diff options
Diffstat (limited to 'contrib/bind/lib/nameser/ns_name.c')
| -rw-r--r-- | contrib/bind/lib/nameser/ns_name.c | 321 |
1 files changed, 296 insertions, 25 deletions
diff --git a/contrib/bind/lib/nameser/ns_name.c b/contrib/bind/lib/nameser/ns_name.c index 2424eed..cf371b6 100644 --- a/contrib/bind/lib/nameser/ns_name.c +++ b/contrib/bind/lib/nameser/ns_name.c @@ -16,7 +16,7 @@ */ #ifndef lint -static const char rcsid[] = "$Id: ns_name.c,v 8.15 2000/03/30 22:53:46 vixie Exp $"; +static const char rcsid[] = "$Id: ns_name.c,v 8.17 2001/10/03 14:34:32 marka Exp $"; #endif #include "port_before.h" @@ -30,13 +30,43 @@ static const char rcsid[] = "$Id: ns_name.c,v 8.15 2000/03/30 22:53:46 vixie Exp #include <resolv.h> #include <string.h> #include <ctype.h> +#include <stdlib.h> +#include <limits.h> #include "port_after.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); @@ -44,6 +74,10 @@ 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 *, + char **, char **, const char *); +static int labellen(const u_char *); +static int decode_bitstring(const char **, char *, const char *); /* Public. */ @@ -57,18 +91,20 @@ static int dn_find(const u_char *, const u_char *, * All other domains are returned in non absolute form */ int -ns_name_ntop(const u_char *src, char *dst, size_t dstsiz) { +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) != 0) { + if ((n & NS_CMPRSFLGS) == NS_CMPRSFLGS) { /* Some kind of compression pointer. */ errno = EMSGSIZE; return (-1); @@ -80,11 +116,31 @@ ns_name_ntop(const u_char *src, char *dst, size_t dstsiz) { } *dn++ = '.'; } - if (dn + n >= eom) { + if ((l = labellen(cp - 1)) < 0) { + errno = EMSGSIZE; /* XXX */ + return(-1); + } + if (dn + l >= eom) { errno = EMSGSIZE; return (-1); } - for ((void)NULL; n > 0; n--) { + 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((const char **)&cp, dn, eom)) < 0) + { + errno = EMSGSIZE; + return(-1); + } + dn += m; + continue; + } + for ((void)NULL; l > 0; l--) { c = *cp++; if (special(c)) { if (dn + 1 >= eom) { @@ -138,9 +194,10 @@ ns_name_ntop(const u_char *src, char *dst, size_t dstsiz) { */ int -ns_name_pton(const char *src, u_char *dst, size_t dstsiz) { +ns_name_pton(const char *src, u_char *dst, size_t dstsiz) +{ u_char *label, *bp, *eom; - int c, n, escaped; + int c, n, escaped, e = 0; char *cp; escaped = 0; @@ -150,7 +207,31 @@ ns_name_pton(const char *src, u_char *dst, size_t dstsiz) { while ((c = *src++) != 0) { if (escaped) { - if ((cp = strchr(digits, c)) != NULL) { + if (c == '[') { /* start a bit string label */ + if ((cp = strchr(src, ']')) == NULL) { + errno = EINVAL; /* ??? */ + return(-1); + } + if ((e = encode_bitsring(&src, + cp + 2, + (char **)&label, + (char **)&bp, + (const char *)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) { @@ -218,6 +299,7 @@ ns_name_pton(const char *src, u_char *dst, size_t dstsiz) { errno = EMSGSIZE; return (-1); } + done: if (label >= eom) { errno = EMSGSIZE; return (-1); @@ -247,28 +329,34 @@ ns_name_pton(const char *src, u_char *dst, size_t dstsiz) { */ int -ns_name_ntol(const u_char *src, u_char *dst, size_t dstsiz) { +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; while ((n = *cp++) != 0) { - if ((n & NS_CMPRSFLGS) != 0) { + if ((n & NS_CMPRSFLGS) == NS_CMPRSFLGS) { /* Some kind of compression pointer. */ errno = EMSGSIZE; return (-1); } *dn++ = n; - if (dn + n >= eom) { + if ((l = labellen(cp - 1)) < 0) { + errno = EMSGSIZE; + return (-1); + } + if (dn + l >= eom) { errno = EMSGSIZE; return (-1); } - for ((void)NULL; n > 0; n--) { + for ((void)NULL; l > 0; l--) { c = *cp++; if (isupper(c)) *dn++ = tolower(c); @@ -292,7 +380,7 @@ ns_name_unpack(const u_char *msg, const u_char *eom, const u_char *src, { const u_char *srcp, *dstlim; u_char *dstp; - int n, len, checked; + int n, len, checked, l; len = -1; checked = 0; @@ -308,16 +396,21 @@ ns_name_unpack(const u_char *msg, const u_char *eom, const u_char *src, /* Check for indirection. */ switch (n & NS_CMPRSFLGS) { case 0: + case NS_TYPE_ELT: /* Limit checks. */ - if (dstp + n + 1 >= dstlim || srcp + n >= eom) { + if ((l = labellen(srcp - 1)) < 0) { + errno = EMSGSIZE; + return(-1); + } + if (dstp + l + 1 >= dstlim || srcp + l >= eom) { errno = EMSGSIZE; return (-1); } - checked += n + 1; + checked += l + 1; *dstp++ = n; - memcpy(dstp, srcp, n); - dstp += n; - srcp += n; + memcpy(dstp, srcp, l); + dstp += l; + srcp += l; break; case NS_CMPRSFLGS: @@ -397,17 +490,23 @@ ns_name_pack(const u_char *src, u_char *dst, int dstsiz, /* make sure the domain we are about to add is legal */ l = 0; do { + int l0; + n = *srcp; - if ((n & NS_CMPRSFLGS) != 0) { + if ((n & NS_CMPRSFLGS) == NS_CMPRSFLGS) { errno = EMSGSIZE; return (-1); } - l += n + 1; + if ((l0 = labellen(srcp)) < 0) { + errno = EINVAL; + return(-1); + } + l += l0 + 1; if (l > MAXCDNAME) { errno = EMSGSIZE; return (-1); } - srcp += n + 1; + srcp += l0 + 1; } while (n != 0); /* from here on we need to reset compression pointer array on error */ @@ -435,9 +534,11 @@ ns_name_pack(const u_char *src, u_char *dst, int dstsiz, } } /* copy label to buffer */ - if (n & NS_CMPRSFLGS) { /* Should not happen. */ + if ((n & NS_CMPRSFLGS) == NS_CMPRSFLGS) { + /* Should not happen. */ goto cleanup; } + n = labellen(srcp); if (dstp + 1 + n >= eob) { goto cleanup; } @@ -527,9 +628,11 @@ ns_name_rollback(const u_char *src, const u_char **dnptrs, * 0 on success, -1 (with errno set) on failure. */ int -ns_name_skip(const u_char **ptrptr, const u_char *eom) { +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) { @@ -538,6 +641,13 @@ ns_name_skip(const u_char **ptrptr, const u_char *eom) { 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; @@ -639,8 +749,11 @@ dn_find(const u_char *domain, const u_char *msg, */ switch (n & NS_CMPRSFLGS) { case 0: /* normal case, n == len */ + n = labellen(cp - 1); /* XXX */ + if (n != *dn++) goto next; + for ((void)NULL; n > 0; n--) if (mklower(*dn++) != mklower(*cp++)) @@ -651,7 +764,6 @@ dn_find(const u_char *domain, const u_char *msg, if (*dn) continue; goto next; - case NS_CMPRSFLGS: /* indirection */ cp = msg + (((n & 0x3f) << 8) | *cp); break; @@ -661,10 +773,169 @@ dn_find(const u_char *domain, const u_char *msg, return (-1); } } - next: + next: ; sp += *sp + 1; } } errno = ENOENT; return (-1); } + +static int +decode_bitstring(const char **cpp, char *dn, const char *eom) +{ + const char *cp = *cpp; + char *beg = dn, tc; + int b, blen, plen; + + 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++; + dn += SPRINTF((dn, "\\[x")); + for (b = blen; b > 7; b -= 8, cp++) + dn += SPRINTF((dn, "%02x", *cp & 0xff)); + if (b > 4) { + tc = *cp++; + dn += SPRINTF((dn, "%02x", tc & (0xff << (8 - b)))); + } else if (b > 0) { + tc = *cp++; + dn += SPRINTF((dn, "%1x", + ((tc >> 4) & 0x0f) & (0x0f << (4 - b)))); + } + dn += SPRINTF((dn, "/%d]", blen)); + + *cpp = cp; + return(dn - beg); +} + +static int +encode_bitsring(const char **bp, const char *end, char **labelp, + char ** dst, const char *eom) +{ + int afterslash = 0; + const char *cp = *bp; + char *tp, 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); +} |
