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authorDaniel Baumann <daniel.baumann@progress-linux.org>2024-04-13 12:18:05 +0000
committerDaniel Baumann <daniel.baumann@progress-linux.org>2024-04-13 12:18:05 +0000
commitb46aad6df449445a9fc4aa7b32bd40005438e3f7 (patch)
tree751aa858ca01f35de800164516b298887382919d /src/proto_tcp.c
parentInitial commit. (diff)
downloadhaproxy-b46aad6df449445a9fc4aa7b32bd40005438e3f7.tar.xz
haproxy-b46aad6df449445a9fc4aa7b32bd40005438e3f7.zip
Adding upstream version 2.9.5.upstream/2.9.5
Signed-off-by: Daniel Baumann <daniel.baumann@progress-linux.org>
Diffstat (limited to 'src/proto_tcp.c')
-rw-r--r--src/proto_tcp.c834
1 files changed, 834 insertions, 0 deletions
diff --git a/src/proto_tcp.c b/src/proto_tcp.c
new file mode 100644
index 0000000..45ce27f
--- /dev/null
+++ b/src/proto_tcp.c
@@ -0,0 +1,834 @@
+/*
+ * 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 <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 */
+ .xprt_type = PROTO_TYPE_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 */
+ .proto_type = PROTO_TYPE_STREAM,
+ .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,
+#ifdef SO_REUSEPORT
+ .flags = PROTO_F_REUSEPORT_SUPPORTED,
+#endif
+};
+
+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 */
+ .xprt_type = PROTO_TYPE_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 */
+ .proto_type = PROTO_TYPE_STREAM,
+ .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,
+#ifdef SO_REUSEPORT
+ .flags = PROTO_F_REUSEPORT_SUPPORTED,
+#endif
+};
+
+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;
+
+ BUG_ON(!conn->dst);
+
+ 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;
+ }
+
+ 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 (fd_set_nonblock(fd) == -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 && fd_set_cloexec(fd) == -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 == EWOULDBLOCK || errno == EADDRINUSE || errno == EADDRNOTAVAIL) {
+ char *msg;
+ if (errno == EAGAIN || errno == EWOULDBLOCK || 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_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;
+ struct buffer *msg = alloc_trash_chunk();
+
+ err = ERR_NONE;
+
+ if (!msg) {
+ if (errlen)
+ snprintf(errmsg, errlen, "out of memory");
+ return ERR_ALERT | ERR_FATAL;
+ }
+
+ /* 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)) {
+ chunk_appendf(msg, "%sreceiving socket not bound", msg->data ? ", " : "");
+ goto tcp_return;
+ }
+
+ if (listener->rx.flags & RX_F_MUST_DUP)
+ goto done;
+
+ fd = listener->rx.fd;
+
+ if (listener->bind_conf->options & BC_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->bind_conf->maxseg > 0) {
+ if (setsockopt(fd, IPPROTO_TCP, TCP_MAXSEG,
+ &listener->bind_conf->maxseg, sizeof(listener->bind_conf->maxseg)) == -1) {
+ chunk_appendf(msg, "%scannot set MSS to %d", msg->data ? ", " : "", listener->bind_conf->maxseg);
+ 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) {
+ chunk_appendf(msg, "%scannot set MSS to %d", msg->data ? ", " : "", defaultmss);
+ err |= ERR_WARN;
+ }
+ }
+#endif
+#if defined(TCP_USER_TIMEOUT)
+ if (listener->bind_conf->tcp_ut) {
+ if (setsockopt(fd, IPPROTO_TCP, TCP_USER_TIMEOUT,
+ &listener->bind_conf->tcp_ut, sizeof(listener->bind_conf->tcp_ut)) == -1) {
+ chunk_appendf(msg, "%scannot set TCP User Timeout", msg->data ? ", " : "");
+ err |= ERR_WARN;
+ }
+ } else
+ setsockopt(fd, IPPROTO_TCP, TCP_USER_TIMEOUT, &zero,
+ sizeof(zero));
+#endif
+#if defined(TCP_DEFER_ACCEPT)
+ if (listener->bind_conf->options & BC_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) {
+ chunk_appendf(msg, "%scannot enable DEFER_ACCEPT", msg->data ? ", " : "");
+ err |= ERR_WARN;
+ }
+ } else
+ setsockopt(fd, IPPROTO_TCP, TCP_DEFER_ACCEPT, &zero,
+ sizeof(zero));
+#endif
+#if defined(TCP_FASTOPEN)
+ if (listener->bind_conf->options & BC_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) {
+ chunk_appendf(msg, "%scannot enable TCP_FASTOPEN", msg->data ? ", " : "");
+ 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) {
+ chunk_appendf(msg, "%scannot disable TCP_FASTOPEN", msg->data ? ", " : "");
+ 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;
+ chunk_appendf(msg, "%scannot listen to socket", msg->data ? ", " : "");
+ goto tcp_close_return;
+ }
+
+#if !defined(TCP_DEFER_ACCEPT) && defined(SO_ACCEPTFILTER)
+ /* the socket needs to listen first */
+ if (listener->bind_conf->options & BC_O_DEF_ACCEPT) {
+ struct accept_filter_arg accept;
+ memset(&accept, 0, sizeof(accept));
+ strlcpy2(accept.af_name, "dataready", sizeof(accept.af_name));
+ if (setsockopt(fd, SOL_SOCKET, SO_ACCEPTFILTER, &accept, sizeof(accept)) == -1) {
+ chunk_appendf(msg, "%scannot enable ACCEPT_FILTER", msg->data ? ", " : "");
+ err |= ERR_WARN;
+ }
+ }
+#endif
+#if defined(TCP_QUICKACK)
+ if (listener->bind_conf->options & BC_O_NOQUICKACK)
+ setsockopt(fd, IPPROTO_TCP, TCP_QUICKACK, &zero, sizeof(zero));
+ else
+ setsockopt(fd, IPPROTO_TCP, TCP_QUICKACK, &one, sizeof(one));
+#endif
+
+ done:
+ /* the socket is ready */
+ listener_set_state(listener, LI_LISTEN);
+ goto tcp_return;
+
+ tcp_close_return:
+ free_trash_chunk(msg);
+ msg = NULL;
+ close(fd);
+ tcp_return:
+ if (msg && errlen && msg->data) {
+ char pn[INET6_ADDRSTRLEN];
+
+ addr_to_str(&listener->rx.addr, pn, sizeof(pn));
+ snprintf(errmsg, errlen, "%s for [%s:%d]", msg->area, pn, get_host_port(&listener->rx.addr));
+ }
+ free_trash_chunk(msg);
+ msg = NULL;
+ 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. Note that inherited FDs
+ * are neither suspended nor resumed, we only enable/disable polling on them.
+ */
+static int tcp_suspend_receiver(struct receiver *rx)
+{
+ const struct sockaddr sa = { .sa_family = AF_UNSPEC };
+ int ret;
+
+ /* We never disconnect a shared FD otherwise we'd break it in the
+ * parent process and any possible subsequent worker inheriting it.
+ * Thus we just stop receiving from it.
+ */
+ if (rx->flags & RX_F_INHERITED)
+ goto done;
+
+ if (connect(rx->fd, &sa, sizeof(sa)) < 0)
+ goto check_already_done;
+ 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 resumed. Note that inherited FDs
+ * are neither suspended nor resumed, we only enable/disable polling on them.
+ */
+static int tcp_resume_receiver(struct receiver *rx)
+{
+ struct listener *l = LIST_ELEM(rx, struct listener *, rx);
+
+ if (rx->fd < 0)
+ return 0;
+
+ if ((rx->flags & RX_F_INHERITED) || 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:
+ */