/* * Copyright (c) 2002-2003 Apple Computer, Inc. All rights reserved. * * @APPLE_LICENSE_HEADER_START@ * * This file contains Original Code and/or Modifications of Original Code * as defined in and that are subject to the Apple Public Source License * Version 2.0 (the 'License'). You may not use this file except in * compliance with the License. Please obtain a copy of the License at * http://www.opensource.apple.com/apsl/ and read it before using this * file. * * The Original Code and all software distributed under the License are * distributed on an 'AS IS' basis, WITHOUT WARRANTY OF ANY KIND, EITHER * EXPRESS OR IMPLIED, AND APPLE HEREBY DISCLAIMS ALL SUCH WARRANTIES, * INCLUDING WITHOUT LIMITATION, ANY WARRANTIES OF MERCHANTABILITY, * FITNESS FOR A PARTICULAR PURPOSE, QUIET ENJOYMENT OR NON-INFRINGEMENT. * Please see the License for the specific language governing rights and * limitations under the License. * * @APPLE_LICENSE_HEADER_END@ * * Formatting notes: * This code follows the "Whitesmiths style" C indentation rules. Plenty of discussion * on C indentation can be found on the web, such as , * but for the sake of brevity here I will say just this: Curly braces are not syntactially * part of an "if" statement; they are the beginning and ending markers of a compound statement; * therefore common sense dictates that if they are part of a compound statement then they * should be indented to the same level as everything else in that compound statement. * Indenting curly braces at the same level as the "if" implies that curly braces are * part of the "if", which is false. (This is as misleading as people who write "char* x,y;" * thinking that variables x and y are both of type "char*" -- and anyone who doesn't * understand why variable y is not of type "char*" just proves the point that poor code * layout leads people to unfortunate misunderstandings about how the C language really works.) Change History (most recent first): $Log$ Revision 1.4 2004/11/29 05:55:45 rpedde Fix for OpenBSD Revision 1.3 2004/11/13 07:14:26 rpedde modularize debugging statements Revision 1.2 2004/10/25 04:51:54 rpedde tune down some of the logging Revision 1.1 2004/03/29 17:55:17 rpedde Flatten mdns stuff Revision 1.4 2004/03/02 00:03:37 rpedde Merge new rendezvous code Revision 1.25 2003/10/30 19:25:49 cheshire Fix signed/unsigned warning on certain compilers Revision 1.24 2003/08/18 23:12:23 cheshire mDNSResponder divide by zero in mDNSPlatformTimeNow() Revision 1.23 2003/08/12 19:56:26 cheshire Update to APSL 2.0 Revision 1.22 2003/08/06 18:46:15 cheshire LogMsg() errors are serious -- always report them to stderr, regardless of debugging level Revision 1.21 2003/08/06 18:20:51 cheshire Makefile cleanup Revision 1.20 2003/08/05 23:56:26 cheshire Update code to compile with the new mDNSCoreReceive() function that requires a TTL (Right now mDNSPosix.c just reports 255 -- we should fix this) Revision 1.19 2003/07/19 03:15:16 cheshire Add generic MemAllocate/MemFree prototypes to mDNSPlatformFunctions.h, and add the obvious trivial implementations to each platform support layer Revision 1.18 2003/07/14 18:11:54 cheshire Fix stricter compiler warnings Revision 1.17 2003/07/13 01:08:38 cheshire There's not much point running mDNS over a point-to-point link; exclude those Revision 1.16 2003/07/02 21:19:59 cheshire Update copyright notices, etc., in source code comments Revision 1.15 2003/06/18 05:48:41 cheshire Fix warnings Revision 1.14 2003/05/26 03:21:30 cheshire Tidy up address structure naming: mDNSIPAddr => mDNSv4Addr (for consistency with mDNSv6Addr) mDNSAddr.addr.ipv4 => mDNSAddr.ip.v4 mDNSAddr.addr.ipv6 => mDNSAddr.ip.v6 Revision 1.13 2003/05/26 03:01:28 cheshire sprintf/vsprintf-style functions are unsafe; use snprintf/vsnprintf instead Revision 1.12 2003/05/21 03:49:18 cheshire Fix warning Revision 1.11 2003/05/06 00:00:50 cheshire Rationalize naming of domainname manipulation functions Revision 1.10 2003/04/25 01:45:57 cheshire mDNS_RegisterNoSuchService needs to include a host name Revision 1.9 2003/03/20 21:10:31 cheshire Fixes done at IETF 56 to make mDNSProxyResponderPosix run on Solaris Revision 1.8 2003/03/15 04:40:38 cheshire Change type called "mDNSOpaqueID" to the more descriptive name "mDNSInterfaceID" Revision 1.7 2003/03/13 03:46:21 cheshire Fixes to make the code build on Linux Revision 1.6 2003/03/08 00:35:56 cheshire Switched to using new "mDNS_Execute" model (see "mDNSCore/Implementer Notes.txt") Revision 1.5 2002/12/23 22:13:31 jgraessl Reviewed by: Stuart Cheshire Initial IPv6 support for mDNSResponder. Revision 1.4 2002/09/27 01:47:45 cheshire Workaround for Linux 2.0 systems that don't have IP_PKTINFO Revision 1.3 2002/09/21 20:44:53 zarzycki Added APSL info Revision 1.2 2002/09/19 21:25:36 cheshire mDNS_snprintf() doesn't need to be in a separate file Revision 1.1 2002/09/17 06:24:34 cheshire First checkin */ #include "mDNSClientAPI.h" // Defines the interface provided to the client layer above #include "mDNSPlatformFunctions.h" // Defines the interface to the supporting layer below #include "mDNSPosix.h" // Defines the specific types needed to run mDNS on this platform #include #include #include #include #include #include #include #include #include #include #include #include "err.h" #include "mDNSUNP.h" // *************************************************************************** // Structures // PosixNetworkInterface is a record extension of the core NetworkInterfaceInfo // type that supports extra fields needed by the Posix platform. // // IMPORTANT: coreIntf must be the first field in the structure because // we cast between pointers to the two different types regularly. typedef struct PosixNetworkInterface PosixNetworkInterface; struct PosixNetworkInterface { NetworkInterfaceInfo coreIntf; const char * intfName; PosixNetworkInterface * aliasIntf; int index; int multicastSocket; int multicastSocketv6; }; // *************************************************************************** // Globals (for debugging) static int num_registered_interfaces = 0; static int num_pkts_accepted = 0; static int num_pkts_rejected = 0; // *************************************************************************** // Functions int gMDNSPlatformPosixVerboseLevel = 0; // Note, this uses mDNS_vsnprintf instead of standard "vsnprintf", because mDNS_vsnprintf knows // how to print special data types like IP addresses and length-prefixed domain names mDNSexport void debugf_(const char *format, ...) { unsigned char buffer[512]; va_list ptr; va_start(ptr,format); buffer[mDNS_vsnprintf((char *)buffer, sizeof(buffer), format, ptr)] = 0; va_end(ptr); DPRINTF(E_INF,L_REND,"%s\n",buffer); } mDNSexport void verbosedebugf_(const char *format, ...) { unsigned char buffer[512]; va_list ptr; va_start(ptr,format); buffer[mDNS_vsnprintf((char *)buffer, sizeof(buffer), format, ptr)] = 0; va_end(ptr); DPRINTF(E_DBG,L_REND,"%s\n",buffer); } mDNSexport void LogMsg(const char *format, ...) { unsigned char buffer[512]; va_list ptr; va_start(ptr,format); buffer[mDNS_vsnprintf((char *)buffer, sizeof(buffer), format, ptr)] = 0; va_end(ptr); DPRINTF(E_WARN,L_REND,"%s\n",buffer); } #define PosixErrorToStatus(errNum) ((errNum) == 0 ? mStatus_NoError : mStatus_UnknownErr) static void SockAddrTomDNSAddr(const struct sockaddr *const sa, mDNSAddr *ipAddr, mDNSIPPort *ipPort) { switch (sa->sa_family) { case AF_INET: { struct sockaddr_in* sin = (struct sockaddr_in*)sa; ipAddr->type = mDNSAddrType_IPv4; ipAddr->ip.v4.NotAnInteger = sin->sin_addr.s_addr; if (ipPort) ipPort->NotAnInteger = sin->sin_port; break; } #ifdef mDNSIPv6Support case AF_INET6: { struct sockaddr_in6* sin6 = (struct sockaddr_in6*)sa; assert(sin6->sin6_len == sizeof(*sin6)); ipAddr->type = mDNSAddrType_IPv6; ipAddr->ip.v6 = *(mDNSv6Addr*)&sin6->sin6_addr; if (ipPort) ipPort->NotAnInteger = sin6->sin6_port; break; } #endif default: verbosedebugf("SockAddrTomDNSAddr: Uknown address family %d\n", sa->sa_family); ipAddr->type = mDNSAddrType_None; if (ipPort) ipPort->NotAnInteger = 0; break; } } #if COMPILER_LIKES_PRAGMA_MARK #pragma mark ***** Send and Receive #endif // mDNS core calls this routine when it needs to send a packet. mDNSexport mStatus mDNSPlatformSendUDP(const mDNS *const m, const DNSMessage *const msg, const mDNSu8 *const end, mDNSInterfaceID InterfaceID, mDNSIPPort srcPort, const mDNSAddr *dst, mDNSIPPort dstPort) { int err; struct sockaddr_storage to; PosixNetworkInterface * thisIntf; assert(m != NULL); assert(msg != NULL); assert(end != NULL); assert( (((char *) end) - ((char *) msg)) > 0 ); assert(InterfaceID != 0); // Can't send from zero source address assert(srcPort.NotAnInteger != 0); // Nor from a zero source port assert(dstPort.NotAnInteger != 0); // Nor from a zero source port if (dst->type == mDNSAddrType_IPv4) { struct sockaddr_in *sin = (struct sockaddr_in*)&to; #ifndef NOT_HAVE_SA_LEN sin->sin_len = sizeof(*sin); #endif sin->sin_family = AF_INET; sin->sin_port = dstPort.NotAnInteger; sin->sin_addr.s_addr = dst->ip.v4.NotAnInteger; } #ifdef mDNSIPv6Support else if (dst->type == mDNSAddrType_IPv6) { struct sockaddr_in6 *sin6 = (struct sockaddr_in6*)&to; mDNSPlatformMemZero(sin6, sizeof(*sin6)); sin6->sin6_len = sizeof(*sin6); sin6->sin6_family = AF_INET6; sin6->sin6_port = dstPort.NotAnInteger; sin6->sin6_addr = *(struct in6_addr*)&dst->ip.v6; } #endif err = 0; thisIntf = (PosixNetworkInterface *)(InterfaceID); if (dst->type == mDNSAddrType_IPv4) err = sendto(thisIntf->multicastSocket, msg, (char*)end - (char*)msg, 0, (struct sockaddr *)&to, GET_SA_LEN(to)); #ifdef mDNSIPv6Support else if (dst->type == mDNSAddrType_IPv6) err = sendto(thisIntf->multicastSocketv6, msg, (char*)end - (char*)msg, 0, (struct sockaddr *)&to, GET_SA_LEN(to)); #endif if (err > 0) err = 0; else if (err < 0) verbosedebugf("mDNSPlatformSendUDP got error %d (%s) sending packet to %#a on interface %#a/%s/%d", errno, strerror(errno), dst, &thisIntf->coreIntf.ip, thisIntf->intfName, thisIntf->index); return PosixErrorToStatus(err); } // This routine is called when the main loop detects that data is available on a socket. static void SocketDataReady(mDNS *const m, PosixNetworkInterface *intf, int skt) { mDNSAddr senderAddr, destAddr; mDNSIPPort senderPort; ssize_t packetLen; DNSMessage packet; struct my_in_pktinfo packetInfo; struct sockaddr_storage from; socklen_t fromLen; int flags; mDNSBool reject; assert(m != NULL); assert(intf != NULL); assert(skt >= 0); fromLen = sizeof(from); flags = 0; packetLen = recvfrom_flags(skt, &packet, sizeof(packet), &flags, (struct sockaddr *) &from, &fromLen, &packetInfo); if (packetLen >= 0) { SockAddrTomDNSAddr((struct sockaddr*)&from, &senderAddr, &senderPort); SockAddrTomDNSAddr((struct sockaddr*)&packetInfo.ipi_addr, &destAddr, NULL); // If we have broken IP_RECVDSTADDR functionality (so far // I've only seen this on OpenBSD) then apply a hack to // convince mDNS Core that this isn't a spoof packet. // Basically what we do is check to see whether the // packet arrived as a multicast and, if so, set its // destAddr to the mDNS address. // // I must admit that I could just be doing something // wrong on OpenBSD and hence triggering this problem // but I'm at a loss as to how. // // If this platform doesn't have IP_PKTINFO or IP_RECVDSTADDR, then we have // no way to tell the destination address or interface this packet arrived on, // so all we can do is just assume it's a multicast #if HAVE_BROKEN_RECVDSTADDR || (!defined(IP_PKTINFO) && !defined(IP_RECVDSTADDR)) if ( (destAddr.ip.v4.NotAnInteger == 0) && (flags & MSG_MCAST) ) { destAddr.type == senderAddr.type; if (senderAddr.type == mDNSAddrType_IPv4) destAddr.ip.v4 = AllDNSLinkGroup; else if (senderAddr.type == mDNSAddrType_IPv6) destAddr.ip.v6 = AllDNSLinkGroupv6; } #endif // We only accept the packet if the interface on which it came // in matches the interface associated with this socket. // We do this match by name or by index, depending on which // information is available. recvfrom_flags sets the name // to "" if the name isn't available, or the index to -1 // if the index is available. This accomodates the various // different capabilities of our target platforms. reject = mDNSfalse; if ( packetInfo.ipi_ifname[0] != 0 ) reject = (strcmp(packetInfo.ipi_ifname, intf->intfName) != 0); else if ( packetInfo.ipi_ifindex != -1 ) reject = (packetInfo.ipi_ifindex != intf->index); if (reject) { verbosedebugf("SocketDataReady ignored a packet from %#a to %#a on interface %s/%d expecting %#a/%s/%d", &senderAddr, &destAddr, packetInfo.ipi_ifname, packetInfo.ipi_ifindex, &intf->coreIntf.ip, intf->intfName, intf->index); packetLen = -1; num_pkts_rejected++; if (num_pkts_rejected > (num_pkts_accepted + 1) * (num_registered_interfaces + 1) * 2) { DPRINTF(E_LOG,L_REND, "*** WARNING: Received %d packets; Accepted %d packets; Rejected %d packets because of interface mismatch\n", num_pkts_accepted + num_pkts_rejected, num_pkts_accepted, num_pkts_rejected); num_pkts_accepted = 0; num_pkts_rejected = 0; } } else { verbosedebugf("SocketDataReady got a packet from %#a to %#a on interface %#a/%s/%d", &senderAddr, &destAddr, &intf->coreIntf.ip, intf->intfName, intf->index); num_pkts_accepted++; } } if (packetLen >= 0 && packetLen < (ssize_t)sizeof(DNSMessageHeader)) { debugf("SocketDataReady packet length (%d) too short", packetLen); packetLen = -1; } if (packetLen >= 0) mDNSCoreReceive(m, &packet, (mDNSu8 *)&packet + packetLen, &senderAddr, senderPort, &destAddr, MulticastDNSPort, intf->coreIntf.InterfaceID, 255); } #if COMPILER_LIKES_PRAGMA_MARK #pragma mark ***** Init and Term #endif // On OS X this gets the text of the field labelled "Computer Name" in the Sharing Prefs Control Panel // Other platforms can either get the information from the appropriate place, // or they can alternatively just require all registering services to provide an explicit name mDNSlocal void GetUserSpecifiedFriendlyComputerName(domainlabel *const namelabel) { MakeDomainLabelFromLiteralString(namelabel, "Fill in Default Service Name Here"); } // This gets the current hostname, truncating it at the first dot if necessary mDNSlocal void GetUserSpecifiedRFC1034ComputerName(domainlabel *const namelabel) { int len = 0; gethostname((char *)(&namelabel->c[1]), MAX_DOMAIN_LABEL); while (len < MAX_DOMAIN_LABEL && namelabel->c[len+1] && namelabel->c[len+1] != '.') len++; namelabel->c[0] = len; } // Searches the interface list looking for the named interface. // Returns a pointer to if it found, or NULL otherwise. static PosixNetworkInterface *SearchForInterfaceByName(mDNS *const m, const char *intfName) { PosixNetworkInterface *intf; assert(m != NULL); assert(intfName != NULL); intf = (PosixNetworkInterface*)(m->HostInterfaces); while ( (intf != NULL) && (strcmp(intf->intfName, intfName) != 0) ) intf = (PosixNetworkInterface *)(intf->coreIntf.next); return intf; } // Frees the specified PosixNetworkInterface structure. The underlying // interface must have already been deregistered with the mDNS core. static void FreePosixNetworkInterface(PosixNetworkInterface *intf) { assert(intf != NULL); if (intf->intfName != NULL) free((void *)intf->intfName); if (intf->multicastSocket != -1) assert(close(intf->multicastSocket) == 0); if (intf->multicastSocketv6 != -1) assert(close(intf->multicastSocketv6) == 0); free(intf); } // Grab the first interface, deregister it, free it, and repeat until done. static void ClearInterfaceList(mDNS *const m) { assert(m != NULL); while (m->HostInterfaces) { PosixNetworkInterface *intf = (PosixNetworkInterface*)(m->HostInterfaces); mDNS_DeregisterInterface(m, &intf->coreIntf); if (gMDNSPlatformPosixVerboseLevel > 0) DPRINTF(E_LOG,L_REND, "Deregistered interface %s\n", intf->intfName); FreePosixNetworkInterface(intf); } num_registered_interfaces = 0; num_pkts_accepted = 0; num_pkts_rejected = 0; } // Sets up a multicast send/receive socket for the specified // port on the interface specified by the IP addrelss intfAddr. static int SetupSocket(struct sockaddr *intfAddr, mDNSIPPort port, int interfaceIndex, int *sktPtr) { int err = 0; static const int kOn = 1; static const int kIntTwoFiveFive = 255; static const unsigned char kByteTwoFiveFive = 255; (void) interfaceIndex; // Unused assert(intfAddr != NULL); assert(sktPtr != NULL); assert(*sktPtr == -1); // Open the socket... if (intfAddr->sa_family == AF_INET) *sktPtr = socket(PF_INET, SOCK_DGRAM, IPPROTO_UDP); #ifdef mDNSIPv6Support else if (intfAddr->sa_family == AF_INET6) *sktPtr = socket(PF_INET6, SOCK_DGRAM, IPPROTO_UDP); #endif else return EINVAL; if (*sktPtr < 0) { err = errno; perror("socket"); } // ... with a shared UDP port if (err == 0) { #if defined(SO_REUSEPORT) err = setsockopt(*sktPtr, SOL_SOCKET, SO_REUSEPORT, &kOn, sizeof(kOn)); #elif defined(SO_REUSEADDR) err = setsockopt(*sktPtr, SOL_SOCKET, SO_REUSEADDR, &kOn, sizeof(kOn)); #else #error This platform has no way to avoid address busy errors on multicast. #endif if (err < 0) { err = errno; perror("setsockopt - SO_REUSExxxx"); } } // We want to receive destination addresses and interface identifiers. if (intfAddr->sa_family == AF_INET) { struct ip_mreq imr; struct sockaddr_in bindAddr; if (err == 0) { #if defined(IP_PKTINFO) // Linux err = setsockopt(*sktPtr, IPPROTO_IP, IP_PKTINFO, &kOn, sizeof(kOn)); if (err < 0) { err = errno; perror("setsockopt - IP_PKTINFO"); } #elif defined(IP_RECVDSTADDR) || defined(IP_RECVIF) // BSD and Solaris #if defined(IP_RECVDSTADDR) err = setsockopt(*sktPtr, IPPROTO_IP, IP_RECVDSTADDR, &kOn, sizeof(kOn)); if (err < 0) { err = errno; perror("setsockopt - IP_RECVDSTADDR"); } #endif #if defined(IP_RECVIF) if (err == 0) { err = setsockopt(*sktPtr, IPPROTO_IP, IP_RECVIF, &kOn, sizeof(kOn)); if (err < 0) { err = errno; perror("setsockopt - IP_RECVIF"); } } #endif #else #warning This platform has no way to get the destination interface information -- will only work for single-homed hosts #endif } // Add multicast group membership on this interface if (err == 0) { imr.imr_multiaddr.s_addr = AllDNSLinkGroup.NotAnInteger; imr.imr_interface = ((struct sockaddr_in*)intfAddr)->sin_addr; err = setsockopt(*sktPtr, IPPROTO_IP, IP_ADD_MEMBERSHIP, &imr, sizeof(imr)); if (err < 0) { err = errno; perror("setsockopt - IP_ADD_MEMBERSHIP"); } } // Specify outgoing interface too if (err == 0) { err = setsockopt(*sktPtr, IPPROTO_IP, IP_MULTICAST_IF, &((struct sockaddr_in*)intfAddr)->sin_addr, sizeof(struct in_addr)); if (err < 0) { err = errno; perror("setsockopt - IP_MULTICAST_IF"); } } // Per the mDNS spec, send unicast packets with TTL 255 if (err == 0) { err = setsockopt(*sktPtr, IPPROTO_IP, IP_TTL, &kIntTwoFiveFive, sizeof(kIntTwoFiveFive)); if (err < 0) { err = errno; perror("setsockopt - IP_TTL"); } } // and multicast packets with TTL 255 too // There's some debate as to whether IP_MULTICAST_TTL is an int or a byte so we just try both. if (err == 0) { err = setsockopt(*sktPtr, IPPROTO_IP, IP_MULTICAST_TTL, &kByteTwoFiveFive, sizeof(kByteTwoFiveFive)); if (err < 0 && errno == EINVAL) err = setsockopt(*sktPtr, IPPROTO_IP, IP_MULTICAST_TTL, &kIntTwoFiveFive, sizeof(kIntTwoFiveFive)); if (err < 0) { err = errno; perror("setsockopt - IP_MULTICAST_TTL"); } } // And start listening for packets if (err == 0) { bindAddr.sin_family = AF_INET; bindAddr.sin_port = port.NotAnInteger; bindAddr.sin_addr.s_addr = INADDR_ANY; // Want to receive multicasts AND unicasts on this socket err = bind(*sktPtr, (struct sockaddr *) &bindAddr, sizeof(bindAddr)); if (err < 0) { err = errno; DPRINTF(E_LOG,L_REND,"bind: %s\n",strerror(errno)); } } } // endif (intfAddr->sa_family == AF_INET) #ifdef mDNSIPv6Support else if (intfAddr->sa_family == AF_INET6) { struct ipv6_mreq imr6; struct sockaddr_in6 bindAddr6; if (err == 0) { #if defined(IPV6_PKTINFO) err = setsockopt(*sktPtr, IPPROTO_IPV6, IPV6_PKTINFO, &kOn, sizeof(kOn)); if (err < 0) { err = errno; perror("setsockopt - IPV6_PKTINFO"); } #else #warning This platform has no way to get the destination interface information for IPv6 -- will only work for single-homed hosts #endif } // Add multicast group membership on this interface if (err == 0) { imr6.ipv6mr_multiaddr = *(const struct in6_addr*)&AllDNSLinkGroupv6; imr6.ipv6mr_interface = interfaceIndex; err = setsockopt(*sktPtr, IPPROTO_IPV6, IPV6_JOIN_GROUP, &imr6, sizeof(imr6)); if (err < 0) { err = errno; verbosedebugf("IPV6_JOIN_GROUP %.16a on %d failed.\n", &imr6.ipv6mr_multiaddr, imr6.ipv6mr_interface); perror("setsockopt - IPV6_JOIN_GROUP"); } } // Specify outgoing interface too if (err == 0) { u_int multicast_if = interfaceIndex; err = setsockopt(*sktPtr, IPPROTO_IPV6, IPV6_MULTICAST_IF, &multicast_if, sizeof(multicast_if)); if (err < 0) { err = errno; perror("setsockopt - IPV6_MULTICAST_IF"); } } // We want to receive only IPv6 packets on this socket. // Without this option, we may get IPv4 addresses as mapped addresses. if (err == 0) { err = setsockopt(*sktPtr, IPPROTO_IPV6, IPV6_V6ONLY, &kOn, sizeof(kOn)); if (err < 0) { err = errno; perror("setsockopt - IPV6_V6ONLY"); } } // Per the mDNS spec, send unicast packets with TTL 255 if (err == 0) { err = setsockopt(*sktPtr, IPPROTO_IPV6, IPV6_UNICAST_HOPS, &kIntTwoFiveFive, sizeof(kIntTwoFiveFive)); if (err < 0) { err = errno; perror("setsockopt - IPV6_UNICAST_HOPS"); } } // and multicast packets with TTL 255 too // There's some debate as to whether IPV6_MULTICAST_HOPS is an int or a byte so we just try both. if (err == 0) { err = setsockopt(*sktPtr, IPPROTO_IPV6, IPV6_MULTICAST_HOPS, &kByteTwoFiveFive, sizeof(kByteTwoFiveFive)); if (err < 0 && errno == EINVAL) err = setsockopt(*sktPtr, IPPROTO_IPV6, IPV6_MULTICAST_HOPS, &kIntTwoFiveFive, sizeof(kIntTwoFiveFive)); if (err < 0) { err = errno; perror("setsockopt - IPV6_MULTICAST_HOPS"); } } // And start listening for packets if (err == 0) { mDNSPlatformMemZero(&bindAddr6, sizeof(bindAddr6)); bindAddr6.sin6_len = sizeof(bindAddr6); bindAddr6.sin6_family = AF_INET6; bindAddr6.sin6_port = port.NotAnInteger; bindAddr6.sin6_flowinfo = 0; // bindAddr6.sin6_addr.s_addr = IN6ADDR_ANY_INIT; // Want to receive multicasts AND unicasts on this socket bindAddr6.sin6_scope_id = 0; err = bind(*sktPtr, (struct sockaddr *) &bindAddr6, sizeof(bindAddr6)); if (err < 0) { err = errno; perror("bind"); fflush(stderr); } } } // endif (intfAddr->sa_family == AF_INET6) #endif // Set the socket to non-blocking. if (err == 0) { err = fcntl(*sktPtr, F_GETFL, 0); if (err < 0) err = errno; else { err = fcntl(*sktPtr, F_SETFL, err | O_NONBLOCK); if (err < 0) err = errno; } } // Clean up if (err != 0 && *sktPtr != -1) { assert(close(*sktPtr) == 0); *sktPtr = -1; } assert( (err == 0) == (*sktPtr != -1) ); return err; } // Creates a PosixNetworkInterface for the interface whose IP address is // intfAddr and whose name is intfName and registers it with mDNS core. static int SetupOneInterface(mDNS *const m, struct sockaddr *intfAddr, const char *intfName) { int err = 0; PosixNetworkInterface *intf; PosixNetworkInterface *alias = NULL; assert(m != NULL); assert(intfAddr != NULL); assert(intfName != NULL); // Allocate the interface structure itself. intf = malloc(sizeof(*intf)); if (intf == NULL) { assert(0); err = ENOMEM; } // And make a copy of the intfName. if (err == 0) { intf->intfName = strdup(intfName); if (intf->intfName == NULL) { assert(0); err = ENOMEM; } } if (err == 0) { // Set up the fields required by the mDNS core. SockAddrTomDNSAddr(intfAddr, &intf->coreIntf.ip, NULL); intf->coreIntf.Advertise = m->AdvertiseLocalAddresses; // Set up the extra fields in PosixNetworkInterface. assert(intf->intfName != NULL); // intf->intfName already set up above intf->index = if_nametoindex(intf->intfName); intf->multicastSocket = -1; intf->multicastSocketv6 = -1; alias = SearchForInterfaceByName(m, intf->intfName); if (alias == NULL) alias = intf; intf->coreIntf.InterfaceID = (mDNSInterfaceID)alias; if (alias != intf) debugf("SetupOneInterface: %s %#a is an alias of %#a", intfName, &intf->coreIntf.ip, &alias->coreIntf.ip); } // Set up the multicast socket if (err == 0) { if (alias->multicastSocket == -1 && intfAddr->sa_family == AF_INET) err = SetupSocket(intfAddr, MulticastDNSPort, intf->index, &alias->multicastSocket); #ifdef mDNSIPv6Support else if (alias->multicastSocketv6 == -1 && intfAddr->sa_family == AF_INET6) err = SetupSocket(intfAddr, MulticastDNSPort, intf->index, &alias->multicastSocketv6); #endif } // The interface is all ready to go, let's register it with the mDNS core. if (err == 0) err = mDNS_RegisterInterface(m, &intf->coreIntf); // Clean up. if (err == 0) { num_registered_interfaces++; debugf("SetupOneInterface: %s %#a Registered", intf->intfName, &intf->coreIntf.ip); if (gMDNSPlatformPosixVerboseLevel > 0) DPRINTF(E_LOG,L_REND, "Registered interface %s\n", intf->intfName); } else { // Use intfName instead of intf->intfName in the next line to avoid dereferencing NULL. debugf("SetupOneInterface: %s %#a failed to register %d", intfName, &intf->coreIntf.ip, err); if (intf) { FreePosixNetworkInterface(intf); intf = NULL; } } assert( (err == 0) == (intf != NULL) ); return err; } static int SetupInterfaceList(mDNS *const m) { mDNSBool foundav4 = mDNSfalse; int err = 0; struct ifi_info *intfList = get_ifi_info(AF_INET, mDNStrue); struct ifi_info *firstLoopback = NULL; assert(m != NULL); debugf("SetupInterfaceList"); if (intfList == NULL) err = ENOENT; #ifdef mDNSIPv6Support if (err == 0) /* Link the IPv6 list to the end of the IPv4 list */ { struct ifi_info **p = &intfList; while (*p) p = &(*p)->ifi_next; *p = get_ifi_info(AF_INET6, mDNStrue); } #endif if (err == 0) { struct ifi_info *i = intfList; while (i) { if ( ((i->ifi_addr->sa_family == AF_INET) #ifdef mDNSIPv6Support || (i->ifi_addr->sa_family == AF_INET6) #endif ) && (i->ifi_flags & IFF_UP) && !(i->ifi_flags & IFF_POINTOPOINT) ) { if (i->ifi_flags & IFF_LOOPBACK) { if (firstLoopback == NULL) firstLoopback = i; } else { if (SetupOneInterface(m, i->ifi_addr, i->ifi_name) == 0) if (i->ifi_addr->sa_family == AF_INET) foundav4 = mDNStrue; } } i = i->ifi_next; } // If we found no normal interfaces but we did find a loopback interface, register the // loopback interface. This allows self-discovery if no interfaces are configured. // Temporary workaround: Multicast loopback on IPv6 interfaces appears not to work. // In the interim, we skip loopback interface only if we found at least one v4 interface to use // if ( (m->HostInterfaces == NULL) && (firstLoopback != NULL) ) if ( !foundav4 && firstLoopback ) (void) SetupOneInterface(m, firstLoopback->ifi_addr, firstLoopback->ifi_name); } // Clean up. if (intfList != NULL) free_ifi_info(intfList); return err; } // mDNS core calls this routine to initialise the platform-specific data. mDNSexport mStatus mDNSPlatformInit(mDNS *const m) { int err; assert(m != NULL); // Tell mDNS core the names of this machine. // Set up the nice label m->nicelabel.c[0] = 0; GetUserSpecifiedFriendlyComputerName(&m->nicelabel); if (m->nicelabel.c[0] == 0) MakeDomainLabelFromLiteralString(&m->nicelabel, "Macintosh"); // Set up the RFC 1034-compliant label m->hostlabel.c[0] = 0; GetUserSpecifiedRFC1034ComputerName(&m->hostlabel); if (m->hostlabel.c[0] == 0) MakeDomainLabelFromLiteralString(&m->hostlabel, "Macintosh"); mDNS_GenerateFQDN(m); // Tell mDNS core about the network interfaces on this machine. err = SetupInterfaceList(m); // We don't do asynchronous initialization on the Posix platform, so by the time // we get here the setup will already have succeeded or failed. If it succeeded, // we should just call mDNSCoreInitComplete() immediately. if (err == 0) mDNSCoreInitComplete(m, mStatus_NoError); return PosixErrorToStatus(err); } // mDNS core calls this routine to clean up the platform-specific data. // In our case all we need to do is to tear down every network interface. mDNSexport void mDNSPlatformClose(mDNS *const m) { assert(m != NULL); ClearInterfaceList(m); } extern mStatus mDNSPlatformPosixRefreshInterfaceList(mDNS *const m) { int err; ClearInterfaceList(m); err = SetupInterfaceList(m); return PosixErrorToStatus(err); } #if COMPILER_LIKES_PRAGMA_MARK #pragma mark ***** Locking #endif // On the Posix platform, locking is a no-op because we only ever enter // mDNS core on the main thread. // mDNS core calls this routine when it wants to prevent // the platform from reentering mDNS core code. mDNSexport void mDNSPlatformLock (const mDNS *const m) { (void) m; // Unused } // mDNS core calls this routine when it release the lock taken by // mDNSPlatformLock and allow the platform to reenter mDNS core code. mDNSexport void mDNSPlatformUnlock (const mDNS *const m) { (void) m; // Unused } #if COMPILER_LIKES_PRAGMA_MARK #pragma mark ***** Strings #endif // mDNS core calls this routine to copy C strings. // On the Posix platform this maps directly to the ANSI C strcpy. mDNSexport void mDNSPlatformStrCopy(const void *src, void *dst) { strcpy((char *)dst, (char *)src); } // mDNS core calls this routine to get the length of a C string. // On the Posix platform this maps directly to the ANSI C strlen. mDNSexport mDNSu32 mDNSPlatformStrLen (const void *src) { return strlen((char*)src); } // mDNS core calls this routine to copy memory. // On the Posix platform this maps directly to the ANSI C memcpy. mDNSexport void mDNSPlatformMemCopy(const void *src, void *dst, mDNSu32 len) { memcpy(dst, src, len); } // mDNS core calls this routine to test whether blocks of memory are byte-for-byte // identical. On the Posix platform this is a simple wrapper around ANSI C memcmp. mDNSexport mDNSBool mDNSPlatformMemSame(const void *src, const void *dst, mDNSu32 len) { return memcmp(dst, src, len) == 0; } // mDNS core calls this routine to clear blocks of memory. // On the Posix platform this is a simple wrapper around ANSI C memset. mDNSexport void mDNSPlatformMemZero( void *dst, mDNSu32 len) { memset(dst, 0, len); } mDNSexport void * mDNSPlatformMemAllocate(mDNSu32 len) { return(malloc(len)); } mDNSexport void mDNSPlatformMemFree (void *mem) { free(mem); } mDNSexport mDNSs32 mDNSPlatformOneSecond = 1024; mDNSexport mStatus mDNSPlatformTimeInit(mDNSs32 *timenow) { // No special setup is required on Posix -- we just use gettimeofday(); // This is not really safe, because gettimeofday can go backwards if the user manually changes the date or time // We should find a better way to do this *timenow = mDNSPlatformTimeNow(); return(mStatus_NoError); } mDNSexport mDNSs32 mDNSPlatformTimeNow() { struct timeval tv; gettimeofday(&tv, NULL); // tv.tv_sec is seconds since 1st January 1970 (GMT, with no adjustment for daylight savings time) // tv.tv_usec is microseconds since the start of this second (i.e. values 0 to 999999) // We use the lower 22 bits of tv.tv_sec for the top 22 bits of our result // and we multiply tv.tv_usec by 16 / 15625 to get a value in the range 0-1023 to go in the bottom 10 bits. // This gives us a proper modular (cyclic) counter that has a resolution of roughly 1ms (actually 1/1024 second) // and correctly cycles every 2^22 seconds (4194304 seconds = approx 48 days). return( (tv.tv_sec << 10) | (tv.tv_usec * 16 / 15625) ); } mDNSexport void mDNSPosixGetFDSet(mDNS *const m, int *nfds, fd_set *readfds, struct timeval *timeout) { mDNSs32 ticks; struct timeval interval; // 1. Call mDNS_Execute() to let mDNSCore do what it needs to do mDNSs32 nextevent = mDNS_Execute(m); // 2. Build our list of active file descriptors PosixNetworkInterface *info = (PosixNetworkInterface *)(m->HostInterfaces); while (info) { if (info->multicastSocket != -1) { if (*nfds < info->multicastSocket + 1) *nfds = info->multicastSocket + 1; FD_SET(info->multicastSocket, readfds); } if (info->multicastSocketv6 != -1) { if (*nfds < info->multicastSocketv6 + 1) *nfds = info->multicastSocketv6 + 1; FD_SET(info->multicastSocketv6, readfds); } info = (PosixNetworkInterface *)(info->coreIntf.next); } // 3. Calculate the time remaining to the next scheduled event (in struct timeval format) ticks = nextevent - mDNSPlatformTimeNow(); if (ticks < 1) ticks = 1; interval.tv_sec = ticks >> 10; // The high 22 bits are seconds interval.tv_usec = ((ticks & 0x3FF) * 15625) / 16; // The low 10 bits are 1024ths // 4. If client's proposed timeout is more than what we want, then reduce it if (timeout->tv_sec > interval.tv_sec || (timeout->tv_sec == interval.tv_sec && timeout->tv_usec > interval.tv_usec)) *timeout = interval; } mDNSexport void mDNSPosixProcessFDSet(mDNS *const m, fd_set *readfds) { PosixNetworkInterface *info; assert(m != NULL); assert(readfds != NULL); info = (PosixNetworkInterface *)(m->HostInterfaces); while (info) { if (info->multicastSocket != -1 && FD_ISSET(info->multicastSocket, readfds)) { FD_CLR(info->multicastSocket, readfds); SocketDataReady(m, info, info->multicastSocket); } if (info->multicastSocketv6 != -1 && FD_ISSET(info->multicastSocketv6, readfds)) { FD_CLR(info->multicastSocketv6, readfds); SocketDataReady(m, info, info->multicastSocketv6); } info = (PosixNetworkInterface *)(info->coreIntf.next); } }