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authorLaurent Bercot <ska-skaware@skarnet.org>2014-12-10 03:05:47 +0000
committerLaurent Bercot <ska-skaware@skarnet.org>2014-12-10 03:05:47 +0000
commit416ef5e2bf59bb2e45066a1d5d91ac677c0f48e5 (patch)
tree1c746d673dcec7a8488c6ac51db8245411034376 /src/libs6dns/s6dns_resolveq.c
downloads6-dns-416ef5e2bf59bb2e45066a1d5d91ac677c0f48e5.tar.xz
Initial commit
Diffstat (limited to 'src/libs6dns/s6dns_resolveq.c')
-rw-r--r--src/libs6dns/s6dns_resolveq.c89
1 files changed, 89 insertions, 0 deletions
diff --git a/src/libs6dns/s6dns_resolveq.c b/src/libs6dns/s6dns_resolveq.c
new file mode 100644
index 0000000..c43db1f
--- /dev/null
+++ b/src/libs6dns/s6dns_resolveq.c
@@ -0,0 +1,89 @@
+/* ISC license. */
+
+#include <errno.h>
+#include <skalibs/uint16.h>
+#include <skalibs/error.h>
+#include <skalibs/tai.h>
+#include <s6-dns/s6dns-domain.h>
+#include <s6-dns/s6dns-message.h>
+#include <s6-dns/s6dns-engine.h>
+#include <s6-dns/s6dns-rci.h>
+#include <s6-dns/s6dns-resolve.h>
+
+int s6dns_resolveq_r (char const *name, unsigned int len, uint16 qtype, s6dns_message_rr_func_t_ref parsefunc, void *data, s6dns_rci_t const *rci, s6dns_debughook_t const *dbh, tain_t const *deadline, tain_t *stamp)
+{
+ s6dns_engine_t dtl[rci->rulesnum] ;
+ unsigned int best = 0 ;
+ unsigned int n ;
+ int e = 0 ;
+ register unsigned int i = 0 ;
+ {
+ s6dns_domain_t domains[rci->rulesnum] ;
+ n = s6dns_domain_fromstring_qualify_encode(domains, name, len, rci->rules.s, rci->rulesnum) ;
+ if (!n) return -1 ;
+ for (; i < n ; i++)
+ {
+ dtl[i] = s6dns_engine_zero ;
+ if (!s6dns_engine_init_r(dtl + i, &rci->servers, S6DNS_O_RECURSIVE, domains[i].s, domains[i].len, qtype, dbh, deadline, stamp))
+ {
+ s6dns_engine_freen(dtl, i) ;
+ return -1 ;
+ }
+ }
+ }
+
+ /*
+ Wait until the "best" answer arrives, then scan until a positive answer
+ is found.
+
+ dtl[i].status == EAGAIN : query still pending
+ other nonzero dtl[i].status : error, give up
+ dtl[i].status == 0 : answer #i has arrived, in which case parse it;
+ r < 0 : error, give up
+ r > 0 : positive answer, return it
+ r == 0 : negative answer. If it's non-fatal (i.e. NXDOMAIN),
+ then move on to the next best FQDN.
+ */
+
+ for (;;)
+ {
+ register int k = s6dns_resolven_loop(dtl, n, 1, deadline, stamp) ;
+ if (k < 0) goto err ;
+ if ((unsigned int)k == best)
+ {
+ for (;; best++)
+ {
+ s6dns_message_header_t h ;
+ register int r ;
+ if (best >= n) goto notfound ;
+ if (error_isagain(dtl[best].status)) break ;
+ if (dtl[best].status) { errno = dtl[best].status ; goto err ; }
+ r = s6dns_message_parse(&h, s6dns_engine_packet(dtl + best), s6dns_engine_packetlen(dtl + best), parsefunc, data) ;
+ if (r < 0) goto err ;
+ else if (r) goto found ;
+ else switch (errno)
+ {
+ case EBUSY :
+ case ENOENT :
+ case ECONNREFUSED :
+ case EIO :
+ break ;
+ default : goto err ;
+ }
+ if (!best) e = errno ;
+ }
+ }
+ }
+
+ found:
+ s6dns_engine_freen(dtl, n) ;
+ return 1 ;
+
+ notfound:
+ s6dns_engine_freen(dtl, n) ;
+ return (errno = e, 0) ;
+
+ err:
+ s6dns_engine_freen(dtl, n) ;
+ return -1 ;
+}