int main() {
udpsock s1 = udplisten(iplocal(NULL, 5555, 0));
udpsock s2 = udplisten(iplocal(NULL, 5556, 0));
ipaddr addr = ipremote("127.0.0.1", 5556, 0, -1);
while(1) {
udpsend(s1, addr, "ABC", 3);
assert(errno == 0);
char buf[3];
size_t sz = udprecv(s2, &addr, buf, sizeof(buf), now() + 100);
if(errno == ETIMEDOUT)
continue;
assert(errno == 0);
assert(sz == 3);
break;
}
while(1) {
udpsend(s2, addr, "DEF", 3);
assert(errno == 0);
char buf[3];
size_t sz = udprecv(s1, &addr, buf, sizeof(buf), now() + 100);
if(errno == ETIMEDOUT)
continue;
assert(errno == 0);
assert(sz == 3);
break;
}
udpclose(s2);
udpclose(s1);
return 0;
}
////////////////////////////////////////////////////////////////////////////////
// listenbootp
// PURPOSE: Listens for bootp response, returns status after one packet
// received.
// PARAMS: (IN) u32 xid - xid from the bootp request we sent.
// (OUT) u32 *ciaddr - Clients (our) IP address.
// (OUT) u32 *siaddr - Servers IP address.
// RETURNS: int - 0 for failure, 1 for success.
////////////////////////////////////////////////////////////////////////////////
static int
listenbootp(u32 xid,
u32 *ciaddr,
u32 *siaddr,
u32 *giaddr,
u32 *smask,
char *bootfile)
{
u8 packet[MAX_PACKET_SIZE];
u16 size = MAX_PACKET_SIZE;
u8 *bootppacket = packet + UDPIP_HEADER_SIZE;
u32 rxid;
u32 iaddr;
u32 time = get_time_timer() + NET_TIMEOUT;
u32 client_iaddr;
u32 server_iaddr;
//scratch variables for parse_options_dhcp; we don't care about these
u8 msg_type;
u32 sid;
while(1)
{
u8 bootp_type;
if (time < get_time_timer())
{
// We timed out receiving reply
// We can't rely on the udplisten timeout because we could
// theoretically receive a steady supply of miscellaneous packets
// so it will never time out.
return 0;
}
if(udplisten(packet, &size, &iaddr, 1))
{
bootp_type = *bootppacket;
bootppacket += 4;
rxid = (*(bootppacket++) << 24);
rxid |= (*(bootppacket++) << 16);
rxid |= (*(bootppacket++) << 8);
rxid |= *(bootppacket++);
bootppacket += sizeof(u32) * 2;
if(rxid == xid && bootp_type == BOOTP_REPLY)
{
client_iaddr = *bootppacket++ << 24;
client_iaddr |= *bootppacket++ << 16;
client_iaddr |= *bootppacket++ << 8;
client_iaddr |= *bootppacket++;
server_iaddr = *bootppacket++ << 24;
server_iaddr |= *bootppacket++ << 16;
server_iaddr |= *bootppacket++ << 8;
server_iaddr |= *bootppacket++;
break;
}
}
}
//skip the relay agent ip field
bootppacket += sizeof(u32);
//skip the hardware address field
bootppacket += 16;
//skip the servername field
bootppacket += 64;
//skip the bootfile field
itc_strcpy(bootfile, (char *)bootppacket);
DEBUG_3("Bootfile: %s\r\n", bootfile);
bootppacket += 128;
//skip the magic cookie
bootppacket += sizeof(u32);
parse_options_dhcp(bootppacket, giaddr, smask, &sid, &msg_type);
*ciaddr = client_iaddr;
*siaddr = server_iaddr;
return 1;
}
