Python-API: Inital commit of Python bindings for the VPP API.

See: https://wiki.fd.io/view/VPP/Python_API

Change-Id: If135fc32208c7031787e1935b399d930e0e1ea1f
Signed-off-by: Ole Troan <ot@cisco.com>

1 files changed, 239 insertions, 0 deletions

diff --git a/vpp-api/python/pneum/pneum.c b/vpp-api/python/pneum/pneum.c
new file mode 100644
index 00000000000..971c79bf6aa
--- /dev/null
+++ b/vpp-api/python/pneum/pneum.c
@@ -0,0 +1,239 @@
+/*
+ * Copyright (c) 2016 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. 
+ */
+#include <stdio.h>
+#include <stdlib.h>
+#include <stddef.h>
+#include <sys/types.h>
+#include <sys/socket.h>
+#include <sys/mman.h>
+#include <sys/stat.h>
+#include <netinet/in.h>
+#include <netdb.h>
+#include <signal.h>
+#include <setjmp.h>
+#include <stdbool.h>
+
+#include <vnet/vnet.h>
+#include <vlib/vlib.h>
+#include <vlib/unix/unix.h>
+#include <vlibapi/api.h>
+#include <vlibmemory/api.h>
+
+#include <api/vpe_msg_enum.h>
+
+#include "pneum.h"
+
+#define vl_typedefs             /* define message structures */
+#include <api/vpe_all_api_h.h> 
+#undef vl_typedefs
+
+#define vl_endianfun             /* define message structures */
+#include <api/vpe_all_api_h.h> 
+#undef vl_endianfun
+
+typedef struct {
+  u8 rx_thread_jmpbuf_valid;
+  u8 connected_to_vlib;
+  jmp_buf rx_thread_jmpbuf;
+  pthread_t rx_thread_handle;
+} pneum_main_t;
+
+pneum_main_t pneum_main;
+
+extern int wrap_pneum_callback(char *data, int len);
+
+/* 
+ * Satisfy external references when -lvlib is not available.
+ */
+void vlib_cli_output (struct vlib_main_t * vm, char * fmt, ...)
+{
+  clib_warning ("vlib_cli_output callled...");
+}
+
+#define vl_api_version(n,v) static u32 vpe_api_version = v;
+#include <api/vpe.api.h>
+#undef vl_api_version
+void
+vl_client_add_api_signatures (vl_api_memclnt_create_t *mp)
+{
+  /*
+   * Send the main API signature in slot 0. This bit of code must
+   * match the checks in ../vpe/api/api.c: vl_msg_api_version_check().
+   */
+  mp->api_versions[0] = clib_host_to_net_u32 (vpe_api_version);
+}
+
+static void
+pneum_api_handler (void *msg)
+{
+  u16 id = ntohs(*((u16 *)msg));
+
+  if (id == VL_API_RX_THREAD_EXIT) {
+    pneum_main_t *pm = &pneum_main;
+    vl_msg_api_free(msg);
+    longjmp(pm->rx_thread_jmpbuf, 1);
+  }
+  msgbuf_t *msgbuf = (msgbuf_t *)(((u8 *)msg) - offsetof(msgbuf_t, data));
+  int l = ntohl(msgbuf->data_len);
+  if (l == 0)
+    clib_warning("Message ID %d has wrong length: %d\n", id, l);
+    
+  /* Call Python callback */
+  (void)wrap_pneum_callback(msg, l);
+  vl_msg_api_free(msg);
+}
+
+static void *
+pneum_rx_thread_fn (void *arg)
+{
+  unix_shared_memory_queue_t *q;
+  pneum_main_t *pm = &pneum_main;
+  api_main_t *am = &api_main;
+  uword msg;
+
+  q = am->vl_input_queue;
+
+  /* So we can make the rx thread terminate cleanly */
+  if (setjmp(pm->rx_thread_jmpbuf) == 0) {
+    pm->rx_thread_jmpbuf_valid = 1;
+    while (1)
+      while (!unix_shared_memory_queue_sub(q, (u8 *)&msg, 0))
+        pneum_api_handler((void *)msg);
+  }
+  pthread_exit(0);
+}
+
+int
+pneum_connect (char *name)
+{
+  int rv = 0;
+  pneum_main_t *pm = &pneum_main;
+
+  /*
+   * Bail out now if we're not running as root
+   */
+  if (geteuid() != 0)
+    return (-1);
+
+  if ((rv = vl_client_api_map("/vpe-api"))) {
+    clib_warning ("vl_client_api map rv %d", rv);
+    return rv;
+  }
+
+  if (vl_client_connect(name, 0, 32) < 0) {
+    vl_client_api_unmap();
+    return (-1);
+  }
+
+  /* Start the rx queue thread */
+  rv = pthread_create(&pm->rx_thread_handle, NULL, pneum_rx_thread_fn, 0);
+  if (rv) {
+    clib_warning("pthread_create returned %d", rv);
+    vl_client_api_unmap();
+    return (-1);
+  }
+
+  pm->connected_to_vlib = 1;
+
+  return (0);
+}
+
+int
+pneum_disconnect (void)
+{
+  api_main_t *am = &api_main;
+  pneum_main_t *pm = &pneum_main;
+
+  fformat (stdout,"disconnecting from vpe \n");
+
+  if (pm->rx_thread_jmpbuf_valid) {
+    vl_api_rx_thread_exit_t *ep;
+    uword junk;
+    ep = vl_msg_api_alloc (sizeof (*ep));
+    ep->_vl_msg_id = ntohs(VL_API_RX_THREAD_EXIT);
+    vl_msg_api_send_shmem(am->vl_input_queue, (u8 *)&ep);
+    pthread_join(pm->rx_thread_handle, (void **) &junk);
+  }
+  if (pm->connected_to_vlib) {
+    vl_client_disconnect();
+    vl_client_api_unmap();
+  }
+  memset (pm, 0, sizeof (*pm));
+
+  return (0);
+}
+
+int
+pneum_read (char **p, int *l)
+{
+  unix_shared_memory_queue_t *q;
+  api_main_t *am = &api_main;
+  uword msg;
+
+  *l = 0;
+
+  if (am->our_pid == 0) return (-1);
+
+  q = am->vl_input_queue;
+  int rv = unix_shared_memory_queue_sub(q, (u8 *)&msg, 0);
+  if (rv == 0) {
+    u16 msg_id = ntohs(*((u16 *)msg));
+    msgbuf_t *msgbuf = (msgbuf_t *)(((u8 *)msg) - offsetof(msgbuf_t, data));
+    *l = ntohl(msgbuf->data_len);
+    if (*l == 0) {
+      printf("Unregistered API message: %d\n", msg_id);
+      return (-1);
+    }
+    *p = (char *)msg;
+  } else {
+    printf("Read failed with %d\n", rv);
+  }  
+  return (rv);
+}
+
+/*
+ * XXX: Makes the assumption that client_index is the first member
+ */
+typedef VL_API_PACKED(struct _vl_api_header {
+  u16 _vl_msg_id;
+  u32 client_index;
+}) vl_api_header_t;
+
+static unsigned int
+pneum_client_index (void)
+{
+  return (api_main.my_client_index);
+}
+
+int
+pneum_write (char *p, int l)
+{
+  int rv = -1;
+  api_main_t *am = &api_main;
+  vl_api_header_t *mp = vl_msg_api_alloc(l);
+  unix_shared_memory_queue_t *q;
+
+  if (!mp) return (-1);
+  memcpy(mp, p, l);
+  mp->client_index = pneum_client_index();
+  q = am->shmem_hdr->vl_input_queue;
+  rv = unix_shared_memory_queue_add(q, (u8 *)&mp, 0);
+  if (rv != 0) {
+    printf("vpe_api_write fails: %d\n", rv);
+    /* Clear message */
+    vl_msg_api_free(mp);
+  }
+  return (rv);
+}