GUAC-743: Implement client mapping structure.

src/guacd/Makefile.am

@@ -22,14 +22,14 @@
 
 AUTOMAKE_OPTIONS = foreign 
 
-AM_CFLAGS = -Werror -Wall -pedantic @LIBGUAC_INCLUDE@
+AM_CFLAGS = -Werror -Wall -pedantic @LIBGUAC_INCLUDE@ @COMMON_INCLUDE@
 
 sbin_PROGRAMS = guacd
 man_MANS = man/guacd.8
 
-noinst_HEADERS = client.h log.h
-guacd_SOURCES  = daemon.c client.c log.c
-guacd_LDADD    = @LIBGUAC_LTLIB@
+noinst_HEADERS = client.h client-map.h log.h
+guacd_SOURCES  = daemon.c client.c client-map.c log.c
+guacd_LDADD    = @LIBGUAC_LTLIB@ @COMMON_LTLIB@
 guacd_LDFLAGS  = @PTHREAD_LIBS@ @SSL_LIBS@
 
 EXTRA_DIST = init.d/guacd.in man/guacd.8

src/guacd/client-map.c

@@ -0,0 +1,164 @@
+/*
+ * Copyright (C) 2014 Glyptodon LLC
+ *
+ * Permission is hereby granted, free of charge, to any person obtaining a copy
+ * of this software and associated documentation files (the "Software"), to deal
+ * in the Software without restriction, including without limitation the rights
+ * to use, copy, modify, merge, publish, distribute, sublicense, and/or sell
+ * copies of the Software, and to permit persons to whom the Software is
+ * furnished to do so, subject to the following conditions:
+ *
+ * The above copyright notice and this permission notice shall be included in
+ * all copies or substantial portions of the Software.
+ *
+ * THE SOFTWARE IS PROVIDED "AS IS", WITHOUT WARRANTY OF ANY KIND, EXPRESS OR
+ * IMPLIED, INCLUDING BUT NOT LIMITED TO THE WARRANTIES OF MERCHANTABILITY,
+ * FITNESS FOR A PARTICULAR PURPOSE AND NONINFRINGEMENT. IN NO EVENT SHALL THE
+ * AUTHORS OR COPYRIGHT HOLDERS BE LIABLE FOR ANY CLAIM, DAMAGES OR OTHER
+ * LIABILITY, WHETHER IN AN ACTION OF CONTRACT, TORT OR OTHERWISE, ARISING FROM,
+ * OUT OF OR IN CONNECTION WITH THE SOFTWARE OR THE USE OR OTHER DEALINGS IN
+ * THE SOFTWARE.
+ */
+
+#include "config.h"
+#include "client.h"
+#include "client-map.h"
+#include "guac_list.h"
+
+#include <guacamole/client.h>
+
+#include <stdlib.h>
+#include <string.h>
+
+/**
+ * Returns a hash code based on the connection ID of the given client.
+ */
+static unsigned int __guacd_client_hash(const char* str) {
+
+    unsigned int hash_value = 0;
+    int c;
+
+    /* Apply each character in string to the hash code */
+    while ((c = *(str++)))
+        hash_value = hash_value * 65599 + c;
+
+    return hash_value;
+
+}
+
+static guac_common_list* __guacd_client_find_bucket(guacd_client_map* map, const char* id) {
+
+    const int index = __guacd_client_hash(id) % GUACD_CLIENT_MAP_BUCKETS;
+    return map->__buckets[index];
+
+}
+
+static guac_common_list_element* __guacd_client_find(guac_common_list* bucket, const char* id) {
+
+    guac_common_list_element* current = bucket->head;
+
+    /* Search for matching element within bucket */
+    while (current != NULL) {
+
+        /* Check connection ID */
+        guac_client* client = (guac_client*) current->data;
+        if (strcmp(client->connection_id, id) == 0)
+            break;
+
+        current = current->next;
+    }
+
+    return current;
+
+}
+
+guacd_client_map* guacd_client_map_alloc() {
+
+    guacd_client_map* map = malloc(sizeof(guacd_client_map));
+    guac_common_list** current;
+
+    int i;
+
+    /* Init all buckets */
+    current = map->__buckets;
+
+    for (i=0; i<GUACD_CLIENT_MAP_BUCKETS; i++) {
+        *current = guac_common_list_alloc();
+        current++;
+    }
+
+    return map;
+
+}
+
+int guacd_client_map_add(guacd_client_map* map, guac_client* client) {
+
+    guac_common_list* bucket = __guacd_client_find_bucket(map, client->connection_id);
+    guac_common_list_element* found;
+
+    /* Retrieve corresponding element, if any */
+    guac_common_list_lock(bucket);
+    found = __guacd_client_find(bucket, client->connection_id);
+
+    /* If no such element, we can add the new client successfully */
+    if (found == NULL) {
+        guac_common_list_add(bucket, client);
+        guac_common_list_unlock(bucket);
+        return 0;
+    }
+
+    /* Otherwise, fail - already exists */
+    guac_common_list_unlock(bucket);
+    return 1;
+
+}
+
+guac_client* guacd_client_map_retrieve(guacd_client_map* map, const char* id) {
+
+    guac_client* client;
+
+    guac_common_list* bucket = __guacd_client_find_bucket(map, id);
+    guac_common_list_element* found;
+
+    /* Retrieve corresponding element, if any */
+    guac_common_list_lock(bucket);
+    found = __guacd_client_find(bucket, id);
+
+    /* If no such element, fail */
+    if (found == NULL) {
+        guac_common_list_unlock(bucket);
+        return NULL;
+    }
+
+    client = (guac_client*) found->data;
+
+    guac_common_list_unlock(bucket);
+    return client;
+
+}
+
+guac_client* guacd_client_map_remove(guacd_client_map* map, const char* id) {
+
+    guac_client* client;
+
+    guac_common_list* bucket = __guacd_client_find_bucket(map, id);
+    guac_common_list_element* found;
+
+    /* Retrieve corresponding element, if any */
+    guac_common_list_lock(bucket);
+    found = __guacd_client_find(bucket, id);
+
+    /* If no such element, fail */
+    if (found == NULL) {
+        guac_common_list_unlock(bucket);
+        return NULL;
+    }
+
+    client = (guac_client*) found->data;
+    guac_common_list_remove(bucket, found);
+
+    guac_common_list_unlock(bucket);
+    return client;
+
+}
+

src/guacd/client-map.h

@@ -0,0 +1,73 @@
+/*
+ * Copyright (C) 2014 Glyptodon LLC
+ *
+ * Permission is hereby granted, free of charge, to any person obtaining a copy
+ * of this software and associated documentation files (the "Software"), to deal
+ * in the Software without restriction, including without limitation the rights
+ * to use, copy, modify, merge, publish, distribute, sublicense, and/or sell
+ * copies of the Software, and to permit persons to whom the Software is
+ * furnished to do so, subject to the following conditions:
+ *
+ * The above copyright notice and this permission notice shall be included in
+ * all copies or substantial portions of the Software.
+ *
+ * THE SOFTWARE IS PROVIDED "AS IS", WITHOUT WARRANTY OF ANY KIND, EXPRESS OR
+ * IMPLIED, INCLUDING BUT NOT LIMITED TO THE WARRANTIES OF MERCHANTABILITY,
+ * FITNESS FOR A PARTICULAR PURPOSE AND NONINFRINGEMENT. IN NO EVENT SHALL THE
+ * AUTHORS OR COPYRIGHT HOLDERS BE LIABLE FOR ANY CLAIM, DAMAGES OR OTHER
+ * LIABILITY, WHETHER IN AN ACTION OF CONTRACT, TORT OR OTHERWISE, ARISING FROM,
+ * OUT OF OR IN CONNECTION WITH THE SOFTWARE OR THE USE OR OTHER DEALINGS IN
+ * THE SOFTWARE.
+ */
+
+
+#ifndef _GUACD_CLIENT_MAP_H
+#define _GUACD_CLIENT_MAP_H
+
+#include "config.h"
+#include "client.h"
+#include "guac_list.h"
+
+#include <guacamole/client.h>
+
+#define GUACD_CLIENT_MAP_BUCKETS GUACD_CLIENT_MAX_CONNECTIONS*2
+
+/**
+ * Set of all active connections to guacd, indexed by connection ID.
+ */
+typedef struct guacd_client_map {
+
+    /**
+     * Internal hash buckets. Each bucket is a linked list containing all
+     * guac_client instances which hash to this bucket location.
+     */
+    guac_common_list* __buckets[GUACD_CLIENT_MAP_BUCKETS];
+
+} guacd_client_map;
+
+/**
+ * Allocates a new client map, which persists for the life of guacd.
+ */
+guacd_client_map* guacd_client_map_alloc();
+
+/**
+ * Adds the given client to the given client map. On success, zero is returned.
+ * If adding the client fails (due to lack of space, or duplicate ID), a
+ * non-zero value is returned instead.
+ */
+int guacd_client_map_add(guacd_client_map* map, guac_client* client);
+
+/**
+ * Retrieves the client having the given ID, or NULL if no such client
+ * is stored.
+ */
+guac_client* guacd_client_map_retrieve(guacd_client_map* map, const char* id);
+
+/**
+ * Removes the client having the given ID, returning the corresponding client.
+ * If no such client exists, NULL is returned.
+ */
+guac_client* guacd_client_map_remove(guacd_client_map* map, const char* id);
+
+#endif
+

src/guacd/client.h

@@ -67,6 +67,13 @@
  */
 #define GUACD_USEC_TIMEOUT (GUACD_TIMEOUT*1000)
 
+/**
+ * The maximum number of concurrent connections to a single instance
+ * of guacd.
+ */
+#define GUACD_CLIENT_MAX_CONNECTIONS 65536
+
 int guacd_client_start(guac_client* client);
 
 #endif
+