REORG: include: move checks.h to haproxy/check{,-t}.h

All includes that were not absolutely necessary were removed because
checks.h happens to very often be part of dependency loops. A warning
was added about this in check-t.h. The fields, enums and structs were
a bit tidied because it's particularly tedious to find anything there.
It would make sense to split this in two or more files (at least
extract tcp-checks).

The file was renamed to the singular because it was one of the rare
exceptions to have an "s" appended to its name compared to the struct
name.
diff --git a/include/types/checks.h b/include/haproxy/check-t.h
similarity index 95%
rename from include/types/checks.h
rename to include/haproxy/check-t.h
index 9d05ffc..832a3f5 100644
--- a/include/types/checks.h
+++ b/include/haproxy/check-t.h
@@ -1,7 +1,9 @@
 /*
- * Health-checks.
+ * include/haproxy/check-t.h
+ * Health-checks definitions, enums, macros and bitfields.
  *
  * Copyright 2008-2009 Krzysztof Piotr Oledzki <ole@ans.pl>
+ * Copyright (C) 2000-2020 Willy Tarreau - w@1wt.eu
  *
  * This program is free software; you can redistribute it and/or
  * modify it under the terms of the GNU General Public License
@@ -10,22 +12,25 @@
  *
  */
 
-#ifndef _TYPES_CHECKS_H
-#define _TYPES_CHECKS_H
+#ifndef _HAPROXY_CHECKS_T_H
+#define _HAPROXY_CHECKS_T_H
 
-#include <haproxy/api-t.h>
 #include <import/ebpttree.h>
-
 #include <import/ist.h>
+#include <haproxy/buf-t.h>
 #include <haproxy/connection-t.h>
 #include <haproxy/list-t.h>
 #include <haproxy/obj_type-t.h>
-#include <haproxy/regex-t.h>
-#include <haproxy/buf-t.h>
+#include <haproxy/api-t.h>
+#include <haproxy/vars-t.h>
 
-#include <haproxy/sample-t.h>
-#include <types/session.h>
-#include <haproxy/task-t.h>
+/* Please note: this file tends to commonly be part of circular dependencies,
+ * so it is important to keep its includes list to the minimum possible (i.e.
+ * only types whose size needs to be known). Since there are no function
+ * prototypes nor pointers here, forward declarations are not really necessary.
+ * This file oughtt to be split into multiple parts, at least regular checks vs
+ * tcp-checks.
+ */
 
 /* enum used by check->result. Must remain in this order, as some code uses
  * result >= CHK_RES_PASSED to declare success.
@@ -131,8 +136,99 @@
 	HANA_OBS_SIZE
 };
 
+/* options for tcp-check connect */
+#define TCPCHK_OPT_NONE            0x0000  /* no options specified, default */
+#define TCPCHK_OPT_SEND_PROXY      0x0001  /* send proxy-protocol string */
+#define TCPCHK_OPT_SSL             0x0002  /* SSL connection */
+#define TCPCHK_OPT_LINGER          0x0004  /* Do not RST connection, let it linger */
+#define TCPCHK_OPT_DEFAULT_CONNECT 0x0008  /* Do a connect using server params */
+#define TCPCHK_OPT_IMPLICIT        0x0010  /* Implicit connect */
+#define TCPCHK_OPT_SOCKS4          0x0020  /* check the connection via socks4 proxy */
+
+enum tcpcheck_send_type {
+	TCPCHK_SEND_UNDEF = 0,  /* Send is not parsed. */
+	TCPCHK_SEND_STRING,     /* Send an ASCII string. */
+	TCPCHK_SEND_BINARY,     /* Send a binary sequence. */
+	TCPCHK_SEND_STRING_LF,  /* Send an ASCII log-format string. */
+	TCPCHK_SEND_BINARY_LF,  /* Send a binary log-format sequence. */
+	TCPCHK_SEND_HTTP,       /* Send an HTTP request */
+};
+
+/* flags for tcp-check send */
+#define TCPCHK_SND_HTTP_FL_URI_FMT    0x0001 /* Use a log-format string for the uri */
+#define TCPCHK_SND_HTTP_FL_BODY_FMT   0x0002 /* Use a log-format string for the body */
+#define TCPCHK_SND_HTTP_FROM_OPT      0x0004 /* Send rule coming from "option httpck" directive */
+
+enum tcpcheck_eval_ret {
+	TCPCHK_EVAL_WAIT = 0,
+	TCPCHK_EVAL_STOP,
+	TCPCHK_EVAL_CONTINUE,
+};
+
+enum tcpcheck_expect_type {
+	TCPCHK_EXPECT_UNDEF = 0,         /* Match is not used. */
+	TCPCHK_EXPECT_STRING,            /* Matches a string. */
+	TCPCHK_EXPECT_STRING_REGEX,      /* Matches a regular pattern. */
+	TCPCHK_EXPECT_STRING_LF,         /* Matches a log-format string. */
+	TCPCHK_EXPECT_BINARY,            /* Matches a binary sequence on a hex-encoded text. */
+	TCPCHK_EXPECT_BINARY_REGEX,      /* Matches a regular pattern on a hex-encoded text. */
+	TCPCHK_EXPECT_BINARY_LF,         /* Matches a log-format binary sequence on a hex-encoded text. */
+	TCPCHK_EXPECT_CUSTOM,            /* Execute a custom function. */
+	TCPCHK_EXPECT_HTTP_STATUS,       /* Matches a list of codes on the HTTP status */
+	TCPCHK_EXPECT_HTTP_STATUS_REGEX, /* Matches a regular pattern on the HTTP status */
+	TCPCHK_EXPECT_HTTP_HEADER,       /* Matches on HTTP headers */
+	TCPCHK_EXPECT_HTTP_BODY,         /* Matches a string oa the HTTP payload */
+	TCPCHK_EXPECT_HTTP_BODY_REGEX,   /* Matches a regular pattern on a HTTP payload */
+	TCPCHK_EXPECT_HTTP_BODY_LF,      /* Matches a log-format string on the HTTP payload */
+};
+
+/* tcp-check expect flags */
+#define TCPCHK_EXPT_FL_INV             0x0001 /* Matching is inversed */
+#define TCPCHK_EXPT_FL_HTTP_HNAME_STR  0x0002 /* Exact match on the HTTP header name */
+#define TCPCHK_EXPT_FL_HTTP_HNAME_BEG  0x0004 /* Prefix match on the HTTP header name */
+#define TCPCHK_EXPT_FL_HTTP_HNAME_END  0x0008 /* Suffix match on the HTTP header name */
+#define TCPCHK_EXPT_FL_HTTP_HNAME_SUB  0x0010 /* Substring match on the HTTP header name */
+#define TCPCHK_EXPT_FL_HTTP_HNAME_REG  0x0020 /* Regex match on the HTTP header name */
+#define TCPCHK_EXPT_FL_HTTP_HNAME_FMT  0x0040 /* The HTTP header name is a log-format string */
+#define TCPCHK_EXPT_FL_HTTP_HVAL_NONE  0x0080 /* No match on the HTTP header value */
+#define TCPCHK_EXPT_FL_HTTP_HVAL_STR   0x0100 /* Exact match on the HTTP header value */
+#define TCPCHK_EXPT_FL_HTTP_HVAL_BEG   0x0200 /* Prefix match on the HTTP header value */
+#define TCPCHK_EXPT_FL_HTTP_HVAL_END   0x0400 /* Suffix match on the HTTP header value */
+#define TCPCHK_EXPT_FL_HTTP_HVAL_SUB   0x0800 /* Substring match on the HTTP header value */
+#define TCPCHK_EXPT_FL_HTTP_HVAL_REG   0x1000 /* Regex match on the HTTP header value*/
+#define TCPCHK_EXPT_FL_HTTP_HVAL_FMT   0x2000 /* The HTTP header value is a log-format string */
+#define TCPCHK_EXPT_FL_HTTP_HVAL_FULL  0x4000 /* Match the full header value ( no stop on commas ) */
+
+#define TCPCHK_EXPT_FL_HTTP_HNAME_TYPE 0x003E /* Mask to get matching method on header name */
+#define TCPCHK_EXPT_FL_HTTP_HVAL_TYPE  0x1F00 /* Mask to get matching method on header value */
+
+/* possible actions for tcpcheck_rule->action */
+enum tcpcheck_rule_type {
+	TCPCHK_ACT_SEND = 0, /* send action, regular string format */
+	TCPCHK_ACT_EXPECT, /* expect action, either regular or binary string */
+	TCPCHK_ACT_CONNECT, /* connect action, to probe a new port */
+	TCPCHK_ACT_COMMENT, /* no action, simply a comment used for logs */
+	TCPCHK_ACT_ACTION_KW, /* custom registered action_kw rule. */
+};
+
+#define TCPCHK_RULES_NONE           0x00000000
+#define TCPCHK_RULES_UNUSED_TCP_RS  0x00000001 /* An unused tcp-check ruleset exists */
+#define TCPCHK_RULES_UNUSED_HTTP_RS 0x00000002 /* An unused http-check ruleset exists */
+#define TCPCHK_RULES_UNUSED_RS      0x00000003 /* Mask for unused ruleset */
+
+#define TCPCHK_RULES_PGSQL_CHK   0x00000010
+#define TCPCHK_RULES_REDIS_CHK   0x00000020
+#define TCPCHK_RULES_SMTP_CHK    0x00000030
+#define TCPCHK_RULES_HTTP_CHK    0x00000040
+#define TCPCHK_RULES_MYSQL_CHK   0x00000050
+#define TCPCHK_RULES_LDAP_CHK    0x00000060
+#define TCPCHK_RULES_SSL3_CHK    0x00000070
+#define TCPCHK_RULES_AGENT_CHK   0x00000080
+#define TCPCHK_RULES_SPOP_CHK    0x00000090
+/* Unused 0x000000A0..0x00000FF0 (reserverd for futur proto) */
+#define TCPCHK_RULES_TCP_CHK     0x00000FF0
+#define TCPCHK_RULES_PROTO_CHK   0x00000FF0 /* Mask to cover protocol check */
+
-struct proxy;
-struct server;
 struct check {
 	enum obj_type obj_type;                 /* object type == OBJ_TYPE_CHECK */
 	struct session *sess;			/* Health check session. */
@@ -171,14 +267,6 @@
 	int via_socks4;                         /* check the connection via socks4 proxy */
 };
 
-#define TCPCHK_OPT_NONE            0x0000  /* no options specified, default */
-#define TCPCHK_OPT_SEND_PROXY      0x0001  /* send proxy-protocol string */
-#define TCPCHK_OPT_SSL             0x0002  /* SSL connection */
-#define TCPCHK_OPT_LINGER          0x0004  /* Do not RST connection, let it linger */
-#define TCPCHK_OPT_DEFAULT_CONNECT 0x0008  /* Do a connect using server params */
-#define TCPCHK_OPT_IMPLICIT        0x0010  /* Implicit connect */
-#define TCPCHK_OPT_SOCKS4          0x0020  /* check the connection via socks4 proxy */
-
 struct tcpcheck_connect {
 	char *sni;                     /* server name to use for SSL connections */
 	char *alpn;                    /* ALPN to use for the SSL connection */
@@ -190,15 +278,6 @@
 	struct sockaddr_storage addr;  /* the address to the connect */
 };
 
-enum tcpcheck_send_type {
-	TCPCHK_SEND_UNDEF = 0,  /* Send is not parsed. */
-	TCPCHK_SEND_STRING,     /* Send an ASCII string. */
-	TCPCHK_SEND_BINARY,     /* Send a binary sequence. */
-	TCPCHK_SEND_STRING_LF,  /* Send an ASCII log-format string. */
-	TCPCHK_SEND_BINARY_LF,  /* Send a binary log-format sequence. */
-	TCPCHK_SEND_HTTP,       /* Send an HTTP request */
-};
-
 struct tcpcheck_http_hdr {
 	struct ist  name;  /* the header name */
 	struct list value; /* the log-format string value */
@@ -210,10 +289,6 @@
 	size_t num;               /* number of entry in the array */
 };
 
-#define TCPCHK_SND_HTTP_FL_URI_FMT    0x0001 /* Use a log-format string for the uri */
-#define TCPCHK_SND_HTTP_FL_BODY_FMT   0x0002 /* Use a log-format string for the body */
-#define TCPCHK_SND_HTTP_FROM_OPT      0x0004 /* Send rule coming from "option httpck" directive */
-
 struct tcpcheck_send {
 	enum tcpcheck_send_type type;
 	union {
@@ -236,49 +311,6 @@
 	};
 };
 
-enum tcpcheck_eval_ret {
-	TCPCHK_EVAL_WAIT = 0,
-	TCPCHK_EVAL_STOP,
-	TCPCHK_EVAL_CONTINUE,
-};
-
-enum tcpcheck_expect_type {
-	TCPCHK_EXPECT_UNDEF = 0,         /* Match is not used. */
-	TCPCHK_EXPECT_STRING,            /* Matches a string. */
-	TCPCHK_EXPECT_STRING_REGEX,      /* Matches a regular pattern. */
-	TCPCHK_EXPECT_STRING_LF,         /* Matches a log-format string. */
-	TCPCHK_EXPECT_BINARY,            /* Matches a binary sequence on a hex-encoded text. */
-	TCPCHK_EXPECT_BINARY_REGEX,      /* Matches a regular pattern on a hex-encoded text. */
-	TCPCHK_EXPECT_BINARY_LF,         /* Matches a log-format binary sequence on a hex-encoded text. */
-	TCPCHK_EXPECT_CUSTOM,            /* Execute a custom function. */
-	TCPCHK_EXPECT_HTTP_STATUS,       /* Matches a list of codes on the HTTP status */
-	TCPCHK_EXPECT_HTTP_STATUS_REGEX, /* Matches a regular pattern on the HTTP status */
-	TCPCHK_EXPECT_HTTP_HEADER,       /* Matches on HTTP headers */
-	TCPCHK_EXPECT_HTTP_BODY,         /* Matches a string oa the HTTP payload */
-	TCPCHK_EXPECT_HTTP_BODY_REGEX,   /* Matches a regular pattern on a HTTP payload */
-	TCPCHK_EXPECT_HTTP_BODY_LF,      /* Matches a log-format string on the HTTP payload */
-};
-
-/* tcp-check expect flags */
-#define TCPCHK_EXPT_FL_INV             0x0001 /* Matching is inversed */
-#define TCPCHK_EXPT_FL_HTTP_HNAME_STR  0x0002 /* Exact match on the HTTP header name */
-#define TCPCHK_EXPT_FL_HTTP_HNAME_BEG  0x0004 /* Prefix match on the HTTP header name */
-#define TCPCHK_EXPT_FL_HTTP_HNAME_END  0x0008 /* Suffix match on the HTTP header name */
-#define TCPCHK_EXPT_FL_HTTP_HNAME_SUB  0x0010 /* Substring match on the HTTP header name */
-#define TCPCHK_EXPT_FL_HTTP_HNAME_REG  0x0020 /* Regex match on the HTTP header name */
-#define TCPCHK_EXPT_FL_HTTP_HNAME_FMT  0x0040 /* The HTTP header name is a log-format string */
-#define TCPCHK_EXPT_FL_HTTP_HVAL_NONE  0x0080 /* No match on the HTTP header value */
-#define TCPCHK_EXPT_FL_HTTP_HVAL_STR   0x0100 /* Exact match on the HTTP header value */
-#define TCPCHK_EXPT_FL_HTTP_HVAL_BEG   0x0200 /* Prefix match on the HTTP header value */
-#define TCPCHK_EXPT_FL_HTTP_HVAL_END   0x0400 /* Suffix match on the HTTP header value */
-#define TCPCHK_EXPT_FL_HTTP_HVAL_SUB   0x0800 /* Substring match on the HTTP header value */
-#define TCPCHK_EXPT_FL_HTTP_HVAL_REG   0x1000 /* Regex match on the HTTP header value*/
-#define TCPCHK_EXPT_FL_HTTP_HVAL_FMT   0x2000 /* The HTTP header value is a log-format string */
-#define TCPCHK_EXPT_FL_HTTP_HVAL_FULL  0x4000 /* Match the full header value ( no stop on commas ) */
-
-#define TCPCHK_EXPT_FL_HTTP_HNAME_TYPE 0x003E /* Mask to get matching method on header name */
-#define TCPCHK_EXPT_FL_HTTP_HVAL_TYPE  0x1F00 /* Mask to get matching method on header value */
-
 struct tcpcheck_expect {
 	enum tcpcheck_expect_type type;   /* Type of pattern used for matching. */
 	unsigned int flags;               /* TCPCHK_EXPT_FL_* */
@@ -318,15 +350,6 @@
 	struct act_rule *rule;
 };
 
-/* possible actions for tcpcheck_rule->action */
-enum tcpcheck_rule_type {
-	TCPCHK_ACT_SEND = 0, /* send action, regular string format */
-	TCPCHK_ACT_EXPECT, /* expect action, either regular or binary string */
-	TCPCHK_ACT_CONNECT, /* connect action, to probe a new port */
-	TCPCHK_ACT_COMMENT, /* no action, simply a comment used for logs */
-	TCPCHK_ACT_ACTION_KW, /* custom registered action_kw rule. */
-};
-
 struct tcpcheck_rule {
 	struct list list;                       /* list linked to from the proxy */
 	enum tcpcheck_rule_type action;         /* type of the rule. */
@@ -340,24 +363,6 @@
 	};
 };
 
-#define TCPCHK_RULES_NONE           0x00000000
-#define TCPCHK_RULES_UNUSED_TCP_RS  0x00000001 /* An unused tcp-check ruleset exists */
-#define TCPCHK_RULES_UNUSED_HTTP_RS 0x00000002 /* An unused http-check ruleset exists */
-#define TCPCHK_RULES_UNUSED_RS      0x00000003 /* Mask for unused ruleset */
-
-#define TCPCHK_RULES_PGSQL_CHK   0x00000010
-#define TCPCHK_RULES_REDIS_CHK   0x00000020
-#define TCPCHK_RULES_SMTP_CHK    0x00000030
-#define TCPCHK_RULES_HTTP_CHK    0x00000040
-#define TCPCHK_RULES_MYSQL_CHK   0x00000050
-#define TCPCHK_RULES_LDAP_CHK    0x00000060
-#define TCPCHK_RULES_SSL3_CHK    0x00000070
-#define TCPCHK_RULES_AGENT_CHK   0x00000080
-#define TCPCHK_RULES_SPOP_CHK    0x00000090
-/* Unused 0x000000A0..0x00000FF0 (reserverd for futur proto) */
-#define TCPCHK_RULES_TCP_CHK     0x00000FF0
-#define TCPCHK_RULES_PROTO_CHK   0x00000FF0 /* Mask to cover protocol check */
-
 /* A list of tcp-check vars, to be registered before executing a ruleset */
 struct tcpcheck_var {
 	struct ist name;         /* the variable name with the scope */
@@ -379,4 +384,4 @@
 };
 
 
-#endif /* _TYPES_CHECKS_H */
+#endif /* _HAPROXY_CHECKS_T_H */
diff --git a/include/proto/checks.h b/include/haproxy/check.h
similarity index 73%
rename from include/proto/checks.h
rename to include/haproxy/check.h
index d24943e..85fc49b 100644
--- a/include/proto/checks.h
+++ b/include/haproxy/check.h
@@ -1,30 +1,33 @@
 /*
-  include/proto/checks.h
-  Functions prototypes for the checks.
-
-  Copyright (C) 2000-2009 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
-*/
+ * include/haproxy/check.h
+ * Functions prototypes for the checks.
+ *
+ * Copyright (C) 2000-2020 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 _PROTO_CHECKS_H
-#define _PROTO_CHECKS_H
+#ifndef _HAPROXY_CHECKS_H
+#define _HAPROXY_CHECKS_H
 
 #include <haproxy/action-t.h>
+#include <haproxy/check-t.h>
+#include <haproxy/list-t.h>
 #include <haproxy/mailers.h>
-#include <types/checks.h>
+#include <types/proxy.h>
+#include <types/server.h>
 
 const char *get_check_status_description(short check_status);
 const char *get_check_status_info(short check_status);
@@ -88,7 +91,7 @@
 
 int set_srv_agent_send(struct server *srv, const char *send);
 
-#endif /* _PROTO_CHECKS_H */
+#endif /* _HAPROXY_CHECKS_H */
 
 /*
  * Local variables:
diff --git a/include/haproxy/obj_type.h b/include/haproxy/obj_type.h
index 5659705..6f741e4 100644
--- a/include/haproxy/obj_type.h
+++ b/include/haproxy/obj_type.h
@@ -23,6 +23,7 @@
 #define _HAPROXY_OBJ_TYPE_H
 
 #include <haproxy/api.h>
+#include <haproxy/check-t.h>
 #include <haproxy/connection-t.h>
 #include <haproxy/listener-t.h>
 #include <haproxy/obj_type-t.h>
@@ -32,7 +33,6 @@
 #include <types/server.h>
 #include <types/stream.h>
 #include <types/stream_interface.h>
-#include <types/checks.h>
 
 static inline enum obj_type obj_type(const enum obj_type *t)
 {
diff --git a/include/proto/http_fetch.h b/include/proto/http_fetch.h
index 3a7261a..2c84435 100644
--- a/include/proto/http_fetch.h
+++ b/include/proto/http_fetch.h
@@ -23,10 +23,10 @@
 #define _PROTO_HTTP_FETCH_H
 
 #include <haproxy/api.h>
+#include <haproxy/check-t.h>
 #include <haproxy/htx.h>
 #include <haproxy/arg-t.h>
 #include <types/channel.h>
-#include <types/checks.h>
 #include <haproxy/sample-t.h>
 
 struct htx *smp_prefetch_htx(struct sample *smp, struct channel *chn, struct check *check, int vol);
diff --git a/include/types/proxy.h b/include/types/proxy.h
index a72232f..5ba68c7 100644
--- a/include/types/proxy.h
+++ b/include/types/proxy.h
@@ -28,6 +28,7 @@
 #include <arpa/inet.h>
 
 #include <haproxy/api-t.h>
+#include <haproxy/check-t.h>
 #include <haproxy/chunk.h>
 #include <haproxy/counters-t.h>
 #include <haproxy/http-t.h>
@@ -40,7 +41,6 @@
 
 #include <types/acl.h>
 #include <types/backend.h>
-#include <types/checks.h>
 #include <types/filters.h>
 #include <haproxy/freq_ctr-t.h>
 #include <types/log.h>
diff --git a/include/types/server.h b/include/types/server.h
index 38326b0..1f9ef1f 100644
--- a/include/types/server.h
+++ b/include/types/server.h
@@ -25,6 +25,7 @@
 #include <netinet/in.h>
 #include <arpa/inet.h>
 
+#include <haproxy/check-t.h>
 #include <haproxy/counters-t.h>
 #include <haproxy/dns-t.h>
 #include <haproxy/api-t.h>
@@ -41,7 +42,6 @@
 #include <types/queue.h>
 #include <types/ssl_sock.h>
 #include <haproxy/task-t.h>
-#include <types/checks.h>
 
 
 /* server states. Only SRV_ST_STOPPED indicates a down server. */