1 /*
2  * include/haproxy/server-t.h
3  * This file defines everything related to servers.
4  *
5  * Copyright (C) 2000-2012 Willy Tarreau - w@1wt.eu
6  *
7  * This library is free software; you can redistribute it and/or
8  * modify it under the terms of the GNU Lesser General Public
9  * License as published by the Free Software Foundation, version 2.1
10  * exclusively.
11  *
12  * This library is distributed in the hope that it will be useful,
13  * but WITHOUT ANY WARRANTY; without even the implied warranty of
14  * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the GNU
15  * Lesser General Public License for more details.
16  *
17  * You should have received a copy of the GNU Lesser General Public
18  * License along with this library; if not, write to the Free Software
19  * Foundation, Inc., 51 Franklin Street, Fifth Floor, Boston, MA  02110-1301  USA
20  */
21 
22 #ifndef _HAPROXY_SERVER_T_H
23 #define _HAPROXY_SERVER_T_H
24 
25 #include <netinet/in.h>
26 #include <arpa/inet.h>
27 
28 #include <import/eb32tree.h>
29 #include <import/ebmbtree.h>
30 
31 #include <haproxy/api-t.h>
32 #include <haproxy/check-t.h>
33 #include <haproxy/connection-t.h>
34 #include <haproxy/counters-t.h>
35 #include <haproxy/dns-t.h>
36 #include <haproxy/freq_ctr-t.h>
37 #include <haproxy/listener-t.h>
38 #include <haproxy/obj_type-t.h>
39 #include <haproxy/openssl-compat.h>
40 #include <haproxy/ssl_sock-t.h>
41 #include <haproxy/task-t.h>
42 #include <haproxy/thread-t.h>
43 
44 
45 /* server states. Only SRV_ST_STOPPED indicates a down server. */
46 enum srv_state {
47 	SRV_ST_STOPPED = 0,              /* the server is down. Please keep set to zero. */
48 	SRV_ST_STARTING,                 /* the server is warming up (up but throttled) */
49 	SRV_ST_RUNNING,                  /* the server is fully up */
50 	SRV_ST_STOPPING,                 /* the server is up but soft-stopping (eg: 404) */
51 } __attribute__((packed));
52 
53 /* Administrative status : a server runs in one of these 3 stats :
54  *   - READY : normal mode
55  *   - DRAIN : takes no new visitor, equivalent to weight == 0
56  *   - MAINT : maintenance mode, no more traffic nor health checks.
57  *
58  * Each server may be in maintenance by itself or may inherit this status from
59  * another server it tracks. It can also be in drain mode by itself or inherit
60  * it from another server. Let's store these origins here as flags. These flags
61  * are combined this way :
62  *
63  *      FMAINT  IMAINT  FDRAIN  IDRAIN  Resulting state
64  *         0       0       0       0    READY
65  *         0       0       0       1    DRAIN
66  *         0       0       1       x    DRAIN
67  *         0       1       x       x    MAINT
68  *         1       x       x       x    MAINT
69  *
70  * This can be simplified this way :
71  *
72  *   state_str = (state & MAINT) ? "MAINT" : (state & DRAIN) : "DRAIN" : "READY"
73  */
74 enum srv_admin {
75 	SRV_ADMF_FMAINT    = 0x01,        /* the server was explicitly forced into maintenance */
76 	SRV_ADMF_IMAINT    = 0x02,        /* the server has inherited the maintenance status from a tracked server */
77 	SRV_ADMF_MAINT     = 0x23,        /* mask to check if any maintenance flag is present */
78 	SRV_ADMF_CMAINT    = 0x04,        /* the server is in maintenance because of the configuration */
79 	SRV_ADMF_FDRAIN    = 0x08,        /* the server was explicitly forced into drain state */
80 	SRV_ADMF_IDRAIN    = 0x10,        /* the server has inherited the drain status from a tracked server */
81 	SRV_ADMF_DRAIN     = 0x18,        /* mask to check if any drain flag is present */
82 	SRV_ADMF_RMAINT    = 0x20,        /* the server is down because of an IP address resolution failure */
83 	SRV_ADMF_HMAINT    = 0x40,        /* the server FQDN has been set from socket stats */
84 } __attribute__((packed));
85 
86 /* options for servers' "init-addr" parameter
87  * this parameter may be used to drive HAProxy's behavior when parsing a server
88  * address at start up time.
89  * These values are stored as a list into an integer ordered from first to last
90  * starting with the lowest to highest bits. SRV_IADDR_END (0) is used to
91  * indicate the end of the list. 3 bits are enough to store each value.
92  */
93 enum srv_initaddr {
94 	SRV_IADDR_END      = 0,           /* end of the list */
95 	SRV_IADDR_NONE     = 1,           /* the server won't have any address at start up */
96 	SRV_IADDR_LIBC     = 2,           /* address set using the libc DNS resolver */
97 	SRV_IADDR_LAST     = 3,           /* we set the IP address found in state-file for this server */
98 	SRV_IADDR_IP       = 4,           /* we set an arbitrary IP address to the server */
99 } __attribute__((packed));
100 
101 /* server-state-file version */
102 #define SRV_STATE_FILE_VERSION 1
103 #define SRV_STATE_FILE_VERSION_MIN 1
104 #define SRV_STATE_FILE_VERSION_MAX 1
105 #define SRV_STATE_FILE_FIELD_NAMES \
106     "be_id "                      \
107     "be_name "                    \
108     "srv_id "                     \
109     "srv_name "                   \
110     "srv_addr "                   \
111     "srv_op_state "               \
112     "srv_admin_state "            \
113     "srv_uweight "                \
114     "srv_iweight "                \
115     "srv_time_since_last_change " \
116     "srv_check_status "           \
117     "srv_check_result "           \
118     "srv_check_health "           \
119     "srv_check_state "            \
120     "srv_agent_state "            \
121     "bk_f_forced_id "             \
122     "srv_f_forced_id "            \
123     "srv_fqdn "                   \
124     "srv_port "                   \
125     "srvrecord"
126 
127 #define SRV_STATE_FILE_MAX_FIELDS 20
128 #define SRV_STATE_FILE_NB_FIELDS_VERSION_1 20
129 #define SRV_STATE_LINE_MAXLEN 512
130 
131 /* server flags -- 32 bits */
132 #define SRV_F_BACKUP       0x0001        /* this server is a backup server */
133 #define SRV_F_MAPPORTS     0x0002        /* this server uses mapped ports */
134 #define SRV_F_NON_STICK    0x0004        /* never add connections allocated to this server to a stick table */
135 #define SRV_F_USE_NS_FROM_PP 0x0008      /* use namespace associated with connection if present */
136 #define SRV_F_FORCED_ID    0x0010        /* server's ID was forced in the configuration */
137 #define SRV_F_CHECKADDR    0x0020        /* this server has a check addr configured */
138 #define SRV_F_CHECKPORT    0x0040        /* this server has a check port configured */
139 #define SRV_F_AGENTADDR    0x0080        /* this server has a agent addr configured */
140 #define SRV_F_COOKIESET    0x0100        /* this server has a cookie configured, so don't generate dynamic cookies */
141 #define SRV_F_FASTOPEN     0x0200        /* Use TCP Fast Open to connect to server */
142 #define SRV_F_SOCKS4_PROXY 0x0400        /* this server uses SOCKS4 proxy */
143 #define SRV_F_NO_RESOLUTION 0x0800       /* disable runtime DNS resolution on this server */
144 
145 /* configured server options for send-proxy (server->pp_opts) */
146 #define SRV_PP_V1               0x0001   /* proxy protocol version 1 */
147 #define SRV_PP_V2               0x0002   /* proxy protocol version 2 */
148 #define SRV_PP_V2_SSL           0x0004   /* proxy protocol version 2 with SSL */
149 #define SRV_PP_V2_SSL_CN        0x0008   /* proxy protocol version 2 with CN */
150 #define SRV_PP_V2_SSL_KEY_ALG   0x0010   /* proxy protocol version 2 with cert key algorithm */
151 #define SRV_PP_V2_SSL_SIG_ALG   0x0020   /* proxy protocol version 2 with cert signature algorithm */
152 #define SRV_PP_V2_SSL_CIPHER    0x0040   /* proxy protocol version 2 with cipher used */
153 #define SRV_PP_V2_AUTHORITY     0x0080   /* proxy protocol version 2 with authority */
154 #define SRV_PP_V2_CRC32C        0x0100   /* proxy protocol version 2 with crc32c */
155 #define SRV_PP_V2_UNIQUE_ID     0x0200   /* proxy protocol version 2 with unique ID */
156 
157 /* function which act on servers need to return various errors */
158 #define SRV_STATUS_OK       0   /* everything is OK. */
159 #define SRV_STATUS_INTERNAL 1   /* other unrecoverable errors. */
160 #define SRV_STATUS_NOSRV    2   /* no server is available */
161 #define SRV_STATUS_FULL     3   /* the/all server(s) are saturated */
162 #define SRV_STATUS_QUEUED   4   /* the/all server(s) are saturated but the connection was queued */
163 
164 /* various constants */
165 #define SRV_UWGHT_RANGE 256
166 #define SRV_UWGHT_MAX   (SRV_UWGHT_RANGE)
167 #define SRV_EWGHT_RANGE (SRV_UWGHT_RANGE * BE_WEIGHT_SCALE)
168 #define SRV_EWGHT_MAX   (SRV_UWGHT_MAX   * BE_WEIGHT_SCALE)
169 
170 /* server ssl options */
171 #define SRV_SSL_O_NONE           0x0000
172 #define SRV_SSL_O_NO_TLS_TICKETS 0x0100 /* disable session resumption tickets */
173 #define SRV_SSL_O_NO_REUSE       0x200  /* disable session reuse */
174 #define SRV_SSL_O_EARLY_DATA     0x400  /* Allow using early data */
175 
176 /* log servers ring's protocols options */
177 enum srv_log_proto {
178         SRV_LOG_PROTO_LEGACY,         // messages on TCP separated by LF
179         SRV_LOG_PROTO_OCTET_COUNTING, // TCP frames: MSGLEN SP MSG
180 };
181 
182 struct pid_list {
183 	struct list list;
184 	pid_t pid;
185 	struct task *t;
186 	int status;
187 	int exited;
188 };
189 
190 /* A tree occurrence is a descriptor of a place in a tree, with a pointer back
191  * to the server itself.
192  */
193 struct server;
194 struct tree_occ {
195 	struct server *server;
196 	struct eb32_node node;
197 };
198 
199 struct proxy;
200 struct server {
201 	enum obj_type obj_type;                 /* object type == OBJ_TYPE_SERVER */
202 	enum srv_state next_state, cur_state;   /* server state among SRV_ST_* */
203 	enum srv_admin next_admin, cur_admin;   /* server maintenance status : SRV_ADMF_* */
204 	signed char use_ssl;		        /* ssl enabled (1: on, 0: disabled, -1 forced off)  */
205 	unsigned int pp_opts;                   /* proxy protocol options (SRV_PP_*) */
206 	struct server *next;
207 	int cklen;				/* the len of the cookie, to speed up checks */
208 	int rdr_len;				/* the length of the redirection prefix */
209 	char *cookie;				/* the id set in the cookie */
210 	char *rdr_pfx;				/* the redirection prefix */
211 
212 	struct proxy *proxy;			/* the proxy this server belongs to */
213 	const struct mux_proto_list *mux_proto;       /* the mux to use for all outgoing connections (specified by the "proto" keyword) */
214 	int served;				/* # of active sessions currently being served (ie not pending) */
215 	int cur_sess;				/* number of currently active sessions (including syn_sent) */
216 	unsigned maxconn, minconn;		/* max # of active sessions (0 = unlimited), min# for dynamic limit. */
217 	int nbpend;				/* number of pending connections */
218 	unsigned int queue_idx;			/* count of pending connections which have been de-queued */
219 	int maxqueue;				/* maximum number of pending connections allowed */
220 	struct freq_ctr sess_per_sec;		/* sessions per second on this server */
221 	struct be_counters counters;		/* statistics counters */
222 
223 	struct eb_root pendconns;		/* pending connections */
224 	struct list actconns;			/* active connections */
225 	struct mt_list *idle_conns;		/* shareable idle connections*/
226 	struct mt_list *safe_conns;		/* safe idle connections */
227 	struct list *available_conns;           /* Connection in used, but with still new streams available */
228 	unsigned int pool_purge_delay;          /* Delay before starting to purge the idle conns pool */
229 	unsigned int low_idle_conns;            /* min idle connection count to start picking from other threads */
230 	unsigned int max_idle_conns;            /* Max number of connection allowed in the orphan connections list */
231 	unsigned int curr_idle_conns;           /* Current number of orphan idling connections, both the idle and the safe lists */
232 	unsigned int curr_idle_nb;              /* Current number of connections in the idle list */
233 	unsigned int curr_safe_nb;              /* Current number of connections in the safe list */
234 	unsigned int curr_used_conns;           /* Current number of used connections */
235 	unsigned int max_used_conns;            /* Max number of used connections (the counter is reset at each connection purges */
236 	unsigned int est_need_conns;            /* Estimate on the number of needed connections (max of curr and previous max_used) */
237 	unsigned int *curr_idle_thr;            /* Current number of orphan idling connections per thread */
238 	unsigned int next_takeover;             /* thread ID to try to steal connections from next time */
239 	int max_reuse;                          /* Max number of requests on a same connection */
240 	struct eb32_node idle_node;             /* When to next do cleanup in the idle connections */
241 	struct task *warmup;                    /* the task dedicated to the warmup when slowstart is set */
242 
243 	struct conn_src conn_src;               /* connection source settings */
244 
245 	struct server *track;                   /* the server we're currently tracking, if any */
246 	struct server *trackers;                /* the list of servers tracking us, if any */
247 	struct server *tracknext;               /* next server tracking <track> in <track>'s trackers list */
248 	char *trackit;				/* temporary variable to make assignment deferrable */
249 	int consecutive_errors;			/* current number of consecutive errors */
250 	int consecutive_errors_limit;		/* number of consecutive errors that triggers an event */
251 	short observe, onerror;			/* observing mode: one of HANA_OBS_*; what to do on error: on of ANA_ONERR_* */
252 	short onmarkeddown;			/* what to do when marked down: one of HANA_ONMARKEDDOWN_* */
253 	short onmarkedup;			/* what to do when marked up: one of HANA_ONMARKEDUP_* */
254 	unsigned int flags;                     /* server flags (SRV_F_*) */
255 	int slowstart;				/* slowstart time in seconds (ms in the conf) */
256 
257 	char *id;				/* just for identification */
258 	unsigned iweight,uweight, cur_eweight;	/* initial weight, user-specified weight, and effective weight */
259 	unsigned wscore;			/* weight score, used during srv map computation */
260 	unsigned next_eweight;			/* next pending eweight to commit */
261 	unsigned rweight;			/* remainer of weight in the current LB tree */
262 	unsigned cumulative_weight;		/* weight of servers prior to this one in the same group, for chash balancing */
263 	unsigned npos, lpos;			/* next and last positions in the LB tree */
264 	struct eb32_node lb_node;               /* node used for tree-based load balancing */
265 	struct eb_root *lb_tree;                /* we want to know in what tree the server is */
266 	struct server *next_full;               /* next server in the temporary full list */
267 	unsigned lb_nodes_tot;                  /* number of allocated lb_nodes (C-HASH) */
268 	unsigned lb_nodes_now;                  /* number of lb_nodes placed in the tree (C-HASH) */
269 	struct tree_occ *lb_nodes;              /* lb_nodes_tot * struct tree_occ */
270 
271 	const struct netns_entry *netns;        /* contains network namespace name or NULL. Network namespace comes from configuration */
272 	/* warning, these structs are huge, keep them at the bottom */
273 	struct sockaddr_storage addr;           /* the address to connect to, doesn't include the port */
274 	struct xprt_ops *xprt;                  /* transport-layer operations */
275 	unsigned int svc_port;                  /* the port to connect to (for relevant families) */
276 	unsigned down_time;			/* total time the server was down */
277 	time_t last_change;			/* last time, when the state was changed */
278 
279 	int puid;				/* proxy-unique server ID, used for SNMP, and "first" LB algo */
280 	int tcp_ut;                             /* for TCP, user timeout */
281 
282 	int do_check;                           /* temporary variable used during parsing to denote if health checks must be enabled */
283 	int do_agent;                           /* temporary variable used during parsing to denote if an auxiliary agent check must be enabled */
284 	struct check check;                     /* health-check specific configuration */
285 	struct check agent;                     /* agent specific configuration */
286 
287 	struct dns_requester *dns_requester;	/* used to link a server to its DNS resolution */
288 	char *resolvers_id;			/* resolvers section used by this server */
289 	struct dns_resolvers *resolvers;	/* pointer to the resolvers structure used by this server */
290 	char *lastaddr;				/* the address string provided by the server-state file */
291 	struct dns_options dns_opts;
292 	int hostname_dn_len;			/* string length of the server hostname in Domain Name format */
293 	char *hostname_dn;			/* server hostname in Domain Name format */
294 	char *hostname;				/* server hostname */
295 	struct sockaddr_storage init_addr;	/* plain IP address specified on the init-addr line */
296 	unsigned int init_addr_methods;		/* initial address setting, 3-bit per method, ends at 0, enough to store 10 entries */
297 	enum srv_log_proto log_proto;		/* used proto to emit messages on server lines from ring section */
298 
299 #ifdef USE_OPENSSL
300 	char *sni_expr;             /* Temporary variable to store a sample expression for SNI */
301 	struct {
302 		SSL_CTX *ctx;
303 		struct {
304 			unsigned char *ptr;
305 			int size;
306 			int allocated_size;
307 			char *sni; /* SNI used for the session */
308 		} * reused_sess;
309 		char *ciphers;			/* cipher suite to use if non-null */
310 #if (HA_OPENSSL_VERSION_NUMBER >= 0x10101000L && !defined OPENSSL_IS_BORINGSSL && !defined LIBRESSL_VERSION_NUMBER)
311 		char *ciphersuites;			/* TLS 1.3 cipher suite to use if non-null */
312 #endif
313 		int options;			/* ssl options */
314 		int verify;			/* verify method (set of SSL_VERIFY_* flags) */
315 		struct tls_version_filter methods;	/* ssl methods */
316 		char *verify_host;              /* hostname of certificate must match this host */
317 		char *ca_file;			/* CAfile to use on verify */
318 		char *crl_file;			/* CRLfile to use on verify */
319 		char *client_crt;		/* client certificate to send */
320 		struct sample_expr *sni;        /* sample expression for SNI */
321 #ifdef OPENSSL_NPN_NEGOTIATED
322 		char *npn_str;                  /* NPN protocol string */
323 		int npn_len;                    /* NPN protocol string length */
324 #endif
325 #ifdef TLSEXT_TYPE_application_layer_protocol_negotiation
326 		char *alpn_str;                 /* ALPN protocol string */
327 		int alpn_len;                   /* ALPN protocol string length */
328 #endif
329 	} ssl_ctx;
330 #endif
331 	struct dns_srvrq *srvrq;		/* Pointer representing the DNS SRV requeest, if any */
332 	struct list srv_rec_item;		/* to attach server to a srv record item */
333 	struct list ip_rec_item;		/* to attach server to a A or AAAA record item */
334 	struct ebpt_node host_dn;		/* hostdn store for srvrq and state file matching*/
335 	__decl_thread(HA_SPINLOCK_T lock);   /* may enclose the proxy's lock, must not be taken under */
336 	struct task *srvrq_check;               /* Task testing SRV record expiration date for this server */
337 	struct {
338 		const char *file;		/* file where the section appears */
339 		struct eb32_node id;		/* place in the tree of used IDs */
340 		struct ebpt_node name;		/* place in the tree of used names */
341 		int line;			/* line where the section appears */
342 	} conf;					/* config information */
343 	/* Template information used only for server objects which
344 	 * serve as template filled at parsing time and used during
345 	 * server allocations from server templates.
346 	 */
347 	struct {
348 		char *prefix;
349 		int nb_low;
350 		int nb_high;
351 	} tmpl_info;
352 	struct {
353 		long duration;
354 		short status, code;
355 		char reason[128];
356 	} op_st_chg;				/* operational status change's reason */
357 	char adm_st_chg_cause[48];		/* administrative status change's cause */
358 
359 	struct sockaddr_storage socks4_addr;	/* the address of the SOCKS4 Proxy, including the port */
360 };
361 
362 
363 /* Storage structure to load server-state lines from a flat file into
364  * an ebtree, for faster processing
365  */
366 struct state_line {
367 	char *line;
368 	struct ebmb_node name_name;
369 	/* WARNING don't put anything after name_name, it's used by the key */
370 };
371 
372 
373 /* Descriptor for a "server" keyword. The ->parse() function returns 0 in case of
374  * success, or a combination of ERR_* flags if an error is encountered. The
375  * function pointer can be NULL if not implemented. The function also has an
376  * access to the current "server" config line. The ->skip value tells the parser
377  * how many words have to be skipped after the keyword. If the function needs to
378  * parse more keywords, it needs to update cur_arg.
379  */
380 struct srv_kw {
381 	const char *kw;
382 	int (*parse)(char **args, int *cur_arg, struct proxy *px, struct server *srv, char **err);
383 	int skip; /* nb min of args to skip, for use when kw is not handled */
384 	int default_ok; /* non-zero if kw is supported in default-server section */
385 };
386 
387 /*
388  * A keyword list. It is a NULL-terminated array of keywords. It embeds a
389  * struct list in order to be linked to other lists, allowing it to easily
390  * be declared where it is needed, and linked without duplicating data nor
391  * allocating memory. It is also possible to indicate a scope for the keywords.
392  */
393 struct srv_kw_list {
394 	const char *scope;
395 	struct list list;
396 	struct srv_kw kw[VAR_ARRAY];
397 };
398 
399 #endif /* _HAPROXY_SERVER_T_H */
400 
401 /*
402  * Local variables:
403  *  c-indent-level: 8
404  *  c-basic-offset: 8
405  * End:
406  */
407