ethtool: dynamic ioctl gstrings struct definition

Bug-Url: #1112

pyroute2/ethtool/ioctl.py

@@ -274,15 +274,16 @@ class EthtoolSsetInfo(ctypes.Structure):
  ]
 
 
-class EthtoolGstrings(ctypes.Structure):
- _fields_ = [
- ("cmd", ctypes.c_uint32),
- ("string_set", ctypes.c_uint32),
- ("len", ctypes.c_uint32),
- # If you have more than 256 features on your NIC
- # they will not be seen by it
- ("strings", ctypes.c_ubyte * ETH_GSTRING_LEN * 256),
- ]
+def generate_EthtoolGstrings(gstrings_length):
+ class EthtoolGstrings(ctypes.Structure):
+ _fields_ = [
+ ("cmd", ctypes.c_uint32),
+ ("string_set", ctypes.c_uint32),
+ ("len", ctypes.c_uint32),
+ ("strings", ctypes.c_ubyte * ETH_GSTRING_LEN * gstrings_length),
+ ]
+
+ return EthtoolGstrings
 
 
 class EthtoolGetFeaturesBlock(ctypes.Structure):
@@ -326,24 +327,42 @@ class FeatureState(ctypes.Structure):
  _fields_ = [("off_flags", ctypes.c_uint32), ("features", EthtoolGfeatures)]
 
 
-class IfReqData(ctypes.Union):
- _fields_ = [
- ("ifr_data", ctypes.POINTER(EthtoolCmd)),
- ("coalesce", ctypes.POINTER(EthtoolCoalesce)),
- ("value", ctypes.POINTER(EthtoolValue)),
- ("sset_info", ctypes.POINTER(EthtoolSsetInfo)),
- ("gstrings", ctypes.POINTER(EthtoolGstrings)),
- ("gfeatures", ctypes.POINTER(EthtoolGfeatures)),
- ("sfeatures", ctypes.POINTER(EthtoolSfeatures)),
- ("glinksettings", ctypes.POINTER(IoctlEthtoolLinkSettings)),
- ("wolinfo", ctypes.POINTER(EthtoolWolInfo)),
- ]
+def generate_IfReqData(gstrings_length):
+ EthtoolGstrings = generate_EthtoolGstrings(gstrings_length)
+
+ class IfReqData(ctypes.Union):
+ _fields_ = [
+ ("ifr_data", ctypes.POINTER(EthtoolCmd)),
+ ("coalesce", ctypes.POINTER(EthtoolCoalesce)),
+ ("value", ctypes.POINTER(EthtoolValue)),
+ ("sset_info", ctypes.POINTER(EthtoolSsetInfo)),
+ ("gstrings", ctypes.POINTER(EthtoolGstrings)),
+ ("gfeatures", ctypes.POINTER(EthtoolGfeatures)),
+ ("sfeatures", ctypes.POINTER(EthtoolSfeatures)),
+ ("glinksettings", ctypes.POINTER(IoctlEthtoolLinkSettings)),
+ ("wolinfo", ctypes.POINTER(EthtoolWolInfo)),
+ ]
+
+ return IfReqData, EthtoolGstrings
+
+
+def generate_IfReq(gstrings_length):
+ IfReqData, EthtoolGstrings = generate_IfReqData(gstrings_length)
+
+ class IfReq(ctypes.Structure):
+ _pack_ = 1
+ _anonymous_ = ("u",)
+ _fields_ = [("ifr_name", ctypes.c_uint8 * IFNAMSIZ), ("u", IfReqData)]
+
+ return IfReq, EthtoolGstrings
 
 
-class IfReq(ctypes.Structure):
+class IfReqSsetInfo(ctypes.Structure):
  _pack_ = 1
- _anonymous_ = ("u",)
- _fields_ = [("ifr_name", ctypes.c_uint8 * IFNAMSIZ), ("u", IfReqData)]
+ _fields_ = [
+ ("ifr_name", ctypes.c_uint8 * IFNAMSIZ),
+ ("info", ctypes.POINTER(EthtoolSsetInfo)),
+ ]
 
 
 class EthtoolFeaturesList:
@@ -439,6 +458,20 @@ def close(self):
  def change_ifname(self, ifname):
  self.ifname = bytearray(ifname, 'utf-8')
  self.ifname.extend(b"\0" * (IFNAMSIZ - len(self.ifname)))
+ sset_info = EthtoolSsetInfo(
+ cmd=ETHTOOL_GSSET_INFO, reserved=0, sset_mask=1 << ETH_SS_FEATURES
+ )
+ ifreq_sset = IfReqSsetInfo()
+ ifreq_sset.ifr_name = (ctypes.c_uint8 * IFNAMSIZ)(*self.ifname)
+ ifreq_sset.info = ctypes.pointer(sset_info)
+ fcntl.ioctl(self.sock, SIOCETHTOOL, ifreq_sset)
+ if sset_info.sset_mask:
+ self.gstrings_length = sset_info.data
+ else:
+ self.gstrings_length = 256
+ IfReq, self.EthtoolGstringsType = generate_IfReq(
+ gstrings_length=self.gstrings_length
+ )
  self.ifreq = IfReq()
  self.ifreq.ifr_name = (ctypes.c_uint8 * IFNAMSIZ)(*self.ifname)
 
@@ -456,24 +489,14 @@ def ioctl(self):
  def get_stringset(
  self, set_id=ETH_SS_FEATURES, drvinfo_offset=0, null_terminate=1
  ):
- sset_info = EthtoolSsetInfo(
- cmd=ETHTOOL_GSSET_INFO, reserved=0, sset_mask=1 << set_id
- )
- self.ifreq.sset_info = ctypes.pointer(sset_info)
- fcntl.ioctl(self.sock, SIOCETHTOOL, self.ifreq)
- if sset_info.sset_mask:
- length = sset_info.data
- else:
- length = 0
-
  strings_found = []
- gstrings = EthtoolGstrings(
- cmd=ETHTOOL_GSTRINGS, string_set=set_id, len=length
+ gstrings = self.EthtoolGstringsType(
+ cmd=ETHTOOL_GSTRINGS, string_set=set_id, len=self.gstrings_length
  )
  self.ifreq.gstrings = ctypes.pointer(gstrings)
  self.ioctl()
 
- for i in range(length):
+ for i in range(self.gstrings_length):
  buf = ''
  for j in range(ETH_GSTRING_LEN):
  code = gstrings.strings[i][j]