diff options
Diffstat (limited to 'cpukit/pppd/auth.c')
| -rw-r--r-- | cpukit/pppd/auth.c | 1128 |
1 files changed, 1128 insertions, 0 deletions
diff --git a/cpukit/pppd/auth.c b/cpukit/pppd/auth.c new file mode 100644 index 0000000000..fb84f1e8fc --- /dev/null +++ b/cpukit/pppd/auth.c @@ -0,0 +1,1128 @@ +/* + * auth.c - PPP authentication and phase control. + * + * Copyright (c) 1993 The Australian National University. + * All rights reserved. + * + * Redistribution and use in source and binary forms are permitted + * provided that the above copyright notice and this paragraph are + * duplicated in all such forms and that any documentation, + * advertising materials, and other materials related to such + * distribution and use acknowledge that the software was developed + * by the Australian National University. The name of the University + * may not be used to endorse or promote products derived from this + * software without specific prior written permission. + * THIS SOFTWARE IS PROVIDED ``AS IS'' AND WITHOUT ANY EXPRESS OR + * IMPLIED WARRANTIES, INCLUDING, WITHOUT LIMITATION, THE IMPLIED + * WARRANTIES OF MERCHANTIBILITY AND FITNESS FOR A PARTICULAR PURPOSE. + * + * Copyright (c) 1989 Carnegie Mellon University. + * All rights reserved. + * + * Redistribution and use in source and binary forms are permitted + * provided that the above copyright notice and this paragraph are + * duplicated in all such forms and that any documentation, + * advertising materials, and other materials related to such + * distribution and use acknowledge that the software was developed + * by Carnegie Mellon University. The name of the + * University may not be used to endorse or promote products derived + * from this software without specific prior written permission. + * THIS SOFTWARE IS PROVIDED ``AS IS'' AND WITHOUT ANY EXPRESS OR + * IMPLIED WARRANTIES, INCLUDING, WITHOUT LIMITATION, THE IMPLIED + * WARRANTIES OF MERCHANTIBILITY AND FITNESS FOR A PARTICULAR PURPOSE. + */ + +#define RCSID "$Id$" + +#include <stdio.h> +#include <stddef.h> +#include <stdlib.h> +#include <unistd.h> +#include <pwd.h> +#include <grp.h> +#include <string.h> +#include <sys/types.h> +#include <sys/stat.h> +#include <sys/socket.h> +#include <fcntl.h> +#if defined(_PATH_LASTLOG) && defined(_linux_) +#include <lastlog.h> +#endif + +#include <netdb.h> +#include <netinet/in.h> +#include <arpa/inet.h> + +#ifdef USE_PAM +#include <security/pam_appl.h> +#endif + +#ifdef HAS_SHADOW +#include <shadow.h> +#ifndef PW_PPP +#define PW_PPP PW_LOGIN +#endif +#endif + +#include "pppd.h" +#include "fsm.h" +#include "lcp.h" +#include "ipcp.h" +#include "upap.h" +#include "chap.h" +#ifdef CBCP_SUPPORT +#include "cbcp.h" +#endif +#include "pathnames.h" + +static const char rcsid[] = RCSID; + +/* The name by which the peer authenticated itself to us. */ +char peer_authname[MAXNAMELEN]; + +/* Records which authentication operations haven't completed yet. */ +static int auth_pending[NUM_PPP]; + +/* List of addresses which the peer may use. */ +static struct permitted_ip *addresses[NUM_PPP]; + +/* Wordlist giving addresses which the peer may use + without authenticating itself. */ +static struct wordlist *noauth_addrs; + +/* Extra options to apply, from the secrets file entry for the peer. */ +static struct wordlist *extra_options; + +/* Number of network protocols which we have opened. */ +static int num_np_open; + +/* Number of network protocols which have come up. */ +static int num_np_up; + +/* Set if we got the contents of passwd[] from the pap-secrets file. */ +static int passwd_from_file; + +/* Set if we require authentication only because we have a default route. */ +static bool default_auth; + +/* Hook for a link status */ +void (*auth_linkup_hook)(void) = NULL; +void (*auth_linkdown_hook)(void) = NULL; + +/* Hook to enable a plugin to control the idle time limit */ +int (*idle_time_hook)(struct ppp_idle *) = NULL; + +/* Hook for a plugin to say whether we can possibly authenticate any peer */ +int (*pap_check_hook)(void) = NULL; + +/* Hook for a plugin to check the PAP user and password */ +int (*pap_auth_hook)(char *user, char *passwd/*, char **msgp, + struct wordlist **paddrs, + struct wordlist **popts*/) = NULL; + +/* Hook for a plugin to know about the PAP user logout */ +void (*pap_logout_hook)(void) = NULL; + +/* Hook for a plugin to get the PAP password for authenticating us */ +int (*pap_passwd_hook)(char *user, char *passwd) = NULL; + +/* + * This is used to ensure that we don't start an auth-up/down + * script while one is already running. + */ +enum script_state { + s_down, + s_up +}; + +static enum script_state auth_state = s_down; +static enum script_state auth_script_state = s_down; + +/* + * Option variables. + */ +bool uselogin = 0; /* Use /etc/passwd for checking PAP */ +bool cryptpap = 0; /* Passwords in pap-secrets are encrypted */ +bool refuse_pap = 0; /* Don't wanna auth. ourselves with PAP */ +bool refuse_chap = 0; /* Don't wanna auth. ourselves with CHAP */ +bool usehostname = 0; /* Use hostname for our_name */ +bool auth_required = 0; /* Always require authentication from peer */ +bool allow_any_ip = 0; /* Allow peer to use any IP address */ +bool explicit_remote = 0; /* User specified explicit remote name */ +char remote_name[MAXNAMELEN]; /* Peer's name for authentication */ + +/* Bits in auth_pending[] */ +#define PAP_WITHPEER 1 +#define PAP_PEER 2 +#define CHAP_WITHPEER 4 +#define CHAP_PEER 8 + +extern char *crypt(const char *, const char *); + +/* Prototypes for procedures local to this file. */ + +static void network_phase(int); +static void check_idle(void *); +static void connect_time_expired(void *); +static int null_login(int); +static int get_pap_passwd(char *); +static int have_pap_secret(int *); +static int have_chap_secret(char *, char *, int, int *); +#if 0 +static int ip_addr_check(uint32_t, struct permitted_ip *); +#endif +static void free_wordlist(struct wordlist *); +static void auth_script(enum script_state s); +static void set_allowed_addrs(int, struct wordlist *, struct wordlist *); + + +/* + * Authentication-related options. + */ +option_t auth_options[] = { + { "require-pap", o_bool, &lcp_wantoptions[0].neg_upap, + "Require PAP authentication from peer", 1, &auth_required, 0, 0 }, + { "+pap", o_bool, &lcp_wantoptions[0].neg_upap, + "Require PAP authentication from peer", 1, &auth_required, 0, 0 }, + { "refuse-pap", o_bool, &refuse_pap, + "Don't agree to auth to peer with PAP", 1, NULL, 0, 0 }, + { "-pap", o_bool, &refuse_pap, + "Don't allow PAP authentication with peer", 1, NULL, 0, 0 }, + { "require-chap", o_bool, &lcp_wantoptions[0].neg_chap, + "Require CHAP authentication from peer", 1, &auth_required, 0, 0 }, + { "+chap", o_bool, &lcp_wantoptions[0].neg_chap, + "Require CHAP authentication from peer", 1, &auth_required, 0, 0 }, + { "refuse-chap", o_bool, &refuse_chap, + "Don't agree to auth to peer with CHAP", 1, NULL, 0, 0 }, + { "-chap", o_bool, &refuse_chap, + "Don't allow CHAP authentication with peer", 1, NULL, 0, 0 }, + { "name", o_string, our_name, + "Set local name for authentication", + OPT_PRIV|OPT_STATIC, NULL, MAXNAMELEN, 0 }, + { "user", o_string, user, + "Set name for auth with peer", OPT_STATIC, NULL, MAXNAMELEN, 0 }, + { "usehostname", o_bool, &usehostname, + "Must use hostname for authentication", 1, NULL, 0, 0 }, + { "remotename", o_string, remote_name, + "Set remote name for authentication", OPT_STATIC, + &explicit_remote, MAXNAMELEN, 0 }, + { "auth", o_bool, &auth_required, + "Require authentication from peer", 1, NULL, 0, 0 }, + { "noauth", o_bool, &auth_required, + "Don't require peer to authenticate", OPT_PRIV, &allow_any_ip, 0, 0 }, + { "login", o_bool, &uselogin, + "Use system password database for PAP", 1, NULL, 0, 0 }, + { "papcrypt", o_bool, &cryptpap, + "PAP passwords are encrypted", 1, NULL, 0, 0 }, +/* Removed for RTEMS PORT + { "+ua", o_special, setupapfile, + "Get PAP user and password from file" }, +*/ + { "password", o_string, passwd, + "Password for authenticating us to the peer", OPT_STATIC, + NULL, MAXSECRETLEN, 0 }, +/* Removed for RTEMS_PORT + { "privgroup", o_special, privgroup, + "Allow group members to use privileged options", OPT_PRIV }, + { "allow-ip", o_special, set_noauth_addr, + "Set IP address(es) which can be used without authentication", + OPT_PRIV }, +*/ + { NULL, 0, NULL, NULL, 0, NULL, 0, 0 } +}; + +/* + * An Open on LCP has requested a change from Dead to Establish phase. + * Do what's necessary to bring the physical layer up. + */ +void +link_required( + int unit ) +{ +} + +/* + * LCP has terminated the link; go to the Dead phase and take the + * physical layer down. + */ +void +link_terminated( + int unit) +{ + if (pppd_phase == PHASE_DEAD) + return; + if (pap_logout_hook) { + pap_logout_hook(); + } + new_phase(PHASE_DEAD); + notice("Connection terminated."); +} + +/* + * LCP has gone down; it will either die or try to re-establish. + */ +void +link_down( + int unit) +{ + int i; + struct protent *protp; + + auth_state = s_down; + if (auth_script_state == s_up) { + update_link_stats(unit); + auth_script(s_down); + } + for (i = 0; (protp = protocols[i]) != NULL; ++i) { + if (!protp->enabled_flag) + continue; + if (protp->protocol != PPP_LCP && protp->lowerdown != NULL) + (*protp->lowerdown)(unit); + if (protp->protocol < 0xC000 && protp->close != NULL) + (*protp->close)(unit, "LCP down"); + } + num_np_open = 0; + num_np_up = 0; + if (pppd_phase != PHASE_DEAD) + new_phase(PHASE_TERMINATE); +} + +/* + * The link is established. + * Proceed to the Dead, Authenticate or Network phase as appropriate. + */ +void +link_established( + int unit ) +{ + int auth; + lcp_options *wo = &lcp_wantoptions[unit]; + lcp_options *go = &lcp_gotoptions[unit]; + lcp_options *ho = &lcp_hisoptions[unit]; + int i; + struct protent *protp; + + /* + * Tell higher-level protocols that LCP is up. + */ + for (i = 0; (protp = protocols[i]) != NULL; ++i) + if (protp->protocol != PPP_LCP && protp->enabled_flag + && protp->lowerup != NULL) + (*protp->lowerup)(unit); + + if (auth_required && !(go->neg_chap || go->neg_upap)) { + /* + * We wanted the peer to authenticate itself, and it refused: + * if we have some address(es) it can use without auth, fine, + * otherwise treat it as though it authenticated with PAP using + * a username * of "" and a password of "". If that's not OK, + * boot it out. + */ + if (noauth_addrs != NULL) { + set_allowed_addrs(unit, noauth_addrs, NULL); + } else if (!wo->neg_upap || !null_login(unit)) { + warn("peer refused to authenticate: terminating link"); + lcp_close(unit, "peer refused to authenticate"); + pppd_status = EXIT_PEER_AUTH_FAILED; + return; + } + } + + new_phase(PHASE_AUTHENTICATE); + auth = 0; + if (go->neg_chap) { + ChapAuthPeer(unit, our_name, go->chap_mdtype); + auth |= CHAP_PEER; + } else if (go->neg_upap) { + upap_authpeer(unit); + auth |= PAP_PEER; + } + if (ho->neg_chap) { + ChapAuthWithPeer(unit, user, ho->chap_mdtype); + auth |= CHAP_WITHPEER; + } else if (ho->neg_upap) { + if (passwd[0] == 0) { + passwd_from_file = 1; + if (!get_pap_passwd(passwd)) + error("No secret found for PAP login"); + } + upap_authwithpeer(unit, user, passwd); + auth |= PAP_WITHPEER; + } + auth_pending[unit] = auth; + + if (!auth) + network_phase(unit); +} + +/* + * Proceed to the network phase. + */ +static void +network_phase( + int unit ) +{ +#ifdef CBCP_SUPPORT + lcp_options *go = &lcp_gotoptions[unit]; +#endif + + /* always run the auth-up script */ + auth_state = s_up; + if (auth_script_state == s_down) { + auth_script(s_up); + } + +#ifdef CBCP_SUPPORT + /* + * If we negotiated callback, do it now. + */ + if (go->neg_cbcp) { + new_phase(PHASE_CALLBACK); + (*cbcp_protent.open)(unit); + return; + } +#endif + + /* + * Process extra options from the secrets file + */ + if (extra_options) { + options_from_list(extra_options, 1); + free_wordlist(extra_options); + extra_options = 0; + } + start_networks(); +} + +void +start_networks(void) +{ + int i; + struct protent *protp; + + new_phase(PHASE_NETWORK); + for (i = 0; (protp = protocols[i]) != NULL; ++i) + if (protp->protocol < 0xC000 && protp->enabled_flag + && protp->open != NULL) { + (*protp->open)(0); + if (protp->protocol != PPP_CCP) + ++num_np_open; + } + + if (num_np_open == 0) + /* nothing to do */ + lcp_close(0, "No network protocols running"); +} + +/* + * The peer has failed to authenticate himself using `protocol'. + */ +void +auth_peer_fail( + int unit, + int protocol) +{ + /* + * Authentication failure: take the link down + */ + lcp_close(unit, "Authentication failed"); + pppd_status = EXIT_PEER_AUTH_FAILED; +} + +/* + * The peer has been successfully authenticated using `protocol'. + */ +void +auth_peer_success( + int unit, + int protocol, + char *name, + int namelen) +{ + int bit; + + switch (protocol) { + case PPP_CHAP: + bit = CHAP_PEER; + break; + case PPP_PAP: + bit = PAP_PEER; + break; + default: + warn("auth_peer_success: unknown protocol %x", protocol); + return; + } + + /* + * Save the authenticated name of the peer for later. + */ + if (namelen > sizeof(peer_authname) - 1) + namelen = sizeof(peer_authname) - 1; + BCOPY(name, peer_authname, namelen); + peer_authname[namelen] = 0; + + /* + * If there is no more authentication still to be done, + * proceed to the network (or callback) phase. + */ + if ((auth_pending[unit] &= ~bit) == 0) + network_phase(unit); +} + +/* + * We have failed to authenticate ourselves to the peer using `protocol'. + */ +void +auth_withpeer_fail( + int unit, + int protocol ) +{ + if (passwd_from_file) + BZERO(passwd, MAXSECRETLEN); + /* + * We've failed to authenticate ourselves to our peer. + * Some servers keep sending CHAP challenges, but there + * is no point in persisting without any way to get updated + * authentication secrets. + */ + lcp_close(unit, "Failed to authenticate ourselves to peer"); + pppd_status = EXIT_AUTH_TOPEER_FAILED; +} + +/* + * We have successfully authenticated ourselves with the peer using `protocol'. + */ +void +auth_withpeer_success( + int unit, + int protocol ) +{ + int bit; + + switch (protocol) { + case PPP_CHAP: + bit = CHAP_WITHPEER; + break; + case PPP_PAP: + if (passwd_from_file) + BZERO(passwd, MAXSECRETLEN); + bit = PAP_WITHPEER; + break; + default: + warn("auth_withpeer_success: unknown protocol %x", protocol); + bit = 0; + } + + /* + * If there is no more authentication still being done, + * proceed to the network (or callback) phase. + */ + if ((auth_pending[unit] &= ~bit) == 0) + network_phase(unit); +} + + +/* + * np_up - a network protocol has come up. + */ +void +np_up( + int unit, + int proto ) +{ + int tlim; + + if (num_np_up == 0) { + /* + * At this point we consider that the link has come up successfully. + */ + pppd_status = EXIT_OK; + unsuccess = 0; + new_phase(PHASE_RUNNING); + + if (idle_time_hook != 0) + tlim = (*idle_time_hook)(NULL); + else + tlim = idle_time_limit; + if (tlim > 0) + TIMEOUT(check_idle, NULL, tlim); + + /* + * Set a timeout to close the connection once the maximum + * connect time has expired. + */ + if (maxconnect > 0) + TIMEOUT(connect_time_expired, 0, maxconnect); + } + ++num_np_up; +} + +/* + * np_down - a network protocol has gone down. + */ +void +np_down( + int unit, + int proto) +{ + if (--num_np_up == 0) { + UNTIMEOUT(check_idle, NULL); + new_phase(PHASE_NETWORK); + } +} + +/* + * np_finished - a network protocol has finished using the link. + */ +void +np_finished( + int unit, + int proto ) +{ + if (--num_np_open <= 0) { + /* no further use for the link: shut up shop. */ + lcp_close(0, "No network protocols running"); + } +} + +/* + * check_idle - check whether the link has been idle for long + * enough that we can shut it down. + */ +static void +check_idle( + void *arg ) +{ + struct ppp_idle idle; + time_t itime; + int tlim; + + if (!get_idle_time(0, &idle)) + return; + if (idle_time_hook != 0) { + tlim = idle_time_hook(&idle); + } else { + itime = MIN(idle.xmit_idle, idle.recv_idle); + tlim = idle_time_limit - itime; + } + if (tlim <= 0) { + /* link is idle: shut it down. */ + notice("Terminating connection due to lack of activity."); + lcp_close(0, "Link inactive"); + need_holdoff = 0; + pppd_status = EXIT_IDLE_TIMEOUT; + } else { + TIMEOUT(check_idle, NULL, tlim); + } +} + +/* + * connect_time_expired - log a message and close the connection. + */ +static void +connect_time_expired( + void *arg) +{ + info("Connect time expired"); + lcp_close(0, "Connect time expired"); /* Close connection */ + pppd_status = EXIT_CONNECT_TIME; +} + +/* + * auth_check_options - called to check authentication options. + */ +int +auth_check_options(void) +{ + lcp_options *wo = &lcp_wantoptions[0]; + int status = 1; + int can_auth; + int lacks_ip; + + /* Default our_name to hostname, and user to our_name */ + if (our_name[0] == 0 || usehostname) + strlcpy(our_name, hostname, sizeof(our_name)); + if (user[0] == 0) + strlcpy(user, our_name, sizeof(user)); + + /* + * If we have a default route, require the peer to authenticate + * unless the noauth option was given or the real user is root. + */ + if (!auth_required && !allow_any_ip && have_route_to(0) && !privileged) { + printf("auth_check_options: turning on\n"); + auth_required = 1; + default_auth = 1; + } + + /* If authentication is required, ask peer for CHAP or PAP. */ + if (auth_required) { + if (!wo->neg_chap && !wo->neg_upap) { + wo->neg_chap = 1; + wo->neg_upap = 1; + } + } else { + wo->neg_chap = 0; + wo->neg_upap = 0; + } + + /* + * Check whether we have appropriate secrets to use + * to authenticate the peer. + */ + lacks_ip = 0; + can_auth = wo->neg_upap && (uselogin || have_pap_secret(&lacks_ip)); + if (!can_auth && wo->neg_chap) { + can_auth = have_chap_secret((explicit_remote? remote_name: NULL), + our_name, 1, &lacks_ip); + } + + if (auth_required && !can_auth && noauth_addrs == NULL) { + if (default_auth) { + option_error( +"By default the remote system is required to authenticate itself"); + option_error( +"(because this system has a default route to the internet)"); + } else if (explicit_remote) + option_error( +"The remote system (%s) is required to authenticate itself", + remote_name); + else + option_error( +"The remote system is required to authenticate itself"); + option_error( +"but I couldn't find any suitable secret (password) for it to use to do so."); + if (lacks_ip) + option_error( +"(None of the available passwords would let it use an IP address.)"); + + status = 0; + } + return ( status ); +} + +/* + * auth_reset - called when LCP is starting negotiations to recheck + * authentication options, i.e. whether we have appropriate secrets + * to use for authenticating ourselves and/or the peer. + */ +void +auth_reset( + int unit) +{ + lcp_options *go = &lcp_gotoptions[unit]; + lcp_options *ao = &lcp_allowoptions[0]; + + ao->neg_upap = !refuse_pap && (passwd[0] != 0 || get_pap_passwd(NULL)); + ao->neg_chap = !refuse_chap + && (passwd[0] != 0 + || have_chap_secret(user, (explicit_remote? remote_name: NULL), + 0, NULL)); + + if (go->neg_upap && !uselogin && !have_pap_secret(NULL)) + go->neg_upap = 0; + if (go->neg_chap) { + if (!have_chap_secret((explicit_remote? remote_name: NULL), + our_name, 1, NULL)) + go->neg_chap = 0; + } +} + + +/* + * check_passwd - Check the user name and passwd against the PAP secrets + * file. If requested, also check against the system password database, + * and login the user if OK. + * + * returns: + * UPAP_AUTHNAK: Authentication failed. + * UPAP_AUTHACK: Authentication succeeded. + * In either case, msg points to an appropriate message. + */ +int +check_passwd( + int unit, + char *auser, + int userlen, + char *apasswd, + int passwdlen, + char **msg) +{ + char passwd[64], user[64]; + + if (pap_auth_hook) + { + slprintf(passwd, sizeof(passwd), "%.*v", passwdlen, apasswd); + slprintf(user, sizeof(user), "%.*v", userlen, auser); + + return (*pap_auth_hook)(user, passwd/*, NULL, NULL, NULL*/) ? + UPAP_AUTHACK : UPAP_AUTHNAK; + } + + return UPAP_AUTHACK; + +#if 0 + int ret = (int)UPAP_AUTHNAK; + + if (( userlen == 0 ) && ( passwdlen == 0 )) { + ret = (int)UPAP_AUTHACK; + } + printf("check_passwd: %d\n", ret); + + return ret; +#endif +} + +/* + * 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 int +null_login( + int unit) +{ + return 0; +} + + +/* + * get_pap_passwd - get a password for authenticating ourselves with + * our peer using PAP. Returns 1 on success, 0 if no suitable password + * could be found. + * Assumes passwd points to MAXSECRETLEN bytes of space (if non-null). + */ +static int +get_pap_passwd( + char *passwd) +{ + int ret = (int)0; + + /* + * Check whether a plugin wants to supply this. + */ + if (pap_passwd_hook) { + ret = (*pap_passwd_hook)(user, passwd); + } + + return ( ret ); +} + + +/* + * have_pap_secret - check whether we have a PAP file with any + * secrets that we could possibly use for authenticating the peer. + */ +static int +have_pap_secret( + int *lacks_ipp) +{ + return 1; + +#if 0 + int ret = (int)0; + + /* let the plugin decide, if there is one */ + printf("have_pap_secret:\n"); + if (pap_check_hook) { + ret = (*pap_check_hook)(); + } + + return ( ret ); +#endif +} + + +/* + * 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 int +have_chap_secret( + char *client, + char *server, + int need_ip, + int *lacks_ipp) +{ + return 0; +} + + +/* + * 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). + */ +int +get_secret( + int unit, + char *client, + char *server, + unsigned char *secret, + int *secret_len, + int am_server) +{ + int len; + char secbuf[MAXWORDLEN]; + + if (!am_server && passwd[0] != 0) { + strlcpy(secbuf, passwd, sizeof(secbuf)); + } else { + return 0; + } + + len = strlen(secbuf); + if (len > MAXSECRETLEN) { + error("Secret for %s on %s is too long", client, server); + len = MAXSECRETLEN; + } + BCOPY(secbuf, secret, len); + BZERO(secbuf, sizeof(secbuf)); + *secret_len = len; + + return 1; +} + +/* + * set_allowed_addrs() - set the list of allowed addresses. + * Also looks for `--' indicating options to apply for this peer + * and leaves the following words in extra_options. + */ +static void +set_allowed_addrs( + int unit, + struct wordlist *addrs, + struct wordlist *opts) +{ + int n; + struct wordlist *ap, **pap; + struct permitted_ip *ip; + char *ptr_word, *ptr_mask; + struct hostent *hp; + struct netent *np; + uint32_t a, mask, ah, offset; + struct ipcp_options *wo = &ipcp_wantoptions[unit]; + uint32_t suggested_ip = 0; + + if (addresses[unit] != NULL) + free(addresses[unit]); + addresses[unit] = NULL; + if (extra_options != NULL) + free_wordlist(extra_options); + extra_options = opts; + + /* + * Count the number of IP addresses given. + */ + for (n = 0, pap = &addrs; (ap = *pap) != NULL; pap = &ap->next) + ++n; + if (n == 0) + return; + ip = (struct permitted_ip *) malloc((n + 1) * sizeof(struct permitted_ip)); + if (ip == 0) + return; + + n = 0; + for (ap = addrs; ap != NULL; ap = ap->next) { + /* "-" means no addresses authorized, "*" means any address allowed */ + ptr_word = ap->word; + if (strcmp(ptr_word, "-") == 0) + break; + if (strcmp(ptr_word, "*") == 0) { + ip[n].permit = 1; + ip[n].base = ip[n].mask = 0; + ++n; + break; + } + + ip[n].permit = 1; + if (*ptr_word == '!') { + ip[n].permit = 0; + ++ptr_word; + } + + mask = ~ (uint32_t) 0; + offset = 0; + ptr_mask = strchr (ptr_word, '/'); + if (ptr_mask != NULL) { + int bit_count; + char *endp; + + bit_count = (int) strtol (ptr_mask+1, &endp, 10); + if (bit_count <= 0 || bit_count > 32) { + warn("invalid address length %v in auth. address list", + ptr_mask+1); + continue; + } + bit_count = 32 - bit_count; /* # bits in host part */ + if (*endp == '+') { + offset = pppifunit + 1; + ++endp; + } + if (*endp != 0) { + warn("invalid address length syntax: %v", ptr_mask+1); + continue; + } + *ptr_mask = '\0'; + mask <<= bit_count; + } + + hp = gethostbyname(ptr_word); + if (hp != NULL && hp->h_addrtype == AF_INET) { + a = *(uint32_t *)hp->h_addr; + } else { + np = getnetbyname (ptr_word); + if (np != NULL && np->n_addrtype == AF_INET) { + a = htonl (np->n_net); + if (ptr_mask == NULL) { + /* calculate appropriate mask for net */ + ah = ntohl(a); + if (IN_CLASSA(ah)) + mask = IN_CLASSA_NET; + else if (IN_CLASSB(ah)) + mask = IN_CLASSB_NET; + else if (IN_CLASSC(ah)) + mask = IN_CLASSC_NET; + } + } else { + a = inet_addr (ptr_word); + } + } + + if (ptr_mask != NULL) + *ptr_mask = '/'; + + if (a == (uint32_t)-1L) { + warn("unknown host %s in auth. address list", ap->word); + continue; + } + if (offset != 0) { + if (offset >= ~mask) { + warn("interface unit %d too large for subnet %v", + pppifunit, ptr_word); + continue; + } + a = htonl((ntohl(a) & mask) + offset); + mask = ~(uint32_t)0; + } + ip[n].mask = htonl(mask); + ip[n].base = a & ip[n].mask; + ++n; + if (~mask == 0 && suggested_ip == 0) + suggested_ip = a; + } + + ip[n].permit = 0; /* make the last entry forbid all addresses */ + ip[n].base = 0; /* to terminate the list */ + ip[n].mask = 0; + + addresses[unit] = ip; + + /* + * If the address given for the peer isn't authorized, or if + * the user hasn't given one, AND there is an authorized address + * which is a single host, then use that if we find one. + */ + if (suggested_ip != 0 + && (wo->hisaddr == 0 || !auth_ip_addr(unit, wo->hisaddr))) + wo->hisaddr = suggested_ip; +} + +/* + * auth_ip_addr - check whether the peer is authorized to use + * a given IP address. Returns 1 if authorized, 0 otherwise. + */ +int +auth_ip_addr( + int unit, + uint32_t addr) +{ +#if 0 + int ok; +#endif + + /* don't allow loopback or multicast address */ + if (bad_ip_adrs(addr)) + return 0; + + return 1; + +#if 0 + if (addresses[unit] != NULL) { + ok = ip_addr_check(addr, addresses[unit]); + if (ok >= 0) + return ok; + } + if (auth_required) + return 0; /* no addresses authorized */ + return allow_any_ip || !have_route_to(addr); +#endif +} + +#if 0 +static int +ip_addr_check( + uint32_t addr, + struct permitted_ip *addrs) +{ + for (; ; ++addrs) + if ((addr & addrs->mask) == addrs->base) + return addrs->permit; +} +#endif + +/* + * 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. + */ +int +bad_ip_adrs( + uint32_t addr) +{ + addr = ntohl(addr); + return (addr >> IN_CLASSA_NSHIFT) == IN_LOOPBACKNET + || IN_MULTICAST(addr) || IN_BADCLASS(addr); +} + +/* + * free_wordlist - release memory allocated for a wordlist. + */ +static void +free_wordlist( + struct wordlist *wp) +{ + struct wordlist *next; + + while (wp != NULL) { + next = wp->next; + free(wp); + wp = next; + } +} + +/* + * auth_script - execute a script with arguments + * interface-name peer-name real-user tty speed + */ +static void +auth_script( + enum script_state s) +{ + switch (s) { + case s_up: + auth_script_state = s_up; + if ( auth_linkup_hook ) { + (*auth_linkup_hook)(); + } + break; + case s_down: + auth_script_state = s_down; + if ( auth_linkdown_hook ) { + (*auth_linkdown_hook)(); + } + break; + } +} |