[u/mdw/putty] / unix / pty.c

#define _XOPEN_SOURCE
#define _XOPEN_SOURCE_EXTENDED
#include <features.h>

#include <stdio.h>
#include <stdlib.h>
#include <string.h>
#include <unistd.h>
#include <signal.h>
#include <fcntl.h>
#include <termios.h>
#include <grp.h>
#include <utmp.h>
#include <pwd.h>
#include <time.h>
#include <sys/types.h>
#include <sys/wait.h>
#include <sys/ioctl.h>

#include "putty.h"

#ifndef FALSE
#define FALSE 0
#endif
#ifndef TRUE
#define TRUE 1
#endif

#ifndef UTMP_FILE
#define UTMP_FILE "/var/run/utmp"
#endif
#ifndef WTMP_FILE
#define WTMP_FILE "/var/log/wtmp"
#endif
#ifndef LASTLOG_FILE
#ifdef _PATH_LASTLOG
#define LASTLOG_FILE _PATH_LASTLOG
#else
#define LASTLOG_FILE "/var/log/lastlog"
#endif
#endif

int pty_master_fd;
static int pty_child_pid;
static sig_atomic_t pty_child_dead;
#ifndef OMIT_UTMP
static struct utmp utmp_entry;
#endif
char **pty_argv;

int pty_child_is_dead(void)
{
    return pty_child_dead;
}

static void pty_size(void);

static void setup_utmp(char *ttyname)
{
#ifndef OMIT_UTMP
#ifdef HAVE_LASTLOG
    struct lastlog lastlog_entry;
    FILE *lastlog;
#endif
    struct passwd *pw;
    char *location = get_x_display();
    FILE *wtmp;

    pw = getpwuid(getuid());
    memset(&utmp_entry, 0, sizeof(utmp_entry));
    utmp_entry.ut_type = USER_PROCESS;
    utmp_entry.ut_pid = getpid();
    strncpy(utmp_entry.ut_line, ttyname+5, lenof(utmp_entry.ut_line));
    strncpy(utmp_entry.ut_id, ttyname+8, lenof(utmp_entry.ut_id));
    strncpy(utmp_entry.ut_user, pw->pw_name, lenof(utmp_entry.ut_user));
    strncpy(utmp_entry.ut_host, location, lenof(utmp_entry.ut_host));
    time(&utmp_entry.ut_time);

#if defined HAVE_PUTUTLINE
    utmpname(UTMP_FILE);
    setutent();
    pututline(&utmp_entry);
    endutent();
#endif

    if ((wtmp = fopen(WTMP_FILE, "a")) != NULL) {
	fwrite(&utmp_entry, 1, sizeof(utmp_entry), wtmp);
	fclose(wtmp);
    }

#ifdef HAVE_LASTLOG
    memset(&lastlog_entry, 0, sizeof(lastlog_entry));
    strncpy(lastlog_entry.ll_line, ttyname+5, lenof(lastlog_entry.ll_line));
    strncpy(lastlog_entry.ll_host, location, lenof(lastlog_entry.ll_host));
    time(&lastlog_entry.ll_time);
    if ((lastlog = fopen(LASTLOG_FILE, "r+")) != NULL) {
	fseek(lastlog, sizeof(lastlog_entry) * getuid(), SEEK_SET);
	fwrite(&lastlog_entry, 1, sizeof(lastlog_entry), lastlog);
	fclose(lastlog);
    }
#endif

#endif
}

static void cleanup_utmp(void)
{
#ifndef OMIT_UTMP
    FILE *wtmp;

    utmp_entry.ut_type = DEAD_PROCESS;
    memset(utmp_entry.ut_user, 0, lenof(utmp_entry.ut_user));
    time(&utmp_entry.ut_time);

    if ((wtmp = fopen(WTMP_FILE, "a")) != NULL) {
	fwrite(&utmp_entry, 1, sizeof(utmp_entry), wtmp);
	fclose(wtmp);
    }

    memset(utmp_entry.ut_line, 0, lenof(utmp_entry.ut_line));
    utmp_entry.ut_time = 0;

#if defined HAVE_PUTUTLINE
    utmpname(UTMP_FILE);
    setutent();
    pututline(&utmp_entry);
    endutent();
#endif

#endif
}

static void sigchld_handler(int signum)
{
    pid_t pid;
    int status;
    pid = waitpid(-1, &status, WNOHANG);
    if (pid == pty_child_pid && (WIFEXITED(status) || WIFSIGNALED(status)))
	pty_child_dead = TRUE;	
}

static void fatal_sig_handler(int signum)
{
    signal(signum, SIG_DFL);
    cleanup_utmp();
    setuid(getuid());
    raise(signum);
}

/*
 * Called to set up the pty.
 * 
 * Returns an error message, or NULL on success.
 *
 * Also places the canonical host name into `realhost'. It must be
 * freed by the caller.
 */
static char *pty_init(char *host, int port, char **realhost, int nodelay)
{
    int slavefd;
    char name[FILENAME_MAX];
    pid_t pid, pgrp;

#ifdef BSD_PTYS
    {
	const char chars1[] = "pqrstuvwxyz";
	const char chars2[] = "0123456789abcdef";
	const char *p1, *p2;
	char master_name[20];

	for (p1 = chars1; *p1; p1++)
	    for (p2 = chars2; *p2; p2++) {
		sprintf(master_name, "/dev/pty%c%c", *p1, *p2);
		pty_master_fd = open(master_name, O_RDWR);
		if (pty_master_fd >= 0) {
		    if (geteuid() == 0 ||
			access(master_name, R_OK | W_OK) == 0)
			goto got_one;
		    close(pty_master_fd);
		}
	    }

	/* If we get here, we couldn't get a tty at all. */
	fprintf(stderr, "pterm: unable to open a pseudo-terminal device\n");
	exit(1);

	got_one:
	strcpy(name, master_name);
	name[5] = 't';		       /* /dev/ptyXX -> /dev/ttyXX */
    }
#else
    pty_master_fd = open("/dev/ptmx", O_RDWR);

    if (pty_master_fd < 0) {
	perror("/dev/ptmx: open");
	exit(1);
    }

    if (grantpt(pty_master_fd) < 0) {
	perror("grantpt");
	exit(1);
    }
    
    if (unlockpt(pty_master_fd) < 0) {
	perror("unlockpt");
	exit(1);
    }

    name[FILENAME_MAX-1] = '\0';
    strncpy(name, ptsname(pty_master_fd), FILENAME_MAX-1);
#endif

    /*
     * Trap as many fatal signals as we can in the hope of having
     * the best chance to clean up utmp before termination.
     */
    signal(SIGHUP, fatal_sig_handler);
    signal(SIGINT, fatal_sig_handler);
    signal(SIGQUIT, fatal_sig_handler);
    signal(SIGILL, fatal_sig_handler);
    signal(SIGABRT, fatal_sig_handler);
    signal(SIGFPE, fatal_sig_handler);
    signal(SIGPIPE, fatal_sig_handler);
    signal(SIGALRM, fatal_sig_handler);
    signal(SIGTERM, fatal_sig_handler);
    signal(SIGSEGV, fatal_sig_handler);
    signal(SIGUSR1, fatal_sig_handler);
    signal(SIGUSR2, fatal_sig_handler);
#ifdef SIGBUS
    signal(SIGBUS, fatal_sig_handler);
#endif
#ifdef SIGPOLL
    signal(SIGPOLL, fatal_sig_handler);
#endif
#ifdef SIGPROF
    signal(SIGPROF, fatal_sig_handler);
#endif
#ifdef SIGSYS
    signal(SIGSYS, fatal_sig_handler);
#endif
#ifdef SIGTRAP
    signal(SIGTRAP, fatal_sig_handler);
#endif
#ifdef SIGVTALRM
    signal(SIGVTALRM, fatal_sig_handler);
#endif
#ifdef SIGXCPU
    signal(SIGXCPU, fatal_sig_handler);
#endif
#ifdef SIGXFSZ
    signal(SIGXFSZ, fatal_sig_handler);
#endif
#ifdef SIGIO
    signal(SIGIO, fatal_sig_handler);
#endif
    /* Also clean up utmp on normal exit. */
    atexit(cleanup_utmp);
    setup_utmp(name);

    /*
     * Fork and execute the command.
     */
    pid = fork();
    if (pid < 0) {
	perror("fork");
	exit(1);
    }

    if (pid == 0) {
	int i;
	/*
	 * We are the child.
	 */

	slavefd = open(name, O_RDWR);
	if (slavefd < 0) {
	    perror("slave pty: open");
	    exit(1);
	}

#ifdef BSD_PTYS
	/* We need to chown/chmod the /dev/ttyXX device. */
	{
	    struct group *gp = getgrnam("tty");
	    fchown(slavefd, getuid(), gp ? gp->gr_gid : -1);
	    fchmod(slavefd, 0600);
	}
#endif

	close(pty_master_fd);
	close(0);
	close(1);
	close(2);
	fcntl(slavefd, F_SETFD, 0);    /* don't close on exec */
	dup2(slavefd, 0);
	dup2(slavefd, 1);
	dup2(slavefd, 2);
	setsid();
	ioctl(slavefd, TIOCSCTTY, 1);
	pgrp = getpid();
	tcsetpgrp(slavefd, pgrp);
	setpgrp();
	close(open(name, O_WRONLY, 0));
	setpgrp();
	/* In case we were setgid-utmp or setuid-root, drop privs. */
	setgid(getgid());
	setuid(getuid());
	/* Close everything _else_, for tidiness. */
	for (i = 3; i < 1024; i++)
	    close(i);
	{
	    char term_env_var[10 + sizeof(cfg.termtype)];
	    sprintf(term_env_var, "TERM=%s", cfg.termtype);
	    putenv(term_env_var);
	}
	if (pty_argv)
	    execvp(pty_argv[0], pty_argv);
	else
	    execl(getenv("SHELL"), getenv("SHELL"), NULL);
	/*
	 * If we're here, exec has gone badly foom.
	 */
	perror("exec");
	exit(127);
    } else {
	close(slavefd);
	pty_child_pid = pid;
	pty_child_dead = FALSE;
	signal(SIGCHLD, sigchld_handler);
    }

    return NULL;
}

/*
 * Called to send data down the pty.
 */
static int pty_send(char *buf, int len)
{
    while (len > 0) {
	int ret = write(pty_master_fd, buf, len);
	if (ret < 0) {
	    perror("write pty master");
	    exit(1);
	}
	buf += ret;
	len -= ret;
    }
    return 0;
}

/*
 * Called to query the current socket sendability status.
 */
static int pty_sendbuffer(void)
{
    return 0;
}

/*
 * Called to set the size of the window
 */
static void pty_size(void)
{
    struct winsize size;

    size.ws_row = (unsigned short)rows;
    size.ws_col = (unsigned short)cols;
    ioctl(pty_master_fd, TIOCSWINSZ, (void *)&size);
    return;
}

/*
 * Send special codes.
 */
static void pty_special(Telnet_Special code)
{
    /* Do nothing! */
    return;
}

static Socket pty_socket(void)
{
    return NULL;		       /* shouldn't ever be needed */
}

static int pty_sendok(void)
{
    return 1;
}

static void pty_unthrottle(int backlog)
{
    /* do nothing */
}

static int pty_ldisc(int option)
{
    return 0;			       /* neither editing nor echoing */
}

static int pty_exitcode(void)
{
    /* Shouldn't ever be required */
    return 0;
}

Backend pty_backend = {
    pty_init,
    pty_send,
    pty_sendbuffer,
    pty_size,
    pty_special,
    pty_socket,
    pty_exitcode,
    pty_sendok,
    pty_ldisc,
    pty_unthrottle,
    1
};
Commit	Line	Data
054d8535	1	#define _XOPEN_SOURCE
88e6b9ca	2	#define _XOPEN_SOURCE_EXTENDED
054d8535	3	#include <features.h>
054d8535	4
1709795f	5	#include <stdio.h>
1709795f	6	#include <stdlib.h>
054d8535	7	#include <string.h>
054d8535	8	#include <unistd.h>
a0e16eb1	9	#include <signal.h>
054d8535	10	#include <fcntl.h>
88e6b9ca	11	#include <termios.h>
be4f86de	12	#include <grp.h>
755a6d84	13	#include <utmp.h>
	14	#include <pwd.h>
	15	#include <time.h>
a0e16eb1	16	#include <sys/types.h>
a0e16eb1	17	#include <sys/wait.h>
88e6b9ca	18	#include <sys/ioctl.h>
1709795f	19
	20	#include "putty.h"
	21
	22	#ifndef FALSE
	23	#define FALSE 0
	24	#endif
	25	#ifndef TRUE
	26	#define TRUE 1
	27	#endif
	28
755a6d84	29	#ifndef UTMP_FILE
	30	#define UTMP_FILE "/var/run/utmp"
	31	#endif
	32	#ifndef WTMP_FILE
	33	#define WTMP_FILE "/var/log/wtmp"
	34	#endif
	35	#ifndef LASTLOG_FILE
	36	#ifdef _PATH_LASTLOG
	37	#define LASTLOG_FILE _PATH_LASTLOG
	38	#else
	39	#define LASTLOG_FILE "/var/log/lastlog"
	40	#endif
	41	#endif
	42
054d8535	43	int pty_master_fd;
a0e16eb1	44	static int pty_child_pid;
a0e16eb1	45	static sig_atomic_t pty_child_dead;
755a6d84	46	#ifndef OMIT_UTMP
	47	static struct utmp utmp_entry;
	48	#endif
6169c758	49	char **pty_argv;
054d8535	50
a0e16eb1	51	int pty_child_is_dead(void)
	52	{
	53	return pty_child_dead;
	54	}
	55
1709795f	56	static void pty_size(void);
1709795f	57
755a6d84	58	static void setup_utmp(char *ttyname)
	59	{
	60	#ifndef OMIT_UTMP
	61	#ifdef HAVE_LASTLOG
	62	struct lastlog lastlog_entry;
	63	FILE *lastlog;
	64	#endif
	65	struct passwd *pw;
	66	char *location = get_x_display();
	67	FILE *wtmp;
	68
	69	pw = getpwuid(getuid());
	70	memset(&utmp_entry, 0, sizeof(utmp_entry));
	71	utmp_entry.ut_type = USER_PROCESS;
	72	utmp_entry.ut_pid = getpid();
	73	strncpy(utmp_entry.ut_line, ttyname+5, lenof(utmp_entry.ut_line));
	74	strncpy(utmp_entry.ut_id, ttyname+8, lenof(utmp_entry.ut_id));
	75	strncpy(utmp_entry.ut_user, pw->pw_name, lenof(utmp_entry.ut_user));
	76	strncpy(utmp_entry.ut_host, location, lenof(utmp_entry.ut_host));
	77	time(&utmp_entry.ut_time);
	78
	79	#if defined HAVE_PUTUTLINE
	80	utmpname(UTMP_FILE);
	81	setutent();
	82	pututline(&utmp_entry);
	83	endutent();
	84	#endif
	85
	86	if ((wtmp = fopen(WTMP_FILE, "a")) != NULL) {
	87	fwrite(&utmp_entry, 1, sizeof(utmp_entry), wtmp);
	88	fclose(wtmp);
	89	}
	90
	91	#ifdef HAVE_LASTLOG
	92	memset(&lastlog_entry, 0, sizeof(lastlog_entry));
	93	strncpy(lastlog_entry.ll_line, ttyname+5, lenof(lastlog_entry.ll_line));
	94	strncpy(lastlog_entry.ll_host, location, lenof(lastlog_entry.ll_host));
	95	time(&lastlog_entry.ll_time);
	96	if ((lastlog = fopen(LASTLOG_FILE, "r+")) != NULL) {
	97	fseek(lastlog, sizeof(lastlog_entry) * getuid(), SEEK_SET);
	98	fwrite(&lastlog_entry, 1, sizeof(lastlog_entry), lastlog);
	99	fclose(lastlog);
	100	}
	101	#endif
	102
	103	#endif
	104	}
	105
	106	static void cleanup_utmp(void)
	107	{
	108	#ifndef OMIT_UTMP
	109	FILE *wtmp;
	110
	111	utmp_entry.ut_type = DEAD_PROCESS;
	112	memset(utmp_entry.ut_user, 0, lenof(utmp_entry.ut_user));
	113	time(&utmp_entry.ut_time);
	114
	115	if ((wtmp = fopen(WTMP_FILE, "a")) != NULL) {
	116	fwrite(&utmp_entry, 1, sizeof(utmp_entry), wtmp);
	117	fclose(wtmp);
	118	}
	119
	120	memset(utmp_entry.ut_line, 0, lenof(utmp_entry.ut_line));
	121	utmp_entry.ut_time = 0;
122
123	#if defined HAVE_PUTUTLINE
124	utmpname(UTMP_FILE);
125	setutent();
126	pututline(&utmp_entry);
127	endutent();
128	#endif
129
130	#endif
131	}
132
a0e16eb1	133	static void sigchld_handler(int signum)
	134	{
	135	pid_t pid;
	136	int status;
	137	pid = waitpid(-1, &status, WNOHANG);
	138	if (pid == pty_child_pid && (WIFEXITED(status) \|\| WIFSIGNALED(status)))
	139	pty_child_dead = TRUE;
	140	}
	141
755a6d84	142	static void fatal_sig_handler(int signum)
	143	{
	144	signal(signum, SIG_DFL);
	145	cleanup_utmp();
	146	setuid(getuid());
	147	raise(signum);
	148	}
	149
1709795f	150	/*
	151	* Called to set up the pty.
	152	*
	153	* Returns an error message, or NULL on success.
	154	*
	155	* Also places the canonical host name into `realhost'. It must be
	156	* freed by the caller.
	157	*/
	158	static char pty_init(char host, int port, char **realhost, int nodelay)
	159	{
054d8535	160	int slavefd;
054d8535	161	char name[FILENAME_MAX];
d37c2d81	162	pid_t pid, pgrp;
054d8535	163
be4f86de	164	#ifdef BSD_PTYS
	165	{
	166	const char chars1[] = "pqrstuvwxyz";
	167	const char chars2[] = "0123456789abcdef";
	168	const char p1, p2;
	169	char master_name[20];
	170
	171	for (p1 = chars1; *p1; p1++)
	172	for (p2 = chars2; *p2; p2++) {
	173	sprintf(master_name, "/dev/pty%c%c", p1, p2);
	174	pty_master_fd = open(master_name, O_RDWR);
	175	if (pty_master_fd >= 0) {
	176	if (geteuid() == 0 \|\|
	177	access(master_name, R_OK \| W_OK) == 0)
	178	goto got_one;
	179	close(pty_master_fd);
	180	}
	181	}
	182
	183	/* If we get here, we couldn't get a tty at all. */
	184	fprintf(stderr, "pterm: unable to open a pseudo-terminal device\n");
	185	exit(1);
	186
	187	got_one:
	188	strcpy(name, master_name);
	189	name[5] = 't'; /* /dev/ptyXX -> /dev/ttyXX */
	190	}
	191	#else
054d8535	192	pty_master_fd = open("/dev/ptmx", O_RDWR);
	193
	194	if (pty_master_fd < 0) {
	195	perror("/dev/ptmx: open");
	196	exit(1);
	197	}
	198
	199	if (grantpt(pty_master_fd) < 0) {
	200	perror("grantpt");
	201	exit(1);
	202	}
	203
	204	if (unlockpt(pty_master_fd) < 0) {
	205	perror("unlockpt");
	206	exit(1);
	207	}
	208
	209	name[FILENAME_MAX-1] = '\0';
	210	strncpy(name, ptsname(pty_master_fd), FILENAME_MAX-1);
be4f86de	211	#endif
054d8535	212
054d8535	213	/*
755a6d84	214	* Trap as many fatal signals as we can in the hope of having
	215	* the best chance to clean up utmp before termination.
	216	*/
	217	signal(SIGHUP, fatal_sig_handler);
	218	signal(SIGINT, fatal_sig_handler);
	219	signal(SIGQUIT, fatal_sig_handler);
	220	signal(SIGILL, fatal_sig_handler);
	221	signal(SIGABRT, fatal_sig_handler);
	222	signal(SIGFPE, fatal_sig_handler);
	223	signal(SIGPIPE, fatal_sig_handler);
	224	signal(SIGALRM, fatal_sig_handler);
	225	signal(SIGTERM, fatal_sig_handler);
	226	signal(SIGSEGV, fatal_sig_handler);
	227	signal(SIGUSR1, fatal_sig_handler);
	228	signal(SIGUSR2, fatal_sig_handler);
	229	#ifdef SIGBUS
	230	signal(SIGBUS, fatal_sig_handler);
	231	#endif
	232	#ifdef SIGPOLL
	233	signal(SIGPOLL, fatal_sig_handler);
	234	#endif
	235	#ifdef SIGPROF
	236	signal(SIGPROF, fatal_sig_handler);
	237	#endif
	238	#ifdef SIGSYS
	239	signal(SIGSYS, fatal_sig_handler);
	240	#endif
	241	#ifdef SIGTRAP
	242	signal(SIGTRAP, fatal_sig_handler);
	243	#endif
	244	#ifdef SIGVTALRM
	245	signal(SIGVTALRM, fatal_sig_handler);
	246	#endif
	247	#ifdef SIGXCPU
	248	signal(SIGXCPU, fatal_sig_handler);
	249	#endif
	250	#ifdef SIGXFSZ
	251	signal(SIGXFSZ, fatal_sig_handler);
	252	#endif
	253	#ifdef SIGIO
	254	signal(SIGIO, fatal_sig_handler);
	255	#endif
	256	/* Also clean up utmp on normal exit. */
	257	atexit(cleanup_utmp);
	258	setup_utmp(name);
	259
	260	/*
054d8535	261	* Fork and execute the command.
	262	*/
	263	pid = fork();
	264	if (pid < 0) {
	265	perror("fork");
88e6b9ca	266	exit(1);
054d8535	267	}
	268
	269	if (pid == 0) {
	270	int i;
	271	/*
	272	* We are the child.
	273	*/
d37c2d81	274
	275	slavefd = open(name, O_RDWR);
	276	if (slavefd < 0) {
	277	perror("slave pty: open");
	278	exit(1);
	279	}
	280
be4f86de	281	#ifdef BSD_PTYS
	282	/* We need to chown/chmod the /dev/ttyXX device. */
	283	{
	284	struct group *gp = getgrnam("tty");
	285	fchown(slavefd, getuid(), gp ? gp->gr_gid : -1);
	286	fchmod(slavefd, 0600);
	287	}
	288	#endif
	289
054d8535	290	close(pty_master_fd);
	291	close(0);
	292	close(1);
	293	close(2);
	294	fcntl(slavefd, F_SETFD, 0); /* don't close on exec */
	295	dup2(slavefd, 0);
	296	dup2(slavefd, 1);
	297	dup2(slavefd, 2);
	298	setsid();
d37c2d81	299	ioctl(slavefd, TIOCSCTTY, 1);
	300	pgrp = getpid();
	301	tcsetpgrp(slavefd, pgrp);
	302	setpgrp();
	303	close(open(name, O_WRONLY, 0));
054d8535	304	setpgrp();
be4f86de	305	/* In case we were setgid-utmp or setuid-root, drop privs. */
	306	setgid(getgid());
	307	setuid(getuid());
054d8535	308	/* Close everything _else_, for tidiness. */
	309	for (i = 3; i < 1024; i++)
	310	close(i);
fe9548aa	311	{
	312	char term_env_var[10 + sizeof(cfg.termtype)];
	313	sprintf(term_env_var, "TERM=%s", cfg.termtype);
	314	putenv(term_env_var);
	315	}
6169c758	316	if (pty_argv)
	317	execvp(pty_argv[0], pty_argv);
	318	else
	319	execl(getenv("SHELL"), getenv("SHELL"), NULL);
054d8535	320	/*
	321	* If we're here, exec has gone badly foom.
	322	*/
	323	perror("exec");
	324	exit(127);
	325	} else {
	326	close(slavefd);
a0e16eb1	327	pty_child_pid = pid;
	328	pty_child_dead = FALSE;
	329	signal(SIGCHLD, sigchld_handler);
054d8535	330	}
054d8535	331
1709795f	332	return NULL;
	333	}
	334
	335	/*
	336	* Called to send data down the pty.
	337	*/
	338	static int pty_send(char *buf, int len)
	339	{
054d8535	340	while (len > 0) {
	341	int ret = write(pty_master_fd, buf, len);
	342	if (ret < 0) {
	343	perror("write pty master");
	344	exit(1);
	345	}
	346	buf += ret;
	347	len -= ret;
	348	}
1709795f	349	return 0;
	350	}
	351
	352	/*
	353	* Called to query the current socket sendability status.
	354	*/
	355	static int pty_sendbuffer(void)
	356	{
	357	return 0;
	358	}
	359
	360	/*
	361	* Called to set the size of the window
	362	*/
	363	static void pty_size(void)
	364	{
88e6b9ca	365	struct winsize size;
	366
	367	size.ws_row = (unsigned short)rows;
	368	size.ws_col = (unsigned short)cols;
	369	ioctl(pty_master_fd, TIOCSWINSZ, (void *)&size);
1709795f	370	return;
	371	}
	372
	373	/*
	374	* Send special codes.
	375	*/
	376	static void pty_special(Telnet_Special code)
	377	{
	378	/* Do nothing! */
	379	return;
	380	}
	381
	382	static Socket pty_socket(void)
	383	{
	384	return NULL; /* shouldn't ever be needed */
	385	}
	386
	387	static int pty_sendok(void)
	388	{
	389	return 1;
	390	}
	391
	392	static void pty_unthrottle(int backlog)
	393	{
	394	/* do nothing */
	395	}
	396
	397	static int pty_ldisc(int option)
	398	{
	399	return 0; /* neither editing nor echoing */
	400	}
	401
	402	static int pty_exitcode(void)
	403	{
	404	/* Shouldn't ever be required */
	405	return 0;
	406	}
	407
	408	Backend pty_backend = {
	409	pty_init,
	410	pty_send,
	411	pty_sendbuffer,
	412	pty_size,
	413	pty_special,
	414	pty_socket,
	415	pty_exitcode,
	416	pty_sendok,
	417	pty_ldisc,
	418	pty_unthrottle,
	419	1
	420	};