4b58ef1a3f
Record the initial state earlier, so it is always safe to restore it. One way this happens is if watch(8) is started by a user that does not have access to /dev/snp. The result is "staircase effect" during later commands. PR: bin/153052 MFC after: 1 week
442 lines
8.6 KiB
C
442 lines
8.6 KiB
C
/*
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* Copyright (c) 1995 Ugen J.S.Antsilevich
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*
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* Redistribution and use in source forms, with and without modification,
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* are permitted provided that this entire comment appears intact.
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*
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* Redistribution in binary form may occur without any restrictions.
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* Obviously, it would be nice if you gave credit where credit is due
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* but requiring it would be too onerous.
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*
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* This software is provided ``AS IS'' without any warranties of any kind.
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*
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* Snoop stuff.
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*/
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#include <sys/cdefs.h>
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__FBSDID("$FreeBSD$");
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#include <sys/param.h>
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#include <sys/fcntl.h>
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#include <sys/filio.h>
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#include <sys/snoop.h>
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#include <sys/stat.h>
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#include <sys/linker.h>
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#include <sys/module.h>
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#include <err.h>
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#include <errno.h>
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#include <locale.h>
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#include <paths.h>
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#include <signal.h>
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#include <stdio.h>
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#include <stdlib.h>
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#include <string.h>
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#include <sysexits.h>
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#include <termcap.h>
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#include <termios.h>
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#include <time.h>
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#include <unistd.h>
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#define MSG_INIT "Snoop started."
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#define MSG_OFLOW "Snoop stopped due to overflow. Reconnecting."
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#define MSG_CLOSED "Snoop stopped due to tty close. Reconnecting."
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#define MSG_CHANGE "Snoop device change by user request."
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#define MSG_NOWRITE "Snoop device change due to write failure."
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#define DEV_NAME_LEN 1024 /* for /dev/ttyXX++ */
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#define MIN_SIZE 256
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#define CHR_SWITCH 24 /* Ctrl+X */
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#define CHR_CLEAR 23 /* Ctrl+V */
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static void clear(void);
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static void timestamp(const char *);
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static void set_tty(void);
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static void unset_tty(void);
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static void fatal(int, const char *);
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static int open_snp(void);
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static void cleanup(int);
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static void usage(void) __dead2;
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static void setup_scr(void);
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static void attach_snp(void);
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static void detach_snp(void);
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static void set_dev(const char *);
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static void ask_dev(char *, const char *);
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int opt_reconn_close = 0;
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int opt_reconn_oflow = 0;
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int opt_interactive = 1;
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int opt_timestamp = 0;
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int opt_write = 0;
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int opt_no_switch = 0;
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const char *opt_snpdev;
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char dev_name[DEV_NAME_LEN];
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int snp_io;
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int std_in = 0, std_out = 1;
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int clear_ok = 0;
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struct termios otty;
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char tbuf[1024], gbuf[1024];
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static void
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clear(void)
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{
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if (clear_ok)
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tputs(gbuf, 1, putchar);
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fflush(stdout);
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}
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static void
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timestamp(const char *buf)
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{
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time_t t;
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char btmp[1024];
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clear();
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printf("\n---------------------------------------------\n");
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t = time(NULL);
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strftime(btmp, 1024, "Time: %d %b %H:%M", localtime(&t));
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printf("%s\n", btmp);
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printf("%s\n", buf);
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printf("---------------------------------------------\n");
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fflush(stdout);
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}
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static void
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set_tty(void)
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{
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struct termios ntty;
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ntty = otty;
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ntty.c_lflag &= ~ICANON; /* disable canonical operation */
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ntty.c_lflag &= ~ECHO;
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#ifdef FLUSHO
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ntty.c_lflag &= ~FLUSHO;
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#endif
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#ifdef PENDIN
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ntty.c_lflag &= ~PENDIN;
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#endif
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#ifdef IEXTEN
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ntty.c_lflag &= ~IEXTEN;
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#endif
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ntty.c_cc[VMIN] = 1; /* minimum of one character */
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ntty.c_cc[VTIME] = 0; /* timeout value */
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ntty.c_cc[VINTR] = 07; /* ^G */
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ntty.c_cc[VQUIT] = 07; /* ^G */
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tcsetattr(std_in, TCSANOW, &ntty);
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}
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static void
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unset_tty(void)
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{
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tcsetattr(std_in, TCSANOW, &otty);
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}
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static void
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fatal(int error, const char *buf)
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{
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unset_tty();
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if (buf)
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errx(error, "fatal: %s", buf);
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else
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exit(error);
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}
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static int
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open_snp(void)
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{
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int f, mode;
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if (opt_write)
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mode = O_RDWR;
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else
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mode = O_RDONLY;
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if (opt_snpdev == NULL)
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f = open(_PATH_DEV "snp", mode);
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else
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f = open(opt_snpdev, mode);
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if (f == -1)
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fatal(EX_OSFILE, "cannot open snoop device");
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return (f);
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}
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static void
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cleanup(int signo __unused)
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{
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if (opt_timestamp)
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timestamp("Logging Exited.");
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close(snp_io);
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unset_tty();
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exit(EX_OK);
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}
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static void
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usage(void)
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{
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fprintf(stderr, "usage: watch [-ciotnW] [tty name]\n");
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exit(EX_USAGE);
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}
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static void
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setup_scr(void)
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{
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char *cbuf = gbuf, *term;
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if (!opt_interactive)
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return;
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if ((term = getenv("TERM")))
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if (tgetent(tbuf, term) == 1)
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if (tgetstr("cl", &cbuf))
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clear_ok = 1;
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set_tty();
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clear();
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}
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static void
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detach_snp(void)
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{
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int fd;
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fd = -1;
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ioctl(snp_io, SNPSTTY, &fd);
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}
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static void
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attach_snp(void)
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{
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int snp_tty;
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snp_tty = open(dev_name, O_RDONLY | O_NONBLOCK);
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if (snp_tty < 0)
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fatal(EX_DATAERR, "can't open device");
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if (ioctl(snp_io, SNPSTTY, &snp_tty) != 0)
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fatal(EX_UNAVAILABLE, "cannot attach to tty");
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close(snp_tty);
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if (opt_timestamp)
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timestamp("Logging Started.");
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}
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static void
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set_dev(const char *name)
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{
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char buf[DEV_NAME_LEN];
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struct stat sb;
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if (strlen(name) > 5 && !strncmp(name, _PATH_DEV, sizeof _PATH_DEV - 1)) {
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snprintf(buf, sizeof buf, "%s", name);
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} else {
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if (strlen(name) == 2)
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sprintf(buf, "%s%s", _PATH_TTY, name);
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else
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sprintf(buf, "%s%s", _PATH_DEV, name);
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}
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if (*name == '\0' || stat(buf, &sb) < 0)
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fatal(EX_DATAERR, "bad device name");
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if ((sb.st_mode & S_IFMT) != S_IFCHR)
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fatal(EX_DATAERR, "must be a character device");
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strncpy(dev_name, buf, DEV_NAME_LEN);
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attach_snp();
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}
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void
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ask_dev(char *dbuf, const char *msg)
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{
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char buf[DEV_NAME_LEN];
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int len;
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clear();
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unset_tty();
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if (msg)
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printf("%s\n", msg);
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if (dbuf)
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printf("Enter device name [%s]:", dbuf);
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else
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printf("Enter device name:");
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if (fgets(buf, DEV_NAME_LEN - 1, stdin)) {
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len = strlen(buf);
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if (buf[len - 1] == '\n')
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buf[len - 1] = '\0';
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if (buf[0] != '\0' && buf[0] != ' ')
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strcpy(dbuf, buf);
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}
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set_tty();
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}
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#define READB_LEN 5
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int
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main(int ac, char *av[])
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{
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int ch, res, rv, nread;
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size_t b_size = MIN_SIZE;
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char *buf, chb[READB_LEN];
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fd_set fd_s;
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(void) setlocale(LC_TIME, "");
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if (isatty(std_out))
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opt_interactive = 1;
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else
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opt_interactive = 0;
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while ((ch = getopt(ac, av, "Wciotnf:")) != -1)
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switch (ch) {
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case 'W':
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opt_write = 1;
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break;
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case 'c':
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opt_reconn_close = 1;
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break;
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case 'i':
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opt_interactive = 1;
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break;
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case 'o':
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opt_reconn_oflow = 1;
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break;
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case 't':
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opt_timestamp = 1;
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break;
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case 'n':
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opt_no_switch = 1;
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break;
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case 'f':
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opt_snpdev = optarg;
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break;
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case '?':
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default:
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usage();
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}
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tcgetattr(std_in, &otty);
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if (modfind("snp") == -1)
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if (kldload("snp") == -1 || modfind("snp") == -1)
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warn("snp module not available");
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signal(SIGINT, cleanup);
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snp_io = open_snp();
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setup_scr();
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if (*(av += optind) == NULL) {
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if (opt_interactive && !opt_no_switch)
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ask_dev(dev_name, MSG_INIT);
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else
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fatal(EX_DATAERR, "no device name given");
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} else
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strncpy(dev_name, *av, DEV_NAME_LEN);
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set_dev(dev_name);
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if (!(buf = (char *) malloc(b_size)))
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fatal(EX_UNAVAILABLE, "malloc failed");
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FD_ZERO(&fd_s);
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for (;;) {
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if (opt_interactive)
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FD_SET(std_in, &fd_s);
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FD_SET(snp_io, &fd_s);
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res = select(snp_io + 1, &fd_s, NULL, NULL, NULL);
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if (opt_interactive && FD_ISSET(std_in, &fd_s)) {
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if ((res = ioctl(std_in, FIONREAD, &nread)) != 0)
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fatal(EX_OSERR, "ioctl(FIONREAD)");
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if (nread > READB_LEN)
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nread = READB_LEN;
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rv = read(std_in, chb, nread);
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if (rv == -1 || rv != nread)
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fatal(EX_IOERR, "read (stdin) failed");
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switch (chb[0]) {
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case CHR_CLEAR:
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clear();
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break;
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case CHR_SWITCH:
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if (!opt_no_switch) {
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detach_snp();
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ask_dev(dev_name, MSG_CHANGE);
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set_dev(dev_name);
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break;
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}
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default:
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if (opt_write) {
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rv = write(snp_io, chb, nread);
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if (rv == -1 || rv != nread) {
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detach_snp();
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if (opt_no_switch)
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fatal(EX_IOERR,
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"write failed");
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ask_dev(dev_name, MSG_NOWRITE);
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set_dev(dev_name);
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}
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}
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}
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}
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if (!FD_ISSET(snp_io, &fd_s))
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continue;
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if ((res = ioctl(snp_io, FIONREAD, &nread)) != 0)
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fatal(EX_OSERR, "ioctl(FIONREAD)");
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switch (nread) {
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case SNP_OFLOW:
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if (opt_reconn_oflow)
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attach_snp();
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else if (opt_interactive && !opt_no_switch) {
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ask_dev(dev_name, MSG_OFLOW);
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set_dev(dev_name);
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} else
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cleanup(-1);
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break;
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case SNP_DETACH:
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case SNP_TTYCLOSE:
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if (opt_reconn_close)
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attach_snp();
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else if (opt_interactive && !opt_no_switch) {
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ask_dev(dev_name, MSG_CLOSED);
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set_dev(dev_name);
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} else
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cleanup(-1);
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break;
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default:
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if (nread < (b_size / 2) && (b_size / 2) > MIN_SIZE) {
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free(buf);
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if (!(buf = (char *) malloc(b_size / 2)))
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fatal(EX_UNAVAILABLE, "malloc failed");
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b_size = b_size / 2;
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}
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if (nread > b_size) {
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b_size = (nread % 2) ? (nread + 1) : (nread);
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free(buf);
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if (!(buf = (char *) malloc(b_size)))
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fatal(EX_UNAVAILABLE, "malloc failed");
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}
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rv = read(snp_io, buf, nread);
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if (rv == -1 || rv != nread)
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fatal(EX_IOERR, "read failed");
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rv = write(std_out, buf, nread);
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if (rv == -1 || rv != nread)
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fatal(EX_IOERR, "write failed");
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}
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} /* While */
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return(0);
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}
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