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|
#!/bin/bash
export LANG=C
set -e
if [ $# -lt 1 ]; then
echo "Usage: PROGNAME=foo LICENSE=bar $0 <bpf object file>"
exit 1
fi
self=$0
filename=$1
funcname=$PROGNAME
generate_head()
{
cat << END
/* AUTO-GENERATED, DO NOT EDIT. */
#include <stddef.h>
#include <stdint.h>
#include "ngx_bpf.h"
END
}
generate_tail()
{
cat << END
ngx_bpf_program_t $PROGNAME = {
.relocs = bpf_reloc_prog_$funcname,
.nrelocs = sizeof(bpf_reloc_prog_$funcname)
/ sizeof(bpf_reloc_prog_$funcname[0]),
.ins = bpf_insn_prog_$funcname,
.nins = sizeof(bpf_insn_prog_$funcname)
/ sizeof(bpf_insn_prog_$funcname[0]),
.license = "$LICENSE",
.type = BPF_PROG_TYPE_SK_REUSEPORT,
};
END
}
process_relocations()
{
echo "static ngx_bpf_reloc_t bpf_reloc_prog_$funcname[] = {"
objdump -r $filename | awk '{
if (enabled && $NF > 0) {
off = strtonum(sprintf("0x%s", $1));
name = $3;
printf(" { \"%s\", %d },\n", name, off/8);
}
if ($1 == "OFFSET") {
enabled=1;
}
}'
echo "};"
echo
}
process_section()
{
echo "static struct bpf_insn bpf_insn_prog_$funcname[] = {"
echo " /* opcode dst src offset imm */"
section_info=$(objdump -h $filename --section=$funcname | grep "1 $funcname")
# dd doesn't know hex
length=$(printf "%d" 0x$(echo $section_info | cut -d ' ' -f3))
offset=$(printf "%d" 0x$(echo $section_info | cut -d ' ' -f6))
for ins in $(dd if="$filename" bs=1 count=$length skip=$offset status=none | xxd -p -c 8)
do
opcode=0x${ins:0:2}
srcdst=0x${ins:2:2}
# bytes are dumped in LE order
offset=0x${ins:6:2}${ins:4:2} # short
immedi=0x${ins:14:2}${ins:12:2}${ins:10:2}${ins:8:2} # int
dst="$(($srcdst & 0xF))"
src="$(($srcdst & 0xF0))"
src="$(($src >> 4))"
opcode=$(printf "0x%x" $opcode)
dst=$(printf "BPF_REG_%d" $dst)
src=$(printf "BPF_REG_%d" $src)
offset=$(printf "%d" $offset)
immedi=$(printf "0x%x" $immedi)
printf " { %4s, %11s, %11s, (int16_t) %6s, %10s },\n" $opcode $dst $src $offset $immedi
done
cat << END
};
END
}
generate_head
process_relocations
process_section
generate_tail
|
