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| author | Paul Moore <pmoore@redhat.com> | 2012-06-01 05:54:56 +0000 |
|---|---|---|
| committer | David S. Miller <davem@davemloft.net> | 2012-06-01 14:18:29 -0400 |
| commit | 20e2a86485967c385d7c7befc1646e4d1d39362e (patch) | |
| tree | e08d5d8dd133a8548e9f5dd0f85e69241ec1e176 /include | |
| parent | cc9b17ad29ecaa20bfe426a8d4dbfb94b13ff1cc (diff) | |
| download | lwn-20e2a86485967c385d7c7befc1646e4d1d39362e.tar.gz lwn-20e2a86485967c385d7c7befc1646e4d1d39362e.zip | |
cipso: handle CIPSO options correctly when NetLabel is disabled
When NetLabel is not enabled, e.g. CONFIG_NETLABEL=n, and the system
receives a CIPSO tagged packet it is dropped (cipso_v4_validate()
returns non-zero). In most cases this is the correct and desired
behavior, however, in the case where we are simply forwarding the
traffic, e.g. acting as a network bridge, this becomes a problem.
This patch fixes the forwarding problem by providing the basic CIPSO
validation code directly in ip_options_compile() without the need for
the NetLabel or CIPSO code. The new validation code can not perform
any of the CIPSO option label/value verification that
cipso_v4_validate() does, but it can verify the basic CIPSO option
format.
The behavior when NetLabel is enabled is unchanged.
Signed-off-by: Paul Moore <pmoore@redhat.com>
Signed-off-by: David S. Miller <davem@davemloft.net>
Diffstat (limited to 'include')
| -rw-r--r-- | include/net/cipso_ipv4.h | 29 |
1 files changed, 28 insertions, 1 deletions
diff --git a/include/net/cipso_ipv4.h b/include/net/cipso_ipv4.h index 9808877c2ab9..a7a683e30b64 100644 --- a/include/net/cipso_ipv4.h +++ b/include/net/cipso_ipv4.h @@ -42,6 +42,7 @@ #include <net/netlabel.h> #include <net/request_sock.h> #include <linux/atomic.h> +#include <asm/unaligned.h> /* known doi values */ #define CIPSO_V4_DOI_UNKNOWN 0x00000000 @@ -285,7 +286,33 @@ static inline int cipso_v4_skbuff_getattr(const struct sk_buff *skb, static inline int cipso_v4_validate(const struct sk_buff *skb, unsigned char **option) { - return -ENOSYS; + unsigned char *opt = *option; + unsigned char err_offset = 0; + u8 opt_len = opt[1]; + u8 opt_iter; + + if (opt_len < 8) { + err_offset = 1; + goto out; + } + + if (get_unaligned_be32(&opt[2]) == 0) { + err_offset = 2; + goto out; + } + + for (opt_iter = 6; opt_iter < opt_len;) { + if (opt[opt_iter + 1] > (opt_len - opt_iter)) { + err_offset = opt_iter + 1; + goto out; + } + opt_iter += opt[opt_iter + 1]; + } + +out: + *option = opt + err_offset; + return err_offset; + } #endif /* CONFIG_NETLABEL */ |