REORG: server-state: Move functions to deal with server-state in its own file

All functions dealing with the server-state files are moved to
server_state.c.

srv_update_state() function was renammed to srv_state_srv_update().
diff --git a/Makefile b/Makefile
index d5c3f4c..77960ba 100644
--- a/Makefile
+++ b/Makefile
@@ -877,7 +877,8 @@
         src/ebimtree.o src/uri_auth.o src/freq_ctr.o src/ebsttree.o            \
         src/ebistree.o src/auth.o src/wdt.o src/http_acl.o                     \
         src/hpack-enc.o src/hpack-huff.o src/ebtree.o src/base64.o             \
-        src/hash.o src/dgram.o src/version.o src/fix.o src/mqtt.o src/dns.o
+        src/hash.o src/dgram.o src/version.o src/fix.o src/mqtt.o src/dns.o    \
+        src/server_state.o
 
 ifneq ($(TRACE),)
 OBJS += src/calltrace.o
diff --git a/src/server.c b/src/server.c
index d31062f..0e7671e 100644
--- a/src/server.c
+++ b/src/server.c
@@ -16,7 +16,6 @@
 #include <ctype.h>
 #include <errno.h>
 
-#include <import/eb64tree.h>
 #include <import/xxhash.h>
 
 #include <haproxy/api.h>
@@ -48,10 +47,7 @@
 
 
 static void srv_update_status(struct server *s);
-static void srv_update_state(struct server *srv, int version, char **params);
 static int srv_apply_lastaddr(struct server *srv, int *err_code);
-static int srv_state_parse_line(char *buf, const int version, char **params);
-static int srv_state_get_version(FILE *f);
 static void srv_cleanup_connections(struct server *srv);
 
 /* List head of all known server keywords */
@@ -2589,890 +2585,6 @@
 	return NULL;
 }
 
-/* Update a server state using the parameters available in the params list.
- * The caller must provide a supported version
- * Grabs the server lock during operation.
- */
-static void srv_update_state(struct server *srv, int version, char **params)
-{
-	char *p;
-	struct buffer *msg;
-	const char *warning;
-
-	/* fields since version 1
-	 * and common to all other upcoming versions
-	 */
-	enum srv_state srv_op_state;
-	enum srv_admin srv_admin_state;
-	unsigned srv_uweight, srv_iweight;
-	unsigned long srv_last_time_change;
-	short srv_check_status;
-	enum chk_result srv_check_result;
-	int srv_check_health;
-	int srv_check_state, srv_agent_state;
-	int bk_f_forced_id;
-	int srv_f_forced_id;
-	int fqdn_set_by_cli;
-	const char *fqdn;
-	const char *port_st;
-	unsigned int port_svc;
-	char *srvrecord;
-	char *addr;
-	int partial_apply = 0;
-#ifdef USE_OPENSSL
-	int use_ssl;
-#endif
-
-	fqdn = NULL;
-	port_svc = 0;
-	msg = alloc_trash_chunk();
-	if (!msg)
-		goto end;
-
-	HA_SPIN_LOCK(SERVER_LOCK, &srv->lock);
-
-	/* Only version 1 supported for now, don't check it. Fields are :
-	 * srv_addr:             params[0]
-	 * srv_op_state:         params[1]
-	 * srv_admin_state:      params[2]
-	 * srv_uweight:          params[3]
-	 * srv_iweight:          params[4]
-	 * srv_last_time_change: params[5]
-	 * srv_check_status:     params[6]
-	 * srv_check_result:     params[7]
-	 * srv_check_health:     params[8]
-	 * srv_check_state:      params[9]
-	 * srv_agent_state:      params[10]
-	 * bk_f_forced_id:       params[11]
-	 * srv_f_forced_id:      params[12]
-	 * srv_fqdn:             params[13]
-	 * srv_port:             params[14]
-	 * srvrecord:            params[15]
-	 * srv_use_ssl:          params[16]
-	 * srv_check_port:       params[17]
-	 * srv_check_addr:       params[18]
-	 * srv_agent_addr:       params[19]
-	 * srv_agent_port:       params[20]
-	 */
-
-	/* validating srv_op_state */
-	p = NULL;
-	errno = 0;
-	srv_op_state = strtol(params[1], &p, 10);
-	if ((p == params[1]) || errno == EINVAL || errno == ERANGE ||
-	    (srv_op_state != SRV_ST_STOPPED &&
-	     srv_op_state != SRV_ST_STARTING &&
-	     srv_op_state != SRV_ST_RUNNING &&
-	     srv_op_state != SRV_ST_STOPPING)) {
-		chunk_appendf(msg, ", invalid srv_op_state value '%s'", params[1]);
-	}
-
-	/* validating srv_admin_state */
-	p = NULL;
-	errno = 0;
-	srv_admin_state = strtol(params[2], &p, 10);
-	fqdn_set_by_cli = !!(srv_admin_state & SRV_ADMF_HMAINT);
-
-	/* inherited statuses will be recomputed later.
-	 * Also disable SRV_ADMF_HMAINT flag (set from stats socket fqdn).
-	 */
-	srv_admin_state &= ~SRV_ADMF_IDRAIN & ~SRV_ADMF_IMAINT & ~SRV_ADMF_HMAINT & ~SRV_ADMF_RMAINT;
-
-	if ((p == params[2]) || errno == EINVAL || errno == ERANGE ||
-	    (srv_admin_state != 0 &&
-	     srv_admin_state != SRV_ADMF_FMAINT &&
-	     srv_admin_state != SRV_ADMF_CMAINT &&
-	     srv_admin_state != (SRV_ADMF_CMAINT | SRV_ADMF_FMAINT) &&
-	     srv_admin_state != (SRV_ADMF_CMAINT | SRV_ADMF_FDRAIN) &&
-	     srv_admin_state != SRV_ADMF_FDRAIN)) {
-		chunk_appendf(msg, ", invalid srv_admin_state value '%s'", params[2]);
-	}
-
-	/* validating srv_uweight */
-	p = NULL;
-	errno = 0;
-	srv_uweight = strtol(params[3], &p, 10);
-	if ((p == params[3]) || errno == EINVAL || errno == ERANGE || (srv_uweight > SRV_UWGHT_MAX))
-		chunk_appendf(msg, ", invalid srv_uweight value '%s'", params[3]);
-
-	/* validating srv_iweight */
-	p = NULL;
-	errno = 0;
-	srv_iweight = strtol(params[4], &p, 10);
-	if ((p == params[4]) || errno == EINVAL || errno == ERANGE || (srv_iweight > SRV_UWGHT_MAX))
-		chunk_appendf(msg, ", invalid srv_iweight value '%s'", params[4]);
-
-	/* validating srv_last_time_change */
-	p = NULL;
-	errno = 0;
-	srv_last_time_change = strtol(params[5], &p, 10);
-	if ((p == params[5]) || errno == EINVAL || errno == ERANGE)
-		chunk_appendf(msg, ", invalid srv_last_time_change value '%s'", params[5]);
-
-	/* validating srv_check_status */
-	p = NULL;
-	errno = 0;
-	srv_check_status = strtol(params[6], &p, 10);
-	if (p == params[6] || errno == EINVAL || errno == ERANGE ||
-	    (srv_check_status >= HCHK_STATUS_SIZE))
-		chunk_appendf(msg, ", invalid srv_check_status value '%s'", params[6]);
-
-	/* validating srv_check_result */
-	p = NULL;
-	errno = 0;
-	srv_check_result = strtol(params[7], &p, 10);
-	if ((p == params[7]) || errno == EINVAL || errno == ERANGE ||
-	    (srv_check_result != CHK_RES_UNKNOWN &&
-	     srv_check_result != CHK_RES_NEUTRAL &&
-	     srv_check_result != CHK_RES_FAILED &&
-	     srv_check_result != CHK_RES_PASSED &&
-	     srv_check_result != CHK_RES_CONDPASS)) {
-		chunk_appendf(msg, ", invalid srv_check_result value '%s'", params[7]);
-	}
-
-	/* validating srv_check_health */
-	p = NULL;
-	errno = 0;
-	srv_check_health = strtol(params[8], &p, 10);
-	if (p == params[8] || errno == EINVAL || errno == ERANGE)
-		chunk_appendf(msg, ", invalid srv_check_health value '%s'", params[8]);
-
-	/* validating srv_check_state */
-	p = NULL;
-	errno = 0;
-	srv_check_state = strtol(params[9], &p, 10);
-	if (p == params[9] || errno == EINVAL || errno == ERANGE ||
-	    (srv_check_state & ~(CHK_ST_INPROGRESS | CHK_ST_CONFIGURED | CHK_ST_ENABLED | CHK_ST_PAUSED | CHK_ST_AGENT)))
-		chunk_appendf(msg, ", invalid srv_check_state value '%s'", params[9]);
-
-	/* validating srv_agent_state */
-	p = NULL;
-	errno = 0;
-	srv_agent_state = strtol(params[10], &p, 10);
-	if (p == params[10] || errno == EINVAL || errno == ERANGE ||
-	    (srv_agent_state & ~(CHK_ST_INPROGRESS | CHK_ST_CONFIGURED | CHK_ST_ENABLED | CHK_ST_PAUSED | CHK_ST_AGENT)))
-		chunk_appendf(msg, ", invalid srv_agent_state value '%s'", params[10]);
-
-	/* validating bk_f_forced_id */
-	p = NULL;
-	errno = 0;
-	bk_f_forced_id = strtol(params[11], &p, 10);
-	if (p == params[11] || errno == EINVAL || errno == ERANGE || !((bk_f_forced_id == 0) || (bk_f_forced_id == 1)))
-		chunk_appendf(msg, ", invalid bk_f_forced_id value '%s'", params[11]);
-
-	/* validating srv_f_forced_id */
-	p = NULL;
-	errno = 0;
-	srv_f_forced_id = strtol(params[12], &p, 10);
-	if (p == params[12] || errno == EINVAL || errno == ERANGE || !((srv_f_forced_id == 0) || (srv_f_forced_id == 1)))
-		chunk_appendf(msg, ", invalid srv_f_forced_id value '%s'", params[12]);
-
-	/* validating srv_fqdn */
-	fqdn = params[13];
-	if (fqdn && *fqdn == '-')
-		fqdn = NULL;
-	if (fqdn && (strlen(fqdn) > DNS_MAX_NAME_SIZE || invalid_domainchar(fqdn))) {
-		chunk_appendf(msg, ", invalid srv_fqdn value '%s'", params[13]);
-		fqdn = NULL;
-	}
-
-	port_st = params[14];
-	if (port_st) {
-		port_svc = strl2uic(port_st, strlen(port_st));
-		if (port_svc > USHRT_MAX) {
-			chunk_appendf(msg, ", invalid srv_port value '%s'", port_st);
-			port_st = NULL;
-		}
-	}
-
-	/* SRV record
-	 * NOTE: in HAProxy, SRV records must start with an underscore '_'
-		 */
-	srvrecord = params[15];
-	if (srvrecord && *srvrecord != '_')
-		srvrecord = NULL;
-
-	/* don't apply anything if one error has been detected */
-	if (msg->data)
-		goto out;
-	partial_apply = 1;
-
-	/* recover operational state and apply it to this server
-	 * and all servers tracking this one */
-	srv->check.health = srv_check_health;
-	switch (srv_op_state) {
-		case SRV_ST_STOPPED:
-			srv->check.health = 0;
-			srv_set_stopped(srv, "changed from server-state after a reload", NULL);
-			break;
-		case SRV_ST_STARTING:
-			/* If rise == 1 there is no STARTING state, let's switch to
-			 * RUNNING
-			 */
-			if (srv->check.rise == 1) {
-				srv->check.health = srv->check.rise + srv->check.fall - 1;
-				srv_set_running(srv, "", NULL);
-				break;
-			}
-			if (srv->check.health < 1 || srv->check.health >= srv->check.rise)
-				srv->check.health = srv->check.rise - 1;
-			srv->next_state = srv_op_state;
-			break;
-		case SRV_ST_STOPPING:
-			/* If fall == 1 there is no STOPPING state, let's switch to
-			 * STOPPED
-			 */
-			if (srv->check.fall == 1) {
-				srv->check.health = 0;
-				srv_set_stopped(srv, "changed from server-state after a reload", NULL);
-				break;
-			}
-			if (srv->check.health < srv->check.rise ||
-			    srv->check.health > srv->check.rise + srv->check.fall - 2)
-				srv->check.health = srv->check.rise;
-			srv_set_stopping(srv, "changed from server-state after a reload", NULL);
-			break;
-		case SRV_ST_RUNNING:
-			srv->check.health = srv->check.rise + srv->check.fall - 1;
-			srv_set_running(srv, "", NULL);
-			break;
-	}
-
-	/* When applying server state, the following rules apply:
-	 * - in case of a configuration change, we apply the setting from the new
-	 *   configuration, regardless of old running state
-	 * - if no configuration change, we apply old running state only if old running
-	 *   state is different from new configuration state
-	 */
-	/* configuration has changed */
-	if ((srv_admin_state & SRV_ADMF_CMAINT) != (srv->next_admin & SRV_ADMF_CMAINT)) {
-		if (srv->next_admin & SRV_ADMF_CMAINT)
-			srv_adm_set_maint(srv);
-		else
-			srv_adm_set_ready(srv);
-	}
-	/* configuration is the same, let's compate old running state and new conf state */
-	else {
-		if (srv_admin_state & SRV_ADMF_FMAINT && !(srv->next_admin & SRV_ADMF_CMAINT))
-			srv_adm_set_maint(srv);
-		else if (!(srv_admin_state & SRV_ADMF_FMAINT) && (srv->next_admin & SRV_ADMF_CMAINT))
-			srv_adm_set_ready(srv);
-	}
-	/* apply drain mode if server is currently enabled */
-	if (!(srv->next_admin & SRV_ADMF_FMAINT) && (srv_admin_state & SRV_ADMF_FDRAIN)) {
-		/* The SRV_ADMF_FDRAIN flag is inherited when srv->iweight is 0
-		 * (srv->iweight is the weight set up in configuration).
-		 * There are two possible reasons for FDRAIN to have been present :
-		 *   - previous config weight was zero
-		 *   - "set server b/s drain" was sent to the CLI
-		 *
-		 * In the first case, we simply want to drop this drain state
-		 * if the new weight is not zero anymore, meaning the administrator
-		 * has intentionally turned the weight back to a positive value to
-		 * enable the server again after an operation. In the second case,
-		 * the drain state was forced on the CLI regardless of the config's
-		 * weight so we don't want a change to the config weight to lose this
-		 * status. What this means is :
-		 *   - if previous weight was 0 and new one is >0, drop the DRAIN state.
-		 *   - if the previous weight was >0, keep it.
-		 */
-		if (srv_iweight > 0 || srv->iweight == 0)
-			srv_adm_set_drain(srv);
-	}
-
-	srv->last_change = date.tv_sec - srv_last_time_change;
-	srv->check.status = srv_check_status;
-	srv->check.result = srv_check_result;
-
-	/* Only case we want to apply is removing ENABLED flag which could have been
-	 * done by the "disable health" command over the stats socket
-	 */
-	if ((srv->check.state & CHK_ST_CONFIGURED) &&
-	    (srv_check_state & CHK_ST_CONFIGURED) &&
-	    !(srv_check_state & CHK_ST_ENABLED))
-		srv->check.state &= ~CHK_ST_ENABLED;
-
-	/* Only case we want to apply is removing ENABLED flag which could have been
-	 * done by the "disable agent" command over the stats socket
-	 */
-	if ((srv->agent.state & CHK_ST_CONFIGURED) &&
-	    (srv_agent_state & CHK_ST_CONFIGURED) &&
-	    !(srv_agent_state & CHK_ST_ENABLED))
-		srv->agent.state &= ~CHK_ST_ENABLED;
-
-	/* We want to apply the previous 'running' weight (srv_uweight) only if there
-	 * was no change in the configuration: both previous and new iweight are equals
-	 *
-	 * It means that a configuration file change has precedence over a unix socket change
-	 * for server's weight
-	 *
-	 * by default, HAProxy applies the following weight when parsing the configuration
-	 *    srv->uweight = srv->iweight
-	 */
-	if (srv_iweight == srv->iweight) {
-		srv->uweight = srv_uweight;
-	}
-	server_recalc_eweight(srv, 1);
-
-	/* load server IP address */
-	if (strcmp(params[0], "-") != 0)
-		srv->lastaddr = strdup(params[0]);
-
-	if (fqdn && srv->hostname) {
-		if (strcmp(srv->hostname, fqdn) == 0) {
-			/* Here we reset the 'set from stats socket FQDN' flag
-			 * to support such transitions:
-			 * Let's say initial FQDN value is foo1 (in configuration file).
-			 * - FQDN changed from stats socket, from foo1 to foo2 value,
-			 * - FQDN changed again from file configuration (with the same previous value
-			 set from stats socket, from foo1 to foo2 value),
-			 * - reload for any other reason than a FQDN modification,
-			 * the configuration file FQDN matches the fqdn server state file value.
-			 * So we must reset the 'set from stats socket FQDN' flag to be consistent with
-			 * any further FQDN modification.
-			 */
-			srv->next_admin &= ~SRV_ADMF_HMAINT;
-		}
-		else {
-			/* If the FDQN has been changed from stats socket,
-			 * apply fqdn state file value (which is the value set
-			 * from stats socket).
-			 * Also ensure the runtime resolver will process this resolution.
-			 */
-			if (fqdn_set_by_cli) {
-				srv_set_fqdn(srv, fqdn, 0);
-				srv->flags &= ~SRV_F_NO_RESOLUTION;
-				srv->next_admin |= SRV_ADMF_HMAINT;
-			}
-		}
-	}
-	/* If all the conditions below are validated, this means
-	 * we're evaluating a server managed by SRV resolution
-	 */
-	else if (fqdn && !srv->hostname && srvrecord) {
-		int res;
-
-		/* we can't apply previous state if SRV record has changed */
-		if (srv->srvrq && strcmp(srv->srvrq->name, srvrecord) != 0) {
-			chunk_appendf(msg, ", SRV record mismatch between configuration ('%s') and state file ('%s) for server '%s'. Previous state not applied", srv->srvrq->name, srvrecord, srv->id);
-			goto out;
-		}
-
-		/* create or find a SRV resolution for this srv record */
-		if (srv->srvrq == NULL && (srv->srvrq = find_srvrq_by_name(srvrecord, srv->proxy)) == NULL)
-			srv->srvrq = new_resolv_srvrq(srv, srvrecord);
-		if (srv->srvrq == NULL) {
-			chunk_appendf(msg, ", can't create or find SRV resolution '%s' for server '%s'", srvrecord, srv->id);
-			goto out;
-		}
-
-		/* prepare DNS resolution for this server */
-		res = srv_prepare_for_resolution(srv, fqdn);
-		if (res == -1) {
-			chunk_appendf(msg, ", can't allocate memory for DNS resolution for server '%s'", srv->id);
-			goto out;
-		}
-
-		/* Unset SRV_F_MAPPORTS for SRV records.
-		 * SRV_F_MAPPORTS is unfortunately set by parse_server()
-		 * because no ports are provided in the configuration file.
-		 * This is because HAProxy will use the port found into the SRV record.
-		 */
-		srv->flags &= ~SRV_F_MAPPORTS;
-	}
-
-	if (port_st)
-		srv->svc_port = port_svc;
-
-
-	if (params[16]) {
-#ifdef USE_OPENSSL
-		use_ssl = strtol(params[16], &p, 10);
-
-		/* configure ssl if connection has been initiated at startup */
-		if (srv->ssl_ctx.ctx != NULL)
-			ssl_sock_set_srv(srv, use_ssl);
-#endif
-	}
-
-	port_st = NULL;
-	if (params[17] && strcmp(params[17], "0") != 0)
-		port_st = params[17];
-	addr = NULL;
-	if (params[18] && strcmp(params[18], "-") != 0)
-		addr = params[18];
-	if (addr || port_st) {
-		warning = srv_update_check_addr_port(srv, addr, port_st);
-		if (warning) {
-			chunk_appendf(msg, ", %s", warning);
-			goto out;
-		}
-	}
-
-	port_st = NULL;
-	if (params[20] && strcmp(params[20], "0") != 0)
-		port_st = params[20];
-	addr = NULL;
-	if (params[19] && strcmp(params[19], "-") != 0)
-		addr = params[19];
-	if (addr || port_st) {
-		warning = srv_update_agent_addr_port(srv, addr, port_st);
-		if (warning) {
-			chunk_appendf(msg, ", %s", warning);
-			goto out;
-		}
-	}
-
- out:
-	HA_SPIN_UNLOCK(SERVER_LOCK, &srv->lock);
-	if (msg->data) {
-		if (partial_apply == 1)
-			ha_warning("server-state partially applied for server '%s/%s'%s\n",
-				   srv->proxy->id, srv->id, msg->area);
-		else
-			ha_warning("server-state application failed for server '%s/%s'%s\n",
-				   srv->proxy->id, srv->id, msg->area);
-	}
- end:
-	free_trash_chunk(msg);
-}
-
-/*
- * Loop on the proxy's servers and try to load its state from <st_tree> using
- * srv_update_state(). The proxy name and the server name are concatenated to
- * form the key. If found the entry is removed from the tree.
- */
-static void srv_state_px_update(const struct proxy *px, int vsn, struct eb_root *st_tree)
-{
-	struct server_state_line *st_line;
-	struct eb64_node *node;
-	struct server *srv;
-	unsigned long key;
-
-	for (srv = px->srv; srv; srv = srv->next) {
-		chunk_printf(&trash, "%s %s", px->id, srv->id);
-		key = XXH3(trash.area, trash.data, 0);
-		node = eb64_lookup(st_tree, key);
-		if (!node)
-			continue; /* next server */
-		st_line = eb64_entry(node, typeof(*st_line), node);
-		srv_update_state(srv, vsn, st_line->params+4);
-
-		/* the node may be released now */
-		eb64_delete(node);
-		free(st_line->line);
-		free(st_line);
-	}
-}
-
-/*
- * read next line from file <f> and return the server state version if one found.
- * If no version is found, then 0 is returned
- * Note that this should be the first read on <f>
- */
-static int srv_state_get_version(FILE *f) {
-	char mybuf[SRV_STATE_LINE_MAXLEN];
-	char *endptr;
-	long int vsn;
-
-	/* first character of first line of the file must contain the version of the export */
-	if (fgets(mybuf, SRV_STATE_LINE_MAXLEN, f) == NULL)
-		return 0;
-
-	vsn = strtol(mybuf, &endptr, 10);
-	if (endptr == mybuf || *endptr != '\n') {
-		/* Empty or truncated line */
-		return 0;
-	}
-
-	if (vsn < SRV_STATE_FILE_VERSION_MIN || vsn > SRV_STATE_FILE_VERSION_MAX) {
-		/* Wrong version number */
-		return 0;
-	}
-
-	return vsn;
-}
-
-
-/*
- * parses server state line stored in <buf> and supposedly in version <version>.
- * Set <params> accordingly on success. It returns 1 on success, 0 if the line
- * must be ignored and -1 on error.
- * The caller must provide a supported version
- */
-static int srv_state_parse_line(char *buf, const int version, char **params)
-{
-	int buflen, arg, ret;
-	char *cur;
-
-	buflen = strlen(buf);
-	cur = buf;
-	ret = 1; /* be optimistic and pretend a success */
-
-	/* we need at least one character (the newline) and a non-truncated line */
-	if (buflen == 0 || buf[buflen - 1] != '\n') {
-		ret = -1;
-		goto out;
-	}
-
-	/* skip blank characters at the beginning of the line */
-	while (isblank((unsigned char)*cur))
-		++cur;
-
-	/* ignore empty or commented lines */
-	if (!*cur || *cur == '\n' || *cur == '#') {
-		ret = 0;
-		goto out;
-	}
-
-	/* Removes trailing '\n' to ease parsing */
-	buf[buflen - 1] = '\0';
-
-	/* we're now ready to move the line into <params> */
-	memset(params, 0, SRV_STATE_FILE_MAX_FIELDS * sizeof(*params));
-	arg = 0;
-	while (*cur) {
-		/* first of all, stop if there are too many fields */
-		if (arg >= SRV_STATE_FILE_MAX_FIELDS)
-			break;
-
-		/* then skip leading spaces */
-		while (*cur && isblank((unsigned char)*cur)) {
-			++cur;
-			if (!*cur)
-				break;
-		}
-
-		/*
-		 * idx:
-		 *   be_id:                params[0]
-		 *   be_name:              params[1]
-		 *   srv_id:               params[2]
-		 *   srv_name:             params[3]
-		 * v1
-		 *   srv_addr:             params[4]
-		 *   srv_op_state:         params[5]
-		 *   srv_admin_state:      params[6]
-		 *   srv_uweight:          params[7]
-		 *   srv_iweight:          params[8]
-		 *   srv_last_time_change: params[9]
-		 *   srv_check_status:     params[10]
-		 *   srv_check_result:     params[11]
-		 *   srv_check_health:     params[12]
-		 *   srv_check_state:      params[13]
-		 *   srv_agent_state:      params[14]
-		 *   bk_f_forced_id:       params[15]
-		 *   srv_f_forced_id:      params[16]
-		 *   srv_fqdn:             params[17]
-		 *   srv_port:             params[18]
-		 *   srvrecord:            params[19]
-		 *
-		 *   srv_use_ssl:          params[20]  (optional field)
-		 *   srv_check_port:       params[21]  (optional field)
-		 *   srv_check_addr:       params[22]  (optional field)
-		 *   srv_agent_addr:       params[23]  (optional field)
-		 *   srv_agent_port:       params[24]  (optional field)
-		 *
-		 */
-		params[arg++] = cur;
-
-		/* look for the end of the current field */
-		while (*cur && !isblank((unsigned char)*cur)) {
-			++cur;
-			if (!*cur)
-				break;
-		}
-
-		/* otherwise, cut the field and move to the next one */
-		*cur++ = '\0';
-	}
-
-	/* if the number of fields does not match the version, then return an error */
-	if (version == 1 &&
-	    (arg < SRV_STATE_FILE_MIN_FIELDS_VERSION_1 ||
-	     arg > SRV_STATE_FILE_MAX_FIELDS_VERSION_1))
-		ret = -1;
-
-  out:
-	return ret;
-}
-
-/*
- * parses a server state line using srv_state_parse_line() and store the result
- * in <st_tree>. If an error occurred during the parsing, the line is
- * ignored. if <px> is defined, it is used to check the backend id/name against
- * the parsed params and to compute the key of the line.
- */
-static int srv_state_parse_and_store_line(char *line, int vsn, struct eb_root *st_tree,
-					  struct proxy *px)
-{
-	struct server_state_line *st_line;
-	int ret = 0;
-
-	/* store line in tree and duplicate the line */
-	st_line = calloc(1, sizeof(*st_line));
-	if (st_line == NULL)
-		goto skip_line;
-	st_line->line = strdup(line);
-	if (st_line->line == NULL)
-		goto skip_line;
-
-	ret = srv_state_parse_line(st_line->line, vsn, st_line->params);
-	if (ret <= 0)
-		goto skip_line;
-
-	/* Check backend name against params if <px> is defined */
-	if (px) {
-		int check_id = (atoi(st_line->params[0]) == px->uuid);
-		int check_name = (strcmp(px->id, st_line->params[1]) == 0);
-		int bk_f_forced_id = (atoi(st_line->params[15]) & PR_O_FORCED_ID);
-
-
-		if (!check_id && !check_name) {
-			/* backend does not match at all: skip the line */
-			goto skip_line;
-		}
-		else if (!check_id) {
-			/* Id mismatch: warn but continue */
-			ha_warning("Proxy '%s': backend ID mismatch: from server state file: '%s', from running config '%d'\n",
-				   px->id, st_line->params[0], px->uuid);
-			send_log(px, LOG_NOTICE, "backend ID mismatch: from server state file: '%s', from running config '%d'\n",
-				 st_line->params[0], px->uuid);
-		}
-		else if (!check_name) {
-			/* Name mismatch: warn and skip the line, except if the backend id was forced
-			 * in the previous configuration */
-			ha_warning("Proxy '%s': backend name mismatch: from server state file: '%s', from running config '%s'\n",
-				   px->id, st_line->params[1], px->id);
-			send_log(px, LOG_NOTICE, "backend name mismatch: from server state file: '%s', from running config '%s'\n",
-				 st_line->params[1], px->id);
-			if (!bk_f_forced_id)
-				goto skip_line;
-		}
-	}
-
-	/*
-	 * The key: "be_name srv_name"
-	 *   if <px> is defined:  be_name == px->id
-	 *   otherwise: be_name == params[1]
-	 */
-	chunk_printf(&trash, "%s %s", (px ? px->id : st_line->params[1]), st_line->params[3]);
-	st_line->node.key = XXH3(trash.area, trash.data, 0);
-	if (eb64_insert(st_tree, &st_line->node) != &st_line->node) {
-		/* this is a duplicate key, probably a hand-crafted file, drop it! */
-		goto skip_line;
-	}
-
-	return ret;
-
-  skip_line:
-	/* free up memory in case of error during the processing of the line */
-	if (st_line) {
-		free(st_line->line);
-		free(st_line);
-	}
-	return ret;
-}
-
-/* Helper function to get the server-state file path.
- * If <filename> starts with a '/', it is considered as an absolute path. In
- * this case or if <global.server_state_base> is not set, <filename> only is
- * considered. Otherwise, the <global.server_state_base> is concatenated to
- * <filename> to produce the file path and copied to <dst_path>. in both cases,
- * the result must not exceeds <maxpathlen>.
- *
- * The len is returned on success or -1 if the path is too long. On error, the
- * caller must not rely on <dst_path>.
- */
-static inline int srv_state_get_filepath(char *dst_path, int maxpathlen, const char *filename)
-{
-	char *sep = (global.server_state_base[strlen(global.server_state_base)-1] != '/' ? "/":  "");
-	int len = 0;
-
-	/* create the globalfilepath variable */
-	if (*filename == '/' || !global.server_state_base) {
-		/* absolute path or no base directory provided */
-		len = strlen(filename);
-		if (len < maxpathlen)
-			strcpy(dst_path, global.server_state_file);
-	}
-	else {
-		/* concat base directory and global server-state file */
-		len = snprintf(dst_path, maxpathlen, "%s%s%s", global.server_state_base, sep, filename);
-	}
-	return (len < maxpathlen ? len: -1);
-}
-
-
-/* This function parses all the proxies and only take care of the backends (since we're looking for server)
- * For each proxy, it does the following:
- *  - opens its server state file (either one or local one)
- *  - read whole file, line by line
- *  - analyse each line to check if it matches our current backend:
- *    - backend name matches
- *    - backend id matches if id is forced and name doesn't match
- *  - if the server pointed by the line is found, then state is applied
- *
- * If the running backend uuid or id differs from the state file, then HAProxy reports
- * a warning.
- *
- * Grabs the server's lock via srv_update_state().
- */
-void apply_server_state(void)
-{
-	/* tree where global state_file is loaded */
-	struct eb_root global_state_tree = EB_ROOT_UNIQUE;
-	struct proxy *curproxy;
-	struct server_state_line *st_line;
-	struct eb64_node *node, *next_node;
-	FILE *f;
-	char mybuf[SRV_STATE_LINE_MAXLEN];
-	char file[MAXPATHLEN];
-	int local_vsn, global_vsn, len, linenum;
-
-	global_vsn = 0; /* no global file */
-	if (!global.server_state_file)
-		goto no_globalfile;
-	len = srv_state_get_filepath(file, MAXPATHLEN, global.server_state_file);
-	if (len == -1) {
-		ha_warning("config: Can't load global server state file: file too long.\n");
-		goto no_globalfile;
-	}
-
-	/* Load global server state in a tree */
-	errno = 0;
-	f = fopen(file, "r");
-	if (!f) {
-		ha_warning("config: Can't open global server state file '%s': %s\n", file, strerror(errno));
-		goto no_globalfile;
-	}
-
-	global_vsn = srv_state_get_version(f);
-	if (global_vsn == 0) {
-		ha_warning("config: Can't get version of the global server state file '%s'.\n",
-			   file);
-		goto close_globalfile;
-	}
-
-	for (linenum = 1; fgets(mybuf, SRV_STATE_LINE_MAXLEN, f); linenum++) {
-		int ret;
-
-		ret = srv_state_parse_and_store_line(mybuf, global_vsn, &global_state_tree, NULL);
-		if (ret == -1) {
-			ha_warning("config: corrupted global server state file '%s' at line %d.\n",
-				   file, linenum);
-			global_vsn = 0;
-			break;
-		}
-	}
-
-  close_globalfile:
-	fclose(f);
-
-  no_globalfile:
-	/* parse all proxies and load states form tree (global file) or from local file */
-	for (curproxy = proxies_list; curproxy != NULL; curproxy = curproxy->next) {
-		struct eb_root local_state_tree = EB_ROOT_UNIQUE;
-
-		/* servers are only in backends */
-		if (!(curproxy->cap & PR_CAP_BE))
-			continue; /* next proxy */
-
-		/* No server-state file for this proxy */
-		if (curproxy->load_server_state_from_file == PR_SRV_STATE_FILE_NONE)
-			continue;  /* next proxy */
-
-		if (curproxy->load_server_state_from_file == PR_SRV_STATE_FILE_GLOBAL) {
-			/* when global file is used, we get data from the tree
-			 * Note that in such case we don't check backend name neither uuid.
-			 * Backend name can't be wrong since it's used as a key to retrieve the server state
-			 * line from the tree.
-			 */
-			if (global_vsn)
-				srv_state_px_update(curproxy, global_vsn, &global_state_tree);
-			continue; /* next proxy */
-		}
-
-		/*
-		 * Here we load a local server state-file
-		 */
-
-		/* create file variable */
-		len = srv_state_get_filepath(file, MAXPATHLEN, curproxy->server_state_file_name);
-		if (len == -1) {
-			ha_warning("Proxy '%s': Can't load local server state file: file too long.\n", curproxy->id);
-			continue; /* next proxy */
-		}
-
-		/* Load local server state in a tree */
-		errno = 0;
-		f = fopen(file, "r");
-		if (!f) {
-			ha_warning("Proxy '%s': Can't open server state file '%s': %s.\n",
-				   curproxy->id, file, strerror(errno));
-			continue; /* next proxy */
-		}
-
-
-		/* first character of first line of the file must contain the version of the export */
-		local_vsn = srv_state_get_version(f);
-		if (local_vsn == 0) {
-			ha_warning("Proxy '%s': Can't get version of the server state file '%s'.\n",
-				   curproxy->id, file);
-			goto close_localfile;
-		}
-
-		/* First, parse lines of the local server-state file and store them in a eb-tree */
-		for (linenum = 1; fgets(mybuf, SRV_STATE_LINE_MAXLEN, f); linenum++) {
-			int ret;
-
-			ret = srv_state_parse_and_store_line(mybuf, local_vsn, &local_state_tree, curproxy);
-			if (ret == -1) {
-				ha_warning("Proxy '%s': corrupted server state file '%s' at line %d.\n",
-					   curproxy->id, file, linenum);
-				local_vsn = 0;
-				break;
-			}
-		}
-
-		if (local_vsn)
-			srv_state_px_update(curproxy, local_vsn, &local_state_tree);
-
-		/* Remove unsused server-state lines */
-		node = eb64_first(&local_state_tree);
-		while (node) {
-			st_line = eb64_entry(node, typeof(*st_line), node);
-			next_node = eb64_next(node);
-			eb64_delete(node);
-
-			if (local_vsn) {
-				/* if no server found, then warn */
-				ha_warning("Proxy '%s': can't find server '%s' in backend '%s'\n",
-					   curproxy->id, st_line->params[3], curproxy->id);
-				send_log(curproxy, LOG_NOTICE, "can't find server '%s' in backend '%s'\n",
-					 st_line->params[3], curproxy->id);
-			}
-
-			free(st_line->line);
-			free(st_line);
-			node = next_node;
-		}
-
-	close_localfile:
-		fclose(f);
-	}
-
-	node = eb64_first(&global_state_tree);
-        while (node) {
-                st_line = eb64_entry(node, typeof(*st_line), node);
-                next_node = eb64_next(node);
-                eb64_delete(node);
-		free(st_line->line);
-		free(st_line);
-                node = next_node;
-        }
-}
-
 /*
  * update a server's current IP address.
  * ip is a pointer to the new IP address, whose address family is ip_sin_family.
diff --git a/src/server_state.c b/src/server_state.c
new file mode 100644
index 0000000..e3d2854
--- /dev/null
+++ b/src/server_state.c
@@ -0,0 +1,914 @@
+/*
+ * Server-state management functions.
+ *
+ * Copyright (C) 2021 HAProxy Technologies, Christopher Faulet <cfaulet@haproxy.com>
+ *
+ * This program is free software; you can redistribute it and/or
+ * modify it under the terms of the GNU General Public License
+ * as published by the Free Software Foundation; either version
+ * 2 of the License, or (at your option) any later version.
+ *
+ */
+
+#include <errno.h>
+
+#include <import/eb64tree.h>
+#include <import/xxhash.h>
+
+#include <haproxy/api.h>
+#include <haproxy/backend.h>
+#include <haproxy/cfgparse.h>
+#include <haproxy/check.h>
+#include <haproxy/errors.h>
+#include <haproxy/global.h>
+#include <haproxy/log.h>
+#include <haproxy/port_range.h>
+#include <haproxy/proxy.h>
+#include <haproxy/resolvers.h>
+#include <haproxy/server.h>
+#include <haproxy/ssl_sock.h>
+
+
+/* Update a server state using the parameters available in the params list.
+ * The caller must provide a supported version
+ * Grabs the server lock during operation.
+ */
+static void srv_state_srv_update(struct server *srv, int version, char **params)
+{
+	char *p;
+	struct buffer *msg;
+	const char *warning;
+
+	/* fields since version 1
+	 * and common to all other upcoming versions
+	 */
+	enum srv_state srv_op_state;
+	enum srv_admin srv_admin_state;
+	unsigned srv_uweight, srv_iweight;
+	unsigned long srv_last_time_change;
+	short srv_check_status;
+	enum chk_result srv_check_result;
+	int srv_check_health;
+	int srv_check_state, srv_agent_state;
+	int bk_f_forced_id;
+	int srv_f_forced_id;
+	int fqdn_set_by_cli;
+	const char *fqdn;
+	const char *port_st;
+	unsigned int port_svc;
+	char *srvrecord;
+	char *addr;
+	int partial_apply = 0;
+#ifdef USE_OPENSSL
+	int use_ssl;
+#endif
+
+	fqdn = NULL;
+	port_svc = 0;
+	msg = alloc_trash_chunk();
+	if (!msg)
+		goto end;
+
+	HA_SPIN_LOCK(SERVER_LOCK, &srv->lock);
+
+	/* Only version 1 supported for now, don't check it. Fields are :
+	 * srv_addr:             params[0]
+	 * srv_op_state:         params[1]
+	 * srv_admin_state:      params[2]
+	 * srv_uweight:          params[3]
+	 * srv_iweight:          params[4]
+	 * srv_last_time_change: params[5]
+	 * srv_check_status:     params[6]
+	 * srv_check_result:     params[7]
+	 * srv_check_health:     params[8]
+	 * srv_check_state:      params[9]
+	 * srv_agent_state:      params[10]
+	 * bk_f_forced_id:       params[11]
+	 * srv_f_forced_id:      params[12]
+	 * srv_fqdn:             params[13]
+	 * srv_port:             params[14]
+	 * srvrecord:            params[15]
+	 * srv_use_ssl:          params[16]
+	 * srv_check_port:       params[17]
+	 * srv_check_addr:       params[18]
+	 * srv_agent_addr:       params[19]
+	 * srv_agent_port:       params[20]
+	 */
+
+	/* validating srv_op_state */
+	p = NULL;
+	errno = 0;
+	srv_op_state = strtol(params[1], &p, 10);
+	if ((p == params[1]) || errno == EINVAL || errno == ERANGE ||
+	    (srv_op_state != SRV_ST_STOPPED &&
+	     srv_op_state != SRV_ST_STARTING &&
+	     srv_op_state != SRV_ST_RUNNING &&
+	     srv_op_state != SRV_ST_STOPPING)) {
+		chunk_appendf(msg, ", invalid srv_op_state value '%s'", params[1]);
+	}
+
+	/* validating srv_admin_state */
+	p = NULL;
+	errno = 0;
+	srv_admin_state = strtol(params[2], &p, 10);
+	fqdn_set_by_cli = !!(srv_admin_state & SRV_ADMF_HMAINT);
+
+	/* inherited statuses will be recomputed later.
+	 * Also disable SRV_ADMF_HMAINT flag (set from stats socket fqdn).
+	 */
+	srv_admin_state &= ~SRV_ADMF_IDRAIN & ~SRV_ADMF_IMAINT & ~SRV_ADMF_HMAINT & ~SRV_ADMF_RMAINT;
+
+	if ((p == params[2]) || errno == EINVAL || errno == ERANGE ||
+	    (srv_admin_state != 0 &&
+	     srv_admin_state != SRV_ADMF_FMAINT &&
+	     srv_admin_state != SRV_ADMF_CMAINT &&
+	     srv_admin_state != (SRV_ADMF_CMAINT | SRV_ADMF_FMAINT) &&
+	     srv_admin_state != (SRV_ADMF_CMAINT | SRV_ADMF_FDRAIN) &&
+	     srv_admin_state != SRV_ADMF_FDRAIN)) {
+		chunk_appendf(msg, ", invalid srv_admin_state value '%s'", params[2]);
+	}
+
+	/* validating srv_uweight */
+	p = NULL;
+	errno = 0;
+	srv_uweight = strtol(params[3], &p, 10);
+	if ((p == params[3]) || errno == EINVAL || errno == ERANGE || (srv_uweight > SRV_UWGHT_MAX))
+		chunk_appendf(msg, ", invalid srv_uweight value '%s'", params[3]);
+
+	/* validating srv_iweight */
+	p = NULL;
+	errno = 0;
+	srv_iweight = strtol(params[4], &p, 10);
+	if ((p == params[4]) || errno == EINVAL || errno == ERANGE || (srv_iweight > SRV_UWGHT_MAX))
+		chunk_appendf(msg, ", invalid srv_iweight value '%s'", params[4]);
+
+	/* validating srv_last_time_change */
+	p = NULL;
+	errno = 0;
+	srv_last_time_change = strtol(params[5], &p, 10);
+	if ((p == params[5]) || errno == EINVAL || errno == ERANGE)
+		chunk_appendf(msg, ", invalid srv_last_time_change value '%s'", params[5]);
+
+	/* validating srv_check_status */
+	p = NULL;
+	errno = 0;
+	srv_check_status = strtol(params[6], &p, 10);
+	if (p == params[6] || errno == EINVAL || errno == ERANGE ||
+	    (srv_check_status >= HCHK_STATUS_SIZE))
+		chunk_appendf(msg, ", invalid srv_check_status value '%s'", params[6]);
+
+	/* validating srv_check_result */
+	p = NULL;
+	errno = 0;
+	srv_check_result = strtol(params[7], &p, 10);
+	if ((p == params[7]) || errno == EINVAL || errno == ERANGE ||
+	    (srv_check_result != CHK_RES_UNKNOWN &&
+	     srv_check_result != CHK_RES_NEUTRAL &&
+	     srv_check_result != CHK_RES_FAILED &&
+	     srv_check_result != CHK_RES_PASSED &&
+	     srv_check_result != CHK_RES_CONDPASS)) {
+		chunk_appendf(msg, ", invalid srv_check_result value '%s'", params[7]);
+	}
+
+	/* validating srv_check_health */
+	p = NULL;
+	errno = 0;
+	srv_check_health = strtol(params[8], &p, 10);
+	if (p == params[8] || errno == EINVAL || errno == ERANGE)
+		chunk_appendf(msg, ", invalid srv_check_health value '%s'", params[8]);
+
+	/* validating srv_check_state */
+	p = NULL;
+	errno = 0;
+	srv_check_state = strtol(params[9], &p, 10);
+	if (p == params[9] || errno == EINVAL || errno == ERANGE ||
+	    (srv_check_state & ~(CHK_ST_INPROGRESS | CHK_ST_CONFIGURED | CHK_ST_ENABLED | CHK_ST_PAUSED | CHK_ST_AGENT)))
+		chunk_appendf(msg, ", invalid srv_check_state value '%s'", params[9]);
+
+	/* validating srv_agent_state */
+	p = NULL;
+	errno = 0;
+	srv_agent_state = strtol(params[10], &p, 10);
+	if (p == params[10] || errno == EINVAL || errno == ERANGE ||
+	    (srv_agent_state & ~(CHK_ST_INPROGRESS | CHK_ST_CONFIGURED | CHK_ST_ENABLED | CHK_ST_PAUSED | CHK_ST_AGENT)))
+		chunk_appendf(msg, ", invalid srv_agent_state value '%s'", params[10]);
+
+	/* validating bk_f_forced_id */
+	p = NULL;
+	errno = 0;
+	bk_f_forced_id = strtol(params[11], &p, 10);
+	if (p == params[11] || errno == EINVAL || errno == ERANGE || !((bk_f_forced_id == 0) || (bk_f_forced_id == 1)))
+		chunk_appendf(msg, ", invalid bk_f_forced_id value '%s'", params[11]);
+
+	/* validating srv_f_forced_id */
+	p = NULL;
+	errno = 0;
+	srv_f_forced_id = strtol(params[12], &p, 10);
+	if (p == params[12] || errno == EINVAL || errno == ERANGE || !((srv_f_forced_id == 0) || (srv_f_forced_id == 1)))
+		chunk_appendf(msg, ", invalid srv_f_forced_id value '%s'", params[12]);
+
+	/* validating srv_fqdn */
+	fqdn = params[13];
+	if (fqdn && *fqdn == '-')
+		fqdn = NULL;
+	if (fqdn && (strlen(fqdn) > DNS_MAX_NAME_SIZE || invalid_domainchar(fqdn))) {
+		chunk_appendf(msg, ", invalid srv_fqdn value '%s'", params[13]);
+		fqdn = NULL;
+	}
+
+	port_st = params[14];
+	if (port_st) {
+		port_svc = strl2uic(port_st, strlen(port_st));
+		if (port_svc > USHRT_MAX) {
+			chunk_appendf(msg, ", invalid srv_port value '%s'", port_st);
+			port_st = NULL;
+		}
+	}
+
+	/* SRV record
+	 * NOTE: in HAProxy, SRV records must start with an underscore '_'
+	 */
+	srvrecord = params[15];
+	if (srvrecord && *srvrecord != '_')
+		srvrecord = NULL;
+
+	/* don't apply anything if one error has been detected */
+	if (msg->data)
+		goto out;
+	partial_apply = 1;
+
+	/* recover operational state and apply it to this server
+	 * and all servers tracking this one */
+	srv->check.health = srv_check_health;
+	switch (srv_op_state) {
+		case SRV_ST_STOPPED:
+			srv->check.health = 0;
+			srv_set_stopped(srv, "changed from server-state after a reload", NULL);
+			break;
+		case SRV_ST_STARTING:
+			/* If rise == 1 there is no STARTING state, let's switch to
+			 * RUNNING
+			 */
+			if (srv->check.rise == 1) {
+				srv->check.health = srv->check.rise + srv->check.fall - 1;
+				srv_set_running(srv, "", NULL);
+				break;
+			}
+			if (srv->check.health < 1 || srv->check.health >= srv->check.rise)
+				srv->check.health = srv->check.rise - 1;
+			srv->next_state = srv_op_state;
+			break;
+		case SRV_ST_STOPPING:
+			/* If fall == 1 there is no STOPPING state, let's switch to
+			 * STOPPED
+			 */
+			if (srv->check.fall == 1) {
+				srv->check.health = 0;
+				srv_set_stopped(srv, "changed from server-state after a reload", NULL);
+				break;
+			}
+			if (srv->check.health < srv->check.rise ||
+			    srv->check.health > srv->check.rise + srv->check.fall - 2)
+				srv->check.health = srv->check.rise;
+			srv_set_stopping(srv, "changed from server-state after a reload", NULL);
+			break;
+		case SRV_ST_RUNNING:
+			srv->check.health = srv->check.rise + srv->check.fall - 1;
+			srv_set_running(srv, "", NULL);
+			break;
+	}
+
+	/* When applying server state, the following rules apply:
+	 * - in case of a configuration change, we apply the setting from the new
+	 *   configuration, regardless of old running state
+	 * - if no configuration change, we apply old running state only if old running
+	 *   state is different from new configuration state
+	 */
+	/* configuration has changed */
+	if ((srv_admin_state & SRV_ADMF_CMAINT) != (srv->next_admin & SRV_ADMF_CMAINT)) {
+		if (srv->next_admin & SRV_ADMF_CMAINT)
+			srv_adm_set_maint(srv);
+		else
+			srv_adm_set_ready(srv);
+	}
+	/* configuration is the same, let's compate old running state and new conf state */
+	else {
+		if (srv_admin_state & SRV_ADMF_FMAINT && !(srv->next_admin & SRV_ADMF_CMAINT))
+			srv_adm_set_maint(srv);
+		else if (!(srv_admin_state & SRV_ADMF_FMAINT) && (srv->next_admin & SRV_ADMF_CMAINT))
+			srv_adm_set_ready(srv);
+	}
+	/* apply drain mode if server is currently enabled */
+	if (!(srv->next_admin & SRV_ADMF_FMAINT) && (srv_admin_state & SRV_ADMF_FDRAIN)) {
+		/* The SRV_ADMF_FDRAIN flag is inherited when srv->iweight is 0
+		 * (srv->iweight is the weight set up in configuration).
+		 * There are two possible reasons for FDRAIN to have been present :
+		 *   - previous config weight was zero
+		 *   - "set server b/s drain" was sent to the CLI
+		 *
+		 * In the first case, we simply want to drop this drain state
+		 * if the new weight is not zero anymore, meaning the administrator
+		 * has intentionally turned the weight back to a positive value to
+		 * enable the server again after an operation. In the second case,
+		 * the drain state was forced on the CLI regardless of the config's
+		 * weight so we don't want a change to the config weight to lose this
+		 * status. What this means is :
+		 *   - if previous weight was 0 and new one is >0, drop the DRAIN state.
+		 *   - if the previous weight was >0, keep it.
+		 */
+		if (srv_iweight > 0 || srv->iweight == 0)
+			srv_adm_set_drain(srv);
+	}
+
+	srv->last_change = date.tv_sec - srv_last_time_change;
+	srv->check.status = srv_check_status;
+	srv->check.result = srv_check_result;
+
+	/* Only case we want to apply is removing ENABLED flag which could have been
+	 * done by the "disable health" command over the stats socket
+	 */
+	if ((srv->check.state & CHK_ST_CONFIGURED) &&
+	    (srv_check_state & CHK_ST_CONFIGURED) &&
+	    !(srv_check_state & CHK_ST_ENABLED))
+		srv->check.state &= ~CHK_ST_ENABLED;
+
+	/* Only case we want to apply is removing ENABLED flag which could have been
+	 * done by the "disable agent" command over the stats socket
+	 */
+	if ((srv->agent.state & CHK_ST_CONFIGURED) &&
+	    (srv_agent_state & CHK_ST_CONFIGURED) &&
+	    !(srv_agent_state & CHK_ST_ENABLED))
+		srv->agent.state &= ~CHK_ST_ENABLED;
+
+	/* We want to apply the previous 'running' weight (srv_uweight) only if there
+	 * was no change in the configuration: both previous and new iweight are equals
+	 *
+	 * It means that a configuration file change has precedence over a unix socket change
+	 * for server's weight
+	 *
+	 * by default, HAProxy applies the following weight when parsing the configuration
+	 *    srv->uweight = srv->iweight
+	 */
+	if (srv_iweight == srv->iweight) {
+		srv->uweight = srv_uweight;
+	}
+	server_recalc_eweight(srv, 1);
+
+	/* load server IP address */
+	if (strcmp(params[0], "-") != 0)
+		srv->lastaddr = strdup(params[0]);
+
+	if (fqdn && srv->hostname) {
+		if (strcmp(srv->hostname, fqdn) == 0) {
+			/* Here we reset the 'set from stats socket FQDN' flag
+			 * to support such transitions:
+			 * Let's say initial FQDN value is foo1 (in configuration file).
+			 * - FQDN changed from stats socket, from foo1 to foo2 value,
+			 * - FQDN changed again from file configuration (with the same previous value
+			 set from stats socket, from foo1 to foo2 value),
+			 * - reload for any other reason than a FQDN modification,
+			 * the configuration file FQDN matches the fqdn server state file value.
+			 * So we must reset the 'set from stats socket FQDN' flag to be consistent with
+			 * any further FQDN modification.
+			 */
+			srv->next_admin &= ~SRV_ADMF_HMAINT;
+		}
+		else {
+			/* If the FDQN has been changed from stats socket,
+			 * apply fqdn state file value (which is the value set
+			 * from stats socket).
+			 * Also ensure the runtime resolver will process this resolution.
+			 */
+			if (fqdn_set_by_cli) {
+				srv_set_fqdn(srv, fqdn, 0);
+				srv->flags &= ~SRV_F_NO_RESOLUTION;
+				srv->next_admin |= SRV_ADMF_HMAINT;
+			}
+		}
+	}
+	/* If all the conditions below are validated, this means
+	 * we're evaluating a server managed by SRV resolution
+	 */
+	else if (fqdn && !srv->hostname && srvrecord) {
+		int res;
+
+		/* we can't apply previous state if SRV record has changed */
+		if (srv->srvrq && strcmp(srv->srvrq->name, srvrecord) != 0) {
+			chunk_appendf(msg, ", SRV record mismatch between configuration ('%s') and state file ('%s) for server '%s'. Previous state not applied", srv->srvrq->name, srvrecord, srv->id);
+			goto out;
+		}
+
+		/* create or find a SRV resolution for this srv record */
+		if (srv->srvrq == NULL && (srv->srvrq = find_srvrq_by_name(srvrecord, srv->proxy)) == NULL)
+			srv->srvrq = new_resolv_srvrq(srv, srvrecord);
+		if (srv->srvrq == NULL) {
+			chunk_appendf(msg, ", can't create or find SRV resolution '%s' for server '%s'", srvrecord, srv->id);
+			goto out;
+		}
+
+		/* prepare DNS resolution for this server */
+		res = srv_prepare_for_resolution(srv, fqdn);
+		if (res == -1) {
+			chunk_appendf(msg, ", can't allocate memory for DNS resolution for server '%s'", srv->id);
+			goto out;
+		}
+
+		/* Unset SRV_F_MAPPORTS for SRV records.
+		 * SRV_F_MAPPORTS is unfortunately set by parse_server()
+		 * because no ports are provided in the configuration file.
+		 * This is because HAProxy will use the port found into the SRV record.
+		 */
+		srv->flags &= ~SRV_F_MAPPORTS;
+	}
+
+	if (port_st)
+		srv->svc_port = port_svc;
+
+
+	if (params[16]) {
+#ifdef USE_OPENSSL
+		use_ssl = strtol(params[16], &p, 10);
+
+		/* configure ssl if connection has been initiated at startup */
+		if (srv->ssl_ctx.ctx != NULL)
+			ssl_sock_set_srv(srv, use_ssl);
+#endif
+	}
+
+	port_st = NULL;
+	if (params[17] && strcmp(params[17], "0") != 0)
+		port_st = params[17];
+	addr = NULL;
+	if (params[18] && strcmp(params[18], "-") != 0)
+		addr = params[18];
+	if (addr || port_st) {
+		warning = srv_update_check_addr_port(srv, addr, port_st);
+		if (warning) {
+			chunk_appendf(msg, ", %s", warning);
+			goto out;
+		}
+	}
+
+	port_st = NULL;
+	if (params[20] && strcmp(params[20], "0") != 0)
+		port_st = params[20];
+	addr = NULL;
+	if (params[19] && strcmp(params[19], "-") != 0)
+		addr = params[19];
+	if (addr || port_st) {
+		warning = srv_update_agent_addr_port(srv, addr, port_st);
+		if (warning) {
+			chunk_appendf(msg, ", %s", warning);
+			goto out;
+		}
+	}
+
+  out:
+	HA_SPIN_UNLOCK(SERVER_LOCK, &srv->lock);
+	if (msg->data) {
+		if (partial_apply == 1)
+			ha_warning("server-state partially applied for server '%s/%s'%s\n",
+				   srv->proxy->id, srv->id, msg->area);
+		else
+			ha_warning("server-state application failed for server '%s/%s'%s\n",
+				   srv->proxy->id, srv->id, msg->area);
+	}
+  end:
+	free_trash_chunk(msg);
+}
+
+/*
+ * Loop on the proxy's servers and try to load its state from <st_tree> using
+ * srv_state_srv_update(). The proxy name and the server name are concatenated
+ * to form the key. If found the entry is removed from the tree.
+ */
+static void srv_state_px_update(const struct proxy *px, int vsn, struct eb_root *st_tree)
+{
+	struct server_state_line *st_line;
+	struct eb64_node *node;
+	struct server *srv;
+	unsigned long key;
+
+	for (srv = px->srv; srv; srv = srv->next) {
+		chunk_printf(&trash, "%s %s", px->id, srv->id);
+		key = XXH3(trash.area, trash.data, 0);
+		node = eb64_lookup(st_tree, key);
+		if (!node)
+			continue; /* next server */
+		st_line = eb64_entry(node, typeof(*st_line), node);
+		srv_state_srv_update(srv, vsn, st_line->params+4);
+
+		/* the node may be released now */
+		eb64_delete(node);
+		free(st_line->line);
+		free(st_line);
+	}
+}
+
+/*
+ * read next line from file <f> and return the server state version if one found.
+ * If no version is found, then 0 is returned
+ * Note that this should be the first read on <f>
+ */
+static int srv_state_get_version(FILE *f) {
+	char mybuf[SRV_STATE_LINE_MAXLEN];
+	char *endptr;
+	long int vsn;
+
+	/* first character of first line of the file must contain the version of the export */
+	if (fgets(mybuf, SRV_STATE_LINE_MAXLEN, f) == NULL)
+		return 0;
+
+	vsn = strtol(mybuf, &endptr, 10);
+	if (endptr == mybuf || *endptr != '\n') {
+		/* Empty or truncated line */
+		return 0;
+	}
+
+	if (vsn < SRV_STATE_FILE_VERSION_MIN || vsn > SRV_STATE_FILE_VERSION_MAX) {
+		/* Wrong version number */
+		return 0;
+	}
+
+	return vsn;
+}
+
+
+/*
+ * parses server state line stored in <buf> and supposedly in version <version>.
+ * Set <params> accordingly on success. It returns 1 on success, 0 if the line
+ * must be ignored and -1 on error.
+ * The caller must provide a supported version
+ */
+static int srv_state_parse_line(char *buf, const int version, char **params)
+{
+	int buflen, arg, ret;
+	char *cur;
+
+	buflen = strlen(buf);
+	cur = buf;
+	ret = 1; /* be optimistic and pretend a success */
+
+	/* we need at least one character and a non-truncated line */
+	if (buflen == 0 || buf[buflen - 1] != '\n') {
+		ret = -1;
+		goto out;
+	}
+
+	/* skip blank characters at the beginning of the line */
+	while (isblank((unsigned char)*cur))
+		++cur;
+
+	/* ignore empty or commented lines */
+	if (!*cur || *cur == '\n' || *cur == '#') {
+		ret = 0;
+		goto out;
+	}
+
+	/* Removes trailing '\n' to ease parsing */
+	buf[buflen - 1] = '\0';
+
+	/* we're now ready to move the line into <params> */
+	memset(params, 0, SRV_STATE_FILE_MAX_FIELDS * sizeof(*params));
+	arg = 0;
+	while (*cur) {
+		/* first of all, stop if there are too many fields */
+		if (arg >= SRV_STATE_FILE_MAX_FIELDS)
+			break;
+
+		/* then skip leading spaces */
+		while (*cur && isblank((unsigned char)*cur)) {
+			++cur;
+			if (!*cur)
+				break;
+		}
+
+		/*
+		 * idx:
+		 *   be_id:                params[0]
+		 *   be_name:              params[1]
+		 *   srv_id:               params[2]
+		 *   srv_name:             params[3]
+		 * v1
+		 *   srv_addr:             params[4]
+		 *   srv_op_state:         params[5]
+		 *   srv_admin_state:      params[6]
+		 *   srv_uweight:          params[7]
+		 *   srv_iweight:          params[8]
+		 *   srv_last_time_change: params[9]
+		 *   srv_check_status:     params[10]
+		 *   srv_check_result:     params[11]
+		 *   srv_check_health:     params[12]
+		 *   srv_check_state:      params[13]
+		 *   srv_agent_state:      params[14]
+		 *   bk_f_forced_id:       params[15]
+		 *   srv_f_forced_id:      params[16]
+		 *   srv_fqdn:             params[17]
+		 *   srv_port:             params[18]
+		 *   srvrecord:            params[19]
+		 *
+		 *   srv_use_ssl:          params[20]  (optional field)
+		 *   srv_check_port:       params[21]  (optional field)
+		 *   srv_check_addr:       params[22]  (optional field)
+		 *   srv_agent_addr:       params[23]  (optional field)
+		 *   srv_agent_port:       params[24]  (optional field)
+		 *
+		 */
+		params[arg++] = cur;
+
+		/* look for the end of the current field */
+		while (*cur && !isblank((unsigned char)*cur)) {
+			++cur;
+			if (!*cur)
+				break;
+		}
+
+		/* otherwise, cut the field and move to the next one */
+		*cur++ = '\0';
+	}
+
+	/* if the number of fields does not match the version, then return an error */
+	if (version == 1 &&
+	    (arg < SRV_STATE_FILE_MIN_FIELDS_VERSION_1 ||
+	     arg > SRV_STATE_FILE_MAX_FIELDS_VERSION_1))
+		ret = -1;
+
+  out:
+	return ret;
+}
+
+
+/*
+ * parses a server state line using srv_state_parse_line() and store the result
+ * in <st_tree>. If an error occurred during the parsing, the line is
+ * ignored. if <px> is defined, it is used to check the backend id/name against
+ * the parsed params and to compute the key of the line.
+ */
+static int srv_state_parse_and_store_line(char *line, int vsn, struct eb_root *st_tree,
+					  struct proxy *px)
+{
+	struct server_state_line *st_line;
+	int ret = 0;
+
+	/* store line in tree and duplicate the line */
+	st_line = calloc(1, sizeof(*st_line));
+	if (st_line == NULL)
+		goto skip_line;
+	st_line->line = strdup(line);
+	if (st_line->line == NULL)
+		goto skip_line;
+
+	ret = srv_state_parse_line(st_line->line, vsn, st_line->params);
+	if (ret <= 0)
+		goto skip_line;
+
+	/* Check backend name against params if <px> is defined */
+	if (px) {
+		int check_id = (atoi(st_line->params[0]) == px->uuid);
+		int check_name = (strcmp(px->id, st_line->params[1]) == 0);
+		int bk_f_forced_id = (atoi(st_line->params[15]) & PR_O_FORCED_ID);
+
+
+		if (!check_id && !check_name) {
+			/* backend does not match at all: skip the line */
+			goto skip_line;
+		}
+		else if (!check_id) {
+			/* Id mismatch: warn but continue */
+			ha_warning("Proxy '%s': backend ID mismatch: from server state file: '%s', from running config '%d'\n",
+				   px->id, st_line->params[0], px->uuid);
+			send_log(px, LOG_NOTICE, "backend ID mismatch: from server state file: '%s', from running config '%d'\n",
+				 st_line->params[0], px->uuid);
+		}
+		else if (!check_name) {
+			/* Name mismatch: warn and skip the line, except if the backend id was forced
+			 * in the previous configuration */
+			ha_warning("Proxy '%s': backend name mismatch: from server state file: '%s', from running config '%s'\n",
+				   px->id, st_line->params[1], px->id);
+			send_log(px, LOG_NOTICE, "backend name mismatch: from server state file: '%s', from running config '%s'\n",
+				 st_line->params[1], px->id);
+			if (!bk_f_forced_id)
+				goto skip_line;
+		}
+	}
+
+	/*
+	 * The key: "be_name srv_name"
+	 *   if <px> is defined:  be_name == px->id
+	 *   otherwise: be_name == params[1]
+	 */
+	chunk_printf(&trash, "%s %s", (px ? px->id : st_line->params[1]), st_line->params[3]);
+	st_line->node.key = XXH3(trash.area, trash.data, 0);
+	if (eb64_insert(st_tree, &st_line->node) != &st_line->node) {
+		/* this is a duplicate key, probably a hand-crafted file, drop it! */
+		goto skip_line;
+	}
+
+	return ret;
+
+  skip_line:
+	/* free up memory in case of error during the processing of the line */
+	if (st_line) {
+		free(st_line->line);
+		free(st_line);
+	}
+	return ret;
+}
+
+/* Helper function to get the server-state file path.
+ * If <filename> starts with a '/', it is considered as an absolute path. In
+ * this case or if <global.server_state_base> is not set, <filename> only is
+ * considered. Otherwise, the <global.server_state_base> is concatenated to
+ * <filename> to produce the file path and copied to <dst_path>. in both cases,
+ * the result must not exceeds <maxpathlen>.
+ *
+ * The len is returned on success or -1 if the path is too long. On error, the
+ * caller must not rely on <dst_path>.
+ */
+static inline int srv_state_get_filepath(char *dst_path, int maxpathlen, const char *filename)
+{
+	char *sep = (global.server_state_base[strlen(global.server_state_base)-1] != '/' ? "/":  "");
+	int len = 0;
+
+	/* create the globalfilepath variable */
+	if (*filename == '/' || !global.server_state_base) {
+		/* absolute path or no base directory provided */
+		len = strlen(filename);
+		if (len < maxpathlen)
+			strcpy(dst_path, global.server_state_file);
+	}
+	else {
+		/* concat base directory and global server-state file */
+		len = snprintf(dst_path, maxpathlen, "%s%s%s", global.server_state_base, sep, filename);
+	}
+	return (len < maxpathlen ? len: -1);
+}
+
+
+/* This function parses all the proxies and only take care of the backends (since we're looking for server)
+ * For each proxy, it does the following:
+ *  - opens its server state file (either one or local one)
+ *  - read whole file, line by line
+ *  - analyse each line to check if it matches our current backend:
+ *    - backend name matches
+ *    - backend id matches if id is forced and name doesn't match
+ *  - if the server pointed by the line is found, then state is applied
+ *
+ * If the running backend uuid or id differs from the state file, then HAProxy reports
+ * a warning.
+ *
+ * Grabs the server's lock via srv_state_srv_update().
+ */
+void apply_server_state(void)
+{
+	/* tree where global state_file is loaded */
+	struct eb_root global_state_tree = EB_ROOT_UNIQUE;
+	struct proxy *curproxy;
+	struct server_state_line *st_line;
+	struct eb64_node *node, *next_node;
+	FILE *f;
+	char mybuf[SRV_STATE_LINE_MAXLEN];
+	char file[MAXPATHLEN];
+	int local_vsn, global_vsn, len, linenum;
+
+	global_vsn = 0; /* no global file */
+	if (!global.server_state_file)
+		goto no_globalfile;
+	len = srv_state_get_filepath(file, MAXPATHLEN, global.server_state_file);
+	if (len == -1) {
+		ha_warning("config: Can't load global server state file: file too long.\n");
+		goto no_globalfile;
+	}
+
+	/* Load global server state in a tree */
+	errno = 0;
+	f = fopen(file, "r");
+	if (!f) {
+		ha_warning("config: Can't open global server state file '%s': %s\n", file, strerror(errno));
+		goto no_globalfile;
+	}
+
+	global_vsn = srv_state_get_version(f);
+	if (global_vsn == 0) {
+		ha_warning("config: Can't get version of the global server state file '%s'.\n",
+			   file);
+		goto close_globalfile;
+	}
+
+	for (linenum = 1; fgets(mybuf, SRV_STATE_LINE_MAXLEN, f); linenum++) {
+		int ret;
+
+		ret = srv_state_parse_and_store_line(mybuf, global_vsn, &global_state_tree, NULL);
+		if (ret == -1) {
+			ha_warning("config: corrupted global server state file '%s' at line %d.\n",
+				   file, linenum);
+			global_vsn = 0;
+			break;
+		}
+	}
+
+  close_globalfile:
+	fclose(f);
+
+  no_globalfile:
+	/* parse all proxies and load states form tree (global file) or from local file */
+	for (curproxy = proxies_list; curproxy != NULL; curproxy = curproxy->next) {
+		struct eb_root local_state_tree = EB_ROOT_UNIQUE;
+
+		/* servers are only in backends */
+		if (!(curproxy->cap & PR_CAP_BE))
+			continue; /* next proxy */
+
+		/* No server-state file for this proxy */
+		if (curproxy->load_server_state_from_file == PR_SRV_STATE_FILE_NONE)
+			continue;  /* next proxy */
+
+		if (curproxy->load_server_state_from_file == PR_SRV_STATE_FILE_GLOBAL) {
+			/* when global file is used, we get data from the tree
+			 * Note that in such case we don't check backend name neither uuid.
+			 * Backend name can't be wrong since it's used as a key to retrieve the server state
+			 * line from the tree.
+			 */
+			if (global_vsn)
+				srv_state_px_update(curproxy, global_vsn, &global_state_tree);
+			continue; /* next proxy */
+		}
+
+		/*
+		 * Here we load a local server state-file
+		 */
+
+		/* create file variable */
+		len = srv_state_get_filepath(file, MAXPATHLEN, curproxy->server_state_file_name);
+		if (len == -1) {
+			ha_warning("Proxy '%s': Can't load local server state file: file too long.\n", curproxy->id);
+			continue; /* next proxy */
+		}
+
+		/* Load local server state in a tree */
+		errno = 0;
+		f = fopen(file, "r");
+		if (!f) {
+			ha_warning("Proxy '%s': Can't open server state file '%s': %s.\n",
+				   curproxy->id, file, strerror(errno));
+			continue; /* next proxy */
+		}
+
+		/* first character of first line of the file must contain the version of the export */
+		local_vsn = srv_state_get_version(f);
+		if (local_vsn == 0) {
+			ha_warning("Proxy '%s': Can't get version of the server state file '%s'.\n",
+				   curproxy->id, file);
+			goto close_localfile;
+		}
+
+		/* First, parse lines of the local server-state file and store them in a eb-tree */
+		for (linenum = 1; fgets(mybuf, SRV_STATE_LINE_MAXLEN, f); linenum++) {
+			int ret;
+
+			ret = srv_state_parse_and_store_line(mybuf, local_vsn, &local_state_tree, curproxy);
+			if (ret == -1) {
+				ha_warning("Proxy '%s': corrupted server state file '%s' at line %d.\n",
+					   curproxy->id, file, linenum);
+				local_vsn = 0;
+				break;
+			}
+		}
+
+		if (local_vsn)
+			srv_state_px_update(curproxy, local_vsn, &local_state_tree);
+
+		/* Remove unsused server-state lines */
+		node = eb64_first(&local_state_tree);
+		while (node) {
+			st_line = eb64_entry(node, typeof(*st_line), node);
+			next_node = eb64_next(node);
+			eb64_delete(node);
+
+			if (local_vsn) {
+				/* if no server found, then warn */
+				ha_warning("Proxy '%s': can't find server '%s' in backend '%s'\n",
+					   curproxy->id, st_line->params[3], curproxy->id);
+				send_log(curproxy, LOG_NOTICE, "can't find server '%s' in backend '%s'\n",
+					 st_line->params[3], curproxy->id);
+			}
+
+			free(st_line->line);
+			free(st_line);
+			node = next_node;
+		}
+
+	close_localfile:
+		fclose(f);
+	}
+
+	node = eb64_first(&global_state_tree);
+        while (node) {
+                st_line = eb64_entry(node, typeof(*st_line), node);
+                next_node = eb64_next(node);
+                eb64_delete(node);
+		free(st_line->line);
+		free(st_line);
+                node = next_node;
+        }
+}