MEDIUM: checks: Implement redis check using tcp-check rules

A share tcp-check ruleset is now created to support redis checks. This way no
extra memory is used if several backends use a redis check.

The following sequence is used :

  tcp-check send "*1\r\n$4\r\nPING\r\n"

  tcp-check expect string "+PONG\r\n" error-status "L7STS" \
      on-error "%[check.payload(),cut_crlf]" on-success "Redis server is ok"
diff --git a/include/common/defaults.h b/include/common/defaults.h
index 43d287d..d52e005 100644
--- a/include/common/defaults.h
+++ b/include/common/defaults.h
@@ -179,7 +179,7 @@
 #define DEF_CHECK_PATH  ""
 #define DEF_SMTP_CHECK_REQ   "HELO localhost\r\n"
 #define DEF_LDAP_CHECK_REQ   "\x30\x0c\x02\x01\x01\x60\x07\x02\x01\x03\x04\x00\x80\x00"
-#define DEF_REDIS_CHECK_REQ  "*1\r\n$4\r\nPING\r\n"
+
 
 #define DEF_HANA_ONERR		HANA_ONERR_FAILCHK
 #define DEF_HANA_ERRLIMIT	10
diff --git a/include/proto/checks.h b/include/proto/checks.h
index d0c827b..1c76a89 100644
--- a/include/proto/checks.h
+++ b/include/proto/checks.h
@@ -69,6 +69,8 @@
 int spoe_prepare_healthcheck_request(char **req, int *len);
 int spoe_handle_healthcheck_response(char *frame, size_t size, char *err, int errlen);
 
+int proxy_parse_redis_check_opt(char **args, int cur_arg, struct proxy *curpx, struct proxy *defpx,
+				const char *file, int line);
 #endif /* _PROTO_CHECKS_H */
 
 /*
diff --git a/include/types/checks.h b/include/types/checks.h
index 30f7d75..b5f4649 100644
--- a/include/types/checks.h
+++ b/include/types/checks.h
@@ -308,9 +308,11 @@
 	};
 };
 
-#define TCPCHK_RULES_NONE   0x00000000
-#define TCPCHK_RULES_SHARED 0x00000001 /* Set for shared list of tcp-check rules */
-#define TCPCHK_RULES_DEF    0x00000002 /* Ruleset inherited from the default section */
+#define TCPCHK_RULES_NONE        0x00000000
+#define TCPCHK_RULES_SHARED      0x00000001 /* Set for shared list of tcp-check rules */
+#define TCPCHK_RULES_DEF         0x00000002 /* Ruleset inherited from the default section */
+
+#define TCPCHK_RULES_REDIS_CHK   0x00000020
 
 /* A list of tcp-check vars, to be registered before executing a ruleset */
 struct tcpcheck_var {
diff --git a/include/types/proxy.h b/include/types/proxy.h
index 270445a..792c252 100644
--- a/include/types/proxy.h
+++ b/include/types/proxy.h
@@ -170,7 +170,7 @@
 /* server health checks */
 #define PR_O2_CHK_NONE  0x00000000      /* no L7 health checks configured (TCP by default) */
 #define PR_O2_PGSQL_CHK 0x10000000      /* use PGSQL check for server health */
-#define PR_O2_REDIS_CHK 0x20000000      /* use LDAP check for server health */
+/* unused: 0x20000000 */
 #define PR_O2_SMTP_CHK  0x30000000      /* use SMTP EHLO check for server health - pvandijk@vision6.com.au */
 #define PR_O2_HTTP_CHK  0x40000000      /* use HTTP 'OPTIONS' method to check server health */
 #define PR_O2_MYSQL_CHK 0x50000000      /* use MYSQL check for server health */
diff --git a/src/cfgparse-listen.c b/src/cfgparse-listen.c
index 0b2ef15..fdcf68e 100644
--- a/src/cfgparse-listen.c
+++ b/src/cfgparse-listen.c
@@ -2495,22 +2495,9 @@
 			if (alertif_too_many_args_idx(2, 1, file, linenum, args, &err_code))
 				goto out;
 		}
-
 		else if (!strcmp(args[1], "redis-check")) {
-			/* use REDIS PING request to check servers' health */
-			if (warnifnotcap(curproxy, PR_CAP_BE, file, linenum, args[1], NULL))
-				err_code |= ERR_WARN;
-
-			free(curproxy->check_req);
-			curproxy->check_req = NULL;
-			curproxy->options2 &= ~PR_O2_CHK_ANY;
-			curproxy->options2 |= PR_O2_REDIS_CHK;
-
-			curproxy->check_req = malloc(sizeof(DEF_REDIS_CHECK_REQ) - 1);
-			memcpy(curproxy->check_req, DEF_REDIS_CHECK_REQ, sizeof(DEF_REDIS_CHECK_REQ) - 1);
-			curproxy->check_len = sizeof(DEF_REDIS_CHECK_REQ) - 1;
-
-			if (alertif_too_many_args_idx(0, 1, file, linenum, args, &err_code))
+			err_code |= proxy_parse_redis_check_opt(args, 0, curproxy, &defproxy, file, linenum);
+			if (err_code & ERR_FATAL)
 				goto out;
 		}
 
diff --git a/src/checks.c b/src/checks.c
index c6bced8..c7f156b 100644
--- a/src/checks.c
+++ b/src/checks.c
@@ -1222,18 +1222,6 @@
 		}
 		break;
 
-	case PR_O2_REDIS_CHK:
-		if (!done && b_data(&check->bi) < 7)
-			goto wait_more_data;
-
-		if (strcmp(b_head(&check->bi), "+PONG\r\n") == 0) {
-			set_server_check_status(check, HCHK_STATUS_L7OKD, "Redis server is ok");
-		}
-		else {
-			set_server_check_status(check, HCHK_STATUS_L7STS, b_head(&check->bi));
-		}
-		break;
-
 	case PR_O2_MYSQL_CHK:
 		if (!done && b_data(&check->bi) < 5)
 			goto wait_more_data;
@@ -5077,6 +5065,135 @@
 	return -1;
 }
 
+
+static struct tcpcheck_ruleset *tcpcheck_ruleset_lookup(const char *name)
+{
+	struct tcpcheck_ruleset *rs;
+
+	list_for_each_entry(rs, &tcpchecks_list, list) {
+		if (strcmp(rs->name, name) == 0)
+			return rs;
+	}
+	return NULL;
+}
+
+static struct tcpcheck_ruleset *tcpcheck_ruleset_create(const char *name)
+{
+	struct tcpcheck_ruleset *rs;
+
+	rs = calloc(1, sizeof(*rs));
+	if (rs == NULL)
+		return NULL;
+
+	rs->name = strdup(name);
+	if (rs->name == NULL) {
+		free(rs);
+		return NULL;
+	}
+
+	LIST_INIT(&rs->list);
+	LIST_INIT(&rs->rules);
+	LIST_ADDQ(&tcpchecks_list, &rs->list);
+	return rs;
+}
+
+static void tcpcheck_ruleset_release(struct tcpcheck_ruleset *rs)
+{
+	struct tcpcheck_rule *r, *rb;
+	if (!rs)
+		return;
+
+	LIST_DEL(&rs->list);
+	list_for_each_entry_safe(r, rb, &rs->rules, list) {
+		LIST_DEL(&r->list);
+		free_tcpcheck(r, 0);
+	}
+	free(rs->name);
+	free(rs);
+}
+
+
+/* Parses the "option redis-check" proxy keyword */
+int proxy_parse_redis_check_opt(char **args, int cur_arg, struct proxy *curpx, struct proxy *defpx,
+				const char *file, int line)
+{
+	static char *redis_req = "*1\r\n$4\r\nPING\r\n";
+	static char *redis_res = "+PONG\r\n";
+
+	struct tcpcheck_ruleset *rs = NULL;
+	struct tcpcheck_rules *rules = &curpx->tcpcheck_rules;
+	struct tcpcheck_rule *chk;
+	char *errmsg = NULL;
+	int err_code = 0;
+
+	if (warnifnotcap(curpx, PR_CAP_BE, file, line, args[cur_arg+1], NULL))
+		err_code |= ERR_WARN;
+
+	if (alertif_too_many_args_idx(0, 1, file, line, args, &err_code))
+		goto out;
+
+	if (rules->list && !(rules->flags & TCPCHK_RULES_SHARED)) {
+		ha_alert("parsing [%s:%d] : A custom tcp-check ruleset is already configured.\n",
+			 file, line);
+		err_code |= ERR_ALERT | ERR_FATAL;
+		goto out;
+	}
+
+	curpx->options2 &= ~PR_O2_CHK_ANY;
+	curpx->options2 |= PR_O2_TCPCHK_CHK;
+
+	free_tcpcheck_vars(&rules->preset_vars);
+	rules->list  = NULL;
+	rules->flags = 0;
+
+	rs = tcpcheck_ruleset_lookup("*redis-check");
+	if (rs)
+		goto ruleset_found;
+
+	rs = tcpcheck_ruleset_create("*redis-check");
+	if (rs == NULL) {
+		ha_alert("parsing [%s:%d] : out of memory.\n", file, line);
+		goto error;
+	}
+
+	chk = parse_tcpcheck_send((char *[]){"tcp-check", "send", redis_req, ""},
+				  1, curpx, &rs->rules, file, line, &errmsg);
+	if (!chk) {
+		ha_alert("parsing [%s:%d] : %s\n", file, line, errmsg);
+		goto error;
+	}
+	chk->index = 0;
+	LIST_ADDQ(&rs->rules, &chk->list);
+
+	chk = parse_tcpcheck_expect((char *[]){"tcp-check", "expect", "string", redis_res,
+				               "error-status", "L7STS",
+				               "on-error", "%[check.payload(),cut_crlf]",
+				               "on-success", "Redis server is ok",
+				               ""},
+		                    1, curpx, &rs->rules, file, line, &errmsg);
+	if (!chk) {
+		ha_alert("parsing [%s:%d] : %s\n", file, line, errmsg);
+		goto error;
+	}
+	chk->index = 1;
+	LIST_ADDQ(&rs->rules, &chk->list);
+
+	LIST_ADDQ(&tcpchecks_list, &rs->list);
+
+  ruleset_found:
+	rules->list = &rs->rules;
+	rules->flags |= (TCPCHK_RULES_SHARED|TCPCHK_RULES_REDIS_CHK);
+
+  out:
+	free(errmsg);
+	return err_code;
+
+  error:
+	tcpcheck_ruleset_release(rs);
+	err_code |= ERR_ALERT | ERR_FATAL;
+	goto out;
+}
+
 static struct cfg_kw_list cfg_kws = {ILH, {
         { CFG_LISTEN, "tcp-check",  proxy_parse_tcpcheck },
         { 0, NULL, NULL },