diff options
Diffstat (limited to 'libc/netbsd/nameser/ns_name.c')
| -rw-r--r-- | libc/netbsd/nameser/ns_name.c | 970 |
1 files changed, 970 insertions, 0 deletions
diff --git a/libc/netbsd/nameser/ns_name.c b/libc/netbsd/nameser/ns_name.c new file mode 100644 index 0000000..85d2f60 --- /dev/null +++ b/libc/netbsd/nameser/ns_name.c @@ -0,0 +1,970 @@ +/* $NetBSD: ns_name.c,v 1.3 2004/11/07 02:19:49 christos Exp $ */ + +/* + * Copyright (c) 2004 by Internet Systems Consortium, Inc. ("ISC") + * 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 ISC DISCLAIMS ALL WARRANTIES + * WITH REGARD TO THIS SOFTWARE INCLUDING ALL IMPLIED WARRANTIES OF + * MERCHANTABILITY AND FITNESS. IN NO EVENT SHALL ISC 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. + */ + +#include <sys/cdefs.h> +#ifndef lint +#ifdef notdef +static const char rcsid[] = "Id: ns_name.c,v 1.3.2.4.4.2 2004/05/04 03:27:47 marka Exp"; +#else +__RCSID("$NetBSD: ns_name.c,v 1.3 2004/11/07 02:19:49 christos Exp $"); +#endif +#endif + +#include <sys/types.h> + +#include <netinet/in.h> +#include "arpa_nameser.h" + +#include <errno.h> +#ifdef ANDROID_CHANGES +#include "resolv_private.h" +#else +#include <resolv.h> +#endif +#include <string.h> +#include <ctype.h> +#include <stdlib.h> +#include <limits.h> + +#ifdef SPRINTF_CHAR +# define SPRINTF(x) strlen(sprintf/**/x) +#else +# define SPRINTF(x) ((size_t)sprintf x) +#endif + +#define NS_TYPE_ELT 0x40 /* EDNS0 extended label type */ +#define DNS_LABELTYPE_BITSTRING 0x41 + +/* Data. */ + +static const char digits[] = "0123456789"; + +static const char digitvalue[256] = { + -1, -1, -1, -1, -1, -1, -1, -1, -1, -1, -1, -1, -1, -1, -1, -1, /*16*/ + -1, -1, -1, -1, -1, -1, -1, -1, -1, -1, -1, -1, -1, -1, -1, -1, /*32*/ + -1, -1, -1, -1, -1, -1, -1, -1, -1, -1, -1, -1, -1, -1, -1, -1, /*48*/ + 0, 1, 2, 3, 4, 5, 6, 7, 8, 9, -1, -1, -1, -1, -1, -1, /*64*/ + -1, 10, 11, 12, 13, 14, 15, -1, -1, -1, -1, -1, -1, -1, -1, -1, /*80*/ + -1, -1, -1, -1, -1, -1, -1, -1, -1, -1, -1, -1, -1, -1, -1, -1, /*96*/ + -1, 10, 11, 12, 13, 14, 15, -1, -1, -1, -1, -1, -1, -1, -1, -1, /*112*/ + -1, -1, -1, -1, -1, -1, -1, -1, -1, -1, -1, -1, -1, -1, -1, -1, /*128*/ + -1, -1, -1, -1, -1, -1, -1, -1, -1, -1, -1, -1, -1, -1, -1, -1, + -1, -1, -1, -1, -1, -1, -1, -1, -1, -1, -1, -1, -1, -1, -1, -1, + -1, -1, -1, -1, -1, -1, -1, -1, -1, -1, -1, -1, -1, -1, -1, -1, + -1, -1, -1, -1, -1, -1, -1, -1, -1, -1, -1, -1, -1, -1, -1, -1, + -1, -1, -1, -1, -1, -1, -1, -1, -1, -1, -1, -1, -1, -1, -1, -1, + -1, -1, -1, -1, -1, -1, -1, -1, -1, -1, -1, -1, -1, -1, -1, -1, + -1, -1, -1, -1, -1, -1, -1, -1, -1, -1, -1, -1, -1, -1, -1, -1, + -1, -1, -1, -1, -1, -1, -1, -1, -1, -1, -1, -1, -1, -1, -1, -1, /*256*/ +}; + +/* 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 *); +static int encode_bitsring(const char **, const char *, + unsigned char **, unsigned char **, + unsigned const char *); +static int labellen(const u_char *); +static int decode_bitstring(const unsigned char **, + char *, const char *); + +/* 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; + int l; + + cp = src; + dn = dst; + eom = dst + dstsiz; + + while ((n = *cp++) != 0) { + if ((n & NS_CMPRSFLGS) == NS_CMPRSFLGS) { + /* Some kind of compression pointer. */ + errno = EMSGSIZE; + return (-1); + } + if (dn != dst) { + if (dn >= eom) { + errno = EMSGSIZE; + return (-1); + } + *dn++ = '.'; + } + if ((l = labellen(cp - 1)) < 0) { + errno = EMSGSIZE; /* XXX */ + return(-1); + } + if (dn + l >= eom) { + errno = EMSGSIZE; + return (-1); + } + if ((n & NS_CMPRSFLGS) == NS_TYPE_ELT) { + int m; + + if (n != DNS_LABELTYPE_BITSTRING) { + /* XXX: labellen should reject this case */ + errno = EINVAL; + return(-1); + } + if ((m = decode_bitstring(&cp, dn, eom)) < 0) + { + errno = EMSGSIZE; + return(-1); + } + dn += m; + continue; + } + for (; l > 0; l--) { + 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 (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, e = 0; + char *cp; + + escaped = 0; + bp = dst; + eom = dst + dstsiz; + label = bp++; + + while ((c = *src++) != 0) { + if (escaped) { + if (c == '[') { /* start a bit string label */ + if ((cp = strchr(src, ']')) == NULL) { + errno = EINVAL; /* ??? */ + return(-1); + } + if ((e = encode_bitsring(&src, cp + 2, + &label, &bp, eom)) + != 0) { + errno = e; + return(-1); + } + escaped = 0; + label = bp++; + if ((c = *src++) == 0) + goto done; + else if (c != '.') { + errno = EINVAL; + return(-1); + } + continue; + } + else if ((cp = strchr(digits, c)) != NULL) { + n = (cp - digits) * 100; + if ((c = *src++) == 0 || + (cp = strchr(digits, c)) == NULL) { + errno = EMSGSIZE; + return (-1); + } + n += (cp - digits) * 10; + if ((c = *src++) == 0 || + (cp = strchr(digits, c)) == NULL) { + errno = EMSGSIZE; + return (-1); + } + n += (cp - digits); + if (n > 255) { + errno = EMSGSIZE; + return (-1); + } + c = n; + } + escaped = 0; + } else if (c == '\\') { + escaped = 1; + continue; + } else if (c == '.') { + c = (bp - label - 1); + if ((c & NS_CMPRSFLGS) != 0) { /* Label too big. */ + errno = EMSGSIZE; + return (-1); + } + if (label >= eom) { + errno = EMSGSIZE; + return (-1); + } + *label = 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 || *src == '.') { + errno = EMSGSIZE; + return (-1); + } + label = bp++; + continue; + } + if (bp >= eom) { + errno = EMSGSIZE; + return (-1); + } + *bp++ = (u_char)c; + } + c = (bp - label - 1); + if ((c & NS_CMPRSFLGS) != 0) { /* Label too big. */ + errno = EMSGSIZE; + return (-1); + } + done: + if (label >= eom) { + errno = EMSGSIZE; + return (-1); + } + *label = 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_ntol(src, dst, dstsiz) + * Convert a network strings labels into all lowercase. + * return: + * Number of bytes written to buffer, or -1 (with errno set) + * notes: + * Enforces label and domain length limits. + */ + +int +ns_name_ntol(const u_char *src, u_char *dst, size_t dstsiz) +{ + const u_char *cp; + u_char *dn, *eom; + u_char c; + u_int n; + int l; + + cp = src; + dn = dst; + eom = dst + dstsiz; + + if (dn >= eom) { + errno = EMSGSIZE; + return (-1); + } + while ((n = *cp++) != 0) { + if ((n & NS_CMPRSFLGS) == NS_CMPRSFLGS) { + /* Some kind of compression pointer. */ + errno = EMSGSIZE; + return (-1); + } + *dn++ = n; + if ((l = labellen(cp - 1)) < 0) { + errno = EMSGSIZE; + return (-1); + } + if (dn + l >= eom) { + errno = EMSGSIZE; + return (-1); + } + for (; l > 0; l--) { + c = *cp++; + if (isupper(c)) + *dn++ = tolower(c); + else + *dn++ = c; + } + } + *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, l; + + 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: + case NS_TYPE_ELT: + /* Limit checks. */ + if ((l = labellen(srcp - 1)) < 0) { + errno = EMSGSIZE; + return(-1); + } + if (dstp + l + 1 >= dstlim || srcp + l >= eom) { + errno = EMSGSIZE; + return (-1); + } + checked += l + 1; + *dstp++ = n; + memcpy(dstp, srcp, (size_t)l); + dstp += l; + srcp += l; + break; + + case NS_CMPRSFLGS: + if (srcp >= eom) { + 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. */ + 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 = 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, first = 1; + + srcp = src; + dstp = dst; + eob = dstp + dstsiz; + 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; + + /* make sure the domain we are about to add is legal */ + l = 0; + do { + int l0; + + n = *srcp; + if ((n & NS_CMPRSFLGS) == NS_CMPRSFLGS) { + errno = EMSGSIZE; + return (-1); + } + if ((l0 = labellen(srcp)) < 0) { + errno = EINVAL; + return(-1); + } + l += l0 + 1; + if (l > MAXCDNAME) { + errno = EMSGSIZE; + return (-1); + } + srcp += l0 + 1; + } while (n != 0); + + /* from here on we need to reset compression pointer array on error */ + 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) { + goto cleanup; + } + *dstp++ = ((u_int32_t)l >> 8) | NS_CMPRSFLGS; + *dstp++ = l % 256; + return (dstp - dst); + } + /* Not found, save it. */ + if (lastdnptr != NULL && cpp < lastdnptr - 1 && + (dstp - msg) < 0x4000 && first) { + *cpp++ = dstp; + *cpp = NULL; + first = 0; + } + } + /* copy label to buffer */ + if ((n & NS_CMPRSFLGS) == NS_CMPRSFLGS) { + /* Should not happen. */ + goto cleanup; + } + n = labellen(srcp); + if (dstp + 1 + n >= eob) { + goto cleanup; + } + memcpy(dstp, srcp, (size_t)(n + 1)); + srcp += n + 1; + dstp += n + 1; + } while (n != 0); + + if (dstp > eob) { +cleanup: + if (msg != NULL) + *lpp = NULL; + errno = EMSGSIZE; + return (-1); + } + return (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)); +} + +/* + * Reset dnptrs so that there are no active references to pointers at or + * after src. + */ +void +ns_name_rollback(const u_char *src, const u_char **dnptrs, + const u_char **lastdnptr) +{ + while (dnptrs < lastdnptr && *dnptrs != NULL) { + if (*dnptrs >= src) { + *dnptrs = NULL; + break; + } + dnptrs++; + } +} + +/* + * 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; + int l; + + 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_TYPE_ELT: /* EDNS0 extended label */ + if ((l = labellen(cp - 1)) < 0) { + errno = EMSGSIZE; /* XXX */ + return(-1); + } + cp += l; + 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: /* '\\' */ + case 0x28: /* '(' */ + case 0x29: /* ')' */ + /* 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++) { + sp = *cpp; + /* + * terminate search on: + * root label + * compression pointer + * unusable offset + */ + while (*sp != 0 && (*sp & NS_CMPRSFLGS) == 0 && + (sp - msg) < 0x4000) { + dn = domain; + cp = sp; + while ((n = *cp++) != 0) { + /* + * check for indirection + */ + switch (n & NS_CMPRSFLGS) { + case 0: /* normal case, n == len */ + n = labellen(cp - 1); /* XXX */ + + if (n != *dn++) + goto next; + + for (; n > 0; n--) + if (mklower(*dn++) != + mklower(*cp++)) + goto next; + /* Is next root for both ? */ + if (*dn == '\0' && *cp == '\0') + return (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: ; + sp += *sp + 1; + } + } + errno = ENOENT; + return (-1); +} + +static int +decode_bitstring(const unsigned char **cpp, char *dn, const char *eom) +{ + const unsigned char *cp = *cpp; + char *beg = dn, tc; + int b, blen, plen, i; + + if ((blen = (*cp & 0xff)) == 0) + blen = 256; + plen = (blen + 3) / 4; + plen += sizeof("\\[x/]") + (blen > 99 ? 3 : (blen > 9) ? 2 : 1); + if (dn + plen >= eom) + return(-1); + + cp++; + i = SPRINTF((dn, "\\[x")); + if (i < 0) + return (-1); + dn += i; + for (b = blen; b > 7; b -= 8, cp++) { + i = SPRINTF((dn, "%02x", *cp & 0xff)); + if (i < 0) + return (-1); + dn += i; + } + if (b > 4) { + tc = *cp++; + i = SPRINTF((dn, "%02x", tc & (0xff << (8 - b)))); + if (i < 0) + return (-1); + dn += i; + } else if (b > 0) { + tc = *cp++; + i = SPRINTF((dn, "%1x", + (((u_int32_t)tc >> 4) & 0x0f) & (0x0f << (4 - b)))); + if (i < 0) + return (-1); + dn += i; + } + i = SPRINTF((dn, "/%d]", blen)); + if (i < 0) + return (-1); + dn += i; + + *cpp = cp; + return(dn - beg); +} + +static int +encode_bitsring(const char **bp, const char *end, unsigned char **labelp, + unsigned char ** dst, unsigned const char *eom) +{ + int afterslash = 0; + const char *cp = *bp; + unsigned char *tp; + char c; + const char *beg_blen; + char *end_blen = NULL; + int value = 0, count = 0, tbcount = 0, blen = 0; + + beg_blen = end_blen = NULL; + + /* a bitstring must contain at least 2 characters */ + if (end - cp < 2) + return(EINVAL); + + /* XXX: currently, only hex strings are supported */ + if (*cp++ != 'x') + return(EINVAL); + if (!isxdigit((*cp) & 0xff)) /* reject '\[x/BLEN]' */ + return(EINVAL); + + for (tp = *dst + 1; cp < end && tp < eom; cp++) { + switch((c = *cp)) { + case ']': /* end of the bitstring */ + if (afterslash) { + if (beg_blen == NULL) + return(EINVAL); + blen = (int)strtol(beg_blen, &end_blen, 10); + if (*end_blen != ']') + return(EINVAL); + } + if (count) + *tp++ = ((value << 4) & 0xff); + cp++; /* skip ']' */ + goto done; + case '/': + afterslash = 1; + break; + default: + if (afterslash) { + if (!isdigit(c&0xff)) + return(EINVAL); + if (beg_blen == NULL) { + + if (c == '0') { + /* blen never begings with 0 */ + return(EINVAL); + } + beg_blen = cp; + } + } else { + if (!isxdigit(c&0xff)) + return(EINVAL); + value <<= 4; + value += digitvalue[(int)c]; + count += 4; + tbcount += 4; + if (tbcount > 256) + return(EINVAL); + if (count == 8) { + *tp++ = value; + count = 0; + } + } + break; + } + } + done: + if (cp >= end || tp >= eom) + return(EMSGSIZE); + + /* + * bit length validation: + * If a <length> is present, the number of digits in the <bit-data> + * MUST be just sufficient to contain the number of bits specified + * by the <length>. If there are insignificant bits in a final + * hexadecimal or octal digit, they MUST be zero. + * RFC 2673, Section 3.2. + */ + if (blen > 0) { + int traillen; + + if (((blen + 3) & ~3) != tbcount) + return(EINVAL); + traillen = tbcount - blen; /* between 0 and 3 */ + if (((value << (8 - traillen)) & 0xff) != 0) + return(EINVAL); + } + else + blen = tbcount; + if (blen == 256) + blen = 0; + + /* encode the type and the significant bit fields */ + **labelp = DNS_LABELTYPE_BITSTRING; + **dst = blen; + + *bp = cp; + *dst = tp; + + return(0); +} + +static int +labellen(const u_char *lp) +{ + int bitlen; + u_char l = *lp; + + if ((l & NS_CMPRSFLGS) == NS_CMPRSFLGS) { + /* should be avoided by the caller */ + return(-1); + } + + if ((l & NS_CMPRSFLGS) == NS_TYPE_ELT) { + if (l == DNS_LABELTYPE_BITSTRING) { + if ((bitlen = *(lp + 1)) == 0) + bitlen = 256; + return((bitlen + 7 ) / 8 + 1); + } + return(-1); /* unknwon ELT */ + } + return(l); +} |