GUACAMOLE-1174: Remove option use-exec, add snprintf result validation, fix code formatting.

src/protocols/kubernetes/kubernetes.c

@@ -217,7 +217,6 @@ void* guac_kubernetes_client_thread(void* data) {
                 settings->kubernetes_namespace,
                 settings->kubernetes_pod,
                 settings->kubernetes_container,
-                settings->use_exec,
                 settings->exec_command)) {
         guac_client_abort(client, GUAC_PROTOCOL_STATUS_SERVER_ERROR,
                 "Unable to generate path for Kubernetes API endpoint: "

src/protocols/kubernetes/settings.c

@@ -31,7 +31,6 @@ const char* GUAC_KUBERNETES_CLIENT_ARGS[] = {
     "namespace",
     "pod",
     "container",
-    "use-exec",
     "exec-command",
     "use-ssl",
     "client-cert",
@@ -89,12 +88,7 @@ enum KUBERNETES_ARGS_IDX {
     IDX_CONTAINER,
 
     /**
-     * Whether exec call should be used. If omitted, attach call will be used.
+     * The command used by exec call. If omitted, attach call will be used.
-     */
-    IDX_USE_EXEC,
-
-    /**
-     * The command used by exec call.
      */
     IDX_EXEC_COMMAND,
 
@@ -287,15 +281,10 @@ guac_kubernetes_settings* guac_kubernetes_parse_args(guac_user* user,
         guac_user_parse_args_string(user, GUAC_KUBERNETES_CLIENT_ARGS, argv,
                 IDX_CONTAINER, NULL);
 
-    /* Parse whether exec call should be used */
-    settings->use_exec =
-        guac_user_parse_args_boolean(user, GUAC_KUBERNETES_CLIENT_ARGS, argv,
-                IDX_USE_EXEC, false);
-
     /* Read exec command (optional) */
     settings->exec_command =
         guac_user_parse_args_string(user, GUAC_KUBERNETES_CLIENT_ARGS, argv,
-                IDX_EXEC_COMMAND, GUAC_KUBERNETES_DEFAULT_EXEC_COMMAND);
+                IDX_EXEC_COMMAND, NULL);
 
     /* Parse whether SSL should be used */
     settings->use_ssl =

src/protocols/kubernetes/settings.h

@@ -47,12 +47,6 @@
  */
 #define GUAC_KUBERNETES_DEFAULT_NAMESPACE "default"
 
-/**
- * The command that should be used by default for exec call if no
- * specific command is provided.
- */
-#define GUAC_KUBERNETES_DEFAULT_EXEC_COMMAND "/bin/sh"
-
 /**
  * The filename to use for the typescript, if not specified.
  */
@@ -104,12 +98,8 @@ typedef struct guac_kubernetes_settings {
     char* kubernetes_container;
 
     /**
-     * Whether exec call should be used, default attach.
+     * The command to generate api endpoint for call exec. 
-     */
+     * If omitted call attach will be used.
-    bool use_exec;
-
-    /**
-     * Exec command, default /bin/sh.
      */
     char* exec_command;
 

src/protocols/kubernetes/url.c

@@ -91,7 +91,7 @@ int guac_kubernetes_escape_url_component(char* output, int length,
 
 int guac_kubernetes_endpoint_uri(char* buffer, int length,
         const char* kubernetes_namespace, const char* kubernetes_pod,
-        const char* kubernetes_container, int use_exec, const char* exec_command) {
+        const char* kubernetes_container, const char* exec_command) {
 
     int written;
 
@@ -111,26 +111,32 @@ int guac_kubernetes_endpoint_uri(char* buffer, int length,
         return 1;
 
     /* Generate endpoint path depending on the call type */
-    char* call="attach";
+    char* call = "attach";
-    if (use_exec)
+    if (exec_command != NULL)
         call = "exec";
 
     char endpoint_path[GUAC_KUBERNETES_MAX_ENDPOINT_LENGTH];
-    snprintf(endpoint_path, GUAC_KUBERNETES_MAX_ENDPOINT_LENGTH*3, 
+
+    written = snprintf(endpoint_path, sizeof(endpoint_path), 
         "/api/v1/namespaces/%s/pods/%s/%s", escaped_namespace, escaped_pod, call);
         
+    if (written < 0 || written >= sizeof(endpoint_path))
+        return 1;
+
     /* Generate endpoint params */
     char endpoint_params[GUAC_KUBERNETES_MAX_ENDPOINT_LENGTH]="";
-    int param_length=0;
 
-    if(use_exec){
+    if (exec_command != NULL) {
         /* Escape exec command */
         if (guac_kubernetes_escape_url_component(escaped_exec_command,
                     sizeof(escaped_exec_command), exec_command))
             return 1;
 
-        param_length += snprintf(endpoint_params, GUAC_KUBERNETES_MAX_ENDPOINT_LENGTH, 
+        written = snprintf(endpoint_params, sizeof(endpoint_params), 
             "command=%s&", escaped_exec_command);
+
+        if (written < 0 || written >= sizeof(endpoint_params))
+            return 1;
     }
 
     if (kubernetes_container != NULL) {
@@ -139,13 +145,17 @@ int guac_kubernetes_endpoint_uri(char* buffer, int length,
                     sizeof(escaped_container), kubernetes_container))
             return 1;
 
-        snprintf(endpoint_params+param_length, GUAC_KUBERNETES_MAX_ENDPOINT_LENGTH-param_length,
+        written = snprintf(endpoint_params, sizeof(endpoint_params),
                 "container=%s&", escaped_container);
+                
+        if (written < 0 || written >= sizeof(endpoint_params))
+            return 1;
     }
 
     /* Combine path and params to uri */
     written = snprintf(buffer, length, "%s?%sstdin=true&stdout=true&tty=true", 
         endpoint_path, endpoint_params);
+        
     /* Endpoint URL was successfully generated if it was written to the given
      * buffer without truncation */
     return !(written < length - 1);

src/protocols/kubernetes/url.h

@@ -73,12 +73,9 @@ int guac_kubernetes_escape_url_component(char* output, int length,
  *     The name of the container to attach to, or NULL to arbitrarily attach
  *     to the first container in the pod.
  *  
- * @param use_exec
- *     Whether use call exec.
- *     Execute a command in a container and attach to it instead of main container process.
- * 
  * @param exec_command
- *     The command used in conjunction with exec call.
+ *     The command used to run a new process and attach to it,
+ *     instead of the main container process.
  *
  * @return
  *     Zero if the endpoint path was successfully written to the provided
@@ -86,7 +83,7 @@ int guac_kubernetes_escape_url_component(char* output, int length,
  */
 int guac_kubernetes_endpoint_uri(char* buffer, int length,
         const char* kubernetes_namespace, const char* kubernetes_pod,
-        const char* kubernetes_container, int use_exec, const char* exec_command);
+        const char* kubernetes_container, const char* exec_command);
 
 #endif