summaryrefslogtreecommitdiffstats
path: root/src/proto_uxst.c
diff options
context:
space:
mode:
Diffstat (limited to 'src/proto_uxst.c')
-rw-r--r--src/proto_uxst.c372
1 files changed, 372 insertions, 0 deletions
diff --git a/src/proto_uxst.c b/src/proto_uxst.c
new file mode 100644
index 0000000..7988e00
--- /dev/null
+++ b/src/proto_uxst.c
@@ -0,0 +1,372 @@
+/*
+ * UNIX SOCK_STREAM protocol layer (uxst)
+ *
+ * Copyright 2000-2010 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 <syslog.h>
+#include <time.h>
+
+#include <sys/socket.h>
+#include <sys/stat.h>
+#include <sys/types.h>
+#include <sys/un.h>
+
+#include <haproxy/api.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/protocol.h>
+#include <haproxy/proto_uxst.h>
+#include <haproxy/sock.h>
+#include <haproxy/sock_unix.h>
+#include <haproxy/tools.h>
+#include <haproxy/version.h>
+
+
+static int uxst_bind_listener(struct listener *listener, char *errmsg, int errlen);
+static int uxst_connect_server(struct connection *conn, int flags);
+static void uxst_enable_listener(struct listener *listener);
+static void uxst_disable_listener(struct listener *listener);
+static int uxst_suspend_receiver(struct receiver *rx);
+
+/* Note: must not be declared <const> as its list will be overwritten */
+struct protocol proto_uxst = {
+ .name = "unix_stream",
+
+ /* connection layer */
+ .xprt_type = PROTO_TYPE_STREAM,
+ .listen = uxst_bind_listener,
+ .enable = uxst_enable_listener,
+ .disable = uxst_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 = uxst_connect_server,
+ .drain = sock_drain,
+ .check_events = sock_check_events,
+ .ignore_events = sock_ignore_events,
+
+ /* binding layer */
+ .rx_suspend = uxst_suspend_receiver,
+
+ /* address family */
+ .fam = &proto_fam_unix,
+
+ /* socket layer */
+ .proto_type = PROTO_TYPE_STREAM,
+ .sock_type = SOCK_STREAM,
+ .sock_prot = 0,
+ .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_uxst.receivers),
+ .nb_receivers = 0,
+};
+
+INITCALL1(STG_REGISTER, protocol_register, &proto_uxst);
+
+/********************************
+ * 1) low-level socket functions
+ ********************************/
+
+
+/********************************
+ * 2) listener-oriented functions
+ ********************************/
+
+/* This function creates a UNIX socket associated to the listener. It changes
+ * the state from ASSIGNED to LISTEN. The socket is NOT enabled for polling.
+ * The return value is composed from ERR_NONE, ERR_RETRYABLE and ERR_FATAL. 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.
+ */
+static int uxst_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";
+ err |= ERR_FATAL | ERR_ALERT;
+ goto uxst_return;
+ }
+
+ if (listener->rx.flags & RX_F_MUST_DUP)
+ goto done;
+
+ fd = listener->rx.fd;
+ ready = sock_accepting_conn(&listener->rx) > 0;
+
+ if (!ready && /* only listen if not already done by external process */
+ listen(fd, listener_backlog(listener)) < 0) {
+ err |= ERR_FATAL | ERR_ALERT;
+ msg = "cannot listen to UNIX socket";
+ goto uxst_close_return;
+ }
+
+ done:
+ /* the socket is now listening */
+ listener_set_state(listener, LI_LISTEN);
+ return err;
+
+ uxst_close_return:
+ close(fd);
+ uxst_return:
+ if (msg && errlen) {
+ char *path_str;
+
+ path_str = sa2str((struct sockaddr_storage *)&listener->rx.addr, 0, 0);
+ snprintf(errmsg, errlen, "%s for [%s]", msg, ((path_str) ? path_str : ""));
+ ha_free(&path_str);
+ }
+ return err;
+}
+
+/* Enable receipt of incoming connections for listener <l>. The receiver must
+ * still be valid.
+ */
+static void uxst_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 uxst_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. For plain unix sockets
+ * we only disable the listener to prevent data from being handled but nothing
+ * more is done since currently it's the new process which handles the renaming.
+ * Abstract sockets are completely unbound and closed so there's no need to stop
+ * the poller.
+ */
+static int uxst_suspend_receiver(struct receiver *rx)
+{
+ struct listener *l = LIST_ELEM(rx, struct listener *, rx);
+
+ if (((struct sockaddr_un *)&rx->addr)->sun_path[0]) {
+ uxst_disable_listener(l);
+ return 1;
+ }
+
+ /* Listener's lock already held. Call lockless version of
+ * unbind_listener. */
+ do_unbind_listener(l);
+ return 0;
+}
+
+
+/*
+ * This function initiates a UNIX connection establishment to the target assigned
+ * to connection <conn> using (si->{target,dst}). The source address is ignored
+ * and will be selected by the system. 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 <delack> argument is ignored.
+ *
+ * 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.
+ */
+static int uxst_connect_server(struct connection *conn, int flags)
+{
+ int fd;
+ struct server *srv;
+ struct proxy *be;
+
+ BUG_ON(!conn->dst);
+
+ 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;
+ break;
+ default:
+ conn->flags |= CO_FL_ERROR;
+ return SF_ERR_INTERNAL;
+ }
+
+ if ((fd = conn->handle.fd = socket(PF_UNIX, SOCK_STREAM, 0)) == -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) {
+ 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 (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));
+
+ if (connect(fd, (struct sockaddr *)conn->dst, get_addr_len(conn->dst)) == -1) {
+ if (errno == EINPROGRESS || errno == EALREADY) {
+ conn->flags |= CO_FL_WAIT_L4_CONN;
+ }
+ else if (errno == EISCONN) {
+ 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 = "can't connect to destination unix socket, check backlog size on the server";
+ 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);
+ 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) {
+ 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)
+ close(fd);
+ conn->err_code = CO_ER_SOCK_ERR;
+ conn->flags |= CO_FL_ERROR;
+ return SF_ERR_SRVCL;
+ }
+ }
+ else {
+ /* connect() already succeeded, which is quite usual for unix
+ * sockets. Let's avoid a second connect() probe to complete it.
+ */
+ conn->flags &= ~CO_FL_WAIT_L4_CONN;
+ }
+
+ /* Prepare to send a few handshakes related to the on-wire protocol. */
+ if (conn->send_proxy_ofs)
+ conn->flags |= CO_FL_SEND_PROXY;
+
+ conn_ctrl_init(conn); /* registers the FD */
+ HA_ATOMIC_AND(&fdtab[fd].state, ~FD_LINGER_RISK); /* no need to disable lingering */
+
+ 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 */
+}
+
+/*
+ * Local variables:
+ * c-indent-level: 8
+ * c-basic-offset: 8
+ * End:
+ */
generated by cgit v1.2.3 (git 2.39.1) at 2024-11-12 11:06:34 +0000