1 /*
2 * Neighbor Discovery snooping for Proxy ARP
3 * Copyright (c) 2014, Qualcomm Atheros, Inc.
4 *
5 * This software may be distributed under the terms of the BSD license.
6 * See README for more details.
7 */
8
9 #include "utils/includes.h"
10 #include <netinet/ip6.h>
11 #include <netinet/icmp6.h>
12
13 #include "utils/common.h"
14 #include "l2_packet/l2_packet.h"
15 #include "hostapd.h"
16 #include "sta_info.h"
17 #include "ap_drv_ops.h"
18 #include "list.h"
19 #include "x_snoop.h"
20
21 struct ip6addr {
22 struct in6_addr addr;
23 struct dl_list list;
24 };
25
26 struct icmpv6_ndmsg {
27 struct ip6_hdr ipv6h;
28 struct icmp6_hdr icmp6h;
29 struct in6_addr target_addr;
30 u8 opt_type;
31 u8 len;
32 u8 opt_lladdr[0];
33 } STRUCT_PACKED;
34
35 #define ROUTER_ADVERTISEMENT 134
36 #define NEIGHBOR_SOLICITATION 135
37 #define NEIGHBOR_ADVERTISEMENT 136
38 #define SOURCE_LL_ADDR 1
39
sta_ip6addr_add(struct sta_info * sta,struct in6_addr * addr)40 static int sta_ip6addr_add(struct sta_info *sta, struct in6_addr *addr)
41 {
42 struct ip6addr *ip6addr;
43
44 ip6addr = os_zalloc(sizeof(*ip6addr));
45 if (!ip6addr)
46 return -1;
47
48 os_memcpy(&ip6addr->addr, addr, sizeof(*addr));
49
50 dl_list_add_tail(&sta->ip6addr, &ip6addr->list);
51
52 return 0;
53 }
54
55
sta_ip6addr_del(struct hostapd_data * hapd,struct sta_info * sta)56 void sta_ip6addr_del(struct hostapd_data *hapd, struct sta_info *sta)
57 {
58 struct ip6addr *ip6addr, *prev;
59
60 dl_list_for_each_safe(ip6addr, prev, &sta->ip6addr, struct ip6addr,
61 list) {
62 hostapd_drv_br_delete_ip_neigh(hapd, 6, (u8 *) &ip6addr->addr);
63 os_free(ip6addr);
64 }
65 }
66
67
sta_has_ip6addr(struct sta_info * sta,struct in6_addr * addr)68 static int sta_has_ip6addr(struct sta_info *sta, struct in6_addr *addr)
69 {
70 struct ip6addr *ip6addr;
71
72 dl_list_for_each(ip6addr, &sta->ip6addr, struct ip6addr, list) {
73 if (ip6addr->addr.s6_addr32[0] == addr->s6_addr32[0] &&
74 ip6addr->addr.s6_addr32[1] == addr->s6_addr32[1] &&
75 ip6addr->addr.s6_addr32[2] == addr->s6_addr32[2] &&
76 ip6addr->addr.s6_addr32[3] == addr->s6_addr32[3])
77 return 1;
78 }
79
80 return 0;
81 }
82
83
ucast_to_stas(struct hostapd_data * hapd,const u8 * buf,size_t len)84 static void ucast_to_stas(struct hostapd_data *hapd, const u8 *buf, size_t len)
85 {
86 struct sta_info *sta;
87
88 for (sta = hapd->sta_list; sta; sta = sta->next) {
89 if (!(sta->flags & WLAN_STA_AUTHORIZED))
90 continue;
91 x_snoop_mcast_to_ucast_convert_send(hapd, sta, (u8 *) buf, len);
92 }
93 }
94
95
handle_ndisc(void * ctx,const u8 * src_addr,const u8 * buf,size_t len)96 static void handle_ndisc(void *ctx, const u8 *src_addr, const u8 *buf,
97 size_t len)
98 {
99 struct hostapd_data *hapd = ctx;
100 struct icmpv6_ndmsg *msg;
101 struct in6_addr *saddr;
102 struct sta_info *sta;
103 int res;
104 char addrtxt[INET6_ADDRSTRLEN + 1];
105
106 if (len < ETH_HLEN + sizeof(struct ip6_hdr) + sizeof(struct icmp6_hdr))
107 return;
108 msg = (struct icmpv6_ndmsg *) &buf[ETH_HLEN];
109 switch (msg->icmp6h.icmp6_type) {
110 case NEIGHBOR_SOLICITATION:
111 if (len < ETH_HLEN + sizeof(*msg))
112 return;
113 if (msg->opt_type != SOURCE_LL_ADDR)
114 return;
115
116 saddr = &msg->ipv6h.ip6_src;
117 if (!(saddr->s6_addr32[0] == 0 && saddr->s6_addr32[1] == 0 &&
118 saddr->s6_addr32[2] == 0 && saddr->s6_addr32[3] == 0)) {
119 if (len < ETH_HLEN + sizeof(*msg) + ETH_ALEN)
120 return;
121 sta = ap_get_sta(hapd, msg->opt_lladdr);
122 if (!sta)
123 return;
124
125 if (sta_has_ip6addr(sta, saddr))
126 return;
127
128 if (inet_ntop(AF_INET6, saddr, addrtxt, sizeof(addrtxt))
129 == NULL)
130 addrtxt[0] = '\0';
131 wpa_printf(MSG_DEBUG, "ndisc_snoop: Learned new IPv6 address %s for "
132 MACSTR, addrtxt, MAC2STR(sta->addr));
133 hostapd_drv_br_delete_ip_neigh(hapd, 6, (u8 *) saddr);
134 res = hostapd_drv_br_add_ip_neigh(hapd, 6, (u8 *) saddr,
135 128, sta->addr);
136 if (res) {
137 wpa_printf(MSG_ERROR,
138 "ndisc_snoop: Adding ip neigh failed: %d",
139 res);
140 return;
141 }
142
143 if (sta_ip6addr_add(sta, saddr))
144 return;
145 }
146 break;
147 case ROUTER_ADVERTISEMENT:
148 if (hapd->conf->disable_dgaf)
149 ucast_to_stas(hapd, buf, len);
150 break;
151 case NEIGHBOR_ADVERTISEMENT:
152 if (hapd->conf->na_mcast_to_ucast)
153 ucast_to_stas(hapd, buf, len);
154 break;
155 default:
156 break;
157 }
158 }
159
160
ndisc_snoop_init(struct hostapd_data * hapd)161 int ndisc_snoop_init(struct hostapd_data *hapd)
162 {
163 hapd->sock_ndisc = x_snoop_get_l2_packet(hapd, handle_ndisc,
164 L2_PACKET_FILTER_NDISC);
165 if (hapd->sock_ndisc == NULL) {
166 wpa_printf(MSG_DEBUG,
167 "ndisc_snoop: Failed to initialize L2 packet processing for NDISC packets: %s",
168 strerror(errno));
169 return -1;
170 }
171
172 return 0;
173 }
174
175
ndisc_snoop_deinit(struct hostapd_data * hapd)176 void ndisc_snoop_deinit(struct hostapd_data *hapd)
177 {
178 l2_packet_deinit(hapd->sock_ndisc);
179 }
180