blob: c9418178ff5fba4c4a2548dc7db3d698d846df26 [file] [log] [blame]
/*
* Listener management functions.
*
* Copyright 2000-2013 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
* as published by the Free Software Foundation; either version
* 2 of the License, or (at your option) any later version.
*
*/
#define _GNU_SOURCE
#include <errno.h>
#include <stdio.h>
#include <string.h>
#include <common/accept4.h>
#include <common/config.h>
#include <common/errors.h>
#include <common/mini-clist.h>
#include <common/standard.h>
#include <common/time.h>
#include <types/global.h>
#include <types/protocol.h>
#include <proto/acl.h>
#include <proto/fd.h>
#include <proto/freq_ctr.h>
#include <proto/log.h>
#include <proto/sample.h>
#include <proto/task.h>
/* List head of all known bind keywords */
static struct bind_kw_list bind_keywords = {
.list = LIST_HEAD_INIT(bind_keywords.list)
};
/* This function adds the specified listener's file descriptor to the polling
* lists if it is in the LI_LISTEN state. The listener enters LI_READY or
* LI_FULL state depending on its number of connections.
*/
void enable_listener(struct listener *listener)
{
if (listener->state == LI_LISTEN) {
if (listener->nbconn < listener->maxconn) {
fd_want_recv(listener->fd);
listener->state = LI_READY;
} else {
listener->state = LI_FULL;
}
}
}
/* This function removes the specified listener's file descriptor from the
* polling lists if it is in the LI_READY or in the LI_FULL state. The listener
* enters LI_LISTEN.
*/
void disable_listener(struct listener *listener)
{
if (listener->state < LI_READY)
return;
if (listener->state == LI_READY)
fd_stop_recv(listener->fd);
if (listener->state == LI_LIMITED)
LIST_DEL(&listener->wait_queue);
listener->state = LI_LISTEN;
}
/* This function tries to temporarily disable a listener, depending on the OS
* capabilities. Linux unbinds the listen socket after a SHUT_RD, and ignores
* SHUT_WR. Solaris refuses either shutdown(). OpenBSD ignores SHUT_RD but
* closes upon SHUT_WR and refuses to rebind. So a common validation path
* involves SHUT_WR && listen && SHUT_RD. In case of success, the FD's polling
* is disabled. It normally returns non-zero, unless an error is reported.
*/
int pause_listener(struct listener *l)
{
if (l->state <= LI_PAUSED)
return 1;
if (l->proto->sock_prot == IPPROTO_TCP) {
if (shutdown(l->fd, SHUT_WR) != 0)
return 0; /* Solaris dies here */
if (listen(l->fd, l->backlog ? l->backlog : l->maxconn) != 0)
return 0; /* OpenBSD dies here */
if (shutdown(l->fd, SHUT_RD) != 0)
return 0; /* should always be OK */
}
if (l->state == LI_LIMITED)
LIST_DEL(&l->wait_queue);
fd_stop_recv(l->fd);
l->state = LI_PAUSED;
return 1;
}
/* This function tries to resume a temporarily disabled listener. Paused, full,
* limited and disabled listeners are handled, which means that this function
* may replace enable_listener(). The resulting state will either be LI_READY
* or LI_FULL. 0 is returned in case of failure to resume (eg: dead socket).
*/
int resume_listener(struct listener *l)
{
if (l->state < LI_PAUSED)
return 0;
if (l->proto->sock_prot == IPPROTO_TCP &&
l->state == LI_PAUSED &&
listen(l->fd, l->backlog ? l->backlog : l->maxconn) != 0)
return 0;
if (l->state == LI_READY)
return 1;
if (l->state == LI_LIMITED)
LIST_DEL(&l->wait_queue);
if (l->nbconn >= l->maxconn) {
l->state = LI_FULL;
return 1;
}
fd_want_recv(l->fd);
l->state = LI_READY;
return 1;
}
/* Marks a ready listener as full so that the session code tries to re-enable
* it upon next close() using resume_listener().
*/
void listener_full(struct listener *l)
{
if (l->state >= LI_READY) {
if (l->state == LI_LIMITED)
LIST_DEL(&l->wait_queue);
fd_stop_recv(l->fd);
l->state = LI_FULL;
}
}
/* Marks a ready listener as limited so that we only try to re-enable it when
* resources are free again. It will be queued into the specified queue.
*/
void limit_listener(struct listener *l, struct list *list)
{
if (l->state == LI_READY) {
LIST_ADDQ(list, &l->wait_queue);
fd_stop_recv(l->fd);
l->state = LI_LIMITED;
}
}
/* This function adds all of the protocol's listener's file descriptors to the
* polling lists when they are in the LI_LISTEN state. It is intended to be
* used as a protocol's generic enable_all() primitive, for use after the
* fork(). It puts the listeners into LI_READY or LI_FULL states depending on
* their number of connections. It always returns ERR_NONE.
*/
int enable_all_listeners(struct protocol *proto)
{
struct listener *listener;
list_for_each_entry(listener, &proto->listeners, proto_list)
enable_listener(listener);
return ERR_NONE;
}
/* This function removes all of the protocol's listener's file descriptors from
* the polling lists when they are in the LI_READY or LI_FULL states. It is
* intended to be used as a protocol's generic disable_all() primitive. It puts
* the listeners into LI_LISTEN, and always returns ERR_NONE.
*/
int disable_all_listeners(struct protocol *proto)
{
struct listener *listener;
list_for_each_entry(listener, &proto->listeners, proto_list)
disable_listener(listener);
return ERR_NONE;
}
/* Dequeues all of the listeners waiting for a resource in wait queue <queue>. */
void dequeue_all_listeners(struct list *list)
{
struct listener *listener, *l_back;
list_for_each_entry_safe(listener, l_back, list, wait_queue) {
/* This cannot fail because the listeners are by definition in
* the LI_LIMITED state. The function also removes the entry
* from the queue.
*/
resume_listener(listener);
}
}
/* This function closes the listening socket for the specified listener,
* provided that it's already in a listening state. The listener enters the
* LI_ASSIGNED state. It always returns ERR_NONE. This function is intended
* to be used as a generic function for standard protocols.
*/
int unbind_listener(struct listener *listener)
{
if (listener->state == LI_READY)
fd_stop_recv(listener->fd);
if (listener->state == LI_LIMITED)
LIST_DEL(&listener->wait_queue);
if (listener->state >= LI_PAUSED) {
fd_delete(listener->fd);
listener->state = LI_ASSIGNED;
}
return ERR_NONE;
}
/* This function closes all listening sockets bound to the protocol <proto>,
* and the listeners end in LI_ASSIGNED state if they were higher. It does not
* detach them from the protocol. It always returns ERR_NONE.
*/
int unbind_all_listeners(struct protocol *proto)
{
struct listener *listener;
list_for_each_entry(listener, &proto->listeners, proto_list)
unbind_listener(listener);
return ERR_NONE;
}
/* Delete a listener from its protocol's list of listeners. The listener's
* state is automatically updated from LI_ASSIGNED to LI_INIT. The protocol's
* number of listeners is updated. Note that the listener must have previously
* been unbound. This is the generic function to use to remove a listener.
*/
void delete_listener(struct listener *listener)
{
if (listener->state != LI_ASSIGNED)
return;
listener->state = LI_INIT;
LIST_DEL(&listener->proto_list);
listener->proto->nb_listeners--;
}
/* This function is called on a read event from a listening socket, corresponding
* to an accept. It tries to accept as many connections as possible, and for each
* calls the listener's accept handler (generally the frontend's accept handler).
*/
void listener_accept(int fd)
{
struct listener *l = fdtab[fd].owner;
struct proxy *p = l->frontend;
int max_accept = l->maxaccept ? l->maxaccept : 1;
int cfd;
int ret;
if (unlikely(l->nbconn >= l->maxconn)) {
listener_full(l);
return;
}
if (global.cps_lim && !(l->options & LI_O_UNLIMITED)) {
int max = freq_ctr_remain(&global.conn_per_sec, global.cps_lim, 0);
if (unlikely(!max)) {
/* frontend accept rate limit was reached */
limit_listener(l, &global_listener_queue);
task_schedule(global_listener_queue_task, tick_add(now_ms, next_event_delay(&global.conn_per_sec, global.cps_lim, 0)));
return;
}
if (max_accept > max)
max_accept = max;
}
if (p && p->fe_sps_lim) {
int max = freq_ctr_remain(&p->fe_sess_per_sec, p->fe_sps_lim, 0);
if (unlikely(!max)) {
/* frontend accept rate limit was reached */
limit_listener(l, &p->listener_queue);
task_schedule(p->task, tick_add(now_ms, next_event_delay(&p->fe_sess_per_sec, p->fe_sps_lim, 0)));
return;
}
if (max_accept > max)
max_accept = max;
}
/* Note: if we fail to allocate a connection because of configured
* limits, we'll schedule a new attempt worst 1 second later in the
* worst case. If we fail due to system limits or temporary resource
* shortage, we try again 100ms later in the worst case.
*/
while (max_accept--) {
struct sockaddr_storage addr;
socklen_t laddr = sizeof(addr);
if (unlikely(actconn >= global.maxconn) && !(l->options & LI_O_UNLIMITED)) {
limit_listener(l, &global_listener_queue);
task_schedule(global_listener_queue_task, tick_add(now_ms, 1000)); /* try again in 1 second */
return;
}
if (unlikely(p && p->feconn >= p->maxconn)) {
limit_listener(l, &p->listener_queue);
return;
}
#ifdef USE_ACCEPT4
cfd = accept4(fd, (struct sockaddr *)&addr, &laddr, SOCK_NONBLOCK);
if (unlikely(cfd == -1 && errno == EINVAL)) {
/* unsupported syscall, fallback to normal accept()+fcntl() */
if ((cfd = accept(fd, (struct sockaddr *)&addr, &laddr)) != -1)
fcntl(cfd, F_SETFL, O_NONBLOCK);
}
#else
cfd = accept(fd, (struct sockaddr *)&addr, &laddr);
#endif
if (unlikely(cfd == -1)) {
switch (errno) {
case EAGAIN:
fd_poll_recv(fd);
return; /* nothing more to accept */
case EINTR:
case ECONNABORTED:
continue;
case ENFILE:
if (p)
send_log(p, LOG_EMERG,
"Proxy %s reached system FD limit at %d. Please check system tunables.\n",
p->id, maxfd);
limit_listener(l, &global_listener_queue);
task_schedule(global_listener_queue_task, tick_add(now_ms, 100)); /* try again in 100 ms */
return;
case EMFILE:
if (p)
send_log(p, LOG_EMERG,
"Proxy %s reached process FD limit at %d. Please check 'ulimit-n' and restart.\n",
p->id, maxfd);
limit_listener(l, &global_listener_queue);
task_schedule(global_listener_queue_task, tick_add(now_ms, 100)); /* try again in 100 ms */
return;
case ENOBUFS:
case ENOMEM:
if (p)
send_log(p, LOG_EMERG,
"Proxy %s reached system memory limit at %d sockets. Please check system tunables.\n",
p->id, maxfd);
limit_listener(l, &global_listener_queue);
task_schedule(global_listener_queue_task, tick_add(now_ms, 100)); /* try again in 100 ms */
return;
default:
/* unexpected result, let's give up and let other tasks run */
return;
}
}
if (unlikely(cfd >= global.maxsock)) {
send_log(p, LOG_EMERG,
"Proxy %s reached the configured maximum connection limit. Please check the global 'maxconn' value.\n",
p->id);
close(cfd);
limit_listener(l, &global_listener_queue);
task_schedule(global_listener_queue_task, tick_add(now_ms, 1000)); /* try again in 1 second */
return;
}
/* increase the per-process number of cumulated connections */
if (!(l->options & LI_O_UNLIMITED)) {
update_freq_ctr(&global.conn_per_sec, 1);
if (global.conn_per_sec.curr_ctr > global.cps_max)
global.cps_max = global.conn_per_sec.curr_ctr;
actconn++;
}
jobs++;
totalconn++;
l->nbconn++;
if (l->counters) {
if (l->nbconn > l->counters->conn_max)
l->counters->conn_max = l->nbconn;
}
ret = l->accept(l, cfd, &addr);
if (unlikely(ret <= 0)) {
/* The connection was closed by session_accept(). Either
* we just have to ignore it (ret == 0) or it's a critical
* error due to a resource shortage, and we must stop the
* listener (ret < 0).
*/
if (!(l->options & LI_O_UNLIMITED))
actconn--;
jobs--;
l->nbconn--;
if (ret == 0) /* successful termination */
continue;
limit_listener(l, &global_listener_queue);
task_schedule(global_listener_queue_task, tick_add(now_ms, 100)); /* try again in 100 ms */
return;
}
if (l->nbconn >= l->maxconn) {
listener_full(l);
return;
}
} /* end of while (max_accept--) */
/* we've exhausted max_accept, so there is no need to poll again */
return;
}
/*
* Registers the bind keyword list <kwl> as a list of valid keywords for next
* parsing sessions.
*/
void bind_register_keywords(struct bind_kw_list *kwl)
{
LIST_ADDQ(&bind_keywords.list, &kwl->list);
}
/* Return a pointer to the bind 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 bind_kw *bind_find_kw(const char *kw)
{
int index;
const char *kwend;
struct bind_kw_list *kwl;
struct bind_kw *ret = NULL;
kwend = strchr(kw, '(');
if (!kwend)
kwend = kw + strlen(kw);
list_for_each_entry(kwl, &bind_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 "bind" keywords to the <out> string pointer. The
* unsupported keywords are only dumped if their supported form was not
* found.
*/
void bind_dump_kws(char **out)
{
struct bind_kw_list *kwl;
int index;
*out = NULL;
list_for_each_entry(kwl, &bind_keywords.list, list) {
for (index = 0; kwl->kw[index].kw != NULL; index++) {
if (kwl->kw[index].parse ||
bind_find_kw(kwl->kw[index].kw) == &kwl->kw[index]) {
memprintf(out, "%s[%4s] %s%s%s\n", *out ? *out : "",
kwl->scope,
kwl->kw[index].kw,
kwl->kw[index].skip ? " <arg>" : "",
kwl->kw[index].parse ? "" : " (not supported)");
}
}
}
}
/************************************************************************/
/* All supported sample and ACL keywords must be declared here. */
/************************************************************************/
/* set temp integer to the number of connexions to the same listening socket */
static int
smp_fetch_dconn(struct proxy *px, struct session *l4, void *l7, unsigned int opt,
const struct arg *args, struct sample *smp, const char *kw)
{
smp->type = SMP_T_UINT;
smp->data.uint = l4->listener->nbconn;
return 1;
}
/* set temp integer to the id of the socket (listener) */
static int
smp_fetch_so_id(struct proxy *px, struct session *l4, void *l7, unsigned int opt,
const struct arg *args, struct sample *smp, const char *kw)
{
smp->type = SMP_T_UINT;
smp->data.uint = l4->listener->luid;
return 1;
}
/* parse the "accept-proxy" bind keyword */
static int bind_parse_accept_proxy(char **args, int cur_arg, struct proxy *px, struct bind_conf *conf, char **err)
{
struct listener *l;
list_for_each_entry(l, &conf->listeners, by_bind)
l->options |= LI_O_ACC_PROXY;
return 0;
}
/* parse the "backlog" bind keyword */
static int bind_parse_backlog(char **args, int cur_arg, struct proxy *px, struct bind_conf *conf, char **err)
{
struct listener *l;
int val;
if (!*args[cur_arg + 1]) {
memprintf(err, "'%s' : missing value", args[cur_arg]);
return ERR_ALERT | ERR_FATAL;
}
val = atol(args[cur_arg + 1]);
if (val <= 0) {
memprintf(err, "'%s' : invalid value %d, must be > 0", args[cur_arg], val);
return ERR_ALERT | ERR_FATAL;
}
list_for_each_entry(l, &conf->listeners, by_bind)
l->backlog = val;
return 0;
}
/* parse the "id" bind keyword */
static int bind_parse_id(char **args, int cur_arg, struct proxy *px, struct bind_conf *conf, char **err)
{
struct eb32_node *node;
struct listener *l, *new;
if (conf->listeners.n != conf->listeners.p) {
memprintf(err, "'%s' can only be used with a single socket", args[cur_arg]);
return ERR_ALERT | ERR_FATAL;
}
if (!*args[cur_arg + 1]) {
memprintf(err, "'%s' : expects an integer argument", args[cur_arg]);
return ERR_ALERT | ERR_FATAL;
}
new = LIST_NEXT(&conf->listeners, struct listener *, by_bind);
new->luid = atol(args[cur_arg + 1]);
new->conf.id.key = new->luid;
if (new->luid <= 0) {
memprintf(err, "'%s' : custom id has to be > 0", args[cur_arg]);
return ERR_ALERT | ERR_FATAL;
}
node = eb32_lookup(&px->conf.used_listener_id, new->luid);
if (node) {
l = container_of(node, struct listener, conf.id);
memprintf(err, "'%s' : custom id %d already used at %s:%d ('bind %s')",
args[cur_arg], l->luid, l->bind_conf->file, l->bind_conf->line,
l->bind_conf->arg);
return ERR_ALERT | ERR_FATAL;
}
eb32_insert(&px->conf.used_listener_id, &new->conf.id);
return 0;
}
/* parse the "maxconn" bind keyword */
static int bind_parse_maxconn(char **args, int cur_arg, struct proxy *px, struct bind_conf *conf, char **err)
{
struct listener *l;
int val;
if (!*args[cur_arg + 1]) {
memprintf(err, "'%s' : missing value", args[cur_arg]);
return ERR_ALERT | ERR_FATAL;
}
val = atol(args[cur_arg + 1]);
if (val <= 0) {
memprintf(err, "'%s' : invalid value %d, must be > 0", args[cur_arg], val);
return ERR_ALERT | ERR_FATAL;
}
list_for_each_entry(l, &conf->listeners, by_bind)
l->maxconn = val;
return 0;
}
/* parse the "name" bind keyword */
static int bind_parse_name(char **args, int cur_arg, struct proxy *px, struct bind_conf *conf, char **err)
{
struct listener *l;
if (!*args[cur_arg + 1]) {
memprintf(err, "'%s' : missing name", args[cur_arg]);
return ERR_ALERT | ERR_FATAL;
}
list_for_each_entry(l, &conf->listeners, by_bind)
l->name = strdup(args[cur_arg + 1]);
return 0;
}
/* parse the "nice" bind keyword */
static int bind_parse_nice(char **args, int cur_arg, struct proxy *px, struct bind_conf *conf, char **err)
{
struct listener *l;
int val;
if (!*args[cur_arg + 1]) {
memprintf(err, "'%s' : missing value", args[cur_arg]);
return ERR_ALERT | ERR_FATAL;
}
val = atol(args[cur_arg + 1]);
if (val < -1024 || val > 1024) {
memprintf(err, "'%s' : invalid value %d, allowed range is -1024..1024", args[cur_arg], val);
return ERR_ALERT | ERR_FATAL;
}
list_for_each_entry(l, &conf->listeners, by_bind)
l->nice = val;
return 0;
}
/* Note: must not be declared <const> as its list will be overwritten.
* Please take care of keeping this list alphabetically sorted.
*/
static struct sample_fetch_kw_list smp_kws = {ILH, {
{ "dst_conn", smp_fetch_dconn, 0, NULL, SMP_T_UINT, SMP_USE_FTEND, },
{ "so_id", smp_fetch_so_id, 0, NULL, SMP_T_UINT, SMP_USE_FTEND, },
{ /* END */ },
}};
/* Note: must not be declared <const> as its list will be overwritten.
* Please take care of keeping this list alphabetically sorted.
*/
static struct acl_kw_list acl_kws = {ILH, {
{ /* END */ },
}};
/* 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 bind_kw_list bind_kws = { "ALL", { }, {
{ "accept-proxy", bind_parse_accept_proxy, 0 }, /* enable PROXY protocol */
{ "backlog", bind_parse_backlog, 1 }, /* set backlog of listening socket */
{ "id", bind_parse_id, 1 }, /* set id of listening socket */
{ "maxconn", bind_parse_maxconn, 1 }, /* set maxconn of listening socket */
{ "name", bind_parse_name, 1 }, /* set name of listening socket */
{ "nice", bind_parse_nice, 1 }, /* set nice of listening socket */
{ /* END */ },
}};
__attribute__((constructor))
static void __listener_init(void)
{
sample_register_fetches(&smp_kws);
acl_register_keywords(&acl_kws);
bind_register_keywords(&bind_kws);
}
/*
* Local variables:
* c-indent-level: 8
* c-basic-offset: 8
* End:
*/