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150 lines
3.8 KiB
150 lines
3.8 KiB
// 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 rtable sch_frag_rt = { 0 }; |
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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_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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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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