include/types/server.h

/*
 * include/types/server.h
 * This file defines everything related to servers.
 *
 * Copyright (C) 2000-2012 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_SERVER_H
#define _TYPES_SERVER_H

#include <netinet/in.h>
#include <arpa/inet.h>

#ifdef USE_OPENSSL
#include <openssl/ssl.h>
#endif

#include <common/config.h>
#include <common/mini-clist.h>
#include <eb32tree.h>

#include <types/connection.h>
#include <types/counters.h>
#include <types/freq_ctr.h>
#include <types/obj_type.h>
#include <types/proxy.h>
#include <types/queue.h>
#include <types/task.h>
#include <types/checks.h>


/* server states. Only SRV_ST_DOWN indicates a down server. */
enum srv_state {
	SRV_ST_STOPPED = 0,              /* the server is down. Please keep set to zero. */
	SRV_ST_STARTING,                 /* the server is warming up (up but throttled) */
	SRV_ST_RUNNING,                  /* the server is fully up */
	SRV_ST_STOPPING,                 /* the server is up but soft-stopping (eg: 404) */
};

/* Administrative status : a server runs in one of these 3 stats :
 *   - READY : normal mode
 *   - DRAIN : takes no new visitor, equivalent to weight == 0
 *   - MAINT : maintenance mode, no more traffic nor health checks.
 *
 * Each server may be in maintenance by itself or may inherit this status from
 * another server it tracks. It can also be in drain mode by itself or inherit
 * it from another server. Let's store these origins here as flags. These flags
 * are combined this way :
 *
 *      FMAINT  IMAINT  FDRAIN  IDRAIN  Resulting state
 *         0       0       0       0    READY
 *         0       0       0       1    DRAIN
 *         0       0       1       x    DRAIN
 *         0       1       x       x    MAINT
 *         1       x       x       x    MAINT
 *
 * This can be simplified this way :
 *
 *   state_str = (state & MAINT) ? "MAINT" : (state & DRAIN) : "DRAIN" : "READY"
 */
enum srv_admin {
	SRV_ADMF_FMAINT    = 0x1,        /* the server was explicitly forced into maintenance */
	SRV_ADMF_IMAINT    = 0x2,        /* the server has inherited the maintenance status from a tracked server */
	SRV_ADMF_MAINT     = 0x3,        /* mask to check if any maintenance flag is present */
	SRV_ADMF_FDRAIN    = 0x4,        /* the server was explicitly forced into drain state */
	SRV_ADMF_IDRAIN    = 0x8,        /* the server has inherited the drain status from a tracked server */
	SRV_ADMF_DRAIN     = 0xC,        /* mask to check if any drain flag is present */
};

/* server flags */
#define SRV_F_BACKUP       0x0001        /* this server is a backup server */
#define SRV_F_MAPPORTS     0x0002        /* this server uses mapped ports */
#define SRV_F_NON_STICK    0x0004        /* never add connections allocated to this server to a stick table */

/* configured server options for send-proxy (server->pp_opts) */
#define SRV_PP_V1          0x0001        /* proxy protocol version 1 */
#define SRV_PP_V2          0x0002        /* proxy protocol version 2 */
#define SRV_PP_V2_SSL      0x0004        /* proxy protocol version 2 with SSL*/
#define SRV_PP_V2_SSL_CN   0x0008        /* proxy protocol version 2 with SSL and CN*/

/* function which act on servers need to return various errors */
#define SRV_STATUS_OK       0   /* everything is OK. */
#define SRV_STATUS_INTERNAL 1   /* other unrecoverable errors. */
#define SRV_STATUS_NOSRV    2   /* no server is available */
#define SRV_STATUS_FULL     3   /* the/all server(s) are saturated */
#define SRV_STATUS_QUEUED   4   /* the/all server(s) are saturated but the connection was queued */

/* various constants */
#define SRV_UWGHT_RANGE 256
#define SRV_UWGHT_MAX   (SRV_UWGHT_RANGE)
#define SRV_EWGHT_RANGE (SRV_UWGHT_RANGE * BE_WEIGHT_SCALE)
#define SRV_EWGHT_MAX   (SRV_UWGHT_MAX   * BE_WEIGHT_SCALE)

#ifdef USE_OPENSSL
/* server ssl options */
#define SRV_SSL_O_NONE         0x0000
#define SRV_SSL_O_NO_VMASK     0x000F /* force version mask */
#define SRV_SSL_O_NO_SSLV3     0x0001 /* disable SSLv3 */
#define SRV_SSL_O_NO_TLSV10    0x0002 /* disable TLSv1.0 */
#define SRV_SSL_O_NO_TLSV11    0x0004 /* disable TLSv1.1 */
#define SRV_SSL_O_NO_TLSV12    0x0008 /* disable TLSv1.2 */
/* 0x000F reserved for 'no' protocol version options */
#define SRV_SSL_O_USE_VMASK    0x00F0 /* force version mask */
#define SRV_SSL_O_USE_SSLV3    0x0010 /* force SSLv3 */
#define SRV_SSL_O_USE_TLSV10   0x0020 /* force TLSv1.0 */
#define SRV_SSL_O_USE_TLSV11   0x0040 /* force TLSv1.1 */
#define SRV_SSL_O_USE_TLSV12   0x0080 /* force TLSv1.2 */
/* 0x00F0 reserved for 'force' protocol version options */
#define SRV_SSL_O_NO_TLS_TICKETS 0x0100 /* disable session resumption tickets */
#endif

struct pid_list {
	struct list list;
	pid_t pid;
	struct task *t;
	int status;
	int exited;
};

/* A tree occurrence is a descriptor of a place in a tree, with a pointer back
 * to the server itself.
 */
struct server;
struct tree_occ {
	struct server *server;
	struct eb32_node node;
};

struct server {
	enum obj_type obj_type;                 /* object type == OBJ_TYPE_SERVER */
	enum srv_state state, prev_state;       /* server state among SRV_ST_* */
	enum srv_admin admin, prev_admin;       /* server maintenance status : SRV_ADMF_* */
	unsigned char flags;                    /* server flags (SRV_F_*) */
	struct server *next;
	int cklen;				/* the len of the cookie, to speed up checks */
	int rdr_len;				/* the length of the redirection prefix */
	char *cookie;				/* the id set in the cookie */
	char *rdr_pfx;				/* the redirection prefix */
	int pp_opts;				/* proxy protocol options (SRV_PP_*) */

	struct proxy *proxy;			/* the proxy this server belongs to */
	int served;				/* # of active sessions currently being served (ie not pending) */
	int cur_sess;				/* number of currently active sessions (including syn_sent) */
	unsigned maxconn, minconn;		/* max # of active sessions (0 = unlimited), min# for dynamic limit. */
	int nbpend;				/* number of pending connections */
	int maxqueue;				/* maximum number of pending connections allowed */
	struct freq_ctr sess_per_sec;		/* sessions per second on this server */
	struct srvcounters counters;		/* statistics counters */

	struct list pendconns;			/* pending connections */
	struct list actconns;			/* active connections */
	struct task *warmup;                    /* the task dedicated to the warmup when slowstart is set */

	struct conn_src conn_src;               /* connection source settings */

	struct server *track;                   /* the server we're currently tracking, if any */
	struct server *trackers;                /* the list of servers tracking us, if any */
	struct server *tracknext;               /* next server tracking <track> in <track>'s trackers list */
	char *trackit;				/* temporary variable to make assignment deferrable */
	int consecutive_errors;			/* current number of consecutive errors */
	int consecutive_errors_limit;		/* number of consecutive errors that triggers an event */
	short observe, onerror;			/* observing mode: one of HANA_OBS_*; what to do on error: on of ANA_ONERR_* */
	short onmarkeddown;			/* what to do when marked down: one of HANA_ONMARKEDDOWN_* */
	short onmarkedup;			/* what to do when marked up: one of HANA_ONMARKEDUP_* */
	int slowstart;				/* slowstart time in seconds (ms in the conf) */

	char *id;				/* just for identification */
	unsigned iweight,uweight, eweight;	/* initial weight, user-specified weight, and effective weight */
	unsigned wscore;			/* weight score, used during srv map computation */
	unsigned prev_eweight;			/* eweight before last change */
	unsigned rweight;			/* remainer of weight in the current LB tree */
	unsigned npos, lpos;			/* next and last positions in the LB tree */
	struct eb32_node lb_node;               /* node used for tree-based load balancing */
	struct eb_root *lb_tree;                /* we want to know in what tree the server is */
	struct server *next_full;               /* next server in the temporary full list */
	unsigned lb_nodes_tot;                  /* number of allocated lb_nodes (C-HASH) */
	unsigned lb_nodes_now;                  /* number of lb_nodes placed in the tree (C-HASH) */
	struct tree_occ *lb_nodes;              /* lb_nodes_tot * struct tree_occ */

	/* warning, these structs are huge, keep them at the bottom */
	struct sockaddr_storage addr;		/* the address to connect to */
	struct protocol *proto;	                /* server address protocol */
	struct xprt_ops *xprt;                  /* transport-layer operations */
	unsigned down_time;			/* total time the server was down */
	time_t last_change;			/* last time, when the state was changed */

	int puid;				/* proxy-unique server ID, used for SNMP, and "first" LB algo */

	struct {                                /* configuration  used by health-check and agent-check */
		struct protocol *proto;	        /* server address protocol for health checks */
		struct sockaddr_storage addr;   /* the address to check, if different from <addr> */
	} check_common;

	struct check check;                     /* health-check specific configuration */
	struct check agent;                     /* agent specific configuration */

#ifdef USE_OPENSSL
	int use_ssl;				/* ssl enabled */
	struct {
		SSL_CTX *ctx;
		SSL_SESSION *reused_sess;
		char *ciphers;			/* cipher suite to use if non-null */
		int options;			/* ssl options */
		int verify;			/* verify method (set of SSL_VERIFY_* flags) */
		char *verify_host;              /* hostname of certificate must match this host */
		char *ca_file;			/* CAfile to use on verify */
		char *crl_file;			/* CRLfile to use on verify */
		char *client_crt;		/* client certificate to send */
	} ssl_ctx;
#endif
	struct {
		const char *file;		/* file where the section appears */
		int line;			/* line where the section appears */
		struct eb32_node id;		/* place in the tree of used IDs */
	} conf;					/* config information */
};

/* Descriptor for a "server" keyword. The ->parse() function returns 0 in case of
 * success, or a combination of ERR_* flags if an error is encountered. The
 * function pointer can be NULL if not implemented. The function also has an
 * access to the current "server" config line. The ->skip value tells the parser
 * how many words have to be skipped after the keyword. If the function needs to
 * parse more keywords, it needs to update cur_arg.
 */
struct srv_kw {
	const char *kw;
	int (*parse)(char **args, int *cur_arg, struct proxy *px, struct server *srv, char **err);
	int skip; /* nb min of args to skip, for use when kw is not handled */
	int default_ok; /* non-zero if kw is supported in default-server section */
};

/*
 * A keyword list. It is a NULL-terminated array of keywords. It embeds a
 * struct list in order to be linked to other lists, allowing it to easily
 * be declared where it is needed, and linked without duplicating data nor
 * allocating memory. It is also possible to indicate a scope for the keywords.
 */
struct srv_kw_list {
	const char *scope;
	struct list list;
	struct srv_kw kw[VAR_ARRAY];
};

#endif /* _TYPES_SERVER_H */

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