diff options
author | Herbert Xu <herbert@gondor.apana.org.au> | 2006-02-27 21:00:40 (GMT) |
---|---|---|
committer | David S. Miller <davem@davemloft.net> | 2006-02-27 21:00:40 (GMT) |
commit | 752c1f4c78fe86d0fd6497387f763306b0d8fc53 (patch) | |
tree | 50d7e52940d1adf0936805645d52e2419e5922cf /net/ipv4/esp4.c | |
parent | 4bf05eceecf2efb4c883e9e9b17825682e7330dd (diff) | |
download | linux-fsl-qoriq-752c1f4c78fe86d0fd6497387f763306b0d8fc53.tar.xz |
[IPSEC]: Kill post_input hook and do NAT-T in esp_input directly
The only reason post_input exists at all is that it gives us the
potential to adjust the checksums incrementally in future which
we ought to do.
However, after thinking about it for a bit we can adjust the
checksums without using this post_input stuff at all. The crucial
point is that only the inner-most NAT-T SA needs to be considered
when adjusting checksums. What's more, the checksum adjustment
comes down to a single u32 due to the linearity of IP checksums.
We just happen to have a spare u32 lying around in our skb structure :)
When ip_summed is set to CHECKSUM_NONE on input, the value of skb->csum
is currently unused. All we have to do is to make that the checksum
adjustment and voila, there goes all the post_input and decap structures!
I've left in the decap data structures for now since it's intricately
woven into the sec_path stuff. We can kill them later too.
Signed-off-by: Herbert Xu <herbert@gondor.apana.org.au>
Signed-off-by: David S. Miller <davem@davemloft.net>
Diffstat (limited to 'net/ipv4/esp4.c')
-rw-r--r-- | net/ipv4/esp4.c | 128 |
1 files changed, 38 insertions, 90 deletions
diff --git a/net/ipv4/esp4.c b/net/ipv4/esp4.c index 3f47419..09590f3 100644 --- a/net/ipv4/esp4.c +++ b/net/ipv4/esp4.c @@ -12,13 +12,6 @@ #include <net/protocol.h> #include <net/udp.h> -/* decapsulation data for use when post-processing */ -struct esp_decap_data { - xfrm_address_t saddr; - __u16 sport; - __u8 proto; -}; - static int esp_output(struct xfrm_state *x, struct sk_buff *skb) { int err; @@ -210,25 +203,47 @@ static int esp_input(struct xfrm_state *x, struct xfrm_decap_state *decap, struc /* ... check padding bits here. Silly. :-) */ - if (x->encap && decap && decap->decap_type) { - struct esp_decap_data *encap_data; - struct udphdr *uh = (struct udphdr *) (iph+1); - - encap_data = (struct esp_decap_data *) (decap->decap_data); - encap_data->proto = 0; - - switch (decap->decap_type) { - case UDP_ENCAP_ESPINUDP: - case UDP_ENCAP_ESPINUDP_NON_IKE: - encap_data->proto = AF_INET; - encap_data->saddr.a4 = iph->saddr; - encap_data->sport = uh->source; - encap_len = (void*)esph - (void*)uh; - break; + if (x->encap) { + struct xfrm_encap_tmpl *encap = x->encap; + struct udphdr *uh; - default: + if (encap->encap_type != decap->decap_type) goto out; + + uh = (struct udphdr *)(iph + 1); + encap_len = (void*)esph - (void*)uh; + + /* + * 1) if the NAT-T peer's IP or port changed then + * advertize the change to the keying daemon. + * This is an inbound SA, so just compare + * SRC ports. + */ + if (iph->saddr != x->props.saddr.a4 || + uh->source != encap->encap_sport) { + xfrm_address_t ipaddr; + + ipaddr.a4 = iph->saddr; + km_new_mapping(x, &ipaddr, uh->source); + + /* XXX: perhaps add an extra + * policy check here, to see + * if we should allow or + * reject a packet from a + * different source + * address/port. + */ } + + /* + * 2) ignore UDP/TCP checksums in case + * of NAT-T in Transport Mode, or + * perform other post-processing fixes + * as per draft-ietf-ipsec-udp-encaps-06, + * section 3.1.2 + */ + if (!x->props.mode) + skb->ip_summed = CHECKSUM_UNNECESSARY; } iph->protocol = nexthdr[1]; @@ -245,63 +260,6 @@ out: return -EINVAL; } -static int esp_post_input(struct xfrm_state *x, struct xfrm_decap_state *decap, struct sk_buff *skb) -{ - - if (x->encap) { - struct xfrm_encap_tmpl *encap; - struct esp_decap_data *decap_data; - - encap = x->encap; - decap_data = (struct esp_decap_data *)(decap->decap_data); - - /* first, make sure that the decap type == the encap type */ - if (encap->encap_type != decap->decap_type) - return -EINVAL; - - switch (encap->encap_type) { - default: - case UDP_ENCAP_ESPINUDP: - case UDP_ENCAP_ESPINUDP_NON_IKE: - /* - * 1) if the NAT-T peer's IP or port changed then - * advertize the change to the keying daemon. - * This is an inbound SA, so just compare - * SRC ports. - */ - if (decap_data->proto == AF_INET && - (decap_data->saddr.a4 != x->props.saddr.a4 || - decap_data->sport != encap->encap_sport)) { - xfrm_address_t ipaddr; - - ipaddr.a4 = decap_data->saddr.a4; - km_new_mapping(x, &ipaddr, decap_data->sport); - - /* XXX: perhaps add an extra - * policy check here, to see - * if we should allow or - * reject a packet from a - * different source - * address/port. - */ - } - - /* - * 2) ignore UDP/TCP checksums in case - * of NAT-T in Transport Mode, or - * perform other post-processing fixes - * as per * draft-ietf-ipsec-udp-encaps-06, - * section 3.1.2 - */ - if (!x->props.mode) - skb->ip_summed = CHECKSUM_UNNECESSARY; - - break; - } - } - return 0; -} - static u32 esp4_get_max_size(struct xfrm_state *x, int mtu) { struct esp_data *esp = x->data; @@ -457,7 +415,6 @@ static struct xfrm_type esp_type = .destructor = esp_destroy, .get_max_size = esp4_get_max_size, .input = esp_input, - .post_input = esp_post_input, .output = esp_output }; @@ -469,15 +426,6 @@ static struct net_protocol esp4_protocol = { static int __init esp4_init(void) { - struct xfrm_decap_state decap; - - if (sizeof(struct esp_decap_data) > - sizeof(decap.decap_data)) { - extern void decap_data_too_small(void); - - decap_data_too_small(); - } - if (xfrm_register_type(&esp_type, AF_INET) < 0) { printk(KERN_INFO "ip esp init: can't add xfrm type\n"); return -EAGAIN; |