forked from luck/tmp_suning_uos_patched
d7bf2ebebc
There are a couple of places in net/sched/ that check skb->protocol and act
on the value there. However, in the presence of VLAN tags, the value stored
in skb->protocol can be inconsistent based on whether VLAN acceleration is
enabled. The commit quoted in the Fixes tag below fixed the users of
skb->protocol to use a helper that will always see the VLAN ethertype.
However, most of the callers don't actually handle the VLAN ethertype, but
expect to find the IP header type in the protocol field. This means that
things like changing the ECN field, or parsing diffserv values, stops
working if there's a VLAN tag, or if there are multiple nested VLAN
tags (QinQ).
To fix this, change the helper to take an argument that indicates whether
the caller wants to skip the VLAN tags or not. When skipping VLAN tags, we
make sure to skip all of them, so behaviour is consistent even in QinQ
mode.
To make the helper usable from the ECN code, move it to if_vlan.h instead
of pkt_sched.h.
v3:
- Remove empty lines
- Move vlan variable definitions inside loop in skb_protocol()
- Also use skb_protocol() helper in IP{,6}_ECN_decapsulate() and
bpf_skb_ecn_set_ce()
v2:
- Use eth_type_vlan() helper in skb_protocol()
- Also fix code that reads skb->protocol directly
- Change a couple of 'if/else if' statements to switch constructs to avoid
calling the helper twice
Reported-by: Ilya Ponetayev <i.ponetaev@ndmsystems.com>
Fixes: d8b9605d26 ("net: sched: fix skb->protocol use in case of accelerated vlan path")
Signed-off-by: Toke Høiland-Jørgensen <toke@redhat.com>
Signed-off-by: David S. Miller <davem@davemloft.net>
309 lines
7.5 KiB
C
309 lines
7.5 KiB
C
/* SPDX-License-Identifier: GPL-2.0 */
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#ifndef _INET_ECN_H_
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#define _INET_ECN_H_
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#include <linux/ip.h>
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#include <linux/skbuff.h>
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#include <linux/if_vlan.h>
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#include <net/inet_sock.h>
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#include <net/dsfield.h>
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enum {
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INET_ECN_NOT_ECT = 0,
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INET_ECN_ECT_1 = 1,
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INET_ECN_ECT_0 = 2,
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INET_ECN_CE = 3,
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INET_ECN_MASK = 3,
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};
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extern int sysctl_tunnel_ecn_log;
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static inline int INET_ECN_is_ce(__u8 dsfield)
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{
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return (dsfield & INET_ECN_MASK) == INET_ECN_CE;
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}
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static inline int INET_ECN_is_not_ect(__u8 dsfield)
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{
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return (dsfield & INET_ECN_MASK) == INET_ECN_NOT_ECT;
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}
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static inline int INET_ECN_is_capable(__u8 dsfield)
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{
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return dsfield & INET_ECN_ECT_0;
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}
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/*
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* RFC 3168 9.1.1
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* The full-functionality option for ECN encapsulation is to copy the
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* ECN codepoint of the inside header to the outside header on
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* encapsulation if the inside header is not-ECT or ECT, and to set the
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* ECN codepoint of the outside header to ECT(0) if the ECN codepoint of
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* the inside header is CE.
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*/
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static inline __u8 INET_ECN_encapsulate(__u8 outer, __u8 inner)
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{
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outer &= ~INET_ECN_MASK;
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outer |= !INET_ECN_is_ce(inner) ? (inner & INET_ECN_MASK) :
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INET_ECN_ECT_0;
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return outer;
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}
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static inline void INET_ECN_xmit(struct sock *sk)
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{
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inet_sk(sk)->tos |= INET_ECN_ECT_0;
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if (inet6_sk(sk) != NULL)
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inet6_sk(sk)->tclass |= INET_ECN_ECT_0;
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}
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static inline void INET_ECN_dontxmit(struct sock *sk)
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{
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inet_sk(sk)->tos &= ~INET_ECN_MASK;
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if (inet6_sk(sk) != NULL)
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inet6_sk(sk)->tclass &= ~INET_ECN_MASK;
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}
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#define IP6_ECN_flow_init(label) do { \
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(label) &= ~htonl(INET_ECN_MASK << 20); \
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} while (0)
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#define IP6_ECN_flow_xmit(sk, label) do { \
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if (INET_ECN_is_capable(inet6_sk(sk)->tclass)) \
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(label) |= htonl(INET_ECN_ECT_0 << 20); \
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} while (0)
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static inline int IP_ECN_set_ce(struct iphdr *iph)
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{
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u32 check = (__force u32)iph->check;
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u32 ecn = (iph->tos + 1) & INET_ECN_MASK;
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/*
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* After the last operation we have (in binary):
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* INET_ECN_NOT_ECT => 01
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* INET_ECN_ECT_1 => 10
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* INET_ECN_ECT_0 => 11
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* INET_ECN_CE => 00
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*/
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if (!(ecn & 2))
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return !ecn;
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/*
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* The following gives us:
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* INET_ECN_ECT_1 => check += htons(0xFFFD)
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* INET_ECN_ECT_0 => check += htons(0xFFFE)
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*/
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check += (__force u16)htons(0xFFFB) + (__force u16)htons(ecn);
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iph->check = (__force __sum16)(check + (check>=0xFFFF));
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iph->tos |= INET_ECN_CE;
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return 1;
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}
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static inline int IP_ECN_set_ect1(struct iphdr *iph)
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{
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u32 check = (__force u32)iph->check;
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if ((iph->tos & INET_ECN_MASK) != INET_ECN_ECT_0)
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return 0;
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check += (__force u16)htons(0x100);
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iph->check = (__force __sum16)(check + (check>=0xFFFF));
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iph->tos ^= INET_ECN_MASK;
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return 1;
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}
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static inline void IP_ECN_clear(struct iphdr *iph)
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{
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iph->tos &= ~INET_ECN_MASK;
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}
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static inline void ipv4_copy_dscp(unsigned int dscp, struct iphdr *inner)
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{
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dscp &= ~INET_ECN_MASK;
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ipv4_change_dsfield(inner, INET_ECN_MASK, dscp);
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}
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struct ipv6hdr;
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/* Note:
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* IP_ECN_set_ce() has to tweak IPV4 checksum when setting CE,
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* meaning both changes have no effect on skb->csum if/when CHECKSUM_COMPLETE
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* In IPv6 case, no checksum compensates the change in IPv6 header,
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* so we have to update skb->csum.
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*/
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static inline int IP6_ECN_set_ce(struct sk_buff *skb, struct ipv6hdr *iph)
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{
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__be32 from, to;
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if (INET_ECN_is_not_ect(ipv6_get_dsfield(iph)))
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return 0;
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from = *(__be32 *)iph;
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to = from | htonl(INET_ECN_CE << 20);
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*(__be32 *)iph = to;
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if (skb->ip_summed == CHECKSUM_COMPLETE)
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skb->csum = csum_add(csum_sub(skb->csum, (__force __wsum)from),
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(__force __wsum)to);
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return 1;
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}
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static inline int IP6_ECN_set_ect1(struct sk_buff *skb, struct ipv6hdr *iph)
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{
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__be32 from, to;
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if ((ipv6_get_dsfield(iph) & INET_ECN_MASK) != INET_ECN_ECT_0)
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return 0;
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from = *(__be32 *)iph;
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to = from ^ htonl(INET_ECN_MASK << 20);
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*(__be32 *)iph = to;
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if (skb->ip_summed == CHECKSUM_COMPLETE)
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skb->csum = csum_add(csum_sub(skb->csum, (__force __wsum)from),
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(__force __wsum)to);
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return 1;
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}
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static inline void ipv6_copy_dscp(unsigned int dscp, struct ipv6hdr *inner)
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{
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dscp &= ~INET_ECN_MASK;
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ipv6_change_dsfield(inner, INET_ECN_MASK, dscp);
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}
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static inline int INET_ECN_set_ce(struct sk_buff *skb)
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{
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switch (skb_protocol(skb, true)) {
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case cpu_to_be16(ETH_P_IP):
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if (skb_network_header(skb) + sizeof(struct iphdr) <=
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skb_tail_pointer(skb))
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return IP_ECN_set_ce(ip_hdr(skb));
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break;
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case cpu_to_be16(ETH_P_IPV6):
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if (skb_network_header(skb) + sizeof(struct ipv6hdr) <=
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skb_tail_pointer(skb))
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return IP6_ECN_set_ce(skb, ipv6_hdr(skb));
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break;
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}
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return 0;
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}
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static inline int INET_ECN_set_ect1(struct sk_buff *skb)
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{
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switch (skb_protocol(skb, true)) {
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case cpu_to_be16(ETH_P_IP):
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if (skb_network_header(skb) + sizeof(struct iphdr) <=
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skb_tail_pointer(skb))
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return IP_ECN_set_ect1(ip_hdr(skb));
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break;
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case cpu_to_be16(ETH_P_IPV6):
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if (skb_network_header(skb) + sizeof(struct ipv6hdr) <=
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skb_tail_pointer(skb))
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return IP6_ECN_set_ect1(skb, ipv6_hdr(skb));
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break;
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}
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return 0;
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}
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/*
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* RFC 6040 4.2
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* To decapsulate the inner header at the tunnel egress, a compliant
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* tunnel egress MUST set the outgoing ECN field to the codepoint at the
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* intersection of the appropriate arriving inner header (row) and outer
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* header (column) in Figure 4
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*
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* +---------+------------------------------------------------+
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* |Arriving | Arriving Outer Header |
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* | Inner +---------+------------+------------+------------+
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* | Header | Not-ECT | ECT(0) | ECT(1) | CE |
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* +---------+---------+------------+------------+------------+
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* | Not-ECT | Not-ECT |Not-ECT(!!!)|Not-ECT(!!!)| <drop>(!!!)|
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* | ECT(0) | ECT(0) | ECT(0) | ECT(1) | CE |
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* | ECT(1) | ECT(1) | ECT(1) (!) | ECT(1) | CE |
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* | CE | CE | CE | CE(!!!)| CE |
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* +---------+---------+------------+------------+------------+
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*
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* Figure 4: New IP in IP Decapsulation Behaviour
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*
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* returns 0 on success
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* 1 if something is broken and should be logged (!!! above)
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* 2 if packet should be dropped
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*/
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static inline int __INET_ECN_decapsulate(__u8 outer, __u8 inner, bool *set_ce)
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{
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if (INET_ECN_is_not_ect(inner)) {
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switch (outer & INET_ECN_MASK) {
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case INET_ECN_NOT_ECT:
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return 0;
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case INET_ECN_ECT_0:
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case INET_ECN_ECT_1:
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return 1;
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case INET_ECN_CE:
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return 2;
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}
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}
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*set_ce = INET_ECN_is_ce(outer);
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return 0;
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}
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static inline int INET_ECN_decapsulate(struct sk_buff *skb,
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__u8 outer, __u8 inner)
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{
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bool set_ce = false;
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int rc;
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rc = __INET_ECN_decapsulate(outer, inner, &set_ce);
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if (!rc) {
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if (set_ce)
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INET_ECN_set_ce(skb);
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else if ((outer & INET_ECN_MASK) == INET_ECN_ECT_1)
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INET_ECN_set_ect1(skb);
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}
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return rc;
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}
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static inline int IP_ECN_decapsulate(const struct iphdr *oiph,
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struct sk_buff *skb)
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{
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__u8 inner;
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switch (skb_protocol(skb, true)) {
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case htons(ETH_P_IP):
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inner = ip_hdr(skb)->tos;
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break;
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case htons(ETH_P_IPV6):
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inner = ipv6_get_dsfield(ipv6_hdr(skb));
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break;
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default:
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return 0;
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}
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return INET_ECN_decapsulate(skb, oiph->tos, inner);
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}
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static inline int IP6_ECN_decapsulate(const struct ipv6hdr *oipv6h,
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struct sk_buff *skb)
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{
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__u8 inner;
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switch (skb_protocol(skb, true)) {
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case htons(ETH_P_IP):
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inner = ip_hdr(skb)->tos;
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break;
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case htons(ETH_P_IPV6):
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inner = ipv6_get_dsfield(ipv6_hdr(skb));
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break;
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default:
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return 0;
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}
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return INET_ECN_decapsulate(skb, ipv6_get_dsfield(oipv6h), inner);
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}
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#endif
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