forked from agorise/c-ipfs
102 lines
2.9 KiB
C
102 lines
2.9 KiB
C
#include <stdlib.h>
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#include <string.h>
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#include "libp2p/utils/logger.h"
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#include "ipfs/namesys/resolver.h"
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/**
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* The opposite of publisher.c
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*
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* These are the resources for resolving an IPNS name, turning it into an ipfs path
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*/
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/**
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* Determine if the incoming path is in ipns format
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* @param path the path to check
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* @returns true(1) if the path begins with "/ipns/"
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*/
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int is_ipns_string(char* path) {
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if (path == NULL)
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return 0;
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if (strstr(path, "/ipns/") == path)
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return 1;
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return 0;
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}
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/***
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* Resolve an IPNS name, only to its next step
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* @param local_node the context
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* @param path the ipns_path (i.e. "ipns/Qm12345...")
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* @param results where to store the results (i.e. "ipns/Qm5678...")
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* @returns true(1) on success, false(0) otherwise
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*/
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int ipfs_namesys_resolver_resolve_once(struct IpfsNode* local_node, const char* path, char** results) {
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struct Cid* cid = NULL;
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if (!ipfs_cid_decode_hash_from_ipfs_ipns_string(path, &cid)) {
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return 0;
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}
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// look locally
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struct DatastoreRecord* record;
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if (local_node->repo->config->datastore->datastore_get(cid->hash, cid->hash_length, &record, local_node->repo->config->datastore)) {
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// we are able to handle this locally... return the results
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*results = (char*) malloc(record->value_size + 1);
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if (*results == NULL) {
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ipfs_cid_free(cid);
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return 0;
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}
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memset(*results, 0, record->value_size + 1);
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memcpy(*results, record->value, record->value_size);
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ipfs_cid_free(cid);
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return 1;
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}
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//TODO: ask the network
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ipfs_cid_free(cid);
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return 0;
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}
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/**
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* Resolve an IPNS name.
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* NOTE: if recursive is set to false, the result could be another ipns path
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* @param local_node the context
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* @param path the ipns path (i.e. "/ipns/Qm12345..")
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* @param recursive true to resolve until the result is not ipns, false to simply get the next step in the path
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* @param result the results (i.e. "/ipfs/QmAb12CD...")
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* @returns true(1) on success, false(0) otherwise
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*/
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int ipfs_namesys_resolver_resolve(struct IpfsNode* local_node, const char* path, int recursive, char** results) {
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char* result = NULL;
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char* current_path = (char*) malloc(strlen(path) + 1);
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if (current_path == NULL) {
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return 0;
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}
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strcpy(current_path, path);
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// if we go more than 10 deep, bail
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int counter = 0;
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do {
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if (counter > 10) {
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libp2p_logger_error("resolver", "Resolver looped %d times. Infinite loop? Last result: %s.\n", counter, current_path);
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free(current_path);
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return 0;
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}
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// resolve the current path
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if (!ipfs_namesys_resolver_resolve_once(local_node, current_path, &result)) {
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libp2p_logger_error("resolver", "Resolver returned false searching for %s.\n", current_path);
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free(current_path);
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return 0;
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}
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// result will not be NULL
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free(current_path);
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current_path = (char*) malloc(strlen(result)+1);
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if (current_path != NULL)
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strcpy(current_path, result);
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free(result);
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counter++;
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} while(recursive && is_ipns_string(current_path));
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*results = current_path;
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return 1;
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}
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