Add the missing case for "ldx #pktlen" to bpf_image().

pcap_compile() does not produce it, but pcapint_filter_with_aux_data()
implements it.  With this change the latter and bpf_image() implement
exactly the same instruction set.

Author: infrastation

bpf_image.c

@@ -176,6 +176,11 @@ bpf_image(const struct bpf_insn *p, int n)
 		operand = "#pktlen";
 		break;
 
+	case BPF_LDX|BPF_W|BPF_LEN:
+		op = "ldx";
+		operand = "#pktlen";
+		break;
+
 	case BPF_LD|BPF_W|BPF_IND:
 		op = "ld";
 		(void)snprintf(operand_buf, sizeof operand_buf, "[x + %d]", p->k);

testprogs/TESTrun

@@ -415,6 +415,7 @@ my @accept_blocks = (
 			(000) rsh      #43981                             ; 0x0074
 			(000) rsh      x                                  ; 0x007c
 			(000) ld       #pktlen                            ; 0x0080
+			(000) ldx      #pktlen                            ; 0x0081
 			(000) neg                                         ; 0x0084
 			(000) txa                                         ; 0x0087
 			(000) mod      #43981                             ; 0x0094