lwip-contrib-mac/apps/netbios/netbios.c
2010-05-16 16:05:41 +00:00

338 lines
11 KiB
C

/**
* @file
* NetBIOS name service sample
*
*/
/*
* 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.
*
*/
#include "lwip/opt.h"
#if LWIP_UDP /* don't build if not configured for use in lwipopts.h */
#include "lwip/udp.h"
#include "lwip/netif.h"
#include <string.h>
/** 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!
*/
/** NetBIOS name of LWIP device
* This must be uppercase until NETBIOS_STRCMP() is defined to a string
* comparision function that is case insensitive.
* If you want to use the netif's hostname, use this (with LWIP_NETIF_HOSTNAME):
* (ip_current_netif() != NULL ? ip_current_netif()->hostname != NULL ? ip_current_netif()->hostname : "" : "")
*/
#ifndef NETBIOS_LWIP_NAME
#define NETBIOS_LWIP_NAME "NETBIOSLWIPDEV"
#endif
/** Since there's no standard function for case-insensitive string comparision,
* we need another define here:
* define this to stricmp() for windows or strcasecmp() for linux.
* If not defined, comparision is case sensitive and NETBIOS_LWIP_NAME must be
* uppercase
*/
#ifndef NETBIOS_STRCMP
#define NETBIOS_STRCMP(str1, str2) strcmp(str1, str2)
#endif
/** default port number for "NetBIOS Name service */
#define NETBIOS_PORT 137
/** 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 300000
/** NetBIOS header flags */
#define NETB_HFLAG_RESPONSE 0x8000
#define NETB_HFLAG_OPCODE 0x7800
#define NETB_HFLAG_OPCODE_NAME_QUERY 0x0000
#define NETB_HFLAG_AUTHORATIVE 0x0400
#define NETB_HFLAG_TRUNCATED 0x0200
#define NETB_HFLAG_RECURS_DESIRED 0x0100
#define NETB_HFLAG_RECURS_AVAILABLE 0x0080
#define NETB_HFLAG_BROADCAST 0x0010
#define NETB_HFLAG_REPLYCODE 0x0008
#define NETB_HFLAG_REPLYCODE_NOERROR 0x0000
/** NetBIOS name flags */
#define NETB_NFLAG_UNIQUE 0x8000
#define NETB_NFLAG_NODETYPE 0x6000
#define NETB_NFLAG_NODETYPE_HNODE 0x6000
#define NETB_NFLAG_NODETYPE_MNODE 0x4000
#define NETB_NFLAG_NODETYPE_PNODE 0x2000
#define NETB_NFLAG_NODETYPE_BNODE 0x0000
/** 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 name part */
#ifdef PACK_STRUCT_USE_INCLUDES
# include "arch/bpstruct.h"
#endif
PACK_STRUCT_BEGIN
struct netbios_name_hdr {
PACK_STRUCT_FIELD(u8_t nametype);
PACK_STRUCT_FIELD(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_FIELD(ip_addr_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
/** NetBIOS decoding name */
static int
netbios_name_decoding( char *name_enc, char *name_dec, int name_dec_len)
{
char *pname;
char cname;
char cnbname;
int index = 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 (cname < 'A' || cname > 'Z') {
/* Not legal. */
return -1;
}
cname -= 'A';
cnbname = cname << 4;
pname++;
cname = *pname;
if (cname == '\0' || cname == '.') {
/* No more characters in the name - but we're in
* the middle of a pair. Not legal. */
return -1;
}
if (cname < 'A' || cname > 'Z') {
/* Not legal. */
return -1;
}
cname -= 'A';
cnbname |= cname;
pname++;
/* Do we have room to store the character? */
if (index < NETBIOS_NAME_LEN) {
/* Yes - store the character. */
name_dec[index++] = (cnbname!=' '?cnbname:'\0');
}
}
return 0;
}
#if 0 /* function currently unused */
/** NetBIOS encoding name */
static int
netbios_name_encoding(char *name_enc, char *name_dec, int name_dec_len)
{
char *pname;
char cname;
unsigned char ucname;
int index = 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 (index >= name_dec_len) {
return -1;
}
/* Yes - store the character. */
ucname = cname;
name_dec[index++] = ('A'+((ucname>>4) & 0x0F));
name_dec[index++] = ('A'+( ucname & 0x0F));
pname++;
}
/* Fill with "space" coding */
for (;index<name_dec_len-1;) {
name_dec[index++] = 'C';
name_dec[index++] = 'A';
}
/* Terminate string */
name_dec[index]='\0';
return 0;
}
#endif /* 0 */
/** NetBIOS Name service recv callback */
static void
netbios_recv(void *arg, struct udp_pcb *upcb, struct pbuf *p, 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_name_hdr* netbios_name_hdr = (struct netbios_name_hdr*)(netbios_hdr+1);
/* 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 */
netbios_name_decoding( (char*)(netbios_name_hdr->encname), netbios_name, sizeof(netbios_name));
/* if the packet is for us */
if (NETBIOS_STRCMP(netbios_name, NETBIOS_LWIP_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_name_hdr->encname, sizeof(netbios_name_hdr->encname));
resp->resp_name.nametype = netbios_name_hdr->nametype;
resp->resp_name.type = netbios_name_hdr->type;
resp->resp_name.cls = netbios_name_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);
ip_addr_copy(resp->resp_name.addr, netif_default->ip_addr);
/* send the NetBIOS response */
udp_sendto(upcb, q, addr, port);
/* free the "reference" pbuf */
pbuf_free(q);
}
}
}
}
/* free the pbuf */
pbuf_free(p);
}
}
void netbios_init(void)
{
struct udp_pcb *pcb;
LWIP_ASSERT("NetBIOS name is too long!", strlen(NETBIOS_LWIP_NAME) < NETBIOS_NAME_LEN);
pcb = udp_new();
if (pcb != NULL) {
/* we have to be allowed to send broadcast packets! */
pcb->so_options |= SOF_BROADCAST;
udp_bind(pcb, IP_ADDR_ANY, NETBIOS_PORT);
udp_recv(pcb, netbios_recv, pcb);
}
}
#endif /* LWIP_UDP */