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Diffstat (limited to 'resolv/res_comp.c')
| -rw-r--r-- | resolv/res_comp.c | 433 |
1 files changed, 433 insertions, 0 deletions
diff --git a/resolv/res_comp.c b/resolv/res_comp.c new file mode 100644 index 0000000..ad24a98 --- /dev/null +++ b/resolv/res_comp.c @@ -0,0 +1,433 @@ +/* + * ++Copyright++ 1985, 1993 + * - + * 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. + * 3. All advertising materials mentioning features or use of this software + * must display the following acknowledgement: + * This product includes software developed by the University of + * California, Berkeley and its contributors. + * 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. + * - + * --Copyright-- + */ + +#if defined(LIBC_SCCS) && !defined(lint) +static char sccsid[] = "@(#)res_comp.c 8.1 (Berkeley) 6/4/93"; +static char rcsid[] = "$Id$"; +#endif /* LIBC_SCCS and not lint */ + +#include <sys/param.h> +#include <netinet/in.h> +#include <arpa/nameser.h> + +#include <stdio.h> +#include <resolv.h> +#include <ctype.h> + +#if defined(BSD) && (BSD >= 199103) +# include <unistd.h> +# include <string.h> +#else +# include "../conf/portability.h" +#endif + +static int dn_find __P((u_char *exp_dn, u_char *msg, + u_char **dnptrs, u_char **lastdnptr)); + +/* + * 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(msg, eomorig, comp_dn, exp_dn, length) + const u_char *msg, *eomorig, *comp_dn; + char *exp_dn; + int length; +{ + register const u_char *cp; + register char *dn; + register int n, c; + char *eom; + int len = -1, checked = 0; + + dn = exp_dn; + cp = comp_dn; + eom = exp_dn + length; + /* + * fetch next label in domain name + */ + while (n = *cp++) { + /* + * Check for indirection + */ + switch (n & INDIR_MASK) { + case 0: + if (dn != exp_dn) { + if (dn >= eom) + return (-1); + *dn++ = '.'; + } + if (dn+n >= eom) + return (-1); + checked += n + 1; + while (--n >= 0) { + if ((c = *cp++) == '.') { + if (dn + n + 2 >= eom) + return (-1); + *dn++ = '\\'; + } + *dn++ = c; + if (cp >= eomorig) /* out of range */ + return (-1); + } + break; + + case INDIR_MASK: + if (len < 0) + len = cp - comp_dn + 1; + cp = msg + (((n & 0x3f) << 8) | (*cp & 0xff)); + if (cp < msg || cp >= eomorig) /* out of range */ + 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 >= eomorig - msg) + return (-1); + break; + + default: + return (-1); /* flag error */ + } + } + *dn = '\0'; + for (dn = exp_dn; (c = *dn) != '\0'; dn++) + if (isascii(c) && isspace(c)) + return (-1); + if (len < 0) + len = cp - comp_dn; + return (len); +} + +/* + * Compress domain name 'exp_dn' into 'comp_dn'. + * Return the size of the compressed name or -1. + * 'length' is the size of the array pointed to by 'comp_dn'. + * 'dnptrs' is a list 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 arrary 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 +dn_comp(exp_dn, comp_dn, length, dnptrs, lastdnptr) + const char *exp_dn; + u_char *comp_dn, **dnptrs, **lastdnptr; + int length; +{ + register u_char *cp, *dn; + register int c, l; + u_char **cpp, **lpp, *sp, *eob; + u_char *msg; + + dn = (u_char *)exp_dn; + cp = comp_dn; + eob = cp + length; + lpp = cpp = NULL; + if (dnptrs != NULL) { + if ((msg = *dnptrs++) != NULL) { + for (cpp = dnptrs; *cpp != NULL; cpp++) + ; + lpp = cpp; /* end of list to search */ + } + } else + msg = NULL; + for (c = *dn++; c != '\0'; ) { + /* look to see if we can use pointers */ + if (msg != NULL) { + if ((l = dn_find(dn-1, msg, dnptrs, lpp)) >= 0) { + if (cp+1 >= eob) + return (-1); + *cp++ = (l >> 8) | INDIR_MASK; + *cp++ = l % 256; + return (cp - comp_dn); + } + /* not found, save it */ + if (lastdnptr != NULL && cpp < lastdnptr-1) { + *cpp++ = cp; + *cpp = NULL; + } + } + sp = cp++; /* save ptr to length byte */ + do { + if (c == '.') { + c = *dn++; + break; + } + if (c == '\\') { + if ((c = *dn++) == '\0') + break; + } + if (cp >= eob) { + if (msg != NULL) + *lpp = NULL; + return (-1); + } + *cp++ = c; + } while ((c = *dn++) != '\0'); + /* catch trailing '.'s but not '..' */ + if ((l = cp - sp - 1) == 0 && c == '\0') { + cp--; + break; + } + if (l <= 0 || l > MAXLABEL) { + if (msg != NULL) + *lpp = NULL; + return (-1); + } + *sp = l; + } + if (cp >= eob) { + if (msg != NULL) + *lpp = NULL; + return (-1); + } + *cp++ = '\0'; + return (cp - comp_dn); +} + +/* + * Skip over a compressed domain name. Return the size or -1. + */ +int +__dn_skipname(comp_dn, eom) + const u_char *comp_dn, *eom; +{ + register const u_char *cp; + register int n; + + cp = comp_dn; + while (cp < eom && (n = *cp++)) { + /* + * check for indirection + */ + switch (n & INDIR_MASK) { + case 0: /* normal case, n == len */ + cp += n; + continue; + case INDIR_MASK: /* indirection */ + cp++; + break; + default: /* illegal type */ + return (-1); + } + break; + } + if (cp > eom) + return (-1); + return (cp - comp_dn); +} + +static int +mklower(ch) + register int ch; +{ + if (isascii(ch) && isupper(ch)) + return (tolower(ch)); + return (ch); +} + +/* + * Search for expanded name from a list of previously compressed names. + * Return the offset from msg if found or -1. + * dnptrs is the pointer to the first name on the list, + * not the pointer to the start of the message. + */ +static int +dn_find(exp_dn, msg, dnptrs, lastdnptr) + u_char *exp_dn, *msg; + u_char **dnptrs, **lastdnptr; +{ + register u_char *dn, *cp, **cpp; + register int n; + u_char *sp; + + for (cpp = dnptrs; cpp < lastdnptr; cpp++) { + dn = exp_dn; + sp = cp = *cpp; + while (n = *cp++) { + /* + * check for indirection + */ + switch (n & INDIR_MASK) { + case 0: /* normal case, n == len */ + while (--n >= 0) { + if (*dn == '.') + goto next; + if (*dn == '\\') + dn++; + if (mklower(*dn++) != mklower(*cp++)) + goto next; + } + if ((n = *dn++) == '\0' && *cp == '\0') + return (sp - msg); + if (n == '.') + continue; + goto next; + + case INDIR_MASK: /* indirection */ + cp = msg + (((n & 0x3f) << 8) | *cp); + break; + + default: /* illegal type */ + return (-1); + } + } + if (*dn == '\0') + return (sp - msg); + next: ; + } + return (-1); +} + +/* + * Routines to insert/extract short/long's. Must account for byte + * order and non-alignment problems. This code at least has the + * advantage of being portable. + * + * used by sendmail. + */ + +u_int16_t +_getshort(msgp) + register const u_char *msgp; +{ + register u_int16_t u; + + GETSHORT(u, msgp); + return (u); +} + +#ifdef NeXT +/* + * nExt machines have some funky library conventions, which we must maintain. + */ +u_int16_t +res_getshort(msgp) + register const u_char *msgp; +{ + return (_getshort(msgp)); +} +#endif + +u_int32_t +_getlong(msgp) + register const u_char *msgp; +{ + register u_int32_t u; + + GETLONG(u, msgp); + return (u); +} + +void +#if defined(__STDC__) || defined(__cplusplus) +__putshort(register u_int16_t s, register u_char *msgp) /* must match proto */ +#else +__putshort(s, msgp) + register u_int16_t s; + register u_char *msgp; +#endif +{ + PUTSHORT(s, msgp); +} + +void +__putlong(l, msgp) + register u_int32_t l; + register u_char *msgp; +{ + PUTLONG(l, msgp); +} + +#ifdef ultrix +/* ultrix 4.0 had some icky packaging in its libc.a. alias for it here. + * there is more gunk of this kind over in res_debug.c. + */ +#undef putshort +void +#if defined(__STDC__) || defined(__cplusplus) +putshort(register u_short s, register u_char *msgp) +#else +putshort(s, msgp) + register u_short s; + register u_char *msgp; +#endif +{ + __putshort(s, msgp); +} +#undef putlong +void +putlong(l, msgp) + register u_int32_t l; + register u_char *msgp; +{ + __putlong(l, msgp); +} + +#undef dn_skipname +dn_skipname(comp_dn, eom) + const u_char *comp_dn, *eom; +{ + return (__dn_skipname(comp_dn, eom)); +} +#endif /* Ultrix 4.0 hackery */ |