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#include "mctypes.h"
#include <stdlib.h>
#include <string.h>
#include <sys/socket.h>
varint to_varint(unsigned int x)
{
varint n = malloc(sizeof(u_int8_t));
unsigned int size = 1;
while (1) {
n = reallocarray(n, size, sizeof(u_int8_t));
n[size - 1] = x & 0x7F;
x >>= 7;
if (x == 0)
return n;
n[size - 1] |= 0x80;
size++;
}
return n;
}
int from_varint(varint x)
{
unsigned int offset = 0;
unsigned int res = 0;
do {
if (offset == 5)
exit(EXIT_FAILURE);
res |= (x[offset] & 0b01111111) << offset * 7;
offset++;
} while ((x[offset-1] & 0b10000000) != 0);
return (int) res;
}
size_t len_varint(varint x)
{
size_t v_size;
for (v_size = 1; (x[v_size - 1] & 0x80) != 0; v_size++);
return v_size;
}
size_t serialize_handshake(handshake hs, void **buf)
{
size_t size = 0;
size_t varint_s;
*buf = malloc(size);
varint_s = len_varint(hs.protocol_version);
*buf = realloc(*buf, size+varint_s);
memcpy(*buf + size, hs.protocol_version, varint_s);
size += varint_s;
varint_s = len_varint(hs.server_address.length);
*buf = realloc(*buf, size+varint_s);
memcpy(*buf + size, hs.server_address.length, varint_s);
size += varint_s;
*buf = realloc(*buf, size+from_varint(hs.server_address.length));
memcpy(*buf + size, hs.server_address.content, from_varint(hs.server_address.length));
size += from_varint(hs.server_address.length);
*buf = realloc(*buf, size+sizeof(unsigned short));
memcpy(*buf + size, &hs.server_port, sizeof(unsigned short));
size += sizeof(unsigned short);
varint_s = len_varint(hs.next_state);
*buf = realloc(*buf, size+varint_s);
memcpy(*buf + size, hs.next_state, varint_s);
size += varint_s;
return size;
}
size_t serialize_packet(packet p, void **buf)
{
size_t v_size = len_varint(p.length);
size_t p_size = from_varint(p.length) + v_size; // total size of packet
size_t size = 0;
*buf = malloc(p_size);
memcpy(*buf, p.length, v_size);
size += v_size;
for (v_size = 1; (p.id[v_size - 1] & 0x80) != 0; v_size++);
memcpy(*buf+size, p.id, v_size);
size += v_size;
memcpy(*buf+size, p.data, from_varint(p.length) - v_size);
return p_size;
}
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