diff options
| author | Willem de Bruijn <willemb@google.com> | 2016-03-09 21:58:33 -0500 |
|---|---|---|
| committer | Ben Hutchings <ben@decadent.org.uk> | 2016-05-01 00:05:26 +0200 |
| commit | 0954b59d9f4b2dcc59f28d1f64c3a21062a64372 (patch) | |
| tree | b4882e85c799d136f5d7a69e97cad9b3b1e46102 | |
| parent | b5518429e70cd783b8ca52335456172c1a0589f6 (diff) | |
ax25: add link layer header validation function
[ Upstream commit ea47781c26510e5d97f80f9aceafe9065bd5e3aa ]
As variable length protocol, AX25 fails link layer header validation
tests based on a minimum length. header_ops.validate allows protocols
to validate headers that are shorter than hard_header_len. Implement
this callback for AX25.
See also http://comments.gmane.org/gmane.linux.network/401064
Signed-off-by: Willem de Bruijn <willemb@google.com>
Signed-off-by: David S. Miller <davem@davemloft.net>
[bwh: Backported to 3.2: adjust context]
Signed-off-by: Ben Hutchings <ben@decadent.org.uk>
| -rw-r--r-- | net/ax25/ax25_ip.c | 15 |
1 files changed, 15 insertions, 0 deletions
diff --git a/net/ax25/ax25_ip.c b/net/ax25/ax25_ip.c index cf0c47a26530..a0c9956b5b23 100644 --- a/net/ax25/ax25_ip.c +++ b/net/ax25/ax25_ip.c @@ -232,9 +232,24 @@ int ax25_rebuild_header(struct sk_buff *skb) #endif +static bool ax25_validate_header(const char *header, unsigned int len) +{ + ax25_digi digi; + + if (!len) + return false; + + if (header[0]) + return true; + + return ax25_addr_parse(header + 1, len - 1, NULL, NULL, &digi, NULL, + NULL); +} + const struct header_ops ax25_header_ops = { .create = ax25_hard_header, .rebuild = ax25_rebuild_header, + .validate = ax25_validate_header, }; EXPORT_SYMBOL(ax25_hard_header); |