ppp_oe.c

lwip-1.4.0

/*****************************************************************************
* ppp_oe.c - PPP Over Ethernet implementation for lwIP.
*
* Copyright (c) 2006 by Marc Boucher, Services Informatiques (MBSI) inc.
*
* The authors hereby grant permission to use, copy, modify, distribute,
* and license this software and its documentation for any purpose, provided
* that existing copyright notices are retained in all copies and that this
* notice and the following disclaimer are included verbatim in any 
* distributions. No written agreement, license, or royalty fee is required
* for any of the authorized uses.
*
* THIS SOFTWARE IS PROVIDED BY THE CONTRIBUTORS *AS IS* AND ANY EXPRESS OR
* IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE IMPLIED WARRANTIES
* OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE ARE DISCLAIMED. 
* IN NO EVENT SHALL THE CONTRIBUTORS BE LIABLE FOR ANY DIRECT, INDIRECT,
* INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL DAMAGES (INCLUDING, BUT
* NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS OR SERVICES; LOSS OF USE,
* DATA, OR PROFITS; OR BUSINESS INTERRUPTION) HOWEVER CAUSED AND ON ANY
* THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT LIABILITY, OR TORT
* (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY OUT OF THE USE OF
* THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF SUCH DAMAGE.
*
******************************************************************************
* REVISION HISTORY
*
* 06-01-01 Marc Boucher <[e-mail]>
*   Ported to lwIP.
*****************************************************************************/



/* based on NetBSD: if_pppoe.c,v 1.64 2006/01/31 23:50:15 martin Exp */

/*-
 * Copyright (c) 2002 The NetBSD Foundation, Inc.
 * All rights reserved.
 *
 * This code is derived from software contributed to The NetBSD Foundation
 * by Martin Husemann <[e-mail]>.
 *
 * Redistribution and use in source and binary forms, with or without
 * modification, are permitted provided that the following conditions
 * are met:
 * 1. Redistributions of source code must retain the above copyright
 *    notice, this list of conditions and the following disclaimer.
 * 2. Redistributions in binary form must reproduce the above copyright
 *    notice, this list of conditions and the following disclaimer in the
 *    documentation and/or other materials provided with the distribution.
 * 3. All advertising materials mentioning features or use of this software
 *    must display the following acknowledgement:
 *        This product includes software developed by the NetBSD
 *        Foundation, Inc. and its contributors.
 * 4. Neither the name of The NetBSD Foundation nor the names of its
 *    contributors may be used to endorse or promote products derived
 *    from this software without specific prior written permission.
 *
 * THIS SOFTWARE IS PROVIDED BY THE NETBSD FOUNDATION, INC. AND CONTRIBUTORS
 * ``AS IS'' AND ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED
 * TO, THE IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR
 * PURPOSE ARE DISCLAIMED.  IN NO EVENT SHALL THE FOUNDATION OR CONTRIBUTORS
 * BE LIABLE FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR
 * CONSEQUENTIAL DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF
 * SUBSTITUTE GOODS OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS
 * INTERRUPTION) HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN
 * CONTRACT, STRICT LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE)
 * ARISING IN ANY WAY OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE
 * POSSIBILITY OF SUCH DAMAGE.
 */

#include "lwip/opt.h"

#if PPPOE_SUPPORT /* don't build if not configured for use in lwipopts.h */

#include "netif/ppp_oe.h"

#include "ppp.h"
#include "pppdebug.h"

#include "lwip/timers.h"
#include "lwip/memp.h"

#include <string.h>
#include <stdio.h>


/* Add a 16 bit unsigned value to a buffer pointed to by PTR */
#define PPPOE_ADD_16(PTR, VAL) \
    *(PTR)++ = (u8_t)((VAL) / 256);    \
    *(PTR)++ = (u8_t)((VAL) % 256)

/* Add a complete PPPoE header to the buffer pointed to by PTR */
#define PPPOE_ADD_HEADER(PTR, CODE, SESS, LEN)  \
    *(PTR)++ = PPPOE_VERTYPE;  \
    *(PTR)++ = (CODE);         \
    PPPOE_ADD_16(PTR, SESS);   \
    PPPOE_ADD_16(PTR, LEN)

#define PPPOE_DISC_TIMEOUT (5*1000)  /* base for quick timeout calculation */
#define PPPOE_SLOW_RETRY   (60*1000) /* persistent retry interval */
#define PPPOE_DISC_MAXPADI  4        /* retry PADI four times (quickly) */
#define PPPOE_DISC_MAXPADR  2        /* retry PADR twice */

#ifdef PPPOE_SERVER
#error "PPPOE_SERVER is not yet supported under lwIP!"
/* from if_spppsubr.c */
#define IFF_PASSIVE IFF_LINK0 /* wait passively for connection */
#endif

#ifndef PPPOE_ERRORSTRING_LEN
#define PPPOE_ERRORSTRING_LEN     64
#endif
static char pppoe_error_tmp[PPPOE_ERRORSTRING_LEN];


/* input routines */
static void pppoe_dispatch_disc_pkt(struct netif *, struct pbuf *);

/* management routines */
static int pppoe_do_disconnect(struct pppoe_softc *);
static void pppoe_abort_connect(struct pppoe_softc *);
static void pppoe_clear_softc(struct pppoe_softc *, const char *);

/* internal timeout handling */
static void pppoe_timeout(void *);

/* sending actual protocol controll packets */
static err_t pppoe_send_padi(struct pppoe_softc *);
static err_t pppoe_send_padr(struct pppoe_softc *);
#ifdef PPPOE_SERVER
static err_t pppoe_send_pado(struct pppoe_softc *);
static err_t pppoe_send_pads(struct pppoe_softc *);
#endif
static err_t pppoe_send_padt(struct netif *, u_int, const u8_t *);

/* internal helper functions */
static struct pppoe_softc * pppoe_find_softc_by_session(u_int, struct netif *);
static struct pppoe_softc * pppoe_find_softc_by_hunique(u8_t *, size_t, struct netif *);

/** linked list of created pppoe interfaces */
static struct pppoe_softc *pppoe_softc_list;

err_t
pppoe_create(struct netif *ethif, int pd, void (*linkStatusCB)(int pd, int up), struct pppoe_softc **scptr)
{
  struct pppoe_softc *sc;

  sc = (struct pppoe_softc *)memp_malloc(MEMP_PPPOE_IF);
  if (sc == NULL) {
    *scptr = NULL;
    return ERR_MEM;
  }
  memset(sc, 0, sizeof(struct pppoe_softc));

  /* changed to real address later */
  MEMCPY(&sc->sc_dest, ethbroadcast.addr, sizeof(sc->sc_dest));

  sc->sc_pd = pd;
  sc->sc_linkStatusCB = linkStatusCB;
  sc->sc_ethif = ethif;

  /* put the new interface at the head of the list */
  sc->next = pppoe_softc_list;
  pppoe_softc_list = sc;

  *scptr = sc;

  return ERR_OK;
}

err_t
pppoe_destroy(struct netif *ifp)
{
  struct pppoe_softc *sc, *prev = NULL;

  for (sc = pppoe_softc_list; sc != NULL; prev = sc, sc = sc->next) {
    if (sc->sc_ethif == ifp) {
      break;
    }
  }

  if(!(sc && (sc->sc_ethif == ifp))) {
    return ERR_IF;
  }

  sys_untimeout(pppoe_timeout, sc);
  if (prev == NULL) {
    /* remove sc from the head of the list */
    pppoe_softc_list = sc->next;
  } else {
    /* remove sc from the list */
    prev->next = sc->next;
  }

#ifdef PPPOE_TODO
  if (sc->sc_concentrator_name) {
    mem_free(sc->sc_concentrator_name);
  }
  if (sc->sc_service_name) {
    mem_free(sc->sc_service_name);
  }
#endif /* PPPOE_TODO */
  memp_free(MEMP_PPPOE_IF, sc);

  return ERR_OK;
}

/*
 * Find the interface handling the specified session.
 * Note: O(number of sessions open), this is a client-side only, mean
 * and lean implementation, so number of open sessions typically should
 * be 1.
 */
static struct pppoe_softc *
pppoe_find_softc_by_session(u_int session, struct netif *rcvif)
{
  struct pppoe_softc *sc;

  if (session == 0) {
    return NULL;
  }

  for (sc = pppoe_softc_list; sc != NULL; sc = sc->next) {
    if (sc->sc_state == PPPOE_STATE_SESSION
        && sc->sc_session == session) {
      if (sc->sc_ethif == rcvif) {
        return sc;
      } else {
        return NULL;
      }
    }
  }
  return NULL;
}

/* Check host unique token passed and return appropriate softc pointer,
 * or NULL if token is bogus. */
static struct pppoe_softc *
pppoe_find_softc_by_hunique(u8_t *token, size_t len, struct netif *rcvif)
{
  struct pppoe_softc *sc, *t;

  if (pppoe_softc_list == NULL) {
    return NULL;
  }

  if (len != sizeof sc) {
    return NULL;
  }
  MEMCPY(&t, token, len);

  for (sc = pppoe_softc_list; sc != NULL; sc = sc->next) {
    if (sc == t) {
      break;
    }
  }

  if (sc == NULL) {
    PPPDEBUG(LOG_DEBUG, ("pppoe: alien host unique tag, no session found\n"));
    return NULL;
  }

  /* should be safe to access *sc now */
  if (sc->sc_state < PPPOE_STATE_PADI_SENT || sc->sc_state >= PPPOE_STATE_SESSION) {
    printf("%c%c%"U16_F": host unique tag found, but it belongs to a connection in state %d\n",
      sc->sc_ethif->name[0], sc->sc_ethif->name[1], sc->sc_ethif->num, sc->sc_state);
    return NULL;
  }
  if (sc->sc_ethif != rcvif) {
    printf("%c%c%"U16_F": wrong interface, not accepting host unique\n",
      sc->sc_ethif->name[0], sc->sc_ethif->name[1], sc->sc_ethif->num);
    return NULL;
  }
  return sc;
}

static void
pppoe_linkstatus_up(struct pppoe_softc *sc)
{
  sc->sc_linkStatusCB(sc->sc_pd, 1);
}

/* analyze and handle a single received packet while not in session state */
static void
pppoe_dispatch_disc_pkt(struct netif *netif, struct pbuf *pb)
{
  u16_t tag, len;
  u16_t session, plen;
  struct pppoe_softc *sc;
  const char *err_msg;
  char devname[6];
  u8_t *ac_cookie;
  u16_t ac_cookie_len;
#ifdef PPPOE_SERVER
  u8_t *hunique;
  size_t hunique_len;
#endif
  struct pppoehdr *ph;
  struct pppoetag pt;
  int off, err, errortag;
  struct eth_hdr *ethhdr;

  pb = pppSingleBuf(pb);

  strcpy(devname, "pppoe");  /* as long as we don't know which instance */
  err_msg = NULL;
  errortag = 0;
  if (pb->len < sizeof(*ethhdr)) {
    goto done;
  }
  ethhdr = (struct eth_hdr *)pb->payload;
  off = sizeof(*ethhdr);

  ac_cookie = NULL;
  ac_cookie_len = 0;
#ifdef PPPOE_SERVER
  hunique = NULL;
  hunique_len = 0;
#endif
  session = 0;
  if (pb->len - off < PPPOE_HEADERLEN) {
    printf("pppoe: packet too short: %d\n", pb->len);
    goto done;
  }

  ph = (struct pppoehdr *) (ethhdr + 1);
  if (ph->vertype != PPPOE_VERTYPE) {
    printf("pppoe: unknown version/type packet: 0x%x\n", ph->vertype);
    goto done;
  }
  session = ntohs(ph->session);
  plen = ntohs(ph->plen);
  off += sizeof(*ph);

  if (plen + off > pb->len) {
    printf("pppoe: packet content does not fit: data available = %d, packet size = %u\n",
        pb->len - off, plen);
    goto done;
  }
  if(pb->tot_len == pb->len) {
    pb->tot_len = pb->len = (u16_t)off + plen; /* ignore trailing garbage */
  }
  tag = 0;
  len = 0;
  sc = NULL;
  while (off + sizeof(pt) <= pb->len) {
    MEMCPY(&pt, (u8_t*)pb->payload + off, sizeof(pt));
    tag = ntohs(pt.tag);
    len = ntohs(pt.len);
    if (off + sizeof(pt) + len > pb->len) {
      printf("pppoe: tag 0x%x len 0x%x is too long\n", tag, len);
      goto done;
    }
    switch (tag) {
      case PPPOE_TAG_EOL:
        goto breakbreak;
      case PPPOE_TAG_SNAME:
        break;  /* ignored */
      case PPPOE_TAG_ACNAME:
        break;  /* ignored */
      case PPPOE_TAG_HUNIQUE:
        if (sc != NULL) {
          break;
        }
#ifdef PPPOE_SERVER
        hunique = (u8_t*)pb->payload + off + sizeof(pt);
        hunique_len = len;
#endif
        sc = pppoe_find_softc_by_hunique((u8_t*)pb->payload + off + sizeof(pt), len, netif);
        if (sc != NULL) {
          snprintf(devname, sizeof(devname), "%c%c%"U16_F, sc->sc_ethif->name[0], sc->sc_ethif->name[1], sc->sc_ethif->num);
        }
        break;
      case PPPOE_TAG_ACCOOKIE:
        if (ac_cookie == NULL) {
          ac_cookie = (u8_t*)pb->payload + off + sizeof(pt);
          ac_cookie_len = len;
        }