text: /***********************************************************************
  *
  * plugin.c
  *
  * pppd plugin for kernel-mode PPPoE on Linux
  *
  * Copyright (C) 2001 by Roaring Penguin Software Inc., Michal Ostrowski
  * and Jamal Hadi Salim.
  *
  * Much code and many ideas derived from pppoe plugin by Michal
  * Ostrowski and Jamal Hadi Salim, which carries this copyright:
  *
  * Copyright 2000 Michal Ostrowski <mostrows@styx.uwaterloo.ca>,
  *                Jamal Hadi Salim <hadi@cyberus.ca>
  * Borrows heavily from the PPPoATM plugin by Mitchell Blank Jr.,
  * which is based in part on work from Jens Axboe and Paul Mackerras.
  *
  * This program is free software; you can redistribute it and/or
  * modify it under the terms of the GNU General Public License
  * as published by the Free Software Foundation; either version
  * 2 of the License, or (at your option) any later version.
  ***********************************************************************/
  
  static char const RCSID[] =
  "$Id: plugin.c,v 1.12 2004/11/04 10:07:37 paulus Exp $";
  
  #define _GNU_SOURCE 1
  #include "pppoe.h"
  
  #include "pppd/pppd.h"
  #include "pppd/fsm.h"
  #include "pppd/lcp.h"
  #include "pppd/ipcp.h"
  #include "pppd/ccp.h"
  #include "pppd/pathnames.h"
  
  #include <linux/types.h>
  #include <syslog.h>
  #include <sys/ioctl.h>
  #include <sys/types.h>
  #include <sys/socket.h>
  #include <sys/stat.h>
  #include <string.h>
  #include <stdlib.h>
  #include <errno.h>
  #include <unistd.h>
  #include <fcntl.h>
  #include <signal.h>
  #include <net/ethernet.h>
  #include <net/if_arp.h>
  #include "ppp_defs.h"
  #include "if_ppp.h"
  #include "if_pppox.h"
  
  #define _PATH_ETHOPT         _ROOT_PATH "/etc/ppp/options."
  
  char pppd_version[] = VERSION;
  
  /* From sys-linux.c in pppd -- MUST FIX THIS! */
  extern int new_style_driver;
  
  char *pppd_pppoe_service = NULL;
  static char *acName = NULL;
  static char *existingSession = NULL;
  static int printACNames = 0;
  
  static int PPPoEDevnameHook(char *cmd, char **argv, int doit);
  static option_t Options[] = {
      { "device name", o_wild, (void *) &PPPoEDevnameHook,
        "PPPoE device name",
        OPT_DEVNAM | OPT_PRIVFIX | OPT_NOARG  | OPT_A2STRVAL | OPT_STATIC,
        devnam},
      { "rp_pppoe_service", o_string, &pppd_pppoe_service,
        "Desired PPPoE service name" },
      { "rp_pppoe_ac",      o_string, &acName,
        "Desired PPPoE access concentrator name" },
      { "rp_pppoe_sess",    o_string, &existingSession,
        "Attach to existing session (sessid:macaddr)" },
      { "rp_pppoe_verbose", o_int, &printACNames,
        "Be verbose about discovered access concentrators"},
      { NULL }
  };
  
  static PPPoEConnection *conn = NULL;
  
  /**********************************************************************
   * %FUNCTION: PPPOEInitDevice
   * %ARGUMENTS:
   * None
   * %RETURNS:
   *
   * %DESCRIPTION:
   * Initializes PPPoE device.
   ***********************************************************************/
  static int
  PPPOEInitDevice(void)
  {
      conn = malloc(sizeof(PPPoEConnection));
      if (!conn) {
  	fatal("Could not allocate memory for PPPoE session");
      }
      memset(conn, 0, sizeof(PPPoEConnection));
      if (acName) {
  	SET_STRING(conn->acName, acName);
      }
      if (pppd_pppoe_service) {
  	SET_STRING(conn->serviceName, pppd_pppoe_service);
      }
      SET_STRING(conn->ifName, devnam);
      conn->discoverySocket = -1;
      conn->sessionSocket = -1;
      conn->useHostUniq = 1;
      conn->printACNames = printACNames;
      return 1;
  }
  
  /**********************************************************************
   * %FUNCTION: PPPOEConnectDevice
   * %ARGUMENTS:
   * None
   * %RETURNS:
   * Non-negative if all goes well; -1 otherwise
   * %DESCRIPTION:
   * Connects PPPoE device.
   ***********************************************************************/
  static int
  PPPOEConnectDevice(void)
  {
      struct sockaddr_pppox sp;
  
      strlcpy(ppp_devnam, devnam, sizeof(ppp_devnam));
      if (existingSession) {
  	unsigned int mac[ETH_ALEN];
  	int i, ses;
  	if (sscanf(existingSession, "%d:%x:%x:%x:%x:%x:%x",
  		   &ses, &mac[0], &mac[1], &mac[2],
  		   &mac[3], &mac[4], &mac[5]) != 7) {
  	    fatal("Illegal value for rp_pppoe_sess option");
  	}
  	conn->session = htons(ses);
  	for (i=0; i<ETH_ALEN; i++) {
  	    conn->peerEth[i] = (unsigned char) mac[i];
  	}
      } else {
  	discovery(conn);
  	if (conn->discoveryState != STATE_SESSION) {
  	    error("Unable to complete PPPoE Discovery");
  	    return -1;
  	}
      }
  
      /* Set PPPoE session-number for further consumption */
      ppp_session_number = ntohs(conn->session);
  
      /* Make the session socket */
      conn->sessionSocket = socket(AF_PPPOX, SOCK_STREAM, PX_PROTO_OE);
      if (conn->sessionSocket < 0) {
  	fatal("Failed to create PPPoE socket: %m");
      }
      sp.sa_family = AF_PPPOX;
      sp.sa_protocol = PX_PROTO_OE;
      sp.sa_addr.pppoe.sid = conn->session;
      memcpy(sp.sa_addr.pppoe.dev, conn->ifName, IFNAMSIZ);
      memcpy(sp.sa_addr.pppoe.remote, conn->peerEth, ETH_ALEN);
  
      /* Set remote_number for ServPoET */
      sprintf(remote_number, "%02X:%02X:%02X:%02X:%02X:%02X",
  	    (unsigned) conn->peerEth[0],
  	    (unsigned) conn->peerEth[1],
  	    (unsigned) conn->peerEth[2],
  	    (unsigned) conn->peerEth[3],
  	    (unsigned) conn->peerEth[4],
  	    (unsigned) conn->peerEth[5]);
  
      if (connect(conn->sessionSocket, (struct sockaddr *) &sp,
  		sizeof(struct sockaddr_pppox)) < 0) {
  	fatal("Failed to connect PPPoE socket: %d %m", errno);
  	return -1;
      }
  
      return conn->sessionSocket;
  }
  
  static void
  PPPOESendConfig(int mtu,
  		u_int32_t asyncmap,
  		int pcomp,
  		int accomp)
  {
      int sock;
      struct ifreq ifr;
  
      if (mtu > MAX_PPPOE_MTU) {
  	warn("Couldn't increase MTU to %d", mtu);
  	mtu = MAX_PPPOE_MTU;
      }
      sock = socket(AF_INET, SOCK_DGRAM, 0);
      if (sock < 0) {
  	error("Couldn't create IP socket: %m");
  	return;
      }
      strlcpy(ifr.ifr_name, ifname, sizeof(ifr.ifr_name));
      ifr.ifr_mtu = mtu;
      if (ioctl(sock, SIOCSIFMTU, &ifr) < 0) {
  	error("Couldn't set interface MTU to %d: %m", mtu);
  	return;
      }
      (void) close (sock);
  }
  
  
  static void
  PPPOERecvConfig(int mru,
  		u_int32_t asyncmap,
  		int pcomp,
  		int accomp)
  {
      if (mru > MAX_PPPOE_MTU)
  	warn("Couldn't increase MRU to %d", mru);
  }
  
  /**********************************************************************
   * %FUNCTION: PPPOEDisconnectDevice
   * %ARGUMENTS:
   * None
   * %RETURNS:
   * Nothing
   * %DESCRIPTION:
   * Disconnects PPPoE device
   ***********************************************************************/
  static void
  PPPOEDisconnectDevice(void)
  {
      struct sockaddr_pppox sp;
  
      sp.sa_family = AF_PPPOX;
      sp.sa_protocol = PX_PROTO_OE;
      sp.sa_addr.pppoe.sid = 0;
      memcpy(sp.sa_addr.pppoe.dev, conn->ifName, IFNAMSIZ);
      memcpy(sp.sa_addr.pppoe.remote, conn->peerEth, ETH_ALEN);
      if (connect(conn->sessionSocket, (struct sockaddr *) &sp,
  		sizeof(struct sockaddr_pppox)) < 0) {
  	fatal("Failed to disconnect PPPoE socket: %d %m", errno);
  	return;
      }
      close(conn->sessionSocket);
      /* don't send PADT?? */
      close(conn->discoverySocket);
  }
  
  static void
  PPPOEDeviceOptions(void)
  {
      char buf[256];
      snprintf(buf, 256, _PATH_ETHOPT "%s",devnam);
      if(!options_from_file(buf, 0, 0, 1))
  	exit(EXIT_OPTION_ERROR);
  
  }
  
  struct channel pppoe_channel;
  
  /**********************************************************************
   * %FUNCTION: PPPoEDevnameHook
   * %ARGUMENTS:
   * cmd -- the command (actually, the device name
   * argv -- argument vector
   * doit -- if non-zero, set device name.  Otherwise, just check if possible
   * %RETURNS:
   * 1 if we will handle this device; 0 otherwise.
   * %DESCRIPTION:
   * Checks if name is a valid interface name; if so, returns 1.  Also
   * sets up devnam (string representation of device).
   ***********************************************************************/
  static int
  PPPoEDevnameHook(char *cmd, char **argv, int doit)
  {
      int r = 1;
      int fd;
      struct ifreq ifr;
  
      /* Only do it if name is "ethXXX", "nasXXX", "tapXXX" or "nic-XXXX.
         In latter case strip off the "nic-" */
      /* Thanks to Russ Couturier for this fix */
      if (strlen(cmd) > 4 && !strncmp(cmd, "nic-", 4)) {
  	/* Strip off "nic-" */
  	cmd += 4;
      } else if (strlen(cmd) < 4
  	       || (strncmp(cmd, "eth", 3) && strncmp(cmd, "nas", 3)
  		   && strncmp(cmd, "tap", 3) && strncmp(cmd, "br", 2))) {
  	return 0;
      }
  
      /* Open a socket */
      if ((fd = socket(PF_PACKET, SOCK_RAW, 0)) < 0) {
  	r = 0;
      }
  
      /* Try getting interface index */
      if (r) {
  	strncpy(ifr.ifr_name, cmd, sizeof(ifr.ifr_name));
  	if (ioctl(fd, SIOCGIFINDEX, &ifr) < 0) {
  	    r = 0;
  	} else {
  	    if (ioctl(fd, SIOCGIFHWADDR, &ifr) < 0) {
  		r = 0;
  	    } else {
  		if (ifr.ifr_hwaddr.sa_family != ARPHRD_ETHER) {
  		    error("Interface %s not Ethernet", cmd);
  		    r=0;
  		}
  	    }
  	}
      }
  
      /* Close socket */
      close(fd);
      if (r) {
  	strncpy(devnam, cmd, sizeof(devnam));
  	if (the_channel != &pppoe_channel) {
  
  	    the_channel = &pppoe_channel;
  	    modem = 0;
  
  	    lcp_allowoptions[0].neg_accompression = 0;
  	    lcp_wantoptions[0].neg_accompression = 0;
  
  	    lcp_allowoptions[0].neg_asyncmap = 0;
  	    lcp_wantoptions[0].neg_asyncmap = 0;
  
  	    lcp_allowoptions[0].neg_pcompression = 0;
  	    lcp_wantoptions[0].neg_pcompression = 0;
  
  	    ccp_allowoptions[0].deflate = 0 ;
  	    ccp_wantoptions[0].deflate = 0 ;
  
  	    ipcp_allowoptions[0].neg_vj=0;
  	    ipcp_wantoptions[0].neg_vj=0;
  
  	    ccp_allowoptions[0].bsd_compress = 0;
  	    ccp_wantoptions[0].bsd_compress = 0;
  
  	    PPPOEInitDevice();
  	}
  	return 1;
      }
  
      return r;
  }
  
  /**********************************************************************
   * %FUNCTION: plugin_init
   * %ARGUMENTS:
   * None
   * %RETURNS:
   * Nothing
   * %DESCRIPTION:
   * Initializes hooks for pppd plugin
   ***********************************************************************/
  void
  plugin_init(void)
  {
      if (!ppp_available() && !new_style_driver) {
  	fatal("Linux kernel does not support PPPoE -- are you running 2.4.x?");
      }
  
      add_options(Options);
  
      info("RP-PPPoE plugin version %s compiled against pppd %s",
  	 RP_VERSION, VERSION);
  }
  
  /**********************************************************************
  *%FUNCTION: fatalSys
  *%ARGUMENTS:
  * str -- error message
  *%RETURNS:
  * Nothing
  *%DESCRIPTION:
  * Prints a message plus the errno value to stderr and syslog and exits.
  ***********************************************************************/
  void
  fatalSys(char const *str)
  {
      char buf[1024];
      int i = errno;
      sprintf(buf, "%.256s: %.256s", str, strerror(i));
      printErr(buf);
      sprintf(buf, "RP-PPPoE: %.256s: %.256s", str, strerror(i));
      sendPADT(conn, buf);
      exit(1);
  }
  
  /**********************************************************************
  *%FUNCTION: rp_fatal
  *%ARGUMENTS:
  * str -- error message
  *%RETURNS:
  * Nothing
  *%DESCRIPTION:
  * Prints a message to stderr and syslog and exits.
  ***********************************************************************/
  void
  rp_fatal(char const *str)
  {
      char buf[1024];
      printErr(str);
      sprintf(buf, "RP-PPPoE: %.256s", str);
      sendPADT(conn, buf);
      exit(1);
  }
  /**********************************************************************
  *%FUNCTION: sysErr
  *%ARGUMENTS:
  * str -- error message
  *%RETURNS:
  * Nothing
  *%DESCRIPTION:
  * Prints a message plus the errno value to syslog.
  ***********************************************************************/
  void
  sysErr(char const *str)
  {
      rp_fatal(str);
  }
  
  
  struct channel pppoe_channel = {
      options: Options,
      process_extra_options: &PPPOEDeviceOptions,
      check_options: NULL,
      connect: &PPPOEConnectDevice,
      disconnect: &PPPOEDisconnectDevice,
      establish_ppp: &generic_establish_ppp,
      disestablish_ppp: &generic_disestablish_ppp,
      send_config: &PPPOESendConfig,
      recv_config: &PPPOERecvConfig,
      close: NULL,
      cleanup: NULL
  };
  