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![Balazs Nemeth](/assets/img/avatar_default.png)
A packet with skb_inner_network_header(skb) == skb_network_header(skb) and ETH_P_MPLS_UC will prevent mpls_gso_segment from pulling any headers from the packet. Subsequently, the call to skb_mac_gso_segment will again call mpls_gso_segment with the same packet leading to an infinite loop. In addition, ensure that the header length is a multiple of four, which should hold irrespective of the number of stacked labels. Signed-off-by: Balazs Nemeth <bnemeth@redhat.com> Acked-by: Willem de Bruijn <willemb@google.com> Reviewed-by: David Ahern <dsahern@kernel.org> Signed-off-by: David S. Miller <davem@davemloft.net>
109 lines
2.4 KiB
C
109 lines
2.4 KiB
C
// SPDX-License-Identifier: GPL-2.0-or-later
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/*
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* MPLS GSO Support
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*
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* Authors: Simon Horman (horms@verge.net.au)
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*
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* Based on: GSO portions of net/ipv4/gre.c
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*/
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#define pr_fmt(fmt) KBUILD_MODNAME ": " fmt
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#include <linux/err.h>
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#include <linux/module.h>
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#include <linux/netdev_features.h>
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#include <linux/netdevice.h>
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#include <linux/skbuff.h>
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#include <net/mpls.h>
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static struct sk_buff *mpls_gso_segment(struct sk_buff *skb,
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netdev_features_t features)
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{
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struct sk_buff *segs = ERR_PTR(-EINVAL);
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u16 mac_offset = skb->mac_header;
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netdev_features_t mpls_features;
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u16 mac_len = skb->mac_len;
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__be16 mpls_protocol;
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unsigned int mpls_hlen;
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skb_reset_network_header(skb);
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mpls_hlen = skb_inner_network_header(skb) - skb_network_header(skb);
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if (unlikely(!mpls_hlen || mpls_hlen % MPLS_HLEN))
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goto out;
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if (unlikely(!pskb_may_pull(skb, mpls_hlen)))
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goto out;
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/* Setup inner SKB. */
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mpls_protocol = skb->protocol;
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skb->protocol = skb->inner_protocol;
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__skb_pull(skb, mpls_hlen);
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skb->mac_len = 0;
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skb_reset_mac_header(skb);
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/* Segment inner packet. */
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mpls_features = skb->dev->mpls_features & features;
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segs = skb_mac_gso_segment(skb, mpls_features);
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if (IS_ERR_OR_NULL(segs)) {
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skb_gso_error_unwind(skb, mpls_protocol, mpls_hlen, mac_offset,
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mac_len);
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goto out;
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}
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skb = segs;
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mpls_hlen += mac_len;
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do {
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skb->mac_len = mac_len;
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skb->protocol = mpls_protocol;
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skb_reset_inner_network_header(skb);
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__skb_push(skb, mpls_hlen);
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skb_reset_mac_header(skb);
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skb_set_network_header(skb, mac_len);
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} while ((skb = skb->next));
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out:
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return segs;
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}
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static struct packet_offload mpls_mc_offload __read_mostly = {
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.type = cpu_to_be16(ETH_P_MPLS_MC),
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.priority = 15,
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.callbacks = {
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.gso_segment = mpls_gso_segment,
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},
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};
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static struct packet_offload mpls_uc_offload __read_mostly = {
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.type = cpu_to_be16(ETH_P_MPLS_UC),
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.priority = 15,
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.callbacks = {
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.gso_segment = mpls_gso_segment,
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},
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};
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static int __init mpls_gso_init(void)
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{
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pr_info("MPLS GSO support\n");
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dev_add_offload(&mpls_uc_offload);
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dev_add_offload(&mpls_mc_offload);
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return 0;
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}
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static void __exit mpls_gso_exit(void)
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{
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dev_remove_offload(&mpls_uc_offload);
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dev_remove_offload(&mpls_mc_offload);
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}
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module_init(mpls_gso_init);
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module_exit(mpls_gso_exit);
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MODULE_DESCRIPTION("MPLS GSO support");
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MODULE_AUTHOR("Simon Horman (horms@verge.net.au)");
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MODULE_LICENSE("GPL");
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