[ipv6] Replace IPv6 stack

Replace the existing partially-implemented IPv6 stack with a fresh
implementation.

This implementation is not yet complete.  The IPv6 transmit and
receive datapaths are functional (including fragment reassembly and
parsing of arbitrary extension headers).  NDP neighbour solicitations
and advertisements are supported.  ICMPv6 echo is supported.

At present, only link-local addresses may be used, and there is no way
to specify an IPv6 address as part of a URI (either directly or via
a DNS lookup).

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

1 files changed, 147 insertions, 101 deletions

diff --git a/src/net/icmpv6.c b/src/net/icmpv6.c
index 72423806..54426be8 100644
--- a/src/net/icmpv6.c
+++ b/src/net/icmpv6.c
@@ -1,126 +1,172 @@
-#include <stdint.h>
+/*
+ * 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 <string.h>
-#include <byteswap.h>
 #include <errno.h>
+#include <byteswap.h>
 #include <ipxe/in.h>
-#include <ipxe/ip6.h>
-#include <ipxe/if_ether.h>
 #include <ipxe/iobuf.h>
-#include <ipxe/ndp.h>
-#include <ipxe/icmp6.h>
 #include <ipxe/tcpip.h>
-#include <ipxe/netdevice.h>
+#include <ipxe/icmpv6.h>
+
+/** @file
+ *
+ * ICMPv6 protocol
+ *
+ */
 
 /**
- * Send neighbour solicitation packet
+ * Process received ICMPv6 echo request packet
  *
- * @v netdev	Network device
- * @v src	Source address
- * @v dest	Destination address
+ * @v iobuf		I/O buffer
+ * @v netdev		Network device
+ * @v sin6_src		Source socket address
+ * @v sin6_dest		Destination socket address
+ * @ret rc		Return status code
+ */
+static int icmpv6_rx_echo ( struct io_buffer *iobuf,
+			    struct net_device *netdev,
+			    struct sockaddr_in6 *sin6_src,
+			    struct sockaddr_in6 *sin6_dest __unused ) {
+	struct sockaddr_tcpip *st_src =
+		( ( struct sockaddr_tcpip * ) sin6_src );
+	struct icmpv6_echo *echo = iobuf->data;
+	size_t len = iob_len ( iobuf );
+	int rc;
+
+	/* Sanity check */
+	if ( iob_len ( iobuf ) < sizeof ( *echo ) ) {
+		DBGC ( netdev, "ICMPv6 echo request too short at %zd bytes "
+		       "(min %zd bytes)\n", iob_len ( iobuf ),
+		       sizeof ( *echo ) );
+		rc = -EINVAL;
+		goto done;
+	}
+	DBGC ( netdev, "ICMPv6 echo request from %s (id %#04x seq %#04x)\n",
+	       inet6_ntoa ( &sin6_dest->sin6_addr ), ntohs ( echo->ident ),
+	       ntohs ( echo->sequence ) );
+
+	/* Convert echo request to echo reply and recalculate checksum */
+	echo->icmp.type = ICMPV6_ECHO_REPLY;
+	echo->icmp.chksum = 0;
+	echo->icmp.chksum = tcpip_chksum ( echo, len );
+
+	/* Transmit echo reply */
+	if ( ( rc = tcpip_tx ( iob_disown ( iobuf ), &icmpv6_protocol, NULL,
+			       st_src, netdev, &echo->icmp.chksum ) ) != 0 ) {
+		DBGC ( netdev, "ICMPv6 could not transmit reply: %s\n",
+		       strerror ( rc ) );
+		goto done;
+	}
+
+ done:
+	free_iob ( iobuf );
+	return rc;
+}
+
+/** ICMPv6 echo request handlers */
+struct icmpv6_handler icmpv6_echo_handler __icmpv6_handler = {
+	.type = ICMPV6_ECHO_REQUEST,
+	.rx = icmpv6_rx_echo,
+};
+
+/**
+ * Identify ICMPv6 handler
  *
- * This function prepares a neighbour solicitation packet and sends it to the
- * network layer.
+ * @v type		ICMPv6 type
+ * @ret handler		ICMPv6 handler, or NULL if not found
  */
-int icmp6_send_solicit ( struct net_device *netdev, struct in6_addr *src __unused,
-			 struct in6_addr *dest ) {
-	union {
-		struct sockaddr_in6 sin6;
-		struct sockaddr_tcpip st;
-	} st_dest;
-	struct ll_protocol *ll_protocol = netdev->ll_protocol;
-	struct neighbour_solicit *nsolicit;
-	struct io_buffer *iobuf = alloc_iob ( sizeof ( *nsolicit ) + MIN_IOB_LEN );
-	iob_reserve ( iobuf, MAX_HDR_LEN );
-	nsolicit = iob_put ( iobuf, sizeof ( *nsolicit ) );
-
-	/* Fill up the headers */
-	memset ( nsolicit, 0, sizeof ( *nsolicit ) );
-	nsolicit->type = ICMP6_NSOLICIT;
-	nsolicit->code = 0;
-	nsolicit->target = *dest;
-	nsolicit->opt_type = 1;
-	nsolicit->opt_len = ( 2 + ll_protocol->ll_addr_len ) / 8;
-	memcpy ( nsolicit->opt_ll_addr, netdev->ll_addr,
-				netdev->ll_protocol->ll_addr_len );
-	/* Partial checksum */
-	nsolicit->csum = 0;
-	nsolicit->csum = tcpip_chksum ( nsolicit, sizeof ( *nsolicit ) );
-
-	/* Solicited multicast address */
-	st_dest.sin6.sin6_family = AF_INET6;
-	st_dest.sin6.sin6_addr.in6_u.u6_addr8[0] = 0xff;
-	st_dest.sin6.sin6_addr.in6_u.u6_addr8[2] = 0x02;
-	st_dest.sin6.sin6_addr.in6_u.u6_addr16[1] = 0x0000;
-	st_dest.sin6.sin6_addr.in6_u.u6_addr32[1] = 0x00000000;
-	st_dest.sin6.sin6_addr.in6_u.u6_addr16[4] = 0x0000;
-	st_dest.sin6.sin6_addr.in6_u.u6_addr16[5] = 0x0001;
-	st_dest.sin6.sin6_addr.in6_u.u6_addr32[3] = dest->in6_u.u6_addr32[3];
-	st_dest.sin6.sin6_addr.in6_u.u6_addr8[13] = 0xff;
-	
-	/* Send packet over IP6 */
-	return tcpip_tx ( iobuf, &icmp6_protocol, NULL, &st_dest.st,
-			  NULL, &nsolicit->csum );
+static struct icmpv6_handler * icmpv6_handler ( unsigned int type ) {
+	struct icmpv6_handler *handler;
+
+	for_each_table_entry ( handler, ICMPV6_HANDLERS ) {
+		if ( handler->type == type )
+			return handler;
+	}
+	return NULL;
 }
 
 /**
- * Process ICMP6 headers
+ * Process a received packet
  *
- * @v iobuf	I/O buffer
- * @v st_src	Source address
- * @v st_dest	Destination address
+ * @v iobuf		I/O buffer
+ * @v netdev		Network device
+ * @v st_src		Partially-filled source address
+ * @v st_dest		Partially-filled destination address
+ * @v pshdr_csum	Pseudo-header checksum
+ * @ret rc		Return status code
  */
-static int icmp6_rx ( struct io_buffer *iobuf, struct net_device *netdev __unused, struct sockaddr_tcpip *st_src,
-		      struct sockaddr_tcpip *st_dest, __unused uint16_t pshdr_csum ) {
-	struct icmp6_header *icmp6hdr = iobuf->data;
+static int icmpv6_rx ( struct io_buffer *iobuf, struct net_device *netdev,
+		       struct sockaddr_tcpip *st_src,
+		       struct sockaddr_tcpip *st_dest, uint16_t pshdr_csum ) {
+	struct sockaddr_in6 *sin6_src = ( ( struct sockaddr_in6 * ) st_src );
+	struct sockaddr_in6 *sin6_dest = ( ( struct sockaddr_in6 * ) st_dest );
+	struct icmpv6_header *icmp = iobuf->data;
+	size_t len = iob_len ( iobuf );
+	struct icmpv6_handler *handler;
+	unsigned int csum;
+	int rc;
 
 	/* Sanity check */
-	if ( iob_len ( iobuf ) < sizeof ( *icmp6hdr ) ) {
-		DBG ( "Packet too short (%zd bytes)\n", iob_len ( iobuf ) );
-		free_iob ( iobuf );
-		return -EINVAL;
+	if ( len < sizeof ( *icmp ) ) {
+		DBGC ( netdev, "ICMPv6 packet too short at %zd bytes (min %zd "
+		       "bytes)\n", len, sizeof ( *icmp ) );
+		rc = -EINVAL;
+		goto done;
 	}
 
-	/* TODO: Verify checksum */
+	/* Verify checksum */
+	csum = tcpip_continue_chksum ( pshdr_csum, icmp, len );
+	if ( csum != 0 ) {
+		DBGC ( netdev, "ICMPv6 checksum incorrect (is %04x, should be "
+		       "0000)\n", csum );
+		DBGC_HDA ( netdev, 0, icmp, len );
+		rc = -EINVAL;
+		goto done;
+	}
 
-	/* Process the ICMP header */
-	switch ( icmp6hdr->type ) {
-	case ICMP6_NADVERT:
-		return ndp_process_advert ( iobuf, st_src, st_dest );
+	/* Identify handler */
+	handler = icmpv6_handler ( icmp->type );
+	if ( ! handler ) {
+		DBGC ( netdev, "ICMPv6 unrecognised type %d\n", icmp->type );
+		rc = -ENOTSUP;
+		goto done;
+	}
+
+	/* Pass to handler */
+	if ( ( rc = handler->rx ( iob_disown ( iobuf ), netdev, sin6_src,
+				  sin6_dest ) ) != 0 ) {
+		DBGC ( netdev, "ICMPv6 could not handle type %d: %s\n",
+		       icmp->type, strerror ( rc ) );
+		goto done;
 	}
-	return -ENOSYS;
-}
 
-#if 0
-void icmp6_test_nadvert (struct net_device *netdev, struct sockaddr_in6 *server_p, char *ll_addr) {
-
-		struct sockaddr_in6 server;
-		memcpy ( &server, server_p, sizeof ( server ) );
-                struct io_buffer *rxiobuf = alloc_iob ( 500 );
-                iob_reserve ( rxiobuf, MAX_HDR_LEN );
-                struct neighbour_advert *nadvert = iob_put ( rxiobuf, sizeof ( *nadvert ) );
-                nadvert->type = 136;
-                nadvert->code = 0;
-                nadvert->flags = ICMP6_FLAGS_SOLICITED;
-		nadvert->csum = 0xffff;
-		nadvert->target = server.sin6_addr;
-                nadvert->opt_type = 2;
-                nadvert->opt_len = 1;
-                memcpy ( nadvert->opt_ll_addr, ll_addr, 6 );
-                struct ip6_header *ip6hdr = iob_push ( rxiobuf, sizeof ( *ip6hdr ) );
-                ip6hdr->ver_traffic_class_flow_label = htonl ( 0x60000000 );
-		ip6hdr->hop_limit = 255;
-		ip6hdr->nxt_hdr = 58;
-		ip6hdr->payload_len = htons ( sizeof ( *nadvert ) );
-                ip6hdr->src = server.sin6_addr;
-                ip6hdr->dest = server.sin6_addr;
-		hex_dump ( rxiobuf->data, iob_len ( rxiobuf ) );
-                net_rx ( rxiobuf, netdev, htons ( ETH_P_IPV6 ), ll_addr );
+ done:
+	free_iob ( iobuf );
+	return rc;
 }
-#endif
 
-/** ICMP6 protocol */
-struct tcpip_protocol icmp6_protocol __tcpip_protocol = {
-	.name = "ICMP6",
-	.rx = icmp6_rx,
-	.tcpip_proto = IP_ICMP6, // 58
+/** ICMPv6 TCP/IP protocol */
+struct tcpip_protocol icmpv6_protocol __tcpip_protocol = {
+	.name = "ICMPv6",
+	.rx = icmpv6_rx,
+	.tcpip_proto = IP_ICMP6,
 };