IFP: Change ifp_list_ctx_remaining_capacity() return type

Now ifp_list_ctx_remaining_capacity() returns an errno_t and receives
the count as an output parameter. It allows better handling and error
reporting in case something goes wrong internally in this function.

Related:
https://pagure.io/SSSD/sssd/issue/3306

Signed-off-by: Fabiano Fidêncio <fidencio@redhat.com>
Reviewed-by: Pavel Březina <pbrezina@redhat.com>

4 files changed, 47 insertions, 15 deletions

diff --git a/src/responder/ifp/ifp_groups.c b/src/responder/ifp/ifp_groups.c
index def241f27..750325423 100644
--- a/src/responder/ifp/ifp_groups.c
+++ b/src/responder/ifp/ifp_groups.c
@@ -87,8 +87,12 @@ static int ifp_groups_list_copy(struct ifp_list_ctx *list_ctx,
                                 struct ldb_result *result)
 {
     size_t copy_count, i;
+    errno_t ret;
 
-    copy_count = ifp_list_ctx_remaining_capacity(list_ctx, result->count);
+    ret = ifp_list_ctx_remaining_capacity(list_ctx, result->count, &copy_count);
+    if (ret != EOK) {
+        goto done;
+    }
 
     for (i = 0; i < copy_count; i++) {
         list_ctx->paths[list_ctx->path_count + i] = \
@@ -96,12 +100,16 @@ static int ifp_groups_list_copy(struct ifp_list_ctx *list_ctx,
                                            list_ctx->dom,
                                            result->msgs[i]);
         if (list_ctx->paths[list_ctx->path_count + i] == NULL) {
-            return ENOMEM;
+            ret = ENOMEM;
+            goto done;
         }
     }
 
     list_ctx->path_count += copy_count;
-    return EOK;
+    ret = EOK;
+
+done:
+    return ret;
 }
 
 static void ifp_groups_find_by_name_done(struct tevent_req *req);
diff --git a/src/responder/ifp/ifp_private.h b/src/responder/ifp/ifp_private.h
index a6e5701b8..ed1b63ad6 100644
--- a/src/responder/ifp/ifp_private.h
+++ b/src/responder/ifp/ifp_private.h
@@ -103,8 +103,9 @@ struct ifp_list_ctx *ifp_list_ctx_new(struct sbus_request *sbus_req,
                                       const char *filter,
                                       uint32_t limit);
 
-size_t ifp_list_ctx_remaining_capacity(struct ifp_list_ctx *list_ctx,
-                                       size_t entries);
+errno_t ifp_list_ctx_remaining_capacity(struct ifp_list_ctx *list_ctx,
+                                        size_t entries,
+                                        size_t *_capacity);
 
 errno_t ifp_ldb_el_output_name(struct resp_ctx *rctx,
                                struct ldb_message *msg,
diff --git a/src/responder/ifp/ifp_users.c b/src/responder/ifp/ifp_users.c
index 90b947ed9..86a1f43a2 100644
--- a/src/responder/ifp/ifp_users.c
+++ b/src/responder/ifp/ifp_users.c
@@ -436,8 +436,12 @@ static int ifp_users_list_copy(struct ifp_list_ctx *list_ctx,
                                struct ldb_result *result)
 {
     size_t copy_count, i;
+    errno_t ret;
 
-    copy_count = ifp_list_ctx_remaining_capacity(list_ctx, result->count);
+    ret = ifp_list_ctx_remaining_capacity(list_ctx, result->count, &copy_count);
+    if (ret != EOK) {
+        goto done;
+    }
 
     for (i = 0; i < copy_count; i++) {
         list_ctx->paths[list_ctx->path_count + i] = \
@@ -445,12 +449,16 @@ static int ifp_users_list_copy(struct ifp_list_ctx *list_ctx,
                                                            list_ctx->dom,
                                                            result->msgs[i]);
         if (list_ctx->paths[list_ctx->path_count + i] == NULL) {
-            return ENOMEM;
+            ret = ENOMEM;
+            goto done;
         }
     }
 
     list_ctx->path_count += copy_count;
-    return EOK;
+    ret = EOK;
+
+done:
+    return ret;
 }
 
 struct name_and_cert_ctx {
@@ -906,7 +914,12 @@ static void ifp_users_list_by_domain_and_name_done(struct tevent_req *req)
         goto done;
     }
 
-    copy_count = ifp_list_ctx_remaining_capacity(list_ctx, result->count);
+    ret = ifp_list_ctx_remaining_capacity(list_ctx, result->count, &copy_count);
+    if (ret != EOK) {
+        error = sbus_error_new(sbus_req, SBUS_ERROR_INTERNAL,
+                               "Failed to get the list remaining capacity\n");
+        goto done;
+    }
 
     for (i = 0; i < copy_count; i++) {
         list_ctx->paths[i] = ifp_users_build_path_from_msg(list_ctx->paths,
diff --git a/src/responder/ifp/ifpsrv_util.c b/src/responder/ifp/ifpsrv_util.c
index 33a49f4b4..6eea3354c 100644
--- a/src/responder/ifp/ifpsrv_util.c
+++ b/src/responder/ifp/ifpsrv_util.c
@@ -381,28 +381,38 @@ struct ifp_list_ctx *ifp_list_ctx_new(struct sbus_request *sbus_req,
     return list_ctx;
 }
 
-size_t ifp_list_ctx_remaining_capacity(struct ifp_list_ctx *list_ctx,
-                                       size_t entries)
+errno_t ifp_list_ctx_remaining_capacity(struct ifp_list_ctx *list_ctx,
+                                        size_t entries,
+                                        size_t *_capacity)
 {
     size_t capacity = list_ctx->limit - list_ctx->path_count;
+    errno_t ret;
 
     if (list_ctx->limit == 0) {
         list_ctx->paths = talloc_zero_array(list_ctx, const char *, entries);
         if (list_ctx->paths == NULL) {
             DEBUG(SSSDBG_CRIT_FAILURE, "talloc_zero_array() failed\n");
-            return 0;
+            ret = ENOMEM;
+            goto done;
         }
-        return entries;
+        capacity = entries;
+        goto immediately;
     }
 
     if (capacity < entries) {
         DEBUG(SSSDBG_MINOR_FAILURE,
               "IFP list request has limit of %"PRIu32" entries but back end "
               "returned %zu entries\n", list_ctx->limit, entries);
-        return capacity;
     } else {
-        return entries;
+        capacity = entries;
     }
+
+immediately:
+    *_capacity = capacity;
+    ret = EOK;
+
+done:
+    return ret;
 }
 
 errno_t ifp_ldb_el_output_name(struct resp_ctx *rctx,