commands.c

经典的unix下telnet的c代码

	}
	/*
	 * Special case for DISPLAY variable.  If it is ":0.0" or
	 * "unix:0.0", we have to get rid of "unix" and insert our
	 * hostname.
	 */
	if ((ep = env_find("DISPLAY"))
	    && ((*ep->value == ':')
		|| (strncmp((char *)ep->value, "unix:", 5) == 0))) {
		char hbuf[MAXHOSTNAMELEN];
		char *cp2 = strchr((char *)ep->value, ':');

		gethostname(hbuf, sizeof hbuf);

		/* If this is not the full name, try to get it via DNS */
		if (strchr(hbuf, '.') == 0) {
			struct hostent *he = gethostbyname(hbuf);
			if (he != 0)
				strncpy(hbuf, he->h_name, sizeof hbuf-1);
			hbuf[sizeof hbuf-1] = '\0';
		}

		if (asprintf (&cp, "%s%s", hbuf, cp2) == -1)
			err(1, "asprintf");

		free(ep->value);
		ep->value = (unsigned char *)cp;
	}
	/*
	 * If USER is not defined, but LOGNAME is, then add
	 * USER with the value from LOGNAME.  By default, we
	 * don't export the USER variable.
	 */
	if ((env_find("USER") == NULL) && (ep = env_find("LOGNAME"))) {
		env_define((unsigned char *)"USER", ep->value);
		env_unexport((unsigned char *)"USER");
	}
	env_export((unsigned char *)"DISPLAY");
	env_export((unsigned char *)"PRINTER");
	env_export((unsigned char *)"XAUTHORITY");
}

	struct env_lst *
env_define(var, value)
	unsigned char *var, *value;
{
	struct env_lst *ep;

	if ((ep = env_find(var))) {
		if (ep->var)
			free(ep->var);
		if (ep->value)
			free(ep->value);
	} else {
		if ((ep = malloc(sizeof(struct env_lst))) == NULL)
			err(1, "malloc");
		ep->next = envlisthead.next;
		envlisthead.next = ep;
		ep->prev = &envlisthead;
		if (ep->next)
			ep->next->prev = ep;
	}
	ep->welldefined = opt_welldefined((char *)var);
	ep->export = 1;
	if ((ep->var = strdup((char *)var)) == NULL)
		err(1, "strdup");
	if ((ep->value = strdup((char *)value)) == NULL)
		err(1, "strdup");
	return(ep);
}

	void
env_undefine(var)
	unsigned char *var;
{
	struct env_lst *ep;

	if ((ep = env_find(var))) {
		ep->prev->next = ep->next;
		if (ep->next)
			ep->next->prev = ep->prev;
		if (ep->var)
			free(ep->var);
		if (ep->value)
			free(ep->value);
		free(ep);
	}
}

	void
env_export(var)
	unsigned char *var;
{
	struct env_lst *ep;

	if ((ep = env_find(var)))
		ep->export = 1;
}

	void
env_unexport(var)
	unsigned char *var;
{
	struct env_lst *ep;

	if ((ep = env_find(var)) != NULL)
		ep->export = 0;
}

	void
env_send(var)
	unsigned char *var;
{
	struct env_lst *ep;

	if (my_state_is_wont(TELOPT_NEW_ENVIRON)
#ifdef	OLD_ENVIRON
	    && my_state_is_wont(TELOPT_OLD_ENVIRON)
#endif
		) {
		fprintf(stderr,
		    "Cannot send '%s': Telnet ENVIRON option not enabled\r\n",
									var);
		return;
	}
	ep = env_find(var);
	if (ep == 0) {
		fprintf(stderr, "Cannot send '%s': variable not defined\r\n",
									var);
		return;
	}
	env_opt_start_info();
	env_opt_add(ep->var);
	env_opt_end(0);
}

	void
env_list()
{
	struct env_lst *ep;

	for (ep = envlisthead.next; ep; ep = ep->next) {
		printf("%c %-20s %s\r\n", ep->export ? '*' : ' ',
					ep->var, ep->value);
	}
}

	unsigned char *
env_default(init, welldefined)
	int init;
{
	static struct env_lst *nep = NULL;

	if (init) {
		nep = &envlisthead;
		return NULL;
	}
	if (nep) {
		while ((nep = nep->next)) {
			if (nep->export && (nep->welldefined == welldefined))
				return(nep->var);
		}
	}
	return(NULL);
}

	unsigned char *
env_getvalue(var)
	unsigned char *var;
{
	struct env_lst *ep;

	if ((ep = env_find(var)))
		return(ep->value);
	return(NULL);
}

#if defined(OLD_ENVIRON) && defined(ENV_HACK)
	void
env_varval(what)
	unsigned char *what;
{
	extern int old_env_var, old_env_value, env_auto;
	int len = strlen((char *)what);

	if (len == 0)
		goto unknown;

	if (strncasecmp((char *)what, "status", len) == 0) {
		if (env_auto)
			printf("%s%s", "VAR and VALUE are/will be ",
					"determined automatically\r\n");
		if (old_env_var == OLD_ENV_VAR)
			printf("VAR and VALUE set to correct definitions\r\n");
		else
			printf("VAR and VALUE definitions are reversed\r\n");
	} else if (strncasecmp((char *)what, "auto", len) == 0) {
		env_auto = 1;
		old_env_var = OLD_ENV_VALUE;
		old_env_value = OLD_ENV_VAR;
	} else if (strncasecmp((char *)what, "right", len) == 0) {
		env_auto = 0;
		old_env_var = OLD_ENV_VAR;
		old_env_value = OLD_ENV_VALUE;
	} else if (strncasecmp((char *)what, "wrong", len) == 0) {
		env_auto = 0;
		old_env_var = OLD_ENV_VALUE;
		old_env_value = OLD_ENV_VAR;
	} else {
unknown:
		printf("Unknown \"varval\" command. (\"auto\", \"right\", \"wrong\", \"status\")\r\n");
	}
}
#endif

#if	defined(AUTHENTICATION)
/*
 * The AUTHENTICATE command.
 */

struct authlist {
	char	*name;
	char	*help;
	int	(*handler)();
	int	narg;
};

static int
	auth_help(void);

struct authlist AuthList[] = {
    { "status",	"Display current status of authentication information",
						auth_status,	0 },
    { "disable", "Disable an authentication type ('auth disable ?' for more)",
						auth_disable,	1 },
    { "enable", "Enable an authentication type ('auth enable ?' for more)",
						auth_enable,	1 },
    { "help",	0,				auth_help,		0 },
    { "?",	"Print help information",	auth_help,		0 },
    { 0 },
};

    static int
auth_help()
{
    struct authlist *c;

    for (c = AuthList; c->name; c++) {
	if (c->help) {
	    if (*c->help)
		printf("%-15s %s\r\n", c->name, c->help);
	    else
		printf("\r\n");
	}
    }
    return 0;
}

    int
auth_cmd(argc, argv)
    int  argc;
    char *argv[];
{
    struct authlist *c;

    if (argc < 2) {
	fprintf(stderr,
	    "Need an argument to 'auth' command.  'auth ?' for help.\r\n");
	return 0;
    }

    c = (struct authlist *)
		genget(argv[1], (char **) AuthList, sizeof(struct authlist));
    if (c == 0) {
	fprintf(stderr, "'%s': unknown argument ('auth ?' for help).\r\n",
    				argv[1]);
	return 0;
    }
    if (Ambiguous(c)) {
	fprintf(stderr, "'%s': ambiguous argument ('auth ?' for help).\r\n",
    				argv[1]);
	return 0;
    }
    if (c->narg + 2 != argc) {
	fprintf(stderr,
	    "Need %s%d argument%s to 'auth %s' command.  'auth ?' for help.\r\n",
		c->narg < argc + 2 ? "only " : "",
		c->narg, c->narg == 1 ? "" : "s", c->name);
	return 0;
    }
    return((*c->handler)(argv[2], argv[3]));
}
#endif

#if    defined(ENCRYPTION)
/*
 * The ENCRYPT command.
 */

struct encryptlist {
       char    *name;
       char    *help;
       int     (*handler)();
       int     needconnect;
       int     minarg;
       int     maxarg;
};
 
static int
       EncryptHelp (void);

struct encryptlist EncryptList[] = {
    { "enable", "Enable encryption. ('encrypt enable ?' for more)",
                                               EncryptEnable, 1, 1, 2 },
    { "disable", "Disable encryption. ('encrypt enable ?' for more)",
                                               EncryptDisable, 0, 1, 2 },
    { "type", "Set encryption type. ('encrypt type ?' for more)",
                                               EncryptType, 0, 1, 1 },
    { "start", "Start encryption. ('encrypt start ?' for more)",
                                               EncryptStart, 1, 0, 1 },
    { "stop", "Stop encryption. ('encrypt stop ?' for more)",
                                               EncryptStop, 1, 0, 1 },
    { "input", "Start encrypting the input stream",
                                               EncryptStartInput, 1, 0, 0 },
    { "-input", "Stop encrypting the input stream",
                                               EncryptStopInput, 1, 0, 0 },
    { "output", "Start encrypting the output stream",
                                               EncryptStartOutput, 1, 0, 0 },
    { "-output", "Stop encrypting the output stream",
                                               EncryptStopOutput, 1, 0, 0 },

    { "status",        "Display current status of authentication information",
                                               EncryptStatus,  0, 0, 0 },
    { "help",  0,                              EncryptHelp,    0, 0, 0 },
    { "?",     "Print help information",       EncryptHelp,    0, 0, 0 },
    { 0 },
};

static int
EncryptHelp()
{
    struct encryptlist *c;

    for (c = EncryptList; c->name; c++) {
       if (c->help) {
           if (*c->help)
               printf("%-15s %s\r\n", c->name, c->help);
           else
               printf("\r\n");
       }
    }
    return 0;
}

static int
encrypt_cmd(int argc, char **argv)
{
    struct encryptlist *c;

    if (argc < 2) {
	fprintf(stderr, "Need at least one argument for 'encrypt' command.\n");
	fprintf(stderr, "('encrypt ?' for help)\n");
	return 0;
    }

    c = (struct encryptlist *)
               genget(argv[1], (char **) EncryptList, sizeof(struct encryptlist));
    if (c == 0) {
        fprintf(stderr, "'%s': unknown argument ('encrypt ?' for help).\r\n",
                               argv[1]);
        return 0;
    }
    if (Ambiguous(c)) {
        fprintf(stderr, "'%s': ambiguous argument ('encrypt ?' for help).\r\n",
                               argv[1]);
        return 0;
    }
    argc -= 2;
    if (argc < c->minarg || argc > c->maxarg) {
       if (c->minarg == c->maxarg) {
           fprintf(stderr, "Need %s%d argument%s ",
               c->minarg < argc ? "only " : "", c->minarg,
               c->minarg == 1 ? "" : "s");
       } else {
           fprintf(stderr, "Need %s%d-%d arguments ",
               c->maxarg < argc ? "only " : "", c->minarg, c->maxarg);
       }
       fprintf(stderr, "to 'encrypt %s' command.  'encrypt ?' for help.\r\n",
               c->name);
       return 0;
    }
    if (c->needconnect && !connected) {
       if (!(argc && (isprefix(argv[2], "help") || isprefix(argv[2], "?")))) {
           printf("?Need to be connected first.\r\n");
           return 0;
       }
    }
    return ((*c->handler)(argc > 0 ? argv[2] : 0,
                       argc > 1 ? argv[3] : 0,
                       argc > 2 ? argv[4] : 0));
}
#endif

#if	defined(unix) && defined(TN3270)
    static void
filestuff(fd)
    int fd;
{
    int res;

#ifdef	F_GETOWN
    setconnmode(0);
    res = fcntl(fd, F_GETOWN, 0);
    setcommandmode();

    if (res == -1) {
	perror("fcntl");
	return;
    }
    printf("\tOwner is %d.\r\n", res);
#endif

    setconnmode(0);
    res = fcntl(fd, F_GETFL, 0);
    setcommandmode();

    if (res == -1) {
	perror("fcntl");
	return;
    }
#ifdef notdef
    printf("\tFlags are 0x%x: %s\r\n", res, decodeflags(res));
#endif
}
#endif /* defined(unix) && defined(TN3270) */

/*
 * Print status about the connection.
 */
    /*ARGSUSED*/
    static int
status(argc, argv)
    int	 argc;
    char *argv[];
{
    if (connected) {
	printf("Connected to %s.\r\n", hostname);
	if ((argc < 2) || strcmp(argv[1], "notmuch")) {
	    int mode = getconnmode();

	    if (my_want_state_is_will(TELOPT_LINEMODE)) {
		printf("Operating with LINEMODE option\r\n");
		printf("%s line editing\r\n", (mode&MODE_EDIT) ? "Local" : "No");
		printf("%s catching of signals\r\n",
					(mode&MODE_TRAPSIG) ? "Local" : "No");
		slcstate();
#ifdef	KLUDGELINEMODE
	    } else if (kludgelinemode && my_want_state_is_dont(TELOPT_SGA)) {
		printf("Operating in obsolete linemode\r\n");
#endif
	    } else {
		printf("Operating in single character mode\r\n");
		if (localchars)
		    printf("Catching signals locally\r\n");
	    }
	    printf("%s character echo\r\n", (mode&MODE_ECHO) ? "Local" : "Remote");
	    if (my_want_state_is_will(TELOPT_LFLOW))
		printf("%s flow control\r\n", (mode&MODE_FLOW) ? "Local" : "No");
#if    defined(ENCRYPTION)
           encrypt_display();
#endif
	}
    } else {
	printf("No connection.\r\n");
    }
#   if !defined(TN3270)
    printf("Escape character is '%s'.\r\n", control(escape));
    (void) fflush(stdout);
#   else /* !defined(TN3270) */
    if ((!In3270) && ((argc < 2) || strcmp(argv[1], "notmuch"))) {
	printf("Escape character is '%s'.\r\n", control(escape));
    }
#   if defined(unix)
    if ((argc >= 2) && !strcmp(argv[1], "everything")) {
	printf("SIGIO received %d time%s.\r\n",
				sigiocount, (sigiocount == 1)? "":"s");
	if (In3270) {
	    printf("Process ID %ld, process group %ld.\r\n",
					    (long)getpid(), (long)getpgrp());
	    printf("Terminal input:\r\n");
	    filestuff(tin);
	    printf("Terminal output:\r\n");
	    filestuff(tout);
	    printf("Network socket:\r\n");
	    filestuff(net);
	}
    }
    if (In3270 && transcom) {
       printf("Transparent mode command is '%s'.\r\n", transcom);
    }
#   endif /* defined(unix) */
    (void) fflush(stdout);
    if (In3270) {
	return 0;
    }
#   endif /* defined(TN3270) */
    fflush(stdout);
    return 1;
}

#ifdef	SIGINFO
/*
 * Function that gets called when SIGINFO is received.
 */
void
ayt_status()
{
    (void) call(status, "status", "notmuch", 0);
}
#endif

static Command *getcmd(char *name);

static void
cmdrc(char *m1, char *m2)
{
    static char rcname[128];
    Command *c;
    FILE *rcfile;
    int gotmachine = 0;
    int l1 = strlen(m1);
    int l2 = strlen(m2);
    char m1save[MAXHOSTNAMELEN];

    if (skiprc)
	return;

    strlcpy(m1save, m1, sizeof(m1save));
    m1 = m1save;

    if (rcname[0] == 0) {
	char *home = getenv("HOME");

	if (home == NULL || *home == '\0')
	    return;
	snprintf (rcname, sizeof(rcname), "%s/.telnetrc",
		  home ? home : "");
    }

    if ((rcfile = fopen(rcname, "r")) == 0) {
	return;
    }