Fuss with compile-time config

13 files changed, 180 insertions, 135 deletions

diff --git a/cmd/sbc_harness/config/config.h b/cmd/sbc_harness/config/config.h
index 5ee8634..e436eb5 100644
--- a/cmd/sbc_harness/config/config.h
+++ b/cmd/sbc_harness/config/config.h
@@ -12,7 +12,18 @@
 /**
  * How many W5500 chips we have.
  */
-#define CONFIG_W5500_NUM              1
+#define CONFIG_W5500_NUM                1
+
+/**
+ * When allocating an arbitrary local port, what range should it be
+ * allocated from?
+ *
+ * These are the default values of the Linux kernel's
+ * net.ipv4.ip_local_port_range, so I figure they're probably good
+ * values to use.
+ */
+#define CONFIG_W5500_LOCAL_PORT_MIN     32768
+#define CONFIG_W5500_LOCAL_PORT_MAX     60999
 
 /* 9P *************************************************************************/
 
@@ -44,10 +55,20 @@
 #define CONFIG_9P_MAX_FIDS            16
 #define CONFIG_9P_MAX_REQS            2
 #define CONFIG_9P_MAX_ERR_SIZE        128 /* 128 is what Plan 9 4e uses */
+#define CONFIG_9P_ENABLE_9P2000       1 /* bool */
+#define CONFIG_9P_ENABLE_9P2000_u     1 /* bool */
+#define CONFIG_9P_ENABLE_9P2000_e     0 /* bool */
+
+/* DHCP ***********************************************************************/
+
+#define CONFIG_DHCP_CAN_RECV_UNICAST_IP_WITHOUT_IP      0
+#define CONFIG_DHCP_DEBUG                               0
+#define CONFIG_DHCP_OPT_SIZE                            312 /* minimum of 312 */
+#define CONFIG_DHCP_SELECTING_NS                        (5*NS_PER_S)
 
 /* COROUTINE ******************************************************************/
 
-#define CONFIG_COROUTINE_DEFAULT_STACK_SIZE    512
+#define CONFIG_COROUTINE_DEFAULT_STACK_SIZE    (2*1024)
 #define CONFIG_COROUTINE_MEASURE_STACK         1 /* bool */
 #define CONFIG_COROUTINE_PROTECT_STACK         1 /* bool */
 #define CONFIG_COROUTINE_DEBUG                 0 /* bool */
diff --git a/cmd/sbc_harness/main.c b/cmd/sbc_harness/main.c
index 8ee2e7d..d015259 100644
--- a/cmd/sbc_harness/main.c
+++ b/cmd/sbc_harness/main.c
@@ -90,7 +90,7 @@ int main() {
 	usb_keyboard_rpc_t keyboard_chan = {0};
 	coroutine_add(usb_keyboard_cr, &keyboard_chan);
 	//coroutine_add(hello_world_cr, &keyboard_chan);
-	coroutine_add_with_stack_size(3*1024, dhcp_cr, &dev_w5500);
+	coroutine_add_with_stack_size(4*1024, dhcp_cr, &dev_w5500);
 
 	/* event loop *********************************************************/
 	coroutine_main();
diff --git a/cmd/srv9p/config/config.h b/cmd/srv9p/config/config.h
index a184e6f..80c8125 100644
--- a/cmd/srv9p/config/config.h
+++ b/cmd/srv9p/config/config.h
@@ -7,7 +7,9 @@
 #ifndef _CONFIG_H_
 #define _CONFIG_H_
 
-#define CONFIG_NETIO_NUM_CONNS        8
+#define CONFIG_SRV9P_NUM_CONNS        8
+
+/* 9P *************************************************************************/
 
 #define CONFIG_9P_PORT                564
 /**
@@ -37,8 +39,11 @@
 #define CONFIG_9P_MAX_FIDS            16
 #define CONFIG_9P_MAX_REQS            2
 #define CONFIG_9P_MAX_ERR_SIZE        128 /* 128 is what Plan 9 4e uses */
-#define CONFIG_9P_ENABLE_9P2000_u
-/*#define CONFIG_9P_ENABLE_9P2000_e*/
+#define CONFIG_9P_ENABLE_9P2000       1 /* bool */
+#define CONFIG_9P_ENABLE_9P2000_u     1 /* bool */
+#define CONFIG_9P_ENABLE_9P2000_e     0 /* bool */
+
+/* COROUTINE ******************************************************************/
 
 #define CONFIG_COROUTINE_DEFAULT_STACK_SIZE    (32*1024)
 #define CONFIG_COROUTINE_MEASURE_STACK         1 /* bool */
@@ -47,7 +52,7 @@
 #define CONFIG_COROUTINE_VALGRIND              1 /* bool */
 #define CONFIG_COROUTINE_NUM                   (1                          /* usb_common   */ +\
                                                 1                          /* usb_keyboard */ +\
-                                                CONFIG_NETIO_NUM_CONNS     /* accept+read  */ +\
-                                                (CONFIG_9P_MAX_REQS*CONFIG_NETIO_NUM_CONNS) /* work+write   */ )
+                                                CONFIG_SRV9P_NUM_CONNS     /* accept+read  */ +\
+                                                (CONFIG_9P_MAX_REQS*CONFIG_SRV9P_NUM_CONNS) /* work+write   */ )
 
 #endif /* _CONFIG_H_ */
diff --git a/cmd/srv9p/main.c b/cmd/srv9p/main.c
index d30c4f9..c5a3367 100644
--- a/cmd/srv9p/main.c
+++ b/cmd/srv9p/main.c
@@ -19,8 +19,8 @@
 
 #include "config.h"
 
-#ifndef CONFIG_NETIO_NUM_CONNS
-	#error config.h must define CONFIG_NETIO_NUM_CONNS
+#ifndef CONFIG_SRV9P_NUM_CONNS
+	#error config.h must define CONFIG_SRV9P_NUM_CONNS
 #endif
 
 /* implementation *************************************************************/
@@ -104,10 +104,10 @@ int main() {
 		.rootdir = get_root,
 	};
 
-	for (int i = 0; i < CONFIG_NETIO_NUM_CONNS; i++)
+	for (int i = 0; i < CONFIG_SRV9P_NUM_CONNS; i++)
 		if (!coroutine_add(read_cr, &srv))
 			error(1, 0, "coroutine_add(read_cr, &srv)");
-	for (int i = 0; i < 2*CONFIG_NETIO_NUM_CONNS; i++)
+	for (int i = 0; i < 2*CONFIG_SRV9P_NUM_CONNS; i++)
 		if (!coroutine_add(lib9p_srv_write_cr, &srv))
 			error(1, 0, "coroutine_add(lib9p_srv_write_cr, &srv)");
 
diff --git a/lib9p/9p.c b/lib9p/9p.c
index 9ea0c46..5943b42 100644
--- a/lib9p/9p.c
+++ b/lib9p/9p.c
@@ -17,7 +17,7 @@
 
 void lib9p_ctx_clear_error(struct lib9p_ctx *ctx) {
 	assert(ctx);
-#ifdef CONFIG_9P_ENABLE_9P2000_u
+#if CONFIG_9P_ENABLE_9P2000_u
 	ctx->err_num = 0;
 #endif
 	ctx->err_msg[0] = '\0';
@@ -34,7 +34,7 @@ int lib9p_error(struct lib9p_ctx *ctx, uint32_t linux_errno, char const *msg) {
 	strncpy(ctx->err_msg, msg, sizeof(ctx->err_msg));
 	ctx->err_msg[sizeof(ctx->err_msg)-1] = '\0';
 
-#ifdef CONFIG_9P_ENABLE_9P2000_u
+#if CONFIG_9P_ENABLE_9P2000_u
 	ctx->err_num = linux_errno;
 #else
 	(void)(linux_errno);
@@ -55,7 +55,7 @@ int lib9p_errorf(struct lib9p_ctx *ctx, uint32_t linux_errno, char const *fmt, .
 	if ((size_t)(n+1) < sizeof(ctx->err_msg))
 		memset(&ctx->err_msg[n+1], 0, sizeof(ctx->err_msg)-(n+1));
 
-#ifdef CONFIG_9P_ENABLE_9P2000_u
+#if CONFIG_9P_ENABLE_9P2000_u
 	ctx->err_num = linux_errno;
 #else
 	(void)(linux_errno);
diff --git a/lib9p/9p.generated.c b/lib9p/9p.generated.c
index 1a00f10..536063a 100644
--- a/lib9p/9p.generated.c
+++ b/lib9p/9p.generated.c
@@ -15,15 +15,15 @@
 
 static const char *version_strs[LIB9P_VER_NUM] = {
 	[LIB9P_VER_unknown] = "unknown",
-#if defined(CONFIG_9P_ENABLE_9P2000)
+#if CONFIG_9P_ENABLE_9P2000
 	[LIB9P_VER_9P2000] = "9P2000",
-#endif /* defined(CONFIG_9P_ENABLE_9P2000) */
-#if defined(CONFIG_9P_ENABLE_9P2000_e)
+#endif /* CONFIG_9P_ENABLE_9P2000 */
+#if CONFIG_9P_ENABLE_9P2000_e
 	[LIB9P_VER_9P2000_e] = "9P2000.e",
-#endif /* defined(CONFIG_9P_ENABLE_9P2000_e) */
-#if defined(CONFIG_9P_ENABLE_9P2000_u)
+#endif /* CONFIG_9P_ENABLE_9P2000_e */
+#if CONFIG_9P_ENABLE_9P2000_u
 	[LIB9P_VER_9P2000_u] = "9P2000.u",
-#endif /* defined(CONFIG_9P_ENABLE_9P2000_u) */
+#endif /* CONFIG_9P_ENABLE_9P2000_u */
 };
 
 const char *lib9p_version_str(enum lib9p_version ver) {
@@ -67,7 +67,7 @@ static ALWAYS_INLINE bool _validate_list(struct _validate_ctx *ctx,
 #define validate_4(ctx) _validate_size_net(ctx, 4)
 #define validate_8(ctx) _validate_size_net(ctx, 8)
 
-#if defined(CONFIG_9P_ENABLE_9P2000) || defined(CONFIG_9P_ENABLE_9P2000_e) || defined(CONFIG_9P_ENABLE_9P2000_u)
+#if CONFIG_9P_ENABLE_9P2000 || CONFIG_9P_ENABLE_9P2000_e || CONFIG_9P_ENABLE_9P2000_u
 static ALWAYS_INLINE bool validate_tag(struct _validate_ctx *ctx) {
 	return validate_2(ctx);
 }
@@ -97,15 +97,15 @@ static ALWAYS_INLINE bool validate_s(struct _validate_ctx *ctx) {
 }
 
 static const lib9p_dm_t dm_masks[LIB9P_VER_NUM] = {
-#if defined(CONFIG_9P_ENABLE_9P2000)
+#if CONFIG_9P_ENABLE_9P2000
 	[LIB9P_VER_9P2000]   = 0b11101100000000000000000111111111,
-#endif /* defined(CONFIG_9P_ENABLE_9P2000) */
-#if defined(CONFIG_9P_ENABLE_9P2000_e)
+#endif /* CONFIG_9P_ENABLE_9P2000 */
+#if CONFIG_9P_ENABLE_9P2000_e
 	[LIB9P_VER_9P2000_e] = 0b11101100000000000000000111111111,
-#endif /* defined(CONFIG_9P_ENABLE_9P2000_e) */
-#if defined(CONFIG_9P_ENABLE_9P2000_u)
+#endif /* CONFIG_9P_ENABLE_9P2000_e */
+#if CONFIG_9P_ENABLE_9P2000_u
 	[LIB9P_VER_9P2000_u] = 0b11101100101111000000000111111111,
-#endif /* defined(CONFIG_9P_ENABLE_9P2000_u) */
+#endif /* CONFIG_9P_ENABLE_9P2000_u */
 };
 static ALWAYS_INLINE bool validate_dm(struct _validate_ctx *ctx) {
 	 if (validate_4(ctx))
@@ -118,15 +118,15 @@ static ALWAYS_INLINE bool validate_dm(struct _validate_ctx *ctx) {
 }
 
 static const lib9p_qt_t qt_masks[LIB9P_VER_NUM] = {
-#if defined(CONFIG_9P_ENABLE_9P2000)
+#if CONFIG_9P_ENABLE_9P2000
 	[LIB9P_VER_9P2000]   = 0b11101100,
-#endif /* defined(CONFIG_9P_ENABLE_9P2000) */
-#if defined(CONFIG_9P_ENABLE_9P2000_e)
+#endif /* CONFIG_9P_ENABLE_9P2000 */
+#if CONFIG_9P_ENABLE_9P2000_e
 	[LIB9P_VER_9P2000_e] = 0b11101100,
-#endif /* defined(CONFIG_9P_ENABLE_9P2000_e) */
-#if defined(CONFIG_9P_ENABLE_9P2000_u)
+#endif /* CONFIG_9P_ENABLE_9P2000_e */
+#if CONFIG_9P_ENABLE_9P2000_u
 	[LIB9P_VER_9P2000_u] = 0b11101110,
-#endif /* defined(CONFIG_9P_ENABLE_9P2000_u) */
+#endif /* CONFIG_9P_ENABLE_9P2000_u */
 };
 static ALWAYS_INLINE bool validate_qt(struct _validate_ctx *ctx) {
 	 if (validate_1(ctx))
@@ -162,27 +162,27 @@ static ALWAYS_INLINE bool validate_stat(struct _validate_ctx *ctx) {
 	    || validate_s(ctx)
 	    || validate_s(ctx)
 	    || validate_s(ctx)
-#if defined(CONFIG_9P_ENABLE_9P2000_u)
+#if CONFIG_9P_ENABLE_9P2000_u
 	    || ( (ctx->ctx->version==LIB9P_VER_9P2000_u) && validate_s(ctx) )
 	    || ( (ctx->ctx->version==LIB9P_VER_9P2000_u) && validate_4(ctx) )
 	    || ( (ctx->ctx->version==LIB9P_VER_9P2000_u) && validate_4(ctx) )
 	    || ( (ctx->ctx->version==LIB9P_VER_9P2000_u) && validate_4(ctx) )
-#endif /* defined(CONFIG_9P_ENABLE_9P2000_u) */
+#endif /* CONFIG_9P_ENABLE_9P2000_u */
 	    || ({ uint32_t exp = ctx->net_offset - _kern_type_offset; (((uint32_t)stat_size) != exp) &&
 	          lib9p_errorf(ctx->ctx, LINUX_EBADMSG, "stat_size value is wrong (actual:%"PRIu32" != correct:%"PRIu32")", (uint32_t)stat_size, exp); })
 	    ;
 }
 
 static const lib9p_o_t o_masks[LIB9P_VER_NUM] = {
-#if defined(CONFIG_9P_ENABLE_9P2000)
+#if CONFIG_9P_ENABLE_9P2000
 	[LIB9P_VER_9P2000]   = 0b01010011,
-#endif /* defined(CONFIG_9P_ENABLE_9P2000) */
-#if defined(CONFIG_9P_ENABLE_9P2000_e)
+#endif /* CONFIG_9P_ENABLE_9P2000 */
+#if CONFIG_9P_ENABLE_9P2000_e
 	[LIB9P_VER_9P2000_e] = 0b01010011,
-#endif /* defined(CONFIG_9P_ENABLE_9P2000_e) */
-#if defined(CONFIG_9P_ENABLE_9P2000_u)
+#endif /* CONFIG_9P_ENABLE_9P2000_e */
+#if CONFIG_9P_ENABLE_9P2000_u
 	[LIB9P_VER_9P2000_u] = 0b01010011,
-#endif /* defined(CONFIG_9P_ENABLE_9P2000_u) */
+#endif /* CONFIG_9P_ENABLE_9P2000_u */
 };
 static ALWAYS_INLINE bool validate_o(struct _validate_ctx *ctx) {
 	 if (validate_1(ctx))
@@ -239,9 +239,9 @@ static FLATTEN bool validate_Tauth(struct _validate_ctx *ctx) {
 	    || validate_fid(ctx)
 	    || validate_s(ctx)
 	    || validate_s(ctx)
-#if defined(CONFIG_9P_ENABLE_9P2000_u)
+#if CONFIG_9P_ENABLE_9P2000_u
 	    || ( (ctx->ctx->version==LIB9P_VER_9P2000_u) && validate_4(ctx) )
-#endif /* defined(CONFIG_9P_ENABLE_9P2000_u) */
+#endif /* CONFIG_9P_ENABLE_9P2000_u */
 	    || ({ uint32_t exp = ctx->net_offset - _size_offset; (((uint32_t)size) != exp) &&
 	          lib9p_errorf(ctx->ctx, LINUX_EBADMSG, "size value is wrong (actual:%"PRIu32" != correct:%"PRIu32")", (uint32_t)size, exp); })
 	    || ({ uint32_t exp = 102; (((uint32_t)typ) != exp) &&
@@ -277,9 +277,9 @@ static FLATTEN bool validate_Tattach(struct _validate_ctx *ctx) {
 	    || validate_fid(ctx)
 	    || validate_s(ctx)
 	    || validate_s(ctx)
-#if defined(CONFIG_9P_ENABLE_9P2000_u)
+#if CONFIG_9P_ENABLE_9P2000_u
 	    || ( (ctx->ctx->version==LIB9P_VER_9P2000_u) && validate_4(ctx) )
-#endif /* defined(CONFIG_9P_ENABLE_9P2000_u) */
+#endif /* CONFIG_9P_ENABLE_9P2000_u */
 	    || ({ uint32_t exp = ctx->net_offset - _size_offset; (((uint32_t)size) != exp) &&
 	          lib9p_errorf(ctx->ctx, LINUX_EBADMSG, "size value is wrong (actual:%"PRIu32" != correct:%"PRIu32")", (uint32_t)size, exp); })
 	    || ({ uint32_t exp = 104; (((uint32_t)typ) != exp) &&
@@ -312,9 +312,9 @@ static FLATTEN bool validate_Rerror(struct _validate_ctx *ctx) {
 	    || (validate_1(ctx) || ({ typ = decode_u8le(&ctx->net_bytes[ctx->net_offset-1]); false; }))
 	    || validate_tag(ctx)
 	    || validate_s(ctx)
-#if defined(CONFIG_9P_ENABLE_9P2000_u)
+#if CONFIG_9P_ENABLE_9P2000_u
 	    || ( (ctx->ctx->version==LIB9P_VER_9P2000_u) && validate_4(ctx) )
-#endif /* defined(CONFIG_9P_ENABLE_9P2000_u) */
+#endif /* CONFIG_9P_ENABLE_9P2000_u */
 	    || ({ uint32_t exp = ctx->net_offset - _size_offset; (((uint32_t)size) != exp) &&
 	          lib9p_errorf(ctx->ctx, LINUX_EBADMSG, "size value is wrong (actual:%"PRIu32" != correct:%"PRIu32")", (uint32_t)size, exp); })
 	    || ({ uint32_t exp = 107; (((uint32_t)typ) != exp) &&
@@ -669,8 +669,8 @@ static FLATTEN bool validate_Rwstat(struct _validate_ctx *ctx) {
 	    ;
 }
 
-#endif /* defined(CONFIG_9P_ENABLE_9P2000) || defined(CONFIG_9P_ENABLE_9P2000_e) || defined(CONFIG_9P_ENABLE_9P2000_u) */
-#if defined(CONFIG_9P_ENABLE_9P2000_e)
+#endif /* CONFIG_9P_ENABLE_9P2000 || CONFIG_9P_ENABLE_9P2000_e || CONFIG_9P_ENABLE_9P2000_u */
+#if CONFIG_9P_ENABLE_9P2000_e
 static FLATTEN bool validate_Tsession(struct _validate_ctx *ctx) {
 	uint32_t size;
 	uint8_t typ;
@@ -770,7 +770,7 @@ static FLATTEN bool validate_Rswrite(struct _validate_ctx *ctx) {
 	          lib9p_errorf(ctx->ctx, LINUX_EBADMSG, "typ value is wrong (actual:%"PRIu32" != correct:%"PRIu32")", (uint32_t)typ, exp); })
 	    ;
 }
-#endif /* defined(CONFIG_9P_ENABLE_9P2000_e) */
+#endif /* CONFIG_9P_ENABLE_9P2000_e */
 
 /* unmarshal_* ****************************************************************/
 
@@ -794,7 +794,7 @@ static ALWAYS_INLINE void unmarshal_8(struct _unmarshal_ctx *ctx, uint64_t *out)
 	ctx->net_offset += 8;
 }
 
-#if defined(CONFIG_9P_ENABLE_9P2000) || defined(CONFIG_9P_ENABLE_9P2000_e) || defined(CONFIG_9P_ENABLE_9P2000_u)
+#if CONFIG_9P_ENABLE_9P2000 || CONFIG_9P_ENABLE_9P2000_e || CONFIG_9P_ENABLE_9P2000_u
 static ALWAYS_INLINE void unmarshal_tag(struct _unmarshal_ctx *ctx, lib9p_tag_t *out) {
 	unmarshal_2(ctx, (uint16_t *)out);
 }
@@ -852,12 +852,12 @@ static ALWAYS_INLINE void unmarshal_stat(struct _unmarshal_ctx *ctx, struct lib9
 	unmarshal_s(ctx, &out->file_owner_uid);
 	unmarshal_s(ctx, &out->file_owner_gid);
 	unmarshal_s(ctx, &out->file_last_modified_uid);
-#if defined(CONFIG_9P_ENABLE_9P2000_u)
+#if CONFIG_9P_ENABLE_9P2000_u
 	if ( (ctx->ctx->version==LIB9P_VER_9P2000_u) ) unmarshal_s(ctx, &out->file_extension);
 	if ( (ctx->ctx->version==LIB9P_VER_9P2000_u) ) unmarshal_4(ctx, &out->file_owner_n_uid);
 	if ( (ctx->ctx->version==LIB9P_VER_9P2000_u) ) unmarshal_4(ctx, &out->file_owner_n_gid);
 	if ( (ctx->ctx->version==LIB9P_VER_9P2000_u) ) unmarshal_4(ctx, &out->file_last_modified_n_uid);
-#endif /* defined(CONFIG_9P_ENABLE_9P2000_u) */
+#endif /* CONFIG_9P_ENABLE_9P2000_u */
 }
 
 static ALWAYS_INLINE void unmarshal_o(struct _unmarshal_ctx *ctx, lib9p_o_t *out) {
@@ -890,9 +890,9 @@ static FLATTEN void unmarshal_Tauth(struct _unmarshal_ctx *ctx, struct lib9p_msg
 	unmarshal_fid(ctx, &out->afid);
 	unmarshal_s(ctx, &out->uname);
 	unmarshal_s(ctx, &out->aname);
-#if defined(CONFIG_9P_ENABLE_9P2000_u)
+#if CONFIG_9P_ENABLE_9P2000_u
 	if ( (ctx->ctx->version==LIB9P_VER_9P2000_u) ) unmarshal_4(ctx, &out->n_uname);
-#endif /* defined(CONFIG_9P_ENABLE_9P2000_u) */
+#endif /* CONFIG_9P_ENABLE_9P2000_u */
 }
 
 static FLATTEN void unmarshal_Rauth(struct _unmarshal_ctx *ctx, struct lib9p_msg_Rauth *out) {
@@ -912,9 +912,9 @@ static FLATTEN void unmarshal_Tattach(struct _unmarshal_ctx *ctx, struct lib9p_m
 	unmarshal_fid(ctx, &out->afid);
 	unmarshal_s(ctx, &out->uname);
 	unmarshal_s(ctx, &out->aname);
-#if defined(CONFIG_9P_ENABLE_9P2000_u)
+#if CONFIG_9P_ENABLE_9P2000_u
 	if ( (ctx->ctx->version==LIB9P_VER_9P2000_u) ) unmarshal_4(ctx, &out->n_uname);
-#endif /* defined(CONFIG_9P_ENABLE_9P2000_u) */
+#endif /* CONFIG_9P_ENABLE_9P2000_u */
 }
 
 static FLATTEN void unmarshal_Rattach(struct _unmarshal_ctx *ctx, struct lib9p_msg_Rattach *out) {
@@ -931,9 +931,9 @@ static FLATTEN void unmarshal_Rerror(struct _unmarshal_ctx *ctx, struct lib9p_ms
 	ctx->net_offset += 1;
 	unmarshal_tag(ctx, &out->tag);
 	unmarshal_s(ctx, &out->ename);
-#if defined(CONFIG_9P_ENABLE_9P2000_u)
+#if CONFIG_9P_ENABLE_9P2000_u
 	if ( (ctx->ctx->version==LIB9P_VER_9P2000_u) ) unmarshal_4(ctx, &out->errno);
-#endif /* defined(CONFIG_9P_ENABLE_9P2000_u) */
+#endif /* CONFIG_9P_ENABLE_9P2000_u */
 }
 
 static FLATTEN void unmarshal_Tflush(struct _unmarshal_ctx *ctx, struct lib9p_msg_Tflush *out) {
@@ -1115,8 +1115,8 @@ static FLATTEN void unmarshal_Rwstat(struct _unmarshal_ctx *ctx, struct lib9p_ms
 	unmarshal_tag(ctx, &out->tag);
 }
 
-#endif /* defined(CONFIG_9P_ENABLE_9P2000) || defined(CONFIG_9P_ENABLE_9P2000_e) || defined(CONFIG_9P_ENABLE_9P2000_u) */
-#if defined(CONFIG_9P_ENABLE_9P2000_e)
+#endif /* CONFIG_9P_ENABLE_9P2000 || CONFIG_9P_ENABLE_9P2000_e || CONFIG_9P_ENABLE_9P2000_u */
+#if CONFIG_9P_ENABLE_9P2000_e
 static FLATTEN void unmarshal_Tsession(struct _unmarshal_ctx *ctx, struct lib9p_msg_Tsession *out) {
 	memset(out, 0, sizeof(*out));
 	ctx->net_offset += 4;
@@ -1174,7 +1174,7 @@ static FLATTEN void unmarshal_Rswrite(struct _unmarshal_ctx *ctx, struct lib9p_m
 	unmarshal_tag(ctx, &out->tag);
 	unmarshal_4(ctx, &out->count);
 }
-#endif /* defined(CONFIG_9P_ENABLE_9P2000_e) */
+#endif /* CONFIG_9P_ENABLE_9P2000_e */
 
 /* marshal_* ******************************************************************/
 
@@ -1218,7 +1218,7 @@ static ALWAYS_INLINE bool marshal_8(struct _marshal_ctx *ctx, uint64_t *val) {
 	return false;
 }
 
-#if defined(CONFIG_9P_ENABLE_9P2000) || defined(CONFIG_9P_ENABLE_9P2000_e) || defined(CONFIG_9P_ENABLE_9P2000_u)
+#if CONFIG_9P_ENABLE_9P2000 || CONFIG_9P_ENABLE_9P2000_e || CONFIG_9P_ENABLE_9P2000_u
 static ALWAYS_INLINE bool marshal_tag(struct _marshal_ctx *ctx, lib9p_tag_t *val) {
 	return marshal_2(ctx, (uint16_t *)val);
 }
@@ -1281,12 +1281,12 @@ static ALWAYS_INLINE bool marshal_stat(struct _marshal_ctx *ctx, struct lib9p_st
 	    || marshal_s(ctx, &val->file_owner_uid)
 	    || marshal_s(ctx, &val->file_owner_gid)
 	    || marshal_s(ctx, &val->file_last_modified_uid)
-#if defined(CONFIG_9P_ENABLE_9P2000_u)
+#if CONFIG_9P_ENABLE_9P2000_u
 	    || ( (ctx->ctx->version==LIB9P_VER_9P2000_u) && marshal_s(ctx, &val->file_extension) )
 	    || ( (ctx->ctx->version==LIB9P_VER_9P2000_u) && marshal_4(ctx, &val->file_owner_n_uid) )
 	    || ( (ctx->ctx->version==LIB9P_VER_9P2000_u) && marshal_4(ctx, &val->file_owner_n_gid) )
 	    || ( (ctx->ctx->version==LIB9P_VER_9P2000_u) && marshal_4(ctx, &val->file_last_modified_n_uid) )
-#endif /* defined(CONFIG_9P_ENABLE_9P2000_u) */
+#endif /* CONFIG_9P_ENABLE_9P2000_u */
 	    || ({ encode_u16le(ctx->net_offset - _kern_type_offset, &ctx->net_bytes[_stat_size_offset]); false; })
 	    ;
 }
@@ -1334,9 +1334,9 @@ static FLATTEN bool marshal_Tauth(struct _marshal_ctx *ctx, struct lib9p_msg_Tau
 	    || marshal_fid(ctx, &val->afid)
 	    || marshal_s(ctx, &val->uname)
 	    || marshal_s(ctx, &val->aname)
-#if defined(CONFIG_9P_ENABLE_9P2000_u)
+#if CONFIG_9P_ENABLE_9P2000_u
 	    || ( (ctx->ctx->version==LIB9P_VER_9P2000_u) && marshal_4(ctx, &val->n_uname) )
-#endif /* defined(CONFIG_9P_ENABLE_9P2000_u) */
+#endif /* CONFIG_9P_ENABLE_9P2000_u */
 	    || ({ encode_u32le(ctx->net_offset - _size_offset, &ctx->net_bytes[_size_offset]); false; })
 	    || ({ encode_u8le(102, &ctx->net_bytes[_typ_offset]); false; })
 	    ;
@@ -1366,9 +1366,9 @@ static FLATTEN bool marshal_Tattach(struct _marshal_ctx *ctx, struct lib9p_msg_T
 	    || marshal_fid(ctx, &val->afid)
 	    || marshal_s(ctx, &val->uname)
 	    || marshal_s(ctx, &val->aname)
-#if defined(CONFIG_9P_ENABLE_9P2000_u)
+#if CONFIG_9P_ENABLE_9P2000_u
 	    || ( (ctx->ctx->version==LIB9P_VER_9P2000_u) && marshal_4(ctx, &val->n_uname) )
-#endif /* defined(CONFIG_9P_ENABLE_9P2000_u) */
+#endif /* CONFIG_9P_ENABLE_9P2000_u */
 	    || ({ encode_u32le(ctx->net_offset - _size_offset, &ctx->net_bytes[_size_offset]); false; })
 	    || ({ encode_u8le(104, &ctx->net_bytes[_typ_offset]); false; })
 	    ;
@@ -1395,9 +1395,9 @@ static FLATTEN bool marshal_Rerror(struct _marshal_ctx *ctx, struct lib9p_msg_Re
 	    || ({ _typ_offset = ctx->net_offset; ({ ctx->net_offset += 1; false; }); })
 	    || marshal_tag(ctx, &val->tag)
 	    || marshal_s(ctx, &val->ename)
-#if defined(CONFIG_9P_ENABLE_9P2000_u)
+#if CONFIG_9P_ENABLE_9P2000_u
 	    || ( (ctx->ctx->version==LIB9P_VER_9P2000_u) && marshal_4(ctx, &val->errno) )
-#endif /* defined(CONFIG_9P_ENABLE_9P2000_u) */
+#endif /* CONFIG_9P_ENABLE_9P2000_u */
 	    || ({ encode_u32le(ctx->net_offset - _size_offset, &ctx->net_bytes[_size_offset]); false; })
 	    || ({ encode_u8le(107, &ctx->net_bytes[_typ_offset]); false; })
 	    ;
@@ -1688,8 +1688,8 @@ static FLATTEN bool marshal_Rwstat(struct _marshal_ctx *ctx, struct lib9p_msg_Rw
 	    ;
 }
 
-#endif /* defined(CONFIG_9P_ENABLE_9P2000) || defined(CONFIG_9P_ENABLE_9P2000_e) || defined(CONFIG_9P_ENABLE_9P2000_u) */
-#if defined(CONFIG_9P_ENABLE_9P2000_e)
+#endif /* CONFIG_9P_ENABLE_9P2000 || CONFIG_9P_ENABLE_9P2000_e || CONFIG_9P_ENABLE_9P2000_u */
+#if CONFIG_9P_ENABLE_9P2000_e
 static FLATTEN bool marshal_Tsession(struct _marshal_ctx *ctx, struct lib9p_msg_Tsession *val) {
 	uint32_t _size_offset;
 	uint32_t _typ_offset;
@@ -1777,7 +1777,7 @@ static FLATTEN bool marshal_Rswrite(struct _marshal_ctx *ctx, struct lib9p_msg_R
 	    || ({ encode_u8le(155, &ctx->net_bytes[_typ_offset]); false; })
 	    ;
 }
-#endif /* defined(CONFIG_9P_ENABLE_9P2000_e) */
+#endif /* CONFIG_9P_ENABLE_9P2000_e */
 
 /* tables / exports ***********************************************************/
 
@@ -2051,7 +2051,7 @@ struct _table_version _lib9p_versions[LIB9P_VER_NUM] = {
 		_NONMSG(0xFE),
 		_NONMSG(0xFF),
 	}},
-#if defined(CONFIG_9P_ENABLE_9P2000)
+#if CONFIG_9P_ENABLE_9P2000
 	[LIB9P_VER_9P2000] = { .msgs = {
 		_NONMSG(0x00),
 		_NONMSG(0x01),
@@ -2310,8 +2310,8 @@ struct _table_version _lib9p_versions[LIB9P_VER_NUM] = {
 		_NONMSG(0xFE),
 		_NONMSG(0xFF),
 	}},
-#endif /* defined(CONFIG_9P_ENABLE_9P2000) */
-#if defined(CONFIG_9P_ENABLE_9P2000_e)
+#endif /* CONFIG_9P_ENABLE_9P2000 */
+#if CONFIG_9P_ENABLE_9P2000_e
 	[LIB9P_VER_9P2000_e] = { .msgs = {
 		_NONMSG(0x00),
 		_NONMSG(0x01),
@@ -2570,8 +2570,8 @@ struct _table_version _lib9p_versions[LIB9P_VER_NUM] = {
 		_NONMSG(0xFE),
 		_NONMSG(0xFF),
 	}},
-#endif /* defined(CONFIG_9P_ENABLE_9P2000_e) */
-#if defined(CONFIG_9P_ENABLE_9P2000_u)
+#endif /* CONFIG_9P_ENABLE_9P2000_e */
+#if CONFIG_9P_ENABLE_9P2000_u
 	[LIB9P_VER_9P2000_u] = { .msgs = {
 		_NONMSG(0x00),
 		_NONMSG(0x01),
@@ -2830,7 +2830,7 @@ struct _table_version _lib9p_versions[LIB9P_VER_NUM] = {
 		_NONMSG(0xFE),
 		_NONMSG(0xFF),
 	}},
-#endif /* defined(CONFIG_9P_ENABLE_9P2000_u) */
+#endif /* CONFIG_9P_ENABLE_9P2000_u */
 };
 
 FLATTEN bool _lib9p_validate_stat(struct _validate_ctx *ctx) {
diff --git a/lib9p/idl.gen b/lib9p/idl.gen
index 3be1d7e..e423196 100755
--- a/lib9p/idl.gen
+++ b/lib9p/idl.gen
@@ -463,7 +463,7 @@ def c_ver_enum(ver: str) -> str:
 
 def c_ver_ifdef(versions: set[str]) -> str:
     return " || ".join(
-        f"defined(CONFIG_9P_ENABLE_{v.replace('.', '_')})" for v in sorted(versions)
+        f"CONFIG_9P_ENABLE_{v.replace('.', '_')}" for v in sorted(versions)
     )
 
 
@@ -545,6 +545,17 @@ def gen_h(versions: set[str], typs: list[Type]) -> str:
 """
 
     ret += f"""
+/* config *********************************************************************/
+
+#include "config.h"
+"""
+    for ver in sorted(versions):
+        ret += "\n"
+        ret += f"#ifndef {c_ver_ifdef({ver})}\n"
+        ret += f"\t#error config.h must define {c_ver_ifdef({ver})}\n"
+        ret += "#endif\n"
+
+    ret += f"""
 /* versions *******************************************************************/
 
 enum {idprefix}version {{
diff --git a/lib9p/include/lib9p/9p.generated.h b/lib9p/include/lib9p/9p.generated.h
index feca8c9..25aacfe 100644
--- a/lib9p/include/lib9p/9p.generated.h
+++ b/lib9p/include/lib9p/9p.generated.h
@@ -6,19 +6,35 @@
 
 #include <stdint.h> /* for uint{n}_t types */
 
+/* config *********************************************************************/
+
+#include "config.h"
+
+#ifndef CONFIG_9P_ENABLE_9P2000
+	#error config.h must define CONFIG_9P_ENABLE_9P2000
+#endif
+
+#ifndef CONFIG_9P_ENABLE_9P2000_e
+	#error config.h must define CONFIG_9P_ENABLE_9P2000_e
+#endif
+
+#ifndef CONFIG_9P_ENABLE_9P2000_u
+	#error config.h must define CONFIG_9P_ENABLE_9P2000_u
+#endif
+
 /* versions *******************************************************************/
 
 enum lib9p_version {
 	LIB9P_VER_unknown = 0, /* "unknown" */
-#if defined(CONFIG_9P_ENABLE_9P2000)
+#if CONFIG_9P_ENABLE_9P2000
 	LIB9P_VER_9P2000,      /* "9P2000" */
-#endif /* defined(CONFIG_9P_ENABLE_9P2000) */
-#if defined(CONFIG_9P_ENABLE_9P2000_e)
+#endif /* CONFIG_9P_ENABLE_9P2000 */
+#if CONFIG_9P_ENABLE_9P2000_e
 	LIB9P_VER_9P2000_e,    /* "9P2000.e" */
-#endif /* defined(CONFIG_9P_ENABLE_9P2000_e) */
-#if defined(CONFIG_9P_ENABLE_9P2000_u)
+#endif /* CONFIG_9P_ENABLE_9P2000_e */
+#if CONFIG_9P_ENABLE_9P2000_u
 	LIB9P_VER_9P2000_u,    /* "9P2000.u" */
-#endif /* defined(CONFIG_9P_ENABLE_9P2000_u) */
+#endif /* CONFIG_9P_ENABLE_9P2000_u */
 	LIB9P_VER_NUM,
 };
 
@@ -26,7 +42,7 @@ const char *lib9p_version_str(enum lib9p_version);
 
 /* non-message types **********************************************************/
 
-#if defined(CONFIG_9P_ENABLE_9P2000) || defined(CONFIG_9P_ENABLE_9P2000_e) || defined(CONFIG_9P_ENABLE_9P2000_u)
+#if CONFIG_9P_ENABLE_9P2000 || CONFIG_9P_ENABLE_9P2000_e || CONFIG_9P_ENABLE_9P2000_u
 typedef uint16_t lib9p_tag_t;
 
 typedef uint32_t lib9p_fid_t;
@@ -51,16 +67,16 @@ typedef uint32_t lib9p_dm_t;
 #define   LIB9P_DM_TMP           ((lib9p_dm_t)(1<<26))
 /* unused                        ((lib9p_dm_t)(1<<25)) */
 /* unused                        ((lib9p_dm_t)(1<<24)) */
-#if defined(CONFIG_9P_ENABLE_9P2000_u)
+#if CONFIG_9P_ENABLE_9P2000_u
 #  define LIB9P_DM_DEVICE        ((lib9p_dm_t)(1<<23))
-#endif /* defined(CONFIG_9P_ENABLE_9P2000_u) */
+#endif /* CONFIG_9P_ENABLE_9P2000_u */
 /* unused                        ((lib9p_dm_t)(1<<22)) */
-#if defined(CONFIG_9P_ENABLE_9P2000_u)
+#if CONFIG_9P_ENABLE_9P2000_u
 #  define LIB9P_DM_NAMEDPIPE     ((lib9p_dm_t)(1<<21))
 #  define LIB9P_DM_SOCKET        ((lib9p_dm_t)(1<<20))
 #  define LIB9P_DM_SETUID        ((lib9p_dm_t)(1<<19))
 #  define LIB9P_DM_SETGID        ((lib9p_dm_t)(1<<18))
-#endif /* defined(CONFIG_9P_ENABLE_9P2000_u) */
+#endif /* CONFIG_9P_ENABLE_9P2000_u */
 /* unused                        ((lib9p_dm_t)(1<<17)) */
 /* unused                        ((lib9p_dm_t)(1<<16)) */
 /* unused                        ((lib9p_dm_t)(1<<15)) */
@@ -90,9 +106,9 @@ typedef uint8_t lib9p_qt_t;
 #define   _LIB9P_QT_PLAN9_MOUNT  ((lib9p_qt_t)(1<<4))
 #define   LIB9P_QT_AUTH          ((lib9p_qt_t)(1<<3))
 #define   LIB9P_QT_TMP           ((lib9p_qt_t)(1<<2))
-#if defined(CONFIG_9P_ENABLE_9P2000_u)
+#if CONFIG_9P_ENABLE_9P2000_u
 #  define LIB9P_QT_SYMLINK       ((lib9p_qt_t)(1<<1))
-#endif /* defined(CONFIG_9P_ENABLE_9P2000_u) */
+#endif /* CONFIG_9P_ENABLE_9P2000_u */
 /* unused                        ((lib9p_qt_t)(1<<0)) */
 
 #define   LIB9P_QT_FILE          ((lib9p_qt_t)(0))
@@ -115,12 +131,12 @@ struct lib9p_stat {
 	struct lib9p_s     file_owner_uid;
 	struct lib9p_s     file_owner_gid;
 	struct lib9p_s     file_last_modified_uid;
-#if defined(CONFIG_9P_ENABLE_9P2000_u)
+#if CONFIG_9P_ENABLE_9P2000_u
 	struct lib9p_s     file_extension;
 	uint32_t           file_owner_n_uid;
 	uint32_t           file_owner_n_gid;
 	uint32_t           file_last_modified_n_uid;
-#endif /* defined(CONFIG_9P_ENABLE_9P2000_u) */
+#endif /* CONFIG_9P_ENABLE_9P2000_u */
 };
 
 typedef uint8_t lib9p_o_t;
@@ -140,12 +156,12 @@ typedef uint8_t lib9p_o_t;
 #define   LIB9P_O_EXEC       ((lib9p_o_t)(3))
 #define   LIB9P_O_MODE_MASK  ((lib9p_o_t)(0b00000011))
 #define   LIB9P_O_FLAG_MASK  ((lib9p_o_t)(0b11111100))
-#endif /* defined(CONFIG_9P_ENABLE_9P2000) || defined(CONFIG_9P_ENABLE_9P2000_e) || defined(CONFIG_9P_ENABLE_9P2000_u) */
+#endif /* CONFIG_9P_ENABLE_9P2000 || CONFIG_9P_ENABLE_9P2000_e || CONFIG_9P_ENABLE_9P2000_u */
 
 /* messages *******************************************************************/
 
 enum lib9p_msg_type { /* uint8_t */
-#if defined(CONFIG_9P_ENABLE_9P2000) || defined(CONFIG_9P_ENABLE_9P2000_e) || defined(CONFIG_9P_ENABLE_9P2000_u)
+#if CONFIG_9P_ENABLE_9P2000 || CONFIG_9P_ENABLE_9P2000_e || CONFIG_9P_ENABLE_9P2000_u
 	LIB9P_TYP_Tversion = 100,
 	LIB9P_TYP_Rversion = 101,
 	LIB9P_TYP_Tauth    = 102,
@@ -173,18 +189,18 @@ enum lib9p_msg_type { /* uint8_t */
 	LIB9P_TYP_Rstat    = 125,
 	LIB9P_TYP_Twstat   = 126,
 	LIB9P_TYP_Rwstat   = 127,
-#endif /* defined(CONFIG_9P_ENABLE_9P2000) || defined(CONFIG_9P_ENABLE_9P2000_e) || defined(CONFIG_9P_ENABLE_9P2000_u) */
-#if defined(CONFIG_9P_ENABLE_9P2000_e)
+#endif /* CONFIG_9P_ENABLE_9P2000 || CONFIG_9P_ENABLE_9P2000_e || CONFIG_9P_ENABLE_9P2000_u */
+#if CONFIG_9P_ENABLE_9P2000_e
 	LIB9P_TYP_Tsession = 150,
 	LIB9P_TYP_Rsession = 151,
 	LIB9P_TYP_Tsread   = 152,
 	LIB9P_TYP_Rsread   = 153,
 	LIB9P_TYP_Tswrite  = 154,
 	LIB9P_TYP_Rswrite  = 155,
-#endif /* defined(CONFIG_9P_ENABLE_9P2000_e) */
+#endif /* CONFIG_9P_ENABLE_9P2000_e */
 };
 
-#if defined(CONFIG_9P_ENABLE_9P2000) || defined(CONFIG_9P_ENABLE_9P2000_e) || defined(CONFIG_9P_ENABLE_9P2000_u)
+#if CONFIG_9P_ENABLE_9P2000 || CONFIG_9P_ENABLE_9P2000_e || CONFIG_9P_ENABLE_9P2000_u
 struct lib9p_msg_Tversion {
 	lib9p_tag_t      tag;
 	uint32_t         max_msg_size;
@@ -202,9 +218,9 @@ struct lib9p_msg_Tauth {
 	lib9p_fid_t      afid;
 	struct lib9p_s   uname;
 	struct lib9p_s   aname;
-#if defined(CONFIG_9P_ENABLE_9P2000_u)
+#if CONFIG_9P_ENABLE_9P2000_u
 	uint32_t         n_uname;
-#endif /* defined(CONFIG_9P_ENABLE_9P2000_u) */
+#endif /* CONFIG_9P_ENABLE_9P2000_u */
 };
 
 struct lib9p_msg_Rauth {
@@ -218,9 +234,9 @@ struct lib9p_msg_Tattach {
 	lib9p_fid_t      afid;
 	struct lib9p_s   uname;
 	struct lib9p_s   aname;
-#if defined(CONFIG_9P_ENABLE_9P2000_u)
+#if CONFIG_9P_ENABLE_9P2000_u
 	uint32_t         n_uname;
-#endif /* defined(CONFIG_9P_ENABLE_9P2000_u) */
+#endif /* CONFIG_9P_ENABLE_9P2000_u */
 };
 
 struct lib9p_msg_Rattach {
@@ -231,9 +247,9 @@ struct lib9p_msg_Rattach {
 struct lib9p_msg_Rerror {
 	lib9p_tag_t      tag;
 	struct lib9p_s   ename;
-#if defined(CONFIG_9P_ENABLE_9P2000_u)
+#if CONFIG_9P_ENABLE_9P2000_u
 	uint32_t         errno;
-#endif /* defined(CONFIG_9P_ENABLE_9P2000_u) */
+#endif /* CONFIG_9P_ENABLE_9P2000_u */
 };
 
 struct lib9p_msg_Tflush {
@@ -347,8 +363,8 @@ struct lib9p_msg_Rwstat {
 	lib9p_tag_t   tag;
 };
 
-#endif /* defined(CONFIG_9P_ENABLE_9P2000) || defined(CONFIG_9P_ENABLE_9P2000_e) || defined(CONFIG_9P_ENABLE_9P2000_u) */
-#if defined(CONFIG_9P_ENABLE_9P2000_e)
+#endif /* CONFIG_9P_ENABLE_9P2000 || CONFIG_9P_ENABLE_9P2000_e || CONFIG_9P_ENABLE_9P2000_u */
+#if CONFIG_9P_ENABLE_9P2000_e
 struct lib9p_msg_Tsession {
 	lib9p_tag_t   tag;
 	uint64_t      key;
@@ -382,4 +398,4 @@ struct lib9p_msg_Rswrite {
 	lib9p_tag_t   tag;
 	uint32_t      count;
 };
-#endif /* defined(CONFIG_9P_ENABLE_9P2000_e) */
+#endif /* CONFIG_9P_ENABLE_9P2000_e */
diff --git a/lib9p/include/lib9p/9p.h b/lib9p/include/lib9p/9p.h
index 9d22354..fb1f97d 100644
--- a/lib9p/include/lib9p/9p.h
+++ b/lib9p/include/lib9p/9p.h
@@ -13,21 +13,13 @@
 #include <libmisc/assert.h>
 
 #include <lib9p/linux-errno.h>
-
-/* configuration **************************************************************/
-
-#include "config.h"
+#include <lib9p/9p.generated.h>
 
 #ifndef CONFIG_9P_MAX_ERR_SIZE
 	#error config.h must define CONFIG_9P_MAX_ERR_SIZE
 #endif
-#ifndef CONFIG_9P_ENABLE_9P2000
-	#define CONFIG_9P_ENABLE_9P2000
-#endif
-
-/* protocol definitions *******************************************************/
 
-#include <lib9p/9p.generated.h> /* *after* config.h */
+/******************************************************************************/
 
 #define LIB9P_NOTAG ((uint16_t)~0U)
 #define LIB9P_NOFID ((uint32_t)~0U)
diff --git a/lib9p/srv.c b/lib9p/srv.c
index 608d470..5bec0d6 100644
--- a/lib9p/srv.c
+++ b/lib9p/srv.c
@@ -134,7 +134,7 @@ static uint32_t rerror_overhead_for_version(enum lib9p_version version,
 }
 
 static void respond_error(struct _lib9p_srv_req *req) {
-#ifdef CONFIG_9P_ENABLE_9P2000_u
+#if CONFIG_9P_ENABLE_9P2000_u
 	assert(req->ctx.basectx.err_num);
 #endif
 	assert(req->ctx.basectx.err_msg[0]);
@@ -147,7 +147,7 @@ static void respond_error(struct _lib9p_srv_req *req) {
 			               CONFIG_9P_MAX_ERR_SIZE),
 			.utf8 = req->ctx.basectx.err_msg,
 		},
-#ifdef CONFIG_9P_ENABLE_9P2000_u
+#if CONFIG_9P_ENABLE_9P2000_u
 		.errno = req->ctx.basectx.err_num,
 #endif
 	};
@@ -334,7 +334,7 @@ _HANDLER_PROTO(clunk);
 _HANDLER_PROTO(remove);
 _HANDLER_PROTO(stat);
 _HANDLER_PROTO(wstat);
-#ifdef CONFIG_9P_ENABLE_9P2000_e
+#if CONFIG_9P_ENABLE_9P2000_e
 _HANDLER_PROTO(session);
 _HANDLER_PROTO(sread);
 _HANDLER_PROTO(swrite);
@@ -356,7 +356,7 @@ static tmessage_handler tmessage_handlers[0x100] = {
 	[LIB9P_TYP_Tremove]  = (tmessage_handler)handle_Tremove,
 	[LIB9P_TYP_Tstat]    = (tmessage_handler)handle_Tstat,
 	[LIB9P_TYP_Twstat]   = (tmessage_handler)handle_Twstat,
-#ifdef CONFIG_9P_ENABLE_9P2000_e
+#if CONFIG_9P_ENABLE_9P2000_e
 	[LIB9P_TYP_Tsession] = (tmessage_handler)handle_Tsession,
 	[LIB9P_TYP_Tsread]   = (tmessage_handler)handle_Tsread,
 	[LIB9P_TYP_Tswrite]  = (tmessage_handler)handle_Tswrite,
@@ -450,11 +450,11 @@ static void handle_Tversion(struct _lib9p_srv_req *ctx,
 	    '0' <= req->version.utf8[5] && req->version.utf8[5] <= '9' &&
 	    (req->version.utf8[6] == '\0' || req->version.utf8[6] == '.')) {
 		version = LIB9P_VER_9P2000;
-#ifdef CONFIG_9P_ENABLE_9P2000_u
+#if CONFIG_9P_ENABLE_9P2000_u
 		if (strcmp(&req->version.utf8[6], ".u") == 0)
 			version = LIB9P_VER_9P2000_u;
 #endif
-#ifdef CONFIG_9P_ENABLE_9P2000_e
+#if CONFIG_9P_ENABLE_9P2000_e
 		if (strcmp(&req->version.utf8[6], ".e") == 0)
 			version = LIB9P_VER_9P2000_e;
 #endif
@@ -943,7 +943,7 @@ static void handle_Twstat(struct _lib9p_srv_req *ctx,
 	            LINUX_EOPNOTSUPP, "wstat not (yet?) implemented");
 }
 
-#ifdef CONFIG_9P_ENABLE_9P2000_e
+#if CONFIG_9P_ENABLE_9P2000_e
 static void handle_Tsession(struct _lib9p_srv_req *ctx,
                             struct lib9p_msg_Tsession *req,
                             struct lib9p_msg_Rsession *resp) {
diff --git a/libdhcp/dhcp_client.c b/libdhcp/dhcp_client.c
index 3673d2c..a7b1d49 100644
--- a/libdhcp/dhcp_client.c
+++ b/libdhcp/dhcp_client.c
@@ -99,13 +99,13 @@
 #include "config.h"
 
 #ifndef CONFIG_DHCP_DEBUG
-	#define CONFIG_DHCP_DEBUG                               1
+	#error config.h must define CONFIG_DHCP_DEBUG
 #endif
 #ifndef CONFIG_DHCP_SELECTING_NS
-	#define CONFIG_DHCP_SELECTING_NS                        (5*NS_PER_S)
+	#error config.h must define CONFIG_DHCP_SELECTING_NS
 #endif
 #ifndef CONFIG_DHCP_CAN_RECV_UNICAST_IP_WITHOUT_IP
-	#define CONFIG_DHCP_CAN_RECV_UNICAST_IP_WITHOUT_IP      false
+	#error config.h must define CONFIG_DHCP_CAN_RECV_UNICAST_IP_WITHOUT_IP
 #endif
 
 /* Implementation *************************************************************/
diff --git a/libdhcp/dhcp_common.h b/libdhcp/dhcp_common.h
index d400721..b265df3 100644
--- a/libdhcp/dhcp_common.h
+++ b/libdhcp/dhcp_common.h
@@ -74,7 +74,7 @@
 #include "config.h"
 
 #ifndef CONFIG_DHCP_OPT_SIZE
-	#define CONFIG_DHCP_OPT_SIZE    DHCP_MSG_MIN_MAX_OPT_SIZE
+	#error config.h must define CONFIG_DHCP_OPT_SIZE (minimum 312)
 #endif
 
 /* RFC 2131 definitions *******************************************************/
diff --git a/libhw/w5500.c b/libhw/w5500.c
index ae48a61..a998ccf 100644
--- a/libhw/w5500.c
+++ b/libhw/w5500.c
@@ -89,11 +89,11 @@
  * net.ipv4.ip_local_port_range, so I figure they're probably good
  * values to use.  */
 #ifndef CONFIG_W5500_LOCAL_PORT_MIN
-	#define CONFIG_W5500_LOCAL_PORT_MIN 32768
+	#error config.h must define CONFIG_W5500_LOCAL_PORT_MIN
 #endif
 
 #ifndef CONFIG_W5500_LOCAL_PORT_MAX
-	#define CONFIG_W5500_LOCAL_PORT_MAX 60999
+	#error config.h must define CONFIG_W5500_LOCAL_PORT_MAX
 #endif
 
 #ifndef CONFIG_W5500_NUM