include/types/session.h

/*
 * include/types/session.h
 * This file defines everything related to sessions.
 *
 * Copyright (C) 2000-2010 Willy Tarreau - w@1wt.eu
 *
 * This library is free software; you can redistribute it and/or
 * modify it under the terms of the GNU Lesser General Public
 * License as published by the Free Software Foundation, version 2.1
 * exclusively.
 *
 * This library is distributed in the hope that it will be useful,
 * but WITHOUT ANY WARRANTY; without even the implied warranty of
 * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the GNU
 * Lesser General Public License for more details.
 *
 * You should have received a copy of the GNU Lesser General Public
 * License along with this library; if not, write to the Free Software
 * Foundation, Inc., 51 Franklin Street, Fifth Floor, Boston, MA  02110-1301  USA
 */

#ifndef _TYPES_SESSION_H
#define _TYPES_SESSION_H


#include <sys/time.h>
#include <unistd.h>
#include <netinet/in.h>
#include <arpa/inet.h>

#include <common/config.h>
#include <common/mini-clist.h>

#include <types/buffers.h>
#include <types/proto_http.h>
#include <types/proxy.h>
#include <types/queue.h>
#include <types/server.h>
#include <types/stream_interface.h>
#include <types/task.h>
#include <types/stick_table.h>


/* various session flags, bits values 0x01 to 0x100 (shift 0) */
#define SN_DIRECT	0x00000001	/* connection made on the server matching the client cookie */
#define SN_ASSIGNED	0x00000002	/* no need to assign a server to this session */
#define SN_ADDR_SET	0x00000004	/* this session's server address has been set */
#define SN_BE_ASSIGNED	0x00000008	/* a backend was assigned. Conns are accounted. */

#define SN_FORCE_PRST	0x00000010	/* force persistence here, even if server is down */
#define SN_MONITOR	0x00000020	/* this session comes from a monitoring system */
#define SN_CURR_SESS	0x00000040	/* a connection is currently being counted on the server */
#define SN_FRT_ADDR_SET	0x00000080	/* set if the frontend address has been filled */
#define SN_REDISP	0x00000100	/* set if this session was redispatched from one server to another */
#define SN_CONN_TAR	0x00000200	/* set if this session is turning around before reconnecting */
#define SN_REDIRECTABLE	0x00000400	/* set if this session is redirectable (GET or HEAD) */
#define SN_TUNNEL	0x00000800	/* tunnel-mode session, nothing to catch after data */

/* session termination conditions, bits values 0x1000 to 0x7000 (0-7 shift 12) */
#define SN_ERR_NONE     0x00000000
#define SN_ERR_CLITO	0x00001000	/* client time-out */
#define SN_ERR_CLICL	0x00002000	/* client closed (read/write error) */
#define SN_ERR_SRVTO	0x00003000	/* server time-out, connect time-out */
#define SN_ERR_SRVCL	0x00004000	/* server closed (connect/read/write error) */
#define SN_ERR_PRXCOND	0x00005000	/* the proxy decided to close (deny...) */
#define SN_ERR_RESOURCE	0x00006000	/* the proxy encountered a lack of a local resources (fd, mem, ...) */
#define SN_ERR_INTERNAL	0x00007000	/* the proxy encountered an internal error */
#define SN_ERR_MASK	0x00007000	/* mask to get only session error flags */
#define SN_ERR_SHIFT	12		/* bit shift */
/* unused:              0x00008000 */

/* session state at termination, bits values 0x10000 to 0x70000 (0-7 shift 16) */
#define SN_FINST_R	0x00010000	/* session ended during client request */
#define SN_FINST_C	0x00020000	/* session ended during server connect */
#define SN_FINST_H	0x00030000	/* session ended during server headers */
#define SN_FINST_D	0x00040000	/* session ended during data phase */
#define SN_FINST_L	0x00050000	/* session ended while pushing last data to client */
#define SN_FINST_Q	0x00060000	/* session ended while waiting in queue for a server slot */
#define SN_FINST_T	0x00070000	/* session ended tarpitted */
#define SN_FINST_MASK	0x00070000	/* mask to get only final session state flags */
#define	SN_FINST_SHIFT	16		/* bit shift */
/* unused:              0x00080000 */

/* WARNING: if new fields are added, they must be initialized in event_accept()
 * and freed in session_free() !
 */

/* Termination sequence tracing.
 *
 * These values have to be set into the field term_trace of a session when
 * closing a session (half or full). They are only meant for post-mortem
 * analysis. The value must be assigned this way :
 *    trace_term(s, TT_XXX);
 *
 * One TT_XXX value is assigned to each location in the code which may be
 * involved in a connection closing. Since a full session close generally
 * involves 4 steps, we will be able to read these steps afterwards by simply
 * checking the code. Value TT_NONE is zero and must never be set, as it means
 * the connection was not closed. Value TT_ANON must be used when no value was
 * assigned to a specific code part. Never ever reuse an already assigned code
 * as it will defeat the purpose of this trace. It is wise to use a per-file
 * anonymous value though.
 */
#define TT_BIT_SHIFT 8
enum {
	TT_NONE     = 0,
	TT_ANON     = 1,
	TT_CLIENT   = 0x10,
	TT_CLIENT_1,
	TT_CLIENT_2,
	TT_HTTP_CLI = 0x20,
	TT_HTTP_CLI_1,
	TT_HTTP_CLI_2,
	TT_HTTP_CLI_3,
	TT_HTTP_CLI_4,
	TT_HTTP_CLI_5,
	TT_HTTP_CLI_6,
	TT_HTTP_CLI_7,
	TT_HTTP_CLI_8,
	TT_HTTP_CLI_9,
	TT_HTTP_CLI_10,
	TT_HTTP_SRV = 0x30,
	TT_HTTP_SRV_1,
	TT_HTTP_SRV_2,
	TT_HTTP_SRV_3,
	TT_HTTP_SRV_4,
	TT_HTTP_SRV_5,
	TT_HTTP_SRV_6,
	TT_HTTP_SRV_7,
	TT_HTTP_SRV_8,
	TT_HTTP_SRV_9,
	TT_HTTP_SRV_10,
	TT_HTTP_SRV_11,
	TT_HTTP_SRV_12,
	TT_HTTP_SRV_13,
	TT_HTTP_SRV_14,
	TT_HTTP_CNT = 0x40,
	TT_HTTP_CNT_1,
	TT_HTTP_URI = 0x50,
	TT_HTTP_URI_1,
};


/*
 * Note: some session flags have dependencies :
 *  - SN_DIRECT cannot exist without SN_ASSIGNED, because a server is
 *    immediately assigned when SN_DIRECT is determined. Both must be cleared
 *    when clearing SN_DIRECT (eg: redispatch).
 *  - ->srv has no meaning without SN_ASSIGNED and must not be checked without
 *    it. ->prev_srv should be used to check previous ->srv. If SN_ASSIGNED is
 *    set and sess->srv is NULL, then it is a dispatch or proxy mode.
 *  - a session being processed has srv_conn set.
 *  - srv_conn might remain after SN_DIRECT has been reset, but the assigned
 *    server should eventually be released.
 */
struct session {
	struct list list;			/* position in global sessions list */
	struct list back_refs;			/* list of users tracking this session */
	struct task *task;			/* the task associated with this session */
	/* application specific below */
	struct listener *listener;		/* the listener by which the request arrived */
	struct proxy *fe;			/* the proxy this session depends on for the client side */
	struct proxy *be;			/* the proxy this session depends on for the server side */
	int conn_retries;			/* number of connect retries left */
	int flags;				/* some flags describing the session */
	unsigned term_trace;			/* term trace: 4*8 bits indicating which part of the code closed */
	struct buffer *req;			/* request buffer */
	struct buffer *rep;			/* response buffer */
	struct stream_interface si[2];          /* client and server stream interfaces */
	struct sockaddr_storage cli_addr;	/* the client address */
	struct sockaddr_storage frt_addr;	/* the frontend address reached by the client if SN_FRT_ADDR_SET is set */
	struct sockaddr_in srv_addr;		/* the address to connect to */
	struct sockaddr_in from_addr;		/* the address to spoof when connecting to the server (transparent mode) */
	struct server *srv;			/* the server the session will be running or has been running on */
	struct server *srv_conn;		/* session already has a slot on a server and is not in queue */
	struct server *prev_srv;		/* the server the was running on, after a redispatch, otherwise NULL */
	struct pendconn *pend_pos;		/* if not NULL, points to the position in the pending queue */
	struct http_txn txn;			/* current HTTP transaction being processed. Should become a list. */

	struct {
		struct stksess *ts;
		struct stktable *table;
		int flags;
	} store[8];				/* tracked stickiness values to store */
	int store_count;

	struct {
		int logwait;			/* log fields waiting to be collected : LW_* */
		struct timeval accept_date;	/* date of the accept() in user date */
		struct timeval tv_accept;	/* date of the accept() in internal date (monotonic) */
		struct timeval tv_request;	/* date the request arrives, {0,0} if never occurs */
		long  t_queue;			/* delay before the session gets out of the connect queue, -1 if never occurs */
		long  t_connect;		/* delay before the connect() to the server succeeds, -1 if never occurs */
		long  t_data;			/* delay before the first data byte from the server ... */
		unsigned long t_close;		/* total session duration */
		unsigned long srv_queue_size;	/* number of sessions waiting for a connect slot on this server at accept() time (in direct assignment) */
		unsigned long prx_queue_size;	/* overall number of sessions waiting for a connect slot on this instance at accept() time */
		long long bytes_in;		/* number of bytes transferred from the client to the server */
		long long bytes_out;		/* number of bytes transferred from the server to the client */
	} logs;
	void (*do_log)(struct session *s);	/* the function to call in order to log (or NULL) */
	void (*srv_error)(struct session *s,	/* the function to call upon unrecoverable server errors (or NULL) */
			  struct stream_interface *si);
	short int data_source;			/* where to get the data we generate ourselves */
	short int data_state;			/* where to get the data we generate ourselves */
	union {
		struct {
			struct proxy *px;
			struct server *sv;
			struct listener *l;
			short px_st, sv_st;	/* DATA_ST_INIT or DATA_ST_DATA */
			unsigned int flags;	/* STAT_* */
			int iid, type, sid;	/* proxy id, type and service id if bounding of stats is enabled */
		} stats;
		struct {
			struct bref bref;	/* back-reference from the session being dumped */
			void *target;		/* session we want to dump, or NULL for all */
			unsigned int uid;	/* if non-null, the uniq_id of the session being dumped */
			int section;		/* section of the session being dumped */
			int pos;		/* last position of the current session's buffer */
		} sess;
		struct {
			int iid;		/* if >= 0, ID of the proxy to filter on */
			struct proxy *px;	/* current proxy being dumped, NULL = not started yet. */
			unsigned int buf;	/* buffer being dumped, 0 = req, 1 = rep */
			unsigned int sid;	/* session ID of error being dumped */
			int ptr;		/* <0: headers, >=0 : text pointer to restart from */
			int bol;		/* pointer to beginning of current line */
		} errors;
		struct {
			const char *msg;	/* pointer to a persistent message to be returned in PRINT state */
		} cli;
	} data_ctx;				/* used by stats I/O handlers to dump the stats */
	unsigned int uniq_id;			/* unique ID used for the traces */
};


#endif /* _TYPES_SESSION_H */

/*
 * Local variables:
 *  c-indent-level: 8
 *  c-basic-offset: 8
 * End:
 */