proc.c - tmux - Rivoreo Source Code Repositories

 /* $OpenBSD$ */

 /*
  * Copyright (c) 2015 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/queue.h>
 #include <sys/socket.h>
 #include <sys/uio.h>
 #include <sys/utsname.h>

 #include <errno.h>
 #include <event.h>
 #include <imsg.h>
 #include <signal.h>
 #include <stdlib.h>
 #include <string.h>
 #include <unistd.h>

 #include "tmux.h"

 struct tmuxproc {
 	const char	 *name;
 	int		  exit;

 	void		(*signalcb)(int);

 	struct event	  ev_sigint;
 	struct event	  ev_sighup;
 	struct event	  ev_sigchld;
 	struct event	  ev_sigcont;
 	struct event	  ev_sigterm;
 	struct event	  ev_sigusr1;
 	struct event	  ev_sigusr2;
 	struct event	  ev_sigwinch;

 	TAILQ_HEAD(, tmuxpeer) peers;
 };

 struct tmuxpeer {
 	struct tmuxproc	*parent;

 	struct imsgbuf	 ibuf;
 	struct event	 event;
 	uid_t		 uid;

 	int		 flags;
 #define PEER_BAD 0x1

 	void		(*dispatchcb)(struct imsg *, void *);
 	void		 *arg;

 	TAILQ_ENTRY(tmuxpeer) entry;
 };

 static int	peer_check_version(struct tmuxpeer *, struct imsg *);
 static void	proc_update_event(struct tmuxpeer *);

 static void
 proc_event_cb(__unused int fd, short events, void *arg)
 {
 	struct tmuxpeer	*peer = arg;
 	ssize_t		 n;
 	struct imsg	 imsg;

 	if (!(peer->flags & PEER_BAD) && (events & EV_READ)) {
 		if (((n = imsg_read(&peer->ibuf)) == -1 && errno != EAGAIN) ||
 		    n == 0) {
 			peer->dispatchcb(NULL, peer->arg);
 			return;
 		}
 		for (;;) {
 			if ((n = imsg_get(&peer->ibuf, &imsg)) == -1) {
 				peer->dispatchcb(NULL, peer->arg);
 				return;
 			}
 			if (n == 0)
 				break;
 			log_debug("peer %p message %d", peer, imsg.hdr.type);

 			if (peer_check_version(peer, &imsg) != 0) {
 				if (imsg.fd != -1)
 					close(imsg.fd);
 				imsg_free(&imsg);
 				break;
 			}

 			peer->dispatchcb(&imsg, peer->arg);
 			imsg_free(&imsg);
 		}
 	}

 	if (events & EV_WRITE) {
 		if (msgbuf_write(&peer->ibuf.w) <= 0 && errno != EAGAIN) {
 			peer->dispatchcb(NULL, peer->arg);
 			return;
 		}
 	}

 	if ((peer->flags & PEER_BAD) && peer->ibuf.w.queued == 0) {
 		peer->dispatchcb(NULL, peer->arg);
 		return;
 	}

 	proc_update_event(peer);
 }

 static void
 proc_signal_cb(int signo, __unused short events, void *arg)
 {
 	struct tmuxproc	*tp = arg;

 	tp->signalcb(signo);
 }

 static int
 peer_check_version(struct tmuxpeer *peer, struct imsg *imsg)
 {
 	int	version;

 	version = imsg->hdr.peerid & 0xff;
 	if (imsg->hdr.type != MSG_VERSION && version != PROTOCOL_VERSION) {
 		log_debug("peer %p bad version %d", peer, version);

 		proc_send(peer, MSG_VERSION, -1, NULL, 0);
 		peer->flags |= PEER_BAD;

 		return (-1);
 	}
 	return (0);
 }

 static void
 proc_update_event(struct tmuxpeer *peer)
 {
 	short	events;

 	event_del(&peer->event);

 	events = EV_READ;
 	if (peer->ibuf.w.queued > 0)
 		events |= EV_WRITE;
 	event_set(&peer->event, peer->ibuf.fd, events, proc_event_cb, peer);

 	event_add(&peer->event, NULL);
 }

 int
 proc_send(struct tmuxpeer *peer, enum msgtype type, int fd, const void *buf,
     size_t len)
 {
 	struct imsgbuf	*ibuf = &peer->ibuf;
 	void		*vp = (void *)buf;
 	int		 retval;

 	if (peer->flags & PEER_BAD)
 		return (-1);
 	log_debug("sending message %d to peer %p (%zu bytes)", type, peer, len);

 	retval = imsg_compose(ibuf, type, PROTOCOL_VERSION, -1, fd, vp, len);
 	if (retval != 1)
 		return (-1);
 	proc_update_event(peer);
 	return (0);
 }

 struct tmuxproc *
 proc_start(const char *name)
 {
 	struct tmuxproc	*tp;
 	struct utsname	 u;

 	log_open(name);
 	setproctitle("%s (%s)", name, socket_path);

 	if (uname(&u) < 0)
 		memset(&u, 0, sizeof u);

 	log_debug("%s started (%ld): version %s, socket %s, protocol %d", name,
 	    (long)getpid(), getversion(), socket_path, PROTOCOL_VERSION);
 	log_debug("on %s %s %s; libevent %s (%s)", u.sysname, u.release,
 	    u.version, event_get_version(), event_get_method());

 	tp = xcalloc(1, sizeof *tp);
 	tp->name = xstrdup(name);
 	TAILQ_INIT(&tp->peers);

 	return (tp);
 }

 void
 proc_loop(struct tmuxproc *tp, int (*loopcb)(void))
 {
 	log_debug("%s loop enter", tp->name);
 	do
 		event_loop(EVLOOP_ONCE);
 	while (!tp->exit && (loopcb == NULL || !loopcb ()));
 	log_debug("%s loop exit", tp->name);
 }

 void
 proc_exit(struct tmuxproc *tp)
 {
 	struct tmuxpeer	*peer;

 	TAILQ_FOREACH(peer, &tp->peers, entry)
 	    imsg_flush(&peer->ibuf);
 	tp->exit = 1;
 }

 void
 proc_set_signals(struct tmuxproc *tp, void (*signalcb)(int))
 {
 	struct sigaction	sa;

 	tp->signalcb = signalcb;

 	memset(&sa, 0, sizeof sa);
 	sigemptyset(&sa.sa_mask);
 	sa.sa_flags = SA_RESTART;
 	sa.sa_handler = SIG_IGN;

 	sigaction(SIGPIPE, &sa, NULL);
 	sigaction(SIGTSTP, &sa, NULL);
 	sigaction(SIGTTIN, &sa, NULL);
 	sigaction(SIGTTOU, &sa, NULL);
 	sigaction(SIGQUIT, &sa, NULL);

 	signal_set(&tp->ev_sigint, SIGINT, proc_signal_cb, tp);
 	signal_add(&tp->ev_sigint, NULL);
 	signal_set(&tp->ev_sighup, SIGHUP, proc_signal_cb, tp);
 	signal_add(&tp->ev_sighup, NULL);
 	signal_set(&tp->ev_sigchld, SIGCHLD, proc_signal_cb, tp);
 	signal_add(&tp->ev_sigchld, NULL);
 	signal_set(&tp->ev_sigcont, SIGCONT, proc_signal_cb, tp);
 	signal_add(&tp->ev_sigcont, NULL);
 	signal_set(&tp->ev_sigterm, SIGTERM, proc_signal_cb, tp);
 	signal_add(&tp->ev_sigterm, NULL);
 	signal_set(&tp->ev_sigusr1, SIGUSR1, proc_signal_cb, tp);
 	signal_add(&tp->ev_sigusr1, NULL);
 	signal_set(&tp->ev_sigusr2, SIGUSR2, proc_signal_cb, tp);
 	signal_add(&tp->ev_sigusr2, NULL);
 	signal_set(&tp->ev_sigwinch, SIGWINCH, proc_signal_cb, tp);
 	signal_add(&tp->ev_sigwinch, NULL);
 }

 void
 proc_clear_signals(struct tmuxproc *tp, int defaults)
 {
 	struct sigaction	sa;

 	memset(&sa, 0, sizeof sa);
 	sigemptyset(&sa.sa_mask);
 	sa.sa_flags = SA_RESTART;
 	sa.sa_handler = SIG_DFL;

 	sigaction(SIGPIPE, &sa, NULL);
 	sigaction(SIGTSTP, &sa, NULL);

 	signal_del(&tp->ev_sigint);
 	signal_del(&tp->ev_sighup);
 	signal_del(&tp->ev_sigchld);
 	signal_del(&tp->ev_sigcont);
 	signal_del(&tp->ev_sigterm);
 	signal_del(&tp->ev_sigusr1);
 	signal_del(&tp->ev_sigusr2);
 	signal_del(&tp->ev_sigwinch);

 	if (defaults) {
 		sigaction(SIGINT, &sa, NULL);
 		sigaction(SIGQUIT, &sa, NULL);
 		sigaction(SIGHUP, &sa, NULL);
 		sigaction(SIGCHLD, &sa, NULL);
 		sigaction(SIGCONT, &sa, NULL);
 		sigaction(SIGTERM, &sa, NULL);
 		sigaction(SIGUSR1, &sa, NULL);
 		sigaction(SIGUSR2, &sa, NULL);
 		sigaction(SIGWINCH, &sa, NULL);
 	}
 }

 struct tmuxpeer *
 proc_add_peer(struct tmuxproc *tp, int fd,
     void (*dispatchcb)(struct imsg *, void *), void *arg)
 {
 	struct tmuxpeer	*peer;
 	gid_t		 gid;

 	peer = xcalloc(1, sizeof *peer);
 	peer->parent = tp;

 	peer->dispatchcb = dispatchcb;
 	peer->arg = arg;

 	imsg_init(&peer->ibuf, fd);
 	event_set(&peer->event, fd, EV_READ, proc_event_cb, peer);

 	if (getpeereid(fd, &peer->uid, &gid) != 0)
 		peer->uid = (uid_t)-1;

 	log_debug("add peer %p: %d (%p)", peer, fd, arg);
 	TAILQ_INSERT_TAIL(&tp->peers, peer, entry);

 	proc_update_event(peer);
 	return (peer);
 }

 void
 proc_remove_peer(struct tmuxpeer *peer)
 {
 	TAILQ_REMOVE(&peer->parent->peers, peer, entry);
 	log_debug("remove peer %p", peer);

 	event_del(&peer->event);
 	imsg_clear(&peer->ibuf);

 	close(peer->ibuf.fd);
 	free(peer);
 }

 void
 proc_kill_peer(struct tmuxpeer *peer)
 {
 	peer->flags |= PEER_BAD;
 }

 void
 proc_flush_peer(struct tmuxpeer *peer)
 {
 	imsg_flush(&peer->ibuf);
 }

 void
 proc_toggle_log(struct tmuxproc *tp)
 {
 	log_toggle(tp->name);
 }

 pid_t
 proc_fork_and_daemon(int *fd)
 {
 	pid_t	pid;
 	int	pair[2];

 	if (socketpair(AF_UNIX, SOCK_STREAM, PF_UNSPEC, pair) != 0)
 		fatal("socketpair failed");
 	switch (pid = fork()) {
 	case -1:
 		fatal("fork failed");
 	case 0:
 		close(pair[0]);
 		*fd = pair[1];
 		if (daemon(1, 0) != 0)
 			fatal("daemon failed");
 		return (0);
 	default:
 		close(pair[1]);
 		*fd = pair[0];
 		return (pid);
 	}
 }

 uid_t
 proc_get_peer_uid(struct tmuxpeer *peer)
 {
 	return (peer->uid);
 }
	/* $OpenBSD$ */

	/*
	* Copyright (c) 2015 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/queue.h>
	#include <sys/socket.h>
	#include <sys/uio.h>
	#include <sys/utsname.h>

	#include <errno.h>
	#include <event.h>
	#include <imsg.h>
	#include <signal.h>
	#include <stdlib.h>
	#include <string.h>
	#include <unistd.h>

	#include "tmux.h"

	struct tmuxproc {
	const char *name;
	int exit;

	void (*signalcb)(int);

	struct event ev_sigint;
	struct event ev_sighup;
	struct event ev_sigchld;
	struct event ev_sigcont;
	struct event ev_sigterm;
	struct event ev_sigusr1;
	struct event ev_sigusr2;
	struct event ev_sigwinch;

	TAILQ_HEAD(, tmuxpeer) peers;
	};

	struct tmuxpeer {
	struct tmuxproc *parent;

	struct imsgbuf ibuf;
	struct event event;
	uid_t uid;

	int flags;
	#define PEER_BAD 0x1

	void (dispatchcb)(struct imsg , void *);
	void *arg;

	TAILQ_ENTRY(tmuxpeer) entry;
	};

	static int peer_check_version(struct tmuxpeer , struct imsg );
	static void proc_update_event(struct tmuxpeer *);

	static void
	proc_event_cb(__unused int fd, short events, void *arg)
	{
	struct tmuxpeer *peer = arg;
	ssize_t n;
	struct imsg imsg;

	if (!(peer->flags & PEER_BAD) && (events & EV_READ)) {
	if (((n = imsg_read(&peer->ibuf)) == -1 && errno != EAGAIN) \|\|
	n == 0) {
	peer->dispatchcb(NULL, peer->arg);
	return;
	}
	for (;;) {
	if ((n = imsg_get(&peer->ibuf, &imsg)) == -1) {
	peer->dispatchcb(NULL, peer->arg);
	return;
	}
	if (n == 0)
	break;
	log_debug("peer %p message %d", peer, imsg.hdr.type);

	if (peer_check_version(peer, &imsg) != 0) {
	if (imsg.fd != -1)
	close(imsg.fd);
	imsg_free(&imsg);
	break;
	}

	peer->dispatchcb(&imsg, peer->arg);
	imsg_free(&imsg);
	}
	}

	if (events & EV_WRITE) {
	if (msgbuf_write(&peer->ibuf.w) <= 0 && errno != EAGAIN) {
	peer->dispatchcb(NULL, peer->arg);
	return;
	}
	}

	if ((peer->flags & PEER_BAD) && peer->ibuf.w.queued == 0) {
	peer->dispatchcb(NULL, peer->arg);
	return;
	}

	proc_update_event(peer);
	}

	static void
	proc_signal_cb(int signo, __unused short events, void *arg)
	{
	struct tmuxproc *tp = arg;

	tp->signalcb(signo);
	}

	static int
	peer_check_version(struct tmuxpeer peer, struct imsg imsg)
	{
	int version;

	version = imsg->hdr.peerid & 0xff;
	if (imsg->hdr.type != MSG_VERSION && version != PROTOCOL_VERSION) {
	log_debug("peer %p bad version %d", peer, version);

	proc_send(peer, MSG_VERSION, -1, NULL, 0);
	peer->flags \|= PEER_BAD;

	return (-1);
	}
	return (0);
	}

	static void
	proc_update_event(struct tmuxpeer *peer)
	{
	short events;

	event_del(&peer->event);

	events = EV_READ;
	if (peer->ibuf.w.queued > 0)
	events \|= EV_WRITE;
	event_set(&peer->event, peer->ibuf.fd, events, proc_event_cb, peer);

	event_add(&peer->event, NULL);
	}

	int
	proc_send(struct tmuxpeer peer, enum msgtype type, int fd, const void buf,
	size_t len)
	{
	struct imsgbuf *ibuf = &peer->ibuf;
	void vp = (void )buf;
	int retval;

	if (peer->flags & PEER_BAD)
	return (-1);
	log_debug("sending message %d to peer %p (%zu bytes)", type, peer, len);

	retval = imsg_compose(ibuf, type, PROTOCOL_VERSION, -1, fd, vp, len);
	if (retval != 1)
	return (-1);
	proc_update_event(peer);
	return (0);
	}

	struct tmuxproc *
	proc_start(const char *name)
	{
	struct tmuxproc *tp;
	struct utsname u;

	log_open(name);
	setproctitle("%s (%s)", name, socket_path);

	if (uname(&u) < 0)
	memset(&u, 0, sizeof u);

	log_debug("%s started (%ld): version %s, socket %s, protocol %d", name,
	(long)getpid(), getversion(), socket_path, PROTOCOL_VERSION);
	log_debug("on %s %s %s; libevent %s (%s)", u.sysname, u.release,
	u.version, event_get_version(), event_get_method());

	tp = xcalloc(1, sizeof *tp);
	tp->name = xstrdup(name);
	TAILQ_INIT(&tp->peers);

	return (tp);
	}

	void
	proc_loop(struct tmuxproc tp, int (loopcb)(void))
	{
	log_debug("%s loop enter", tp->name);
	do
	event_loop(EVLOOP_ONCE);
	while (!tp->exit && (loopcb == NULL \|\| !loopcb ()));
	log_debug("%s loop exit", tp->name);
	}

	void
	proc_exit(struct tmuxproc *tp)
	{
	struct tmuxpeer *peer;

	TAILQ_FOREACH(peer, &tp->peers, entry)
	imsg_flush(&peer->ibuf);
	tp->exit = 1;
	}

	void
	proc_set_signals(struct tmuxproc tp, void (signalcb)(int))
	{
	struct sigaction sa;

	tp->signalcb = signalcb;

	memset(&sa, 0, sizeof sa);
	sigemptyset(&sa.sa_mask);
	sa.sa_flags = SA_RESTART;
	sa.sa_handler = SIG_IGN;

	sigaction(SIGPIPE, &sa, NULL);
	sigaction(SIGTSTP, &sa, NULL);
	sigaction(SIGTTIN, &sa, NULL);
	sigaction(SIGTTOU, &sa, NULL);
	sigaction(SIGQUIT, &sa, NULL);

	signal_set(&tp->ev_sigint, SIGINT, proc_signal_cb, tp);
	signal_add(&tp->ev_sigint, NULL);
	signal_set(&tp->ev_sighup, SIGHUP, proc_signal_cb, tp);
	signal_add(&tp->ev_sighup, NULL);
	signal_set(&tp->ev_sigchld, SIGCHLD, proc_signal_cb, tp);
	signal_add(&tp->ev_sigchld, NULL);
	signal_set(&tp->ev_sigcont, SIGCONT, proc_signal_cb, tp);
	signal_add(&tp->ev_sigcont, NULL);
	signal_set(&tp->ev_sigterm, SIGTERM, proc_signal_cb, tp);
	signal_add(&tp->ev_sigterm, NULL);
	signal_set(&tp->ev_sigusr1, SIGUSR1, proc_signal_cb, tp);
	signal_add(&tp->ev_sigusr1, NULL);
	signal_set(&tp->ev_sigusr2, SIGUSR2, proc_signal_cb, tp);
	signal_add(&tp->ev_sigusr2, NULL);
	signal_set(&tp->ev_sigwinch, SIGWINCH, proc_signal_cb, tp);
	signal_add(&tp->ev_sigwinch, NULL);
	}

	void
	proc_clear_signals(struct tmuxproc *tp, int defaults)
	{
	struct sigaction sa;

	memset(&sa, 0, sizeof sa);
	sigemptyset(&sa.sa_mask);
	sa.sa_flags = SA_RESTART;
	sa.sa_handler = SIG_DFL;

	sigaction(SIGPIPE, &sa, NULL);
	sigaction(SIGTSTP, &sa, NULL);

	signal_del(&tp->ev_sigint);
	signal_del(&tp->ev_sighup);
	signal_del(&tp->ev_sigchld);
	signal_del(&tp->ev_sigcont);
	signal_del(&tp->ev_sigterm);
	signal_del(&tp->ev_sigusr1);
	signal_del(&tp->ev_sigusr2);
	signal_del(&tp->ev_sigwinch);

	if (defaults) {
	sigaction(SIGINT, &sa, NULL);
	sigaction(SIGQUIT, &sa, NULL);
	sigaction(SIGHUP, &sa, NULL);
	sigaction(SIGCHLD, &sa, NULL);
	sigaction(SIGCONT, &sa, NULL);
	sigaction(SIGTERM, &sa, NULL);
	sigaction(SIGUSR1, &sa, NULL);
	sigaction(SIGUSR2, &sa, NULL);
	sigaction(SIGWINCH, &sa, NULL);
	}
	}

	struct tmuxpeer *
	proc_add_peer(struct tmuxproc *tp, int fd,
	void (dispatchcb)(struct imsg , void ), void arg)
	{
	struct tmuxpeer *peer;
	gid_t gid;

	peer = xcalloc(1, sizeof *peer);
	peer->parent = tp;

	peer->dispatchcb = dispatchcb;
	peer->arg = arg;

	imsg_init(&peer->ibuf, fd);
	event_set(&peer->event, fd, EV_READ, proc_event_cb, peer);

	if (getpeereid(fd, &peer->uid, &gid) != 0)
	peer->uid = (uid_t)-1;

	log_debug("add peer %p: %d (%p)", peer, fd, arg);
	TAILQ_INSERT_TAIL(&tp->peers, peer, entry);

	proc_update_event(peer);
	return (peer);
	}

	void
	proc_remove_peer(struct tmuxpeer *peer)
	{
	TAILQ_REMOVE(&peer->parent->peers, peer, entry);
	log_debug("remove peer %p", peer);

	event_del(&peer->event);
	imsg_clear(&peer->ibuf);

	close(peer->ibuf.fd);
	free(peer);
	}

	void
	proc_kill_peer(struct tmuxpeer *peer)
	{
	peer->flags \|= PEER_BAD;
	}

	void
	proc_flush_peer(struct tmuxpeer *peer)
	{
	imsg_flush(&peer->ibuf);
	}

	void
	proc_toggle_log(struct tmuxproc *tp)
	{
	log_toggle(tp->name);
	}

	pid_t
	proc_fork_and_daemon(int *fd)
	{
	pid_t pid;
	int pair[2];

	if (socketpair(AF_UNIX, SOCK_STREAM, PF_UNSPEC, pair) != 0)
	fatal("socketpair failed");
	switch (pid = fork()) {
	case -1:
	fatal("fork failed");
	case 0:
	close(pair[0]);
	*fd = pair[1];
	if (daemon(1, 0) != 0)
	fatal("daemon failed");
	return (0);
	default:
	close(pair[1]);
	*fd = pair[0];
	return (pid);
	}
	}

	uid_t
	proc_get_peer_uid(struct tmuxpeer *peer)
	{
	return (peer->uid);
	}