/*
* 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(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)
{
struct ether_header *ep;
u_int orig_length;
u_short ether_type;
u_short extracted_ether_type;
if (caplen < ETHER_HDRLEN || length < ETHER_HDRLEN) {
ND_PRINT((ndo, "[|ether]"));
return;
}
if (ndo->ndo_eflag) {
if (print_encap_header != NULL)
(*print_encap_header)(ndo, encap_header_arg);
ether_hdr_print(ndo, p, length);
}
orig_length = length;
length -= ETHER_HDRLEN;
caplen -= ETHER_HDRLEN;
ep = (struct ether_header *)p;
p += ETHER_HDRLEN;
ether_type = EXTRACT_16BITS(&ep->ether_type);
recurse:
/*
* Is it (gag) an 802.3 encapsulation?
*/
if (ether_type <= ETHERMTU) {
/* Try to print the LLC-layer header & higher layers */
if (llc_print(ndo, p, length, caplen, ESRC(ep), EDST(ep),
&extracted_ether_type) == 0) {
/* ether_type not known, print raw packet */
if (!ndo->ndo_eflag) {
if (print_encap_header != NULL)
(*print_encap_header)(ndo, encap_header_arg);
ether_hdr_print(ndo, (u_char *)ep, orig_length);
}
if (!ndo->ndo_suppress_default_print)
ND_DEFAULTPRINT(p, caplen);
}
} else if (ether_type == ETHERTYPE_8021Q ||
ether_type == ETHERTYPE_8021Q9100 ||
ether_type == ETHERTYPE_8021Q9200 ||
ether_type == ETHERTYPE_8021QinQ) {
/*
* Print VLAN information, and then go back and process
* the enclosed type field.
*/
if (caplen < 4 || length < 4) {
ND_PRINT((ndo, "[|vlan]"));
return;
}
if (ndo->ndo_eflag) {
uint16_t tag = EXTRACT_16BITS(p);
ND_PRINT((ndo, "%s, ", ieee8021q_tci_string(tag)));
}
ether_type = EXTRACT_16BITS(p + 2);
if (ndo->ndo_eflag && ether_type > ETHERMTU)
ND_PRINT((ndo, "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(ndo, p, length, caplen, ESRC(ep), EDST(ep),
&extracted_ether_type) == 0) {
/* ether_type not known, print raw packet */
if (!ndo->ndo_eflag) {
if (print_encap_header != NULL)
(*print_encap_header)(ndo, encap_header_arg);
ether_hdr_print(ndo, (u_char *)ep, orig_length);
}
if (!ndo->ndo_suppress_default_print)
ND_DEFAULTPRINT(p, caplen);
}
} else {
if (ethertype_print(ndo, ether_type, p, length, caplen) == 0) {
/* ether_type not known, print raw packet */
if (!ndo->ndo_eflag) {
if (print_encap_header != NULL)
(*print_encap_header)(ndo, encap_header_arg);
ether_hdr_print(ndo, (u_char *)ep, orig_length);
}
if (!ndo->ndo_suppress_default_print)
ND_DEFAULTPRINT(p, caplen);
}
}
}
/*
* This is the top level routine of the printer. 'p' points to the
* Linux "cooked capture" header of the packet, 'h->ts' is the timestamp,
* 'h->len' is the length of the packet off the wire, and 'h->caplen'
* is the number of bytes actually captured.
*/
u_int
sll_if_print(netdissect_options *ndo, const struct pcap_pkthdr *h, const u_char *p)
{
u_int caplen = h->caplen;
u_int length = h->len;
register const struct sll_header *sllp;
u_short ether_type;
int llc_hdrlen;
u_int hdrlen;
if (caplen < SLL_HDR_LEN) {
/*
* XXX - this "can't happen" because "pcap-linux.c" always
* adds this many bytes of header to every packet in a
* cooked socket capture.
*/
ND_PRINT((ndo, "[|sll]"));
return (caplen);
}
sllp = (const struct sll_header *)p;
if (ndo->ndo_eflag)
sll_print(ndo, sllp, length);
/*
* Go past the cooked-mode header.
*/
length -= SLL_HDR_LEN;
caplen -= SLL_HDR_LEN;
p += SLL_HDR_LEN;
hdrlen = SLL_HDR_LEN;
ether_type = EXTRACT_16BITS(&sllp->sll_protocol);
recurse:
/*
* Is it (gag) an 802.3 encapsulation, or some non-Ethernet
* packet type?
*/
if (ether_type <= ETHERMTU) {
/*
* Yes - what type is it?
*/
switch (ether_type) {
case LINUX_SLL_P_802_3:
/*
* Ethernet_802.3 IPX frame.
*/
ipx_print(ndo, p, length);
break;
case LINUX_SLL_P_802_2:
/*
* 802.2.
* Try to print the LLC-layer header & higher layers.
*/
llc_hdrlen = llc_print(ndo, p, length, caplen, NULL, NULL);
if (llc_hdrlen < 0)
goto unknown; /* unknown LLC type */
hdrlen += llc_hdrlen;
break;
default:
/*FALLTHROUGH*/
unknown:
/* packet type not known, print raw packet */
if (!ndo->ndo_suppress_default_print)
ND_DEFAULTPRINT(p, caplen);
break;
}
} else if (ether_type == ETHERTYPE_8021Q) {
/*
* Print VLAN information, and then go back and process
* the enclosed type field.
*/
if (caplen < 4) {
ND_PRINT((ndo, "[|vlan]"));
return (hdrlen + caplen);
}
if (length < 4) {
ND_PRINT((ndo, "[|vlan]"));
return (hdrlen + length);
}
if (ndo->ndo_eflag) {
uint16_t tag = EXTRACT_16BITS(p);
ND_PRINT((ndo, "%s, ", ieee8021q_tci_string(tag)));
}
ether_type = EXTRACT_16BITS(p + 2);
if (ether_type <= ETHERMTU)
ether_type = LINUX_SLL_P_802_2;
if (!ndo->ndo_qflag) {
ND_PRINT((ndo, "ethertype %s, ",
tok2str(ethertype_values, "Unknown", ether_type)));
}
p += 4;
length -= 4;
caplen -= 4;
hdrlen += 4;
goto recurse;
} else {
if (ethertype_print(ndo, ether_type, p, length, caplen) == 0) {
/* ether_type not known, print raw packet */
if (!ndo->ndo_eflag)
sll_print(ndo, sllp, length + SLL_HDR_LEN);
if (!ndo->ndo_suppress_default_print)
ND_DEFAULTPRINT(p, caplen);
}
}
return (hdrlen);
}
