blob: 1edbea42ac2e0a68207e00a9f966370c27968d33 [file] [log] [blame]
/*
* AF_INET/AF_INET6 SOCK_STREAM protocol layer (tcp)
*
* 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.
*
*/
#include <ctype.h>
#include <errno.h>
#include <fcntl.h>
#include <stdio.h>
#include <stdlib.h>
#include <string.h>
#include <time.h>
#include <sys/param.h>
#include <sys/socket.h>
#include <sys/types.h>
#include <netinet/tcp.h>
#include <netinet/in.h>
#include <haproxy/api.h>
#include <haproxy/arg.h>
#include <haproxy/connection.h>
#include <haproxy/errors.h>
#include <haproxy/fd.h>
#include <haproxy/global.h>
#include <haproxy/list.h>
#include <haproxy/listener.h>
#include <haproxy/log.h>
#include <haproxy/namespace.h>
#include <haproxy/port_range.h>
#include <haproxy/proto_tcp.h>
#include <haproxy/protocol.h>
#include <haproxy/proxy-t.h>
#include <haproxy/sock.h>
#include <haproxy/sock_inet.h>
#include <haproxy/tools.h>
static int tcp_bind_listener(struct listener *listener, char *errmsg, int errlen);
static int tcp_suspend_receiver(struct receiver *rx);
static int tcp_resume_receiver(struct receiver *rx);
static void tcp_enable_listener(struct listener *listener);
static void tcp_disable_listener(struct listener *listener);
/* Note: must not be declared <const> as its list will be overwritten */
struct protocol proto_tcpv4 = {
.name = "tcpv4",
/* connection layer */
.ctrl_type = SOCK_STREAM,
.listen = tcp_bind_listener,
.enable = tcp_enable_listener,
.disable = tcp_disable_listener,
.add = default_add_listener,
.unbind = default_unbind_listener,
.suspend = default_suspend_listener,
.resume = default_resume_listener,
.accept_conn = sock_accept_conn,
.ctrl_init = sock_conn_ctrl_init,
.ctrl_close = sock_conn_ctrl_close,
.connect = tcp_connect_server,
.drain = sock_drain,
.check_events = sock_check_events,
.ignore_events = sock_ignore_events,
/* binding layer */
.rx_suspend = tcp_suspend_receiver,
.rx_resume = tcp_resume_receiver,
/* address family */
.fam = &proto_fam_inet4,
/* socket layer */
.sock_type = SOCK_STREAM,
.sock_prot = IPPROTO_TCP,
.rx_enable = sock_enable,
.rx_disable = sock_disable,
.rx_unbind = sock_unbind,
.rx_listening = sock_accepting_conn,
.default_iocb = sock_accept_iocb,
.receivers = LIST_HEAD_INIT(proto_tcpv4.receivers),
.nb_receivers = 0,
};
INITCALL1(STG_REGISTER, protocol_register, &proto_tcpv4);
/* Note: must not be declared <const> as its list will be overwritten */
struct protocol proto_tcpv6 = {
.name = "tcpv6",
/* connection layer */
.ctrl_type = SOCK_STREAM,
.listen = tcp_bind_listener,
.enable = tcp_enable_listener,
.disable = tcp_disable_listener,
.add = default_add_listener,
.unbind = default_unbind_listener,
.suspend = default_suspend_listener,
.resume = default_resume_listener,
.accept_conn = sock_accept_conn,
.ctrl_init = sock_conn_ctrl_init,
.ctrl_close = sock_conn_ctrl_close,
.connect = tcp_connect_server,
.drain = sock_drain,
.check_events = sock_check_events,
.ignore_events = sock_ignore_events,
/* binding layer */
.rx_suspend = tcp_suspend_receiver,
.rx_resume = tcp_resume_receiver,
/* address family */
.fam = &proto_fam_inet6,
/* socket layer */
.sock_type = SOCK_STREAM,
.sock_prot = IPPROTO_TCP,
.rx_enable = sock_enable,
.rx_disable = sock_disable,
.rx_unbind = sock_unbind,
.rx_listening = sock_accepting_conn,
.default_iocb = sock_accept_iocb,
.receivers = LIST_HEAD_INIT(proto_tcpv6.receivers),
.nb_receivers = 0,
};
INITCALL1(STG_REGISTER, protocol_register, &proto_tcpv6);
/* Binds ipv4/ipv6 address <local> to socket <fd>, unless <flags> is set, in which
* case we try to bind <remote>. <flags> is a 2-bit field consisting of :
* - 0 : ignore remote address (may even be a NULL pointer)
* - 1 : use provided address
* - 2 : use provided port
* - 3 : use both
*
* The function supports multiple foreign binding methods :
* - linux_tproxy: we directly bind to the foreign address
* The second one can be used as a fallback for the first one.
* This function returns 0 when everything's OK, 1 if it could not bind, to the
* local address, 2 if it could not bind to the foreign address.
*/
int tcp_bind_socket(int fd, int flags, struct sockaddr_storage *local, struct sockaddr_storage *remote)
{
struct sockaddr_storage bind_addr;
int foreign_ok = 0;
int ret;
static THREAD_LOCAL int ip_transp_working = 1;
static THREAD_LOCAL int ip6_transp_working = 1;
switch (local->ss_family) {
case AF_INET:
if (flags && ip_transp_working) {
/* This deserves some explanation. Some platforms will support
* multiple combinations of certain methods, so we try the
* supported ones until one succeeds.
*/
if (sock_inet4_make_foreign(fd))
foreign_ok = 1;
else
ip_transp_working = 0;
}
break;
case AF_INET6:
if (flags && ip6_transp_working) {
if (sock_inet6_make_foreign(fd))
foreign_ok = 1;
else
ip6_transp_working = 0;
}
break;
}
if (flags) {
memset(&bind_addr, 0, sizeof(bind_addr));
bind_addr.ss_family = remote->ss_family;
switch (remote->ss_family) {
case AF_INET:
if (flags & 1)
((struct sockaddr_in *)&bind_addr)->sin_addr = ((struct sockaddr_in *)remote)->sin_addr;
if (flags & 2)
((struct sockaddr_in *)&bind_addr)->sin_port = ((struct sockaddr_in *)remote)->sin_port;
break;
case AF_INET6:
if (flags & 1)
((struct sockaddr_in6 *)&bind_addr)->sin6_addr = ((struct sockaddr_in6 *)remote)->sin6_addr;
if (flags & 2)
((struct sockaddr_in6 *)&bind_addr)->sin6_port = ((struct sockaddr_in6 *)remote)->sin6_port;
break;
default:
/* we don't want to try to bind to an unknown address family */
foreign_ok = 0;
}
}
setsockopt(fd, SOL_SOCKET, SO_REUSEADDR, &one, sizeof(one));
if (foreign_ok) {
if (is_inet_addr(&bind_addr)) {
ret = bind(fd, (struct sockaddr *)&bind_addr, get_addr_len(&bind_addr));
if (ret < 0)
return 2;
}
}
else {
if (is_inet_addr(local)) {
ret = bind(fd, (struct sockaddr *)local, get_addr_len(local));
if (ret < 0)
return 1;
}
}
if (!flags)
return 0;
if (!foreign_ok)
/* we could not bind to a foreign address */
return 2;
return 0;
}
/*
* This function initiates a TCP connection establishment to the target assigned
* to connection <conn> using (si->{target,dst}). A source address may be
* pointed to by conn->src in case of transparent proxying. Normal source
* bind addresses are still determined locally (due to the possible need of a
* source port). conn->target may point either to a valid server or to a backend,
* depending on conn->target. Only OBJ_TYPE_PROXY and OBJ_TYPE_SERVER are
* supported. The <data> parameter is a boolean indicating whether there are data
* waiting for being sent or not, in order to adjust data write polling and on
* some platforms, the ability to avoid an empty initial ACK. The <flags> argument
* allows the caller to force using a delayed ACK when establishing the connection
* - 0 = no delayed ACK unless data are advertised and backend has tcp-smart-connect
* - CONNECT_DELACK_SMART_CONNECT = delayed ACK if backend has tcp-smart-connect, regardless of data
* - CONNECT_DELACK_ALWAYS = delayed ACK regardless of backend options
*
* Note that a pending send_proxy message accounts for data.
*
* It can return one of :
* - SF_ERR_NONE if everything's OK
* - SF_ERR_SRVTO if there are no more servers
* - SF_ERR_SRVCL if the connection was refused by the server
* - SF_ERR_PRXCOND if the connection has been limited by the proxy (maxconn)
* - SF_ERR_RESOURCE if a system resource is lacking (eg: fd limits, ports, ...)
* - SF_ERR_INTERNAL for any other purely internal errors
* Additionally, in the case of SF_ERR_RESOURCE, an emergency log will be emitted.
*
* The connection's fd is inserted only when SF_ERR_NONE is returned, otherwise
* it's invalid and the caller has nothing to do.
*/
int tcp_connect_server(struct connection *conn, int flags)
{
int fd;
struct server *srv;
struct proxy *be;
struct conn_src *src;
int use_fastopen = 0;
struct sockaddr_storage *addr;
conn->flags |= CO_FL_WAIT_L4_CONN; /* connection in progress */
switch (obj_type(conn->target)) {
case OBJ_TYPE_PROXY:
be = objt_proxy(conn->target);
srv = NULL;
break;
case OBJ_TYPE_SERVER:
srv = objt_server(conn->target);
be = srv->proxy;
/* Make sure we check that we have data before activating
* TFO, or we could trigger a kernel issue whereby after
* a successful connect() == 0, any subsequent connect()
* will return EINPROGRESS instead of EISCONN.
*/
use_fastopen = (srv->flags & SRV_F_FASTOPEN) &&
((flags & (CONNECT_CAN_USE_TFO | CONNECT_HAS_DATA)) ==
(CONNECT_CAN_USE_TFO | CONNECT_HAS_DATA));
break;
default:
conn->flags |= CO_FL_ERROR;
return SF_ERR_INTERNAL;
}
if (!conn->dst) {
conn->flags |= CO_FL_ERROR;
return SF_ERR_INTERNAL;
}
fd = conn->handle.fd = sock_create_server_socket(conn);
if (fd == -1) {
qfprintf(stderr, "Cannot get a server socket.\n");
if (errno == ENFILE) {
conn->err_code = CO_ER_SYS_FDLIM;
send_log(be, LOG_EMERG,
"Proxy %s reached system FD limit (maxsock=%d). Please check system tunables.\n",
be->id, global.maxsock);
}
else if (errno == EMFILE) {
conn->err_code = CO_ER_PROC_FDLIM;
send_log(be, LOG_EMERG,
"Proxy %s reached process FD limit (maxsock=%d). Please check 'ulimit-n' and restart.\n",
be->id, global.maxsock);
}
else if (errno == ENOBUFS || errno == ENOMEM) {
conn->err_code = CO_ER_SYS_MEMLIM;
send_log(be, LOG_EMERG,
"Proxy %s reached system memory limit (maxsock=%d). Please check system tunables.\n",
be->id, global.maxsock);
}
else if (errno == EAFNOSUPPORT || errno == EPROTONOSUPPORT) {
conn->err_code = CO_ER_NOPROTO;
}
else
conn->err_code = CO_ER_SOCK_ERR;
/* this is a resource error */
conn->flags |= CO_FL_ERROR;
return SF_ERR_RESOURCE;
}
if (fd >= global.maxsock) {
/* do not log anything there, it's a normal condition when this option
* is used to serialize connections to a server !
*/
ha_alert("socket(): not enough free sockets. Raise -n argument. Giving up.\n");
close(fd);
conn->err_code = CO_ER_CONF_FDLIM;
conn->flags |= CO_FL_ERROR;
return SF_ERR_PRXCOND; /* it is a configuration limit */
}
if ((fcntl(fd, F_SETFL, O_NONBLOCK)==-1) ||
(setsockopt(fd, IPPROTO_TCP, TCP_NODELAY, &one, sizeof(one)) == -1)) {
qfprintf(stderr,"Cannot set client socket to non blocking mode.\n");
close(fd);
conn->err_code = CO_ER_SOCK_ERR;
conn->flags |= CO_FL_ERROR;
return SF_ERR_INTERNAL;
}
if (master == 1 && (fcntl(fd, F_SETFD, FD_CLOEXEC) == -1)) {
ha_alert("Cannot set CLOEXEC on client socket.\n");
close(fd);
conn->err_code = CO_ER_SOCK_ERR;
conn->flags |= CO_FL_ERROR;
return SF_ERR_INTERNAL;
}
if (be->options & PR_O_TCP_SRV_KA) {
setsockopt(fd, SOL_SOCKET, SO_KEEPALIVE, &one, sizeof(one));
#ifdef TCP_KEEPCNT
if (be->srvtcpka_cnt)
setsockopt(fd, IPPROTO_TCP, TCP_KEEPCNT, &be->srvtcpka_cnt, sizeof(be->srvtcpka_cnt));
#endif
#ifdef TCP_KEEPIDLE
if (be->srvtcpka_idle)
setsockopt(fd, IPPROTO_TCP, TCP_KEEPIDLE, &be->srvtcpka_idle, sizeof(be->srvtcpka_idle));
#endif
#ifdef TCP_KEEPINTVL
if (be->srvtcpka_intvl)
setsockopt(fd, IPPROTO_TCP, TCP_KEEPINTVL, &be->srvtcpka_intvl, sizeof(be->srvtcpka_intvl));
#endif
}
/* allow specific binding :
* - server-specific at first
* - proxy-specific next
*/
if (srv && srv->conn_src.opts & CO_SRC_BIND)
src = &srv->conn_src;
else if (be->conn_src.opts & CO_SRC_BIND)
src = &be->conn_src;
else
src = NULL;
if (src) {
int ret, flags = 0;
if (conn->src && is_inet_addr(conn->src)) {
switch (src->opts & CO_SRC_TPROXY_MASK) {
case CO_SRC_TPROXY_CLI:
case CO_SRC_TPROXY_ADDR:
flags = 3;
break;
case CO_SRC_TPROXY_CIP:
case CO_SRC_TPROXY_DYN:
flags = 1;
break;
}
}
#ifdef SO_BINDTODEVICE
/* Note: this might fail if not CAP_NET_RAW */
if (src->iface_name)
setsockopt(fd, SOL_SOCKET, SO_BINDTODEVICE, src->iface_name, src->iface_len + 1);
#endif
if (src->sport_range) {
int attempts = 10; /* should be more than enough to find a spare port */
struct sockaddr_storage sa;
ret = 1;
memcpy(&sa, &src->source_addr, sizeof(sa));
do {
/* note: in case of retry, we may have to release a previously
* allocated port, hence this loop's construct.
*/
port_range_release_port(fdinfo[fd].port_range, fdinfo[fd].local_port);
fdinfo[fd].port_range = NULL;
if (!attempts)
break;
attempts--;
fdinfo[fd].local_port = port_range_alloc_port(src->sport_range);
if (!fdinfo[fd].local_port) {
conn->err_code = CO_ER_PORT_RANGE;
break;
}
fdinfo[fd].port_range = src->sport_range;
set_host_port(&sa, fdinfo[fd].local_port);
ret = tcp_bind_socket(fd, flags, &sa, conn->src);
if (ret != 0)
conn->err_code = CO_ER_CANT_BIND;
} while (ret != 0); /* binding NOK */
}
else {
#ifdef IP_BIND_ADDRESS_NO_PORT
static THREAD_LOCAL int bind_address_no_port = 1;
setsockopt(fd, IPPROTO_IP, IP_BIND_ADDRESS_NO_PORT, (const void *) &bind_address_no_port, sizeof(int));
#endif
ret = tcp_bind_socket(fd, flags, &src->source_addr, conn->src);
if (ret != 0)
conn->err_code = CO_ER_CANT_BIND;
}
if (unlikely(ret != 0)) {
port_range_release_port(fdinfo[fd].port_range, fdinfo[fd].local_port);
fdinfo[fd].port_range = NULL;
close(fd);
if (ret == 1) {
ha_alert("Cannot bind to source address before connect() for backend %s. Aborting.\n",
be->id);
send_log(be, LOG_EMERG,
"Cannot bind to source address before connect() for backend %s.\n",
be->id);
} else {
ha_alert("Cannot bind to tproxy source address before connect() for backend %s. Aborting.\n",
be->id);
send_log(be, LOG_EMERG,
"Cannot bind to tproxy source address before connect() for backend %s.\n",
be->id);
}
conn->flags |= CO_FL_ERROR;
return SF_ERR_RESOURCE;
}
}
#if defined(TCP_QUICKACK)
/* disabling tcp quick ack now allows the first request to leave the
* machine with the first ACK. We only do this if there are pending
* data in the buffer.
*/
if (flags & (CONNECT_DELACK_ALWAYS) ||
((flags & CONNECT_DELACK_SMART_CONNECT ||
(flags & CONNECT_HAS_DATA) || conn->send_proxy_ofs) &&
(be->options2 & PR_O2_SMARTCON)))
setsockopt(fd, IPPROTO_TCP, TCP_QUICKACK, &zero, sizeof(zero));
#endif
#ifdef TCP_USER_TIMEOUT
/* there is not much more we can do here when it fails, it's still minor */
if (srv && srv->tcp_ut)
setsockopt(fd, IPPROTO_TCP, TCP_USER_TIMEOUT, &srv->tcp_ut, sizeof(srv->tcp_ut));
#endif
if (use_fastopen) {
#if defined(TCP_FASTOPEN_CONNECT)
setsockopt(fd, IPPROTO_TCP, TCP_FASTOPEN_CONNECT, &one, sizeof(one));
#endif
}
if (global.tune.server_sndbuf)
setsockopt(fd, SOL_SOCKET, SO_SNDBUF, &global.tune.server_sndbuf, sizeof(global.tune.server_sndbuf));
if (global.tune.server_rcvbuf)
setsockopt(fd, SOL_SOCKET, SO_RCVBUF, &global.tune.server_rcvbuf, sizeof(global.tune.server_rcvbuf));
addr = (conn->flags & CO_FL_SOCKS4) ? &srv->socks4_addr : conn->dst;
if (connect(fd, (const struct sockaddr *)addr, get_addr_len(addr)) == -1) {
if (errno == EINPROGRESS || errno == EALREADY) {
/* common case, let's wait for connect status */
conn->flags |= CO_FL_WAIT_L4_CONN;
}
else if (errno == EISCONN) {
/* should normally not happen but if so, indicates that it's OK */
conn->flags &= ~CO_FL_WAIT_L4_CONN;
}
else if (errno == EAGAIN || errno == EADDRINUSE || errno == EADDRNOTAVAIL) {
char *msg;
if (errno == EAGAIN || errno == EADDRNOTAVAIL) {
msg = "no free ports";
conn->err_code = CO_ER_FREE_PORTS;
}
else {
msg = "local address already in use";
conn->err_code = CO_ER_ADDR_INUSE;
}
qfprintf(stderr,"Connect() failed for backend %s: %s.\n", be->id, msg);
port_range_release_port(fdinfo[fd].port_range, fdinfo[fd].local_port);
fdinfo[fd].port_range = NULL;
close(fd);
send_log(be, LOG_ERR, "Connect() failed for backend %s: %s.\n", be->id, msg);
conn->flags |= CO_FL_ERROR;
return SF_ERR_RESOURCE;
} else if (errno == ETIMEDOUT) {
//qfprintf(stderr,"Connect(): ETIMEDOUT");
port_range_release_port(fdinfo[fd].port_range, fdinfo[fd].local_port);
fdinfo[fd].port_range = NULL;
close(fd);
conn->err_code = CO_ER_SOCK_ERR;
conn->flags |= CO_FL_ERROR;
return SF_ERR_SRVTO;
} else {
// (errno == ECONNREFUSED || errno == ENETUNREACH || errno == EACCES || errno == EPERM)
//qfprintf(stderr,"Connect(): %d", errno);
port_range_release_port(fdinfo[fd].port_range, fdinfo[fd].local_port);
fdinfo[fd].port_range = NULL;
close(fd);
conn->err_code = CO_ER_SOCK_ERR;
conn->flags |= CO_FL_ERROR;
return SF_ERR_SRVCL;
}
}
else {
/* connect() == 0, this is great! */
conn->flags &= ~CO_FL_WAIT_L4_CONN;
}
conn->flags |= CO_FL_ADDR_TO_SET;
conn_ctrl_init(conn); /* registers the FD */
HA_ATOMIC_OR(&fdtab[fd].state, FD_LINGER_RISK); /* close hard if needed */
if (conn->flags & CO_FL_WAIT_L4_CONN) {
fd_want_send(fd);
fd_cant_send(fd);
fd_cant_recv(fd);
}
return SF_ERR_NONE; /* connection is OK */
}
/* This function tries to bind a TCPv4/v6 listener. It may return a warning or
* an error message in <errmsg> if the message is at most <errlen> bytes long
* (including '\0'). Note that <errmsg> may be NULL if <errlen> is also zero.
* The return value is composed from ERR_ABORT, ERR_WARN,
* ERR_ALERT, ERR_RETRYABLE and ERR_FATAL. ERR_NONE indicates that everything
* was alright and that no message was returned. ERR_RETRYABLE means that an
* error occurred but that it may vanish after a retry (eg: port in use), and
* ERR_FATAL indicates a non-fixable error. ERR_WARN and ERR_ALERT do not alter
* the meaning of the error, but just indicate that a message is present which
* should be displayed with the respective level. Last, ERR_ABORT indicates
* that it's pointless to try to start other listeners. No error message is
* returned if errlen is NULL.
*/
int tcp_bind_listener(struct listener *listener, char *errmsg, int errlen)
{
int fd, err;
int ready;
char *msg = NULL;
err = ERR_NONE;
/* ensure we never return garbage */
if (errlen)
*errmsg = 0;
if (listener->state != LI_ASSIGNED)
return ERR_NONE; /* already bound */
if (!(listener->rx.flags & RX_F_BOUND)) {
msg = "receiving socket not bound";
goto tcp_return;
}
fd = listener->rx.fd;
if (listener->options & LI_O_NOLINGER)
setsockopt(fd, SOL_SOCKET, SO_LINGER, &nolinger, sizeof(struct linger));
else {
struct linger tmplinger;
socklen_t len = sizeof(tmplinger);
if (getsockopt(fd, SOL_SOCKET, SO_LINGER, &tmplinger, &len) == 0 &&
(tmplinger.l_onoff == 1 || tmplinger.l_linger == 0)) {
tmplinger.l_onoff = 0;
tmplinger.l_linger = 0;
setsockopt(fd, SOL_SOCKET, SO_LINGER, &tmplinger,
sizeof(tmplinger));
}
}
#if defined(TCP_MAXSEG)
if (listener->maxseg > 0) {
if (setsockopt(fd, IPPROTO_TCP, TCP_MAXSEG,
&listener->maxseg, sizeof(listener->maxseg)) == -1) {
msg = "cannot set MSS";
err |= ERR_WARN;
}
} else {
/* we may want to try to restore the default MSS if the socket was inherited */
int tmpmaxseg = -1;
int defaultmss;
socklen_t len = sizeof(tmpmaxseg);
if (listener->rx.addr.ss_family == AF_INET)
defaultmss = sock_inet_tcp_maxseg_default;
else
defaultmss = sock_inet6_tcp_maxseg_default;
getsockopt(fd, IPPROTO_TCP, TCP_MAXSEG, &tmpmaxseg, &len);
if (defaultmss > 0 &&
tmpmaxseg != defaultmss &&
setsockopt(fd, IPPROTO_TCP, TCP_MAXSEG, &defaultmss, sizeof(defaultmss)) == -1) {
msg = "cannot set MSS";
err |= ERR_WARN;
}
}
#endif
#if defined(TCP_USER_TIMEOUT)
if (listener->tcp_ut) {
if (setsockopt(fd, IPPROTO_TCP, TCP_USER_TIMEOUT,
&listener->tcp_ut, sizeof(listener->tcp_ut)) == -1) {
msg = "cannot set TCP User Timeout";
err |= ERR_WARN;
}
} else
setsockopt(fd, IPPROTO_TCP, TCP_USER_TIMEOUT, &zero,
sizeof(zero));
#endif
#if defined(TCP_DEFER_ACCEPT)
if (listener->options & LI_O_DEF_ACCEPT) {
/* defer accept by up to one second */
int accept_delay = 1;
if (setsockopt(fd, IPPROTO_TCP, TCP_DEFER_ACCEPT, &accept_delay, sizeof(accept_delay)) == -1) {
msg = "cannot enable DEFER_ACCEPT";
err |= ERR_WARN;
}
} else
setsockopt(fd, IPPROTO_TCP, TCP_DEFER_ACCEPT, &zero,
sizeof(zero));
#endif
#if defined(TCP_FASTOPEN)
if (listener->options & LI_O_TCP_FO) {
/* TFO needs a queue length, let's use the configured backlog */
int qlen = listener_backlog(listener);
if (setsockopt(fd, IPPROTO_TCP, TCP_FASTOPEN, &qlen, sizeof(qlen)) == -1) {
msg = "cannot enable TCP_FASTOPEN";
err |= ERR_WARN;
}
} else {
socklen_t len;
int qlen;
len = sizeof(qlen);
/* Only disable fast open if it was enabled, we don't want
* the kernel to create a fast open queue if there's none.
*/
if (getsockopt(fd, IPPROTO_TCP, TCP_FASTOPEN, &qlen, &len) == 0 &&
qlen != 0) {
if (setsockopt(fd, IPPROTO_TCP, TCP_FASTOPEN, &zero,
sizeof(zero)) == -1) {
msg = "cannot disable TCP_FASTOPEN";
err |= ERR_WARN;
}
}
}
#endif
ready = sock_accepting_conn(&listener->rx) > 0;
if (!ready && /* only listen if not already done by external process */
listen(fd, listener_backlog(listener)) == -1) {
err |= ERR_RETRYABLE | ERR_ALERT;
msg = "cannot listen to socket";
goto tcp_close_return;
}
#if !defined(TCP_DEFER_ACCEPT) && defined(SO_ACCEPTFILTER)
/* the socket needs to listen first */
if (listener->options & LI_O_DEF_ACCEPT) {
struct accept_filter_arg accept;
memset(&accept, 0, sizeof(accept));
strcpy(accept.af_name, "dataready");
if (setsockopt(fd, SOL_SOCKET, SO_ACCEPTFILTER, &accept, sizeof(accept)) == -1) {
msg = "cannot enable ACCEPT_FILTER";
err |= ERR_WARN;
}
}
#endif
#if defined(TCP_QUICKACK)
if (listener->options & LI_O_NOQUICKACK)
setsockopt(fd, IPPROTO_TCP, TCP_QUICKACK, &zero, sizeof(zero));
else
setsockopt(fd, IPPROTO_TCP, TCP_QUICKACK, &one, sizeof(one));
#endif
/* the socket is ready */
listener_set_state(listener, LI_LISTEN);
goto tcp_return;
tcp_close_return:
close(fd);
tcp_return:
if (msg && errlen) {
char pn[INET6_ADDRSTRLEN];
addr_to_str(&listener->rx.addr, pn, sizeof(pn));
snprintf(errmsg, errlen, "%s [%s:%d]", msg, pn, get_host_port(&listener->rx.addr));
}
return err;
}
/* Enable receipt of incoming connections for listener <l>. The receiver must
* still be valid.
*/
static void tcp_enable_listener(struct listener *l)
{
fd_want_recv_safe(l->rx.fd);
}
/* Disable receipt of incoming connections for listener <l>. The receiver must
* still be valid.
*/
static void tcp_disable_listener(struct listener *l)
{
fd_stop_recv(l->rx.fd);
}
/* Suspend a receiver. Returns < 0 in case of failure, 0 if the receiver
* was totally stopped, or > 0 if correctly suspended.
*/
static int tcp_suspend_receiver(struct receiver *rx)
{
const struct sockaddr sa = { .sa_family = AF_UNSPEC };
int ret;
/* we never do that with a shared FD otherwise we'd break it in the
* parent process and any possible subsequent worker inheriting it.
*/
if (rx->flags & RX_F_INHERITED)
return -1;
if (connect(rx->fd, &sa, sizeof(sa)) < 0)
goto check_already_done;
fd_stop_recv(rx->fd);
return 1;
check_already_done:
/* in case one of the shutdown() above fails, it might be because we're
* dealing with a socket that is shared with other processes doing the
* same. Let's check if it's still accepting connections.
*/
ret = sock_accepting_conn(rx);
if (ret <= 0) {
/* unrecoverable or paused by another process */
fd_stop_recv(rx->fd);
return ret == 0;
}
/* still listening, that's not good */
return -1;
}
/* Resume a receiver. Returns < 0 in case of failure, 0 if the receiver
* was totally stopped, or > 0 if correctly suspended.
*/
static int tcp_resume_receiver(struct receiver *rx)
{
struct listener *l = LIST_ELEM(rx, struct listener *, rx);
if (rx->fd < 0)
return 0;
if (listen(rx->fd, listener_backlog(l)) == 0) {
fd_want_recv(l->rx.fd);
return 1;
}
return -1;
}
/*
* Local variables:
* c-indent-level: 8
* c-basic-offset: 8
* End:
*/