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commit: 70ec13029e5cc8a1decfab7134d3addea8612bd7 |
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Author: Mike Gilbert <floppym <AT> gentoo <DOT> org> |
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AuthorDate: Fri Aug 30 18:24:47 2019 +0000 |
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Commit: Zac Medico <zmedico <AT> gentoo <DOT> org> |
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CommitDate: Sat Aug 31 03:10:03 2019 +0000 |
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URL: https://gitweb.gentoo.org/proj/portage.git/commit/?id=70ec1302 |
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|
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Use RTNETLINK to configure the loopback interface |
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|
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This eliminates the dependency on iproute2 on Linux. |
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|
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Bug: https://bugs.gentoo.org/690758 |
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Signed-off-by: Mike Gilbert <floppym <AT> gentoo.org> |
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Signed-off-by: Zac Medico <zmedico <AT> gentoo.org> |
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|
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lib/portage/process.py | 26 +++++------- |
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lib/portage/util/netlink.py | 98 +++++++++++++++++++++++++++++++++++++++++++++ |
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2 files changed, 108 insertions(+), 16 deletions(-) |
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|
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diff --git a/lib/portage/process.py b/lib/portage/process.py |
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index 2a2cbd972..df63ae72f 100644 |
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--- a/lib/portage/process.py |
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+++ b/lib/portage/process.py |
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@@ -10,7 +10,6 @@ import multiprocessing |
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import platform |
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import signal |
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import socket |
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-import struct |
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import subprocess |
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import sys |
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import traceback |
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@@ -489,17 +488,6 @@ def _configure_loopback_interface(): |
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Configure the loopback interface. |
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""" |
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|
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- IFF_UP = 0x1 |
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- ifreq = struct.pack('16sh', b'lo', IFF_UP) |
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- SIOCSIFFLAGS = 0x8914 |
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- |
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- sock = socket.socket(socket.AF_INET, socket.SOCK_DGRAM, 0) |
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- try: |
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- fcntl.ioctl(sock, SIOCSIFFLAGS, ifreq) |
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- except IOError as e: |
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- writemsg("Unable to enable loopback interface: %s\n" % e.strerror, noiselevel=-1) |
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- sock.close() |
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- |
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# We add some additional addresses to work around odd behavior in glibc's |
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# getaddrinfo() implementation when the AI_ADDRCONFIG flag is set. |
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# |
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@@ -514,12 +502,18 @@ def _configure_loopback_interface(): |
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# Bug: https://bugs.gentoo.org/690758 |
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# Bug: https://sourceware.org/bugzilla/show_bug.cgi?id=12377#c13 |
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|
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+ # Avoid importing this module on systems that may not support netlink sockets. |
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+ from portage.util.netlink import RtNetlink |
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+ |
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try: |
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- subprocess.call(['ip', 'address', 'add', '10.0.0.1/8', 'dev', 'lo']) |
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- if _has_ipv6(): |
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- subprocess.call(['ip', 'address', 'add', 'fd00::1/8', 'dev', 'lo']) |
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+ with RtNetlink() as rtnl: |
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+ ifindex = rtnl.get_link_ifindex(b'lo') |
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+ rtnl.set_link_up(ifindex) |
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+ rtnl.add_address(ifindex, socket.AF_INET, '10.0.0.1', 8) |
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+ if _has_ipv6(): |
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+ rtnl.add_address(ifindex, socket.AF_INET6, 'fd::1', 8) |
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except EnvironmentError as e: |
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- writemsg("Error calling 'ip': %s\n" % e.strerror, noiselevel=-1) |
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+ writemsg("Unable to configure loopback interface: %s\n" % e.strerror, noiselevel=-1) |
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|
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def _exec(binary, mycommand, opt_name, fd_pipes, |
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env, gid, groups, uid, umask, cwd, |
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|
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diff --git a/lib/portage/util/netlink.py b/lib/portage/util/netlink.py |
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new file mode 100644 |
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index 000000000..950ed8f69 |
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--- /dev/null |
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+++ b/lib/portage/util/netlink.py |
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@@ -0,0 +1,98 @@ |
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+# Copyright 2019 Gentoo Authors |
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+# Distributed under the terms of the GNU General Public License v2 |
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+ |
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+from io import BytesIO |
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+from os import strerror |
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+from struct import Struct |
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+ |
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+import socket |
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+from socket import ( |
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+ AF_NETLINK, AF_UNSPEC, |
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+ MSG_PEEK, MSG_TRUNC, |
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+ NETLINK_ROUTE, |
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+ SOCK_DGRAM, |
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+ inet_pton, |
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+) |
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+ |
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+IFA_LOCAL = 2 |
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+IFF_UP = 0x1 |
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+IFLA_IFNAME = 3 |
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+NLMSG_ERROR = 2 |
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+RTM_NEWLINK = 16 |
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+RTM_GETLINK = 18 |
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+RTM_NEWADDR = 20 |
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+NLM_F_REQUEST = 0x1 |
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+NLM_F_ACK = 0x4 |
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+NLM_F_EXCL = 0x200 |
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+NLM_F_CREATE = 0x400 |
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+ |
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+nlmsghdr = Struct('=IHHII') |
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+nlmsgerr = Struct('i') |
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+rtattr = Struct('HH') |
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+ifinfomsg = Struct('BHiII') |
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+ifaddrmsg = Struct('BBBBi') |
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+ |
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+def create_nlmsg(nlmsg_type, nlmsg_flags, nlmsg_seq, nlmsg_pid, data): |
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+ nlmsg_len = nlmsghdr.size + len(data) |
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+ return nlmsghdr.pack(nlmsg_len, nlmsg_type, nlmsg_flags, nlmsg_seq, nlmsg_pid) + data |
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+ |
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+def create_rtattr(rta_type, data): |
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+ rta_len = rtattr.size + len(data) |
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+ return rtattr.pack(rta_len, rta_type) + data |
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+ |
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+def parse_message(msg): |
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+ buf = BytesIO(msg) |
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+ hdr = nlmsghdr.unpack(buf.read(nlmsghdr.size)) |
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+ if hdr[1] == NLMSG_ERROR: |
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+ err = nlmsgerr.unpack(buf.read(nlmsgerr.size)) |
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+ error = -err[0] |
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+ if error != 0: |
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+ raise OSError(error, strerror(error)) |
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+ elif hdr[1] == RTM_NEWLINK: |
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+ # kernel responds to RTM_GETLINK with RTM_NEWLINK. |
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+ # We only care about the ifindex for get_link_ifindex. |
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+ return ifinfomsg.unpack(buf.read(ifinfomsg.size)) |
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+ |
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+class RtNetlink: |
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+ def __init__(self): |
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+ self.sock = socket.socket(AF_NETLINK, SOCK_DGRAM, NETLINK_ROUTE) |
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+ self.addr = (0, 0) |
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+ try: |
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+ self.sock.bind(self.addr) |
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+ except socket.error: |
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+ self.sock.close() |
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+ raise |
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+ |
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+ def __enter__(self): |
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+ return self |
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+ |
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+ def __exit__(self, exc_type, exc_value, traceback): |
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+ self.sock.close() |
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+ |
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+ def send_message(self, msg): |
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+ self.sock.sendto(msg, self.addr) |
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+ # Messages are variable length, but 128 is enough for the the ones we care about. |
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+ resp = self.sock.recv(128) |
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+ return parse_message(resp) |
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+ |
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+ def get_link_ifindex(self, ifname): |
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+ body = ifinfomsg.pack(AF_UNSPEC, 0, 0, 0, 0) |
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+ body += create_rtattr(IFLA_IFNAME, ifname) |
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+ flags = NLM_F_REQUEST |
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+ msg = create_nlmsg(RTM_GETLINK, flags, 1, 0, body) |
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+ resp = self.send_message(msg) |
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+ return resp[2] |
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+ |
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+ def set_link_up(self, ifindex): |
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+ body = ifinfomsg.pack(AF_UNSPEC, 0, ifindex, IFF_UP, IFF_UP) |
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+ flags = NLM_F_REQUEST|NLM_F_ACK |
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+ msg = create_nlmsg(RTM_NEWLINK, flags, 1, 0, body) |
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+ self.send_message(msg) |
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+ |
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+ def add_address(self, ifindex, family, address, prefixlen): |
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+ body = ifaddrmsg.pack(family, prefixlen, 0, 0, ifindex) |
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+ addr = inet_pton(family, address) |
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+ body += create_rtattr(IFA_LOCAL, addr) |
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+ flags = NLM_F_REQUEST|NLM_F_ACK|NLM_F_EXCL|NLM_F_CREATE |
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+ msg = create_nlmsg(RTM_NEWADDR, flags, 1, 0, body) |
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+ self.send_message(msg) |