use false case as an alias to detach filter

Author: devnexen

ext/sockets/sockets.c

@@ -512,6 +512,8 @@ static PHP_MINIT_FUNCTION(sockets)
 #endif
 #ifdef SO_ATTACH_REUSEPORT_CBPF
 	REGISTER_LONG_CONSTANT("SO_ATTACH_REUSEPORT_CBPF", SO_ATTACH_REUSEPORT_CBPF, CONST_CS | CONST_PERSISTENT);
+	REGISTER_LONG_CONSTANT("SO_DETACH_FILTER", SO_DETACH_FILTER, CONST_CS | CONST_PERSISTENT);
+	REGISTER_LONG_CONSTANT("SO_DETACH_BPF", SO_DETACH_BPF, CONST_CS | CONST_PERSISTENT);
 #endif
 	REGISTER_LONG_CONSTANT("SO_KEEPALIVE",	SO_KEEPALIVE,	CONST_CS | CONST_PERSISTENT);
 	REGISTER_LONG_CONSTANT("SO_DONTROUTE",	SO_DONTROUTE,	CONST_CS | CONST_PERSISTENT);
@@ -2015,18 +2017,22 @@ PHP_FUNCTION(socket_set_option)
 		case SO_ATTACH_REUSEPORT_CBPF: {
 			convert_to_long(arg4);
 			if (!Z_LVAL_P(arg4)) {
-				RETURN_FALSE;
+				ov = 1;
+				optlen = sizeof(ov);
+				opt_ptr = &ov;
+				optname = SO_DETACH_BPF;
+			} else {
+				static struct sock_filter cbpf[] = {
+					BPF_STMT((BPF_LD|BPF_W|BPF_ABS), (uint32_t)(SKF_AD_OFF+SKF_AD_CPU)),
+					BPF_STMT((BPF_RET|BPF_A), 0),
+				};
+				static struct sock_fprog bpfprog = {
+					.len = (sizeof(cbpf) / sizeof(cbpf[0])),
+					.filter = cbpf,
+				};
+				optlen = sizeof(bpfprog);
+				opt_ptr = &bpfprog;
 			}
-			static struct sock_filter cbpf[] = {
-				BPF_STMT((BPF_LD|BPF_W|BPF_ABS), (uint32_t)(SKF_AD_OFF+SKF_AD_CPU)),
-				BPF_STMT((BPF_RET|BPF_A), 0),
-			};
-			static struct sock_fprog bpfprog = {
-				.len = (sizeof(cbpf) / sizeof(cbpf[0])),
-				.filter = cbpf,
-			};
-			optlen = sizeof(bpfprog);
-			opt_ptr = &bpfprog;
 			break;
 		}
 #endif