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bpf: update BPF_PROG_LOAD decoding

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Implement decoding of union bpf_attr.prog_flags field for BPF_PROG_LOAD
command introduced by linux kernel commit v4.12-rc2~34^2~29^2~2.

* configure.ac: Check for prog_flags member of union bpf_attr
instead of kern_version.
* xlat/bpf_prog_flags.in: New file.
* bpf.c: Include "xlat/bpf_prog_flags.h".
(decode_BPF_PROG_LOAD): Add prog_flags field to the structure, print it.
* tests/bpf.c: Update macro guards of BPF_PROG_LOAD decoder test.
(init_BPF_PROG_LOAD_first, print_BPF_PROG_LOAD_attr): Update expected
output.
(init_BPF_PROG_LOAD_attr): Initialize prog_flags field, update offset.
This commit is contained in:
Дмитрий Левин 2017-07-27 00:44:31 +00:00
parent a1e8d312ed
commit c024f1a60f
4 changed files with 17 additions and 15 deletions
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10
bpf.c
View File

@ -36,6 +36,7 @@
#include "xlat/bpf_commands.h"
#include "xlat/bpf_map_types.h"
#include "xlat/bpf_prog_types.h"
#include "xlat/bpf_prog_flags.h"
#include "xlat/bpf_map_update_elem_flags.h"
#include "xlat/bpf_attach_type.h"
#include "xlat/bpf_attach_flags.h"
@ -202,11 +203,9 @@ DEF_BPF_CMD_DECODER(BPF_PROG_LOAD)
uint64_t ATTRIBUTE_ALIGNED(8) insns, license;
uint32_t log_level, log_size;
uint64_t ATTRIBUTE_ALIGNED(8) log_buf;
uint32_t kern_version;
uint32_t kern_version, prog_flags;
} attr = {};
const size_t attr_size =
offsetofend(struct bpf_prog_load, kern_version);
const unsigned int len = size < attr_size ? size : attr_size;
const unsigned int len = size < sizeof(attr) ? size : sizeof(attr);
memcpy(&attr, data, len);
@ -219,7 +218,8 @@ DEF_BPF_CMD_DECODER(BPF_PROG_LOAD)
PRINT_FIELD_U(", ", attr, log_size);
PRINT_FIELD_X(", ", attr, log_buf);
PRINT_FIELD_U(", ", attr, kern_version);
decode_attr_extra_data(tcp, data, size, attr_size);
PRINT_FIELD_FLAGS(", ", attr, prog_flags, bpf_prog_flags, "BPF_F_???");
decode_attr_extra_data(tcp, data, size, sizeof(attr));
tprints("}");
return RVAL_DECODED | RVAL_FD;

2
configure.ac
View File

@ -431,8 +431,8 @@ AC_CHECK_HEADERS([linux/bpf.h], [
st_CHECK_UNION_BPF_ATTR([attach_flags])
st_CHECK_UNION_BPF_ATTR([bpf_fd])
st_CHECK_UNION_BPF_ATTR([flags])
st_CHECK_UNION_BPF_ATTR([kern_version])
st_CHECK_UNION_BPF_ATTR([max_entries])
st_CHECK_UNION_BPF_ATTR([prog_flags])
])
AC_CHECK_TYPES([struct statfs], [

19
tests/bpf.c
View File

@ -34,8 +34,8 @@
&& (defined HAVE_UNION_BPF_ATTR_ATTACH_FLAGS \
|| defined HAVE_UNION_BPF_ATTR_BPF_FD \
|| defined HAVE_UNION_BPF_ATTR_FLAGS \
|| defined HAVE_UNION_BPF_ATTR_KERN_VERSION \
|| defined HAVE_UNION_BPF_ATTR_MAX_ENTRIES)
|| defined HAVE_UNION_BPF_ATTR_MAX_ENTRIES \
|| defined HAVE_UNION_BPF_ATTR_PROG_FLAGS)
# include <stddef.h>
# include <stdio.h>
@ -344,7 +344,7 @@ init_BPF_MAP_GET_NEXT_KEY_attr(const unsigned long eop)
# endif /* HAVE_UNION_BPF_ATTR_FLAGS */
# ifdef HAVE_UNION_BPF_ATTR_KERN_VERSION
# ifdef HAVE_UNION_BPF_ATTR_PROG_FLAGS
static unsigned int
init_BPF_PROG_LOAD_first(const unsigned long eop)
@ -363,7 +363,7 @@ print_BPF_PROG_LOAD_first(const unsigned long addr)
printf("prog_type=BPF_PROG_TYPE_SOCKET_FILTER, insn_cnt=0, insns=0"
", license=NULL, log_level=0, log_size=0, log_buf=0"
", kern_version=0");
", kern_version=0, prog_flags=0");
}
static const struct bpf_insn insns[] = {
@ -382,10 +382,11 @@ init_BPF_PROG_LOAD_attr(const unsigned long eop)
.log_level = 42,
.log_size = sizeof(log_buf),
.log_buf = (uintptr_t) log_buf,
.kern_version = 0xcafef00d
.kern_version = 0xcafef00d,
.prog_flags = 1
};
static const unsigned int offset =
offsetofend(union bpf_attr, kern_version);
offsetofend(union bpf_attr, prog_flags);
const unsigned long addr = eop - offset;
memcpy((void *) addr, &attr, offset);
@ -397,12 +398,12 @@ print_BPF_PROG_LOAD_attr(const unsigned long addr)
{
printf("prog_type=BPF_PROG_TYPE_SOCKET_FILTER, insn_cnt=%u, insns=%p"
", license=\"GPL\", log_level=42, log_size=4096, log_buf=%p"
", kern_version=%u",
", kern_version=%u, prog_flags=BPF_F_STRICT_ALIGNMENT",
(unsigned int) ARRAY_SIZE(insns), insns,
log_buf, 0xcafef00d);
}
# endif /* HAVE_UNION_BPF_ATTR_KERN_VERSION */
# endif /* HAVE_UNION_BPF_ATTR_PROG_FLAGS */
/*
* bpf() syscall and its first six commands were introduced in Linux kernel
@ -554,7 +555,7 @@ main(void)
TEST_BPF(BPF_MAP_GET_NEXT_KEY);
# endif
# ifdef HAVE_UNION_BPF_ATTR_KERN_VERSION
# ifdef HAVE_UNION_BPF_ATTR_PROG_FLAGS
TEST_BPF(BPF_PROG_LOAD);
# endif

1
xlat/bpf_prog_flags.in Normal file
View File

@ -0,0 +1 @@
BPF_F_STRICT_ALIGNMENT 1