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ipv6: format

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This commit is contained in:
giomba 2021-12-24 17:56:17 +01:00
parent dc03eeb307
commit 3d206c0d23
2 changed files with 272 additions and 224 deletions
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214
src/ipv6.cpp
View File

@ -1,37 +1,42 @@
#include "ipv6.h"
#include "udp.h"
namespace ipv6 {
/******** costants ********/
const IPv6Addr ALL_NODES_ADDRESS("\xff\x02\x00\x00\x00\x00\x00\x00\x00\x00\x00\x00\x00\x00\x00\x01"); /* ff02::1 */
namespace ipv6
{
/******** costants ********/
const IPv6Addr ALL_NODES_ADDRESS("\xff\x02\x00\x00\x00\x00\x00\x00\x00\x00\x00\x00\x00\x00\x00\x01"); /* ff02::1 */
/******** variables ********/
uint8_t HOP_LIMIT = 64;
IPv6Addr LINK_LOCAL_ADDRESS;
IPv6Addr GLOBAL_ADDRESS;
bool slaac_enable;
/******** variables ********/
uint8_t HOP_LIMIT = 64;
IPv6Addr LINK_LOCAL_ADDRESS;
IPv6Addr GLOBAL_ADDRESS;
bool slaac_enable;
/******** buffers ********/
IPv6Packet packetin;
IPv6Packet packetout;
/******** buffers ********/
IPv6Packet packetin;
IPv6Packet packetout;
/******** FUNCTIONS *******/
void setEUI(const char* eui) {
/******** FUNCTIONS *******/
void setEUI(const char *eui)
{
memset(&LINK_LOCAL_ADDRESS, 0, 16);
memcpy(&LINK_LOCAL_ADDRESS, "\xfe\x80", 2);
memcpy( ((char*)&LINK_LOCAL_ADDRESS) + 8 , eui, 8);
}
void SLAAC(bool enable) {
memcpy(((char *)&LINK_LOCAL_ADDRESS) + 8, eui, 8);
}
void SLAAC(bool enable)
{
slaac_enable = enable;
}
void setGlobalAddress(const char* address) {
}
void setGlobalAddress(const char *address)
{
memcpy(&GLOBAL_ADDRESS, address, 16);
}
}
uint16_t compute_checksum(const IPv6Addr* src_addr, const IPv6Addr* dst_addr, uint8_t next_header, int upper_len, const char* payload, int len) {
uint16_t compute_checksum(const IPv6Addr *src_addr, const IPv6Addr *dst_addr, uint8_t next_header, int upper_len, const char *payload, int len)
{
char buffer[LEN];
uint32_t total;
uint16_t* ptr;
uint16_t *ptr;
int words;
int i = len;
@ -41,108 +46,134 @@ uint16_t compute_checksum(const IPv6Addr* src_addr, const IPv6Addr* dst_addr, ui
*/
/* actual payload */
memcpy(buffer, payload, len);
if (len % 2) { /* pad with 0 if length is odd */
if (len % 2)
{ /* pad with 0 if length is odd */
buffer[len] = 0;
i++;
}
/* pseudo ipv6 header -- see RFC 2460, Section 8.1 */
memcpy(buffer + i, src_addr, 16); i += 16;
memcpy(buffer + i, dst_addr, 16); i += 16;
memset(buffer + i, 0, 3); i+= 3; /* first 3 bytes always 0, because len always < 256 */
buffer[i] = upper_len & 0xff; i += 1;
memset(buffer + i, 0, 3); i += 3; /* zero, as per-standard */
buffer[i] = next_header; i += 1;
memcpy(buffer + i, src_addr, 16);
i += 16;
memcpy(buffer + i, dst_addr, 16);
i += 16;
memset(buffer + i, 0, 3);
i += 3; /* first 3 bytes always 0, because len always < 256 */
buffer[i] = upper_len & 0xff;
i += 1;
memset(buffer + i, 0, 3);
i += 3; /* zero, as per-standard */
buffer[i] = next_header;
i += 1;
/* do computation */
total = 0;
ptr = (uint16_t*)buffer;
ptr = (uint16_t *)buffer;
words = (i + 1) / 2;
while (words--) total += *ptr++;
while (words--)
total += *ptr++;
while (total & 0xffff0000) {
while (total & 0xffff0000)
{
total = (total >> 16) + (total & 0xffff);
}
return ~((uint16_t) total);
}
return ~((uint16_t)total);
}
/******** IPv6Addr ********/
IPv6Addr::IPv6Addr() {;}
/******** IPv6Addr ********/
IPv6Addr::IPv6Addr() { ; }
IPv6Addr::IPv6Addr(const char* address) {
IPv6Addr::IPv6Addr(const char *address)
{
memcpy(this->address, address, 16);
}
}
/******** IPv6Packet ********/
IPv6Packet::IPv6Packet() {
/******** IPv6Packet ********/
IPv6Packet::IPv6Packet()
{
memset(packet, 0, LEN);
*(packet) = 0x60; /* IP version 6 */
*(packet + 7) = HOP_LIMIT; /* hop limit / ttl */
}
}
IPv6Packet::IPv6Packet(const char* buffer, int len) {
IPv6Packet::IPv6Packet(const char *buffer, int len)
{
memcpy(this->packet, buffer, len);
}
}
void IPv6Packet::setNextHeader(uint8_t next_header) {
void IPv6Packet::setNextHeader(uint8_t next_header)
{
*(packet + 6) = next_header;
}
}
void IPv6Packet::setLen(int len) {
void IPv6Packet::setLen(int len)
{
*(packet + 4) = len >> 8;
*(packet + 5) = len & 0xff;
}
int IPv6Packet::getLen() {
}
int IPv6Packet::getLen()
{
return ((*(packet + 4)) << 8) + (*(packet + 5));
}
}
void IPv6Packet::setSrcAddress(const IPv6Addr* address) {
void IPv6Packet::setSrcAddress(const IPv6Addr *address)
{
memcpy(packet + 8, address, 16);
}
void IPv6Packet::setDstAddress(const IPv6Addr* address) {
}
void IPv6Packet::setDstAddress(const IPv6Addr *address)
{
memcpy(packet + 24, address, 16);
}
}
const IPv6Addr* IPv6Packet::getSrcAddress() {
return (const IPv6Addr*) (packet + 8);
}
const IPv6Addr* IPv6Packet::getDstAddress() {
return (const IPv6Addr*) (packet + 24);
}
const IPv6Addr *IPv6Packet::getSrcAddress()
{
return (const IPv6Addr *)(packet + 8);
}
const IPv6Addr *IPv6Packet::getDstAddress()
{
return (const IPv6Addr *)(packet + 24);
}
void IPv6Packet::setFlow(const char* flow) {
void IPv6Packet::setFlow(const char *flow)
{
/* three bytes
4 most significant bits are ignored
because only 20 bits can be used */
*(packet + 1) = (*(packet + 1)) | (flow[0] & 0x0f); /* pay attention to TC field */
memcpy(packet + 2, flow + 1, 2);
}
}
void IPv6Packet::setPayload(char* payload, int len) {
void IPv6Packet::setPayload(char *payload, int len)
{
*(packet + 4 + 0) = len >> 8;
*(packet + 4 + 1) = len & 0xff;
memcpy(packet + 40, payload, len); /* payload */
}
}
void IPv6Packet::send() {
void IPv6Packet::send()
{
slip::send(packet, 40 + this->getLen());
}
}
void IPv6Packet::doAction() {
void IPv6Packet::doAction()
{
/* if destination is my address (global or link-local), or destination is "all nodes" address, then... */
if (
(memcmp(&(ALL_NODES_ADDRESS), packet + 24, 16) == 0) ||
(memcmp(&(LINK_LOCAL_ADDRESS), packet + 24, 16) == 0) ||
(memcmp(&(GLOBAL_ADDRESS), packet + 24, 16) == 0)) {
(memcmp(&(GLOBAL_ADDRESS), packet + 24, 16) == 0))
{
int ilen = this->getLen(); /* input payload length */
int olen; /* output payload length */
switch(*(packet + 6)) { /* next header */
switch (*(packet + 6))
{ /* next header */
case NH_ICMP:
if ((olen = handleICMP((char*)&packetout + 40, packet + 40, ilen)) != -1) {
if ((olen = handleICMP((char *)&packetout + 40, packet + 40, ilen)) != -1)
{
packetout.setLen(olen);
packetout.setFlow(((char*)(&packetin)) + 1);
packetout.setFlow(((char *)(&packetin)) + 1);
packetout.setSrcAddress(packetin.getDstAddress());
packetout.setDstAddress(packetin.getSrcAddress());
packetout.setNextHeader(NH_ICMP);
@ -150,9 +181,10 @@ void IPv6Packet::doAction() {
}
break;
case NH_UDP:
if ((olen = udp::handleUDP((char*)&packetout + 40, packet + 40, ilen)) != -1) {
if ((olen = udp::handleUDP((char *)&packetout + 40, packet + 40, ilen)) != -1)
{
packetout.setLen(olen);
packetout.setFlow(((char*)(&packetin)) + 1);
packetout.setFlow(((char *)(&packetin)) + 1);
packetout.setSrcAddress(packetin.getDstAddress());
packetout.setDstAddress(packetin.getSrcAddress());
packetout.setNextHeader(NH_UDP);
@ -164,12 +196,13 @@ void IPv6Packet::doAction() {
break;
}
} /* ...else discard packet */
}
}
/* handles ICMP and (possibly) generate a reply
/* handles ICMP and (possibly) generate a reply
* returns length of generated packet (written to output_buffer), or -1 if there is no reply packet
*/
int handleICMP(char* output_buffer, const char* input_buffer, int len) {
*/
int handleICMP(char *output_buffer, const char *input_buffer, int len)
{
uint8_t type = *(input_buffer);
/* compute checksum, and assert validity of incoming message */
@ -186,11 +219,13 @@ int handleICMP(char* output_buffer, const char* input_buffer, int len) {
output_buffer,
len);
if (memcmp(&computed_checksum, received_checksum, 2) != 0) { /* if checksum is not valid, return */
if (memcmp(&computed_checksum, received_checksum, 2) != 0)
{ /* if checksum is not valid, return */
return -1;
}
if (type == ICMP_ECHO_REQUEST_TYPE) { /* if it is ICMPv6 Echo Request, then... */
if (type == ICMP_ECHO_REQUEST_TYPE)
{ /* if it is ICMPv6 Echo Request, then... */
/* Build an echo reply:
* the reply has the same exact format of the request,
* except for Type and Checksum */
@ -206,20 +241,25 @@ int handleICMP(char* output_buffer, const char* input_buffer, int len) {
len);
memcpy(output_buffer + 2, &checksum, 2);
return len;
} else if (type == ICMP_RADV_TYPE && slaac_enable) { /* if it is IVMPc6 Router Advertisement, then... */
ICMPv6_RADV* radv = (ICMPv6_RADV*)input_buffer;
}
else if (type == ICMP_RADV_TYPE && slaac_enable)
{ /* if it is IVMPc6 Router Advertisement, then... */
ICMPv6_RADV *radv = (ICMPv6_RADV *)input_buffer;
HOP_LIMIT = (radv->cur_hop_limit != 0) ? radv->cur_hop_limit : 64;
for (
ICMPv6_RADV_Option* option = (ICMPv6_RADV_Option*) (radv + 1);
ICMPv6_RADV_Option *option = (ICMPv6_RADV_Option *)(radv + 1);
option != input_buffer + len;
option = (ICMPv6_RADV_Option*) ( ((char*)(option)) + option->len )) {
if (option->type == 3 && option->len == 4) { /* if it is a ICMPv6 Prefix Information, then... */
ICMPv6_RADV_PrefixInformation* p = (ICMPv6_RADV_PrefixInformation*) option;
option = (ICMPv6_RADV_Option *)(((char *)(option)) + option->len))
{
if (option->type == 3 && option->len == 4)
{ /* if it is a ICMPv6 Prefix Information, then... */
ICMPv6_RADV_PrefixInformation *p = (ICMPv6_RADV_PrefixInformation *)option;
if (p->prefix_length != 64) continue; /* only /64 prefix is supported */
if (! (p->la_flags & 0x40)) continue; /* only SLAAC is supported */
if (p->prefix_length != 64)
continue; /* only /64 prefix is supported */
if (!(p->la_flags & 0x40))
continue; /* only SLAAC is supported */
memcpy(&GLOBAL_ADDRESS, p->prefix, 8); /* set prefix -- leave host bits unchanged */
break;
}
@ -228,6 +268,6 @@ int handleICMP(char* output_buffer, const char* input_buffer, int len) {
return -1;
}
return -1;
}
}
}

48
src/ipv6.h
View File

@ -4,7 +4,8 @@
#include "Arduino.h"
#include "slip.h"
namespace ipv6 {
namespace ipv6
{
/* maximum length for an IPv6 packet */
const uint8_t LEN = 128;
@ -17,31 +18,35 @@ namespace ipv6 {
const uint8_t NH_ICMP = 58;
const uint8_t NH_UDP = 17;
class IPv6Addr {
class IPv6Addr
{
private:
char address[16];
public:
IPv6Addr();
IPv6Addr(const char* address);
IPv6Addr(const char *address);
};
extern const IPv6Addr ALL_NODES_ADDRESS;
class IPv6Packet {
class IPv6Packet
{
private:
char packet[LEN];
public:
IPv6Packet();
IPv6Packet(const char* buffer, int len);
IPv6Packet(const char *buffer, int len);
void setLen(int len);
int getLen();
void setSrcAddress(const IPv6Addr* address);
const IPv6Addr* getSrcAddress();
void setDstAddress(const IPv6Addr* address);
const IPv6Addr* getDstAddress();
void setSrcAddress(const IPv6Addr *address);
const IPv6Addr *getSrcAddress();
void setDstAddress(const IPv6Addr *address);
const IPv6Addr *getDstAddress();
void setNextHeader(uint8_t next_header);
void setFlow(const char* flow);
void setPayload(char* payload, int len);
void setFlow(const char *flow);
void setPayload(char *payload, int len);
void send();
void doAction();
@ -52,20 +57,21 @@ namespace ipv6 {
extern IPv6Packet packetout;
/* Note: content of message may be changed */
int handleICMP(char* output_buffer, const char* input_buffer, int len);
int handleICMP(char *output_buffer, const char *input_buffer, int len);
/* Compute internet checksum. Actually it is not so straightforward: */
uint16_t compute_checksum(
const IPv6Addr* src_addr, /* source IPv6 address */
const IPv6Addr* dst_addr, /* destination IPv6 address */
const IPv6Addr *src_addr, /* source IPv6 address */
const IPv6Addr *dst_addr, /* destination IPv6 address */
uint8_t next_header, /* IPv6 next header number */
int upper_len, /* length as found in the upper layer protocol */
const char* payload, /* IPv6 payload */
const char *payload, /* IPv6 payload */
int len /* IPv6 payload length */
);
/* RFC 4861 -- begin */
struct ICMPv6_RADV {
struct ICMPv6_RADV
{
uint8_t type;
uint8_t code;
char checksum[2];
@ -76,12 +82,14 @@ namespace ipv6 {
uint32_t retrans_time;
};
struct ICMPv6_RADV_Option {
struct ICMPv6_RADV_Option
{
uint8_t type;
uint8_t len;
};
struct ICMPv6_RADV_PrefixInformation {
struct ICMPv6_RADV_PrefixInformation
{
uint8_t type;
uint8_t len;
uint8_t prefix_length;
@ -93,9 +101,9 @@ namespace ipv6 {
};
/* RFC 4861 -- end */
void setEUI(const char* eui); /* 64bit Extended Unique Identifier */
void setEUI(const char *eui); /* 64bit Extended Unique Identifier */
void SLAAC(bool enable); /* enable IPv6 automatic prefix configuration (listens for RADV) */
void setGlobalAddress(const char* address); /* global IPv6 address, manually configured */
void setGlobalAddress(const char *address); /* global IPv6 address, manually configured */
}
#endif