UTIL: Add function to parse internal fqname format

Add lightweight function to parse internal fqname format
(shortname@domain). This function does not require the
sss_names to be initialized.

Reviewed-by: Jakub Hrozek <jhrozek@redhat.com>

4 files changed, 64 insertions, 0 deletions

diff --git a/src/util/usertools.c b/src/util/usertools.c
index 18639d9b6..bea7e58a8 100644
--- a/src/util/usertools.c
+++ b/src/util/usertools.c
@@ -716,3 +716,59 @@ errno_t sss_user_by_name_or_uid(const char *input, uid_t *_uid, gid_t *_gid)
     }
     return EOK;
 }
+
+/* Accepts fqname in the format shortname@domname only. */
+errno_t sss_parse_internal_fqname(TALLOC_CTX *mem_ctx,
+                                  const char *fqname,
+                                  char **_shortname,
+                                  char **_dom_name)
+{
+    errno_t ret;
+    char *separator;
+    char *shortname = NULL;
+    char *dom_name = NULL;
+    size_t shortname_len;
+    TALLOC_CTX *tmp_ctx;
+
+    if (fqname == NULL) {
+        return EINVAL;
+    }
+
+    tmp_ctx = talloc_new(NULL);
+    if (tmp_ctx == NULL) {
+        return ENOMEM;
+    }
+
+    separator = strrchr(fqname, '@');
+    if (separator == NULL || *(separator + 1) == '\0' || separator == fqname) {
+        /*The name does not contain name or domain component. */
+        ret = ERR_WRONG_NAME_FORMAT;
+        goto done;
+    }
+
+    if (_dom_name != NULL) {
+        dom_name = talloc_strdup(tmp_ctx, separator + 1);
+        if (dom_name == NULL) {
+            ret = ENOMEM;
+            goto done;
+        }
+
+        *_dom_name = talloc_steal(mem_ctx, dom_name);
+    }
+
+    if (_shortname != NULL) {
+        shortname_len = strlen(fqname) - strlen(separator);
+        shortname = talloc_strndup(tmp_ctx, fqname, shortname_len);
+        if (shortname == NULL) {
+            ret = ENOMEM;
+            goto done;
+        }
+
+        *_shortname = talloc_steal(mem_ctx, shortname);
+    }
+
+    ret = EOK;
+done:
+    talloc_free(tmp_ctx);
+    return ret;
+}
diff --git a/src/util/util.h b/src/util/util.h
index 92076488a..57819cf8a 100644
--- a/src/util/util.h
+++ b/src/util/util.h
@@ -272,6 +272,12 @@ char *
 sss_get_domain_name(TALLOC_CTX *mem_ctx, const char *orig_name,
                     struct sss_domain_info *dom);
 
+/* Accepts fqname in the format shortname@domname only. */
+errno_t sss_parse_internal_fqname(TALLOC_CTX *mem_ctx,
+                                  const char *fqname,
+                                  char **_shortname,
+                                  char **_dom_name);
+
 /* from backup-file.c */
 int backup_file(const char *src, int dbglvl);
 
diff --git a/src/util/util_errors.c b/src/util/util_errors.c
index 522b0f4ff..620be3c0a 100644
--- a/src/util/util_errors.c
+++ b/src/util/util_errors.c
@@ -97,6 +97,7 @@ struct err_string error_to_str[] = {
     { "No timestamp cache record" }, /* ERR_TS_CACHE_MISS */
     { "Dereference threshold reached" }, /* ERR_DEREF_THRESHOLD */
     { "The user is not handled by SSSD" }, /* ERR_NON_SSSD_USER */
+    { "The internal name format cannot be parsed" }, /* ERR_WRONG_NAME_FORMAT */
     { "ERR_LAST" } /* ERR_LAST */
 };
 
diff --git a/src/util/util_errors.h b/src/util/util_errors.h
index 15ec5974b..1f00ba348 100644
--- a/src/util/util_errors.h
+++ b/src/util/util_errors.h
@@ -119,6 +119,7 @@ enum sssd_errors {
     ERR_TS_CACHE_MISS,
     ERR_DEREF_THRESHOLD,
     ERR_NON_SSSD_USER,
+    ERR_WRONG_NAME_FORMAT,
     ERR_LAST            /* ALWAYS LAST */
 };