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// SPDX-License-Identifier: GPL-2.0
/*
* Copied from Linux Monitor (LiMon) - Networking.
*
* Copyright 1994 - 2000 Neil Russell.
* (See License)
* Copyright 2000 Roland Borde
* Copyright 2000 Paolo Scaffardi
* Copyright 2000-2002 Wolfgang Denk, wd@denx.de
*/
#include <common.h>
#include <net.h>
#if defined(CONFIG_CDP_VERSION)
#include <timestamp.h>
#endif
#include "cdp.h"
/* Ethernet bcast address */
const u8 net_cdp_ethaddr[6] = { 0x01, 0x00, 0x0c, 0xcc, 0xcc, 0xcc };
#define CDP_DEVICE_ID_TLV 0x0001
#define CDP_ADDRESS_TLV 0x0002
#define CDP_PORT_ID_TLV 0x0003
#define CDP_CAPABILITIES_TLV 0x0004
#define CDP_VERSION_TLV 0x0005
#define CDP_PLATFORM_TLV 0x0006
#define CDP_NATIVE_VLAN_TLV 0x000a
#define CDP_APPLIANCE_VLAN_TLV 0x000e
#define CDP_TRIGGER_TLV 0x000f
#define CDP_POWER_CONSUMPTION_TLV 0x0010
#define CDP_SYSNAME_TLV 0x0014
#define CDP_SYSOBJECT_TLV 0x0015
#define CDP_MANAGEMENT_ADDRESS_TLV 0x0016
#define CDP_TIMEOUT 250UL /* one packet every 250ms */
static int cdp_seq;
static int cdp_ok;
ushort cdp_native_vlan;
ushort cdp_appliance_vlan;
static const uchar cdp_snap_hdr[8] = {
0xAA, 0xAA, 0x03, 0x00, 0x00, 0x0C, 0x20, 0x00 };
static ushort cdp_compute_csum(const uchar *buff, ushort len)
{
ushort csum;
int odd;
ulong result = 0;
ushort leftover;
ushort *p;
if (len > 0) {
odd = 1 & (ulong)buff;
if (odd) {
result = *buff << 8;
len--;
buff++;
}
while (len > 1) {
p = (ushort *)buff;
result += *p++;
buff = (uchar *)p;
if (result & 0x80000000)
result = (result & 0xFFFF) + (result >> 16);
len -= 2;
}
if (len) {
leftover = (signed short)(*(const signed char *)buff);
/*
* CISCO SUCKS big time! (and blows too):
* CDP uses the IP checksum algorithm with a twist;
* for the last byte it *sign* extends and sums.
*/
result = (result & 0xffff0000) |
((result + leftover) & 0x0000ffff);
}
while (result >> 16)
result = (result & 0xFFFF) + (result >> 16);
if (odd)
result = ((result >> 8) & 0xff) |
((result & 0xff) << 8);
}
/* add up 16-bit and 17-bit words for 17+c bits */
result = (result & 0xffff) + (result >> 16);
/* add up 16-bit and 2-bit for 16+c bit */
result = (result & 0xffff) + (result >> 16);
/* add up carry.. */
result = (result & 0xffff) + (result >> 16);
/* negate */
csum = ~(ushort)result;
/* run time endian detection */
if (csum != htons(csum)) /* little endian */
csum = htons(csum);
return csum;
}
static int cdp_send_trigger(void)
{
uchar *pkt;
ushort *s;
ushort *cp;
struct ethernet_hdr *et;
int len;
ushort chksum;
#if defined(CONFIG_CDP_DEVICE_ID) || defined(CONFIG_CDP_PORT_ID) || \
defined(CONFIG_CDP_VERSION) || defined(CONFIG_CDP_PLATFORM)
char buf[32];
#endif
pkt = net_tx_packet;
et = (struct ethernet_hdr *)pkt;
/* NOTE: trigger sent not on any VLAN */
/* form ethernet header */
memcpy(et->et_dest, net_cdp_ethaddr, 6);
memcpy(et->et_src, net_ethaddr, 6);
pkt += ETHER_HDR_SIZE;
/* SNAP header */
memcpy((uchar *)pkt, cdp_snap_hdr, sizeof(cdp_snap_hdr));
pkt += sizeof(cdp_snap_hdr);
/* CDP header */
*pkt++ = 0x02; /* CDP version 2 */
*pkt++ = 180; /* TTL */
s = (ushort *)pkt;
cp = s;
/* checksum (0 for later calculation) */
*s++ = htons(0);
/* CDP fields */
#ifdef CONFIG_CDP_DEVICE_ID
*s++ = htons(CDP_DEVICE_ID_TLV);
*s++ = htons(CONFIG_CDP_DEVICE_ID);
sprintf(buf, CONFIG_CDP_DEVICE_ID_PREFIX "%pm", net_ethaddr);
memcpy((uchar *)s, buf, 16);
s += 16 / 2;
#endif
#ifdef CONFIG_CDP_PORT_ID
*s++ = htons(CDP_PORT_ID_TLV);
memset(buf, 0, sizeof(buf));
sprintf(buf, CONFIG_CDP_PORT_ID, eth_get_dev_index());
len = strlen(buf);
if (len & 1) /* make it even */
len++;
*s++ = htons(len + 4);
memcpy((uchar *)s, buf, len);
s += len / 2;
#endif
#ifdef CONFIG_CDP_CAPABILITIES
*s++ = htons(CDP_CAPABILITIES_TLV);
*s++ = htons(8);
*(ulong *)s = htonl(CONFIG_CDP_CAPABILITIES);
s += 2;
#endif
#ifdef CONFIG_CDP_VERSION
*s++ = htons(CDP_VERSION_TLV);
memset(buf, 0, sizeof(buf));
strcpy(buf, CONFIG_CDP_VERSION);
len = strlen(buf);
if (len & 1) /* make it even */
len++;
*s++ = htons(len + 4);
memcpy((uchar *)s, buf, len);
s += len / 2;
#endif
#ifdef CONFIG_CDP_PLATFORM
*s++ = htons(CDP_PLATFORM_TLV);
memset(buf, 0, sizeof(buf));
strcpy(buf, CONFIG_CDP_PLATFORM);
len = strlen(buf);
if (len & 1) /* make it even */
len++;
*s++ = htons(len + 4);
memcpy((uchar *)s, buf, len);
s += len / 2;
#endif
#ifdef CONFIG_CDP_TRIGGER
*s++ = htons(CDP_TRIGGER_TLV);
*s++ = htons(8);
*(ulong *)s = htonl(CONFIG_CDP_TRIGGER);
s += 2;
#endif
#ifdef CONFIG_CDP_POWER_CONSUMPTION
*s++ = htons(CDP_POWER_CONSUMPTION_TLV);
*s++ = htons(6);
*s++ = htons(CONFIG_CDP_POWER_CONSUMPTION);
#endif
/* length of ethernet packet */
len = (uchar *)s - ((uchar *)net_tx_packet + ETHER_HDR_SIZE);
et->et_protlen = htons(len);
len = ETHER_HDR_SIZE + sizeof(cdp_snap_hdr);
chksum = cdp_compute_csum((uchar *)net_tx_packet + len,
(uchar *)s - (net_tx_packet + len));
if (chksum == 0)
chksum = 0xFFFF;
*cp = htons(chksum);
net_send_packet(net_tx_packet, (uchar *)s - net_tx_packet);
return 0;
}
static void cdp_timeout_handler(void)
{
cdp_seq++;
if (cdp_seq < 3) {
net_set_timeout_handler(CDP_TIMEOUT, cdp_timeout_handler);
cdp_send_trigger();
return;
}
/* if not OK try again */
if (!cdp_ok)
net_start_again();
else
net_set_state(NETLOOP_SUCCESS);
}
void cdp_receive(const uchar *pkt, unsigned len)
{
const uchar *t;
const ushort *ss;
ushort type, tlen;
ushort vlan, nvlan;
/* minimum size? */
if (len < sizeof(cdp_snap_hdr) + 4)
goto pkt_short;
/* check for valid CDP SNAP header */
if (memcmp(pkt, cdp_snap_hdr, sizeof(cdp_snap_hdr)) != 0)
return;
pkt += sizeof(cdp_snap_hdr);
len -= sizeof(cdp_snap_hdr);
/* Version of CDP protocol must be >= 2 and TTL != 0 */
if (pkt[0] < 0x02 || pkt[1] == 0)
return;
/*
* if version is greater than 0x02 maybe we'll have a problem;
* output a warning
*/
if (pkt[0] != 0x02)
printf("**WARNING: CDP packet received with a protocol version "
"%d > 2\n", pkt[0] & 0xff);
if (cdp_compute_csum(pkt, len) != 0)
return;
pkt += 4;
len -= 4;
vlan = htons(-1);
nvlan = htons(-1);
while (len > 0) {
if (len < 4)
goto pkt_short;
ss = (const ushort *)pkt;
type = ntohs(ss[0]);
tlen = ntohs(ss[1]);
if (tlen > len)
goto pkt_short;
pkt += tlen;
len -= tlen;
ss += 2; /* point ss to the data of the TLV */
tlen -= 4;
switch (type) {
case CDP_DEVICE_ID_TLV:
break;
case CDP_ADDRESS_TLV:
break;
case CDP_PORT_ID_TLV:
break;
case CDP_CAPABILITIES_TLV:
break;
case CDP_VERSION_TLV:
break;
case CDP_PLATFORM_TLV:
break;
case CDP_NATIVE_VLAN_TLV:
nvlan = *ss;
break;
case CDP_APPLIANCE_VLAN_TLV:
t = (const uchar *)ss;
while (tlen > 0) {
if (tlen < 3)
goto pkt_short;
ss = (const ushort *)(t + 1);
#ifdef CONFIG_CDP_APPLIANCE_VLAN_TYPE
if (t[0] == CONFIG_CDP_APPLIANCE_VLAN_TYPE)
vlan = *ss;
#else
/* XXX will this work; dunno */
vlan = ntohs(*ss);
#endif
t += 3; tlen -= 3;
}
break;
case CDP_TRIGGER_TLV:
break;
case CDP_POWER_CONSUMPTION_TLV:
break;
case CDP_SYSNAME_TLV:
break;
case CDP_SYSOBJECT_TLV:
break;
case CDP_MANAGEMENT_ADDRESS_TLV:
break;
}
}
cdp_appliance_vlan = vlan;
cdp_native_vlan = nvlan;
cdp_ok = 1;
return;
pkt_short:
printf("** CDP packet is too short\n");
return;
}
void cdp_start(void)
{
printf("Using %s device\n", eth_get_name());
cdp_seq = 0;
cdp_ok = 0;
cdp_native_vlan = htons(-1);
cdp_appliance_vlan = htons(-1);
net_set_timeout_handler(CDP_TIMEOUT, cdp_timeout_handler);
cdp_send_trigger();
}