92 lines
2.6 KiB
C
92 lines
2.6 KiB
C
/*-*- Mode: C; c-basic-offset: 8; indent-tabs-mode: nil -*-*/
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/***
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This file is part of systemd.
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Copyright 2010 Lennart Poettering
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systemd is free software; you can redistribute it and/or modify it
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under the terms of the GNU Lesser General Public License as published by
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the Free Software Foundation; either version 2.1 of the License, or
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(at your option) any later version.
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systemd is distributed in the hope that it will be useful, but
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WITHOUT ANY WARRANTY; without even the implied warranty of
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MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the GNU
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Lesser General Public License for more details.
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You should have received a copy of the GNU Lesser General Public License
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along with systemd; If not, see <http://www.gnu.org/licenses/>.
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***/
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#include <net/if.h>
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#include <stdlib.h>
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#include "sd-netlink.h"
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#include "netlink-util.h"
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#include "missing.h"
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#include "loopback-setup.h"
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static int start_loopback(sd_netlink *rtnl) {
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_cleanup_netlink_message_unref_ sd_netlink_message *req = NULL;
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int r;
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r = sd_rtnl_message_new_link(rtnl, &req, RTM_SETLINK, LOOPBACK_IFINDEX);
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if (r < 0)
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return r;
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r = sd_rtnl_message_link_set_flags(req, IFF_UP, IFF_UP);
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if (r < 0)
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return r;
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r = sd_netlink_call(rtnl, req, 0, NULL);
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if (r < 0)
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return r;
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return 0;
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}
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static bool check_loopback(sd_netlink *rtnl) {
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_cleanup_netlink_message_unref_ sd_netlink_message *req = NULL, *reply = NULL;
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unsigned flags;
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int r;
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r = sd_rtnl_message_new_link(rtnl, &req, RTM_GETLINK, LOOPBACK_IFINDEX);
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if (r < 0)
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return false;
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r = sd_netlink_call(rtnl, req, 0, &reply);
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if (r < 0)
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return false;
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r = sd_rtnl_message_link_get_flags(reply, &flags);
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if (r < 0)
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return false;
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return flags & IFF_UP;
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}
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int loopback_setup(void) {
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_cleanup_netlink_unref_ sd_netlink *rtnl = NULL;
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int r;
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r = sd_netlink_open(&rtnl);
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if (r < 0)
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return r;
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r = start_loopback(rtnl);
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if (r < 0) {
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/* If we lack the permissions to configure the
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* loopback device, but we find it to be already
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* configured, let's exit cleanly, in order to
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* supported unprivileged containers. */
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if (r == -EPERM && check_loopback(rtnl))
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return 0;
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return log_warning_errno(r, "Failed to configure loopback device: %m");
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}
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return 0;
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}
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