c-ipfs/merkledag/node.c
2017-09-25 17:56:10 -05:00

815 lines
22 KiB
C

/**
* An implementation of an IPFS node
* Copying the go-ipfs-node project
*/
#include <stdlib.h>
#include <stdio.h>
#include <string.h>
#include <strings.h>
#include "inttypes.h"
#include "mh/multihash.h"
#include "mh/hashes.h"
#include "ipfs/cid/cid.h"
#include "ipfs/merkledag/node.h"
#include "ipfs/unixfs/unixfs.h"
extern char *strtok_r(char *, const char *, char **);
// for protobuf Node (all fields optional) data (optional bytes) links (repeated node_link)
enum WireType ipfs_node_message_fields[] = { WIRETYPE_LENGTH_DELIMITED, WIRETYPE_LENGTH_DELIMITED };
// for protobuf NodeLink (all fields optional) hash name tsize
enum WireType ipfs_node_link_message_fields[] = { WIRETYPE_LENGTH_DELIMITED, WIRETYPE_LENGTH_DELIMITED, WIRETYPE_VARINT };
/*====================================================================================
* Link Functions
*===================================================================================*/
/* ipfs_node_link_new
* @Param name: The name of the link (char *)
* @Param size: Size of the link (size_t)
* @Param ahash: An Qmhash
*/
int ipfs_node_link_create(char * name, unsigned char * ahash, size_t hash_size, struct NodeLink** node_link)
{
ipfs_node_link_new(node_link);
if (*node_link == NULL)
return 0;
struct NodeLink* link = *node_link;
// hash
link->hash_size = hash_size;
link->hash = (unsigned char*)malloc(hash_size);
memcpy(link->hash, ahash, hash_size);
// name
if (name != NULL && strlen(name) > 0) {
link->name = malloc(strlen(name) + 1);
if ( link->name == NULL) {
free(link);
return 0;
}
strcpy(link->name, name);
}
// t_size
link->t_size = 0;
// other, non-protobuffed data
link->next = NULL;
return 1;
}
int ipfs_node_link_new(struct NodeLink** node_link) {
*node_link = malloc(sizeof(struct NodeLink));
if (*node_link == NULL)
return 0;
struct NodeLink* link = *node_link;
link->hash = NULL;
link->hash_size = 0;
link->name = NULL;
link->next = NULL;
link->t_size = 0;
return 1;
}
/* ipfs_node_link_free
* @param node_link: Free the link you have allocated.
*/
int ipfs_node_link_free(struct NodeLink * node_link)
{
if (node_link != NULL) {
if (node_link->hash != NULL)
free(node_link->hash);
if (node_link->name != NULL)
free(node_link->name);
free(node_link);
}
return 1;
}
/***
* Find length of encoded version of NodeLink
* @param link the link to examine
* @returns the maximum length of the encoded NodeLink
*/
size_t ipfs_node_link_protobuf_encode_size(const struct NodeLink* link) {
if (link == NULL)
return 0;
// hash, name, tsize
size_t size = 0;
if (link->hash_size > 0) {
size += 11 + link->hash_size;
}
if (link->name != NULL && strlen(link->name) > 0) {
size += 11 + strlen(link->name);
}
if (link->t_size > 0) {
size += 22;
}
return size;
}
/**
* Encode a NodeLink in protobuf format
* @param link the link to work with
* @param buffer the buffer to fill
* @param max_buffer_length the length of the buffer
* @param bytes_written the number of bytes written to buffer
* @returns true(1) on success
*/
int ipfs_node_link_protobuf_encode(const struct NodeLink* link, unsigned char* buffer, size_t max_buffer_length, size_t* bytes_written) {
// 3 fields, hash (length delimited), name (length delimited), tsize (varint)
size_t bytes_used = 0;
int retVal = 0;
*bytes_written = 0;
// hash
if (link->hash_size > 0) {
size_t hash_length = mh_new_length(MH_H_SHA2_256, link->hash_size);
unsigned char hash[hash_length];
mh_new(hash, MH_H_SHA2_256, link->hash, link->hash_size);
retVal = protobuf_encode_length_delimited(1, ipfs_node_link_message_fields[0], (char*)hash, hash_length, &buffer[*bytes_written], max_buffer_length - *bytes_written, &bytes_used);
if (retVal == 0) {
return 0;
}
*bytes_written += bytes_used;
}
// name is optional, but they encode it anyways
if (link->name != NULL && strlen(link->name) > 0) {
retVal = protobuf_encode_string(2, ipfs_node_link_message_fields[1], link->name, &buffer[*bytes_written], max_buffer_length - *bytes_written, &bytes_used);
if (retVal == 0)
return 0;
*bytes_written += bytes_used;
} else {
retVal = protobuf_encode_string(2, ipfs_node_link_message_fields[1], "", &buffer[*bytes_written], max_buffer_length - *bytes_written, &bytes_used);
if (retVal == 0)
return 0;
*bytes_written += bytes_used;
}
// tsize
if (link->t_size > 0) {
retVal = protobuf_encode_varint(3, ipfs_node_link_message_fields[2], link->t_size, &buffer[*bytes_written], max_buffer_length - *bytes_written, &bytes_used);
if (retVal == 0)
return 0;
*bytes_written += bytes_used;
}
return 1;
}
/**
* Turn a protobuf encoded byte array into a NodeLink object
* @param buffer the buffer to look in
* @param buffer_length the length of the buffer
* @param link the link to fill
* @returns true(1) on success
*/
int ipfs_node_link_protobuf_decode(unsigned char* buffer, size_t buffer_length, struct NodeLink** node_link) {
size_t pos = 0;
int retVal = 0;
struct NodeLink* link = NULL;
// allocate memory for object
if (ipfs_node_link_new(node_link) == 0)
goto exit;
link = *node_link;
while(pos < buffer_length) {
size_t bytes_read = 0;
int field_no;
enum WireType field_type;
if (protobuf_decode_field_and_type(&buffer[pos], buffer_length, &field_no, &field_type, &bytes_read) == 0) {
goto exit;
}
pos += bytes_read;
switch(field_no) {
case (1): { // hash
size_t hash_size = 0;
unsigned char* hash;
if (protobuf_decode_length_delimited(&buffer[pos], buffer_length - pos, (char**)&hash, &hash_size, &bytes_read) == 0)
goto exit;
if (hash_size < 2) {
goto exit;
}
link->hash_size = hash_size - 2;
link->hash = (unsigned char*)malloc(link->hash_size);
memcpy((char*)link->hash, (char*)&hash[2], link->hash_size);
free(hash);
pos += bytes_read;
break;
}
case (2): { // name
if (protobuf_decode_string(&buffer[pos], buffer_length - pos, &link->name, &bytes_read) == 0)
goto exit;
pos += bytes_read;
break;
}
case (3): { // t_size
if (protobuf_decode_varint(&buffer[pos], buffer_length - pos, (unsigned long long*)&link->t_size, &bytes_read) == 0)
goto exit;
pos += bytes_read;
break;
}
}
}
retVal = 1;
exit:
if (retVal == 0) {
if (link != NULL)
ipfs_node_link_free(link);
}
return retVal;
}
/***
* return an approximate size of the encoded node
*/
size_t ipfs_hashtable_node_protobuf_encode_size(const struct HashtableNode* node) {
size_t size = 0;
// links
struct NodeLink* current = node->head_link;
while(current != NULL) {
size += 11 + ipfs_node_link_protobuf_encode_size(current);
current = current->next;
}
// data
if (node->data_size > 0) {
size += 11 + node->data_size;
}
return size;
}
/***
* Encode a node into a protobuf byte stream
* @param node the node to encode
* @param buffer where to put it
* @param max_buffer_length the length of buffer
* @param bytes_written how much of buffer was used
* @returns true(1) on success
*/
int ipfs_hashtable_node_protobuf_encode(const struct HashtableNode* node, unsigned char* buffer, size_t max_buffer_length, size_t* bytes_written) {
size_t bytes_used = 0;
*bytes_written = 0;
int retVal = 0;
// links
struct NodeLink* current = node->head_link;
while (current != NULL) {
size_t temp_size = ipfs_node_link_protobuf_encode_size(current);
unsigned char temp[temp_size];
retVal = ipfs_node_link_protobuf_encode(current, temp, temp_size, &bytes_used);
if (retVal == 0)
return 0;
retVal = protobuf_encode_length_delimited(2, ipfs_node_message_fields[1], (char*)temp, bytes_used, &buffer[*bytes_written], max_buffer_length - *bytes_written, &bytes_used);
if (retVal == 0)
return 0;
*bytes_written += bytes_used;
current = current->next;
}
// data
if (node->data_size > 0) {
retVal = protobuf_encode_length_delimited(1, ipfs_node_message_fields[0], (char*)node->data, node->data_size, &buffer[*bytes_written], max_buffer_length - *bytes_written, &bytes_used);
if (retVal == 0)
return 0;
*bytes_written += bytes_used;
}
return 1;
}
/***
* Decode a stream of bytes into a Node structure
* @param buffer where to get the bytes from
* @param buffer_length the length of buffer
* @param node pointer to the Node to be created
* @returns true(1) on success
*/
int ipfs_hashtable_node_protobuf_decode(unsigned char* buffer, size_t buffer_length, struct HashtableNode** node) {
/*
* Field 1: data
* Field 2: link
*/
size_t pos = 0;
int retVal = 0;
unsigned char* temp_buffer = NULL;
size_t temp_size;
struct NodeLink* temp_link = NULL;
if (buffer_length == 0)
goto exit;
if (ipfs_hashtable_node_new(node) == 0)
goto exit;
while(pos < buffer_length) {
size_t bytes_read = 0;
int field_no;
enum WireType field_type;
if (protobuf_decode_field_and_type(&buffer[pos], buffer_length, &field_no, &field_type, &bytes_read) == 0) {
goto exit;
}
pos += bytes_read;
switch(field_no) {
case (1): { // data
if (protobuf_decode_length_delimited(&buffer[pos], buffer_length - pos, (char**)&((*node)->data), &((*node)->data_size), &bytes_read) == 0)
goto exit;
pos += bytes_read;
break;
}
case (2): {// links
if (protobuf_decode_length_delimited(&buffer[pos], buffer_length - pos, (char**)&temp_buffer, &temp_size, &bytes_read) == 0)
goto exit;
pos += bytes_read;
if (ipfs_node_link_protobuf_decode(temp_buffer, temp_size, &temp_link)) {
ipfs_hashtable_node_add_link(*node, temp_link);
}
free(temp_buffer);
temp_buffer = NULL;
break;
}
}
}
retVal = 1;
exit:
if (retVal == 0) {
ipfs_hashtable_node_free(*node);
}
if (temp_buffer != NULL)
free(temp_buffer);
return retVal;
}
/*====================================================================================
* Node Functions
*===================================================================================*/
/*ipfs_node_new
* Creates an empty node, allocates the required memory
* Returns a fresh new node with no data set in it.
*/
int ipfs_hashtable_node_new(struct HashtableNode** node)
{
*node = (struct HashtableNode *)malloc(sizeof(struct HashtableNode));
if (*node == NULL)
return 0;
(*node)->hash = NULL;
(*node)->hash_size = 0;
(*node)->data = NULL;
(*node)->data_size = 0;
(*node)->encoded = NULL;
(*node)->head_link = NULL;
return 1;
}
/***
* Allocates memory for a node, and sets the data section to indicate
* that this node is a directory
* @param node the node to initialize
* @returns true(1) on success, otherwise false(0)
*/
int ipfs_hashtable_node_create_directory(struct HashtableNode** node) {
// initialize parent_node
if (ipfs_hashtable_node_new(node) == 0)
return 0;
// put a UnixFS protobuf in the data section
struct UnixFS* unix_fs;
if (ipfs_unixfs_new(&unix_fs) == 0) {
ipfs_hashtable_node_free(*node);
return 0;
}
unix_fs->data_type = UNIXFS_DIRECTORY;
size_t protobuf_len = ipfs_unixfs_protobuf_encode_size(unix_fs);
unsigned char protobuf[protobuf_len];
if (ipfs_unixfs_protobuf_encode(unix_fs, protobuf, protobuf_len, &protobuf_len) == 0) {
ipfs_hashtable_node_free(*node);
ipfs_unixfs_free(unix_fs);
return 0;
}
ipfs_unixfs_free(unix_fs);
ipfs_hashtable_node_set_data(*node, protobuf, protobuf_len);
return 1;
}
int ipfs_hashtable_node_is_directory(struct HashtableNode* node) {
if (node->data_size < 2) {
return 0;
}
struct UnixFS* unix_fs;
if (ipfs_unixfs_protobuf_decode(node->data, node->data_size, &unix_fs) == 0) {
return 0;
}
int retVal = (unix_fs->data_type == UNIXFS_DIRECTORY);
ipfs_unixfs_free(unix_fs);
return retVal;
}
/**
* Set the cached struct element
* @param node the node to be modified
* @param cid the Cid to be copied into the Node->cached element
* @returns true(1) on success
*/
int ipfs_hashtable_node_set_hash(struct HashtableNode* node, const unsigned char* hash, size_t hash_size)
{
// don't reallocate if it is the same size
if (node->hash != NULL && hash_size != node->hash_size) {
free(node->hash);
node->hash = NULL;
node->hash_size = 0;
}
// we must reallocate
if (node->hash == NULL && hash_size > 0) {
node->hash = (unsigned char*)malloc(hash_size);
if (node->hash == NULL)
return 0;
}
if (hash_size > 0) { // don't bother if there is nothing to copy
memcpy(node->hash, hash, hash_size);
node->hash_size = hash_size;
}
return 1;
}
/*ipfs_node_set_data
* Sets the data of a node
* @param Node: The node which you want to set data in.
* @param Data, the data you want to assign to the node
* Sets pointers of encoded & cached to NULL /following go method
* returns 1 on success 0 on failure
*/
int ipfs_hashtable_node_set_data(struct HashtableNode* node, unsigned char * Data, size_t data_size)
{
if(!node || !Data)
{
return 0;
}
if (node->data != NULL) {
free(node->data);
}
node->data = malloc(sizeof(unsigned char) * data_size);
if (node->data == NULL)
return 0;
memcpy(node->data, Data, data_size);
node->data_size = data_size;
return 1;
}
/*ipfs_node_set_encoded
* @param NODE: the node you wish to alter (struct Node *)
* @param Data: The data you wish to set in encoded.(unsigned char *)
* returns 1 on success 0 on failure
*/
int ipfs_hashtable_node_set_encoded(struct HashtableNode * N, unsigned char * Data)
{
if(!N || !Data)
{
return 0;
}
N->encoded = Data;
//I don't know if these will be needed, enable them if you need them.
//N->cached = NULL;
//N->data = NULL;
return 1;
}
/*ipfs_node_get_data
* Gets data from a node
* @param Node: = The node you want to get data from. (unsigned char *)
* Returns data of node.
*/
unsigned char * ipfs_hashtable_node_get_data(struct HashtableNode * N)
{
unsigned char * DATA;
DATA = N->data;
return DATA;
}
struct NodeLink* ipfs_node_link_last(struct HashtableNode* node) {
struct NodeLink* current = node->head_link;
while(current != NULL) {
if (current->next == NULL)
break;
current = current->next;
}
return current;
}
int ipfs_node_remove_link(struct HashtableNode* node, struct NodeLink* toRemove) {
struct NodeLink* current = node->head_link;
struct NodeLink* previous = NULL;
while(current != NULL && current != toRemove) {
previous = current;
current = current->next;
}
if (current != NULL) {
if (previous == NULL) {
// we're trying to delete the head
previous = current->next;
ipfs_node_link_free(current);
node->head_link = previous;
} else {
// we're in the middle or end
previous = current->next;
ipfs_node_link_free(current);
}
return 1;
}
return 0;
}
/*ipfs_node_free
* Once you are finished using a node, always delete it using this.
* It will take care of the links inside it.
* @param N: the node you want to free. (struct Node *)
*/
int ipfs_hashtable_node_free(struct HashtableNode * N)
{
if(N != NULL)
{
// remove links
struct NodeLink* current = N->head_link;
while (current != NULL) {
struct NodeLink* toDelete = current;
current = current->next;
ipfs_node_remove_link(N, toDelete);
}
if(N->hash != NULL)
{
free(N->hash);
N->hash = NULL;
N->hash_size = 0;
}
if (N->data) {
free(N->data);
N->data = NULL;
N->data_size = 0;
}
if (N->encoded != NULL) {
free(N->encoded);
}
free(N);
N = NULL;
}
return 1;
}
/*ipfs_node_get_link_by_name
* Returns a copy of the link with given name
* @param Name: (char * name) searches for link with this name
* Returns the link struct if it's found otherwise returns NULL
*/
struct NodeLink * ipfs_hashtable_node_get_link_by_name(struct HashtableNode * N, char * Name)
{
struct NodeLink* current = N->head_link;
while(current != NULL && strcmp(Name, current->name) != 0) {
current = current->next;
}
return current;
}
/*ipfs_node_remove_link_by_name
* Removes a link from node if found by name.
* @param name: Name of link (char * name)
* returns 1 on success, 0 on failure.
*/
int ipfs_hashtable_node_remove_link_by_name(char * Name, struct HashtableNode * mynode)
{
struct NodeLink* current = mynode->head_link;
struct NodeLink* previous = NULL;
while( (current != NULL)
&& (( Name == NULL && current->name != NULL )
|| ( Name != NULL && current->name == NULL )
|| ( Name != NULL && current->name != NULL && strcmp(Name, current->name) != 0) ) ) {
previous = current;
current = current->next;
}
if (current != NULL) {
// we found it
if (previous == NULL) {
// we're first, use the next one (if there is one)
if (current->next != NULL)
mynode->head_link = current->next;
} else {
// we're somewhere in the middle, remove me from the list
previous->next = current->next;
ipfs_node_link_free(current);
}
return 1;
}
return 0;
}
/* ipfs_node_add_link
* Adds a link to your node
* @param node the node to add to
* @param mylink: the link to add
* @returns true(1) on success
*/
int ipfs_hashtable_node_add_link(struct HashtableNode* node, struct NodeLink * mylink)
{
if(node->head_link != NULL) {
// add to existing by finding last one
struct NodeLink* current_end = node->head_link;
while(current_end->next != NULL) {
current_end = current_end->next;
}
// now we have the last one, add to it
current_end->next = mylink;
}
else
{
node->head_link = mylink;
}
return 1;
}
/*ipfs_node_new_from_link
* Create a node from a link
* @param mylink: the link you want to create it from. (struct Cid *)
* @param linksize: sizeof(the link in mylink) (size_T)
* Returns a fresh new node with the link you specified. Has to be freed with Node_Free preferably.
*/
int ipfs_hashtable_node_new_from_link(struct NodeLink * mylink, struct HashtableNode** node)
{
*node = (struct HashtableNode *) malloc(sizeof(struct HashtableNode));
if (*node == NULL)
return 0;
(*node)->head_link = NULL;
ipfs_hashtable_node_add_link(*node, mylink);
(*node)->hash = NULL;
(*node)->hash_size = 0;
(*node)->data = NULL;
(*node)->data_size = 0;
(*node)->encoded = NULL;
return 1;
}
/**
* create a new Node struct with data
* @param data: bytes buffer you want to create the node from
* @param data_size the size of the data buffer
* @param node a pointer to the node to be created
* returns a node with the data you inputted.
*/
int ipfs_hashtable_node_new_from_data(unsigned char * data, size_t data_size, struct HashtableNode** node)
{
if(data)
{
if (ipfs_hashtable_node_new(node) == 0)
return 0;
return ipfs_hashtable_node_set_data(*node, data, data_size);
}
return 0;
}
/***
* create a Node struct from encoded data
* @param data: encoded bytes buffer you want to create the node from. Note: this copies the pointer, not a memcpy
* @param node a pointer to the node that will be created
* @returns true(1) on success
*/
int ipfs_hashtable_node_new_from_encoded(unsigned char * data, struct HashtableNode** node)
{
if(data)
{
if (ipfs_hashtable_node_new(node) == 0)
return 0;
(*node)->encoded = data;
return 1;
}
return 0;
}
/*Node_Resolve_Max_Size
* !!!This shouldn't concern you!
*Gets the ammount of words that will be returned by Node_Resolve
*@Param1: The string that will be processed (eg: char * sentence = "foo/bar/bin")
*Returns either -1 if something went wrong or the ammount of words that would be processed.
*/
int Node_Resolve_Max_Size(char * input1)
{
if(!input1)
{
return -1; // Input is null, therefor nothing can be processed.
}
char input[strlen(input1)+1];
bzero(input, strlen(input1));
strcpy(input, input1);
int num = 0;
char * tr;
char * end;
tr=strtok_r(input,"/",&end);
for(int i = 0;tr;i++)
{
tr=strtok_r(NULL,"/",&end);
num++;
}
return num;
}
/*Node_Resolve Basically stores everything in a pointer array eg: char * bla[Max_Words_]
* !!!This shouldn't concern you!!!
*@param1: Pointer array(char * foo[x], X=Whatever ammount there is. should be used with the helper function Node_Resolve_Max_Size)
*@param2: Sentence to gather words/paths from (Eg: char * meh = "foo/bar/bin")
*@Returns 1 or 0, 0 if something went wrong, 1 if everything went smoothly.
*/
int Node_Resolve(char ** result, char * input1)
{
if(!input1)
{
return 0; // Input is null, therefor nothing can be processed.
}
char input[strlen(input1)+1];
bzero(input, strlen(input1));
strcpy(input, input1);
char * tr;
char * end;
tr=strtok_r(input,"/",&end);
for(int i = 0;tr;i++)
{
result[i] = (char *) malloc(strlen(tr)+1);
strcpy(result[i], tr);
tr=strtok_r(NULL,"/",&end);
}
return 1;
}
/*Node_Resolve_Links
* Processes a path returning all links.
* @param N: The node you want to get links from
* @param path: The "foo/bar/bin" path
*/
struct Link_Proc * Node_Resolve_Links(struct HashtableNode * N, char * path)
{
if(!N || !path)
{
return NULL;
}
int expected_link_ammount = Node_Resolve_Max_Size(path);
struct Link_Proc * LProc = (struct Link_Proc *) malloc(sizeof(struct Link_Proc) + sizeof(struct NodeLink) * expected_link_ammount);
LProc->ammount = 0;
char * linknames[expected_link_ammount];
Node_Resolve(linknames, path);
for(int i=0;i<expected_link_ammount; i++)
{
struct NodeLink * proclink;
proclink = ipfs_hashtable_node_get_link_by_name(N, linknames[i]);
if(proclink)
{
LProc->links[i] = (struct NodeLink *)malloc(sizeof(struct NodeLink));
memcpy(LProc->links[i], proclink, sizeof(struct NodeLink));
LProc->ammount++;
free(proclink);
}
}
//Freeing pointer array
for(int i=0;i<expected_link_ammount; i++)
{
free(linknames[i]);
}
return LProc;
}
/*Free_link_Proc
* frees the Link_Proc struct you created.
* @param1: Link_Proc struct (struct Link_Proc *)
*/
void Free_Link_Proc(struct Link_Proc * LPRC)
{
if(LPRC->ammount != 0)
{
for(int i=0;i<LPRC->ammount;i++)
{
ipfs_node_link_free(LPRC->links[i]);
}
}
free(LPRC);
}
/*Node_Tree() Basically a unix-like ls
*@Param1: Result char * foo[strlen(sentence)]
*@Param2: char sentence[] = foo/bar/bin/whatever
*Return: 0 if failure, 1 if success
*/
int Node_Tree(char * result, char * input1) //I don't know where you use this but here it is.
{
if(!input1)
{
return 0;
}
char input[strlen(input1)+1];
bzero(input, strlen(input1));
strcpy(input, input1);
for(int i=0; i<strlen(input); i++)
{
if(input[i] == '/')
{
input[i] = ' ';
}
}
strcpy(result, input);
return 1;
}