lib,nhrpd,bgpd/bmp: pass resolver failure details

To keep the calling code agnostic of the DNS resolver libary used, pass
a strerror-style string instead of a status code that would need extra
handling.

Signed-off-by: David Lamparter <equinox@diac24.net>

5 files changed, 28 insertions, 17 deletions

diff --git a/bgpd/bgp_bmp.c b/bgpd/bgp_bmp.c
index b57af89eeb..b184c9f567 100644
--- a/bgpd/bgp_bmp.c
+++ b/bgpd/bgp_bmp.c
@@ -1662,14 +1662,16 @@ static void bmp_active_connect(struct bmp_active *ba)
 	bmp_active_setup(ba);
 }
 
-static void bmp_active_resolved(struct resolver_query *resq, int numaddrs,
-				union sockunion *addr)
+static void bmp_active_resolved(struct resolver_query *resq, const char *errstr,
+				int numaddrs, union sockunion *addr)
 {
 	struct bmp_active *ba = container_of(resq, struct bmp_active, resq);
 	unsigned i;
 
 	if (numaddrs <= 0) {
-		zlog_warn("bmp[%s]: hostname resolution failed", ba->hostname);
+		zlog_warn("bmp[%s]: hostname resolution failed: %s",
+			  ba->hostname, errstr);
+		ba->last_err = errstr;
 		ba->curretry += ba->curretry / 2;
 		ba->addrpos = 0;
 		ba->addrtotal = 0;
@@ -1701,6 +1703,8 @@ static int bmp_active_thread(struct thread *t)
 	THREAD_OFF(ba->t_read);
 	THREAD_OFF(ba->t_write);
 
+	ba->last_err = NULL;
+
 	if (ba->socket == -1) {
 		resolver_resolve(&ba->resq, AF_UNSPEC, ba->hostname,
 				 bmp_active_resolved);
@@ -1713,8 +1717,9 @@ static int bmp_active_thread(struct thread *t)
 
 	sockunion2str(&ba->addrs[ba->addrpos], buf, sizeof(buf));
 	if (ret < 0 || status != 0) {
-		zlog_warn("bmp[%s]: failed to connect to %s:%d",
-			  ba->hostname, buf, ba->port);
+		ba->last_err = strerror(status);
+		zlog_warn("bmp[%s]: failed to connect to %s:%d: %s",
+			  ba->hostname, buf, ba->port, ba->last_err);
 		goto out_next;
 	}
 
diff --git a/bgpd/bgp_bmp.h b/bgpd/bgp_bmp.h
index 9d270e808c..94a17f70da 100644
--- a/bgpd/bgp_bmp.h
+++ b/bgpd/bgp_bmp.h
@@ -182,6 +182,7 @@ struct bmp_active {
 	unsigned addrpos, addrtotal;
 	union sockunion addrs[8];
 	int socket;
+	const char *last_err;
 	struct thread *t_timer, *t_read, *t_write;
 };
 
diff --git a/lib/resolver.c b/lib/resolver.c
index 938ebd4143..1be47bd6e1 100644
--- a/lib/resolver.c
+++ b/lib/resolver.c
@@ -145,7 +145,8 @@ static void ares_address_cb(void *arg, int status, int timeouts,
 {
 	struct resolver_query *query = (struct resolver_query *)arg;
 	union sockunion addr[16];
-	void (*callback)(struct resolver_query *, int, union sockunion *);
+	void (*callback)(struct resolver_query *, const char *, int,
+			 union sockunion *);
 	size_t i;
 
 	callback = query->callback;
@@ -153,9 +154,10 @@ static void ares_address_cb(void *arg, int status, int timeouts,
 
 	if (status != ARES_SUCCESS) {
 		if (resolver_debug)
-			zlog_debug("[%p] Resolving failed", query);
+			zlog_debug("[%p] Resolving failed (%s)",
+				   query, ares_strerror(status));
 
-		callback(query, -1, NULL);
+		callback(query, ares_strerror(status), -1, NULL);
 		return;
 	}
 
@@ -177,25 +179,26 @@ static void ares_address_cb(void *arg, int status, int timeouts,
 	if (resolver_debug)
 		zlog_debug("[%p] Resolved with %d results", query, (int)i);
 
-	callback(query, i, &addr[0]);
+	callback(query, NULL, i, &addr[0]);
 }
 
 static int resolver_cb_literal(struct thread *t)
 {
 	struct resolver_query *query = THREAD_ARG(t);
-	void (*callback)(struct resolver_query *, int, union sockunion *);
+	void (*callback)(struct resolver_query *, const char *, int,
+			 union sockunion *);
 
 	callback = query->callback;
 	query->callback = NULL;
 
-	callback(query, 1, &query->literal_addr);
+	callback(query, ARES_SUCCESS, 1, &query->literal_addr);
 	return 0;
 }
 
 void resolver_resolve(struct resolver_query *query, int af,
 		      const char *hostname,
-		      void (*callback)(struct resolver_query *, int,
-				       union sockunion *))
+		      void (*callback)(struct resolver_query *, const char *,
+				       int, union sockunion *))
 {
 	int ret;
 
diff --git a/lib/resolver.h b/lib/resolver.h
index a418377a29..59bf0d0f55 100644
--- a/lib/resolver.h
+++ b/lib/resolver.h
@@ -14,7 +14,8 @@
 #include "sockunion.h"
 
 struct resolver_query {
-	void (*callback)(struct resolver_query *, int n, union sockunion *);
+	void (*callback)(struct resolver_query *, const char *errstr, int n,
+			 union sockunion *);
 
 	/* used to immediate provide the result if IP literal is passed in */
 	union sockunion literal_addr;
@@ -24,6 +25,7 @@ struct resolver_query {
 void resolver_init(struct thread_master *tm);
 void resolver_resolve(struct resolver_query *query, int af,
 		      const char *hostname, void (*cb)(struct resolver_query *,
-						       int, union sockunion *));
+						       const char *, int,
+						       union sockunion *));
 
 #endif /* _FRR_RESOLVER_H */
diff --git a/nhrpd/nhrp_nhs.c b/nhrpd/nhrp_nhs.c
index 360972c327..bec6c014a0 100644
--- a/nhrpd/nhrp_nhs.c
+++ b/nhrpd/nhrp_nhs.c
@@ -238,8 +238,8 @@ nhrp_reg_by_nbma(struct nhrp_nhs *nhs, const union sockunion *nbma_addr)
 	return NULL;
 }
 
-static void nhrp_nhs_resolve_cb(struct resolver_query *q, int n,
-				union sockunion *addrs)
+static void nhrp_nhs_resolve_cb(struct resolver_query *q, const char *errstr,
+				int n, union sockunion *addrs)
 {
 	struct nhrp_nhs *nhs = container_of(q, struct nhrp_nhs, dns_resolve);
 	struct nhrp_interface *nifp = nhs->ifp->info;