def nl_wait_for_ack(sk):
"""Wait for ACK.
https://github.com/thom311/libnl/blob/libnl3_2_25/lib/nl.c#L1058
Waits until an ACK is received for the latest not yet acknowledged Netlink message.
Positional arguments:
sk -- Netlink socket (nl_sock class instance).
Returns:
Number of received messages or a negative error code from nl_recvmsgs().
"""
cb = nl_cb_clone(sk.s_cb)
nl_cb_set(cb, NL_CB_ACK, NL_CB_CUSTOM, lambda *_: NL_STOP, None)
return int(nl_recvmsgs(sk, cb))
def nl_wait_for_ack(sk):
"""Wait for ACK.
https://github.com/thom311/libnl/blob/libnl3_2_25/lib/nl.c#L1058
Waits until an ACK is received for the latest not yet acknowledged Netlink message.
Positional arguments:
sk -- Netlink socket (nl_sock class instance).
Returns:
Number of received messages or a negative error code from nl_recvmsgs().
"""
cb = nl_cb_clone(sk.s_cb)
nl_cb_set(cb, NL_CB_ACK, NL_CB_CUSTOM, lambda *_: NL_STOP, None)
return int(nl_recvmsgs(sk, cb))
def genl_ctrl_probe_by_name(sk, name):
"""Look up generic Netlink family by family name querying the kernel directly.
https://github.com/thom311/libnl/blob/libnl3_2_25/lib/genl/ctrl.c#L237
Directly query's the kernel for a given family name.
Note: This API call differs from genl_ctrl_search_by_name in that it queries the kernel directly, allowing for
module autoload to take place to resolve the family request. Using an nl_cache prevents that operation.
Positional arguments:
sk -- Generic Netlink socket (nl_sock class instance).
name -- family name (bytes).
Returns:
Generic Netlink family `genl_family` class instance or None if no match was found.
"""
ret = genl_family_alloc()
if not ret:
return None
genl_family_set_name(ret, name)
msg = nlmsg_alloc()
orig = nl_socket_get_cb(sk)
cb = nl_cb_clone(orig)
genlmsg_put(msg, NL_AUTO_PORT, NL_AUTO_SEQ, GENL_ID_CTRL, 0, 0,
CTRL_CMD_GETFAMILY, 1)
nla_put_string(msg, CTRL_ATTR_FAMILY_NAME, name)
nl_cb_set(cb, NL_CB_VALID, NL_CB_CUSTOM, probe_response, ret)
if nl_send_auto(sk, msg) < 0:
return None
if nl_recvmsgs(sk, cb) < 0:
return None
if wait_for_ack(
sk
) < 0: # If search was successful, request may be ACKed after data.
return None
if genl_family_get_id(ret) != 0:
return ret
def genl_ctrl_probe_by_name(sk, name):
"""Look up generic Netlink family by family name querying the kernel directly.
https://github.com/thom311/libnl/blob/libnl3_2_25/lib/genl/ctrl.c#L237
Directly query's the kernel for a given family name.
Note: This API call differs from genl_ctrl_search_by_name in that it queries the kernel directly, allowing for
module autoload to take place to resolve the family request. Using an nl_cache prevents that operation.
Positional arguments:
sk -- Generic Netlink socket (nl_sock class instance).
name -- family name (bytes).
Returns:
Generic Netlink family `genl_family` class instance or None if no match was found.
"""
ret = genl_family_alloc()
if not ret:
return None
genl_family_set_name(ret, name)
msg = nlmsg_alloc()
orig = nl_socket_get_cb(sk)
cb = nl_cb_clone(orig)
genlmsg_put(msg, NL_AUTO_PORT, NL_AUTO_SEQ, GENL_ID_CTRL, 0, 0, CTRL_CMD_GETFAMILY, 1)
nla_put_string(msg, CTRL_ATTR_FAMILY_NAME, name)
nl_cb_set(cb, NL_CB_VALID, NL_CB_CUSTOM, probe_response, ret)
if nl_send_auto(sk, msg) < 0:
return None
if nl_recvmsgs(sk, cb) < 0:
return None
if wait_for_ack(sk) < 0: # If search was successful, request may be ACKed after data.
return None
if genl_family_get_id(ret) != 0:
return ret
