res_init.c

bind 9.3结合mysql数据库

			if (inet_aton(net, &a)) {
			    statp->sort_list[nsort].addr = a;
			    if (ISSORTMASK(n)) {
				*cp++ = n;
				net = cp;
				while (*cp && *cp != ';' &&
					isascii(*cp) &&
					!isspace((unsigned char)*cp))
				    cp++;
				n = *cp;
				*cp = 0;
				if (inet_aton(net, &a)) {
				    statp->sort_list[nsort].mask = a.s_addr;
				} else {
				    statp->sort_list[nsort].mask = 
					net_mask(statp->sort_list[nsort].addr);
				}
			    } else {
				statp->sort_list[nsort].mask = 
				    net_mask(statp->sort_list[nsort].addr);
			    }
			    nsort++;
			}
			*cp = n;
		    }
		    continue;
		}
#endif
		if (MATCH(buf, "options")) {
		    res_setoptions(statp, buf + sizeof("options") - 1, "conf");
		    continue;
		}
	    }
	    if (nserv > 0) 
		statp->nscount = nserv;
#ifdef RESOLVSORT
	    statp->nsort = nsort;
#endif
	    (void) fclose(fp);
	}
/*
 * Last chance to get a nameserver.  This should not normally
 * be necessary
 */
#ifdef NO_RESOLV_CONF
	if(nserv == 0)
		nserv = get_nameservers(statp);
#endif

	if (statp->defdname[0] == 0 &&
	    gethostname(buf, sizeof(statp->defdname) - 1) == 0 &&
	    (cp = strchr(buf, '.')) != NULL)
		strcpy(statp->defdname, cp + 1);

	/* find components of local domain that might be searched */
	if (havesearch == 0) {
		pp = statp->dnsrch;
		*pp++ = statp->defdname;
		*pp = NULL;

		dots = 0;
		for (cp = statp->defdname; *cp; cp++)
			dots += (*cp == '.');

		cp = statp->defdname;
		while (pp < statp->dnsrch + MAXDFLSRCH) {
			if (dots < LOCALDOMAINPARTS)
				break;
			cp = strchr(cp, '.') + 1;    /* we know there is one */
			*pp++ = cp;
			dots--;
		}
		*pp = NULL;
#ifdef DEBUG
		if (statp->options & RES_DEBUG) {
			printf(";; res_init()... default dnsrch list:\n");
			for (pp = statp->dnsrch; *pp; pp++)
				printf(";;\t%s\n", *pp);
			printf(";;\t..END..\n");
		}
#endif
	}

	if ((cp = getenv("RES_OPTIONS")) != NULL)
		res_setoptions(statp, cp, "env");
	statp->options |= RES_INIT;
	return (0);
}

static void
res_setoptions(res_state statp, const char *options, const char *source)
{
	const char *cp = options;
	int i;
	struct __res_state_ext *ext = statp->_u._ext.ext;

#ifdef DEBUG
	if (statp->options & RES_DEBUG)
		printf(";; res_setoptions(\"%s\", \"%s\")...\n",
		       options, source);
#endif
	while (*cp) {
		/* skip leading and inner runs of spaces */
		while (*cp == ' ' || *cp == '\t')
			cp++;
		/* search for and process individual options */
		if (!strncmp(cp, "ndots:", sizeof("ndots:") - 1)) {
			i = atoi(cp + sizeof("ndots:") - 1);
			if (i <= RES_MAXNDOTS)
				statp->ndots = i;
			else
				statp->ndots = RES_MAXNDOTS;
#ifdef DEBUG
			if (statp->options & RES_DEBUG)
				printf(";;\tndots=%d\n", statp->ndots);
#endif
		} else if (!strncmp(cp, "timeout:", sizeof("timeout:") - 1)) {
			i = atoi(cp + sizeof("timeout:") - 1);
			if (i <= RES_MAXRETRANS)
				statp->retrans = i;
			else
				statp->retrans = RES_MAXRETRANS;
#ifdef DEBUG
			if (statp->options & RES_DEBUG)
				printf(";;\ttimeout=%d\n", statp->retrans);
#endif
		} else if (!strncmp(cp, "attempts:", sizeof("attempts:") - 1)){
			i = atoi(cp + sizeof("attempts:") - 1);
			if (i <= RES_MAXRETRY)
				statp->retry = i;
			else
				statp->retry = RES_MAXRETRY;
#ifdef DEBUG
			if (statp->options & RES_DEBUG)
				printf(";;\tattempts=%d\n", statp->retry);
#endif
		} else if (!strncmp(cp, "debug", sizeof("debug") - 1)) {
#ifdef DEBUG
			if (!(statp->options & RES_DEBUG)) {
				printf(";; res_setoptions(\"%s\", \"%s\")..\n",
				       options, source);
				statp->options |= RES_DEBUG;
			}
			printf(";;\tdebug\n");
#endif
		} else if (!strncmp(cp, "no_tld_query",
				    sizeof("no_tld_query") - 1) ||
			   !strncmp(cp, "no-tld-query",
				    sizeof("no-tld-query") - 1)) {
			statp->options |= RES_NOTLDQUERY;
		} else if (!strncmp(cp, "inet6", sizeof("inet6") - 1)) {
			statp->options |= RES_USE_INET6;
		} else if (!strncmp(cp, "rotate", sizeof("rotate") - 1)) {
			statp->options |= RES_ROTATE;
		} else if (!strncmp(cp, "no-check-names",
				    sizeof("no-check-names") - 1)) {
			statp->options |= RES_NOCHECKNAME;
		}
#ifdef RES_USE_EDNS0
		else if (!strncmp(cp, "edns0", sizeof("edns0") - 1)) {
			statp->options |= RES_USE_EDNS0;
		}
#endif
		else if (!strncmp(cp, "dname", sizeof("dname") - 1)) {
			statp->options |= RES_USE_DNAME;
		}
		else if (!strncmp(cp, "nibble:", sizeof("nibble:") - 1)) {
			if (ext == NULL)
				goto skip;
			cp += sizeof("nibble:") - 1;
			i = MIN(strcspn(cp, " \t"), sizeof(ext->nsuffix) - 1);
			strncpy(ext->nsuffix, cp, i);
			ext->nsuffix[i] = '\0';
		}
		else if (!strncmp(cp, "nibble2:", sizeof("nibble2:") - 1)) {
			if (ext == NULL)
				goto skip;
			cp += sizeof("nibble2:") - 1;
			i = MIN(strcspn(cp, " \t"), sizeof(ext->nsuffix2) - 1);
			strncpy(ext->nsuffix2, cp, i);
			ext->nsuffix2[i] = '\0';
		}
		else if (!strncmp(cp, "v6revmode:", sizeof("v6revmode:") - 1)) {
			cp += sizeof("v6revmode:") - 1;
			/* "nibble" and "bitstring" used to be valid */
			if (!strncmp(cp, "single", sizeof("single") - 1)) {
				statp->options |= RES_NO_NIBBLE2;
			} else if (!strncmp(cp, "both", sizeof("both") - 1)) {
				statp->options &=
					 ~RES_NO_NIBBLE2;
			}
		}
		else {
			/* XXX - print a warning here? */
		}
   skip:
		/* skip to next run of spaces */
		while (*cp && *cp != ' ' && *cp != '\t')
			cp++;
	}
}

#ifdef RESOLVSORT
/* XXX - should really support CIDR which means explicit masks always. */
static u_int32_t
net_mask(in)		/* XXX - should really use system's version of this */
	struct in_addr in;
{
	register u_int32_t i = ntohl(in.s_addr);

	if (IN_CLASSA(i))
		return (htonl(IN_CLASSA_NET));
	else if (IN_CLASSB(i))
		return (htonl(IN_CLASSB_NET));
	return (htonl(IN_CLASSC_NET));
}
#endif

u_int
res_randomid(void) {
	struct timeval now;

	gettimeofday(&now, NULL);
	return (0xffff & (now.tv_sec ^ now.tv_usec ^ getpid()));
}

/*
 * This routine is for closing the socket if a virtual circuit is used and
 * the program wants to close it.  This provides support for endhostent()
 * which expects to close the socket.
 *
 * This routine is not expected to be user visible.
 */
void
res_nclose(res_state statp) {
	int ns;

	if (statp->_vcsock >= 0) { 
		(void) close(statp->_vcsock);
		statp->_vcsock = -1;
		statp->_flags &= ~(RES_F_VC | RES_F_CONN);
	}
	for (ns = 0; ns < statp->_u._ext.nscount; ns++) {
		if (statp->_u._ext.nssocks[ns] != -1) {
			(void) close(statp->_u._ext.nssocks[ns]);
			statp->_u._ext.nssocks[ns] = -1;
		}
	}
}

void
res_ndestroy(res_state statp) {
	res_nclose(statp);
	if (statp->_u._ext.ext != NULL)
		free(statp->_u._ext.ext);
	statp->options &= ~RES_INIT;
	statp->_u._ext.ext = NULL;
}

const char *
res_get_nibblesuffix(res_state statp) {
	if (statp->_u._ext.ext)
		return (statp->_u._ext.ext->nsuffix);
	return ("ip6.arpa");
}

const char *
res_get_nibblesuffix2(res_state statp) {
	if (statp->_u._ext.ext)
		return (statp->_u._ext.ext->nsuffix2);
	return ("ip6.int");
}

void
res_setservers(res_state statp, const union res_sockaddr_union *set, int cnt) {
	int i, nserv;
	size_t size;

	/* close open servers */
	res_nclose(statp);

	/* cause rtt times to be forgotten */
	statp->_u._ext.nscount = 0;

	nserv = 0;
	for (i = 0; i < cnt && nserv < MAXNS; i++) {
		switch (set->sin.sin_family) {
		case AF_INET:
			size = sizeof(set->sin);
			if (statp->_u._ext.ext)
				memcpy(&statp->_u._ext.ext->nsaddrs[nserv],
					&set->sin, size);
			if (size <= sizeof(statp->nsaddr_list[nserv]))
				memcpy(&statp->nsaddr_list[nserv],
					&set->sin, size);
			else
				statp->nsaddr_list[nserv].sin_family = 0;
			nserv++;
			break;

#ifdef HAS_INET6_STRUCTS
		case AF_INET6:
			size = sizeof(set->sin6);
			if (statp->_u._ext.ext)
				memcpy(&statp->_u._ext.ext->nsaddrs[nserv],
					&set->sin6, size);
			if (size <= sizeof(statp->nsaddr_list[nserv]))
				memcpy(&statp->nsaddr_list[nserv],
					&set->sin6, size);
			else
				statp->nsaddr_list[nserv].sin_family = 0;
			nserv++;
			break;
#endif

		default:
			break;
		}
		set++;
	}
	statp->nscount = nserv;
	
}

int
res_getservers(res_state statp, union res_sockaddr_union *set, int cnt) {
	int i;
	size_t size;
	u_int16_t family;

	for (i = 0; i < statp->nscount && i < cnt; i++) {
		if (statp->_u._ext.ext)
			family = statp->_u._ext.ext->nsaddrs[i].sin.sin_family;
		else 
			family = statp->nsaddr_list[i].sin_family;

		switch (family) {
		case AF_INET:
			size = sizeof(set->sin);
			if (statp->_u._ext.ext)
				memcpy(&set->sin,
				       &statp->_u._ext.ext->nsaddrs[i],
				       size);
			else
				memcpy(&set->sin, &statp->nsaddr_list[i],
				       size);
			break;

#ifdef HAS_INET6_STRUCTS
		case AF_INET6:
			size = sizeof(set->sin6);
			if (statp->_u._ext.ext)
				memcpy(&set->sin6,
				       &statp->_u._ext.ext->nsaddrs[i],
				       size);
			else
				memcpy(&set->sin6, &statp->nsaddr_list[i],
				       size);
			break;
#endif

		default:
			set->sin.sin_family = 0;
			break;
		}
		set++;
	}
	return (statp->nscount);
}