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 :
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 :
40 11 : static int sta_ip6addr_add(struct sta_info *sta, struct in6_addr *addr)
41 : {
42 : struct ip6addr *ip6addr;
43 :
44 11 : ip6addr = os_zalloc(sizeof(*ip6addr));
45 11 : if (!ip6addr)
46 0 : return -1;
47 :
48 11 : os_memcpy(&ip6addr->addr, addr, sizeof(*addr));
49 :
50 11 : dl_list_add_tail(&sta->ip6addr, &ip6addr->list);
51 :
52 11 : return 0;
53 : }
54 :
55 :
56 2777 : void sta_ip6addr_del(struct hostapd_data *hapd, struct sta_info *sta)
57 : {
58 : struct ip6addr *ip6addr, *prev;
59 :
60 2788 : dl_list_for_each_safe(ip6addr, prev, &sta->ip6addr, struct ip6addr,
61 : list) {
62 11 : hostapd_drv_br_delete_ip_neigh(hapd, 6, (u8 *) &ip6addr->addr);
63 11 : os_free(ip6addr);
64 : }
65 2777 : }
66 :
67 :
68 17 : static int sta_has_ip6addr(struct sta_info *sta, struct in6_addr *addr)
69 : {
70 : struct ip6addr *ip6addr;
71 :
72 22 : dl_list_for_each(ip6addr, &sta->ip6addr, struct ip6addr, list) {
73 22 : if (ip6addr->addr.s6_addr32[0] == addr->s6_addr32[0] &&
74 17 : ip6addr->addr.s6_addr32[1] == addr->s6_addr32[1] &&
75 12 : ip6addr->addr.s6_addr32[2] == addr->s6_addr32[2] &&
76 6 : ip6addr->addr.s6_addr32[3] == addr->s6_addr32[3])
77 6 : return 1;
78 : }
79 :
80 11 : return 0;
81 : }
82 :
83 :
84 3 : static void ucast_to_stas(struct hostapd_data *hapd, const u8 *buf, size_t len)
85 : {
86 : struct sta_info *sta;
87 :
88 9 : for (sta = hapd->sta_list; sta; sta = sta->next) {
89 6 : if (!(sta->flags & WLAN_STA_AUTHORIZED))
90 0 : continue;
91 6 : x_snoop_mcast_to_ucast_convert_send(hapd, sta, (u8 *) buf, len);
92 : }
93 3 : }
94 :
95 :
96 85 : static void handle_ndisc(void *ctx, const u8 *src_addr, const u8 *buf,
97 : size_t len)
98 : {
99 85 : 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 85 : if (len < ETH_HLEN + sizeof(struct ip6_hdr) + sizeof(struct icmp6_hdr))
107 33 : return;
108 85 : msg = (struct icmpv6_ndmsg *) &buf[ETH_HLEN];
109 85 : switch (msg->icmp6h.icmp6_type) {
110 : case NEIGHBOR_SOLICITATION:
111 52 : if (len < ETH_HLEN + sizeof(*msg))
112 13 : return;
113 39 : if (msg->opt_type != SOURCE_LL_ADDR)
114 2 : return;
115 :
116 : /*
117 : * IPv6 header may not be 32-bit aligned in the buffer, so use
118 : * a local copy to avoid unaligned reads.
119 : */
120 37 : os_memcpy(&saddr, &msg->ipv6h.ip6_src, sizeof(saddr));
121 53 : if (!(saddr.s6_addr32[0] == 0 && saddr.s6_addr32[1] == 0 &&
122 16 : saddr.s6_addr32[2] == 0 && saddr.s6_addr32[3] == 0)) {
123 29 : if (len < ETH_HLEN + sizeof(*msg) + ETH_ALEN)
124 2 : return;
125 27 : sta = ap_get_sta(hapd, msg->opt_lladdr);
126 27 : if (!sta)
127 10 : return;
128 :
129 17 : if (sta_has_ip6addr(sta, &saddr))
130 6 : return;
131 :
132 11 : if (inet_ntop(AF_INET6, &saddr, addrtxt,
133 : sizeof(addrtxt)) == NULL)
134 0 : addrtxt[0] = '\0';
135 66 : wpa_printf(MSG_DEBUG, "ndisc_snoop: Learned new IPv6 address %s for "
136 66 : MACSTR, addrtxt, MAC2STR(sta->addr));
137 11 : hostapd_drv_br_delete_ip_neigh(hapd, 6, (u8 *) &saddr);
138 11 : res = hostapd_drv_br_add_ip_neigh(hapd, 6,
139 : (u8 *) &saddr,
140 11 : 128, sta->addr);
141 11 : if (res) {
142 0 : wpa_printf(MSG_ERROR,
143 : "ndisc_snoop: Adding ip neigh failed: %d",
144 : res);
145 0 : return;
146 : }
147 :
148 11 : if (sta_ip6addr_add(sta, &saddr))
149 0 : return;
150 : }
151 19 : break;
152 : case ROUTER_ADVERTISEMENT:
153 2 : if (hapd->conf->disable_dgaf)
154 1 : ucast_to_stas(hapd, buf, len);
155 2 : break;
156 : case NEIGHBOR_ADVERTISEMENT:
157 8 : if (hapd->conf->na_mcast_to_ucast)
158 2 : ucast_to_stas(hapd, buf, len);
159 8 : break;
160 : default:
161 23 : break;
162 : }
163 : }
164 :
165 :
166 5 : int ndisc_snoop_init(struct hostapd_data *hapd)
167 : {
168 5 : hapd->sock_ndisc = x_snoop_get_l2_packet(hapd, handle_ndisc,
169 : L2_PACKET_FILTER_NDISC);
170 5 : if (hapd->sock_ndisc == NULL) {
171 0 : wpa_printf(MSG_DEBUG,
172 : "ndisc_snoop: Failed to initialize L2 packet processing for NDISC packets: %s",
173 0 : strerror(errno));
174 0 : return -1;
175 : }
176 :
177 5 : return 0;
178 : }
179 :
180 :
181 1682 : void ndisc_snoop_deinit(struct hostapd_data *hapd)
182 : {
183 1682 : l2_packet_deinit(hapd->sock_ndisc);
184 1682 : }
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