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 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 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 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 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 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 /* 117 * IPv6 header may not be 32-bit aligned in the buffer, so use 118 * a local copy to avoid unaligned reads. 119 */ 120 os_memcpy(&saddr, &msg->ipv6h.ip6_src, sizeof(saddr)); 121 if (!(saddr.s6_addr32[0] == 0 && saddr.s6_addr32[1] == 0 && 122 saddr.s6_addr32[2] == 0 && saddr.s6_addr32[3] == 0)) { 123 if (len < ETH_HLEN + sizeof(*msg) + ETH_ALEN) 124 return; 125 sta = ap_get_sta(hapd, msg->opt_lladdr); 126 if (!sta) 127 return; 128 129 if (sta_has_ip6addr(sta, &saddr)) 130 return; 131 132 if (inet_ntop(AF_INET6, &saddr, addrtxt, 133 sizeof(addrtxt)) == NULL) 134 addrtxt[0] = '\0'; 135 wpa_printf(MSG_DEBUG, "ndisc_snoop: Learned new IPv6 address %s for " 136 MACSTR, addrtxt, MAC2STR(sta->addr)); 137 hostapd_drv_br_delete_ip_neigh(hapd, 6, (u8 *) &saddr); 138 res = hostapd_drv_br_add_ip_neigh(hapd, 6, 139 (u8 *) &saddr, 140 128, sta->addr); 141 if (res) { 142 wpa_printf(MSG_ERROR, 143 "ndisc_snoop: Adding ip neigh failed: %d", 144 res); 145 return; 146 } 147 148 if (sta_ip6addr_add(sta, &saddr)) 149 return; 150 } 151 break; 152 case ROUTER_ADVERTISEMENT: 153 if (hapd->conf->disable_dgaf) 154 ucast_to_stas(hapd, buf, len); 155 break; 156 case NEIGHBOR_ADVERTISEMENT: 157 if (hapd->conf->na_mcast_to_ucast) 158 ucast_to_stas(hapd, buf, len); 159 break; 160 default: 161 break; 162 } 163 } 164 165 166 int ndisc_snoop_init(struct hostapd_data *hapd) 167 { 168 hapd->sock_ndisc = x_snoop_get_l2_packet(hapd, handle_ndisc, 169 L2_PACKET_FILTER_NDISC); 170 if (hapd->sock_ndisc == NULL) { 171 wpa_printf(MSG_DEBUG, 172 "ndisc_snoop: Failed to initialize L2 packet processing for NDISC packets: %s", 173 strerror(errno)); 174 return -1; 175 } 176 177 return 0; 178 } 179 180 181 void ndisc_snoop_deinit(struct hostapd_data *hapd) 182 { 183 l2_packet_deinit(hapd->sock_ndisc); 184 } 185