package bpf

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package bpf
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Module
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Class
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Embedded eBPF assembler

Types

type size =
  1. | W
    (*

    word = 32 bit

    *)
  2. | H
    (*

    half-word = 16 bit

    *)
  3. | B
    (*

    byte

    *)
  4. | DW
    (*

    double word = 64 bit

    *)
type reg =
  1. | R0
  2. | R1
  3. | R2
  4. | R3
  5. | R4
  6. | R5
  7. | R6
  8. | R7
  9. | R8
  10. | R9
  11. | R10
type int16 = int
type cond = [
  1. | `EQ
    (*

    equal

    *)
  2. | `GE
    (*

    greater or equal

    *)
  3. | `GT
    (*

    greater than

    *)
  4. | `NE
    (*

    not equal

    *)
  5. | `SET
    (*

    bitwise AND

    *)
  6. | `SGE
    (*

    signed greater or equal

    *)
  7. | `SGT
    (*

    signed greater than

    *)
]
type +'label insn

Single eBPF instruction. 'label is type of labels, can be any hashable type, e.g. string, int, open variant, etc

Memory instructions

val ldx : size -> reg -> (reg * int16) -> 'a insn
val lddw : reg -> int64 -> 'a insn
val stx : size -> (reg * int16) -> reg -> 'a insn
val st : size -> (reg * int16) -> int -> 'a insn

Branch instructions

val label : 'label -> 'label insn

mark label position, each label should be unique

val ret : 'a insn
val call : int -> 'a insn
val jump : 'label -> 'label insn
val jmpi : 'label -> reg -> cond -> int -> 'label insn
val jmp : 'label -> reg -> cond -> reg -> 'label insn

raw jump instructions with manually-computed offset

you probably want to use functions above which take labels

val jump_ : int16 -> 'a insn
val jmpi_ : int16 -> reg -> cond -> int -> 'a insn
val jmp_ : int16 -> reg -> cond -> reg -> 'a insn

ALU (arithmetic/logic) instructions

module type ALU = sig ... end
module I32 : ALU

64-bit instructions, for 32-bit instructions use I32

include ALU
val add : reg -> reg -> 'a insn
val addi : reg -> int -> 'a insn
val sub : reg -> reg -> 'a insn
val subi : reg -> int -> 'a insn
val mul : reg -> reg -> 'a insn
val muli : reg -> int -> 'a insn
val div : reg -> reg -> 'a insn
val divi : reg -> int -> 'a insn
val or_ : reg -> reg -> 'a insn
val ori : reg -> int -> 'a insn
val and_ : reg -> reg -> 'a insn
val andi : reg -> int -> 'a insn
val lsh : reg -> reg -> 'a insn
val lshi : reg -> int -> 'a insn
val rsh : reg -> reg -> 'a insn
val rshi : reg -> int -> 'a insn
val neg : reg -> reg -> 'a insn
val negi : reg -> int -> 'a insn
val mod_ : reg -> reg -> 'a insn
val modi : reg -> int -> 'a insn
val xor : reg -> reg -> 'a insn
val xori : reg -> int -> 'a insn
val mov : reg -> reg -> 'a insn
val movi : reg -> int -> 'a insn
val arsh : reg -> reg -> 'a insn
val arshi : reg -> int -> 'a insn

Byteswap instructions

val le16 : reg -> 'a insn
val be16 : reg -> 'a insn
val le32 : reg -> 'a insn
val be32 : reg -> 'a insn
val le64 : reg -> 'a insn
val be64 : reg -> 'a insn

Assembler

type options = {
  1. disable_all_checks : bool;
    (*

    disable all checks, may generate invalid code

    *)
  2. jump_back : bool;
    (*

    allow jump backwards, may result in infinite loop

    *)
  3. jump_self : bool;
    (*

    allow jump to self, guaranteed infinite loop

    *)
}
val default : options
val assemble : ?options:options -> 'a insn list -> string