/*
 *  Licensed to the Apache Software Foundation (ASF) under one or more
 *  contributor license agreements.  See the NOTICE file distributed with
 *  this work for additional information regarding copyright ownership.
 *  The ASF licenses this file to You 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.
 */

/***************************************************************************
 * Description: Definitions of the objects used during the service step.   *
 *              These are the web server (ws) the worker and the connection*
 *              JVM connection point                                       *
 * Author:      Gal Shachor <shachor@il.ibm.com>                           *
 * Author:      Dan Milstein <danmil@shore.net>                            *
 * Author:      Henri Gomez <hgomez@apache.org>                            *
 * Version:     $Revision: 1497079 $                                          *
 ***************************************************************************/

#ifndef JK_SERVICE_H
#define JK_SERVICE_H

#include "jk_global.h"
#include "jk_logger.h"
#include "jk_pool.h"
#include "jk_map.h"
#include "jk_uri_worker_map.h"
#include "jk_msg_buff.h"

#define JK_RETRIES 2

#ifdef __cplusplus
extern "C"
{
#endif                          /* __cplusplus */

/*
 * Env Information to be provided to worker at init time
 * With AJP14 support we need to have access to many informations
 * about web-server, uri to worker map....
 */

struct jk_worker_env
{

    /* The original configuration map */
    jk_map_t *init_data;

    /* The URI to WORKER map, will be feeded by AJP14 autoconf feature */
    jk_uri_worker_map_t *uri_to_worker;

    unsigned int num_of_workers;
    char **worker_list;

    /* Web-Server we're running on (Apache/IIS/NES) */
    char *server_name;

    /* Virtual server handled - "*" is all virtual */
    char *virtual;
    
    /* Optional APR pool used for configuration */
    void *pool;
};
typedef struct jk_worker_env jk_worker_env_t;

struct jk_ws_service;
struct jk_endpoint;
struct jk_worker;
typedef struct jk_ws_service jk_ws_service_t;
typedef struct jk_endpoint jk_endpoint_t;
typedef struct jk_worker jk_worker_t;

struct svc_extension
{
    /* reply_timeout overwrite */
    int reply_timeout;
    /* Whether to ignore session routing info */
    int sticky_ignore;
    /* Whether the request is stateless and should not
     * influence session load balancing */
    int stateless;
    /* activation state overwrites for load balancers */
    /* Dynamically allocated array with one entry per lb member. */
    int *activation;
    /* fail_on_status overwrites */
    /* Number of elements in the array fail_on_status. */
    int fail_on_status_size;
    /* Dynamically allocated array with one entry per status. */
    int *fail_on_status;
    /* Use server error pages for responses >= 400. */
    int use_server_error_pages;
    /* session_cookie overwrite */
    char *session_cookie;
    /* session_path overwrite */
    char *session_path;
    /* Whether mod_jk should set the session cookie itself */
    int set_session_cookie;
    /* An optional PATH to add the the set session cookie */
    char *session_cookie_path;
};
typedef struct svc_extension svc_extension_t;

/*
 * The web server service 'class'.  An instance of this class is created
 * for each request which is forwarded from the web server to the servlet
 * container.  Contains the basic information about the request
 * (e.g. protocol, req_uri, etc), and also contains a series of methods
 * which provide access to core web server functionality (start_response,
 * read, write).  This class might be more accurately called ws_request.
 *
 * As with all the core jk classes, this is essentially an abstract base
 * class which is implemented/extended by classes which are specific to a
 * particular web server.  By using an abstract base class in this manner,
 * workers can be written for different protocols (e.g. ajp12, ajp13, ajp14)
 * without the workers having to worry about which web server they are
 * talking to.
 *
 * This particular OO-in-C system uses a 'ws_private' pointer to point to
 * the platform-specific data.  So in the subclasses, the methods do most
 * of their work by getting their hands on the ws_private pointer and then
 * using that to get at the correctly formatted data and functions for
 * their platform.
 *
 * Try imagining this as a 'public abstract class', and the ws_private
 * pointer as a sort of extra 'this' reference.  Or imagine that you are
 * seeing the internal vtables of your favorite OO language.  Whatever
 * works for you.
 *
 * See apache1.3/mod_jk.c and iis/jk_isapi_plugin.c for examples.
 */
struct jk_ws_service
{

    /*
     * A 'this' pointer which is used by the subclasses of this class to
     * point to data which is specific to a given web server platform
     * (e.g. Apache or IIS).
     */
    void *ws_private;

    /*
     * Provides memory management.  All data specific to this request is
     * allocated within this pool, which can then be reclaimed at the end
     * of the request handling cycle.
     *
     * Alive as long as the request is alive.
     */
    jk_pool_t *pool;

    /*
     * CGI Environment needed by servlets
     */
    const char *method;
    const char *protocol;
    char *req_uri;
    const char *remote_addr;
    const char *remote_port;
    const char *remote_host;
    const char *remote_user;
    const char *auth_type;
    const char *query_string;
    const char *server_name;
    unsigned server_port;
    char *server_software;
    jk_uint64_t content_length; /* 64 bit integer that represents the content */
    /* length should be 0 if unknown.        */
    unsigned is_chunked;    /* 1 if content length is unknown (chunked rq) */
    unsigned no_more_chunks;        /* 1 if last chunk has been read */
    jk_uint64_t content_read;  /* number of bytes read */

    /*
     * SSL information
     *
     * is_ssl       - True if request is in ssl connection
     * ssl_cert     - If available, base64 ASN.1 encoded client certificates.
     * ssl_cert_len - Length of ssl_cert, 0 if certificates are not available.
     * ssl_cipher   - The ssl cipher suite in use.
     * ssl_session  - The ssl session string
     *
     * In some servers it is impossible to extract all this information, in this
     * case, we are passing NULL.
     */
    int is_ssl;
    char *ssl_cert;
    unsigned ssl_cert_len;
    char *ssl_cipher;
    char *ssl_session;

    /*
     * SSL extra information for Servlet 2.3 API
     *
     * ssl_key_size - ssl key size in use
     */
    int ssl_key_size;

    /*
     * Headers, names and values.
     */
    char **headers_names;   /* Names of the request headers  */
    char **headers_values;  /* Values of the request headers */
    unsigned num_headers;   /* Number of request headers     */

    /*
     * Request attributes.
     *
     * These attributes that were extracted from the web server and are
     * sent to Tomcat.
     *
     * The developer should be able to read them from the ServletRequest
     * attributes. Tomcat is required to append org.apache.tomcat. to
     * these attrinbute names.
     */
    char **attributes_names;        /* Names of the request attributes  */
    char **attributes_values;       /* Values of the request attributes */
    unsigned num_attributes;        /* Number of request attributes     */

    /*
     * Response headers, names and values.
     * These are additional headers that we want to add to
     * the headers send to us from tomcat.
     * Example: a stickyness cookie header
     */
    char **resp_headers_names;   /* Names of the response headers  */
    char **resp_headers_values;  /* Values of the response headers */
    unsigned num_resp_headers;   /* Number of response headers     */

    /*
     * JK_TRUE iff handled by a load balancer, the request
     * contained a route and it is the route of the current worker.
     */
    int sticky;

    /*
     * The route is in use when the adapter load balance among
     * several workers. It is the ID of a specific target in the load balance
     * group. We are using this variable to implement target session
     * affinity
     */
    const char *route;

    /*
     * Activation state of the worker in the load balancer.
     * Will be forwarded as a request attribute.
     */
    const char *activation;

    /* Temp solution for auth. For native1 it'll be sent on each request,
       if an option is present. For native2 it'll be sent with the first
       request. On java side, both cases will work. For tomcat3.2 or
       a version that doesn't support secret - don't set the secret,
       and it'll work.
     */
    const char *secret;

    /*
     * Area to get POST data for fail-over recovery in POST
     */
    jk_msg_buf_t *reco_buf;
    int reco_status;

    /*
     * If set call flush after each write
     */
    int flush_packets;

    /*
     * If set call flush after AJP13_SEND_HEADERS.
     */
    int flush_header;

    /*
     * service extensions
     */
    svc_extension_t extension;

    /*
     * JK_TRUE if response headers have been sent back
     */
    int response_started;

    /*
     * JK_TRUE if response should not be send to the client
     */
    int response_blocked;

    /*
     * HTTP status sent from container.
     */
    int http_response_status;

    /* Uri worker map. Added for virtual host support
     */
    jk_uri_worker_map_t *uw_map;

    /*
     * Callbacks into the web server.  For each, the first argument is
     * essentially a 'this' pointer.  All return JK_TRUE on success
     * and JK_FALSE on failure.
     */
    /*
     * Send the response headers to the browser.
     */
    int (JK_METHOD * start_response) (jk_ws_service_t *s,
                                      int status,
                                      const char *reason,
                                      const char *const *header_names,
                                      const char *const *header_values,
                                      unsigned num_of_headers);

    /*
     * Read a chunk of the request body into a buffer.  Attempt to read len
     * bytes into the buffer.  Write the number of bytes actually read into
     * actually_read.
     */
    int (JK_METHOD * read) (jk_ws_service_t *s,
                            void *buffer,
                            unsigned len, unsigned *actually_read);

    /*
     * Write a chunk of response data back to the browser.
     */
    int (JK_METHOD * write) (jk_ws_service_t *s,
                             const void *buffer, unsigned len);

    /*
     * Flush a chunk of response data back to the browser.
     */
    void (JK_METHOD * flush) (jk_ws_service_t *s);

    /*
     * Done with sending response back to the browser.
     */
    void (JK_METHOD * done) (jk_ws_service_t *s);

    /*
     * If set do not reuse socket after each full response
     */
    int disable_reuse;

    /*
     * Add more data to log facilities.
     */
    void (JK_METHOD * add_log_items) (jk_ws_service_t *s,
                                      const char *const *log_names,
                                      const char *const *log_values,
                                      unsigned num_of_items);

    /*
     * Iterate through all vhosts
     */
    void *(JK_METHOD * next_vhost) (void *d);

    /*
     * String representation of a vhost
     */
    void (JK_METHOD * vhost_to_text) (void *d, char *buf, size_t len);

    /*
     * Get uw_map associated with a vhost
     */
    jk_uri_worker_map_t *(JK_METHOD * vhost_to_uw_map) (void *d);
};

/*
 * The endpoint 'class', which represents one end of a connection to the
 * servlet engine.  Basically, supports nothing other than forwarding the
 * request to the servlet engine.  Endpoints can be persistent (as with
 * ajp13/ajp14, where a single connection is reused many times), or can last for a
 * single request (as with ajp12, where a new connection is created for
 * every request).
 *
 * An endpoint for a given protocol is obtained by the web server plugin
 * from a worker object for that protocol.  See below for details.
 *
 * As with all the core jk classes, this is essentially an abstract base
 * class which is implemented/extended by classes which are specific to a
 * particular protocol.  By using an abstract base class in this manner,
 * plugins can be written for different servers (e.g. IIS, Apache) without
 * the plugins having to worry about which protocol they are talking.
 *
 * This particular OO-in-C system uses a 'endpoint_private' pointer to
 * point to the protocol-specific data/functions.  So in the subclasses, the
 * methods do most of their work by getting their hands on the
 * endpoint_private pointer and then using that to get at the functions for
 * their protocol.
 *
 * Try imagining this as a 'public abstract class', and the
 * endpoint_private pointer as a sort of extra 'this' reference.  Or
 * imagine that you are seeing the internal vtables of your favorite OO
 * language.  Whatever works for you.
 *
 * See jk_ajp13_worker.c/jk_ajp14_worker.c and jk_ajp12_worker.c for examples.
 */
struct jk_endpoint
{
    jk_uint64_t rd;
    jk_uint64_t wr;

    /*
     * Flag to pass back recoverability status from
     * a load balancer member to the load balancer itself.
     * Depending on the configuration and request status
     * recovery is not allowed.
     */
    int recoverable;

    /*
     * A 'this' pointer which is used by the subclasses of this class to
     * point to data/functions which are specific to a given protocol
     * (e.g. ajp12 or ajp13 or ajp14).
     */
    void *endpoint_private;

    /*
     * Forward a request to the servlet engine.  The request is described
     * by the jk_ws_service_t object.
     * is_error is either 0 meaning recoverable or set to
     * the HTTP error code.
     */
    int (JK_METHOD * service) (jk_endpoint_t *e,
                               jk_ws_service_t *s,
                               jk_logger_t *l, int *is_error);

    /*
     * Called when this particular endpoint has finished processing a
     * request.  For some protocols (e.g. ajp12), this frees the memory
     * associated with the endpoint.  For others (e.g. ajp13/ajp14), this can
     * return the endpoint to a cache of already opened endpoints.
     *
     * Note that the first argument is *not* a 'this' pointer, but is
     * rather a pointer to a 'this' pointer.  This is necessary, because
     * we may need to free this object.
     */
    int (JK_METHOD * done) (jk_endpoint_t **p, jk_logger_t *l);
};

/*
 * The worker 'class', which represents something to which the web server
 * can delegate requests.
 *
 * This can mean communicating with a particular servlet engine instance,
 * using a particular protocol.  A single web server instance may have
 * multiple workers communicating with a single servlet engine (it could be
 * using ajp12 for some requests and ajp13/ajp14 for others).  Or, a single web
 * server instance could have multiple workers communicating with different
 * servlet engines using the same protocol (it could be load balancing
 * among many engines, using ajp13/ajp14 for all communication).
 *
 * There is also a load balancing worker (jk_lb_worker.c), which itself
 * manages a group of workers.
 *
 * Web servers are configured to forward requests to a given worker.  To
 * handle those requests, the worker's get_endpoint method is called, and
 * then the service() method of that endpoint is called.
 *
 * As with all the core jk classes, this is essentially an abstract base
 * class which is implemented/extended by classes which are specific to a
 * particular protocol (or request-handling system).  By using an abstract
 * base class in this manner, plugins can be written for different servers
 * (e.g. IIS, Apache) without the plugins having to worry about which
 * protocol they are talking.
 *
 * This particular OO-in-C system uses a 'worker_private' pointer to
 * point to the protocol-specific data/functions.  So in the subclasses, the
 * methods do most of their work by getting their hands on the
 * worker_private pointer and then using that to get at the functions for
 * their protocol.
 *
 * Try imagining this as a 'public abstract class', and the
 * worker_private pointer as a sort of extra 'this' reference.  Or
 * imagine that you are seeing the internal vtables of your favorite OO
 * language.  Whatever works for you.
 *
 * See jk_ajp14_worker.c, jk_ajp13_worker.c and jk_ajp12_worker.c for examples.
 */
struct jk_worker
{

    jk_worker_env_t *we;

    /*
     * A 'this' pointer which is used by the subclasses of this class to
     * point to data/functions which are specific to a given protocol
     * (e.g. ajp12 or ajp13 or ajp14).
     */
    void *worker_private;

    int   type;
    /*
     * For all of the below (except destroy), the first argument is
     * essentially a 'this' pointer.
     */

    /*
     * Given a worker which is in the process of being created, and a list
     * of configuration options (or 'properties'), check to see if it the
     * options are.  This will always be called before the init() method.
     * The init/validate distinction is a bit hazy to me.
     * See jk_ajp13_worker.c/jk_ajp14_worker.c and jk_worker.c->wc_create_worker()
     */
    int (JK_METHOD * validate) (jk_worker_t *w,
                                jk_map_t *props,
                                jk_worker_env_t *we, jk_logger_t *l);

    /*
     * Update worker either from jk_status or reloading from workers.properties
     */
    int (JK_METHOD * update) (jk_worker_t *w,
                              jk_map_t *props,
                              jk_worker_env_t *we, jk_logger_t *l);

    /*
     * Do whatever initialization needs to be done to start this worker up.
     * Configuration options are passed in via the props parameter.
     */
    int (JK_METHOD * init) (jk_worker_t *w,
                            jk_map_t *props,
                            jk_worker_env_t *we, jk_logger_t *l);


    /*
     * Obtain an endpoint to service a particular request.  A pointer to
     * the endpoint is stored in pend.
     */
    int (JK_METHOD * get_endpoint) (jk_worker_t *w,
                                    jk_endpoint_t **pend, jk_logger_t *l);

    /*
     * Shutdown this worker.  The first argument is not a 'this' pointer,
     * but rather a pointer to 'this', so that the object can be free'd (I
     * think -- though that doesn't seem to be happening.  Hmmm).
     */
    int (JK_METHOD * destroy) (jk_worker_t **w, jk_logger_t *l);

    /*
     * Maintain this worker.
     */
    int (JK_METHOD * maintain) (jk_worker_t *w, time_t now, jk_logger_t *l);

};

/*
 * Essentially, an abstract base class (or factory class) with a single
 * method -- think of it as createWorker() or the Factory Method Design
 * Pattern.  There is a different worker_factory function for each of the
 * different types of workers.  The set of all these functions is created
 * at startup from the list in jk_worker_list.h, and then the correct one
 * is chosen in jk_worker.c->wc_create_worker().  See jk_worker.c and
 * jk_ajp13_worker.c/jk_ajp14_worker.c for examples.
 *
 * This allows new workers to be written without modifing the plugin code
 * for the various web servers (since the only link is through
 * jk_worker_list.h).
 */
typedef int (JK_METHOD * worker_factory) (jk_worker_t **w,
                                          const char *name,
                                          jk_logger_t *l);

void jk_init_ws_service(jk_ws_service_t *s);


#ifdef __cplusplus
}
#endif                          /* __cplusplus */

#endif                          /* JK_SERVICE_H */
