static void ila_csum_do_neutral(struct ila_addr *iaddr,
struct ila_params *p)
{
__sum16 *adjust = (__force __sum16 *)&iaddr->ident.v16[3];
__wsum diff, fval;
/* Check if checksum adjust value has been cached */
if (p->locator_match.v64) {
diff = p->csum_diff;
} else {
diff = compute_csum_diff8((__be32 *)iaddr,
(__be32 *)&p->locator);
}
fval = (__force __wsum)(ila_csum_neutral_set(iaddr->ident) ?
~CSUM_NEUTRAL_FLAG : CSUM_NEUTRAL_FLAG);
diff = csum_add(diff, fval);
*adjust = ~csum_fold(csum_add(diff, csum_unfold(*adjust)));
/* Flip the csum-neutral bit. Either we are doing a SIR->ILA
* translation with ILA_CSUM_NEUTRAL_MAP as the csum_method
* and the C-bit is not set, or we are doing an ILA-SIR
* tranlsation and the C-bit is set.
*/
iaddr->ident.csum_neutral ^= 1;
}
static inline void
tcp_partial_csum_update(int af, struct tcphdr *tcph,
const union nf_inet_addr *oldip,
const union nf_inet_addr *newip,
__be16 oldlen, __be16 newlen)
{
#ifdef CONFIG_IP_VS_IPV6
if (af == AF_INET6)
tcph->check =
~csum_fold(ip_vs_check_diff16(oldip->ip6, newip->ip6,
ip_vs_check_diff2(oldlen, newlen,
csum_unfold(tcph->check))));
else
#endif
tcph->check =
~csum_fold(ip_vs_check_diff4(oldip->ip, newip->ip,
ip_vs_check_diff2(oldlen, newlen,
csum_unfold(tcph->check))));
}
static bool ip6t_npt_map_pfx(const struct ip6t_npt_tginfo *npt,
struct in6_addr *addr)
{
unsigned int pfx_len;
unsigned int i, idx;
__be32 mask;
__sum16 sum;
pfx_len = max(npt->src_pfx_len, npt->dst_pfx_len);
for (i = 0; i < pfx_len; i += 32) {
if (pfx_len - i >= 32)
mask = 0;
else
mask = htonl((1 << (i - pfx_len + 32)) - 1);
idx = i / 32;
addr->s6_addr32[idx] &= mask;
addr->s6_addr32[idx] |= ~mask & npt->dst_pfx.in6.s6_addr32[idx];
}
if (pfx_len <= 48)
idx = 3;
else {
for (idx = 4; idx < ARRAY_SIZE(addr->s6_addr16); idx++) {
if ((__force __sum16)addr->s6_addr16[idx] !=
CSUM_MANGLED_0)
break;
}
if (idx == ARRAY_SIZE(addr->s6_addr16))
return false;
}
sum = ~csum_fold(csum_add(csum_unfold((__force __sum16)addr->s6_addr16[idx]),
csum_unfold(npt->adjustment)));
if (sum == CSUM_MANGLED_0)
sum = 0;
*(__force __sum16 *)&addr->s6_addr16[idx] = sum;
return true;
}
void rpl_inet_proto_csum_replace16(__sum16 *sum, struct sk_buff *skb,
const __be32 *from, const __be32 *to,
int pseudohdr)
{
__be32 diff[] = {
~from[0], ~from[1], ~from[2], ~from[3],
to[0], to[1], to[2], to[3],
};
if (skb->ip_summed != CHECKSUM_PARTIAL) {
*sum = csum_fold(csum_partial(diff, sizeof(diff),
~csum_unfold(*sum)));
if (skb->ip_summed == CHECKSUM_COMPLETE && pseudohdr)
skb->csum = ~csum_partial(diff, sizeof(diff),
~skb->csum);
} else if (pseudohdr)
*sum = ~csum_fold(csum_partial(diff, sizeof(diff),
csum_unfold(*sum)));
}
void xtnu_proto_csum_replace4(__sum16 * sum, struct sk_buff *skb,
__be32 from, __be32 to, bool pseudohdr)
{
__be32 diff[] = { ~from, to };
const void *dv = diff; /* kludge for < v2.6.19-555-g72685fc */
#if LINUX_VERSION_CODE >= KERNEL_VERSION(2, 6, 19)
if (skb->ip_summed != CHECKSUM_PARTIAL) {
*sum = csum_fold(csum_partial(dv, sizeof(diff),
~csum_unfold(*sum)));
if (skb->ip_summed == CHECKSUM_COMPLETE && pseudohdr)
skb->csum = ~csum_partial(dv, sizeof(diff), ~skb->csum);
} else if (pseudohdr) {
*sum = ~csum_fold(csum_partial(dv, sizeof(diff),
csum_unfold(*sum)));
}
#else
*sum = csum_fold(csum_partial(dv, sizeof(diff), ~csum_unfold(*sum)));
#endif
}
static struct sk_buff *__skb_udp_tunnel_segment(struct sk_buff *skb,
netdev_features_t features,
struct sk_buff *(*gso_inner_segment)(struct sk_buff *skb,
netdev_features_t features),
__be16 new_protocol, bool is_ipv6)
{
int tnl_hlen = skb_inner_mac_header(skb) - skb_transport_header(skb);
bool remcsum, need_csum, offload_csum, gso_partial;
struct sk_buff *segs = ERR_PTR(-EINVAL);
struct udphdr *uh = udp_hdr(skb);
u16 mac_offset = skb->mac_header;
__be16 protocol = skb->protocol;
u16 mac_len = skb->mac_len;
int udp_offset, outer_hlen;
__wsum partial;
bool need_ipsec;
if (unlikely(!pskb_may_pull(skb, tnl_hlen)))
goto out;
/* Adjust partial header checksum to negate old length.
* We cannot rely on the value contained in uh->len as it is
* possible that the actual value exceeds the boundaries of the
* 16 bit length field due to the header being added outside of an
* IP or IPv6 frame that was already limited to 64K - 1.
*/
if (skb_shinfo(skb)->gso_type & SKB_GSO_PARTIAL)
partial = (__force __wsum)uh->len;
else
partial = (__force __wsum)htonl(skb->len);
partial = csum_sub(csum_unfold(uh->check), partial);
/* setup inner skb. */
skb->encapsulation = 0;
SKB_GSO_CB(skb)->encap_level = 0;
__skb_pull(skb, tnl_hlen);
skb_reset_mac_header(skb);
skb_set_network_header(skb, skb_inner_network_offset(skb));
skb->mac_len = skb_inner_network_offset(skb);
skb->protocol = new_protocol;
need_csum = !!(skb_shinfo(skb)->gso_type & SKB_GSO_UDP_TUNNEL_CSUM);
skb->encap_hdr_csum = need_csum;
remcsum = !!(skb_shinfo(skb)->gso_type & SKB_GSO_TUNNEL_REMCSUM);
skb->remcsum_offload = remcsum;
need_ipsec = skb_dst(skb) && dst_xfrm(skb_dst(skb));
/* Try to offload checksum if possible */
offload_csum = !!(need_csum &&
!need_ipsec &&
(skb->dev->features &
(is_ipv6 ? (NETIF_F_HW_CSUM | NETIF_F_IPV6_CSUM) :
(NETIF_F_HW_CSUM | NETIF_F_IP_CSUM))));
features &= skb->dev->hw_enc_features;
/* The only checksum offload we care about from here on out is the
* outer one so strip the existing checksum feature flags and
* instead set the flag based on our outer checksum offload value.
*/
if (remcsum) {
features &= ~NETIF_F_CSUM_MASK;
if (!need_csum || offload_csum)
features |= NETIF_F_HW_CSUM;
}
/* segment inner packet. */
segs = gso_inner_segment(skb, features);
if (IS_ERR_OR_NULL(segs)) {
skb_gso_error_unwind(skb, protocol, tnl_hlen, mac_offset,
mac_len);
goto out;
}
gso_partial = !!(skb_shinfo(segs)->gso_type & SKB_GSO_PARTIAL);
outer_hlen = skb_tnl_header_len(skb);
udp_offset = outer_hlen - tnl_hlen;
skb = segs;
do {
unsigned int len;
if (remcsum)
skb->ip_summed = CHECKSUM_NONE;
/* Set up inner headers if we are offloading inner checksum */
if (skb->ip_summed == CHECKSUM_PARTIAL) {
skb_reset_inner_headers(skb);
skb->encapsulation = 1;
}
skb->mac_len = mac_len;
skb->protocol = protocol;
__skb_push(skb, outer_hlen);
skb_reset_mac_header(skb);
skb_set_network_header(skb, mac_len);
skb_set_transport_header(skb, udp_offset);
len = skb->len - udp_offset;
uh = udp_hdr(skb);
/* If we are only performing partial GSO the inner header
* will be using a length value equal to only one MSS sized
* segment instead of the entire frame.
*/
if (gso_partial && skb_is_gso(skb)) {
uh->len = htons(skb_shinfo(skb)->gso_size +
SKB_GSO_CB(skb)->data_offset +
skb->head - (unsigned char *)uh);
} else {
uh->len = htons(len);
}
if (!need_csum)
continue;
uh->check = ~csum_fold(csum_add(partial,
(__force __wsum)htonl(len)));
if (skb->encapsulation || !offload_csum) {
uh->check = gso_make_checksum(skb, ~uh->check);
if (uh->check == 0)
uh->check = CSUM_MANGLED_0;
} else {
skb->ip_summed = CHECKSUM_PARTIAL;
skb->csum_start = skb_transport_header(skb) - skb->head;
skb->csum_offset = offsetof(struct udphdr, check);
}
} while ((skb = skb->next));
out:
return segs;
}
u16 bpf_pseudo_csum_replace4(u16 csum, u32 from, u32 to)
{
u32 diff[] = { ~from, to };
return ~csum_fold(csum_partial(diff, sizeof(diff),
csum_unfold(csum)));
}
