Need to define a gtp_gso_segment since the GTP header includes a length
field that must be set per packet. Also, GPv0 header includes a sequence
number that is incremented per packet.
Signed-off-by: Tom Herbert <t...@quantonium.net>
---
drivers/net/gtp.c | 176 +++++++++++++++++++++++++++++++++++++++----
include/uapi/linux/if_link.h | 1 -
2 files changed, 163 insertions(+), 14 deletions(-)
diff --git a/drivers/net/gtp.c b/drivers/net/gtp.c
index 2f9d810cf19f..a2c4d9804a8f 100644
--- a/drivers/net/gtp.c
+++ b/drivers/net/gtp.c
@@ -120,6 +120,8 @@ static u32 gtp_h_initval;
static void pdp_context_delete(struct pdp_ctx *pctx);
+static int gtp_gso_type;
+
static inline u32 gtp0_hashfn(u64 tid)
{
u32 *tid32 = (u32 *) &tid;
@@ -430,6 +432,69 @@ static int gtp1u_udp_encap_recv(struct sock *sk, struct
sk_buff *skb)
return 1;
}
+static struct sk_buff *gtp_gso_segment(struct sk_buff *skb,
+ netdev_features_t features)
+{
+ struct sk_buff *segs = ERR_PTR(-EINVAL);
+ int tnl_hlen = skb->mac_len;
+ struct gtp0_header *gtp0;
+
+ if (unlikely(!pskb_may_pull(skb, tnl_hlen)))
+ return ERR_PTR(-EINVAL);
+
+ /* Make sure we have a mininal GTP header */
+ if (unlikely(tnl_hlen < min_t(size_t, sizeof(struct gtp0_header),
+ sizeof(struct gtp1_header))))
+ return ERR_PTR(-EINVAL);
+
+ /* Determine version */
+ gtp0 = (struct gtp0_header *)skb->data;
+ switch (gtp0->flags >> 5) {
+ case GTP_V0: {
+ u16 tx_seq;
+
+ if (unlikely(tnl_hlen != sizeof(struct gtp0_header)))
+ return ERR_PTR(-EINVAL);
+
+ tx_seq = ntohs(gtp0->seq);
+
+ /* segment inner packet. */
+ segs = skb_mac_gso_segment(skb, features);
+ if (!IS_ERR_OR_NULL(segs)) {
+ skb = segs;
+ do {
+ gtp0 = (struct gtp0_header *)
+ skb_mac_header(skb);
+ gtp0->length = ntohs(skb->len - tnl_hlen);
+ gtp0->seq = htons(tx_seq);
+ tx_seq++;
+ } while ((skb = skb->next));
+ }
+ break;
+ }
+ case GTP_V1: {
+ struct gtp1_header *gtp1;
+
+ if (unlikely(tnl_hlen != sizeof(struct gtp1_header)))
+ return ERR_PTR(-EINVAL);
+
+ /* segment inner packet. */
+ segs = skb_mac_gso_segment(skb, features);
+ if (!IS_ERR_OR_NULL(segs)) {
+ skb = segs;
+ do {
+ gtp1 = (struct gtp1_header *)
+ skb_mac_header(skb);
+ gtp1->length = ntohs(skb->len - tnl_hlen);
+ } while ((skb = skb->next));
+ }
+ break;
+ }
+ }
+
+ return segs;
+}
+
static struct sk_buff **gtp_gro_receive_finish(struct sock *sk,
struct sk_buff **head,
struct sk_buff *skb,
@@ -688,18 +753,25 @@ static inline void gtp0_push_header(struct sk_buff *skb,
struct pdp_ctx *pctx)
{
int payload_len = skb->len;
struct gtp0_header *gtp0;
+ u32 tx_seq;
gtp0 = skb_push(skb, sizeof(*gtp0));
gtp0->flags = 0x1e; /* v0, GTP-non-prime. */
gtp0->type = GTP_TPDU;
gtp0->length = htons(payload_len);
- gtp0->seq = htons((atomic_inc_return(&pctx->tx_seq) - 1) %
- 0xffff);
gtp0->flow = htons(pctx->u.v0.flow);
gtp0->number = 0xff;
gtp0->spare[0] = gtp0->spare[1] = gtp0->spare[2] = 0xff;
gtp0->tid = cpu_to_be64(pctx->u.v0.tid);
+
+ /* If skb is GSO allocate sequence numbers for all the segments */
+ tx_seq = skb_shinfo(skb)->gso_segs ?
+ atomic_add_return(skb_shinfo(skb)->gso_segs,
+ &pctx->tx_seq) :
+ atomic_inc_return(&pctx->tx_seq);
+
+ gtp0->seq = (htons((u16)tx_seq) - 1) & 0xffff;
}
static inline void gtp1_push_header(struct sk_buff *skb, struct pdp_ctx *pctx)
@@ -737,6 +809,59 @@ static void gtp_push_header(struct sk_buff *skb, struct
pdp_ctx *pctx)
}
}
+static size_t gtp_max_header_len(int version)
+
+{
+ switch (version) {
+ case GTP_V0:
+ return sizeof(struct gtp0_header);
+ case GTP_V1:
+ return sizeof(struct gtp1_header) + 4;
+ }
+
+ /* Should not happen */
+ return 0;
+}
+
+static int gtp_build_skb(struct sk_buff *skb, struct dst_entry *dst,
+ struct pdp_ctx *pctx, bool xnet, int ip_hdr_len,
+ bool udp_sum)
+{
+ int type = (udp_sum ? SKB_GSO_UDP_TUNNEL_CSUM : SKB_GSO_UDP_TUNNEL) |
+ gtp_gso_type;
+ int min_headroom;
+ u16 protocol;
+ int err;
+
+ skb_scrub_packet(skb, xnet);
+
+ min_headroom = LL_RESERVED_SPACE(dst->dev) + dst->header_len +
+ gtp_max_header_len(pctx->gtp_version) + ip_hdr_len;
+
+ err = skb_cow_head(skb, min_headroom);
+ if (unlikely(err))
+ goto free_dst;
+
+ err = iptunnel_handle_offloads(skb, type);
+ if (err)
+ goto free_dst;
+
+ protocol = ipver_to_eth(ip_hdr(skb));
+
+ gtp_push_header(skb, pctx);
+
+ /* GTP header is treated as inner MAC header */
+ skb_reset_inner_mac_header(skb);
+
+ skb_set_inner_protocol(skb, protocol);
+
+ return 0;
+
+free_dst:
+ dst_release(dst);
+ return err;
+}
+
static int gtp_xmit(struct sk_buff *skb, struct net_device *dev,
struct pdp_ctx *pctx)
{
@@ -746,13 +871,6 @@ static int gtp_xmit(struct sk_buff *skb, struct net_device
*dev,
bool udp_csum;
int err = 0;
- /* Ensure there is sufficient headroom. */
- err = skb_cow_head(skb, dev->needed_headroom);
- if (unlikely(err))
- goto out_err;
-
- skb_reset_inner_headers(skb);
-
if (pctx->peer_af == AF_INET) {
__be32 saddr = inet_sk(sk)->inet_saddr;
struct rtable *rt;
@@ -768,9 +886,13 @@ static int gtp_xmit(struct sk_buff *skb, struct net_device
*dev,
goto out_err;
}
- skb_dst_drop(skb);
+ err = gtp_build_skb(skb, &rt->dst, pctx, xnet,
+ sizeof(struct iphdr),
+ !(pctx->cfg_flags &
+ GTP_F_UDP_ZERO_CSUM_TX));
+ if (err)
+ goto out_err;
- gtp_push_header(skb, pctx);
udp_csum = !(pctx->cfg_flags & GTP_F_UDP_ZERO_CSUM_TX);
udp_tunnel_xmit_skb(rt, sk, skb, saddr,
pctx->peer_addr_ip4.s_addr,
@@ -797,9 +919,13 @@ static int gtp_xmit(struct sk_buff *skb, struct net_device
*dev,
goto out_err;
}
- skb_dst_drop(skb);
+ err = gtp_build_skb(skb, dst, pctx, xnet,
+ sizeof(struct ipv6hdr),
+ !(pctx->cfg_flags &
+ GTP_F_UDP_ZERO_CSUM6_TX));
+ if (err)
+ goto out_err;
- gtp_push_header(skb, pctx);
udp_csum = !(pctx->cfg_flags & GTP_F_UDP_ZERO_CSUM6_TX);
udp_tunnel6_xmit_skb(dst, sk, skb, dev,
&saddr, &pctx->peer_addr_ip6,
@@ -898,6 +1024,12 @@ static const struct net_device_ops gtp_netdev_ops = {
.ndo_get_stats64 = ip_tunnel_get_stats64,
};
+#define GTP_FEATURES (NETIF_F_SG | \
+ NETIF_F_FRAGLIST | \
+ NETIF_F_HIGHDMA | \
+ NETIF_F_GSO_SOFTWARE | \
+ NETIF_F_HW_CSUM)
+
static void gtp_link_setup(struct net_device *dev)
{
struct gtp_dev *gtp = netdev_priv(dev);
@@ -912,7 +1044,13 @@ static void gtp_link_setup(struct net_device *dev)
dev->flags = IFF_POINTOPOINT | IFF_NOARP | IFF_MULTICAST;
dev->priv_flags |= IFF_NO_QUEUE;
+
dev->features |= NETIF_F_LLTX;
+ dev->features |= GTP_FEATURES;
+
+ dev->hw_features |= GTP_FEATURES;
+ dev->hw_features |= NETIF_F_GSO_SOFTWARE;
+
netif_keep_dst(dev);
/* Assume largest header, ie. GTPv0. */
@@ -1903,6 +2041,11 @@ static struct pernet_operations gtp_net_ops = {
.size = sizeof(struct gtp_net),
};
+static const struct skb_gso_app gtp_gso_app = {
+ .check_flags = SKB_GSO_UDP_TUNNEL | SKB_GSO_UDP_TUNNEL_CSUM,
+ .gso_segment = gtp_gso_segment,
+};
+
static int __init gtp_init(void)
{
int err;
@@ -1921,6 +2064,10 @@ static int __init gtp_init(void)
if (err < 0)
goto unreg_genl_family;
+ gtp_gso_type = skb_gso_app_register(>p_gso_app);
+ if (!gtp_gso_type)
+ pr_warn("GTP unable to create UDP app gso type");
+
pr_info("GTP module loaded (pdp ctx size %zd bytes)\n",
sizeof(struct pdp_ctx));
return 0;
@@ -1937,6 +2084,9 @@ late_initcall(gtp_init);
static void __exit gtp_fini(void)
{
+ if (gtp_gso_type)
+ skb_gso_app_unregister(gtp_gso_type, >p_gso_app);
+
unregister_pernet_subsys(>p_net_ops);
genl_unregister_family(>p_genl_family);
rtnl_link_unregister(>p_link_ops);
diff --git a/include/uapi/linux/if_link.h b/include/uapi/linux/if_link.h
index 14a32d745e24..7c15db44eab3 100644
--- a/include/uapi/linux/if_link.h
+++ b/include/uapi/linux/if_link.h
@@ -558,7 +558,6 @@ enum {
IFLA_GTP_UDP_CSUM,
IFLA_GTP_UDP_ZERO_CSUM6_TX,
IFLA_GTP_UDP_ZERO_CSUM6_RX,
-
__IFLA_GTP_MAX,
};
#define IFLA_GTP_MAX (__IFLA_GTP_MAX - 1)
--
2.11.0
