With -e, print the LLC header before the SNAP header; without it, cut the SNAP header.

With -e, write out everything; without -e, just write the SNAP header
and, if the OUI is 000000, don't report it, and report the PID as an
ethertype.

3 files changed, 63 insertions, 50 deletions

diff --git a/print-llc.c b/print-llc.c
index 0132bdaa..3839240a 100644
--- a/print-llc.c
+++ b/print-llc.c
@@ -237,13 +237,22 @@ llc_print(netdissect_options *ndo, const u_char *p, u_int length, u_int caplen,
 	length -= hdrlen;
 	caplen -= hdrlen;
 
-	/*
-	 * Check for SNAP UI packets; if we have one, there's no point
-	 * in printing the LLC header information, as we already know it -
-	 * the relevant protocol-selection information is the SNAP OUI
-	 * and PID, so it's sufficient to print that for frames we
-	 * don't know how to print and for the "-e" flag.
-	 */
+	if (ndo->ndo_eflag) {
+                ND_PRINT((ndo, "LLC, dsap %s (0x%02x) %s, ssap %s (0x%02x) %s",
+                       tok2str(llc_values, "Unknown", dsap),
+                       dsap,
+                       tok2str(llc_ig_flag_values, "Unknown", dsap_field & LLC_IG),
+                       tok2str(llc_values, "Unknown", ssap),
+                       ssap,
+                       tok2str(llc_flag_values, "Unknown", ssap_field & LLC_GSAP)));
+
+		if (is_u) {
+			ND_PRINT((ndo, ", ctrl 0x%02x: ", control));
+		} else {
+			ND_PRINT((ndo, ", ctrl 0x%04x: ", control));
+		}
+	}
+
 	if (ssap == LLCSAP_SNAP && dsap == LLCSAP_SNAP
 	    && control == LLC_UI) {
 		/*
@@ -262,22 +271,6 @@ llc_print(netdissect_options *ndo, const u_char *p, u_int length, u_int caplen,
 			return (hdrlen + 5);	/* include LLC and SNAP header */
 	}
 
-	if (ndo->ndo_eflag) {
-                ND_PRINT((ndo, "LLC, dsap %s (0x%02x) %s, ssap %s (0x%02x) %s",
-                       tok2str(llc_values, "Unknown", dsap),
-                       dsap,
-                       tok2str(llc_ig_flag_values, "Unknown", dsap_field & LLC_IG),
-                       tok2str(llc_values, "Unknown", ssap),
-                       ssap,
-                       tok2str(llc_flag_values, "Unknown", ssap_field & LLC_GSAP)));
-
-		if (is_u) {
-			ND_PRINT((ndo, ", ctrl 0x%02x: ", control));
-		} else {
-			ND_PRINT((ndo, ", ctrl 0x%04x: ", control));
-		}
-	}
-
 	if (ssap == LLCSAP_8021D && dsap == LLCSAP_8021D &&
 	    control == LLC_UI) {
 		stp_print(ndo, p, length);
@@ -387,30 +380,19 @@ llc_print(netdissect_options *ndo, const u_char *p, u_int length, u_int caplen,
 	return (-hdrlen);
 }
 
-static void
-snap_hdr_print(netdissect_options *ndo, const uint8_t *esrc, const uint8_t *edst,
-	uint32_t orgcode, u_short et, u_int length)
+static const struct tok *
+oui_to_struct_tok(uint32_t orgcode)
 {
 	const struct tok *tok = null_values;
 	const struct oui_tok *otp;
 
-	if (esrc != NULL && edst != NULL) {
-		ND_PRINT((ndo, "%s > %s ",
-				etheraddr_string(ndo, esrc),
-				etheraddr_string(ndo, edst)));
-	}
 	for (otp = &oui_to_tok[0]; otp->tok != NULL; otp++) {
 		if (otp->oui == orgcode) {
 			tok = otp->tok;
 			break;
 		}
 	}
-	ND_PRINT((ndo, "SNAP oui %s (0x%06x), %s %s (0x%04x), length %u: ",
-	     tok2str(oui_values, "Unknown", orgcode),
-	     orgcode,
-	     (orgcode == 0x000000 ? "ethertype" : "pid"),
-	     tok2str(tok, "Unknown", et),
-	     et, length));
+	return (tok);
 }
 
 int
@@ -430,9 +412,15 @@ snap_print(netdissect_options *ndo, const u_char *p, u_int length, u_int caplen,
 	if (ndo->ndo_eflag) {
 		/*
 		 * Somebody's already printed the MAC addresses, if there
-		 * are any, so just print the SNAP header.
+		 * are any, so just print the SNAP header, not the MAC
+		 * addresses.
 		 */
-		snap_hdr_print(ndo, NULL, NULL, orgcode, et, length - 5);
+		ND_PRINT((ndo, "oui %s (0x%06x), %s %s (0x%04x), length %u: ",
+		     tok2str(oui_values, "Unknown", orgcode),
+		     orgcode,
+		     (orgcode == 0x000000 ? "ethertype" : "pid"),
+		     tok2str(oui_to_struct_tok(orgcode), "Unknown", et),
+		     et, length - 5));
 	}
 	p += 5;
 	length -= 5;
@@ -561,8 +549,33 @@ snap_print(netdissect_options *ndo, const u_char *p, u_int length, u_int caplen,
 			return (1);
 		}
 	}
-	if (!ndo->ndo_eflag)
-		snap_hdr_print(ndo, esrc, edst, orgcode, et, length);
+	if (!ndo->ndo_eflag) {
+		/*
+		 * Nobody printed the MAC addresses, so print them, if
+		 * we have any.
+		 */
+		if (esrc != NULL && edst != NULL) {
+			ND_PRINT((ndo, "%s > %s ",
+				etheraddr_string(ndo, esrc),
+				etheraddr_string(ndo, edst)));
+		}
+		/*
+		 * Print the SNAP header, but if the OUI is 000000, don't
+		 * bother printing it, and report the PID as being an
+		 * ethertype.
+		 */
+		if (orgcode == 0x000000) {
+			ND_PRINT((ndo, "SNAP, ethertype %s (0x%04x), length %u: ",
+			     tok2str(ethertype_values, "Unknown", et),
+			     et, length));
+		} else {
+			ND_PRINT((ndo, "SNAP, oui %s (0x%06x), pid %s (0x%04x), length %u: ",
+			     tok2str(oui_values, "Unknown", orgcode),
+			     orgcode,
+			     tok2str(oui_to_struct_tok(orgcode), "Unknown", et),
+			     et, length));
+		}
+	}
 	return (0);
 
 trunc:
diff --git a/tests/dtp-v.out b/tests/dtp-v.out
index cc06c265..4eb566b9 100644
--- a/tests/dtp-v.out
+++ b/tests/dtp-v.out
@@ -3,7 +3,7 @@ DTPv1, length 38
 	Status TLV (0x0002) TLV, length 5, 0x4
 	DTP type TLV (0x0003) TLV, length 5, 0x40
 	Neighbor TLV (0x0004) TLV, length 10, 00:19:06:ea:b8:85
-00:19:06:ea:b8:85 > 01:00:0c:00:00:00 SNAP oui Cisco (0x00000c), pid Unknown (0x0003), length 68: 
+00:19:06:ea:b8:85 > 01:00:0c:00:00:00 SNAP, oui Cisco (0x00000c), pid Unknown (0x0003), length 68: 
 	0x0000:  aaaa 0300 000c 0003 0000 0000 0100 0ccc  ................
 	0x0010:  cccc 0019 06ea b885 0025 aaaa 0300 000c  .........%......
 	0x0020:  2004 0100 0100 084c 6162 0000 0200 0504  .......Lab......
@@ -14,7 +14,7 @@ DTPv1, length 38
 	Status TLV (0x0002) TLV, length 5, 0x4
 	DTP type TLV (0x0003) TLV, length 5, 0x40
 	Neighbor TLV (0x0004) TLV, length 10, 00:19:06:ea:b8:85
-00:19:06:ea:b8:85 > 01:00:0c:00:00:00 SNAP oui Cisco (0x00000c), pid Unknown (0x0003), length 68: 
+00:19:06:ea:b8:85 > 01:00:0c:00:00:00 SNAP, oui Cisco (0x00000c), pid Unknown (0x0003), length 68: 
 	0x0000:  aaaa 0300 000c 0003 0000 0000 0100 0ccc  ................
 	0x0010:  cccc 0019 06ea b885 0025 aaaa 0300 000c  .........%......
 	0x0020:  2004 0100 0100 084c 6162 0000 0200 0504  .......Lab......
@@ -25,7 +25,7 @@ DTPv1, length 38
 	Status TLV (0x0002) TLV, length 5, 0x4
 	DTP type TLV (0x0003) TLV, length 5, 0x40
 	Neighbor TLV (0x0004) TLV, length 10, 00:19:06:ea:b8:85
-00:19:06:ea:b8:85 > 01:00:0c:00:00:00 SNAP oui Cisco (0x00000c), pid Unknown (0x0003), length 68: 
+00:19:06:ea:b8:85 > 01:00:0c:00:00:00 SNAP, oui Cisco (0x00000c), pid Unknown (0x0003), length 68: 
 	0x0000:  aaaa 0300 000c 0003 0000 0000 0100 0ccc  ................
 	0x0010:  cccc 0019 06ea b885 0025 aaaa 0300 000c  .........%......
 	0x0020:  2004 0100 0100 084c 6162 0000 0200 0504  .......Lab......
@@ -36,7 +36,7 @@ DTPv1, length 38
 	Status TLV (0x0002) TLV, length 5, 0x4
 	DTP type TLV (0x0003) TLV, length 5, 0x40
 	Neighbor TLV (0x0004) TLV, length 10, 00:19:06:ea:b8:85
-00:19:06:ea:b8:85 > 01:00:0c:00:00:00 SNAP oui Cisco (0x00000c), pid Unknown (0x0003), length 68: 
+00:19:06:ea:b8:85 > 01:00:0c:00:00:00 SNAP, oui Cisco (0x00000c), pid Unknown (0x0003), length 68: 
 	0x0000:  aaaa 0300 000c 0003 0000 0000 0100 0ccc  ................
 	0x0010:  cccc 0019 06ea b885 0025 aaaa 0300 000c  .........%......
 	0x0020:  2004 0100 0100 084c 6162 0000 0200 0504  .......Lab......
@@ -47,7 +47,7 @@ DTPv1, length 38
 	Status TLV (0x0002) TLV, length 5, 0x4
 	DTP type TLV (0x0003) TLV, length 5, 0x40
 	Neighbor TLV (0x0004) TLV, length 10, 00:19:06:ea:b8:85
-00:19:06:ea:b8:85 > 01:00:0c:00:00:00 SNAP oui Cisco (0x00000c), pid Unknown (0x0003), length 68: 
+00:19:06:ea:b8:85 > 01:00:0c:00:00:00 SNAP, oui Cisco (0x00000c), pid Unknown (0x0003), length 68: 
 	0x0000:  aaaa 0300 000c 0003 0000 0000 0100 0ccc  ................
 	0x0010:  cccc 0019 06ea b885 0025 aaaa 0300 000c  .........%......
 	0x0020:  2004 0100 0100 084c 6162 0000 0200 0504  .......Lab......
diff --git a/tests/lldp_cdp-ev.out b/tests/lldp_cdp-ev.out
index 055e3f41..5743b466 100644
--- a/tests/lldp_cdp-ev.out
+++ b/tests/lldp_cdp-ev.out
@@ -1,4 +1,4 @@
-00:18:ba:98:68:8f > 01:00:0c:cc:cc:cc, 802.3, length 388: SNAP oui Cisco (0x00000c), pid CDP (0x2000), length 366: CDPv2, ttl: 180s, checksum: 0x0bea (unverified), length 366
+00:18:ba:98:68:8f > 01:00:0c:cc:cc:cc, 802.3, length 388: LLC, dsap SNAP (0xaa) Individual, ssap SNAP (0xaa) Command, ctrl 0x03: oui Cisco (0x00000c), pid CDP (0x2000), length 366: CDPv2, ttl: 180s, checksum: 0x0bea (unverified), length 366
 	Device-ID (0x01), value length: 2 bytes: 'S1'
 	Version String (0x05), value length: 190 bytes: 
 	  Cisco IOS Software, C3560 Software (C3560-ADVIPSERVICESK9-M), Version 12.2(44)SE, RELEASE SOFTWARE (fc1)
@@ -17,7 +17,7 @@
 	Management Addresses (0x16), value length: 13 bytes: IPv4 (1) 0.0.0.0
 	unknown field type (0x1a), value length: 12 bytes: 
 	  0x0000:  0000 0001 0000 0000 ffff ffff
-00:19:2f:a7:b2:8d > 01:00:0c:cc:cc:cc, 802.3, length 392: SNAP oui Cisco (0x00000c), pid CDP (0x2000), length 370: CDPv2, ttl: 180s, checksum: 0x971d (unverified), length 370
+00:19:2f:a7:b2:8d > 01:00:0c:cc:cc:cc, 802.3, length 392: LLC, dsap SNAP (0xaa) Individual, ssap SNAP (0xaa) Command, ctrl 0x03: oui Cisco (0x00000c), pid CDP (0x2000), length 370: CDPv2, ttl: 180s, checksum: 0x971d (unverified), length 370
 	Device-ID (0x01), value length: 2 bytes: 'S2'
 	Version String (0x05), value length: 190 bytes: 
 	  Cisco IOS Software, C3560 Software (C3560-ADVIPSERVICESK9-M), Version 12.2(44)SE, RELEASE SOFTWARE (fc1)
@@ -124,7 +124,7 @@
 	    PMD autoneg capability [Sym PAUSE for fdx, Asym and Sym PAUSE for fdx, 1000BASE-{X LX SX CX} fdx, 1000BASE-T hdx] (0x0036)
 	    MAU type 100BASETX fdx (0x0010)
 	End TLV (0), length 0
-00:18:ba:98:68:8f > 01:00:0c:cc:cc:cc, 802.3, length 388: SNAP oui Cisco (0x00000c), pid CDP (0x2000), length 366: CDPv2, ttl: 180s, checksum: 0x0be9 (unverified), length 366
+00:18:ba:98:68:8f > 01:00:0c:cc:cc:cc, 802.3, length 388: LLC, dsap SNAP (0xaa) Individual, ssap SNAP (0xaa) Command, ctrl 0x03: oui Cisco (0x00000c), pid CDP (0x2000), length 366: CDPv2, ttl: 180s, checksum: 0x0be9 (unverified), length 366
 	Device-ID (0x01), value length: 2 bytes: 'S1'
 	Version String (0x05), value length: 190 bytes: 
 	  Cisco IOS Software, C3560 Software (C3560-ADVIPSERVICESK9-M), Version 12.2(44)SE, RELEASE SOFTWARE (fc1)
@@ -143,7 +143,7 @@
 	Management Addresses (0x16), value length: 13 bytes: IPv4 (1) 0.0.0.0
 	unknown field type (0x1a), value length: 12 bytes: 
 	  0x0000:  0000 0001 0000 0000 ffff ffff
-00:19:2f:a7:b2:8d > 01:00:0c:cc:cc:cc, 802.3, length 392: SNAP oui Cisco (0x00000c), pid CDP (0x2000), length 370: CDPv2, ttl: 180s, checksum: 0x971c (unverified), length 370
+00:19:2f:a7:b2:8d > 01:00:0c:cc:cc:cc, 802.3, length 392: LLC, dsap SNAP (0xaa) Individual, ssap SNAP (0xaa) Command, ctrl 0x03: oui Cisco (0x00000c), pid CDP (0x2000), length 370: CDPv2, ttl: 180s, checksum: 0x971c (unverified), length 370
 	Device-ID (0x01), value length: 2 bytes: 'S2'
 	Version String (0x05), value length: 190 bytes: 
 	  Cisco IOS Software, C3560 Software (C3560-ADVIPSERVICESK9-M), Version 12.2(44)SE, RELEASE SOFTWARE (fc1)