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 static int sta_ip6addr_add(struct sta_info *sta, struct in6_addr *addr) 42 { 43 struct ip6addr *ip6addr; 44 45 ip6addr = os_zalloc(sizeof(*ip6addr)); 46 if (!ip6addr) 47 return -1; 48 49 os_memcpy(&ip6addr->addr, addr, sizeof(*addr)); 50 51 dl_list_add_tail(&sta->ip6addr, &ip6addr->list); 52 53 return 0; 54 } 55 56 57 void sta_ip6addr_del(struct hostapd_data *hapd, struct sta_info *sta) 58 { 59 struct ip6addr *ip6addr, *prev; 60 61 dl_list_for_each_safe(ip6addr, prev, &sta->ip6addr, struct ip6addr, 62 list) { 63 hostapd_drv_br_delete_ip_neigh(hapd, 6, (u8 *) &ip6addr->addr); 64 dl_list_del(&ip6addr->list); 65 os_free(ip6addr); 66 } 67 } 68 69 70 static int sta_has_ip6addr(struct sta_info *sta, struct in6_addr *addr) 71 { 72 struct ip6addr *ip6addr; 73 74 dl_list_for_each(ip6addr, &sta->ip6addr, struct ip6addr, list) { 75 if (ip6addr->addr.s6_addr32[0] == addr->s6_addr32[0] && 76 ip6addr->addr.s6_addr32[1] == addr->s6_addr32[1] && 77 ip6addr->addr.s6_addr32[2] == addr->s6_addr32[2] && 78 ip6addr->addr.s6_addr32[3] == addr->s6_addr32[3]) 79 return 1; 80 } 81 82 return 0; 83 } 84 85 86 static void ucast_to_stas(struct hostapd_data *hapd, const u8 *buf, size_t len) 87 { 88 struct sta_info *sta; 89 90 for (sta = hapd->sta_list; sta; sta = sta->next) { 91 if (!(sta->flags & WLAN_STA_AUTHORIZED)) 92 continue; 93 x_snoop_mcast_to_ucast_convert_send(hapd, sta, (u8 *) buf, len); 94 } 95 } 96 97 98 static void handle_ndisc(void *ctx, const u8 *src_addr, const u8 *buf, 99 size_t len) 100 { 101 struct hostapd_data *hapd = ctx; 102 struct icmpv6_ndmsg *msg; 103 struct in6_addr saddr; 104 struct sta_info *sta; 105 int res; 106 char addrtxt[INET6_ADDRSTRLEN + 1]; 107 108 if (len < ETH_HLEN + sizeof(struct ip6_hdr) + sizeof(struct icmp6_hdr)) 109 return; 110 msg = (struct icmpv6_ndmsg *) &buf[ETH_HLEN]; 111 switch (msg->icmp6h.icmp6_type) { 112 case NEIGHBOR_SOLICITATION: 113 if (len < ETH_HLEN + sizeof(*msg)) 114 return; 115 if (msg->opt_type != SOURCE_LL_ADDR) 116 return; 117 118 /* 119 * IPv6 header may not be 32-bit aligned in the buffer, so use 120 * a local copy to avoid unaligned reads. 121 */ 122 os_memcpy(&saddr, &msg->ipv6h.ip6_src, sizeof(saddr)); 123 if (!(saddr.s6_addr32[0] == 0 && saddr.s6_addr32[1] == 0 && 124 saddr.s6_addr32[2] == 0 && saddr.s6_addr32[3] == 0)) { 125 if (len < ETH_HLEN + sizeof(*msg) + ETH_ALEN) 126 return; 127 sta = ap_get_sta(hapd, msg->opt_lladdr); 128 if (!sta) 129 return; 130 131 if (sta_has_ip6addr(sta, &saddr)) 132 return; 133 134 if (inet_ntop(AF_INET6, &saddr, addrtxt, 135 sizeof(addrtxt)) == NULL) 136 addrtxt[0] = '\0'; 137 wpa_printf(MSG_DEBUG, "ndisc_snoop: Learned new IPv6 address %s for " 138 MACSTR, addrtxt, MAC2STR(sta->addr)); 139 hostapd_drv_br_delete_ip_neigh(hapd, 6, (u8 *) &saddr); 140 res = hostapd_drv_br_add_ip_neigh(hapd, 6, 141 (u8 *) &saddr, 142 128, sta->addr); 143 if (res) { 144 wpa_printf(MSG_ERROR, 145 "ndisc_snoop: Adding ip neigh failed: %d", 146 res); 147 return; 148 } 149 150 if (sta_ip6addr_add(sta, &saddr)) 151 return; 152 } 153 break; 154 #ifdef CONFIG_HS20 155 case ROUTER_ADVERTISEMENT: 156 if (hapd->conf->disable_dgaf) 157 ucast_to_stas(hapd, buf, len); 158 break; 159 #endif /* CONFIG_HS20 */ 160 case NEIGHBOR_ADVERTISEMENT: 161 if (hapd->conf->na_mcast_to_ucast) 162 ucast_to_stas(hapd, buf, len); 163 break; 164 default: 165 break; 166 } 167 } 168 169 170 int ndisc_snoop_init(struct hostapd_data *hapd) 171 { 172 hapd->sock_ndisc = x_snoop_get_l2_packet(hapd, handle_ndisc, 173 L2_PACKET_FILTER_NDISC); 174 if (hapd->sock_ndisc == NULL) { 175 wpa_printf(MSG_DEBUG, 176 "ndisc_snoop: Failed to initialize L2 packet processing for NDISC packets: %s", 177 strerror(errno)); 178 return -1; 179 } 180 181 return 0; 182 } 183 184 185 void ndisc_snoop_deinit(struct hostapd_data *hapd) 186 { 187 l2_packet_deinit(hapd->sock_ndisc); 188 hapd->sock_ndisc = NULL; 189 } 190