freebsd-dev/contrib/ldns/dname.c
Dag-Erling Smørgrav 986ba33c7a Upgrade LDNS to 1.7.0.
I've been holding back on this because 1.7.0 requires OpenSSL 1.1.0 or
newer for full DANE support.  But we can't wait forever, and nothing in
base uses DANE anyway, so here we go.
2018-05-12 12:00:18 +00:00

603 lines
13 KiB
C

/*
* dname.c
*
* dname specific rdata implementations
* A dname is a rdf structure with type LDNS_RDF_TYPE_DNAME
* It is not a /real/ type! All function must therefor check
* for LDNS_RDF_TYPE_DNAME.
*
* a Net::DNS like library for C
*
* (c) NLnet Labs, 2004-2006
*
* See the file LICENSE for the license
*/
#include <ldns/config.h>
#include <ldns/ldns.h>
#ifdef HAVE_NETINET_IN_H
#include <netinet/in.h>
#endif
#ifdef HAVE_SYS_SOCKET_H
#include <sys/socket.h>
#endif
#ifdef HAVE_NETDB_H
#include <netdb.h>
#endif
#ifdef HAVE_ARPA_INET_H
#include <arpa/inet.h>
#endif
/* Returns whether the last label in the name is a root label (a empty label).
* Note that it is not enough to just test the last character to be 0,
* because it may be part of the last label itself.
*/
static bool
ldns_dname_last_label_is_root_label(const ldns_rdf* dname)
{
size_t src_pos;
size_t len = 0;
for (src_pos = 0; src_pos < ldns_rdf_size(dname); src_pos += len + 1) {
len = ldns_rdf_data(dname)[src_pos];
}
assert(src_pos == ldns_rdf_size(dname));
return src_pos > 0 && len == 0;
}
ldns_rdf *
ldns_dname_cat_clone(const ldns_rdf *rd1, const ldns_rdf *rd2)
{
ldns_rdf *new;
uint16_t new_size;
uint8_t *buf;
uint16_t left_size;
if (ldns_rdf_get_type(rd1) != LDNS_RDF_TYPE_DNAME ||
ldns_rdf_get_type(rd2) != LDNS_RDF_TYPE_DNAME) {
return NULL;
}
/* remove root label if it is present at the end of the left
* rd, by reducing the size with 1
*/
left_size = ldns_rdf_size(rd1);
if (ldns_dname_last_label_is_root_label(rd1)) {
left_size--;
}
/* we overwrite the nullbyte of rd1 */
new_size = left_size + ldns_rdf_size(rd2);
buf = LDNS_XMALLOC(uint8_t, new_size);
if (!buf) {
return NULL;
}
/* put the two dname's after each other */
memcpy(buf, ldns_rdf_data(rd1), left_size);
memcpy(buf + left_size, ldns_rdf_data(rd2), ldns_rdf_size(rd2));
new = ldns_rdf_new_frm_data(LDNS_RDF_TYPE_DNAME, new_size, buf);
LDNS_FREE(buf);
return new;
}
ldns_status
ldns_dname_cat(ldns_rdf *rd1, const ldns_rdf *rd2)
{
uint16_t left_size;
uint16_t size;
uint8_t* newd;
if (ldns_rdf_get_type(rd1) != LDNS_RDF_TYPE_DNAME ||
ldns_rdf_get_type(rd2) != LDNS_RDF_TYPE_DNAME) {
return LDNS_STATUS_ERR;
}
/* remove root label if it is present at the end of the left
* rd, by reducing the size with 1
*/
left_size = ldns_rdf_size(rd1);
if (ldns_dname_last_label_is_root_label(rd1)) {
left_size--;
}
size = left_size + ldns_rdf_size(rd2);
newd = LDNS_XREALLOC(ldns_rdf_data(rd1), uint8_t, size);
if(!newd) {
return LDNS_STATUS_MEM_ERR;
}
ldns_rdf_set_data(rd1, newd);
memcpy(ldns_rdf_data(rd1) + left_size, ldns_rdf_data(rd2),
ldns_rdf_size(rd2));
ldns_rdf_set_size(rd1, size);
return LDNS_STATUS_OK;
}
ldns_rdf*
ldns_dname_reverse(const ldns_rdf *dname)
{
size_t rd_size;
uint8_t* buf;
ldns_rdf* new;
size_t src_pos;
size_t len ;
assert(ldns_rdf_get_type(dname) == LDNS_RDF_TYPE_DNAME);
rd_size = ldns_rdf_size(dname);
buf = LDNS_XMALLOC(uint8_t, rd_size);
if (! buf) {
return NULL;
}
new = ldns_rdf_new(LDNS_RDF_TYPE_DNAME, rd_size, buf);
if (! new) {
LDNS_FREE(buf);
return NULL;
}
/* If dname ends in a root label, the reverse should too.
*/
if (ldns_dname_last_label_is_root_label(dname)) {
buf[rd_size - 1] = 0;
rd_size -= 1;
}
for (src_pos = 0; src_pos < rd_size; src_pos += len + 1) {
len = ldns_rdf_data(dname)[src_pos];
memcpy(&buf[rd_size - src_pos - len - 1],
&ldns_rdf_data(dname)[src_pos], len + 1);
}
return new;
}
ldns_rdf *
ldns_dname_clone_from(const ldns_rdf *d, uint16_t n)
{
uint8_t *data;
uint8_t label_size;
size_t data_size;
if (!d ||
ldns_rdf_get_type(d) != LDNS_RDF_TYPE_DNAME ||
ldns_dname_label_count(d) < n) {
return NULL;
}
data = ldns_rdf_data(d);
data_size = ldns_rdf_size(d);
while (n > 0) {
label_size = data[0] + 1;
data += label_size;
if (data_size < label_size) {
/* this label is very broken */
return NULL;
}
data_size -= label_size;
n--;
}
return ldns_dname_new_frm_data(data_size, data);
}
ldns_rdf *
ldns_dname_left_chop(const ldns_rdf *d)
{
uint8_t label_pos;
ldns_rdf *chop;
if (!d) {
return NULL;
}
if (ldns_rdf_get_type(d) != LDNS_RDF_TYPE_DNAME) {
return NULL;
}
if (ldns_dname_label_count(d) == 0) {
/* root label */
return NULL;
}
/* 05blaat02nl00 */
label_pos = ldns_rdf_data(d)[0];
chop = ldns_dname_new_frm_data(ldns_rdf_size(d) - label_pos - 1,
ldns_rdf_data(d) + label_pos + 1);
return chop;
}
uint8_t
ldns_dname_label_count(const ldns_rdf *r)
{
uint16_t src_pos;
uint16_t len;
uint8_t i;
size_t r_size;
if (!r) {
return 0;
}
i = 0;
src_pos = 0;
r_size = ldns_rdf_size(r);
if (ldns_rdf_get_type(r) != LDNS_RDF_TYPE_DNAME) {
return 0;
} else {
len = ldns_rdf_data(r)[src_pos]; /* start of the label */
/* single root label */
if (1 == r_size) {
return 0;
} else {
while ((len > 0) && src_pos < r_size) {
src_pos++;
src_pos += len;
len = ldns_rdf_data(r)[src_pos];
i++;
}
}
}
return i;
}
ldns_rdf *
ldns_dname_new(uint16_t s, void *d)
{
ldns_rdf *rd;
if (!s || !d) {
return NULL;
}
rd = LDNS_MALLOC(ldns_rdf);
if (!rd) {
return NULL;
}
ldns_rdf_set_size(rd, s);
ldns_rdf_set_type(rd, LDNS_RDF_TYPE_DNAME);
ldns_rdf_set_data(rd, d);
return rd;
}
ldns_rdf *
ldns_dname_new_frm_str(const char *str)
{
return ldns_rdf_new_frm_str(LDNS_RDF_TYPE_DNAME, str);
}
ldns_rdf *
ldns_dname_new_frm_data(uint16_t size, const void *data)
{
return ldns_rdf_new_frm_data(LDNS_RDF_TYPE_DNAME, size, data);
}
void
ldns_dname2canonical(const ldns_rdf *rd)
{
uint8_t *rdd;
uint16_t i;
if (ldns_rdf_get_type(rd) != LDNS_RDF_TYPE_DNAME) {
return;
}
rdd = (uint8_t*)ldns_rdf_data(rd);
for (i = 0; i < ldns_rdf_size(rd); i++, rdd++) {
*rdd = (uint8_t)LDNS_DNAME_NORMALIZE((int)*rdd);
}
}
bool
ldns_dname_is_subdomain(const ldns_rdf *sub, const ldns_rdf *parent)
{
uint8_t sub_lab;
uint8_t par_lab;
int8_t i, j;
ldns_rdf *tmp_sub = NULL;
ldns_rdf *tmp_par = NULL;
ldns_rdf *sub_clone;
ldns_rdf *parent_clone;
bool result = true;
if (ldns_rdf_get_type(sub) != LDNS_RDF_TYPE_DNAME ||
ldns_rdf_get_type(parent) != LDNS_RDF_TYPE_DNAME ||
ldns_rdf_compare(sub, parent) == 0) {
return false;
}
/* would be nicer if we do not have to clone... */
sub_clone = ldns_dname_clone_from(sub, 0);
parent_clone = ldns_dname_clone_from(parent, 0);
ldns_dname2canonical(sub_clone);
ldns_dname2canonical(parent_clone);
sub_lab = ldns_dname_label_count(sub_clone);
par_lab = ldns_dname_label_count(parent_clone);
/* if sub sits above parent, it cannot be a child/sub domain */
if (sub_lab < par_lab) {
result = false;
} else {
/* check all labels the from the parent labels, from right to left.
* When they /all/ match we have found a subdomain
*/
j = sub_lab - 1; /* we count from zero, thank you */
for (i = par_lab -1; i >= 0; i--) {
tmp_sub = ldns_dname_label(sub_clone, j);
tmp_par = ldns_dname_label(parent_clone, i);
if (!tmp_sub || !tmp_par) {
/* deep free does null check */
ldns_rdf_deep_free(tmp_sub);
ldns_rdf_deep_free(tmp_par);
result = false;
break;
}
if (ldns_rdf_compare(tmp_sub, tmp_par) != 0) {
/* they are not equal */
ldns_rdf_deep_free(tmp_sub);
ldns_rdf_deep_free(tmp_par);
result = false;
break;
}
ldns_rdf_deep_free(tmp_sub);
ldns_rdf_deep_free(tmp_par);
j--;
}
}
ldns_rdf_deep_free(sub_clone);
ldns_rdf_deep_free(parent_clone);
return result;
}
int
ldns_dname_compare(const ldns_rdf *dname1, const ldns_rdf *dname2)
{
size_t lc1, lc2, lc1f, lc2f;
size_t i;
int result = 0;
uint8_t *lp1, *lp2;
/* see RFC4034 for this algorithm */
/* this algorithm assumes the names are normalized to case */
/* only when both are not NULL we can say anything about them */
if (!dname1 && !dname2) {
return 0;
}
if (!dname1 || !dname2) {
return -1;
}
/* asserts must happen later as we are looking in the
* dname, which could be NULL. But this case is handled
* above
*/
assert(ldns_rdf_get_type(dname1) == LDNS_RDF_TYPE_DNAME);
assert(ldns_rdf_get_type(dname2) == LDNS_RDF_TYPE_DNAME);
lc1 = ldns_dname_label_count(dname1);
lc2 = ldns_dname_label_count(dname2);
if (lc1 == 0 && lc2 == 0) {
return 0;
}
if (lc1 == 0) {
return -1;
}
if (lc2 == 0) {
return 1;
}
lc1--;
lc2--;
/* we start at the last label */
while (true) {
/* find the label first */
lc1f = lc1;
lp1 = ldns_rdf_data(dname1);
while (lc1f > 0) {
lp1 += *lp1 + 1;
lc1f--;
}
/* and find the other one */
lc2f = lc2;
lp2 = ldns_rdf_data(dname2);
while (lc2f > 0) {
lp2 += *lp2 + 1;
lc2f--;
}
/* now check the label character for character. */
for (i = 1; i < (size_t)(*lp1 + 1); i++) {
if (i > *lp2) {
/* apparently label 1 is larger */
result = 1;
goto done;
}
if (LDNS_DNAME_NORMALIZE((int) *(lp1 + i)) <
LDNS_DNAME_NORMALIZE((int) *(lp2 + i))) {
result = -1;
goto done;
} else if (LDNS_DNAME_NORMALIZE((int) *(lp1 + i)) >
LDNS_DNAME_NORMALIZE((int) *(lp2 + i))) {
result = 1;
goto done;
}
}
if (*lp1 < *lp2) {
/* apparently label 2 is larger */
result = -1;
goto done;
}
if (lc1 == 0 && lc2 > 0) {
result = -1;
goto done;
} else if (lc1 > 0 && lc2 == 0) {
result = 1;
goto done;
} else if (lc1 == 0 && lc2 == 0) {
result = 0;
goto done;
}
lc1--;
lc2--;
}
done:
return result;
}
int
ldns_dname_is_wildcard(const ldns_rdf* dname)
{
return ( ldns_dname_label_count(dname) > 0 &&
ldns_rdf_data(dname)[0] == 1 &&
ldns_rdf_data(dname)[1] == '*');
}
int
ldns_dname_match_wildcard(const ldns_rdf *dname, const ldns_rdf *wildcard)
{
ldns_rdf *wc_chopped;
int result;
/* check whether it really is a wildcard */
if (ldns_dname_is_wildcard(wildcard)) {
/* ok, so the dname needs to be a subdomain of the wildcard
* without the *
*/
wc_chopped = ldns_dname_left_chop(wildcard);
result = (int) ldns_dname_is_subdomain(dname, wc_chopped);
ldns_rdf_deep_free(wc_chopped);
} else {
result = (ldns_dname_compare(dname, wildcard) == 0);
}
return result;
}
/* nsec test: does prev <= middle < next
* -1 = yes
* 0 = error/can't tell
* 1 = no
*/
int
ldns_dname_interval(const ldns_rdf *prev, const ldns_rdf *middle,
const ldns_rdf *next)
{
int prev_check, next_check;
assert(ldns_rdf_get_type(prev) == LDNS_RDF_TYPE_DNAME);
assert(ldns_rdf_get_type(middle) == LDNS_RDF_TYPE_DNAME);
assert(ldns_rdf_get_type(next) == LDNS_RDF_TYPE_DNAME);
prev_check = ldns_dname_compare(prev, middle);
next_check = ldns_dname_compare(middle, next);
/* <= next. This cannot be the case for nsec, because then we would
* have gotten the nsec of next...
*/
if (next_check == 0) {
return 0;
}
/* <= */
if ((prev_check == -1 || prev_check == 0) &&
/* < */
next_check == -1) {
return -1;
} else {
return 1;
}
}
bool
ldns_dname_str_absolute(const char *dname_str)
{
const char* s;
if(dname_str && strcmp(dname_str, ".") == 0)
return 1;
if(!dname_str || strlen(dname_str) < 2)
return 0;
if(dname_str[strlen(dname_str) - 1] != '.')
return 0;
if(dname_str[strlen(dname_str) - 2] != '\\')
return 1; /* ends in . and no \ before it */
/* so we have the case of ends in . and there is \ before it */
for(s=dname_str; *s; s++) {
if(*s == '\\') {
if(s[1] && s[2] && s[3] /* check length */
&& isdigit((unsigned char)s[1])
&& isdigit((unsigned char)s[2])
&& isdigit((unsigned char)s[3]))
s += 3;
else if(!s[1] || isdigit((unsigned char)s[1])) /* escape of nul,0-9 */
return 0; /* parse error */
else s++; /* another character escaped */
}
else if(!*(s+1) && *s == '.')
return 1; /* trailing dot, unescaped */
}
return 0;
}
bool
ldns_dname_absolute(const ldns_rdf *rdf)
{
char *str = ldns_rdf2str(rdf);
if (str) {
bool r = ldns_dname_str_absolute(str);
LDNS_FREE(str);
return r;
}
return false;
}
ldns_rdf *
ldns_dname_label(const ldns_rdf *rdf, uint8_t labelpos)
{
uint8_t labelcnt;
uint16_t src_pos;
uint16_t len;
ldns_rdf *tmpnew;
size_t s;
uint8_t *data;
if (ldns_rdf_get_type(rdf) != LDNS_RDF_TYPE_DNAME) {
return NULL;
}
labelcnt = 0;
src_pos = 0;
s = ldns_rdf_size(rdf);
len = ldns_rdf_data(rdf)[src_pos]; /* label start */
while ((len > 0) && src_pos < s) {
if (labelcnt == labelpos) {
/* found our label */
data = LDNS_XMALLOC(uint8_t, len + 2);
if (!data) {
return NULL;
}
memcpy(data, ldns_rdf_data(rdf) + src_pos, len + 1);
data[len + 2 - 1] = 0;
tmpnew = ldns_rdf_new( LDNS_RDF_TYPE_DNAME
, len + 2, data);
if (!tmpnew) {
LDNS_FREE(data);
return NULL;
}
return tmpnew;
}
src_pos++;
src_pos += len;
len = ldns_rdf_data(rdf)[src_pos];
labelcnt++;
}
return NULL;
}