ppp.c

最新的lwip 1.3.0版本在ucos平台上的移植

/* The main PPP process function.  This implements the state machine according
 * to section 4 of RFC 1661: The Point-To-Point Protocol. */
static void
pppMain(void *arg)
{
  int pd = (int)arg;
  struct pbuf *p;
  PPPControl* pc;
  int c;

  pc = &pppControl[pd];

  p = pbuf_alloc(PBUF_RAW, PPP_MRU+PPP_HDRLEN, PBUF_RAM);
  if (!p) {
    LWIP_ASSERT("p != NULL", p);
    pc->errCode = PPPERR_ALLOC;
    goto out;
  }

  /*
   * Start the connection and handle incoming events (packet or timeout).
   */
  PPPDEBUG((LOG_INFO, "pppMain: unit %d: Connecting\n", pd));
  tcpip_callback(pppStartCB, arg);
  while (lcp_phase[pd] != PHASE_DEAD) {
    if (pc->kill_link) {
      PPPDEBUG((LOG_DEBUG, "pppMain: unit %d kill_link -> pppStopCB\n", pd));
      pc->errCode = PPPERR_USER;
      /* This will leave us at PHASE_DEAD. */
      tcpip_callback(pppStopCB, arg);
      pc->kill_link = 0;
    } else if (pc->sig_hup) {
      PPPDEBUG((LOG_DEBUG, "pppMain: unit %d sig_hup -> pppHupCB\n", pd));
      pc->sig_hup = 0;
      tcpip_callback(pppHupCB, arg);
    } else {
      c = sio_read(pc->fd, p->payload, p->len);
      if(c > 0) {
        pppInProc(pd, p->payload, c);
      } else {
        PPPDEBUG((LOG_DEBUG, "pppMain: unit %d sio_read len=%d returned %d\n", pd, p->len, c));
        sys_msleep(1); /* give other tasks a chance to run */
      }
    }
  }
  PPPDEBUG((LOG_INFO, "pppMain: unit %d: PHASE_DEAD\n", pd));
  pppDrop(pc); /* bug fix #17726 */
  pbuf_free(p);

out:
  PPPDEBUG((LOG_DEBUG, "pppMain: unit %d: linkStatusCB=%lx errCode=%d\n", pd, pc->linkStatusCB, pc->errCode));
  if(pc->linkStatusCB) {
    pc->linkStatusCB(pc->linkStatusCtx, pc->errCode ? pc->errCode : PPPERR_PROTOCOL, NULL);
  }

  pc->openFlag = 0;
}
#endif /* PPPOS_SUPPORT */

#if PPPOE_SUPPORT

void
pppOverEthernetInitFailed(void* arg)
{
  PPPControl* pc;
  int pd = (int)arg;

  pppHupCB(arg);
  pppStopCB(arg);

  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, "pppMain: unit %d: Connecting\n", pd));
    tcpip_callback(pppStartCB, (void*)pd);
  } else {
    PPPControl* pc;
    pc = &pppControl[pd];
    tcpip_callback(pppOverEthernetInitFailed, (void*)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);

  /*
   * 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%04X in phase %d\n", protocol, lcp_phase[pd]));
      goto drop;
    }
  }

  switch(protocol) {
    case PPP_VJC_COMP:      /* VJ compressed TCP */
#if 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  /* 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 /* VJ_SUPPORT */
      break;

    case PPP_VJC_UNCOMP:    /* VJ uncompressed TCP */
#if 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  /* 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 /* 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);
          goto out;
        }
      }

      /* No handler for this protocol so reject the packet. */
      PPPDEBUG((LOG_INFO, "pppInput[%d]: rejecting unsupported proto 0x%04X 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);
      SMEMCPY(nb->payload, &protocol, sizeof(protocol));
#endif /* BYTE_ORDER == LITTLE_ENDIAN */
      lcp_sprotrej(pd, nb->payload, nb->len);
    }
    break;
  }

drop:
  LINK_STATS_INC(link.drop);

out:
  pbuf_free(nb);
  return;
}

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

  LINK_STATS_INC(link.drop);
}

/**
 * Process a received octet string.
 */
static void
pppInProc(int pd, u_char *s, int l)
{
  PPPControl *pc = &pppControl[pd];
  struct pbuf *nextNBuf;
  u_char curChar;

  PPPDEBUG((LOG_DEBUG, "pppInProc[%d]: got %d bytes\n", pd, l));
  while (l-- > 0) {
    curChar = *s++;
    
    /* Handle special characters. */
    if (ESCAPE_P(pc->inACCM, curChar)) {
      /* 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) {
        pc->inEscaped = 1;
      /* Check for the flag character. */
      } else if (curChar == PPP_FLAG) {
         /* If this is just an extra flag character, ignore it. */
         if (pc->inState <= PDADDRESS) {
           /* ignore it */;
         /* If we haven't received the packet header, drop what has come in. */
         } else if (pc->inState < PDDATA) {
           PPPDEBUG((LOG_WARNING,
                    "pppInProc[%d]: Dropping incomplete packet %d\n", 
                     pd, pc->inState));
           LINK_STATS_INC(link.lenerr);
           pppDrop(pc);
         /* If the fcs is invalid, drop the packet. */
         } else if (pc->inFCS != PPP_GOODFCS) {
           PPPDEBUG((LOG_INFO,
                    "pppInProc[%d]: Dropping bad fcs 0x%04X proto=0x%04X\n", 
                     pd, pc->inFCS, pc->inProtocol));
           LINK_STATS_INC(link.chkerr);
           pppDrop(pc);
         /* Otherwise it's a good packet so pass it on. */
         } else {
           /* Trim off the checksum. */
           if(pc->inTail->len >= 2) {
             pc->inTail->len -= 2;

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

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

           /* Dispatch the packet thereby consuming it. */
           if(tcpip_callback(pppInput, pc->inHead) != ERR_OK) {
             PPPDEBUG((LOG_ERR, "pppInProc[%d]: tcpip_callback() failed, dropping packet\n", pd));
             pbuf_free(pc->inHead);
             LINK_STATS_INC(link.drop);
           }
           pc->inHead = NULL;
           pc->inTail = NULL;
         }

         /* Prepare for a new packet. */
         pc->inFCS = PPP_INITFCS;
         pc->inState = PDADDRESS;
         pc->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", pd, curChar));
      }
    /* Process other characters. */
    } else {
      /* Unencode escaped characters. */
      if (pc->inEscaped) {
        pc->inEscaped = 0;
        curChar ^= PPP_TRANS;
      }

      /* Process character relative to current state. */
      switch(pc->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. */
          pc->inFCS = PPP_INITFCS;

        /* Fall through */
        case PDADDRESS:                 /* Process address field. */
          if (curChar == PPP_ALLSTATIONS) {
            pc->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) {
            pc->inState = PDPROTOCOL1;
            break;
          }
#if 0
          else {
            PPPDEBUG((LOG_WARNING,
                     "pppInProc[%d]: Invalid control <%d>\n", pd, curChar));
                      pc->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) {
            pc->inProtocol = curChar;
            pc->inState = PDDATA;
          } else {
            pc->inProtocol = (u_int)curChar << 8;
            pc->inState = PDPROTOCOL2;
          }
          break;
        case PDPROTOCOL2:               /* Process protocol field 2. */
          pc->inProtocol |= curChar;
          pc->inState = PDDATA;
          break;
        case PDDATA:                    /* Process data byte. */
          /* Make space to receive processed data. */
          if (pc->inTail == NULL || pc->inTail->len == PBUF_POOL_BUFSIZE) {
            if(pc->inTail) {
              pc->inTail->tot_len = pc->inTail->len;
              if (pc->inTail != pc->inHead) {
                pbuf_cat(pc->inHead, pc->inTail);
              }
            }
            /* 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", pd));
              LINK_STATS_INC(link.memerr);
              pppDrop(pc);
              pc->inState = PDSTART;  /* Wait for flag sequence. */
              break;
            }
            if (pc->inHead == NULL) {
              struct pppInputHeader *pih = nextNBuf->payload;

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

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

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

      /* update the frame check sequence number. */
      pc->inFCS = PPP_FCS(pc->inFCS, curChar);
    }
  }

  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. */
  if(tcpip_callback(pppInput, pb) != ERR_OK) {
    PPPDEBUG((LOG_ERR, "pppInProcOverEthernet[%d]: tcpip_callback() failed, dropping packet\n", pd));
    goto drop;
  }

  return;

drop:
  LINK_STATS_INC(link.drop);
  pbuf_free(pb);
  return;
}
#endif /* PPPOE_SUPPORT */

#endif /* PPP_SUPPORT */