Correct to match reality regarding interface names.

PR:		51006
Submitted by:	"Dmitry Pryanishnikov" <dmitry@atlantis.dp.ua>
mdoc clue by:	"Simon L. Nielsen" <simon@nitro.dk>
MFC after:	10 days

2 files changed, 11 insertions, 6 deletions

diff --git a/sbin/ipfw/ipfw.8 b/sbin/ipfw/ipfw.8
index 4c4fd5f..2cc2a69 100644
--- a/sbin/ipfw/ipfw.8
+++ b/sbin/ipfw/ipfw.8
@@ -2119,9 +2119,13 @@ going through the rule list.
 This may be fixed in a later version.
 .Pp
 Packets diverted to userland, and then reinserted by a userland process
-(such as
-.Xr natd 8 )
-will lose various packet attributes, including their source interface.
+may lose various packet attributes.
+The packet source interface name
+will be preserved if it is shorter than 8 bytes and the userland process
+saves and reuses the sockaddr_in
+(as does
+.Xr natd 8 ) ;
+otherwise, it may be lost.
 If a packet is reinserted in this manner, later rules may be incorrectly
 applied, making the order of
 .Cm divert
diff --git a/share/man/man4/divert.4 b/share/man/man4/divert.4
index 0087ace..73a6cb1 100644
--- a/share/man/man4/divert.4
+++ b/share/man/man4/divert.4
@@ -50,9 +50,10 @@ and the IP address set to the (first) address of
 the interface on which the packet was received (if the packet
 was incoming) or
 .Dv INADDR_ANY
-(if the packet was outgoing). In the case of an incoming packet the interface
-name will also be placed in the 8 bytes following the address,
-(assuming it fits).
+(if the packet was outgoing).
+The interface name (if defined
+for the packet) will be placed in the 8 bytes following the address,
+if it fits.
 .Sh WRITING PACKETS
 Writing to a divert socket is similar to writing to a raw IP socket;
 the packet is injected ``as is'' into the normal kernel IP packet