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Done some optimizations on TCP's constructor from buffer.

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This commit is contained in:
Matias Fontanini
2013-09-15 16:01:00 -03:00
parent 20f3911e12
commit d7d2dec5cb
1 changed files with 19 additions and 30 deletions
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49
src/tcp.cpp
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@@ -56,41 +56,30 @@ TCP::TCP(const uint8_t *buffer, uint32_t total_sz)
if(total_sz < sizeof(tcphdr))
throw malformed_packet();
std::memcpy(&_tcp, buffer, sizeof(tcphdr));
if(data_offset() * sizeof(uint32_t) > total_sz || data_offset() * sizeof(uint32_t) < sizeof(tcphdr))
throw malformed_packet();
const uint8_t *header_end = buffer + (data_offset() * sizeof(uint32_t));
total_sz = total_sz - (header_end - buffer);
buffer += sizeof(tcphdr);
total_sz -= sizeof(tcphdr);
_total_options_size = 0;
_options_size = 0;
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; ++i) {
if(index == header_end)
throw malformed_packet();
args[i] = buffer[index++];
// NOP and EOL contain no length field
if(args[0] == NOP || args[0] == EOL)
break;
}
// We don't want to store NOPs and EOLs
if(args[0] != NOP && args[0] != EOL) {
// Not enough size for this option
args[1] -= (sizeof(uint8_t) << 1);
if(header_end - index < args[1])
throw malformed_packet();
if(args[1])
add_option(option((OptionTypes)args[0], buffer + index, buffer + index + args[1]));
else
add_option(option((OptionTypes)args[0], args[1], 0));
index += args[1];
}
else
add_option(option((OptionTypes)args[0], 0));
while(buffer < header_end) {
if(*buffer <= NOP) {
add_option(option((OptionTypes)*buffer, 0));
++buffer;
}
else {
if(buffer + 1 == header_end)
throw malformed_packet();
const uint8_t len = buffer[1] - (sizeof(uint8_t) << 1);
const uint8_t *data_start = buffer + 2;
if(data_start + len > header_end)
throw malformed_packet();
add_option(option((OptionTypes)*buffer, data_start, data_start + len));
buffer = data_start + len;
}
buffer += index;
total_sz -= index;
}
if(total_sz)
inner_pdu(new RawPDU(buffer, total_sz));