MEDIUM: Split up struct server's check element

This is in preparation for associating a agent check
with a server which runs as well as the server's existing check.

The split has been made by:
* Moving elements of struct server's check element that will
  be shared by both checks into a new check_common element
  of struct server.
* Moving the remaining elements to a new struct check and
  making struct server's check element a struct check.
* Adding a server element to struct check, a back-pointer
  to the server element it is a member of.
  - At this time the server could be obtained using
    container_of, however, this will not be so easy
    once a second struct check element is added to struct server
    to accommodate an agent health check.

Signed-off-by: Simon Horman <horms@verge.net.au>
diff --git a/include/types/server.h b/include/types/server.h
index 0d50575..9d07d5a 100644
--- a/include/types/server.h
+++ b/include/types/server.h
@@ -103,6 +103,22 @@
 	struct eb32_node node;
 };
 
+struct check {
+	struct connection *conn;		/* connection state for health checks */
+
+	short port;				/* the port to use for the health checks */
+	struct buffer *bi, *bo;			/* input and output buffers to send/recv check */
+	struct task *task;			/* the task associated to the health check processing, NULL if disabled */
+	struct timeval start;			/* last health check start time */
+	long duration;				/* time in ms took to finish last health check */
+	short status, code;			/* check result, check code */
+	char desc[HCHK_DESC_LEN];		/* health check descritpion */
+	int use_ssl;				/* use SSL for health checks */
+	int send_proxy;				/* send a PROXY protocol header with checks */
+	int inter, fastinter, downinter;        /* checks: time in milliseconds */
+	struct server *server;			/* back-pointer to server */
+};
+
 struct server {
 	enum obj_type obj_type;                 /* object type == OBJ_TYPE_SERVER */
 	struct server *next;
@@ -137,7 +153,6 @@
 	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 inter, fastinter, downinter;	/* checks: time in milliseconds */
 	int slowstart;				/* slowstart time in seconds (ms in the conf) */
 	int result;				/* health-check result : SRV_CHK_* */
 
@@ -163,21 +178,13 @@
 
 	int puid;				/* proxy-unique server ID, used for SNMP, and "first" LB algo */
 
-	struct {                                /* health-check specific configuration */
-		struct connection *conn;        /* connection state for health checks */
+	struct {                                /* configuration  used by health-check and agent-check */
 		struct protocol *proto;	        /* server address protocol for health checks */
 		struct xprt_ops *xprt;          /* transport layer operations for health checks */
 		struct sockaddr_storage addr;   /* the address to check, if different from <addr> */
-		short port;                     /* the port to use for the health checks */
-		struct buffer *bi, *bo;         /* input and output buffers to send/recv check */
-		struct task *task;              /* the task associated to the health check processing, NULL if disabled */
-		struct timeval start;           /* last health check start time */
-		long duration;                  /* time in ms took to finish last health check */
-		short status, code;             /* check result, check code */
-		char desc[HCHK_DESC_LEN];       /* health check descritpion */
-		int use_ssl;                    /* use SSL for health checks */
-		int send_proxy;                 /* send a PROXY protocol header with checks */
-	} check;
+	} check_common;
+
+	struct check check;                     /* health-check specific configuration */
 
 #ifdef USE_OPENSSL
 	int use_ssl;				/* ssl enabled */
diff --git a/src/cfgparse.c b/src/cfgparse.c
index 28507dd..539c4ec 100644
--- a/src/cfgparse.c
+++ b/src/cfgparse.c
@@ -1322,9 +1322,9 @@
 	defproxy.maxconn = cfg_maxpconn;
 	defproxy.conn_retries = CONN_RETRIES;
 
-	defproxy.defsrv.inter = DEF_CHKINTR;
-	defproxy.defsrv.fastinter = 0;
-	defproxy.defsrv.downinter = 0;
+	defproxy.defsrv.check.inter = DEF_CHKINTR;
+	defproxy.defsrv.check.fastinter = 0;
+	defproxy.defsrv.check.downinter = 0;
 	defproxy.defsrv.rise = DEF_RISETIME;
 	defproxy.defsrv.fall = DEF_FALLTIME;
 	defproxy.defsrv.check.port = 0;
@@ -4241,8 +4241,8 @@
 			}
 
 			newsrv->addr = *sk;
-			newsrv->proto = newsrv->check.proto = protocol_by_family(newsrv->addr.ss_family);
-			newsrv->xprt  = newsrv->check.xprt  = &raw_sock;
+			newsrv->proto = newsrv->check_common.proto = protocol_by_family(newsrv->addr.ss_family);
+			newsrv->xprt  = newsrv->check_common.xprt  = &raw_sock;
 
 			if (!newsrv->proto) {
 				Alert("parsing [%s:%d] : Unknown protocol family %d '%s'\n",
@@ -4251,11 +4251,11 @@
 				goto out;
 			}
 
-			newsrv->check.use_ssl	= curproxy->defsrv.check.use_ssl;
+			newsrv->check.use_ssl = curproxy->defsrv.check.use_ssl;
 			newsrv->check.port	= curproxy->defsrv.check.port;
-			newsrv->inter		= curproxy->defsrv.inter;
-			newsrv->fastinter	= curproxy->defsrv.fastinter;
-			newsrv->downinter	= curproxy->defsrv.downinter;
+			newsrv->check.inter	= curproxy->defsrv.check.inter;
+			newsrv->check.fastinter	= curproxy->defsrv.check.fastinter;
+			newsrv->check.downinter	= curproxy->defsrv.check.downinter;
 			newsrv->rise		= curproxy->defsrv.rise;
 			newsrv->fall		= curproxy->defsrv.fall;
 			newsrv->maxqueue	= curproxy->defsrv.maxqueue;
@@ -4343,7 +4343,7 @@
 					err_code |= ERR_ALERT | ERR_FATAL;
 					goto out;
 				}
-				newsrv->inter = val;
+				newsrv->check.inter = val;
 				cur_arg += 2;
 			}
 			else if (!strcmp(args[cur_arg], "fastinter")) {
@@ -4360,7 +4360,7 @@
 					err_code |= ERR_ALERT | ERR_FATAL;
 					goto out;
 				}
-				newsrv->fastinter = val;
+				newsrv->check.fastinter = val;
 				cur_arg += 2;
 			}
 			else if (!strcmp(args[cur_arg], "downinter")) {
@@ -4377,7 +4377,7 @@
 					err_code |= ERR_ALERT | ERR_FATAL;
 					goto out;
 				}
-				newsrv->downinter = val;
+				newsrv->check.downinter = val;
 				cur_arg += 2;
 			}
 			else if (!defsrv && !strcmp(args[cur_arg], "addr")) {
@@ -4408,7 +4408,7 @@
 					goto out;
 				}
 
-				newsrv->check.addr = *sk;
+				newsrv->check_common.addr = *sk;
 				cur_arg += 2;
 			}
 			else if (!strcmp(args[cur_arg], "port")) {
@@ -4844,15 +4844,15 @@
 			 * same as for the production traffic. Otherwise we use raw_sock by
 			 * default, unless one is specified.
 			 */
-			if (!newsrv->check.port && !is_addr(&newsrv->check.addr)) {
+			if (!newsrv->check.port && !is_addr(&newsrv->check_common.addr)) {
 #ifdef USE_OPENSSL
 				newsrv->check.use_ssl |= newsrv->use_ssl;
 #endif
 				newsrv->check.send_proxy |= (newsrv->state & SRV_SEND_PROXY);
 			}
-			/* try to get the port from check.addr if check.port not set */
+			/* try to get the port from check_core.addr if check.port not set */
 			if (!newsrv->check.port)
-				newsrv->check.port = get_host_port(&newsrv->check.addr);
+				newsrv->check.port = get_host_port(&newsrv->check_common.addr);
 
 			if (!newsrv->check.port)
 				newsrv->check.port = realport; /* by default */
@@ -4902,6 +4902,7 @@
 
 			newsrv->check.conn->t.sock.fd = -1; /* no check in progress yet */
 			newsrv->check.status = HCHK_STATUS_INI;
+			newsrv->check.server = newsrv;
 			newsrv->state |= SRV_CHECKED;
 		}
 
diff --git a/src/checks.c b/src/checks.c
index 512eb2e..19cf011 100644
--- a/src/checks.c
+++ b/src/checks.c
@@ -691,8 +691,8 @@
 	s->consecutive_errors = 0;
 	s->counters.failed_hana++;
 
-	if (s->fastinter) {
-		expire = tick_add(now_ms, MS_TO_TICKS(s->fastinter));
+	if (s->check.fastinter) {
+		expire = tick_add(now_ms, MS_TO_TICKS(s->check.fastinter));
 		if (s->check.task->expire > expire) {
 			s->check.task->expire = expire;
 			/* requeue check task with new expire */
@@ -1354,14 +1354,14 @@
 		conn->flags = CO_FL_NONE;
 		conn->err_code = CO_ER_NONE;
 		conn->target = &s->obj_type;
-		conn_prepare(conn, &check_conn_cb, s->check.proto, s->check.xprt, s);
+		conn_prepare(conn, &check_conn_cb, s->check_common.proto, s->check_common.xprt, s);
 
 		/* no client address */
 		clear_addr(&conn->addr.from);
 
-		if (is_addr(&s->check.addr))
+		if (is_addr(&s->check_common.addr))
 			/* we'll connect to the check addr specified on the server */
-			conn->addr.to = s->check.addr;
+			conn->addr.to = s->check_common.addr;
 		else
 			/* we'll connect to the addr on the server */
 			conn->addr.to = s->addr;
@@ -1380,9 +1380,9 @@
 		 * connect() when a pure TCP check is used (without PROXY protocol).
 		 */
 		ret = SN_ERR_INTERNAL;
-		if (s->check.proto->connect)
-			ret = s->check.proto->connect(conn, s->proxy->options2 & PR_O2_CHK_ANY,
-		                                      s->check.send_proxy ? 1 : (s->proxy->options2 & PR_O2_CHK_ANY) ? 0 : 2);
+		if (s->check_common.proto->connect)
+			ret = s->check_common.proto->connect(conn, s->proxy->options2 & PR_O2_CHK_ANY,
+							     s->check.send_proxy ? 1 : (s->proxy->options2 & PR_O2_CHK_ANY) ? 0 : 2);
 		conn->flags |= CO_FL_WAKE_DATA;
 		if (s->check.send_proxy)
 			conn->flags |= CO_FL_LOCAL_SPROXY;
@@ -1393,7 +1393,7 @@
 			 * to establish but only when timeout.check is set
 			 * as it may be to short for a full check otherwise
 			 */
-			t->expire = tick_add(now_ms, MS_TO_TICKS(s->inter));
+			t->expire = tick_add(now_ms, MS_TO_TICKS(s->check.inter));
 
 			if (s->proxy->timeout.check && s->proxy->timeout.connect) {
 				int t_con = tick_add(now_ms, s->proxy->timeout.connect);
@@ -1431,7 +1431,7 @@
 			int t_con;
 
 			t_con = tick_add(t->expire, s->proxy->timeout.connect);
-			t->expire = tick_add(t->expire, MS_TO_TICKS(s->inter));
+			t->expire = tick_add(t->expire, MS_TO_TICKS(s->check.inter));
 
 			if (s->proxy->timeout.check)
 				t->expire = tick_first(t->expire, t_con);
@@ -1524,7 +1524,7 @@
 
  reschedule:
 	while (tick_is_expired(t->expire, now_ms))
-		t->expire = tick_add(t->expire, MS_TO_TICKS(s->inter));
+		t->expire = tick_add(t->expire, MS_TO_TICKS(s->check.inter));
  out_wait:
 	return t;
 }
diff --git a/src/server.c b/src/server.c
index e542bb7..e0ce6d9 100644
--- a/src/server.c
+++ b/src/server.c
@@ -33,12 +33,12 @@
 int srv_getinter(const struct server *s)
 {
 	if ((s->state & SRV_CHECKED) && (s->health == s->rise + s->fall - 1))
-		return s->inter;
+		return s->check.inter;
 
 	if (!(s->state & SRV_RUNNING) && s->health==0)
-		return (s->downinter)?(s->downinter):(s->inter);
+		return (s->check.downinter)?(s->check.downinter):(s->check.inter);
 
-	return (s->fastinter)?(s->fastinter):(s->inter);
+	return (s->check.fastinter)?(s->check.fastinter):(s->check.inter);
 }
 
 /*
diff --git a/src/ssl_sock.c b/src/ssl_sock.c
index 06c744a..e1e18c3 100644
--- a/src/ssl_sock.c
+++ b/src/ssl_sock.c
@@ -916,7 +916,7 @@
 	if (srv->use_ssl)
 		srv->xprt = &ssl_sock;
 	if (srv->check.use_ssl)
-		srv->check.xprt = &ssl_sock;
+		srv->check_common.xprt = &ssl_sock;
 
 	srv->ssl_ctx.ctx = SSL_CTX_new(SSLv23_client_method());
 	if (!srv->ssl_ctx.ctx) {