mod_proxy.h

Apache官方在今天放出产品系列2.2的最新版本2.2.11的源码包 最流行的HTTP服务器软件之一

/* worker status flags */
#define PROXY_WORKER_INITIALIZED    0x0001
#define PROXY_WORKER_IGNORE_ERRORS  0x0002
#define PROXY_WORKER_IN_SHUTDOWN    0x0010
#define PROXY_WORKER_DISABLED       0x0020
#define PROXY_WORKER_STOPPED        0x0040
#define PROXY_WORKER_IN_ERROR       0x0080
#define PROXY_WORKER_HOT_STANDBY    0x0100

#define PROXY_WORKER_NOT_USABLE_BITMAP ( PROXY_WORKER_IN_SHUTDOWN | \
PROXY_WORKER_DISABLED | PROXY_WORKER_STOPPED | PROXY_WORKER_IN_ERROR )

/* NOTE: these check the shared status */
#define PROXY_WORKER_IS_INITIALIZED(f)   ( (f)->s && \
  ( (f)->s->status &  PROXY_WORKER_INITIALIZED ) )

#define PROXY_WORKER_IS_STANDBY(f)   ( (f)->s && \
  ( (f)->s->status &  PROXY_WORKER_HOT_STANDBY ) )

#define PROXY_WORKER_IS_USABLE(f)   ( (f)->s && \
  ( !( (f)->s->status & PROXY_WORKER_NOT_USABLE_BITMAP) ) && \
  PROXY_WORKER_IS_INITIALIZED(f) )

/* default worker retry timeout in seconds */
#define PROXY_WORKER_DEFAULT_RETRY  60
#define PROXY_WORKER_MAX_ROUTE_SIZ  63

/* Runtime worker status informations. Shared in scoreboard */
typedef struct {
    int             status;
    apr_time_t      error_time; /* time of the last error */
    int             retries;    /* number of retries on this worker */
    int             lbstatus;   /* Current lbstatus */
    int             lbfactor;   /* dynamic lbfactor */
    apr_off_t       transferred;/* Number of bytes transferred to remote */
    apr_off_t       read;       /* Number of bytes read from remote */
    apr_size_t      elected;    /* Number of times the worker was elected */
    char            route[PROXY_WORKER_MAX_ROUTE_SIZ+1];
    char            redirect[PROXY_WORKER_MAX_ROUTE_SIZ+1];
    void            *context;   /* general purpose storage */
    apr_size_t      busy;       /* busyness factor */
    int             lbset;      /* load balancer cluster set */
} proxy_worker_stat;

/* Worker configuration */
struct proxy_worker {
    int             id;         /* scoreboard id */
    apr_interval_time_t retry;  /* retry interval */
    int             lbfactor;   /* initial load balancing factor */
    const char      *name;
    const char      *scheme;    /* scheme to use ajp|http|https */
    const char      *hostname;  /* remote backend address */
    const char      *route;     /* balancing route */
    const char      *redirect;  /* temporary balancing redirection route */
    int             status;     /* temporary worker status */
    apr_port_t      port;
    int             min;        /* Desired minimum number of available connections */
    int             smax;       /* Soft maximum on the total number of connections */
    int             hmax;       /* Hard maximum on the total number of connections */
    apr_interval_time_t ttl;    /* maximum amount of time in seconds a connection
                                 * may be available while exceeding the soft limit */
    apr_interval_time_t timeout; /* connection timeout */
    char            timeout_set;
    apr_interval_time_t acquire; /* acquire timeout when the maximum number of connections is exceeded */
    char            acquire_set;
    apr_size_t      recv_buffer_size;
    char            recv_buffer_size_set;
    apr_size_t      io_buffer_size;
    char            io_buffer_size_set;
    char            keepalive;
    char            keepalive_set;
    proxy_conn_pool     *cp;        /* Connection pool to use */
    proxy_worker_stat   *s;         /* Shared data */
    void            *opaque;    /* per scheme worker data */
    int             is_address_reusable;
#if APR_HAS_THREADS
    apr_thread_mutex_t  *mutex;  /* Thread lock for updating address cache */
#endif
    void            *context;   /* general purpose storage */
    enum {
         flush_off,
         flush_on,
         flush_auto
    } flush_packets;           /* control AJP flushing */
    int             flush_wait;  /* poll wait time in microseconds if flush_auto */
    int             lbset;      /* load balancer cluster set */
    apr_interval_time_t ping_timeout;
    char ping_timeout_set;
    char            retry_set;
    char            disablereuse;
    char            disablereuse_set;
    apr_interval_time_t conn_timeout;
    char            conn_timeout_set;
};

/*
 * Wait 10000 microseconds to find out if more data is currently
 * available at the backend. Just an arbitrary choose.
 */
#define PROXY_FLUSH_WAIT 10000

struct proxy_balancer {
    apr_array_header_t *workers; /* array of proxy_workers */
    const char *name;            /* name of the load balancer */
    const char *sticky;          /* sticky session identifier */
    int         sticky_force;    /* Disable failover for sticky sessions */
    apr_interval_time_t timeout; /* Timeout for waiting on free connection */
    int                 max_attempts; /* Number of attempts before failing */
    char                max_attempts_set;
    proxy_balancer_method *lbmethod;

    /* XXX: Perhaps we will need the proc mutex too.
     * Altrough we are only using arithmetic operations
     * it may lead to a incorrect calculations.
     * For now use only the thread mutex.
     */
#if APR_HAS_THREADS
    apr_thread_mutex_t  *mutex;  /* Thread lock for updating lb params */
#endif
    void            *context;   /* general purpose storage */
    int             scolonsep;  /* true if ';' seps sticky session paths */
};

struct proxy_balancer_method {
    const char *name;            /* name of the load balancer method*/
    proxy_worker *(*finder)(proxy_balancer *balancer,
                            request_rec *r);
    void            *context;   /* general purpose storage */
};

#if APR_HAS_THREADS
#define PROXY_THREAD_LOCK(x)      apr_thread_mutex_lock((x)->mutex)
#define PROXY_THREAD_UNLOCK(x)    apr_thread_mutex_unlock((x)->mutex)
#else
#define PROXY_THREAD_LOCK(x)      APR_SUCCESS
#define PROXY_THREAD_UNLOCK(x)    APR_SUCCESS
#endif

/* hooks */

/* Create a set of PROXY_DECLARE(type), PROXY_DECLARE_NONSTD(type) and 
 * PROXY_DECLARE_DATA with appropriate export and import tags for the platform
 */
#if !defined(WIN32)
#define PROXY_DECLARE(type)            type
#define PROXY_DECLARE_NONSTD(type)     type
#define PROXY_DECLARE_DATA
#elif defined(PROXY_DECLARE_STATIC)
#define PROXY_DECLARE(type)            type __stdcall
#define PROXY_DECLARE_NONSTD(type)     type
#define PROXY_DECLARE_DATA
#elif defined(PROXY_DECLARE_EXPORT)
#define PROXY_DECLARE(type)            __declspec(dllexport) type __stdcall
#define PROXY_DECLARE_NONSTD(type)     __declspec(dllexport) type
#define PROXY_DECLARE_DATA             __declspec(dllexport)
#else
#define PROXY_DECLARE(type)            __declspec(dllimport) type __stdcall
#define PROXY_DECLARE_NONSTD(type)     __declspec(dllimport) type
#define PROXY_DECLARE_DATA             __declspec(dllimport)
#endif

/**
 * Hook an optional proxy hook.  Unlike static hooks, this uses a macro
 * instead of a function.
 */
#define PROXY_OPTIONAL_HOOK(name,fn,pre,succ,order) \
        APR_OPTIONAL_HOOK(proxy,name,fn,pre,succ,order)

APR_DECLARE_EXTERNAL_HOOK(proxy, PROXY, int, scheme_handler, (request_rec *r, 
                          proxy_worker *worker, proxy_server_conf *conf, char *url, 
                          const char *proxyhost, apr_port_t proxyport))
APR_DECLARE_EXTERNAL_HOOK(proxy, PROXY, int, canon_handler, (request_rec *r, 
                          char *url))

APR_DECLARE_EXTERNAL_HOOK(proxy, PROXY, int, create_req, (request_rec *r, request_rec *pr))
APR_DECLARE_EXTERNAL_HOOK(proxy, PROXY, int, fixups, (request_rec *r)) 

/**
 * pre request hook.
 * It will return the most suitable worker at the moment
 * and coresponding balancer.
 * The url is rewritten from balancer://cluster/uri to scheme://host:port/uri
 * and then the scheme_handler is called.
 *
 */
APR_DECLARE_EXTERNAL_HOOK(proxy, PROXY, int, pre_request, (proxy_worker **worker,
                          proxy_balancer **balancer,
                          request_rec *r,
                          proxy_server_conf *conf, char **url))                          
/**
 * post request hook.
 * It is called after request for updating runtime balancer status.
 */
APR_DECLARE_EXTERNAL_HOOK(proxy, PROXY, int, post_request, (proxy_worker *worker,
                          proxy_balancer *balancer, request_rec *r,
                          proxy_server_conf *conf))

/**
 * request status hook
 * It is called after all proxy processing has been done.  This gives other
 * modules a chance to create default content on failure, for example
 */
APR_DECLARE_EXTERNAL_HOOK(proxy, PROXY, int, request_status,
                          (int *status, request_rec *r))

/* proxy_util.c */

PROXY_DECLARE(request_rec *)ap_proxy_make_fake_req(conn_rec *c, request_rec *r);
PROXY_DECLARE(int) ap_proxy_hex2c(const char *x);
PROXY_DECLARE(void) ap_proxy_c2hex(int ch, char *x);
PROXY_DECLARE(char *)ap_proxy_canonenc(apr_pool_t *p, const char *x, int len, enum enctype t,
                                       int forcedec, int proxyreq);
PROXY_DECLARE(char *)ap_proxy_canon_netloc(apr_pool_t *p, char **const urlp, char **userp,
                                           char **passwordp, char **hostp, apr_port_t *port);
PROXY_DECLARE(const char *)ap_proxy_date_canon(apr_pool_t *p, const char *x);
PROXY_DECLARE(int) ap_proxy_liststr(const char *list, const char *val);
PROXY_DECLARE(char *)ap_proxy_removestr(apr_pool_t *pool, const char *list, const char *val);
PROXY_DECLARE(int) ap_proxy_hex2sec(const char *x);
PROXY_DECLARE(void) ap_proxy_sec2hex(int t, char *y);
PROXY_DECLARE(int) ap_proxyerror(request_rec *r, int statuscode, const char *message);
PROXY_DECLARE(int) ap_proxy_is_ipaddr(struct dirconn_entry *This, apr_pool_t *p);
PROXY_DECLARE(int) ap_proxy_is_domainname(struct dirconn_entry *This, apr_pool_t *p);
PROXY_DECLARE(int) ap_proxy_is_hostname(struct dirconn_entry *This, apr_pool_t *p);
PROXY_DECLARE(int) ap_proxy_is_word(struct dirconn_entry *This, apr_pool_t *p);
PROXY_DECLARE(int) ap_proxy_checkproxyblock(request_rec *r, proxy_server_conf *conf, apr_sockaddr_t *uri_addr);
PROXY_DECLARE(int) ap_proxy_pre_http_request(conn_rec *c, request_rec *r);
PROXY_DECLARE(apr_status_t) ap_proxy_string_read(conn_rec *c, apr_bucket_brigade *bb, char *buff, size_t bufflen, int *eos);
PROXY_DECLARE(void) ap_proxy_table_unmerge(apr_pool_t *p, apr_table_t *t, char *key);
/* DEPRECATED (will be replaced with ap_proxy_connect_backend */
PROXY_DECLARE(int) ap_proxy_connect_to_backend(apr_socket_t **, const char *, apr_sockaddr_t *, const char *, proxy_server_conf *, server_rec *, apr_pool_t *);
PROXY_DECLARE(apr_status_t) ap_proxy_ssl_connection_cleanup(proxy_conn_rec *conn,
                                                            request_rec *r);
PROXY_DECLARE(int) ap_proxy_ssl_enable(conn_rec *c);
PROXY_DECLARE(int) ap_proxy_ssl_disable(conn_rec *c);
PROXY_DECLARE(int) ap_proxy_conn_is_https(conn_rec *c);
PROXY_DECLARE(const char *) ap_proxy_ssl_val(apr_pool_t *p, server_rec *s, conn_rec *c, request_rec *r, const char *var);

/* Header mapping functions, and a typedef of their signature */
PROXY_DECLARE(const char *) ap_proxy_location_reverse_map(request_rec *r, proxy_dir_conf *conf, const char *url);
PROXY_DECLARE(const char *) ap_proxy_cookie_reverse_map(request_rec *r, proxy_dir_conf *conf, const char *str);

#if !defined(WIN32)
typedef const char *(*ap_proxy_header_reverse_map_fn)(request_rec *,
                       proxy_dir_conf *, const char *);
#elif defined(PROXY_DECLARE_STATIC)
typedef const char *(__stdcall *ap_proxy_header_reverse_map_fn)(request_rec *,
                                 proxy_dir_conf *, const char *);
#elif defined(PROXY_DECLARE_EXPORT)
typedef __declspec(dllexport) const char *
  (__stdcall *ap_proxy_header_reverse_map_fn)(request_rec *,
               proxy_dir_conf *, const char *);
#else
typedef __declspec(dllimport) const char *
  (__stdcall *ap_proxy_header_reverse_map_fn)(request_rec *,
               proxy_dir_conf *, const char *);
#endif


/* Connection pool API */
/**
 * Get the worker from proxy configuration
 * @param p     memory pool used for finding worker
 * @param conf  current proxy server configuration
 * @param url   url to find the worker from