FO: Use SRV TTL in fail over code

Resolves:
https://fedorahosted.org/sssd/ticket/1884

Removes the hardcoded SRV TTL timeout and uses TTL from the DNS instead.

Reviewed-by: Pavel Březina <pbrezina@redhat.com>

9 files changed, 48 insertions, 9 deletions

diff --git a/src/providers/ad/ad_srv.c b/src/providers/ad/ad_srv.c
index ac9dfa187..910f82dd0 100644
--- a/src/providers/ad/ad_srv.c
+++ b/src/providers/ad/ad_srv.c
@@ -176,7 +176,7 @@ static void ad_get_dc_servers_done(struct tevent_req *subreq)
     req = tevent_req_callback_data(subreq, struct tevent_req);
     state = tevent_req_data(req, struct ad_get_dc_servers_state);
 
-    ret = fo_discover_srv_recv(state, subreq, &domain,
+    ret = fo_discover_srv_recv(state, subreq, &domain, NULL,
                                &state->servers, &state->num_servers);
     talloc_zfree(subreq);
     if (ret != EOK) {
@@ -616,6 +616,7 @@ struct ad_srv_plugin_state {
 
     const char *site;
     char *dns_domain;
+    uint32_t ttl;
     char *forest;
     struct fo_server_info *primary_servers;
     size_t num_primary_servers;
@@ -837,6 +838,7 @@ static void ad_srv_plugin_servers_done(struct tevent_req *subreq)
     state = tevent_req_data(req, struct ad_srv_plugin_state);
 
     ret = fo_discover_servers_recv(state, subreq, &state->dns_domain,
+                                   &state->ttl,
                                    &state->primary_servers,
                                    &state->num_primary_servers,
                                    &state->backup_servers,
@@ -874,6 +876,7 @@ static void ad_srv_plugin_servers_done(struct tevent_req *subreq)
 errno_t ad_srv_plugin_recv(TALLOC_CTX *mem_ctx,
                            struct tevent_req *req,
                            char **_dns_domain,
+                           uint32_t *_ttl,
                            struct fo_server_info **_primary_servers,
                            size_t *_num_primary_servers,
                            struct fo_server_info **_backup_servers,
@@ -904,6 +907,9 @@ errno_t ad_srv_plugin_recv(TALLOC_CTX *mem_ctx,
         *_dns_domain = talloc_steal(mem_ctx, state->dns_domain);
     }
 
+    if (_ttl) {
+        *_ttl = state->ttl;
+    }
 
     return EOK;
 }
diff --git a/src/providers/ad/ad_srv.h b/src/providers/ad/ad_srv.h
index be3ac2826..ae5efe447 100644
--- a/src/providers/ad/ad_srv.h
+++ b/src/providers/ad/ad_srv.h
@@ -42,6 +42,7 @@ struct tevent_req *ad_srv_plugin_send(TALLOC_CTX *mem_ctx,
 errno_t ad_srv_plugin_recv(TALLOC_CTX *mem_ctx,
                             struct tevent_req *req,
                             char **_dns_domain,
+                            uint32_t *_ttl,
                             struct fo_server_info **_primary_servers,
                             size_t *_num_primary_servers,
                             struct fo_server_info **_backup_servers,
diff --git a/src/providers/data_provider_fo.c b/src/providers/data_provider_fo.c
index ef1f0b2ed..dab796d46 100644
--- a/src/providers/data_provider_fo.c
+++ b/src/providers/data_provider_fo.c
@@ -70,7 +70,6 @@ static int be_fo_get_options(struct be_ctx *ctx,
     opts->service_resolv_timeout = dp_opt_get_int(ctx->be_res->opts,
                                                   DP_RES_OPT_RESOLVER_TIMEOUT);
     opts->retry_timeout = 30;
-    opts->srv_retry_timeout = 14400;
     opts->srv_retry_neg_timeout = 15;
     opts->family_order = ctx->be_res->family_order;
 
diff --git a/src/providers/fail_over.c b/src/providers/fail_over.c
index c16c70ddb..814208152 100644
--- a/src/providers/fail_over.c
+++ b/src/providers/fail_over.c
@@ -117,6 +117,7 @@ struct srv_data {
     struct fo_server *meta;
 
     int srv_lookup_status;
+    int ttl;
     struct timeval last_status_change;
 };
 
@@ -149,7 +150,6 @@ fo_context_init(TALLOC_CTX *mem_ctx, struct fo_options *opts)
         return NULL;
     }
 
-    ctx->opts->srv_retry_timeout = opts->srv_retry_timeout;
     ctx->opts->srv_retry_neg_timeout = opts->srv_retry_neg_timeout;
     ctx->opts->retry_timeout = opts->retry_timeout;
     ctx->opts->family_order  = opts->family_order;
@@ -272,7 +272,7 @@ get_srv_data_status(struct srv_data *data)
     if (data->srv_lookup_status == SRV_RESOLVE_ERROR) {
         timeout = data->meta->service->ctx->opts->srv_retry_neg_timeout;
     } else {
-        timeout = data->meta->service->ctx->opts->srv_retry_timeout;
+        timeout = data->ttl;
     }
 
     if (timeout && STATUS_DIFF(data, tv) > timeout) {
@@ -1285,8 +1285,9 @@ resolve_srv_done(struct tevent_req *subreq)
     size_t num_backup_servers = 0;
     char *dns_domain = NULL;
     int ret;
+    uint32_t ttl;
 
-    ret = state->fo_ctx->srv_recv_fn(state, subreq, &dns_domain,
+    ret = state->fo_ctx->srv_recv_fn(state, subreq, &dns_domain, &ttl,
                                      &primary_servers, &num_primary_servers,
                                      &backup_servers, &num_backup_servers);
     talloc_free(subreq);
@@ -1300,6 +1301,7 @@ resolve_srv_done(struct tevent_req *subreq)
             goto done;
         }
 
+        state->meta->srv_data->ttl = ttl;
         talloc_zfree(state->meta->srv_data->dns_domain);
         state->meta->srv_data->dns_domain = talloc_steal(state->meta->srv_data,
                                                          dns_domain);
diff --git a/src/providers/fail_over.h b/src/providers/fail_over.h
index b1ec6a23c..d44ad2ff1 100644
--- a/src/providers/fail_over.h
+++ b/src/providers/fail_over.h
@@ -78,7 +78,6 @@ struct fo_server;
  * try when looking up the service.
  */
 struct fo_options {
-    time_t srv_retry_timeout;
     time_t srv_retry_neg_timeout;
     time_t retry_timeout;
     int service_resolv_timeout;
diff --git a/src/providers/fail_over_srv.c b/src/providers/fail_over_srv.c
index 5c06d2876..5f474eaee 100644
--- a/src/providers/fail_over_srv.c
+++ b/src/providers/fail_over_srv.c
@@ -30,6 +30,7 @@ struct fo_discover_srv_state {
     char *dns_domain;
     struct fo_server_info *servers;
     size_t num_servers;
+    uint32_t ttl;
 };
 
 static void fo_discover_srv_done(struct tevent_req *subreq);
@@ -83,7 +84,7 @@ static void fo_discover_srv_done(struct tevent_req *subreq)
     state = tevent_req_data(req, struct fo_discover_srv_state);
 
     ret = resolv_discover_srv_recv(state, subreq,
-                                   &reply_list, NULL, &state->dns_domain);
+                                   &reply_list, &state->ttl, &state->dns_domain);
     talloc_zfree(subreq);
     if (ret == ENOENT) {
         ret = ERR_SRV_NOT_FOUND;
@@ -143,6 +144,7 @@ done:
 errno_t fo_discover_srv_recv(TALLOC_CTX *mem_ctx,
                              struct tevent_req *req,
                              char **_dns_domain,
+                             uint32_t *_ttl,
                              struct fo_server_info **_servers,
                              size_t *_num_servers)
 {
@@ -159,6 +161,10 @@ errno_t fo_discover_srv_recv(TALLOC_CTX *mem_ctx,
         *_servers = talloc_steal(mem_ctx, state->servers);
     }
 
+    if (_ttl != NULL) {
+        *_ttl = state->ttl;
+    }
+
     if (_num_servers != NULL) {
         *_num_servers = state->num_servers;
     }
@@ -175,6 +181,7 @@ struct fo_discover_servers_state {
     const char *backup_domain;
 
     char *dns_domain;
+    uint32_t ttl;
     struct fo_server_info *primary_servers;
     size_t num_primary_servers;
     struct fo_server_info *backup_servers;
@@ -212,6 +219,7 @@ struct tevent_req *fo_discover_servers_send(TALLOC_CTX *mem_ctx,
             state->backup_servers = NULL;
             state->num_backup_servers = 0;
             state->dns_domain = NULL;
+            state->ttl = 0;
 
             ret = EOK;
             goto immediately;
@@ -289,6 +297,7 @@ static void fo_discover_servers_primary_done(struct tevent_req *subreq)
 
     ret = fo_discover_srv_recv(state, subreq,
                                &state->dns_domain,
+                               &state->ttl,
                                &state->primary_servers,
                                &state->num_primary_servers);
     talloc_zfree(subreq);
@@ -361,7 +370,7 @@ static void fo_discover_servers_backup_done(struct tevent_req *subreq)
     state = tevent_req_data(req, struct fo_discover_servers_state);
 
     ret = fo_discover_srv_recv(state, subreq, NULL,
-                               &state->backup_servers,
+                               NULL, &state->backup_servers,
                                &state->num_backup_servers);
     talloc_zfree(subreq);
     if (ret != EOK) {
@@ -385,6 +394,7 @@ static void fo_discover_servers_backup_done(struct tevent_req *subreq)
 errno_t fo_discover_servers_recv(TALLOC_CTX *mem_ctx,
                                  struct tevent_req *req,
                                  char **_dns_domain,
+                                 uint32_t *_ttl,
                                  struct fo_server_info **_primary_servers,
                                  size_t *_num_primary_servers,
                                  struct fo_server_info **_backup_servers,
@@ -415,6 +425,10 @@ errno_t fo_discover_servers_recv(TALLOC_CTX *mem_ctx,
         *_dns_domain = talloc_steal(mem_ctx, state->dns_domain);
     }
 
+    if (_ttl) {
+        *_ttl = state->ttl;
+    }
+
 
     return EOK;
 }
@@ -436,6 +450,7 @@ struct fo_resolve_srv_dns_state {
     const char *discovery_domain;
 
     char *dns_domain;
+    uint32_t ttl;
     struct fo_server_info *servers;
     size_t num_servers;
 };
@@ -644,7 +659,8 @@ static void fo_resolve_srv_dns_done(struct tevent_req *subreq)
     req = tevent_req_callback_data(subreq, struct tevent_req);
     state = tevent_req_data(req, struct fo_resolve_srv_dns_state);
 
-    ret = fo_discover_srv_recv(state, subreq, &state->dns_domain,
+    ret = fo_discover_srv_recv(state, subreq,
+                               &state->dns_domain, &state->ttl,
                                &state->servers, &state->num_servers);
     talloc_zfree(subreq);
     if (ret != EOK) {
@@ -663,6 +679,7 @@ done:
 errno_t fo_resolve_srv_dns_recv(TALLOC_CTX *mem_ctx,
                                 struct tevent_req *req,
                                 char **_dns_domain,
+                                uint32_t *_ttl,
                                 struct fo_server_info **_primary_servers,
                                 size_t *_num_primary_servers,
                                 struct fo_server_info **_backup_servers,
@@ -694,5 +711,9 @@ errno_t fo_resolve_srv_dns_recv(TALLOC_CTX *mem_ctx,
         *_dns_domain = talloc_steal(mem_ctx, state->dns_domain);
     }
 
+    if (_ttl) {
+        *_ttl = state->ttl;
+    }
+
     return EOK;
 }
diff --git a/src/providers/fail_over_srv.h b/src/providers/fail_over_srv.h
index c4b50ba33..fe4088e02 100644
--- a/src/providers/fail_over_srv.h
+++ b/src/providers/fail_over_srv.h
@@ -65,6 +65,7 @@ typedef errno_t
 (*fo_srv_lookup_plugin_recv_t)(TALLOC_CTX *mem_ctx,
                                struct tevent_req *req,
                                char **_dns_domain,
+                               uint32_t *_ttl,
                                struct fo_server_info **_primary_servers,
                                size_t *_num_primary_servers,
                                struct fo_server_info **_backup_servers,
@@ -80,6 +81,7 @@ struct tevent_req *fo_discover_srv_send(TALLOC_CTX *mem_ctx,
 errno_t fo_discover_srv_recv(TALLOC_CTX *mem_ctx,
                              struct tevent_req *req,
                              char **_dns_domain,
+                             uint32_t *_ttl,
                              struct fo_server_info **_servers,
                              size_t *_num_servers);
 
@@ -94,6 +96,7 @@ struct tevent_req *fo_discover_servers_send(TALLOC_CTX *mem_ctx,
 errno_t fo_discover_servers_recv(TALLOC_CTX *mem_ctx,
                                  struct tevent_req *req,
                                  char **_dns_domain,
+                                 uint32_t *_ttl,
                                  struct fo_server_info **_primary_servers,
                                  size_t *_num_primary_servers,
                                  struct fo_server_info **_backup_servers,
@@ -121,6 +124,7 @@ struct tevent_req *fo_resolve_srv_dns_send(TALLOC_CTX *mem_ctx,
 errno_t fo_resolve_srv_dns_recv(TALLOC_CTX *mem_ctx,
                                 struct tevent_req *req,
                                 char **_dns_domain,
+                                uint32_t *_ttl,
                                 struct fo_server_info **_primary_servers,
                                 size_t *_num_primary_servers,
                                 struct fo_server_info **_backup_servers,
diff --git a/src/providers/ipa/ipa_srv.c b/src/providers/ipa/ipa_srv.c
index 4be5f3317..747771134 100644
--- a/src/providers/ipa/ipa_srv.c
+++ b/src/providers/ipa/ipa_srv.c
@@ -69,6 +69,7 @@ fail:
 
 struct ipa_srv_plugin_state {
     char *dns_domain;
+    uint32_t ttl;
     struct fo_server_info *primary_servers;
     size_t num_primary_servers;
     struct fo_server_info *backup_servers;
@@ -164,6 +165,7 @@ static void ipa_srv_plugin_done(struct tevent_req *subreq)
     state = tevent_req_data(req, struct ipa_srv_plugin_state);
 
     ret = fo_discover_servers_recv(state, subreq, &state->dns_domain,
+                                   &state->ttl,
                                    &state->primary_servers,
                                    &state->num_primary_servers,
                                    &state->backup_servers,
@@ -183,6 +185,7 @@ static void ipa_srv_plugin_done(struct tevent_req *subreq)
 errno_t ipa_srv_plugin_recv(TALLOC_CTX *mem_ctx,
                             struct tevent_req *req,
                             char **_dns_domain,
+                            uint32_t *_ttl,
                             struct fo_server_info **_primary_servers,
                             size_t *_num_primary_servers,
                             struct fo_server_info **_backup_servers,
@@ -213,6 +216,9 @@ errno_t ipa_srv_plugin_recv(TALLOC_CTX *mem_ctx,
         *_dns_domain = talloc_steal(mem_ctx, state->dns_domain);
     }
 
+    if (_ttl) {
+        *_ttl = state->ttl;
+    }
 
     return EOK;
 }
diff --git a/src/providers/ipa/ipa_srv.h b/src/providers/ipa/ipa_srv.h
index 1bfd2eeae..d089c9f64 100644
--- a/src/providers/ipa/ipa_srv.h
+++ b/src/providers/ipa/ipa_srv.h
@@ -39,6 +39,7 @@ struct tevent_req *ipa_srv_plugin_send(TALLOC_CTX *mem_ctx,
 errno_t ipa_srv_plugin_recv(TALLOC_CTX *mem_ctx,
                             struct tevent_req *req,
                             char **_dns_domain,
+                            uint32_t *_ttl,
                             struct fo_server_info **_primary_servers,
                             size_t *_num_primary_servers,
                             struct fo_server_info **_backup_servers,