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freebsd-nq/usr.sbin/watch/watch.c
Ollivier Robert 2bb69a4847 1. change tty handling from sgttyb to termios, 
2. fix a potential buffer oflow,
3. makes watch(8) conform to sysexits(3).

Not a strong 2.2 candidate even if it would be nice.

Reviewed by:	joerg, imp
1997-03-13 08:35:45 +00:00

424 lines
8.0 KiB
C
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/*
* Copyright (c) 1995 Ugen J.S.Antsilevich
*
* Redistribution and use in source forms, with and without modification,
* are permitted provided that this entire comment appears intact.
*
* Redistribution in binary form may occur without any restrictions.
* Obviously, it would be nice if you gave credit where credit is due
* but requiring it would be too onerous.
*
* This software is provided ``AS IS'' without any warranties of any kind.
*
* Snoop stuff.
*/
#include <stdio.h>
#include <unistd.h>
#include <stdlib.h>
#include <signal.h>
#include <string.h>
#include <termcap.h>
#include <termios.h>
#include <locale.h>
#include <sys/types.h>
#include <sys/stat.h>
#include <sys/time.h>
#include <sys/select.h>
#include <sys/fcntl.h>
#include <sys/filio.h>
#include <sys/snoop.h>
#include <sysexits.h>
#define MSG_INIT "Snoop started."
#define MSG_OFLOW "Snoop stopped due to overflow. Reconnecting."
#define MSG_CLOSED "Snoop stopped due to tty close. Reconnecting."
#define MSG_CHANGE "Snoop device change by user request."
#define MSG_NOWRITE "Snoop device change due to write failure."
#define DEV_NAME_LEN 1024 /* for /dev/ttyXX++ */
#define MIN_SIZE 256
#define CHR_SWITCH 24 /* Ctrl+X */
#define CHR_CLEAR 23 /* Ctrl+V */
int opt_reconn_close = 0;
int opt_reconn_oflow = 0;
int opt_interactive = 1;
int opt_timestamp = 0;
int opt_write = 0;
int opt_no_switch = 0;
char dev_name[DEV_NAME_LEN];
int snp_io;
dev_t snp_tty;
int std_in = 0, std_out = 1;
int clear_ok = 0;
struct termios otty;
char tbuf[1024], buf[1024];
void
clear()
{
if (clear_ok)
tputs(buf, 1, putchar);
fflush(stdout);
}
void
timestamp(buf)
char *buf;
{
time_t t;
char btmp[1024];
clear();
printf("\n---------------------------------------------\n");
t = time(NULL);
strftime(btmp, 1024, "Time: %d %b %H:%M", localtime(&t));
printf("%s\n", btmp);
printf("%s\n", buf);
printf("---------------------------------------------\n");
fflush(stdout);
}
void
set_tty()
{
struct termios ntty;
tcgetattr (std_in, &otty);
ntty = otty;
ntty.c_lflag &= ~ICANON; /* disable canonical operation */
ntty.c_lflag &= ~ECHO;
#ifdef FLUSHO
ntty.c_lflag &= ~FLUSHO;
#endif
#ifdef PENDIN
ntty.c_lflag &= ~PENDIN;
#endif
#ifdef IEXTEN
ntty.c_lflag &= ~IEXTEN;
#endif
ntty.c_cc[VMIN] = 1; /* minimum of one character */
ntty.c_cc[VTIME] = 0; /* timeout value */
ntty.c_cc[VINTR] = 07; /* ^G */
ntty.c_cc[VQUIT] = 07; /* ^G */
tcsetattr (std_in, TCSANOW, &ntty);
}
void
unset_tty()
{
tcsetattr (std_in, TCSANOW, &otty);
}
void
fatal(err, buf)
unsigned int err;
char *buf;
{
unset_tty();
if (buf)
fprintf(stderr, "Fatal: %s\n", buf);
exit(err);
}
int
open_snp()
{
char snp[] = {"/dev/snpX"};
char c;
int f, mode;
if (opt_write)
mode = O_RDWR;
else
mode = O_RDONLY;
for (c = '0'; c <= '9'; c++) {
snp[8] = c;
if ((f = open(snp, mode)) < 0)
continue;
return f;
}
fatal(EX_OSFILE, "Cannot open snoop device.");
}
void
cleanup()
{
if (opt_timestamp)
timestamp("Logging Exited.");
close(snp_io);
unset_tty();
exit(EX_OK);
}
void
show_usage()
{
printf("watch -[ciotnW] [tty name]\n");
exit(EX_USAGE);
}
void
setup_scr()
{
char *cbuf = buf, *term;
if (!opt_interactive)
return;
if ((term = getenv("TERM")))
if (tgetent(tbuf, term) == 1)
if (tgetstr("cl", &cbuf))
clear_ok = 1;
set_tty();
clear();
}
int
ctoh(c)
char c;
{
if (c >= '0' && c <= '9')
return (int) (c - '0');
if (c >= 'a' && c <= 'f')
return (int) (c - 'a' + 10);
fatal(EX_DATAERR, "Bad tty number.");
}
void
detach_snp()
{
dev_t dev;
dev = -1;
ioctl(snp_io, SNPSTTY, &dev);
}
void
attach_snp()
{
if (ioctl(snp_io, SNPSTTY, &snp_tty) != 0)
fatal(EX_UNAVAILABLE, "Cannot attach to tty.");
if (opt_timestamp)
timestamp("Logging Started.");
}
void
set_dev(name)
char *name;
{
char buf[DEV_NAME_LEN];
struct stat sb;
if (strlen(name) > 5 && !strncmp(name, "/dev/", 5)) {
snprintf(buf, sizeof buf, "%s", name);
}
else {
if (strlen(name) == 2)
sprintf(buf, "/dev/tty%s", name);
else
sprintf(buf, "/dev/%s", name);
}
if (*name == '\0' || stat(buf, &sb) < 0)
fatal(EX_DATAERR, "Bad device name.");
if ((sb.st_mode & S_IFMT) != S_IFCHR)
fatal(EX_DATAERR, "Must be a character device.");
snp_tty = sb.st_rdev;
attach_snp();
}
void
ask_dev(dev_name, msg)
char *dev_name, *msg;
{
char buf[DEV_NAME_LEN];
int len;
clear();
unset_tty();
if (msg)
printf("%s\n", msg);
if (dev_name)
printf("Enter device name [%s]:", dev_name);
else
printf("Enter device name:");
if (fgets(buf, DEV_NAME_LEN - 1, stdin)) {
len = strlen(buf);
if (buf[len - 1] == '\n')
buf[len - 1] = '\0';
if (buf[0] != '\0' && buf[0] != ' ')
strcpy(dev_name, buf);
}
set_tty();
}
#define READB_LEN 5
void
main(ac, av)
int ac;
char **av;
{
int res, nread, b_size = MIN_SIZE;
extern int optind;
char ch, *buf, chb[READB_LEN];
fd_set fd_s;
(void) setlocale(LC_TIME, "");
if (isatty(std_out))
opt_interactive = 1;
else
opt_interactive = 0;
while ((ch = getopt(ac, av, "Wciotn")) != EOF)
switch (ch) {
case 'W':
opt_write = 1;
break;
case 'c':
opt_reconn_close = 1;
break;
case 'i':
opt_interactive = 1;
break;
case 'o':
opt_reconn_oflow = 1;
break;
case 't':
opt_timestamp = 1;
break;
case 'n':
opt_no_switch = 1;
break;
case '?':
default:
show_usage();
exit(1);
}
signal(SIGINT, cleanup);
setup_scr();
snp_io = open_snp();
if (*(av += optind) == NULL) {
if (opt_interactive && !opt_no_switch)
ask_dev(dev_name, MSG_INIT);
else
fatal(EX_DATAERR, "No device name given.");
} else
strncpy(dev_name, *av, DEV_NAME_LEN);
set_dev(dev_name);
if (!(buf = (char *) malloc(b_size)))
fatal(EX_UNAVAILABLE, "Cannot malloc().");
FD_ZERO(&fd_s);
while (1) {
if (opt_interactive)
FD_SET(std_in, &fd_s);
FD_SET(snp_io, &fd_s);
res = select(snp_io + 1, &fd_s, NULL, NULL, NULL);
if (opt_interactive && FD_ISSET(std_in, &fd_s)) {
if ((res = ioctl(std_in, FIONREAD, &nread)) != 0)
fatal(EX_OSERR, "ioctl() failed.");
if (nread > READB_LEN)
nread = READB_LEN;
if (read(std_in,chb,nread)!=nread)
fatal(EX_IOERR, "read (stdin) failed.");
switch (chb[0]) {
case CHR_CLEAR:
clear();
break;
case CHR_SWITCH:
if (opt_no_switch)
break;
detach_snp();
ask_dev(dev_name, MSG_CHANGE);
set_dev(dev_name);
break;
default:
if (opt_write) {
if (write(snp_io,chb,nread) != nread) {
detach_snp();
if (opt_no_switch)
fatal(EX_IOERR, "Write failed.");
ask_dev(dev_name, MSG_NOWRITE);
set_dev(dev_name);
}
}
}
}
if (!FD_ISSET(snp_io, &fd_s))
continue;
if ((res = ioctl(snp_io, FIONREAD, &nread)) != 0)
fatal(EX_OSERR, "ioctl() failed.");
switch (nread) {
case SNP_OFLOW:
if (opt_reconn_oflow)
attach_snp();
else if (opt_interactive && !opt_no_switch) {
ask_dev(dev_name, MSG_OFLOW);
set_dev(dev_name);
} else
cleanup();
case SNP_DETACH:
case SNP_TTYCLOSE:
if (opt_reconn_close)
attach_snp();
else if (opt_interactive && !opt_no_switch) {
ask_dev(dev_name, MSG_CLOSED);
set_dev(dev_name);
} else
cleanup();
default:
if (nread < (b_size / 2) && (b_size / 2) > MIN_SIZE) {
free(buf);
if (!(buf = (char *) malloc(b_size / 2)))
fatal(EX_UNAVAILABLE, "Cannot malloc()");
b_size = b_size / 2;
}
if (nread > b_size) {
b_size = (nread % 2) ? (nread + 1) : (nread);
free(buf);
if (!(buf = (char *) malloc(b_size)))
fatal(EX_UNAVAILABLE, "Cannot malloc()");
}
if (read(snp_io, buf, nread) < nread)
fatal(EX_IOERR, "read failed.");
if (write(std_out, buf, nread) < nread)
fatal(EX_IOERR, "write failed.");
}
} /* While */
}
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