More of the BPF code ported

bpf.odin

@@ -0,0 +1,147 @@
+package odin_libpcap
+
+import _c "core:c"
+
+BPF_RELEASE :: 199606 // BSD style release dat.
+
+when ODIN_OS == .Windows {
+	bpf_int32 :: _c.long
+	bpf_u_int32 :: _c.ulong
+} else {
+	bpf_int32 :: _c.int
+	bpf_u_int32 :: _c.uint
+}
+
+BPF_ALIGNMENT :: size_of(i64) // Double check could be long 32.
+
+BPF_WORDALIGN :: proc(x: uint) { 	// MACRO - May want to take another look
+	var := ((x) + BPF_ALIGNMENT - 1) &~ (BPF_ALIGNMENT - 1)
+	// I THINK this is just rounding to the next multiple of sizeof(lone)
+	// Might work on both memory addresses and data sizes?
+}
+
+bpf_program :: struct {
+	bf_len:   _c.uint,
+	bf_insns: ^bpf_insn,
+}
+
+// Instruction Data Structure.
+bpf_insn :: struct {
+	code: _c.ushort,
+	jt:   _c.uchar,
+	jf:   _c.uchar,
+	k:    bpf_u_int32,
+}
+
+
+// The upper 8 bits of the opcode aren't used. BSD/OS used 0x8000.
+
+// instruction classes
+// #define BPF_CLA ::SS(code) ((code) & 0x07)
+BPF_CLASS :: proc(code: uint) -> uint {
+	return (code) & 0x07
+}
+BPF_LD :: 0x00
+BPF_LDX :: 0x01
+BPF_ST :: 0x02
+BPF_STX :: 0x03
+BPF_ALU :: 0x04
+BPF_JMP :: 0x05
+BPF_RET :: 0x06
+BPF_MISC :: 0x07
+
+// ld/ldx fields 
+// #define BPF_SIZ ::E(code)	((code) & 0x18)
+BPF_W :: 0x00
+BPF_H :: 0x08
+BPF_B :: 0x10
+//				0x18	reserved; used by BSD/OS 
+// #define BPF_MOD ::E(code)	((code) & 0xe0)
+BPF_IMM :: 0x00
+BPF_ABS :: 0x20
+BPF_IND :: 0x40
+BPF_MEM :: 0x60
+BPF_LEN :: 0x80
+BPF_MSH :: 0xa0
+//				0xc0	reserved; used by BSD/OS 
+//				0xe0	reserved; used by BSD/OS 
+
+// alu/jmp fields 
+// #define BPF_OP( ::code)	((code) & 0xf0)
+BPF_ADD :: 0x00
+BPF_SUB :: 0x10
+BPF_MUL :: 0x20
+BPF_DIV :: 0x30
+BPF_OR :: 0x40
+BPF_AND :: 0x50
+BPF_LSH :: 0x60
+BPF_RSH :: 0x70
+BPF_NEG :: 0x80
+BPF_MOD :: 0x90
+BPF_XOR :: 0xa0
+//				0xb0	reserved 
+//				0xc0	reserved 
+//				0xd0	reserved 
+//				0xe0	reserved 
+//				0xf0	reserved 
+
+BPF_JA :: 0x00
+BPF_JEQ :: 0x10
+BPF_JGT :: 0x20
+BPF_JGE :: 0x30
+BPF_JSET :: 0x40
+//				0x50	reserved; used on BSD/OS 
+//				0x60	reserved 
+//				0x70	reserved 
+//				0x80	reserved 
+//				0x90	reserved 
+//				0xa0	reserved 
+//				0xb0	reserved 
+//				0xc0	reserved 
+//				0xd0	reserved 
+//				0xe0	reserved 
+//				0xf0	reserved 
+// #define BPF_SRC ::(code)	((code) & 0x08)
+BPF_K :: 0x00
+BPF_X :: 0x08
+
+// ret - BPF_K a ::nd BPF_X a ::lso apply 
+// #define BPF_RVA ::L(code)	((code) & 0x18)
+BPF_A :: 0x10
+//				0x18	reserved 
+
+// misc 
+// #define BPF_MIS ::COP(code) ((code) & 0xf8)
+BPF_TAX :: 0x00
+//				0x08	reserved 
+//				0x10	reserved 
+//				0x18	reserved 
+// #define	BPF_COP ::		0x20	NetBSD "coprocessor" extensions 
+//				0x28	reserved 
+//				0x30	reserved 
+//				0x38	reserved 
+// #define	BPF_COP ::X	0x40	NetBSD "coprocessor" extensions 
+//					also used on BSD/OS 
+//				0x48	reserved 
+//				0x50	reserved 
+//				0x58	reserved 
+//				0x60	reserved 
+//				0x68	reserved 
+//				0x70	reserved 
+//				0x78	reserved 
+BPF_TXA :: 0x80
+//				0x88	reserved 
+//				0x90	reserved 
+//				0x98	reserved 
+//				0xa0	reserved 
+//				0xa8	reserved 
+//				0xb0	reserved 
+//				0xb8	reserved 
+//				0xc0	reserved; used on BSD/OS 
+//				0xc8	reserved 
+//				0xd0	reserved 
+//				0xd8	reserved 
+//				0xe0	reserved 
+//				0xe8	reserved 
+//				0xf0	reserved 
+//				0xf8	reserved