in netutils/pppd/lcp.c [113:420]
void lcp_rx(struct ppp_context_s *ctx, uint8_t * buffer, uint16_t count)
{
FAR uint8_t *bptr = buffer;
FAR uint8_t *tptr;
uint8_t error = 0;
uint8_t id;
uint16_t len;
uint16_t j;
switch (*bptr++)
{
case CONF_REQ: /* config request */
/* Parse request and see if we can ACK it */
id = *bptr++;
UNUSED(id);
len = (*bptr++ << 8);
len |= *bptr++;
/* len -= 2; */
/* In case of new peer connection */
ipcp_init(ctx);
/* Clear LCP state to keep it in negotiation phase. LCP_TX_UP will be
* re-set once a CONF_ACK is received.
*/
ctx->lcp_state &= ~LCP_TX_UP;
DEBUG1(("received [LCP Config Request id %u\n", id));
if (scan_packet
(ctx, (uint16_t)LCP, g_lcplist, buffer, bptr, (uint16_t)(len - 4)))
{
/* Must do the -4 here, !scan packet */
DEBUG1((" options were rejected\n"));
}
else
{
/* Lets try to implement what peer wants */
tptr = bptr;
error = 0;
/* First scan for unknown values */
while (bptr < (buffer + len))
{
switch (*bptr++)
{
case LPC_MRU: /* mru */
j = *bptr++;
j -= 2;
if (j == 2)
{
ctx->ppp_tx_mru = ((int)*bptr++) << 8;
ctx->ppp_tx_mru |= *bptr++;
DEBUG1(("<mru %d> ", ctx->ppp_tx_mru));
}
else
{
DEBUG1(("<mru ?? > "));
}
break;
case LPC_ACCM:
bptr++; /* skip length */
j = *bptr++;
j += *bptr++;
j += *bptr++;
j += *bptr++;
if (j == 0)
{
/* OK */
DEBUG1(("<asyncmap sum=0x%04x>", j));
ctx->ahdlc_flags |= PPP_TX_ASYNC_MAP;
}
else if (j == 0x3fc)
{
/* OK */
DEBUG1(("<asyncmap sum=0x%04x>, assume all ones", j));
ctx->ahdlc_flags &= ~PPP_TX_ASYNC_MAP;
}
else
{
/* Fail. We only support default or all zeros */
DEBUG1(("We only support default or all zeros ACCM "));
error = 1;
*tptr++ = LPC_ACCM;
*tptr++ = 0x6;
*tptr++ = 0;
*tptr++ = 0;
*tptr++ = 0;
*tptr++ = 0;
}
break;
#ifdef CONFIG_NETUTILS_PPPD_PAP
case LPC_AUTH:
bptr++;
if ((*bptr++ == 0xc0) && (*bptr++ == 0x23))
{
/* Negotiate PAP */
DEBUG1(("<auth pap> "));
ctx->lcp_state |= LCP_RX_AUTH;
}
else
{
/* We only support PAP */
DEBUG1(("<auth ?? >"));
error = 1;
*tptr++ = LPC_AUTH;
*tptr++ = 0x4;
*tptr++ = 0xc0;
*tptr++ = 0x23;
}
break;
#endif /* CONFIG_NETUTILS_PPPD_PAP */
case LPC_MAGICNUMBER:
DEBUG1(("<magic > "));
/* Compare incoming number to our number */
bptr++; /* For now just dump */
bptr++;
bptr++;
bptr++;
bptr++;
break;
case LPC_PFC:
bptr++;
DEBUG1(("<pcomp> "));
ctx->ahdlc_flags |= PPP_PFC;
break;
case LPC_ACFC:
bptr++;
DEBUG1(("<accomp> "));
ctx->ahdlc_flags |= PPP_ACFC;
break;
}
}
/* Error? if we we need to send a config Reject ++++ this is good
* for a subroutine.
*/
if (error)
{
/* Write the config NAK packet we've built above, take on the
* header
*/
bptr = buffer;
*bptr++ = CONF_NAK; /* Write Conf_rej */
bptr++; /* tptr++; skip over ID */
/* Write new length */
*bptr++ = 0;
*bptr = tptr - buffer;
/* Write the reject frame */
DEBUG1(("\nWriting NAK frame\n"));
/* Send packet:
* ahdlc_txz(procol,header,data,headerlen,datalen);
*/
ahdlc_tx(ctx, LCP, 0, buffer, 0, (uint16_t)(tptr - buffer));
DEBUG1(("- end NAK Write frame\n"));
}
else
{
/* If we get here then we are OK, lets send an ACK and tell the
* rest of our modules our negotiated config.
*/
DEBUG1(("\nSend ACK!\n"));
bptr = buffer;
*bptr++ = CONF_ACK; /* Write Conf_ACK */
bptr++; /* Skip ID (send same one) */
/* Set stuff */
/* ppp_flags |= tflag;
* DEBUG2("SET- stuff -- are we up? c=%d dif=%d\n", count,
* (uint16_t)(bptr-buffer));
*/
/* Write the ACK frame */
DEBUG2(("Writing ACK frame\n"));
/* Send packet:
* ahdlc_txz(procol,header,data,headerlen,datalen);
*/
ahdlc_tx(ctx, LCP, 0, buffer, 0, count /* bptr-buffer */);
DEBUG2(("- end ACK Write frame\n"));
ctx->lcp_state |= LCP_RX_UP;
}
}
break;
case CONF_ACK: /* config Ack Anytime we do an ack reset the
* timer to force send. */
DEBUG1(("LCP-ACK - "));
/* Check that ID matches one sent */
if (*bptr++ == ctx->ppp_id)
{
/* Change state to PPP up. */
DEBUG1((">>>>>>>> good ACK id up! %d\n", ctx->ppp_id));
/* Copy negotiated values over */
ctx->lcp_state |= LCP_TX_UP;
}
else
{
DEBUG1(("*************++++++++++ bad id %d\n", ctx->ppp_id));
}
break;
case CONF_NAK: /* Config Nack */
DEBUG1(("LCP-CONF NAK\n"));
ctx->ppp_id++;
break;
case CONF_REJ: /* Config Reject */
DEBUG1(("LCP-CONF REJ\n"));
ctx->ppp_id++;
break;
case TERM_REQ: /* Terminate Request */
DEBUG1(("LCP-TERM-REQ -"));
bptr = buffer;
*bptr++ = TERM_ACK; /* Write TERM_ACK */
/* Write the reject frame */
DEBUG1(("Writing TERM_ACK frame\n"));
/* Send packet ahdlc_txz(procol,header,data,headerlen,datalen); */
ahdlc_tx(ctx, LCP, 0, buffer, 0, count);
ctx->lcp_state &= ~LCP_TX_UP;
ctx->lcp_state |= LCP_TERM_PEER;
break;
case TERM_ACK:
DEBUG1(("LCP-TERM ACK\n"));
break;
case ECHO_REQ:
if ((ctx->lcp_state & LCP_TX_UP) && (ctx->lcp_state & LCP_RX_UP))
{
bptr = buffer;
*bptr++ = ECHO_REP; /* Write ECHO-REPLY */
bptr += 3; /* Skip id and length */
*bptr++ = 0; /* Zero Magic */
*bptr++ = 0;
*bptr++ = 0;
*bptr++ = 0;
/* Write the echo reply frame */
DEBUG1(("\nWriting ECHO-REPLY frame\n"));
/* Send packet ahdlc_txz(procol,header,data,headerlen,datalen); */
ahdlc_tx(ctx, LCP, 0, buffer, 0, count);
DEBUG1(("- end ECHO-REPLY Write frame\n"));
}
break;
case ECHO_REP:
DEBUG1(("LCP-ECHO REPLY\n"));
if ((ctx->lcp_state & LCP_TX_UP) && (ctx->lcp_state & LCP_RX_UP))
{
ctx->ppp_id++;
}
break;
default:
DEBUG1(("LCP unknown packet: %02x", *(bptr - 1)));
break;
}
}