Detect cycle in the fail over on subsequent resolve requests only

5 files changed, 28 insertions, 23 deletions

diff --git a/src/providers/data_provider_fo.c b/src/providers/data_provider_fo.c
index c358e68d1..51d6ae211 100644
--- a/src/providers/data_provider_fo.c
+++ b/src/providers/data_provider_fo.c
@@ -342,6 +342,7 @@ struct be_resolve_server_state {
     int attempts;
 
     struct fo_server *srv;
+    bool first_try;
 };
 
 static void be_resolve_server_done(struct tevent_req *subreq);
@@ -349,7 +350,8 @@ static void be_resolve_server_done(struct tevent_req *subreq);
 struct tevent_req *be_resolve_server_send(TALLOC_CTX *memctx,
                                           struct tevent_context *ev,
                                           struct be_ctx *ctx,
-                                          const char *service_name)
+                                          const char *service_name,
+                                          bool first_try)
 {
     struct tevent_req *req, *subreq;
     struct be_resolve_server_state *state;
@@ -370,6 +372,7 @@ struct tevent_req *be_resolve_server_send(TALLOC_CTX *memctx,
 
     state->svc = svc;
     state->attempts = 0;
+    state->first_try = first_try;
 
     subreq = fo_resolve_service_send(state, ev,
                                      ctx->be_fo->resolv,
@@ -443,7 +446,7 @@ static void be_resolve_server_done(struct tevent_req *subreq)
     }
 
     /* all fine we got the server */
-    if (state->svc->first_resolved == NULL) {
+    if (state->svc->first_resolved == NULL || state->first_try == true) {
         DEBUG(SSSDBG_TRACE_LIBS, ("Saving the first resolved server\n"));
         state->svc->first_resolved = state->srv;
     } else if (state->svc->first_resolved == state->srv) {
diff --git a/src/providers/dp_backend.h b/src/providers/dp_backend.h
index 96c774783..6e98e7ef3 100644
--- a/src/providers/dp_backend.h
+++ b/src/providers/dp_backend.h
@@ -207,7 +207,8 @@ int be_fo_add_server(struct be_ctx *ctx, const char *service_name,
 struct tevent_req *be_resolve_server_send(TALLOC_CTX *memctx,
                                           struct tevent_context *ev,
                                           struct be_ctx *ctx,
-                                          const char *service_name);
+                                          const char *service_name,
+                                          bool first_try);
 int be_resolve_server_recv(struct tevent_req *req, struct fo_server **srv);
 
 void be_fo_set_port_status(struct be_ctx *ctx,
diff --git a/src/providers/krb5/krb5_auth.c b/src/providers/krb5/krb5_auth.c
index 72992ba75..0306426cc 100644
--- a/src/providers/krb5/krb5_auth.c
+++ b/src/providers/krb5/krb5_auth.c
@@ -320,6 +320,9 @@ int krb5_auth_recv(struct tevent_req *req, int *pam_status, int *dp_err)
     return EOK;
 }
 
+static struct tevent_req *krb5_next_kdc(struct tevent_req *req);
+static struct tevent_req *krb5_next_kpasswd(struct tevent_req *req);
+
 struct tevent_req *krb5_auth_send(TALLOC_CTX *mem_ctx,
                                   struct tevent_context *ev,
                                   struct be_ctx *be_ctx,
@@ -507,16 +510,14 @@ struct tevent_req *krb5_auth_send(TALLOC_CTX *mem_ctx,
 
     kr->srv = NULL;
     kr->kpasswd_srv = NULL;
-    subreq = be_resolve_server_send(state, state->ev, state->be_ctx,
-                                    krb5_ctx->service->name);
-    if (subreq == NULL) {
-        DEBUG(1, ("be_resolve_server_send failed.\n"));
-        ret = ENOMEM;
+
+    subreq = krb5_next_kdc(req);
+    if (!subreq) {
+        DEBUG(SSSDBG_CRIT_FAILURE, ("krb5_next_kdc failed.\n"));
+        ret = EIO;
         goto done;
     }
 
-    tevent_req_set_callback(subreq, krb5_resolve_kdc_done, req);
-
     return req;
 
 done:
@@ -557,16 +558,12 @@ static void krb5_resolve_kdc_done(struct tevent_req *subreq)
         }
     } else {
         if (kr->krb5_ctx->kpasswd_service != NULL) {
-            subreq = be_resolve_server_send(state, state->ev, state->be_ctx,
-                                            kr->krb5_ctx->kpasswd_service->name);
+            subreq = krb5_next_kpasswd(req);
             if (subreq == NULL) {
-                DEBUG(1, ("be_resolve_server_send failed.\n"));
-                ret = ENOMEM;
+                DEBUG(SSSDBG_CRIT_FAILURE, ("krb5_next_kpasswd failed.\n"));
+                ret = EIO;
                 goto failed;
             }
-
-            tevent_req_set_callback(subreq, krb5_resolve_kpasswd_done, req);
-
             return;
         }
     }
@@ -718,7 +715,6 @@ done:
 }
 
 static struct tevent_req *krb5_next_server(struct tevent_req *req);
-static struct tevent_req *krb5_next_kdc(struct tevent_req *req);
 static struct tevent_req *krb5_next_kpasswd(struct tevent_req *req);
 
 static void krb5_child_done(struct tevent_req *subreq)
@@ -1004,7 +1000,8 @@ static struct tevent_req *krb5_next_kdc(struct tevent_req *req)
 
     next_req = be_resolve_server_send(state, state->ev,
                                       state->be_ctx,
-                                      state->krb5_ctx->service->name);
+                                      state->krb5_ctx->service->name,
+                                      state->kr->srv == NULL ? true : false);
     if (next_req == NULL) {
         DEBUG(1, ("be_resolve_server_send failed.\n"));
         return NULL;
@@ -1021,7 +1018,8 @@ static struct tevent_req *krb5_next_kpasswd(struct tevent_req *req)
 
     next_req = be_resolve_server_send(state, state->ev,
                                 state->be_ctx,
-                                state->krb5_ctx->kpasswd_service->name);
+                                state->krb5_ctx->kpasswd_service->name,
+                                state->kr->kpasswd_srv == NULL ? true : false);
     if (next_req == NULL) {
         DEBUG(1, ("be_resolve_server_send failed.\n"));
         return NULL;
diff --git a/src/providers/ldap/ldap_auth.c b/src/providers/ldap/ldap_auth.c
index 8b6173e14..734249ced 100644
--- a/src/providers/ldap/ldap_auth.c
+++ b/src/providers/ldap/ldap_auth.c
@@ -517,7 +517,8 @@ static struct tevent_req *auth_get_server(struct tevent_req *req)
     next_req = be_resolve_server_send(state,
                                       state->ev,
                                       state->ctx->be,
-                                      state->sdap_service->name);
+                                      state->sdap_service->name,
+                                      state->srv == NULL ? true : false);
     if (!next_req) {
         DEBUG(1, ("be_resolve_server_send failed.\n"));
         return NULL;
diff --git a/src/providers/ldap/sdap_async_connection.c b/src/providers/ldap/sdap_async_connection.c
index 22aa4f91e..2b7f8c93d 100644
--- a/src/providers/ldap/sdap_async_connection.c
+++ b/src/providers/ldap/sdap_async_connection.c
@@ -884,7 +884,8 @@ static struct tevent_req *sdap_kinit_next_kdc(struct tevent_req *req)
 
     next_req = be_resolve_server_send(state, state->ev,
                                       state->be,
-                                      state->krb_service_name);
+                                      state->krb_service_name,
+                                      state->kdc_srv == NULL ? true : false);
     if (next_req == NULL) {
         DEBUG(1, ("be_resolve_server_send failed.\n"));
         return NULL;
@@ -1215,7 +1216,8 @@ static int sdap_cli_resolve_next(struct tevent_req *req)
     /* NOTE: this call may cause service->uri to be refreshed
      * with a new valid server. Do not use service->uri before */
     subreq = be_resolve_server_send(state, state->ev,
-                                    state->be, state->service->name);
+                                    state->be, state->service->name,
+                                    state->srv == NULL ? true : false);
     if (!subreq) {
         return ENOMEM;
     }