From ca3ccd8748434719e4670ce812d1310013fad518 Mon Sep 17 00:00:00 2001 From: David Lamparter Date: Wed, 26 Sep 2012 14:52:39 +0200 Subject: zebra: fix sockaddr_dl length assumptions (BZ#737) Quagga makes bad assumptions about sockaddr_dl (on NetBSD, but possibly on other systems as well). Particularly, sizeof(struct sockaddr_dl) returns a size that does not include the full sdl_data field, leading to not enough data being copied. This breaks IPv6 RAs in particular, as a broken mac address from sockaddr_dl will be included in the packets. From: Matthias-Christian Ott Tested-by: Uwe Toenjes <6bone@6bone.informatik.uni-leipzig.de> [further simplified + more comments] Signed-off-by: David Lamparter --- lib/if.h | 8 +++++++- 1 file changed, 7 insertions(+), 1 deletion(-) (limited to 'lib/if.h') diff --git a/lib/if.h b/lib/if.h index 841ce51e..2116e12e 100644 --- a/lib/if.h +++ b/lib/if.h @@ -103,7 +103,13 @@ struct interface /* Hardware address. */ #ifdef HAVE_STRUCT_SOCKADDR_DL - struct sockaddr_dl sdl; + union { + /* note that sdl_storage is never accessed, it only exists to make space. + * all actual uses refer to sdl - but use sizeof(sdl_storage)! this fits + * best with C aliasing rules. */ + struct sockaddr_dl sdl; + struct sockaddr_storage sdl_storage; + }; #else unsigned short hw_type; u_char hw_addr[INTERFACE_HWADDR_MAX]; -- cgit v1.2.1