[RFC,1/2] tap: stop "vendoring" linux bpf headers

Message ID 20240130034925.44869-2-stephen@networkplumber.org (mailing list archive)
State Superseded, archived
Delegated to: Ferruh Yigit
Headers
Series net/tap RSS BPF rewrite |

Checks

Context Check Description
ci/checkpatch success coding style OK
ci/Intel-compilation fail Compilation issues
ci/intel-Testing success Testing PASS
ci/intel-Functional success Functional PASS

Commit Message

Stephen Hemminger Jan. 30, 2024, 3:46 a.m. UTC
  The proper place for finding bpf structures and functions is
in linux/bpf.h. The original version was trying to workaround the
case where the build environment was running on old pre BPF
version of Glibc, but the target environment had BPF. This is not
a supportable build method, and not how rest of DPDK works.

Having own private (and divergent) version headers leads to future
problems when BPF definitions evolve.

Since DPDK officially supports only LTS or later kernel
there is no need for the #ifdef workarounds in the TAP flow
code. Cloning headers leads to problems and no longer needed.

Signed-off-by: Stephen Hemminger <stephen@networkplumber.org>
---
 drivers/net/tap/bpf/bpf_extract.py |   1 -
 drivers/net/tap/tap_bpf.h          | 121 -----------------------------
 drivers/net/tap/tap_bpf_api.c      |  20 +++--
 drivers/net/tap/tap_bpf_insns.h    |   1 -
 drivers/net/tap/tap_flow.c         |  89 ---------------------
 5 files changed, 13 insertions(+), 219 deletions(-)
 delete mode 100644 drivers/net/tap/tap_bpf.h
  

Patch

diff --git a/drivers/net/tap/bpf/bpf_extract.py b/drivers/net/tap/bpf/bpf_extract.py
index b630c42b809f..73c4dafe4eca 100644
--- a/drivers/net/tap/bpf/bpf_extract.py
+++ b/drivers/net/tap/bpf/bpf_extract.py
@@ -65,7 +65,6 @@  def write_header(out, source):
         print(f' * Auto-generated from {source}', file=out)
     print(" * This not the original source file. Do NOT edit it.", file=out)
     print(" */\n", file=out)
-    print("#include <tap_bpf.h>", file=out)
 
 
 def main():
diff --git a/drivers/net/tap/tap_bpf.h b/drivers/net/tap/tap_bpf.h
deleted file mode 100644
index 0d38bc111fe0..000000000000
--- a/drivers/net/tap/tap_bpf.h
+++ /dev/null
@@ -1,121 +0,0 @@ 
-/* SPDX-License-Identifier: BSD-3-Clause OR GPL-2.0
- * Copyright 2017 Mellanox Technologies, Ltd
- */
-
-#ifndef __TAP_BPF_H__
-#define __TAP_BPF_H__
-
-#include <tap_autoconf.h>
-
-/* Do not #include <linux/bpf.h> since eBPF must compile on different
- * distros which may include partial definitions for eBPF (while the
- * kernel itself may support eBPF). Instead define here all that is needed
- */
-
-/* BPF_MAP_UPDATE_ELEM command flags */
-#define	BPF_ANY	0 /* create a new element or update an existing */
-
-/* BPF architecture instruction struct */
-struct bpf_insn {
-	__u8	code;
-	__u8	dst_reg:4;
-	__u8	src_reg:4;
-	__s16	off;
-	__s32	imm; /* immediate value */
-};
-
-/* BPF program types */
-enum bpf_prog_type {
-	BPF_PROG_TYPE_UNSPEC,
-	BPF_PROG_TYPE_SOCKET_FILTER,
-	BPF_PROG_TYPE_KPROBE,
-	BPF_PROG_TYPE_SCHED_CLS,
-	BPF_PROG_TYPE_SCHED_ACT,
-};
-
-/* BPF commands types */
-enum bpf_cmd {
-	BPF_MAP_CREATE,
-	BPF_MAP_LOOKUP_ELEM,
-	BPF_MAP_UPDATE_ELEM,
-	BPF_MAP_DELETE_ELEM,
-	BPF_MAP_GET_NEXT_KEY,
-	BPF_PROG_LOAD,
-};
-
-/* BPF maps types */
-enum bpf_map_type {
-	BPF_MAP_TYPE_UNSPEC,
-	BPF_MAP_TYPE_HASH,
-};
-
-/* union of anonymous structs used with TAP BPF commands */
-union bpf_attr {
-	/* BPF_MAP_CREATE command */
-	struct {
-		__u32	map_type;
-		__u32	key_size;
-		__u32	value_size;
-		__u32	max_entries;
-		__u32	map_flags;
-		__u32	inner_map_fd;
-	};
-
-	/* BPF_MAP_UPDATE_ELEM, BPF_MAP_DELETE_ELEM commands */
-	struct {
-		__u32		map_fd;
-		__aligned_u64	key;
-		union {
-			__aligned_u64 value;
-			__aligned_u64 next_key;
-		};
-		__u64		flags;
-	};
-
-	/* BPF_PROG_LOAD command */
-	struct {
-		__u32		prog_type;
-		__u32		insn_cnt;
-		__aligned_u64	insns;
-		__aligned_u64	license;
-		__u32		log_level;
-		__u32		log_size;
-		__aligned_u64	log_buf;
-		__u32		kern_version;
-		__u32		prog_flags;
-	};
-} __rte_aligned(8);
-
-#ifndef __NR_bpf
-# if defined(__i386__)
-#  define __NR_bpf 357
-# elif defined(__x86_64__)
-#  define __NR_bpf 321
-# elif defined(__arm__)
-#  define __NR_bpf 386
-# elif defined(__aarch64__)
-#  define __NR_bpf 280
-# elif defined(__sparc__)
-#  define __NR_bpf 349
-# elif defined(__s390__)
-#  define __NR_bpf 351
-# elif defined(__powerpc__)
-#  define __NR_bpf 361
-# elif defined(__riscv)
-#  define __NR_bpf 280
-# elif defined(__loongarch__)
-#  define __NR_bpf 280
-# else
-#  error __NR_bpf not defined
-# endif
-#endif
-
-enum {
-	BPF_MAP_ID_KEY,
-	BPF_MAP_ID_SIMPLE,
-};
-
-static int bpf_load(enum bpf_prog_type type, const struct bpf_insn *insns,
-		size_t insns_cnt, const char *license);
-
-#endif /* __TAP_BPF_H__ */
diff --git a/drivers/net/tap/tap_bpf_api.c b/drivers/net/tap/tap_bpf_api.c
index 15283f8917ed..9e05e2ddf19b 100644
--- a/drivers/net/tap/tap_bpf_api.c
+++ b/drivers/net/tap/tap_bpf_api.c
@@ -2,19 +2,19 @@ 
  * Copyright 2017 Mellanox Technologies, Ltd
  */
 
-#include <errno.h>
-#include <string.h>
 #include <unistd.h>
-#include <sys/queue.h>
+#include <syscall.h>
+#include <linux/bpf.h>
 
-#include <rte_malloc.h>
-#include <rte_eth_tap.h>
 #include <tap_flow.h>
 #include <tap_autoconf.h>
-#include <tap_tcmsgs.h>
-#include <tap_bpf.h>
+
 #include <tap_bpf_insns.h>
 
+
+static int bpf_load(enum bpf_prog_type type, const struct bpf_insn *insns,
+		size_t insns_cnt, const char *license);
+
 /**
  * Load BPF program (section cls_q) into the kernel and return a bpf fd
  *
@@ -89,7 +89,13 @@  static inline __u64 ptr_to_u64(const void *ptr)
 static inline int sys_bpf(enum bpf_cmd cmd, union bpf_attr *attr,
 			unsigned int size)
 {
+#ifdef __NR_bpf
 	return syscall(__NR_bpf, cmd, attr, size);
+#else
+	TAP_LOG(ERR, "No bpf syscall, kernel headers too old?\n");
+	errno = ENOSYS;
+	return -1;
+#endif
 }
 
 /**
diff --git a/drivers/net/tap/tap_bpf_insns.h b/drivers/net/tap/tap_bpf_insns.h
index 53fa76c4e6b0..88aec6885a06 100644
--- a/drivers/net/tap/tap_bpf_insns.h
+++ b/drivers/net/tap/tap_bpf_insns.h
@@ -3,7 +3,6 @@ 
  * This not the original source file. Do NOT edit it.
  */
 
-#include <tap_bpf.h>
 
 static struct bpf_insn cls_q_insns[] = {
 	{0x61,    2,    1,       52, 0x00000000},
diff --git a/drivers/net/tap/tap_flow.c b/drivers/net/tap/tap_flow.c
index ed4d42f92f9f..a5d38ee7c46c 100644
--- a/drivers/net/tap/tap_flow.c
+++ b/drivers/net/tap/tap_flow.c
@@ -18,95 +18,6 @@ 
 #include <tap_tcmsgs.h>
 #include <tap_rss.h>
 
-#ifndef HAVE_TC_FLOWER
-/*
- * For kernels < 4.2, this enum is not defined. Runtime checks will be made to
- * avoid sending TC messages the kernel cannot understand.
- */
-enum {
-	TCA_FLOWER_UNSPEC,
-	TCA_FLOWER_CLASSID,
-	TCA_FLOWER_INDEV,
-	TCA_FLOWER_ACT,
-	TCA_FLOWER_KEY_ETH_DST,         /* ETH_ALEN */
-	TCA_FLOWER_KEY_ETH_DST_MASK,    /* ETH_ALEN */
-	TCA_FLOWER_KEY_ETH_SRC,         /* ETH_ALEN */
-	TCA_FLOWER_KEY_ETH_SRC_MASK,    /* ETH_ALEN */
-	TCA_FLOWER_KEY_ETH_TYPE,        /* be16 */
-	TCA_FLOWER_KEY_IP_PROTO,        /* u8 */
-	TCA_FLOWER_KEY_IPV4_SRC,        /* be32 */
-	TCA_FLOWER_KEY_IPV4_SRC_MASK,   /* be32 */
-	TCA_FLOWER_KEY_IPV4_DST,        /* be32 */
-	TCA_FLOWER_KEY_IPV4_DST_MASK,   /* be32 */
-	TCA_FLOWER_KEY_IPV6_SRC,        /* struct in6_addr */
-	TCA_FLOWER_KEY_IPV6_SRC_MASK,   /* struct in6_addr */
-	TCA_FLOWER_KEY_IPV6_DST,        /* struct in6_addr */
-	TCA_FLOWER_KEY_IPV6_DST_MASK,   /* struct in6_addr */
-	TCA_FLOWER_KEY_TCP_SRC,         /* be16 */
-	TCA_FLOWER_KEY_TCP_DST,         /* be16 */
-	TCA_FLOWER_KEY_UDP_SRC,         /* be16 */
-	TCA_FLOWER_KEY_UDP_DST,         /* be16 */
-};
-#endif
-#ifndef HAVE_TC_VLAN_ID
-enum {
-	/* TCA_FLOWER_FLAGS, */
-	TCA_FLOWER_KEY_VLAN_ID = TCA_FLOWER_KEY_UDP_DST + 2, /* be16 */
-	TCA_FLOWER_KEY_VLAN_PRIO,       /* u8   */
-	TCA_FLOWER_KEY_VLAN_ETH_TYPE,   /* be16 */
-};
-#endif
-/*
- * For kernels < 4.2 BPF related enums may not be defined.
- * Runtime checks will be carried out to gracefully report on TC messages that
- * are rejected by the kernel. Rejection reasons may be due to:
- * 1. enum is not defined
- * 2. enum is defined but kernel is not configured to support BPF system calls,
- *    BPF classifications or BPF actions.
- */
-#ifndef HAVE_TC_BPF
-enum {
-	TCA_BPF_UNSPEC,
-	TCA_BPF_ACT,
-	TCA_BPF_POLICE,
-	TCA_BPF_CLASSID,
-	TCA_BPF_OPS_LEN,
-	TCA_BPF_OPS,
-};
-#endif
-#ifndef HAVE_TC_BPF_FD
-enum {
-	TCA_BPF_FD = TCA_BPF_OPS + 1,
-	TCA_BPF_NAME,
-};
-#endif
-#ifndef HAVE_TC_ACT_BPF
-#define tc_gen \
-	__u32                 index; \
-	__u32                 capab; \
-	int                   action; \
-	int                   refcnt; \
-	int                   bindcnt
-
-struct tc_act_bpf {
-	tc_gen;
-};
-
-enum {
-	TCA_ACT_BPF_UNSPEC,
-	TCA_ACT_BPF_TM,
-	TCA_ACT_BPF_PARMS,
-	TCA_ACT_BPF_OPS_LEN,
-	TCA_ACT_BPF_OPS,
-};
-
-#endif
-#ifndef HAVE_TC_ACT_BPF_FD
-enum {
-	TCA_ACT_BPF_FD = TCA_ACT_BPF_OPS + 1,
-	TCA_ACT_BPF_NAME,
-};
-#endif
 
 /* RSS key management */
 enum bpf_rss_key_e {