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freebsd-skq/contrib/ldns/resolver.c
des fe6d937978 MFH (r266114, r266138): upgrade to latest ldns and unbound 
MFH (r266139-r266143, r266145, r266149, r266150): fix props
MFH (r266179, r266180, r266193, r266238, r266777): misc cleanup
MFH (r266863): create and use /var/unbound/conf.d
MFH (r268839): import unblock-lan-zones patch from upstream
MFH (r268840): fix reverse lookups on private networks
MFH (r268883): avoid spamming source tree during build

PR:		190739 (for r268883)
2014-07-29 20:57:38 +00:00

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/*
* resolver.c
*
* resolver implementation
*
* 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>
#include <strings.h>
/* Access function for reading
* and setting the different Resolver
* options */
/* read */
uint16_t
ldns_resolver_port(const ldns_resolver *r)
{
return r->_port;
}
ldns_rdf *
ldns_resolver_source(const ldns_resolver *r)
{
return r->_source;
}
uint16_t
ldns_resolver_edns_udp_size(const ldns_resolver *r)
{
return r->_edns_udp_size;
}
uint8_t
ldns_resolver_retry(const ldns_resolver *r)
{
return r->_retry;
}
uint8_t
ldns_resolver_retrans(const ldns_resolver *r)
{
return r->_retrans;
}
bool
ldns_resolver_fallback(const ldns_resolver *r)
{
return r->_fallback;
}
uint8_t
ldns_resolver_ip6(const ldns_resolver *r)
{
return r->_ip6;
}
bool
ldns_resolver_recursive(const ldns_resolver *r)
{
return r->_recursive;
}
bool
ldns_resolver_debug(const ldns_resolver *r)
{
return r->_debug;
}
bool
ldns_resolver_dnsrch(const ldns_resolver *r)
{
return r->_dnsrch;
}
bool
ldns_resolver_fail(const ldns_resolver *r)
{
return r->_fail;
}
bool
ldns_resolver_defnames(const ldns_resolver *r)
{
return r->_defnames;
}
ldns_rdf *
ldns_resolver_domain(const ldns_resolver *r)
{
return r->_domain;
}
ldns_rdf **
ldns_resolver_searchlist(const ldns_resolver *r)
{
return r->_searchlist;
}
ldns_rdf **
ldns_resolver_nameservers(const ldns_resolver *r)
{
return r->_nameservers;
}
size_t
ldns_resolver_nameserver_count(const ldns_resolver *r)
{
return r->_nameserver_count;
}
bool
ldns_resolver_dnssec(const ldns_resolver *r)
{
return r->_dnssec;
}
bool
ldns_resolver_dnssec_cd(const ldns_resolver *r)
{
return r->_dnssec_cd;
}
ldns_rr_list *
ldns_resolver_dnssec_anchors(const ldns_resolver *r)
{
return r->_dnssec_anchors;
}
bool
ldns_resolver_trusted_key(const ldns_resolver *r, ldns_rr_list * keys, ldns_rr_list * trusted_keys)
{
size_t i;
bool result = false;
ldns_rr_list * trust_anchors;
ldns_rr * cur_rr;
if (!r || !keys) { return false; }
trust_anchors = ldns_resolver_dnssec_anchors(r);
if (!trust_anchors) { return false; }
for (i = 0; i < ldns_rr_list_rr_count(keys); i++) {
cur_rr = ldns_rr_list_rr(keys, i);
if (ldns_rr_list_contains_rr(trust_anchors, cur_rr)) {
if (trusted_keys) { ldns_rr_list_push_rr(trusted_keys, cur_rr); }
result = true;
}
}
return result;
}
bool
ldns_resolver_igntc(const ldns_resolver *r)
{
return r->_igntc;
}
bool
ldns_resolver_usevc(const ldns_resolver *r)
{
return r->_usevc;
}
size_t *
ldns_resolver_rtt(const ldns_resolver *r)
{
return r->_rtt;
}
size_t
ldns_resolver_nameserver_rtt(const ldns_resolver *r, size_t pos)
{
size_t *rtt;
assert(r != NULL);
rtt = ldns_resolver_rtt(r);
if (pos >= ldns_resolver_nameserver_count(r)) {
/* error ?*/
return 0;
} else {
return rtt[pos];
}
}
struct timeval
ldns_resolver_timeout(const ldns_resolver *r)
{
return r->_timeout;
}
char *
ldns_resolver_tsig_keyname(const ldns_resolver *r)
{
return r->_tsig_keyname;
}
char *
ldns_resolver_tsig_algorithm(const ldns_resolver *r)
{
return r->_tsig_algorithm;
}
char *
ldns_resolver_tsig_keydata(const ldns_resolver *r)
{
return r->_tsig_keydata;
}
bool
ldns_resolver_random(const ldns_resolver *r)
{
return r->_random;
}
size_t
ldns_resolver_searchlist_count(const ldns_resolver *r)
{
return r->_searchlist_count;
}
/* write */
void
ldns_resolver_set_port(ldns_resolver *r, uint16_t p)
{
r->_port = p;
}
void
ldns_resolver_set_source(ldns_resolver *r, ldns_rdf *s)
{
r->_source = s;
}
ldns_rdf *
ldns_resolver_pop_nameserver(ldns_resolver *r)
{
ldns_rdf **nameservers;
ldns_rdf *pop;
size_t ns_count;
size_t *rtt;
assert(r != NULL);
ns_count = ldns_resolver_nameserver_count(r);
nameservers = ldns_resolver_nameservers(r);
rtt = ldns_resolver_rtt(r);
if (ns_count == 0 || !nameservers) {
return NULL;
}
pop = nameservers[ns_count - 1];
if (ns_count == 1) {
LDNS_FREE(nameservers);
LDNS_FREE(rtt);
ldns_resolver_set_nameservers(r, NULL);
ldns_resolver_set_rtt(r, NULL);
} else {
nameservers = LDNS_XREALLOC(nameservers, ldns_rdf *,
(ns_count - 1));
rtt = LDNS_XREALLOC(rtt, size_t, (ns_count - 1));
ldns_resolver_set_nameservers(r, nameservers);
ldns_resolver_set_rtt(r, rtt);
}
/* decr the count */
ldns_resolver_dec_nameserver_count(r);
return pop;
}
ldns_status
ldns_resolver_push_nameserver(ldns_resolver *r, ldns_rdf *n)
{
ldns_rdf **nameservers;
size_t ns_count;
size_t *rtt;
if (ldns_rdf_get_type(n) != LDNS_RDF_TYPE_A &&
ldns_rdf_get_type(n) != LDNS_RDF_TYPE_AAAA) {
return LDNS_STATUS_ERR;
}
ns_count = ldns_resolver_nameserver_count(r);
nameservers = ldns_resolver_nameservers(r);
rtt = ldns_resolver_rtt(r);
/* make room for the next one */
if (ns_count == 0) {
nameservers = LDNS_XMALLOC(ldns_rdf *, 1);
} else {
nameservers = LDNS_XREALLOC(nameservers, ldns_rdf *, (ns_count + 1));
}
if(!nameservers)
return LDNS_STATUS_MEM_ERR;
/* set the new value in the resolver */
ldns_resolver_set_nameservers(r, nameservers);
/* don't forget the rtt */
if (ns_count == 0) {
rtt = LDNS_XMALLOC(size_t, 1);
} else {
rtt = LDNS_XREALLOC(rtt, size_t, (ns_count + 1));
}
if(!rtt)
return LDNS_STATUS_MEM_ERR;
/* slide n in its slot. */
/* we clone it here, because then we can free the original
* rr's where it stood */
nameservers[ns_count] = ldns_rdf_clone(n);
rtt[ns_count] = LDNS_RESOLV_RTT_MIN;
ldns_resolver_incr_nameserver_count(r);
ldns_resolver_set_rtt(r, rtt);
return LDNS_STATUS_OK;
}
ldns_status
ldns_resolver_push_nameserver_rr(ldns_resolver *r, ldns_rr *rr)
{
ldns_rdf *address;
if ((!rr) || (ldns_rr_get_type(rr) != LDNS_RR_TYPE_A &&
ldns_rr_get_type(rr) != LDNS_RR_TYPE_AAAA)) {
return LDNS_STATUS_ERR;
}
address = ldns_rr_rdf(rr, 0); /* extract the ip number */
if (address) {
return ldns_resolver_push_nameserver(r, address);
} else {
return LDNS_STATUS_ERR;
}
}
ldns_status
ldns_resolver_push_nameserver_rr_list(ldns_resolver *r, ldns_rr_list *rrlist)
{
ldns_rr *rr;
ldns_status stat;
size_t i;
stat = LDNS_STATUS_OK;
if (rrlist) {
for(i = 0; i < ldns_rr_list_rr_count(rrlist); i++) {
rr = ldns_rr_list_rr(rrlist, i);
if (ldns_resolver_push_nameserver_rr(r, rr) != LDNS_STATUS_OK) {
stat = LDNS_STATUS_ERR;
break;
}
}
return stat;
} else {
return LDNS_STATUS_ERR;
}
}
void
ldns_resolver_set_edns_udp_size(ldns_resolver *r, uint16_t s)
{
r->_edns_udp_size = s;
}
void
ldns_resolver_set_recursive(ldns_resolver *r, bool re)
{
r->_recursive = re;
}
void
ldns_resolver_set_dnssec(ldns_resolver *r, bool d)
{
r->_dnssec = d;
}
void
ldns_resolver_set_dnssec_cd(ldns_resolver *r, bool d)
{
r->_dnssec_cd = d;
}
void
ldns_resolver_set_dnssec_anchors(ldns_resolver *r, ldns_rr_list * l)
{
r->_dnssec_anchors = l;
}
ldns_status
ldns_resolver_push_dnssec_anchor(ldns_resolver *r, ldns_rr *rr)
{
ldns_rr_list * trust_anchors;
if ((!rr) || (ldns_rr_get_type(rr) != LDNS_RR_TYPE_DNSKEY &&
ldns_rr_get_type(rr) != LDNS_RR_TYPE_DS)) {
return LDNS_STATUS_ERR;
}
if (!(trust_anchors = ldns_resolver_dnssec_anchors(r))) { /* Initialize */
trust_anchors = ldns_rr_list_new();
ldns_resolver_set_dnssec_anchors(r, trust_anchors);
}
return (ldns_rr_list_push_rr(trust_anchors, ldns_rr_clone(rr))) ? LDNS_STATUS_OK : LDNS_STATUS_ERR;
}
void
ldns_resolver_set_igntc(ldns_resolver *r, bool i)
{
r->_igntc = i;
}
void
ldns_resolver_set_usevc(ldns_resolver *r, bool vc)
{
r->_usevc = vc;
}
void
ldns_resolver_set_debug(ldns_resolver *r, bool d)
{
r->_debug = d;
}
void
ldns_resolver_set_ip6(ldns_resolver *r, uint8_t ip6)
{
r->_ip6 = ip6;
}
void
ldns_resolver_set_fail(ldns_resolver *r, bool f)
{
r->_fail =f;
}
static void
ldns_resolver_set_searchlist_count(ldns_resolver *r, size_t c)
{
r->_searchlist_count = c;
}
void
ldns_resolver_set_nameserver_count(ldns_resolver *r, size_t c)
{
r->_nameserver_count = c;
}
void
ldns_resolver_set_dnsrch(ldns_resolver *r, bool d)
{
r->_dnsrch = d;
}
void
ldns_resolver_set_retry(ldns_resolver *r, uint8_t retry)
{
r->_retry = retry;
}
void
ldns_resolver_set_retrans(ldns_resolver *r, uint8_t retrans)
{
r->_retrans = retrans;
}
void
ldns_resolver_set_fallback(ldns_resolver *r, bool fallback)
{
r->_fallback = fallback;
}
void
ldns_resolver_set_nameservers(ldns_resolver *r, ldns_rdf **n)
{
r->_nameservers = n;
}
void
ldns_resolver_set_defnames(ldns_resolver *r, bool d)
{
r->_defnames = d;
}
void
ldns_resolver_set_rtt(ldns_resolver *r, size_t *rtt)
{
r->_rtt = rtt;
}
void
ldns_resolver_set_nameserver_rtt(ldns_resolver *r, size_t pos, size_t value)
{
size_t *rtt;
assert(r != NULL);
rtt = ldns_resolver_rtt(r);
if (pos >= ldns_resolver_nameserver_count(r)) {
/* error ?*/
} else {
rtt[pos] = value;
}
}
void
ldns_resolver_incr_nameserver_count(ldns_resolver *r)
{
size_t c;
c = ldns_resolver_nameserver_count(r);
ldns_resolver_set_nameserver_count(r, ++c);
}
void
ldns_resolver_dec_nameserver_count(ldns_resolver *r)
{
size_t c;
c = ldns_resolver_nameserver_count(r);
if (c == 0) {
return;
} else {
ldns_resolver_set_nameserver_count(r, --c);
}
}
void
ldns_resolver_set_domain(ldns_resolver *r, ldns_rdf *d)
{
r->_domain = d;
}
void
ldns_resolver_set_timeout(ldns_resolver *r, struct timeval timeout)
{
r->_timeout.tv_sec = timeout.tv_sec;
r->_timeout.tv_usec = timeout.tv_usec;
}
void
ldns_resolver_push_searchlist(ldns_resolver *r, ldns_rdf *d)
{
ldns_rdf **searchlist;
size_t list_count;
if (ldns_rdf_get_type(d) != LDNS_RDF_TYPE_DNAME) {
return;
}
list_count = ldns_resolver_searchlist_count(r);
searchlist = ldns_resolver_searchlist(r);
searchlist = LDNS_XREALLOC(searchlist, ldns_rdf *, (list_count + 1));
if (searchlist) {
r->_searchlist = searchlist;
searchlist[list_count] = ldns_rdf_clone(d);
ldns_resolver_set_searchlist_count(r, list_count + 1);
} /* no way to report mem err */
}
void
ldns_resolver_set_tsig_keyname(ldns_resolver *r, char *tsig_keyname)
{
LDNS_FREE(r->_tsig_keyname);
r->_tsig_keyname = strdup(tsig_keyname);
}
void
ldns_resolver_set_tsig_algorithm(ldns_resolver *r, char *tsig_algorithm)
{
LDNS_FREE(r->_tsig_algorithm);
r->_tsig_algorithm = strdup(tsig_algorithm);
}
void
ldns_resolver_set_tsig_keydata(ldns_resolver *r, char *tsig_keydata)
{
LDNS_FREE(r->_tsig_keydata);
r->_tsig_keydata = strdup(tsig_keydata);
}
void
ldns_resolver_set_random(ldns_resolver *r, bool b)
{
r->_random = b;
}
/* more sophisticated functions */
ldns_resolver *
ldns_resolver_new(void)
{
ldns_resolver *r;
r = LDNS_MALLOC(ldns_resolver);
if (!r) {
return NULL;
}
r->_searchlist = NULL;
r->_nameservers = NULL;
r->_rtt = NULL;
/* defaults are filled out */
ldns_resolver_set_searchlist_count(r, 0);
ldns_resolver_set_nameserver_count(r, 0);
ldns_resolver_set_usevc(r, 0);
ldns_resolver_set_port(r, LDNS_PORT);
ldns_resolver_set_domain(r, NULL);
ldns_resolver_set_defnames(r, false);
ldns_resolver_set_retry(r, 3);
ldns_resolver_set_retrans(r, 2);
ldns_resolver_set_fallback(r, true);
ldns_resolver_set_fail(r, false);
ldns_resolver_set_edns_udp_size(r, 0);
ldns_resolver_set_dnssec(r, false);
ldns_resolver_set_dnssec_cd(r, false);
ldns_resolver_set_dnssec_anchors(r, NULL);
ldns_resolver_set_ip6(r, LDNS_RESOLV_INETANY);
ldns_resolver_set_igntc(r, false);
ldns_resolver_set_recursive(r, false);
ldns_resolver_set_dnsrch(r, true);
ldns_resolver_set_source(r, NULL);
/* randomize the nameserver to be queried
* when there are multiple
*/
ldns_resolver_set_random(r, true);
ldns_resolver_set_debug(r, 0);
r->_timeout.tv_sec = LDNS_DEFAULT_TIMEOUT_SEC;
r->_timeout.tv_usec = LDNS_DEFAULT_TIMEOUT_USEC;
/* TODO: fd=0 is actually a valid socket (stdin),
replace with -1 */
r->_socket = 0;
r->_axfr_soa_count = 0;
r->_axfr_i = 0;
r->_cur_axfr_pkt = NULL;
r->_tsig_keyname = NULL;
r->_tsig_keydata = NULL;
r->_tsig_algorithm = NULL;
return r;
}
ldns_status
ldns_resolver_new_frm_fp(ldns_resolver **res, FILE *fp)
{
return ldns_resolver_new_frm_fp_l(res, fp, NULL);
}
ldns_status
ldns_resolver_new_frm_fp_l(ldns_resolver **res, FILE *fp, int *line_nr)
{
ldns_resolver *r;
const char *keyword[LDNS_RESOLV_KEYWORDS];
char word[LDNS_MAX_LINELEN + 1];
int8_t expect;
uint8_t i;
ldns_rdf *tmp;
#ifdef HAVE_SSL
ldns_rr *tmp_rr;
#endif
ssize_t gtr, bgtr;
ldns_buffer *b;
int lnr = 0, oldline;
FILE* myfp = fp;
if(!line_nr) line_nr = &lnr;
if(!fp) {
myfp = fopen("/etc/resolv.conf", "r");
if(!myfp)
return LDNS_STATUS_FILE_ERR;
}
/* do this better
* expect =
* 0: keyword
* 1: default domain dname
* 2: NS aaaa or a record
*/
/* recognized keywords */
keyword[LDNS_RESOLV_NAMESERVER] = "nameserver";
keyword[LDNS_RESOLV_DEFDOMAIN] = "domain";
keyword[LDNS_RESOLV_SEARCH] = "search";
/* these two are read but not used atm TODO */
keyword[LDNS_RESOLV_SORTLIST] = "sortlist";
keyword[LDNS_RESOLV_OPTIONS] = "options";
keyword[LDNS_RESOLV_ANCHOR] = "anchor";
expect = LDNS_RESOLV_KEYWORD;
r = ldns_resolver_new();
if (!r) {
if(!fp) fclose(myfp);
return LDNS_STATUS_MEM_ERR;
}
gtr = 1;
word[0] = 0;
oldline = *line_nr;
expect = LDNS_RESOLV_KEYWORD;
while (gtr > 0) {
/* check comments */
if (word[0] == '#') {
word[0]='x';
if(oldline == *line_nr) {
/* skip until end of line */
int c;
do {
c = fgetc(myfp);
} while(c != EOF && c != '\n');
if(c=='\n') (*line_nr)++;
}
/* and read next to prepare for further parsing */
oldline = *line_nr;
continue;
}
oldline = *line_nr;
switch(expect) {
case LDNS_RESOLV_KEYWORD:
/* keyword */
gtr = ldns_fget_token_l(myfp, word, LDNS_PARSE_NORMAL, 0, line_nr);
if (gtr != 0) {
if(word[0] == '#') continue;
for(i = 0; i < LDNS_RESOLV_KEYWORDS; i++) {
if (strcasecmp(keyword[i], word) == 0) {
/* chosen the keyword and
* expect values carefully
*/
expect = i;
break;
}
}
/* no keyword recognized */
if (expect == LDNS_RESOLV_KEYWORD) {
/* skip line */
/*
ldns_resolver_deep_free(r);
if(!fp) fclose(myfp);
return LDNS_STATUS_SYNTAX_KEYWORD_ERR;
*/
}
}
break;
case LDNS_RESOLV_DEFDOMAIN:
/* default domain dname */
gtr = ldns_fget_token_l(myfp, word, LDNS_PARSE_NORMAL, 0, line_nr);
if (gtr == 0) {
if(!fp) fclose(myfp);
return LDNS_STATUS_SYNTAX_MISSING_VALUE_ERR;
}
if(word[0] == '#') {
expect = LDNS_RESOLV_KEYWORD;
continue;
}
tmp = ldns_rdf_new_frm_str(LDNS_RDF_TYPE_DNAME, word);
if (!tmp) {
ldns_resolver_deep_free(r);
if(!fp) fclose(myfp);
return LDNS_STATUS_SYNTAX_DNAME_ERR;
}
/* DOn't free, because we copy the pointer */
ldns_resolver_set_domain(r, tmp);
expect = LDNS_RESOLV_KEYWORD;
break;
case LDNS_RESOLV_NAMESERVER:
/* NS aaaa or a record */
gtr = ldns_fget_token_l(myfp, word, LDNS_PARSE_NORMAL, 0, line_nr);
if (gtr == 0) {
if(!fp) fclose(myfp);
return LDNS_STATUS_SYNTAX_MISSING_VALUE_ERR;
}
if(word[0] == '#') {
expect = LDNS_RESOLV_KEYWORD;
continue;
}
if(strchr(word, '%')) {
/* snip off interface labels,
* fe80::222:19ff:fe31:4222%eth0 */
strchr(word, '%')[0]=0;
}
tmp = ldns_rdf_new_frm_str(LDNS_RDF_TYPE_AAAA, word);
if (!tmp) {
/* try ip4 */
tmp = ldns_rdf_new_frm_str(LDNS_RDF_TYPE_A, word);
}
/* could not parse it, exit */
if (!tmp) {
ldns_resolver_deep_free(r);
if(!fp) fclose(myfp);
return LDNS_STATUS_SYNTAX_ERR;
}
(void)ldns_resolver_push_nameserver(r, tmp);
ldns_rdf_deep_free(tmp);
expect = LDNS_RESOLV_KEYWORD;
break;
case LDNS_RESOLV_SEARCH:
/* search list domain dname */
gtr = ldns_fget_token_l(myfp, word, LDNS_PARSE_SKIP_SPACE, 0, line_nr);
b = LDNS_MALLOC(ldns_buffer);
if(!b) {
ldns_resolver_deep_free(r);
if(!fp) fclose(myfp);
return LDNS_STATUS_MEM_ERR;
}
ldns_buffer_new_frm_data(b, word, (size_t) gtr);
if(ldns_buffer_status(b) != LDNS_STATUS_OK) {
LDNS_FREE(b);
ldns_resolver_deep_free(r);
if(!fp) fclose(myfp);
return LDNS_STATUS_MEM_ERR;
}
bgtr = ldns_bget_token(b, word, LDNS_PARSE_NORMAL, (size_t) gtr + 1);
while (bgtr > 0) {
gtr -= bgtr;
if(word[0] == '#') {
expect = LDNS_RESOLV_KEYWORD;
break;
}
tmp = ldns_rdf_new_frm_str(LDNS_RDF_TYPE_DNAME, word);
if (!tmp) {
ldns_resolver_deep_free(r);
ldns_buffer_free(b);
if(!fp) fclose(myfp);
return LDNS_STATUS_SYNTAX_DNAME_ERR;
}
ldns_resolver_push_searchlist(r, tmp);
ldns_rdf_deep_free(tmp);
bgtr = ldns_bget_token(b, word, LDNS_PARSE_NORMAL,
(size_t) gtr + 1);
}
ldns_buffer_free(b);
if (expect != LDNS_RESOLV_KEYWORD) {
gtr = 1;
expect = LDNS_RESOLV_KEYWORD;
}
break;
case LDNS_RESOLV_SORTLIST:
gtr = ldns_fget_token_l(myfp, word, LDNS_PARSE_SKIP_SPACE, 0, line_nr);
/* sortlist not implemented atm */
expect = LDNS_RESOLV_KEYWORD;
break;
case LDNS_RESOLV_OPTIONS:
gtr = ldns_fget_token_l(myfp, word, LDNS_PARSE_SKIP_SPACE, 0, line_nr);
/* options not implemented atm */
expect = LDNS_RESOLV_KEYWORD;
break;
case LDNS_RESOLV_ANCHOR:
/* a file containing a DNSSEC trust anchor */
gtr = ldns_fget_token_l(myfp, word, LDNS_PARSE_NORMAL, 0, line_nr);
if (gtr == 0) {
ldns_resolver_deep_free(r);
if(!fp) fclose(myfp);
return LDNS_STATUS_SYNTAX_MISSING_VALUE_ERR;
}
if(word[0] == '#') {
expect = LDNS_RESOLV_KEYWORD;
continue;
}
#ifdef HAVE_SSL
tmp_rr = ldns_read_anchor_file(word);
(void) ldns_resolver_push_dnssec_anchor(r, tmp_rr);
ldns_rr_free(tmp_rr);
#endif
expect = LDNS_RESOLV_KEYWORD;
break;
}
}
if(!fp)
fclose(myfp);
if (res) {
*res = r;
return LDNS_STATUS_OK;
} else {
ldns_resolver_deep_free(r);
return LDNS_STATUS_NULL;
}
}
ldns_status
ldns_resolver_new_frm_file(ldns_resolver **res, const char *filename)
{
ldns_resolver *r;
FILE *fp;
ldns_status s;
if (!filename) {
fp = fopen(LDNS_RESOLV_CONF, "r");
} else {
fp = fopen(filename, "r");
}
if (!fp) {
return LDNS_STATUS_FILE_ERR;
}
s = ldns_resolver_new_frm_fp(&r, fp);
fclose(fp);
if (s == LDNS_STATUS_OK) {
if (res) {
*res = r;
return LDNS_STATUS_OK;
} else {
ldns_resolver_free(r);
return LDNS_STATUS_NULL;
}
}
return s;
}
void
ldns_resolver_free(ldns_resolver *res)
{
LDNS_FREE(res);
}
void
ldns_resolver_deep_free(ldns_resolver *res)
{
size_t i;
if (res) {
if (res->_searchlist) {
for (i = 0; i < ldns_resolver_searchlist_count(res); i++) {
ldns_rdf_deep_free(res->_searchlist[i]);
}
LDNS_FREE(res->_searchlist);
}
if (res->_nameservers) {
for (i = 0; i < res->_nameserver_count; i++) {
ldns_rdf_deep_free(res->_nameservers[i]);
}
LDNS_FREE(res->_nameservers);
}
if (ldns_resolver_domain(res)) {
ldns_rdf_deep_free(ldns_resolver_domain(res));
}
if (res->_tsig_keyname) {
LDNS_FREE(res->_tsig_keyname);
}
if (res->_tsig_keydata) {
LDNS_FREE(res->_tsig_keydata);
}
if (res->_tsig_algorithm) {
LDNS_FREE(res->_tsig_algorithm);
}
if (res->_cur_axfr_pkt) {
ldns_pkt_free(res->_cur_axfr_pkt);
}
if (res->_rtt) {
LDNS_FREE(res->_rtt);
}
if (res->_dnssec_anchors) {
ldns_rr_list_deep_free(res->_dnssec_anchors);
}
LDNS_FREE(res);
}
}
ldns_status
ldns_resolver_search_status(ldns_pkt** pkt,
ldns_resolver *r, const ldns_rdf *name,
ldns_rr_type t, ldns_rr_class c, uint16_t flags)
{
ldns_rdf *new_name;
ldns_rdf **search_list;
size_t i;
ldns_status s = LDNS_STATUS_OK;
if (ldns_dname_absolute(name)) {
/* query as-is */
return ldns_resolver_query_status(pkt, r, name, t, c, flags);
} else if (ldns_resolver_dnsrch(r)) {
search_list = ldns_resolver_searchlist(r);
for (i = 0; i < ldns_resolver_searchlist_count(r); i++) {
new_name = ldns_dname_cat_clone(name, search_list[i]);
s = ldns_resolver_query_status(pkt, r,
new_name, t, c, flags);
ldns_rdf_free(new_name);
if (pkt) {
if (s == LDNS_STATUS_OK && *pkt &&
ldns_pkt_get_rcode(*pkt) ==
LDNS_RCODE_NOERROR) {
return LDNS_STATUS_OK;
}
ldns_pkt_free(*pkt);
}
}
}
return s;
}
ldns_pkt *
ldns_resolver_search(const ldns_resolver *r,const ldns_rdf *name,
ldns_rr_type t, ldns_rr_class c, uint16_t flags)
{
ldns_pkt* pkt = NULL;
if (ldns_resolver_search_status(&pkt, (ldns_resolver *)r,
name, t, c, flags) != LDNS_STATUS_OK) {
ldns_pkt_free(pkt);
}
return pkt;
}
ldns_status
ldns_resolver_query_status(ldns_pkt** pkt,
ldns_resolver *r, const ldns_rdf *name,
ldns_rr_type t, ldns_rr_class c, uint16_t flags)
{
ldns_rdf *newname;
ldns_status status;
if (!ldns_resolver_defnames(r) || !ldns_resolver_domain(r)) {
return ldns_resolver_send(pkt, r, name, t, c, flags);
}
newname = ldns_dname_cat_clone(name, ldns_resolver_domain(r));
if (!newname) {
return LDNS_STATUS_MEM_ERR;
}
status = ldns_resolver_send(pkt, r, newname, t, c, flags);
ldns_rdf_free(newname);
return status;
}
ldns_pkt *
ldns_resolver_query(const ldns_resolver *r, const ldns_rdf *name,
ldns_rr_type t, ldns_rr_class c, uint16_t flags)
{
ldns_pkt* pkt = NULL;
if (ldns_resolver_query_status(&pkt, (ldns_resolver *)r,
name, t, c, flags) != LDNS_STATUS_OK) {
ldns_pkt_free(pkt);
}
return pkt;
}
static size_t *
ldns_resolver_backup_rtt(ldns_resolver *r)
{
size_t *new_rtt;
size_t *old_rtt = ldns_resolver_rtt(r);
if (old_rtt && ldns_resolver_nameserver_count(r)) {
new_rtt = LDNS_XMALLOC(size_t
, ldns_resolver_nameserver_count(r));
memcpy(new_rtt, old_rtt, sizeof(size_t)
* ldns_resolver_nameserver_count(r));
ldns_resolver_set_rtt(r, new_rtt);
return old_rtt;
}
return NULL;
}
static void
ldns_resolver_restore_rtt(ldns_resolver *r, size_t *old_rtt)
{
size_t *cur_rtt = ldns_resolver_rtt(r);
if (cur_rtt) {
LDNS_FREE(cur_rtt);
}
ldns_resolver_set_rtt(r, old_rtt);
}
ldns_status
ldns_resolver_send_pkt(ldns_pkt **answer, ldns_resolver *r,
ldns_pkt *query_pkt)
{
ldns_pkt *answer_pkt = NULL;
ldns_status stat = LDNS_STATUS_OK;
size_t *rtt;
stat = ldns_send(&answer_pkt, (ldns_resolver *)r, query_pkt);
if (stat != LDNS_STATUS_OK) {
if(answer_pkt) {
ldns_pkt_free(answer_pkt);
answer_pkt = NULL;
}
} else {
/* if tc=1 fall back to EDNS and/or TCP */
/* check for tcp first (otherwise we don't care about tc=1) */
if (!ldns_resolver_usevc(r) && ldns_resolver_fallback(r)) {
if (ldns_pkt_tc(answer_pkt)) {
/* was EDNS0 set? */
if (ldns_pkt_edns_udp_size(query_pkt) == 0) {
ldns_pkt_set_edns_udp_size(query_pkt
, 4096);
ldns_pkt_free(answer_pkt);
/* Nameservers should not become
* unreachable because fragments are
* dropped (network error). We might
* still have success with TCP.
* Therefore maintain reachability
* statuses of the nameservers by
* backup and restore the rtt list.
*/
rtt = ldns_resolver_backup_rtt(r);
stat = ldns_send(&answer_pkt, r
, query_pkt);
ldns_resolver_restore_rtt(r, rtt);
}
/* either way, if it is still truncated, use TCP */
if (stat != LDNS_STATUS_OK ||
ldns_pkt_tc(answer_pkt)) {
ldns_resolver_set_usevc(r, true);
ldns_pkt_free(answer_pkt);
stat = ldns_send(&answer_pkt, r, query_pkt);
ldns_resolver_set_usevc(r, false);
}
}
}
}
if (answer) {
*answer = answer_pkt;
}
return stat;
}
ldns_status
ldns_resolver_prepare_query_pkt(ldns_pkt **query_pkt, ldns_resolver *r,
const ldns_rdf *name, ldns_rr_type t,
ldns_rr_class c, uint16_t flags)
{
struct timeval now;
/* prepare a question pkt from the parameters
* and then send this */
if (t == LDNS_RR_TYPE_IXFR) {
*query_pkt = ldns_pkt_ixfr_request_new(ldns_rdf_clone(name),
c, flags, NULL);
} else {
*query_pkt = ldns_pkt_query_new(ldns_rdf_clone(name), t, c, flags);
}
if (!*query_pkt) {
return LDNS_STATUS_ERR;
}
/* set DO bit if necessary */
if (ldns_resolver_dnssec(r)) {
if (ldns_resolver_edns_udp_size(r) == 0) {
ldns_resolver_set_edns_udp_size(r, 4096);
}
ldns_pkt_set_edns_do(*query_pkt, true);
if (ldns_resolver_dnssec_cd(r) || (flags & LDNS_CD)) {
ldns_pkt_set_cd(*query_pkt, true);
}
}
/* transfer the udp_edns_size from the resolver to the packet */
if (ldns_resolver_edns_udp_size(r) != 0) {
ldns_pkt_set_edns_udp_size(*query_pkt, ldns_resolver_edns_udp_size(r));
}
/* set the timestamp */
now.tv_sec = time(NULL);
now.tv_usec = 0;
ldns_pkt_set_timestamp(*query_pkt, now);
if (ldns_resolver_debug(r)) {
ldns_pkt_print(stdout, *query_pkt);
}
/* only set the id if it is not set yet */
if (ldns_pkt_id(*query_pkt) == 0) {
ldns_pkt_set_random_id(*query_pkt);
}
return LDNS_STATUS_OK;
}
ldns_status
ldns_resolver_send(ldns_pkt **answer, ldns_resolver *r, const ldns_rdf *name,
ldns_rr_type t, ldns_rr_class c, uint16_t flags)
{
ldns_pkt *query_pkt;
ldns_pkt *answer_pkt;
ldns_status status;
assert(r != NULL);
assert(name != NULL);
answer_pkt = NULL;
/* do all the preprocessing here, then fire of an query to
* the network */
if (0 == t) {
t= LDNS_RR_TYPE_A;
}
if (0 == c) {
c= LDNS_RR_CLASS_IN;
}
if (0 == ldns_resolver_nameserver_count(r)) {
return LDNS_STATUS_RES_NO_NS;
}
if (ldns_rdf_get_type(name) != LDNS_RDF_TYPE_DNAME) {
return LDNS_STATUS_RES_QUERY;
}
status = ldns_resolver_prepare_query_pkt(&query_pkt, r, name,
t, c, flags);
if (status != LDNS_STATUS_OK) {
return status;
}
/* if tsig values are set, tsign it */
/* TODO: make last 3 arguments optional too? maybe make complete
rr instead of separate values in resolver (and packet)
Jelte
should this go in pkt_prepare?
*/
if (ldns_resolver_tsig_keyname(r) && ldns_resolver_tsig_keydata(r)) {
#ifdef HAVE_SSL
status = ldns_pkt_tsig_sign(query_pkt,
ldns_resolver_tsig_keyname(r),
ldns_resolver_tsig_keydata(r),
300, ldns_resolver_tsig_algorithm(r), NULL);
if (status != LDNS_STATUS_OK) {
ldns_pkt_free(query_pkt);
return LDNS_STATUS_CRYPTO_TSIG_ERR;
}
#else
ldns_pkt_free(query_pkt);
return LDNS_STATUS_CRYPTO_TSIG_ERR;
#endif /* HAVE_SSL */
}
status = ldns_resolver_send_pkt(&answer_pkt, r, query_pkt);
ldns_pkt_free(query_pkt);
/* allows answer to be NULL when not interested in return value */
if (answer) {
*answer = answer_pkt;
}
return status;
}
ldns_rr *
ldns_axfr_next(ldns_resolver *resolver)
{
ldns_rr *cur_rr;
uint8_t *packet_wire;
size_t packet_wire_size;
ldns_lookup_table *rcode;
ldns_status status;
/* check if start() has been called */
if (!resolver || resolver->_socket == 0) {
return NULL;
}
if (resolver->_cur_axfr_pkt) {
if (resolver->_axfr_i == ldns_pkt_ancount(resolver->_cur_axfr_pkt)) {
ldns_pkt_free(resolver->_cur_axfr_pkt);
resolver->_cur_axfr_pkt = NULL;
return ldns_axfr_next(resolver);
}
cur_rr = ldns_rr_clone(ldns_rr_list_rr(
ldns_pkt_answer(resolver->_cur_axfr_pkt),
resolver->_axfr_i));
resolver->_axfr_i++;
if (ldns_rr_get_type(cur_rr) == LDNS_RR_TYPE_SOA) {
resolver->_axfr_soa_count++;
if (resolver->_axfr_soa_count >= 2) {
#ifndef USE_WINSOCK
close(resolver->_socket);
#else
closesocket(resolver->_socket);
#endif
resolver->_socket = 0;
ldns_pkt_free(resolver->_cur_axfr_pkt);
resolver->_cur_axfr_pkt = NULL;
}
}
return cur_rr;
} else {
packet_wire = ldns_tcp_read_wire(resolver->_socket, &packet_wire_size);
if(!packet_wire)
return NULL;
status = ldns_wire2pkt(&resolver->_cur_axfr_pkt, packet_wire,
packet_wire_size);
LDNS_FREE(packet_wire);
resolver->_axfr_i = 0;
if (status != LDNS_STATUS_OK) {
/* TODO: make status return type of this function (...api change) */
#ifdef STDERR_MSGS
fprintf(stderr, "Error parsing rr during AXFR: %s\n", ldns_get_errorstr_by_id(status));
#endif
/* we must now also close the socket, otherwise subsequent uses of the
same resolver structure will fail because the link is still open or
in an undefined state */
#ifndef USE_WINSOCK
close(resolver->_socket);
#else
closesocket(resolver->_socket);
#endif
resolver->_socket = 0;
return NULL;
} else if (ldns_pkt_get_rcode(resolver->_cur_axfr_pkt) != 0) {
rcode = ldns_lookup_by_id(ldns_rcodes, (int) ldns_pkt_get_rcode(resolver->_cur_axfr_pkt));
#ifdef STDERR_MSGS
if (rcode) {
fprintf(stderr, "Error in AXFR: %s\n",
rcode->name);
} else {
fprintf(stderr, "Error in AXFR: %d\n",
(int) ldns_pkt_get_rcode(
resolver->_cur_axfr_pkt));
}
#endif
/* we must now also close the socket, otherwise subsequent uses of the
same resolver structure will fail because the link is still open or
in an undefined state */
#ifndef USE_WINSOCK
close(resolver->_socket);
#else
closesocket(resolver->_socket);
#endif
resolver->_socket = 0;
return NULL;
} else {
return ldns_axfr_next(resolver);
}
}
}
/* this function is needed to abort a transfer that is in progress;
* without it an aborted transfer will lead to the AXFR code in the
* library staying in an indetermined state because the socket for the
* AXFR is never closed
*/
void
ldns_axfr_abort(ldns_resolver *resolver)
{
/* Only abort if an actual AXFR is in progress */
if (resolver->_socket != 0)
{
#ifndef USE_WINSOCK
close(resolver->_socket);
#else
closesocket(resolver->_socket);
#endif
resolver->_socket = 0;
}
}
bool
ldns_axfr_complete(const ldns_resolver *res)
{
/* complete when soa count is 2? */
return res->_axfr_soa_count == 2;
}
ldns_pkt *
ldns_axfr_last_pkt(const ldns_resolver *res)
{
return res->_cur_axfr_pkt;
}
/* random isn't really that good */
void
ldns_resolver_nameservers_randomize(ldns_resolver *r)
{
uint16_t i, j;
ldns_rdf **ns, *tmpns;
size_t *rtt, tmprtt;
/* should I check for ldns_resolver_random?? */
assert(r != NULL);
ns = ldns_resolver_nameservers(r);
rtt = ldns_resolver_rtt(r);
for (i = 0; i < ldns_resolver_nameserver_count(r); i++) {
j = ldns_get_random() % ldns_resolver_nameserver_count(r);
tmpns = ns[i];
ns[i] = ns[j];
ns[j] = tmpns;
tmprtt = rtt[i];
rtt[i] = rtt[j];
rtt[j] = tmprtt;
}
ldns_resolver_set_nameservers(r, ns);
}
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