[ping] Add concept of a ping socket

Signed-off-by: Michael Brown <mcb30@ipxe.org>

1 files changed, 273 insertions, 0 deletions

diff --git a/src/net/ping.c b/src/net/ping.c
new file mode 100644
index 00000000..d9da87ad
--- /dev/null
+++ b/src/net/ping.c
@@ -0,0 +1,273 @@
+/*
+ * Copyright (C) 2013 Michael Brown <mbrown@fensystems.co.uk>.
+ *
+ * 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 any later version.
+ *
+ * This program is distributed in the hope that it will be useful, but
+ * WITHOUT ANY WARRANTY; without even the implied warranty of
+ * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the GNU
+ * General Public License for more details.
+ *
+ * You should have received a copy of the GNU General Public License
+ * along with this program; if not, write to the Free Software
+ * Foundation, Inc., 51 Franklin Street, Fifth Floor, Boston, MA
+ * 02110-1301, USA.
+ */
+
+FILE_LICENCE ( GPL2_OR_LATER );
+
+#include <stdlib.h>
+#include <string.h>
+#include <errno.h>
+#include <byteswap.h>
+#include <ipxe/refcnt.h>
+#include <ipxe/list.h>
+#include <ipxe/iobuf.h>
+#include <ipxe/tcpip.h>
+#include <ipxe/icmp.h>
+#include <ipxe/interface.h>
+#include <ipxe/xfer.h>
+#include <ipxe/open.h>
+#include <ipxe/netdevice.h>
+#include <ipxe/ping.h>
+
+/** @file
+ *
+ * ICMP ping protocol
+ *
+ */
+
+/**
+ * A ping connection
+ *
+ */
+struct ping_connection {
+	/** Reference counter */
+	struct refcnt refcnt;
+	/** List of ping connections */
+	struct list_head list;
+
+	/** Remote socket address */
+	struct sockaddr_tcpip peer;
+	/** Local port number */
+	uint16_t port;
+
+	/** Data transfer interface */
+	struct interface xfer;
+};
+
+/** List of registered ping connections */
+static LIST_HEAD ( ping_conns );
+
+/**
+ * Identify ping connection by local port number
+ *
+ * @v port		Local port number
+ * @ret ping		Ping connection, or NULL
+ */
+static struct ping_connection * ping_demux ( unsigned int port ) {
+	struct ping_connection *ping;
+
+	list_for_each_entry ( ping, &ping_conns, list ) {
+		if ( ping->port == port )
+			return ping;
+	}
+	return NULL;
+}
+
+/**
+ * Check if local port number is available
+ *
+ * @v port		Local port number
+ * @ret port		Local port number, or negative error
+ */
+static int ping_port_available ( int port ) {
+
+	return ( ping_demux ( port ) ? -EADDRINUSE : port );
+}
+
+/**
+ * Process ICMP ping reply
+ *
+ * @v iobuf		I/O buffer
+ * @v st_src		Source address
+ * @ret rc		Return status code
+ */
+int ping_rx ( struct io_buffer *iobuf, struct sockaddr_tcpip *st_src ) {
+	struct icmp_echo *echo = iobuf->data;
+	struct ping_connection *ping;
+	struct xfer_metadata meta;
+	int rc;
+
+	/* Sanity check: should already have been checked by ICMP layer */
+	assert ( iob_len ( iobuf ) >= sizeof ( *echo ) );
+
+	/* Identify connection */
+	ping = ping_demux ( ntohs ( echo->ident ) );
+	DBGC ( ping, "PING %p reply id %#04x seq %#04x\n",
+	       ping, ntohs ( echo->ident ), ntohs ( echo->sequence ) );
+	if ( ! ping ) {
+		rc = -ENOTCONN;
+		goto discard;
+	}
+
+	/* Strip header, construct metadata, and pass data to upper layer */
+	iob_pull ( iobuf, sizeof ( *echo ) );
+	memset ( &meta, 0, sizeof ( meta ) );
+	meta.src = ( ( struct sockaddr * ) st_src );
+	meta.flags = XFER_FL_ABS_OFFSET;
+	meta.offset = ntohs ( echo->sequence );
+	return xfer_deliver ( &ping->xfer, iob_disown ( iobuf ), &meta );
+
+ discard:
+	free_iob ( iobuf );
+	return rc;
+}
+
+/**
+ * Allocate I/O buffer for ping
+ *
+ * @v ping		Ping connection
+ * @v len		Payload size
+ * @ret iobuf		I/O buffer, or NULL
+ */
+static struct io_buffer *
+ping_alloc_iob ( struct ping_connection *ping __unused, size_t len ) {
+	size_t header_len;
+	struct io_buffer *iobuf;
+
+	header_len = ( MAX_LL_NET_HEADER_LEN + sizeof ( struct icmp_echo ) );
+	iobuf = alloc_iob ( header_len + len );
+	if ( iobuf )
+		iob_reserve ( iobuf, header_len );
+	return iobuf;
+}
+
+/**
+ * Deliver datagram as I/O buffer
+ *
+ * @v ping		Ping connection
+ * @v iobuf		I/O buffer
+ * @v meta		Data transfer metadata
+ * @ret rc		Return status code
+ */
+static int ping_deliver ( struct ping_connection *ping, struct io_buffer *iobuf,
+			  struct xfer_metadata *meta ) {
+	struct icmp_echo *echo = iob_push ( iobuf, sizeof ( *echo ) );
+	int rc;
+
+	/* Construct header */
+	memset ( echo, 0, sizeof ( *echo ) );
+	echo->ident = htons ( ping->port );
+	echo->sequence = htons ( meta->offset );
+
+	/* Transmit echo request */
+	if ( ( rc = icmp_tx_echo_request ( iob_disown ( iobuf ),
+					   &ping->peer ) ) != 0 ) {
+		DBGC ( ping, "PING %p could not transmit: %s\n",
+		       ping, strerror ( rc ) );
+		return rc;
+	}
+
+	return 0;
+}
+
+/**
+ * Close ping connection
+ *
+ * @v ping		Ping connection
+ * @v rc		Reason for close
+ */
+static void ping_close ( struct ping_connection *ping, int rc ) {
+
+	/* Close data transfer interface */
+	intf_shutdown ( &ping->xfer, rc );
+
+	/* Remove from list of connections and drop list's reference */
+	list_del ( &ping->list );
+	ref_put ( &ping->refcnt );
+
+	DBGC ( ping, "PING %p closed\n", ping );
+}
+
+/** Ping data transfer interface operations */
+static struct interface_operation ping_xfer_operations[] = {
+	INTF_OP ( xfer_deliver, struct ping_connection *, ping_deliver ),
+	INTF_OP ( xfer_alloc_iob, struct ping_connection *, ping_alloc_iob ),
+	INTF_OP ( intf_close, struct ping_connection *, ping_close ),
+};
+
+/** Ping data transfer interface descriptor */
+static struct interface_descriptor ping_xfer_desc =
+	INTF_DESC ( struct ping_connection, xfer, ping_xfer_operations );
+
+/**
+ * Open a ping connection
+ *
+ * @v xfer		Data transfer interface
+ * @v peer		Peer socket address
+ * @v local		Local socket address, or NULL
+ * @ret rc		Return status code
+ */
+static int ping_open ( struct interface *xfer, struct sockaddr *peer,
+		       struct sockaddr *local ) {
+	struct sockaddr_tcpip *st_peer = ( struct sockaddr_tcpip * ) peer;
+	struct sockaddr_tcpip *st_local = ( struct sockaddr_tcpip * ) local;
+	struct ping_connection *ping;
+	int port;
+	int rc;
+
+	/* Allocate and initialise structure */
+	ping = zalloc ( sizeof ( *ping ) );
+	if ( ! ping ) {
+		rc = -ENOMEM;
+		goto err_alloc;
+	}
+	DBGC ( ping, "PING %p allocated\n", ping );
+	ref_init ( &ping->refcnt, NULL );
+	intf_init ( &ping->xfer, &ping_xfer_desc, &ping->refcnt );
+	memcpy ( &ping->peer, st_peer, sizeof ( ping->peer ) );
+
+	/* Bind to local port */
+	port = tcpip_bind ( st_local, ping_port_available );
+	if ( port < 0 ) {
+		rc = port;
+		DBGC ( ping, "PING %p could not bind: %s\n",
+		       ping, strerror ( rc ) );
+		goto err_bind;
+	}
+	ping->port = port;
+	DBGC ( ping, "PING %p bound to id %#04x\n", ping, port );
+
+	/* Attach parent interface, transfer reference to connection
+	 * list, and return
+	 */
+	intf_plug_plug ( &ping->xfer, xfer );
+	list_add ( &ping->list, &ping_conns );
+	return 0;
+
+ err_bind:
+	ref_put ( &ping->refcnt );
+ err_alloc:
+	return rc;
+}
+
+/** Ping IPv4 socket opener */
+struct socket_opener ping_ipv4_socket_opener __socket_opener = {
+	.semantics	= PING_SOCK_ECHO,
+	.family		= AF_INET,
+	.open		= ping_open,
+};
+
+/** Ping IPv6 socket opener */
+struct socket_opener ping_ipv6_socket_opener __socket_opener = {
+	.semantics	= PING_SOCK_ECHO,
+	.family		= AF_INET6,
+	.open		= ping_open,
+};
+
+/** Linkage hack */
+int ping_sock_echo = PING_SOCK_ECHO;