Line data Source code
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 : #include "ndisc_snoop.h"
21 :
22 : struct ip6addr {
23 : struct in6_addr addr;
24 : struct dl_list list;
25 : };
26 :
27 : struct icmpv6_ndmsg {
28 : struct ip6_hdr ipv6h;
29 : struct icmp6_hdr icmp6h;
30 : struct in6_addr target_addr;
31 : u8 opt_type;
32 : u8 len;
33 : u8 opt_lladdr[0];
34 : } STRUCT_PACKED;
35 :
36 : #define ROUTER_ADVERTISEMENT 134
37 : #define NEIGHBOR_SOLICITATION 135
38 : #define NEIGHBOR_ADVERTISEMENT 136
39 : #define SOURCE_LL_ADDR 1
40 :
41 11 : static int sta_ip6addr_add(struct sta_info *sta, struct in6_addr *addr)
42 : {
43 : struct ip6addr *ip6addr;
44 :
45 11 : ip6addr = os_zalloc(sizeof(*ip6addr));
46 11 : if (!ip6addr)
47 0 : return -1;
48 :
49 11 : os_memcpy(&ip6addr->addr, addr, sizeof(*addr));
50 :
51 11 : dl_list_add_tail(&sta->ip6addr, &ip6addr->list);
52 :
53 11 : return 0;
54 : }
55 :
56 :
57 4105 : void sta_ip6addr_del(struct hostapd_data *hapd, struct sta_info *sta)
58 : {
59 : struct ip6addr *ip6addr, *prev;
60 :
61 4116 : dl_list_for_each_safe(ip6addr, prev, &sta->ip6addr, struct ip6addr,
62 : list) {
63 11 : hostapd_drv_br_delete_ip_neigh(hapd, 6, (u8 *) &ip6addr->addr);
64 11 : os_free(ip6addr);
65 : }
66 4105 : }
67 :
68 :
69 17 : static int sta_has_ip6addr(struct sta_info *sta, struct in6_addr *addr)
70 : {
71 : struct ip6addr *ip6addr;
72 :
73 22 : dl_list_for_each(ip6addr, &sta->ip6addr, struct ip6addr, list) {
74 22 : if (ip6addr->addr.s6_addr32[0] == addr->s6_addr32[0] &&
75 17 : ip6addr->addr.s6_addr32[1] == addr->s6_addr32[1] &&
76 12 : ip6addr->addr.s6_addr32[2] == addr->s6_addr32[2] &&
77 6 : ip6addr->addr.s6_addr32[3] == addr->s6_addr32[3])
78 6 : return 1;
79 : }
80 :
81 11 : return 0;
82 : }
83 :
84 :
85 3 : static void ucast_to_stas(struct hostapd_data *hapd, const u8 *buf, size_t len)
86 : {
87 : struct sta_info *sta;
88 :
89 9 : for (sta = hapd->sta_list; sta; sta = sta->next) {
90 6 : if (!(sta->flags & WLAN_STA_AUTHORIZED))
91 0 : continue;
92 6 : x_snoop_mcast_to_ucast_convert_send(hapd, sta, (u8 *) buf, len);
93 : }
94 3 : }
95 :
96 :
97 90 : static void handle_ndisc(void *ctx, const u8 *src_addr, const u8 *buf,
98 : size_t len)
99 : {
100 90 : struct hostapd_data *hapd = ctx;
101 : struct icmpv6_ndmsg *msg;
102 : struct in6_addr saddr;
103 : struct sta_info *sta;
104 : int res;
105 : char addrtxt[INET6_ADDRSTRLEN + 1];
106 :
107 90 : if (len < ETH_HLEN + sizeof(struct ip6_hdr) + sizeof(struct icmp6_hdr))
108 39 : return;
109 90 : msg = (struct icmpv6_ndmsg *) &buf[ETH_HLEN];
110 90 : switch (msg->icmp6h.icmp6_type) {
111 : case NEIGHBOR_SOLICITATION:
112 58 : if (len < ETH_HLEN + sizeof(*msg))
113 19 : return;
114 39 : if (msg->opt_type != SOURCE_LL_ADDR)
115 2 : return;
116 :
117 : /*
118 : * IPv6 header may not be 32-bit aligned in the buffer, so use
119 : * a local copy to avoid unaligned reads.
120 : */
121 37 : os_memcpy(&saddr, &msg->ipv6h.ip6_src, sizeof(saddr));
122 53 : if (!(saddr.s6_addr32[0] == 0 && saddr.s6_addr32[1] == 0 &&
123 16 : saddr.s6_addr32[2] == 0 && saddr.s6_addr32[3] == 0)) {
124 29 : if (len < ETH_HLEN + sizeof(*msg) + ETH_ALEN)
125 2 : return;
126 27 : sta = ap_get_sta(hapd, msg->opt_lladdr);
127 27 : if (!sta)
128 10 : return;
129 :
130 17 : if (sta_has_ip6addr(sta, &saddr))
131 6 : return;
132 :
133 11 : if (inet_ntop(AF_INET6, &saddr, addrtxt,
134 : sizeof(addrtxt)) == NULL)
135 0 : addrtxt[0] = '\0';
136 66 : wpa_printf(MSG_DEBUG, "ndisc_snoop: Learned new IPv6 address %s for "
137 66 : MACSTR, addrtxt, MAC2STR(sta->addr));
138 11 : hostapd_drv_br_delete_ip_neigh(hapd, 6, (u8 *) &saddr);
139 11 : res = hostapd_drv_br_add_ip_neigh(hapd, 6,
140 : (u8 *) &saddr,
141 11 : 128, sta->addr);
142 11 : if (res) {
143 0 : wpa_printf(MSG_ERROR,
144 : "ndisc_snoop: Adding ip neigh failed: %d",
145 : res);
146 0 : return;
147 : }
148 :
149 11 : if (sta_ip6addr_add(sta, &saddr))
150 0 : return;
151 : }
152 19 : break;
153 : case ROUTER_ADVERTISEMENT:
154 2 : if (hapd->conf->disable_dgaf)
155 1 : ucast_to_stas(hapd, buf, len);
156 2 : break;
157 : case NEIGHBOR_ADVERTISEMENT:
158 8 : if (hapd->conf->na_mcast_to_ucast)
159 2 : ucast_to_stas(hapd, buf, len);
160 8 : break;
161 : default:
162 22 : break;
163 : }
164 : }
165 :
166 :
167 12 : int ndisc_snoop_init(struct hostapd_data *hapd)
168 : {
169 12 : hapd->sock_ndisc = x_snoop_get_l2_packet(hapd, handle_ndisc,
170 : L2_PACKET_FILTER_NDISC);
171 12 : if (hapd->sock_ndisc == NULL) {
172 0 : wpa_printf(MSG_DEBUG,
173 : "ndisc_snoop: Failed to initialize L2 packet processing for NDISC packets: %s",
174 0 : strerror(errno));
175 0 : return -1;
176 : }
177 :
178 12 : return 0;
179 : }
180 :
181 :
182 2046 : void ndisc_snoop_deinit(struct hostapd_data *hapd)
183 : {
184 2046 : l2_packet_deinit(hapd->sock_ndisc);
185 2046 : }
|
