/** * @file * @brief * Wireless EThernet (WET) Bridge. * * WET STA and WET client are inter-exchangable in this file and refer to * addressable entities whose traffic are sent and received through this * bridge, including the hosting device. * * Supported protocol families: IP v4. * * Tx: replace frames' source MAC address with wireless interface's; * update the IP-MAC address mapping table entry. * * Rx: replace frames' the destination MAC address with what found in * the IP-MAC address mapping table. * * All data structures defined in this file are optimized for IP v4. To * support other protocol families, write protocol specific handlers. * Doing so may require data structures changes to expand various address * storages to fit the protocol specific needs, for example, IPX needs 10 * octets for its network address. Also one may need to define the data * structures in a more generic way so that they work with all supported * protocol families, for example, the wet_sta strcture may be defined * as follow: * * struct wet_sta { * uint8 nal; network address length * uint8 na[NETA_MAX_LEN]; network address * uint8 mac[ETHER_ADDR_LEN]; * ... * }; * * Copyright (C) 2020, Broadcom. * * Unless you and Broadcom execute a separate written software license * agreement governing use of this software, this software is licensed to you * under the terms of the GNU General Public License version 2 (the "GPL"), * available at http://www.broadcom.com/licenses/GPLv2.php, with the * following added to such license: * * As a special exception, the copyright holders of this software give you * permission to link this software with independent modules, and to copy and * distribute the resulting executable under terms of your choice, provided that * you also meet, for each linked independent module, the terms and conditions of * the license of that module. An independent module is a module which is not * derived from this software. The special exception does not apply to any * modifications of the software. * * * <> * * $Id$ */ /** * @file * @brief * XXX Twiki: [WirelessEthernet] */ #include #include #include #include #include #include #include <802.11.h> #include #include #include <802.3.h> #include #include #include #include #include #include #include #include /* IP/MAC address mapping entry */ typedef struct wet_sta wet_sta_t; struct wet_sta { /* client */ uint8 ip[IPV4_ADDR_LEN]; /* client IP addr */ struct ether_addr mac; /* client MAC addr */ uint8 flags[DHCP_FLAGS_LEN]; /* orig. dhcp flags */ /* internal */ wet_sta_t *next; /* free STA link */ wet_sta_t *next_ip; /* hash link by IP */ wet_sta_t *next_mac; /* hash link by MAC */ }; #define WET_NUMSTAS (1 << 8) /* max. # clients, must be multiple of 2 */ #define WET_STA_HASH_SIZE (WET_NUMSTAS/2) /* must be <= WET_NUMSTAS */ #define WET_STA_HASH_IP(ip) ((ip)[3]&(WET_STA_HASH_SIZE-1)) /* hash by IP */ #define WET_STA_HASH_MAC(ea) (((ea)[3]^(ea)[4]^(ea)[5])&(WET_STA_HASH_SIZE-1)) /* hash by MAC */ #define WET_STA_HASH_UNK -1 /* Unknown hash */ #define IP_ISMULTI(ip) (((ip) & 0xf0000000) == 0xe0000000) /* Check for multicast by IP */ /* WET private info structure */ struct dhd_wet_info { /* pointer to dhdpublic info struct */ dhd_pub_t *pub; /* Host addresses */ uint8 ip[IPV4_ADDR_LEN]; struct ether_addr mac; /* STA storage, one entry per eth. client */ wet_sta_t sta[WET_NUMSTAS]; /* Free sta list */ wet_sta_t *stafree; /* Used sta hash by IP */ wet_sta_t *stahash_ip[WET_STA_HASH_SIZE]; /* Used sta hash by MAC */ wet_sta_t *stahash_mac[WET_STA_HASH_SIZE]; }; /* forward declarations */ static int wet_eth_proc(dhd_wet_info_t *weth, void *sdu, uint8 *frame, int length, int send); static int wet_vtag_proc(dhd_wet_info_t *weth, void *sdu, uint8 * eh, uint8 *vtag, int length, int send); static int wet_ip_proc(dhd_wet_info_t *weth, void *sdu, uint8 * eh, uint8 *iph, int length, int send); static int wet_arp_proc(dhd_wet_info_t *weth, void *sdu, uint8 *eh, uint8 *arph, int length, int send); static int wet_udp_proc(dhd_wet_info_t *weth, uint8 *eh, uint8 *iph, uint8 *udph, int length, int send); static int wet_dhcpc_proc(dhd_wet_info_t *weth, uint8 *eh, uint8 *iph, uint8 *udph, uint8 *dhcp, int length, int send); static int wet_dhcps_proc(dhd_wet_info_t *weth, uint8 *eh, uint8 *iph, uint8 *udph, uint8 *dhcp, int length, int send); static int wet_sta_alloc(dhd_wet_info_t *weth, wet_sta_t **saddr); static int wet_sta_update_all(dhd_wet_info_t *weth, uint8 *iaddr, struct ether_addr *eaddr, wet_sta_t **saddr); static int wet_sta_update_mac(dhd_wet_info_t *weth, struct ether_addr *eaddr, wet_sta_t **saddr); static int wet_sta_remove_mac_entry(dhd_wet_info_t *weth, struct ether_addr *eaddr); static int wet_sta_find_ip(dhd_wet_info_t *weth, uint8 *iaddr, wet_sta_t **saddr); static int wet_sta_find_mac(dhd_wet_info_t *weth, struct ether_addr *eaddr, wet_sta_t **saddr); static void csum_fixup_16(uint8 *chksum, uint8 *optr, int olen, uint8 *nptr, int nlen); /* * Protocol handler. 'ph' points to protocol specific header, * for example, it points to IP header if it is IP packet. */ typedef int (*prot_proc_t)(dhd_wet_info_t *weth, void *sdu, uint8 *eh, uint8 *ph, int length, int send); /* Protocol handlers hash table - hash by ether type */ typedef struct prot_hdlr prot_hdlr_t; struct prot_hdlr { uint16 type; /* ether type */ prot_proc_t prot_proc; prot_hdlr_t *next; /* next proto handler that has the same hash */ }; #define WET_PROT_HASH_SIZE (1 << 3) #define WET_PROT_HASH(t) ((t)[1]&(WET_PROT_HASH_SIZE-1)) static prot_hdlr_t ept_tbl[] = { /* 0 */ {HTON16(ETHER_TYPE_8021Q), wet_vtag_proc, NULL}, /* 0x8100 */ }; static prot_hdlr_t prot_hash[WET_PROT_HASH_SIZE] = { /* 0 */ {HTON16(ETHER_TYPE_IP), wet_ip_proc, &ept_tbl[0]}, /* 0x0800 */ /* 1 */ {0, NULL, NULL}, /* unused */ /* 2 */ {0, NULL, NULL}, /* unused */ /* 3 */ {0, NULL, NULL}, /* unused */ /* 4 */ {0, NULL, NULL}, /* unused */ /* 5 */ {0, NULL, NULL}, /* unused */ /* 6 */ {HTON16(ETHER_TYPE_ARP), wet_arp_proc, NULL}, /* 0x0806 */ /* 7 */ {0, NULL, NULL}, /* unused */ }; /* * IPv4 handler. 'ph' points to protocol specific header, * for example, it points to UDP header if it is UDP packet. */ typedef int (*ipv4_proc_t)(dhd_wet_info_t *weth, uint8 *eh, uint8 *iph, uint8 *ph, int length, int send); /* IPv4 handlers hash table - hash by protocol type */ typedef struct ipv4_hdlr ipv4_hdlr_t; struct ipv4_hdlr { uint8 type; /* protocol type */ ipv4_proc_t ipv4_proc; ipv4_hdlr_t *next; /* next proto handler that has the same hash */ }; #define WET_IPV4_HASH_SIZE (1 << 1) #define WET_IPV4_HASH(p) ((p)&(WET_IPV4_HASH_SIZE-1)) static ipv4_hdlr_t ipv4_hash[WET_IPV4_HASH_SIZE] = { /* 0 */ {0, NULL, NULL}, /* unused */ /* 1 */ {IP_PROT_UDP, wet_udp_proc, NULL}, /* 0x11 */ }; /* * UDP handler. 'ph' points to protocol specific header, * for example, it points to DHCP header if it is DHCP packet. */ typedef int (*udp_proc_t)(dhd_wet_info_t *weth, uint8 *eh, uint8 *iph, uint8 *udph, uint8 *ph, int length, int send); /* UDP handlers hash table - hash by port number */ typedef struct udp_hdlr udp_hdlr_t; struct udp_hdlr { uint16 port; /* udp dest. port */ udp_proc_t udp_proc; udp_hdlr_t *next; /* next proto handler that has the same hash */ }; #define WET_UDP_HASH_SIZE (1 << 3) #define WET_UDP_HASH(p) ((p)[1]&(WET_UDP_HASH_SIZE-1)) static udp_hdlr_t udp_hash[WET_UDP_HASH_SIZE] = { /* 0 */ {0, NULL, NULL}, /* unused */ /* 1 */ {0, NULL, NULL}, /* unused */ /* 2 */ {0, NULL, NULL}, /* unused */ /* 3 */ {HTON16(DHCP_PORT_SERVER), wet_dhcpc_proc, NULL}, /* 0x43 */ /* 4 */ {HTON16(DHCP_PORT_CLIENT), wet_dhcps_proc, NULL}, /* 0x44 */ /* 5 */ {0, NULL, NULL}, /* unused */ /* 6 */ {0, NULL, NULL}, /* unused */ /* 7 */ {0, NULL, NULL}, /* unused */ }; #define WETHWADDR(weth) ((weth)->pub->mac.octet) #define WETOSH(weth) ((weth)->pub->osh) /* special values */ /* 802.3 llc/snap header */ static uint8 llc_snap_hdr[SNAP_HDR_LEN] = {0xaa, 0xaa, 0x03, 0x00, 0x00, 0x00}; static uint8 ipv4_bcast[IPV4_ADDR_LEN] = {0xff, 0xff, 0xff, 0xff}; /* IP v4 broadcast address */ static uint8 ipv4_null[IPV4_ADDR_LEN] = {0x00, 0x00, 0x00, 0x00}; /* IP v4 NULL address */ dhd_wet_info_t * dhd_get_wet_info(dhd_pub_t *pub) { dhd_wet_info_t *p; int i; p = (dhd_wet_info_t *)MALLOCZ(pub->osh, sizeof(dhd_wet_info_t)); if (p == NULL) { return 0; } for (i = 0; i < WET_NUMSTAS - 1; i ++) p->sta[i].next = &p->sta[i + 1]; p->stafree = &p->sta[0]; p->pub = pub; return p; } void dhd_free_wet_info(dhd_pub_t *pub, void *wet) { if (wet) { MFREE(pub->osh, wet, sizeof(dhd_wet_info_t)); } } void dhd_set_wet_host_ipv4(dhd_pub_t *pub, void *parms, uint32 len) { dhd_wet_info_t *p; p = (dhd_wet_info_t *)pub->wet_info; bcopy(parms, p->ip, len); } void dhd_set_wet_host_mac(dhd_pub_t *pub, void *parms, uint32 len) { dhd_wet_info_t *p; p = (dhd_wet_info_t *)pub->wet_info; bcopy(parms, &p->mac, len); } /* process Ethernet frame */ /* * Return: * = 0 if frame is done ok * < 0 if unable to handle the frame * > 0 if no further process */ static int BCMFASTPATH(wet_eth_proc)(dhd_wet_info_t *weth, void *sdu, uint8 *frame, int length, int send) { uint8 *pt = frame + ETHER_TYPE_OFFSET; uint16 type; uint8 *ph; prot_hdlr_t *phdlr; /* intercept Ethernet II frame (type > 1500) */ if (length >= ETHER_HDR_LEN && (pt[0] > (ETHER_MAX_DATA >> 8) || (pt[0] == (ETHER_MAX_DATA >> 8) && pt[1] > (ETHER_MAX_DATA & 0xff)))) ; /* intercept 802.3 LLC/SNAP frame (type <= 1500) */ else if (length >= ETHER_HDR_LEN + SNAP_HDR_LEN + ETHER_TYPE_LEN) { uint8 *llc = frame + ETHER_HDR_LEN; if (bcmp(llc_snap_hdr, llc, SNAP_HDR_LEN)) return 0; pt = llc + SNAP_HDR_LEN; } /* frame too short bail out */ else { DHD_ERROR(("wet_eth_proc: %s short eth frame, ignored\n", send ? "send" : "recv")); return -1; } ph = pt + ETHER_TYPE_LEN; length -= ph - frame; /* Call protocol specific handler to process frame. */ type = *(uint16 *)pt; for (phdlr = &prot_hash[WET_PROT_HASH(pt)]; phdlr != NULL; phdlr = phdlr->next) { if (phdlr->type != type || !phdlr->prot_proc) continue; return (phdlr->prot_proc)(weth, sdu, frame, ph, length, send); } if (!bcmp(WETHWADDR(weth), frame + ETHER_SRC_OFFSET, ETHER_ADDR_LEN)) { return 0; } else { DHD_INFO(("%s: %s unknown type (0x%X), ignored %s\n", __FUNCTION__, send ? "send" : "recv", type, (type == 0xDD86) ? "IPv6":"")); /* ignore unsupported protocol from different mac addr than us */ return BCME_UNSUPPORTED; } } /* process 8021p/Q tagged frame */ /* * Return: * = 0 if frame is done ok * < 0 if unable to handle the frame * > 0 if no further process */ static int BCMFASTPATH(wet_vtag_proc)(dhd_wet_info_t *weth, void *sdu, uint8 * eh, uint8 *vtag, int length, int send) { uint16 type; uint8 *pt; prot_hdlr_t *phdlr; /* check minimum length */ if (length < ETHERVLAN_HDR_LEN) { DHD_ERROR(("wet_vtag_proc: %s short VLAN frame, ignored\n", send ? "send" : "recv")); return -1; } /* * FIXME: check recursiveness to prevent stack from overflow * in case someone sent frames 8100xxxxxxxx8100xxxxxxxx... */ /* Call protocol specific handler to process frame. */ type = *(uint16 *)(pt = vtag + VLAN_TAG_LEN); for (phdlr = &prot_hash[WET_PROT_HASH(pt)]; phdlr != NULL; phdlr = phdlr->next) { if (phdlr->type != type || !phdlr->prot_proc) continue; return (phdlr->prot_proc)(weth, sdu, eh, pt + ETHER_TYPE_LEN, length, send); } return 0; } /* process IP frame */ /* * Return: * = 0 if frame is done ok * < 0 if unable to handle the frame * > 0 if no further process */ static int BCMFASTPATH(wet_ip_proc)(dhd_wet_info_t *weth, void *sdu, uint8 *eh, uint8 *iph, int length, int send) { uint8 type; int ihl; wet_sta_t *sta; ipv4_hdlr_t *iphdlr; uint8 *iaddr; struct ether_addr *ea = NULL; int ret, ea_off = 0; char eabuf[ETHER_ADDR_STR_LEN]; BCM_REFERENCE(eabuf); /* IPv4 only */ if (length < 1 || (IP_VER(iph) != IP_VER_4)) { DHD_INFO(("wet_ip_proc: %s non IPv4 frame, ignored\n", send ? "send" : "recv")); return -1; } ihl = IPV4_HLEN(iph); /* minimum length */ if (length < ihl) { DHD_ERROR(("wet_ip_proc: %s short IPv4 frame, ignored\n", send ? "send" : "recv")); return -1; } /* protocol specific handling */ type = IPV4_PROT(iph); for (iphdlr = &ipv4_hash[WET_IPV4_HASH(type)]; iphdlr; iphdlr = iphdlr->next) { if (iphdlr->type != type || !iphdlr->ipv4_proc) continue; if ((ret = (iphdlr->ipv4_proc)(weth, eh, iph, iph + ihl, length - ihl, send))) return ret; } /* generic IP packet handling * Replace source MAC in Ethernet header with wireless's and * keep track of IP MAC mapping when sending frame. */ if (send) { uint32 iaddr_dest, iaddr_src; bool wet_table_upd = TRUE; iaddr = iph + IPV4_SRC_IP_OFFSET; iaddr_dest = ntoh32(*((uint32 *)(iph + IPV4_DEST_IP_OFFSET))); iaddr_src = ntoh32(*(uint32 *)(iaddr)); /* Do not process and update knowledge base on receipt of a local IP * multicast frame */ if (IP_ISMULTI(iaddr_dest) && !iaddr_src) { DHD_INFO(("recv multicast frame from %s.Don't update hash table\n", bcm_ether_ntoa((struct ether_addr*) (eh + ETHER_SRC_OFFSET), eabuf))); wet_table_upd = FALSE; } if (wet_table_upd && wet_sta_update_all(weth, iaddr, (struct ether_addr*)(eh + ETHER_SRC_OFFSET), &sta) < 0) { DHD_INFO(("wet_ip_proc: unable to update STA %u.%u.%u.%u %s\n", iaddr[0], iaddr[1], iaddr[2], iaddr[3], bcm_ether_ntoa( (struct ether_addr*)(eh + ETHER_SRC_OFFSET), eabuf))); return -1; } ea = (struct ether_addr *)WETHWADDR(weth); ea_off = ETHER_SRC_OFFSET; eacopy(ea, eh + ea_off); } /* * Replace dest MAC in Ethernet header using the found one * when receiving frame. */ /* no action for received bcast/mcast ethernet frame */ else if (!ETHER_ISMULTI(eh)) { iaddr = iph + IPV4_DEST_IP_OFFSET; if (wet_sta_find_ip(weth, iaddr, &sta) < 0) { DHD_ERROR(("wet_ip_proc: unable to find STA %u.%u.%u.%u\n", iaddr[0], iaddr[1], iaddr[2], iaddr[3])); return -1; } ea = &sta->mac; ea_off = ETHER_DEST_OFFSET; eacopy(ea, eh + ea_off); } return 0; } /* process ARP frame - ARP proxy */ /* * Return: * = 0 if frame is done ok * < 0 if unable to handle the frame * > 0 if no further process */ static int BCMFASTPATH(wet_arp_proc)(dhd_wet_info_t *weth, void *sdu, uint8 *eh, uint8 *arph, int length, int send) { wet_sta_t *sta; uint8 *iaddr; char eabuf[ETHER_ADDR_STR_LEN]; BCM_REFERENCE(eabuf); /* * FIXME: validate ARP header: * h/w Ethernet 2, proto IP x800, h/w addr size 6, proto addr size 4. */ /* * Replace source MAC in Ethernet header as well as source MAC in * ARP protocol header when processing frame sent. */ if (send) { iaddr = arph + ARP_SRC_IP_OFFSET; if (wet_sta_update_all(weth, iaddr, (struct ether_addr*)(eh + ETHER_SRC_OFFSET), &sta) < 0) { DHD_INFO(("wet_arp_proc: unable to update STA %u.%u.%u.%u %s\n", iaddr[0], iaddr[1], iaddr[2], iaddr[3], bcm_ether_ntoa( (struct ether_addr*)(eh + ETHER_SRC_OFFSET), eabuf))); return -1; } bcopy(WETHWADDR(weth), eh + ETHER_SRC_OFFSET, ETHER_ADDR_LEN); bcopy(WETHWADDR(weth), arph+ARP_SRC_ETH_OFFSET, ETHER_ADDR_LEN); } /* * Replace dest MAC in Ethernet header as well as dest MAC in * ARP protocol header when processing frame recv'd. Process ARP * replies and Unicast ARP requests. */ else if ((*(uint16 *)(arph + ARP_OPC_OFFSET) == HTON16(ARP_OPC_REPLY)) || ((*(uint16 *)(arph + ARP_OPC_OFFSET) == HTON16(ARP_OPC_REQUEST)) && (!ETHER_ISMULTI(eh)))) { iaddr = arph + ARP_TGT_IP_OFFSET; if (wet_sta_find_ip(weth, iaddr, &sta) < 0) { DHD_INFO(("wet_arp_proc: unable to find STA %u.%u.%u.%u\n", iaddr[0], iaddr[1], iaddr[2], iaddr[3])); return -1; } bcopy(&sta->mac, arph + ARP_TGT_ETH_OFFSET, ETHER_ADDR_LEN); bcopy(&sta->mac, eh + ETHER_DEST_OFFSET, ETHER_ADDR_LEN); } return 0; } /* process UDP frame */ /* * Return: * = 0 if frame is done ok * < 0 if unable to handle the frame * > 0 if no further process */ static int BCMFASTPATH(wet_udp_proc)(dhd_wet_info_t *weth, uint8 *eh, uint8 *iph, uint8 *udph, int length, int send) { udp_hdlr_t *udphdlr; uint16 port; /* check frame length, at least UDP_HDR_LEN */ if ((length -= UDP_HDR_LEN) < 0) { DHD_ERROR(("wet_udp_proc: %s short UDP frame, ignored\n", send ? "send" : "recv")); return -1; } /* * Unfortunately we must spend some time here to deal with * some higher layer protocol special processings. * See individual handlers for protocol specific details. */ port = *(uint16 *)(udph + UDP_DEST_PORT_OFFSET); for (udphdlr = &udp_hash[WET_UDP_HASH((uint8 *)&port)]; udphdlr; udphdlr = udphdlr->next) { if (udphdlr->port != port || !udphdlr->udp_proc) continue; return (udphdlr->udp_proc)(weth, eh, iph, udph, udph + UDP_HDR_LEN, length, send); } return 0; } /* * DHCP is a 'complex' protocol for WET, mainly because it * uses its protocol body to convey IP/MAC info. It is impossible * to forward frames correctly back and forth without looking * into the DHCP's body and interpreting it. See RFC2131 sect. * 4.1 'Constructing and sending DHCP messages' for details * of using/parsing various fields in the body. * * DHCP pass through: * * Must alter DHCP flag to broadcast so that the server * can reply with the broadcast address before we can * provide DHCP relay functionality. Otherwise the DHCP * server will send DHCP replies using the DHCP client's * MAC address. Such replies will not be delivered simply * because: * * 1. The AP's bridge will not forward the replies back to * this device through the wireless link because it does not * know such node exists on this link. The bridge's forwarding * table on the AP will have this device's MAC address only. * It does not know anything else behind this device. * * 2. The AP's wireless driver won't allow such frames out * either even if they made their way out the AP's bridge * through the bridge's DLF broadcasting because there is * no such STA associated with the AP. * * 3. This device's MAC won't allow such frames pass * through in non-promiscuous mode even when they made * their way out of the AP's wireless interface somehow. * * DHCP relay: * * Once the WET is configured with the host MAC address it can * relay the host request as if it were sent from WET itself. * * Once the WET is configured with the host IP address it can * pretend to be the host and act as a relay agent. * * process DHCP client frame (client to server, or server to relay agent) * Return: * = 0 if frame is done ok * < 0 if unable to handle the frame * > 0 if no further process */ static int BCMFASTPATH(wet_dhcpc_proc)(dhd_wet_info_t *weth, uint8 *eh, uint8 *iph, uint8 *udph, uint8 *dhcp, int length, int send) { wet_sta_t *sta; uint16 flags; char eabuf[ETHER_ADDR_STR_LEN]; uint16 port; uint8 *ipv4; const struct ether_addr *ether; BCM_REFERENCE(eabuf); /* * FIXME: validate DHCP body: * htype Ethernet 1, hlen Ethernet 6, frame length at least 242. */ /* only interested in requests when sending to server */ if (send && *(dhcp + DHCP_TYPE_OFFSET) != DHCP_TYPE_REQUEST) return 0; /* only interested in replies when receiving from server as a relay agent */ if (!send && *(dhcp + DHCP_TYPE_OFFSET) != DHCP_TYPE_REPLY) return 0; /* send request */ if (send) { /* find existing or alloc new IP/MAC mapping entry */ if (wet_sta_update_mac(weth, (struct ether_addr*)(dhcp + DHCP_CHADDR_OFFSET), &sta) < 0) { DHD_INFO(("wet_dhcpc_proc: unable to update STA %s\n", bcm_ether_ntoa( (struct ether_addr*)(dhcp + DHCP_CHADDR_OFFSET), eabuf))); return -1; } bcopy(dhcp + DHCP_FLAGS_OFFSET, &flags, DHCP_FLAGS_LEN); /* We can always relay the host's request when we know its MAC addr. */ if (!ETHER_ISNULLADDR(weth->mac.octet) && !bcmp(dhcp + DHCP_CHADDR_OFFSET, &weth->mac, ETHER_ADDR_LEN)) { /* replace chaddr with host's MAC */ csum_fixup_16(udph + UDP_CHKSUM_OFFSET, dhcp + DHCP_CHADDR_OFFSET, ETHER_ADDR_LEN, WETHWADDR(weth), ETHER_ADDR_LEN); bcopy(WETHWADDR(weth), dhcp + DHCP_CHADDR_OFFSET, ETHER_ADDR_LEN); /* force reply to be unicast */ flags &= ~HTON16(DHCP_FLAG_BCAST); } /* We can relay other clients' requests when we know the host's IP addr. */ else if (!IPV4_ADDR_NULL(weth->ip)) { /* we can only handle the first hop otherwise drop it */ if (!IPV4_ADDR_NULL(dhcp + DHCP_GIADDR_OFFSET)) { DHD_INFO(("wet_dhcpc_proc: not first hop, ignored\n")); return -1; } /* replace giaddr with host's IP */ csum_fixup_16(udph + UDP_CHKSUM_OFFSET, dhcp + DHCP_GIADDR_OFFSET, IPV4_ADDR_LEN, weth->ip, IPV4_ADDR_LEN); bcopy(weth->ip, dhcp + DHCP_GIADDR_OFFSET, IPV4_ADDR_LEN); /* force reply to be unicast */ flags &= ~HTON16(DHCP_FLAG_BCAST); } /* * Request comes in when we don't know the host's MAC and/or IP * addresses hence we can't relay the request. We must notify the * server of our addressing limitation by turning on the broadcast * bit at this point as what the function comments point out. */ else flags |= HTON16(DHCP_FLAG_BCAST); /* update flags */ bcopy(dhcp + DHCP_FLAGS_OFFSET, sta->flags, DHCP_FLAGS_LEN); if (flags != *(uint16 *)sta->flags) { csum_fixup_16(udph + UDP_CHKSUM_OFFSET, dhcp + DHCP_FLAGS_OFFSET, DHCP_FLAGS_LEN, (uint8 *)&flags, DHCP_FLAGS_LEN); bcopy((uint8 *)&flags, dhcp + DHCP_FLAGS_OFFSET, DHCP_FLAGS_LEN); } /* replace the Ethernet source MAC with ours */ bcopy(WETHWADDR(weth), eh + ETHER_SRC_OFFSET, ETHER_ADDR_LEN); } /* relay recv'd reply to its destiny */ else if (!IPV4_ADDR_NULL(weth->ip) && !bcmp(dhcp + DHCP_GIADDR_OFFSET, weth->ip, IPV4_ADDR_LEN)) { /* find IP/MAC mapping entry */ if (wet_sta_find_mac(weth, (struct ether_addr*)(dhcp + DHCP_CHADDR_OFFSET), &sta) < 0) { DHD_INFO(("wet_dhcpc_proc: unable to find STA %s\n", bcm_ether_ntoa( (struct ether_addr*)(dhcp + DHCP_CHADDR_OFFSET), eabuf))); return -1; } /* * XXX the following code works for the first hop only */ /* restore the DHCP giaddr with its original */ csum_fixup_16(udph + UDP_CHKSUM_OFFSET, dhcp + DHCP_GIADDR_OFFSET, IPV4_ADDR_LEN, ipv4_null, IPV4_ADDR_LEN); bcopy(ipv4_null, dhcp + DHCP_GIADDR_OFFSET, IPV4_ADDR_LEN); /* restore the original client's dhcp flags */ if (bcmp(dhcp + DHCP_FLAGS_OFFSET, sta->flags, DHCP_FLAGS_LEN)) { csum_fixup_16(udph + UDP_CHKSUM_OFFSET, dhcp + DHCP_FLAGS_OFFSET, DHCP_FLAGS_LEN, sta->flags, DHCP_FLAGS_LEN); bcopy(sta->flags, dhcp + DHCP_FLAGS_OFFSET, DHCP_FLAGS_LEN); } /* replace the dest UDP port with DHCP client port */ port = HTON16(DHCP_PORT_CLIENT); csum_fixup_16(udph + UDP_CHKSUM_OFFSET, udph + UDP_DEST_PORT_OFFSET, UDP_PORT_LEN, (uint8 *)&port, UDP_PORT_LEN); bcopy((uint8 *)&port, udph + UDP_DEST_PORT_OFFSET, UDP_PORT_LEN); /* replace the dest MAC & IP addr with the client's */ if (*(uint16 *)sta->flags & HTON16(DHCP_FLAG_BCAST)) { ipv4 = ipv4_bcast; ether = ðer_bcast; } else { ipv4 = dhcp + DHCP_YIADDR_OFFSET; ether = &sta->mac; } csum_fixup_16(udph + UDP_CHKSUM_OFFSET, iph + IPV4_DEST_IP_OFFSET, IPV4_ADDR_LEN, ipv4, IPV4_ADDR_LEN); csum_fixup_16(iph + IPV4_CHKSUM_OFFSET, iph + IPV4_DEST_IP_OFFSET, IPV4_ADDR_LEN, ipv4, IPV4_ADDR_LEN); bcopy(ipv4, iph + IPV4_DEST_IP_OFFSET, IPV4_ADDR_LEN); bcopy(ether, eh + ETHER_DEST_OFFSET, ETHER_ADDR_LEN); } /* it should not recv non-relay reply at all, but just in case */ else { DHD_INFO(("wet_dhcpc_proc: ignore recv'd frame from %s\n", bcm_ether_ntoa((struct ether_addr*)(dhcp + DHCP_CHADDR_OFFSET), eabuf))); return -1; } /* no further processing! */ return 1; } /* process DHCP server frame (server to client) */ /* * Return: * = 0 if frame is done ok * < 0 if unable to handle the frame * > 0 if no further process */ static int BCMFASTPATH(wet_dhcps_proc)(dhd_wet_info_t *weth, uint8 *eh, uint8 *iph, uint8 *udph, uint8 *dhcp, int length, int send) { wet_sta_t *sta; char eabuf[ETHER_ADDR_STR_LEN]; BCM_REFERENCE(eabuf); /* * FIXME: validate DHCP body: * htype Ethernet 1, hlen Ethernet 6, frame length at least 242. */ /* only interested in replies when receiving from server */ if (send || *(dhcp + DHCP_TYPE_OFFSET) != DHCP_TYPE_REPLY) return 0; /* find IP/MAC mapping entry */ if (wet_sta_find_mac(weth, (struct ether_addr*)(dhcp + DHCP_CHADDR_OFFSET), &sta) < 0) { DHD_INFO(("wet_dhcps_proc: unable to find STA %s\n", bcm_ether_ntoa((struct ether_addr*)(dhcp + DHCP_CHADDR_OFFSET), eabuf))); return -1; } /* relay the reply to the host when we know the host's MAC addr */ if (!ETHER_ISNULLADDR(weth->mac.octet) && !bcmp(dhcp + DHCP_CHADDR_OFFSET, WETHWADDR(weth), ETHER_ADDR_LEN)) { csum_fixup_16(udph + UDP_CHKSUM_OFFSET, dhcp + DHCP_CHADDR_OFFSET, ETHER_ADDR_LEN, weth->mac.octet, ETHER_ADDR_LEN); bcopy(&weth->mac, dhcp + DHCP_CHADDR_OFFSET, ETHER_ADDR_LEN); } /* restore the original client's dhcp flags if necessary */ if (bcmp(dhcp + DHCP_FLAGS_OFFSET, sta->flags, DHCP_FLAGS_LEN)) { csum_fixup_16(udph + UDP_CHKSUM_OFFSET, dhcp + DHCP_FLAGS_OFFSET, DHCP_FLAGS_LEN, sta->flags, DHCP_FLAGS_LEN); bcopy(sta->flags, dhcp + DHCP_FLAGS_OFFSET, DHCP_FLAGS_LEN); } /* replace the dest MAC with that of client's */ if (*(uint16 *)sta->flags & HTON16(DHCP_FLAG_BCAST)) bcopy((const uint8 *)ðer_bcast, eh + ETHER_DEST_OFFSET, ETHER_ADDR_LEN); else bcopy(&sta->mac, eh + ETHER_DEST_OFFSET, ETHER_ADDR_LEN); /* no further processing! */ return 1; } /* alloc IP/MAC mapping entry * Returns 0 if succeeded; < 0 otherwise. */ static int wet_sta_alloc(dhd_wet_info_t *weth, wet_sta_t **saddr) { wet_sta_t *sta; /* allocate a new one */ if (!weth->stafree) { DHD_INFO(("wet_sta_alloc: no room for another STA\n")); return -1; } sta = weth->stafree; weth->stafree = sta->next; /* init them just in case */ sta->next = NULL; sta->next_ip = NULL; sta->next_mac = NULL; *saddr = sta; return 0; } /* update IP/MAC mapping entry and hash * Returns 0 if succeeded; < 0 otherwise. */ static int BCMFASTPATH(wet_sta_update_all)(dhd_wet_info_t *weth, uint8 *iaddr, struct ether_addr *eaddr, wet_sta_t **saddr) { wet_sta_t *sta; int i; char eabuf[ETHER_ADDR_STR_LEN]; BCM_REFERENCE(eabuf); /* find the existing one and remove it from the old IP hash link */ if (!wet_sta_find_mac(weth, eaddr, &sta)) { i = WET_STA_HASH_IP(sta->ip); if (bcmp(sta->ip, iaddr, IPV4_ADDR_LEN)) { wet_sta_t *sta2, **next; for (next = &weth->stahash_ip[i], sta2 = *next; sta2; sta2 = sta2->next_ip) { if (sta2 == sta) break; next = &sta2->next_ip; } if (sta2) { *next = sta2->next_ip; sta2->next_ip = NULL; } i = WET_STA_HASH_UNK; } } /* allocate a new one and hash it by MAC */ else if (!wet_sta_alloc(weth, &sta)) { i = WET_STA_HASH_MAC(eaddr->octet); bcopy(eaddr, &sta->mac, ETHER_ADDR_LEN); sta->next_mac = weth->stahash_mac[i]; weth->stahash_mac[i] = sta; i = WET_STA_HASH_UNK; } /* bail out if we can't find nor create any */ else { DHD_INFO(("wet_sta_update_all: unable to alloc STA %u.%u.%u.%u %s\n", iaddr[0], iaddr[1], iaddr[2], iaddr[3], bcm_ether_ntoa(eaddr, eabuf))); return -1; } /* update IP and hash by new IP */ if (i == WET_STA_HASH_UNK) { i = WET_STA_HASH_IP(iaddr); bcopy(iaddr, sta->ip, IPV4_ADDR_LEN); sta->next_ip = weth->stahash_ip[i]; weth->stahash_ip[i] = sta; /* start here and look for other entries with same IP address */ { wet_sta_t *sta2, *prev; prev = sta; for (sta2 = sta->next_ip; sta2; sta2 = sta2->next_ip) { /* does this entry have the same IP address? */ if (!bcmp(sta->ip, sta2->ip, IPV4_ADDR_LEN)) { /* sta2 currently points to the entry we need to remove */ /* fix next pointers */ prev->next_ip = sta2->next_ip; sta2->next_ip = NULL; /* now we need to find this guy in the MAC list and remove it from that list too. */ wet_sta_remove_mac_entry(weth, &sta2->mac); /* entry should be completely out of the table now, add it to the free list */ memset(sta2, 0, sizeof(wet_sta_t)); sta2->next = weth->stafree; weth->stafree = sta2; sta2 = prev; } prev = sta2; } } } *saddr = sta; return 0; } /* update IP/MAC mapping entry and hash */ static int BCMFASTPATH(wet_sta_update_mac)(dhd_wet_info_t *weth, struct ether_addr *eaddr, wet_sta_t **saddr) { wet_sta_t *sta; int i; char eabuf[ETHER_ADDR_STR_LEN]; BCM_REFERENCE(eabuf); /* find the existing one */ if (!wet_sta_find_mac(weth, eaddr, &sta)) ; /* allocate a new one and hash it */ else if (!wet_sta_alloc(weth, &sta)) { i = WET_STA_HASH_MAC(eaddr->octet); bcopy(eaddr, &sta->mac, ETHER_ADDR_LEN); sta->next_mac = weth->stahash_mac[i]; weth->stahash_mac[i] = sta; } /* bail out if we can't find nor create any */ else { DHD_INFO(("wet_sta_update_mac: unable to alloc STA %s\n", bcm_ether_ntoa(eaddr, eabuf))); return -1; } *saddr = sta; return 0; } /* Remove MAC entry from hash list * NOTE: This only removes the entry matching "eaddr" from the MAC * list. The caller needs to remove from the IP list and * put back onto the free list to completely remove the entry * from the WET table. */ static int BCMFASTPATH(wet_sta_remove_mac_entry)(dhd_wet_info_t *weth, struct ether_addr *eaddr) { wet_sta_t *sta, *prev; int i = WET_STA_HASH_MAC(eaddr->octet); char eabuf[ETHER_ADDR_STR_LEN]; int found = 0; BCM_REFERENCE(eabuf); /* find the existing one */ for (sta = prev = weth->stahash_mac[i]; sta; sta = sta->next_mac) { if (!bcmp(&sta->mac, eaddr, ETHER_ADDR_LEN)) { found = 1; break; } prev = sta; } /* bail out if we can't find */ if (!found) { DHD_INFO(("wet_sta_remove_mac_entry: unable to find STA %s entry\n", bcm_ether_ntoa(eaddr, eabuf))); return -1; } /* fix the list */ if (prev == sta) weth->stahash_mac[i] = sta->next_mac; /* removing first entry in this bucket */ else prev->next_mac = sta->next_mac; return 0; } /* find IP/MAC mapping entry by IP address * Returns 0 if succeeded; < 0 otherwise. */ static int BCMFASTPATH(wet_sta_find_ip)(dhd_wet_info_t *weth, uint8 *iaddr, wet_sta_t **saddr) { int i = WET_STA_HASH_IP(iaddr); wet_sta_t *sta; /* find the existing one by IP */ for (sta = weth->stahash_ip[i]; sta; sta = sta->next_ip) { if (bcmp(sta->ip, iaddr, IPV4_ADDR_LEN)) continue; *saddr = sta; return 0; } /* sta has not been learned */ DHD_INFO(("wet_sta_find_ip: unable to find STA %u.%u.%u.%u\n", iaddr[0], iaddr[1], iaddr[2], iaddr[3])); return -1; } /* find IP/MAC mapping entry by MAC address * Returns 0 if succeeded; < 0 otherwise. */ static int BCMFASTPATH(wet_sta_find_mac)(dhd_wet_info_t *weth, struct ether_addr *eaddr, wet_sta_t **saddr) { int i = WET_STA_HASH_MAC(eaddr->octet); wet_sta_t *sta; char eabuf[ETHER_ADDR_STR_LEN]; BCM_REFERENCE(eabuf); /* find the existing one by MAC */ for (sta = weth->stahash_mac[i]; sta; sta = sta->next_mac) { if (bcmp(&sta->mac, eaddr, ETHER_ADDR_LEN)) continue; *saddr = sta; return 0; } /* sta has not been learnt */ DHD_INFO(("wet_sta_find_mac: unable to find STA %s\n", bcm_ether_ntoa(eaddr, eabuf))); return -1; } /* Adjust 16 bit checksum - taken from RFC 3022. * * The algorithm below is applicable only for even offsets (i.e., optr * below must be at an even offset from start of header) and even lengths * (i.e., olen and nlen below must be even). */ static void BCMFASTPATH(csum_fixup_16)(uint8 *chksum, uint8 *optr, int olen, uint8 *nptr, int nlen) { long x, old, new; ASSERT(!((uintptr_t)optr&1) && !(olen&1)); ASSERT(!((uintptr_t)nptr&1) && !(nlen&1)); x = (chksum[0]<< 8)+chksum[1]; if (!x) return; x = ~x & 0xFFFF; while (olen) { old = (optr[0]<< 8)+optr[1]; optr += 2; x -= old & 0xffff; if (x <= 0) { x--; x &= 0xffff; } olen -= 2; } while (nlen) { new = (nptr[0]<< 8)+nptr[1]; nptr += 2; x += new & 0xffff; if (x & 0x10000) { x++; x &= 0xffff; } nlen -= 2; } x = ~x & 0xFFFF; chksum[0] = (uint8)(x >> 8); chksum[1] = (uint8)x; } /* Process frames in transmit direction by replacing source MAC with * wireless's and keep track of IP MAC address mapping table. * Return: * = 0 if frame is done ok; * < 0 if unable to handle the frame; * * To avoid other interfaces to see our changes specially * changes to broadcast frame which definitely will be seen by * other bridged interfaces we must copy the frame to our own * buffer, modify it, and then sent it. * Return the new sdu in 'new'. */ int BCMFASTPATH(dhd_wet_send_proc)(void *wet, void *sdu, void **new) { dhd_wet_info_t *weth = (dhd_wet_info_t *)wet; uint8 *frame = PKTDATA(WETOSH(weth), sdu); int length = PKTLEN(WETOSH(weth), sdu); void *pkt = sdu; /* * FIXME: need to tell if buffer is shared and only * do copy on shared buffer. */ /* * copy broadcast/multicast frame to our own packet * otherwise we will screw up others because we alter * the frame content. */ if (length < ETHER_HDR_LEN) { DHD_ERROR(("dhd_wet_send_proc: unable to process short frame\n")); return -1; } if (ETHER_ISMULTI(frame)) { length = pkttotlen(WETOSH(weth), sdu); if (!(pkt = PKTGET(WETOSH(weth), length, TRUE))) { DHD_ERROR(("dhd_wet_send_proc: unable to alloc, dropped\n")); return -1; } frame = PKTDATA(WETOSH(weth), pkt); pktcopy(WETOSH(weth), sdu, 0, length, frame); /* Transfer priority */ PKTSETPRIO(pkt, PKTPRIO(sdu)); PKTFREE(WETOSH(weth), sdu, TRUE); PKTSETLEN(WETOSH(weth), pkt, length); } *new = pkt; /* process frame */ return wet_eth_proc(weth, sdu, frame, length, 1) < 0 ? -1 : 0; } /* * Process frames in receive direction by replacing destination MAC with * the one found in IP MAC address mapping table. * Return: * = 0 if frame is done ok; * < 0 if unable to handle the frame; */ int BCMFASTPATH(dhd_wet_recv_proc)(void *wet, void *sdu) { dhd_wet_info_t *weth = (dhd_wet_info_t *)wet; /* process frame */ return wet_eth_proc(weth, sdu, PKTDATA(WETOSH(weth), sdu), PKTLEN(WETOSH(weth), sdu), 0) < 0 ? -1 : 0; } /* Delete WET Database */ void dhd_wet_sta_delete_list(dhd_pub_t *dhd_pub) { wet_sta_t *sta; int i, j; dhd_wet_info_t *weth = dhd_pub->wet_info; for (i = 0; i < WET_STA_HASH_SIZE; i ++) { for (sta = weth->stahash_mac[i]; sta; sta = sta->next_mac) { wet_sta_t *sta2, **next; j = WET_STA_HASH_IP(sta->ip); for (next = &weth->stahash_ip[j], sta2 = *next; sta2; sta2 = sta2->next_ip) { if (sta2 == sta) break; next = &sta2->next_ip; } if (sta2) { *next = sta2->next_ip; sta2->next_ip = NULL; } j = WET_STA_HASH_UNK; wet_sta_remove_mac_entry(weth, &sta->mac); memset(sta, 0, sizeof(wet_sta_t)); } } } void dhd_wet_dump(dhd_pub_t *dhdp, struct bcmstrbuf *b) { char eabuf[ETHER_ADDR_STR_LEN]; wet_sta_t *sta; int i; dhd_wet_info_t *weth = dhdp->wet_info; bcm_bprintf(b, "Host MAC: %s\n", bcm_ether_ntoa(&weth->mac, eabuf)); bcm_bprintf(b, "Host IP: %u.%u.%u.%u\n", weth->ip[0], weth->ip[1], weth->ip[2], weth->ip[3]); bcm_bprintf(b, "Entry\tEnetAddr\t\tInetAddr\n"); for (i = 0; i < WET_NUMSTAS; i ++) { /* FIXME: it leaves the last sta entry unfiltered, who cares! */ if (weth->sta[i].next) continue; /* format the entry dump */ sta = &weth->sta[i]; bcm_bprintf(b, "%u\t%s\t%u.%u.%u.%u\n", i, bcm_ether_ntoa(&sta->mac, eabuf), sta->ip[0], sta->ip[1], sta->ip[2], sta->ip[3]); } }