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

diff --git a/Clients/Makefile b/Clients/Makefile
index 383af31..925c20e 100755
--- a/Clients/Makefile
+++ b/Clients/Makefile
@@ -36,7 +36,7 @@ TARGETS = build/dns-sd build/dns-sd64
 LIBS =
 else
 TARGETS = build/dns-sd
-LIBS = -L../mDNSPosix/build/prod/ -ldns_sd
+LIBS ?= -L../mDNSPosix/build/prod/ -ldns_sd
 endif
 
 all: $(TARGETS)
diff --git a/mDNSPosix/PosixDaemon.c b/mDNSPosix/PosixDaemon.c
index 88b3292..e86a6c7 100644
--- a/mDNSPosix/PosixDaemon.c
+++ b/mDNSPosix/PosixDaemon.c
@@ -37,6 +37,11 @@
 #include <fcntl.h>
 #include <pwd.h>
 #include <sys/types.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
@@ -184,16 +189,50 @@ 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)
     {
         const struct passwd *pw = getpwnam("nobody");
         if (pw != NULL)
+          {
             setuid(pw->pw_uid);
+#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
             LogMsg("WARNING: mdnsd continuing as root because user \"nobody\" does not exist");
     }
 
+#ifdef __linux__
+    if (mStatus_NoError == err)
+      err = mDNSPlatformPosixRefreshInterfaceList(&mDNSStorage);
+#endif /* __linux__ */
+
     if (mStatus_NoError == err)
         err = MainLoop(&mDNSStorage);
 
diff --git a/mDNSPosix/mDNSPosix.c b/mDNSPosix/mDNSPosix.c
index 6effa12..7c1d6eb 100755
--- a/mDNSPosix/mDNSPosix.c
+++ b/mDNSPosix/mDNSPosix.c
@@ -733,6 +741,29 @@ mDNSlocal int SetupSocket(struct sockaddr *intfAddr, mDNSIPPort port, int interf
             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)
         {
@@ -814,6 +845,29 @@ mDNSlocal int SetupSocket(struct sockaddr *intfAddr, mDNSIPPort port, int interf
             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)
         {
@@ -958,19 +1017,14 @@ mDNSlocal int SetupInterfaceList(mDNS *const m)
     int err            = 0;
     struct ifi_info *intfList      = get_ifi_info(AF_INET, mDNStrue);
     struct ifi_info *firstLoopback = NULL;
+    struct ifi_info **p = &intfList;
 
     assert(m != NULL);
     debugf("SetupInterfaceList");
 
-    if (intfList == NULL) err = ENOENT;
-
 #if HAVE_IPV6
-    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);
-    }
+    while (*p) p = &(*p)->ifi_next;
+    *p = get_ifi_info(AF_INET6, mDNStrue);
 #endif
 
     if (err == 0)
@@ -1046,7 +1100,7 @@ mDNSlocal mStatus OpenIfNotifySocket(int *pFD)
     /* Subscribe the socket to Link & IP addr notifications. */
     mDNSPlatformMemZero(&snl, sizeof snl);
     snl.nl_family = AF_NETLINK;
-    snl.nl_groups = RTMGRP_LINK | RTMGRP_IPV4_IFADDR;
+    snl.nl_groups = RTMGRP_LINK | RTMGRP_IPV4_IFADDR | RTMGRP_IPV6_IFADDR;
     ret = bind(sock, (struct sockaddr *) &snl, sizeof snl);
     if (0 == ret)
         *pFD = sock;
@@ -1124,11 +1178,18 @@ mDNSlocal mDNSu32       ProcessRoutingNotification(int sd)
         PrintNetLinkMsg(pNLMsg);
 #endif
 
+        // this result isn't used anywhere as a number, just as
+        // non-zero - however, I have seen devices with more than 32
+        // interfaces at some point..
+        // (on Linux, every tunnel increases index for example)
+
         // Process the NetLink message
         if (pNLMsg->nlmsg_type == RTM_GETLINK || pNLMsg->nlmsg_type == RTM_NEWLINK)
-            result |= 1 << ((struct ifinfomsg*) NLMSG_DATA(pNLMsg))->ifi_index;
+          result |= 1;
+        // << ((struct ifinfomsg*) NLMSG_DATA(pNLMsg))->ifi_index;
         else if (pNLMsg->nlmsg_type == RTM_DELADDR || pNLMsg->nlmsg_type == RTM_NEWADDR)
-            result |= 1 << ((struct ifaddrmsg*) NLMSG_DATA(pNLMsg))->ifa_index;
+          result |= 1;
+        // << ((struct ifaddrmsg*) NLMSG_DATA(pNLMsg))->ifa_index;
 
         // Advance pNLMsg to the next message in the buffer
         if ((pNLMsg->nlmsg_flags & NLM_F_MULTI) != 0 && pNLMsg->nlmsg_type != NLMSG_DONE)
@@ -1299,8 +1360,12 @@ mDNSexport mStatus mDNSPlatformInit(mDNS *const m)
     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);
diff --git a/mDNSPosix/mDNSUNP.c b/mDNSPosix/mDNSUNP.c
index b392fc7..f551ad5 100755
--- a/mDNSPosix/mDNSUNP.c
+++ b/mDNSPosix/mDNSUNP.c
@@ -63,6 +63,7 @@
 #if defined(AF_INET6) && HAVE_IPV6 && HAVE_LINUX
 #include <netdb.h>
 #include <arpa/inet.h>
+#include <linux/if_addr.h>
 
 /* Converts a prefix length to IPv6 network mask */
 void plen_to_mask(int plen, char *addr) {
@@ -86,7 +87,7 @@ struct ifi_info *get_ifi_info_linuxv6(int family, int doaliases)
     FILE *fp = NULL;
     char addr[8][5];
     int flags, myflags, index, plen, scope;
-    char ifname[9], lastname[IFNAMSIZ];
+    char ifname[IFNAMSIZ], lastname[IFNAMSIZ];
     char addr6[32+7+1]; /* don't forget the seven ':' */
     struct addrinfo hints, *res0;
     int err;
@@ -92,7 +93,8 @@ struct ifi_info *get_ifi_info_linuxv6(int family, int doaliases)
     int err;
     int sockfd = -1;
     struct ifreq ifr;
-
+    char mask[64] = "%4s%4s%4s%4s%4s%4s%4s%4s %02x %02x %02x %02x %";
+    sprintf(mask+strlen(mask), "%ds\n", IFNAMSIZ);
     res0=NULL;
     ifihead = NULL;
     ifipnext = &ifihead;
@@ -104,11 +106,12 @@ struct ifi_info *get_ifi_info_linuxv6(int family, int doaliases)
             goto gotError;
         }
         while (fscanf(fp,
-                      "%4s%4s%4s%4s%4s%4s%4s%4s %02x %02x %02x %02x %8s\n",
+                      mask,
                       addr[0],addr[1],addr[2],addr[3],
                       addr[4],addr[5],addr[6],addr[7],
                       &index, &plen, &scope, &flags, ifname) != EOF) {
 
+            if (flags & IFA_F_DEPRECATED) continue;
             myflags = 0;
             if (strncmp(lastname, ifname, IFNAMSIZ) == 0) {
                 if (doaliases == 0)
diff --git a/mDNSShared/dnsextd_parser.y b/mDNSShared/dnsextd_parser.y
index 18c5990..d4b63ce 100644
--- 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 +419,7 @@ 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 );
 }