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Code Issues Releases Wiki Activity

TCP now stores options when instantiated from a buffer.

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This commit is contained in:
Matias Fontanini
2011-08-19 11:40:13 -03:00
parent 03aa49428c
commit 2513488b92
3 changed files with 106 additions and 46 deletions
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47
src/tcp.cpp
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@@ -47,16 +47,47 @@ Tins::TCP::TCP(const uint8_t *buffer, uint32_t total_sz) : PDU(IPPROTO_TCP) {
throw std::runtime_error("Not enought size for an TCP header in the buffer.");
std::memcpy(&_tcp, buffer, sizeof(tcphdr));
/* Options... */
buffer += sizeof(tcphdr);
total_sz -= sizeof(tcphdr);
uint32_t index = 0, header_end = (data_offset() * sizeof(uint32_t)) - sizeof(tcphdr);
if(total_sz >= header_end) {
uint8_t args[2] = {0};
while(index < header_end) {
for(unsigned i(0); i < 2 && args[0] != NOP; ++i) {
args[i] = buffer[index++];
if(index == header_end)
throw std::runtime_error("Not enought size for a TCP header in the buffer.");
}
// We don't want to store NOPs and EOLs
if(args[0] != NOP && args[0] != EOL) {
if(args[1]) {
// Not enough size for this option
if(header_end - index < args[1] - (sizeof(uint8_t) << 1)) {
throw std::runtime_error("Not enought size for a TCP header in the buffer.");
}
args[1] -= (sizeof(uint8_t) << 1);
add_option((Options)args[0], args[1], buffer + index);
}
index += args[1];
}
else if(args[0] == EOL)
index = header_end;
else // Skip the NOP
args[0] = 0;
}
buffer += index;
total_sz -= index;
_total_options_size = header_end;
_options_size = (_total_options_size / 4) * 4;
}
if(total_sz)
inner_pdu(new RawPDU(buffer + sizeof(tcphdr), total_sz));
inner_pdu(new RawPDU(buffer, total_sz));
}
Tins::TCP::~TCP() {
for(unsigned i(0); i < _options.size(); ++i)
delete[] _options[i].data;
for(std::list<TCPOption>::iterator it = _options.begin(); it != _options.end(); ++it)
delete[] it->data;
}
void Tins::TCP::dport(uint16_t new_dport) {
@@ -166,7 +197,7 @@ void Tins::TCP::set_flag(Flags tcp_flag, uint8_t value) {
};
}
void Tins::TCP::add_option(Options tcp_option, uint8_t length, uint8_t *data) {
void Tins::TCP::add_option(Options tcp_option, uint8_t length, const uint8_t *data) {
uint8_t *new_data = new uint8_t[length], padding;
memcpy(new_data, data, length);
_options.push_back(TCPOption(tcp_option, length, new_data));
@@ -184,8 +215,8 @@ void Tins::TCP::write_serialization(uint8_t *buffer, uint32_t total_sz, const PD
uint8_t *tcp_start = buffer;
buffer += sizeof(tcphdr);
_tcp.doff = (sizeof(tcphdr) + _total_options_size) / sizeof(uint32_t);
for(unsigned i(0); i < _options.size(); ++i)
buffer = _options[i].write(buffer);
for(std::list<TCPOption>::iterator it = _options.begin(); it != _options.end(); ++it)
buffer = it->write(buffer);
if(_options_size < _total_options_size) {
uint8_t padding = _total_options_size;