resolv.c

Axis 221 camera embedded programing interface

	if (buflen < sizeof(char *)*(ALIAS_DIM))
		return ERANGE;
	alias=(char **)buf;
	buf+=sizeof(char **)*(ALIAS_DIM);
	buflen-=sizeof(char **)*(ALIAS_DIM);

	if (buflen<256)
		return ERANGE;
	strncpy(buf, name, buflen);

	alias[0] = buf;
	alias[1] = NULL;

	/* First check if this is already an address */
	if (inet_aton(name, in)) {
	    result_buf->h_name = buf;
	    result_buf->h_addrtype = AF_INET;
	    result_buf->h_length = sizeof(*in);
	    result_buf->h_addr_list = (char **) addr_list;
	    result_buf->h_aliases = alias;
	    *result=result_buf;
	    *h_errnop = NETDB_SUCCESS;
	    return NETDB_SUCCESS;
	}

	for (;;) {

	BIGLOCK;
	__nameserversXX=__nameservers;
	__nameserverXX=__nameserver;
	BIGUNLOCK;
		i = __dns_lookup(buf, T_A, __nameserversXX, __nameserverXX, &packet, &a);

		if (i < 0) {
			*h_errnop = HOST_NOT_FOUND;
			DPRINTF("__dns_lookup\n");
			return TRY_AGAIN;
		}

		strncpy(buf, a.dotted, buflen);
		free(a.dotted);

		if (a.atype == T_CNAME) {		/* CNAME */
			DPRINTF("Got a CNAME in gethostbyname()\n");
			i = __decode_dotted(packet, a.rdoffset, buf, buflen);
			free(packet);

			if (i < 0) {
				*h_errnop = NO_RECOVERY;
				DPRINTF("__decode_dotted\n");
				return -1;
			}
			if (++nest > MAX_RECURSE) {
				*h_errnop = NO_RECOVERY;
				DPRINTF("recursion\n");
				return -1;
			}
			continue;
		} else if (a.atype == T_A) {	/* ADDRESS */
			memcpy(in, a.rdata, sizeof(*in));
			result_buf->h_name = buf;
			result_buf->h_addrtype = AF_INET;
			result_buf->h_length = sizeof(*in);
			result_buf->h_addr_list = (char **) addr_list;
#ifdef __UCLIBC_MJN3_ONLY__
#warning TODO -- generate the full list
#endif
			result_buf->h_aliases = alias; /* TODO: generate the full list */
			free(packet);
			break;
		} else {
			free(packet);
			*h_errnop=HOST_NOT_FOUND;
			return TRY_AGAIN;
		}
	}

	*result=result_buf;
	*h_errnop = NETDB_SUCCESS;
	return NETDB_SUCCESS;
}
#endif

#ifdef L_gethostbyname2_r

int gethostbyname2_r(const char *name, int family,
			    struct hostent * result_buf,
			    char * buf, size_t buflen,
			    struct hostent ** result,
			    int * h_errnop)
{
#ifndef __UCLIBC_HAS_IPV6__
	return family == AF_INET ? gethostbyname_r(name, result_buf, buf, buflen, result, h_errnop) : HOST_NOT_FOUND;
#else /* __UCLIBC_HAS_IPV6__ */
	struct in6_addr *in;
	struct in6_addr **addr_list;
	unsigned char *packet;
	struct resolv_answer a;
	int i;
	int nest = 0;
	int __nameserversXX;
	char ** __nameserverXX;

	if (family == AF_INET)
		return gethostbyname_r(name, result_buf, buf, buflen, result, h_errnop);

	if (family != AF_INET6)
		return EINVAL;

	__open_nameservers();
	*result=NULL;
	if (!name)
		return EINVAL;

	/* do /etc/hosts first */
	{
		int old_errno = errno;	/* Save the old errno and reset errno */
		__set_errno(0);			/* to check for missing /etc/hosts. */

		if ((i=__get_hosts_byname_r(name, AF_INET, result_buf,
									buf, buflen, result, h_errnop))==0)
			return i;
		switch (*h_errnop) {
			case HOST_NOT_FOUND:
			case NO_ADDRESS:
				break;
			case NETDB_INTERNAL:
				if (errno == ENOENT) {
					break;
				}
				/* else fall through */
			default:
				return i;
		}
		__set_errno(old_errno);
	}

	DPRINTF("Nothing found in /etc/hosts\n");

	*h_errnop = NETDB_INTERNAL;
	if (buflen < sizeof(*in))
		return ERANGE;
	in=(struct in6_addr*)buf;
	buf+=sizeof(*in);
	buflen-=sizeof(*in);

	if (buflen < sizeof(*addr_list)*2)
		return ERANGE;
	addr_list=(struct in6_addr**)buf;
	buf+=sizeof(*addr_list)*2;
	buflen-=sizeof(*addr_list)*2;

	addr_list[0] = in;
	addr_list[1] = 0;
	
	if (buflen<256)
		return ERANGE;
	strncpy(buf, name, buflen);

	/* First check if this is already an address */
	if (inet_pton(AF_INET6, name, in)) {
	    result_buf->h_name = buf;
	    result_buf->h_addrtype = AF_INET6;
	    result_buf->h_length = sizeof(*in);
	    result_buf->h_addr_list = (char **) addr_list;
	    *result=result_buf;
	    *h_errnop = NETDB_SUCCESS;
	    return NETDB_SUCCESS;
	}

	for (;;) {
	BIGLOCK;
	__nameserversXX=__nameservers;
	__nameserverXX=__nameserver;
	BIGUNLOCK;

		i = __dns_lookup(buf, T_AAAA, __nameserversXX, __nameserverXX, &packet, &a);

		if (i < 0) {
			*h_errnop = HOST_NOT_FOUND;
			return TRY_AGAIN;
		}

		strncpy(buf, a.dotted, buflen);
		free(a.dotted);

		if (a.atype == T_CNAME) {		/* CNAME */
			DPRINTF("Got a CNAME in gethostbyname()\n");
			i = __decode_dotted(packet, a.rdoffset, buf, buflen);
			free(packet);

			if (i < 0) {
				*h_errnop = NO_RECOVERY;
				return -1;
			}
			if (++nest > MAX_RECURSE) {
				*h_errnop = NO_RECOVERY;
				return -1;
			}
			continue;
		} else if (a.atype == T_AAAA) {	/* ADDRESS */
			memcpy(in, a.rdata, sizeof(*in));
			result_buf->h_name = buf;
			result_buf->h_addrtype = AF_INET6;
			result_buf->h_length = sizeof(*in);
			result_buf->h_addr_list = (char **) addr_list;
			free(packet);
			break;
		} else {
			free(packet);
			*h_errnop=HOST_NOT_FOUND;
			return TRY_AGAIN;
		}
	}

	*result=result_buf;
	*h_errnop = NETDB_SUCCESS;
	return NETDB_SUCCESS;
#endif /* __UCLIBC_HAS_IPV6__ */
}
#endif

#ifdef L_gethostbyaddr_r
int gethostbyaddr_r (const void *addr, socklen_t len, int type,
			    struct hostent * result_buf,
			    char * buf, size_t buflen,
			    struct hostent ** result,
			    int * h_errnop)

{
	struct in_addr *in;
	struct in_addr **addr_list;
#ifdef __UCLIBC_HAS_IPV6__
	char *qp;
	size_t plen;
	struct in6_addr	*in6;
	struct in6_addr	**addr_list6;
#endif /* __UCLIBC_HAS_IPV6__ */
	unsigned char *packet;
	struct resolv_answer a;
	int i;
	int nest = 0;
	int __nameserversXX;
	char ** __nameserverXX;

	*result=NULL;
	if (!addr)
		return EINVAL;
        
	switch (type) {
		case AF_INET:
			if (len != sizeof(struct in_addr))
				return EINVAL;
			break;
#ifdef __UCLIBC_HAS_IPV6__
		case AF_INET6:
			if (len != sizeof(struct in6_addr))
				return EINVAL;
			break;
#endif /* __UCLIBC_HAS_IPV6__ */
		default:
			return EINVAL;
	}

	/* do /etc/hosts first */
	if ((i=__get_hosts_byaddr_r(addr, len, type, result_buf,
				  buf, buflen, result, h_errnop))==0)
		return i;
	switch (*h_errnop) {
		case HOST_NOT_FOUND:
		case NO_ADDRESS:
			break;
		default:
			return i;
	}

	__open_nameservers();

#ifdef __UCLIBC_HAS_IPV6__
	qp=buf;
	plen=buflen;
#endif /* __UCLIBC_HAS_IPV6__ */

	*h_errnop = NETDB_INTERNAL;
	if (buflen < sizeof(*in))
		return ERANGE;
	in=(struct in_addr*)buf;
	buf+=sizeof(*in);
	buflen-=sizeof(*in);

	if (buflen < sizeof(*addr_list)*2)
		return ERANGE;
	addr_list=(struct in_addr**)buf;
	buf+=sizeof(*addr_list)*2;
	buflen-=sizeof(*addr_list)*2;

#ifdef __UCLIBC_HAS_IPV6__
	if (plen < sizeof(*in6))
		return ERANGE;
	in6=(struct in6_addr*)qp;
	qp+=sizeof(*in6);
	plen-=sizeof(*in6);

	if (plen < sizeof(*addr_list6)*2)
		return ERANGE;
	addr_list6=(struct in6_addr**)qp;
	qp+=sizeof(*addr_list6)*2;
	plen-=sizeof(*addr_list6)*2;

	if (plen < buflen) {
		buflen=plen;
		buf=qp;
	}
#endif /* __UCLIBC_HAS_IPV6__ */

	if (buflen<256)
		return ERANGE;

	if(type == AF_INET) {
		unsigned char *tmp_addr = (unsigned char *)addr;

		memcpy(&in->s_addr, addr, len);

		addr_list[0] = in;

		sprintf(buf, "%u.%u.%u.%u.in-addr.arpa",
			tmp_addr[3], tmp_addr[2], tmp_addr[1], tmp_addr[0]);
#ifdef __UCLIBC_HAS_IPV6__
	} else {
		memcpy(in6->s6_addr, addr, len);

		addr_list6[0] = in6;
		qp = buf;

		for (i = len - 1; i >= 0; i--) {
			qp += sprintf(qp, "%x.%x.", in6->s6_addr[i] & 0xf,
				(in6->s6_addr[i] >> 4) & 0xf);
    	}
    	strcpy(qp, "ip6.int");
#endif /* __UCLIBC_HAS_IPV6__ */
	}

	addr_list[1] = 0;

	for (;;) {

	BIGLOCK;
	__nameserversXX=__nameservers;
	__nameserverXX=__nameserver;
	BIGUNLOCK;
		i = __dns_lookup(buf, T_PTR, __nameserversXX, __nameserverXX, &packet, &a);

		if (i < 0) {
			*h_errnop = HOST_NOT_FOUND;
			return TRY_AGAIN;
		}

		strncpy(buf, a.dotted, buflen);
		free(a.dotted);

		if (a.atype == T_CNAME) {		/* CNAME */
			DPRINTF("Got a CNAME in gethostbyaddr()\n");
			i = __decode_dotted(packet, a.rdoffset, buf, buflen);
			free(packet);

			if (i < 0) {
				*h_errnop = NO_RECOVERY;
				return -1;
			}
			if (++nest > MAX_RECURSE) {
				*h_errnop = NO_RECOVERY;
				return -1;
			}
			continue;
		} else if (a.atype == T_PTR) {	/* ADDRESS */
			i = __decode_dotted(packet, a.rdoffset, buf, buflen);
			free(packet);

			result_buf->h_name = buf;
			result_buf->h_addrtype = type;

			if(type == AF_INET) {
				result_buf->h_length = sizeof(*in);
#ifdef __UCLIBC_HAS_IPV6__
			} else {
				result_buf->h_length = sizeof(*in6);
#endif /* __UCLIBC_HAS_IPV6__ */
    		}

			result_buf->h_addr_list = (char **) addr_list;
			break;
		} else {
			free(packet);
			*h_errnop = NO_ADDRESS;
			return TRY_AGAIN;
		}
	}

	*result=result_buf;
	*h_errnop = NETDB_SUCCESS;
	return NETDB_SUCCESS;
}
#endif

#ifdef L_res_comp
/*
 * Expand compressed domain name 'comp_dn' to full domain name.
 * 'msg' is a pointer to the begining of the message,
 * 'eomorig' points to the first location after the message,
 * 'exp_dn' is a pointer to a buffer of size 'length' for the result.
 * Return size of compressed name or -1 if there was an error.
 */
int __dn_expand(const u_char *msg, const u_char *eom, const u_char *src,
          char *dst, int dstsiz)
{
	int n = ns_name_uncompress(msg, eom, src, dst, (size_t)dstsiz);

	if (n > 0 && dst[0] == '.')
		dst[0] = '\0';
	return (n);
}
#endif /* L_res_comp */

#ifdef L_ns_name
/*
 * printable(ch)
 *      Thinking in noninternationalized USASCII (per the DNS spec),
 *      is this character visible and not a space when printed ?
 * return:
 *      boolean.
 */
static int printable(int ch) 
{
        return (ch > 0x20 && ch < 0x7f);
}

/*
 * special(ch)
 *      Thinking in noninternationalized USASCII (per the DNS spec),
 *      is this characted special ("in need of quoting") ?
 * return:
 *      boolean.
 */
static int special(int ch) 
{
        switch (ch) {
        case 0x22: /* '"' */
        case 0x2E: /* '.' */
        case 0x3B: /* ';' */
        case 0x5C: /* '\\' */
        /* Special modifiers in zone files. */
        case 0x40: /* '@' */
        case 0x24: /* '$' */
                return (1);
        default:
                return (0);
        }
}

/*
 * ns_name_uncompress(msg, eom, src, dst, dstsiz)
 *      Expand compressed domain name to presentation format.
 * return:
 *      Number of bytes read out of `src', or -1 (with errno set).
 * note:
 *      Root domain returns as "." not "".
 */
int __ns_name_uncompress(const u_char *msg, const u_char *eom, 
		const u_char *src, char *dst, size_t dstsiz)
{
	u_char tmp[NS_MAXCDNAME];
	int n;

	if ((n = ns_name_unpack(msg, eom, src, tmp, sizeof tmp)) == -1)
		return (-1);
	if (ns_name_ntop(tmp, dst, dstsiz) == -1)
		return (-1);
	return (n);
}


/*
 * ns_name_ntop(src, dst, dstsiz)
 *      Convert an encoded domain name to printable ascii as per RFC1035.
 * return:
 *      Number of bytes written to buffer, or -1 (with errno set)
 * notes:
 *      The root is returned as "."
 *      All other domains are returned in non absolute form
 */
int __ns_name_ntop(const u_char *src, char *dst, size_t dstsiz) {
	const u_char *cp;
	char *dn, *eom;
	u_char c;
	u_int n;
	const char digits[] = "0123456789";

	cp = src;
	dn = dst;
	eom = dst + dstsiz;

	while ((n = *cp++) != 0) {
		if ((n & NS_CMPRSFLGS) != 0) {
			/* Some kind of compression pointer. */
			__set_errno (EMSGSIZE);
			return (-1);
		}
		if (dn != dst) {
			if (dn >= eom) {
				__set_errno (EMSGSIZE);
				return (-1);
			}
			*dn++ = '.';
		}
		if (dn + n >= eom) {
			__set_errno (EMSGSIZE);
			return (-1);
		}
		for ((void)NULL; n > 0; n--) {
			c = *cp++;
			if (special(c)) {
				if (dn + 1 >= eom) {
					__set_errno (EMSGSIZE);
					return (-1);
				}
				*dn++ = '\\';
				*dn++ = (char)c;
			} else if (!printable(c)) {
				if (dn + 3 >= eom) {
					__set_errno (EMSGSIZE);
					return (-1);
				}
				*dn++ = '\\';
				*dn++ = digits[c / 100];
				*dn++ = digits[(c % 100) / 10];
				*dn++ = digits[c % 10];
			} else {
				if (dn >= eom) {
					__set_errno (EMSGSIZE);
					return (-1);
				}
				*dn++ = (char)c;
			}
		}
	}
	if (dn == dst) {
		if (dn >= eom) {
			__set_errno (EMSGSIZE);
			return (-1);
		}
		*dn++ = '.';
	}
	if (dn >= eom) {
		__set_errno (EMSGSIZE);
		return (-1);
	}
	*dn++ = '\0';
        return (dn - dst);
}

/*
 * ns_name_unpack(msg, eom, src, dst, dstsiz)
 *      Unpack a domain name from a message, source may be compressed.
 * return:
 *      -1 if it fails, or consumed octets if it succeeds.
 */
int __ns_name_unpack(const u_char *msg, const u_char *eom, const u_char *src,
               u_char *dst, size_t dstsiz)
{
	const u_char *srcp, *dstlim;
	u_char *dstp;
	int n, len, checked;

	len = -1;
	checked = 0;
	dstp = dst;
	srcp = src;
	dstlim = dst + dstsiz;
	if (srcp < msg || srcp >= eom) {
		__set_errno (EMSGSIZE);
		return (-1);
	}
	/* Fetch next label in domain name. */
	while ((n = *srcp++) != 0) {
		/* Check for indirection. */
		switch (n & NS_CMPRSFLGS) {
		case 0:
			/* Limit checks. */
			if (dstp + n + 1 >= dstlim || srcp + n >= eom) {
				__set_errno (EMSGSIZE);
				return (-1);
			}
			checked += n + 1;
			*dstp++ = n;
			memcpy(dstp, srcp, n);
			dstp += n;
			srcp += n;
			break;

		case NS_CMPRSFLGS:
			if (srcp >= eom) {
				__set_errno (EMSGSIZE);
				return (-1);
			}
			if (len < 0)
				len = srcp - src + 1;
			srcp = msg + (((n & 0x3f) << 8) | (*srcp & 0xff));
			if (srcp < msg || srcp >= eom) {  /* Out of range. */
				__set_errno (EMSGSIZE);
				return (-1);
			}
			checked += 2;
			/*
			 * Check for loops in the compressed name;
			 * if we've looked at the whole message,
			 * there must be a loop.
			 */
			if (checked >= eom - msg) {
				__set_errno (EMSGSIZE);
				return (-1);
			}
			break;

		default:
			__set_errno (EMSGSIZE);
			return (-1);                    /* flag error */
		}
	}
	*dstp = '\0';
	if (len < 0)
		len = srcp - src;
	return (len);
}
#endif /* L_ns_name */