Andrew Boyson
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
Diff: ip4/ip4.c
- Revision:
- 136:8a65abb0dc63
- Parent:
- 116:60521b29e4c9
- Child:
- 142:a8c0890a58d1
--- a/ip4/ip4.c Sat Mar 23 12:25:48 2019 +0000
+++ b/ip4/ip4.c Sat Apr 06 11:20:20 2019 +0000
@@ -1,3 +1,4 @@
+
#include <stdint.h>
#include <stdbool.h>
@@ -12,152 +13,107 @@
#include "eth.h"
#include "ip.h"
#include "ip4addr.h"
+#include "ip4hdr.h"
#include "ntp.h"
#include "mac.h"
#include "fault.h"
+#include "checksum.h"
bool Ip4Trace = true;
#define OFF_LINK_TTL 64
-__packed struct header
-{
- uint8_t versionIhl;
- uint8_t tos;
- uint16_t length;
- uint16_t id;
- uint16_t flagsOffset;
- uint8_t ttl;
- uint8_t protocol;
- uint16_t checksum;
- uint32_t src;
- uint32_t dst;
-};
-
-//Header variables
-static uint8_t version;
-static int headerLength;
-static uint8_t tos;
-static uint16_t totalLength;
-static uint16_t id;
-static bool dontFragment;
-static bool moreFragments;
-static uint16_t offset;
-static uint8_t ttl;
-static uint8_t protocol;
-static uint16_t checksum;
-static uint16_t calcsum;
-static uint32_t srcIp;
-static uint32_t dstIp;
-
-static void readHeader(struct header * pHeader)
-{
- version = pHeader->versionIhl >> 4;
- uint8_t ihl = pHeader->versionIhl & 0xF;
- headerLength = ihl * 4;
- tos = pHeader->tos;
- totalLength = NetToHost16(pHeader->length);
- id = NetToHost16(pHeader->id);
- uint16_t flagsOffset = NetToHost16(pHeader->flagsOffset);
- dontFragment = flagsOffset & 0x4000;
- moreFragments = flagsOffset & 0x8000;
- offset = flagsOffset & 0x1FFF;
- ttl = pHeader->ttl;
- protocol = pHeader->protocol;
- checksum = NetToHost16(pHeader->checksum);
- calcsum = NetCheckSum(headerLength, pHeader);
- srcIp = pHeader->src;
- dstIp = pHeader->dst;
-}
-static void writeHeader(struct header * pHeader)
-{
- uint16_t flagsOffset = offset;
- if (dontFragment) flagsOffset |= 0x4000;
- if (moreFragments) flagsOffset |= 0x8000;
-
- uint8_t ihl = headerLength >> 2;
- pHeader->versionIhl = (version << 4) + ihl;
- pHeader->tos = tos;
- pHeader->id = NetToHost16(id);
- pHeader->flagsOffset = NetToHost16(flagsOffset);
- pHeader->ttl = ttl;
- pHeader->protocol = protocol;
-
- pHeader->dst = dstIp;
- pHeader->src = srcIp;
- pHeader->length = NetToHost16(totalLength);
- pHeader->checksum = 0;
- pHeader->checksum = NetCheckSum(headerLength, pHeader);
- calcsum = 0;
-}
-
-static void logHeader()
+static void logHeader(char* pPacket)
{
if (NetTraceVerbose)
{
Log ("IP4 header\r\n");
- LogF(" Version %d\r\n", version);
+ LogF(" Version %d\r\n", Ip4HdrGetVersion (pPacket));
+ int headerLength = Ip4HdrGetHeaderLen (pPacket);
LogF(" Header length %d\r\n", headerLength);
- LogF(" Type of service %d\r\n", tos);
- LogF(" Total length %d\r\n", totalLength);
- LogF(" Identification %d\r\n", id);
- if (dontFragment) LogF(" Don't fragment\r\n");
- else LogF(" Do fragment\r\n");
- if (moreFragments) LogF(" More fragments\r\n");
- else LogF(" No more fragments\r\n");
- LogF(" Offset %d\r\n", offset);
- LogF(" Time to live %d\r\n", ttl);
- LogF(" Protocol "); IpProtocolLog(protocol); Log("\r\n");
- LogF(" Checksum (hex) %04hX\r\n", checksum);
- LogF(" Calculated (hex) %04hX\r\n", calcsum);
- LogF(" Source IP "); Ip4AddressLog(srcIp); Log("\r\n");
- LogF(" Destination IP "); Ip4AddressLog(dstIp); Log("\r\n");
+ LogF(" Type of service %d\r\n", Ip4HdrGetTos (pPacket));
+ LogF(" Total length %d\r\n", Ip4HdrGetLength (pPacket));
+ LogF(" Identification %d\r\n", Ip4HdrGetId (pPacket));
+ if (Ip4HdrGetDontFrag(pPacket)) LogF(" Don't fragment\r\n");
+ else LogF(" Do fragment\r\n");
+ if (Ip4HdrGetMoreFrags(pPacket)) LogF(" More fragments\r\n");
+ else LogF(" No more fragments\r\n");
+ LogF(" Frag offset %d\r\n", Ip4HdrGetFragOffset(pPacket));
+ LogF(" Time to live %d\r\n", Ip4HdrGetTtl (pPacket));
+ LogF(" Protocol "); IpProtocolLog(Ip4HdrGetProtocol(pPacket)); Log("\r\n");
+ LogF(" Checksum (hex) %04hX\r\n", Ip4HdrGetChecksum(pPacket));
+ LogF(" Calculated (hex) %04hX\r\n", CheckSum(headerLength, pPacket));
+ LogF(" Source IP "); Ip4AddressLog(Ip4HdrGetSrc(pPacket)); Log("\r\n");
+ LogF(" Destination IP "); Ip4AddressLog(Ip4HdrGetDst(pPacket)); Log("\r\n");
}
else
{
Log ("IP4 header ");
- IpProtocolLog(protocol);
+ IpProtocolLog(Ip4HdrGetProtocol(pPacket));
Log(" ");
- Ip4AddressLog(srcIp);
+ Ip4AddressLog(Ip4HdrGetSrc(pPacket));
Log(" >>> ");
- Ip4AddressLog(dstIp);
+ Ip4AddressLog(Ip4HdrGetDst(pPacket));
Log("\r\n");
}
}
+static void makeHeader(char* pPacket, uint16_t totalLength, uint8_t ttl, uint8_t protocol, uint32_t srcIp, uint32_t dstIp)
+{
+ static uint16_t id = 0;
+ Ip4HdrSetVersion (pPacket, 4 );
+ Ip4HdrSetHeaderLen(pPacket, IP4_HEADER_LENGTH);
+ Ip4HdrSetTos (pPacket, 0 );
+ Ip4HdrSetLength (pPacket, totalLength );
+ Ip4HdrSetId (pPacket, id++ ); //Used by the recipient for collating packets fragmented in transit; unique per packet sent
+ Ip4HdrSetFragInfo (pPacket, 0 ); //No flags and no offset
+ Ip4HdrSetTtl (pPacket, ttl );
+ Ip4HdrSetProtocol (pPacket, protocol );
+ Ip4HdrSetSrc (pPacket, srcIp );
+ Ip4HdrSetDst (pPacket, dstIp );
+ Ip4HdrSetChecksum (pPacket, 0 );
+ uint16_t checksum = CheckSum(IP4_HEADER_LENGTH, pPacket);
+ Ip4HdrSetChecksum (pPacket, checksum );
+}
+static char* traceHeader;
static void (*pTraceBack)(void);
static void trace()
{
pTraceBack();
- logHeader();
+ logHeader(traceHeader);
}
-int Ip4HandleReceivedPacket(void (*traceback)(void), void* pPacketRx, int sizeRx, void* pPacketTx, int* pSizeTx, char* macRemote)
+
+int Ip4HandleReceivedPacket(void (*traceback)(void), char* pPacketRx, int sizeRx, char* pPacketTx, int* pSizeTx, char* macRemote)
{
int lastFaultPoint = FaultPoint;
FaultPoint = FAULT_POINT_Ip4HandleReceivedPacket;
-
+
+ traceHeader = pPacketRx;
pTraceBack = traceback;
- struct header * pHeaderRx = (struct header*)pPacketRx;
- struct header * pHeaderTx = (struct header*)pPacketTx;
+
+ int headerLengthRx = Ip4HdrGetHeaderLen(pPacketRx);
+ uint16_t totalLengthRx = Ip4HdrGetLength (pPacketRx);
+ uint8_t protocol = Ip4HdrGetProtocol (pPacketRx);
+ uint32_t srcIp = Ip4HdrGetSrc (pPacketRx);
+ uint32_t dstIp = Ip4HdrGetDst (pPacketRx);
- char* pDataRx = (char*)pHeaderRx + headerLength;
- char* pDataTx = (char*)pHeaderTx + headerLength;
-
- readHeader(pHeaderRx);
- if (totalLength < sizeRx) sizeRx = totalLength;
- int dataLengthRx = sizeRx - headerLength;
- int dataLengthTx = *pSizeTx - sizeof(struct header);
-
+ char* pDataRx = pPacketRx + headerLengthRx;
+ char* pDataTx = pPacketTx + IP4_HEADER_LENGTH;
+
+ if (sizeRx > totalLengthRx) sizeRx = totalLengthRx;
+ int dataLengthRx = sizeRx - headerLengthRx;
+ int dataLengthTx = *pSizeTx - IP4_HEADER_LENGTH;
+
bool isMe = dstIp == DhcpLocalIp;
bool isLocalBroadcast = dstIp == (DhcpLocalIp | 0xFF000000); // dstIp == 192.168.1.255; '|' is lower precendence than '=='
bool isBroadcast = dstIp == IP4_BROADCAST_ADDRESS; // dstIp == 255.255.255.255
- bool isMulticast = (dstIp & 0xE0) == 0xE0; //224.x.x.x == 1110 0000 == E0.xx.xx.xx == xx.xx.xx.E0 in little endian
-
+ bool isMulticast = (dstIp & 0xE0) == 0xE0; // 224.x.x.x == 1110 0000 == E0.xx.xx.xx == xx.xx.xx.E0 in little endian
+
bool doIt = isMe || isLocalBroadcast || isBroadcast || isMulticast;
if (!doIt)
{
if (Ip4Trace);
{
- LogTimeF("IP4 filtered out ip "); Ip4AddressLog(dstIp);
+ LogTimeF("IP4 filtered out ip "); Ip4AddressLog(dstIp);
Log(" from ");
Ip4AddressLog(srcIp);
Log("\r\n");
@@ -165,10 +121,10 @@
FaultPoint = lastFaultPoint;
return DO_NOTHING;
}
-
+
int remArIndex = Ar4AddIpRecord(trace, macRemote, srcIp);
Nr4MakeRequestForNameFromIp(srcIp);
-
+
int action = DO_NOTHING;
switch (protocol)
{
@@ -178,7 +134,7 @@
case TCP: action = Tcp4HandleReceivedPacket(trace, pDataRx, dataLengthRx, pDataTx, &dataLengthTx, &srcIp, &dstIp, remArIndex); break;
case IP6IN4: break;
default:
- LogTimeF("IP4 received packet unknown protocol %d\r\n");
+ LogTimeF("IP4 received packet unknown protocol %d\r\n", protocol);
FaultPoint = lastFaultPoint;
return DO_NOTHING;
}
@@ -187,7 +143,8 @@
FaultPoint = lastFaultPoint;
return DO_NOTHING;
}
-
+
+ uint8_t ttl = 0;
if (DhcpIpNeedsToBeRouted(dstIp))
{
Ar4IpToMac(DhcpRouterIp, macRemote); //Send back to the router
@@ -198,36 +155,29 @@
ttl = 255;
}
- totalLength = sizeof(struct header) + dataLengthTx;
- headerLength = sizeof(struct header);
-
- writeHeader(pHeaderTx);
+ *pSizeTx = IP4_HEADER_LENGTH + dataLengthTx;
- *pSizeTx = totalLength;
+ makeHeader(pPacketTx, *pSizeTx, ttl, protocol, srcIp, dstIp);
- if (ActionGetTracePart(action)) logHeader();
+ if (ActionGetTracePart(action)) logHeader(pPacketTx);
FaultPoint = lastFaultPoint;
return action;
}
-int Ip4PollForPacketToSend(void* pPacket, int* pSize, char* pDstMac)
-{
- headerLength = sizeof(struct header);
- char* pData = (char*)pPacket + headerLength;
- version = 4;
- tos = 0;
- id = 0;
- dontFragment = true;
- moreFragments = false;
- offset = 0;
-
- int dataLength = *pSize - sizeof(struct header);
-
- int action = DO_NOTHING;
+int Ip4PollForPacketToSend(char* pPacket, int* pSize, char* pDstMac)
+{
+ char* pData = pPacket + IP4_HEADER_LENGTH;
+ int dataLength = *pSize - IP4_HEADER_LENGTH;
+
+ uint8_t protocol = 0;
+ uint32_t srcIp = 0;
+ uint32_t dstIp = 0;
+ int action = DO_NOTHING;
if (!action) { action = Udp4PollForPacketToSend(pData, &dataLength, &srcIp, &dstIp); protocol = UDP; }
if (!action) { action = Tcp4PollForPacketToSend(pData, &dataLength, &srcIp, &dstIp); protocol = TCP; }
if (!action) return DO_NOTHING;
int dest = ActionGetDestPart(action);
+ uint8_t ttl = 0;
switch (dest)
{
case UNICAST:
@@ -259,16 +209,11 @@
return DO_NOTHING;
}
- struct header* pHeader = (struct header*)pPacket;
-
- totalLength = sizeof(struct header) + dataLength;
- headerLength = sizeof(struct header);
+ *pSize = IP4_HEADER_LENGTH + dataLength;
+
+ makeHeader(pPacket, *pSize, ttl, protocol, srcIp, dstIp);
- writeHeader(pHeader);
-
- *pSize = totalLength;
-
- if (ActionGetTracePart(action)) logHeader();
+ if (ActionGetTracePart(action)) logHeader(pPacket);
return action;
}