lib9p: Add the DM bitfield

5 files changed, 102 insertions, 32 deletions

diff --git a/lib9p/9P2000.txt b/lib9p/9P2000.txt
index da9b223..3fb9e51 100644
--- a/lib9p/9P2000.txt
+++ b/lib9p/9P2000.txt
@@ -30,18 +30,37 @@ d = "len[4] len*(dat[1])"
 # string (u16le `n`, then `n` bytes of UTF-8)
 s = "len[2] len*(utf8[1])"
 
+# "d"? mode - (file permissions and attributes)
+bitfield dm 32
+	31/DIR
+	30/APPEND
+	29/EXCL
+	# DMMOUNT has been around in Plan 9 forever, but is
+	# undocumented, and is explicitly excluded from the 9P2000
+	# draft RFC.  As I understand it, DMMOUNT indicates that the
+	# file is mounted by the kernel as a 9P transport; that the
+	# kernel has a lock on doing I/O on it, so userspace can't do
+	# I/O on it.
+	28/_PLAN9_MOUNT
+	27/AUTH
+	26/TMP
+	#...
+	8/OWNER_R
+	7/OWNER_W
+	6/OWNER_X
+	5/GROUP_R
+	4/GROUP_W
+	3/GROUP_X
+	2/OTHER_R
+	1/OTHER_W
+	0/OTHER_X
+
 # QID Type (see qid below)
 bitfield qt 8
 	7/DIR
 	6/APPEND
 	5/EXCL
-	# QTMOUNT has been around in Plan 9 forever, but is
-	# undocumented, and is explicitly excluded from the 9P2000
-	# draft RFC.  As I understand it, QTMOUNT indicates that the
-	# file is mounted by the kernel as a 9P transport; that the
-	# kernel has a lock on doing I/O on it, so userspace can't do
-	# I/O on it.
-	4/_PLAN9_MOUNT
+	4/_PLAN9_MOUNT # see DMMOUNT above
 	3/AUTH
 	# Fun historical fact: QTTMP was a relatively late addition to
 	# Plan 9, in 2003-12.
@@ -73,7 +92,7 @@ stat = "stat_size[2]"
        "kern_type[2]"
        "kern_dev[4]"
        "file_qid[qid]"
-       "file_mode[4]"
+       "file_mode[dm]"
        "file_atime[4]"
        "file_mtime[4]"
        "file_size[8]"
@@ -117,7 +136,7 @@ bitfield o 8
 111/Rwalk    = "nwqid[2] nwqid*(wqid[qid])"
 112/Topen    = "fid[4] mode[o]"
 113/Ropen    = "qid[qid] iounit[4]"
-114/Tcreate  = "fid[4] name[s] perm[4] mode[o]"
+114/Tcreate  = "fid[4] name[s] perm[dm] mode[o]"
 115/Rcreate  = "qid[qid] iounit[4]"
 116/Tread    = "fid[4] offset[8] count[4]"
 117/Rread    = "data[d]" # for directories data is the sequence "cnt*(entries[stat])"
diff --git a/lib9p/9P2000.u.txt b/lib9p/9P2000.u.txt
index 29fd2d8..3958a92 100644
--- a/lib9p/9P2000.u.txt
+++ b/lib9p/9P2000.u.txt
@@ -19,19 +19,10 @@ Tauth += "n_uname[4]"
 
 Rerror += "errno[4]"
 
-qt += 1/SYMLINK
+dm += 23/DEVICE
+      21/NAMEDPIPE
+      20/SOCKET
+      19/SETUID
+      18/SETGID
 
-# DMDIR       = 1<<31
-# DMAPPEND    = 1<<30
-# DMEXCL      = 1<<29
-# DMMOUNT     = 1<<28
-# DMAUTH      = 1<<27
-# DMTMP       = 1<<26
-# #           = 1<<25
-# #           = 1<<24
-# DMDEVICE    = 1<<23 # .u
-# #           = 1<<22
-# DMNAMEDPIPE = 1<<21 # .u
-# DMSOCKET    = 1<<20 # .u
-# DMSETUID    = 1<<19 # .u
-# DMSETGID    = 1<<18 # .u
+qt += 1/SYMLINK
diff --git a/lib9p/include/lib9p/_types.h b/lib9p/include/lib9p/_types.h
index d853cf3..e22404c 100644
--- a/lib9p/include/lib9p/_types.h
+++ b/lib9p/include/lib9p/_types.h
@@ -19,6 +19,40 @@ const char *lib9p_version_str(enum lib9p_version);
 
 /* non-message types **********************************************************/
 
+typedef uint32_t lib9p_dm_t;
+#define LIB9P_DM_DIR           ((lib9p_dm_t)(1<<31))
+#define LIB9P_DM_APPEND        ((lib9p_dm_t)(1<<30))
+#define LIB9P_DM_EXCL          ((lib9p_dm_t)(1<<29))
+#define _LIB9P_DM_PLAN9_MOUNT  ((lib9p_dm_t)(1<<28))
+#define LIB9P_DM_AUTH          ((lib9p_dm_t)(1<<27))
+#define LIB9P_DM_TMP           ((lib9p_dm_t)(1<<26))
+#define _LIB9P_DM_UNUSED_25    ((lib9p_dm_t)(1<<25))
+#define _LIB9P_DM_UNUSED_24    ((lib9p_dm_t)(1<<24))
+#define LIB9P_DM_DEVICE        ((lib9p_dm_t)(1<<23)) /* 9P2000.u */
+#define _LIB9P_DM_UNUSED_22    ((lib9p_dm_t)(1<<22))
+#define LIB9P_DM_NAMEDPIPE     ((lib9p_dm_t)(1<<21)) /* 9P2000.u */
+#define LIB9P_DM_SOCKET        ((lib9p_dm_t)(1<<20)) /* 9P2000.u */
+#define LIB9P_DM_SETUID        ((lib9p_dm_t)(1<<19)) /* 9P2000.u */
+#define LIB9P_DM_SETGID        ((lib9p_dm_t)(1<<18)) /* 9P2000.u */
+#define _LIB9P_DM_UNUSED_17    ((lib9p_dm_t)(1<<17))
+#define _LIB9P_DM_UNUSED_16    ((lib9p_dm_t)(1<<16))
+#define _LIB9P_DM_UNUSED_15    ((lib9p_dm_t)(1<<15))
+#define _LIB9P_DM_UNUSED_14    ((lib9p_dm_t)(1<<14))
+#define _LIB9P_DM_UNUSED_13    ((lib9p_dm_t)(1<<13))
+#define _LIB9P_DM_UNUSED_12    ((lib9p_dm_t)(1<<12))
+#define _LIB9P_DM_UNUSED_11    ((lib9p_dm_t)(1<<11))
+#define _LIB9P_DM_UNUSED_10    ((lib9p_dm_t)(1<<10))
+#define _LIB9P_DM_UNUSED_9     ((lib9p_dm_t)(1<<9))
+#define LIB9P_DM_OWNER_R       ((lib9p_dm_t)(1<<8))
+#define LIB9P_DM_OWNER_W       ((lib9p_dm_t)(1<<7))
+#define LIB9P_DM_OWNER_X       ((lib9p_dm_t)(1<<6))
+#define LIB9P_DM_GROUP_R       ((lib9p_dm_t)(1<<5))
+#define LIB9P_DM_GROUP_W       ((lib9p_dm_t)(1<<4))
+#define LIB9P_DM_GROUP_X       ((lib9p_dm_t)(1<<3))
+#define LIB9P_DM_OTHER_R       ((lib9p_dm_t)(1<<2))
+#define LIB9P_DM_OTHER_W       ((lib9p_dm_t)(1<<1))
+#define LIB9P_DM_OTHER_X       ((lib9p_dm_t)(1<<0))
+
 typedef uint8_t lib9p_qt_t;
 #define LIB9P_QT_DIR           ((lib9p_qt_t)(1<<7))
 #define LIB9P_QT_APPEND        ((lib9p_qt_t)(1<<6))
@@ -65,7 +99,7 @@ struct lib9p_stat {
 	uint16_t           kern_type;
 	uint32_t           kern_dev;
 	struct lib9p_qid   file_qid;
-	uint32_t           file_mode;
+	lib9p_dm_t         file_mode;
 	uint32_t           file_atime;
 	uint32_t           file_mtime;
 	uint64_t           file_size;
@@ -187,7 +221,7 @@ struct lib9p_msg_Ropen {
 struct lib9p_msg_Tcreate {
 	uint32_t         fid;
 	struct lib9p_s   name;
-	uint32_t         perm;
+	lib9p_dm_t       perm;
 	lib9p_o_t        mode;
 };
 
diff --git a/lib9p/types.c b/lib9p/types.c
index 50ac1cf..2d0bb1b 100644
--- a/lib9p/types.c
+++ b/lib9p/types.c
@@ -343,6 +343,22 @@ static ALWAYS_INLINE bool validate_s(struct _validate_ctx *ctx) {
 	return false;
 }
 
+static ALWAYS_INLINE bool validate_dm(struct _validate_ctx *ctx) {
+	 if (validate_4(ctx))
+		return true;
+	static const lib9p_dm_t masks[LIB9P_VER_NUM] = {
+		[LIB9P_VER_9P2000] = 0b11111100000000000000000111111111,
+		[LIB9P_VER_9P2000_e] = 0b11111100000000000000000111111111,
+		[LIB9P_VER_9P2000_u] = 0b11111100101111000000000111111111,
+	};
+	lib9p_dm_t mask = masks[ctx->ctx->version];
+	lib9p_dm_t val = decode_u32le(&ctx->net_bytes[ctx->net_offset-4]);
+	if (val & ~mask)
+		return lib9p_errorf(ctx->ctx, LINUX_EBADMSG, "unknown bits in dm bitfield: %#04"PRIx32,
+		                    val & ~mask);
+	return false;
+}
+
 static ALWAYS_INLINE bool validate_qt(struct _validate_ctx *ctx) {
 	 if (validate_1(ctx))
 		return true;
@@ -370,7 +386,7 @@ static ALWAYS_INLINE bool validate_stat(struct _validate_ctx *ctx) {
 	    || validate_2(ctx)
 	    || validate_4(ctx)
 	    || validate_qid(ctx)
-	    || validate_4(ctx)
+	    || validate_dm(ctx)
 	    || validate_4(ctx)
 	    || validate_4(ctx)
 	    || validate_8(ctx)
@@ -465,7 +481,7 @@ static FLATTEN bool validate_Ropen(struct _validate_ctx *ctx) {
 static FLATTEN bool validate_Tcreate(struct _validate_ctx *ctx) {
 	return validate_4(ctx)
 	    || validate_s(ctx)
-	    || validate_4(ctx)
+	    || validate_dm(ctx)
 	    || validate_o(ctx);
 }
 
@@ -596,6 +612,10 @@ static ALWAYS_INLINE void unmarshal_s(struct _unmarshal_ctx *ctx, struct lib9p_s
 		unmarshal_1(ctx, &out->utf8[i]);
 }
 
+static ALWAYS_INLINE void unmarshal_dm(struct _unmarshal_ctx *ctx, lib9p_dm_t *out) {
+	unmarshal_4(ctx, (uint32_t *)out);
+}
+
 static ALWAYS_INLINE void unmarshal_qt(struct _unmarshal_ctx *ctx, lib9p_qt_t *out) {
 	unmarshal_1(ctx, (uint8_t *)out);
 }
@@ -613,7 +633,7 @@ static ALWAYS_INLINE void unmarshal_stat(struct _unmarshal_ctx *ctx, struct lib9
 	unmarshal_2(ctx, &out->kern_type);
 	unmarshal_4(ctx, &out->kern_dev);
 	unmarshal_qid(ctx, &out->file_qid);
-	unmarshal_4(ctx, &out->file_mode);
+	unmarshal_dm(ctx, &out->file_mode);
 	unmarshal_4(ctx, &out->file_atime);
 	unmarshal_4(ctx, &out->file_mtime);
 	unmarshal_8(ctx, &out->file_size);
@@ -720,7 +740,7 @@ static FLATTEN void unmarshal_Tcreate(struct _unmarshal_ctx *ctx, struct lib9p_m
 	memset(out, 0, sizeof(*out));
 	unmarshal_4(ctx, &out->fid);
 	unmarshal_s(ctx, &out->name);
-	unmarshal_4(ctx, &out->perm);
+	unmarshal_dm(ctx, &out->perm);
 	unmarshal_o(ctx, &out->mode);
 }
 
@@ -894,6 +914,10 @@ static ALWAYS_INLINE bool marshal_s(struct _marshal_ctx *ctx, struct lib9p_s *va
 	       });
 }
 
+static ALWAYS_INLINE bool marshal_dm(struct _marshal_ctx *ctx, lib9p_dm_t *val) {
+	return marshal_4(ctx, (uint32_t *)val);
+}
+
 static ALWAYS_INLINE bool marshal_qt(struct _marshal_ctx *ctx, lib9p_qt_t *val) {
 	return marshal_1(ctx, (uint8_t *)val);
 }
@@ -909,7 +933,7 @@ static ALWAYS_INLINE bool marshal_stat(struct _marshal_ctx *ctx, struct lib9p_st
 	    || marshal_2(ctx, &val->kern_type)
 	    || marshal_4(ctx, &val->kern_dev)
 	    || marshal_qid(ctx, &val->file_qid)
-	    || marshal_4(ctx, &val->file_mode)
+	    || marshal_dm(ctx, &val->file_mode)
 	    || marshal_4(ctx, &val->file_atime)
 	    || marshal_4(ctx, &val->file_mtime)
 	    || marshal_8(ctx, &val->file_size)
@@ -1007,7 +1031,7 @@ static FLATTEN bool marshal_Ropen(struct _marshal_ctx *ctx, struct lib9p_msg_Rop
 static FLATTEN bool marshal_Tcreate(struct _marshal_ctx *ctx, struct lib9p_msg_Tcreate *val) {
 	return marshal_4(ctx, &val->fid)
 	    || marshal_s(ctx, &val->name)
-	    || marshal_4(ctx, &val->perm)
+	    || marshal_dm(ctx, &val->perm)
 	    || marshal_o(ctx, &val->mode);
 }
 
diff --git a/lib9p/types.gen b/lib9p/types.gen
index 1b43fa4..3e800e8 100755
--- a/lib9p/types.gen
+++ b/lib9p/types.gen
@@ -238,6 +238,7 @@ def parse_file(
                     if not isinstance(_bf, Bitfield):
                         raise NameError(f"Type {repr(_bf.name)} is not a bitfield")
                     bf = _bf
+                    prev = bf
                 else:
                     if not isinstance(prev, Bitfield):
                         raise SyntaxError(
@@ -269,6 +270,7 @@ def parse_file(
                     if not isinstance(_bf, Bitfield):
                         raise NameError(f"Type {repr(_bf.name)} is not a bitfield")
                     bf = _bf
+                    prev = bf
                 else:
                     if not isinstance(prev, Bitfield):
                         raise SyntaxError(