(void)printf(", length %u: ", length);
}
+/*
+ * 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.
+ */
void
-ether_print(const u_char *p, u_int length, u_int caplen)
+ether_print(const u_char *p, u_int length, u_int caplen,
+ void (*print_encap_header)(const u_char *), const u_char *encap_header_arg)
{
struct ether_header *ep;
+ u_int orig_length;
u_short ether_type;
u_short extracted_ether_type;
- if (caplen < ETHER_HDRLEN) {
+ if (caplen < ETHER_HDRLEN || length < ETHER_HDRLEN) {
printf("[|ether]");
return;
}
- if (eflag)
+ if (eflag) {
+ if (print_encap_header != NULL)
+ (*print_encap_header)(encap_header_arg);
ether_hdr_print(p, length);
+ }
+ orig_length = length;
length -= ETHER_HDRLEN;
caplen -= ETHER_HDRLEN;
ether_type = EXTRACT_16BITS(&ep->ether_type);
+recurse:
/*
* Is it (gag) an 802.3 encapsulation?
*/
if (llc_print(p, length, caplen, ESRC(ep), EDST(ep),
&extracted_ether_type) == 0) {
/* ether_type not known, print raw packet */
- if (!eflag)
- ether_hdr_print((u_char *)ep, length + ETHER_HDRLEN);
+ if (!eflag) {
+ if (print_encap_header != NULL)
+ (*print_encap_header)(encap_header_arg);
+ ether_hdr_print((u_char *)ep, orig_length);
+ }
+
+ if (!suppress_default_print)
+ default_print(p, caplen);
+ }
+ } else if (ether_type == ETHERTYPE_8021Q) {
+ /*
+ * Print VLAN information, and then go back and process
+ * the enclosed type field.
+ */
+ if (caplen < 4 || length < 4) {
+ printf("[|vlan]");
+ return;
+ }
+ if (eflag) {
+ u_int16_t tag = EXTRACT_16BITS(p);
+
+ printf("vlan %u, p %u%s, ",
+ tag & 0xfff,
+ tag >> 13,
+ (tag & 0x1000) ? ", CFI" : "");
+ }
+
+ ether_type = EXTRACT_16BITS(p + 2);
+ if (eflag && ether_type > ETHERMTU)
+ printf("ethertype %s, ", tok2str(ethertype_values,"0x%04x", ether_type));
+ p += 4;
+ length -= 4;
+ caplen -= 4;
+ goto recurse;
+ } else if (ether_type == ETHERTYPE_JUMBO) {
+ /*
+ * Alteon jumbo frames.
+ * See
+ *
+ * http://tools.ietf.org/html/draft-ietf-isis-ext-eth-01
+ *
+ * which indicates that, following the type field,
+ * there's an LLC header and payload.
+ */
+ /* Try to print the LLC-layer header & higher layers */
+ if (llc_print(p, length, caplen, ESRC(ep), EDST(ep),
+ &extracted_ether_type) == 0) {
+ /* ether_type not known, print raw packet */
+ if (!eflag) {
+ if (print_encap_header != NULL)
+ (*print_encap_header)(encap_header_arg);
+ ether_hdr_print((u_char *)ep, orig_length);
+ }
+
+ if (!suppress_default_print)
+ default_print(p, caplen);
+ }
+ } else {
+ if (ethertype_print(ether_type, p, length, caplen) == 0) {
+ /* ether_type not known, print raw packet */
+ if (!eflag) {
+ if (print_encap_header != NULL)
+ (*print_encap_header)(encap_header_arg);
+ ether_hdr_print((u_char *)ep, orig_length);
+ }
if (!suppress_default_print)
default_print(p, caplen);
}
- } else if (ether_encap_print(ether_type, p, length, caplen,
- &extracted_ether_type) == 0) {
- /* ether_type not known, print raw packet */
- if (!eflag)
- ether_hdr_print((u_char *)ep, length + ETHER_HDRLEN);
-
- if (!suppress_default_print)
- default_print(p, caplen);
- }
+ }
}
/*
u_int
ether_if_print(const struct pcap_pkthdr *h, const u_char *p)
{
- ether_print(p, h->len, h->caplen);
+ ether_print(p, h->len, h->caplen, NULL, NULL);
return (ETHER_HDRLEN);
}
/*
- * Prints the packet encapsulated in an Ethernet data segment
- * (or an equivalent encapsulation), given the Ethernet type code.
+ * Prints the packet payload, given an Ethernet type code for the payload's
+ * protocol.
*
* Returns non-zero if it can do so, zero if the ethertype is unknown.
- *
- * The Ethernet type code is passed through a pointer; if it was
- * ETHERTYPE_8021Q, it gets updated to be the Ethernet type of
- * the 802.1Q payload, for the benefit of lower layers that might
- * want to know what it is.
*/
int
-ether_encap_print(u_short ether_type, const u_char *p,
- u_int length, u_int caplen, u_short *extracted_ether_type)
+ethertype_print(u_short ether_type, const u_char *p, u_int length, u_int caplen)
{
- recurse:
- *extracted_ether_type = ether_type;
-
switch (ether_type) {
case ETHERTYPE_IP:
ipx_print(p, length);
return (1);
- case ETHERTYPE_8021Q:
- if (eflag) {
- u_int16_t tag = EXTRACT_16BITS(p);
-
- printf("vlan %u, p %u%s, ",
- tag & 0xfff,
- tag >> 13,
- (tag & 0x1000) ? ", CFI" : "");
- }
-
- ether_type = EXTRACT_16BITS(p + 2);
- p += 4;
- length -= 4;
- caplen -= 4;
-
- if (ether_type > ETHERMTU) {
- if (eflag)
- printf("ethertype %s, ",
- tok2str(ethertype_values,"0x%04x", ether_type));
- goto recurse;
- }
-
- *extracted_ether_type = 0;
-
- if (llc_print(p, length, caplen, p - 18, p - 12,
- extracted_ether_type) == 0) {
- ether_hdr_print(p - 18, length + 4);
-
- if (!suppress_default_print) {
- default_print(p - 18, caplen + 4);
- }
- }
-
-
- return (1);
-
- case ETHERTYPE_JUMBO:
- ether_type = EXTRACT_16BITS(p);
- p += 2;
- length -= 2;
- caplen -= 2;
-
- if (ether_type > ETHERMTU) {
- if (eflag)
- printf("ethertype %s, ",
- tok2str(ethertype_values,"0x%04x", ether_type));
- goto recurse;
- }
-
- *extracted_ether_type = 0;
-
- if (llc_print(p, length, caplen, p - 16, p - 10,
- extracted_ether_type) == 0) {
- ether_hdr_print(p - 16, length + 2);
-
- if (!suppress_default_print) {
- default_print(p - 16, caplen + 2);
- }
- }
-
- return (1);
-
case ETHERTYPE_ISO:
isoclns_print(p+1, length-1, length-1);
return(1);
projects / tcpdump / blobdiff