);
232
233			/* Save the flags. */
234			client_flags = flags;
235
236			/* Set up the initial command. */
237			cmdflags = 0;
238			if (shellcmd != NULL) {
239			msg = MSG_SHELL;
240			cmdflags = CMD_STARTSERVER;
241			} else if (argc == 0) {
242			msg = MSG_COMMAND;
243			cmdflags = CMD_STARTSERVER;
244			} else {
245			msg = MSG_COMMAND;
246
247			/*
248			* It sucks parsing the command string twice (in client and
249			* later in server) but it is necessary to get the start server
250			* flag.
251			*/
252			cmdlist = cmd_list_parse(argc, argv, NULL, 0, &cause);
253			if (cmdlist == NULL) {
254			fprintf(stderr, "%s\n", cause);
255			return (1);
256			}
257			cmdflags &= ~CMD_STARTSERVER;
258			TAILQ_FOREACH(cmd, &cmdlist->list, qentry) {
259			if (cmd->entry->flags & CMD_STARTSERVER)
260			cmdflags \|= CMD_STARTSERVER;
261			}
262			cmd_list_free(cmdlist);
263			}
264
265			/* Create client process structure (starts logging). */
266			client_proc = proc_start("client", base, 0, client_signal);
267
268			/* Initialize the client socket and start the server. */
269			fd = client_connect(base, socket_path, cmdflags & CMD_STARTSERVER);
270			if (fd == -1) {
271			if (errno == ECONNREFUSED) {
272			fprintf(stderr, "no server running on %s\n",
273			socket_path);
274			} else {
275			fprintf(stderr, "error connecting to %s (%s)\n",
276			socket_path, strerror(errno));
277			}
278			return (1);
279			}
280			client_peer = proc_add_peer(client_proc, fd, client_dispatch,
281			(void *)shellcmd);
282
283			/* Save these before pledge(). */
284			if ((cwd = getcwd(path, sizeof path)) == NULL) {
285			if ((cwd = find_home()) == NULL)
286			cwd = "/";
287			}
288			if ((ttynam = ttyname(STDIN_FILENO)) == NULL)
289			ttynam = "";
290
291			/*
292			* Drop privileges for client. "proc exec" is needed for -c and for
293			* locking (which uses system(3)).
294			*
295			* "tty" is needed to restore termios(4) and also for some reason -CC
296			* does not work properly without it (input is not recognised).
297			*
298			* "sendfd" is dropped later in client_dispatch_wait().
299			*/
300			if (pledge("stdio unix sendfd proc exec tty wpath cpath rpath", NULL) != 0)
301			fatal("pledge failed");
302
303			/* Free stuff that is not used in the client. */
304			options_free(global_options);
305			options_free(global_s_options);
306			options_free(global_w_options);
307			environ_free(global_environ);
308
309			/* Create stdin handler. */
310			setblocking(STDIN_FILENO, 0);
311			event_set(&client_stdin, STDIN_FILENO, EV_READ\|EV_PERSIST,
312			client_stdin_callback, NULL);
313			if (client_flags & CLIENT_CONTROLCONTROL) {
314			if (tcgetattr(STDIN_FILENO, &saved_tio) != 0)
315			fatal("tcgetattr failed");
316			cfmakeraw(&tio);
317			tio.c_iflag = ICRNL\|IXANY;
318			tio.c_oflag = OPOST\|ONLCR;
319			tio.c_lflag = NOKERNINFO;
320			tio.c_cflag = CREAD\|CS8\|HUPCL;
321			tio.c_cc[VMIN] = 1;
322			tio.c_cc[VTIME] = 0;
323			cfsetispeed(&tio, cfgetispeed(&saved_tio));
324			cfsetospeed(&tio, cfgetospeed(&saved_tio));
325			tcsetattr(STDIN_FILENO, TCSANOW, &tio);
326			}
327
328			/* Send identify messages. */
329			client_send_identify(ttynam, cwd);
330
331			/* Send first command. */
332			if (msg == MSG_COMMAND) {
333			/* How big is the command? */
334			size = 0;
335			for (i = 0; i < argc; i++)
336			size += strlen(argv[i]) + 1;
337			data = xmalloc((sizeof *data) + size);
338
339			/* Prepare command for server. */
340			data->argc = argc;
341			if (cmd_pack_argv(argc, argv, (char *)(data + 1), size) != 0) {
342			fprintf(stderr, "command too long\n");
343			free(data);
344			return (1);
345			}
346			size += sizeof *data;
347
348			/* Send the command. */
349			if (proc_send(client_peer, msg, -1, data, size) != 0) {
350			fprintf(stderr, "failed to send command\n");
351			free(data);
352			return (1);
353			}
354			free(data);
355			} else if (msg == MSG_SHELL)
356			proc_send(client_peer, msg, -1, NULL, 0);
357
358			/* Start main loop. */
359			proc_loop(client_proc, NULL);
360
361			/* Print the exit message, if any, and exit. */
362			if (client_attached) {
363			if (client_exitreason != CLIENT_EXIT_NONE)
364			printf("[%s]\n", client_exit_message());
365
366			ppid = getppid();
367			if (client_exittype == MSG_DETACHKILL && ppid > 1)
368			kill(ppid, SIGHUP);
369			} else if (client_flags & CLIENT_CONTROLCONTROL) {
370			if (client_exitreason != CLIENT_EXIT_NONE)
371			printf("%%exit %s\n", client_exit_message());
372			else
373			printf("%%exit\n");
374			printf("\033\\");
375			tcsetattr(STDOUT_FILENO, TCSAFLUSH, &saved_tio);
376			} else if (client_exitreason != CLIENT_EXIT_NONE)
377			fprintf(stderr, "%s\n", client_exit_message());
378			setblocking(STDIN_FILENO, 1);
379			return (client_exitval);
380			}
381
382			/* Send identify messages to server. */
383			void
384			client_send_identify(const char ttynam, const char cwd)
385			{
386			const char *s;
387			char **ss;
388			size_t sslen;
389			int fd, flags = client_flags;
390			pid_t pid;
391
392			proc_send(client_peer, MSG_IDENTIFY_FLAGS, -1, &flags, sizeof flags);
393
394			if ((s = getenv("TERM")) == NULL)
395			s = "";
396			proc_send(client_peer, MSG_IDENTIFY_TERM, -1, s, strlen(s) + 1);
397
398			proc_send(client_peer, MSG_IDENTIFY_TTYNAME, -1, ttynam,
399			strlen(ttynam) + 1);
400			proc_send(client_peer, MSG_IDENTIFY_CWD, -1, cwd, strlen(cwd) + 1);
401
402			if ((fd = dup(STDIN_FILENO)) == -1)
403			fatal("dup failed");
404			proc_send(client_peer, MSG_IDENTIFY_STDIN, fd, NULL, 0);
405
406			pid = getpid();
407			proc_send(client_peer, MSG_IDENTIFY_CLIENTPID, -1, &pid, sizeof pid);
408
409			for (ss = environ; *ss != NULL; ss++) {
410			sslen = strlen(*ss) + 1;
411			if (sslen > MAX_IMSGSIZE - IMSG_HEADER_SIZE)
412			continue;
413			proc_send(client_peer, MSG_IDENTIFY_ENVIRON, -1, *ss, sslen);
414			}
415
416			proc_send(client_peer, MSG_IDENTIFY_DONE, -1, NULL, 0);
417			}
418
419			/* Callback for client stdin read events. */
420			void
421			client_stdin_callback(__unused int fd, __unused short events,
422			__unused void *arg)
423			{
424			struct msg_stdin_data data;
425
426			data.size = read(STDIN_FILENO, data.data, sizeof data.data);
427			if (data.size < 0 && (errno == EINTR \|\| errno == EAGAIN))
428			return;
429
430			proc_send(client_peer, MSG_STDIN, -1, &data, sizeof data);
431			if (data.size <= 0)
432			event_del(&client_stdin);
433			}
434
435			/* Force write to file descriptor. */
436			void
437			client_write(int fd, const char *data, size_t size)
438			{
439			ssize_t used;
440
441			while (size != 0) {
442			used = write(fd, data, size);
443			if (used == -1) {
444			if (errno == EINTR \|\| errno == EAGAIN)
445			continue;
446			break;
447			}
448			data += used;
449			size -= used;
450			}
451			}
452
453			/* Run command in shell; used for -c. */
454			__dead void
455			client_exec(const char shell, const char shellcmd)
456			{
457			const char name, ptr;
458			char *argv0;
459
460			log_debug("shell %s, command %s", shell, shellcmd);
461
462			ptr = strrchr(shell, '/');
463			if (ptr != NULL && *(ptr + 1) != '\0')
464			name = ptr + 1;
465			else
466			name = shell;
467			if (client_flags & CLIENT_LOGIN)
468			xasprintf(&argv0, "-%s", name);
469			else
470			xasprintf(&argv0, "%s", name);
471			setenv("SHELL", shell, 1);
472
473			setblocking(STDIN_FILENO, 1);
474			setblocking(STDOUT_FILENO, 1);
475			setblocking(STDERR_FILENO, 1);
476			closefrom(STDERR_FILENO + 1);
477
478			execl(shell, argv0, "-c", shellcmd, (char *) NULL);
479			fatal("execl failed");
480			}
481
482			/* Callback to handle signals in the client. */
483			void
484			client_signal(int sig)
485			{
486			struct sigaction sigact;
487			int status;
488
489			if (sig == SIGCHLD)
490			waitpid(WAIT_ANY, &status, WNOHANG);
491			else if (!client_attached) {
492			if (sig == SIGTERM)
493			proc_exit(client_proc);
494			} else {
495			switch (sig) {
496			case SIGHUP:
497			client_exitreason = CLIENT_EXIT_LOST_TTY;
498			client_exitval = 1;
499			proc_send(client_peer, MSG_EXITING, -1, NULL, 0);
500			break;
501			case SIGTERM:
502			client_exitreason = CLIENT_EXIT_TERMINATED;
503			client_exitval = 1;
504			proc_send(client_peer, MSG_EXITING, -1, NULL, 0);
505			break;
506			case SIGWINCH:
507			proc_send(client_peer, MSG_RESIZE, -1, NULL, 0);
508			break;
509			case SIGCONT:
510			memset(&sigact, 0, sizeof sigact);
511			sigemptyset(&sigact.sa_mask);
512			sigact.sa_flags = SA_RESTART;
513			sigact.sa_handler = SIG_IGN;
514			if (sigaction(SIGTSTP, &sigact, NULL) != 0)
515			fatal("sigaction failed");
516			proc_send(client_peer, MSG_WAKEUP, -1, NULL, 0);
517			break;
518			}
519			}
520			}
521
522			/* Callback for client read events. */
523			void
524			client_dispatch(struct imsg imsg, void arg)
525			{
526			if (imsg == NULL) {
527			client_exitreason = CLIENT_EXIT_LOST_SERVER;
528			client_exitval = 1;
529			proc_exit(client_proc);
530			return;
531			}
532
533			if (client_attached)
534			client_dispatch_attached(imsg);
535			else
536			client_dispatch_wait(imsg, arg);
537			}
538
539			/* Dispatch imsgs when in wait state (before MSG_READY). */
540			void
541			client_dispatch_wait(struct imsg imsg, const char shellcmd)
542			{
543			char *data;
544			ssize_t datalen;
545			struct msg_stdout_data stdoutdata;
546			struct msg_stderr_data stderrdata;
547			int retval;
548			static int pledge_applied;
549
550			/*
551			* "sendfd" is no longer required once all of the identify messages
552			* have been sent. We know the server won't send us anything until that
553			* point (because we don't ask it to), so we can drop "sendfd" once we
554			* get the first message from the server.
555			*/
556			if (!pledge_applied) {
557			if (pledge("stdio unix proc exec tty wpath cpath rpath", NULL) != 0)
558			fatal("pledge failed");
559			pledge_applied = 1;
560			};
561
562			data = imsg->data;
563			datalen = imsg->hdr.len - IMSG_HEADER_SIZE;
564
565			switch (imsg->hdr.type) {
566			case MSG_EXIT:
567			case MSG_SHUTDOWN:
568			if (datalen != sizeof retval && datalen != 0)
569			fatalx("bad MSG_EXIT size");
570			if (datalen == sizeof retval) {
571			memcpy(&retval, data, sizeof retval);
572			client_exitval = retval;
573			}
574			proc_exit(client_proc);
575			break;
576			case MSG_READY:
577			if (datalen != 0)
578			fatalx("bad MSG_READY size");
579
580			event_del(&client_stdin);
581			client_attached = 1;
582			proc_send(client_peer, MSG_RESIZE, -1, NULL, 0);
583			break;
584			case MSG_STDIN:
585			if (datalen != 0)
586			fatalx("bad MSG_STDIN size");
587
588			event_add(&client_stdin, NULL);
589			break;
590			case MSG_STDOUT:
591			if (datalen != sizeof stdoutdata)
592			fatalx("bad MSG_STDOUT size");
593			memcpy(&stdoutdata, data, sizeof stdoutdata);
594
595			client_write(STDOUT_FILENO, stdoutdata.data,
596			stdoutdata.size);
597			break;
598			case MSG_STDERR:
599			if (datalen != sizeof stderrdata)
600			fatalx("bad MSG_STDERR size");
601			memcpy(&stderrdata, data, sizeof stderrdata);
602
603			client_write(STDERR_FILENO, stderrdata.data,
604			stderrdata.size);
605			break;
606			case MSG_VERSION:
607			if (datalen != 0)
608			fatalx("bad MSG_VERSION size");
609
610			fprintf(stderr, "protocol version mismatch "
611			"(client %d, server %u)\n", PROTOCOL_VERSION,
612			imsg->hdr.peerid & 0xff);
613			client_exitval = 1;
614			proc_exit(client_proc);
615			break;
616			case MSG_SHELL:
617			if (datalen == 0 \|\| data[datalen - 1] != '\0')
618			fatalx("bad MSG_SHELL string");
619
620			clear_signals(0);
621			client_exec(data, shellcmd);
622			/* NOTREACHED */
623			case MSG_DETACH:
624			case MSG_DETACHKILL:
625			proc_send(client_peer, MSG_EXITING, -1, NULL, 0);
626			break;
627			case MSG_EXITED:
628			proc_exit(client_proc);
629			break;
630			}
631			}
632
633			/* Dispatch imsgs in attached state (after MSG_READY). */
634			void
635			client_dispatch_attached(struct imsg *imsg)
636			{
637			struct sigaction sigact;
638			char *data;
639			ssize_t datalen;
640
641			data = imsg->data;
642			datalen = imsg->hdr.len - IMSG_HEADER_SIZE;
643
644			switch (imsg->hdr.type) {
645			case MSG_DETACH:
646			case MSG_DETACHKILL:
647			if (datalen == 0 \|\| data[datalen - 1] != '\0')
648			fatalx("bad MSG_DETACH string");
649
650			client_exitsession = xstrdup(data);
651			client_exittype = imsg->hdr.type;
652			if (imsg->hdr.type == MSG_DETACHKILL)
653			client_exitreason = CLIENT_EXIT_DETACHED_HUP;
654			else
655			client_exitreason = CLIENT_EXIT_DETACHED;
656			proc_send(client_peer, MSG_EXITING, -1, NULL, 0);
657			break;
658			case MSG_EXIT:
659			if (datalen != 0 && datalen != sizeof (int))
660			fatalx("bad MSG_EXIT size");
661
662			proc_send(client_peer, MSG_EXITING, -1, NULL, 0);
663			client_exitreason = CLIENT_EXIT_EXITED;
664			break;
665			case MSG_EXITED:
666			if (datalen != 0)
667			fatalx("bad MSG_EXITED size");
668
669			proc_exit(client_proc);
670			break;
671			case MSG_SHUTDOWN:
672			if (datalen != 0)
673			fatalx("bad MSG_SHUTDOWN size");
674
675			proc_send(client_peer, MSG_EXITING, -1, NULL, 0);
676			client_exitreason = CLIENT_EXIT_SERVER_EXITED;
677			client_exitval = 1;
678			break;
679			case MSG_SUSPEND:
680			if (datalen != 0)
681			fatalx("bad MSG_SUSPEND size");
682
683			memset(&sigact, 0, sizeof sigact);
684			sigemptyset(&sigact.sa_mask);
685			sigact.sa_flags = SA_RESTART;
686			sigact.sa_handler = SIG_DFL;
687			if (sigaction(SIGTSTP, &sigact, NULL) != 0)
688			fatal("sigaction failed");
689			kill(getpid(), SIGTSTP);
690			break;
691			case MSG_LOCK:
692			if (datalen == 0 \|\| data[datalen - 1] != '\0')
693			fatalx("bad MSG_LOCK string");
694
695			system(data);
696			proc_send(client_peer, MSG_UNLOCK, -1, NULL, 0);
697			break;
698			}
699			}