1 files changed, 116 insertions, 1 deletions

diff --git a/lib/libc/asr/res_search_async.c b/lib/libc/asr/res_search_async.c
index c3cae7683dd..8bc950db7bb 100644
--- a/lib/libc/asr/res_search_async.c
+++ b/lib/libc/asr/res_search_async.c
@@ -1,4 +1,4 @@
-/*	$OpenBSD: res_search_async.c,v 1.8 2013/06/01 14:34:34 eric Exp $	*/
+/*	$OpenBSD: res_search_async.c,v 1.9 2013/06/01 15:02:01 eric Exp $	*/
 /*
  * Copyright (c) 2012 Eric Faurot <eric@openbsd.org>
  *
@@ -29,6 +29,8 @@
 #include "asr_private.h"
 
 static int res_search_async_run(struct async *, struct async_res *);
+size_t asr_domcat(const char *, const char *, char *, size_t);
+int asr_iter_domain(struct async *, const char *, char *, size_t);
 
 /*
  * Unlike res_query_async(), this function returns a valid packet only if
@@ -200,3 +202,116 @@ res_search_async_run(struct async *as, struct async_res *ar)
 	}
 	goto next;
 }
+
+/*
+ * Concatenate a name and a domain name. The result has no trailing dot.
+ * Return the resulting string length, or 0 in case of error.
+ */
+size_t
+asr_domcat(const char *name, const char *domain, char *buf, size_t buflen)
+{
+	size_t	r;
+
+	r = asr_make_fqdn(name, domain, buf, buflen);
+	if (r == 0)
+		return (0);
+	buf[r - 1] = '\0';
+
+	return (r - 1);
+}
+
+enum {
+	DOM_INIT,
+	DOM_DOMAIN,
+	DOM_DONE
+};
+
+/*
+ * Implement the search domain strategy.
+ *
+ * This function works as a generator that constructs complete domains in
+ * buffer "buf" of size "len" for the given host name "name", according to the
+ * search rules defined by the resolving context.  It is supposed to be called
+ * multiple times (with the same name) to generate the next possible domain
+ * name, if any.
+ *
+ * It returns -1 if all possibilities have been exhausted, 0 if there was an
+ * error generating the next name, or the resulting name length.
+ */
+int
+asr_iter_domain(struct async *as, const char *name, char * buf, size_t len)
+{
+	const char	*c;
+	int		 dots;
+
+	switch (as->as_dom_step) {
+
+	case DOM_INIT:
+		/* First call */
+
+		/*
+		 * If "name" is an FQDN, that's the only result and we
+		 * don't try anything else.
+		 */
+		if (strlen(name) && name[strlen(name) - 1] ==  '.') {
+			DPRINT("asr: asr_iter_domain(\"%s\") fqdn\n", name);
+			as->as_dom_flags |= ASYNC_DOM_FQDN;
+			as->as_dom_step = DOM_DONE;
+			return (asr_domcat(name, NULL, buf, len));
+		}
+
+		/*
+		 * Otherwise, we iterate through the specified search domains.
+		 */
+		as->as_dom_step = DOM_DOMAIN;
+		as->as_dom_idx = 0;
+
+		/*
+		 * If "name" as enough dots, use it as-is first, as indicated
+		 * in resolv.conf(5).
+		 */
+		dots = 0;
+		for (c = name; *c; c++)
+			dots += (*c == '.');
+		if (dots >= as->as_ctx->ac_ndots) {
+			DPRINT("asr: asr_iter_domain(\"%s\") ndots\n", name);
+			as->as_dom_flags |= ASYNC_DOM_NDOTS;
+			if (strlcpy(buf, name, len) >= len)
+				return (0);
+			return (strlen(buf));
+		}
+		/* Otherwise, starts using the search domains */
+		/* FALLTHROUGH */
+
+	case DOM_DOMAIN:
+		if (as->as_dom_idx < as->as_ctx->ac_domcount) {
+			DPRINT("asr: asr_iter_domain(\"%s\") domain \"%s\"\n",
+			    name, as->as_ctx->ac_dom[as->as_dom_idx]);
+			as->as_dom_flags |= ASYNC_DOM_DOMAIN;
+			return (asr_domcat(name,
+			    as->as_ctx->ac_dom[as->as_dom_idx++], buf, len));
+		}
+
+		/* No more domain to try. */
+
+		as->as_dom_step = DOM_DONE;
+
+		/*
+		 * If the name was not tried as an absolute name before,
+		 * do it now.
+		 */
+		if (!(as->as_dom_flags & ASYNC_DOM_NDOTS)) {
+			DPRINT("asr: asr_iter_domain(\"%s\") as is\n", name);
+			as->as_dom_flags |= ASYNC_DOM_ASIS;
+			if (strlcpy(buf, name, len) >= len)
+				return (0);
+			return (strlen(buf));
+		}
+		/* Otherwise, we are done. */
+
+	case DOM_DONE:
+	default:
+		DPRINT("asr: asr_iter_domain(\"%s\") done\n", name);
+		return (-1);
+	}
+}