dig.c

早期freebsd实现

	      sscanf(++ptr, "%d", &_res.retrans);
	    }

	  } else if (strncmp(option, "ret", 3) == 0) {    /* retry */
	    ptr = strchr(option, '=');
	    if (ptr != NULL) {
	      sscanf(++ptr, "%d", &_res.retry);
	    }

	} else if (strncmp(option, "i", 1) == 0) {	/* ignore */
	    _res.options |= RES_IGNTC;
	} else if (strncmp(option, "noi", 3) == 0) {
	    _res.options &= ~RES_IGNTC;
	} else if (strncmp(option, "pr", 2) == 0) {	/* primary */
	    _res.options |= RES_PRIMARY;
	} else if (strncmp(option, "nop", 3) == 0) {
	    _res.options &= ~RES_PRIMARY;
	} else if (strncmp(option, "rec", 3) == 0) {	/* recurse */
	    _res.options |= RES_RECURSE;
	} else if (strncmp(option, "norec", 5) == 0) {
	    _res.options &= ~RES_RECURSE;
	} else if (strncmp(option, "v", 1) == 0) {	/* vc */
	    _res.options |= RES_USEVC;
	} else if (strncmp(option, "nov", 3) == 0) {
	    _res.options &= ~RES_USEVC;
	} else if (strncmp(option, "pfset", 5) == 0) {
	    ptr = strchr(option, '=');
	    if (ptr != NULL) {
	      _res.pfcode = xstrtonum(++ptr);
	    }
	} else if (strncmp(option, "pfand", 5) == 0) {
	    ptr = strchr(option, '=');
	    if (ptr != NULL) {
	      _res.pfcode = _res.pfcode & xstrtonum(++ptr);
	    }
	} else if (strncmp(option, "pfor", 4) == 0) {
	    ptr = strchr(option, '=');
	    if (ptr != NULL) {
	      _res.pfcode |= xstrtonum(++ptr);
	    }
	} else if (strncmp(option, "pfmin", 5) == 0) {
	      _res.pfcode = PRF_MIN;
	} else if (strncmp(option, "pfdef", 5) == 0) {
	      _res.pfcode = PRF_DEF;
	} else if (strncmp(option, "an", 2) == 0) {  /* answer section */
	      _res.pfcode |= RES_PRF_ANS;
	} else if (strncmp(option, "noan", 4) == 0) {
	      _res.pfcode &= ~RES_PRF_ANS;
	} else if (strncmp(option, "qu", 2) == 0) {  /* question section */
	      _res.pfcode |= RES_PRF_QUES;
	} else if (strncmp(option, "noqu", 4) == 0) {  
	      _res.pfcode &= ~RES_PRF_QUES;
	} else if (strncmp(option, "au", 2) == 0) {  /* authority section */
	      _res.pfcode |= RES_PRF_AUTH;
	} else if (strncmp(option, "noau", 4) == 0) {  
	      _res.pfcode &= ~RES_PRF_AUTH;
	} else if (strncmp(option, "ad", 2) == 0) {  /* addition section */
	      _res.pfcode |= RES_PRF_ADD;
	} else if (strncmp(option, "noad", 4) == 0) {  
	      _res.pfcode &= ~RES_PRF_ADD;
	} else if (strncmp(option, "tt", 2) == 0) {  /* TTL & ID */
	      _res.pfcode |= RES_PRF_TTLID;
	} else if (strncmp(option, "nott", 4) == 0) {  
	      _res.pfcode &= ~RES_PRF_TTLID;
	} else if (strncmp(option, "he", 2) == 0) {  /* head flags stats */
	      _res.pfcode |= RES_PRF_HEAD2;
	} else if (strncmp(option, "nohe", 4) == 0) {  
	      _res.pfcode &= ~RES_PRF_HEAD2;
	} else if (strncmp(option, "H", 1) == 0) {  /* header all */
	      _res.pfcode |= RES_PRF_HEADX;
	} else if (strncmp(option, "noH", 3) == 0) {  
	      _res.pfcode &= ~(RES_PRF_HEADX);
	} else if (strncmp(option, "qr", 2) == 0) {  /* query */
	      _res.pfcode |= RES_PRF_QUERY;
	} else if (strncmp(option, "noqr", 4) == 0) {  
	      _res.pfcode &= ~RES_PRF_QUERY;
	} else if (strncmp(option, "rep", 3) == 0) {  /* reply */
	      _res.pfcode |= RES_PRF_REPLY;
	} else if (strncmp(option, "norep", 5) == 0) {  
	      _res.pfcode &= ~RES_PRF_REPLY;
	} else if (strncmp(option, "cm", 2) == 0) {  /* command line */
	      _res.pfcode |= RES_PRF_CMD;
	} else if (strncmp(option, "nocm", 4) == 0) {  
	      _res.pfcode &= ~RES_PRF_CMD;
	} else if (strncmp(option, "cl", 2) == 0) {  /* class mnemonic */
	      _res.pfcode |= RES_PRF_CLASS;
	} else if (strncmp(option, "nocl", 4) == 0) {  
	      _res.pfcode &= ~RES_PRF_CLASS;
	} else if (strncmp(option, "st", 2) == 0) {  /* stats*/
	      _res.pfcode |= RES_PRF_STATS;
	} else if (strncmp(option, "nost", 4) == 0) {  
	      _res.pfcode &= ~RES_PRF_STATS;
	} else {
	    fprintf(stderr, "; *** Invalid option: %s\n",  option);
	    return(ERROR);
	}
	res_re_init();
	return(SUCCESS);
}



/*
 * Force a reinitialization when the domain is changed.
 */
res_re_init()
{
	static char localdomain[] = "LOCALDOMAIN";
	char *buf;
	long pfcode = _res.pfcode;

	/* this is ugly but putenv() is more portable than setenv() */
	buf = malloc((sizeof localdomain) +strlen(_res.defdname) +10/*fuzz*/);
	sprintf(buf, "%s=%s", localdomain, _res.defdname);
	putenv(buf);	/* keeps the argument, so we won't free it */
	_res.options &= ~RES_INIT;
	res_init();
	_res.pfcode = pfcode;
}


/*
 * convert char string (decimal, octal, or hex) to integer
 */
int
xstrtonum(p)
	char *p;
{
	int v = 0;
	int i;
	int b = 10;
	int flag = 0;
	while (*p != 0) {
		if (!flag++)
			if (*p == '0') {
				b = 8; p++;
				continue;
			}
		if (isupper(*p))
			*p=tolower(*p);
		if (*p == 'x') {
			b = 16; p++;
			continue;
		}
		if (isdigit(*p)) {
			i = *p - '0';
		} else if (isxdigit(*p)) {
			i = *p - 'a' + 10;
		} else {
			fprintf(stderr,
				"; *** Bad char in numeric string..ignored\n");
			i = -1;
		}
		if (i >= b) {
			fprintf(stderr,
				"; *** Bad char in numeric string..ignored\n");
			i = -1;
		}
		if (i >= 0)
			v = v * b + i;
		p++;
	}
	return(v);
}

/* this code was cloned from nslookup/list.c */

extern char *p_rr(), *_res_resultcodes[];	/* res_debug.c */

typedef union {
    HEADER qb1;
    char qb2[PACKETSZ];
} querybuf;

static int
printZone(zone, sin)
	char *zone;
	struct sockaddr_in *sin;
{
	querybuf		buf;
	HEADER			*headerPtr;
	int			msglen;
	int			amtToRead;
	int			numRead;
	int			numAnswers = 0;
	int			result;
	int			soacnt = 0;
	int			sockFD;
	u_short			len;
	char			*cp, *nmp;
	char			dname[2][NAME_LEN];
	char			file[NAME_LEN];
	static char		*answer = NULL;
	static int		answerLen = 0;
	enum {
	    NO_ERRORS,
	    ERR_READING_LEN,
	    ERR_READING_MSG,
	    ERR_PRINTING
	} error = NO_ERRORS;

	/*
	 *  Create a query packet for the requested zone name.
	 */
	msglen = res_mkquery(QUERY, zone, queryClass, T_AXFR,
				(char *)0, 0, 0,
				(char *) &buf, sizeof(buf));
	if (msglen < 0) {
	    if (_res.options & RES_DEBUG) {
		fprintf(stderr, ";; res_mkquery failed\n");
	    }
	    return (ERROR);
	}

	/*
	 *  Set up a virtual circuit to the server.
	 */
	if ((sockFD = socket(sin->sin_family, SOCK_STREAM, 0)) < 0) {
	    int e = errno;
	    perror(";; socket");
	    return(e);
	}
	if (connect(sockFD, (struct sockaddr *)sin, sizeof(*sin)) < 0) {
	    int e = errno;
	    perror(";; connect");
	    (void) close(sockFD);
	    sockFD = -1;
	    return e;
	}

	/*
	 * Send length & message for zone transfer
	 */

        len = htons(msglen);

        if (write(sockFD, (char *)&len, sizeof(len)) != sizeof(len) ||
            write(sockFD, (char *) &buf, msglen) != msglen) {
		int e = errno;
		perror(";; write");
		(void) close(sockFD);
		sockFD = -1;
		return(e);
	}

	dname[0][0] = '\0';
	while (1) {
	    u_int16_t tmp;

	    /*
	     * Read the length of the response.
	     */

	    cp = (char *) &tmp;
	    amtToRead = sizeof(u_short);
	    while (amtToRead > 0 && (numRead=read(sockFD, cp, amtToRead)) > 0){
		cp	  += numRead;
		amtToRead -= numRead;
	    }
	    if (numRead <= 0) {
		error = ERR_READING_LEN;
		break;
	    }

	    if ((len = htons(tmp)) == 0) {
		break;	/* nothing left to read */
	    }

	    /*
	     * The server sent too much data to fit the existing buffer --
	     * allocate a new one.
	     */
	    if (len > answerLen) {
		if (answerLen != 0) {
		    free(answer);
		}
		answerLen = len;
		answer = Malloc(answerLen);
	    }

	    /*
	     * Read the response.
	     */

	    amtToRead = len;
	    cp = answer;
	    while (amtToRead > 0 && (numRead=read(sockFD, cp, amtToRead)) > 0) {
		cp += numRead;
		amtToRead -= numRead;
	    }
	    if (numRead <= 0) {
		error = ERR_READING_MSG;
		break;
	    }

	    result = printRR(stdout, answer, cp);
	    if (result != 0) {
		error = ERR_PRINTING;
		break;
	    }

	    numAnswers++;
	    cp = answer + sizeof(HEADER);
	    if (ntohs(((HEADER* )answer)->qdcount) > 0)
		cp += dn_skipname((u_char *)cp,
		    (u_char *)answer + len) + QFIXEDSZ;
	    nmp = cp;
	    cp += dn_skipname((u_char *)cp, (u_char *)answer + len);
	    if ((_getshort(cp) == T_SOA)) {
		dn_expand((u_char *)answer, (u_char *)answer + len,
		    (u_char *)nmp, (u_char *)dname[soacnt],
			sizeof(dname[0]));
	        if (soacnt) {
		    if (strcmp(dname[0], dname[1]) == 0)
			break;
		} else
		    soacnt++;
	    }
	}

	fprintf(stdout, ";; Received %d record%s.\n",
		numAnswers, (numAnswers != 1) ? "s" : "");

	(void) close(sockFD);
	sockFD = -1;

	switch (error) {
	    case NO_ERRORS:
		return (0);

	    case ERR_READING_LEN:
		return(EMSGSIZE);

	    case ERR_PRINTING:
		return(result);

	    case ERR_READING_MSG:
		return(EMSGSIZE);

	    default:
		return(EFAULT);
	}
}

static int
printRR(file, msg, eom)
    FILE	*file;
    u_char	*msg, *eom;
{
    register u_char	*cp;
    HEADER		*headerPtr;
    int			type, class, dlen, nameLen;
    u_int32_t		ttl;
    int			n, pref;
    struct in_addr	inaddr;
    char		name[NAME_LEN];
    char		name2[NAME_LEN];
    Boolean		stripped;

    /*
     * Read the header fields.
     */
    headerPtr = (HEADER *)msg;
    cp = msg + sizeof(HEADER);
    if (headerPtr->rcode != NOERROR) {
	return(headerPtr->rcode);
    }

    /*
     *  We are looking for info from answer resource records.
     *  If there aren't any, return with an error. We assume
     *  there aren't any question records.
     */

    if (ntohs(headerPtr->ancount) == 0) {
	return(NO_INFO);
    } else {
	if (ntohs(headerPtr->qdcount) > 0) {
	    nameLen = dn_skipname(cp, eom);
	    if (nameLen < 0)
		return (ERROR);
	    cp += nameLen + QFIXEDSZ;
	}
	cp = (u_char*) p_rr(cp, msg, stdout);
    }
    return(SUCCESS);
}