Add the capacity for the rfc1490 node to handle cisco style encasulation

which is often used alongside rfc1490 in frame relay links.

Submitted by:	Gleb Smirnoff <glebius@cell.sick.ru>

share/man/man4/ng_rfc1490.4

@@ -88,7 +88,25 @@ Transmits and receives raw IP frames.
 Transmits and receives PPP frames.
 .El
 .Sh CONTROL MESSAGES
-This node type only supports the generic control messages.
+This node type supports the generic control messages, plus the following:
+.Bl -tag -width foo
+.It Dv NGM_RFC1490_SETENCAP
+This command sets encapsulation method for the node.
+The desired method must be passed as a string message argument,
+and must be one of the following supported encapsulation modes:
+.Bl -tag
+.It Qq ietf-ip
+IP packets are sent using simple RFC1490/2427 encapsulation.
+.It Qq ietf-snap
+IP packets are sent inside SNAP frames.
+Also conforms to RFC1490/2427.
+.It Qq cisco
+IP packets are sent and received using proprietary Cisco encapsulation
+method.
+.El
+.It Dv NGM_RFC1490_GETENCAP
+This command returns current encapsulation method on the node.
+.El
 .Sh SHUTDOWN
 This node shuts down upon receipt of a
 .Dv NGM_SHUTDOWN
@@ -111,6 +129,9 @@ Not all of RFC 1490 is implemented.
 .%T "PPP in Frame Relay"
 .%O RFC 1973
 .Re
+.Rs
+http://www.cisco.com/warp/public/121/frf8modes.pdf
+.Re
 .Sh HISTORY
 The
 .Nm

sys/netgraph/ng_rfc1490.c

@@ -61,6 +61,7 @@
 
 #include <netgraph/ng_message.h>
 #include <netgraph/netgraph.h>
+#include <netgraph/ng_parse.h>
 #include <netgraph/ng_rfc1490.h>
 
 /*
@@ -78,12 +79,34 @@
 #define NLPID_ESIS	0x82
 #define NLPID_ISIS	0x83
 
+#define ERROUT(x)	do { error = (x); goto done; } while (0)
+
+/* Encapsulation methods we understand */
+enum {
+	NG_RFC1490_ENCAP_IETF_IP = 1,	/* see RFC2427, chapter 7, table 1 */
+	NG_RFC1490_ENCAP_IETF_SNAP,	/* see RFC2427, chapter 7, table 2 */
+	NG_RFC1490_ENCAP_CISCO,		/* Cisco's proprietary encapsulation */
+};
+
+struct ng_rfc1490_encap_t {
+	u_int8_t	method;
+	const char	*name;
+};
+
+static const struct ng_rfc1490_encap_t ng_rfc1490_encaps[] = {
+	{ NG_RFC1490_ENCAP_IETF_IP,	"ietf-ip" },
+	{ NG_RFC1490_ENCAP_IETF_SNAP,	"ietf-snap" },
+	{ NG_RFC1490_ENCAP_CISCO,	"cisco" },
+	{ 0, NULL},
+};
+
 /* Node private data */
 struct ng_rfc1490_private {
 	hook_p  downlink;
 	hook_p  ppp;
 	hook_p  inet;
 	hook_p  ethernet;
+	const struct ng_rfc1490_encap_t *enc;
 };
 typedef struct ng_rfc1490_private *priv_p;
 
@@ -95,6 +118,25 @@ static ng_newhook_t	ng_rfc1490_newhook;
 static ng_rcvdata_t	ng_rfc1490_rcvdata;
 static ng_disconnect_t	ng_rfc1490_disconnect;
 
+/* List of commands and how to convert arguments to/from ASCII */
+static const struct ng_cmdlist ng_rfc1490_cmds[] = {
+	{
+	  NGM_RFC1490_COOKIE,
+	  NGM_RFC1490_SET_ENCAP,
+	  "setencap",
+	  &ng_parse_string_type,
+	  NULL
+	},
+	{
+	  NGM_RFC1490_COOKIE,
+	  NGM_RFC1490_GET_ENCAP,
+	  "getencap",
+	  NULL,
+	  &ng_parse_string_type
+	},
+	{ 0 }
+};
+
 /* Node type descriptor */
 static struct ng_type typestruct = {
 	.version =	NG_ABI_VERSION,
@@ -105,6 +147,7 @@ static struct ng_type typestruct = {
 	.newhook =	ng_rfc1490_newhook,
 	.rcvdata =	ng_rfc1490_rcvdata,
 	.disconnect =	ng_rfc1490_disconnect,
+	.cmdlist =	ng_rfc1490_cmds,
 };
 NETGRAPH_INIT(rfc1490, &typestruct);
 
@@ -125,6 +168,9 @@ ng_rfc1490_constructor(node_p node)
 	if (priv == NULL)
 		return (ENOMEM);
 
+	/* Initialize to default encapsulation method - ietf-ip */
+	priv->enc = ng_rfc1490_encaps;
+
 	NG_NODE_SET_PRIVATE(node, priv);
 
 	/* Done */
@@ -161,13 +207,65 @@ ng_rfc1490_newhook(node_p node, hook_p hook, const char *name)
 }
 
 /*
- * Receive a control message. We don't support any special ones.
+ * Receive a control message.
  */
 static int
 ng_rfc1490_rcvmsg(node_p node, item_p item, hook_p lasthook)
 {
-	NG_FREE_ITEM(item);
+	const priv_p priv = NG_NODE_PRIVATE(node);
-	return (EINVAL);
+	struct ng_mesg *msg;
+	struct ng_mesg *resp = NULL;
+	int error = 0;
+
+	NGI_GET_MSG(item, msg);
+
+	if (msg->header.typecookie == NGM_RFC1490_COOKIE) {
+		switch (msg->header.cmd) {
+		case NGM_RFC1490_SET_ENCAP:
+		{
+			const struct ng_rfc1490_encap_t *enc;
+			char *s;
+			size_t len;
+
+			if (msg->header.arglen == 0)
+				ERROUT(EINVAL);
+
+			s = (char *)msg->data;
+			len = msg->header.arglen - 1;
+
+			/* Search for matching encapsulation method */
+			for (enc = ng_rfc1490_encaps; enc->method != 0; enc++ )
+				if ((strlen(enc->name) == len) &&
+				    !strncmp(enc->name, s, len))
+					break;	/* found */
+
+			if (enc->method != 0)
+				priv->enc = enc;
+			else
+				error = EINVAL;
+			break;
+		}
+		case NGM_RFC1490_GET_ENCAP:
+
+			NG_MKRESPONSE(resp, msg, strlen(priv->enc->name) + 1, M_NOWAIT);
+			if (resp == NULL)
+				ERROUT(ENOMEM);
+
+			strlcpy((char *)resp->data, priv->enc->name,
+			    strlen(priv->enc->name) + 1);
+			break;
+
+		default:
+			error = EINVAL;
+			break;
+		}
+	} else
+		error = EINVAL;
+
+done:
+	NG_RESPOND_MSG(error, node, item, resp);
+	NG_FREE_MSG(msg);
+	return (error);
 }
 
 /*
@@ -177,15 +275,15 @@ ng_rfc1490_rcvmsg(node_p node, item_p item, hook_p lasthook)
  *                            Q.922 control
  *                                 |
  *                                 |
- *            --------------------------------------------
+ *            ---------------------------------------------------------------------
- *            | 0x03                                     |
+ *            | 0x03                                     |                        |
- *           UI                                       I Frame
+ *           UI                                       I Frame                   Cisco
- *            |                                          |
+ *            |                                          |                  Encapsulation
- *      ---------------------------------         --------------
+ *      ---------------------------------         --------------                  |
- *      | 0x08  | 0x81  |0xCC   |0xCF   | 0x00    |..01....    |..10....
+ *      | 0x08  | 0x81  |0xCC   |0xCF   | 0x00    |..01....    |..10....   --------------
- *      |       |       |       |       | 0x80    |            |
+ *      |       |       |       |       | 0x80    |            |           |0x800       |
- *     Q.933   CLNP    IP(*)   PPP(*)  SNAP     ISO 8208    ISO 8208
+ *     Q.933   CLNP    IP(*)   PPP(*)  SNAP     ISO 8208    ISO 8208       |            |
- *      |                    (rfc1973)  |       Modulo 8    Modulo 128
+ *      |                    (rfc1973)  |       Modulo 8    Modulo 128     IP(*)     Others
  *      |                               |
  *      --------------------           OUI
  *      |                  |            |
@@ -197,13 +295,12 @@ ng_rfc1490_rcvmsg(node_p node, item_p item, hook_p lasthook)
  *      -------------------        -----------------...     ----------
  *      |0x51 |0x4E |     |0x4C    |0x7      |0xB  |        |0x806   |
  *      |     |     |     |        |         |     |        |        |
- *     7776  Q.922 Others 802.2   802.3(*)  802.6 Others    ARP(*)  Others
+ *     7776  Q.922 Others 802.2   802.3(*)  802.6 Others    IP(*)   Others
  *
  *
  */
 
 #define MAX_ENCAPS_HDR	8
-#define ERROUT(x)	do { error = (x); goto done; } while (0)
 #define OUICMP(P,A,B,C)	((P)[0]==(A) && (P)[1]==(B) && (P)[2]==(C))
 
 static int
@@ -224,6 +321,9 @@ ng_rfc1490_rcvdata(hook_p hook, item_p item)
 			ERROUT(ENOBUFS);
 		ptr = start = mtod(m, const u_char *);
 
+		if (priv->enc->method == NG_RFC1490_ENCAP_CISCO)
+			goto switch_on_etype;
+
 		/* Must be UI frame */
 		if (*ptr++ != HDLC_UI)
 			ERROUT(0);
@@ -239,7 +339,7 @@ ng_rfc1490_rcvdata(hook_p hook, item_p item)
 				u_int16_t etype;
 
 				ptr += 3;
-				etype = ntohs(*((const u_int16_t *)ptr));
+switch_on_etype:		etype = ntohs(*((const u_int16_t *)ptr));
 				ptr += 2;
 				m_adj(m, ptr - start);
 				switch (etype) {
@@ -293,11 +393,37 @@ ng_rfc1490_rcvdata(hook_p hook, item_p item)
 		mtod(m, u_char *)[1] = NLPID_PPP;
 		NG_FWD_NEW_DATA(error, item, priv->downlink, m);
 	} else if (hook == priv->inet) {
+		switch (priv->enc->method) {
+		case NG_RFC1490_ENCAP_IETF_IP:
 			M_PREPEND(m, 2, M_DONTWAIT);	/* Prepend IP NLPID */
 			if (!m)
 				ERROUT(ENOBUFS);
 			mtod(m, u_char *)[0] = HDLC_UI;
 			mtod(m, u_char *)[1] = NLPID_IP;
+			break;
+		case NG_RFC1490_ENCAP_IETF_SNAP:
+			/*
+			 *  According to RFC2427 frame should begin with
+			 *  HDLC_UI  PAD  NLIPID  OUI      PID
+			 *  03      00   80      00 00 00  08 00
+			 */
+			M_PREPEND(m, 8, M_DONTWAIT);
+			if (!m)
+				ERROUT(ENOBUFS);
+			mtod(m, u_char *)[0] = HDLC_UI;
+			mtod(m, u_char *)[1] = 0x00;			/* PAD */
+			mtod(m, u_char *)[2] = NLPID_SNAP;
+			bzero((char *)(mtod(m, u_char *) + 3), 3);	/* OUI 0-0-0 */
+			*((u_int16_t *)mtod(m, u_int16_t *) + 6/sizeof(u_int16_t))
+			    = htons(ETHERTYPE_IP);  /* PID */
+			break;
+		case NG_RFC1490_ENCAP_CISCO:
+			M_PREPEND(m, 2, M_DONTWAIT);	/* Prepend IP ethertype */
+			if (!m)
+				ERROUT(ENOBUFS);
+			*((u_int16_t *)mtod(m, u_int16_t *)) = htons(ETHERTYPE_IP);
+			break;
+		}
 		NG_FWD_NEW_DATA(error, item, priv->downlink, m);
 	} else if (hook == priv->ethernet) {
 		M_PREPEND(m, 8, M_DONTWAIT);	/* Prepend NLPID, OUI, PID */

sys/netgraph/ng_rfc1490.h

@@ -1,4 +1,3 @@
-
 /*
  * ng_rfc1490.h
  *
@@ -45,7 +44,7 @@
 
 /* Node type name */
 #define NG_RFC1490_NODE_TYPE		"rfc1490"
-#define NGM_RFC1490_COOKIE		861060632
+#define NGM_RFC1490_COOKIE		1086947474
 
 /* Hook names */
 #define NG_RFC1490_HOOK_DOWNSTREAM	"downstream"
@@ -53,4 +52,10 @@
 #define NG_RFC1490_HOOK_PPP		"ppp"
 #define NG_RFC1490_HOOK_ETHERNET	"ethernet"
 
+/* Netgraph commands */
+enum {
+	NGM_RFC1490_SET_ENCAP,		/* sets encapsulation method */
+	NGM_RFC1490_GET_ENCAP,		/* gets current encapsulation method */
+};
+
 #endif /* _NETGRAPH_NG_RFC1490_H_ */