RESPONDERS: Refactor setent_req_list

Makes the setent_add_ref() and setent_notify_*() functions more generic
to be reusable by the autofs responder.

6 files changed, 133 insertions, 100 deletions

diff --git a/src/responder/common/responder.h b/src/responder/common/responder.h
index 1c85b9d28..0eabe647d 100644
--- a/src/responder/common/responder.h
+++ b/src/responder/common/responder.h
@@ -94,11 +94,6 @@ struct resp_ctx {
     void *pvt_ctx;
 };
 
-/* Needed for the NSS responder */
-struct getent_ref_tracker {
-    void *pvt;
-};
-
 struct cli_ctx {
     struct tevent_context *ev;
     struct resp_ctx *rctx;
@@ -163,6 +158,17 @@ void sss_cmd_done(struct cli_ctx *cctx, void *freectx);
 int sss_cmd_get_version(struct cli_ctx *cctx);
 struct cli_protocol_version *register_cli_protocol_version(void);
 
+struct setent_req_list;
+
+/* A facility for notifying setent requests */
+struct tevent_req *setent_get_req(struct setent_req_list *sl);
+errno_t setent_add_ref(TALLOC_CTX *memctx,
+                       void *pvt,
+                       struct setent_req_list **list,
+                       struct tevent_req *req);
+void setent_notify(struct setent_req_list *list, errno_t err);
+void setent_notify_done(struct setent_req_list *list);
+
 typedef void (*sss_dp_callback_t)(uint16_t err_maj, uint32_t err_min,
                                   const char *err_msg, void *ptr);
 
diff --git a/src/responder/common/responder_cmd.c b/src/responder/common/responder_cmd.c
index bfac8f979..28315e060 100644
--- a/src/responder/common/responder_cmd.c
+++ b/src/responder/common/responder_cmd.c
@@ -155,3 +155,82 @@ int sss_cmd_execute(struct cli_ctx *cctx, struct sss_cmd_table *sss_cmds)
 
     return EINVAL;
 }
+
+struct setent_req_list {
+    struct setent_req_list *prev;
+    struct setent_req_list *next;
+    /* Need to point to the head of the list from a talloc destructor */
+    struct setent_req_list *head;
+
+    void *pvt;
+
+    struct tevent_req *req;
+};
+
+struct tevent_req *
+setent_get_req(struct setent_req_list *sl)
+{
+    return sl->req;
+}
+
+int setent_remove_ref(TALLOC_CTX *ctx)
+{
+    struct setent_req_list *entry =
+            talloc_get_type(ctx, struct setent_req_list);
+    DLIST_REMOVE(entry->head, entry);
+    return 0;
+}
+
+errno_t setent_add_ref(TALLOC_CTX *memctx,
+                       void *pvt,
+                       struct setent_req_list **list,
+                       struct tevent_req *req)
+{
+    struct setent_req_list *entry;
+
+    entry = talloc_zero(memctx, struct setent_req_list);
+    if (!entry) {
+        return ENOMEM;
+    }
+
+    entry->req = req;
+    entry->pvt = pvt;
+    DLIST_ADD_END(*list, entry, struct setent_req_list *);
+    entry->head = *list;
+
+    talloc_set_destructor((TALLOC_CTX *)entry, setent_remove_ref);
+    return EOK;
+}
+
+void setent_notify(struct setent_req_list *list, errno_t err)
+{
+    struct setent_req_list *reql;
+
+    /* Notify the waiting clients */
+    while ((reql = list)) {
+        /* Each tevent_req_done() call will free
+         * the request, removing it from the list.
+         */
+        if (err == EOK) {
+            tevent_req_done(reql->req);
+        } else {
+            tevent_req_error(reql->req, err);
+        }
+
+        if (reql == list) {
+            /* The consumer failed to free the
+             * request. Log a bug and continue.
+             */
+            DEBUG(SSSDBG_FATAL_FAILURE,
+                  ("BUG: a callback did not free its request. "
+                   "May leak memory\n"));
+            /* Skip to the next since a memory leak is non-fatal */
+            list = list->next;
+        }
+    }
+}
+
+void setent_notify_done(struct setent_req_list *list)
+{
+    return setent_notify(list, EOK);
+}
diff --git a/src/responder/nss/nsssrv_cmd.c b/src/responder/nss/nsssrv_cmd.c
index 1dff829ee..43ae947c5 100644
--- a/src/responder/nss/nsssrv_cmd.c
+++ b/src/responder/nss/nsssrv_cmd.c
@@ -77,31 +77,26 @@ int nss_cmd_done(struct nss_cmd_ctx *cmdctx, int ret)
 /***************************
  *  Enumeration procedures *
  ***************************/
-
-errno_t setent_add_ref(TALLOC_CTX *memctx,
-                       struct getent_ctx *getent_ctx,
-                       struct tevent_req *req)
+struct tevent_req *nss_setent_get_req(struct getent_ctx *getent_ctx)
 {
-    struct setent_req_list *entry =
-            talloc_zero(memctx, struct setent_req_list);
-    if (!entry) {
-        return ENOMEM;
-    }
+    return setent_get_req(getent_ctx->reqs);
+}
 
-    entry->req = req;
-    entry->getent_ctx = getent_ctx;
-    DLIST_ADD_END(getent_ctx->reqs, entry, struct setent_req_list *);
+errno_t nss_setent_add_ref(TALLOC_CTX *memctx,
+                           struct getent_ctx *getent_ctx,
+                           struct tevent_req *req)
+{
+    return setent_add_ref(memctx, getent_ctx, &getent_ctx->reqs, req);
+}
 
-    talloc_set_destructor((TALLOC_CTX *)entry, setent_remove_ref);
-    return EOK;
+void nss_setent_notify_error(struct getent_ctx *getent_ctx, errno_t ret)
+{
+    return setent_notify(getent_ctx->reqs, ret);
 }
 
-int setent_remove_ref(TALLOC_CTX *ctx)
+void nss_setent_notify_done(struct getent_ctx *getent_ctx)
 {
-    struct setent_req_list *entry =
-            talloc_get_type(ctx, struct setent_req_list);
-    DLIST_REMOVE(entry->getent_ctx->reqs, entry);
-    return 0;
+    return setent_notify_done(getent_ctx->reqs);
 }
 
 struct setent_ctx {
@@ -1246,7 +1241,7 @@ struct tevent_req *nss_cmd_setpwent_send(TALLOC_CTX *mem_ctx,
              * Register for notification when it's
              * ready.
              */
-            ret = setent_add_ref(state->client, state->nctx->pctx, req);
+            ret = nss_setent_add_ref(state->client, state->nctx->pctx, req);
             if (ret != EOK) {
                 talloc_free(req);
                 return NULL;
@@ -1268,7 +1263,8 @@ struct tevent_req *nss_cmd_setpwent_send(TALLOC_CTX *mem_ctx,
     state->getent_ctx = nctx->pctx;
 
     /* Add a callback reference for ourselves */
-    setent_add_ref(state->client, state->nctx->pctx, req);
+    ret = nss_setent_add_ref(state->client, state->nctx->pctx, req);
+    if (ret) goto error;
 
     /* ok, start the searches */
     step_ctx = talloc_zero(state->getent_ctx, struct setent_step_ctx);
@@ -1323,7 +1319,6 @@ static errno_t nss_cmd_setpwent_step(struct setent_step_ctx *step_ctx)
     struct nss_ctx *nctx = step_ctx->nctx;
     struct sysdb_ctx *sysdb;
     struct ldb_result *res;
-    struct setent_req_list *req;
     struct timeval tv;
     struct tevent_timer *te;
     struct tevent_req *dpreq;
@@ -1434,13 +1429,7 @@ static errno_t nss_cmd_setpwent_step(struct setent_step_ctx *step_ctx)
     }
 
     /* Notify the waiting clients */
-    while (nctx->pctx->reqs) {
-        tevent_req_done(nctx->pctx->reqs->req);
-        /* Freeing each entry in the list removes it from the dlist */
-        req = nctx->pctx->reqs;
-        nctx->pctx->reqs = nctx->pctx->reqs->next;
-        talloc_free(req);
-    }
+    setent_notify_done(nctx->pctx->reqs);
 
     if (step_ctx->returned_to_mainloop) {
         return EAGAIN;
@@ -1470,7 +1459,6 @@ static void nss_cmd_setpwent_dp_callback(uint16_t err_maj, uint32_t err_min,
 {
     struct setent_step_ctx *step_ctx =
             talloc_get_type(ptr, struct setent_step_ctx);
-    struct getent_ctx *pctx = step_ctx->nctx->pctx;
     int ret;
 
     if (err_maj) {
@@ -1483,11 +1471,7 @@ static void nss_cmd_setpwent_dp_callback(uint16_t err_maj, uint32_t err_min,
     ret = nss_cmd_setpwent_step(step_ctx);
     if (ret != EOK && ret != EAGAIN) {
         /* Notify any waiting processes of failure */
-        while(step_ctx->nctx->pctx->reqs) {
-            tevent_req_error(pctx->reqs->req, ret);
-            /* Freeing each entry in the list removes it from the dlist */
-            talloc_free(pctx->reqs);
-        }
+        nss_setent_notify_error(step_ctx->nctx->pctx, ret);
     }
 }
 
@@ -2555,7 +2539,7 @@ struct tevent_req *nss_cmd_setgrent_send(TALLOC_CTX *mem_ctx,
              * Register for notification when it's
              * ready.
              */
-            ret = setent_add_ref(state->client, state->nctx->gctx, req);
+            ret = nss_setent_add_ref(state->client, state->nctx->gctx, req);
             if (ret != EOK) {
                 talloc_free(req);
                 return NULL;
@@ -2577,7 +2561,8 @@ struct tevent_req *nss_cmd_setgrent_send(TALLOC_CTX *mem_ctx,
     state->getent_ctx = nctx->gctx;
 
     /* Add a callback reference for ourselves */
-    setent_add_ref(state->client, state->nctx->gctx, req);
+    ret = nss_setent_add_ref(state->client, state->nctx->gctx, req);
+    if (ret) goto error;
 
     /* ok, start the searches */
     step_ctx = talloc_zero(state->getent_ctx, struct setent_step_ctx);
@@ -2632,7 +2617,6 @@ static errno_t nss_cmd_setgrent_step(struct setent_step_ctx *step_ctx)
     struct nss_ctx *nctx = step_ctx->nctx;
     struct sysdb_ctx *sysdb;
     struct ldb_result *res;
-    struct setent_req_list *req;
     struct timeval tv;
     struct tevent_timer *te;
     struct tevent_req *dpreq;
@@ -2741,13 +2725,7 @@ static errno_t nss_cmd_setgrent_step(struct setent_step_ctx *step_ctx)
     }
 
     /* Notify the waiting clients */
-    while (nctx->gctx->reqs) {
-        tevent_req_done(nctx->gctx->reqs->req);
-        /* Freeing each entry in the list removes it from the dlist */
-        req = nctx->gctx->reqs;
-        nctx->gctx->reqs = nctx->gctx->reqs->next;
-        talloc_free(req);
-    }
+    setent_notify_done(nctx->gctx->reqs);
 
     if (step_ctx->returned_to_mainloop) {
         return EAGAIN;
@@ -2778,7 +2756,6 @@ static void nss_cmd_setgrent_dp_callback(uint16_t err_maj, uint32_t err_min,
 {
     struct setent_step_ctx *step_ctx =
             talloc_get_type(ptr, struct setent_step_ctx);
-    struct getent_ctx *gctx = step_ctx->nctx->gctx;
     int ret;
 
     if (err_maj) {
@@ -2791,11 +2768,7 @@ static void nss_cmd_setgrent_dp_callback(uint16_t err_maj, uint32_t err_min,
     ret = nss_cmd_setgrent_step(step_ctx);
     if (ret != EOK && ret != EAGAIN) {
         /* Notify any waiting processes of failure */
-        while(step_ctx->nctx->gctx->reqs) {
-            tevent_req_error(gctx->reqs->req, ret);
-            /* Freeing each entry in the list removes it from the dlist */
-            talloc_free(gctx->reqs);
-        }
+        nss_setent_notify_error(step_ctx->nctx->gctx, ret);
     }
 }
 
diff --git a/src/responder/nss/nsssrv_netgroup.c b/src/responder/nss/nsssrv_netgroup.c
index 2b9707ab8..9943bca60 100644
--- a/src/responder/nss/nsssrv_netgroup.c
+++ b/src/responder/nss/nsssrv_netgroup.c
@@ -254,7 +254,7 @@ static struct tevent_req *setnetgrent_send(TALLOC_CTX *mem_ctx,
         /* Result object is still being constructed
          * Register for notification when it's ready
          */
-        ret = setent_add_ref(cmdctx->cctx, state->netgr, req);
+        ret = nss_setent_add_ref(cmdctx->cctx, state->netgr, req);
         if (ret != EOK) {
             goto error;
         }
@@ -281,7 +281,7 @@ static struct tevent_req *setnetgrent_send(TALLOC_CTX *mem_ctx,
         state->netgr->lookup_table = nctx->netgroups;
 
         /* Add a reference for ourselves */
-        ret = setent_add_ref(cmdctx->cctx, state->netgr, req);
+        ret = nss_setent_add_ref(cmdctx->cctx, state->netgr, req);
         if (ret != EOK) {
             talloc_free(state->netgr);
             goto error;
@@ -557,15 +557,7 @@ static void lookup_netgr_dp_callback(uint16_t err_maj, uint32_t err_min,
     }
 
     /* We have results to return */
-    while(dctx->netgr->reqs) {
-        if (ret == EOK) {
-            tevent_req_done(dctx->netgr->reqs->req);
-        } else {
-            tevent_req_error(dctx->netgr->reqs->req, ret);
-        }
-        /* Freeing each entry in the list removes it from the dlist */
-        talloc_free(dctx->netgr->reqs);
-    }
+    nss_setent_notify_error(dctx->netgr, ret);
 }
 
 static void setnetgrent_result_timeout(struct tevent_context *ev,
diff --git a/src/responder/nss/nsssrv_private.h b/src/responder/nss/nsssrv_private.h
index 876552fb9..0f581574a 100644
--- a/src/responder/nss/nsssrv_private.h
+++ b/src/responder/nss/nsssrv_private.h
@@ -45,14 +45,6 @@ struct dom_ctx {
     struct ldb_result *res;
 };
 
-struct setent_req_list {
-    struct setent_req_list *prev;
-    struct setent_req_list *next;
-    struct getent_ctx *getent_ctx;
-
-    struct tevent_req *req;
-};
-
 struct getent_ctx {
     struct dom_ctx *doms;
     int num;
@@ -109,10 +101,16 @@ struct setent_step_ctx {
 /* Finish the request */
 int nss_cmd_done(struct nss_cmd_ctx *cmdctx, int ret);
 
-int setent_remove_ref(TALLOC_CTX *ctx);
-errno_t setent_add_ref(TALLOC_CTX *memctx,
-                       struct getent_ctx *getent_ctx,
-                       struct tevent_req *req);
+/* Respond with no entries */
+int fill_empty(struct sss_packet *packet);
+
+errno_t nss_setent_add_ref(TALLOC_CTX *memctx,
+                           struct getent_ctx *getent_ctx,
+                           struct tevent_req *req);
+struct tevent_req *nss_setent_get_req(struct getent_ctx *getent_ctx);
+
+void nss_setent_notify_error(struct getent_ctx *getent_ctx, errno_t ret);
+void nss_setent_notify_done(struct getent_ctx *getent_ctx);
 
 errno_t check_cache(struct nss_dom_ctx *dctx,
                     struct nss_ctx *nctx,
diff --git a/src/responder/nss/nsssrv_services.c b/src/responder/nss/nsssrv_services.c
index da37708b4..3ce3d0902 100644
--- a/src/responder/nss/nsssrv_services.c
+++ b/src/responder/nss/nsssrv_services.c
@@ -1215,7 +1215,7 @@ setservent_send(TALLOC_CTX *mem_ctx, struct cli_ctx *cctx)
              * Register for notification when it's
              * ready.
              */
-            ret = setent_add_ref(state, state->nctx->svcctx, req);
+            ret = nss_setent_add_ref(state, state->nctx->svcctx, req);
             if (ret != EOK) goto immediate;
         }
         return req;
@@ -1252,7 +1252,10 @@ setservent_send(TALLOC_CTX *mem_ctx, struct cli_ctx *cctx)
     }
 
     /* Add a callback reference for ourselves */
-    setent_add_ref(state, state->nctx->svcctx, req);
+    ret = nss_setent_add_ref(state, state->nctx->svcctx, req);
+    if (ret != EOK) {
+        goto immediate;
+    }
 
     /* ok, start the searches */
     step_ctx = talloc_zero(state->getent_ctx, struct setent_step_ctx);
@@ -1510,7 +1513,6 @@ setservent_finalize(struct setent_step_ctx *step_ctx)
     struct resp_ctx *rctx = step_ctx->rctx;
     struct timeval tv;
     struct tevent_timer *te;
-    struct setent_req_list *reql;
 
     /* We've finished all our lookups
      * The result object is now safe to read.
@@ -1530,24 +1532,7 @@ setservent_finalize(struct setent_step_ctx *step_ctx)
                "Entries may become stale.\n"));
     }
 
-    /* Notify the waiting clients */
-    while ((reql = nctx->svcctx->reqs)) {
-        /* Each tevent_req_done() call will free
-         * the request, removing it from the list.
-         */
-        tevent_req_done(reql->req);
-
-        if (reql == nctx->svcctx->reqs) {
-            /* The consumer failed to free the
-             * request. Log a bug and continue.
-             */
-            DEBUG(SSSDBG_FATAL_FAILURE,
-                  ("BUG: a callback did not free its request. "
-                   "May leak memory\n"));
-            /* Skip to the next since a memory leak is non-fatal */
-            nctx->svcctx->reqs = nctx->svcctx->reqs->next;
-        }
-    }
+    nss_setent_notify_done(nctx->svcctx);
 }
 
 static void