/* * Copyright (C) 2004 Internet Systems Consortium, Inc. ("ISC") * Copyright (C) 1999-2001, 2003 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. */ /* $Id: rdataslab.c,v 1.29.2.3 2004/03/09 06:11:06 marka Exp $ */ #include #include #include #include #include /* Required for HP/UX (and others?) */ #include #include #include #include #include /* Note: the "const void *" are just to make qsort happy. */ static int compare_rdata(const void *p1, const void *p2) { const dns_rdata_t *rdata1 = p1; const dns_rdata_t *rdata2 = p2; return (dns_rdata_compare(rdata1, rdata2)); } isc_result_t dns_rdataslab_fromrdataset(dns_rdataset_t *rdataset, isc_mem_t *mctx, isc_region_t *region, unsigned int reservelen) { dns_rdata_t *rdatas; unsigned char *rawbuf; unsigned int buflen; isc_result_t result; unsigned int nitems; unsigned int nalloc; unsigned int i; buflen = reservelen + 2; nalloc = dns_rdataset_count(rdataset); nitems = nalloc; if (nitems == 0) return (ISC_R_FAILURE); rdatas = isc_mem_get(mctx, nalloc * sizeof(dns_rdata_t)); if (rdatas == NULL) return (ISC_R_NOMEMORY); /* * Save all of the rdata members into an array. */ result = dns_rdataset_first(rdataset); if (result != ISC_R_SUCCESS) goto free_rdatas; for (i = 0; i < nalloc && result == ISC_R_SUCCESS; i++) { INSIST(result == ISC_R_SUCCESS); dns_rdata_init(&rdatas[i]); dns_rdataset_current(rdataset, &rdatas[i]); result = dns_rdataset_next(rdataset); } if (result != ISC_R_NOMORE) goto free_rdatas; if (i != nalloc) { /* * Somehow we iterated over fewer rdatas than * dns_rdataset_count() said there were! */ result = ISC_R_FAILURE; goto free_rdatas; } qsort(rdatas, nalloc, sizeof(dns_rdata_t), compare_rdata); /* * Remove duplicates and compute the total storage required. * * If an rdata is not a duplicate, accumulate the storage size * required for the rdata. We do not store the class, type, etc, * just the rdata, so our overhead is 2 bytes for the number of * records, and 2 for each rdata length, and then the rdata itself. */ for (i = 1; i < nalloc; i++) { if (compare_rdata(&rdatas[i-1], &rdatas[i]) == 0) { rdatas[i-1].data = NULL; rdatas[i-1].length = 0; nitems--; } else buflen += (2 + rdatas[i-1].length); } /* * Don't forget the last item! */ buflen += (2 + rdatas[i-1].length); /* * Ensure that singleton types are actually singletons. */ if (nitems > 1 && dns_rdatatype_issingleton(rdataset->type)) { /* * We have a singleton type, but there's more than one * RR in the rdataset. */ result = DNS_R_SINGLETON; goto free_rdatas; } /* * Allocate the memory, set up a buffer, start copying in * data. */ rawbuf = isc_mem_get(mctx, buflen); if (rawbuf == NULL) { result = ISC_R_NOMEMORY; goto free_rdatas; } region->base = rawbuf; region->length = buflen; rawbuf += reservelen; *rawbuf++ = (nitems & 0xff00) >> 8; *rawbuf++ = (nitems & 0x00ff); for (i = 0; i < nalloc; i++) { if (rdatas[i].data == NULL) continue; *rawbuf++ = (rdatas[i].length & 0xff00) >> 8; *rawbuf++ = (rdatas[i].length & 0x00ff); memcpy(rawbuf, rdatas[i].data, rdatas[i].length); rawbuf += rdatas[i].length; } result = ISC_R_SUCCESS; free_rdatas: isc_mem_put(mctx, rdatas, nalloc * sizeof(dns_rdata_t)); return (result); } unsigned int dns_rdataslab_size(unsigned char *slab, unsigned int reservelen) { unsigned int count, length; unsigned char *current; REQUIRE(slab != NULL); current = slab + reservelen; count = *current++ * 256; count += *current++; while (count > 0) { count--; length = *current++ * 256; length += *current++; current += length; } return ((unsigned int)(current - slab)); } /* * Make the dns_rdata_t 'rdata' refer to the slab item * beginning at '*current', which is part of a slab of type * 'type' and class 'rdclass', and advance '*current' to * point to the next item in the slab. */ static inline void rdata_from_slab(unsigned char **current, dns_rdataclass_t rdclass, dns_rdatatype_t type, dns_rdata_t *rdata) { unsigned char *tcurrent = *current; isc_region_t region; region.length = *tcurrent++ * 256; region.length += *tcurrent++; region.base = tcurrent; tcurrent += region.length; dns_rdata_fromregion(rdata, rdclass, type, ®ion); *current = tcurrent; } /* * Return true iff 'slab' (slab data of type 'type' and class 'rdclass') * contains an rdata identical to 'rdata'. This does case insensitive * comparisons per DNSSEC. */ static inline isc_boolean_t rdata_in_slab(unsigned char *slab, unsigned int reservelen, dns_rdataclass_t rdclass, dns_rdatatype_t type, dns_rdata_t *rdata) { unsigned int count, i; unsigned char *current; dns_rdata_t trdata = DNS_RDATA_INIT; current = slab + reservelen; count = *current++ * 256; count += *current++; for (i = 0; i < count; i++) { rdata_from_slab(¤t, rdclass, type, &trdata); if (dns_rdata_compare(&trdata, rdata) == 0) return (ISC_TRUE); dns_rdata_reset(&trdata); } return (ISC_FALSE); } isc_result_t dns_rdataslab_merge(unsigned char *oslab, unsigned char *nslab, unsigned int reservelen, isc_mem_t *mctx, dns_rdataclass_t rdclass, dns_rdatatype_t type, unsigned int flags, unsigned char **tslabp) { unsigned char *ocurrent, *ostart, *ncurrent, *tstart, *tcurrent; unsigned int ocount, ncount, count, olength, tlength, tcount, length; isc_region_t nregion; dns_rdata_t ordata = DNS_RDATA_INIT; dns_rdata_t nrdata = DNS_RDATA_INIT; isc_boolean_t added_something = ISC_FALSE; unsigned int oadded = 0; unsigned int nadded = 0; unsigned int nncount = 0; /* * XXX Need parameter to allow "delete rdatasets in nslab" merge, * or perhaps another merge routine for this purpose. */ REQUIRE(tslabp != NULL && *tslabp == NULL); REQUIRE(oslab != NULL && nslab != NULL); ocurrent = oslab + reservelen; ocount = *ocurrent++ * 256; ocount += *ocurrent++; ostart = ocurrent; ncurrent = nslab + reservelen; ncount = *ncurrent++ * 256; ncount += *ncurrent++; INSIST(ocount > 0 && ncount > 0); /* * Yes, this is inefficient! */ /* * Figure out the length of the old slab's data. */ olength = 0; for (count = 0; count < ocount; count++) { length = *ocurrent++ * 256; length += *ocurrent++; olength += length + 2; ocurrent += length; } /* * Start figuring out the target length and count. */ tlength = reservelen + 2 + olength; tcount = ocount; /* * Add in the length of rdata in the new slab that aren't in * the old slab. */ do { nregion.length = *ncurrent++ * 256; nregion.length += *ncurrent++; nregion.base = ncurrent; dns_rdata_init(&nrdata); dns_rdata_fromregion(&nrdata, rdclass, type, &nregion); if (!rdata_in_slab(oslab, reservelen, rdclass, type, &nrdata)) { /* * This rdata isn't in the old slab. */ tlength += nregion.length + 2; tcount++; nncount++; added_something = ISC_TRUE; } ncurrent += nregion.length; ncount--; } while (ncount > 0); ncount = nncount; if (((flags & DNS_RDATASLAB_EXACT) != 0) && (tcount != ncount + ocount)) return (DNS_R_NOTEXACT); if (!added_something && (flags & DNS_RDATASLAB_FORCE) == 0) return (DNS_R_UNCHANGED); /* * Ensure that singleton types are actually singletons. */ if (tcount > 1 && dns_rdatatype_issingleton(type)) { /* * We have a singleton type, but there's more than one * RR in the rdataset. */ return (DNS_R_SINGLETON); } /* * Copy the reserved area from the new slab. */ tstart = isc_mem_get(mctx, tlength); if (tstart == NULL) return (ISC_R_NOMEMORY); memcpy(tstart, nslab, reservelen); tcurrent = tstart + reservelen; /* * Write the new count. */ *tcurrent++ = (tcount & 0xff00) >> 8; *tcurrent++ = (tcount & 0x00ff); /* * Merge the two slabs. */ ocurrent = ostart; INSIST(ocount != 0); rdata_from_slab(&ocurrent, rdclass, type, &ordata); ncurrent = nslab + reservelen + 2; if (ncount > 0) { do { dns_rdata_reset(&nrdata); rdata_from_slab(&ncurrent, rdclass, type, &nrdata); } while (rdata_in_slab(oslab, reservelen, rdclass, type, &nrdata)); } while (oadded < ocount || nadded < ncount) { isc_boolean_t fromold; if (oadded == ocount) fromold = ISC_FALSE; else if (nadded == ncount) fromold = ISC_TRUE; else fromold = ISC_TF(compare_rdata(&ordata, &nrdata) < 0); if (fromold) { length = ordata.length; *tcurrent++ = (length & 0xff00) >> 8; *tcurrent++ = (length & 0x00ff); memcpy(tcurrent, ordata.data, length); tcurrent += length; oadded++; if (oadded < ocount) { dns_rdata_reset(&ordata); rdata_from_slab(&ocurrent, rdclass, type, &ordata); } } else { length = nrdata.length; *tcurrent++ = (length & 0xff00) >> 8; *tcurrent++ = (length & 0x00ff); memcpy(tcurrent, nrdata.data, length); tcurrent += length; nadded++; if (nadded < ncount) { do { dns_rdata_reset(&nrdata); rdata_from_slab(&ncurrent, rdclass, type, &nrdata); } while (rdata_in_slab(oslab, reservelen, rdclass, type, &nrdata)); } } } INSIST(tcurrent == tstart + tlength); *tslabp = tstart; return (ISC_R_SUCCESS); } isc_result_t dns_rdataslab_subtract(unsigned char *mslab, unsigned char *sslab, unsigned int reservelen, isc_mem_t *mctx, dns_rdataclass_t rdclass, dns_rdatatype_t type, unsigned int flags, unsigned char **tslabp) { unsigned char *mcurrent, *sstart, *scurrent, *tstart, *tcurrent; unsigned int mcount, scount, rcount ,count, tlength, tcount; dns_rdata_t srdata = DNS_RDATA_INIT; dns_rdata_t mrdata = DNS_RDATA_INIT; REQUIRE(tslabp != NULL && *tslabp == NULL); REQUIRE(mslab != NULL && sslab != NULL); mcurrent = mslab + reservelen; mcount = *mcurrent++ * 256; mcount += *mcurrent++; scurrent = sslab + reservelen; scount = *scurrent++ * 256; scount += *scurrent++; sstart = scurrent; INSIST(mcount > 0 && scount > 0); /* * Yes, this is inefficient! */ /* * Start figuring out the target length and count. */ tlength = reservelen + 2; tcount = 0; rcount = 0; /* * Add in the length of rdata in the mslab that aren't in * the sslab. */ do { unsigned char *mrdatabegin = mcurrent; rdata_from_slab(&mcurrent, rdclass, type, &mrdata); scurrent = sstart; for (count = 0; count < scount; count++) { dns_rdata_reset(&srdata); rdata_from_slab(&scurrent, rdclass, type, &srdata); if (dns_rdata_compare(&mrdata, &srdata) == 0) break; } if (count == scount) { /* * This rdata isn't in the sslab, and thus isn't * being subtracted. */ tlength += mcurrent - mrdatabegin; tcount++; } else rcount++; mcount--; dns_rdata_reset(&mrdata); } while (mcount > 0); /* * Check that all the records originally existed. The numeric * check only works as rdataslabs do not contain duplicates. */ if (((flags & DNS_RDATASLAB_EXACT) != 0) && (rcount != scount)) return (DNS_R_NOTEXACT); /* * Don't continue if the new rdataslab would be empty. */ if (tcount == 0) return (DNS_R_NXRRSET); /* * If nothing is going to change, we can stop. */ if (rcount == 0) return (DNS_R_UNCHANGED); /* * Copy the reserved area from the mslab. */ tstart = isc_mem_get(mctx, tlength); if (tstart == NULL) return (ISC_R_NOMEMORY); memcpy(tstart, mslab, reservelen); tcurrent = tstart + reservelen; /* * Write the new count. */ *tcurrent++ = (tcount & 0xff00) >> 8; *tcurrent++ = (tcount & 0x00ff); /* * Copy the parts of mslab not in sslab. */ mcurrent = mslab + reservelen; mcount = *mcurrent++ * 256; mcount += *mcurrent++; do { unsigned char *mrdatabegin = mcurrent; rdata_from_slab(&mcurrent, rdclass, type, &mrdata); scurrent = sstart; for (count = 0; count < scount; count++) { dns_rdata_reset(&srdata); rdata_from_slab(&scurrent, rdclass, type, &srdata); if (dns_rdata_compare(&mrdata, &srdata) == 0) break; } if (count == scount) { /* * This rdata isn't in the sslab, and thus should be * copied to the tslab. */ unsigned int length = mcurrent - mrdatabegin; memcpy(tcurrent, mrdatabegin, length); tcurrent += length; } dns_rdata_reset(&mrdata); mcount--; } while (mcount > 0); INSIST(tcurrent == tstart + tlength); *tslabp = tstart; return (ISC_R_SUCCESS); } isc_boolean_t dns_rdataslab_equal(unsigned char *slab1, unsigned char *slab2, unsigned int reservelen) { unsigned char *current1, *current2; unsigned int count1, count2; unsigned int length1, length2; current1 = slab1 + reservelen; count1 = *current1++ * 256; count1 += *current1++; current2 = slab2 + reservelen; count2 = *current2++ * 256; count2 += *current2++; if (count1 != count2) return (ISC_FALSE); while (count1 > 0) { length1 = *current1++ * 256; length1 += *current1++; length2 = *current2++ * 256; length2 += *current2++; if (length1 != length2 || memcmp(current1, current2, length1) != 0) return (ISC_FALSE); current1 += length1; current2 += length1; count1--; } return (ISC_TRUE); } isc_boolean_t dns_rdataslab_equalx(unsigned char *slab1, unsigned char *slab2, unsigned int reservelen, dns_rdataclass_t rdclass, dns_rdatatype_t type) { unsigned char *current1, *current2; unsigned int count1, count2; dns_rdata_t rdata1 = DNS_RDATA_INIT; dns_rdata_t rdata2 = DNS_RDATA_INIT; current1 = slab1 + reservelen; count1 = *current1++ * 256; count1 += *current1++; current2 = slab2 + reservelen; count2 = *current2++ * 256; count2 += *current2++; if (count1 != count2) return (ISC_FALSE); while (count1-- > 0) { rdata_from_slab(¤t1, rdclass, type, &rdata1); rdata_from_slab(¤t2, rdclass, type, &rdata2); if (dns_rdata_compare(&rdata1, &rdata2) != 0) return (ISC_FALSE); dns_rdata_reset(&rdata1); dns_rdata_reset(&rdata2); } return (ISC_TRUE); }