/* * logout - Logout the user. */static voidlogout(){    char *tty;    tty = strrchr(ppp_if[ppp_unit]->devname, '/');    if (tty == NULL)	tty = ppp_if[ppp_unit]->devname;    else	tty++;    ppp_if[ppp_unit]->logged_in = FALSE;}#endif	/* notyet *//* * null_login - Check if a username of "" and a password of "" are * acceptable, and iff so, set the list of acceptable IP addresses * and return 1. */static intnull_login(unit)    int unit;{    char *filename;    FILE *f = NULL;    int i, ret;    struct wordlist *addrs = NULL;    char secret[MAXWORDLEN];    i = pppSecretFind ("", ppp_if[unit]->our_name, secret, &addrs);    ret = i >= 0 && (i & NONWILD_CLIENT) != 0 && secret[0] == 0;    if (!ret)	{        /*         * Open the file of upap secrets and scan for a suitable secret.         * We don't accept a wildcard client.         */        if ((filename = ppp_if[unit]->options->pap_file) != NULL)            f = fopen(filename, "r");        if (f == NULL)            return 0;        check_access(f, filename);        i = scan_authfile(f, "", ppp_if[unit]->our_name, secret, &addrs,		      filename);        ret = i >= 0 && (i & NONWILD_CLIENT) != 0 && secret[0] == 0;        fclose(f);        }    if (ret) {        if (ppp_if[unit]->addresses != NULL)            free_wordlist(ppp_if[unit]->addresses);        ppp_if[unit]->addresses = addrs;        }    return ret;}/* * get_upap_passwd - get a password for authenticating ourselves with * our peer using PAP.  Returns 1 on success, 0 if no suitable password * could be found. */static intget_upap_passwd(){    char *filename;    FILE *f = NULL;    char secret[MAXWORDLEN];    if (pppSecretFind (ppp_if[ppp_unit]->user, ppp_if[ppp_unit]->remote_name,	secret, NULL) < 0)        {        if ((filename = ppp_if[ppp_unit]->options->pap_file) != NULL)            f = fopen(filename, "r");        if (f == NULL)	    return 0;        check_access(f, filename);        if (scan_authfile(f, ppp_if[ppp_unit]->user,	    ppp_if[ppp_unit]->remote_name, secret, NULL, filename) < 0)	    {            fclose(f);	    return 0;	    }        fclose(f);        }    strncpy(ppp_if[ppp_unit]->passwd, secret, MAXSECRETLEN);    ppp_if[ppp_unit]->passwd[MAXSECRETLEN-1] = 0;    return 1;}/* * have_upap_secret - check whether we have a PAP file with any * secrets that we could possibly use for authenticating the peer. */static inthave_upap_secret(){    FILE *f = NULL;    int ret;    char *filename;    if (ppp_if[ppp_unit]->uselogin)	return 1;    if (pppSecretFind (NULL, ppp_if[ppp_unit]->our_name, NULL, NULL) < 0)        {        if ((filename = ppp_if[ppp_unit]->options->pap_file) != NULL)            f = fopen(filename, "r");        if (f == NULL)	    return 0;        ret = scan_authfile(f, NULL, ppp_if[ppp_unit]->our_name, NULL, NULL,			filename);        fclose(f);        if (ret < 0)	    return 0;	}    return 1;}/* * have_chap_secret - check whether we have a CHAP file with a * secret that we could possibly use for authenticating `client' * on `server'.  Either can be the null string, meaning we don't * know the identity yet. */static inthave_chap_secret(client, server)    char *client;    char *server;{    FILE *f = NULL;    int ret;    char *filename;    if (client[0] == 0)        client = NULL;    else if (server[0] == 0)        server = NULL;    if (pppSecretFind (client, server, NULL, NULL) < 0)	{        if ((filename = ppp_if[ppp_unit]->options->chap_file) != NULL)            f = fopen(filename, "r");        if (f == NULL)            return 0;        ret = scan_authfile(f, client, server, NULL, NULL, filename);        fclose(f);        if (ret < 0)	    return 0;	}    return 1;}/* * get_secret - open the CHAP secret file and return the secret * for authenticating the given client on the given server. * (We could be either client or server). */intget_secret(unit, client, server, secret, secret_len, save_addrs)    int unit;    char *client;    char *server;    char *secret;    int *secret_len;    int save_addrs;{    FILE *f = NULL;    int ret, len;    char *filename;    struct wordlist *addrs = NULL;    char secbuf[MAXWORDLEN];    secbuf[0] = 0;    if (pppSecretFind (client, server, secbuf, &addrs) < 0)	{        if ((filename = ppp_if[unit]->options->chap_file) != NULL)            f = fopen(filename, "r");        if (f == NULL) {	    syslog(LOG_ERR, "Can't open chap secret file %s", filename);	    return 0;        }        check_access(f, filename);        ret = scan_authfile(f, client, server, secbuf, &addrs, filename);        fclose(f);        if (ret < 0)	    return 0;        }    if (save_addrs) {	if (ppp_if[unit]->addresses != NULL)	    free_wordlist(ppp_if[unit]->addresses);	ppp_if[unit]->addresses = addrs;    }    len = strlen(secbuf);    if (len > MAXSECRETLEN) {	syslog(LOG_ERR, "Secret for %s on %s is too long", client, server);	len = MAXSECRETLEN;    }    BCOPY(secbuf, secret, len);    *secret_len = len;    return 1;}/* * auth_ip_addr - check whether the peer is authorized to use * a given IP address.  Returns 1 if authorized, 0 otherwise. */intauth_ip_addr(unit, addr)    int unit;    u_long addr;{    u_long a;    struct wordlist *addrs;    /* don't allow loopback or multicast address */    if (bad_ip_adrs(addr))        return 0;    if ((addrs = ppp_if[unit]->addresses) == NULL)	return 1;		/* no restriction */    for (; addrs != NULL; addrs = addrs->next) {	/* "-" means no addresses authorized */	if (strcmp(addrs->word, "-") == 0)	    break;	if ((a = inet_addr(addrs->word)) == -1) {	    if ((a = hostGetByName (addrs->word)) == NULL) {		syslog(LOG_WARNING, "unknown host %s in auth. address list",		       addrs->word);		continue;		}	}	if (addr == a)	    return 1;    }    return 0;			/* not in list => can't have it */}/* * bad_ip_adrs - return 1 if the IP address is one we don't want * to use, such as an address in the loopback net or a multicast address. * addr is in network byte order. */intbad_ip_adrs(addr)    u_long addr;{    addr = ntohl(addr);#if	CPU==SIMSPARCSOLARIS    return IN_MULTICAST(addr) || IN_BADCLASS(addr);#else    return (addr >> IN_CLASSA_NSHIFT) == IN_LOOPBACKNET        || IN_MULTICAST(addr) || IN_BADCLASS(addr);#endif}/* * check_access - complain if a secret file has too-liberal permissions. */voidcheck_access(f, fileName)    FILE *f;    char *fileName;{    struct stat sbuf;    if (fstat(fileno(f), &sbuf) < 0) {	syslog(LOG_WARNING, "cannot stat secret file %s: %m", fileName);    } else if ((sbuf.st_mode & (S_IRWXG | S_IRWXO)) != 0) {	syslog(LOG_WARNING, "Warning - secret file %s has world and/or group access", fileName);    }}/* * scan_authfile - Scan an authorization file for a secret suitable * for authenticating `client' on `server'.  The return value is -1 * if no secret is found, otherwise >= 0.  The return value has * NONWILD_CLIENT set if the secret didn't have "*" for the client, and * NONWILD_SERVER set if the secret didn't have "*" for the server. * Any following words on the line (i.e. address authorization * info) are placed in a wordlist and returned in *addrs.   */static intscan_authfile(f, client, server, secret, addrs, fileName)    FILE *f;    char *client;    char *server;    char *secret;    struct wordlist **addrs;    char *fileName;{    int newline, xxx;    int got_flag, best_flag;    FILE *sf;    struct wordlist *ap, *addr_list, *addr_last;    char word[MAXWORDLEN];    char atfile[MAXWORDLEN];    if (addrs != NULL)	*addrs = NULL;    addr_list = NULL;    if (!getword(f, word, &newline, fileName))	return -1;		/* file is empty??? */    newline = 1;    best_flag = -1;    for (;;) {	/*	 * Skip until we find a word at the start of a line.	 */	while (!newline && getword(f, word, &newline, fileName))	    ;	if (!newline)	    break;		/* got to end of file */	/*	 * Got a client - check if it's a match or a wildcard.	 */	got_flag = 0;	if (client != NULL && client[0] && strcmp(word, client) != 0 &&	    !ISWILD(word)) {	    newline = 0;	    continue;	}	if (!ISWILD(word))	    got_flag = NONWILD_CLIENT;	/*	 * Now get a server and check if it matches.	 */	if (!getword(f, word, &newline, fileName))	    break;	if (newline)	    continue;	if (server != NULL && server[0] && strcmp(word, server) != 0 &&	    !ISWILD(word))	    continue;	if (!ISWILD(word))	    got_flag |= NONWILD_SERVER;	/*	 * Got some sort of a match - see if it's better than what	 * we have already.	 */	if (got_flag <= best_flag)	    continue;	/*	 * Get the secret.	 */	if (!getword(f, word, &newline, fileName))	    break;	if (newline)	    continue;	/*	 * Special syntax: @filename means read secret from file.	 */	if (word[0] == '@') {	    strcpy(atfile, word+1);	    if ((sf = fopen(atfile, "r")) == NULL) {		syslog(LOG_WARNING, "can't open indirect secret file %s",                       atfile);		continue;	    }	    check_access(sf, atfile);	    if (!getword(sf, word, &xxx, atfile)) {		syslog(LOG_WARNING, "no secret in indirect secret file %s",                       atfile);		fclose(sf);		continue;	    }	    fclose(sf);	}	if (secret != NULL)	    strcpy(secret, word);			best_flag = got_flag;	/*	 * Now read address authorization info and make a wordlist.	 */	if (addr_list)	    free_wordlist(addr_list);	addr_list = addr_last = NULL;	for (;;) {	    if (!getword(f, word, &newline, fileName) || newline)		break;	    ap = (struct wordlist *) malloc(sizeof(struct wordlist)					    + strlen(word));	    if (ap == NULL)		novm("authorized addresses");	    ap->next = NULL;	    strcpy(ap->word, word);	    if (addr_list == NULL)		addr_list = ap;	    else		addr_last->next = ap;	    addr_last = ap;	}	if (!newline)	    break;    }    if (addrs != NULL)	*addrs = addr_list;    else if (addr_list != NULL)	free_wordlist(addr_list);    return best_flag;}/* * free_wordlist - release memory allocated for a wordlist. */static voidfree_wordlist(wp)    struct wordlist *wp;{    struct wordlist *next;    while (wp != NULL) {	next = wp->next;	free(wp);	wp = next;    }}