Attachment 685285 Details for Bug 901555 – Correct behaviour for TCP queries to allowed address via banned interface.

[patch] Correct behaviour for TCP queries to allowed address via banned interface.

dnsmasq-2.65-Correct-behaviour-for-TCP-queries-to-allowed-address.patch (text/plain), 6.27 KB, created by Tomáš Hozza on 2013-01-22 16:36:46 UTC

(hide)

Description:

Filename:

MIME Type:

Creator: Tomáš Hozza

Created: 2013-01-22 16:36:46 UTC

Size: 6.27 KB

patch

obsolete

>diff -up dnsmasq-2.65/src/dnsmasq.c.CVE-2013-0198 dnsmasq-2.65/src/dnsmasq.c
>--- dnsmasq-2.65/src/dnsmasq.c.CVE-2013-0198	2012-12-14 12:48:26.000000000 +0100
>+++ dnsmasq-2.65/src/dnsmasq.c	2013-01-22 16:32:30.387640907 +0100
>@@ -1384,7 +1384,7 @@ static void check_dns_listeners(fd_set *
> 
>       if (listener->tcpfd != -1 && FD_ISSET(listener->tcpfd, set))
> 	{
>-	  int confd;
>+	  int confd, client_ok = 1;
> 	  struct irec *iface = NULL;
> 	  pid_t p;
> 	  union mysockaddr tcp_addr;
>@@ -1395,25 +1395,49 @@ static void check_dns_listeners(fd_set *
> 	  if (confd == -1 ||
> 	      getsockname(confd, (struct sockaddr *)&tcp_addr, &tcp_len) == -1)
> 	    continue;
>-	  
>-	  if (option_bool(OPT_NOWILD) || option_bool(OPT_CLEVERBIND))
>+
>+	   if (option_bool(OPT_NOWILD))
> 	    iface = listener->iface; /* May be NULL */
>-	  else
>-	    {
>-	      /* Check for allowed interfaces when binding the wildcard address:
>-		 we do this by looking for an interface with the same address as 
>-		 the local address of the TCP connection, then looking to see if that's
>-		 an allowed interface. As a side effect, we get the netmask of the
>-		 interface too, for localisation. */
>-	      
>-	      /* interface may be new since startup */
>-	      if (enumerate_interfaces())
>-		for (iface = daemon->interfaces; iface; iface = iface->next)
>-		  if (sockaddr_isequal(&iface->addr, &tcp_addr))
>-		    break;
>-	    }
>-	  
>-	  if (!iface && !(option_bool(OPT_NOWILD) || option_bool(OPT_CLEVERBIND)))
>+	   else 
>+	     {
>+	       int if_index;
>+
>+	       /* In full wildcard mode, need to refresh interface list.
>+		  This happens automagically in CLEVERBIND */
>+	        if (!option_bool(OPT_CLEVERBIND))
>+		  enumerate_interfaces();
>+
>+		/* if we can find the arrival interface, check it's one that's allowed */
>+		if ((if_index = tcp_interface(confd, tcp_addr.sa.sa_family)) != 0)
>+		 {
>+		   for (iface = daemon->interfaces; iface; iface = iface->next)
>+		     if (iface->index == if_index)
>+		       break;
>+		   
>+		   if (!iface)
>+		     client_ok = 0;
>+		 }
>+	       
>+	       if (option_bool(OPT_CLEVERBIND))
>+		 iface = listener->iface; /* May be NULL */
>+	       else
>+		 {
>+		   /* Check for allowed interfaces when binding the wildcard address:
>+		      we do this by looking for an interface with the same address as 
>+		      the local address of the TCP connection, then looking to see if that's
>+		      an allowed interface. As a side effect, we get the netmask of the
>+		      interface too, for localisation. */
>+		   
>+		   for (iface = daemon->interfaces; iface; iface = iface->next)
>+		     if (sockaddr_isequal(&iface->addr, &tcp_addr))
>+		       break;
>+		   
>+		   if (!iface)
>+		     client_ok = 0;
>+		 }
>+	     }
>+	  	  
>+	  if (!client_ok)
> 	    {
> 	      shutdown(confd, SHUT_RDWR);
> 	      close(confd);
>diff -up dnsmasq-2.65/src/dnsmasq.h.CVE-2013-0198 dnsmasq-2.65/src/dnsmasq.h
>--- dnsmasq-2.65/src/dnsmasq.h.CVE-2013-0198	2012-12-14 12:48:26.000000000 +0100
>+++ dnsmasq-2.65/src/dnsmasq.h	2013-01-22 16:32:30.387640907 +0100
>@@ -412,7 +412,7 @@ struct server {
> struct irec {
>   union mysockaddr addr;
>   struct in_addr netmask; /* only valid for IPv4 */
>-  int tftp_ok, dhcp_ok, mtu, done, dad;
>+  int tftp_ok, dhcp_ok, mtu, done, dad, index;
>   char *name;
>   struct irec *next;
> };
>@@ -955,6 +955,7 @@ void create_bound_listeners(int die);
> int is_dad_listeners(void);
> int iface_check(int family, struct all_addr *addr, char *name);
> int fix_fd(int fd);
>+int tcp_interface(int fd, int af);
> struct in_addr get_ifaddr(char *intr);
> #ifdef HAVE_IPV6
> int set_ipv6pktinfo(int fd);
>diff -up dnsmasq-2.65/src/network.c.CVE-2013-0198 dnsmasq-2.65/src/network.c
>--- dnsmasq-2.65/src/network.c.CVE-2013-0198	2012-12-14 12:48:26.000000000 +0100
>+++ dnsmasq-2.65/src/network.c	2013-01-22 17:33:00.349128334 +0100
>@@ -239,6 +239,7 @@ static int iface_allowed(struct irec **i
>       iface->mtu = mtu;
>       iface->dad = dad;
>       iface->done = 0;
>+      iface->index = if_index;
>       if ((iface->name = whine_malloc(strlen(ifr.ifr_name)+1)))
> 	{
> 	  strcpy(iface->name, ifr.ifr_name);
>@@ -420,6 +421,77 @@ int set_ipv6pktinfo(int fd)
>   return 0;
> }
> #endif
>+
>+
>+/* Find the interface on which a TCP connection arrived, if possible, or zero otherwise. */
>+int tcp_interface(int fd, int af)
>+{ 
>+  int if_index = 0;
>+
>+#ifdef HAVE_LINUX_NETWORK
>+  int opt = 1;
>+  struct cmsghdr *cmptr;
>+  struct msghdr msg;
>+  
>+  /* use mshdr do that the CMSDG_* macros are available */
>+  msg.msg_control = daemon->packet;
>+  msg.msg_controllen = daemon->packet_buff_sz;
>+  
>+  /* we overwrote the buffer... */
>+  daemon->srv_save = NULL;
>+  
>+  if (af == AF_INET)
>+    {
>+      if (setsockopt(fd, IPPROTO_IP, IP_PKTINFO, &opt, sizeof(opt)) != -1 &&
>+	  getsockopt(fd, IPPROTO_IP, IP_PKTOPTIONS, msg.msg_control, (socklen_t *)&msg.msg_controllen) != -1)
>+	for (cmptr = CMSG_FIRSTHDR(&msg); cmptr; cmptr = CMSG_NXTHDR(&msg, cmptr))
>+	  if (cmptr->cmsg_level == IPPROTO_IP && cmptr->cmsg_type == IP_PKTINFO)
>+            {
>+              union {
>+                unsigned char *c;
>+                struct in_pktinfo *p;
>+              } p;
>+	      
>+	      p.c = CMSG_DATA(cmptr);
>+	      if_index = p.p->ipi_ifindex;
>+	    }
>+    }
>+#ifdef HAVE_IPV6
>+  else
>+    {
>+      /* Only the RFC-2292 API has the ability to find the interface for TCP connections,
>+	 it was removed in RFC-3542 !!!! 
>+
>+	 Fortunately, Linux kept the 2292 ABI when it moved to 3542. The following code always
>+	 uses the old ABI, and should work with pre- and post-3542 kernel headers */
>+
>+#ifdef IPV6_2292PKTOPTIONS   
>+#  define PKTOPTIONS IPV6_2292PKTOPTIONS
>+#else
>+#  define PKTOPTIONS IPV6_PKTOPTIONS
>+#endif
>+
>+      if (set_ipv6pktinfo(fd) &&
>+	  getsockopt(fd, IPPROTO_IPV6, PKTOPTIONS, msg.msg_control, (socklen_t *)&msg.msg_controllen) != -1)
>+	{
>+          for (cmptr = CMSG_FIRSTHDR(&msg); cmptr; cmptr = CMSG_NXTHDR(&msg, cmptr))
>+            if (cmptr->cmsg_level == IPPROTO_IPV6 && cmptr->cmsg_type == daemon->v6pktinfo)
>+              {
>+                union {
>+                  unsigned char *c;
>+                  struct in6_pktinfo *p;
>+                } p;
>+                p.c = CMSG_DATA(cmptr);
>+		
>+		if_index = p.p->ipi6_ifindex;
>+              }
>+	}
>+    }
>+#endif /* IPV6 */
>+#endif /* Linux */
>+ 
>+  return if_index;
>+}
>       
> static struct listener *create_listeners(union mysockaddr *addr, int do_tftp, int dienow)
> {

Actions: View | Diff

Attachments on bug 901555: 685285