Add dynamic loading of backends.
[onak.git] / keydb_dynamic.c
diff --git a/keydb_dynamic.c b/keydb_dynamic.c
new file mode 100644 (file)
index 0000000..ca489ae
--- /dev/null
@@ -0,0 +1,531 @@
+/*
+ * keydb_dynamic.c - backend that can load the other backends
+ *
+ * Brett Parker <iDunno@sommitrealweird.co.uk>
+ *
+ * Copyright 2005 Project Purple
+ */
+
+#include <stdio.h>
+
+#include "decodekey.h"
+#include "hash.h"
+#include "keydb.h"
+#include "keyid.h"
+#include "keystructs.h"
+#include "mem.h"
+#include "merge.h"
+#include "parsekey.h"
+#include "sendsync.h"
+#include "keydb_dynamic.h"
+
+struct dynamic_backend *get_backend(void)
+{
+       return &__dynamicdb_backend__;
+}
+
+bool backend_loaded(void)
+{
+       return __dynamicdb_backend__.loaded;
+}
+
+bool load_backend(void)
+{
+       char *soname = NULL;
+       void *handle;
+       struct dynamic_backend *backend = get_backend();
+
+       if (backend->loaded) {
+               close_backend();
+       }
+
+       if (config.backends_dir == NULL) {
+               soname = malloc(strlen(config.db_backend)
+                       + strlen("/libkeydb_")
+                       + strlen(".so")
+                       + 1);
+
+               sprintf(soname, "libkeydb_%s.so", config.db_backend);
+       } else {
+               soname = malloc(strlen(config.db_backend)
+                       + strlen("/libkeydb_")
+                       + strlen(".so")
+                       + strlen(config.backends_dir)
+                       + 1);
+
+               sprintf(soname, "%s/libkeydb_%s.so", config.backends_dir,
+                       config.db_backend);
+       }
+               
+       logthing(LOGTHING_INFO, "Loading dynamic backend: %s", soname);
+
+       handle = dlopen(soname, RTLD_LAZY);
+       if (handle == NULL) {
+               logthing(LOGTHING_ERROR,
+                               "Failed to open handle to library '%s': %s",
+                               soname, dlerror());
+               free(soname);
+               soname = NULL;
+               return false;
+       }
+       free(soname);
+       soname = NULL;
+
+       backend->initdb = (initdbfunc_t) dlsym(handle, "initdb");
+       backend->cleanupdb = (cleanupdbfunc_t) dlsym(handle, "cleanupdb");
+       backend->starttrans = (starttransfunc_t) dlsym(handle, "starttrans");
+       backend->endtrans = (endtransfunc_t) dlsym(handle, "endtrans");
+       backend->fetch_key = (fetch_keyfunc_t) dlsym(handle, "fetch_key");
+       backend->store_key = (store_keyfunc_t) dlsym(handle, "store_key");
+       backend->delete_key = (delete_keyfunc_t) dlsym(handle, "delete_key");
+       backend->fetch_key_text = (fetch_key_textfunc_t)
+                                 dlsym (handle, "fetch_key_text");
+       backend->update_keys = (update_keysfunc_t)
+                              dlsym(handle, "update_keys");
+       backend->keyid2uid = (keyid2uidfunc_t) dlsym(handle, "keyid2uid");
+       backend->cached_getkeysigs = (cached_getkeysigsfunc_t)
+                                    dlsym(handle, "cached_getkeysigs");
+       backend->getfullkeyid = (getfullkeyidfunc_t)
+                               dlsym(handle, "getfullkeyid");
+       backend->iterate_keys = (iterate_keysfunc_t)
+                               dlsym(handle, "iterate_keys");
+
+       backend->handle = handle;
+       backend->loaded = true;
+
+       return true;
+}
+
+bool close_backend(void)
+{
+       struct dynamic_backend *backend;
+       backend = get_backend();
+       
+       backend->initdb = NULL;
+       backend->cleanupdb = NULL;
+       backend->starttrans = NULL;
+       backend->endtrans = NULL;
+       backend->fetch_key = NULL;
+       backend->store_key = NULL;
+       backend->delete_key = NULL;
+       backend->fetch_key_text = NULL;
+       backend->update_keys = NULL;
+       backend->keyid2uid = NULL;
+       backend->cached_getkeysigs = NULL;
+       backend->getfullkeyid = NULL;
+       backend->iterate_keys = NULL;
+       backend->loaded = false;
+       dlclose(backend->handle);
+       backend->handle = NULL;
+
+       return true;
+}
+
+/**
+ *     keyid2uid - Takes a keyid and returns the primary UID for it.
+ *     @keyid: The keyid to lookup.
+ */
+char *keyid2uid(uint64_t keyid)
+{
+       struct openpgp_publickey *publickey = NULL;
+       struct openpgp_signedpacket_list *curuid = NULL;
+       char buf[1024];
+
+       struct dynamic_backend *backend;
+       if (!backend_loaded()) {
+               load_backend();
+       }
+       
+       if (backend_loaded()) {
+               backend = get_backend();
+               if (backend->keyid2uid != NULL) {
+                       return backend->keyid2uid(keyid);
+               }
+       }
+       
+       buf[0]=0;
+       if (fetch_key(keyid, &publickey, false) && publickey != NULL) {
+               curuid = publickey->uids;
+               while (curuid != NULL && buf[0] == 0) {
+                       if (curuid->packet->tag == 13) {
+                               snprintf(buf, 1023, "%.*s",
+                                               (int) curuid->packet->length,
+                                               curuid->packet->data);
+                       }
+                       curuid = curuid -> next;
+               }
+               free_publickey(publickey);
+       }
+
+       if (buf[0] == 0) {
+               return NULL;
+       } else {
+               return strdup(buf);
+       }
+}
+
+/**
+ *     getkeysigs - Gets a linked list of the signatures on a key.
+ *     @keyid: The keyid to get the sigs for.
+ *     @revoked: Is the key revoked?
+ *
+ *     This function gets the list of signatures on a key. Used for key 
+ *     indexing and doing stats bits. If revoked is non-NULL then if the key
+ *     is revoked it's set to true.
+ */
+struct ll *getkeysigs(uint64_t keyid, bool *revoked)
+{
+       struct ll *sigs = NULL;
+       struct openpgp_signedpacket_list *uids = NULL;
+       struct openpgp_publickey *publickey = NULL;
+       
+       struct dynamic_backend *backend;
+       if ( !backend_loaded() ) {
+               load_backend();
+       }
+       
+       if (backend_loaded()) {
+               backend = get_backend();
+               if (backend->getkeysigs != NULL) {
+                       return backend->getkeysigs(keyid,revoked);
+               }
+       }
+
+       fetch_key(keyid, &publickey, false);
+       
+       if (publickey != NULL) {
+               for (uids = publickey->uids; uids != NULL; uids = uids->next) {
+                       sigs = keysigs(sigs, uids->sigs);
+               }
+               if (revoked != NULL) {
+                       *revoked = (publickey->revocations != NULL);
+               }
+               free_publickey(publickey);
+       }
+
+       return sigs;
+}
+
+/**
+ *     cached_getkeysigs - Gets the signatures on a key.
+ *     @keyid: The key we want the signatures for.
+ *     
+ *     This function gets the signatures on a key. It's the same as the
+ *     getkeysigs function above except we use the hash module to cache the
+ *     data so if we need it again it's already loaded.
+ */
+struct ll *cached_getkeysigs(uint64_t keyid)
+{
+       struct stats_key *key = NULL;
+       struct stats_key *signedkey = NULL;
+       struct ll        *cursig = NULL;
+       bool              revoked = false;
+       
+       struct dynamic_backend *backend;
+
+       if (keyid == 0)  {
+               return NULL;
+       }
+       
+       if (!backend_loaded()) {
+               load_backend();
+       }
+       
+       if (backend_loaded()) {
+               backend = get_backend();
+               if (backend->cached_getkeysigs != NULL) {
+                       return backend->cached_getkeysigs(keyid);
+               }
+       }
+
+       key = createandaddtohash(keyid);
+
+       if (key->gotsigs == false) {
+               key->sigs = getkeysigs(key->keyid, &revoked);
+               key->revoked = revoked;
+               for (cursig = key->sigs; cursig != NULL;
+                               cursig = cursig->next) {
+                       signedkey = (struct stats_key *) cursig->object;
+                       signedkey->signs = lladd(signedkey->signs, key);
+               }
+               key->gotsigs = true;
+       }
+
+       return key->sigs;
+}
+
+/**
+ *     getfullkeyid - Maps a 32bit key id to a 64bit one.
+ *     @keyid: The 32bit keyid.
+ *
+ *     This function maps a 32bit key id to the full 64bit one. It returns the
+ *     full keyid. If the key isn't found a keyid of 0 is returned.
+ */
+uint64_t getfullkeyid(uint64_t keyid)
+{
+       struct openpgp_publickey *publickey = NULL;
+       struct dynamic_backend *backend;
+       
+       if (!backend_loaded()) {
+               load_backend();
+       }
+       
+       if (backend_loaded()) {
+               backend = get_backend();
+               if (backend->getfullkeyid != NULL) {
+                       return backend->getfullkeyid(keyid);
+               }
+       }
+
+       if (keyid < 0x100000000LL) {
+               fetch_key(keyid, &publickey, false);
+               if (publickey != NULL) {
+                       keyid = get_keyid(publickey);
+                       free_publickey(publickey);
+                       publickey = NULL;
+               } else {
+                       keyid = 0;
+               }
+       }
+       
+       return keyid;
+}
+
+/**
+ *     update_keys - Takes a list of public keys and updates them in the DB.
+ *     @keys: The keys to update in the DB.
+ *     @sendsync: Should we send a sync mail to our peers.
+ *
+ *     Takes a list of keys and adds them to the database, merging them with
+ *     the key in the database if it's already present there. The key list is
+ *     update to contain the minimum set of updates required to get from what
+ *     we had before to what we have now (ie the set of data that was added to
+ *     the DB). Returns the number of entirely new keys added.
+ */
+int update_keys(struct openpgp_publickey **keys, bool sendsync)
+{
+       struct openpgp_publickey *curkey = NULL;
+       struct openpgp_publickey *oldkey = NULL;
+       struct openpgp_publickey *prev = NULL;
+       struct dynamic_backend *backend;
+       int newkeys = 0;
+       bool intrans;
+       
+       if (!backend_loaded()) {
+               load_backend();
+       }
+       
+       if (backend_loaded()) {
+               backend = get_backend();
+               if (backend->update_keys != NULL) {
+                       return backend->update_keys(keys, sendsync);
+               }
+       }
+
+       for (curkey = *keys; curkey != NULL; curkey = curkey->next) {
+               intrans = starttrans();
+               logthing(LOGTHING_INFO,
+                       "Fetching key 0x%llX, result: %d",
+                       get_keyid(curkey),
+                       fetch_key(get_keyid(curkey), &oldkey, intrans));
+
+               /*
+                * If we already have the key stored in the DB then merge it
+                * with the new one that's been supplied. Otherwise the key
+                * we've just got is the one that goes in the DB and also the
+                * one that we send out.
+                */
+               if (oldkey != NULL) {
+                       merge_keys(oldkey, curkey);
+                       if (curkey->revocations == NULL &&
+                                       curkey->uids == NULL &&
+                                       curkey->subkeys == NULL) {
+                               if (prev == NULL) {
+                                       *keys = curkey->next;
+                               } else {
+                                       prev->next = curkey->next;
+                                       curkey->next = NULL;
+                                       free_publickey(curkey);
+                                       curkey = prev;
+                               }
+                       } else {
+                               prev = curkey;
+                               logthing(LOGTHING_INFO,
+                                       "Merged key; storing updated key.");
+                               store_key(oldkey, intrans, true);
+                       }
+                       free_publickey(oldkey);
+                       oldkey = NULL;
+               
+               } else {
+                       logthing(LOGTHING_INFO,
+                               "Storing completely new key.");
+                       store_key(curkey, intrans, false);
+                       newkeys++;
+               }
+               endtrans();
+               intrans = false;
+       }
+
+       if (sendsync && keys != NULL) {
+               sendkeysync(*keys);
+       }
+
+       return newkeys;
+}
+
+void initdb(bool readonly)
+{
+       struct dynamic_backend *backend;
+       backend = get_backend();
+       
+       if (!backend_loaded()) {
+               load_backend();
+       }
+
+       if (backend->loaded) {
+               if (backend->initdb != NULL) {
+                       backend->initdb(readonly);
+               }
+       }
+}
+
+void cleanupdb(void)
+{
+       struct dynamic_backend *backend;
+       backend = get_backend();
+
+       if (backend->loaded) {
+               if (backend->cleanupdb != NULL) {
+                       backend->cleanupdb();
+               }
+       }
+
+       close_backend();
+}
+
+bool starttrans()
+{
+       struct dynamic_backend *backend;
+       backend = get_backend();
+
+       if (!backend_loaded()) {
+               load_backend();
+       }
+       
+       if (backend->loaded) {
+               if (backend->starttrans != NULL) {
+                       return backend->starttrans();
+               }
+       }
+
+       return false;
+}
+
+void endtrans()
+{
+       struct dynamic_backend *backend;
+       backend = get_backend();
+
+       if (!backend_loaded()) {
+               load_backend();
+       }
+       
+       if (backend->loaded) {
+               if (backend->endtrans != NULL) {
+                       backend->endtrans();
+               }
+       }
+}
+
+int fetch_key(uint64_t keyid, struct openpgp_publickey **publickey,
+               bool intrans)
+{
+       struct dynamic_backend *backend;
+       backend = get_backend();
+
+       if (!backend_loaded()) {
+               load_backend();
+       }
+       
+       if (backend->loaded) {
+               if (backend->fetch_key != NULL) {
+                       return backend->fetch_key(keyid,publickey,intrans);
+               }
+       }
+
+       return -1;
+}
+
+int store_key(struct openpgp_publickey *publickey, bool intrans, bool update)
+{
+       struct dynamic_backend *backend;
+       backend = get_backend();
+
+       if (!backend_loaded()) {
+               load_backend();
+       }
+       
+       if (backend->loaded) {
+               if (backend->store_key != NULL) {
+                       return backend->store_key(publickey,intrans,update);
+               }
+       }
+
+       return -1;
+}
+
+int delete_key(uint64_t keyid, bool intrans)
+{
+       struct dynamic_backend *backend;
+       backend = get_backend();
+
+       if (!backend_loaded()) {
+               load_backend();
+       }
+       
+       if (backend->loaded) {
+               if (backend->delete_key != NULL) {
+                       return backend->delete_key(keyid, intrans);
+               }
+       }
+
+       return -1;
+}
+
+int fetch_key_text(const char *search, struct openpgp_publickey **publickey)
+{
+       struct dynamic_backend *backend;
+       backend = get_backend();
+
+       if (!backend_loaded()) {
+               load_backend();
+       }
+       
+       if (backend->loaded) {
+               if (backend->fetch_key_text != NULL) {
+                       return backend->fetch_key_text(search, publickey);
+               }
+       }
+
+       return -1;
+}
+
+int iterate_keys(void (*iterfunc)(void *ctx, struct openpgp_publickey *key),
+               void *ctx)
+{
+       struct dynamic_backend *backend;
+       backend = get_backend();
+
+       if (!backend_loaded()) {
+               load_backend();
+       }
+       
+       if (backend->loaded) {
+               if (backend->iterate_keys != NULL) {
+                       return backend->iterate_keys(iterfunc, ctx);
+               }
+       }
+
+       return -1;
+}