Implement the 'ipsec' option to match packets coming out of an ipsec tunnel.

Should work with both regular and fast ipsec (mutually exclusive).
See manpage for more details.

Submitted by: Ari Suutari (ari.suutari@syncrontech.com)
Revised by: sam
MFC after: 1 week

2 files changed, 22 insertions, 0 deletions

diff --git a/sbin/ipfw/ipfw.8 b/sbin/ipfw/ipfw.8
index 42d1956..ba2ded6 100644
--- a/sbin/ipfw/ipfw.8
+++ b/sbin/ipfw/ipfw.8
@@ -927,6 +927,18 @@ with a
 .It Cm ipprecedence Ar precedence
 Matches IP packets whose precedence field is equal to
 .Ar precedence .
+.It Cm ipsec
+Matches packets that have IPSEC history associated with them
+(i.e. the packet comes encapsulated in IPSEC, the kernel
+has IPSEC support and IPSEC_FILTERGIF option, and can correctly
+decapsulate it).
+.Pp
+Note that specifying
+.Cm ipsec
+is different from specifying
+.Cm proto Ar ipsec
+as the latter will only look at the specific IP protocol field,
+irrespective of IPSEC kernel support and the validity of the IPSEC data.
 .It Cm iptos Ar spec
 Matches IP packets whose
 .Cm tos
diff --git a/sbin/ipfw/ipfw2.c b/sbin/ipfw/ipfw2.c
index cef3752..12d774f 100644
--- a/sbin/ipfw/ipfw2.c
+++ b/sbin/ipfw/ipfw2.c
@@ -225,6 +225,7 @@ enum tokens {
 	TOK_MAC,
 	TOK_MACTYPE,
 	TOK_VERREVPATH,
+	TOK_IPSEC,
 
 	TOK_PLR,
 	TOK_NOERROR,
@@ -335,6 +336,7 @@ struct _s_x rule_options[] = {
 	{ "mac",		TOK_MAC },
 	{ "mac-type",		TOK_MACTYPE },
 	{ "verrevpath",		TOK_VERREVPATH },
+	{ "ipsec",		TOK_IPSEC },
 
 	{ "not",		TOK_NOT },		/* pseudo option */
 	{ "!", /* escape ? */	TOK_NOT },		/* pseudo option */
@@ -1226,6 +1228,10 @@ show_ipfw(struct ip_fw *rule, int pcwidth, int bcwidth)
 				printf(" verrevpath");
 				break;
 
+			case O_IPSEC:
+				printf(" ipsec");
+				break;
+
 			case O_KEEP_STATE:
 				printf(" keep-state");
 				break;
@@ -3270,6 +3276,10 @@ read_options:
 			fill_cmd(cmd, O_VERREVPATH, 0, 0);
 			break;
 
+		case TOK_IPSEC:
+			fill_cmd(cmd, O_IPSEC, 0, 0);
+			break;
+
 		default:
 			errx(EX_USAGE, "unrecognised option [%d] %s\n", i, s);
 		}