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Code Issues Releases Wiki Activity

UDP PDU is now working.

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This commit is contained in:
Matias
2011-08-12 21:17:44 -03:00
parent 81bcdeb402
commit 398ba31111
8 changed files with 121 additions and 44 deletions
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2
include/ip.h
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@@ -164,7 +164,7 @@ namespace Tins {
static const uint8_t DEFAULT_TTL;
void init_ip_fields();
void write_serialization(uint8_t *buffer, uint32_t total_sz, PDU *parent);
void write_serialization(uint8_t *buffer, uint32_t total_sz, const PDU *parent);
iphdr _ip;
std::vector<IpOption> _ip_options;

7
include/pdu.h
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@@ -108,7 +108,7 @@ namespace Tins {
virtual bool send(PacketSender* sender) { return false; }
protected:
/* Serialize this PDU storing the result in buffer. */
void serialize(uint8_t *buffer, uint32_t total_sz, PDU *parent);
void serialize(uint8_t *buffer, uint32_t total_sz, const PDU *parent);
/** \brief Serialices this TCP PDU.
*
@@ -118,7 +118,10 @@ namespace Tins {
* \param total_sz The size available in the buffer.
* \param parent The PDU that's one level below this one on the stack. Might be 0.
*/
virtual void write_serialization(uint8_t *buffer, uint32_t total_sz, PDU *parent) = 0;
virtual void write_serialization(uint8_t *buffer, uint32_t total_sz, const PDU *parent) = 0;
static uint32_t do_checksum(uint8_t *start, uint8_t *end);
static uint32_t pseudoheader_checksum(uint32_t source_ip, uint32_t dest_ip, uint32_t len, uint32_t flag);
private:
uint32_t _flag;
PDU *_inner_pdu;

11
include/tcp.h
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@@ -111,6 +111,10 @@ namespace Tins {
*/
inline uint16_t urg_ptr() const { return _tcp.urg_ptr; }
/** \brief Returns the payload.
*/
inline const uint8_t *payload() const { return _payload; }
/** \brief Set the destination port.
* \param new_dport New destination port.
*/
@@ -183,7 +187,7 @@ namespace Tins {
/** \brief Returns the header size.
*
* This metod overrides PDU::header_size. This size includes the
* payload and options size.
* payload and options size. \sa PDU::header_size
*/
uint32_t header_size() const;
private:
@@ -239,10 +243,7 @@ namespace Tins {
* \param total_sz The size available in the buffer.
* \param parent The PDU that's one level below this one on the stack.
*/
void write_serialization(uint8_t *buffer, uint32_t total_sz, PDU *parent);
uint32_t do_checksum(uint8_t *start, uint8_t *end) const;
uint32_t pseudoheader_checksum(uint32_t source_ip, uint32_t dest_ip) const;
void write_serialization(uint8_t *buffer, uint32_t total_sz, const PDU *parent);
tcphdr _tcp;
std::vector<TCPOption> _options;

38
include/udp.h
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@@ -22,6 +22,31 @@ namespace Tins {
* */
UDP(uint16_t sport = 0, uint16_t dport = 0);
/** \brief Returns the payload.
*/
inline const uint8_t *payload() const { return _payload; }
/** \brief Returns the destination port
*/
inline uint16_t dport() const { return _udp.dport; }
/** \brief Returns the source port
*/
inline uint16_t sport() const { return _udp.sport; }
/** \brief Set the destination port.
*
* \param new_dport The new destination port.
*/
void dport(uint16_t new_dport);
/** \brief Set the source port.
*
* \param new_sport The new source port.
*/
void sport(uint16_t new_sport);
/** \brief Set the payload.
*
* Payload is NOT copied. Therefore, pointers provided as
@@ -30,6 +55,14 @@ namespace Tins {
* \param new_payload_size New payload's size
*/
void payload(uint8_t *new_payload, uint32_t new_payload_size);
/* Virtual methods */
/** \brief Returns the header size.
*
* This metod overrides PDU::header_size. This size includes the
* payload and options size. \sa PDU::header_size
*/
uint32_t header_size() const;
private:
struct udphdr {
uint16_t sport;
@@ -38,8 +71,11 @@ namespace Tins {
uint16_t check;
} __attribute__((packed));
void write_serialization(uint8_t *buffer, uint32_t total_sz, const PDU *parent);
udphdr _udp;
uint8_t *payload;
uint8_t *_payload;
uint32_t _payload_size;
};
};

2
src/ip.cpp
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@@ -165,7 +165,7 @@ bool Tins::IP::send(PacketSender* sender) {
return sender->send_l3(this, (const struct sockaddr*)&link_addr, sizeof(link_addr));
}
void Tins::IP::write_serialization(uint8_t *buffer, uint32_t total_sz, PDU *) {
void Tins::IP::write_serialization(uint8_t *buffer, uint32_t total_sz, const PDU *) {
uint32_t my_sz = header_size();
uint32_t new_flag;
assert(total_sz >= my_sz);

30
src/pdu.cpp
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@@ -20,8 +20,10 @@
*/
#include <cassert>
#include "utils.h"
#include "pdu.h"
Tins::PDU::PDU(uint32_t flag, PDU *next_pdu) : _flag(flag), _inner_pdu(next_pdu) {
}
@@ -56,7 +58,7 @@ uint8_t *Tins::PDU::serialize(uint32_t &sz) {
return buffer;
}
void Tins::PDU::serialize(uint8_t *buffer, uint32_t total_sz, PDU *parent) {
void Tins::PDU::serialize(uint8_t *buffer, uint32_t total_sz, const PDU *parent) {
uint32_t sz = header_size() + trailer_size();
/* Must not happen... */
assert(total_sz >= sz);
@@ -65,3 +67,29 @@ void Tins::PDU::serialize(uint8_t *buffer, uint32_t total_sz, PDU *parent) {
write_serialization(buffer, total_sz, parent);
}
/* Static methods */
uint32_t Tins::PDU::do_checksum(uint8_t *start, uint8_t *end) {
uint32_t checksum(0);
uint16_t *ptr = (uint16_t*)start, *last = (uint16_t*)end, padding(0);
if(((end - start) & 1) == 1) {
last = (uint16_t*)end - 1;
padding = *(end - 1) << 8;
}
while(ptr < last)
checksum += Utils::net_to_host_s(*(ptr++));
return checksum + padding;
}
uint32_t Tins::PDU::pseudoheader_checksum(uint32_t source_ip, uint32_t dest_ip, uint32_t len, uint32_t flag) {
uint32_t checksum(0);
source_ip = Utils::net_to_host_l(source_ip);
dest_ip = Utils::net_to_host_l(dest_ip);
uint16_t *ptr = (uint16_t*)&source_ip;
checksum += *ptr + ptr[1];
ptr = (uint16_t*)&dest_ip;
checksum += *ptr + ptr[1];
checksum += flag + len;
return checksum;
}

36
src/tcp.cpp
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@@ -128,36 +128,11 @@ void Tins::TCP::add_option(Options tcp_option, uint8_t length, uint8_t *data) {
_total_options_size = (padding) ? _options_size - padding + 4 : _options_size;
}
uint32_t Tins::TCP::do_checksum(uint8_t *start, uint8_t *end) const {
uint32_t checksum(0);
uint16_t *ptr = (uint16_t*)start, *last = (uint16_t*)end, padding(0);
if(((end - start) & 1) == 1) {
last = (uint16_t*)end - 1;
padding = *(end - 1) << 8;
}
while(ptr < last)
checksum += Utils::net_to_host_s(*(ptr++));
return checksum + padding;
}
uint32_t Tins::TCP::pseudoheader_checksum(uint32_t source_ip, uint32_t dest_ip) const {
uint32_t checksum(0), len(header_size());
source_ip = Utils::net_to_host_l(source_ip);
dest_ip = Utils::net_to_host_l(dest_ip);
uint16_t *ptr = (uint16_t*)&source_ip;
checksum += *ptr + ptr[1];
ptr = (uint16_t*)&dest_ip;
checksum += *ptr + ptr[1];
checksum += IPPROTO_TCP + len;
return checksum;
}
uint32_t Tins::TCP::header_size() const {
return sizeof(tcphdr) + _payload_size + _total_options_size;
}
void Tins::TCP::write_serialization(uint8_t *buffer, uint32_t total_sz, PDU *parent) {
void Tins::TCP::write_serialization(uint8_t *buffer, uint32_t total_sz, const PDU *parent) {
assert(total_sz >= header_size());
uint8_t *tcp_start = buffer;
buffer += sizeof(tcphdr);
@@ -175,11 +150,10 @@ void Tins::TCP::write_serialization(uint8_t *buffer, uint32_t total_sz, PDU *par
memcpy(buffer, _payload, _payload_size);
buffer += _payload_size;
IP *ip_packet = dynamic_cast<IP*>(parent);
if(ip_packet) {
_tcp.check = 0;
uint32_t checksum = pseudoheader_checksum(ip_packet->source_address(), ip_packet->dest_address()) +
do_checksum(tcp_start + sizeof(tcphdr), buffer) + do_checksum((uint8_t*)&_tcp, ((uint8_t*)&_tcp) + sizeof(tcphdr));
const IP *ip_packet = dynamic_cast<const IP*>(parent);
if(!_tcp.check && ip_packet) {
uint32_t checksum = PDU::pseudoheader_checksum(ip_packet->source_address(), ip_packet->dest_address(), header_size(), IPPROTO_TCP) +
PDU::do_checksum(tcp_start + sizeof(tcphdr), buffer) + PDU::do_checksum((uint8_t*)&_tcp, ((uint8_t*)&_tcp) + sizeof(tcphdr));
while (checksum >> 16)
checksum = (checksum & 0xffff)+(checksum >> 16);
_tcp.check = Utils::net_to_host_s(~checksum);

39
src/udp.cpp
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@@ -1,14 +1,49 @@
#ifndef WIN32
#include <netinet/in.h>
#endif
#include <cassert>
#include <cstring>
#include "utils.h"
#include "udp.h"
#include "ip.h"
Tins::UDP::UDP(uint16_t sport, uint16_t dport) : PDU(IPPROTO_UDP), _payload(0) {
Tins::UDP::UDP(uint16_t sport, uint16_t dport) : PDU(IPPROTO_UDP), _payload(0), _payload_size(0) {
_udp.sport = sport;
_udp.dport = dport;
_udp.check = 0;
_udp.len = 0;
}
void Tins::UDP::payload(uint8_t *new_payload, uint32_t new_payload_size) {
_payload = new_payload;
_udp.len = sizeof(udphdr) + new_payload_size;
_payload_size = new_payload_size;
_udp.len = Utils::net_to_host_s(sizeof(udphdr) + _payload_size);
}
void Tins::UDP::dport(uint16_t new_dport) {
_udp.dport = new_dport;
}
void Tins::UDP::sport(uint16_t new_sport) {
_udp.sport = new_sport;
}
uint32_t Tins::UDP::header_size() const {
/* Round? */
return sizeof(udphdr) + _payload_size;
}
void Tins::UDP::write_serialization(uint8_t *buffer, uint32_t total_sz, const PDU *parent) {
assert(total_sz >= sizeof(udphdr) + _payload_size);
const IP *ip_packet = dynamic_cast<const IP*>(parent);
if(!_udp.check && ip_packet) {
uint32_t checksum = PDU::pseudoheader_checksum(ip_packet->source_address(), ip_packet->dest_address(), header_size(), IPPROTO_UDP) +
PDU::do_checksum(_payload, _payload + _payload_size) + PDU::do_checksum((uint8_t*)&_udp, ((uint8_t*)&_udp) + sizeof(udphdr));
while (checksum >> 16)
checksum = (checksum & 0xffff)+(checksum >> 16);
_udp.check = Utils::net_to_host_s(~checksum);
}
std::memcpy(buffer, &_udp, sizeof(udphdr));
std::memcpy(buffer + sizeof(udphdr), _payload, _payload_size);
}