X-Git-Url: https://git.tcpdump.org/tcpdump/blobdiff_plain/01017da63c1c0d4b241ea29a43e5d5bd1a3a53dd..cc82ffa44fabb75e4ea10033452699b389c57b8a:/print-ether.c

diff --git a/print-ether.c b/print-ether.c
index d6dd9572..8382e1ee 100644
--- a/print-ether.c
+++ b/print-ether.c
@@ -106,7 +106,8 @@ const struct tok ethertype_values[] = {
 
 static void
 ether_hdr_print(netdissect_options *ndo,
-                const u_char *bp, u_int length)
+		const u_char *bp, u_int length,
+		u_int hdrlen)
 {
 	const struct ether_header *ehp;
 	uint16_t length_type;
@@ -114,31 +115,32 @@ ether_hdr_print(netdissect_options *ndo,
 	ehp = (const struct ether_header *)bp;
 
 	ND_PRINT("%s > %s",
-		     etheraddr_string(ndo, ehp->ether_shost),
-		     etheraddr_string(ndo, ehp->ether_dhost));
+		 etheraddr_string(ndo, ehp->ether_shost),
+		 etheraddr_string(ndo, ehp->ether_dhost));
 
-	length_type = EXTRACT_BE_U_2(ehp->ether_length_type);
+	length_type = GET_BE_U_2(bp + (hdrlen - sizeof(ehp->ether_length_type)));
 	if (!ndo->ndo_qflag) {
-	        if (length_type <= MAX_ETHERNET_LENGTH_VAL) {
-		        ND_PRINT(", 802.3");
+		if (length_type <= MAX_ETHERNET_LENGTH_VAL) {
+			ND_PRINT(", 802.3");
 			length = length_type;
 		} else
-		        ND_PRINT(", ethertype %s (0x%04x)",
-				       tok2str(ethertype_values,"Unknown", length_type),
-                                       length_type);
-        } else {
-                if (length_type <= MAX_ETHERNET_LENGTH_VAL) {
-                        ND_PRINT(", 802.3");
+			ND_PRINT(", ethertype %s (0x%04x)",
+				 tok2str(ethertype_values,"Unknown", length_type),
+				 length_type);
+	} else {
+		if (length_type <= MAX_ETHERNET_LENGTH_VAL) {
+			ND_PRINT(", 802.3");
 			length = length_type;
 		} else
-                        ND_PRINT(", %s", tok2str(ethertype_values,"Unknown Ethertype (0x%04x)", length_type));
-        }
+			ND_PRINT(", %s", tok2str(ethertype_values,"Unknown Ethertype (0x%04x)", length_type));
+	}
 
 	ND_PRINT(", length %u: ", length);
 }
 
 /*
- * Print an Ethernet frame.
+ * Print an Ethernet frame while specyfing a non-standard Ethernet header
+ * length.
  * This might be encapsulated within another frame; we might be passed
  * a pointer to a function that can print header information for that
  * frame's protocol, and an argument to pass to that function.
@@ -146,46 +148,51 @@ ether_hdr_print(netdissect_options *ndo,
  * FIXME: caplen can and should be derived from ndo->ndo_snapend and p.
  */
 u_int
-ether_print(netdissect_options *ndo,
-            const u_char *p, u_int length, u_int caplen,
-            void (*print_encap_header)(netdissect_options *ndo, const u_char *),
-            const u_char *encap_header_arg)
+ether_hdr_len_print(netdissect_options *ndo,
+		    const u_char *p, u_int length, u_int caplen,
+		    void (*print_encap_header)(netdissect_options *ndo, const u_char *),
+		    const u_char *encap_header_arg, u_int hdrlen)
 {
 	const struct ether_header *ehp;
 	u_int orig_length;
 	u_short length_type;
-	u_int hdrlen;
 	int llc_hdrlen;
 	struct lladdr_info src, dst;
 
-	ndo->ndo_protocol = "ether";
-	if (caplen < ETHER_HDRLEN) {
+	/* Unless specified otherwise, assume a standard Ethernet header */
+	if (hdrlen == ETHER_HDRLEN)
+		ndo->ndo_protocol = "ether";
+
+	if (caplen < hdrlen) {
 		nd_print_trunc(ndo);
 		return (caplen);
 	}
-	if (length < ETHER_HDRLEN) {
+	if (length < hdrlen) {
 		nd_print_trunc(ndo);
 		return (length);
 	}
 
+	/* If the offset is set, then the upper printer is responsible for
+	 * printing the relevant part of the Ethernet header.
+	 */
 	if (ndo->ndo_eflag) {
 		if (print_encap_header != NULL)
 			(*print_encap_header)(ndo, encap_header_arg);
-		ether_hdr_print(ndo, p, length);
+		ether_hdr_print(ndo, p, length, hdrlen);
 	}
+
 	orig_length = length;
 
-	length -= ETHER_HDRLEN;
-	caplen -= ETHER_HDRLEN;
+	length -= hdrlen;
+	caplen -= hdrlen;
 	ehp = (const struct ether_header *)p;
-	p += ETHER_HDRLEN;
-	hdrlen = ETHER_HDRLEN;
+	p += hdrlen;
 
 	src.addr = ehp->ether_shost;
 	src.addr_string = etheraddr_string;
 	dst.addr = ehp->ether_dhost;
 	dst.addr_string = etheraddr_string;
-	length_type = EXTRACT_BE_U_2(ehp->ether_length_type);
+	length_type = GET_BE_U_2((const u_char *)ehp + (hdrlen - sizeof(ehp->ether_length_type)));
 
 recurse:
 	/*
@@ -202,9 +209,9 @@ recurse:
 		}
 		hdrlen += llc_hdrlen;
 	} else if (length_type == ETHERTYPE_8021Q  ||
-                length_type == ETHERTYPE_8021Q9100 ||
-                length_type == ETHERTYPE_8021Q9200 ||
-                length_type == ETHERTYPE_8021QinQ) {
+		length_type == ETHERTYPE_8021Q9100 ||
+		length_type == ETHERTYPE_8021Q9200 ||
+		length_type == ETHERTYPE_8021QinQ) {
 		/*
 		 * Print VLAN information, and then go back and process
 		 * the enclosed type field.
@@ -219,13 +226,13 @@ recurse:
 			nd_print_trunc(ndo);
 			return (hdrlen + length);
 		}
-	        if (ndo->ndo_eflag) {
-			uint16_t tag = EXTRACT_BE_U_2(p);
+		if (ndo->ndo_eflag) {
+			uint16_t tag = GET_BE_U_2(p);
 
 			ND_PRINT("%s, ", ieee8021q_tci_string(tag));
 		}
 
-		length_type = EXTRACT_BE_U_2(p + 2);
+		length_type = GET_BE_U_2(p + 2);
 		if (ndo->ndo_eflag && length_type > MAX_ETHERNET_LENGTH_VAL)
 			ND_PRINT("ethertype %s, ", tok2str(ethertype_values,"0x%04x", length_type));
 		p += 4;
@@ -258,7 +265,8 @@ recurse:
 			if (!ndo->ndo_eflag) {
 				if (print_encap_header != NULL)
 					(*print_encap_header)(ndo, encap_header_arg);
-				ether_hdr_print(ndo, (const u_char *)ehp, orig_length);
+				ether_hdr_print(ndo, (const u_char *)ehp, orig_length,
+						hdrlen);
 			}
 
 			if (!ndo->ndo_suppress_default_print)
@@ -268,6 +276,25 @@ recurse:
 	return (hdrlen);
 }
 
+/*
+ * Print an Ethernet frame.
+ * This might be encapsulated within another frame; we might be passed
+ * a pointer to a function that can print header information for that
+ * frame's protocol, and an argument to pass to that function.
+ *
+ * FIXME: caplen can and should be derived from ndo->ndo_snapend and p.
+ */
+u_int
+ether_print(netdissect_options *ndo,
+	    const u_char *p, u_int length, u_int caplen,
+	    void (*print_encap_header)(netdissect_options *ndo, const u_char *),
+	    const u_char *encap_header_arg)
+{
+	return (ether_hdr_len_print(ndo, p, length, caplen,
+				    print_encap_header, encap_header_arg,
+				    ETHER_HDRLEN));
+}
+
 /*
  * This is the top level routine of the printer.  'p' points
  * to the ether header of the packet, 'h->len' is the length
@@ -276,7 +303,7 @@ recurse:
  */
 u_int
 ether_if_print(netdissect_options *ndo, const struct pcap_pkthdr *h,
-               const u_char *p)
+	       const u_char *p)
 {
 	ndo->ndo_protocol = "ether_if";
 	return (ether_print(ndo, p, h->len, h->caplen, NULL, NULL));
@@ -293,7 +320,7 @@ ether_if_print(netdissect_options *ndo, const struct pcap_pkthdr *h,
  */
 u_int
 netanalyzer_if_print(netdissect_options *ndo, const struct pcap_pkthdr *h,
-                     const u_char *p)
+		     const u_char *p)
 {
 	/*
 	 * Fail if we don't have enough data for the Hilscher pseudo-header.
@@ -320,8 +347,8 @@ netanalyzer_if_print(netdissect_options *ndo, const struct pcap_pkthdr *h,
  */
 u_int
 netanalyzer_transparent_if_print(netdissect_options *ndo,
-                                 const struct pcap_pkthdr *h,
-                                 const u_char *p)
+				 const struct pcap_pkthdr *h,
+				 const u_char *p)
 {
 	/*
 	 * Fail if we don't have enough data for the Hilscher pseudo-header,
@@ -346,14 +373,14 @@ netanalyzer_transparent_if_print(netdissect_options *ndo,
 
 int
 ethertype_print(netdissect_options *ndo,
-                u_short ether_type, const u_char *p,
-                u_int length, u_int caplen,
-                const struct lladdr_info *src, const struct lladdr_info *dst)
+		u_short ether_type, const u_char *p,
+		u_int length, u_int caplen,
+		const struct lladdr_info *src, const struct lladdr_info *dst)
 {
 	switch (ether_type) {
 
 	case ETHERTYPE_IP:
-	        ip_print(ndo, p, length);
+		ip_print(ndo, p, length);
 		return (1);
 
 	case ETHERTYPE_IPV6:
@@ -362,7 +389,7 @@ ethertype_print(netdissect_options *ndo,
 
 	case ETHERTYPE_ARP:
 	case ETHERTYPE_REVARP:
-	        arp_print(ndo, p, length, caplen);
+		arp_print(ndo, p, length, caplen);
 		return (1);
 
 	case ETHERTYPE_DN:
@@ -401,11 +428,11 @@ ethertype_print(netdissect_options *ndo,
 		return (1);
 
 	case ETHERTYPE_EAPOL:
-	        eap_print(ndo, p, length);
+		eap_print(ndo, p, length);
 		return (1);
 
 	case ETHERTYPE_RRCP:
-	        rrcp_print(ndo, p, length, src, dst);
+		rrcp_print(ndo, p, length, src, dst);
 		return (1);
 
 	case ETHERTYPE_PPP:
@@ -416,11 +443,11 @@ ethertype_print(netdissect_options *ndo,
 		return (1);
 
 	case ETHERTYPE_MPCP:
-	        mpcp_print(ndo, p, length);
+		mpcp_print(ndo, p, length);
 		return (1);
 
 	case ETHERTYPE_SLOW:
-	        slow_print(ndo, p, length);
+		slow_print(ndo, p, length);
 		return (1);
 
 	case ETHERTYPE_CFM:
@@ -432,13 +459,13 @@ ethertype_print(netdissect_options *ndo,
 		lldp_print(ndo, p, length);
 		return (1);
 
-        case ETHERTYPE_NSH:
-                nsh_print(ndo, p, length);
-                return (1);
+	case ETHERTYPE_NSH:
+		nsh_print(ndo, p, length);
+		return (1);
 
-        case ETHERTYPE_LOOPBACK:
+	case ETHERTYPE_LOOPBACK:
 		loopback_print(ndo, p, length);
-                return (1);
+		return (1);
 
 	case ETHERTYPE_MPLS:
 	case ETHERTYPE_MPLS_MULTI:
@@ -453,14 +480,14 @@ ethertype_print(netdissect_options *ndo,
 		msnlb_print(ndo, p);
 		return (1);
 
-        case ETHERTYPE_GEONET_OLD:
-        case ETHERTYPE_GEONET:
-                geonet_print(ndo, p, length, src);
-                return (1);
+	case ETHERTYPE_GEONET_OLD:
+	case ETHERTYPE_GEONET:
+		geonet_print(ndo, p, length, src);
+		return (1);
 
-        case ETHERTYPE_CALM_FAST:
-                calm_fast_print(ndo, p, length, src);
-                return (1);
+	case ETHERTYPE_CALM_FAST:
+		calm_fast_print(ndo, p, length, src);
+		return (1);
 
 	case ETHERTYPE_AOE:
 		aoe_print(ndo, p, length);