mirror of
https://github.com/openvswitch/ovs
synced 2025-10-25 15:07:05 +00:00
213e1f54b4
Most kernels provide some form of ip fragmentation. However, until recently many of them would always send ICMP responses for over_MTU packets, even when operating in bridge mode. Backport the check to ensure this doesn't occur. Signed-off-by: Joe Stringer <joestringer@nicira.com> Acked-by: Pravin B Shelar <pshelar@nicira.com>
111 lines
2.8 KiB
C
111 lines
2.8 KiB
C
#ifndef __NET_IP_WRAPPER_H
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#define __NET_IP_WRAPPER_H 1
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#include_next <net/ip.h>
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#include <net/route.h>
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#include <linux/version.h>
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#ifndef HAVE_IP_IS_FRAGMENT
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static inline bool ip_is_fragment(const struct iphdr *iph)
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{
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return (iph->frag_off & htons(IP_MF | IP_OFFSET)) != 0;
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}
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#endif
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#ifndef HAVE_INET_GET_LOCAL_PORT_RANGE_USING_NET
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static inline void rpl_inet_get_local_port_range(struct net *net, int *low,
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int *high)
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{
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inet_get_local_port_range(low, high);
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}
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#define inet_get_local_port_range rpl_inet_get_local_port_range
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#endif
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/* IPv4 datagram length is stored into 16bit field (tot_len) */
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#ifndef IP_MAX_MTU
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#define IP_MAX_MTU 0xFFFFU
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#endif
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#ifndef HAVE_IP_SKB_DST_MTU
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static inline bool rpl_ip_sk_use_pmtu(const struct sock *sk)
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{
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return inet_sk(sk)->pmtudisc < IP_PMTUDISC_PROBE;
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}
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#define ip_sk_use_pmtu rpl_ip_sk_use_pmtu
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static inline unsigned int ip_dst_mtu_maybe_forward(const struct dst_entry *dst,
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bool forwarding)
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{
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#if LINUX_VERSION_CODE >= KERNEL_VERSION(3,14,0)
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struct net *net = dev_net(dst->dev);
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if (net->ipv4.sysctl_ip_fwd_use_pmtu ||
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dst_metric_locked(dst, RTAX_MTU) ||
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!forwarding)
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return dst_mtu(dst);
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#endif
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return min(dst->dev->mtu, IP_MAX_MTU);
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}
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static inline unsigned int rpl_ip_skb_dst_mtu(const struct sk_buff *skb)
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{
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if (!skb->sk || ip_sk_use_pmtu(skb->sk)) {
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bool forwarding = IPCB(skb)->flags & IPSKB_FORWARDED;
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return ip_dst_mtu_maybe_forward(skb_dst(skb), forwarding);
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} else {
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return min(skb_dst(skb)->dev->mtu, IP_MAX_MTU);
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}
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}
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#define ip_skb_dst_mtu rpl_ip_skb_dst_mtu
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#endif /* HAVE_IP_SKB_DST_MTU */
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#ifdef HAVE_IP_FRAGMENT_TAKES_SOCK
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#define OVS_VPORT_OUTPUT_PARAMS struct sock *sock, struct sk_buff *skb
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#else
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#define OVS_VPORT_OUTPUT_PARAMS struct sk_buff *skb
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#endif
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#ifdef OVS_FRAGMENT_BACKPORT
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#if LINUX_VERSION_CODE < KERNEL_VERSION(4,2,0)
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static inline bool ip_defrag_user_in_between(u32 user,
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enum ip_defrag_users lower_bond,
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enum ip_defrag_users upper_bond)
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{
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return user >= lower_bond && user <= upper_bond;
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}
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#endif
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#ifndef HAVE_IP_DO_FRAGMENT
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static inline int rpl_ip_do_fragment(struct sock *sk, struct sk_buff *skb,
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int (*output)(OVS_VPORT_OUTPUT_PARAMS))
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{
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unsigned int mtu = ip_skb_dst_mtu(skb);
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struct iphdr *iph = ip_hdr(skb);
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struct rtable *rt = skb_rtable(skb);
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struct net_device *dev = rt->dst.dev;
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if (unlikely(((iph->frag_off & htons(IP_DF)) && !skb->ignore_df) ||
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(IPCB(skb)->frag_max_size &&
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IPCB(skb)->frag_max_size > mtu))) {
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pr_warn("Dropping packet in ip_do_fragment()\n");
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IP_INC_STATS(dev_net(dev), IPSTATS_MIB_FRAGFAILS);
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kfree_skb(skb);
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return -EMSGSIZE;
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}
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#ifndef HAVE_IP_FRAGMENT_TAKES_SOCK
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return ip_fragment(skb, output);
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#else
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return ip_fragment(sk, skb, output);
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#endif
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}
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#define ip_do_fragment rpl_ip_do_fragment
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#endif /* IP_DO_FRAGMENT */
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#endif /* OVS_FRAGMENT_BACKPORT */
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#endif
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