/*
- * Copyright (C) 2015 "IoT.bzh"
+ * Copyright (C) 2015, 2016 "IoT.bzh"
* Author "Fulup Ar Foll"
*
- * This program is free software: you can redistribute it and/or modify
- * it under the terms of the GNU General Public License as published by
- * the Free Software Foundation, either version 3 of the License, or
- * (at your option) any later version.
+ * Licensed under the Apache License, Version 2.0 (the "License");
+ * you may not use this file except in compliance with the License.
+ * You may obtain a copy of the License at
*
- * This program is distributed in the hope that it will be useful,
- * but WITHOUT ANY WARRANTY; without even the implied warranty of
- * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the
- * GNU General Public License for more details.
+ * http://www.apache.org/licenses/LICENSE-2.0
*
- * You should have received a copy of the GNU General Public License
- * along with this program. If not, see <http://www.gnu.org/licenses/>.
+ * Unless required by applicable law or agreed to in writing, software
+ * distributed under the License is distributed on an "AS IS" BASIS,
+ * WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
+ * See the License for the specific language governing permissions and
+ * limitations under the License.
*/
-
-#include "local-def.h"
-#include <dirent.h>
-#include <string.h>
+#define _GNU_SOURCE
+#include <stdio.h>
#include <time.h>
-#include <sys/stat.h>
-#include <sys/types.h>
+#include <pthread.h>
+#include <stdlib.h>
+#include <string.h>
+#include <uuid/uuid.h>
+#include <assert.h>
+#include <errno.h>
+
+#include <json-c/json.h>
+
+#include "session.h"
+#include "verbose.h"
+
+#define NOW (time(NULL))
+
+struct client_value
+{
+ void *value;
+ void (*free_value)(void*);
+};
+
+struct afb_event_listener_list
+{
+ struct afb_event_listener_list *next;
+ struct afb_event_listener listener;
+ int refcount;
+};
+
+struct AFB_clientCtx
+{
+ unsigned refcount;
+ time_t expiration; // expiration time of the token
+ time_t access;
+ char uuid[37]; // long term authentication of remote client
+ char token[37]; // short term authentication of remote client
+ struct client_value *values;
+ struct afb_event_listener_list *listeners;
+};
+
+// Session UUID are store in a simple array [for 10 sessions this should be enough]
+static struct {
+ pthread_mutex_t mutex; // declare a mutex to protect hash table
+ struct AFB_clientCtx **store; // sessions store
+ int count; // current number of sessions
+ int max;
+ int timeout;
+ int apicount;
+ char initok[37];
+ struct afb_event_listener_list *listeners;
+} sessions;
+
+/* generate a uuid */
+static void new_uuid(char uuid[37])
+{
+ uuid_t newuuid;
+ uuid_generate(newuuid);
+ uuid_unparse_lower(newuuid, uuid);
+}
+
+// Free context [XXXX Should be protected again memory abort XXXX]
+static void ctxUuidFreeCB (struct AFB_clientCtx *client)
+{
+ int idx;
-#define AFB_SESSION_JTYPE "AFB_session"
-#define AFB_SESSION_JLIST "AFB_sessions"
-#define AFB_SESSION_JINFO "AFB_infos"
+ // If application add a handle let's free it now
+ assert (client->values != NULL);
-#define AFB_CURRENT_SESSION "active-session" // file link name within sndcard dir
-#define AFB_DEFAULT_SESSION "current-session" // should be in sync with UI
+ // Free client handle with a standard Free function, with app callback or ignore it
+ for (idx=0; idx < sessions.apicount; idx ++)
+ ctxClientValueSet(client, idx, NULL, NULL);
+}
+// Create a new store in RAM, not that is too small it will be automatically extended
+void ctxStoreInit (int max_session_count, int timeout, const char *initok, int context_count)
+{
+ // let's create as store as hashtable does not have any
+ sessions.store = calloc (1 + (unsigned)max_session_count, sizeof(struct AFB_clientCtx));
+ sessions.max = max_session_count;
+ sessions.timeout = timeout;
+ sessions.apicount = context_count;
+ if (initok == NULL)
+ /* without token, a secret is made to forbid creation of sessions */
+ new_uuid(sessions.initok);
+ else if (strlen(initok) < sizeof(sessions.store[0]->token))
+ strcpy(sessions.initok, initok);
+ else {
+ ERROR("initial token '%s' too long (max length 36)", initok);
+ exit(1);
+ }
+}
+static struct AFB_clientCtx *ctxStoreSearch (const char* uuid)
+{
+ int idx;
+ struct AFB_clientCtx *client;
+ assert (uuid != NULL);
-// verify we can read/write in session dir
-PUBLIC AFB_ERROR sessionCheckdir (AFB_session *session) {
+ pthread_mutex_lock(&sessions.mutex);
- int err;
+ for (idx=0; idx < sessions.max; idx++) {
+ client = sessions.store[idx];
+ if (client && (0 == strcmp (uuid, client->uuid)))
+ goto found;
+ }
+ client = NULL;
- // in case session dir would not exist create one
- if (verbose) fprintf (stderr, "AFB:notice checking session dir [%s]\n", session->config->sessiondir);
- mkdir(session->config->sessiondir, S_IRWXU | S_IRWXG | S_IROTH | S_IXOTH);
+found:
+ pthread_mutex_unlock(&sessions.mutex);
+ return client;
+}
- // change for session directory
- err = chdir(session->config->sessiondir);
- if (err) {
- fprintf(stderr,"AFB: Fail to chdir to %s error=%s\n", session->config->sessiondir, strerror(err));
- return err;
- }
+static int ctxStoreDel (struct AFB_clientCtx *client)
+{
+ int idx;
+ int status;
- // verify we can write session in directory
- json_object *dummy= json_object_new_object();
- json_object_object_add (dummy, "checked" , json_object_new_int (getppid()));
- err = json_object_to_file ("./AFB-probe.json", dummy);
- if (err < 0) return err;
+ assert (client != NULL);
- return AFB_SUCCESS;
-}
+ pthread_mutex_lock(&sessions.mutex);
-// let's return only sessions files
-STATIC int fileSelect (const struct dirent *entry) {
- return (strstr (entry->d_name, ".afb") != NULL);
+ for (idx=0; idx < sessions.max; idx++) {
+ if (sessions.store[idx] == client) {
+ sessions.store[idx] = NULL;
+ sessions.count--;
+ status = 1;
+ goto deleted;
+ }
+ }
+ status = 0;
+deleted:
+ pthread_mutex_unlock(&sessions.mutex);
+ return status;
}
-STATIC json_object *checkCardDirExit (AFB_session *session, AFB_request *request ) {
- int sessionDir, cardDir;
+static int ctxStoreAdd (struct AFB_clientCtx *client)
+{
+ int idx;
+ int status;
- // card name should be more than 3 character long !!!!
- if (strlen (request->plugin) < 3) {
- return (jsonNewMessage (AFB_FAIL,"Fail invalid plugin=%s", request->plugin));
- }
+ assert (client != NULL);
- // open session directory
- sessionDir = open (session->config->sessiondir, O_DIRECTORY);
- if (sessionDir < 0) {
- return (jsonNewMessage (AFB_FAIL,"Fail to open directory [%s] error=%s", session->config->sessiondir, strerror(sessionDir)));
- }
+ pthread_mutex_lock(&sessions.mutex);
- // create session sndcard directory if it does not exit
- cardDir = openat (sessionDir, request->plugin, O_DIRECTORY);
- if (cardDir < 0) {
- cardDir = mkdirat (sessionDir, request->plugin, O_RDWR | S_IRWXU | S_IRGRP);
- if (cardDir < 0) {
- return (jsonNewMessage (AFB_FAIL,"Fail to create directory [%s/%s] error=%s", session->config->sessiondir, request->plugin, strerror(cardDir)));
- }
+ for (idx=0; idx < sessions.max; idx++) {
+ if (NULL == sessions.store[idx]) {
+ sessions.store[idx] = client;
+ sessions.count++;
+ status = 1;
+ goto added;
+ }
}
- close (sessionDir);
- return NULL;
+ status = 0;
+added:
+ pthread_mutex_unlock(&sessions.mutex);
+ return status;
}
-// create a session in current directory
-PUBLIC json_object *sessionList (AFB_session *session, AFB_request *request) {
- json_object *sessionsJ, *ajgResponse;
- struct stat fstat;
- struct dirent **namelist;
- int count, sessionDir;
-
- // if directory for card's sessions does not exist create it
- ajgResponse = checkCardDirExit (session, request);
- if (ajgResponse != NULL) return ajgResponse;
-
- // open session directory
- sessionDir = open (session->config->sessiondir, O_DIRECTORY);
- if (sessionDir < 0) {
- return (jsonNewMessage (AFB_FAIL,"Fail to open directory [%s] error=%s", session->config->sessiondir, strerror(sessionDir)));
- }
+// Check if context timeout or not
+static int ctxStoreTooOld (struct AFB_clientCtx *ctx, time_t now)
+{
+ assert (ctx != NULL);
+ return ctx->expiration < now;
+}
- count = scandirat (sessionDir, request->plugin, &namelist, fileSelect, alphasort);
- close (sessionDir);
+// Check if context is active or not
+static int ctxIsActive (struct AFB_clientCtx *ctx, time_t now)
+{
+ assert (ctx != NULL);
+ return ctx->uuid[0] != 0 && ctx->expiration >= now;
+}
- if (count < 0) {
- return (jsonNewMessage (AFB_FAIL,"Fail to scan sessions directory [%s/%s] error=%s", session->config->sessiondir, request->plugin, strerror(sessionDir)));
- }
- if (count == 0) return (jsonNewMessage (AFB_EMPTY,"[%s] no session at [%s]", request->plugin, session->config->sessiondir));
-
- // loop on each session file, retrieve its date and push it into json response object
- sessionsJ = json_object_new_array();
- while (count--) {
- json_object *sessioninfo;
- char timestamp [64];
- char *filename;
-
- // extract file name and last modification date
- filename = namelist[count]->d_name;
- printf("%s\n", filename);
- stat(filename,&fstat);
- strftime (timestamp, sizeof(timestamp), "%c", localtime (&fstat.st_mtime));
- filename[strlen(filename)-4] = '\0'; // remove .afb extension from filename
-
- // create an object by session with last update date
- sessioninfo = json_object_new_object();
- json_object_object_add (sessioninfo, "date" , json_object_new_string (timestamp));
- json_object_object_add (sessioninfo, "session" , json_object_new_string (filename));
- json_object_array_add (sessionsJ, sessioninfo);
-
- free(namelist[count]);
- }
+// Loop on every entry and remove old context sessions.hash
+static void ctxStoreCleanUp (time_t now)
+{
+ struct AFB_clientCtx *ctx;
+ long idx;
+
+ // Loop on Sessions Table and remove anything that is older than timeout
+ for (idx=0; idx < sessions.max; idx++) {
+ ctx = sessions.store[idx];
+ if (ctx != NULL && ctxStoreTooOld(ctx, now)) {
+ ctxClientClose (ctx);
+ }
+ }
+}
- // free scandir structure
- free(namelist);
+// This function will return exiting client context or newly created client context
+struct AFB_clientCtx *ctxClientGetSession (const char *uuid, int *created)
+{
+ struct AFB_clientCtx *clientCtx;
+ time_t now;
+
+ /* cleaning */
+ now = NOW;
+ ctxStoreCleanUp (now);
+
+ /* search for an existing one not too old */
+ if (uuid != NULL) {
+ if (strlen(uuid) >= sizeof clientCtx->uuid) {
+ errno = EINVAL;
+ goto error;
+ }
+ clientCtx = ctxStoreSearch(uuid);
+ if (clientCtx != NULL) {
+ *created = 0;
+ goto found;
+ }
+ }
+
+ /* returns a new one */
+ clientCtx = calloc(1, sizeof(struct AFB_clientCtx) + ((unsigned)sessions.apicount * sizeof(*clientCtx->values)));
+ if (clientCtx == NULL) {
+ errno = ENOMEM;
+ goto error;
+ }
+ clientCtx->values = (void*)(clientCtx + 1);
+
+ /* generate the uuid */
+ if (uuid == NULL) {
+ new_uuid(clientCtx->uuid);
+ } else {
+ strcpy(clientCtx->uuid, uuid);
+ }
+
+ /* init the token */
+ strcpy(clientCtx->token, sessions.initok);
+ clientCtx->expiration = now + sessions.timeout;
+ if (!ctxStoreAdd (clientCtx)) {
+ errno = ENOMEM;
+ goto error2;
+ }
+ *created = 1;
+
+found:
+ clientCtx->access = now;
+ clientCtx->refcount++;
+ return clientCtx;
+
+error2:
+ free(clientCtx);
+error:
+ return NULL;
+}
- // everything is OK let's build final response
- ajgResponse = json_object_new_object();
- json_object_object_add (ajgResponse, "jtype" , json_object_new_string (AFB_SESSION_JLIST));
- json_object_object_add (ajgResponse, "status" , jsonNewStatus(AFB_SUCCESS));
- json_object_object_add (ajgResponse, "data" , sessionsJ);
+struct AFB_clientCtx *ctxClientAddRef(struct AFB_clientCtx *clientCtx)
+{
+ if (clientCtx != NULL)
+ clientCtx->refcount++;
+ return clientCtx;
+}
- return (ajgResponse);
+void ctxClientUnref(struct AFB_clientCtx *clientCtx)
+{
+ if (clientCtx != NULL) {
+ assert(clientCtx->refcount != 0);
+ --clientCtx->refcount;
+ if (clientCtx->refcount == 0 && clientCtx->uuid[0] == 0) {
+ ctxStoreDel (clientCtx);
+ free(clientCtx);
+ }
+ }
}
-// Create a link toward last used sessionname within sndcard directory
-STATIC void makeSessionLink (const char *cardname, const char *sessionname) {
- char linkname [256], filename [256];
- int err;
- // create a link to keep track of last uploaded sessionname for this card
- strncpy (filename, sessionname, sizeof(filename));
- strncat (filename, ".afb", sizeof(filename));
-
- strncpy (linkname, cardname, sizeof(linkname));
- strncat (linkname, "/", sizeof(filename));
- strncat (linkname, AFB_CURRENT_SESSION, sizeof(linkname));
- strncat (linkname, ".afb", sizeof(filename));
- unlink (linkname); // remove previous link if any
- err = symlink (filename, linkname);
- if (err < 0) fprintf (stderr, "Fail to create link %s->%s error=%s\n", linkname, filename, strerror(errno));
+// Free Client Session Context
+void ctxClientClose (struct AFB_clientCtx *clientCtx)
+{
+ assert(clientCtx != NULL);
+ if (clientCtx->uuid[0] != 0) {
+ clientCtx->uuid[0] = 0;
+ ctxUuidFreeCB (clientCtx);
+ while(clientCtx->listeners != NULL)
+ ctxClientEventListenerRemove(clientCtx, clientCtx->listeners->listener);
+ if (clientCtx->refcount == 0) {
+ ctxStoreDel (clientCtx);
+ free(clientCtx);
+ }
+ }
}
-// Load Json session object from disk
-PUBLIC json_object *sessionFromDisk (AFB_session *session, AFB_request *request, char *name) {
- json_object *jsonSession, *jtype, *response;
- const char *ajglabel;
- char filename [256];
- int defsession;
+// Sample Generic Ping Debug API
+int ctxTokenCheck (struct AFB_clientCtx *clientCtx, const char *token)
+{
+ assert(clientCtx != NULL);
+ assert(token != NULL);
- if (name == NULL) {
- return (jsonNewMessage (AFB_FATAL,"session name missing &session=MySessionName"));
- }
+ // compare current token with previous one
+ if (!ctxIsActive (clientCtx, NOW))
+ return 0;
- // check for current session request
- defsession = (strcmp (name, AFB_DEFAULT_SESSION) ==0);
+ if (clientCtx->token[0] && strcmp (token, clientCtx->token) != 0)
+ return 0;
- // if directory for card's sessions does not exist create it
- response = checkCardDirExit (session, request);
- if (response != NULL) return response;
+ return 1;
+}
- // add name and file extension to session name
- strncpy (filename, request->plugin, sizeof(filename));
- strncat (filename, "/", sizeof(filename));
- if (defsession) strncat (filename, AFB_CURRENT_SESSION, sizeof(filename)-1);
- else strncat (filename, name, sizeof(filename)-1);
- strncat (filename, ".afb", sizeof(filename));
+// generate a new token and update client context
+void ctxTokenNew (struct AFB_clientCtx *clientCtx)
+{
+ assert(clientCtx != NULL);
- // just upload json object and return without any further processing
- jsonSession = json_object_from_file (filename);
+ // Old token was valid let's regenerate a new one
+ new_uuid(clientCtx->token);
- if (jsonSession == NULL) return (jsonNewMessage (AFB_EMPTY,"File [%s] not found", filename));
+ // keep track of time for session timeout and further clean up
+ clientCtx->expiration = NOW + sessions.timeout;
+}
- // verify that file is a JSON ALSA session type
- if (!json_object_object_get_ex (jsonSession, "jtype", &jtype)) {
- json_object_put (jsonSession);
- return (jsonNewMessage (AFB_EMPTY,"File [%s] 'jtype' descriptor not found", filename));
- }
+static int add_listener(struct afb_event_listener_list **head, struct afb_event_listener listener)
+{
+ struct afb_event_listener_list *iter, **prv;
+
+ prv = head;
+ for (;;) {
+ iter = *prv;
+ if (iter == NULL) {
+ iter = calloc(1, sizeof *iter);
+ if (iter == NULL) {
+ errno = ENOMEM;
+ return -1;
+ }
+ iter->listener = listener;
+ iter->refcount = 1;
+ *prv = iter;
+ return 0;
+ }
+ if (iter->listener.itf == listener.itf && iter->listener.closure == listener.closure) {
+ iter->refcount++;
+ return 0;
+ }
+ prv = &iter->next;
+ }
+}
- // check type value is AFB_SESSION_JTYPE
- ajglabel = json_object_get_string (jtype);
- if (strcmp (AFB_SESSION_JTYPE, ajglabel)) {
- json_object_put (jsonSession);
- return (jsonNewMessage (AFB_FATAL,"File [%s] jtype=[%s] != [%s]", filename, ajglabel, AFB_SESSION_JTYPE));
- }
+int ctxClientEventListenerAdd(struct AFB_clientCtx *clientCtx, struct afb_event_listener listener)
+{
+ return add_listener(clientCtx != NULL ? &clientCtx->listeners : &sessions.listeners, listener);
+}
+
+static void remove_listener(struct afb_event_listener_list **head, struct afb_event_listener listener)
+{
+ struct afb_event_listener_list *iter, **prv;
+
+ prv = head;
+ for (;;) {
+ iter = *prv;
+ if (iter == NULL)
+ return;
+ if (iter->listener.itf == listener.itf && iter->listener.closure == listener.closure) {
+ if (!--iter->refcount) {
+ *prv = iter->next;
+ free(iter);
+ }
+ return;
+ }
+ prv = &iter->next;
+ }
+}
- // create a link to keep track of last uploaded session for this card
- if (!defsession) makeSessionLink (request->plugin, name);
+void ctxClientEventListenerRemove(struct AFB_clientCtx *clientCtx, struct afb_event_listener listener)
+{
+ remove_listener(clientCtx != NULL ? &clientCtx->listeners : &sessions.listeners, listener);
+}
+
+static int send(struct afb_event_listener_list *head, const char *event, struct json_object *object)
+{
+ struct afb_event_listener_list *iter;
+ int result;
+
+ result = 0;
+ iter = head;
+ while (iter != NULL) {
+ if (iter->listener.itf->expects == NULL || iter->listener.itf->expects(iter->listener.closure, event)) {
+ iter->listener.itf->send(iter->listener.closure, event, json_object_get(object));
+ result++;
+ }
+ iter = iter->next;
+ }
+
+ return result;
+}
+
+int ctxClientEventSend(struct AFB_clientCtx *clientCtx, const char *event, struct json_object *object)
+{
+ long idx;
+ time_t now;
+ int result;
+
+ now = NOW;
+ if (clientCtx != NULL) {
+ result = ctxIsActive(clientCtx, now) ? send(clientCtx->listeners, event, object) : 0;
+ } else {
+ result = send(sessions.listeners, event, object);
+ for (idx=0; idx < sessions.max; idx++) {
+ clientCtx = ctxClientAddRef(sessions.store[idx]);
+ if (clientCtx != NULL && ctxIsActive(clientCtx, now)) {
+ clientCtx = ctxClientAddRef(clientCtx);
+ result += send(clientCtx->listeners, event, object);
+ }
+ ctxClientUnref(clientCtx);
+ }
+ }
+ return result;
+}
+
+const char *ctxClientGetUuid (struct AFB_clientCtx *clientCtx)
+{
+ assert(clientCtx != NULL);
+ return clientCtx->uuid;
+}
+
+const char *ctxClientGetToken (struct AFB_clientCtx *clientCtx)
+{
+ assert(clientCtx != NULL);
+ return clientCtx->token;
+}
- return (jsonSession);
+void *ctxClientValueGet(struct AFB_clientCtx *clientCtx, int index)
+{
+ assert(clientCtx != NULL);
+ assert(index >= 0);
+ assert(index < sessions.apicount);
+ return clientCtx->values[index].value;
}
-// push Json session object to disk
-PUBLIC json_object * sessionToDisk (AFB_session *session, AFB_request *request, char *name, json_object *jsonSession) {
- char filename [256];
- time_t rawtime;
- struct tm * timeinfo;
- int err, defsession;
- static json_object *response;
-
- // we should have a session name
- if (name == NULL) return (jsonNewMessage (AFB_FATAL,"session name missing &session=MySessionName"));
-
- // check for current session request
- defsession = (strcmp (name, AFB_DEFAULT_SESSION) ==0);
-
- // if directory for card's sessions does not exist create it
- response = checkCardDirExit (session, request);
- if (response != NULL) return response;
-
- // add cardname and file extension to session name
- strncpy (filename, request->plugin, sizeof(filename));
- strncat (filename, "/", sizeof(filename));
- if (defsession) strncat (filename, AFB_CURRENT_SESSION, sizeof(filename)-1);
- else strncat (filename, name, sizeof(filename)-1);
- strncat (filename, ".afb", sizeof(filename)-1);
-
-
- json_object_object_add(jsonSession, "jtype", json_object_new_string (AFB_SESSION_JTYPE));
-
- // add a timestamp and store session on disk
- time ( &rawtime ); timeinfo = localtime ( &rawtime );
- // A copy of the string is made and the memory is managed by the json_object
- json_object_object_add (jsonSession, "timestamp", json_object_new_string (asctime (timeinfo)));
-
-
- // do we have extra session info ?
- if (request->post) {
- static json_object *info, *jtype;
- const char *ajglabel;
-
- // extract session info from args
- info = json_tokener_parse (request->post);
- if (!info) {
- response = jsonNewMessage (AFB_FATAL,"sndcard=%s session=%s invalid json args=%s", request->plugin, name, request->post);
- goto OnErrorExit;
- }
-
- // info is a valid AFB_info type
- if (!json_object_object_get_ex (info, "jtype", &jtype)) {
- response = jsonNewMessage (AFB_EMPTY,"sndcard=%s session=%s No 'AFB_type' args=%s", request->plugin, name, request->post);
- goto OnErrorExit;
- }
-
- // check type value is AFB_INFO_JTYPE
- ajglabel = json_object_get_string (jtype);
- if (strcmp (AFB_SESSION_JINFO, ajglabel)) {
- json_object_put (info); // release info json object
- response = jsonNewMessage (AFB_FATAL,"File [%s] jtype=[%s] != [%s] data=%s", filename, ajglabel, AFB_SESSION_JTYPE, request->post);
- goto OnErrorExit;
- }
-
- // this is valid info data for our session
- json_object_object_add (jsonSession, "info", info);
- }
-
- // Finally save session on disk
- err = json_object_to_file (filename, jsonSession);
- if (err < 0) {
- response = jsonNewMessage (AFB_FATAL,"Fail save session = [%s] to disk", filename);
- goto OnErrorExit;
- }
-
-
- // create a link to keep track of last uploaded session for this card
- if (!defsession) makeSessionLink (request->plugin, name);
-
- // we're donne let's return status message
- response = jsonNewMessage (AFB_SUCCESS,"Session= [%s] saved on disk", filename);
- json_object_put (jsonSession);
- return (response);
-
-OnErrorExit:
- json_object_put (jsonSession);
- return response;
+void ctxClientValueSet(struct AFB_clientCtx *clientCtx, int index, void *value, void (*free_value)(void*))
+{
+ struct client_value prev;
+ assert(clientCtx != NULL);
+ assert(index >= 0);
+ assert(index < sessions.apicount);
+ prev = clientCtx->values[index];
+ clientCtx->values[index] = (struct client_value){.value = value, .free_value = free_value};
+ if (prev.value != NULL && prev.free_value != NULL)
+ prev.free_value(prev.value);
}