c-libp2p/peer/peer.c
2017-07-17 16:14:20 -05:00

317 lines
9.2 KiB
C

#include <stdlib.h>
#include <time.h>
#include "libp2p/peer/peer.h"
#include "libp2p/utils/linked_list.h"
#include "multiaddr/multiaddr.h"
#include "protobuf.h"
#include "libp2p/net/multistream.h"
#include "libp2p/utils/logger.h"
/**
* create a new Peer struct
* @returns a struct or NULL if there was a problem
*/
struct Libp2pPeer* libp2p_peer_new() {
struct Libp2pPeer* out = (struct Libp2pPeer*)malloc(sizeof(struct Libp2pPeer));
if (out != NULL) {
out->id = NULL;
out->id_size = 0;
out->addr_head = NULL;
out->connection_type = CONNECTION_TYPE_NOT_CONNECTED;
out->connection = NULL;
}
return out;
}
/**
* Create a new Peer based on a multiaddress
* @param in the multiaddress
* @returns a Peer initialized with the values from "in"
*/
struct Libp2pPeer* libp2p_peer_new_from_multiaddress(const struct MultiAddress* in) {
struct Libp2pPeer* out = libp2p_peer_new();
char* id = multiaddress_get_peer_id(in);
if (id != NULL) {
out->id_size = strlen(id) + 1;
out->id = malloc(out->id_size);
strcpy(out->id, id);
free(id);
}
out->addr_head = libp2p_utils_linked_list_new();
out->addr_head->item = multiaddress_copy(in);
return out;
}
/**
* Attempt to connect to the peer, setting connection_type correctly
* NOTE: If successful, this will set peer->connection to the stream
* @param peer the peer to connect to
* @returns true(1) on success, false(0) if we could not connect
*/
int libp2p_peer_connect(struct Libp2pPeer* peer, int timeout) {
time_t now, prev = time(NULL);
// find an appropriate address
struct Libp2pLinkedList* current_address = peer->addr_head;
while (current_address != NULL && peer->connection_type != CONNECTION_TYPE_CONNECTED) {
struct MultiAddress *ma = (struct MultiAddress*)current_address->item;
if (multiaddress_is_ip(ma)) {
char* ip = NULL;
if (!multiaddress_get_ip_address(ma, &ip))
continue;
int port = multiaddress_get_ip_port(ma);
peer->connection = libp2p_net_multistream_connect(ip, port);
if (peer->connection != NULL) {
peer->connection_type = CONNECTION_TYPE_CONNECTED;
}
free(ip);
} // is IP
now = time(NULL);
if (now >= (prev + timeout))
break;
} // trying to connect
return peer->connection_type == CONNECTION_TYPE_CONNECTED;
}
/**
* Create a new peer struct with some data
* @param id the id
* @param id_size the length of the id
* @param multi_addr the MultiAddresss
* @returns the Libp2pPeer or NULL if there was a problem
*/
/*
struct Libp2pPeer* libp2p_peer_new_from_data(const char* id, size_t id_size, const struct MultiAddress* multi_addr) {
struct Libp2pPeer* out = libp2p_peer_new();
if (out != NULL) {
out->id = malloc(id_size);
strncpy(out->id, id, id_size);
out->id_size = id_size;
out->addr_head = libp2p_utils_linked_list_new();
if (out->addr_head == NULL) {
libp2p_peer_free(out);
return NULL;
}
out->addr_head->item = multiaddress_copy(multi_addr);
if (out->addr_head->item == NULL) {
libp2p_peer_free(out);
return NULL;
}
}
return out;
}
*/
void libp2p_peer_free(struct Libp2pPeer* in) {
if (in != NULL) {
if (in->addr_head != NULL && in->addr_head->item != NULL) {
libp2p_logger_debug("peer", "Freeing peer %s\n", ((struct MultiAddress*)in->addr_head->item)->string);
} else {
libp2p_logger_debug("peer", "Freeing peer with no multiaddress.\n");
}
if (in->id != NULL)
free(in->id);
if (in->connection != NULL) {
libp2p_net_multistream_stream_free(in->connection);
in->connection = NULL;
}
// free the memory in the linked list
struct Libp2pLinkedList* current = in->addr_head;
while (current != NULL) {
struct Libp2pLinkedList* temp = current->next;
multiaddress_free((struct MultiAddress*)current->item);
free(current);
current = temp;
}
free(in);
}
}
/**
* Make a copy of a peer
* @param in what is to be copied
* @returns a new struct, that does not rely on the old
*/
struct Libp2pPeer* libp2p_peer_copy(struct Libp2pPeer* in) {
struct Libp2pPeer* out = libp2p_peer_new();
if (out != NULL) {
out->id_size = in->id_size;
out->id = malloc(in->id_size);
if (out->id == NULL) {
libp2p_peer_free(out);
return NULL;
}
memcpy(out->id, in->id, in->id_size);
out->connection_type = in->connection_type;
// loop through the addresses
struct Libp2pLinkedList* current_in = in->addr_head;
struct Libp2pLinkedList* current_out = NULL;
while (current_in != NULL) {
struct MultiAddress* addr = (struct MultiAddress*)current_in->item;
struct Libp2pLinkedList* copy_item = libp2p_utils_linked_list_new();
copy_item->item = multiaddress_copy(addr);
if (out->addr_head == NULL) {
out->addr_head = copy_item;
} else {
current_out->next = copy_item;
}
current_out = copy_item;
current_in = current_in->next;
}
out->connection = in->connection;
}
return out;
}
/***
* Determine if the passed in peer and id match
* @param in the peer to check
* @param peer_id peer id, zero terminated string
* @returns true if peer matches
*/
int libp2p_peer_matches_id(struct Libp2pPeer* in, const unsigned char* peer_id) {
if (strlen((char*)peer_id) == in->id_size) {
if (strncmp(in->id, (char*)peer_id, in->id_size) == 0)
return 1;
}
return 0;
}
/***
* Determine if we are currently connected to this peer
* @param in the peer to check
* @returns true(1) if connected
*/
int libp2p_peer_is_connected(struct Libp2pPeer* in) {
if (in->connection_type == CONNECTION_TYPE_CONNECTED) {
if (in->connection == NULL) {
in->connection_type = CONNECTION_TYPE_NOT_CONNECTED;
}
}
return in->connection_type == CONNECTION_TYPE_CONNECTED;
}
size_t libp2p_peer_protobuf_encode_size(struct Libp2pPeer* in) {
int sz = 0;
if (in != NULL) {
// id + connection_type
sz = 11 + in->id_size + 11;
// loop through the multiaddresses
struct Libp2pLinkedList* current = in->addr_head;
while (current != NULL) {
// find the length of the MultiAddress converted into bytes
struct MultiAddress* data = (struct MultiAddress*)current->item;
sz += 11 + data->bsize;
current = current->next;
}
}
return sz;
}
int libp2p_peer_protobuf_encode(struct Libp2pPeer* in, unsigned char* buffer, size_t max_buffer_size, size_t* bytes_written) {
// data & data_size
size_t bytes_used = 0;
*bytes_written = 0;
int retVal = 0;
// field 1 (id)
retVal = protobuf_encode_length_delimited(1, WIRETYPE_LENGTH_DELIMITED, in->id, in->id_size, &buffer[*bytes_written], max_buffer_size - *bytes_written, &bytes_used);
if (retVal == 0)
return 0;
*bytes_written += bytes_used;
// field 2 (repeated)
struct Libp2pLinkedList* current = in->addr_head;
while (current != NULL) {
struct MultiAddress* data = (struct MultiAddress*)current->item;
retVal = protobuf_encode_length_delimited(2, WIRETYPE_LENGTH_DELIMITED, (char*)data->bytes, data->bsize, &buffer[*bytes_written], max_buffer_size - *bytes_written, &bytes_used);
if (retVal == 0)
return 0;
*bytes_written += bytes_used;
current = current->next;
}
// field 3 (varint)
retVal = protobuf_encode_varint(3, WIRETYPE_VARINT, in->connection_type, &buffer[*bytes_written], max_buffer_size - *bytes_written, &bytes_used);
if (retVal == 0)
return 0;
*bytes_written += bytes_used;
return 1;
}
int libp2p_peer_protobuf_encode_with_alloc(struct Libp2pPeer* in, unsigned char** buffer, size_t *buffer_size) {
*buffer_size = libp2p_peer_protobuf_encode_size(in);
*buffer = malloc(*buffer_size);
return libp2p_peer_protobuf_encode(in, *buffer, *buffer_size, buffer_size);
}
int libp2p_peer_protobuf_decode(unsigned char* in, size_t in_size, struct Libp2pPeer** out) {
size_t pos = 0;
int retVal = 0;
char* buffer = NULL;
size_t buffer_size = 0;
struct Libp2pLinkedList* current = NULL;
struct Libp2pLinkedList* last = NULL;
struct MultiAddress* ma = NULL;
*out = libp2p_peer_new();
if ( *out == NULL)
goto exit;
struct Libp2pPeer* ptr = *out;
ptr->addr_head = NULL;
while(pos < in_size) {
size_t bytes_read = 0;
int field_no;
enum WireType field_type;
if (protobuf_decode_field_and_type(&in[pos], in_size, &field_no, &field_type, &bytes_read) == 0) {
goto exit;
}
pos += bytes_read;
switch(field_no) {
case (1): // id
if (!protobuf_decode_length_delimited(&in[pos], in_size - pos, (char**)&(ptr->id),&(ptr->id_size), &bytes_read))
goto exit;
pos += bytes_read;
break;
case (2): { // multiaddress bytes
if (!protobuf_decode_length_delimited(&in[pos], in_size - pos, &buffer, &buffer_size, &bytes_read))
goto exit;
pos += bytes_read;
// now turn it into multiaddress
struct Libp2pLinkedList* current = libp2p_utils_linked_list_new();
if (current == NULL)
goto exit;
struct MultiAddress* address = multiaddress_new_from_bytes((unsigned char*)buffer, buffer_size);
current->item = (void*)address;
free(buffer);
buffer = NULL;
// assign the values
if (ptr->addr_head == NULL) {
ptr->addr_head = current;
} else {
last->next = current;
}
last = current;
current = NULL;
break;
}
case (3): // enum as varint
if (!protobuf_decode_varint(&in[pos], in_size - pos, (long long unsigned int*)&ptr->connection_type, &bytes_read))
goto exit;
pos += bytes_read;
break;
}
}
retVal = 1;
exit:
if (retVal == 0) {
free(*out);
*out = NULL;
}
if (buffer != NULL)
free(buffer);
return retVal;
}