Andrew Boyson / net

A stack which works with or without an Mbed os library. Provides IPv4 or IPv6 with a full 1500 byte buffer.

Dependents:   oldheating gps motorhome heating

ip4/udptcp4.cpp@10:f0854784e960, 2017-04-16 (annotated)

Committer:
andrewboyson
Date:
Sun Apr 16 14:21:55 2017 +0000
Revision:
10:f0854784e960
Child:
11:c051adb70c5a
MDNS and LLMNR now working.

Who changed what in which revision?

UserRevisionLine numberNew contents of line
andrewboyson 10:f0854784e960 1 #include "mbed.h"
andrewboyson 10:f0854784e960 2 #include "log.h"
andrewboyson 10:f0854784e960 3 #include "net.h"
andrewboyson 10:f0854784e960 4 #include "dhcp.h"
andrewboyson 10:f0854784e960 5 #include "ip4.h"
andrewboyson 10:f0854784e960 6 #include "tcp.h"
andrewboyson 10:f0854784e960 7 #include "udp.h"
andrewboyson 10:f0854784e960 8
andrewboyson 10:f0854784e960 9 #define DEBUG false
andrewboyson 10:f0854784e960 10
andrewboyson 10:f0854784e960 11 static uint16_t calculateChecksum(uint8_t pro, uint32_t srcIp, uint32_t dstIp, int size, void* pPacket)
andrewboyson 10:f0854784e960 12 {
andrewboyson 10:f0854784e960 13 __packed struct pseudo
andrewboyson 10:f0854784e960 14 {
andrewboyson 10:f0854784e960 15 uint32_t src;
andrewboyson 10:f0854784e960 16 uint32_t dst;
andrewboyson 10:f0854784e960 17 uint8_t zer;
andrewboyson 10:f0854784e960 18 uint8_t pro;
andrewboyson 10:f0854784e960 19 uint16_t len;
andrewboyson 10:f0854784e960 20 } pseudo;
andrewboyson 10:f0854784e960 21
andrewboyson 10:f0854784e960 22 pseudo.src = srcIp;
andrewboyson 10:f0854784e960 23 pseudo.dst = dstIp;
andrewboyson 10:f0854784e960 24 pseudo.zer = 0;
andrewboyson 10:f0854784e960 25 pseudo.pro = pro;
andrewboyson 10:f0854784e960 26 pseudo.len = NetToHost16(size);
andrewboyson 10:f0854784e960 27
andrewboyson 10:f0854784e960 28 return NetCheckSumTwo(sizeof(pseudo), &pseudo, size, pPacket);
andrewboyson 10:f0854784e960 29 }
andrewboyson 10:f0854784e960 30 static void destIpFromAction(int action, uint32_t* pDstIp)
andrewboyson 10:f0854784e960 31 {
andrewboyson 10:f0854784e960 32 switch (action)
andrewboyson 10:f0854784e960 33 {
andrewboyson 10:f0854784e960 34 case UNICAST:
andrewboyson 10:f0854784e960 35 break;
andrewboyson 10:f0854784e960 36 case UNICAST_DNS:
andrewboyson 10:f0854784e960 37 *pDstIp = DhcpDnsServer;
andrewboyson 10:f0854784e960 38 break;
andrewboyson 10:f0854784e960 39 case UNICAST_DHCP:
andrewboyson 10:f0854784e960 40 *pDstIp = DhcpServer;
andrewboyson 10:f0854784e960 41 break;
andrewboyson 10:f0854784e960 42 case MULTICAST_NODE:
andrewboyson 10:f0854784e960 43 *pDstIp = IP4_MULTICAST_ALL_HOSTS;
andrewboyson 10:f0854784e960 44 break;
andrewboyson 10:f0854784e960 45 case MULTICAST_ROUTER:
andrewboyson 10:f0854784e960 46 *pDstIp = IP4_MULTICAST_ALL_ROUTERS;
andrewboyson 10:f0854784e960 47 break;
andrewboyson 10:f0854784e960 48 case MULTICAST_MDNS:
andrewboyson 10:f0854784e960 49 *pDstIp = IP4_MULTICAST_DNS_ADDRESS;
andrewboyson 10:f0854784e960 50 break;
andrewboyson 10:f0854784e960 51 case MULTICAST_LLMNR:
andrewboyson 10:f0854784e960 52 *pDstIp = IP4_MULTICAST_LLMNR_ADDRESS;
andrewboyson 10:f0854784e960 53 break;
andrewboyson 10:f0854784e960 54 case BROADCAST:
andrewboyson 10:f0854784e960 55 *pDstIp = IP4_BROADCAST_ADDRESS;
andrewboyson 10:f0854784e960 56 break;
andrewboyson 10:f0854784e960 57 default:
andrewboyson 10:f0854784e960 58 LogTimeF("UdpTcp4 destIpFromAction unknown action %d\r\n", action);
andrewboyson 10:f0854784e960 59 return;
andrewboyson 10:f0854784e960 60 }
andrewboyson 10:f0854784e960 61 }
andrewboyson 10:f0854784e960 62 static void finalisePacket(uint8_t pro, int action, void* pPacket, int size, uint32_t* pSrcIp, uint32_t* pDstIp)
andrewboyson 10:f0854784e960 63 {
andrewboyson 10:f0854784e960 64 if (!action) return;
andrewboyson 10:f0854784e960 65
andrewboyson 10:f0854784e960 66 destIpFromAction(action, pDstIp);
andrewboyson 10:f0854784e960 67
andrewboyson 10:f0854784e960 68 *pSrcIp = DhcpLocalIp;
andrewboyson 10:f0854784e960 69
andrewboyson 10:f0854784e960 70 switch (pro)
andrewboyson 10:f0854784e960 71 {
andrewboyson 10:f0854784e960 72 case TCP: TcpMakeHeader(size, pPacket); break;
andrewboyson 10:f0854784e960 73 case UDP: UdpMakeHeader(size, pPacket); break;
andrewboyson 10:f0854784e960 74 }
andrewboyson 10:f0854784e960 75
andrewboyson 10:f0854784e960 76 uint16_t checksum = calculateChecksum(pro, *pSrcIp, *pDstIp, size, pPacket);
andrewboyson 10:f0854784e960 77
andrewboyson 10:f0854784e960 78 switch (pro)
andrewboyson 10:f0854784e960 79 {
andrewboyson 10:f0854784e960 80 case TCP: TcpAddChecksum(pPacket, checksum); break;
andrewboyson 10:f0854784e960 81 case UDP: UdpAddChecksum(pPacket, checksum); break;
andrewboyson 10:f0854784e960 82 }
andrewboyson 10:f0854784e960 83
andrewboyson 10:f0854784e960 84 if (DEBUG) TcpLogHeader("IPv4 packet sent", pPacket, 0);
andrewboyson 10:f0854784e960 85 }
andrewboyson 10:f0854784e960 86
andrewboyson 10:f0854784e960 87 int Tcp4HandleReceivedPacket(uint32_t* pSrcIp, uint32_t* pDstIp, int* pSize, void * pPacket)
andrewboyson 10:f0854784e960 88 {
andrewboyson 10:f0854784e960 89 uint16_t calculatedChecksum = calculateChecksum(TCP, *pSrcIp, *pDstIp, *pSize, pPacket);
andrewboyson 10:f0854784e960 90 if (DEBUG) TcpLogHeader("IPv4 packet received", pPacket, calculatedChecksum);
andrewboyson 10:f0854784e960 91
andrewboyson 10:f0854784e960 92 TcpReadHeader(pPacket, *pSize);
andrewboyson 10:f0854784e960 93
andrewboyson 10:f0854784e960 94 int action = TcpHandleReceivedPacket(pSize, pPacket);
andrewboyson 10:f0854784e960 95
andrewboyson 10:f0854784e960 96 *pDstIp = *pSrcIp;
andrewboyson 10:f0854784e960 97
andrewboyson 10:f0854784e960 98 finalisePacket(TCP, action, pPacket, *pSize, pSrcIp, pDstIp);
andrewboyson 10:f0854784e960 99
andrewboyson 10:f0854784e960 100 return action;
andrewboyson 10:f0854784e960 101 }
andrewboyson 10:f0854784e960 102
andrewboyson 10:f0854784e960 103 int Udp4HandleReceivedPacket(uint32_t* pSrcIp, uint32_t* pDstIp, int* pSize, void * pPacket)
andrewboyson 10:f0854784e960 104 {
andrewboyson 10:f0854784e960 105 uint16_t calculatedChecksum = calculateChecksum(UDP, *pSrcIp, *pDstIp, *pSize, pPacket);
andrewboyson 10:f0854784e960 106 if (DEBUG) UdpLogHeader("IPv4 packet received", pPacket, calculatedChecksum);
andrewboyson 10:f0854784e960 107
andrewboyson 10:f0854784e960 108 UdpReadHeader(pPacket, *pSize);
andrewboyson 10:f0854784e960 109
andrewboyson 10:f0854784e960 110 int action = UdpHandleReceivedPacket(pSize, pPacket);
andrewboyson 10:f0854784e960 111
andrewboyson 10:f0854784e960 112 *pDstIp = *pSrcIp;
andrewboyson 10:f0854784e960 113
andrewboyson 10:f0854784e960 114 finalisePacket(UDP, action, pPacket, *pSize, pSrcIp, pDstIp); //Note that the ports are reversed here
andrewboyson 10:f0854784e960 115
andrewboyson 10:f0854784e960 116 return action;
andrewboyson 10:f0854784e960 117 }
andrewboyson 10:f0854784e960 118 int Udp4PollForPacketToSend(void* pPacket, int* pSize, uint32_t* pSrcIp, uint32_t* pDstIp)
andrewboyson 10:f0854784e960 119 {
andrewboyson 10:f0854784e960 120 int action = UdpPollForPacketToSend(IPV4, pSize, pPacket);
andrewboyson 10:f0854784e960 121
andrewboyson 10:f0854784e960 122 finalisePacket(UDP, action, pPacket, *pSize, pSrcIp, pDstIp);
andrewboyson 10:f0854784e960 123
andrewboyson 10:f0854784e960 124 return action;
andrewboyson 10:f0854784e960 125 }