misc: move osi to plugin

Type: refactor

This patch moves osi into a plugin, and also modifies
the init functions of llc and snap to preserve init
order dependency (llc_init --> osi_init --> snap_init).

While the initial intent was to move osi/llc/snap together
into a single plugin, there exists a dependency on llc
in vnet/ethernet, which would require further refactoring
and testing work.

Change-Id: Ic0eff030ee29c8d316c0e0fe13931451aa193527
Signed-off-by: Hadi Rayan Al-Sandid <halsandi@cisco.com>

7 files changed, 854 insertions, 0 deletions

diff --git a/src/plugins/osi/CMakeLists.txt b/src/plugins/osi/CMakeLists.txt
new file mode 100644
index 00000000000..8ab014770ea
--- /dev/null
+++ b/src/plugins/osi/CMakeLists.txt
@@ -0,0 +1,24 @@
+# Copyright (c) 2023 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.
+
+add_vpp_plugin(osi
+
+  SOURCES
+  osi.c
+  node.c
+  pg.c
+  plugin.c
+
+  INSTALL_HEADERS
+  osi.h
+)
diff --git a/src/plugins/osi/FEATURE.yaml b/src/plugins/osi/FEATURE.yaml
new file mode 100644
index 00000000000..337be1c7146
--- /dev/null
+++ b/src/plugins/osi/FEATURE.yaml
@@ -0,0 +1,11 @@
+---
+name: OSI plugin
+maintainer:
+  - community <vpp-dev@lists.fd.io>
+features:
+  - Adds support for OSI protocols (SAP types)
+  - Registered as input protocol for PPP, HDLC, and LLC
+missing:
+  - No tests for this feature currently exist
+description: ""
+state: experimental
diff --git a/src/plugins/osi/node.c b/src/plugins/osi/node.c
new file mode 100644
index 00000000000..a36b1525e0e
--- /dev/null
+++ b/src/plugins/osi/node.c
@@ -0,0 +1,335 @@
+/*
+ * Copyright (c) 2015 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.
+ */
+/*
+ * osi_node.c: osi packet processing
+ *
+ * Copyright (c) 2010 Eliot Dresselhaus
+ *
+ * Permission is hereby granted, free of charge, to any person obtaining
+ * a copy of this software and associated documentation files (the
+ * "Software"), to deal in the Software without restriction, including
+ * without limitation the rights to use, copy, modify, merge, publish,
+ * distribute, sublicense, and/or sell copies of the Software, and to
+ * permit persons to whom the Software is furnished to do so, subject to
+ * the following conditions:
+ *
+ * The above copyright notice and this permission notice shall be
+ * included in all copies or substantial portions of the Software.
+ *
+ *  THE SOFTWARE IS PROVIDED "AS IS", WITHOUT WARRANTY OF ANY KIND,
+ *  EXPRESS OR IMPLIED, INCLUDING BUT NOT LIMITED TO THE WARRANTIES OF
+ *  MERCHANTABILITY, FITNESS FOR A PARTICULAR PURPOSE AND
+ *  NONINFRINGEMENT. IN NO EVENT SHALL THE AUTHORS OR COPYRIGHT HOLDERS BE
+ *  LIABLE FOR ANY CLAIM, DAMAGES OR OTHER LIABILITY, WHETHER IN AN ACTION
+ *  OF CONTRACT, TORT OR OTHERWISE, ARISING FROM, OUT OF OR IN CONNECTION
+ *  WITH THE SOFTWARE OR THE USE OR OTHER DEALINGS IN THE SOFTWARE.
+ */
+
+#include <vlib/vlib.h>
+#include <vnet/pg/pg.h>
+#include <osi/osi.h>
+#include <vnet/ppp/ppp.h>
+#include <vnet/hdlc/hdlc.h>
+#include <vnet/llc/llc.h>
+
+#define foreach_osi_input_next			\
+  _ (PUNT, "error-punt")			\
+  _ (DROP, "error-drop")
+
+typedef enum
+{
+#define _(s,n) OSI_INPUT_NEXT_##s,
+  foreach_osi_input_next
+#undef _
+    OSI_INPUT_N_NEXT,
+} osi_input_next_t;
+
+typedef struct
+{
+  u8 packet_data[32];
+} osi_input_trace_t;
+
+static u8 *
+format_osi_input_trace (u8 * s, va_list * va)
+{
+  CLIB_UNUSED (vlib_main_t * vm) = va_arg (*va, vlib_main_t *);
+  CLIB_UNUSED (vlib_node_t * node) = va_arg (*va, vlib_node_t *);
+  osi_input_trace_t *t = va_arg (*va, osi_input_trace_t *);
+
+  s = format (s, "%U", format_osi_header, t->packet_data);
+
+  return s;
+}
+
+static uword
+osi_input (vlib_main_t * vm,
+	   vlib_node_runtime_t * node, vlib_frame_t * from_frame)
+{
+  osi_main_t *lm = &osi_main;
+  u32 n_left_from, next_index, *from, *to_next;
+
+  from = vlib_frame_vector_args (from_frame);
+  n_left_from = from_frame->n_vectors;
+
+  if (node->flags & VLIB_NODE_FLAG_TRACE)
+    vlib_trace_frame_buffers_only (vm, node,
+				   from,
+				   n_left_from,
+				   sizeof (from[0]),
+				   sizeof (osi_input_trace_t));
+
+  next_index = node->cached_next_index;
+
+  while (n_left_from > 0)
+    {
+      u32 n_left_to_next;
+
+      vlib_get_next_frame (vm, node, next_index, to_next, n_left_to_next);
+
+      while (n_left_from >= 4 && n_left_to_next >= 2)
+	{
+	  u32 bi0, bi1;
+	  vlib_buffer_t *b0, *b1;
+	  osi_header_t *h0, *h1;
+	  u8 next0, next1, enqueue_code;
+
+	  /* Prefetch next iteration. */
+	  {
+	    vlib_buffer_t *b2, *b3;
+
+	    b2 = vlib_get_buffer (vm, from[2]);
+	    b3 = vlib_get_buffer (vm, from[3]);
+
+	    vlib_prefetch_buffer_header (b2, LOAD);
+	    vlib_prefetch_buffer_header (b3, LOAD);
+
+	    CLIB_PREFETCH (b2->data, sizeof (h0[0]), LOAD);
+	    CLIB_PREFETCH (b3->data, sizeof (h1[0]), LOAD);
+	  }
+
+	  bi0 = from[0];
+	  bi1 = from[1];
+	  to_next[0] = bi0;
+	  to_next[1] = bi1;
+	  from += 2;
+	  to_next += 2;
+	  n_left_to_next -= 2;
+	  n_left_from -= 2;
+
+	  b0 = vlib_get_buffer (vm, bi0);
+	  b1 = vlib_get_buffer (vm, bi1);
+
+	  h0 = vlib_buffer_get_current (b0);
+	  h1 = vlib_buffer_get_current (b1);
+
+	  next0 = lm->input_next_by_protocol[h0->protocol];
+	  next1 = lm->input_next_by_protocol[h1->protocol];
+
+	  b0->error =
+	    node->errors[next0 ==
+			 OSI_INPUT_NEXT_DROP ? OSI_ERROR_UNKNOWN_PROTOCOL :
+			 OSI_ERROR_NONE];
+	  b1->error =
+	    node->errors[next1 ==
+			 OSI_INPUT_NEXT_DROP ? OSI_ERROR_UNKNOWN_PROTOCOL :
+			 OSI_ERROR_NONE];
+
+	  enqueue_code = (next0 != next_index) + 2 * (next1 != next_index);
+
+	  if (PREDICT_FALSE (enqueue_code != 0))
+	    {
+	      switch (enqueue_code)
+		{
+		case 1:
+		  /* A B A */
+		  to_next[-2] = bi1;
+		  to_next -= 1;
+		  n_left_to_next += 1;
+		  vlib_set_next_frame_buffer (vm, node, next0, bi0);
+		  break;
+
+		case 2:
+		  /* A A B */
+		  to_next -= 1;
+		  n_left_to_next += 1;
+		  vlib_set_next_frame_buffer (vm, node, next1, bi1);
+		  break;
+
+		case 3:
+		  /* A B B or A B C */
+		  to_next -= 2;
+		  n_left_to_next += 2;
+		  vlib_set_next_frame_buffer (vm, node, next0, bi0);
+		  vlib_set_next_frame_buffer (vm, node, next1, bi1);
+		  if (next0 == next1)
+		    {
+		      vlib_put_next_frame (vm, node, next_index,
+					   n_left_to_next);
+		      next_index = next1;
+		      vlib_get_next_frame (vm, node, next_index, to_next,
+					   n_left_to_next);
+		    }
+		}
+	    }
+	}
+
+      while (n_left_from > 0 && n_left_to_next > 0)
+	{
+	  u32 bi0;
+	  vlib_buffer_t *b0;
+	  osi_header_t *h0;
+	  u8 next0;
+
+	  bi0 = from[0];
+	  to_next[0] = bi0;
+	  from += 1;
+	  to_next += 1;
+	  n_left_from -= 1;
+	  n_left_to_next -= 1;
+
+	  b0 = vlib_get_buffer (vm, bi0);
+
+	  h0 = vlib_buffer_get_current (b0);
+
+	  next0 = lm->input_next_by_protocol[h0->protocol];
+
+	  b0->error =
+	    node->errors[next0 ==
+			 OSI_INPUT_NEXT_DROP ? OSI_ERROR_UNKNOWN_PROTOCOL :
+			 OSI_ERROR_NONE];
+
+	  /* Sent packet to wrong next? */
+	  if (PREDICT_FALSE (next0 != next_index))
+	    {
+	      /* Return old frame; remove incorrectly enqueued packet. */
+	      vlib_put_next_frame (vm, node, next_index, n_left_to_next + 1);
+
+	      /* Send to correct next. */
+	      next_index = next0;
+	      vlib_get_next_frame (vm, node, next_index, to_next,
+				   n_left_to_next);
+
+	      to_next[0] = bi0;
+	      to_next += 1;
+	      n_left_to_next -= 1;
+	    }
+	}
+
+      vlib_put_next_frame (vm, node, next_index, n_left_to_next);
+    }
+
+  return from_frame->n_vectors;
+}
+
+static char *osi_error_strings[] = {
+#define _(f,s) s,
+  foreach_osi_error
+#undef _
+};
+
+VLIB_REGISTER_NODE (osi_input_node) = {
+  .function = osi_input,
+  .name = "osi-input",
+  /* Takes a vector of packets. */
+  .vector_size = sizeof (u32),
+
+  .n_errors = OSI_N_ERROR,
+  .error_strings = osi_error_strings,
+
+  .n_next_nodes = OSI_INPUT_N_NEXT,
+  .next_nodes = {
+#define _(s,n) [OSI_INPUT_NEXT_##s] = n,
+    foreach_osi_input_next
+#undef _
+  },
+
+  .format_buffer = format_osi_header_with_length,
+  .format_trace = format_osi_input_trace,
+  .unformat_buffer = unformat_osi_header,
+};
+
+static void
+osi_setup_node (vlib_main_t *vm, u32 node_index)
+{
+  vlib_node_t *n = vlib_get_node (vm, node_index);
+  pg_node_t *pn = pg_get_node (node_index);
+
+  n->format_buffer = format_osi_header_with_length;
+  n->unformat_buffer = unformat_osi_header;
+  pn->unformat_edit = unformat_pg_osi_header;
+}
+
+static clib_error_t *
+osi_input_init (vlib_main_t * vm)
+{
+  clib_error_t *error = 0;
+  osi_main_t *lm = &osi_main;
+
+  if ((error = vlib_call_init_function (vm, osi_init)))
+    return error;
+
+  osi_setup_node (vm, osi_input_node.index);
+
+  {
+    int i;
+    for (i = 0; i < ARRAY_LEN (lm->input_next_by_protocol); i++)
+      lm->input_next_by_protocol[i] = OSI_INPUT_NEXT_DROP;
+  }
+
+  ppp_register_input_protocol (vm, PPP_PROTOCOL_osi, osi_input_node.index);
+  hdlc_register_input_protocol (vm, HDLC_PROTOCOL_osi, osi_input_node.index);
+  llc_register_input_protocol (vm, LLC_PROTOCOL_osi_layer1,
+			       osi_input_node.index);
+  llc_register_input_protocol (vm, LLC_PROTOCOL_osi_layer2,
+			       osi_input_node.index);
+  llc_register_input_protocol (vm, LLC_PROTOCOL_osi_layer3,
+			       osi_input_node.index);
+  llc_register_input_protocol (vm, LLC_PROTOCOL_osi_layer4,
+			       osi_input_node.index);
+  llc_register_input_protocol (vm, LLC_PROTOCOL_osi_layer5,
+			       osi_input_node.index);
+
+  return 0;
+}
+
+VLIB_INIT_FUNCTION (osi_input_init);
+
+void
+osi_register_input_protocol (osi_protocol_t protocol, u32 node_index)
+{
+  osi_main_t *lm = &osi_main;
+  vlib_main_t *vm = lm->vlib_main;
+  osi_protocol_info_t *pi;
+
+  {
+    clib_error_t *error = vlib_call_init_function (vm, osi_input_init);
+    if (error)
+      clib_error_report (error);
+  }
+
+  pi = osi_get_protocol_info (lm, protocol);
+  pi->node_index = node_index;
+  pi->next_index = vlib_node_add_next (vm, osi_input_node.index, node_index);
+
+  lm->input_next_by_protocol[protocol] = pi->next_index;
+}
+
+/*
+ * fd.io coding-style-patch-verification: ON
+ *
+ * Local Variables:
+ * eval: (c-set-style "gnu")
+ * End:
+ */
diff --git a/src/plugins/osi/osi.c b/src/plugins/osi/osi.c
new file mode 100644
index 00000000000..67c7053f388
--- /dev/null
+++ b/src/plugins/osi/osi.c
@@ -0,0 +1,199 @@
+/*
+ * Copyright (c) 2015 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.
+ */
+/*
+ * osi.c: osi support
+ *
+ * Copyright (c) 2010 Eliot Dresselhaus
+ *
+ * Permission is hereby granted, free of charge, to any person obtaining
+ * a copy of this software and associated documentation files (the
+ * "Software"), to deal in the Software without restriction, including
+ * without limitation the rights to use, copy, modify, merge, publish,
+ * distribute, sublicense, and/or sell copies of the Software, and to
+ * permit persons to whom the Software is furnished to do so, subject to
+ * the following conditions:
+ *
+ * The above copyright notice and this permission notice shall be
+ * included in all copies or substantial portions of the Software.
+ *
+ *  THE SOFTWARE IS PROVIDED "AS IS", WITHOUT WARRANTY OF ANY KIND,
+ *  EXPRESS OR IMPLIED, INCLUDING BUT NOT LIMITED TO THE WARRANTIES OF
+ *  MERCHANTABILITY, FITNESS FOR A PARTICULAR PURPOSE AND
+ *  NONINFRINGEMENT. IN NO EVENT SHALL THE AUTHORS OR COPYRIGHT HOLDERS BE
+ *  LIABLE FOR ANY CLAIM, DAMAGES OR OTHER LIABILITY, WHETHER IN AN ACTION
+ *  OF CONTRACT, TORT OR OTHERWISE, ARISING FROM, OUT OF OR IN CONNECTION
+ *  WITH THE SOFTWARE OR THE USE OR OTHER DEALINGS IN THE SOFTWARE.
+ */
+
+#include <vnet/vnet.h>
+#include <osi/osi.h>
+
+/* Global main structure. */
+osi_main_t osi_main;
+
+u8 *
+format_osi_protocol (u8 * s, va_list * args)
+{
+  osi_protocol_t p = va_arg (*args, u32);
+  osi_main_t *pm = &osi_main;
+  osi_protocol_info_t *pi = osi_get_protocol_info (pm, p);
+
+  if (pi)
+    s = format (s, "%s", pi->name);
+  else
+    s = format (s, "0x%02x", p);
+
+  return s;
+}
+
+u8 *
+format_osi_header_with_length (u8 * s, va_list * args)
+{
+  osi_main_t *pm = &osi_main;
+  osi_header_t *h = va_arg (*args, osi_header_t *);
+  u32 max_header_bytes = va_arg (*args, u32);
+  osi_protocol_t p = h->protocol;
+  u32 indent, header_bytes;
+
+  header_bytes = sizeof (h[0]);
+  if (max_header_bytes != 0 && header_bytes > max_header_bytes)
+    return format (s, "osi header truncated");
+
+  indent = format_get_indent (s);
+
+  s = format (s, "OSI %U", format_osi_protocol, p);
+
+  if (max_header_bytes != 0 && header_bytes > max_header_bytes)
+    {
+      osi_protocol_info_t *pi = osi_get_protocol_info (pm, p);
+      vlib_node_t *node = vlib_get_node (pm->vlib_main, pi->node_index);
+      if (node->format_buffer)
+	s = format (s, "\n%U%U",
+		    format_white_space, indent,
+		    node->format_buffer, (void *) (h + 1),
+		    max_header_bytes - header_bytes);
+    }
+
+  return s;
+}
+
+u8 *
+format_osi_header (u8 * s, va_list * args)
+{
+  osi_header_t *h = va_arg (*args, osi_header_t *);
+  return format (s, "%U", format_osi_header_with_length, h, 0);
+}
+
+/* Returns osi protocol as an int in host byte order. */
+uword
+unformat_osi_protocol (unformat_input_t * input, va_list * args)
+{
+  u8 *result = va_arg (*args, u8 *);
+  osi_main_t *pm = &osi_main;
+  int p, i;
+
+  /* Numeric type. */
+  if (unformat (input, "0x%x", &p) || unformat (input, "%d", &p))
+    {
+      if (p >= (1 << 8))
+	return 0;
+      *result = p;
+      return 1;
+    }
+
+  /* Named type. */
+  if (unformat_user (input, unformat_vlib_number_by_name,
+		     pm->protocol_info_by_name, &i))
+    {
+      osi_protocol_info_t *pi = vec_elt_at_index (pm->protocol_infos, i);
+      *result = pi->protocol;
+      return 1;
+    }
+
+  return 0;
+}
+
+uword
+unformat_osi_header (unformat_input_t * input, va_list * args)
+{
+  u8 **result = va_arg (*args, u8 **);
+  osi_header_t _h, *h = &_h;
+  u8 p;
+
+  if (!unformat (input, "%U", unformat_osi_protocol, &p))
+    return 0;
+
+  h->protocol = p;
+
+  /* Add header to result. */
+  {
+    void *p;
+    u32 n_bytes = sizeof (h[0]);
+
+    vec_add2 (*result, p, n_bytes);
+    clib_memcpy (p, h, n_bytes);
+  }
+
+  return 1;
+}
+
+static void
+add_protocol (osi_main_t * pm, osi_protocol_t protocol, char *protocol_name)
+{
+  osi_protocol_info_t *pi;
+  u32 i;
+
+  vec_add2 (pm->protocol_infos, pi, 1);
+  i = pi - pm->protocol_infos;
+
+  pi->name = protocol_name;
+  pi->protocol = protocol;
+  pi->next_index = pi->node_index = ~0;
+
+  hash_set (pm->protocol_info_by_protocol, protocol, i);
+  hash_set_mem (pm->protocol_info_by_name, pi->name, i);
+}
+
+static clib_error_t *
+osi_init (vlib_main_t * vm)
+{
+  osi_main_t *pm = &osi_main;
+
+  clib_memset (pm, 0, sizeof (pm[0]));
+  pm->vlib_main = vm;
+
+  pm->protocol_info_by_name = hash_create_string (0, sizeof (uword));
+  pm->protocol_info_by_protocol = hash_create (0, sizeof (uword));
+
+#define _(f,n) add_protocol (pm, OSI_PROTOCOL_##f, #f);
+  foreach_osi_protocol;
+#undef _
+
+  return vlib_call_init_function (vm, osi_input_init);
+}
+
+/* init order dependency: llc_init -> osi_init -> snap_init*/
+/* Otherwise, osi_input_init will wipe out e.g. the snap init */
+VLIB_INIT_FUNCTION (osi_init) = {
+  .init_order = VLIB_INITS ("llc_init", "osi_init", "snap_init"),
+};
+
+/*
+ * fd.io coding-style-patch-verification: ON
+ *
+ * Local Variables:
+ * eval: (c-set-style "gnu")
+ * End:
+ */
diff --git a/src/plugins/osi/osi.h b/src/plugins/osi/osi.h
new file mode 100644
index 00000000000..fb248ed9cc5
--- /dev/null
+++ b/src/plugins/osi/osi.h
@@ -0,0 +1,156 @@
+/*
+ * Copyright (c) 2015 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.
+ */
+/*
+ * osi.h: OSI definitions
+ *
+ * Copyright (c) 2008 Eliot Dresselhaus
+ *
+ * Permission is hereby granted, free of charge, to any person obtaining
+ * a copy of this software and associated documentation files (the
+ * "Software"), to deal in the Software without restriction, including
+ * without limitation the rights to use, copy, modify, merge, publish,
+ * distribute, sublicense, and/or sell copies of the Software, and to
+ * permit persons to whom the Software is furnished to do so, subject to
+ * the following conditions:
+ *
+ * The above copyright notice and this permission notice shall be
+ * included in all copies or substantial portions of the Software.
+ *
+ *  THE SOFTWARE IS PROVIDED "AS IS", WITHOUT WARRANTY OF ANY KIND,
+ *  EXPRESS OR IMPLIED, INCLUDING BUT NOT LIMITED TO THE WARRANTIES OF
+ *  MERCHANTABILITY, FITNESS FOR A PARTICULAR PURPOSE AND
+ *  NONINFRINGEMENT. IN NO EVENT SHALL THE AUTHORS OR COPYRIGHT HOLDERS BE
+ *  LIABLE FOR ANY CLAIM, DAMAGES OR OTHER LIABILITY, WHETHER IN AN ACTION
+ *  OF CONTRACT, TORT OR OTHERWISE, ARISING FROM, OUT OF OR IN CONNECTION
+ *  WITH THE SOFTWARE OR THE USE OR OTHER DEALINGS IN THE SOFTWARE.
+ */
+
+#ifndef included_osi_h
+#define included_osi_h
+
+#include <vnet/vnet.h>
+
+#define foreach_osi_protocol			\
+  _ (null, 0x0)					\
+  _ (x_29, 0x01)				\
+  _ (x_633, 0x03)				\
+  _ (q_931, 0x08)				\
+  _ (q_933, 0x08)				\
+  _ (q_2931, 0x09)				\
+  _ (q_2119, 0x0c)				\
+  _ (snap, 0x80)				\
+  _ (clnp, 0x81)				\
+  _ (esis, 0x82)				\
+  _ (isis, 0x83)				\
+  _ (idrp, 0x85)				\
+  _ (x25_esis, 0x8a)				\
+  _ (iso10030, 0x8c)				\
+  _ (iso11577, 0x8d)				\
+  _ (ip6, 0x8e)					\
+  _ (compressed, 0xb0)				\
+  _ (sndcf, 0xc1)				\
+  _ (ip4, 0xcc)					\
+  _ (ppp, 0xcf)
+
+typedef enum
+{
+#define _(f,n) OSI_PROTOCOL_##f = n,
+  foreach_osi_protocol
+#undef _
+} osi_protocol_t;
+
+typedef struct
+{
+  u8 protocol;
+
+  u8 payload[0];
+} osi_header_t;
+
+typedef struct
+{
+  /* Name (a c string). */
+  char *name;
+
+  /* OSI protocol (SAP type). */
+  osi_protocol_t protocol;
+
+  /* Node which handles this type. */
+  u32 node_index;
+
+  /* Next index for this type. */
+  u32 next_index;
+} osi_protocol_info_t;
+
+#define foreach_osi_error			\
+  _ (NONE, "no error")				\
+  _ (UNKNOWN_PROTOCOL, "unknown osi protocol")
+
+typedef enum
+{
+#define _(f,s) OSI_ERROR_##f,
+  foreach_osi_error
+#undef _
+    OSI_N_ERROR,
+} osi_error_t;
+
+typedef struct
+{
+  vlib_main_t *vlib_main;
+
+  osi_protocol_info_t *protocol_infos;
+
+  /* Hash tables mapping name/protocol to protocol info index. */
+  uword *protocol_info_by_name, *protocol_info_by_protocol;
+
+  /* osi-input next index indexed by protocol. */
+  u8 input_next_by_protocol[256];
+} osi_main_t;
+
+always_inline osi_protocol_info_t *
+osi_get_protocol_info (osi_main_t * m, osi_protocol_t protocol)
+{
+  uword *p = hash_get (m->protocol_info_by_protocol, protocol);
+  return p ? vec_elt_at_index (m->protocol_infos, p[0]) : 0;
+}
+
+extern osi_main_t osi_main;
+
+/* Register given node index to take input for given osi type. */
+void osi_register_input_protocol (osi_protocol_t protocol, u32 node_index);
+
+format_function_t format_osi_protocol;
+format_function_t format_osi_header;
+format_function_t format_osi_header_with_length;
+
+/* Parse osi protocol as 0xXXXX or protocol name. */
+unformat_function_t unformat_osi_protocol;
+
+/* Parse osi header. */
+unformat_function_t unformat_osi_header;
+unformat_function_t unformat_pg_osi_header;
+
+void osi_register_input_protocol (osi_protocol_t protocol, u32 node_index);
+
+format_function_t format_osi_header;
+
+#endif /* included_osi_h */
+
+/*
+ * fd.io coding-style-patch-verification: ON
+ *
+ * Local Variables:
+ * eval: (c-set-style "gnu")
+ * End:
+ */
diff --git a/src/plugins/osi/pg.c b/src/plugins/osi/pg.c
new file mode 100644
index 00000000000..3bac693c127
--- /dev/null
+++ b/src/plugins/osi/pg.c
@@ -0,0 +1,106 @@
+/*
+ * Copyright (c) 2015 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.
+ */
+/*
+ * osi_pg.c: packet generator osi interface
+ *
+ * Copyright (c) 2008 Eliot Dresselhaus
+ *
+ * Permission is hereby granted, free of charge, to any person obtaining
+ * a copy of this software and associated documentation files (the
+ * "Software"), to deal in the Software without restriction, including
+ * without limitation the rights to use, copy, modify, merge, publish,
+ * distribute, sublicense, and/or sell copies of the Software, and to
+ * permit persons to whom the Software is furnished to do so, subject to
+ * the following conditions:
+ *
+ * The above copyright notice and this permission notice shall be
+ * included in all copies or substantial portions of the Software.
+ *
+ *  THE SOFTWARE IS PROVIDED "AS IS", WITHOUT WARRANTY OF ANY KIND,
+ *  EXPRESS OR IMPLIED, INCLUDING BUT NOT LIMITED TO THE WARRANTIES OF
+ *  MERCHANTABILITY, FITNESS FOR A PARTICULAR PURPOSE AND
+ *  NONINFRINGEMENT. IN NO EVENT SHALL THE AUTHORS OR COPYRIGHT HOLDERS BE
+ *  LIABLE FOR ANY CLAIM, DAMAGES OR OTHER LIABILITY, WHETHER IN AN ACTION
+ *  OF CONTRACT, TORT OR OTHERWISE, ARISING FROM, OUT OF OR IN CONNECTION
+ *  WITH THE SOFTWARE OR THE USE OR OTHER DEALINGS IN THE SOFTWARE.
+ */
+
+#include <vlib/vlib.h>
+#include <vnet/pg/pg.h>
+#include <osi/osi.h>
+
+typedef struct
+{
+  pg_edit_t protocol;
+} pg_osi_header_t;
+
+static inline void
+pg_osi_header_init (pg_osi_header_t * e)
+{
+  pg_edit_init (&e->protocol, osi_header_t, protocol);
+}
+
+uword
+unformat_pg_osi_header (unformat_input_t * input, va_list * args)
+{
+  pg_stream_t *s = va_arg (*args, pg_stream_t *);
+  pg_osi_header_t *h;
+  u32 group_index, error;
+
+  h = pg_create_edit_group (s, sizeof (h[0]), sizeof (osi_header_t),
+			    &group_index);
+  pg_osi_header_init (h);
+
+  error = 1;
+  if (!unformat (input, "%U",
+		 unformat_pg_edit, unformat_osi_protocol, &h->protocol))
+    goto done;
+
+  {
+    osi_main_t *pm = &osi_main;
+    osi_protocol_info_t *pi = 0;
+    pg_node_t *pg_node = 0;
+
+    if (h->protocol.type == PG_EDIT_FIXED)
+      {
+	u8 t = *h->protocol.values[PG_EDIT_LO];
+	pi = osi_get_protocol_info (pm, t);
+	if (pi && pi->node_index != ~0)
+	  pg_node = pg_get_node (pi->node_index);
+      }
+
+    if (pg_node && pg_node->unformat_edit
+	&& unformat_user (input, pg_node->unformat_edit, s))
+      ;
+
+    else if (!unformat_user (input, unformat_pg_payload, s))
+      goto done;
+  }
+
+  error = 0;
+done:
+  if (error)
+    pg_free_edit_group (s);
+  return error == 0;
+}
+
+
+/*
+ * fd.io coding-style-patch-verification: ON
+ *
+ * Local Variables:
+ * eval: (c-set-style "gnu")
+ * End:
+ */
diff --git a/src/plugins/osi/plugin.c b/src/plugins/osi/plugin.c
new file mode 100644
index 00000000000..5fc412e093e
--- /dev/null
+++ b/src/plugins/osi/plugin.c
@@ -0,0 +1,23 @@
+/*
+ * plugin.c: osi
+ *
+ * Copyright (c) 2023 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 <vlib/vlib.h>
+#include <vnet/plugin/plugin.h>
+#include <vpp/app/version.h>
+VLIB_PLUGIN_REGISTER () = {
+  .version = VPP_BUILD_VER,
+  .description = "OSI plugin",
+};
\ No newline at end of file