Improves naming of session's module

Make names looking like other names

Change-Id: I63ce3d8a3d84193eca9d517cecb1888d630a9b2d
Signed-off-by: José Bollo <jose.bollo@iot.bzh>

1 files changed, 461 insertions, 0 deletions

diff --git a/src/afb-session.c b/src/afb-session.c
new file mode 100644
index 00000000..db81457c
--- /dev/null
+++ b/src/afb-session.c
@@ -0,0 +1,461 @@
+/*
+ * Copyright (C) 2015, 2016, 2017 "IoT.bzh"
+ * Author "Fulup Ar Foll"
+ * Author: José Bollo <jose.bollo@iot.bzh>
+ *
+ * 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
+ *
+ *   http://www.apache.org/licenses/LICENSE-2.0
+ *
+ * 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.
+ */
+
+#define _GNU_SOURCE
+#include <stdio.h>
+#include <time.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 "afb-session.h"
+#include "verbose.h"
+
+#define NOW (time(NULL))
+
+struct value
+{
+	void *value;
+	void (*freecb)(void*);
+};
+
+struct cookie
+{
+	struct cookie *next;
+	const void *key;
+	void *value;
+	void (*freecb)(void*);
+};
+
+struct afb_session
+{
+	unsigned refcount;
+	unsigned loa;
+	int timeout;
+	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 value *values;
+	struct cookie *cookies;
+};
+
+// 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_session **store;          // sessions store
+	int count;                      // current number of sessions
+	int max;
+	int timeout;
+	int apicount;
+	char initok[37];
+} 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 free_data (struct afb_session *session)
+{
+	int idx;
+	struct cookie *cookie;
+
+	// If application add a handle let's free it now
+	assert (session->values != NULL);
+
+	// Free session handle with a standard Free function, with app callback or ignore it
+	for (idx=0; idx < sessions.apicount; idx ++)
+		afb_session_set_value(session, idx, NULL, NULL);
+
+	// free cookies
+	cookie = session->cookies;
+	while (cookie != NULL) {
+		session->cookies = cookie->next;
+		if (cookie->value != NULL && cookie->freecb != NULL)
+			cookie->freecb(cookie->value);
+		free(cookie);
+		cookie = session->cookies;
+	}
+}
+
+// Create a new store in RAM, not that is too small it will be automatically extended
+void afb_session_init (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_session));
+	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_session *search (const char* uuid)
+{
+	int  idx;
+	struct afb_session *session;
+
+	assert (uuid != NULL);
+
+	pthread_mutex_lock(&sessions.mutex);
+
+	for (idx=0; idx < sessions.max; idx++) {
+		session = sessions.store[idx];
+		if (session && (0 == strcmp (uuid, session->uuid)))
+			goto found;
+	}
+	session = NULL;
+
+found:
+	pthread_mutex_unlock(&sessions.mutex);
+	return session;
+}
+
+static int destroy (struct afb_session *session)
+{
+	int idx;
+	int status;
+
+	assert (session != NULL);
+
+	pthread_mutex_lock(&sessions.mutex);
+
+	for (idx=0; idx < sessions.max; idx++) {
+		if (sessions.store[idx] == session) {
+			sessions.store[idx] = NULL;
+			sessions.count--;
+			status = 1;
+			goto deleted;
+		}
+	}
+	status = 0;
+deleted:
+	pthread_mutex_unlock(&sessions.mutex);
+	return status;
+}
+
+static int add (struct afb_session *session)
+{
+	int idx;
+	int status;
+
+	assert (session != NULL);
+
+	pthread_mutex_lock(&sessions.mutex);
+
+	for (idx=0; idx < sessions.max; idx++) {
+		if (NULL == sessions.store[idx]) {
+			sessions.store[idx] = session;
+			sessions.count++;
+			status = 1;
+			goto added;
+		}
+	}
+	status = 0;
+added:
+	pthread_mutex_unlock(&sessions.mutex);
+	return status;
+}
+
+// Check if context timeout or not
+static int is_expired (struct afb_session *ctx, time_t now)
+{
+	assert (ctx != NULL);
+	return ctx->expiration < now;
+}
+
+// Check if context is active or not
+static int is_active (struct afb_session *ctx, time_t now)
+{
+	assert (ctx != NULL);
+	return ctx->uuid[0] != 0 && ctx->expiration >= now;
+}
+
+// Loop on every entry and remove old context sessions.hash
+static void cleanup (time_t now)
+{
+	struct afb_session *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 && is_expired(ctx, now)) {
+			afb_session_close (ctx);
+		}
+	}
+}
+
+static struct afb_session *make_session (const char *uuid, int timeout, time_t now)
+{
+	struct afb_session *session;
+
+	/* allocates a new one */
+	session = calloc(1, sizeof(struct afb_session) + ((unsigned)sessions.apicount * sizeof(*session->values)));
+	if (session == NULL) {
+		errno = ENOMEM;
+		goto error;
+	}
+	session->values = (void*)(session + 1);
+
+	/* generate the uuid */
+	if (uuid == NULL) {
+		new_uuid(session->uuid);
+	} else {
+		if (strlen(uuid) >= sizeof session->uuid) {
+			errno = EINVAL;
+			goto error2;
+		}
+		strcpy(session->uuid, uuid);
+	}
+
+	/* init the token */
+	strcpy(session->token, sessions.initok);
+	session->timeout = timeout;
+	if (timeout != 0)
+		session->expiration = now + timeout;
+	else {
+		session->expiration = (time_t)(~(time_t)0);
+		if (session->expiration < 0)
+			session->expiration = (time_t)(((unsigned long long)session->expiration) >> 1);
+	}
+	if (!add (session)) {
+		errno = ENOMEM;
+		goto error2;
+	}
+
+	session->access = now;
+	session->refcount = 1;
+	return session;
+
+error2:
+	free(session);
+error:
+	return NULL;
+}
+
+struct afb_session *afb_session_create (const char *uuid, int timeout)
+{
+	time_t now;
+
+	/* cleaning */
+	now = NOW;
+	cleanup (now);
+
+	/* search for an existing one not too old */
+	if (uuid != NULL && search(uuid) != NULL) {
+		errno = EEXIST;
+		return NULL;
+	}
+
+	return make_session(uuid, timeout, now);
+}
+
+// This function will return exiting session or newly created session
+struct afb_session *afb_session_get (const char *uuid, int *created)
+{
+	struct afb_session *session;
+	time_t now;
+
+	/* cleaning */
+	now = NOW;
+	cleanup (now);
+
+	/* search for an existing one not too old */
+	if (uuid != NULL) {
+		session = search(uuid);
+		if (session != NULL) {
+			*created = 0;
+			session->access = now;
+			session->refcount++;
+			return session;
+		}
+	}
+
+	*created = 1;
+	return make_session(uuid, sessions.timeout, now);
+}
+
+struct afb_session *afb_session_addref(struct afb_session *session)
+{
+	if (session != NULL)
+		session->refcount++;
+	return session;
+}
+
+void afb_session_unref(struct afb_session *session)
+{
+	if (session != NULL) {
+		assert(session->refcount != 0);
+		--session->refcount;
+		if (session->refcount == 0 && session->uuid[0] == 0) {
+			destroy (session);
+			free(session);
+		}
+	}
+}
+
+// Free Client Session Context
+void afb_session_close (struct afb_session *session)
+{
+	assert(session != NULL);
+	if (session->uuid[0] != 0) {
+		session->uuid[0] = 0;
+	        free_data (session);
+		if (session->refcount == 0) {
+			destroy (session);
+			free(session);
+		}
+	}
+}
+
+// Sample Generic Ping Debug API
+int afb_session_check_token (struct afb_session *session, const char *token)
+{
+	assert(session != NULL);
+	assert(token != NULL);
+
+	// compare current token with previous one
+	if (!is_active (session, NOW))
+		return 0;
+
+	if (session->token[0] && strcmp (token, session->token) != 0)
+		return 0;
+
+	return 1;
+}
+
+// generate a new token and update client context
+void afb_session_new_token (struct afb_session *session)
+{
+	assert(session != NULL);
+
+	// Old token was valid let's regenerate a new one
+	new_uuid(session->token);
+
+	// keep track of time for session timeout and further clean up
+	if (session->timeout != 0)
+		session->expiration = NOW + session->timeout;
+}
+
+const char *afb_session_uuid (struct afb_session *session)
+{
+	assert(session != NULL);
+	return session->uuid;
+}
+
+const char *afb_session_token (struct afb_session *session)
+{
+	assert(session != NULL);
+	return session->token;
+}
+
+unsigned afb_session_get_LOA (struct afb_session *session)
+{
+	assert(session != NULL);
+	return session->loa;
+}
+
+void afb_session_set_LOA (struct afb_session *session, unsigned loa)
+{
+	assert(session != NULL);
+	session->loa = loa;
+}
+
+void *afb_session_get_value(struct afb_session *session, int index)
+{
+	assert(session != NULL);
+	assert(index >= 0);
+	assert(index < sessions.apicount);
+	return session->values[index].value;
+}
+
+void afb_session_set_value(struct afb_session *session, int index, void *value, void (*freecb)(void*))
+{
+	struct value prev;
+	assert(session != NULL);
+	assert(index >= 0);
+	assert(index < sessions.apicount);
+	prev = session->values[index];
+	session->values[index] = (struct value){.value = value, .freecb = freecb};
+	if (prev.value != NULL && prev.value != value && prev.freecb != NULL)
+		prev.freecb(prev.value);
+}
+
+void *afb_session_get_cookie(struct afb_session *session, const void *key)
+{
+	struct cookie *cookie;
+
+	cookie = session->cookies;
+	while(cookie != NULL) {
+		if (cookie->key == key)
+			return cookie->value;
+		cookie = cookie->next;
+	}
+	return NULL;
+}
+
+int afb_session_set_cookie(struct afb_session *session, const void *key, void *value, void (*freecb)(void*))
+{
+	struct cookie *cookie;
+
+	/* search for a replacement */
+	cookie = session->cookies;
+	while(cookie != NULL) {
+		if (cookie->key == key) {
+			if (cookie->value != NULL && cookie->value != value && cookie->freecb != NULL)
+				cookie->freecb(cookie->value);
+			cookie->value = value;
+			cookie->freecb = freecb;
+			return 0;
+		}
+		cookie = cookie->next;
+	}
+
+	/* allocates */
+	cookie = malloc(sizeof *cookie);
+	if (cookie == NULL) {
+		errno = ENOMEM;
+		return -1;
+	}
+
+	cookie->key = key;
+	cookie->value = value;
+	cookie->freecb = freecb;
+	cookie->next = session->cookies;
+	session->cookies = cookie;
+	return 0;
+}
+