hash func start

This commit is contained in:
gonzalef 2020-03-31 15:57:31 +02:00
commit a469108dc5
6 changed files with 319 additions and 58 deletions

1
src/install.sh Executable file
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@ -0,0 +1 @@
sudo apt-get install libssl-dev

27
src/misc.c Normal file
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@ -0,0 +1,27 @@
#include "misc.h"
char *hash_data(pub_data *data) {
// Copy data to buf to pass it as string argument
char cpy_data[data->length + 1];
memcpy(cpy_data, data->data, data->length);
cpy_data[data->length] = '\0';
// All three fields are concatenated into a single buf
char *concat_data = concat(3, data->id, data->seqno, data->data);
// The resulting buf is hashed
char *hash = SHA256(concat_data, data->length + 10, 0);
// Free the concatenated buf
free(concat_data);
return hash_trunc(hash);
}
char *hash_network(list *data_list) {
}
char *hash_trunc(char *hash256bit);
char *concat(int argc, ...);

23
src/misc.h Normal file
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@ -0,0 +1,23 @@
#ifndef MISC_H
#define MISC_H
#include <openssl/sha.h>
#include <stdarg.h>
#include "node.h"
#include "tlv.h"
// General list
typedef struct list {
void *data;
void *next;
} list;
// Hash functions
char *hash_data(pub_data *data);
char *hash_network(list *data_list);
char *hash_trunc(char *hash256bit);
char *concat(int argc, ...);
#endif

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@ -1,50 +1,248 @@
// This is the main file of the Dazibao project. It represents the node, and
// handles all of the main logic, including the network connexions.
#include <stdlib.h>
#include <stdio.h>
#include <sys/types.h>
#include <sys/socket.h>
#include <netinet/in.h>
#include <string.h>
#include "tlv.h"
#include "node.h"
// Will return a packet when we receive one that's valid.
packet listen_for_packets(){
// For every packet recivied,
// then we make sure it's conform
// We then extract the data from it to make it easy to work with
int check_header(char * req[], int buffer_size, packet * packet_to_return){
packet * packet_to_return = (packet*) req;
// We need to check a few things ;
// The first byte must be worth 95,
if (packet_to_return->magic != 95) {
perror(">> The magic number of the packet is no good.");
return -1;
}
// The second byte must be worth 1,
if (packet_to_return->version != 1) {
perror(">> The version number of the packet is no good.");
return -1;
}
if (packet_to_return.length + 4 > buffer_size ) {
perror(">> The packet length is bigger than the UDP datagram, which is not possible with the current laws of physics.");
return -1;
}
// We need to make sure the TLV announces a length that will no go onto
// another tlv, as we might end up reading bullshit.
int validate_tlv(unsigned char *data, int pos){
switch(data[pos]) {
case 0:
break;
case 1:
break;
case 2:
if(data[pos+1] != 0) return 0;
break;
case 3:
if(data[pos+1] != 18) return 0;
break;
case 4:
if(data[pos+1] != 16) return 0;
break;
case 5:
if(data[pos+1] != 0) return 0;
break;
case 6:
if(data[pos+1] != 26) return 0;
break;
case 7:
if(data[pos+1] != 8) return 0;
break;
case 8:
if(data[pos+1] < 26 || data[pos+1] > 218) return 0;
break;
case 9:
break;
default:
return 0;
}
return 1;
// We listen forever for new paquets;
void listen_for_packets(){
// Create new socket for UDP
int s = socket(AF_INET6, SOCK_DGRAM, 0);
if(s < 0) {
perror(">> Error, cannot create socket.");
perror(">> Exiting...")
exit(1);
}
struct sockaddr_in6 server;
memset(&server, 0, sizeof(server));
server.sin6_family = AF_INET6;
server.sin6_port = htons(LISTEN_PORT);
int rc = bind(s, (struct sockaddr*)&server, sizeof(server));
if(rc < 0) {
perror(">> Error, cannot bind socket to choosen port.");
perror(">> Exiting...")
exit(1);
}
// A paquet has at most a length of 1024 bytes
char req[1024];
struct sockaddr_in6 client;
struct iovec io = { .iov_len = 1024, .iov_base = req };
struct msghdr msg_to_receive = {
.msg_name = &client,
.msg_namelen = sizeof(client),
.msg_iov = &io,
.msg_iovlen = 1
};
while(1){
memset(req, '\0', 1024);
struct sockaddr_in6 client;
unsigned int client_len = sizeof(client);
rc = recvmsg(s, &msg_to_receive, 0);
if(rc < 0) {
perror(">> Error while receiving a new datagram.");
perror(">> Ignoring, continuing...")
continue;
}
printf(">> New paquet received :\n");
printf("%s\n", req);
// We verify the received packet is well formated,
// and we return it in the struct designed to work with it.
struct packet * formated_rec_datagram;
if(check_header(&req, 1024, formated_rec_datagram) < 0){
perror(">> Error while checking the header, aborting this packet, by choice, and conviction.");
continue;
}
struct tlv_list received_tlvs;
if (validate_tlvs(formated_rec_datagram) < 0) {
/* code */
}
}
}
// If the sender is not in the neighbourhood, and we have 15 neighbours, we
// ignore the packet. Otherwise, we add him to the neighbourhood, marked as
// temporary.
int update_neighbours(){
};
// We need to make sure the TLV announces a length that will no go onto
// another tlv, as we might end up reading bullshit.
int validate_tlv(char *data, int pos, short packet_len){
char type = data[pos];
// Nothing to do in this case
if(type == 0)
return 0;
// Check that we can read a length
if(pos + 1 >= packet_len)
return -1;
unsigned char tlv_len = data[pos+1];
// Check that the tlv does not exceed the packet length
if(pos + length >= packet_len)
return -1;
// Returns the type of the tlv or -1 if something went wrong
switch(type) {
case 1:
return 1;
case 2:
if(tlv_len != LEN_NEIGHBOUR_REQ) return -1;
return 2;
case 3:
if(tlv_len != LEN_NEIGHBOUR) return -1;
return 3;
case 4:
if(tlv_len != LEN_NETWORK_HASH) return -1;
return 4;
case 5:
if(tlv_len != LEN_NETWORK_STATE_REQ) return -1;
return 5;
case 6:
if(tlv_len != LEN_NODE_HASH) return -1;
return 6;
case 7:
if(tlv_len != LEN_NODE_STATE_REQ) return -1;
return 7;
case 8:
if(tlv_len < MIN_LEN_NODE_STATE || tlv_len > MAX_LEN_NODE_STATE) return -1;
return 8;
case 9:
return 9;
default:
return -1;
}
}
// We then look at the differents TLVs in the packet.
void work_with_tlvs(char *data, short packet_len){
int pos = 0;
unsigned char tlv_len;
tlv tmp_tlv;
while(pos < packet_len) {
switch(validate_tlv(data, pos, packet_len)) {
case 0:
// We received a padding tlv so it is ignored
pos += 1;
break;
case 1:
// We received a padding tlv so it is ignored
tlv_len = data[pos+1];
pos += tlv_len + 2;
break;
case 2:
// We received a neighbour request so a neighbor tlv has to be sent
tlv_len = data[pos+1];
pos += tlv_len + 2;
// NOT FINISHED - Where are ip and seqno stored?
build_neighbour(&tmp_tlv, ip, seqno);
// NOT FINISHED - What packet is it added to?
add_tlv(packet, &tmp_tlv, 3);
break;
case 3:
// We received a neighbour tlv so a tlv network hash is sent to that address
tlv_len = data[pos+1];
pos += tlv_len + 2;
tlv.neighbour = (neighbour*) (data + pos);
break;
case 4:
// We reveived a network hash tlv so
tlv_len = data[pos+1];
pos += tlv_len +2;
// NOT FINISHED - Where is network_hash?
build_neighbour(&tmp_tlv, network_hash);
// NOT FINISHED - What packet is it added to?
add_tlv(packet, &tmp_tlv, 4);
break;
case 5:
// We received a network state request tlv so a series of tlv node hash have to be sent for each data known
pos += 2;
// NOT FINISHED - for each known data
list *tmp_list = data_list;
pub_data *tmp_data;
while(tmp_list != NULL) {
tmp_data = (pub_data*) tmp_list->data;
build_node_hash(&tmp_tlv, tmp_data->id, tmp_data->seqno);
}
break;
case 6:
// We received a node hash tlv
break;
case 7:
// We received a node state request tlv
break;
case 8:
// We received a node state tlv
break;
case 9:
// We received a warning tlv so it's message is printed
break;
default:
return ;
}
}
}
void work_with_tlvs(struct tlvs_list receivied_tlvs){
// For every TLV,
@ -84,10 +282,10 @@ void work_with_tlvs(struct tlvs_list receivied_tlvs){
// we store the entry in our data table.
}
int main(int argc, char const *argv[]) {
int continue = 1;
int main(int argc, const char *argv[]) {
int cont = 1;
while(continue){
while(cont){
// We create the neighbourhood table
neighbour_peer neighbour_list[NEIGHBOUR_MAX];
@ -97,17 +295,8 @@ int main(int argc, char const *argv[]) {
// Listen for incoming packets
listen_for_packets();
// For every packet recivied, we fork,
// then we make sure it's conform
// We then extract the data from it to make it easy to work with
check_header();
// If the sender is not in the neighbourhood, and we have 15 neighbours, we
// ignore the packet. Otherwise, we add him to the neighbourhood, marked as
// temporary.
update_neighbours();
// We then look at the differents TLVs in the packet.
work_with_tlvs();
// This is in it's own fork.
time_t delay = time(NULL) + 20;
while(! (delay < time(NULL)){
// Theses functions are there for general book-keeping,and run in there own

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@ -3,6 +3,12 @@
#ifndef NODE_H
#define NODE_H
#include "tlv.h"
#include "misc.h"
// On which port do we listen to
#define LISTEN_PORT 1212
// The node ID
#define NODE_ID 203242402519736214145149136169422092269247115186189140178187251487819615911212154252117172522111472481308026129190139512419121015210238252292031613214452118122204415160254
@ -29,24 +35,31 @@ typedef struct neighbour_peer {
* Di : the data of the message 192 bytes
*/
typedef struct message {
long node_id_publisher;
typedef struct pub_data {
unsigned char length;
long id;
short seqno;
char *data;
} message;
} pub_data;
// static lists
static list *data_list;
static list *neighbour_list;
// TODO
// fonctions signatures
void listen_for_packets();
void check_header();
int check_header(char * received_datagram[], int len, packet pack);
void update_neighbours();
int update_neighbours();
int validate_tlv(unsigned char *data, int pos);
void work_with_tlvs();
int validate_tlv(unsigned char *data, int pos);
void add_tlv(packet *packet, tlv *tlv, char type);
// threaded functions

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@ -6,6 +6,15 @@
#ifndef TLV_H
#define TLV_H
#define LEN_NEIGHBOUR_REQ 0
#define LEN_NEIGHBOUR 18
#define LEN_NETWORK_HASH 16
#define LEN_NETWORK_STATE_REQ 0
#define LEN_NODE_HASH 26
#define LEN_NODE_STATE_REQ 8
#define MIN_LEN_NODE_STATE 26
#define MAX_LEN_NODE_STATE 218
// 8 octets min (struct pointer 4 octets), 1024 octets max
typedef struct packet {
unsigned char magic; // 95 (si autre, ignorer)
@ -99,11 +108,10 @@ typedef union tlv {
warning *warning;
} tlv;
// creer un tlv
// build tlv from token
int build_tlv(tlv *tlv, cmd_token token);
// creer un tlv specifique
// build specific tlv
int build_pad1(tlv *tlv);
int build_padn(tlv *tlv, size_t len);
int build_neighbour_req(tlv *tlv);