/*
* Returns non-zero IFF it succeeds in printing the header
*/
int
llc_print(const u_char *p, u_int length, u_int caplen,
const u_char *esrc, const u_char *edst, u_short *extracted_ethertype)
{
u_int8_t dsap, ssap;
u_int16_t control;
int is_u;
register int ret;
if (caplen < 3) {
(void)printf("[|llc]");
default_print((u_char *)p, caplen);
return(0);
}
dsap = *p;
ssap = *(p + 1);
/*
* OK, what type of LLC frame is this? The length
* of the control field depends on that - I frames
* have a two-byte control field, and U frames have
* a one-byte control field.
*/
control = *(p + 2);
if ((control & LLC_U_FMT) == LLC_U_FMT) {
/*
* U frame.
*/
is_u = 1;
} else {
/*
* The control field in I and S frames is
* 2 bytes...
*/
if (caplen < 4) {
(void)printf("[|llc]");
default_print((u_char *)p, caplen);
return(0);
}
/*
* ...and is little-endian.
*/
control = EXTRACT_LE_16BITS(p + 2);
is_u = 0;
}
#if !defined(EMBED) || defined(CONFIG_IPX) || defined(CONFIG_IPX_MODULE)
if (ssap == LLCSAP_GLOBAL && dsap == LLCSAP_GLOBAL) {
/*
* This is an Ethernet_802.3 IPX frame; it has an
* 802.3 header (i.e., an Ethernet header where the
* type/length field is <= ETHERMTU, i.e. it's a length
* field, not a type field), but has no 802.2 header -
* the IPX packet starts right after the Ethernet header,
* with a signature of two bytes of 0xFF (which is
* LLCSAP_GLOBAL).
*
* (It might also have been an Ethernet_802.3 IPX at
* one time, but got bridged onto another network,
* such as an 802.11 network; this has appeared in at
* least one capture file.)
*/
if (eflag)
printf("IPX-802.3: ");
ipx_print(p, length);
return (1);
}
#endif
if (eflag) {
if (is_u) {
printf("LLC, dsap %s (0x%02x), ssap %s (0x%02x), cmd 0x%02x: ",
tok2str(llc_values, "Unknown", dsap),
dsap,
tok2str(llc_values, "Unknown", ssap),
ssap,
control);
} else {
printf("LLC, dsap %s (0x%02x), ssap %s (0x%02x), cmd 0x%04x: ",
tok2str(llc_values, "Unknown", dsap),
dsap,
tok2str(llc_values, "Unknown", ssap),
ssap,
control);
}
}
#if !defined(EMBED) || defined(CONFIG_BRIDGE) || defined(CONFIG_BRIDGE_MODULE)
if (ssap == LLCSAP_8021D && dsap == LLCSAP_8021D &&
control == LLC_UI) {
stp_print(p+3, length-3);
return (1);
}
#endif
if (ssap == LLCSAP_IP && dsap == LLCSAP_IP &&
control == LLC_UI) {
ip_print(gndo, p+4, length-4);
return (1);
}
#if !defined(EMBED) || defined(CONFIG_IPX) || defined(CONFIG_IPX_MODULE)
if (ssap == LLCSAP_IPX && dsap == LLCSAP_IPX &&
control == LLC_UI) {
/*
* This is an Ethernet_802.2 IPX frame, with an 802.3
* header and an 802.2 LLC header with the source and
* destination SAPs being the IPX SAP.
*
* Skip DSAP, LSAP, and control field.
*/
printf("(NOV-802.2) ");
ipx_print(p+3, length-3);
return (1);
}
#endif
#ifdef TCPDUMP_DO_SMB
if (ssap == LLCSAP_NETBEUI && dsap == LLCSAP_NETBEUI
&& (!(control & LLC_S_FMT) || control == LLC_U_FMT)) {
/*
* we don't actually have a full netbeui parser yet, but the
* smb parser can handle many smb-in-netbeui packets, which
* is very useful, so we call that
*
* We don't call it for S frames, however, just I frames
* (which are frames that don't have the low-order bit,
* LLC_S_FMT, set in the first byte of the control field)
* and UI frames (whose control field is just 3, LLC_U_FMT).
*/
/*
* Skip the LLC header.
*/
if (is_u) {
p += 3;
length -= 3;
caplen -= 3;
} else {
p += 4;
length -= 4;
caplen -= 4;
}
netbeui_print(control, p, length);
return (1);
}
#endif
#if !defined(EMBED)
if (ssap == LLCSAP_ISONS && dsap == LLCSAP_ISONS
&& control == LLC_UI) {
isoclns_print(p + 3, length - 3, caplen - 3);
return (1);
}
#endif
if (ssap == LLCSAP_SNAP && dsap == LLCSAP_SNAP
&& control == LLC_UI) {
/*
* XXX - what *is* the right bridge pad value here?
* Does anybody ever bridge one form of LAN traffic
* over a networking type that uses 802.2 LLC?
*/
ret = snap_print(p+3, length-3, caplen-3, extracted_ethertype,
2);
if (ret)
return (ret);
}
if (!eflag) {
if ((ssap & ~LLC_GSAP) == dsap) {
if (esrc == NULL || edst == NULL)
(void)printf("%s ", llcsap_string(dsap));
else
(void)printf("%s > %s %s ",
etheraddr_string(esrc),
etheraddr_string(edst),
llcsap_string(dsap));
} else {
if (esrc == NULL || edst == NULL)
(void)printf("%s > %s ",
llcsap_string(ssap & ~LLC_GSAP),
llcsap_string(dsap));
else
(void)printf("%s %s > %s %s ",
etheraddr_string(esrc),
llcsap_string(ssap & ~LLC_GSAP),
etheraddr_string(edst),
llcsap_string(dsap));
}
}
if (is_u) {
const char *m;
char f;
m = tok2str(cmd2str, "%02x", LLC_U_CMD(control));
switch ((ssap & LLC_GSAP) | (control & LLC_U_POLL)) {
case 0: f = 'C'; break;
case LLC_GSAP: f = 'R'; break;
case LLC_U_POLL: f = 'P'; break;
case LLC_GSAP|LLC_U_POLL: f = 'F'; break;
default: f = '?'; break;
}
printf("%s/%c", m, f);
p += 3;
length -= 3;
caplen -= 3;
if ((control & ~LLC_U_POLL) == LLC_XID) {
if (*p == LLC_XID_FI) {
printf(": %02x %02x", p[1], p[2]);
p += 3;
length -= 3;
caplen -= 3;
}
}
} else {
char f;
switch ((ssap & LLC_GSAP) | (control & LLC_IS_POLL)) {
case 0: f = 'C'; break;
case LLC_GSAP: f = 'R'; break;
case LLC_IS_POLL: f = 'P'; break;
case LLC_GSAP|LLC_IS_POLL: f = 'F'; break;
default: f = '?'; break;
}
if ((control & LLC_S_FMT) == LLC_S_FMT) {
static const char *llc_s[] = { "rr", "rej", "rnr", "03" };
(void)printf("%s (r=%d,%c)",
llc_s[LLC_S_CMD(control)],
LLC_IS_NR(control),
f);
} else {
(void)printf("I (s=%d,r=%d,%c)",
LLC_I_NS(control),
LLC_IS_NR(control),
f);
}
p += 4;
length -= 4;
caplen -= 4;
}
return(1);
}
/*
* Returns non-zero IFF it succeeds in printing the header
*/
int
llc_print(const u_char *p, u_int length, u_int caplen,
const u_char *esrc, const u_char *edst)
{
struct llc llc;
register u_short et;
register int ret;
if (caplen < 3) {
(void)printf("[|llc]");
default_print((u_char *)p, caplen);
return(0);
}
/* Watch out for possible alignment problems */
memcpy((char *)&llc, (char *)p, min(caplen, sizeof(llc)));
if (llc.ssap == LLCSAP_GLOBAL && llc.dsap == LLCSAP_GLOBAL) {
ipx_print(p, length);
return (1);
}
#ifdef notyet
else if (p[0] == 0xf0 && p[1] == 0xf0)
netbios_print(p, length);
#endif
if (llc.ssap == LLCSAP_ISONS && llc.dsap == LLCSAP_ISONS
&& llc.llcui == LLC_UI) {
isoclns_print(p + 3, length - 3, caplen - 3, esrc, edst);
return (1);
}
if (llc.ssap == LLCSAP_SNAP && llc.dsap == LLCSAP_SNAP
&& llc.llcui == LLC_UI) {
if (caplen < sizeof(llc)) {
(void)printf("[|llc-snap]");
default_print((u_char *)p, caplen);
return (0);
}
if (vflag)
(void)printf("snap %s ", protoid_string(llc.llcpi));
caplen -= sizeof(llc);
length -= sizeof(llc);
p += sizeof(llc);
/* This is an encapsulated Ethernet packet */
et = EXTRACT_16BITS(&llc.ethertype[0]);
ret = ether_encap_print(et, p, length, caplen);
if (ret)
return (ret);
}
if ((llc.ssap & ~LLC_GSAP) == llc.dsap) {
if (eflag)
(void)printf("%s ", llcsap_string(llc.dsap));
else
(void)printf("%s > %s %s ",
etheraddr_string(esrc),
etheraddr_string(edst),
llcsap_string(llc.dsap));
} else {
if (eflag)
(void)printf("%s > %s ",
llcsap_string(llc.ssap & ~LLC_GSAP),
llcsap_string(llc.dsap));
else
(void)printf("%s %s > %s %s ",
etheraddr_string(esrc),
llcsap_string(llc.ssap & ~LLC_GSAP),
etheraddr_string(edst),
llcsap_string(llc.dsap));
}
if ((llc.llcu & LLC_U_FMT) == LLC_U_FMT) {
const char *m;
char f;
m = tok2str(cmd2str, "%02x", LLC_U_CMD(llc.llcu));
switch ((llc.ssap & LLC_GSAP) | (llc.llcu & LLC_U_POLL)) {
case 0: f = 'C'; break;
case LLC_GSAP: f = 'R'; break;
case LLC_U_POLL: f = 'P'; break;
case LLC_GSAP|LLC_U_POLL: f = 'F'; break;
default: f = '?'; break;
}
printf("%s/%c", m, f);
p += 3;
length -= 3;
caplen -= 3;
if ((llc.llcu & ~LLC_U_POLL) == LLC_XID) {
if (*p == LLC_XID_FI) {
printf(": %02x %02x", p[1], p[2]);
p += 3;
length -= 3;
caplen -= 3;
}
}
} else {
char f;
llc.llcis = ntohs(llc.llcis);
switch ((llc.ssap & LLC_GSAP) | (llc.llcu & LLC_U_POLL)) {
case 0: f = 'C'; break;
case LLC_GSAP: f = 'R'; break;
case LLC_U_POLL: f = 'P'; break;
case LLC_GSAP|LLC_U_POLL: f = 'F'; break;
default: f = '?'; break;
}
if ((llc.llcu & LLC_S_FMT) == LLC_S_FMT) {
static char *llc_s[] = { "rr", "rej", "rnr", "03" };
(void)printf("%s (r=%d,%c)",
llc_s[LLC_S_CMD(llc.llcis)],
LLC_IS_NR(llc.llcis),
f);
} else {
(void)printf("I (s=%d,r=%d,%c)",
LLC_I_NS(llc.llcis),
LLC_IS_NR(llc.llcis),
f);
}
p += 4;
length -= 4;
caplen -= 4;
}
(void)printf(" len=%d", length);
if (caplen > 0) {
default_print_unaligned(p, caplen);
}
return(1);
}
