summaryrefslogtreecommitdiffstats
path: root/net/sched/sch_frag.c
diff options
context:
space:
mode:
Diffstat (limited to 'net/sched/sch_frag.c')
-rw-r--r--net/sched/sch_frag.c152
1 files changed, 152 insertions, 0 deletions
diff --git a/net/sched/sch_frag.c b/net/sched/sch_frag.c
new file mode 100644
index 000000000..a9bd0a235
--- /dev/null
+++ b/net/sched/sch_frag.c
@@ -0,0 +1,152 @@
+// SPDX-License-Identifier: GPL-2.0 OR Linux-OpenIB
+#include <linux/if_vlan.h>
+#include <net/netlink.h>
+#include <net/sch_generic.h>
+#include <net/pkt_sched.h>
+#include <net/dst.h>
+#include <net/ip.h>
+#include <net/ip6_fib.h>
+
+struct sch_frag_data {
+ unsigned long dst;
+ struct qdisc_skb_cb cb;
+ __be16 inner_protocol;
+ u16 vlan_tci;
+ __be16 vlan_proto;
+ unsigned int l2_len;
+ u8 l2_data[VLAN_ETH_HLEN];
+ int (*xmit)(struct sk_buff *skb);
+};
+
+static DEFINE_PER_CPU(struct sch_frag_data, sch_frag_data_storage);
+
+static int sch_frag_xmit(struct net *net, struct sock *sk, struct sk_buff *skb)
+{
+ struct sch_frag_data *data = this_cpu_ptr(&sch_frag_data_storage);
+
+ if (skb_cow_head(skb, data->l2_len) < 0) {
+ kfree_skb(skb);
+ return -ENOMEM;
+ }
+
+ __skb_dst_copy(skb, data->dst);
+ *qdisc_skb_cb(skb) = data->cb;
+ skb->inner_protocol = data->inner_protocol;
+ if (data->vlan_tci & VLAN_CFI_MASK)
+ __vlan_hwaccel_put_tag(skb, data->vlan_proto,
+ data->vlan_tci & ~VLAN_CFI_MASK);
+ else
+ __vlan_hwaccel_clear_tag(skb);
+
+ /* Reconstruct the MAC header. */
+ skb_push(skb, data->l2_len);
+ memcpy(skb->data, &data->l2_data, data->l2_len);
+ skb_postpush_rcsum(skb, skb->data, data->l2_len);
+ skb_reset_mac_header(skb);
+
+ return data->xmit(skb);
+}
+
+static void sch_frag_prepare_frag(struct sk_buff *skb,
+ int (*xmit)(struct sk_buff *skb))
+{
+ unsigned int hlen = skb_network_offset(skb);
+ struct sch_frag_data *data;
+
+ data = this_cpu_ptr(&sch_frag_data_storage);
+ data->dst = skb->_skb_refdst;
+ data->cb = *qdisc_skb_cb(skb);
+ data->xmit = xmit;
+ data->inner_protocol = skb->inner_protocol;
+ if (skb_vlan_tag_present(skb))
+ data->vlan_tci = skb_vlan_tag_get(skb) | VLAN_CFI_MASK;
+ else
+ data->vlan_tci = 0;
+ data->vlan_proto = skb->vlan_proto;
+ data->l2_len = hlen;
+ memcpy(&data->l2_data, skb->data, hlen);
+
+ memset(IPCB(skb), 0, sizeof(struct inet_skb_parm));
+ skb_pull(skb, hlen);
+}
+
+static unsigned int
+sch_frag_dst_get_mtu(const struct dst_entry *dst)
+{
+ return dst->dev->mtu;
+}
+
+static struct dst_ops sch_frag_dst_ops = {
+ .family = AF_UNSPEC,
+ .mtu = sch_frag_dst_get_mtu,
+};
+
+static int sch_fragment(struct net *net, struct sk_buff *skb,
+ u16 mru, int (*xmit)(struct sk_buff *skb))
+{
+ int ret = -1;
+
+ if (skb_network_offset(skb) > VLAN_ETH_HLEN) {
+ net_warn_ratelimited("L2 header too long to fragment\n");
+ goto err;
+ }
+
+ if (skb_protocol(skb, true) == htons(ETH_P_IP)) {
+ struct rtable sch_frag_rt = { 0 };
+ unsigned long orig_dst;
+
+ sch_frag_prepare_frag(skb, xmit);
+ dst_init(&sch_frag_rt.dst, &sch_frag_dst_ops, NULL, 1,
+ DST_OBSOLETE_NONE, DST_NOCOUNT);
+ sch_frag_rt.dst.dev = skb->dev;
+
+ orig_dst = skb->_skb_refdst;
+ skb_dst_set_noref(skb, &sch_frag_rt.dst);
+ IPCB(skb)->frag_max_size = mru;
+
+ ret = ip_do_fragment(net, skb->sk, skb, sch_frag_xmit);
+ refdst_drop(orig_dst);
+ } else if (skb_protocol(skb, true) == htons(ETH_P_IPV6)) {
+ unsigned long orig_dst;
+ struct rt6_info sch_frag_rt;
+
+ sch_frag_prepare_frag(skb, xmit);
+ memset(&sch_frag_rt, 0, sizeof(sch_frag_rt));
+ dst_init(&sch_frag_rt.dst, &sch_frag_dst_ops, NULL, 1,
+ DST_OBSOLETE_NONE, DST_NOCOUNT);
+ sch_frag_rt.dst.dev = skb->dev;
+
+ orig_dst = skb->_skb_refdst;
+ skb_dst_set_noref(skb, &sch_frag_rt.dst);
+ IP6CB(skb)->frag_max_size = mru;
+
+ ret = ipv6_stub->ipv6_fragment(net, skb->sk, skb,
+ sch_frag_xmit);
+ refdst_drop(orig_dst);
+ } else {
+ net_warn_ratelimited("Fail frag %s: eth=%x, MRU=%d, MTU=%d\n",
+ netdev_name(skb->dev),
+ ntohs(skb_protocol(skb, true)), mru,
+ skb->dev->mtu);
+ goto err;
+ }
+
+ return ret;
+err:
+ kfree_skb(skb);
+ return ret;
+}
+
+int sch_frag_xmit_hook(struct sk_buff *skb, int (*xmit)(struct sk_buff *skb))
+{
+ u16 mru = tc_skb_cb(skb)->mru;
+ int err;
+
+ if (mru && skb->len > mru + skb->dev->hard_header_len)
+ err = sch_fragment(dev_net(skb->dev), skb, mru, xmit);
+ else
+ err = xmit(skb);
+
+ return err;
+}
+EXPORT_SYMBOL_GPL(sch_frag_xmit_hook);