c-ipfs/namesys/routing.c

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#include <stdio.h>
#include <stdlib.h>
#include <string.h>
#include <time.h>
#include "ipfs/namesys/routing.h"
#include "ipfs/util/time.h"
#include "mh/multihash.h"
#include "ipfs/namesys/pb.h"
#include "ipfs/namesys/namesys.h"
#include "ipfs/cid/cid.h"
char* ipfs_routing_cache_get (char *key, struct ipns_entry *ientry)
{
int i;
struct routingResolver *cache;
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struct timespec now;
if (key && ientry) {
cache = ientry->cache;
if (cache) {
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timespec_get (&now);
for (i = 0 ; i < cache->next ; i++) {
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if (((now.tv_sec < cache->data[i]->eol.tv_sec ||
(now.tv_sec == cache->data[i]->eol.tv_sec && now.tv_nsec < cache->data[i]->eol.tv_nsec))) &&
strcmp(cache->data[i]->key, key) == 0) {
return cache->data[i]->value;
}
}
}
}
return NULL;
}
void ipfs_routing_cache_set (char *key, char *value, struct ipns_entry *ientry)
{
struct cacheEntry *n;
struct routingResolver *cache;
if (key && value && ientry) {
cache = ientry->cache;
if (cache && cache->next < cache->cachesize) {
n = malloc(sizeof (struct cacheEntry));
if (n) {
n->key = key;
n->value = value;
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timespec_get (&n->eol); // now
n->eol.tv_sec += DefaultResolverCacheTTL; // sum TTL seconds to time seconds.
cache->data[cache->next++] = n;
}
}
}
}
// NewRoutingResolver constructs a name resolver using the IPFS Routing system
// to implement SFS-like naming on top.
// cachesize is the limit of the number of entries in the lru cache. Setting it
// to '0' will disable caching.
struct routingResolver* ipfs_namesys_new_routing_resolver (struct libp2p_routing_value_store *route, int cachesize)
{
struct routingResolver *ret;
if (!route) {
fprintf(stderr, "attempt to create resolver with NULL routing system\n");
exit (1);
}
ret = calloc (1, sizeof (struct routingResolver));
if (!ret) {
return NULL;
}
ret->data = calloc(cachesize, sizeof(void*));
if (!ret) {
free (ret);
return NULL;
}
ret->cachesize = cachesize;
return ret;
}
// ipfs_namesys_routing_resolve implements Resolver.
int ipfs_namesys_routing_resolve (char **path, char *name, struct namesys_pb *pb)
{
return ipfs_namesys_routing_resolve_n(path, name, DefaultDepthLimit, pb);
}
// ipfs_namesys_routing_resolve_n implements Resolver.
int ipfs_namesys_routing_resolve_n (char **path, char *name, int depth, struct namesys_pb *pb)
{
return ipfs_namesys_routing_resolve_once (path, name, depth, "/ipns/", pb);
}
// ipfs_namesys_routing_resolve_once implements resolver. Uses the IPFS
// routing system to resolve SFS-like names.
int ipfs_namesys_routing_resolve_once (char **path, char *name, int depth, char *prefix, struct namesys_pb *pb)
{
int err, l, s, ok;
struct MultiHash hash;
char *h, *string, *val;
struct libp2p_crypto_pubkey pubkey;
if (!path || !name | !prefix) {
return ErrInvalidParam;
}
// log.Debugf("RoutingResolve: '%s'", name)
*path = ipfs_routing_cache_get (name, pb->IpnsEntry);
if (*path) {
return 0; // cached
}
if (memcmp(name, prefix, strlen(prefix)) == 0) {
name += strlen (prefix); // trim prefix.
}
err = libp2p_b58_to_multihash (name, strlen(name), &hash);
if (err) {
// name should be a multihash. if it isn't, error out here.
//log.Warningf("RoutingResolve: bad input hash: [%s]\n", name)
return err;
}
// use the routing system to get the name.
// /ipns/<name>
l = strlen(prefix);
s = (hash.size * 2) + 1;
h = malloc(l + s); // alloc to fit prefix + hexhash + null terminator
if (!h) {
return ErrAllocFailed;
}
memcpy(h, prefix, l); // copy prefix
if (!libp2p_multihash_hex_string(&hash, h+l, s)) { // hexstring just after prefix.
return ErrUnknow;
}
err = ipfs_namesys_routing_get_value (val, h);
if (err) {
//log.Warning("RoutingResolve get failed.")
return err;
}
//err = protobuf decode (val, pb.IpnsEntry);
if (err) {
return err;
}
// name should be a public key retrievable from ipfs
err = ipfs_namesys_routing_getpublic_key (pubkey, &hash);
if (err) {
return err;
}
// check sig with pk
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err = libp2p_crypto_verify (ipns_entry_data_for_sig(pb->IpnsEntry), pb->IpnsEntry->signature, &ok);
if (err || !ok) {
char buf[500];
snprintf(buf, sizeof(buf), Err[ErrInvalidSignatureFmt], pubkey);
l = strlen(buf) + 1;
Err[ErrInvalidSignature] = malloc(l);
if (!Err[ErrInvalidSignature]) {
return ErrAllocFailed;
}
memcpy(Err[ErrInvalidSignature], buf, l);
return ErrInvalidSignature;
}
// ok sig checks out. this is a valid name.
// check for old style record:
err = ipfs_namesys_pb_get_value (&string, pb->IpnsEntry);
if (err) {
return err;
}
err = libp2p_multihash_from_hex_string(string, strlen(string), &hash);
if (err) {
// Not a multihash, probably a new record
err = ipfs_path_parse(path, string);
if (err) {
return err;
}
} else {
// Its an old style multihash record
//log.Warning("Detected old style multihash record")
struct Cid *cid;
err = ipfs_cid_new(0, hash.data, hash.size, CID_PROTOBUF, &cid);
if (err) {
return err;
}
err = ipfs_path_parse_from_cid (path, cid);
if (err) {
return err;
}
}
ipfs_routing_cache_set (name, *path, pb->IpnsEntry);
return 0;
}
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int ipfs_namesys_routing_check_EOL (struct timespec *ts, struct namesys_pb *pb)
{
int err;
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if (*(pb->IpnsEntry->validityType) == IpnsEntry_EOL) {
err = ipfs_util_time_parse_RFC3339 (ts, pb->IpnsEntry->validity);
if (!err) {
return 1;
}
}
return 0;
}