commit bce6e4902320eb10b3d01093b1070db90115a77c Author: Ondrej Lichtner olichtne@redhat.com Date: Fri Aug 16 09:54:45 2013 +0200

NetUtils: rewrite scan_netdevs function

The scan_netdev function was starting to be a bit unreliable sometimes causing crashes. It also wasn't a very pretty solution of the problem.

The new scan_netdev function connects to a netlink socket and requests a dump of all interfaces on the system, and parses the result to return a similar data structure to the previous implementation of the function. Again it contains the addditional kernel index of the interface that will be used in the future.

Signed-off-by: Ondrej Lichtner olichtne@redhat.com Signed-off-by: Jiri Pirko jiri@resnulli.us

lnst/Common/NetUtils.py | 57 ++++++++++++++++++++++++++++++++++++---------- 1 files changed, 44 insertions(+), 13 deletions(-) --- diff --git a/lnst/Common/NetUtils.py b/lnst/Common/NetUtils.py index fb39a41..efa14f5 100644 --- a/lnst/Common/NetUtils.py +++ b/lnst/Common/NetUtils.py @@ -15,26 +15,57 @@ import os import re import socket import subprocess +from resource import getpagesize +from pyroute2.netlink import NetlinkSocket +from pyroute2.netlink import NLM_F_REQUEST +from pyroute2.netlink import NLM_F_DUMP +from pyroute2.netlink import NLMSG_DONE +from pyroute2.netlink import NLMSG_ERROR +from pyroute2.netlink.generic import NETLINK_ROUTE +from pyroute2.netlink.iproute import MarshalRtnl +from pyroute2.netlink.iproute import RTM_GETLINK +from pyroute2.netlink.iproute import RTM_NEWLINK +from pyroute2.netlink.rtnl.ifinfmsg import ifinfmsg

def normalize_hwaddr(hwaddr): return hwaddr.upper().rstrip("\n")

def scan_netdevs(): - sys_dir = "/sys/class/net" scan = [] - for root, dirs, files in os.walk(sys_dir): - if "lo" in dirs: - dirs.remove("lo") - for d in dirs: - dev_path = os.path.join(sys_dir, d) - addr_path = os.path.join(dev_path, "address") - if not os.path.isfile(addr_path): + nl_socket = NetlinkSocket(family=NETLINK_ROUTE) + msg = ifinfmsg() + msg["family"] = socket.AF_UNSPEC + msg["header"]["type"] = RTM_GETLINK + msg["header"]["flags"] = NLM_F_REQUEST | NLM_F_DUMP + msg["header"]["pid"] = os.getpid() + msg["header"]["sequence_number"] = 1 + msg.encode() + + nl_socket.sendto(msg.buf.getvalue(), (0,0)) + + finished = False + marshal = MarshalRtnl() + while not finished: + response = nl_socket.recv(getpagesize()) + parts = marshal.parse(response) + for part in parts: + if part["header"]["type"] in [NLMSG_DONE, NLMSG_ERROR]: + finished = True continue - handle = open(addr_path, "rb") - addr = handle.read() - handle.close() - addr = normalize_hwaddr(addr) - scan.append({"name": d, "hwaddr": addr}) + if part["header"]["sequence_number"] != 1: + continue + + if part["header"]["type"] == RTM_NEWLINK: + new_link = {} + for name, value in part["attrs"]: + if name == "IFLA_IFNAME": + new_link["name"] = value + elif name == "IFLA_ADDRESS": + new_link["hwaddr"] = normalize_hwaddr(value) + new_link["index"] = part["index"] + scan.append(new_link) + + nl_socket.close() return scan

def test_tcp_connection(host, port):