haproxy/src/server.c

/*
 * Server management functions.
 *
 * Copyright 2000-2012 Willy Tarreau <w@1wt.eu>
 * Copyright 2007-2008 Krzysztof Piotr Oledzki <ole@ans.pl>
 *
 * 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 <common/config.h>
#include <common/errors.h>
#include <common/time.h>

#include <proto/server.h>

/* List head of all known server keywords */
static struct srv_kw_list srv_keywords = {
	.list = LIST_HEAD_INIT(srv_keywords.list)
};

int srv_downtime(const struct server *s)
{
	if ((s->state & SRV_RUNNING) && s->last_change < now.tv_sec)		// ignore negative time
		return s->down_time;

	return now.tv_sec - s->last_change + s->down_time;
}

int srv_getinter(const struct check *check)
{
	const struct server *s = check->server;

	if ((s->state & SRV_CHECKED) && (check->health == check->rise + check->fall - 1))
		return check->inter;

	if (!(s->state & SRV_RUNNING) && check->health == 0)
		return (check->downinter)?(check->downinter):(check->inter);

	return (check->fastinter)?(check->fastinter):(check->inter);
}

/*
 * Registers the server keyword list <kwl> as a list of valid keywords for next
 * parsing sessions.
 */
void srv_register_keywords(struct srv_kw_list *kwl)
{
	LIST_ADDQ(&srv_keywords.list, &kwl->list);
}

/* Return a pointer to the server keyword <kw>, or NULL if not found. If the
 * keyword is found with a NULL ->parse() function, then an attempt is made to
 * find one with a valid ->parse() function. This way it is possible to declare
 * platform-dependant, known keywords as NULL, then only declare them as valid
 * if some options are met. Note that if the requested keyword contains an
 * opening parenthesis, everything from this point is ignored.
 */
struct srv_kw *srv_find_kw(const char *kw)
{
	int index;
	const char *kwend;
	struct srv_kw_list *kwl;
	struct srv_kw *ret = NULL;

	kwend = strchr(kw, '(');
	if (!kwend)
		kwend = kw + strlen(kw);

	list_for_each_entry(kwl, &srv_keywords.list, list) {
		for (index = 0; kwl->kw[index].kw != NULL; index++) {
			if ((strncmp(kwl->kw[index].kw, kw, kwend - kw) == 0) &&
			    kwl->kw[index].kw[kwend-kw] == 0) {
				if (kwl->kw[index].parse)
					return &kwl->kw[index]; /* found it !*/
				else
					ret = &kwl->kw[index];  /* may be OK */
			}
		}
	}
	return ret;
}

/* Dumps all registered "server" keywords to the <out> string pointer. The
 * unsupported keywords are only dumped if their supported form was not
 * found.
 */
void srv_dump_kws(char **out)
{
	struct srv_kw_list *kwl;
	int index;

	*out = NULL;
	list_for_each_entry(kwl, &srv_keywords.list, list) {
		for (index = 0; kwl->kw[index].kw != NULL; index++) {
			if (kwl->kw[index].parse ||
			    srv_find_kw(kwl->kw[index].kw) == &kwl->kw[index]) {
				memprintf(out, "%s[%4s] %s%s%s%s\n", *out ? *out : "",
				          kwl->scope,
				          kwl->kw[index].kw,
				          kwl->kw[index].skip ? " <arg>" : "",
				          kwl->kw[index].default_ok ? " [dflt_ok]" : "",
				          kwl->kw[index].parse ? "" : " (not supported)");
			}
		}
	}
}

/* parse the "id" server keyword */
static int srv_parse_id(char **args, int *cur_arg, struct proxy *curproxy, struct server *newsrv, char **err)
{
	struct eb32_node *node;

	if (!*args[*cur_arg + 1]) {
		memprintf(err, "'%s' : expects an integer argument", args[*cur_arg]);
		return ERR_ALERT | ERR_FATAL;
	}

	newsrv->puid = atol(args[*cur_arg + 1]);
	newsrv->conf.id.key = newsrv->puid;

	if (newsrv->puid <= 0) {
		memprintf(err, "'%s' : custom id has to be > 0", args[*cur_arg]);
		return ERR_ALERT | ERR_FATAL;
	}

	node = eb32_lookup(&curproxy->conf.used_server_id, newsrv->puid);
	if (node) {
		struct server *target = container_of(node, struct server, conf.id);
		memprintf(err, "'%s' : custom id %d already used at %s:%d ('server %s')",
		          args[*cur_arg], newsrv->puid, target->conf.file, target->conf.line,
		          target->id);
		return ERR_ALERT | ERR_FATAL;
	}

	eb32_insert(&curproxy->conf.used_server_id, &newsrv->conf.id);
	return 0;
}

/* Note: must not be declared <const> as its list will be overwritten.
 * Please take care of keeping this list alphabetically sorted, doing so helps
 * all code contributors.
 * Optional keywords are also declared with a NULL ->parse() function so that
 * the config parser can report an appropriate error when a known keyword was
 * not enabled.
 */
static struct srv_kw_list srv_kws = { "ALL", { }, {
	{ "id",           srv_parse_id,           1,  0 }, /* set id# of server */
	{ NULL, NULL, 0 },
}};

__attribute__((constructor))
static void __listener_init(void)
{
	srv_register_keywords(&srv_kws);
}

/* Recomputes the server's eweight based on its state, uweight, the current time,
 * and the proxy's algorihtm. To be used after updating sv->uweight. The warmup
 * state is automatically disabled if the time is elapsed.
 */
void server_recalc_eweight(struct server *sv)
{
	struct proxy *px = sv->proxy;
	unsigned w;

	if (now.tv_sec < sv->last_change || now.tv_sec >= sv->last_change + sv->slowstart) {
		/* go to full throttle if the slowstart interval is reached */
		sv->state &= ~SRV_WARMINGUP;
	}

	/* We must take care of not pushing the server to full throttle during slow starts.
	 * It must also start immediately, at least at the minimal step when leaving maintenance.
	 */
	if ((sv->state & SRV_WARMINGUP) && (px->lbprm.algo & BE_LB_PROP_DYN))
		w = (px->lbprm.wdiv * (now.tv_sec - sv->last_change) + sv->slowstart) / sv->slowstart;
	else
		w = px->lbprm.wdiv;

	sv->eweight = (sv->uweight * w + px->lbprm.wmult - 1) / px->lbprm.wmult;

	/* now propagate the status change to any LB algorithms */
	if (px->lbprm.update_server_eweight)
		px->lbprm.update_server_eweight(sv);
	else if (sv->eweight) {
		if (px->lbprm.set_server_status_up)
			px->lbprm.set_server_status_up(sv);
	}
	else {
		if (px->lbprm.set_server_status_down)
			px->lbprm.set_server_status_down(sv);
	}
}

/*
 * Parses weight_str and configures sv accordingly.
 * Returns NULL on success, error message string otherwise.
 */
const char *server_parse_weight_change_request(struct server *sv,
					       const char *weight_str)
{
	struct proxy *px;
	long int w;
	char *end;

	px = sv->proxy;

	/* if the weight is terminated with '%', it is set relative to
	 * the initial weight, otherwise it is absolute.
	 */
	if (!*weight_str)
		return "Require <weight> or <weight%>.\n";

	w = strtol(weight_str, &end, 10);
	if (end == weight_str)
		return "Empty weight string empty or preceded by garbage";
	else if (end[0] == '%' && end[1] == '\0') {
		if (w < 0)
			return "Relative weight must be positive.\n";
		/* Avoid integer overflow */
		if (w > 25600)
			w = 25600;
		w = sv->iweight * w / 100;
		if (w > 256)
			w = 256;
	}
	else if (w < 0 || w > 256)
		return "Absolute weight can only be between 0 and 256 inclusive.\n";
	else if (end[0] != '\0')
		return "Trailing garbage in weight string";

	if (w && w != sv->iweight && !(px->lbprm.algo & BE_LB_PROP_DYN))
		return "Backend is using a static LB algorithm and only accepts weights '0%' and '100%'.\n";

	sv->uweight = w;
	server_recalc_eweight(sv);

	return NULL;
}

/*
 * Local variables:
 *  c-indent-level: 8
 *  c-basic-offset: 8
 * End:
 */