Attachment 660514 Details for Bug 721350 – Proposed solution 1B

[patch] Proposed solution 1B

glibc-improve-addrconfig.patch (text/plain), 6.50 KB, created by Tore Anderson on 2012-12-09 23:48:22 UTC

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Creator: Tore Anderson

Created: 2012-12-09 23:48:22 UTC

Size: 6.50 KB

patch

obsolete

>diff -ru glibc-2.16.90-67cbf9a2.orig/sysdeps/posix/getaddrinfo.c glibc-2.16.90-67cbf9a2/sysdeps/posix/getaddrinfo.c
>--- glibc-2.16.90-67cbf9a2.orig/sysdeps/posix/getaddrinfo.c	2012-12-07 21:55:19.000000000 +0000
>+++ glibc-2.16.90-67cbf9a2/sysdeps/posix/getaddrinfo.c	2012-12-09 23:24:47.615410906 +0000
>@@ -829,14 +829,47 @@
> 		}
> 	    }
> 
>+	  /* AI_ADDRCONFIG determines whether or not we should suppress any
>+	   * hostname lookups. If the local host has only IPv4 interfaces,
>+	   * then suppress lookups for IPv6 addresses, and vice versa; if
>+	   * the local host has only IPv6 interfaces, suppress any lookups
>+	   * for IPv4 addresses..
>+	   * 
>+	   * Link-local IPv6 addresses and loopback addresses of either
>+	   * family are ignored when determining whether or not the host has
>+	   * an interface of the given address family, cf. __check_pf().
>+	   *
>+	   * This logic is only applied for AF_UNSPEC. If the caller
>+	   * explicitly requested an address family, give him what he asked
>+	   * for.
>+	   *
>+	   * If we didn't find any interfaces of either address family,
>+	   * we ignore AI_ADDRCONFIG and return all available resutlts.  */
>+	  int suppress_af = 0;
>+	  if (req->ai_family == AF_UNSPEC && req->ai_flags & AI_ADDRCONFIG)
>+	    {
>+	      struct in6addrinfo *in6ai = NULL;
>+	      size_t in6ailen = 0;
>+	      bool seen_ipv4 = false;
>+	      bool seen_ipv6 = false;
>+	      __check_pf (&seen_ipv4, &seen_ipv6, &in6ai, &in6ailen);
>+	      __free_in6ai (in6ai);
>+
>+	      if(seen_ipv4 && !seen_ipv6)
>+		  suppress_af = AF_INET6;
>+	      else if(seen_ipv6 && !seen_ipv4)
>+		  suppress_af = AF_INET;
>+	    }
>+
> 	  while (!no_more)
> 	    {
> 	      no_data = 0;
> 	      nss_gethostbyname4_r fct4 = NULL;
> 
> 	      /* gethostbyname4_r sends out parallel A and AAAA queries and
>-		 is thus only suitable for PF_UNSPEC.  */
>-	      if (req->ai_family == PF_UNSPEC)
>+		 is thus only suitable for PF_UNSPEC, and only if we're not
>+		 suppressing lookups for IPv4 or IPv6 addresses.  */
>+	      if (req->ai_family == PF_UNSPEC && !suppress_af)
> 		fct4 = __nss_lookup_function (nip, "gethostbyname4_r");
> 
> 	      if (fct4 != NULL)
>@@ -941,20 +974,22 @@
> 
> 		  if (fct != NULL)
> 		    {
>-		      if (req->ai_family == AF_INET6
>-			  || req->ai_family == AF_UNSPEC)
>+		      if ((req->ai_family == AF_INET6
>+			   || req->ai_family == AF_UNSPEC)
>+			  && suppress_af != AF_INET6)
> 			{
> 			  gethosts (AF_INET6, struct in6_addr);
> 			  no_inet6_data = no_data;
> 			  inet6_status = status;
> 			}
>-		      if (req->ai_family == AF_INET
>-			  || req->ai_family == AF_UNSPEC
>-			  || (req->ai_family == AF_INET6
>-			      && (req->ai_flags & AI_V4MAPPED)
>-			      /* Avoid generating the mapped addresses if we
>-				 know we are not going to need them.  */
>-			      && ((req->ai_flags & AI_ALL) || !got_ipv6)))
>+		      if ((req->ai_family == AF_INET
>+			   || req->ai_family == AF_UNSPEC
>+			   || (req->ai_family == AF_INET6
>+			       && (req->ai_flags & AI_V4MAPPED)
>+			       /* Avoid generating the mapped addresses if we
>+				  know we are not going to need them.  */
>+			       && ((req->ai_flags & AI_ALL) || !got_ipv6)))
>+			  && suppress_af != AF_INET)
> 			{
> 			  gethosts (AF_INET, struct in_addr);
> 
>@@ -2373,7 +2408,6 @@
>   int nresults = 0;
>   struct addrinfo *p = NULL;
>   struct gaih_service gaih_service, *pservice;
>-  struct addrinfo local_hints;
> 
>   if (name != NULL && name[0] == '*' && name[1] == 0)
>     name = NULL;
>@@ -2399,42 +2433,6 @@
>   if ((hints->ai_flags & AI_CANONNAME) && name == NULL)
>     return EAI_BADFLAGS;
> 
>-  struct in6addrinfo *in6ai = NULL;
>-  size_t in6ailen = 0;
>-  bool seen_ipv4 = false;
>-  bool seen_ipv6 = false;
>-  bool check_pf_called = false;
>-
>-  if (hints->ai_flags & AI_ADDRCONFIG)
>-    {
>-      /* We might need information about what interfaces are available.
>-	 Also determine whether we have IPv4 or IPv6 interfaces or both.  We
>-	 cannot cache the results since new interfaces could be added at
>-	 any time.  */
>-      __check_pf (&seen_ipv4, &seen_ipv6, &in6ai, &in6ailen);
>-      check_pf_called = true;
>-
>-      /* Now make a decision on what we return, if anything.  */
>-      if (hints->ai_family == PF_UNSPEC && (seen_ipv4 || seen_ipv6))
>-	{
>-	  /* If we haven't seen both IPv4 and IPv6 interfaces we can
>-	     narrow down the search.  */
>-	  if ((! seen_ipv4 || ! seen_ipv6) && (seen_ipv4 || seen_ipv6))
>-	    {
>-	      local_hints = *hints;
>-	      local_hints.ai_family = seen_ipv4 ? PF_INET : PF_INET6;
>-	      hints = &local_hints;
>-	    }
>-	}
>-      else if ((hints->ai_family == PF_INET && ! seen_ipv4)
>-	       || (hints->ai_family == PF_INET6 && ! seen_ipv6))
>-	{
>-	  /* We cannot possibly return a valid answer.  */
>-	  __free_in6ai (in6ai);
>-	  return EAI_NONAME;
>-	}
>-    }
>-
>   if (service && service[0])
>     {
>       char *c;
>@@ -2443,10 +2441,7 @@
>       if (*c != '\0')
> 	{
> 	  if (hints->ai_flags & AI_NUMERICSERV)
>-	    {
>-	      __free_in6ai (in6ai);
> 	      return EAI_NONAME;
>-	    }
> 
> 	  gaih_service.num = -1;
> 	}
>@@ -2466,7 +2461,6 @@
>       if (last_i != 0)
> 	{
> 	  freeaddrinfo (p);
>-	  __free_in6ai (in6ai);
> 
> 	  return -(last_i & GAIH_EAI);
> 	}
>@@ -2477,10 +2471,7 @@
> 	}
>     }
>   else
>-    {
>-      __free_in6ai (in6ai);
>       return EAI_FAMILY;
>-    }
> 
>   if (naddrs > 1)
>     {
>@@ -2495,9 +2486,12 @@
>       struct addrinfo *last = NULL;
>       char *canonname = NULL;
> 
>-      /* Now we definitely need the interface information.  */
>-      if (! check_pf_called)
>-	__check_pf (&seen_ipv4, &seen_ipv6, &in6ai, &in6ailen);
>+      /* Now we need the interface information.  */
>+      struct in6addrinfo *in6ai = NULL;
>+      size_t in6ailen = 0;
>+      bool seen_ipv4 = false;
>+      bool seen_ipv6 = false;
>+      __check_pf (&seen_ipv4, &seen_ipv6, &in6ai, &in6ailen);
> 
>       /* If we have information about deprecated and temporary addresses
> 	 sort the array now.  */
>@@ -2664,9 +2658,9 @@
> 
>       /* Fill in the canonical name into the new first entry.  */
>       p->ai_canonname = canonname;
>-    }
> 
>-  __free_in6ai (in6ai);
>+      __free_in6ai (in6ai);
>+    }
> 
>   if (p)
>     {
>diff -ru glibc-2.16.90-67cbf9a2.orig/sysdeps/unix/sysv/linux/check_pf.c glibc-2.16.90-67cbf9a2/sysdeps/unix/sysv/linux/check_pf.c
>--- glibc-2.16.90-67cbf9a2.orig/sysdeps/unix/sysv/linux/check_pf.c	2012-12-07 21:55:19.000000000 +0000
>+++ glibc-2.16.90-67cbf9a2/sysdeps/unix/sysv/linux/check_pf.c	2012-12-09 11:50:36.176246801 +0000
>@@ -233,7 +233,8 @@
> 		    }
> 		  else
> 		    {
>-		      if (!IN6_IS_ADDR_LOOPBACK (address))
>+		      if (!IN6_IS_ADDR_LOOPBACK (address) &&
>+			  !IN6_IS_ADDR_LINKLOCAL (address))
> 			seen_ipv6 = true;
> 		    }
> 		}

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Attachments on bug 721350: 512857 | 513595 | 660514