bpf: fix _htons occurences in test_progs

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>
This commit is contained in:
Daniel Borkmann
2017-04-27 01:39:34 +02:00
committed by David S. Miller
parent d24f7c7fb9
commit 43bcf707cc
4 changed files with 31 additions and 15 deletions

View File

@@ -19,9 +19,8 @@
#include <linux/udp.h>
#include "bpf_helpers.h"
#include "test_iptunnel_common.h"
#include "bpf_util.h"
#define htons __builtin_bswap16
#define ntohs __builtin_bswap16
int _version SEC("version") = 1;
static inline __u32 rol32(__u32 word, unsigned int shift)
@@ -355,7 +354,7 @@ static __always_inline int process_packet(void *data, __u64 off, void *data_end,
iph_len = sizeof(struct ipv6hdr);
protocol = ip6h->nexthdr;
pckt.proto = protocol;
pkt_bytes = ntohs(ip6h->payload_len);
pkt_bytes = bpf_ntohs(ip6h->payload_len);
off += iph_len;
if (protocol == IPPROTO_FRAGMENT) {
return TC_ACT_SHOT;
@@ -377,7 +376,7 @@ static __always_inline int process_packet(void *data, __u64 off, void *data_end,
protocol = iph->protocol;
pckt.proto = protocol;
pkt_bytes = ntohs(iph->tot_len);
pkt_bytes = bpf_ntohs(iph->tot_len);
off += IPV4_HDR_LEN_NO_OPT;
if (iph->frag_off & PCKT_FRAGMENTED)
@@ -464,9 +463,9 @@ int balancer_ingress(struct __sk_buff *ctx)
if (data + nh_off > data_end)
return TC_ACT_SHOT;
eth_proto = eth->eth_proto;
if (eth_proto == htons(ETH_P_IP))
if (eth_proto == bpf_htons(ETH_P_IP))
return process_packet(data, nh_off, data_end, false, ctx);
else if (eth_proto == htons(ETH_P_IPV6))
else if (eth_proto == bpf_htons(ETH_P_IPV6))
return process_packet(data, nh_off, data_end, true, ctx);
else
return TC_ACT_SHOT;