/*!
* \brief Send DHCP datagram and wait for a specified answer.
*
* \param slen Length of message to send.
* \param xtype Expected response type.
*
* \return The number of data bytes received, 0 on timeout or -1 in
* case of a failure.
*/
int DhcpTransact(u_short slen, u_char xtype)
{
u_char type;
u_char retry;
int rlen = 0;
for (retry = 0; retry < 3; ) {
/*
* Send a message, if nothing has been received yet.
*/
if (rlen == 0) {
if (UdpOutput(INADDR_BROADCAST, DHCP_SERVERPORT, DHCP_CLIENTPORT, slen) < 0) {
/* Transmit failure, must be a NIC problem. Give up. */
return -1;
}
}
/*
* Do a retry on timouts or failures. A receive failures may be
* caused by a hardware failure or a bad frame.
*/
if ((rlen = UdpInput(DHCP_CLIENTPORT, 5000)) <= 0) {
retry++;
continue;
}
/*
* Check if the response contains the expected ID and
* message type.
*/
if (rframe.u.bootp.bp_xid == sframe.u.bootp.bp_xid &&
DhcpGetOption(DHCPOPT_MSGTYPE, &type, 1) == 1 &&
type == xtype) {
DEBUG("[DHCP]");
break;
}
}
return rlen;
}
/*!
* \brief Download a file from a TFTP server and burn it into the flash ROM.
*
* \return 0 on success, -1 otherwise.
*/
int TftpRecv(void)
{
u_char retry;
int rlen = 0;
int slen;
u_short tport = 69;
u_short block = 0;
u_char *cp;
u_char *cp1;
/*
* Prepare the transmit buffer for a file request.
*/
sframe.u.tftp.th_opcode = htons(TFTP_RRQ);
slen = 2;
cp = (u_char *)sframe.u.tftp.th_u.tu_stuff;
cp1 = bootfile;
do {
*cp = *cp1++;
slen++;
} while(*cp++);
*cp++ = 'o';
*cp++ = 'c';
*cp++ = 't';
*cp++ = 'e';
*cp++ = 't';
*cp++ = 0;
slen += 6;
/*
* Lopp until we receive a packet with less than 512 bytes of data.
*/
do {
/*
* Send file request or acknowledge and receive
* a data block.
*/
for (retry = 0; retry < 3; retry++) {
if (UdpOutput(server_ip, tport, SPORT, slen) >= 0) {
if ((rlen = UdpInput(SPORT, 5000)) >= 4)
break;
}
}
/*
* Can't reach the TFTP server or got a malformed
* repsonse.
*/
if (rlen < 4)
return -1;
/*
* Accept data blocks only. Anything else will stop
* the transfer with an error.
*/
if (ntohs(rframe.u.tftp.th_opcode) != TFTP_DATA)
return -1;
/*
* If this was the first block we received, prepare
* the send buffer for sending ACKs.
*/
if (block == 0) {
tport = ntohs(rframe.udp_hdr.uh_sport);
sframe.u.tftp.th_opcode = htons(TFTP_ACK);
slen = 4;
}
/*
* If this block is out of sequence, we ignore it.
* However, if we missed the first block, return
* with an error.
*/
if (ntohs(rframe.u.tftp.th_u.tu_block) != block + 1) {
if (block == 0)
return -1;
continue;
}
/*
* Burn the received data into the flash ROM.
*/
if (rlen > 4) {
FlashPage(block << 1, rframe.u.tftp.th_data, rlen - 4);
if (rlen > 260)
FlashPage((block << 1) + 1, &rframe.u.tftp.th_data[256], rlen - 260);
}
/*
* Update our block counter.
*/
block++;
sframe.u.tftp.th_u.tu_block = htons(block);
} while (rlen >= 516);
/*
* Send the last ACK.
*/
UdpOutput(server_ip, tport, SPORT, slen);
return 0;
}
