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:
+ */