/* * Copyright (c) 2018-2026 Joachim Wiberg * All rights reserved. * * Redistribution and use in source and binary forms, with or without * modification, are permitted provided that the following conditions are met: * * Redistributions of source code must retain the above copyright * notice, this list of conditions and the following disclaimer. * * Redistributions in binary form must reproduce the above copyright * notice, this list of conditions and the following disclaimer in the * documentation and/or other materials provided with the distribution. * * Neither the name of the copyright holders nor the names of its * contributors may be used to endorse or promote products derived from * this software without specific prior written permission. * * THIS SOFTWARE IS PROVIDED BY THE COPYRIGHT HOLDERS AND CONTRIBUTORS "AS IS" * AND ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE * IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE * ARE DISCLAIMED. IN NO EVENT SHALL THE COPYRIGHT HOLDERS OR CONTRIBUTORS BE * LIABLE FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR * CONSEQUENTIAL DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF * SUBSTITUTE GOODS OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS * INTERRUPTION) HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN * CONTRACT, STRICT LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) * ARISING IN ANY WAY OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE * POSSIBILITY OF SUCH DAMAGE. */ #include "config.h" #include #include /* needed for u_int on DragonFly BSD */ #include #include #include #include #include #include #include #include #include #include #include "mdnsd.h" static TAILQ_HEAD(iflist, iface) iface_list = TAILQ_HEAD_INITIALIZER(iface_list); struct iface *iface_iterator(int first) { static struct iface *next = NULL; struct iface *iface; if (first) iface = TAILQ_FIRST(&iface_list); else iface = next; /* prepare for next, in case iface is unlinked */ if (iface) next = TAILQ_NEXT(iface, link); return iface; } struct iface *iface_find(const char *ifname) { struct iface *iface; for (iface = iface_iterator(1); iface; iface = iface_iterator(0)) { if (strcmp(iface->ifname, ifname)) continue; return iface; } return NULL; } void iface_free(struct iface *iface) { if (!iface) return; TAILQ_REMOVE(&iface_list, iface, link); free(iface); } static void mark(void) { struct iface *iface; for (iface = iface_iterator(1); iface; iface = iface_iterator(0)) { iface->unused = 1; iface->inaddr_old = iface->inaddr; memset(&iface->inaddr, 0, sizeof(iface->inaddr)); iface->in6addr_old = iface->in6addr; memset(&iface->in6addr, 0, sizeof(iface->in6addr)); } } static int sweep(void) { struct iface *iface; int changed = 0; for (iface = iface_iterator(1); iface; iface = iface_iterator(0)) { if (iface->unused) continue; if (!iface->changed) continue; if (iface->inaddr.s_addr == iface->inaddr_old.s_addr && IN6_ARE_ADDR_EQUAL(&iface->in6addr, &iface->in6addr_old)) { iface->changed = 0; continue; } changed++; } return changed; } void iface_init(char *ifname) { struct ifaddrs *ifaddr, *ifa; struct iface *iface = NULL; int rc = -1; rc = getifaddrs(&ifaddr); if (rc) { ERR("Failed fetching system interfaces: %s", strerror(errno)); return; } mark(); for (ifa = ifaddr; ifa; ifa = ifa->ifa_next) { struct in6_addr ina; char buf[INET6_ADDRSTRLEN]; if (!ifa->ifa_addr) continue; if (ifa->ifa_flags & IFF_LOOPBACK) continue; /* skip for now, mDNSResponder has it as fallback */ if (!(ifa->ifa_flags & IFF_MULTICAST)) continue; if (!(ifa->ifa_flags & IFF_UP)) continue; /* skip for now, not enabled */ if (ifa->ifa_addr->sa_family != AF_INET && ifa->ifa_addr->sa_family != AF_INET6) continue; if (ifname && strcmp(ifname, ifa->ifa_name)) continue; /* Validate IP address */ socklen_t salen = ifa->ifa_addr->sa_family == AF_INET ? sizeof(struct sockaddr_in) : sizeof(struct sockaddr_in6); rc = getnameinfo(ifa->ifa_addr, salen, buf, sizeof(buf), NULL, 0, NI_NUMERICHOST); if (rc) continue; /* Use address from getnameinfo() */ char* pc = strchr(buf, '%'); if (pc != NULL) /* inet_pton cannot handle the interface part of a link local IPv6 address. */ *pc = '\0'; if (inet_pton(ifa->ifa_addr->sa_family, buf, &ina) <= 0) continue; if (!iface) iface = iface_find(ifa->ifa_name); if (!iface) { iface = calloc(1, sizeof(*iface)); if (!iface) { ERR("Failed allocating memory for iface %s: %s", ifa->ifa_name, strerror(errno)); exit(1); } DBG("Creating iface instance for interface %s, address %s", ifa->ifa_name, buf); TAILQ_INSERT_TAIL(&iface_list, iface, link); strlcpy(iface->ifname, ifa->ifa_name, sizeof(iface->ifname)); iface->ifindex = if_nametoindex(ifa->ifa_name); iface->hostid = 1; iface->sd = -1; iface->sd6 = -1; } else { iface->unused = 0; } if (ifa->ifa_addr->sa_family == AF_INET) { if (iface->inaddr.s_addr != ina.s6_addr32[0]) { if (is_zeronet(&iface->inaddr) || is_linklocal(&iface->inaddr)) { iface->inaddr.s_addr = ina.s6_addr32[0]; iface->changed = 1; } } } else { if (! IN6_ARE_ADDR_EQUAL(&iface->in6addr, &ina)) { if (IN6_IS_ADDR_UNSPECIFIED(&iface->in6addr) /* Everything is better than no address (::) */ /* Any address is preferred over link local address */ || IN6_IS_ADDR_LINKLOCAL(&iface->in6addr) /* Any address is preferred over a site local address except for a link local address. */ || (IN6_IS_ADDR_SITELOCAL(&iface->in6addr) && !IN6_IS_ADDR_LINKLOCAL(&ina)) /* A unique local address shall only be overwritten by a global address. */ || ((iface->in6addr.s6_addr[0] & 0xfe) == 0xfc && !IN6_IS_ADDR_SITELOCAL(&ina) && !IN6_IS_ADDR_LINKLOCAL(&ina)) ) { iface->in6addr = ina; iface->changed = 1; } } } /* prepare for next */ if (!ifname) iface = NULL; } freeifaddrs(ifaddr); sweep(); } void iface_exit(void) { struct iface *iface, *tmp; TAILQ_FOREACH_SAFE(iface, &iface_list, link, tmp) { TAILQ_REMOVE(&iface_list, iface, link); free(iface); } }