dpif: Add dpif_port_get_name call

Add ability to lookup a device name by its dpif port number.

diff --git a/lib/dpif.c b/lib/dpif.c
index 80f6ed6..4475913 100644 (file)
--- a/lib/dpif.c
+++ b/lib/dpif.c
@@ -352,6 +352,28 @@ dpif_port_query_by_name(const struct dpif *dpif, const char *devname,
     }
 }
 
+/* Looks up port number 'port_no' in 'dpif'.  On success, returns 0 and copies
+ * the port's name into the 'name_size' bytes in 'name', ensuring that the
+ * result is null-terminated.  On failure, returns a positive errno value and
+ * makes 'name' the empty string. */
+int
+dpif_port_get_name(struct dpif *dpif, uint16_t port_no,
+                   char *name, size_t name_size)
+{
+    struct odp_port port;
+    int error;
+
+    assert(name_size > 0);
+
+    error = dpif_port_query_by_number(dpif, port_no, &port);
+    if (!error) {
+        ovs_strlcpy(name, port.devname, name_size);
+    } else {
+        *name = '\0';
+    }
+    return error;
+}
+
 int
 dpif_port_list(const struct dpif *dpif,
                struct odp_port **ports, size_t *n_ports)

diff --git a/lib/dpif.h b/lib/dpif.h
index 1e5412a..f31fb3b 100644 (file)
--- a/lib/dpif.h
+++ b/lib/dpif.h
@@ -62,6 +62,8 @@ int dpif_port_query_by_number(const struct dpif *, uint16_t port_no,
                               struct odp_port *);
 int dpif_port_query_by_name(const struct dpif *, const char *devname,
                             struct odp_port *);
+int dpif_port_get_name(struct dpif *dpif, uint16_t port_no,
+                       char *name, size_t name_size);
 int dpif_port_list(const struct dpif *, struct odp_port **, size_t *n_ports);
 
 int dpif_port_group_set(struct dpif *, uint16_t group,