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#include <protocol.h>
Packet_t* generate_packet(uint64_t type, const uint8_t* data, uint64_t data_size)
{
Packet_t* packet = calloc(1, get_packet_size_without_data() + data_size);
srand(time(NULL));
packet->magic = PACKET_MAGIC;
packet->id = rand();
packet->type = type;
packet->data_size = data_size;
packet->data = NULL;
memcpy(&packet->data, data, data_size);
packet->checksum = get_packet_checksum(packet);
printf("GENERATED PACKET:\n");
print_packet(packet);
return packet;
}
int handle_packet(const Packet_t* packet)
{
int ret = is_packet_valid(packet);
if(ret < 0)
{
printf("Packet is invalid!\n");
return ret;
}
printf("PACKET VALIDATED!\n");
printf("RECIEVED PACKET:\n");
switch(packet->id)
{
default:
print_packet(packet);
break;
}
return 0;
}
int is_packet_valid(const Packet_t* packet)
{
if(packet->magic != PACKET_MAGIC)
{
perror("Invalid packet magic!\n");
return -EINVAL;
}
uint64_t checksum = get_packet_checksum(packet);
if(packet->checksum != checksum)
{
printf("packet checksum: %llu\n", checksum);
printf("expected checksum: %llu\n", packet->checksum);
perror("Invalid packet checksum!\n");
printf("PACKET AFTER RECIEVED:\n");
print_packet(packet);
return -EINVAL;
}
return 0;
}
uint64_t get_packet_checksum(const Packet_t* packet)
{
//FIXME: This is not a proper checksum implementation.
uint64_t sum = 0;
uint64_t i = sizeof(packet->checksum); //start calculating checksum from outside checksum var in struct
for(; i < get_packet_size_without_data() + packet->data_size; ++i)
sum += ((uint8_t*)packet)[i];
return sum;
}
void print_packet(const Packet_t* packet)
{
printf("Packet:\n");
printf("\tmagic: %llu\n", packet->magic);
printf("\tchecksum: %llu\n", packet->checksum);
printf("\tid: %llu\n", packet->id);
printf("\ttype: %llu\n", packet->type);
printf("\tdata size: %llu\n", packet->data_size);
printf("\tdata string: %s\n\tdata raw: ", (char*)&packet->data);
show_raw((uint8_t*)&packet->data, packet->data_size);
}
size_t get_packet_size_without_data()
{
return sizeof(Packet_t) - sizeof(uint8_t*);
}
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