/*-*- Mode: C; c-basic-offset: 8; indent-tabs-mode: nil -*-*/ /*** This file is part of systemd. Copyright 2010 Lennart Poettering systemd is free software; you can redistribute it and/or modify it under the terms of the GNU Lesser General Public License as published by the Free Software Foundation; either version 2.1 of the License, or (at your option) any later version. systemd is distributed in the hope that it will be useful, but WITHOUT ANY WARRANTY; without even the implied warranty of MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the GNU Lesser General Public License for more details. You should have received a copy of the GNU Lesser General Public License along with systemd; If not, see <http://www.gnu.org/licenses/>. ***/ #include <errno.h> #include <sys/socket.h> #include <net/if.h> #include <asm/types.h> #include <netinet/in.h> #include <string.h> #include <stdlib.h> #include <unistd.h> #include "util.h" #include "macro.h" #include "loopback-setup.h" #include "socket-util.h" #include "sd-rtnl.h" #include "rtnl-util.h" static int pipe_handler(sd_rtnl *rtnl, sd_rtnl_message *m, void *userdata) { int *counter = userdata; int r; (*counter) --; r = sd_rtnl_message_get_errno(m); return r == -EEXIST ? 0 : r; } static int add_addresses(sd_rtnl *rtnl, int if_loopback, struct in_addr *ipv4_address, int *counter) { _cleanup_rtnl_message_unref_ sd_rtnl_message *ipv4 = NULL, *ipv6 = NULL; int r; r = sd_rtnl_message_new_addr(rtnl, &ipv4, RTM_NEWADDR, if_loopback, AF_INET); if (r < 0) return r; r = sd_rtnl_message_addr_set_prefixlen(ipv4, 8); if (r < 0) return r; r = sd_rtnl_message_addr_set_flags(ipv4, IFA_F_PERMANENT); if (r < 0) return r; r = sd_rtnl_message_addr_set_scope(ipv4, RT_SCOPE_HOST); if (r < 0) return r; r = sd_rtnl_message_append_in_addr(ipv4, IFA_LOCAL, ipv4_address); if (r < 0) return r; r = sd_rtnl_call_async(rtnl, ipv4, &pipe_handler, counter, 0, NULL); if (r < 0) return r; (*counter) ++; if (!socket_ipv6_is_supported()) return 0; r = sd_rtnl_message_new_addr(rtnl, &ipv6, RTM_NEWADDR, if_loopback, AF_INET6); if (r < 0) return r; r = sd_rtnl_message_addr_set_prefixlen(ipv6, 128); if (r < 0) return r; r = sd_rtnl_message_addr_set_flags(ipv6, IFA_F_PERMANENT); if (r < 0) return r; r = sd_rtnl_message_addr_set_scope(ipv6, RT_SCOPE_HOST); if (r < 0) return r; r = sd_rtnl_message_append_in6_addr(ipv6, IFA_LOCAL, &in6addr_loopback); if (r < 0) return r; r = sd_rtnl_call_async(rtnl, ipv6, &pipe_handler, counter, 0, NULL); if (r < 0) return r; (*counter) ++; return 0; } static int start_interface(sd_rtnl *rtnl, int if_loopback, struct in_addr *ipv4_address, int *counter) { _cleanup_rtnl_message_unref_ sd_rtnl_message *req = NULL; int r; r = sd_rtnl_message_new_link(rtnl, &req, RTM_SETLINK, if_loopback); if (r < 0) return r; r = sd_rtnl_message_link_set_flags(req, IFF_UP, IFF_UP); 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_rtnl_unref_ sd_rtnl *rtnl = NULL; int r, if_loopback, counter = 0; bool eperm = false; struct in_addr ipv4_address; errno = 0; if_loopback = (int) if_nametoindex("lo"); if (if_loopback <= 0) return errno ? -errno : -ENODEV; ipv4_address.s_addr = htonl(INADDR_LOOPBACK); r = sd_rtnl_open(&rtnl, 0); if (r < 0) return r; r = add_addresses(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; }