samples/bpf: fix a build issue

With latest net-next:

====
clang  -nostdinc -isystem /usr/lib/gcc/x86_64-redhat-linux/6.3.1/include -I./arch/x86/include -I./arch/x86/include/generated/uapi -I./arch/x86/include/generated  -I./include -I./arch/x86/include/uapi -I./include/uapi -I./include/generated/uapi -include ./include/linux/kconfig.h  -Isamples/bpf \
    -D__KERNEL__ -D__ASM_SYSREG_H -Wno-unused-value -Wno-pointer-sign \
    -Wno-compare-distinct-pointer-types \
    -Wno-gnu-variable-sized-type-not-at-end \
    -Wno-address-of-packed-member -Wno-tautological-compare \
    -Wno-unknown-warning-option \
    -O2 -emit-llvm -c samples/bpf/tcp_synrto_kern.c -o -| llc -march=bpf -filetype=obj -o samples/bpf/tcp_synrto_kern.o
samples/bpf/tcp_synrto_kern.c:20:10: fatal error: 'bpf_endian.h' file not found
          ^~~~~~~~~~~~~~
1 error generated.
====

net has the same issue.

Add support for ntohl and htonl in tools/testing/selftests/bpf/bpf_endian.h.
Also move bpf_helpers.h from samples/bpf to selftests/bpf and change
compiler include logic so that programs in samples/bpf can access the headers
in selftests/bpf, but not the other way around.

Signed-off-by: Yonghong Song <yhs@fb.com>
Acked-by: Daniel Borkmann <daniel@iogearbox.net>
Acked-by: Lawrence Brakmo <brakmo@fb.com>
Signed-off-by: David S. Miller <davem@davemloft.net>

3 files changed, 212 insertions, 1 deletions

diff --git a/tools/testing/selftests/bpf/Makefile b/tools/testing/selftests/bpf/Makefile
index 2ca51a8a588c..153c3a181a4c 100644
--- a/tools/testing/selftests/bpf/Makefile
+++ b/tools/testing/selftests/bpf/Makefile
@@ -37,6 +37,5 @@ CLANG ?= clang
 
 %.o: %.c
         $(CLANG) -I. -I./include/uapi -I../../../include/uapi \
-                -I../../../../samples/bpf/ \
                 -Wno-compare-distinct-pointer-types \
                 -O2 -target bpf -c $< -o $@
diff --git a/tools/testing/selftests/bpf/bpf_endian.h b/tools/testing/selftests/bpf/bpf_endian.h
index 487cbfb89beb..74af266aa512 100644
--- a/tools/testing/selftests/bpf/bpf_endian.h
+++ b/tools/testing/selftests/bpf/bpf_endian.h
@@ -23,11 +23,19 @@
 # define __bpf_htons(x)                 __builtin_bswap16(x)
 # define __bpf_constant_ntohs(x)        ___constant_swab16(x)
 # define __bpf_constant_htons(x)        ___constant_swab16(x)
+# define __bpf_ntohl(x)                 __builtin_bswap32(x)
+# define __bpf_htonl(x)                 __builtin_bswap32(x)
+# define __bpf_constant_ntohl(x)        ___constant_swab32(x)
+# define __bpf_constant_htonl(x)        ___constant_swab32(x)
 #elif __BYTE_ORDER__ == __ORDER_BIG_ENDIAN__
 # define __bpf_ntohs(x)                 (x)
 # define __bpf_htons(x)                 (x)
 # define __bpf_constant_ntohs(x)        (x)
 # define __bpf_constant_htons(x)        (x)
+# define __bpf_ntohl(x)                 (x)
+# define __bpf_htonl(x)                 (x)
+# define __bpf_constant_ntohl(x)        (x)
+# define __bpf_constant_htonl(x)        (x)
 #else
 # error "Fix your compiler's __BYTE_ORDER__?!"
 #endif
@@ -38,5 +46,11 @@
 #define bpf_ntohs(x)                            \
         (__builtin_constant_p(x) ?              \
          __bpf_constant_ntohs(x) : __bpf_ntohs(x))
+#define bpf_htonl(x)                            \
+        (__builtin_constant_p(x) ?              \
+         __bpf_constant_htonl(x) : __bpf_htonl(x))
+#define bpf_ntohl(x)                            \
+        (__builtin_constant_p(x) ?              \
+         __bpf_constant_ntohl(x) : __bpf_ntohl(x))
 
 #endif /* __BPF_ENDIAN__ */
diff --git a/tools/testing/selftests/bpf/bpf_helpers.h b/tools/testing/selftests/bpf/bpf_helpers.h
new file mode 100644
index 000000000000..d50ac342dc92
--- /dev/null
+++ b/tools/testing/selftests/bpf/bpf_helpers.h
@@ -0,0 +1,198 @@
+#ifndef __BPF_HELPERS_H
+#define __BPF_HELPERS_H
+
+/* helper macro to place programs, maps, license in
+ * different sections in elf_bpf file. Section names
+ * are interpreted by elf_bpf loader
+ */
+#define SEC(NAME) __attribute__((section(NAME), used))
+
+/* helper functions called from eBPF programs written in C */
+static void *(*bpf_map_lookup_elem)(void *map, void *key) =
+        (void *) BPF_FUNC_map_lookup_elem;
+static int (*bpf_map_update_elem)(void *map, void *key, void *value,
+                                  unsigned long long flags) =
+        (void *) BPF_FUNC_map_update_elem;
+static int (*bpf_map_delete_elem)(void *map, void *key) =
+        (void *) BPF_FUNC_map_delete_elem;
+static int (*bpf_probe_read)(void *dst, int size, void *unsafe_ptr) =
+        (void *) BPF_FUNC_probe_read;
+static unsigned long long (*bpf_ktime_get_ns)(void) =
+        (void *) BPF_FUNC_ktime_get_ns;
+static int (*bpf_trace_printk)(const char *fmt, int fmt_size, ...) =
+        (void *) BPF_FUNC_trace_printk;
+static void (*bpf_tail_call)(void *ctx, void *map, int index) =
+        (void *) BPF_FUNC_tail_call;
+static unsigned long long (*bpf_get_smp_processor_id)(void) =
+        (void *) BPF_FUNC_get_smp_processor_id;
+static unsigned long long (*bpf_get_current_pid_tgid)(void) =
+        (void *) BPF_FUNC_get_current_pid_tgid;
+static unsigned long long (*bpf_get_current_uid_gid)(void) =
+        (void *) BPF_FUNC_get_current_uid_gid;
+static int (*bpf_get_current_comm)(void *buf, int buf_size) =
+        (void *) BPF_FUNC_get_current_comm;
+static unsigned long long (*bpf_perf_event_read)(void *map,
+                                                 unsigned long long flags) =
+        (void *) BPF_FUNC_perf_event_read;
+static int (*bpf_clone_redirect)(void *ctx, int ifindex, int flags) =
+        (void *) BPF_FUNC_clone_redirect;
+static int (*bpf_redirect)(int ifindex, int flags) =
+        (void *) BPF_FUNC_redirect;
+static int (*bpf_perf_event_output)(void *ctx, void *map,
+                                    unsigned long long flags, void *data,
+                                    int size) =
+        (void *) BPF_FUNC_perf_event_output;
+static int (*bpf_get_stackid)(void *ctx, void *map, int flags) =
+        (void *) BPF_FUNC_get_stackid;
+static int (*bpf_probe_write_user)(void *dst, void *src, int size) =
+        (void *) BPF_FUNC_probe_write_user;
+static int (*bpf_current_task_under_cgroup)(void *map, int index) =
+        (void *) BPF_FUNC_current_task_under_cgroup;
+static int (*bpf_skb_get_tunnel_key)(void *ctx, void *key, int size, int flags) =
+        (void *) BPF_FUNC_skb_get_tunnel_key;
+static int (*bpf_skb_set_tunnel_key)(void *ctx, void *key, int size, int flags) =
+        (void *) BPF_FUNC_skb_set_tunnel_key;
+static int (*bpf_skb_get_tunnel_opt)(void *ctx, void *md, int size) =
+        (void *) BPF_FUNC_skb_get_tunnel_opt;
+static int (*bpf_skb_set_tunnel_opt)(void *ctx, void *md, int size) =
+        (void *) BPF_FUNC_skb_set_tunnel_opt;
+static unsigned long long (*bpf_get_prandom_u32)(void) =
+        (void *) BPF_FUNC_get_prandom_u32;
+static int (*bpf_xdp_adjust_head)(void *ctx, int offset) =
+        (void *) BPF_FUNC_xdp_adjust_head;
+static int (*bpf_setsockopt)(void *ctx, int level, int optname, void *optval,
+                             int optlen) =
+        (void *) BPF_FUNC_setsockopt;
+
+/* llvm builtin functions that eBPF C program may use to
+ * emit BPF_LD_ABS and BPF_LD_IND instructions
+ */
+struct sk_buff;
+unsigned long long load_byte(void *skb,
+                             unsigned long long off) asm("llvm.bpf.load.byte");
+unsigned long long load_half(void *skb,
+                             unsigned long long off) asm("llvm.bpf.load.half");
+unsigned long long load_word(void *skb,
+                             unsigned long long off) asm("llvm.bpf.load.word");
+
+/* a helper structure used by eBPF C program
+ * to describe map attributes to elf_bpf loader
+ */
+struct bpf_map_def {
+        unsigned int type;
+        unsigned int key_size;
+        unsigned int value_size;
+        unsigned int max_entries;
+        unsigned int map_flags;
+        unsigned int inner_map_idx;
+};
+
+static int (*bpf_skb_load_bytes)(void *ctx, int off, void *to, int len) =
+        (void *) BPF_FUNC_skb_load_bytes;
+static int (*bpf_skb_store_bytes)(void *ctx, int off, void *from, int len, int flags) =
+        (void *) BPF_FUNC_skb_store_bytes;
+static int (*bpf_l3_csum_replace)(void *ctx, int off, int from, int to, int flags) =
+        (void *) BPF_FUNC_l3_csum_replace;
+static int (*bpf_l4_csum_replace)(void *ctx, int off, int from, int to, int flags) =
+        (void *) BPF_FUNC_l4_csum_replace;
+static int (*bpf_skb_under_cgroup)(void *ctx, void *map, int index) =
+        (void *) BPF_FUNC_skb_under_cgroup;
+static int (*bpf_skb_change_head)(void *, int len, int flags) =
+        (void *) BPF_FUNC_skb_change_head;
+
+#if defined(__x86_64__)
+
+#define PT_REGS_PARM1(x) ((x)->di)
+#define PT_REGS_PARM2(x) ((x)->si)
+#define PT_REGS_PARM3(x) ((x)->dx)
+#define PT_REGS_PARM4(x) ((x)->cx)
+#define PT_REGS_PARM5(x) ((x)->r8)
+#define PT_REGS_RET(x) ((x)->sp)
+#define PT_REGS_FP(x) ((x)->bp)
+#define PT_REGS_RC(x) ((x)->ax)
+#define PT_REGS_SP(x) ((x)->sp)
+#define PT_REGS_IP(x) ((x)->ip)
+
+#elif defined(__s390x__)
+
+#define PT_REGS_PARM1(x) ((x)->gprs[2])
+#define PT_REGS_PARM2(x) ((x)->gprs[3])
+#define PT_REGS_PARM3(x) ((x)->gprs[4])
+#define PT_REGS_PARM4(x) ((x)->gprs[5])
+#define PT_REGS_PARM5(x) ((x)->gprs[6])
+#define PT_REGS_RET(x) ((x)->gprs[14])
+#define PT_REGS_FP(x) ((x)->gprs[11]) /* Works only with CONFIG_FRAME_POINTER */
+#define PT_REGS_RC(x) ((x)->gprs[2])
+#define PT_REGS_SP(x) ((x)->gprs[15])
+#define PT_REGS_IP(x) ((x)->psw.addr)
+
+#elif defined(__aarch64__)
+
+#define PT_REGS_PARM1(x) ((x)->regs[0])
+#define PT_REGS_PARM2(x) ((x)->regs[1])
+#define PT_REGS_PARM3(x) ((x)->regs[2])
+#define PT_REGS_PARM4(x) ((x)->regs[3])
+#define PT_REGS_PARM5(x) ((x)->regs[4])
+#define PT_REGS_RET(x) ((x)->regs[30])
+#define PT_REGS_FP(x) ((x)->regs[29]) /* Works only with CONFIG_FRAME_POINTER */
+#define PT_REGS_RC(x) ((x)->regs[0])
+#define PT_REGS_SP(x) ((x)->sp)
+#define PT_REGS_IP(x) ((x)->pc)
+
+#elif defined(__mips__)
+
+#define PT_REGS_PARM1(x) ((x)->regs[4])
+#define PT_REGS_PARM2(x) ((x)->regs[5])
+#define PT_REGS_PARM3(x) ((x)->regs[6])
+#define PT_REGS_PARM4(x) ((x)->regs[7])
+#define PT_REGS_PARM5(x) ((x)->regs[8])
+#define PT_REGS_RET(x) ((x)->regs[31])
+#define PT_REGS_FP(x) ((x)->regs[30]) /* Works only with CONFIG_FRAME_POINTER */
+#define PT_REGS_RC(x) ((x)->regs[1])
+#define PT_REGS_SP(x) ((x)->regs[29])
+#define PT_REGS_IP(x) ((x)->cp0_epc)
+
+#elif defined(__powerpc__)
+
+#define PT_REGS_PARM1(x) ((x)->gpr[3])
+#define PT_REGS_PARM2(x) ((x)->gpr[4])
+#define PT_REGS_PARM3(x) ((x)->gpr[5])
+#define PT_REGS_PARM4(x) ((x)->gpr[6])
+#define PT_REGS_PARM5(x) ((x)->gpr[7])
+#define PT_REGS_RC(x) ((x)->gpr[3])
+#define PT_REGS_SP(x) ((x)->sp)
+#define PT_REGS_IP(x) ((x)->nip)
+
+#elif defined(__sparc__)
+
+#define PT_REGS_PARM1(x) ((x)->u_regs[UREG_I0])
+#define PT_REGS_PARM2(x) ((x)->u_regs[UREG_I1])
+#define PT_REGS_PARM3(x) ((x)->u_regs[UREG_I2])
+#define PT_REGS_PARM4(x) ((x)->u_regs[UREG_I3])
+#define PT_REGS_PARM5(x) ((x)->u_regs[UREG_I4])
+#define PT_REGS_RET(x) ((x)->u_regs[UREG_I7])
+#define PT_REGS_RC(x) ((x)->u_regs[UREG_I0])
+#define PT_REGS_SP(x) ((x)->u_regs[UREG_FP])
+#if defined(__arch64__)
+#define PT_REGS_IP(x) ((x)->tpc)
+#else
+#define PT_REGS_IP(x) ((x)->pc)
+#endif
+
+#endif
+
+#ifdef __powerpc__
+#define BPF_KPROBE_READ_RET_IP(ip, ctx)         ({ (ip) = (ctx)->link; })
+#define BPF_KRETPROBE_READ_RET_IP               BPF_KPROBE_READ_RET_IP
+#elif defined(__sparc__)
+#define BPF_KPROBE_READ_RET_IP(ip, ctx)         ({ (ip) = PT_REGS_RET(ctx); })
+#define BPF_KRETPROBE_READ_RET_IP               BPF_KPROBE_READ_RET_IP
+#else
+#define BPF_KPROBE_READ_RET_IP(ip, ctx)         ({                              \
+                bpf_probe_read(&(ip), sizeof(ip), (void *)PT_REGS_RET(ctx)); })
+#define BPF_KRETPROBE_READ_RET_IP(ip, ctx)      ({                              \
+                bpf_probe_read(&(ip), sizeof(ip),                               \
+                                (void *)(PT_REGS_FP(ctx) + sizeof(ip))); })
+#endif
+
+#endif