packages/net/mdnsresponder/patches/100-linux_fixes.patch

--- a/Clients/Makefile
+++ b/Clients/Makefile
@@ -42,7 +42,7 @@ TARGETS = build/dns-sd build/dns-sd64
 LIBS =
 else
 TARGETS = build/dns-sd
-LIBS = -L../mDNSPosix/$(BUILDDIR)/ -ldns_sd
+LIBS ?= -L../mDNSPosix/$(BUILDDIR)/ -ldns_sd
 endif
 
 all: $(TARGETS)
--- a/mDNSPosix/PosixDaemon.c
+++ b/mDNSPosix/PosixDaemon.c
@@ -38,6 +38,11 @@
 #include <pwd.h>
 #include <sys/types.h>
 #include <sys/socket.h>
+#ifdef __linux__
+#include <sys/capability.h> /* !!! We require libcap-dev for this. Oh well. */
+/* prctl is required to enable inheriting of capabilities across setuid */
+#include <sys/prctl.h>
+#endif /* __linux__ */
 
 #if __APPLE__
 #undef daemon
@@ -194,6 +199,18 @@ int main(int argc, char **argv)
 
     Reconfigure(&mDNSStorage);
 
+#ifdef __linux__
+    /*
+     * SO_BINDTODEVICE is privileged operation; however, we can get
+     * around it using capabilities instead of remaining root.
+     */
+    if (mStatus_NoError == err)
+      {
+        if (prctl(PR_SET_KEEPCAPS, 1, 0, 0, 0) < 0)
+          perror("prctl PR_SET_KEEPCAPS");
+      }
+#endif /* __linux__ */
+
     // Now that we're finished with anything privileged, switch over to running as "nobody"
     if (mStatus_NoError == err)
     {
@@ -209,6 +226,21 @@ int main(int argc, char **argv)
             {
                 LogMsg("WARNING: mdnsd continuing as root because setuid to \"nobody\" failed with %s", strerror(errno));
             }
+#ifdef __linux__
+            struct __user_cap_header_struct ch;
+            struct __user_cap_data_struct cd[_LINUX_CAPABILITY_U32S_3];
+
+            memset(&ch, 0, sizeof(ch));
+            ch.version = _LINUX_CAPABILITY_VERSION_3;
+            ch.pid = getpid();
+            memset(&cd[0], 0, sizeof(cd));
+            /* CAP_NET_RAW is required to use SO_BINDTODEVICE */
+            int caps = CAP_TO_MASK(CAP_NET_RAW);
+            cd[0].permitted = caps;
+            cd[0].effective = caps;
+            if (capset(&ch, &cd[0]) < 0)
+              perror("capset");
+#endif /* __linux__ */
         }
         else
         {
@@ -216,6 +248,11 @@ int main(int argc, char **argv)
         }
     }
 
+#ifdef __linux__
+    if (mStatus_NoError == err)
+      err = mDNSPlatformPosixRefreshInterfaceList(&mDNSStorage);
+#endif /* __linux__ */
+
     if (mStatus_NoError == err)
         err = MainLoop(&mDNSStorage);
 
--- a/mDNSPosix/mDNSPosix.c
+++ b/mDNSPosix/mDNSPosix.c
@@ -1223,6 +1223,29 @@ mDNSlocal int SetupSocket(struct sockadd
             if (err < 0) { err = errno; perror("setsockopt - IP_MULTICAST_TTL"); }
         }
 
+#ifdef __linux__
+#ifdef SO_BINDTODEVICE
+        if (err == 0 && interfaceIndex)
+        {
+            char ifname[IFNAMSIZ];
+            if (if_indextoname(interfaceIndex, ifname))
+              {
+                err = setsockopt(*sktPtr, SOL_SOCKET, SO_BINDTODEVICE, ifname, strlen(ifname));
+                if (err < 0)
+                  {
+                    err = errno;
+                    perror("setsockopt - SO_BINDTODEVICE");
+                  }
+              }
+            else
+              {
+                err = errno;
+                perror("if_indextoname");
+              }
+        }
+#endif /* SO_BINDTODEVICE */
+#endif /* __linux__ */
+
         // And start listening for packets
         if (err == 0)
         {
@@ -1298,6 +1321,29 @@ mDNSlocal int SetupSocket(struct sockadd
             if (err < 0) { err = errno; perror("setsockopt - IPV6_MULTICAST_HOPS"); }
         }
 
+#ifdef __linux__
+#ifdef SO_BINDTODEVICE
+        if (err == 0 && interfaceIndex)
+        {
+            char ifname[IFNAMSIZ];
+            if (if_indextoname(interfaceIndex, ifname))
+              {
+                err = setsockopt(*sktPtr, SOL_SOCKET, SO_BINDTODEVICE, ifname, strlen(ifname));
+                if (err < 0)
+                  {
+                    err = errno;
+                    perror("setsockopt - SO_BINDTODEVICE");
+                  }
+              }
+            else
+              {
+                err = errno;
+                perror("if_indextoname");
+              }
+        }
+#endif /* SO_BINDTODEVICE */
+#endif /* __linux__ */
+
         // And start listening for packets
         if (err == 0)
         {
@@ -1899,8 +1945,12 @@ mDNSexport mStatus mDNSPlatformInit(mDNS
     if (err == mStatus_NoError) err = SetupSocket(&sa, zeroIPPort, 0, &m->p->unicastSocket6);
 #endif
 
+    // In Linux case, we can't set up sockets with different owner -
+    // it blows up SO_REUSEPORT. So we do this step bit later.
+#ifndef __linux__
     // Tell mDNS core about the network interfaces on this machine.
     if (err == mStatus_NoError) err = SetupInterfaceList(m);
+#endif /* !__linux__ */
 
     // Tell mDNS core about DNS Servers
     mDNS_Lock(m);
--- a/mDNSShared/dnsextd_parser.y
+++ b/mDNSShared/dnsextd_parser.y
@@ -15,6 +15,8 @@
  * limitations under the License.
  */
 
+%parse-param { void *context }
+
 %{
 #include <stdio.h>
 #include <stdlib.h>
@@ -23,7 +25,7 @@
 #include "DebugServices.h"
 #include "dnsextd.h"
 
-void yyerror( const char* error );
+void yyerror( void* context, const char* error );
 int  yylex(void);
 
 
@@ -409,7 +411,7 @@ int yywrap(void);
 
 extern int yylineno;
 
-void yyerror( const char *str )
+void yyerror( void* context, const char *str )
 {
         fprintf( stderr,"%s:%d: error: %s\n", g_filename, yylineno, str );
 }