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 коммит произвёл David S. Miller
Родитель d24f7c7fb9
Коммит 43bcf707cc
4 изменённых файлов: 31 добавлений и 15 удалений

Просмотреть файл

@ -6,6 +6,25 @@
#include <string.h>
#include <errno.h>
#include <asm/byteorder.h>
#if __BYTE_ORDER == __LITTLE_ENDIAN
# define __bpf_ntohs(x) __builtin_bswap16(x)
# define __bpf_htons(x) __builtin_bswap16(x)
#elif __BYTE_ORDER == __BIG_ENDIAN
# define __bpf_ntohs(x) (x)
# define __bpf_htons(x) (x)
#else
# error "Fix your __BYTE_ORDER?!"
#endif
#define bpf_htons(x) \
(__builtin_constant_p(x) ? \
__constant_htons(x) : __bpf_htons(x))
#define bpf_ntohs(x) \
(__builtin_constant_p(x) ? \
__constant_ntohs(x) : __bpf_ntohs(x))
static inline unsigned int bpf_num_possible_cpus(void)
{
static const char *fcpu = "/sys/devices/system/cpu/possible";

Просмотреть файл

@ -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;

Просмотреть файл

@ -14,8 +14,8 @@
#include <linux/tcp.h>
#include <linux/pkt_cls.h>
#include "bpf_helpers.h"
#include "bpf_util.h"
#define _htons __builtin_bswap16
#define barrier() __asm__ __volatile__("": : :"memory")
int _version SEC("version") = 1;
@ -32,7 +32,7 @@ int process(struct __sk_buff *skb)
if (eth + 1 > data_end)
return TC_ACT_SHOT;
if (eth->h_proto == _htons(ETH_P_IP)) {
if (eth->h_proto == bpf_htons(ETH_P_IP)) {
struct iphdr *iph = (struct iphdr *)(eth + 1);
if (iph + 1 > data_end)
@ -40,7 +40,7 @@ int process(struct __sk_buff *skb)
ihl_len = iph->ihl * 4;
proto = iph->protocol;
tcp = (struct tcphdr *)((void *)(iph) + ihl_len);
} else if (eth->h_proto == _htons(ETH_P_IPV6)) {
} else if (eth->h_proto == bpf_htons(ETH_P_IPV6)) {
struct ipv6hdr *ip6h = (struct ipv6hdr *)(eth + 1);
if (ip6h + 1 > data_end)

Просмотреть файл

@ -30,8 +30,6 @@ typedef __u16 __sum16;
#include "test_iptunnel_common.h"
#include "bpf_util.h"
#define _htons __builtin_bswap16
static int error_cnt, pass_cnt;
#define MAGIC_BYTES 123
@ -42,10 +40,10 @@ static struct {
struct iphdr iph;
struct tcphdr tcp;
} __packed pkt_v4 = {
.eth.h_proto = _htons(ETH_P_IP),
.eth.h_proto = bpf_htons(ETH_P_IP),
.iph.ihl = 5,
.iph.protocol = 6,
.iph.tot_len = _htons(MAGIC_BYTES),
.iph.tot_len = bpf_htons(MAGIC_BYTES),
.tcp.urg_ptr = 123,
};
@ -55,9 +53,9 @@ static struct {
struct ipv6hdr iph;
struct tcphdr tcp;
} __packed pkt_v6 = {
.eth.h_proto = _htons(ETH_P_IPV6),
.eth.h_proto = bpf_htons(ETH_P_IPV6),
.iph.nexthdr = 6,
.iph.payload_len = _htons(MAGIC_BYTES),
.iph.payload_len = bpf_htons(MAGIC_BYTES),
.tcp.urg_ptr = 123,
};