mDNSResponder: Update to v567

The sources can be obtained via:

https://opensource.apple.com/tarballs/mDNSResponder/mDNSResponder-567.tar.gz

Update #3522.

4 files changed, 113 insertions, 22 deletions

diff --git a/mDNSResponder/mDNSPosix/Makefile b/mDNSResponder/mDNSPosix/Makefile
index d095a0f4..817a3775 100755
--- a/mDNSResponder/mDNSPosix/Makefile
+++ b/mDNSResponder/mDNSPosix/Makefile
@@ -1,6 +1,6 @@
 # -*- tab-width: 4 -*-
 #
-# Copyright (c) 2002-2004, Apple Computer, Inc. All rights reserved.
+# Copyright (c) 2002-2004, 2015, Apple Computer, Inc. All rights reserved.
 #
 # Redistribution and use in source and binary forms, with or without 
 # modification, are permitted provided that the following conditions are met:
@@ -30,8 +30,8 @@
 # If "make os=xxx" gives lots of errors like "Missing dependency operator",
 # then try typing "gmake os=xxx" instead.
 #
-# This Makefile builds an mDNSResponder daemon and a libdns_sd.so shared library 
-# for Linux. It also builds several example programs for embedded systems. 
+# This Makefile builds an mDNSResponder daemon and a libdns_sd.so shared library
+# for Linux. It also builds several example programs for embedded systems.
 #
 # Make with no arguments to build all production targets.
 # 'make DEBUG=1' to build debugging targets.
@@ -57,6 +57,7 @@ JDK = /usr/jdk
 CC = @cc
 BISON = @bison
 FLEX = @flex
+ST = @strip
 LD = ld -shared
 CP = cp
 RM = rm
@@ -71,18 +72,18 @@ JAVACFLAGS_OS = -fPIC -shared -ldns_sd
 # Set up diverging paths for debug vs. prod builds
 DEBUG=0
 ifeq ($(DEBUG),1)
-CFLAGS_DEBUG = -g -DMDNS_DEBUGMSGS=2 
+CFLAGS_DEBUG = -g -DMDNS_DEBUGMSGS=2
 OBJDIR = objects/debug
 BUILDDIR = build/debug
-STRIP = echo 
+STRIP = echo
 else
 # We use -Os for two reasons:
 # 1. We want to make small binaries, suitable for putting into hardware devices
 # 2. Some of the code analysis warnings only work when some form of optimization is enabled
-CFLAGS_DEBUG = -Os -DMDNS_DEBUGMSGS=0 
+CFLAGS_DEBUG = -Os -DMDNS_DEBUGMSGS=0
 OBJDIR ?= objects/prod
 BUILDDIR ?= build/prod
-STRIP = strip -S 
+STRIP = $(ST) -S
 endif
 
 # Configure per-OS peculiarities
@@ -95,14 +96,14 @@ LD = gcc -shared
 LINKOPTS = -lsocket -lnsl -lresolv
 JAVACFLAGS_OS += -I$(JDK)/include/solaris
 ifneq ($(DEBUG),1)
-STRIP = strip
+STRIP = $(ST)
 endif
 else
 
 # any target that contains the string "linux"
 ifeq ($(findstring linux,$(os)),linux)
 CFLAGS_OS = -D_GNU_SOURCE -DHAVE_IPV6 -DNOT_HAVE_SA_LEN -DUSES_NETLINK -DHAVE_LINUX -DTARGET_OS_LINUX -fno-strict-aliasing
-LD = gcc -shared
+LD = $(CC) -shared
 FLEXFLAGS_OS = -l
 JAVACFLAGS_OS += -I$(JDK)/include/linux
 
@@ -151,11 +152,11 @@ LD = $(CC) -dynamiclib
 LINKOPTS = -lSystem
 LDSUFFIX = dylib
 JDK = /System/Library/Frameworks/JavaVM.framework/Home
-JAVACFLAGS_OS = -dynamiclib -I/System/Library/Frameworks/JavaVM.framework/Headers -framework JavaVM 
+JAVACFLAGS_OS = -dynamiclib -I/System/Library/Frameworks/JavaVM.framework/Headers -framework JavaVM
 else
 
 $(error ERROR: Must specify target OS on command-line, e.g. "make os=x [target]".\
-Supported operating systems include: x, linux, linux-uclibc, netbsd, freebsd, openbsd, solaris) 
+Supported operating systems include: x, linux, linux-uclibc, netbsd, freebsd, openbsd, solaris)
 endif
 endif
 endif
diff --git a/mDNSResponder/mDNSPosix/NetMonitor.c b/mDNSResponder/mDNSPosix/NetMonitor.c
index 1354f1f8..a3823c54 100644
--- a/mDNSResponder/mDNSPosix/NetMonitor.c
+++ b/mDNSResponder/mDNSPosix/NetMonitor.c
@@ -120,6 +120,7 @@ struct timeval tv_start, tv_end, tv_interval;
 static int FilterInterface = 0;
 static FilterList *Filters;
 #define ExactlyOneFilter (Filters && !Filters->next)
+static mDNSBool AddressType = mDNSAddrType_IPv4;
 
 static int NumPktQ, NumPktL, NumPktR, NumPktB;  // Query/Legacy/Response/Bad
 static int NumProbes, NumGoodbyes, NumQuestions, NumLegacy, NumAnswers, NumAdditionals;
@@ -464,9 +465,9 @@ mDNSlocal const mDNSu8 *FindUpdate(mDNS *const m, const DNSMessage *const query,
 
 mDNSlocal void DisplayPacketHeader(mDNS *const m, const DNSMessage *const msg, const mDNSu8 *const end, const mDNSAddr *srcaddr, mDNSIPPort srcport, const mDNSAddr *dstaddr, const mDNSInterfaceID InterfaceID)
 {
-    const char *const ptype =   (msg->h.flags.b[0] & kDNSFlag0_QR_Response)             ? "-R- " :
+    const char *const ptype = (msg->h.flags.b[0] & kDNSFlag0_QR_Response)             ? "-R- " :
                               (srcport.NotAnInteger == MulticastDNSPort.NotAnInteger) ? "-Q- " : "-LQ-";
-
+    const unsigned length = end - (mDNSu8 *)msg;
     struct timeval tv;
     struct tm tm;
     const mDNSu32 index = mDNSPlatformInterfaceIndexfromInterfaceID(m, InterfaceID, mDNSfalse);
@@ -477,7 +478,7 @@ mDNSlocal void DisplayPacketHeader(mDNS *const m, const DNSMessage *const msg, c
     mprintf("\n%d:%02d:%02d.%06d Interface %d/%s\n", tm.tm_hour, tm.tm_min, tm.tm_sec, tv.tv_usec, index, if_name);
 
     mprintf("%#-16a %s             Q:%3d  Ans:%3d  Auth:%3d  Add:%3d  Size:%5d bytes",
-            srcaddr, ptype, msg->h.numQuestions, msg->h.numAnswers, msg->h.numAuthorities, msg->h.numAdditionals, end - (mDNSu8 *)msg);
+            srcaddr, ptype, msg->h.numQuestions, msg->h.numAnswers, msg->h.numAuthorities, msg->h.numAdditionals, length);
 
     if (msg->h.id.NotAnInteger) mprintf("  ID:%u", mDNSVal16(msg->h.id));
 
@@ -488,7 +489,27 @@ mDNSlocal void DisplayPacketHeader(mDNS *const m, const DNSMessage *const msg, c
         if (msg->h.flags.b[0] & kDNSFlag0_QR_Response) mprintf("   Truncated");
         else mprintf("   Truncated (KA list continues in next packet)");
     }
+
     mprintf("\n");
+
+    if (length < sizeof(DNSMessageHeader) + NormalMaxDNSMessageData - 192)
+        if (msg->h.flags.b[0] & kDNSFlag0_TC)
+            mprintf("%#-16a **** WARNING: Packet suspiciously small. Payload size (excluding IP and UDP headers)\n"
+                    "%#-16a **** should usually be closer to %d bytes before truncation becomes necessary.\n",
+                    srcaddr, srcaddr, sizeof(DNSMessageHeader) + NormalMaxDNSMessageData);
+}
+
+mDNSlocal void DisplaySizeCheck(const DNSMessage *const msg, const mDNSu8 *const end, const mDNSAddr *srcaddr, int num_opts)
+{
+    const unsigned length = end - (mDNSu8 *)msg;
+    const int num_records = msg->h.numAnswers + msg->h.numAuthorities + msg->h.numAdditionals - num_opts;
+
+    if (length > sizeof(DNSMessageHeader) + NormalMaxDNSMessageData)
+        if (num_records > 1)
+            mprintf("%#-16a **** ERROR: Oversized packet with %d records.\n"
+                    "%#-16a **** Many network devices cannot receive packets larger than %d bytes.\n"
+                    "%#-16a **** To minimize interoperability failures, oversized packets MUST be limited to a single resource record.\n",
+                    srcaddr, num_records, srcaddr, 40 + 8 + sizeof(DNSMessageHeader) + NormalMaxDNSMessageData, srcaddr);
 }
 
 mDNSlocal void DisplayResourceRecord(const mDNSAddr *const srcaddr, const char *const op, const ResourceRecord *const pktrr)
@@ -594,7 +615,7 @@ mDNSlocal void HexDump(const mDNSu8 *ptr, const mDNSu8 *const end)
 
 mDNSlocal void DisplayError(const mDNSAddr *srcaddr, const mDNSu8 *ptr, const mDNSu8 *const end, char *msg)
 {
-    mprintf("%#-16a **** ERROR: FAILED TO READ %s **** \n", srcaddr, msg);
+    mprintf("%#-16a **** ERROR: FAILED TO READ %s ****\n", srcaddr, msg);
     HexDump(ptr, end);
 }
 
@@ -602,6 +623,7 @@ mDNSlocal void DisplayQuery(mDNS *const m, const DNSMessage *const msg, const mD
                             const mDNSAddr *srcaddr, mDNSIPPort srcport, const mDNSAddr *dstaddr, const mDNSInterfaceID InterfaceID)
 {
     int i;
+    int num_opts = 0;
     const mDNSu8 *ptr = msg->data;
     const mDNSu8 *auth = LocateAuthorities(msg, end);
     mDNSBool MQ = (srcport.NotAnInteger == MulticastDNSPort.NotAnInteger);
@@ -611,7 +633,7 @@ mDNSlocal void DisplayQuery(mDNS *const m, const DNSMessage *const msg, const mD
     DisplayPacketHeader(m, msg, end, srcaddr, srcport, dstaddr, InterfaceID);
     if (msg->h.id.NotAnInteger != 0xFFFF)
     {
-        if (MQ) NumPktQ++;else NumPktL++;
+        if (MQ) NumPktQ++; else NumPktL++;
     }
 
     for (i=0; i<msg->h.numQuestions; i++)
@@ -648,6 +670,8 @@ mDNSlocal void DisplayQuery(mDNS *const m, const DNSMessage *const msg, const mD
         ptr = GetLargeResourceRecord(m, msg, ptr, end, InterfaceID, kDNSRecordTypePacketAns, &pkt);
         if (!ptr) { DisplayError(srcaddr, ep, end, "KNOWN ANSWER"); return; }
         DisplayResourceRecord(srcaddr, "(KA)", &pkt.r.resrec);
+        if (pkt.r.resrec.rrtype == kDNSType_OPT)
+            { num_opts++; mprintf("%#-16a **** ERROR: OPT RECORD IN ANSWER SECTION ****\n", srcaddr); }
 
         // In the case of queries with long multi-packet KA lists, we count each subsequent KA packet
         // the same as a single query, to more accurately reflect the burden on the network
@@ -664,6 +688,8 @@ mDNSlocal void DisplayQuery(mDNS *const m, const DNSMessage *const msg, const mD
         // After we display an Update record with its matching question (above) we zero out its type and class
         // If any remain that haven't been zero'd out, display them here
         if (pkt.r.resrec.rrtype || pkt.r.resrec.rrclass) DisplayResourceRecord(srcaddr, "(AU)", &pkt.r.resrec);
+        if (pkt.r.resrec.rrtype == kDNSType_OPT)
+            { num_opts++; mprintf("%#-16a **** ERROR: OPT RECORD IN AUTHORITY SECTION ****\n", srcaddr); }
     }
 
     for (i=0; i<msg->h.numAdditionals; i++)
@@ -672,8 +698,15 @@ mDNSlocal void DisplayQuery(mDNS *const m, const DNSMessage *const msg, const mD
         ptr = GetLargeResourceRecord(m, msg, ptr, end, InterfaceID, kDNSRecordTypePacketAdd, &pkt);
         if (!ptr) { DisplayError(srcaddr, ep, end, "ADDITIONAL"); return; }
         DisplayResourceRecord(srcaddr, pkt.r.resrec.rrtype == kDNSType_OPT ? "(OP)" : "(AD)", &pkt.r.resrec);
+        if (pkt.r.resrec.rrtype == kDNSType_OPT) num_opts++;
     }
 
+    DisplaySizeCheck(msg, end, srcaddr, num_opts);
+
+    // We don't hexdump the DNSMessageHeader here because those six fields (id, flags, numQuestions, numAnswers, numAuthorities, numAdditionals)
+    // have already been swapped to host byte order and displayed, so including them in the hexdump is confusing
+    if (num_opts > 1) { mprintf("%#-16a **** ERROR: MULTIPLE OPT RECORDS ****\n", srcaddr); HexDump(msg->data, end); }
+
     if (entry) AnalyseHost(m, entry, InterfaceID);
 }
 
@@ -681,6 +714,7 @@ mDNSlocal void DisplayResponse(mDNS *const m, const DNSMessage *const msg, const
                                const mDNSAddr *srcaddr, mDNSIPPort srcport, const mDNSAddr *dstaddr, const mDNSInterfaceID InterfaceID)
 {
     int i;
+    int num_opts = 0;
     const mDNSu8 *ptr = msg->data;
     HostEntry *entry = GotPacketFromHost(srcaddr, HostPkt_R, msg->h.id);
     LargeCacheRecord pkt;
@@ -718,6 +752,8 @@ mDNSlocal void DisplayResponse(mDNS *const m, const DNSMessage *const msg, const
             DisplayResourceRecord(srcaddr, "(DE)", &pkt.r.resrec);
             recordstat(entry, pkt.r.resrec.name, OP_goodbye, pkt.r.resrec.rrtype);
         }
+        if (pkt.r.resrec.rrtype == kDNSType_OPT)
+            { num_opts++; mprintf("%#-16a **** ERROR: OPT RECORD IN ANSWER SECTION ****\n", srcaddr); }
     }
 
     for (i=0; i<msg->h.numAuthorities; i++)
@@ -725,9 +761,12 @@ mDNSlocal void DisplayResponse(mDNS *const m, const DNSMessage *const msg, const
         const mDNSu8 *ep = ptr;
         ptr = GetLargeResourceRecord(m, msg, ptr, end, InterfaceID, kDNSRecordTypePacketAuth, &pkt);
         if (!ptr) { DisplayError(srcaddr, ep, end, "AUTHORITY"); return; }
-        if (pkt.r.resrec.rrtype != kDNSType_NSEC3)
+        DisplayResourceRecord(srcaddr, "(AU)", &pkt.r.resrec);
+        if (pkt.r.resrec.rrtype == kDNSType_OPT)
+            { num_opts++; mprintf("%#-16a **** ERROR: OPT RECORD IN AUTHORITY SECTION ****\n", srcaddr); }
+        else if (pkt.r.resrec.rrtype != kDNSType_NSEC3)
             mprintf("%#-16a (?)  **** ERROR: SHOULD NOT HAVE AUTHORITY IN mDNS RESPONSE **** %-5s %##s\n",
-                    srcaddr, DNSTypeName(pkt.r.resrec.rrtype), pkt.r.resrec.name->c);
+                srcaddr, DNSTypeName(pkt.r.resrec.rrtype), pkt.r.resrec.name->c);
     }
 
     for (i=0; i<msg->h.numAdditionals; i++)
@@ -736,12 +775,19 @@ mDNSlocal void DisplayResponse(mDNS *const m, const DNSMessage *const msg, const
         ptr = GetLargeResourceRecord(m, msg, ptr, end, InterfaceID, kDNSRecordTypePacketAdd, &pkt);
         if (!ptr) { DisplayError(srcaddr, ep, end, "ADDITIONAL"); return; }
         NumAdditionals++;
+        if (pkt.r.resrec.rrtype == kDNSType_OPT) num_opts++;
         DisplayResourceRecord(srcaddr,
                               pkt.r.resrec.rrtype == kDNSType_OPT ? "(OP)" : (pkt.r.resrec.RecordType & kDNSRecordTypePacketUniqueMask) ? "(AD)" : "(AD+)",
                               &pkt.r.resrec);
         if (entry) RecordHostInfo(entry, &pkt.r.resrec);
     }
 
+    DisplaySizeCheck(msg, end, srcaddr, num_opts);
+
+    // We don't hexdump the DNSMessageHeader here because those six fields (id, flags, numQuestions, numAnswers, numAuthorities, numAdditionals)
+    // have already been swapped to host byte order and displayed, so including them in the hexdump is confusing
+    if (num_opts > 1) { mprintf("%#-16a **** ERROR: MULTIPLE OPT RECORDS ****\n", srcaddr); HexDump(msg->data, end); }
+
     if (entry) AnalyseHost(m, entry, InterfaceID);
 }
 
@@ -763,7 +809,7 @@ mDNSlocal void ProcessUnicastResponse(mDNS *const m, const DNSMessage *const msg
 mDNSlocal mDNSBool AddressMatchesFilterList(const mDNSAddr *srcaddr)
 {
     FilterList *f;
-    if (!Filters) return(srcaddr->type == mDNSAddrType_IPv4);
+    if (!Filters) return(srcaddr->type == AddressType);
     for (f=Filters; f; f=f->next) if (mDNSSameAddress(srcaddr, &f->FilterAddr)) return(mDNStrue);
     return(mDNSfalse);
 }
@@ -930,9 +976,14 @@ mDNSexport int main(int argc, char **argv)
         if (i+1 < argc && !strcmp(argv[i], "-i") && atoi(argv[i+1]))
         {
             FilterInterface = atoi(argv[i+1]);
-            i += 2;
+            i += 1;
             printf("Monitoring interface %d\n", FilterInterface);
         }
+        else if (!strcmp(argv[i], "-6"))
+        {
+            AddressType = mDNSAddrType_IPv6;
+            printf("Monitoring IPv6 traffic\n");
+        }
         else
         {
             struct in_addr s4;
diff --git a/mDNSResponder/mDNSPosix/mDNSPosix.c b/mDNSResponder/mDNSPosix/mDNSPosix.c
index 6bc22af3..bdfb71f2 100755
--- a/mDNSResponder/mDNSPosix/mDNSPosix.c
+++ b/mDNSResponder/mDNSPosix/mDNSPosix.c
@@ -90,6 +90,8 @@ static GenLinkedList gEventSources;             // linked list of PosixEventSour
 static sigset_t gEventSignalSet;                // Signals which event loop listens for
 static sigset_t gEventSignals;                  // Signals which were received while inside loop
 
+static PosixNetworkInterface *gRecentInterfaces;
+
 // ***************************************************************************
 // Globals (for debugging)
 
@@ -574,6 +576,13 @@ mDNSexport mDNSu32 mDNSPlatformInterfaceIndexfromInterfaceID(mDNS *const m, mDNS
     while ((intf != NULL) && (mDNSInterfaceID) intf != id)
         intf = (PosixNetworkInterface *)(intf->coreIntf.next);
 
+    if (intf) return intf->index;
+
+    // If we didn't find the interface, check the RecentInterfaces list as well
+    intf = gRecentInterfaces;
+    while ((intf != NULL) && (mDNSInterfaceID) intf != id)
+        intf = (PosixNetworkInterface *)(intf->coreIntf.next);
+
     return intf ? intf->index : 0;
 }
 
@@ -587,7 +596,11 @@ mDNSlocal void FreePosixNetworkInterface(PosixNetworkInterface *intf)
 #if HAVE_IPV6
     if (intf->multicastSocket6 != -1) assert(close(intf->multicastSocket6) == 0);
 #endif
-    free(intf);
+
+    // Move interface to the RecentInterfaces list for a minute
+    intf->LastSeen = mDNSPlatformUTC();
+    intf->coreIntf.next = &gRecentInterfaces->coreIntf;
+    gRecentInterfaces = intf;
 }
 
 // Grab the first interface, deregister it, free it, and repeat until done.
@@ -643,6 +656,14 @@ mDNSlocal int SetupSocket(struct sockaddr *intfAddr, mDNSIPPort port, int interf
             #error This platform has no way to avoid address busy errors on multicast.
         #endif
         if (err < 0) { err = errno; perror("setsockopt - SO_REUSExxxx"); }
+
+        // Enable inbound packets on IFEF_AWDL interface.
+        // Only done for multicast sockets, since we don't expect unicast socket operations
+        // on the IFEF_AWDL interface. Operation is a no-op for other interface types.
+        #ifndef SO_RECV_ANYIF
+        #define SO_RECV_ANYIF   0x1104      /* unrestricted inbound processing */
+        #endif
+        if (setsockopt(*sktPtr, SOL_SOCKET, SO_RECV_ANYIF, &kOn, sizeof(kOn)) < 0) perror("setsockopt - SO_RECV_ANYIF");
     }
 
     // We want to receive destination addresses and interface identifiers.
@@ -978,6 +999,17 @@ mDNSlocal int SetupInterfaceList(mDNS *const m)
 
     // Clean up.
     if (intfList != NULL) free_ifi_info(intfList);
+
+    // Clean up any interfaces that have been hanging around on the RecentInterfaces list for more than a minute
+    PosixNetworkInterface **ri = &gRecentInterfaces;
+    const mDNSs32 utc = mDNSPlatformUTC();
+    while (*ri)
+    {
+        PosixNetworkInterface *pi = *ri;
+        if (utc - pi->LastSeen < 60) ri = (PosixNetworkInterface **)&pi->coreIntf.next;
+        else { *ri = (PosixNetworkInterface *)pi->coreIntf.next; free(pi); }
+    }
+
     return err;
 }
 
@@ -1318,9 +1350,15 @@ mDNSexport void mDNSPlatformClose(mDNS *const m)
 #endif
 }
 
+// This is used internally by InterfaceChangeCallback.
+// It's also exported so that the Standalone Responder (mDNSResponderPosix)
+// can call it in response to a SIGHUP (mainly for debugging purposes).
 mDNSexport mStatus mDNSPlatformPosixRefreshInterfaceList(mDNS *const m)
 {
     int err;
+    // This is a pretty heavyweight way to process interface changes --
+    // destroying the entire interface list and then making fresh one from scratch.
+    // We should make it like the OS X version, which leaves unchanged interfaces alone.
     ClearInterfaceList(m);
     err = SetupInterfaceList(m);
     return PosixErrorToStatus(err);
diff --git a/mDNSResponder/mDNSPosix/mDNSPosix.h b/mDNSResponder/mDNSPosix/mDNSPosix.h
index f6dab9e9..9e16bb89 100755
--- a/mDNSResponder/mDNSPosix/mDNSPosix.h
+++ b/mDNSResponder/mDNSPosix/mDNSPosix.h
@@ -38,7 +38,8 @@ typedef struct PosixNetworkInterface PosixNetworkInterface;
 
 struct PosixNetworkInterface
 {
-    NetworkInterfaceInfo coreIntf;
+    NetworkInterfaceInfo coreIntf;		// MUST be the first element in this structure
+    mDNSs32 LastSeen;
     const char *            intfName;
     PosixNetworkInterface * aliasIntf;
     int index;