151 строка
3.8 KiB
C
151 строка
3.8 KiB
C
// SPDX-License-Identifier: GPL-2.0 OR Linux-OpenIB
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#include <net/netlink.h>
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#include <net/sch_generic.h>
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#include <net/dst.h>
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#include <net/ip.h>
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#include <net/ip6_fib.h>
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struct sch_frag_data {
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unsigned long dst;
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struct qdisc_skb_cb cb;
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__be16 inner_protocol;
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u16 vlan_tci;
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__be16 vlan_proto;
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unsigned int l2_len;
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u8 l2_data[VLAN_ETH_HLEN];
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int (*xmit)(struct sk_buff *skb);
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};
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static DEFINE_PER_CPU(struct sch_frag_data, sch_frag_data_storage);
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static int sch_frag_xmit(struct net *net, struct sock *sk, struct sk_buff *skb)
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{
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struct sch_frag_data *data = this_cpu_ptr(&sch_frag_data_storage);
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if (skb_cow_head(skb, data->l2_len) < 0) {
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kfree_skb(skb);
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return -ENOMEM;
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}
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__skb_dst_copy(skb, data->dst);
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*qdisc_skb_cb(skb) = data->cb;
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skb->inner_protocol = data->inner_protocol;
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if (data->vlan_tci & VLAN_CFI_MASK)
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__vlan_hwaccel_put_tag(skb, data->vlan_proto,
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data->vlan_tci & ~VLAN_CFI_MASK);
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else
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__vlan_hwaccel_clear_tag(skb);
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/* Reconstruct the MAC header. */
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skb_push(skb, data->l2_len);
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memcpy(skb->data, &data->l2_data, data->l2_len);
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skb_postpush_rcsum(skb, skb->data, data->l2_len);
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skb_reset_mac_header(skb);
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return data->xmit(skb);
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}
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static void sch_frag_prepare_frag(struct sk_buff *skb,
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int (*xmit)(struct sk_buff *skb))
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{
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unsigned int hlen = skb_network_offset(skb);
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struct sch_frag_data *data;
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data = this_cpu_ptr(&sch_frag_data_storage);
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data->dst = skb->_skb_refdst;
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data->cb = *qdisc_skb_cb(skb);
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data->xmit = xmit;
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data->inner_protocol = skb->inner_protocol;
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if (skb_vlan_tag_present(skb))
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data->vlan_tci = skb_vlan_tag_get(skb) | VLAN_CFI_MASK;
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else
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data->vlan_tci = 0;
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data->vlan_proto = skb->vlan_proto;
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data->l2_len = hlen;
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memcpy(&data->l2_data, skb->data, hlen);
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memset(IPCB(skb), 0, sizeof(struct inet_skb_parm));
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skb_pull(skb, hlen);
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}
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static unsigned int
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sch_frag_dst_get_mtu(const struct dst_entry *dst)
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{
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return dst->dev->mtu;
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}
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static struct dst_ops sch_frag_dst_ops = {
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.family = AF_UNSPEC,
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.mtu = sch_frag_dst_get_mtu,
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};
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static int sch_fragment(struct net *net, struct sk_buff *skb,
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u16 mru, int (*xmit)(struct sk_buff *skb))
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{
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int ret = -1;
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if (skb_network_offset(skb) > VLAN_ETH_HLEN) {
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net_warn_ratelimited("L2 header too long to fragment\n");
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goto err;
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}
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if (skb_protocol(skb, true) == htons(ETH_P_IP)) {
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struct dst_entry sch_frag_dst;
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unsigned long orig_dst;
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sch_frag_prepare_frag(skb, xmit);
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dst_init(&sch_frag_dst, &sch_frag_dst_ops, NULL, 1,
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DST_OBSOLETE_NONE, DST_NOCOUNT);
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sch_frag_dst.dev = skb->dev;
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orig_dst = skb->_skb_refdst;
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skb_dst_set_noref(skb, &sch_frag_dst);
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IPCB(skb)->frag_max_size = mru;
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ret = ip_do_fragment(net, skb->sk, skb, sch_frag_xmit);
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refdst_drop(orig_dst);
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} else if (skb_protocol(skb, true) == htons(ETH_P_IPV6)) {
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unsigned long orig_dst;
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struct rt6_info sch_frag_rt;
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sch_frag_prepare_frag(skb, xmit);
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memset(&sch_frag_rt, 0, sizeof(sch_frag_rt));
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dst_init(&sch_frag_rt.dst, &sch_frag_dst_ops, NULL, 1,
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DST_OBSOLETE_NONE, DST_NOCOUNT);
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sch_frag_rt.dst.dev = skb->dev;
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orig_dst = skb->_skb_refdst;
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skb_dst_set_noref(skb, &sch_frag_rt.dst);
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IP6CB(skb)->frag_max_size = mru;
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ret = ipv6_stub->ipv6_fragment(net, skb->sk, skb,
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sch_frag_xmit);
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refdst_drop(orig_dst);
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} else {
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net_warn_ratelimited("Fail frag %s: eth=%x, MRU=%d, MTU=%d\n",
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netdev_name(skb->dev),
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ntohs(skb_protocol(skb, true)), mru,
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skb->dev->mtu);
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goto err;
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}
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return ret;
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err:
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kfree_skb(skb);
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return ret;
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}
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int sch_frag_xmit_hook(struct sk_buff *skb, int (*xmit)(struct sk_buff *skb))
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{
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u16 mru = qdisc_skb_cb(skb)->mru;
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int err;
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if (mru && skb->len > mru + skb->dev->hard_header_len)
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err = sch_fragment(dev_net(skb->dev), skb, mru, xmit);
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else
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err = xmit(skb);
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return err;
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}
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EXPORT_SYMBOL_GPL(sch_frag_xmit_hook);
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