lib: add and use new yang function for finding schema nodes

Add a wrapper around lys_find_xpath which has an unfortunate API
returning an allocated set of schema nodes when we only ever expect and
want one.

Another libyang function `lys_find_path` returns a single node; however,
that function can assert/abort on invalid path values so is unsuitable
for user input.

Replace previous uses of `lys_find_path` with new API when dealing with
possible invalid path values (i.e., from a user).

Signed-off-by: Christian Hopps <chopps@labn.net>

diff --git a/lib/northbound.c b/lib/northbound.c
index 307cf0fb496abf840e571d2087351424e47c2d11..ba9b6d59b4ac7048b845fcffd8a3eb35a9a0f918 100644 (file)
--- a/lib/northbound.c
+++ b/lib/northbound.c
@@ -167,7 +167,7 @@ struct nb_node *nb_node_find(const char *path)
         * Use libyang to find the schema node associated to the path and get
         * the northbound node from there (snode private pointer).
         */
-       snode = lys_find_path(ly_native_ctx, NULL, path, 0);
+       snode = yang_find_snode(ly_native_ctx, path, 0);
        if (!snode)
                return NULL;
 

diff --git a/lib/yang.c b/lib/yang.c
index 70a3251ab39db4280c8c3a904fac85d7febee71b..4dd8654217183cfcdec1d41abf4c14cb689f2d5c 100644 (file)
--- a/lib/yang.c
+++ b/lib/yang.c
@@ -250,6 +250,23 @@ void yang_snode_get_path(const struct lysc_node *snode,
        }
 }
 
+struct lysc_node *yang_find_snode(struct ly_ctx *ly_ctx, const char *xpath,
+                                 uint32_t options)
+{
+       struct lysc_node *snode;
+       struct ly_set *set;
+       LY_ERR err;
+
+       err = lys_find_xpath(ly_native_ctx, NULL, xpath, options, &set);
+       if (err || !set->count)
+               return NULL;
+
+       snode = set->snodes[0];
+       ly_set_free(set, NULL);
+
+       return snode;
+}
+
 struct lysc_node *yang_snode_real_parent(const struct lysc_node *snode)
 {
        struct lysc_node *parent = snode->parent;

diff --git a/lib/yang.h b/lib/yang.h
index 654c246f0dc99f47e3e0110ad091d628199a832b..37369c09bf81b735603358ed8d95936f7c1a8145 100644 (file)
--- a/lib/yang.h
+++ b/lib/yang.h
@@ -210,6 +210,27 @@ extern void yang_snode_get_path(const struct lysc_node *snode,
                                enum yang_path_type type, char *xpath,
                                size_t xpath_len);
 
+
+/*
+ * Find libyang schema node for the given xpath. Uses `lys_find_xpath`,
+ * returning only the first of a set of nodes -- normally there should only
+ * be one.
+ *
+ * ly_ctx
+ *    libyang context to operate on.
+ *
+ * xpath
+ *    XPath expression (absolute or relative) to find the schema node for.
+ *
+ * options
+ *    Libyang findxpathoptions value (see lys_find_xpath).
+ *
+ * Returns:
+ *    The libyang schema node if found, or NULL if not found.
+ */
+extern struct lysc_node *yang_find_snode(struct ly_ctx *ly_ctx,
+                                        const char *xpath, uint32_t options);
+
 /*
  * Find first parent schema node which is a presence-container or a list
  * (non-presence containers are ignored).

diff --git a/lib/yang_translator.c b/lib/yang_translator.c
index de668230abe63edd868f564d40a541d719bdf811..eae7577a0d1c2c905261a9c211c73deb283f08dc 100644 (file)
--- a/lib/yang_translator.c
+++ b/lib/yang_translator.c
@@ -235,8 +235,8 @@ struct yang_translator *yang_translator_load(const char *path)
                xpath_custom =
                        yang_dnode_get_string(set->dnodes[i], "./custom");
 
-               snode_custom = lys_find_path(translator->ly_ctx, NULL,
-                                            xpath_custom, 0);
+               snode_custom =
+                       yang_find_snode(translator->ly_ctx, xpath_custom, 0);
                if (!snode_custom) {
                        flog_warn(EC_LIB_YANG_TRANSLATOR_LOAD,
                                  "%s: unknown data path: %s", __func__,
@@ -247,8 +247,7 @@ struct yang_translator *yang_translator_load(const char *path)
 
                xpath_native =
                        yang_dnode_get_string(set->dnodes[i], "./native");
-               snode_native =
-                       lys_find_path(ly_native_ctx, NULL, xpath_native, 0);
+               snode_native = yang_find_snode(ly_native_ctx, xpath_native, 0);
                if (!snode_native) {
                        flog_warn(EC_LIB_YANG_TRANSLATOR_LOAD,
                                  "%s: unknown data path: %s", __func__,
@@ -315,7 +314,7 @@ yang_translate_xpath(const struct yang_translator *translator, int dir,
        else
                ly_ctx = ly_native_ctx;
 
-       snode = lys_find_path(ly_ctx, NULL, xpath, 0);
+       snode = yang_find_snode(ly_ctx, xpath, 0);
        if (!snode) {
                flog_warn(EC_LIB_YANG_TRANSLATION_ERROR,
                          "%s: unknown data path: %s", __func__, xpath);

diff --git a/lib/yang_wrappers.c b/lib/yang_wrappers.c
index 509c4dd8560cbfa41dcd9cc603fdbc13f612935e..dc049a374a9e47ad19ec19e917f61af27d45c64e 100644 (file)
--- a/lib/yang_wrappers.c
+++ b/lib/yang_wrappers.c
@@ -89,7 +89,7 @@ static const char *yang_get_default_value(const char *xpath)
        const struct lysc_node *snode;
        const char *value;
 
-       snode = lys_find_path(ly_native_ctx, NULL, xpath, 0);
+       snode = yang_find_snode(ly_native_ctx, xpath, 0);
        if (snode == NULL) {
                flog_err(EC_LIB_YANG_UNKNOWN_DATA_PATH,
                         "%s: unknown data path: %s", __func__, xpath);
@@ -206,7 +206,7 @@ int yang_str2enum(const char *xpath, const char *value)
        const struct lysc_type_enum *type;
        const struct lysc_type_bitenum_item *enums;
 
-       snode = lys_find_path(ly_native_ctx, NULL, xpath, 0);
+       snode = yang_find_snode(ly_native_ctx, xpath, 0);
        if (snode == NULL) {
                flog_err(EC_LIB_YANG_UNKNOWN_DATA_PATH,
                         "%s: unknown data path: %s", __func__, xpath);
@@ -241,7 +241,7 @@ struct yang_data *yang_data_new_enum(const char *xpath, int value)
        const struct lysc_type_enum *type;
        const struct lysc_type_bitenum_item *enums;
 
-       snode = lys_find_path(ly_native_ctx, NULL, xpath, 0);
+       snode = yang_find_snode(ly_native_ctx, xpath, 0);
        if (snode == NULL) {
                flog_err(EC_LIB_YANG_UNKNOWN_DATA_PATH,
                         "%s: unknown data path: %s", __func__, xpath);