Initial implementation of namesys.

This commit is contained in:
Jose Marcial Vieira Bisneto 2016-11-23 17:19:16 -03:00
parent 81a0cc791e
commit 7ddba70ada
3 changed files with 229 additions and 0 deletions

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#ifndef NAMESYS_H
#define NAMESYS_H
#define DefaultDepthLimit 32
char *ErrNamesys[] = {
NULL,
"ErrAllocFailed",
"ErrNULLPointer",
"Could not publish name."
"Could not resolve name.",
"Could not resolve name (recursion limit exceeded).",
"expired record",
"unrecognized validity type"
};
enum {
ErrAllocFailed = 1,
ErrNULLPointer,
ErrPublishFailed,
ErrResolveFailed,
ErrResolveRecursion,
ErrExpiredRecord,
ErrUnrecognizedValidity
} NamesysErrs;
typedef struct s_resolvers {
char *protocol;
int (*func)(char**, char*);
} resolvers;
//TODO ciPrivKey from c-libp2p-crypto
typedef void* ciPrivKey;
typedef struct s_publishers {
char *protocol;
int (*func) (ciPrivKey, char*);
int (*func_eol) (ciPrivKey, char*, time_t);
} publishers;
typedef struct s_mpns {
resolvers *resolver;
publishers *Publisher;
} mpns;
#endif //NAMESYS_H

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namesys/base.c Normal file
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#include <string.h>
#include <time.h>
#include "ipfs/cid/cid.h"
#include "ipfs/path/path.h"
#include "ipfs/namesys/namesys.h"
typedef struct s_resolver {
// resolveOnce looks up a name once (without recursion).
int (*resolveOnce) (char **, char *);
} resolver;
int resolve (resolver *r, char **p, char *str, int depth, char **prefixes)
{
int err, i;
char ipfs_prefix[] = "/ipfs/";
for (;;) {
err = r->resolveOnce(p, str);
if (err) {
//log.Warningf("Could not resolve %s", name);
*p = NULL;
return err;
}
//log.Debugf("Resolved %s to %s", name, p.String());
if (memcmp(p, ipfs_prefix, strlen(ipfs_prefix)) == 0) {
// we've bottomed out with an IPFS path
return 0;
}
if (depth == 1) {
return ErrResolveRecursion;
}
for (i = 0 ; prefixes[i] ; i++) {
if (memcmp(*p, prefixes[i], strlen(prefixes[i])) == 0) {
if (SegmentsLength(prefixes) == 1) {
str += strlen(prefixes[i]);
}
break;
}
}
if ( !prefixes[i] ) {
return 0;
}
if (depth > 1) {
depth--;
}
}
}

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namesys/namesys.c Normal file
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#include <string.h>
#include <stdlib.h>
#include <time.h>
#include "ipfs/cid/cid.h"
#include "ipfs/path/path.h"
#include "ipfs/namesys/namesys.h"
/* mpns (a multi-protocol NameSystem) implements generic IPFS naming.
*
* Uses several Resolvers:
* (a) IPFS routing naming: SFS-like PKI names.
* (b) dns domains: resolves using links in DNS TXT records
* (c) proquints: interprets string as the raw byte data.
*
* It can only publish to: (a) IPFS routing naming.
*/
mpns **ns;
// NewNameSystem will construct the IPFS naming system based on Routing
/*
func NewNameSystem(r routing.ValueStore, ds ds.Datastore, cachesize int) NameSystem {
return &mpns{
resolvers: map[string]resolver{
"dns": newDNSResolver(),
"proquint": new(ProquintResolver),
"dht": NewRoutingResolver(r, cachesize),
},
publishers: map[string]Publisher{
"/ipns/": NewRoutingPublisher(r, ds),
},
}
}*/
const DefaultResolverCacheTTL = time.Minute;
// Resolve implements Resolver.
int Resolve(char *name)
{
return ResolveN(name, DefaultDepthLimit);
}
// ResolveN implements Resolver.
int ResolveN(char *name, int depth)
{
char ipfs_prefix[] = "/ipfs/";
if (memcmp(name, ipfs_prefix, strlen(ipfs_prefix)) == 0) {
return ParsePath(name);
}
if (*name == '/') {
int err;
char *str = malloc(sizeof(ipfs_prefix) + strlen(name));
if (!str) {
return ErrAllocFailed;
}
strcpy(str, ipfs_prefix);
strcat(str, name+1); // ignore inital / from name, because ipfs_prefix already has it.
err = ParsePath(str); // save return value.
free (str); // so we can free allocated memory before return.
return err;
}
return resolve(ns, name, depth, "/ipns/");
}
// resolveOnce implements resolver.
int resolveOnce (char **path, char *name)
{
char ipns_prefix[] = "/ipns/";
char *ptr = NULL;
char **segs;
int i, err = 0;
if (!name) { // NULL pointer.
return ErrNULLPointer;
}
if (memcmp (name, ipns_prefix, strlen(ipns_prefix)) == 0) { // prefix missing.
ptr = malloc(strlen(name) + sizeof(ipns_prefix));
if (!ptr) { // allocation fail.
return ErrAllocFailed;
}
strcpy(ptr, ipns_prefix);
strcat(ptr, name);
segs = Segments(ptr);
free (ptr);
} else {
segs = Segments(name);
}
if (!segs || SegmentsLength(segs) < 2) {
//log.Warningf("Invalid name syntax for %s", name);
return ErrResolveFailed;
}
for (i = 0 ; ns[i] ; i++) {
char *p;
//log.Debugf("Attempting to resolve %s with %s", segments[1], ns[i]->resolver->protocol);
err = ns[i]->resolver->func(&p, segs[1]);
if (!err) {
if (SegmentsLength(segs) > 2) {
*path = PathFromSegments(p, segs+2);
} else {
*path = p;
}
return 0;
}
}
//log.Warningf("No resolver found for %s", name);
return ErrResolveFailed;
}
// Publish implements Publisher
int Publish (char *proto, ciPrivKey name, char *value)
{
int i;
for (i = 0 ; ns[i] ; i++) {
if (strcmp(ns[i]->Publisher->protocol, proto)==0) {
return ns[i]->Publisher->func(name, value);
}
}
return ErrPublishFailed;
}
int PublishWithEOL (char *proto, ciPrivKey name, char *value, time_t eol)
{
int i;
for (i = 0 ; ns[i] ; i++) {
if (strcmp(ns[i]->Publisher->protocol, proto)==0) {
return ns[i]->Publisher->func_eol(name, value, eol);
}
}
return ErrPublishFailed;
}