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: 6882804c916b ("selftests/bpf: add a test for overlapping packet range checks")
Fixes: 37821613626e ("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>

diff --git a/tools/testing/selftests/bpf/bpf_util.h b/tools/testing/selftests/bpf/bpf_util.h
index 84a5d1823f028344e7a4339e8aa5eb45506d797d..7de27966103d310ba4c9905ace65bb5b6594b45e 100644 (file)
--- a/tools/testing/selftests/bpf/bpf_util.h
+++ b/tools/testing/selftests/bpf/bpf_util.h
@@ -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";

diff --git a/tools/testing/selftests/bpf/test_l4lb.c b/tools/testing/selftests/bpf/test_l4lb.c
index 368bfe8b9842cfa71c5f63635522051c9371e206..b68b21274bac0c97ef8b9f8ba48284cee4a88f2b 100644 (file)
--- a/tools/testing/selftests/bpf/test_l4lb.c
+++ b/tools/testing/selftests/bpf/test_l4lb.c
@@ -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;

diff --git a/tools/testing/selftests/bpf/test_pkt_access.c b/tools/testing/selftests/bpf/test_pkt_access.c
index fd1e0832d40943f8cb30a3ed562eb360cf8e7675..711300508ee093e212f77b738ccb6b249126bbae 100644 (file)
--- a/tools/testing/selftests/bpf/test_pkt_access.c
+++ b/tools/testing/selftests/bpf/test_pkt_access.c
@@ -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)

diff --git a/tools/testing/selftests/bpf/test_progs.c b/tools/testing/selftests/bpf/test_progs.c
index 5275d4a1df24db41d24d5820b185a9ae836a2085..7c2d899c8f4372b0e69518347c67ba81851f972e 100644 (file)
--- a/tools/testing/selftests/bpf/test_progs.c
+++ b/tools/testing/selftests/bpf/test_progs.c
@@ -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,
 };