Change the way domains are linked.

- Use a double-linked list for domains and subdomains.
- Never remove a subdomain, simply mark it as disabled if it becomes
  unused.
- Rework the way subdomains are refreshed.
  Now sysdb_update_subdomains() actually updates the current subdomains
  and marks as disabled the ones not found in the sysdb or add new ones
  found. It never removes them.
  Removal of missing domains from sysdb is deferred to the providers,
  which will perform it at refresh time, for the ipa provider that is
  done by ipa_subdomains_write_mappings() now.
  sysdb_update_subdomains() is then used to update the memory hierarchy
  of the subdomains.

- Removes sysdb_get_subdomains()
- Removes copy_subdomain()
- Add sysdb_subdomain_delete()

3 files changed, 33 insertions, 26 deletions

diff --git a/src/util/domain_info_utils.c b/src/util/domain_info_utils.c
index 59d5c534b..6db7e157a 100644
--- a/src/util/domain_info_utils.c
+++ b/src/util/domain_info_utils.c
@@ -29,8 +29,8 @@ struct sss_domain_info *get_next_domain(struct sss_domain_info *domain,
 
     dom = domain;
     while (dom) {
-        if (descend && dom->subdomain_count > 0) {
-            dom = dom->subdomains[0];
+        if (descend && dom->subdomains) {
+            dom = dom->subdomains;
         } else if (dom->next) {
             dom = dom->next;
         } else if (descend && dom->parent) {
@@ -44,6 +44,27 @@ struct sss_domain_info *get_next_domain(struct sss_domain_info *domain,
     return dom;
 }
 
+struct sss_domain_info *find_subdomain_by_name(struct sss_domain_info *domain,
+                                               const char *name,
+                                               bool match_any)
+{
+    struct sss_domain_info *dom = domain;
+
+    while (dom && dom->disabled) {
+        dom = get_next_domain(dom, true);
+    }
+    while (dom) {
+        if (strcasecmp(dom->name, name) == 0 ||
+            ((match_any == true) && (dom->flat_name != NULL) &&
+             (strcasecmp(dom->flat_name, name) == 0))) {
+            return dom;
+        }
+        dom = get_next_domain(dom, true);
+    }
+
+    return NULL;
+}
+
 struct sss_domain_info *new_subdomain(TALLOC_CTX *mem_ctx,
                                       struct sss_domain_info *parent,
                                       const char *name,
@@ -136,14 +157,6 @@ fail:
     return NULL;
 }
 
-struct sss_domain_info *copy_subdomain(TALLOC_CTX *mem_ctx,
-                                       struct sss_domain_info *subdomain)
-{
-    return new_subdomain(mem_ctx, subdomain->parent,
-                         subdomain->name, subdomain->realm,
-                         subdomain->flat_name, subdomain->domain_id);
-}
-
 errno_t sssd_domain_init(TALLOC_CTX *mem_ctx,
                          struct confdb_ctx *cdb,
                          const char *domain_name,
diff --git a/src/util/usertools.c b/src/util/usertools.c
index 33a2a7bd5..587fd9cbf 100644
--- a/src/util/usertools.c
+++ b/src/util/usertools.c
@@ -298,24 +298,16 @@ int sss_parse_name(TALLOC_CTX *memctx,
     return EOK;
 }
 
-static struct sss_domain_info * match_any_domain_or_subdomain_name (
-        struct sss_domain_info *dom, const char *dmatch)
+static struct sss_domain_info * match_any_domain_or_subdomain_name(
+                                                struct sss_domain_info *dom,
+                                                const char *dmatch)
 {
-    uint32_t i;
-
-    if (strcasecmp (dom->name, dmatch) == 0 ||
-        (dom->flat_name != NULL && strcasecmp(dom->flat_name, dmatch) == 0))
+    if (strcasecmp(dom->name, dmatch) == 0 ||
+        (dom->flat_name != NULL && strcasecmp(dom->flat_name, dmatch) == 0)) {
         return dom;
-
-    for (i = 0; i < dom->subdomain_count; i++) {
-        if (strcasecmp(dom->subdomains[i]->name, dmatch) == 0 ||
-            (dom->subdomains[i]->flat_name != NULL &&
-             strcasecmp(dom->subdomains[i]->flat_name, dmatch) == 0)) {
-            return dom->subdomains[i];
-        }
     }
 
-    return NULL;
+    return find_subdomain_by_name(dom, dmatch, true);
 }
 
 int sss_parse_name_for_domains(TALLOC_CTX *memctx,
diff --git a/src/util/util.h b/src/util/util.h
index de212811f..7697dbb51 100644
--- a/src/util/util.h
+++ b/src/util/util.h
@@ -568,14 +568,16 @@ void to_sized_string(struct sized_string *out, const char *in);
 /* form domain_info.c */
 struct sss_domain_info *get_next_domain(struct sss_domain_info *domain,
                                         bool descend);
+struct sss_domain_info *find_subdomain_by_name(struct sss_domain_info *domain,
+                                               const char *name,
+                                               bool match_any);
+
 struct sss_domain_info *new_subdomain(TALLOC_CTX *mem_ctx,
                                       struct sss_domain_info *parent,
                                       const char *name,
                                       const char *realm,
                                       const char *flat_name,
                                       const char *id);
-struct sss_domain_info *copy_subdomain(TALLOC_CTX *mem_ctx,
-                                       struct sss_domain_info *subdomain);
 
 errno_t sssd_domain_init(TALLOC_CTX *mem_ctx,
                          struct confdb_ctx *cdb,