From 652fb944050f237df8986232e4846202e1dc40ff Mon Sep 17 00:00:00 2001
From: david <david@e0a8ed71-7df4-0310-8962-fdc924857419>
Date: Tue, 27 Mar 2012 21:48:53 +0000
Subject: [PATCH] Make -e assign IPv6 scope ids for everything, not only
 route_dst.

You could use "-e en0" to automatically add scope ids to your IPv6
addresses, so you didn't need the write "fe80::1234%en0". But this only
happened for the route_dst calculation, and could lead to later failures
in sendmsg when the address didn't have a scope id.
---
 TargetGroup.cc | 21 ++++++++++++++++++++-
 tcpip.cc       | 24 +++---------------------
 2 files changed, 23 insertions(+), 22 deletions(-)

diff --git a/TargetGroup.cc b/TargetGroup.cc
index 8b34a5942..5dfe058e1 100644
--- a/TargetGroup.cc
+++ b/TargetGroup.cc
@@ -100,6 +100,7 @@
 #include "NmapOps.h"
 #include "nmap_error.h"
 #include "global_structures.h"
+#include "libnetutil/netutil.h"
 
 extern NmapOps o;
 
@@ -385,6 +386,21 @@ int TargetGroup::skip_range(_octet_nums octet) {
   return hosts_skipped;
 }
 
+/* Get the sin6_scope_id member of a sockaddr_in6, based on a device name. This
+   is used to assign scope to all addresses that otherwise lack a scope id when
+   the -e option is used. */
+static int get_scope_id(const char *devname) {
+  struct interface_info *ii;
+
+  if (devname == NULL || devname[0] == '\0')
+    return 0;
+  ii = getInterfaceByName(devname, AF_INET6);
+  if (ii != NULL)
+    return ii->ifindex;
+  else
+    return 0;
+}
+
  /* Grab the next host from this expression (if any) and updates its internal
     state to reflect that the IP was given out.  Returns 0 and
     fills in ss if successful.  ss must point to a pre-allocated
@@ -467,7 +483,10 @@ int TargetGroup::get_next_host(struct sockaddr_storage *ss, size_t *sslen) {
     sin6->sin6_len = *sslen;
 #endif /* SIN_LEN */
     memcpy(sin6->sin6_addr.s6_addr, ip6.sin6_addr.s6_addr, 16);
-    sin6->sin6_scope_id = ip6.sin6_scope_id;
+    if (ip6.sin6_scope_id == 0)
+      sin6->sin6_scope_id = get_scope_id(o.device);
+    else
+      sin6->sin6_scope_id = ip6.sin6_scope_id;
 #else
     fatal("IPV6 not supported on this platform");
 #endif // HAVE_IPV6
diff --git a/tcpip.cc b/tcpip.cc
index 29fa2834c..ba094568d 100644
--- a/tcpip.cc
+++ b/tcpip.cc
@@ -2013,34 +2013,16 @@ pcap_if_t *getpcapinterfaces() {
 
 
 
-/* Assign the sin6_scope_id member of a sockaddr_in6, based on a device name.
-   This is used to assign scope to all addresses with the -e option is used. */
-static void assign_scope_id(struct sockaddr_in6 *sin6, const char *devname) {
-  struct interface_info *ii;
-
-  if (devname == NULL || devname[0] == '\0')
-    return;
-  ii = getInterfaceByName(devname, sin6->sin6_family);
-  if (ii != NULL)
-    sin6->sin6_scope_id = ii->ifindex;
-}
-
 
 int nmap_route_dst(const struct sockaddr_storage *dst, struct route_nfo *rnfo) {
-  struct sockaddr_storage dst_mod, spoofss;
+  struct sockaddr_storage spoofss;
   size_t spoofsslen;
 
-  /* Make a copy that we may modify (only to possibly add a sin6_scope_id). */
-  dst_mod = *dst;
-
-  if (dst_mod.ss_family == AF_INET6)
-    assign_scope_id((struct sockaddr_in6 *) &dst_mod, o.device);
-
   if (o.spoofsource) {
     o.SourceSockAddr(&spoofss, &spoofsslen);
-    return route_dst(&dst_mod, rnfo, o.device, &spoofss);
+    return route_dst(dst, rnfo, o.device, &spoofss);
   } else {
-    return route_dst(&dst_mod, rnfo, o.device, NULL);
+    return route_dst(dst, rnfo, o.device, NULL);
   }
 }