/* * Copyright (c) 1996 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. */ /* * Portions copyright (c) 1999, 2000 * Intel Corporation. * 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. * * 3. All advertising materials mentioning features or use of this software * must display the following acknowledgement: * * This product includes software developed by Intel Corporation and * its contributors. * * 4. Neither the name of Intel Corporation or its contributors may be * used to endorse or promote products derived from this software * without specific prior written permission. * * THIS SOFTWARE IS PROVIDED BY INTEL CORPORATION 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 INTEL CORPORATION 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. * */ #ifndef lint static char rcsid[] = "$Id: ns_name.c,v 1.1.1.1 2003/11/19 01:51:32 kyu3 Exp $"; #endif #include #include #include #include #include #include /* Data. */ static char digits[] = "0123456789"; /* Forward. */ static int special(int); static int printable(int); static int dn_find(const u_char *, const u_char *, const u_char * const *, const u_char * const *); /* Public. */ /* * 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; cp = src; dn = dst; eom = dst + dstsiz; while ((n = *cp++) != 0) { if ((n & NS_CMPRSFLGS) != 0) { /* Some kind of compression pointer. */ errno = EMSGSIZE; return (-1); } if (dn != dst) { if (dn >= eom) { errno = EMSGSIZE; return (-1); } *dn++ = '.'; } if (dn + n >= eom) { errno = EMSGSIZE; return (-1); } for ((void)NULL; n > 0; n--) { c = *cp++; if (special(c)) { if (dn + 1 >= eom) { errno = EMSGSIZE; return (-1); } *dn++ = '\\'; *dn++ = (char)c; } else if (!printable(c)) { if (dn + 3 >= eom) { errno = EMSGSIZE; return (-1); } *dn++ = '\\'; *dn++ = digits[c / 100]; *dn++ = digits[(c % 100) / 10]; *dn++ = digits[c % 10]; } else { if (dn >= eom) { errno = EMSGSIZE; return (-1); } *dn++ = (char)c; } } } if (dn == dst) { if (dn >= eom) { errno = EMSGSIZE; return (-1); } *dn++ = '.'; } if (dn >= eom) { errno = EMSGSIZE; return (-1); } *dn++ = '\0'; return ((int)(dn - dst)); } /* * ns_name_pton(src, dst, dstsiz) * Convert a ascii string into an encoded domain name as per RFC1035. * return: * -1 if it fails * 1 if string was fully qualified * 0 is string was not fully qualified * notes: * Enforces label and domain length limits. */ int ns_name_pton(const char *src, u_char *dst, size_t dstsiz) { u_char *label, *bp, *eom; int c, n, escaped; char *cp; escaped = 0; bp = dst; eom = dst + dstsiz; label = bp++; while ((c = *src++) != 0) { if (escaped) { if ((cp = strchr(digits, c)) != NULL) { n = (int)(cp - digits) * 100; if ((c = *src++) == 0 || (cp = strchr(digits, c)) == NULL) { errno = EMSGSIZE; return (-1); } n += (int)(cp - digits) * 10; if ((c = *src++) == 0 || (cp = strchr(digits, c)) == NULL) { errno = EMSGSIZE; return (-1); } n += (int)(cp - digits); if (n > 255) { errno = EMSGSIZE; return (-1); } c = n; } escaped = 0; } else if (c == '\\') { escaped = 1; continue; } else if (c == '.') { c = ((int)(bp - label) - 1); if ((c & NS_CMPRSFLGS) != 0) { /* Label too big. */ errno = EMSGSIZE; return (-1); } if (label >= eom) { errno = EMSGSIZE; return (-1); } *label = (u_char)c; /* Fully qualified ? */ if (*src == '\0') { if (c != 0) { if (bp >= eom) { errno = EMSGSIZE; return (-1); } *bp++ = '\0'; } if ((bp - dst) > MAXCDNAME) { errno = EMSGSIZE; return (-1); } return (1); } if (c == 0) { errno = EMSGSIZE; return (-1); } label = bp++; continue; } if (bp >= eom) { errno = EMSGSIZE; return (-1); } *bp++ = (u_char)c; } c = ((int)(bp - label) - 1); if ((c & NS_CMPRSFLGS) != 0) { /* Label too big. */ errno = EMSGSIZE; return (-1); } if (label >= eom) { errno = EMSGSIZE; return (-1); } *label = (u_char)c; if (c != 0) { if (bp >= eom) { errno = EMSGSIZE; return (-1); } *bp++ = 0; } if ((bp - dst) > MAXCDNAME) { /* src too big */ errno = EMSGSIZE; return (-1); } return (0); } /* * 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) { 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) { errno = EMSGSIZE; return (-1); } checked += n + 1; *dstp++ = (u_char)n; memcpy(dstp, srcp, n); dstp += n; srcp += n; break; case NS_CMPRSFLGS: if (srcp >= eom) { errno = EMSGSIZE; return (-1); } if (len < 0) len = (int)(srcp - src) + 1; srcp = msg + (((n & 0x3f) << 8) | (*srcp & 0xff)); if (srcp < msg || srcp >= eom) { /* Out of range. */ 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) { errno = EMSGSIZE; return (-1); } break; default: errno = EMSGSIZE; return (-1); /* flag error */ } } *dstp = '\0'; if (len < 0) len = (int)(srcp - src); return (len); } /* * ns_name_pack(src, dst, dstsiz, dnptrs, lastdnptr) * Pack domain name 'domain' into 'comp_dn'. * return: * Size of the compressed name, or -1. * notes: * 'dnptrs' is an array of pointers to previous compressed names. * dnptrs[0] is a pointer to the beginning of the message. The array * ends with NULL. * 'lastdnptr' is a pointer to the end of the array pointed to * by 'dnptrs'. * Side effects: * The list of pointers in dnptrs is updated for labels inserted into * the message as we compress the name. If 'dnptr' is NULL, we don't * try to compress names. If 'lastdnptr' is NULL, we don't update the * list. */ int ns_name_pack(const u_char *src, u_char *dst, int dstsiz, const u_char **dnptrs, const u_char **lastdnptr) { u_char *dstp; const u_char **cpp, **lpp, *eob, *msg; const u_char *srcp; int n, l; srcp = src; dstp = dst; eob = dstp + dstsiz; lpp = cpp = NULL; if (dnptrs != NULL) { if ((msg = *dnptrs++) != NULL) { for (cpp = dnptrs; *cpp != NULL; cpp++) (void)NULL; lpp = cpp; /* end of list to search */ } } else msg = NULL; /* make sure the domain we are about to add is legal */ l = 0; do { n = *srcp; if ((n & NS_CMPRSFLGS) != 0) { errno = EMSGSIZE; return (-1); } l += n + 1; if (l > MAXCDNAME) { errno = EMSGSIZE; return (-1); } srcp += n + 1; } while (n != 0); srcp = src; do { /* Look to see if we can use pointers. */ n = *srcp; if (n != 0 && msg != NULL) { l = dn_find(srcp, msg, (const u_char * const *)dnptrs, (const u_char * const *)lpp); if (l >= 0) { if (dstp + 1 >= eob) { errno = EMSGSIZE; return (-1); } *dstp++ = (u_char)((l >> 8) | NS_CMPRSFLGS ); *dstp++ = (u_char)( l % 256 ); return ((int)(dstp - dst)); } /* Not found, save it. */ if (lastdnptr != NULL && cpp < lastdnptr - 1 && (dstp - msg) < 0x4000) { *cpp++ = dstp; *cpp = NULL; } } /* copy label to buffer */ if (n & NS_CMPRSFLGS) { /* Should not happen. */ errno = EMSGSIZE; return (-1); } if (dstp + 1 + n >= eob) { errno = EMSGSIZE; return (-1); } memcpy(dstp, srcp, n + 1); srcp += n + 1; dstp += n + 1; } while (n != 0); if (dstp > eob) { if (msg != NULL) *lpp = NULL; errno = EMSGSIZE; return (-1); } return ((int)(dstp - dst)); } /* * 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_compress(src, dst, dstsiz, dnptrs, lastdnptr) * Compress a domain name into wire format, using compression pointers. * return: * Number of bytes consumed in `dst' or -1 (with errno set). * notes: * 'dnptrs' is an array of pointers to previous compressed names. * dnptrs[0] is a pointer to the beginning of the message. * The list ends with NULL. 'lastdnptr' is a pointer to the end of the * array pointed to by 'dnptrs'. Side effect is to update the list of * pointers for labels inserted into the message as we compress the name. * If 'dnptr' is NULL, we don't try to compress names. If 'lastdnptr' * is NULL, we don't update the list. */ int ns_name_compress(const char *src, u_char *dst, size_t dstsiz, const u_char **dnptrs, const u_char **lastdnptr) { u_char tmp[NS_MAXCDNAME]; if (ns_name_pton(src, tmp, sizeof tmp) == -1) return (-1); return (ns_name_pack(tmp, dst, (int)dstsiz, dnptrs, lastdnptr)); } /* * ns_name_skip(ptrptr, eom) * Advance *ptrptr to skip over the compressed name it points at. * return: * 0 on success, -1 (with errno set) on failure. */ int ns_name_skip(const u_char **ptrptr, const u_char *eom) { const u_char *cp; u_int n; cp = *ptrptr; while (cp < eom && (n = *cp++) != 0) { /* Check for indirection. */ switch (n & NS_CMPRSFLGS) { case 0: /* normal case, n == len */ cp += n; continue; case NS_CMPRSFLGS: /* indirection */ cp++; break; default: /* illegal type */ errno = EMSGSIZE; return (-1); } break; } if (cp > eom) { errno = EMSGSIZE; return (-1); } *ptrptr = cp; return (0); } /* Private. */ /* * 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); } } /* * 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); } /* * Thinking in noninternationalized USASCII (per the DNS spec), * convert this character to lower case if it's upper case. */ static int mklower(int ch) { if (ch >= 0x41 && ch <= 0x5A) return (ch + 0x20); return (ch); } /* * dn_find(domain, msg, dnptrs, lastdnptr) * Search for the counted-label name in an array of compressed names. * return: * offset from msg if found, or -1. * notes: * dnptrs is the pointer to the first name on the list, * not the pointer to the start of the message. */ static int dn_find(const u_char *domain, const u_char *msg, const u_char * const *dnptrs, const u_char * const *lastdnptr) { const u_char *dn, *cp, *sp; const u_char * const *cpp; u_int n; for (cpp = dnptrs; cpp < lastdnptr; cpp++) { dn = domain; sp = cp = *cpp; while ((n = *cp++) != 0) { /* * check for indirection */ switch (n & NS_CMPRSFLGS) { case 0: /* normal case, n == len */ if (n != *dn++) goto next; for ((void)NULL; n > 0; n--) if (mklower(*dn++) != mklower(*cp++)) goto next; /* Is next root for both ? */ if (*dn == '\0' && *cp == '\0') return ((int)(sp - msg)); if (*dn) continue; goto next; case NS_CMPRSFLGS: /* indirection */ cp = msg + (((n & 0x3f) << 8) | *cp); break; default: /* illegal type */ errno = EMSGSIZE; return (-1); } } next: ; } errno = ENOENT; return (-1); }