u-boot/net/ndisc.c

290 lines
7.9 KiB
C
Raw Normal View History

// SPDX-License-Identifier: GPL-2.0+
/*
* Copyright (C) 2013 Allied Telesis Labs NZ
* Chris Packham, <judge.packham@gmail.com>
*
* Copyright (C) 2022 YADRO
* Viacheslav Mitrofanov <v.v.mitrofanov@yadro.com>
*/
/* Neighbour Discovery for IPv6 */
#include <common.h>
#include <net.h>
#include <net6.h>
#include <ndisc.h>
/* IPv6 destination address of packet waiting for ND */
struct in6_addr net_nd_sol_packet_ip6 = ZERO_IPV6_ADDR;
/* IPv6 address we are expecting ND advert from */
static struct in6_addr net_nd_rep_packet_ip6 = ZERO_IPV6_ADDR;
/* MAC destination address of packet waiting for ND */
uchar *net_nd_packet_mac;
/* pointer to packet waiting to be transmitted after ND is resolved */
uchar *net_nd_tx_packet;
static uchar net_nd_packet_buf[PKTSIZE_ALIGN + PKTALIGN];
/* size of packet waiting to be transmitted */
int net_nd_tx_packet_size;
/* the timer for ND resolution */
ulong net_nd_timer_start;
/* the number of requests we have sent so far */
int net_nd_try;
#define IP6_NDISC_OPT_SPACE(len) (((len) + 2 + 7) & ~7)
/**
* ndisc_insert_option() - Insert an option into a neighbor discovery packet
*
* @ndisc: pointer to ND packet
* @type: option type to insert
* @data: option data to insert
* @len: data length
* Return: the number of bytes inserted (which may be >= len)
*/
static int
ndisc_insert_option(struct nd_msg *ndisc, int type, u8 *data, int len)
{
int space = IP6_NDISC_OPT_SPACE(len);
ndisc->opt[0] = type;
ndisc->opt[1] = space >> 3;
memcpy(&ndisc->opt[2], data, len);
len += 2;
/* fill the remainder with 0 */
if (space - len > 0)
memset(&ndisc->opt[len], '\0', space - len);
return space;
}
/**
* ndisc_extract_enetaddr() - Extract the Ethernet address from a ND packet
*
* Note that the link layer address could be anything but the only networking
* media that u-boot supports is Ethernet so we assume we're extracting a 6
* byte Ethernet MAC address.
*
* @ndisc: pointer to ND packet
* @enetaddr: extracted MAC addr
*/
static void ndisc_extract_enetaddr(struct nd_msg *ndisc, uchar enetaddr[6])
{
memcpy(enetaddr, &ndisc->opt[2], 6);
}
/**
* ndisc_has_option() - Check if the ND packet has the specified option set
*
* @ip6: pointer to IPv6 header
* @type: option type to check
* Return: 1 if ND has that option, 0 therwise
*/
static int ndisc_has_option(struct ip6_hdr *ip6, __u8 type)
{
struct nd_msg *ndisc = (struct nd_msg *)(((uchar *)ip6) + IP6_HDR_SIZE);
if (ip6->payload_len <= sizeof(struct icmp6hdr))
return 0;
return ndisc->opt[0] == type;
}
static void ip6_send_ns(struct in6_addr *neigh_addr)
{
struct in6_addr dst_adr;
unsigned char enetaddr[6];
struct nd_msg *msg;
__u16 len;
uchar *pkt;
unsigned short csum;
unsigned int pcsum;
debug("sending neighbor solicitation for %pI6c our address %pI6c\n",
neigh_addr, &net_link_local_ip6);
/* calculate src, dest IPv6 addr and dest Eth addr */
ip6_make_snma(&dst_adr, neigh_addr);
ip6_make_mult_ethdstaddr(enetaddr, &dst_adr);
len = sizeof(struct icmp6hdr) + IN6ADDRSZ +
IP6_NDISC_OPT_SPACE(INETHADDRSZ);
pkt = (uchar *)net_tx_packet;
pkt += net_set_ether(pkt, enetaddr, PROT_IP6);
pkt += ip6_add_hdr(pkt, &net_link_local_ip6, &dst_adr, PROT_ICMPV6,
IPV6_NDISC_HOPLIMIT, len);
/* ICMPv6 - NS */
msg = (struct nd_msg *)pkt;
msg->icmph.icmp6_type = IPV6_NDISC_NEIGHBOUR_SOLICITATION;
msg->icmph.icmp6_code = 0;
memset(&msg->icmph.icmp6_cksum, 0, sizeof(__be16));
memset(&msg->icmph.icmp6_unused, 0, sizeof(__be32));
/* Set the target address and llsaddr option */
net_copy_ip6(&msg->target, neigh_addr);
ndisc_insert_option(msg, ND_OPT_SOURCE_LL_ADDR, net_ethaddr,
INETHADDRSZ);
/* checksum */
pcsum = csum_partial((__u8 *)msg, len, 0);
csum = csum_ipv6_magic(&net_link_local_ip6, &dst_adr,
len, PROT_ICMPV6, pcsum);
msg->icmph.icmp6_cksum = csum;
pkt += len;
/* send it! */
net_send_packet(net_tx_packet, (pkt - net_tx_packet));
}
static void
ip6_send_na(uchar *eth_dst_addr, struct in6_addr *neigh_addr,
struct in6_addr *target)
{
struct nd_msg *msg;
__u16 len;
uchar *pkt;
unsigned short csum;
debug("sending neighbor advertisement for %pI6c to %pI6c (%pM)\n",
target, neigh_addr, eth_dst_addr);
len = sizeof(struct icmp6hdr) + IN6ADDRSZ +
IP6_NDISC_OPT_SPACE(INETHADDRSZ);
pkt = (uchar *)net_tx_packet;
pkt += net_set_ether(pkt, eth_dst_addr, PROT_IP6);
pkt += ip6_add_hdr(pkt, &net_link_local_ip6, neigh_addr,
PROT_ICMPV6, IPV6_NDISC_HOPLIMIT, len);
/* ICMPv6 - NA */
msg = (struct nd_msg *)pkt;
msg->icmph.icmp6_type = IPV6_NDISC_NEIGHBOUR_ADVERTISEMENT;
msg->icmph.icmp6_code = 0;
memset(&msg->icmph.icmp6_cksum, 0, sizeof(__be16));
memset(&msg->icmph.icmp6_unused, 0, sizeof(__be32));
msg->icmph.icmp6_dataun.u_nd_advt.solicited = 1;
msg->icmph.icmp6_dataun.u_nd_advt.override = 1;
/* Set the target address and lltargetaddr option */
net_copy_ip6(&msg->target, target);
ndisc_insert_option(msg, ND_OPT_TARGET_LL_ADDR, net_ethaddr,
INETHADDRSZ);
/* checksum */
csum = csum_ipv6_magic(&net_link_local_ip6,
neigh_addr, len, PROT_ICMPV6,
csum_partial((__u8 *)msg, len, 0));
msg->icmph.icmp6_cksum = csum;
pkt += len;
/* send it! */
net_send_packet(net_tx_packet, (pkt - net_tx_packet));
}
void ndisc_request(void)
{
if (!ip6_addr_in_subnet(&net_ip6, &net_nd_sol_packet_ip6,
net_prefix_length)) {
if (ip6_is_unspecified_addr(&net_gateway6)) {
puts("## Warning: gatewayip6 is needed but not set\n");
net_nd_rep_packet_ip6 = net_nd_sol_packet_ip6;
} else {
net_nd_rep_packet_ip6 = net_gateway6;
}
} else {
net_nd_rep_packet_ip6 = net_nd_sol_packet_ip6;
}
ip6_send_ns(&net_nd_rep_packet_ip6);
}
int ndisc_timeout_check(void)
{
ulong t;
if (ip6_is_unspecified_addr(&net_nd_sol_packet_ip6))
return 0;
t = get_timer(0);
/* check for NDISC timeout */
if ((t - net_nd_timer_start) > NDISC_TIMEOUT) {
net_nd_try++;
if (net_nd_try >= NDISC_TIMEOUT_COUNT) {
puts("\nNeighbour discovery retry count exceeded; "
"starting again\n");
net_nd_try = 0;
net_set_state(NETLOOP_FAIL);
} else {
net_nd_timer_start = t;
ndisc_request();
}
}
return 1;
}
void ndisc_init(void)
{
net_nd_packet_mac = NULL;
net_nd_tx_packet = NULL;
net_nd_sol_packet_ip6 = net_null_addr_ip6;
net_nd_rep_packet_ip6 = net_null_addr_ip6;
net_nd_tx_packet_size = 0;
net_nd_tx_packet = &net_nd_packet_buf[0] + (PKTALIGN - 1);
net_nd_tx_packet -= (ulong)net_nd_tx_packet % PKTALIGN;
}
int ndisc_receive(struct ethernet_hdr *et, struct ip6_hdr *ip6, int len)
{
struct icmp6hdr *icmp =
(struct icmp6hdr *)(((uchar *)ip6) + IP6_HDR_SIZE);
struct nd_msg *ndisc = (struct nd_msg *)icmp;
uchar neigh_eth_addr[6];
switch (icmp->icmp6_type) {
case IPV6_NDISC_NEIGHBOUR_SOLICITATION:
debug("received neighbor solicitation for %pI6c from %pI6c\n",
&ndisc->target, &ip6->saddr);
if (ip6_is_our_addr(&ndisc->target) &&
ndisc_has_option(ip6, ND_OPT_SOURCE_LL_ADDR)) {
ndisc_extract_enetaddr(ndisc, neigh_eth_addr);
ip6_send_na(neigh_eth_addr, &ip6->saddr,
&ndisc->target);
}
break;
case IPV6_NDISC_NEIGHBOUR_ADVERTISEMENT:
/* are we waiting for a reply ? */
if (ip6_is_unspecified_addr(&net_nd_sol_packet_ip6))
break;
if ((memcmp(&ndisc->target, &net_nd_rep_packet_ip6,
sizeof(struct in6_addr)) == 0) &&
ndisc_has_option(ip6, ND_OPT_TARGET_LL_ADDR)) {
ndisc_extract_enetaddr(ndisc, neigh_eth_addr);
/* save address for later use */
if (!net_nd_packet_mac)
memcpy(net_nd_packet_mac, neigh_eth_addr, 7);
/* modify header, and transmit it */
memcpy(((struct ethernet_hdr *)net_nd_tx_packet)->et_dest,
neigh_eth_addr, 6);
net_send_packet(net_nd_tx_packet,
net_nd_tx_packet_size);
/* no ND request pending now */
net_nd_sol_packet_ip6 = net_null_addr_ip6;
net_nd_tx_packet_size = 0;
net_nd_packet_mac = NULL;
}
break;
default:
debug("Unexpected ICMPv6 type 0x%x\n", icmp->icmp6_type);
return -1;
}
return 0;
}