ppp.c

lwip-1.4.0

  }
}
#endif /* PPPOS_SUPPORT && PPP_INPROC_OWNTHREAD */

#if PPPOE_SUPPORT

void
pppOverEthernetInitFailed(int pd)
{
  PPPControl* pc;

  pppHup(pd);
  pppStop(pd);

  pc = &pppControl[pd];
  pppoe_destroy(&pc->netif);
  pc->openFlag = 0;

  if(pc->linkStatusCB) {
    pc->linkStatusCB(pc->linkStatusCtx, pc->errCode ? pc->errCode : PPPERR_PROTOCOL, NULL);
  }
}

static void
pppOverEthernetLinkStatusCB(int pd, int up)
{
  if(up) {
    PPPDEBUG(LOG_INFO, ("pppOverEthernetLinkStatusCB: unit %d: Connecting\n", pd));
    pppStart(pd);
  } else {
    pppOverEthernetInitFailed(pd);
  }
}
#endif /* PPPOE_SUPPORT */

struct pbuf *
pppSingleBuf(struct pbuf *p)
{
  struct pbuf *q, *b;
  u_char *pl;

  if(p->tot_len == p->len) {
    return p;
  }

  q = pbuf_alloc(PBUF_RAW, p->tot_len, PBUF_RAM);
  if(!q) {
    PPPDEBUG(LOG_ERR,
             ("pppSingleBuf: unable to alloc new buf (%d)\n", p->tot_len));
    return p; /* live dangerously */
  }

  for(b = p, pl = q->payload; b != NULL; b = b->next) {
    MEMCPY(pl, b->payload, b->len);
    pl += b->len;
  }

  pbuf_free(p);

  return q;
}

struct pppInputHeader {
  int unit;
  u16_t proto;
};

/*
 * Pass the processed input packet to the appropriate handler.
 * This function and all handlers run in the context of the tcpip_thread
 */
static void
pppInput(void *arg)
{
  struct pbuf *nb = (struct pbuf *)arg;
  u16_t protocol;
  int pd;

  pd = ((struct pppInputHeader *)nb->payload)->unit;
  protocol = ((struct pppInputHeader *)nb->payload)->proto;
    
  if(pbuf_header(nb, -(int)sizeof(struct pppInputHeader))) {
    LWIP_ASSERT("pbuf_header failed\n", 0);
    goto drop;
  }

  LINK_STATS_INC(link.recv);
  snmp_inc_ifinucastpkts(&pppControl[pd].netif);
  snmp_add_ifinoctets(&pppControl[pd].netif, nb->tot_len);

  /*
   * Toss all non-LCP packets unless LCP is OPEN.
   * Until we get past the authentication phase, toss all packets
   * except LCP, LQR and authentication packets.
   */
  if((lcp_phase[pd] <= PHASE_AUTHENTICATE) && (protocol != PPP_LCP)) {
    if(!((protocol == PPP_LQR) || (protocol == PPP_PAP) || (protocol == PPP_CHAP)) ||
        (lcp_phase[pd] != PHASE_AUTHENTICATE)) {
      PPPDEBUG(LOG_INFO, ("pppInput: discarding proto 0x%"X16_F" in phase %d\n", protocol, lcp_phase[pd]));
      goto drop;
    }
  }

  switch(protocol) {
    case PPP_VJC_COMP:      /* VJ compressed TCP */
#if PPPOS_SUPPORT && VJ_SUPPORT
      PPPDEBUG(LOG_INFO, ("pppInput[%d]: vj_comp in pbuf len=%d\n", pd, nb->len));
      /*
       * Clip off the VJ header and prepend the rebuilt TCP/IP header and
       * pass the result to IP.
       */
      if ((vj_uncompress_tcp(&nb, &pppControl[pd].vjComp) >= 0) && (pppControl[pd].netif.input)) {
        pppControl[pd].netif.input(nb, &pppControl[pd].netif);
        return;
      }
      /* Something's wrong so drop it. */
      PPPDEBUG(LOG_WARNING, ("pppInput[%d]: Dropping VJ compressed\n", pd));
#else  /* PPPOS_SUPPORT && VJ_SUPPORT */
      /* No handler for this protocol so drop the packet. */
      PPPDEBUG(LOG_INFO, ("pppInput[%d]: drop VJ Comp in %d:%s\n", pd, nb->len, nb->payload));
#endif /* PPPOS_SUPPORT && VJ_SUPPORT */
      break;

    case PPP_VJC_UNCOMP:    /* VJ uncompressed TCP */
#if PPPOS_SUPPORT && VJ_SUPPORT
      PPPDEBUG(LOG_INFO, ("pppInput[%d]: vj_un in pbuf len=%d\n", pd, nb->len));
      /*
       * Process the TCP/IP header for VJ header compression and then pass
       * the packet to IP.
       */
      if ((vj_uncompress_uncomp(nb, &pppControl[pd].vjComp) >= 0) && pppControl[pd].netif.input) {
        pppControl[pd].netif.input(nb, &pppControl[pd].netif);
        return;
      }
      /* Something's wrong so drop it. */
      PPPDEBUG(LOG_WARNING, ("pppInput[%d]: Dropping VJ uncompressed\n", pd));
#else  /* PPPOS_SUPPORT && VJ_SUPPORT */
      /* No handler for this protocol so drop the packet. */
      PPPDEBUG(LOG_INFO,
               ("pppInput[%d]: drop VJ UnComp in %d:.*H\n", 
                pd, nb->len, LWIP_MIN(nb->len * 2, 40), nb->payload));
#endif /* PPPOS_SUPPORT && VJ_SUPPORT */
      break;

    case PPP_IP:            /* Internet Protocol */
      PPPDEBUG(LOG_INFO, ("pppInput[%d]: ip in pbuf len=%d\n", pd, nb->len));
      if (pppControl[pd].netif.input) {
        pppControl[pd].netif.input(nb, &pppControl[pd].netif);
        return;
      }
      break;

    default: {
      struct protent *protp;
      int i;

      /*
       * Upcall the proper protocol input routine.
       */
      for (i = 0; (protp = ppp_protocols[i]) != NULL; ++i) {
        if (protp->protocol == protocol && protp->enabled_flag) {
          PPPDEBUG(LOG_INFO, ("pppInput[%d]: %s len=%d\n", pd, protp->name, nb->len));
          nb = pppSingleBuf(nb);
          (*protp->input)(pd, nb->payload, nb->len);
          PPPDEBUG(LOG_DETAIL, ("pppInput[%d]: packet processed\n", pd));
          goto out;
        }
      }

      /* No handler for this protocol so reject the packet. */
      PPPDEBUG(LOG_INFO, ("pppInput[%d]: rejecting unsupported proto 0x%"X16_F" len=%d\n", pd, protocol, nb->len));
      if (pbuf_header(nb, sizeof(protocol))) {
        LWIP_ASSERT("pbuf_header failed\n", 0);
        goto drop;
      }
#if BYTE_ORDER == LITTLE_ENDIAN
      protocol = htons(protocol);
#endif /* BYTE_ORDER == LITTLE_ENDIAN */
      SMEMCPY(nb->payload, &protocol, sizeof(protocol));
      lcp_sprotrej(pd, nb->payload, nb->len);
    }
    break;
  }

drop:
  LINK_STATS_INC(link.drop);
  snmp_inc_ifindiscards(&pppControl[pd].netif);

out:
  pbuf_free(nb);
  return;
}

#if PPPOS_SUPPORT
/*
 * Drop the input packet.
 */
static void
pppDrop(PPPControlRx *pcrx)
{
  if (pcrx->inHead != NULL) {
#if 0
    PPPDEBUG(LOG_INFO, ("pppDrop: %d:%.*H\n", pcrx->inHead->len, min(60, pcrx->inHead->len * 2), pcrx->inHead->payload));
#endif
    PPPDEBUG(LOG_INFO, ("pppDrop: pbuf len=%d, addr %p\n", pcrx->inHead->len, (void*)pcrx->inHead));
    if (pcrx->inTail && (pcrx->inTail != pcrx->inHead)) {
      pbuf_free(pcrx->inTail);
    }
    pbuf_free(pcrx->inHead);
    pcrx->inHead = NULL;
    pcrx->inTail = NULL;
  }
#if VJ_SUPPORT
  vj_uncompress_err(&pppControl[pcrx->pd].vjComp);
#endif /* VJ_SUPPORT */

  LINK_STATS_INC(link.drop);
  snmp_inc_ifindiscards(&pppControl[pcrx->pd].netif);
}

/** Pass received raw characters to PPPoS to be decoded. This function is
 * thread-safe and can be called from a dedicated RX-thread or from a main-loop.
 *
 * @param pd PPP descriptor index, returned by pppOpen()
 * @param data received data
 * @param len length of received data
 */
void
pppos_input(int pd, u_char* data, int len)
{
  pppInProc(&pppControl[pd].rx, data, len);
}

/**
 * Process a received octet string.
 */
static void
pppInProc(PPPControlRx *pcrx, u_char *s, int l)
{
  struct pbuf *nextNBuf;
  u_char curChar;
  u_char escaped;
  SYS_ARCH_DECL_PROTECT(lev);

  PPPDEBUG(LOG_DEBUG, ("pppInProc[%d]: got %d bytes\n", pcrx->pd, l));
  while (l-- > 0) {
    curChar = *s++;

    SYS_ARCH_PROTECT(lev);
    escaped = ESCAPE_P(pcrx->inACCM, curChar);
    SYS_ARCH_UNPROTECT(lev);
    /* Handle special characters. */
    if (escaped) {
      /* Check for escape sequences. */
      /* XXX Note that this does not handle an escaped 0x5d character which
       * would appear as an escape character.  Since this is an ASCII ']'
       * and there is no reason that I know of to escape it, I won't complicate
       * the code to handle this case. GLL */
      if (curChar == PPP_ESCAPE) {
        pcrx->inEscaped = 1;
      /* Check for the flag character. */
      } else if (curChar == PPP_FLAG) {
        /* If this is just an extra flag character, ignore it. */
        if (pcrx->inState <= PDADDRESS) {
          /* ignore it */;
        /* If we haven't received the packet header, drop what has come in. */
        } else if (pcrx->inState < PDDATA) {
          PPPDEBUG(LOG_WARNING,
                   ("pppInProc[%d]: Dropping incomplete packet %d\n", 
                    pcrx->pd, pcrx->inState));
          LINK_STATS_INC(link.lenerr);
          pppDrop(pcrx);
        /* If the fcs is invalid, drop the packet. */
        } else if (pcrx->inFCS != PPP_GOODFCS) {
          PPPDEBUG(LOG_INFO,
                   ("pppInProc[%d]: Dropping bad fcs 0x%"X16_F" proto=0x%"X16_F"\n", 
                    pcrx->pd, pcrx->inFCS, pcrx->inProtocol));
          /* Note: If you get lots of these, check for UART frame errors or try different baud rate */
          LINK_STATS_INC(link.chkerr);
          pppDrop(pcrx);
        /* Otherwise it's a good packet so pass it on. */
        } else {
          struct pbuf *inp;
          /* Trim off the checksum. */
          if(pcrx->inTail->len >= 2) {
            pcrx->inTail->len -= 2;

            pcrx->inTail->tot_len = pcrx->inTail->len;
            if (pcrx->inTail != pcrx->inHead) {
              pbuf_cat(pcrx->inHead, pcrx->inTail);
            }
          } else {
            pcrx->inTail->tot_len = pcrx->inTail->len;
            if (pcrx->inTail != pcrx->inHead) {
              pbuf_cat(pcrx->inHead, pcrx->inTail);
            }

            pbuf_realloc(pcrx->inHead, pcrx->inHead->tot_len - 2);
          }

          /* Dispatch the packet thereby consuming it. */
          inp = pcrx->inHead;
          /* Packet consumed, release our references. */
          pcrx->inHead = NULL;
          pcrx->inTail = NULL;
#if PPP_INPROC_MULTITHREADED
          if(tcpip_callback_with_block(pppInput, inp, 0) != ERR_OK) {
            PPPDEBUG(LOG_ERR, ("pppInProc[%d]: tcpip_callback() failed, dropping packet\n", pcrx->pd));
            pbuf_free(inp);
            LINK_STATS_INC(link.drop);
            snmp_inc_ifindiscards(&pppControl[pcrx->pd].netif);
          }
#else /* PPP_INPROC_MULTITHREADED */
          pppInput(inp);
#endif /* PPP_INPROC_MULTITHREADED */
        }

        /* Prepare for a new packet. */
        pcrx->inFCS = PPP_INITFCS;
        pcrx->inState = PDADDRESS;
        pcrx->inEscaped = 0;
      /* Other characters are usually control characters that may have
       * been inserted by the physical layer so here we just drop them. */
      } else {
        PPPDEBUG(LOG_WARNING,
                 ("pppInProc[%d]: Dropping ACCM char <%d>\n", pcrx->pd, curChar));
      }
    /* Process other characters. */
    } else {
      /* Unencode escaped characters. */
      if (pcrx->inEscaped) {
        pcrx->inEscaped = 0;
        curChar ^= PPP_TRANS;
      }

      /* Process character relative to current state. */
      switch(pcrx->inState) {
        case PDIDLE:                    /* Idle state - waiting. */
          /* Drop the character if it's not 0xff
           * we would have processed a flag character above. */
          if (curChar != PPP_ALLSTATIONS) {
            break;
          }

        /* Fall through */
        case PDSTART:                   /* Process start flag. */
          /* Prepare for a new packet. */
          pcrx->inFCS = PPP_INITFCS;

        /* Fall through */
        case PDADDRESS:                 /* Process address field. */
          if (curChar == PPP_ALLSTATIONS) {
            pcrx->inState = PDCONTROL;
            break;
          }
          /* Else assume compressed address and control fields so
           * fall through to get the protocol... */
        case PDCONTROL:                 /* Process control field. */
          /* If we don't get a valid control code, restart. */
          if (curChar == PPP_UI) {
            pcrx->inState = PDPROTOCOL1;
            break;
          }
#if 0
          else {
            PPPDEBUG(LOG_WARNING,
                     ("pppInProc[%d]: Invalid control <%d>\n", pcrx->pd, curChar));
            pcrx->inState = PDSTART;
          }
#endif
        case PDPROTOCOL1:               /* Process protocol field 1. */
          /* If the lower bit is set, this is the end of the protocol
           * field. */
          if (curChar & 1) {
            pcrx->inProtocol = curChar;
            pcrx->inState = PDDATA;
          } else {
            pcrx->inProtocol = (u_int)curChar << 8;
            pcrx->inState = PDPROTOCOL2;
          }
          break;
        case PDPROTOCOL2:               /* Process protocol field 2. */
          pcrx->inProtocol |= curChar;
          pcrx->inState = PDDATA;
          break;
        case PDDATA:                    /* Process data byte. */
          /* Make space to receive processed data. */
          if (pcrx->inTail == NULL || pcrx->inTail->len == PBUF_POOL_BUFSIZE) {
            if (pcrx->inTail != NULL) {
              pcrx->inTail->tot_len = pcrx->inTail->len;
              if (pcrx->inTail != pcrx->inHead) {
                pbuf_cat(pcrx->inHead, pcrx->inTail);
                /* give up the inTail reference now */
                pcrx->inTail = NULL;
              }
            }
            /* If we haven't started a packet, we need a packet header. */
            nextNBuf = pbuf_alloc(PBUF_RAW, 0, PBUF_POOL);
            if (nextNBuf == NULL) {
              /* No free buffers.  Drop the input packet and let the
               * higher layers deal with it.  Continue processing
               * the received pbuf chain in case a new packet starts. */
              PPPDEBUG(LOG_ERR, ("pppInProc[%d]: NO FREE MBUFS!\n", pcrx->pd));
              LINK_STATS_INC(link.memerr);
              pppDrop(pcrx);
              pcrx->inState = PDSTART;  /* Wait for flag sequence. */
              break;
            }
            if (pcrx->inHead == NULL) {
              struct pppInputHeader *pih = nextNBuf->payload;

              pih->unit = pcrx->pd;
              pih->proto = pcrx->inProtocol;

              nextNBuf->len += sizeof(*pih);

              pcrx->inHead = nextNBuf;
            }
            pcrx->inTail = nextNBuf;
          }
          /* Load character into buffer. */
          ((u_char*)pcrx->inTail->payload)[pcrx->inTail->len++] = curChar;
          break;
      }

      /* update the frame check sequence number. */
      pcrx->inFCS = PPP_FCS(pcrx->inFCS, curChar);
    }
  } /* while (l-- > 0), all bytes processed */

  avRandomize();
}
#endif /* PPPOS_SUPPORT */

#if PPPOE_SUPPORT
void
pppInProcOverEthernet(int pd, struct pbuf *pb)
{
  struct pppInputHeader *pih;
  u16_t inProtocol;

  if(pb->len < sizeof(inProtocol)) {
    PPPDEBUG(LOG_ERR, ("pppInProcOverEthernet: too small for protocol field\n"));
    goto drop;
  }

  inProtocol = (((u8_t *)pb->payload)[0] << 8) | ((u8_t*)pb->payload)[1];

  /* make room for pppInputHeader - should not fail */
  if (pbuf_header(pb, sizeof(*pih) - sizeof(inProtocol)) != 0) {
    PPPDEBUG(LOG_ERR, ("pppInProcOverEthernet: could not allocate room for header\n"));
    goto drop;
  }

  pih = pb->payload;

  pih->unit = pd;
  pih->proto = inProtocol;

  /* Dispatch the packet thereby consuming it. */
  pppInput(pb);
  return;

drop:
  LINK_STATS_INC(link.drop);
  snmp_inc_ifindiscards(&pppControl[pd].netif);
  pbuf_free(pb);
  return;
}
#endif /* PPPOE_SUPPORT */

#if LWIP_NETIF_STATUS_CALLBACK
/** Set the status callback of a PPP's netif
 *
 * @param pd The PPP descriptor returned by pppOpen()
 * @param status_callback pointer to the status callback function
 *
 * @see netif_set_status_callback
 */
void
ppp_set_netif_statuscallback(int pd, netif_status_callback_fn status_callback)
{
  netif_set_status_callback(&pppControl[pd].netif, status_callback); 
}
#endif /* LWIP_NETIF_STATUS_CALLBACK */

#if LWIP_NETIF_LINK_CALLBACK
/** Set the link callback of a PPP's netif
 *
 * @param pd The PPP descriptor returned by pppOpen()
 * @param link_callback pointer to the link callback function
 *
 * @see netif_set_link_callback
 */
void
ppp_set_netif_linkcallback(int pd, netif_status_callback_fn link_callback)
{
  netif_set_link_callback(&pppControl[pd].netif, link_callback); 
}
#endif /* LWIP_NETIF_LINK_CALLBACK */

#endif /* PPP_SUPPORT */