Add new C API

Change-Id: I717ce3cd7c867c155de149ec56623269d26d0ff7
Signed-off-by: Klement Sekera <ksekera@cisco.com>

1 files changed, 285 insertions, 0 deletions

diff --git a/src/vpp-api/vapi/vapi.h b/src/vpp-api/vapi/vapi.h
new file mode 100644
index 00000000000..1e1d567a0db
--- /dev/null
+++ b/src/vpp-api/vapi/vapi.h
@@ -0,0 +1,285 @@
+/*
+ *------------------------------------------------------------------
+ * Copyright (c) 2017 Cisco and/or its affiliates.
+ * Licensed under the Apache License, Version 2.0 (the "License");
+ * you may not use this file except in compliance with the License.
+ * You may obtain a copy of the License at:
+ *
+ *     http://www.apache.org/licenses/LICENSE-2.0
+ *
+ * Unless required by applicable law or agreed to in writing, software
+ * distributed under the License is distributed on an "AS IS" BASIS,
+ * WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
+ * See the License for the specific language governing permissions and
+ * limitations under the License.
+ *------------------------------------------------------------------
+ */
+
+#ifndef vpp_api_h_included
+#define vpp_api_h_included
+
+#include <string.h>
+#include <stdbool.h>
+#include <vppinfra/types.h>
+
+/**
+ * @file vapi.h
+ *
+ * common vpp api C declarations
+ *
+ * This file declares the common C API functions. These include connect,
+ * disconnect and utility functions as well as the low-level vapi_send and
+ * vapi_recv API. This is only the transport layer.
+ *
+ * Message formats and higher-level APIs are generated by running the
+ * vapi_c_gen.py script (which is run for in-tree APIs as part of the build
+ * process). It's not recommended to mix the higher and lower level APIs. Due
+ * to version issues, the higher-level APIs are not part of the shared library.
+ */
+
+typedef enum
+{
+  VAPI_OK = 0,	      /**< success */
+  VAPI_EINVAL,	      /**< invalid value encountered */
+  VAPI_EAGAIN,	      /**< operation would block */
+  VAPI_ENOTSUP,	      /**< operation not supported */
+  VAPI_ENOMEM,	      /**< out of memory */
+  VAPI_ENORESP,	      /**< no response to request */
+  VAPI_EMAP_FAIL,     /**< failure while mapping api */
+  VAPI_ECON_FAIL,     /**< failure while connecting to vpp */
+  VAPI_EINCOMPATIBLE, /**< fundamental incompatibility while connecting to vpp
+                           (control ping/control ping reply mismatch) */
+  VAPI_MUTEX_FAILURE, /**< failure manipulating internal mutex(es) */
+  VAPI_EUSER,	      /**< user error used for breaking dispatch,
+                           never used by VAPI */
+} vapi_error_e;
+
+typedef enum
+{
+  VAPI_MODE_BLOCKING = 1,    /**< operations block until response received */
+  VAPI_MODE_NONBLOCKING = 2, /**< operations never block */
+} vapi_mode_e;
+
+typedef enum
+{
+  VAPI_WAIT_FOR_READ,	    /**< wait until a message can be read */
+  VAPI_WAIT_FOR_WRITE,	    /**< wait until a message can be written */
+  VAPI_WAIT_FOR_READ_WRITE, /**< wait until a read or write can be done */
+} vapi_wait_mode_e;
+
+typedef int vapi_msg_id_t;
+typedef struct vapi_ctx_s *vapi_ctx_t;
+
+/**
+ * @brief allocate vapi message of given size
+ *
+ * @note message must be freed by vapi_msg_free if not consumed by vapi_send
+ * call
+ *
+ * @param ctx opaque vapi context
+ *
+ * @return pointer to message or NULL if out of memory
+ */
+void *vapi_msg_alloc (vapi_ctx_t ctx, size_t size);
+
+/**
+ * @brief free a vapi message
+ *
+ * @note messages received by vapi_recv must be freed when no longer needed
+ *
+ * @param ctx opaque vapi context
+ * @param msg message to be freed
+ */
+void vapi_msg_free (vapi_ctx_t ctx, void *msg);
+
+/**
+ * @brief allocate vapi context
+ *
+ * @param[out] pointer to result variable
+ *
+ * @return VAPI_OK on success, other error code on error
+ */
+vapi_error_e vapi_ctx_alloc (vapi_ctx_t * result);
+
+/**
+ * @brief free vapi context
+ */
+void vapi_ctx_free (vapi_ctx_t ctx);
+
+/**
+ * @brief check if message identified by it's message id is known by the vpp to
+ * which the connection is open
+ */
+bool vapi_is_msg_available (vapi_ctx_t ctx, vapi_msg_id_t type);
+
+/**
+ * @brief connect to vpp
+ *
+ * @param ctx opaque vapi context, must be allocated using vapi_ctx_alloc first
+ * @param name application name
+ * @param chroot_prefix shared memory prefix
+ * @param max_outstanding_requests max number of outstanding requests queued
+ * @param response_queue_size size of the response queue
+ * @param mode mode of operation - blocking or nonblocking
+ *
+ * @return VAPI_OK on success, other error code on error
+ */
+vapi_error_e vapi_connect (vapi_ctx_t ctx, const char *name,
+			   const char *chroot_prefix,
+			   int max_outstanding_requests,
+			   int response_queue_size, vapi_mode_e mode);
+
+/**
+ * @brief disconnect from vpp
+ *
+ * @param ctx opaque vapi context
+ *
+ * @return VAPI_OK on success, other error code on error
+ */
+vapi_error_e vapi_disconnect (vapi_ctx_t ctx);
+
+/**
+ * @brief get event file descriptor
+ *
+ * @note this file descriptor becomes readable when messages (from vpp)
+ * are waiting in queue
+ *
+ * @param ctx opaque vapi context
+ * @param[out] fd pointer to result variable
+ *
+ * @return VAPI_OK on success, other error code on error
+ */
+vapi_error_e vapi_get_fd (vapi_ctx_t ctx, int *fd);
+
+/**
+ * @brief low-level api for sending messages to vpp
+ *
+ * @note it is not recommended to use this api directly, use generated api
+ * instead
+ *
+ * @param ctx opaque vapi context
+ * @param msg message to send
+ *
+ * @return VAPI_OK on success, other error code on error
+ */
+vapi_error_e vapi_send (vapi_ctx_t ctx, void *msg);
+
+/**
+ * @brief low-level api for atomically sending two messages to vpp - either
+ * both messages are sent or neither one is
+ *
+ * @note it is not recommended to use this api directly, use generated api
+ * instead
+ *
+ * @param ctx opaque vapi context
+ * @param msg1 first message to send
+ * @param msg2 second message to send
+ *
+ * @return VAPI_OK on success, other error code on error
+ */
+vapi_error_e vapi_send2 (vapi_ctx_t ctx, void *msg1, void *msg2);
+
+/**
+ * @brief low-level api for reading messages from vpp
+ *
+ * @note it is not recommended to use this api directly, use generated api
+ * instead
+ *
+ * @param ctx opaque vapi context
+ * @param[out] msg pointer to result variable containing message
+ * @param[out] msg_size pointer to result variable containing message size
+ *
+ * @return VAPI_OK on success, other error code on error
+ */
+vapi_error_e vapi_recv (vapi_ctx_t ctx, void **msg, size_t * msg_size);
+
+/**
+ * @brief wait for connection to become readable or writable
+ *
+ * @param ctx opaque vapi context
+ * @param mode type of property to wait for - readability, writability or both
+ *
+ * @return VAPI_OK on success, other error code on error
+ */
+vapi_error_e vapi_wait (vapi_ctx_t ctx, vapi_wait_mode_e mode);
+
+/**
+ * @brief pick next message sent by vpp and call the appropriate callback
+ *
+ * @return VAPI_OK on success, other error code on error
+ */
+vapi_error_e vapi_dispatch_one (vapi_ctx_t ctx);
+
+/**
+ * @brief loop vapi_dispatch_one until responses to all currently outstanding
+ * requests have been received and their callbacks called
+ *
+ * @note the dispatch loop is interrupted if any error is encountered or
+ * returned from the callback, in which case this error is returned as the
+ * result of vapi_dispatch. In this case it might be necessary to call dispatch
+ * again to process the remaining messages. Returning VAPI_EUSER from
+ * a callback allows the user to break the dispatch loop (and distinguish
+ * this case in the calling code from other failures). VAPI never returns
+ * VAPI_EUSER on its own.
+ *
+ * @return VAPI_OK on success, other error code on error
+ */
+vapi_error_e vapi_dispatch (vapi_ctx_t ctx);
+
+/** generic vapi event callback */
+typedef vapi_error_e (*vapi_event_cb) (vapi_ctx_t ctx, void *callback_ctx,
+				       void *payload);
+
+/**
+ * @brief set event callback to call when message with given id is dispatched
+ *
+ * @param ctx opaque vapi context
+ * @param id message id
+ * @param callback callback
+ * @param callback_ctx context pointer stored and passed to callback
+ */
+void vapi_set_event_cb (vapi_ctx_t ctx, vapi_msg_id_t id,
+			vapi_event_cb callback, void *callback_ctx);
+
+/**
+ * @brief clear event callback for given message id
+ *
+ * @param ctx opaque vapi context
+ * @param id message id
+ */
+void vapi_clear_event_cb (vapi_ctx_t ctx, vapi_msg_id_t id);
+
+/** generic vapi event callback */
+typedef vapi_error_e (*vapi_generic_event_cb) (vapi_ctx_t ctx,
+					       void *callback_ctx,
+					       vapi_msg_id_t id, void *msg);
+/**
+ * @brief set generic event callback
+ *
+ * @note this callback is called by dispatch if no message-type specific
+ * callback is set (so it's a fallback callback)
+ *
+ * @param ctx opaque vapi context
+ * @param callback callback
+ * @param callback_ctx context pointer stored and passed to callback
+ */
+void vapi_set_generic_event_cb (vapi_ctx_t ctx,
+				vapi_generic_event_cb callback,
+				void *callback_ctx);
+
+/**
+ * @brief clear generic event callback
+ *
+ * @param ctx opaque vapi context
+ */
+void vapi_clear_generic_event_cb (vapi_ctx_t ctx);
+
+#endif
+
+/*
+ * fd.io coding-style-patch-verification: ON
+ *
+ * Local Variables:
+ * eval: (c-set-style "gnu")
+ * End:
+ */