def dump_attrs(ofd, attrs, attrlen, prefix=0):
"""https://github.com/thom311/libnl/blob/libnl3_2_25/lib/msg.c#L869.
Positional arguments:
ofd -- function to call with arguments similar to `logging.debug`.
attrs -- nlattr class instance.
attrlen -- length of payload (integer).
Keyword arguments:
prefix -- additional number of whitespace pairs to prefix each log statement with.
"""
prefix_whitespaces = ' ' * prefix
rem = c_int()
for nla in nla_for_each_attr(attrs, attrlen, rem):
alen = nla_len(nla)
if nla.nla_type == 0:
ofd('%s [ATTR PADDING] %d octets', prefix_whitespaces, alen)
else:
is_nested = ' NESTED' if nla_is_nested(nla) else ''
ofd('%s [ATTR %02d%s] %d octets', prefix_whitespaces, nla.nla_type, is_nested, alen)
if nla_is_nested(nla):
dump_attrs(ofd, nla_data(nla), alen, prefix + 1)
else:
dump_attr(ofd, nla, prefix)
padlen = nla_padlen(alen)
if padlen > 0:
ofd('%s [PADDING] %d octets', prefix_whitespaces, padlen)
dump_hex(ofd, bytearray_ptr(nla_data(nla), alen), padlen, prefix)
if rem.value:
ofd('%s [LEFTOVER] %d octets', prefix_whitespaces, rem)
def nlmsg_for_each_attr(nlh, hdrlen, rem):
"""Iterate over a stream of attributes in a message.
https://github.com/thom311/libnl/blob/libnl3_2_25/include/netlink/msg.h#L123
Positional arguments:
nlh -- Netlink message header (nlmsghdr class instance).
hdrlen -- length of family header (integer).
rem -- initialized to len, holds bytes currently remaining in stream (c_int).
Returns:
Generator yielding nl_attr instances.
"""
return nla_for_each_attr(nlmsg_attrdata(nlh, hdrlen), nlmsg_attrlen(nlh, hdrlen), rem)
