DNS(vxWorks内核)

/* resolvLib.c - DNS resolver library */ /* Copyright 1984 - 2001 Wind River Systems, Inc */ #include <copyright_wrs.h> /* modification history ------------------------- 01k,15oct01,rae merge from truestack ver 01l, base 01j (SPRs 67238, 28659) 01j,06oct98,jmp moved doc to resolvLibDoc.c. 01i,14dec97,jdi doc: cleanup. 01h,19aug97,jag fixed man page problems in resolvInit() SPR#9173, fixed SPR#9174, SPR#9175. Deleted getHostInfo(), getbyaddrWrapper() 01g,04aug97,kbw fixed man page problems found in beta review 01f,19may97,spm added checks for NULL pointers to user interface (SPR #8603) 01e,30apr97,kbw fiddled man page text 01d,01apr97,kbw fixed man page text, changed parameter name to "length" in resolvDNExpand 01c,01apr97,jag removed unused variable resolvDefaultDomainName. Added routines: resolvHostLibGetByAddr(), resolvHostLibGetByName(). Added necessary man pages. 01b,05feb97,jag added debug function pointer in resolvInit. MAX_DOMAIN_NAME 01a,12aug96,rjc written */ /* !!!!!!!!!!!!!!!!!!!!!!!!!!!!!! WARNING !!!!!!!!!!!!!!!!!!!!!!!!!!!!!! DOCUMENTATION of this library is located in resolvLibDoc.c If you modify any documented routine, please update resolvLibDoc.c. !!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!! */ /* includes */ #include <vxWorks.h> #include <resolvLib.h> #include <semLib.h> #include <hostLib.h> #include <stdlib.h> #include <sockLib.h> #include <netinet/in.h> #include <inetLib.h> #include <stdio.h> #include <ctype.h> #include <errnoLib.h> #include <string.h> /* defines */ #define LOCAL_ENTRIES_TTL 60 /* Local entries have a ttl for 60 seconds */ #define ALIGNMENT 4 /* for word alignment */ #define MAX_DOMAIN_NAME 260 /* Max domain name including EOS marker */ #define MAX_HOSTLIB_BUF 512 /* hostLib interface functions buffer */ /* macro to align ptr to buffer and decrement buffer size accordingly */ #define ALIGN_BUF_PTR(pBuf, bufLen, alignment) \ while ((UINT) (pBuf) % (alignment) != 0) \ { \ ++ (pBuf); \ -- (bufLen); \ } /* typedefs */ /* Globals */ /* * Resolver state default settings. Structure moved here from res_init.c */ struct __res_state _res = { RES_TIMEOUT, /* retransmition time interval */ 4, /* number of times to retransmit */ RES_DEFAULT, /* options flags */ 1, /* number of name servers */ }; /* This variable point to the optional debug routine */ FUNCPTR pdnsDebugFunc; /* locals */ LOCAL RESOLV_PARAMS_S resolvParams; /* resolver settings */ LOCAL STATUS resolvHostLibGetByAddr (int addr, char * pHostName); LOCAL int resolvHostLibGetByName (char * pHostName); /* externs */ extern struct hostent * _gethostbyname (); extern struct hostent * _gethostbyaddr (); /* Ptrs defined in hostLib.c. These ptrs are set by the resolver library */ extern FUNCPTR _presolvHostLibGetByName; extern FUNCPTR _presolvHostLibGetByAddr; /******************************************************************************* * * hostEntFormat - Formats a char array as a structure of type hostent * * This routine formarts a character array pointed to by <ppBuf> of the length * specified by <pBuflen>. It creates a hostent structure in the buffer along * with the `h_aliases' and `h_addr_list' vectors big enough for <numAliases> * aliases and <numAddrs> addresses respectively. On a successful return * <ppBuf> and <pBuflen> specify the remaining unused part of the buffer. * * NOMANUAL * * RETURNS: A pointer to a hostent structure on success, or NULL if the * input buffer is too small. */ LOCAL struct hostent * hostEntFormat ( char ** ppBuf, /* Pointer to character buffer pointer */ int * pBufLen, /* Pointer to the buffer length */ int numAliases, /* Max # of host aliases expected */ int numAddrs /* Max # of host addresses expected */ ) { char * pTmp; struct hostent * pHostEnt; pTmp = *ppBuf; if (((numAliases + 1 + numAddrs + 1) * sizeof (char *) + sizeof (struct hostent) + 3 + 3) > *pBufLen) { return (NULL); } ALIGN_BUF_PTR (pTmp, *pBufLen, ALIGNMENT); pHostEnt = (struct hostent *) pTmp; pTmp += sizeof (struct hostent); *pBufLen -= sizeof (struct hostent); ALIGN_BUF_PTR (pTmp, *pBufLen, ALIGNMENT); pHostEnt->h_aliases = (char **) pTmp; pTmp += (numAliases + 1)* sizeof (char **); *pBufLen -= (numAliases + 1) * sizeof (char **); pHostEnt->h_addr_list = (char **) pTmp; pTmp += (numAddrs + 1) * sizeof (char **); *pBufLen -= (numAddrs + 1) * sizeof (char **); *ppBuf = pTmp; return (pHostEnt); } /******************************************************************************* * * resolvInit - initialize the resolver library * * This function initializes the resolver. <pNameServer> is a single IP address * for a name server in dotted decimal notation. <pDefaultDomainName> is the * default domain name to be appended to names without a dot. The function * pointer <pdnsDebugRtn> is set to the resolver debug function. Additional * name servers can be configured using the function resolvParamsSet(). * * RETURNS: OK or ERROR. * * SEE ALSO: * resolvGetHostByName(), resolvGetHostByAddr(), resolvDNExpand(), * resolvDNComp(), resolvSend(), resolvParamsSet(), resolvParamsGet(), * resolvQuery() */ STATUS resolvInit ( char * pNameServer, /* pointer to Name server IP address */ char * pDefaultDomainName, /* default domain name */ FUNCPTR pdnsDebugRtn /* function ptr to debug routine */ ) { int nserv = 0; /* number of nameserver records read from file */ struct in_addr ipAddr; /* Initialize global pointer to the DNS debug routine */ printf("## %s: nameServer=%s, default domain name=%s!\n", __FUNCTION__, pNameServer, pDefaultDomainName); pdnsDebugFunc = (FUNCPTR) NULL; if (pdnsDebugRtn != NULL) pdnsDebugFunc = pdnsDebugRtn; _res.nsaddr.sin_addr.s_addr = INADDR_ANY; _res.nsaddr.sin_family = AF_INET; _res.nsaddr.sin_port = htons(NAMESERVER_PORT); _res.ndots = 1; _res.pfcode = 0; strncpy (_res.lookups, "b", sizeof _res.lookups); if (inet_aton (pNameServer, &ipAddr) == OK) { _res.nsaddr_list [nserv].sin_addr = ipAddr; _res.nsaddr_list [nserv].sin_family = AF_INET; _res.nsaddr_list [nserv].sin_port = htons(NAMESERVER_PORT); nserv++; } else { /* Illegal IP address for DNS server */ return (ERROR); } _res.nscount = nserv; /* Number of name servers */ _res.dnsrch [0] = _res.defdname; _res.options |= RES_INIT | RES_DEFNAMES | RES_DEBUG; (void) strcpy (_res.defdname, pDefaultDomainName); /* The resolver is initialized to query only the DNS server */ resolvParams.queryOrder = QUERY_DNS_ONLY; /* Install pointers used by hostLib to access the resolver library */ _presolvHostLibGetByName = resolvHostLibGetByName; _presolvHostLibGetByAddr = resolvHostLibGetByAddr; return (OK); } /******************************************************************************* * * resolvHostGetByName - queries the static host table for the host name * * Retrieve host information installed by hostAdd() and install it in the * `hostent' structure referenced in <pHostEnt>. This routine uses the * buffer referenced in <pBuf> to store hostname and network address * information. * * NOMANUAL * * RETURNS: A pointer to hostent, or NULL if the entry was not found. */ LOCAL struct hostent * resolvHostGetByName ( char * pHostName, /* pointer to the name of the host */