/** * @file * NetBIOS name service responder */ /** * @defgroup netbiosns NETBIOS responder * @ingroup apps * * This is an example implementation of a NetBIOS name server. * It responds to name queries for a configurable name. * Name resolving is not supported. * * Note that the device doesn't broadcast it's own name so can't * detect duplicate names! */ /* * Redistribution and use in source and binary forms, with or without modification, * are permitted provided that the following conditions are met: * * 1. Redistributions of source code must retain the above copyright notice, * this list of conditions and the following disclaimer. * 2. Redistributions in binary form must reproduce the above copyright notice, * this list of conditions and the following disclaimer in the documentation * and/or other materials provided with the distribution. * 3. The name of the author may not be used to endorse or promote products * derived from this software without specific prior written permission. * * THIS SOFTWARE IS PROVIDED BY THE AUTHOR ``AS IS'' AND ANY EXPRESS OR IMPLIED * WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE IMPLIED WARRANTIES OF * MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE ARE DISCLAIMED. IN NO EVENT * SHALL THE AUTHOR BE LIABLE FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, * EXEMPLARY, OR CONSEQUENTIAL DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT * OF SUBSTITUTE GOODS OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS * INTERRUPTION) HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN * CONTRACT, STRICT LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING * IN ANY WAY OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY * OF SUCH DAMAGE. * * This file is part of the lwIP TCP/IP stack. * * Modifications by Ray Abram to respond to NetBIOS name requests when Incoming name = * * - based on code from "https://github.com/esp8266/Arduino/commit/1f7989b31d26d7df9776a08f36d685eae7ac8f99" * - with permission to relicense to BSD from original author: * http://www.xpablo.cz/?p=751#more-751 */ #include "lwip/netbiosns.h" #if LWIP_IPV4 && LWIP_UDP /* don't build if not configured for use in lwipopts.h */ #include "lwip/def.h" #include "lwip/udp.h" #include "lwip/ip.h" #include "lwip/netif.h" #include "lwip/prot/iana.h" #include /** size of a NetBIOS name */ #define NETBIOS_NAME_LEN 16 /** The Time-To-Live for NetBIOS name responds (in seconds) * Default is 300000 seconds (3 days, 11 hours, 20 minutes) */ #define NETBIOS_NAME_TTL 300000u /** NetBIOS header flags */ #define NETB_HFLAG_RESPONSE 0x8000U #define NETB_HFLAG_OPCODE 0x7800U #define NETB_HFLAG_OPCODE_NAME_QUERY 0x0000U #define NETB_HFLAG_AUTHORATIVE 0x0400U #define NETB_HFLAG_TRUNCATED 0x0200U #define NETB_HFLAG_RECURS_DESIRED 0x0100U #define NETB_HFLAG_RECURS_AVAILABLE 0x0080U #define NETB_HFLAG_BROADCAST 0x0010U #define NETB_HFLAG_REPLYCODE 0x0008U #define NETB_HFLAG_REPLYCODE_NOERROR 0x0000U /* NetBIOS question types */ #define NETB_QTYPE_NB 0x0020U #define NETB_QTYPE_NBSTAT 0x0021U /** NetBIOS name flags */ #define NETB_NFLAG_UNIQUE 0x8000U #define NETB_NFLAG_NODETYPE 0x6000U #define NETB_NFLAG_NODETYPE_HNODE 0x6000U #define NETB_NFLAG_NODETYPE_MNODE 0x4000U #define NETB_NFLAG_NODETYPE_PNODE 0x2000U #define NETB_NFLAG_NODETYPE_BNODE 0x0000U #define NETB_NFLAG_NAME_IN_CONFLICT 0x0800U /* 1=Yes, 0=No */ #define NETB_NFLAG_NAME_IS_ACTIVE 0x0400U /* 1=Yes, 0=No */ #define NETB_NFLAG_NAME_IS_PERMANENT 0x0200U /* 1=Yes (Name is Permanent Node Name), 0=No */ /** NetBIOS message header */ #ifdef PACK_STRUCT_USE_INCLUDES # include "arch/bpstruct.h" #endif PACK_STRUCT_BEGIN struct netbios_hdr { PACK_STRUCT_FIELD(u16_t trans_id); PACK_STRUCT_FIELD(u16_t flags); PACK_STRUCT_FIELD(u16_t questions); PACK_STRUCT_FIELD(u16_t answerRRs); PACK_STRUCT_FIELD(u16_t authorityRRs); PACK_STRUCT_FIELD(u16_t additionalRRs); } PACK_STRUCT_STRUCT; PACK_STRUCT_END #ifdef PACK_STRUCT_USE_INCLUDES # include "arch/epstruct.h" #endif /** NetBIOS message question part */ #ifdef PACK_STRUCT_USE_INCLUDES # include "arch/bpstruct.h" #endif PACK_STRUCT_BEGIN struct netbios_question_hdr { PACK_STRUCT_FLD_8(u8_t nametype); PACK_STRUCT_FLD_8(u8_t encname[(NETBIOS_NAME_LEN * 2) + 1]); PACK_STRUCT_FIELD(u16_t type); PACK_STRUCT_FIELD(u16_t cls); } PACK_STRUCT_STRUCT; PACK_STRUCT_END #ifdef PACK_STRUCT_USE_INCLUDES # include "arch/epstruct.h" #endif /** NetBIOS message name part */ #ifdef PACK_STRUCT_USE_INCLUDES # include "arch/bpstruct.h" #endif PACK_STRUCT_BEGIN struct netbios_name_hdr { PACK_STRUCT_FLD_8(u8_t nametype); PACK_STRUCT_FLD_8(u8_t encname[(NETBIOS_NAME_LEN * 2) + 1]); PACK_STRUCT_FIELD(u16_t type); PACK_STRUCT_FIELD(u16_t cls); PACK_STRUCT_FIELD(u32_t ttl); PACK_STRUCT_FIELD(u16_t datalen); PACK_STRUCT_FIELD(u16_t flags); PACK_STRUCT_FLD_S(ip4_addr_p_t addr); } PACK_STRUCT_STRUCT; PACK_STRUCT_END #ifdef PACK_STRUCT_USE_INCLUDES # include "arch/epstruct.h" #endif /** NetBIOS message */ #ifdef PACK_STRUCT_USE_INCLUDES # include "arch/bpstruct.h" #endif PACK_STRUCT_BEGIN struct netbios_resp { struct netbios_hdr resp_hdr; struct netbios_name_hdr resp_name; } PACK_STRUCT_STRUCT; PACK_STRUCT_END #ifdef PACK_STRUCT_USE_INCLUDES # include "arch/epstruct.h" #endif /** The NBNS Structure Responds to a Name Query */ #ifdef PACK_STRUCT_USE_INCLUDES # include "arch/bpstruct.h" #endif PACK_STRUCT_BEGIN struct netbios_answer { struct netbios_hdr answer_hdr; /** the length of the next string */ PACK_STRUCT_FIELD(u8_t name_size); /** WARNING!!! this item may be of a different length (we use this struct for transmission) */ PACK_STRUCT_FLD_8(u8_t query_name[(NETBIOS_NAME_LEN * 2) + 1]); PACK_STRUCT_FIELD(u16_t packet_type); PACK_STRUCT_FIELD(u16_t cls); PACK_STRUCT_FIELD(u32_t ttl); PACK_STRUCT_FIELD(u16_t data_length); #define OFFSETOF_STRUCT_NETBIOS_ANSWER_NUMBER_OF_NAMES 56 /** number of names */ PACK_STRUCT_FLD_8(u8_t number_of_names); /** node name */ PACK_STRUCT_FLD_8(u8_t answer_name[NETBIOS_NAME_LEN]); /** node flags */ PACK_STRUCT_FIELD(u16_t answer_name_flags); /** Unit ID */ PACK_STRUCT_FLD_8(u8_t unit_id[6]); /** Jumpers */ PACK_STRUCT_FLD_8(u8_t jumpers); /** Test result */ PACK_STRUCT_FLD_8(u8_t test_result); /** Version number */ PACK_STRUCT_FIELD(u16_t version_number); /** Period of statistics */ PACK_STRUCT_FIELD(u16_t period_of_statistics); /** Statistics */ PACK_STRUCT_FIELD(u16_t number_of_crcs); /** Statistics */ PACK_STRUCT_FIELD(u16_t number_of_alignment_errors); /** Statistics */ PACK_STRUCT_FIELD(u16_t number_of_collisions); /** Statistics */ PACK_STRUCT_FIELD(u16_t number_of_send_aborts); /** Statistics */ PACK_STRUCT_FIELD(u32_t number_of_good_sends); /** Statistics */ PACK_STRUCT_FIELD(u32_t number_of_good_receives); /** Statistics */ PACK_STRUCT_FIELD(u16_t number_of_retransmits); /** Statistics */ PACK_STRUCT_FIELD(u16_t number_of_no_resource_condition); /** Statistics */ PACK_STRUCT_FIELD(u16_t number_of_free_command_blocks); /** Statistics */ PACK_STRUCT_FIELD(u16_t total_number_of_command_blocks); /** Statistics */ PACK_STRUCT_FIELD(u16_t max_total_number_of_command_blocks); /** Statistics */ PACK_STRUCT_FIELD(u16_t number_of_pending_sessions); /** Statistics */ PACK_STRUCT_FIELD(u16_t max_number_of_pending_sessions); /** Statistics */ PACK_STRUCT_FIELD(u16_t max_total_sessions_possible); /** Statistics */ PACK_STRUCT_FIELD(u16_t session_data_packet_size); } PACK_STRUCT_STRUCT; PACK_STRUCT_END #ifdef PACK_STRUCT_USE_INCLUDES # include "arch/epstruct.h" #endif #ifdef NETBIOS_LWIP_NAME #define NETBIOS_LOCAL_NAME NETBIOS_LWIP_NAME #else static char netbiosns_local_name[NETBIOS_NAME_LEN]; #define NETBIOS_LOCAL_NAME netbiosns_local_name #endif static struct udp_pcb *netbiosns_pcb; /** Decode a NetBIOS name (from packet to string) */ static int netbiosns_name_decode(const char *name_enc, char *name_dec, int name_dec_len) { const char *pname; char cname; char cnbname; int idx = 0; LWIP_UNUSED_ARG(name_dec_len); /* Start decoding netbios name. */ pname = name_enc; for (;;) { /* Every two characters of the first level-encoded name * turn into one character in the decoded name. */ cname = *pname; if (cname == '\0') { break; /* no more characters */ } if (cname == '.') { break; /* scope ID follows */ } if (!lwip_isupper(cname)) { /* Not legal. */ return -1; } cname -= 'A'; cnbname = cname << 4; pname++; cname = *pname; if (!lwip_isupper(cname)) { /* Not legal. */ return -1; } cname -= 'A'; cnbname |= cname; pname++; /* Do we have room to store the character? */ if (idx < NETBIOS_NAME_LEN) { /* Yes - store the character. */ name_dec[idx++] = (cnbname != ' ' ? cnbname : '\0'); } } return 0; } #if 0 /* function currently unused */ /** Encode a NetBIOS name (from string to packet) - currently unused because we don't ask for names. */ static int netbiosns_name_encode(char *name_enc, char *name_dec, int name_dec_len) { char *pname; char cname; unsigned char ucname; int idx = 0; /* Start encoding netbios name. */ pname = name_enc; for (;;) { /* Every two characters of the first level-encoded name * turn into one character in the decoded name. */ cname = *pname; if (cname == '\0') { break; /* no more characters */ } if (cname == '.') { break; /* scope ID follows */ } if ((cname < 'A' || cname > 'Z') && (cname < '0' || cname > '9')) { /* Not legal. */ return -1; } /* Do we have room to store the character? */ if (idx >= name_dec_len) { return -1; } /* Yes - store the character. */ ucname = cname; name_dec[idx++] = ('A' + ((ucname >> 4) & 0x0F)); name_dec[idx++] = ('A' + ( ucname & 0x0F)); pname++; } /* Fill with "space" coding */ for (; idx < name_dec_len - 1;) { name_dec[idx++] = 'C'; name_dec[idx++] = 'A'; } /* Terminate string */ name_dec[idx] = '\0'; return 0; } #endif /* 0 */ /** NetBIOS Name service recv callback */ static void netbiosns_recv(void *arg, struct udp_pcb *upcb, struct pbuf *p, const ip_addr_t *addr, u16_t port) { LWIP_UNUSED_ARG(arg); /* if packet is valid */ if (p != NULL) { char netbios_name[NETBIOS_NAME_LEN + 1]; struct netbios_hdr *netbios_hdr = (struct netbios_hdr *)p->payload; struct netbios_question_hdr *netbios_question_hdr = (struct netbios_question_hdr *)(netbios_hdr + 1); /* is the packet long enough (we need the header in one piece) */ if (p->len < (sizeof(struct netbios_hdr) + sizeof(struct netbios_question_hdr))) { /* packet too short */ pbuf_free(p); return; } /* we only answer if we got a default interface */ if (netif_default != NULL) { /* @todo: do we need to check answerRRs/authorityRRs/additionalRRs? */ /* if the packet is a NetBIOS name query question */ if (((netbios_hdr->flags & PP_NTOHS(NETB_HFLAG_OPCODE)) == PP_NTOHS(NETB_HFLAG_OPCODE_NAME_QUERY)) && ((netbios_hdr->flags & PP_NTOHS(NETB_HFLAG_RESPONSE)) == 0) && (netbios_hdr->questions == PP_NTOHS(1))) { /* decode the NetBIOS name */ netbiosns_name_decode((char *)(netbios_question_hdr->encname), netbios_name, sizeof(netbios_name)); /* check the request type */ if (netbios_question_hdr->type == PP_HTONS(NETB_QTYPE_NB)) { /* if the packet is for us */ if (lwip_strnicmp(netbios_name, NETBIOS_LOCAL_NAME, sizeof(NETBIOS_LOCAL_NAME)) == 0) { struct pbuf *q; struct netbios_resp *resp; q = pbuf_alloc(PBUF_TRANSPORT, sizeof(struct netbios_resp), PBUF_RAM); if (q != NULL) { resp = (struct netbios_resp *)q->payload; /* prepare NetBIOS header response */ resp->resp_hdr.trans_id = netbios_hdr->trans_id; resp->resp_hdr.flags = PP_HTONS(NETB_HFLAG_RESPONSE | NETB_HFLAG_OPCODE_NAME_QUERY | NETB_HFLAG_AUTHORATIVE | NETB_HFLAG_RECURS_DESIRED); resp->resp_hdr.questions = 0; resp->resp_hdr.answerRRs = PP_HTONS(1); resp->resp_hdr.authorityRRs = 0; resp->resp_hdr.additionalRRs = 0; /* prepare NetBIOS header datas */ MEMCPY( resp->resp_name.encname, netbios_question_hdr->encname, sizeof(netbios_question_hdr->encname)); resp->resp_name.nametype = netbios_question_hdr->nametype; resp->resp_name.type = netbios_question_hdr->type; resp->resp_name.cls = netbios_question_hdr->cls; resp->resp_name.ttl = PP_HTONL(NETBIOS_NAME_TTL); resp->resp_name.datalen = PP_HTONS(sizeof(resp->resp_name.flags) + sizeof(resp->resp_name.addr)); resp->resp_name.flags = PP_HTONS(NETB_NFLAG_NODETYPE_BNODE); ip4_addr_copy(resp->resp_name.addr, *netif_ip4_addr(netif_default)); /* send the NetBIOS response */ udp_sendto(upcb, q, addr, port); /* free the "reference" pbuf */ pbuf_free(q); } } #if LWIP_NETBIOS_RESPOND_NAME_QUERY } else if (netbios_question_hdr->type == PP_HTONS(NETB_QTYPE_NBSTAT)) { /* if the packet is for us or general query */ if (!lwip_strnicmp(netbios_name, NETBIOS_LOCAL_NAME, sizeof(NETBIOS_LOCAL_NAME)) || !lwip_strnicmp(netbios_name, "*", sizeof(NETBIOS_LOCAL_NAME))) { /* general query - ask for our IP address */ struct pbuf *q; struct netbios_answer *resp; q = pbuf_alloc(PBUF_TRANSPORT, sizeof(struct netbios_answer), PBUF_RAM); if (q != NULL) { /* buffer to which a response is compiled */ resp = (struct netbios_answer *) q->payload; /* Init response to zero, especially the statistics fields */ memset(resp, 0, sizeof(*resp)); /* copy the query to the response ID */ resp->answer_hdr.trans_id = netbios_hdr->trans_id; /* acknowledgment of termination */ resp->answer_hdr.flags = PP_HTONS(NETB_HFLAG_RESPONSE | NETB_HFLAG_OPCODE_NAME_QUERY | NETB_HFLAG_AUTHORATIVE); /* resp->answer_hdr.questions = PP_HTONS(0); done by memset() */ /* serial number of the answer */ resp->answer_hdr.answerRRs = PP_HTONS(1); /* resp->answer_hdr.authorityRRs = PP_HTONS(0); done by memset() */ /* resp->answer_hdr.additionalRRs = PP_HTONS(0); done by memset() */ /* we will copy the length of the station name */ resp->name_size = netbios_question_hdr->nametype; /* we will copy the queried name */ MEMCPY(resp->query_name, netbios_question_hdr->encname, (NETBIOS_NAME_LEN * 2) + 1); /* NBSTAT */ resp->packet_type = PP_HTONS(0x21); /* Internet name */ resp->cls = PP_HTONS(1); /* resp->ttl = PP_HTONL(0); done by memset() */ resp->data_length = PP_HTONS(sizeof(struct netbios_answer) - offsetof(struct netbios_answer, number_of_names)); resp->number_of_names = 1; /* make windows see us as workstation, not as a server */ memset(resp->answer_name, 0x20, NETBIOS_NAME_LEN - 1); /* strlen is checked to be < NETBIOS_NAME_LEN during initialization */ MEMCPY(resp->answer_name, NETBIOS_LOCAL_NAME, strlen(NETBIOS_LOCAL_NAME)); /* b-node, unique, active */ resp->answer_name_flags = PP_HTONS(NETB_NFLAG_NAME_IS_ACTIVE); /* Set responder netif MAC address */ SMEMCPY(resp->unit_id, ip_current_input_netif()->hwaddr, sizeof(resp->unit_id)); udp_sendto(upcb, q, addr, port); pbuf_free(q); } } #endif /* LWIP_NETBIOS_RESPOND_NAME_QUERY */ } } } /* free the pbuf */ pbuf_free(p); } } /** * @ingroup netbiosns * Init netbios responder */ void netbiosns_init(void) { /* LWIP_ASSERT_CORE_LOCKED(); is checked by udp_new() */ #ifdef NETBIOS_LWIP_NAME LWIP_ASSERT("NetBIOS name is too long!", strlen(NETBIOS_LWIP_NAME) < NETBIOS_NAME_LEN); #endif netbiosns_pcb = udp_new_ip_type(IPADDR_TYPE_ANY); if (netbiosns_pcb != NULL) { /* we have to be allowed to send broadcast packets! */ ip_set_option(netbiosns_pcb, SOF_BROADCAST); udp_bind(netbiosns_pcb, IP_ANY_TYPE, LWIP_IANA_PORT_NETBIOS); udp_recv(netbiosns_pcb, netbiosns_recv, netbiosns_pcb); } } #ifndef NETBIOS_LWIP_NAME /** * @ingroup netbiosns * Set netbios name. ATTENTION: the hostname must be less than 15 characters! * the NetBIOS name spec says the name MUST be upper case, so incoming name is forced into uppercase :-) */ void netbiosns_set_name(const char *hostname) { size_t i; size_t copy_len = strlen(hostname); LWIP_ASSERT_CORE_LOCKED(); LWIP_ASSERT("NetBIOS name is too long!", copy_len < NETBIOS_NAME_LEN); if (copy_len >= NETBIOS_NAME_LEN) { copy_len = NETBIOS_NAME_LEN - 1; } /* make name into upper case */ for (i = 0; i < copy_len; i++ ) { netbiosns_local_name[i] = (char)lwip_toupper(hostname[i]); } netbiosns_local_name[copy_len] = '\0'; } #endif /* NETBIOS_LWIP_NAME */ /** * @ingroup netbiosns * Stop netbios responder */ void netbiosns_stop(void) { LWIP_ASSERT_CORE_LOCKED(); if (netbiosns_pcb != NULL) { udp_remove(netbiosns_pcb); netbiosns_pcb = NULL; } } #endif /* LWIP_IPV4 && LWIP_UDP */