diff options
Diffstat (limited to 'Documentation/networking/filter.txt')
| -rw-r--r-- | Documentation/networking/filter.txt | 30 |
1 files changed, 16 insertions, 14 deletions
diff --git a/Documentation/networking/filter.txt b/Documentation/networking/filter.txt index 4443ce958862..2196b824e96c 100644 --- a/Documentation/networking/filter.txt +++ b/Documentation/networking/filter.txt @@ -203,11 +203,11 @@ opcodes as defined in linux/filter.h stand for: Instruction Addressing mode Description - ld 1, 2, 3, 4, 10 Load word into A + ld 1, 2, 3, 4, 12 Load word into A ldi 4 Load word into A ldh 1, 2 Load half-word into A ldb 1, 2 Load byte into A - ldx 3, 4, 5, 10 Load word into X + ldx 3, 4, 5, 12 Load word into X ldxi 4 Load word into X ldxb 5 Load byte into X @@ -216,14 +216,14 @@ opcodes as defined in linux/filter.h stand for: jmp 6 Jump to label ja 6 Jump to label - jeq 7, 8 Jump on A == k - jneq 8 Jump on A != k - jne 8 Jump on A != k - jlt 8 Jump on A < k - jle 8 Jump on A <= k - jgt 7, 8 Jump on A > k - jge 7, 8 Jump on A >= k - jset 7, 8 Jump on A & k + jeq 7, 8, 9, 10 Jump on A == <x> + jneq 9, 10 Jump on A != <x> + jne 9, 10 Jump on A != <x> + jlt 9, 10 Jump on A < <x> + jle 9, 10 Jump on A <= <x> + jgt 7, 8, 9, 10 Jump on A > <x> + jge 7, 8, 9, 10 Jump on A >= <x> + jset 7, 8, 9, 10 Jump on A & <x> add 0, 4 A + <x> sub 0, 4 A - <x> @@ -240,7 +240,7 @@ opcodes as defined in linux/filter.h stand for: tax Copy A into X txa Copy X into A - ret 4, 9 Return + ret 4, 11 Return The next table shows addressing formats from the 2nd column: @@ -254,9 +254,11 @@ The next table shows addressing formats from the 2nd column: 5 4*([k]&0xf) Lower nibble * 4 at byte offset k in the packet 6 L Jump label L 7 #k,Lt,Lf Jump to Lt if true, otherwise jump to Lf - 8 #k,Lt Jump to Lt if predicate is true - 9 a/%a Accumulator A - 10 extension BPF extension + 8 x/%x,Lt,Lf Jump to Lt if true, otherwise jump to Lf + 9 #k,Lt Jump to Lt if predicate is true + 10 x/%x,Lt Jump to Lt if predicate is true + 11 a/%a Accumulator A + 12 extension BPF extension The Linux kernel also has a couple of BPF extensions that are used along with the class of load instructions by "overloading" the k argument with |