summaryrefslogtreecommitdiff
path: root/net/ipv6
diff options
context:
space:
mode:
Diffstat (limited to 'net/ipv6')
-rw-r--r--net/ipv6/output_core.c31
-rw-r--r--net/ipv6/udp_offload.c85
2 files changed, 113 insertions, 3 deletions
diff --git a/net/ipv6/output_core.c b/net/ipv6/output_core.c
index 4a7e5ffa5108..4fe7c90962dd 100644
--- a/net/ipv6/output_core.c
+++ b/net/ipv6/output_core.c
@@ -31,6 +31,37 @@ static u32 __ipv6_select_ident(struct net *net, u32 hashrnd,
return id;
}
+/* This function exists only for tap drivers that must support broken
+ * clients requesting UFO without specifying an IPv6 fragment ID.
+ *
+ * This is similar to ipv6_select_ident() but we use an independent hash
+ * seed to limit information leakage.
+ *
+ * The network header must be set before calling this.
+ */
+__be32 ipv6_proxy_select_ident(struct net *net, struct sk_buff *skb)
+{
+ static u32 ip6_proxy_idents_hashrnd __read_mostly;
+ struct in6_addr buf[2];
+ struct in6_addr *addrs;
+ u32 id;
+
+ addrs = skb_header_pointer(skb,
+ skb_network_offset(skb) +
+ offsetof(struct ipv6hdr, saddr),
+ sizeof(buf), buf);
+ if (!addrs)
+ return 0;
+
+ net_get_random_once(&ip6_proxy_idents_hashrnd,
+ sizeof(ip6_proxy_idents_hashrnd));
+
+ id = __ipv6_select_ident(net, ip6_proxy_idents_hashrnd,
+ &addrs[1], &addrs[0]);
+ return htonl(id);
+}
+EXPORT_SYMBOL_GPL(ipv6_proxy_select_ident);
+
__be32 ipv6_select_ident(struct net *net,
const struct in6_addr *daddr,
const struct in6_addr *saddr)
diff --git a/net/ipv6/udp_offload.c b/net/ipv6/udp_offload.c
index 455fd4e39333..a0f89ad76f9d 100644
--- a/net/ipv6/udp_offload.c
+++ b/net/ipv6/udp_offload.c
@@ -17,15 +17,94 @@
#include <net/ip6_checksum.h>
#include "ip6_offload.h"
-static struct sk_buff *udp6_tunnel_segment(struct sk_buff *skb,
- netdev_features_t features)
+static struct sk_buff *udp6_ufo_fragment(struct sk_buff *skb,
+ netdev_features_t features)
{
struct sk_buff *segs = ERR_PTR(-EINVAL);
+ unsigned int mss;
+ unsigned int unfrag_ip6hlen, unfrag_len;
+ struct frag_hdr *fptr;
+ u8 *packet_start, *prevhdr;
+ u8 nexthdr;
+ u8 frag_hdr_sz = sizeof(struct frag_hdr);
+ __wsum csum;
+ int tnl_hlen;
+ int err;
+
+ mss = skb_shinfo(skb)->gso_size;
+ if (unlikely(skb->len <= mss))
+ goto out;
if (skb->encapsulation && skb_shinfo(skb)->gso_type &
(SKB_GSO_UDP_TUNNEL|SKB_GSO_UDP_TUNNEL_CSUM))
segs = skb_udp_tunnel_segment(skb, features, true);
+ else {
+ const struct ipv6hdr *ipv6h;
+ struct udphdr *uh;
+
+ if (!pskb_may_pull(skb, sizeof(struct udphdr)))
+ goto out;
+
+ /* Do software UFO. Complete and fill in the UDP checksum as HW cannot
+ * do checksum of UDP packets sent as multiple IP fragments.
+ */
+
+ uh = udp_hdr(skb);
+ ipv6h = ipv6_hdr(skb);
+
+ uh->check = 0;
+ csum = skb_checksum(skb, 0, skb->len, 0);
+ uh->check = udp_v6_check(skb->len, &ipv6h->saddr,
+ &ipv6h->daddr, csum);
+ if (uh->check == 0)
+ uh->check = CSUM_MANGLED_0;
+
+ skb->ip_summed = CHECKSUM_UNNECESSARY;
+
+ /* If there is no outer header we can fake a checksum offload
+ * due to the fact that we have already done the checksum in
+ * software prior to segmenting the frame.
+ */
+ if (!skb->encap_hdr_csum)
+ features |= NETIF_F_HW_CSUM;
+
+ /* Check if there is enough headroom to insert fragment header. */
+ tnl_hlen = skb_tnl_header_len(skb);
+ if (skb->mac_header < (tnl_hlen + frag_hdr_sz)) {
+ if (gso_pskb_expand_head(skb, tnl_hlen + frag_hdr_sz))
+ goto out;
+ }
+
+ /* Find the unfragmentable header and shift it left by frag_hdr_sz
+ * bytes to insert fragment header.
+ */
+ err = ip6_find_1stfragopt(skb, &prevhdr);
+ if (err < 0)
+ return ERR_PTR(err);
+ unfrag_ip6hlen = err;
+ nexthdr = *prevhdr;
+ *prevhdr = NEXTHDR_FRAGMENT;
+ unfrag_len = (skb_network_header(skb) - skb_mac_header(skb)) +
+ unfrag_ip6hlen + tnl_hlen;
+ packet_start = (u8 *) skb->head + SKB_GSO_CB(skb)->mac_offset;
+ memmove(packet_start-frag_hdr_sz, packet_start, unfrag_len);
+
+ SKB_GSO_CB(skb)->mac_offset -= frag_hdr_sz;
+ skb->mac_header -= frag_hdr_sz;
+ skb->network_header -= frag_hdr_sz;
+
+ fptr = (struct frag_hdr *)(skb_network_header(skb) + unfrag_ip6hlen);
+ fptr->nexthdr = nexthdr;
+ fptr->reserved = 0;
+ fptr->identification = ipv6_proxy_select_ident(dev_net(skb->dev), skb);
+
+ /* Fragment the skb. ipv6 header and the remaining fields of the
+ * fragment header are updated in ipv6_gso_segment()
+ */
+ segs = skb_segment(skb, features);
+ }
+out:
return segs;
}
@@ -75,7 +154,7 @@ static int udp6_gro_complete(struct sk_buff *skb, int nhoff)
static const struct net_offload udpv6_offload = {
.callbacks = {
- .gso_segment = udp6_tunnel_segment,
+ .gso_segment = udp6_ufo_fragment,
.gro_receive = udp6_gro_receive,
.gro_complete = udp6_gro_complete,
},