FreeBSD-5.3/usr.sbin/watch/watch.c
/*
* 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 <sys/cdefs.h>
__FBSDID("$FreeBSD: src/usr.sbin/watch/watch.c,v 1.31 2004/08/10 01:49:46 csjp Exp $");
#include <sys/param.h>
#include <sys/fcntl.h>
#include <sys/filio.h>
#include <sys/snoop.h>
#include <sys/stat.h>
#include <sys/linker.h>
#include <sys/module.h>
#include <err.h>
#include <errno.h>
#include <locale.h>
#include <paths.h>
#include <signal.h>
#include <stdio.h>
#include <stdlib.h>
#include <string.h>
#include <sysexits.h>
#include <termcap.h>
#include <termios.h>
#include <time.h>
#include <unistd.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 */
static void clear(void);
static void timestamp(const char *);
static void set_tty(void);
static void unset_tty(void);
static void fatal(int, const char *);
static int open_snp(void);
static void cleanup(int);
static void usage(void) __dead2;
static void setup_scr(void);
static void attach_snp(void);
static void detach_snp(void);
static void set_dev(const char *);
static void ask_dev(char *, const char *);
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;
const char *opt_snpdev;
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], gbuf[1024];
static void
clear(void)
{
if (clear_ok)
tputs(gbuf, 1, putchar);
fflush(stdout);
}
static void
timestamp(const 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);
}
static void
set_tty(void)
{
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);
}
static void
unset_tty(void)
{
tcsetattr (std_in, TCSANOW, &otty);
}
static void
fatal(int error, const char *buf)
{
unset_tty();
if (buf)
errx(error, "fatal: %s", buf);
else
exit(error);
}
static int
open_snp(void)
{
char snp[] = {_PATH_DEV "snpX"};
char c;
int f, mode, pos;
pos = strlen(snp) - 1;
if (opt_write)
mode = O_RDWR;
else
mode = O_RDONLY;
if (opt_snpdev == NULL)
for (c = '0'; c <= '9'; c++) {
snp[pos] = c;
if ((f = open(snp, mode)) < 0) {
if (errno == EBUSY)
continue;
err(1, "open %s", snp);
}
return f;
}
else
if ((f = open(opt_snpdev, mode)) != -1)
return (f);
fatal(EX_OSFILE, "cannot open snoop device");
return (0);
}
static void
cleanup(int signo __unused)
{
if (opt_timestamp)
timestamp("Logging Exited.");
close(snp_io);
unset_tty();
exit(EX_OK);
}
static void
usage(void)
{
fprintf(stderr, "usage: watch [-ciotnW] [tty name]\n");
exit(EX_USAGE);
}
static void
setup_scr(void)
{
char *cbuf = gbuf, *term;
if (!opt_interactive)
return;
if ((term = getenv("TERM")))
if (tgetent(tbuf, term) == 1)
if (tgetstr("cl", &cbuf))
clear_ok = 1;
set_tty();
clear();
}
static void
detach_snp(void)
{
dev_t dev;
dev = NODEV;
ioctl(snp_io, SNPSTTY, &dev);
}
static void
attach_snp(void)
{
if (ioctl(snp_io, SNPSTTY, &snp_tty) != 0)
fatal(EX_UNAVAILABLE, "cannot attach to tty");
if (opt_timestamp)
timestamp("Logging Started.");
}
static void
set_dev(const char *name)
{
char buf[DEV_NAME_LEN];
struct stat sb;
if (strlen(name) > 5 && !strncmp(name, _PATH_DEV, sizeof _PATH_DEV - 1)) {
snprintf(buf, sizeof buf, "%s", name);
} else {
if (strlen(name) == 2)
sprintf(buf, "%s%s", _PATH_TTY, name);
else
sprintf(buf, "%s%s", _PATH_DEV, 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(char *dbuf, const char *msg)
{
char buf[DEV_NAME_LEN];
int len;
clear();
unset_tty();
if (msg)
printf("%s\n", msg);
if (dbuf)
printf("Enter device name [%s]:", dbuf);
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(dbuf, buf);
}
set_tty();
}
#define READB_LEN 5
int
main(int ac, char *av[])
{
int ch, res, rv, nread;
size_t b_size = MIN_SIZE;
char *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, "Wciotnf:")) != -1)
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 'f':
opt_snpdev = optarg;
break;
case '?':
default:
usage();
}
if (modfind("snp") == -1)
if (kldload("snp") == -1 || modfind("snp") == -1)
warn("snp module not available");
signal(SIGINT, cleanup);
snp_io = open_snp();
setup_scr();
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, "malloc failed");
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(FIONREAD)");
if (nread > READB_LEN)
nread = READB_LEN;
rv = read(std_in, chb, nread);
if (rv == -1 || rv != nread)
fatal(EX_IOERR, "read (stdin) failed");
switch (chb[0]) {
case CHR_CLEAR:
clear();
break;
case CHR_SWITCH:
if (!opt_no_switch) {
detach_snp();
ask_dev(dev_name, MSG_CHANGE);
set_dev(dev_name);
break;
}
default:
if (opt_write) {
rv = write(snp_io, chb, nread);
if (rv == -1 || rv != 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(FIONREAD)");
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(-1);
break;
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(-1);
break;
default:
if (nread < (b_size / 2) && (b_size / 2) > MIN_SIZE) {
free(buf);
if (!(buf = (char *) malloc(b_size / 2)))
fatal(EX_UNAVAILABLE, "malloc failed");
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, "malloc failed");
}
rv = read(snp_io, buf, nread);
if (rv == -1 || rv != nread)
fatal(EX_IOERR, "read failed");
rv = write(std_out, buf, nread);
if (rv == -1 || rv != nread)
fatal(EX_IOERR, "write failed");
}
} /* While */
return(0);
}