[gPXE-devel] [PATCH 26/31] [ipv6] handle unaligned prefixes in router advertisements

[matthew at theiselins.net]

From: Matthew Iselin <matthew at theiselins.net>

Signed-off-by: Matthew Iselin <matthew at theiselins.net>
---
 src/net/ndp.c |    9 +++++----
 1 files changed, 5 insertions(+), 4 deletions(-)

diff --git a/src/net/ndp.c b/src/net/ndp.c
index 5205554..be1fa94 100644
--- a/src/net/ndp.c
+++ b/src/net/ndp.c
@@ -177,8 +177,8 @@ int ndp_process_radvert ( struct io_buffer *iobuf, struct sockaddr_tcpip *st_src
 			prefix_len = opt->prefix_len;
 
 			if ( prefix_len % 8 ) {
-				/* FIXME: non-aligned prefixes unhandled */
-				DBG ( "ndp: prefix length is unaligned, connectivity may suffer.\n" );
+				/* Copy one extra prefix byte. */
+				prefix_len += 8;
 			}
 
 			if ( prefix_len > 64 ) {
@@ -186,6 +186,9 @@ int ndp_process_radvert ( struct io_buffer *iobuf, struct sockaddr_tcpip *st_src
 				DBG ( "ndp: prefix length is quite long, connectivity may suffer.\n" );
 			}
 
+			/* Copy the prefix first and then add the EUI-64 */
+			memcpy( &host_addr.s6_addr, opt->prefix, prefix_len / 8 );
+
 			/* Create an IPv6 address for this station based on the prefix. */
 			ll_size = netdev->ll_protocol->ll_addr_len;
 			if ( ll_size < 6 ) {
@@ -194,8 +197,6 @@ int ndp_process_radvert ( struct io_buffer *iobuf, struct sockaddr_tcpip *st_src
 				ipv6_generate_eui64 ( host_addr.s6_addr + 8, netdev->ll_addr );
 			}
 
-			memcpy( &host_addr.s6_addr, opt->prefix, prefix_len / 8 );
-
 			rc = 0;
 			}
 			break;
-- 
1.7.2.5