Allow PacketAliasSetTarget() to be passed the following:

  INADDR_NONE:   Incoming packets go to the alias address (the default)
  INADDR_ANY:    Incoming packets are not NAT'd (direct access to the
                 internal network from outside)
  anything else: Incoming packets go to the specified address

Change a few inaddr::s_addr == 0 to inaddr::s_addr == INADDR_ANY
while I'm there.

2 files changed, 22 insertions, 13 deletions

diff --git a/sys/netinet/libalias/alias_db.c b/sys/netinet/libalias/alias_db.c
index 296f0d1..b0a2642 100644
--- a/sys/netinet/libalias/alias_db.c
+++ b/sys/netinet/libalias/alias_db.c
@@ -863,7 +863,7 @@ AddLink(struct in_addr  src_addr,
         link->src_addr          = src_addr;
         link->dst_addr          = dst_addr;
         link->alias_addr        = alias_addr;
-        link->proxy_addr.s_addr = 0;
+        link->proxy_addr.s_addr = INADDR_ANY;
         link->src_port          = src_port;
         link->dst_port          = dst_port;
         link->proxy_port        = 0;
@@ -893,7 +893,7 @@ AddLink(struct in_addr  src_addr,
         }
 
     /* Determine alias flags */
-        if (dst_addr.s_addr == 0)
+        if (dst_addr.s_addr == INADDR_ANY)
             link->flags |= LINK_UNKNOWN_DEST_ADDR;
         if (dst_port == 0)
             link->flags |= LINK_UNKNOWN_DEST_PORT;
@@ -1127,7 +1127,7 @@ _FindLinkIn(struct in_addr dst_addr,
    loop will have to know about this. */
 
     flags_in = 0;
-    if (dst_addr.s_addr == 0)
+    if (dst_addr.s_addr == INADDR_ANY)
         flags_in |= LINK_UNKNOWN_DEST_ADDR;
     if (dst_port == 0)
         flags_in |= LINK_UNKNOWN_DEST_PORT;
@@ -1455,14 +1455,16 @@ FindOriginalAddress(struct in_addr alias_addr)
     if (link == NULL)
     {
         newDefaultLink = 1;
-        if (targetAddress.s_addr != 0)
-            return targetAddress;
-        else
+        if (targetAddress.s_addr == INADDR_ANY)
+            return alias_addr;
+        else if (targetAddress.s_addr == INADDR_NONE)
             return aliasAddress;
+        else
+            return targetAddress;
     }
     else
     {
-        if (link->src_addr.s_addr == 0)
+        if (link->src_addr.s_addr == INADDR_ANY)
             return aliasAddress;
         else
             return link->src_addr;
@@ -1483,7 +1485,7 @@ FindAliasAddress(struct in_addr original_addr)
     }
     else
     {
-        if (link->alias_addr.s_addr == 0)
+        if (link->alias_addr.s_addr == INADDR_ANY)
             return aliasAddress;
         else
             return link->alias_addr;
@@ -1601,7 +1603,7 @@ GetStateOut(struct alias_link *link)
 struct in_addr
 GetOriginalAddress(struct alias_link *link)
 {
-    if (link->src_addr.s_addr == 0)
+    if (link->src_addr.s_addr == INADDR_ANY)
         return aliasAddress;
     else
         return(link->src_addr);
@@ -1618,7 +1620,7 @@ GetDestAddress(struct alias_link *link)
 struct in_addr
 GetAliasAddress(struct alias_link *link)
 {
-    if (link->alias_addr.s_addr == 0)
+    if (link->alias_addr.s_addr == INADDR_ANY)
         return aliasAddress;
     else
         return link->alias_addr;
@@ -2139,8 +2141,8 @@ PacketAliasInit(void)
         deleteAllLinks = 0;
     }
 
-    aliasAddress.s_addr = 0;
-    targetAddress.s_addr = 0;
+    aliasAddress.s_addr = INADDR_ANY;
+    targetAddress.s_addr = INADDR_NONE;
 
     icmpLinkCount = 0;
     udpLinkCount = 0;
diff --git a/sys/netinet/libalias/libalias.3 b/sys/netinet/libalias/libalias.3
index df1440c..66acc92 100644
--- a/sys/netinet/libalias/libalias.3
+++ b/sys/netinet/libalias/libalias.3
@@ -701,9 +701,16 @@ host machine, it will be sent to the address
 indicated by a call to PacketAliasSetTarget().
 
 If this function is not called, or is called
-with a zero address argument, then all new
+with a INADDR_NONE address argument, then all new
 incoming packets go to the address set by
 PacketAliasSetAddress.
+
+If this function is called with a INADDR_ANY address
+argument, then all new incoming packets go to the
+address specified in the packet.
+This allows external machines to talk directly to
+internal machines if they can route packets to the
+machine in question.
 .Ss 6.2 PacketAliasCheckNewLink()
 
 .Ft int