mirror of
https://github.com/isc-projects/bind9.git
synced 2026-04-29 18:09:11 -04:00
names are now linkable; offsets is optional
This commit is contained in:
Bob Halley
parent
9d1650c9fd
commit
86131d8d7a
2 changed files with 114 additions and 48 deletions
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@ -150,13 +150,7 @@ dns_bitlabel_t dns_label_getbit(dns_label_t *label, unsigned int n);
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/***
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*** Note
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***
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*** Some provision still needs to be made for splitting bitstring labels,
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*** and for merging them, but doing either one requires memory in the
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*** obvious implementation.
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***
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*** Perhaps we can simply leave merging to FromWire, and deal with splitting
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*** by some other, noncopying method. I suspect copying is the way to go,
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*** however.
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*** Some provision still needs to be made for splitting bitstring labels.
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***/
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@ -188,7 +182,8 @@ struct dns_name {
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unsigned char *ndata;
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unsigned int length;
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unsigned int labels;
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unsigned char offsets[128];
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unsigned char *offsets;
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ISC_LINK(dns_name_t) link;
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};
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extern dns_name_t *dns_rootname;
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@ -197,13 +192,20 @@ extern dns_name_t *dns_rootname;
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*** Initialization
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***/
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void dns_name_init(dns_name_t *name);
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void dns_name_init(dns_name_t *name, unsigned char *offsets);
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/*
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* Make 'name' empty.
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*
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* Notes:
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* 'offsets' is never required to be non-NULL, but specifying a
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* dns_offsets_t for 'offsets' will improve the performance of most
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* name operations if the name is used more than once.
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*
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* Requires:
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* 'name' is a valid name (i.e. not NULL, points to a struct dns_name)
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*
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* offsets == NULL or offsets is a dns_offsets_t.
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*
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* Ensures:
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* dns_name_countlabels(name) == 0
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*/
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@ -216,10 +218,8 @@ void dns_name_invalidate(dns_name_t *name);
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* 'name' is a valid name.
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*
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* Ensures:
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* If assertion checking is enabled, future attempts to use 'name' without
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* initializing it will cause an assertion failure. A name can be
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* initialized by calling dns_name_init(), or by calling one of the
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* dns_name_from*() functions.
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* If assertion checking is enabled, future attempts to use 'name'
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* without initializing it will cause an assertion failure.
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*/
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/***
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@ -402,11 +402,13 @@ dns_result_t dns_name_fromwire(dns_name_t *name,
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* *** WARNING ***
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*
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* This routine will often be used when 'source' contains raw network
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* data. An error in this routine could result in a denial of service,
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* or in the hijacking of the server.
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* data. A programming error in this routine could result in a denial
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* of service, or in the hijacking of the server.
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*
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* Requires:
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*
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* 'name' is a valid name.
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*
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* 'source' is a valid buffer of type ISC_BUFFERTYPE_BINARY, and the
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* first byte of the used region should be the first byte of a DNS wire
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* format message.
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@ -496,12 +498,12 @@ dns_result_t dns_name_fromtext(dns_name_t *name,
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*
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* Requires:
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*
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* 'name' is a valid name.
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*
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* 'source' is a valid buffer of type ISC_BUFFERTYPE_TEXT.
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*
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* 'target' is a valid region of type ISC_BUFFERTYPE_BINARY.
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*
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* 'name' is a valid name.
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*
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* Ensures:
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*
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* If result is success:
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126
lib/dns/name.c
126
lib/dns/name.c
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@ -124,12 +124,31 @@ static unsigned char maptolower[] = {
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#define CONVERTTOASCII(c)
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#define CONVERTFROMASCII(c)
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static struct dns_name root = { NAME_MAGIC, "", 1, 1 };
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#define INIT_OFFSETS(name, var, default) \
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if (name->offsets != NULL) \
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var = name->offsets; \
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else \
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var = default;
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#define SETUP_OFFSETS(name, var, default) \
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if (name->offsets != NULL) \
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var = name->offsets; \
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else { \
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var = default; \
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set_offsets(name, var, ISC_FALSE, ISC_FALSE); \
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}
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static struct dns_name root = {
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NAME_MAGIC,
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"", 1, 1, NULL,
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{(void *)-1, (void *)-1}
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};
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dns_name_t *dns_rootname = &root;
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static void set_offsets(dns_name_t *, isc_boolean_t, isc_boolean_t);
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static void compact(dns_name_t *);
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static void set_offsets(dns_name_t *name, unsigned char *offsets,
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isc_boolean_t set_labels, isc_boolean_t set_length);
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static void compact(dns_name_t *name, unsigned char *offsets);
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/*
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* Yes, get_bit and set_bit are lame. We define them here so they can
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@ -224,7 +243,7 @@ dns_label_getbit(dns_label_t *label, unsigned int n) {
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}
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void
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dns_name_init(dns_name_t *name) {
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dns_name_init(dns_name_t *name, unsigned char *offsets) {
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/*
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* Make 'name' empty.
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*/
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@ -233,6 +252,8 @@ dns_name_init(dns_name_t *name) {
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name->ndata = NULL;
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name->length = 0;
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name->labels = 0;
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name->offsets = offsets;
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ISC_LINK_INIT(name, link);
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}
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void
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@ -247,10 +268,15 @@ dns_name_invalidate(dns_name_t *name) {
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name->ndata = NULL;
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name->length = 0;
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name->labels = 0;
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name->offsets = NULL;
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ISC_LINK_INIT(name, link);
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}
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isc_boolean_t
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dns_name_isabsolute(dns_name_t *name) {
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unsigned char *offsets;
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dns_offsets_t odata;
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/*
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* Does 'name' end in the root label?
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*/
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@ -258,7 +284,9 @@ dns_name_isabsolute(dns_name_t *name) {
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REQUIRE(VALID_NAME(name));
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REQUIRE(name->labels > 0);
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if (name->ndata[name->offsets[name->labels - 1]] == 0)
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SETUP_OFFSETS(name, offsets, odata);
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if (name->ndata[offsets[name->labels - 1]] == 0)
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return (ISC_TRUE);
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return (ISC_FALSE);
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}
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@ -270,6 +298,8 @@ dns_name_compare(dns_name_t *name1, dns_name_t *name2) {
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unsigned char c1, c2;
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int cdiff, ldiff;
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unsigned char *label1, *label2;
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unsigned char *offsets1, *offsets2;
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dns_offsets_t odata1, odata2;
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/*
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* Determine the relative ordering under the DNSSEC order relation of
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@ -281,6 +311,9 @@ dns_name_compare(dns_name_t *name1, dns_name_t *name2) {
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REQUIRE(VALID_NAME(name2));
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REQUIRE(name2->labels > 0);
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SETUP_OFFSETS(name1, offsets1, odata1);
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SETUP_OFFSETS(name2, offsets2, odata2);
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l1 = name1->labels;
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l2 = name2->labels;
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if (l1 < l2) {
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@ -298,8 +331,8 @@ dns_name_compare(dns_name_t *name1, dns_name_t *name2) {
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l--;
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l1--;
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l2--;
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label1 = &name1->ndata[name1->offsets[l1]];
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label2 = &name2->ndata[name2->offsets[l2]];
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label1 = &name1->ndata[offsets1[l1]];
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label2 = &name2->ndata[offsets2[l2]];
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count1 = *label1++;
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count2 = *label2++;
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if (count1 <= 63 && count2 <= 63) {
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@ -376,6 +409,8 @@ dns_name_issubdomain(dns_name_t *name1, dns_name_t *name2) {
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unsigned int b1, b2, n;
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unsigned char c1, c2;
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unsigned char *label1, *label2;
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unsigned char *offsets1, *offsets2;
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dns_offsets_t odata1, odata2;
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/*
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* Is 'name1' a subdomain of 'name2'?
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@ -397,6 +432,9 @@ dns_name_issubdomain(dns_name_t *name1, dns_name_t *name2) {
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REQUIRE((a1 && a2) || (!a1 && !a2));
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SETUP_OFFSETS(name1, offsets1, odata1);
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SETUP_OFFSETS(name2, offsets2, odata2);
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l1 = name1->labels;
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l2 = name2->labels;
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if (l1 < l2)
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@ -405,8 +443,8 @@ dns_name_issubdomain(dns_name_t *name1, dns_name_t *name2) {
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while (l2 > 0) {
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l1--;
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l2--;
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label1 = &name1->ndata[name1->offsets[l1]];
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label2 = &name2->ndata[name2->offsets[l2]];
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label1 = &name1->ndata[offsets1[l1]];
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label2 = &name2->ndata[offsets2[l2]];
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count1 = *label1++;
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count2 = *label2++;
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if (count1 <= 63 && count2 <= 63) {
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@ -462,6 +500,9 @@ dns_name_countlabels(dns_name_t *name) {
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void
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dns_name_getlabel(dns_name_t *name, unsigned int n, dns_label_t *label) {
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unsigned char *offsets;
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dns_offsets_t odata;
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/*
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* Make 'label' refer to the 'n'th least significant label of 'name'.
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*/
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@ -471,11 +512,13 @@ dns_name_getlabel(dns_name_t *name, unsigned int n, dns_label_t *label) {
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REQUIRE(n < name->labels);
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REQUIRE(label != NULL);
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label->base = &name->ndata[name->offsets[n]];
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SETUP_OFFSETS(name, offsets, odata);
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label->base = &name->ndata[offsets[n]];
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if (n == name->labels - 1)
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label->length = name->length - name->offsets[n];
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label->length = name->length - offsets[n];
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else
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label->length = name->offsets[n + 1] - name->offsets[n];
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label->length = offsets[n + 1] - offsets[n];
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}
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void
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@ -483,6 +526,9 @@ dns_name_getlabelsequence(dns_name_t *source,
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unsigned int first, unsigned int n,
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dns_name_t *target)
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{
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unsigned char *offsets;
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dns_offsets_t odata;
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/*
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* Make 'target' refer to the 'n' labels including and following
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* 'first' in 'source'.
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@ -494,33 +540,40 @@ dns_name_getlabelsequence(dns_name_t *source,
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REQUIRE(first < source->labels);
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REQUIRE(first + n <= source->labels);
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target->ndata = &source->ndata[source->offsets[first]];
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SETUP_OFFSETS(source, offsets, odata);
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target->ndata = &source->ndata[offsets[first]];
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if (first + n == source->labels)
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target->length = source->length - source->offsets[first];
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target->length = source->length - offsets[first];
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else
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target->length = source->offsets[first + n] -
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source->offsets[first];
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target->length = offsets[first + n] - offsets[first];
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target->labels = n;
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set_offsets(target, ISC_FALSE, ISC_FALSE);
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if (target->offsets != NULL)
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set_offsets(target, target->offsets, ISC_FALSE, ISC_FALSE);
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}
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void
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dns_name_fromregion(dns_name_t *name, isc_region_t *r) {
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unsigned char *offsets;
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dns_offsets_t odata;
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/*
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* Make 'name' refer to region 'r'.
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*/
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REQUIRE(name != NULL);
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REQUIRE(VALID_NAME(name));
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REQUIRE(r != NULL);
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REQUIRE(r->length <= 255);
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INIT_OFFSETS(name, offsets, odata);
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name->magic = NAME_MAGIC;
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name->ndata = r->base;
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name->length = r->length;
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if (r->length > 0)
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set_offsets(name, ISC_TRUE, ISC_TRUE);
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set_offsets(name, offsets, ISC_TRUE, ISC_TRUE);
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else
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name->labels = 0;
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}
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@ -552,6 +605,8 @@ dns_name_fromtext(dns_name_t *name, isc_buffer_t *source,
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unsigned int n1, n2, vlen, tlen, nrem, digits, labels, tused;
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isc_boolean_t done, saw_bitstring;
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unsigned char dqchars[4];
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unsigned char *offsets;
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dns_offsets_t odata;
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/*
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* Convert the textual representation of a DNS name at source
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@ -563,10 +618,12 @@ dns_name_fromtext(dns_name_t *name, isc_buffer_t *source,
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* will remain relative.
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*/
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REQUIRE(name != NULL);
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REQUIRE(VALID_NAME(name));
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REQUIRE(isc_buffer_type(source) == ISC_BUFFERTYPE_TEXT);
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REQUIRE(isc_buffer_type(target) == ISC_BUFFERTYPE_BINARY);
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INIT_OFFSETS(name, offsets, odata);
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/*
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* Initialize things to make the compiler happy; they're not required.
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*/
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@ -991,10 +1048,11 @@ dns_name_fromtext(dns_name_t *name, isc_buffer_t *source,
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/*
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* We should build the offsets table directly.
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*/
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set_offsets(name, ISC_FALSE, ISC_FALSE);
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if (name->offsets != NULL || saw_bitstring)
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set_offsets(name, offsets, ISC_FALSE, ISC_FALSE);
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if (saw_bitstring)
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compact(name);
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compact(name, offsets);
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isc_buffer_forward(source, tused);
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isc_buffer_add(target, name->length);
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@ -1165,8 +1223,9 @@ dns_name_totext(dns_name_t *name, isc_boolean_t omit_final_dot,
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}
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static void
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set_offsets(dns_name_t *name, isc_boolean_t set_labels,
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isc_boolean_t set_length) {
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set_offsets(dns_name_t *name, unsigned char *offsets, isc_boolean_t set_labels,
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isc_boolean_t set_length)
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{
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unsigned int offset, count, nlabels, nrem, n;
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unsigned char *ndata;
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@ -1176,7 +1235,7 @@ set_offsets(dns_name_t *name, isc_boolean_t set_labels,
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nlabels = 0;
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while (nrem > 0) {
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INSIST(nlabels < 128);
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name->offsets[nlabels++] = offset;
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offsets[nlabels++] = offset;
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count = *ndata++;
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nrem--;
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offset++;
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@ -1208,7 +1267,7 @@ set_offsets(dns_name_t *name, isc_boolean_t set_labels,
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}
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static void
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compact(dns_name_t *name) {
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compact(dns_name_t *name, unsigned char *offsets) {
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unsigned char *head, *curr, *last;
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unsigned int count, n, bit;
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unsigned int headbits, currbits, tailbits, newbits;
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@ -1227,11 +1286,11 @@ compact(dns_name_t *name) {
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n = name->labels - 1;
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while (n > 0) {
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head = &name->ndata[name->offsets[n]];
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head = &name->ndata[offsets[n]];
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if (head[0] == DNS_LABELTYPE_BITSTRING && head[1] != 0) {
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if (n != 0) {
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n--;
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curr = &name->ndata[name->offsets[n]];
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curr = &name->ndata[offsets[n]];
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if (curr[0] != DNS_LABELTYPE_BITSTRING)
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break;
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/*
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@ -1358,17 +1417,21 @@ dns_name_fromwire(dns_name_t *name, isc_buffer_t *source,
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isc_boolean_t saw_bitstring, done;
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fw_state state = fw_start;
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unsigned int c;
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unsigned char *offsets;
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dns_offsets_t odata;
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/*
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* Copy the possibly-compressed name at source into target,
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* decompressing it.
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*/
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REQUIRE(name != NULL);
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REQUIRE(VALID_NAME(name));
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REQUIRE(isc_buffer_type(source) == ISC_BUFFERTYPE_BINARY);
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REQUIRE(isc_buffer_type(target) == ISC_BUFFERTYPE_BINARY);
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REQUIRE(dctx != NULL);
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INIT_OFFSETS(name, offsets, odata);
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/*
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* Invalidate 'name'.
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*/
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@ -1520,10 +1583,11 @@ dns_name_fromwire(dns_name_t *name, isc_buffer_t *source,
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/*
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* We should build the offsets table directly.
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*/
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set_offsets(name, ISC_FALSE, ISC_FALSE);
|
||||
if (name->offsets != NULL || saw_bitstring)
|
||||
set_offsets(name, offsets, ISC_FALSE, ISC_FALSE);
|
||||
|
||||
if (saw_bitstring)
|
||||
compact(name);
|
||||
compact(name, offsets);
|
||||
|
||||
isc_buffer_forward(source, cused);
|
||||
isc_buffer_add(target, name->length);
|
||||
|
|
|
|||
Loading…
Reference in a new issue