43bcf707cc
Dave reported that on sparc test_progs generates buggy swapped eth->h_proto protocol comparisons: 10: (15) if r3 == 0xdd86 goto pc+9 R0=imm2,min_value=2,max_value=2 R1=pkt(id=0,off=0,r=14) R2=pkt_end R3=inv R4=pkt(id=0,off=14,r=14) R5=inv56 R10=fp This is due to the unconditional ... #define htons __builtin_bswap16 #define ntohs __builtin_bswap16 ... in test_progs that causes this. Make use of asm/byteorder.h and use __constant_htons() where possible and only perform the bswap16 when on little endian in non-constant case. Fixes:6882804c91("selftests/bpf: add a test for overlapping packet range checks") Fixes:3782161362("selftests/bpf: add l4 load balancer test based on sched_cls") Reported-by: David S. Miller <davem@davemloft.net> Signed-off-by: Daniel Borkmann <daniel@iogearbox.net> Acked-by: Alexei Starovoitov <ast@kernel.org> Signed-off-by: David S. Miller <davem@davemloft.net>
65 lines
1.6 KiB
C
65 lines
1.6 KiB
C
/* Copyright (c) 2017 Facebook
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*
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* This program is free software; you can redistribute it and/or
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* modify it under the terms of version 2 of the GNU General Public
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* License as published by the Free Software Foundation.
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*/
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#include <stddef.h>
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#include <linux/bpf.h>
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#include <linux/if_ether.h>
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#include <linux/if_packet.h>
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#include <linux/ip.h>
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#include <linux/ipv6.h>
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#include <linux/in.h>
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#include <linux/tcp.h>
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#include <linux/pkt_cls.h>
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#include "bpf_helpers.h"
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#include "bpf_util.h"
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#define barrier() __asm__ __volatile__("": : :"memory")
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int _version SEC("version") = 1;
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SEC("test1")
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int process(struct __sk_buff *skb)
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{
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void *data_end = (void *)(long)skb->data_end;
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void *data = (void *)(long)skb->data;
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struct ethhdr *eth = (struct ethhdr *)(data);
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struct tcphdr *tcp = NULL;
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__u8 proto = 255;
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__u64 ihl_len;
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if (eth + 1 > data_end)
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return TC_ACT_SHOT;
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if (eth->h_proto == bpf_htons(ETH_P_IP)) {
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struct iphdr *iph = (struct iphdr *)(eth + 1);
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if (iph + 1 > data_end)
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return TC_ACT_SHOT;
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ihl_len = iph->ihl * 4;
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proto = iph->protocol;
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tcp = (struct tcphdr *)((void *)(iph) + ihl_len);
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} else if (eth->h_proto == bpf_htons(ETH_P_IPV6)) {
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struct ipv6hdr *ip6h = (struct ipv6hdr *)(eth + 1);
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if (ip6h + 1 > data_end)
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return TC_ACT_SHOT;
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ihl_len = sizeof(*ip6h);
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proto = ip6h->nexthdr;
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tcp = (struct tcphdr *)((void *)(ip6h) + ihl_len);
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}
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if (tcp) {
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if (((void *)(tcp) + 20) > data_end || proto != 6)
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return TC_ACT_SHOT;
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barrier(); /* to force ordering of checks */
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if (((void *)(tcp) + 18) > data_end)
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return TC_ACT_SHOT;
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if (tcp->urg_ptr == 123)
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return TC_ACT_OK;
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}
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return TC_ACT_UNSPEC;
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}
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