diff options
Diffstat (limited to 'libc/inet/resolv.c')
| -rw-r--r-- | libc/inet/resolv.c | 311 |
1 files changed, 311 insertions, 0 deletions
diff --git a/libc/inet/resolv.c b/libc/inet/resolv.c index b29c1d984..cd595c93d 100644 --- a/libc/inet/resolv.c +++ b/libc/inet/resolv.c @@ -7,6 +7,75 @@ * modify it under the terms of the GNU Library General Public * License as published by the Free Software Foundation; either * version 2 of the License, or (at your option) any later version. +*/ + +/* + * Portions Copyright (c) 1985, 1993 + * The Regents of the University of California. All rights reserved. + * + * 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. + * 4. Neither the name of the University nor the names of its contributors + * may be used to endorse or promote products derived from this software + * without specific prior written permission. + * + * THIS SOFTWARE IS PROVIDED BY THE REGENTS AND CONTRIBUTORS ``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 REGENTS OR CONTRIBUTORS 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. + */ + +/* + * Portions Copyright (c) 1993 by Digital Equipment Corporation. + * + * Permission to use, copy, modify, and distribute this software for any + * purpose with or without fee is hereby granted, provided that the above + * copyright notice and this permission notice appear in all copies, and that + * the name of Digital Equipment Corporation not be used in advertising or + * publicity pertaining to distribution of the document or software without + * specific, written prior permission. + * + * THE SOFTWARE IS PROVIDED "AS IS" AND DIGITAL EQUIPMENT CORP. DISCLAIMS ALL + * WARRANTIES WITH REGARD TO THIS SOFTWARE, INCLUDING ALL IMPLIED WARRANTIES + * OF MERCHANTABILITY AND FITNESS. IN NO EVENT SHALL DIGITAL EQUIPMENT + * CORPORATION BE LIABLE FOR ANY SPECIAL, DIRECT, INDIRECT, OR CONSEQUENTIAL + * DAMAGES OR ANY DAMAGES WHATSOEVER RESULTING FROM LOSS OF USE, DATA OR + * PROFITS, WHETHER IN AN ACTION OF CONTRACT, NEGLIGENCE OR OTHER TORTIOUS + * ACTION, ARISING OUT OF OR IN CONNECTION WITH THE USE OR PERFORMANCE OF THIS + * SOFTWARE. + */ + +/* + * Portions Copyright (c) 1996-1999 by Internet Software Consortium. + * + * Permission to use, copy, modify, and distribute this software for any + * purpose with or without fee is hereby granted, provided that the above + * copyright notice and this permission notice appear in all copies. + * + * THE SOFTWARE IS PROVIDED "AS IS" AND INTERNET SOFTWARE CONSORTIUM DISCLAIMS + * ALL WARRANTIES WITH REGARD TO THIS SOFTWARE INCLUDING ALL IMPLIED WARRANTIES + * OF MERCHANTABILITY AND FITNESS. IN NO EVENT SHALL INTERNET SOFTWARE + * CONSORTIUM BE LIABLE FOR ANY SPECIAL, DIRECT, INDIRECT, OR CONSEQUENTIAL + * DAMAGES OR ANY DAMAGES WHATSOEVER RESULTING FROM LOSS OF USE, DATA OR + * PROFITS, WHETHER IN AN ACTION OF CONTRACT, NEGLIGENCE OR OTHER TORTIOUS + * ACTION, ARISING OUT OF OR IN CONNECTION WITH THE USE OR PERFORMANCE OF THIS + * SOFTWARE. + */ + +/* * * 5-Oct-2000 W. Greathouse wgreathouse@smva.com * Fix memory leak and memory corruption. @@ -54,6 +123,10 @@ * Fixed __decode_dotted to count the terminating null character * in a host name. * + * 02-Oct-2003 Tony J. White <tjw@tjw.org> + * Lifted dn_expand() and dependent ns_name_uncompress(), ns_name_unpack(), + * and ns_name_ntop() from glibc 2.3.2 for compatibility with ipsec-tools + * and openldap. * */ @@ -186,6 +259,13 @@ extern int __decode_answer(unsigned char * message, int offset, extern int __length_question(unsigned char * message, int offset); extern int __open_nameservers(void); extern void __close_nameservers(void); +extern int __dn_expand(const u_char *, const u_char *, const u_char *, + char *, int); +extern int __ns_name_uncompress(const u_char *, const u_char *, + const u_char *, char *, size_t); +extern int __ns_name_ntop(const u_char *, char *, size_t); +extern int __ns_name_unpack(const u_char *, const u_char *, const u_char *, + u_char *, size_t); #ifdef L_encodeh @@ -1987,3 +2067,234 @@ int gethostbyaddr_r (const void *addr, socklen_t len, int type, 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 */ |