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author | Willem de Bruijn <willemb@google.com> | 2016-03-10 03:58:33 +0100 |
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committer | David S. Miller <davem@davemloft.net> | 2016-03-10 04:13:01 +0100 |
commit | ea47781c26510e5d97f80f9aceafe9065bd5e3aa (patch) | |
tree | 155f27a643ca906b31d66a6cff3440fdea97b5cb | |
parent | net: validate variable length ll headers (diff) | |
download | linux-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.c | 15 |
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); |