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/*
* Neighbor Discovery snooping for Proxy ARP
* Copyright (c) 2014, Qualcomm Atheros, Inc.
*
* This software may be distributed under the terms of the BSD license.
* See README for more details.
*/
#include "utils/includes.h"
#include <netinet/ip6.h>
#include <netinet/icmp6.h>
#include "utils/common.h"
#include "l2_packet/l2_packet.h"
#include "hostapd.h"
#include "sta_info.h"
#include "ap_drv_ops.h"
#include "list.h"
#include "x_snoop.h"
#include "ndisc_snoop.h"
struct ip6addr {
struct in6_addr addr;
struct dl_list list;
};
struct icmpv6_ndmsg {
struct ip6_hdr ipv6h;
struct icmp6_hdr icmp6h;
struct in6_addr target_addr;
u8 opt_type;
u8 len;
u8 opt_lladdr[0];
} STRUCT_PACKED;
#define ROUTER_ADVERTISEMENT 134
#define NEIGHBOR_SOLICITATION 135
#define NEIGHBOR_ADVERTISEMENT 136
#define SOURCE_LL_ADDR 1
static int sta_ip6addr_add(struct sta_info *sta, struct in6_addr *addr)
{
struct ip6addr *ip6addr;
ip6addr = os_zalloc(sizeof(*ip6addr));
if (!ip6addr)
return -1;
os_memcpy(&ip6addr->addr, addr, sizeof(*addr));
dl_list_add_tail(&sta->ip6addr, &ip6addr->list);
return 0;
}
void sta_ip6addr_del(struct hostapd_data *hapd, struct sta_info *sta)
{
struct ip6addr *ip6addr, *prev;
dl_list_for_each_safe(ip6addr, prev, &sta->ip6addr, struct ip6addr,
list) {
hostapd_drv_br_delete_ip_neigh(hapd, 6, (u8 *) &ip6addr->addr);
os_free(ip6addr);
}
}
static int sta_has_ip6addr(struct sta_info *sta, struct in6_addr *addr)
{
struct ip6addr *ip6addr;
dl_list_for_each(ip6addr, &sta->ip6addr, struct ip6addr, list) {
if (ip6addr->addr.s6_addr32[0] == addr->s6_addr32[0] &&
ip6addr->addr.s6_addr32[1] == addr->s6_addr32[1] &&
ip6addr->addr.s6_addr32[2] == addr->s6_addr32[2] &&
ip6addr->addr.s6_addr32[3] == addr->s6_addr32[3])
return 1;
}
return 0;
}
static void ucast_to_stas(struct hostapd_data *hapd, const u8 *buf, size_t len)
{
struct sta_info *sta;
for (sta = hapd->sta_list; sta; sta = sta->next) {
if (!(sta->flags & WLAN_STA_AUTHORIZED))
continue;
x_snoop_mcast_to_ucast_convert_send(hapd, sta, (u8 *) buf, len);
}
}
static void handle_ndisc(void *ctx, const u8 *src_addr, const u8 *buf,
size_t len)
{
struct hostapd_data *hapd = ctx;
struct icmpv6_ndmsg *msg;
struct in6_addr saddr;
struct sta_info *sta;
int res;
char addrtxt[INET6_ADDRSTRLEN + 1];
if (len < ETH_HLEN + sizeof(struct ip6_hdr) + sizeof(struct icmp6_hdr))
return;
msg = (struct icmpv6_ndmsg *) &buf[ETH_HLEN];
switch (msg->icmp6h.icmp6_type) {
case NEIGHBOR_SOLICITATION:
if (len < ETH_HLEN + sizeof(*msg))
return;
if (msg->opt_type != SOURCE_LL_ADDR)
return;
/*
* IPv6 header may not be 32-bit aligned in the buffer, so use
* a local copy to avoid unaligned reads.
*/
os_memcpy(&saddr, &msg->ipv6h.ip6_src, sizeof(saddr));
if (!(saddr.s6_addr32[0] == 0 && saddr.s6_addr32[1] == 0 &&
saddr.s6_addr32[2] == 0 && saddr.s6_addr32[3] == 0)) {
if (len < ETH_HLEN + sizeof(*msg) + ETH_ALEN)
return;
sta = ap_get_sta(hapd, msg->opt_lladdr);
if (!sta)
return;
if (sta_has_ip6addr(sta, &saddr))
return;
if (inet_ntop(AF_INET6, &saddr, addrtxt,
sizeof(addrtxt)) == NULL)
addrtxt[0] = '\0';
wpa_printf(MSG_DEBUG, "ndisc_snoop: Learned new IPv6 address %s for "
MACSTR, addrtxt, MAC2STR(sta->addr));
hostapd_drv_br_delete_ip_neigh(hapd, 6, (u8 *) &saddr);
res = hostapd_drv_br_add_ip_neigh(hapd, 6,
(u8 *) &saddr,
128, sta->addr);
if (res) {
wpa_printf(MSG_ERROR,
"ndisc_snoop: Adding ip neigh failed: %d",
res);
return;
}
if (sta_ip6addr_add(sta, &saddr))
return;
}
break;
case ROUTER_ADVERTISEMENT:
if (hapd->conf->disable_dgaf)
ucast_to_stas(hapd, buf, len);
break;
case NEIGHBOR_ADVERTISEMENT:
if (hapd->conf->na_mcast_to_ucast)
ucast_to_stas(hapd, buf, len);
break;
default:
break;
}
}
int ndisc_snoop_init(struct hostapd_data *hapd)
{
hapd->sock_ndisc = x_snoop_get_l2_packet(hapd, handle_ndisc,
L2_PACKET_FILTER_NDISC);
if (hapd->sock_ndisc == NULL) {
wpa_printf(MSG_DEBUG,
"ndisc_snoop: Failed to initialize L2 packet processing for NDISC packets: %s",
strerror(errno));
return -1;
}
return 0;
}
void ndisc_snoop_deinit(struct hostapd_data *hapd)
{
l2_packet_deinit(hapd->sock_ndisc);
hapd->sock_ndisc = NULL;
}
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