src/core/loopback-setup.c

	loopback-setup.c revision fc25d7f8050f262fa6cafeb2a1032e6eb3e7b412
08bcebf36eb85f5e75b968de8c648e6614cc534bLennart Poettering/*-*- Mode: C; c-basic-offset: 8; indent-tabs-mode: nil -*-*/
08bcebf36eb85f5e75b968de8c648e6614cc534bLennart Poettering
08bcebf36eb85f5e75b968de8c648e6614cc534bLennart Poettering/***
08bcebf36eb85f5e75b968de8c648e6614cc534bLennart Poettering  This file is part of systemd.
08bcebf36eb85f5e75b968de8c648e6614cc534bLennart Poettering
08bcebf36eb85f5e75b968de8c648e6614cc534bLennart Poettering  Copyright 2010 Lennart Poettering
08bcebf36eb85f5e75b968de8c648e6614cc534bLennart Poettering
08bcebf36eb85f5e75b968de8c648e6614cc534bLennart Poettering  systemd is free software; you can redistribute it and/or modify it
08bcebf36eb85f5e75b968de8c648e6614cc534bLennart Poettering  under the terms of the GNU Lesser General Public License as published by
08bcebf36eb85f5e75b968de8c648e6614cc534bLennart Poettering  the Free Software Foundation; either version 2.1 of the License, or
08bcebf36eb85f5e75b968de8c648e6614cc534bLennart Poettering  (at your option) any later version.
08bcebf36eb85f5e75b968de8c648e6614cc534bLennart Poettering
08bcebf36eb85f5e75b968de8c648e6614cc534bLennart Poettering  systemd is distributed in the hope that it will be useful, but
08bcebf36eb85f5e75b968de8c648e6614cc534bLennart Poettering  WITHOUT ANY WARRANTY; without even the implied warranty of
08bcebf36eb85f5e75b968de8c648e6614cc534bLennart Poettering  MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the GNU
08bcebf36eb85f5e75b968de8c648e6614cc534bLennart Poettering  Lesser General Public License for more details.
08bcebf36eb85f5e75b968de8c648e6614cc534bLennart Poettering
08bcebf36eb85f5e75b968de8c648e6614cc534bLennart Poettering  You should have received a copy of the GNU Lesser General Public License
08bcebf36eb85f5e75b968de8c648e6614cc534bLennart Poettering  along with systemd; If not, see <http://www.gnu.org/licenses/>.
08bcebf36eb85f5e75b968de8c648e6614cc534bLennart Poettering***/
08bcebf36eb85f5e75b968de8c648e6614cc534bLennart Poettering
08bcebf36eb85f5e75b968de8c648e6614cc534bLennart Poettering#include <errno.h>
08bcebf36eb85f5e75b968de8c648e6614cc534bLennart Poettering#include <sys/socket.h>
08bcebf36eb85f5e75b968de8c648e6614cc534bLennart Poettering#include <net/if.h>
08bcebf36eb85f5e75b968de8c648e6614cc534bLennart Poettering#include <asm/types.h>
08bcebf36eb85f5e75b968de8c648e6614cc534bLennart Poettering#include <netinet/in.h>
08bcebf36eb85f5e75b968de8c648e6614cc534bLennart Poettering#include <linux/rtnetlink.h>
08bcebf36eb85f5e75b968de8c648e6614cc534bLennart Poettering#include <string.h>
08bcebf36eb85f5e75b968de8c648e6614cc534bLennart Poettering#include <stdlib.h>
08bcebf36eb85f5e75b968de8c648e6614cc534bLennart Poettering#include <unistd.h>
08bcebf36eb85f5e75b968de8c648e6614cc534bLennart Poettering
08bcebf36eb85f5e75b968de8c648e6614cc534bLennart Poettering#include "util.h"
08bcebf36eb85f5e75b968de8c648e6614cc534bLennart Poettering#include "macro.h"
08bcebf36eb85f5e75b968de8c648e6614cc534bLennart Poettering#include "loopback-setup.h"
08bcebf36eb85f5e75b968de8c648e6614cc534bLennart Poettering#include "socket-util.h"
08bcebf36eb85f5e75b968de8c648e6614cc534bLennart Poettering#include "sd-rtnl.h"
08bcebf36eb85f5e75b968de8c648e6614cc534bLennart Poettering#include "rtnl-util.h"
08bcebf36eb85f5e75b968de8c648e6614cc534bLennart Poettering
08bcebf36eb85f5e75b968de8c648e6614cc534bLennart Poetteringstatic int pipe_handler(sd_rtnl *rtnl, sd_rtnl_message *m, void *userdata) {
08bcebf36eb85f5e75b968de8c648e6614cc534bLennart Poettering        int *counter = userdata;
08bcebf36eb85f5e75b968de8c648e6614cc534bLennart Poettering        int r;
08bcebf36eb85f5e75b968de8c648e6614cc534bLennart Poettering
08bcebf36eb85f5e75b968de8c648e6614cc534bLennart Poettering        (*counter) --;
08bcebf36eb85f5e75b968de8c648e6614cc534bLennart Poettering
08bcebf36eb85f5e75b968de8c648e6614cc534bLennart Poettering        r = sd_rtnl_message_get_errno(m);
08bcebf36eb85f5e75b968de8c648e6614cc534bLennart Poettering
08bcebf36eb85f5e75b968de8c648e6614cc534bLennart Poettering        return r == -EEXIST ? 0 : r;
08bcebf36eb85f5e75b968de8c648e6614cc534bLennart Poettering}
08bcebf36eb85f5e75b968de8c648e6614cc534bLennart Poettering
08bcebf36eb85f5e75b968de8c648e6614cc534bLennart Poetteringstatic int add_adresses(sd_rtnl *rtnl, int if_loopback, uint32_t ipv4_address, int *counter) {
08bcebf36eb85f5e75b968de8c648e6614cc534bLennart Poettering        _cleanup_sd_rtnl_message_unref_ sd_rtnl_message *ipv4 = NULL, *ipv6 = NULL;
08bcebf36eb85f5e75b968de8c648e6614cc534bLennart Poettering        int r;
08bcebf36eb85f5e75b968de8c648e6614cc534bLennart Poettering
08bcebf36eb85f5e75b968de8c648e6614cc534bLennart Poettering        r = sd_rtnl_message_addr_new(RTM_NEWADDR, if_loopback, AF_INET, 8, IFA_F_PERMANENT, RT_SCOPE_HOST, &ipv4);
08bcebf36eb85f5e75b968de8c648e6614cc534bLennart Poettering        if (r < 0)
08bcebf36eb85f5e75b968de8c648e6614cc534bLennart Poettering                return r;
08bcebf36eb85f5e75b968de8c648e6614cc534bLennart Poettering
08bcebf36eb85f5e75b968de8c648e6614cc534bLennart Poettering        r = sd_rtnl_message_append(ipv4, IFA_LOCAL, &ipv4_address);
08bcebf36eb85f5e75b968de8c648e6614cc534bLennart Poettering        if (r < 0)
08bcebf36eb85f5e75b968de8c648e6614cc534bLennart Poettering                return r;
08bcebf36eb85f5e75b968de8c648e6614cc534bLennart Poettering
08bcebf36eb85f5e75b968de8c648e6614cc534bLennart Poettering        r = sd_rtnl_call_async(rtnl, ipv4, &pipe_handler, counter, 0, NULL);
08bcebf36eb85f5e75b968de8c648e6614cc534bLennart Poettering        if (r < 0)
08bcebf36eb85f5e75b968de8c648e6614cc534bLennart Poettering                return r;
08bcebf36eb85f5e75b968de8c648e6614cc534bLennart Poettering
08bcebf36eb85f5e75b968de8c648e6614cc534bLennart Poettering        (*counter) ++;
08bcebf36eb85f5e75b968de8c648e6614cc534bLennart Poettering
08bcebf36eb85f5e75b968de8c648e6614cc534bLennart Poettering        if (!socket_ipv6_is_supported())
08bcebf36eb85f5e75b968de8c648e6614cc534bLennart Poettering                return 0;
08bcebf36eb85f5e75b968de8c648e6614cc534bLennart Poettering
08bcebf36eb85f5e75b968de8c648e6614cc534bLennart Poettering        r = sd_rtnl_message_addr_new(RTM_NEWADDR, if_loopback, AF_INET6, 128, 0, 0, &ipv6);
08bcebf36eb85f5e75b968de8c648e6614cc534bLennart Poettering        if (r < 0)
08bcebf36eb85f5e75b968de8c648e6614cc534bLennart Poettering                return r;
08bcebf36eb85f5e75b968de8c648e6614cc534bLennart Poettering
08bcebf36eb85f5e75b968de8c648e6614cc534bLennart Poettering        r = sd_rtnl_message_append(ipv6, IFA_LOCAL, &in6addr_loopback);
08bcebf36eb85f5e75b968de8c648e6614cc534bLennart Poettering        if (r < 0)
08bcebf36eb85f5e75b968de8c648e6614cc534bLennart Poettering                return r;
08bcebf36eb85f5e75b968de8c648e6614cc534bLennart Poettering
08bcebf36eb85f5e75b968de8c648e6614cc534bLennart Poettering        r = sd_rtnl_call_async(rtnl, ipv6, &pipe_handler, counter, 0, NULL);
08bcebf36eb85f5e75b968de8c648e6614cc534bLennart Poettering        if (r < 0)
08bcebf36eb85f5e75b968de8c648e6614cc534bLennart Poettering                return r;
08bcebf36eb85f5e75b968de8c648e6614cc534bLennart Poettering
08bcebf36eb85f5e75b968de8c648e6614cc534bLennart Poettering        (*counter) ++;

        return 0;
}

static int start_interface(sd_rtnl *rtnl, int if_loopback, uint32_t ipv4_address, int *counter) {
        _cleanup_sd_rtnl_message_unref_ sd_rtnl_message *req = NULL;
        int r;

        r = sd_rtnl_message_link_new(RTM_NEWLINK, if_loopback, &req);
        if (r < 0)
                return r;

        r = sd_rtnl_message_link_set_flags(req, IFF_UP);
        if (r < 0)
                return r;

        r = sd_rtnl_message_append(req, IFA_LOCAL, &ipv4_address);
        if (r < 0)
                return r;

        r = sd_rtnl_call_async(rtnl, req, &pipe_handler, counter, 0, NULL);
        if (r < 0)
                return r;

        (*counter) ++;

        return 0;
}

static int check_loopback(void) {
        int r;
        _cleanup_close_ int fd = -1;
        union {
                struct sockaddr sa;
                struct sockaddr_in in;
        } sa = {
                .in.sin_family = AF_INET,
                .in.sin_addr.s_addr = INADDR_LOOPBACK,
        };

        /* If we failed to set up the loop back device, check whether
         * it might already be set up */

        fd = socket(AF_INET, SOCK_DGRAM|SOCK_NONBLOCK|SOCK_CLOEXEC, 0);
        if (fd < 0)
                return -errno;

        if (bind(fd, &sa.sa, sizeof(sa.in)) >= 0)
                r = 1;
        else
                r = errno == EADDRNOTAVAIL ? 0 : -errno;

        return r;
}

int loopback_setup(void) {
        _cleanup_sd_rtnl_unref_ sd_rtnl *rtnl = NULL;
        int r, if_loopback, counter = 0;
        bool eperm = false;
        uint32_t ipv4_address = htonl(INADDR_LOOPBACK);

        errno = 0;
        if_loopback = (int) if_nametoindex("lo");
        if (if_loopback <= 0)
                return errno ? -errno : -ENODEV;

        r = sd_rtnl_open(0, &rtnl);
        if (r < 0)
                return r;

        r = add_adresses(rtnl, if_loopback, ipv4_address, &counter);
        if (r < 0)
                return r;

        r = start_interface(rtnl, if_loopback, ipv4_address, &counter);
        if (r < 0)
                return r;

        while (counter > 0) {
                r = sd_rtnl_wait(rtnl, 0);
                if (r < 0)
                        return r;

                r = sd_rtnl_process(rtnl, 0);
                if (r < 0) {
                        if (r == -EPERM)
                                eperm = true;
                        else {
                                log_warning("Failed to configure loopback device: %s", strerror(-r));
                                return r;
                        }
                }
        }

        if (eperm && check_loopback() < 0) {
                log_warning("Failed to configure loopback device: %s", strerror(EPERM));
                return -EPERM;
        }

        return 0;
}