diff options
Diffstat (limited to 'contrib/wpa/hostapd/iapp.c')
-rw-r--r-- | contrib/wpa/hostapd/iapp.c | 553 |
1 files changed, 553 insertions, 0 deletions
diff --git a/contrib/wpa/hostapd/iapp.c b/contrib/wpa/hostapd/iapp.c new file mode 100644 index 000000000000..6d6dba8f7b9a --- /dev/null +++ b/contrib/wpa/hostapd/iapp.c @@ -0,0 +1,553 @@ +/* + * hostapd / IEEE 802.11F-2003 Inter-Access Point Protocol (IAPP) + * Copyright (c) 2002-2007, Jouni Malinen <j@w1.fi> + * + * This program is free software; you can redistribute it and/or modify + * it under the terms of the GNU General Public License version 2 as + * published by the Free Software Foundation. + * + * Alternatively, this software may be distributed under the terms of BSD + * license. + * + * See README and COPYING for more details. + * + * Note: IEEE 802.11F-2003 was a experimental use specification. It has expired + * and IEEE has withdrawn it. In other words, it is likely better to look at + * using some other mechanism for AP-to-AP communication than extending the + * implementation here. + */ + +/* TODO: + * Level 1: no administrative or security support + * (e.g., static BSSID to IP address mapping in each AP) + * Level 2: support for dynamic mapping of BSSID to IP address + * Level 3: support for encryption and authentication of IAPP messages + * - add support for MOVE-notify and MOVE-response (this requires support for + * finding out IP address for previous AP using RADIUS) + * - add support for Send- and ACK-Security-Block to speedup IEEE 802.1X during + * reassociation to another AP + * - implement counters etc. for IAPP MIB + * - verify endianness of fields in IAPP messages; are they big-endian as + * used here? + * - RADIUS connection for AP registration and BSSID to IP address mapping + * - TCP connection for IAPP MOVE, CACHE + * - broadcast ESP for IAPP ADD-notify + * - ESP for IAPP MOVE messages + * - security block sending/processing + * - IEEE 802.11 context transfer + */ + +#include "includes.h" +#include <net/if.h> +#include <sys/ioctl.h> +#ifdef USE_KERNEL_HEADERS +#include <linux/if_packet.h> +#else /* USE_KERNEL_HEADERS */ +#include <netpacket/packet.h> +#endif /* USE_KERNEL_HEADERS */ + +#include "hostapd.h" +#include "ieee802_11.h" +#include "iapp.h" +#include "eloop.h" +#include "sta_info.h" + + +#define IAPP_MULTICAST "224.0.1.178" +#define IAPP_UDP_PORT 3517 +#define IAPP_TCP_PORT 3517 + +struct iapp_hdr { + u8 version; + u8 command; + be16 identifier; + be16 length; + /* followed by length-6 octets of data */ +} __attribute__ ((packed)); + +#define IAPP_VERSION 0 + +enum IAPP_COMMAND { + IAPP_CMD_ADD_notify = 0, + IAPP_CMD_MOVE_notify = 1, + IAPP_CMD_MOVE_response = 2, + IAPP_CMD_Send_Security_Block = 3, + IAPP_CMD_ACK_Security_Block = 4, + IAPP_CMD_CACHE_notify = 5, + IAPP_CMD_CACHE_response = 6, +}; + + +/* ADD-notify - multicast UDP on the local LAN */ +struct iapp_add_notify { + u8 addr_len; /* ETH_ALEN */ + u8 reserved; + u8 mac_addr[ETH_ALEN]; + be16 seq_num; +} __attribute__ ((packed)); + + +/* Layer 2 Update frame (802.2 Type 1 LLC XID Update response) */ +struct iapp_layer2_update { + u8 da[ETH_ALEN]; /* broadcast */ + u8 sa[ETH_ALEN]; /* STA addr */ + be16 len; /* 6 */ + u8 dsap; /* null DSAP address */ + u8 ssap; /* null SSAP address, CR=Response */ + u8 control; + u8 xid_info[3]; +} __attribute__ ((packed)); + + +/* MOVE-notify - unicast TCP */ +struct iapp_move_notify { + u8 addr_len; /* ETH_ALEN */ + u8 reserved; + u8 mac_addr[ETH_ALEN]; + u16 seq_num; + u16 ctx_block_len; + /* followed by ctx_block_len bytes */ +} __attribute__ ((packed)); + + +/* MOVE-response - unicast TCP */ +struct iapp_move_response { + u8 addr_len; /* ETH_ALEN */ + u8 status; + u8 mac_addr[ETH_ALEN]; + u16 seq_num; + u16 ctx_block_len; + /* followed by ctx_block_len bytes */ +} __attribute__ ((packed)); + +enum { + IAPP_MOVE_SUCCESSFUL = 0, + IAPP_MOVE_DENIED = 1, + IAPP_MOVE_STALE_MOVE = 2, +}; + + +/* CACHE-notify */ +struct iapp_cache_notify { + u8 addr_len; /* ETH_ALEN */ + u8 reserved; + u8 mac_addr[ETH_ALEN]; + u16 seq_num; + u8 current_ap[ETH_ALEN]; + u16 ctx_block_len; + /* ctx_block_len bytes of context block followed by 16-bit context + * timeout */ +} __attribute__ ((packed)); + + +/* CACHE-response - unicast TCP */ +struct iapp_cache_response { + u8 addr_len; /* ETH_ALEN */ + u8 status; + u8 mac_addr[ETH_ALEN]; + u16 seq_num; +} __attribute__ ((packed)); + +enum { + IAPP_CACHE_SUCCESSFUL = 0, + IAPP_CACHE_STALE_CACHE = 1, +}; + + +/* Send-Security-Block - unicast TCP */ +struct iapp_send_security_block { + u8 iv[8]; + u16 sec_block_len; + /* followed by sec_block_len bytes of security block */ +} __attribute__ ((packed)); + + +/* ACK-Security-Block - unicast TCP */ +struct iapp_ack_security_block { + u8 iv[8]; + u8 new_ap_ack_authenticator[48]; +} __attribute__ ((packed)); + + +struct iapp_data { + struct hostapd_data *hapd; + u16 identifier; /* next IAPP identifier */ + struct in_addr own, multicast; + int udp_sock; + int packet_sock; +}; + + +static void iapp_send_add(struct iapp_data *iapp, u8 *mac_addr, u16 seq_num) +{ + char buf[128]; + struct iapp_hdr *hdr; + struct iapp_add_notify *add; + struct sockaddr_in addr; + + /* Send IAPP ADD-notify to remove possible association from other APs + */ + + hdr = (struct iapp_hdr *) buf; + hdr->version = IAPP_VERSION; + hdr->command = IAPP_CMD_ADD_notify; + hdr->identifier = host_to_be16(iapp->identifier++); + hdr->length = host_to_be16(sizeof(*hdr) + sizeof(*add)); + + add = (struct iapp_add_notify *) (hdr + 1); + add->addr_len = ETH_ALEN; + add->reserved = 0; + os_memcpy(add->mac_addr, mac_addr, ETH_ALEN); + + add->seq_num = host_to_be16(seq_num); + + os_memset(&addr, 0, sizeof(addr)); + addr.sin_family = AF_INET; + addr.sin_addr.s_addr = iapp->multicast.s_addr; + addr.sin_port = htons(IAPP_UDP_PORT); + if (sendto(iapp->udp_sock, buf, (char *) (add + 1) - buf, 0, + (struct sockaddr *) &addr, sizeof(addr)) < 0) + perror("sendto[IAPP-ADD]"); +} + + +static void iapp_send_layer2_update(struct iapp_data *iapp, u8 *addr) +{ + struct iapp_layer2_update msg; + + /* Send Level 2 Update Frame to update forwarding tables in layer 2 + * bridge devices */ + + /* 802.2 Type 1 Logical Link Control (LLC) Exchange Identifier (XID) + * Update response frame; IEEE Std 802.2-1998, 5.4.1.2.1 */ + + os_memset(msg.da, 0xff, ETH_ALEN); + os_memcpy(msg.sa, addr, ETH_ALEN); + msg.len = host_to_be16(6); + msg.dsap = 0; /* NULL DSAP address */ + msg.ssap = 0x01; /* NULL SSAP address, CR Bit: Response */ + msg.control = 0xaf; /* XID response lsb.1111F101. + * F=0 (no poll command; unsolicited frame) */ + msg.xid_info[0] = 0x81; /* XID format identifier */ + msg.xid_info[1] = 1; /* LLC types/classes: Type 1 LLC */ + msg.xid_info[2] = 1 << 1; /* XID sender's receive window size (RW) + * FIX: what is correct RW with 802.11? */ + + if (send(iapp->packet_sock, &msg, sizeof(msg), 0) < 0) + perror("send[L2 Update]"); +} + + +/** + * iapp_new_station - IAPP processing for a new STA + * @iapp: IAPP data + * @sta: The associated station + */ +void iapp_new_station(struct iapp_data *iapp, struct sta_info *sta) +{ + struct ieee80211_mgmt *assoc; + u16 seq; + + if (iapp == NULL) + return; + + assoc = sta->last_assoc_req; + seq = assoc ? WLAN_GET_SEQ_SEQ(le_to_host16(assoc->seq_ctrl)) : 0; + + /* IAPP-ADD.request(MAC Address, Sequence Number, Timeout) */ + hostapd_logger(iapp->hapd, sta->addr, HOSTAPD_MODULE_IAPP, + HOSTAPD_LEVEL_DEBUG, "IAPP-ADD.request(seq=%d)", seq); + iapp_send_layer2_update(iapp, sta->addr); + iapp_send_add(iapp, sta->addr, seq); + + if (assoc && WLAN_FC_GET_STYPE(le_to_host16(assoc->frame_control)) == + WLAN_FC_STYPE_REASSOC_REQ) { + /* IAPP-MOVE.request(MAC Address, Sequence Number, Old AP, + * Context Block, Timeout) + */ + /* TODO: Send IAPP-MOVE to the old AP; Map Old AP BSSID to + * IP address */ + } +} + + +static void iapp_process_add_notify(struct iapp_data *iapp, + struct sockaddr_in *from, + struct iapp_hdr *hdr, int len) +{ + struct iapp_add_notify *add = (struct iapp_add_notify *) (hdr + 1); + struct sta_info *sta; + + if (len != sizeof(*add)) { + printf("Invalid IAPP-ADD packet length %d (expected %lu)\n", + len, (unsigned long) sizeof(*add)); + return; + } + + sta = ap_get_sta(iapp->hapd, add->mac_addr); + + /* IAPP-ADD.indication(MAC Address, Sequence Number) */ + hostapd_logger(iapp->hapd, add->mac_addr, HOSTAPD_MODULE_IAPP, + HOSTAPD_LEVEL_INFO, + "Received IAPP ADD-notify (seq# %d) from %s:%d%s", + be_to_host16(add->seq_num), + inet_ntoa(from->sin_addr), ntohs(from->sin_port), + sta ? "" : " (STA not found)"); + + if (!sta) + return; + + /* TODO: could use seq_num to try to determine whether last association + * to this AP is newer than the one advertised in IAPP-ADD. Although, + * this is not really a reliable verification. */ + + hostapd_logger(iapp->hapd, add->mac_addr, HOSTAPD_MODULE_IAPP, + HOSTAPD_LEVEL_DEBUG, + "Removing STA due to IAPP ADD-notify"); + sta->flags &= ~(WLAN_STA_AUTH | WLAN_STA_ASSOC | WLAN_STA_AUTHORIZED); + eloop_cancel_timeout(ap_handle_timer, iapp->hapd, sta); + eloop_register_timeout(0, 0, ap_handle_timer, iapp->hapd, sta); + sta->timeout_next = STA_REMOVE; +} + + +/** + * iapp_receive_udp - Process IAPP UDP frames + * @sock: File descriptor for the socket + * @eloop_ctx: IAPP data (struct iapp_data *) + * @sock_ctx: Not used + */ +static void iapp_receive_udp(int sock, void *eloop_ctx, void *sock_ctx) +{ + struct iapp_data *iapp = eloop_ctx; + int len, hlen; + unsigned char buf[128]; + struct sockaddr_in from; + socklen_t fromlen; + struct iapp_hdr *hdr; + + /* Handle incoming IAPP frames (over UDP/IP) */ + + fromlen = sizeof(from); + len = recvfrom(iapp->udp_sock, buf, sizeof(buf), 0, + (struct sockaddr *) &from, &fromlen); + if (len < 0) { + perror("recvfrom"); + return; + } + + if (from.sin_addr.s_addr == iapp->own.s_addr) + return; /* ignore own IAPP messages */ + + hostapd_logger(iapp->hapd, NULL, HOSTAPD_MODULE_IAPP, + HOSTAPD_LEVEL_DEBUG, + "Received %d byte IAPP frame from %s%s\n", + len, inet_ntoa(from.sin_addr), + len < (int) sizeof(*hdr) ? " (too short)" : ""); + + if (len < (int) sizeof(*hdr)) + return; + + hdr = (struct iapp_hdr *) buf; + hlen = be_to_host16(hdr->length); + hostapd_logger(iapp->hapd, NULL, HOSTAPD_MODULE_IAPP, + HOSTAPD_LEVEL_DEBUG, + "RX: version=%d command=%d id=%d len=%d\n", + hdr->version, hdr->command, + be_to_host16(hdr->identifier), hlen); + if (hdr->version != IAPP_VERSION) { + printf("Dropping IAPP frame with unknown version %d\n", + hdr->version); + return; + } + if (hlen > len) { + printf("Underflow IAPP frame (hlen=%d len=%d)\n", hlen, len); + return; + } + if (hlen < len) { + printf("Ignoring %d extra bytes from IAPP frame\n", + len - hlen); + len = hlen; + } + + switch (hdr->command) { + case IAPP_CMD_ADD_notify: + iapp_process_add_notify(iapp, &from, hdr, hlen - sizeof(*hdr)); + break; + case IAPP_CMD_MOVE_notify: + /* TODO: MOVE is using TCP; so move this to TCP handler once it + * is implemented.. */ + /* IAPP-MOVE.indication(MAC Address, New BSSID, + * Sequence Number, AP Address, Context Block) */ + /* TODO: process */ + break; + default: + printf("Unknown IAPP command %d\n", hdr->command); + break; + } +} + + +struct iapp_data * iapp_init(struct hostapd_data *hapd, const char *iface) +{ + struct ifreq ifr; + struct sockaddr_ll addr; + int ifindex; + struct sockaddr_in *paddr, uaddr; + struct iapp_data *iapp; + struct ip_mreqn mreq; + + iapp = os_zalloc(sizeof(*iapp)); + if (iapp == NULL) + return NULL; + iapp->hapd = hapd; + iapp->udp_sock = iapp->packet_sock = -1; + + /* TODO: + * open socket for sending and receiving IAPP frames over TCP + */ + + iapp->udp_sock = socket(PF_INET, SOCK_DGRAM, 0); + if (iapp->udp_sock < 0) { + perror("socket[PF_INET,SOCK_DGRAM]"); + iapp_deinit(iapp); + return NULL; + } + + os_memset(&ifr, 0, sizeof(ifr)); + os_strlcpy(ifr.ifr_name, iface, sizeof(ifr.ifr_name)); + if (ioctl(iapp->udp_sock, SIOCGIFINDEX, &ifr) != 0) { + perror("ioctl(SIOCGIFINDEX)"); + iapp_deinit(iapp); + return NULL; + } + ifindex = ifr.ifr_ifindex; + + if (ioctl(iapp->udp_sock, SIOCGIFADDR, &ifr) != 0) { + perror("ioctl(SIOCGIFADDR)"); + iapp_deinit(iapp); + return NULL; + } + paddr = (struct sockaddr_in *) &ifr.ifr_addr; + if (paddr->sin_family != AF_INET) { + printf("Invalid address family %i (SIOCGIFADDR)\n", + paddr->sin_family); + iapp_deinit(iapp); + return NULL; + } + iapp->own.s_addr = paddr->sin_addr.s_addr; + + if (ioctl(iapp->udp_sock, SIOCGIFBRDADDR, &ifr) != 0) { + perror("ioctl(SIOCGIFBRDADDR)"); + iapp_deinit(iapp); + return NULL; + } + paddr = (struct sockaddr_in *) &ifr.ifr_addr; + if (paddr->sin_family != AF_INET) { + printf("Invalid address family %i (SIOCGIFBRDADDR)\n", + paddr->sin_family); + iapp_deinit(iapp); + return NULL; + } + inet_aton(IAPP_MULTICAST, &iapp->multicast); + + os_memset(&uaddr, 0, sizeof(uaddr)); + uaddr.sin_family = AF_INET; + uaddr.sin_port = htons(IAPP_UDP_PORT); + if (bind(iapp->udp_sock, (struct sockaddr *) &uaddr, + sizeof(uaddr)) < 0) { + perror("bind[UDP]"); + iapp_deinit(iapp); + return NULL; + } + + os_memset(&mreq, 0, sizeof(mreq)); + mreq.imr_multiaddr = iapp->multicast; + mreq.imr_address.s_addr = INADDR_ANY; + mreq.imr_ifindex = 0; + if (setsockopt(iapp->udp_sock, SOL_IP, IP_ADD_MEMBERSHIP, &mreq, + sizeof(mreq)) < 0) { + perror("setsockopt[UDP,IP_ADD_MEMBERSHIP]"); + iapp_deinit(iapp); + return NULL; + } + + iapp->packet_sock = socket(PF_PACKET, SOCK_RAW, htons(ETH_P_ALL)); + if (iapp->packet_sock < 0) { + perror("socket[PF_PACKET,SOCK_RAW]"); + iapp_deinit(iapp); + return NULL; + } + + os_memset(&addr, 0, sizeof(addr)); + addr.sll_family = AF_PACKET; + addr.sll_ifindex = ifindex; + if (bind(iapp->packet_sock, (struct sockaddr *) &addr, + sizeof(addr)) < 0) { + perror("bind[PACKET]"); + iapp_deinit(iapp); + return NULL; + } + + if (eloop_register_read_sock(iapp->udp_sock, iapp_receive_udp, + iapp, NULL)) { + printf("Could not register read socket for IAPP.\n"); + iapp_deinit(iapp); + return NULL; + } + + printf("IEEE 802.11F (IAPP) using interface %s\n", iface); + + /* TODO: For levels 2 and 3: send RADIUS Initiate-Request, receive + * RADIUS Initiate-Accept or Initiate-Reject. IAPP port should actually + * be openned only after receiving Initiate-Accept. If Initiate-Reject + * is received, IAPP is not started. */ + + return iapp; +} + + +void iapp_deinit(struct iapp_data *iapp) +{ + struct ip_mreqn mreq; + + if (iapp == NULL) + return; + + if (iapp->udp_sock >= 0) { + os_memset(&mreq, 0, sizeof(mreq)); + mreq.imr_multiaddr = iapp->multicast; + mreq.imr_address.s_addr = INADDR_ANY; + mreq.imr_ifindex = 0; + if (setsockopt(iapp->udp_sock, SOL_IP, IP_DROP_MEMBERSHIP, + &mreq, sizeof(mreq)) < 0) { + perror("setsockopt[UDP,IP_DEL_MEMBERSHIP]"); + } + + eloop_unregister_read_sock(iapp->udp_sock); + close(iapp->udp_sock); + } + if (iapp->packet_sock >= 0) { + eloop_unregister_read_sock(iapp->packet_sock); + close(iapp->packet_sock); + } + os_free(iapp); +} + +int iapp_reconfig(struct hostapd_data *hapd, struct hostapd_config *oldconf, + struct hostapd_bss_config *oldbss) +{ + if (hapd->conf->ieee802_11f != oldbss->ieee802_11f || + os_strcmp(hapd->conf->iapp_iface, oldbss->iapp_iface) != 0) { + iapp_deinit(hapd->iapp); + hapd->iapp = NULL; + + if (hapd->conf->ieee802_11f) { + hapd->iapp = iapp_init(hapd, hapd->conf->iapp_iface); + if (hapd->iapp == NULL) + return -1; + } + } + + return 0; +} |