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authorWillem de Bruijn <willemb@google.com>2016-03-10 03:58:33 +0100
committerDavid S. Miller <davem@davemloft.net>2016-03-10 04:13:01 +0100
commitea47781c26510e5d97f80f9aceafe9065bd5e3aa (patch)
tree155f27a643ca906b31d66a6cff3440fdea97b5cb
parentnet: validate variable length ll headers (diff)
downloadlinux-ea47781c26510e5d97f80f9aceafe9065bd5e3aa.tar.xz
linux-ea47781c26510e5d97f80f9aceafe9065bd5e3aa.zip
ax25: add link layer header validation function
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>
-rw-r--r--net/ax25/ax25_ip.c15
1 files changed, 15 insertions, 0 deletions
diff --git a/net/ax25/ax25_ip.c b/net/ax25/ax25_ip.c
index b563a3f5f2a8..2fa3be965101 100644
--- a/net/ax25/ax25_ip.c
+++ b/net/ax25/ax25_ip.c
@@ -228,8 +228,23 @@ netdev_tx_t ax25_ip_xmit(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,
+ .validate = ax25_validate_header,
};
EXPORT_SYMBOL(ax25_header_ops);