File: [local] / src / usr.bin / cu / cu.c (download)
Revision 1.28, Fri Jun 28 13:35:00 2019 UTC (4 years, 11 months ago) by deraadt
Branch: MAIN
CVS Tags: OPENBSD_7_3_BASE, OPENBSD_7_3, OPENBSD_7_2_BASE, OPENBSD_7_2, OPENBSD_7_1_BASE, OPENBSD_7_1, OPENBSD_7_0_BASE, OPENBSD_7_0, OPENBSD_6_9_BASE, OPENBSD_6_9, OPENBSD_6_8_BASE, OPENBSD_6_8, OPENBSD_6_7_BASE, OPENBSD_6_7, OPENBSD_6_6_BASE, OPENBSD_6_6 Changes since 1.27: +2 -2 lines
When system calls indicate an error they return -1, not some arbitrary
value < 0. errno is only updated in this case. Change all (most?)
callers of syscalls to follow this better, and let's see if this strictness
helps us in the future.
|
/* $OpenBSD: cu.c,v 1.28 2019/06/28 13:35:00 deraadt Exp $ */
/*
* Copyright (c) 2012 Nicholas Marriott <nicm@openbsd.org>
*
* 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/ioctl.h>
#include <ctype.h>
#include <err.h>
#include <event.h>
#include <fcntl.h>
#include <getopt.h>
#include <paths.h>
#include <pwd.h>
#include <signal.h>
#include <stdio.h>
#include <stdlib.h>
#include <string.h>
#include <termios.h>
#include <unistd.h>
#include <limits.h>
#include "cu.h"
extern char *__progname;
FILE *record_file;
struct termios saved_tio;
struct bufferevent *input_ev;
struct bufferevent *output_ev;
int escape_char = '~';
int is_direct = -1;
int restricted = 0;
const char *line_path = NULL;
int line_speed = -1;
int line_fd;
struct termios line_tio;
struct bufferevent *line_ev;
struct event sigterm_ev;
struct event sighup_ev;
enum {
STATE_NONE,
STATE_NEWLINE,
STATE_ESCAPE
} last_state = STATE_NEWLINE;
__dead void usage(void);
void signal_event(int, short, void *);
void stream_read(struct bufferevent *, void *);
void stream_error(struct bufferevent *, short, void *);
void line_read(struct bufferevent *, void *);
void line_error(struct bufferevent *, short, void *);
void try_remote(const char *, const char *, const char *);
__dead void
usage(void)
{
fprintf(stderr, "usage: %s [-dr] [-E escape_char] [-l line] "
"[-s speed | -speed]\n", __progname);
fprintf(stderr, " %s [host]\n", __progname);
exit(1);
}
int
main(int argc, char **argv)
{
const char *errstr;
char *tmp, *s, *host;
int opt, i, flags;
if (pledge("stdio rpath wpath cpath getpw proc exec tty",
NULL) == -1)
err(1, "pledge");
if (isatty(STDIN_FILENO) && tcgetattr(STDIN_FILENO, &saved_tio) != 0)
err(1, "tcgetattr");
/*
* Convert obsolescent -### speed to modern -s### syntax which getopt()
* can handle.
*/
for (i = 1; i < argc; i++) {
if (strcmp("--", argv[i]) == 0)
break;
if (argv[i][0] != '-' || !isdigit((u_char)argv[i][1]))
continue;
if (asprintf(&argv[i], "-s%s", &argv[i][1]) == -1)
errx(1, "speed asprintf");
}
while ((opt = getopt(argc, argv, "drE:l:s:")) != -1) {
switch (opt) {
case 'd':
is_direct = 1;
break;
case 'r':
if (pledge("stdio rpath wpath tty", NULL) == -1)
err(1, "pledge");
restricted = 1;
break;
case 'E':
if (optarg[0] == '^' && optarg[2] == '\0' &&
(u_char)optarg[1] >= 64 && (u_char)optarg[1] < 128)
escape_char = (u_char)optarg[1] & 31;
else if (strlen(optarg) == 1)
escape_char = (u_char)optarg[0];
else
errx(1, "invalid escape character: %s", optarg);
break;
case 'l':
line_path = optarg;
break;
case 's':
line_speed = strtonum(optarg, 0, INT_MAX, &errstr);
if (errstr != NULL)
errx(1, "speed is %s: %s", errstr, optarg);
break;
default:
usage();
}
}
argc -= optind;
argv += optind;
if (argc != 0 && argc != 1)
usage();
if (line_path != NULL || line_speed != -1 || is_direct != -1) {
if (argc != 0)
usage();
} else {
if (argc == 1)
host = argv[0];
else
host = getenv("HOST");
if (host != NULL && *host != '\0') {
if (*host == '/')
line_path = host;
else {
s = getenv("REMOTE");
if (s != NULL && *s == '/')
try_remote(host, s, NULL);
else
try_remote(host, NULL, s);
}
}
}
if (line_path == NULL)
line_path = "/dev/cua00";
if (line_speed == -1)
line_speed = 9600;
if (is_direct == -1)
is_direct = 0;
if (strchr(line_path, '/') == NULL) {
if (asprintf(&tmp, "%s%s", _PATH_DEV, line_path) == -1)
err(1, "asprintf");
line_path = tmp;
}
flags = O_RDWR;
if (is_direct)
flags |= O_NONBLOCK;
line_fd = open(line_path, flags);
if (line_fd == -1)
err(1, "open(\"%s\")", line_path);
if (restricted && pledge("stdio tty", NULL) == -1)
err(1, "pledge");
if (!isatty(line_fd))
err(1, "%s", line_path);
if (ioctl(line_fd, TIOCEXCL) != 0)
err(1, "ioctl(TIOCEXCL)");
if (tcgetattr(line_fd, &line_tio) != 0)
err(1, "tcgetattr");
if (set_line(line_speed) != 0)
err(1, "tcsetattr");
event_init();
signal_set(&sigterm_ev, SIGTERM, signal_event, NULL);
signal_add(&sigterm_ev, NULL);
signal_set(&sighup_ev, SIGHUP, signal_event, NULL);
signal_add(&sighup_ev, NULL);
if (signal(SIGINT, SIG_IGN) == SIG_ERR)
err(1, "signal");
if (signal(SIGQUIT, SIG_IGN) == SIG_ERR)
err(1, "signal");
set_termios(); /* after this use cu_err and friends */
/* stdin and stdout get separate events */
input_ev = bufferevent_new(STDIN_FILENO, stream_read, NULL,
stream_error, NULL);
bufferevent_enable(input_ev, EV_READ);
output_ev = bufferevent_new(STDOUT_FILENO, NULL, NULL, stream_error,
NULL);
bufferevent_enable(output_ev, EV_WRITE);
set_blocking(line_fd, 0);
line_ev = bufferevent_new(line_fd, line_read, NULL, line_error,
NULL);
bufferevent_enable(line_ev, EV_READ|EV_WRITE);
printf("Connected to %s (speed %d)\r\n", line_path, line_speed);
event_dispatch();
restore_termios();
printf("\r\n[EOT]\n");
exit(0);
}
void
signal_event(int fd, short events, void *data)
{
restore_termios();
printf("\r\n[SIG%s]\n", sys_signame[fd]);
exit(0);
}
void
set_blocking(int fd, int state)
{
int mode;
state = state ? 0 : O_NONBLOCK;
if ((mode = fcntl(fd, F_GETFL)) == -1)
cu_err(1, "fcntl");
if ((mode & O_NONBLOCK) != state) {
mode = (mode & ~O_NONBLOCK) | state;
if (fcntl(fd, F_SETFL, mode) == -1)
cu_err(1, "fcntl");
}
}
void
set_termios(void)
{
struct termios tio;
if (!isatty(STDIN_FILENO))
return;
memcpy(&tio, &saved_tio, sizeof(tio));
tio.c_lflag &= ~(ICANON|IEXTEN|ECHO);
tio.c_iflag &= ~(INPCK|ICRNL);
tio.c_oflag &= ~OPOST;
tio.c_cc[VMIN] = 1;
tio.c_cc[VTIME] = 0;
tio.c_cc[VDISCARD] = _POSIX_VDISABLE;
tio.c_cc[VDSUSP] = _POSIX_VDISABLE;
tio.c_cc[VINTR] = _POSIX_VDISABLE;
tio.c_cc[VLNEXT] = _POSIX_VDISABLE;
tio.c_cc[VQUIT] = _POSIX_VDISABLE;
tio.c_cc[VSUSP] = _POSIX_VDISABLE;
if (tcsetattr(STDIN_FILENO, TCSAFLUSH, &tio) != 0)
cu_err(1, "tcsetattr");
}
void
restore_termios(void)
{
if (isatty(STDIN_FILENO))
tcsetattr(STDIN_FILENO, TCSAFLUSH, &saved_tio);
}
int
set_line(int speed)
{
struct termios tio;
memcpy(&tio, &line_tio, sizeof(tio));
tio.c_iflag &= ~(ISTRIP|ICRNL);
tio.c_oflag &= ~OPOST;
tio.c_lflag &= ~(ICANON|ISIG|IEXTEN|ECHO);
tio.c_cflag &= ~(CSIZE|PARENB);
tio.c_cflag |= CREAD|CS8|CLOCAL;
tio.c_cc[VMIN] = 1;
tio.c_cc[VTIME] = 0;
cfsetspeed(&tio, speed);
if (tcsetattr(line_fd, TCSAFLUSH, &tio) != 0)
return (-1);
return (0);
}
void
stream_read(struct bufferevent *bufev, void *data)
{
char *new_data, *ptr;
size_t new_size;
int state_change;
new_data = EVBUFFER_DATA(input_ev->input);
new_size = EVBUFFER_LENGTH(input_ev->input);
if (new_size == 0)
return;
state_change = isatty(STDIN_FILENO);
for (ptr = new_data; ptr < new_data + new_size; ptr++) {
switch (last_state) {
case STATE_NONE:
if (state_change && *ptr == '\r')
last_state = STATE_NEWLINE;
break;
case STATE_NEWLINE:
if (state_change && (u_char)*ptr == escape_char) {
last_state = STATE_ESCAPE;
continue;
}
if (*ptr != '\r')
last_state = STATE_NONE;
break;
case STATE_ESCAPE:
do_command(*ptr);
last_state = STATE_NEWLINE;
continue;
}
bufferevent_write(line_ev, ptr, 1);
}
evbuffer_drain(input_ev->input, new_size);
}
void
stream_error(struct bufferevent *bufev, short what, void *data)
{
event_loopexit(NULL);
}
void
line_read(struct bufferevent *bufev, void *data)
{
char *new_data;
size_t new_size;
new_data = EVBUFFER_DATA(line_ev->input);
new_size = EVBUFFER_LENGTH(line_ev->input);
if (new_size == 0)
return;
if (record_file != NULL)
fwrite(new_data, 1, new_size, record_file);
bufferevent_write(output_ev, new_data, new_size);
evbuffer_drain(line_ev->input, new_size);
}
void
line_error(struct bufferevent *bufev, short what, void *data)
{
event_loopexit(NULL);
}
void
try_remote(const char *host, const char *path, const char *entry)
{
const char *paths[] = { "/etc/remote", NULL, NULL };
char *cp, *s;
long l;
int error;
if (path != NULL) {
paths[0] = path;
paths[1] = "/etc/remote";
}
if (entry != NULL && cgetset(entry) != 0)
cu_errx(1, "cgetset failed");
error = cgetent(&cp, (char **)paths, (char *)host);
if (error < 0) {
switch (error) {
case -1:
cu_errx(1, "unknown host %s", host);
case -2:
cu_errx(1, "can't open remote file");
case -3:
cu_errx(1, "loop in remote file");
default:
cu_errx(1, "unknown error in remote file");
}
}
if (is_direct == -1 && cgetcap(cp, "dc", ':') != NULL)
is_direct = 1;
if (line_path == NULL && cgetstr(cp, "dv", &s) >= 0)
line_path = s;
if (line_speed == -1 && cgetnum(cp, "br", &l) >= 0) {
if (l < 0 || l > INT_MAX)
cu_errx(1, "speed out of range");
line_speed = l;
}
}
/* Expands tildes in the file name. Based on code from ssh/misc.c. */
char *
tilde_expand(const char *filename1)
{
const char *filename, *path, *sep;
char user[128], *out;
struct passwd *pw;
u_int len, slash;
int rv;
if (*filename1 != '~')
goto no_change;
filename = filename1 + 1;
path = strchr(filename, '/');
if (path != NULL && path > filename) { /* ~user/path */
slash = path - filename;
if (slash > sizeof(user) - 1)
goto no_change;
memcpy(user, filename, slash);
user[slash] = '\0';
if ((pw = getpwnam(user)) == NULL)
goto no_change;
} else if ((pw = getpwuid(getuid())) == NULL) /* ~/path */
goto no_change;
/* Make sure directory has a trailing '/' */
len = strlen(pw->pw_dir);
if (len == 0 || pw->pw_dir[len - 1] != '/')
sep = "/";
else
sep = "";
/* Skip leading '/' from specified path */
if (path != NULL)
filename = path + 1;
if ((rv = asprintf(&out, "%s%s%s", pw->pw_dir, sep, filename)) == -1)
cu_err(1, "asprintf");
if (rv >= PATH_MAX) {
free(out);
goto no_change;
}
return (out);
no_change:
out = strdup(filename1);
if (out == NULL)
cu_err(1, "strdup");
return (out);
}