diff mbox series

[net-next,v1,1/2] tools: ynl: add user-header and struct attr support

Message ID 20230316120142.94268-2-donald.hunter@gmail.com (mailing list archive)
State Superseded
Delegated to: Netdev Maintainers
Headers show
Series ynl: add support for user headers and struct attrs | expand

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Context Check Description
netdev/series_format success Posting correctly formatted
netdev/tree_selection success Clearly marked for net-next
netdev/fixes_present success Fixes tag not required for -next series
netdev/header_inline success No static functions without inline keyword in header files
netdev/build_32bit success Errors and warnings before: 18 this patch: 18
netdev/cc_maintainers warning 3 maintainers not CCed: corbet@lwn.net sdf@google.com linux-doc@vger.kernel.org
netdev/build_clang success Errors and warnings before: 18 this patch: 18
netdev/verify_signedoff success Signed-off-by tag matches author and committer
netdev/deprecated_api success None detected
netdev/check_selftest success No net selftest shell script
netdev/verify_fixes success No Fixes tag
netdev/build_allmodconfig_warn success Errors and warnings before: 18 this patch: 18
netdev/checkpatch warning WARNING: Missing commit description - Add an appropriate one
netdev/kdoc success Errors and warnings before: 0 this patch: 0
netdev/source_inline success Was 0 now: 0

Commit Message

Donald Hunter March 16, 2023, 12:01 p.m. UTC 
Signed-off-by: Donald Hunter <donald.hunter@gmail.com>
---
 Documentation/netlink/genetlink-legacy.yaml | 10 +++-
 tools/net/ynl/lib/ynl.py                    | 58 ++++++++++++++++++---
 2 files changed, 60 insertions(+), 8 deletions(-)

Comments

Jakub Kicinski March 18, 2023, 4:50 a.m. UTC | #1 
On Thu, 16 Mar 2023 12:01:41 +0000 Donald Hunter wrote:
> Subject: [PATCH net-next v1 1/2] tools: ynl: add user-header and struct attr support

The use of "and" usually indicates it should be 2 separate patches ;)

> Signed-off-by: Donald Hunter <donald.hunter@gmail.com>
> ---
>  Documentation/netlink/genetlink-legacy.yaml | 10 +++-
>  tools/net/ynl/lib/ynl.py                    | 58 ++++++++++++++++++---
>  2 files changed, 60 insertions(+), 8 deletions(-)
> 
> diff --git a/Documentation/netlink/genetlink-legacy.yaml b/Documentation/netlink/genetlink-legacy.yaml
> index c6b8c77f7d12..7f019c0a9762 100644
> --- a/Documentation/netlink/genetlink-legacy.yaml
> +++ b/Documentation/netlink/genetlink-legacy.yaml
> @@ -53,6 +53,9 @@ properties:
>        Defines if the input policy in the kernel is global, per-operation, or split per operation type.
>        Default is split.
>      enum: [ split, per-op, global ]
> +  user-header:
> +    description: Name of the struct definition for the user header for the family.
> +    type: string

Took me a minute to remember this is header as in protocol header 
not header as in C header file :) Would it possibly be better to call it
fixed-header ? Can't really decide myself.

But the description definitely need to be more verbose:

description: |
  Name of the structure defining the fixed-length protocol header.
  This header is placed in a message after the netlink and genetlink
  headers and before any attributes.

>    # End genetlink-legacy
>  
>    definitions:
> @@ -172,7 +175,7 @@ properties:
>                  type: string
>                type: &attr-type
>                  enum: [ unused, pad, flag, binary, u8, u16, u32, u64, s32, s64,
> -                        string, nest, array-nest, nest-type-value ]
> +                        string, nest, array-nest, nest-type-value, struct ]
>                doc:
>                  description: Documentation of the attribute.
>                  type: string
> @@ -218,6 +221,11 @@ properties:
>                      description: Max length for a string or a binary attribute.
>                      $ref: '#/$defs/len-or-define'
>                sub-type: *attr-type
> +              # Start genetlink-legacy
> +              struct:
> +                description: Name of the struct type used for the attribute.
> +                type: string
> +              # End genetlink-legacy
>  
>        # Make sure name-prefix does not appear in subsets (subsets inherit naming)
>        dependencies:
> diff --git a/tools/net/ynl/lib/ynl.py b/tools/net/ynl/lib/ynl.py
> index 90764a83c646..584b1e0a6b2f 100644
> --- a/tools/net/ynl/lib/ynl.py
> +++ b/tools/net/ynl/lib/ynl.py
> @@ -68,6 +68,11 @@ class Netlink:
>  
>  
>  class NlAttr:
> +    type_formats = { 'u8' : ('B', 1),
> +                     'u16': ('H', 2),
> +                     'u32': ('I', 4),
> +                     'u64': ('Q', 8) }
> +
>      def __init__(self, raw, offset):
>          self._len, self._type = struct.unpack("HH", raw[offset:offset + 4])
>          self.type = self._type & ~Netlink.NLA_TYPE_MASK
> @@ -93,6 +98,21 @@ class NlAttr:
>      def as_bin(self):
>          return self.raw
>  
> +    def as_array(self, type):
> +        format, _ = self.type_formats[type]
> +        return list({ x[0] for x in struct.iter_unpack(format, self.raw) })

The Python is strong within you :)

> +    def as_struct(self, members):
> +        value = dict()
> +        offset = 0
> +        for m in members:
> +            type = m['type']

Accessing the spec components directly is a bit of an anti-pattern,
can we parse the struct description into Python objects in
tools/net/ynl/lib/nlspec.py ?

> +            format, size = self.type_formats[type]
> +            decoded = struct.unpack_from(format, self.raw, offset)
> +            offset += size
> +            value[m['name']] = decoded[0]
> +        return value
> +
>      def __repr__(self):
>          return f"[type:{self.type} len:{self._len}] {self.raw}"
>  
> @@ -200,7 +220,7 @@ def _genl_msg(nl_type, nl_flags, genl_cmd, genl_version, seq=None):
>      if seq is None:
>          seq = random.randint(1, 1024)
>      nlmsg = struct.pack("HHII", nl_type, nl_flags, seq, 0)
> -    genlmsg = struct.pack("bbH", genl_cmd, genl_version, 0)
> +    genlmsg = struct.pack("BBH", genl_cmd, genl_version, 0)

Should also be a separate patch

>      return nlmsg + genlmsg
>  
>  
> @@ -258,14 +278,22 @@ def _genl_load_families():
>  
>  
>  class GenlMsg:
> -    def __init__(self, nl_msg):
> +    def __init__(self, nl_msg, extra_headers = []):
>          self.nl = nl_msg
>  
>          self.hdr = nl_msg.raw[0:4]
> -        self.raw = nl_msg.raw[4:]
> +        offset = 4
>  
> -        self.genl_cmd, self.genl_version, _ = struct.unpack("bbH", self.hdr)
> +        self.genl_cmd, self.genl_version, _ = struct.unpack("BBH", self.hdr)
>  
> +        self.user_attrs = dict()
> +        for m in extra_headers:
> +            format, size = NlAttr.type_formats[m['type']]
> +            decoded = struct.unpack_from(format, nl_msg.raw, offset)
> +            offset += size
> +            self.user_attrs[m['name']] = decoded[0]


user_attrs?

> +        self.raw = nl_msg.raw[offset:]
>          self.raw_attrs = NlAttrs(self.raw)
>  
>      def __repr__(self):
> @@ -315,6 +343,7 @@ class YnlFamily(SpecFamily):
>              setattr(self, op.ident_name, bound_f)
>  
>          self.family = GenlFamily(self.yaml['name'])
> +        self._user_header = self.yaml.get('user-header', None)
>  
>      def ntf_subscribe(self, mcast_name):
>          if mcast_name not in self.family.genl_family['mcast']:
> @@ -358,7 +387,7 @@ class YnlFamily(SpecFamily):
>                  raw >>= 1
>                  i += 1
>          else:
> -            value = enum['entries'][raw - i]
> +            value = enum.entries_by_val[raw - i]['name']

Also a separate fix :S

>          rsp[attr_spec['name']] = value
>  
>      def _decode(self, attrs, space):
> @@ -381,6 +410,14 @@ class YnlFamily(SpecFamily):
>                  decoded = attr.as_bin()
>              elif attr_spec["type"] == 'flag':
>                  decoded = True
> +            elif attr_spec["type"] == 'struct':
> +                s = attr_spec['struct']
> +                decoded = attr.as_struct(self.consts[s]['members'])
> +            elif attr_spec["type"] == 'array-nest':
> +                decoded = attr.as_array(attr_spec["sub-type"])
> +            elif attr_spec["type"] == 'unused':
> +                print(f"Warning: skipping unused attribute {attr_spec['name']}")
> +                continue
>              else:
>                  raise Exception(f'Unknown {attr.type} {attr_spec["name"]} {attr_spec["type"]}')
>  
> @@ -472,6 +509,13 @@ class YnlFamily(SpecFamily):
>  
>          req_seq = random.randint(1024, 65535)
>          msg = _genl_msg(self.family.family_id, nl_flags, op.req_value, 1, req_seq)
> +        user_headers = []
> +        if self._user_header:
> +            user_headers = self.consts[self._user_header]['members']
> +            for m in user_headers:
> +                value = vals.pop(m['name'])
> +                format, _ = NlAttr.type_formats[m['type']]
> +                msg += struct.pack(format, value)
>          for name, value in vals.items():
>              msg += self._add_attr(op.attr_set.name, name, value)
>          msg = _genl_msg_finalize(msg)
> @@ -498,7 +542,7 @@ class YnlFamily(SpecFamily):
>                      done = True
>                      break
>  
> -                gm = GenlMsg(nl_msg)
> +                gm = GenlMsg(nl_msg, user_headers)
>                  # Check if this is a reply to our request
>                  if nl_msg.nl_seq != req_seq or gm.genl_cmd != op.rsp_value:
>                      if gm.genl_cmd in self.async_msg_ids:
> @@ -508,7 +552,7 @@ class YnlFamily(SpecFamily):
>                          print('Unexpected message: ' + repr(gm))
>                          continue
>  
> -                rsp.append(self._decode(gm.raw_attrs, op.attr_set.name))
> +                rsp.append(self._decode(gm.raw_attrs, op.attr_set.name) | gm.user_attrs)
>  
>          if not rsp:
>              return None
Donald Hunter March 18, 2023, 4:46 p.m. UTC | #2 
On Sat, 18 Mar 2023 at 04:50, Jakub Kicinski <kuba@kernel.org> wrote:
>
> On Thu, 16 Mar 2023 12:01:41 +0000 Donald Hunter wrote:
> > Subject: [PATCH net-next v1 1/2] tools: ynl: add user-header and struct attr support
>
> The use of "and" usually indicates it should be 2 separate patches ;)

Ack. I'll try and split it into two.

> > +  user-header:
> > +    description: Name of the struct definition for the user header for the family.
> > +    type: string
>
> Took me a minute to remember this is header as in protocol header
> not header as in C header file :) Would it possibly be better to call it
> fixed-header ? Can't really decide myself.

I went with user header because the generic netlink howto calls it the
"optional user specific message header" but happy to go with fixed-header.

> But the description definitely need to be more verbose:
>
> description: |
>   Name of the structure defining the fixed-length protocol header.
>   This header is placed in a message after the netlink and genetlink
>   headers and before any attributes.

Agreed, this is a much clearer description.

> > +    def as_array(self, type):
> > +        format, _ = self.type_formats[type]
> > +        return list({ x[0] for x in struct.iter_unpack(format, self.raw) })
>
> The Python is strong within you :)
>
> > +    def as_struct(self, members):
> > +        value = dict()
> > +        offset = 0
> > +        for m in members:
> > +            type = m['type']
>
> Accessing the spec components directly is a bit of an anti-pattern,
> can we parse the struct description into Python objects in
> tools/net/ynl/lib/nlspec.py ?

Ack, will do.

> > +            format, size = self.type_formats[type]
> > +            decoded = struct.unpack_from(format, self.raw, offset)
> > +            offset += size
> > +            value[m['name']] = decoded[0]
> > +        return value
> > +
> >      def __repr__(self):
> >          return f"[type:{self.type} len:{self._len}] {self.raw}"
> >
> > @@ -200,7 +220,7 @@ def _genl_msg(nl_type, nl_flags, genl_cmd, genl_version, seq=None):
> >      if seq is None:
> >          seq = random.randint(1, 1024)
> >      nlmsg = struct.pack("HHII", nl_type, nl_flags, seq, 0)
> > -    genlmsg = struct.pack("bbH", genl_cmd, genl_version, 0)
> > +    genlmsg = struct.pack("BBH", genl_cmd, genl_version, 0)
>
> Should also be a separate patch

Yep, I will separate this into its own patch.

> >      return nlmsg + genlmsg
> >
> >
> > @@ -258,14 +278,22 @@ def _genl_load_families():
> >
> >
> >  class GenlMsg:
> > -    def __init__(self, nl_msg):
> > +    def __init__(self, nl_msg, extra_headers = []):
> >          self.nl = nl_msg
> >
> >          self.hdr = nl_msg.raw[0:4]
> > -        self.raw = nl_msg.raw[4:]
> > +        offset = 4
> >
> > -        self.genl_cmd, self.genl_version, _ = struct.unpack("bbH", self.hdr)
> > +        self.genl_cmd, self.genl_version, _ = struct.unpack("BBH", self.hdr)
> >
> > +        self.user_attrs = dict()
> > +        for m in extra_headers:
> > +            format, size = NlAttr.type_formats[m['type']]
> > +            decoded = struct.unpack_from(format, nl_msg.raw, offset)
> > +            offset += size
> > +            self.user_attrs[m['name']] = decoded[0]
>
> user_attrs?

Um, attrs of the user-header. I'll try to name this better.

> > +        self.raw = nl_msg.raw[offset:]
> >          self.raw_attrs = NlAttrs(self.raw)
> >
> >      def __repr__(self):
> > @@ -315,6 +343,7 @@ class YnlFamily(SpecFamily):
> >              setattr(self, op.ident_name, bound_f)
> >
> >          self.family = GenlFamily(self.yaml['name'])
> > +        self._user_header = self.yaml.get('user-header', None)
> >
> >      def ntf_subscribe(self, mcast_name):
> >          if mcast_name not in self.family.genl_family['mcast']:
> > @@ -358,7 +387,7 @@ class YnlFamily(SpecFamily):
> >                  raw >>= 1
> >                  i += 1
> >          else:
> > -            value = enum['entries'][raw - i]
> > +            value = enum.entries_by_val[raw - i]['name']
>
> Also a separate fix :S

Ack, will do.
diff mbox series

Patch

diff --git a/Documentation/netlink/genetlink-legacy.yaml b/Documentation/netlink/genetlink-legacy.yaml
index c6b8c77f7d12..7f019c0a9762 100644
--- a/Documentation/netlink/genetlink-legacy.yaml
+++ b/Documentation/netlink/genetlink-legacy.yaml
@@ -53,6 +53,9 @@  properties:
       Defines if the input policy in the kernel is global, per-operation, or split per operation type.
       Default is split.
     enum: [ split, per-op, global ]
+  user-header:
+    description: Name of the struct definition for the user header for the family.
+    type: string
   # End genetlink-legacy
 
   definitions:
@@ -172,7 +175,7 @@  properties:
                 type: string
               type: &attr-type
                 enum: [ unused, pad, flag, binary, u8, u16, u32, u64, s32, s64,
-                        string, nest, array-nest, nest-type-value ]
+                        string, nest, array-nest, nest-type-value, struct ]
               doc:
                 description: Documentation of the attribute.
                 type: string
@@ -218,6 +221,11 @@  properties:
                     description: Max length for a string or a binary attribute.
                     $ref: '#/$defs/len-or-define'
               sub-type: *attr-type
+              # Start genetlink-legacy
+              struct:
+                description: Name of the struct type used for the attribute.
+                type: string
+              # End genetlink-legacy
 
       # Make sure name-prefix does not appear in subsets (subsets inherit naming)
       dependencies:
diff --git a/tools/net/ynl/lib/ynl.py b/tools/net/ynl/lib/ynl.py
index 90764a83c646..584b1e0a6b2f 100644
--- a/tools/net/ynl/lib/ynl.py
+++ b/tools/net/ynl/lib/ynl.py
@@ -68,6 +68,11 @@  class Netlink:
 
 
 class NlAttr:
+    type_formats = { 'u8' : ('B', 1),
+                     'u16': ('H', 2),
+                     'u32': ('I', 4),
+                     'u64': ('Q', 8) }
+
     def __init__(self, raw, offset):
         self._len, self._type = struct.unpack("HH", raw[offset:offset + 4])
         self.type = self._type & ~Netlink.NLA_TYPE_MASK
@@ -93,6 +98,21 @@  class NlAttr:
     def as_bin(self):
         return self.raw
 
+    def as_array(self, type):
+        format, _ = self.type_formats[type]
+        return list({ x[0] for x in struct.iter_unpack(format, self.raw) })
+
+    def as_struct(self, members):
+        value = dict()
+        offset = 0
+        for m in members:
+            type = m['type']
+            format, size = self.type_formats[type]
+            decoded = struct.unpack_from(format, self.raw, offset)
+            offset += size
+            value[m['name']] = decoded[0]
+        return value
+
     def __repr__(self):
         return f"[type:{self.type} len:{self._len}] {self.raw}"
 
@@ -200,7 +220,7 @@  def _genl_msg(nl_type, nl_flags, genl_cmd, genl_version, seq=None):
     if seq is None:
         seq = random.randint(1, 1024)
     nlmsg = struct.pack("HHII", nl_type, nl_flags, seq, 0)
-    genlmsg = struct.pack("bbH", genl_cmd, genl_version, 0)
+    genlmsg = struct.pack("BBH", genl_cmd, genl_version, 0)
     return nlmsg + genlmsg
 
 
@@ -258,14 +278,22 @@  def _genl_load_families():
 
 
 class GenlMsg:
-    def __init__(self, nl_msg):
+    def __init__(self, nl_msg, extra_headers = []):
         self.nl = nl_msg
 
         self.hdr = nl_msg.raw[0:4]
-        self.raw = nl_msg.raw[4:]
+        offset = 4
 
-        self.genl_cmd, self.genl_version, _ = struct.unpack("bbH", self.hdr)
+        self.genl_cmd, self.genl_version, _ = struct.unpack("BBH", self.hdr)
 
+        self.user_attrs = dict()
+        for m in extra_headers:
+            format, size = NlAttr.type_formats[m['type']]
+            decoded = struct.unpack_from(format, nl_msg.raw, offset)
+            offset += size
+            self.user_attrs[m['name']] = decoded[0]
+
+        self.raw = nl_msg.raw[offset:]
         self.raw_attrs = NlAttrs(self.raw)
 
     def __repr__(self):
@@ -315,6 +343,7 @@  class YnlFamily(SpecFamily):
             setattr(self, op.ident_name, bound_f)
 
         self.family = GenlFamily(self.yaml['name'])
+        self._user_header = self.yaml.get('user-header', None)
 
     def ntf_subscribe(self, mcast_name):
         if mcast_name not in self.family.genl_family['mcast']:
@@ -358,7 +387,7 @@  class YnlFamily(SpecFamily):
                 raw >>= 1
                 i += 1
         else:
-            value = enum['entries'][raw - i]
+            value = enum.entries_by_val[raw - i]['name']
         rsp[attr_spec['name']] = value
 
     def _decode(self, attrs, space):
@@ -381,6 +410,14 @@  class YnlFamily(SpecFamily):
                 decoded = attr.as_bin()
             elif attr_spec["type"] == 'flag':
                 decoded = True
+            elif attr_spec["type"] == 'struct':
+                s = attr_spec['struct']
+                decoded = attr.as_struct(self.consts[s]['members'])
+            elif attr_spec["type"] == 'array-nest':
+                decoded = attr.as_array(attr_spec["sub-type"])
+            elif attr_spec["type"] == 'unused':
+                print(f"Warning: skipping unused attribute {attr_spec['name']}")
+                continue
             else:
                 raise Exception(f'Unknown {attr.type} {attr_spec["name"]} {attr_spec["type"]}')
 
@@ -472,6 +509,13 @@  class YnlFamily(SpecFamily):
 
         req_seq = random.randint(1024, 65535)
         msg = _genl_msg(self.family.family_id, nl_flags, op.req_value, 1, req_seq)
+        user_headers = []
+        if self._user_header:
+            user_headers = self.consts[self._user_header]['members']
+            for m in user_headers:
+                value = vals.pop(m['name'])
+                format, _ = NlAttr.type_formats[m['type']]
+                msg += struct.pack(format, value)
         for name, value in vals.items():
             msg += self._add_attr(op.attr_set.name, name, value)
         msg = _genl_msg_finalize(msg)
@@ -498,7 +542,7 @@  class YnlFamily(SpecFamily):
                     done = True
                     break
 
-                gm = GenlMsg(nl_msg)
+                gm = GenlMsg(nl_msg, user_headers)
                 # Check if this is a reply to our request
                 if nl_msg.nl_seq != req_seq or gm.genl_cmd != op.rsp_value:
                     if gm.genl_cmd in self.async_msg_ids:
@@ -508,7 +552,7 @@  class YnlFamily(SpecFamily):
                         print('Unexpected message: ' + repr(gm))
                         continue
 
-                rsp.append(self._decode(gm.raw_attrs, op.attr_set.name))
+                rsp.append(self._decode(gm.raw_attrs, op.attr_set.name) | gm.user_attrs)
 
         if not rsp:
             return None