VPP-344 Add LLDP feature

Change-Id: Iac96773e7f9028c0f09c3388893e69f67177439d
Signed-off-by: Klement Sekera <ksekera@cisco.com>

1 files changed, 257 insertions, 0 deletions

diff --git a/vnet/vnet/lldp/lldp_input.c b/vnet/vnet/lldp/lldp_input.c
new file mode 100644
index 00000000000..5a5655398f2
--- /dev/null
+++ b/vnet/vnet/lldp/lldp_input.c
@@ -0,0 +1,257 @@
+/*
+ * Copyright (c) 2011-2016 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.
+ */
+/**
+ * @file
+ * @brief LLDP packet parsing implementation
+ */
+#include <vnet/lldp/lldp_node.h>
+#include <vnet/lldp/lldp_protocol.h>
+
+lldp_tlv_code_t
+lldp_tlv_get_code (const lldp_tlv_t * tlv)
+{
+  return tlv->head.byte1 >> 1;
+}
+
+void
+lldp_tlv_set_code (lldp_tlv_t * tlv, lldp_tlv_code_t code)
+{
+  tlv->head.byte1 = (tlv->head.byte1 & 1) + (code << 1);
+}
+
+u16
+lldp_tlv_get_length (const lldp_tlv_t * tlv)
+{
+  return (((u16) (tlv->head.byte1 & 1)) << 8) + tlv->head.byte2;
+}
+
+void
+lldp_tlv_set_length (lldp_tlv_t * tlv, u16 length)
+{
+  tlv->head.byte2 = length & ((1 << 8) - 1);
+  if (length > (1 << 8) - 1)
+    {
+      tlv->head.byte1 |= 1;
+    }
+  else
+    {
+      tlv->head.byte1 &= (1 << 8) - 2;
+    }
+}
+
+lldp_main_t lldp_main;
+
+static int
+lldp_packet_scan (lldp_main_t * lm, lldp_intf_t * n, const lldp_tlv_t * pkt)
+{
+  lldp_error_t e = LLDP_ERROR_NONE;
+  const lldp_tlv_t *tlv = pkt;
+
+/* first check if the header fits in before extracting data from it */
+#define TLV_VIOLATES_PKT_BOUNDARY(pkt, tlv)                               \
+    (((((u8 *)tlv) + sizeof(lldp_tlv_t)) > ((u8 *)pkt + vec_len(pkt))) || \
+     ((((u8 *)tlv) + lldp_tlv_get_length(tlv)) > ((u8 *)pkt + vec_len(pkt))))
+
+  /* first tlv is always chassis id, followed by port id and ttl tlvs */
+  if (TLV_VIOLATES_PKT_BOUNDARY (pkt, tlv) ||
+      LLDP_TLV_NAME (chassis_id) != lldp_tlv_get_code (tlv))
+    {
+      return LLDP_ERROR_BAD_TLV;
+    }
+
+  u16 l = lldp_tlv_get_length (tlv);
+  if (l < STRUCT_SIZE_OF (lldp_chassis_id_tlv_t, subtype) +
+      LLDP_MIN_CHASS_ID_LEN ||
+      l > STRUCT_SIZE_OF (lldp_chassis_id_tlv_t, subtype) +
+      LLDP_MAX_CHASS_ID_LEN)
+    {
+      return LLDP_ERROR_BAD_TLV;
+    }
+
+  u8 chid_subtype = ((lldp_chassis_id_tlv_t *) tlv)->subtype;
+  u8 *chid = ((lldp_chassis_id_tlv_t *) tlv)->id;
+  u8 chid_len = l - STRUCT_SIZE_OF (lldp_chassis_id_tlv_t, subtype);
+
+  tlv = (lldp_tlv_t *) ((u8 *) tlv + STRUCT_SIZE_OF (lldp_tlv_t, head) + l);
+
+  if (TLV_VIOLATES_PKT_BOUNDARY (pkt, tlv) ||
+      LLDP_TLV_NAME (port_id) != lldp_tlv_get_code (tlv))
+    {
+      return LLDP_ERROR_BAD_TLV;
+    }
+  l = lldp_tlv_get_length (tlv);
+  if (l < STRUCT_SIZE_OF (lldp_port_id_tlv_t, subtype) +
+      LLDP_MIN_PORT_ID_LEN ||
+      l > STRUCT_SIZE_OF (lldp_chassis_id_tlv_t, subtype) +
+      LLDP_MAX_PORT_ID_LEN)
+    {
+      return LLDP_ERROR_BAD_TLV;
+    }
+
+  u8 portid_subtype = ((lldp_port_id_tlv_t *) tlv)->subtype;
+  u8 *portid = ((lldp_port_id_tlv_t *) tlv)->id;
+  u8 portid_len = l - STRUCT_SIZE_OF (lldp_port_id_tlv_t, subtype);
+
+  tlv = (lldp_tlv_t *) ((u8 *) tlv + STRUCT_SIZE_OF (lldp_tlv_t, head) + l);
+
+  if (TLV_VIOLATES_PKT_BOUNDARY (pkt, tlv) ||
+      LLDP_TLV_NAME (ttl) != lldp_tlv_get_code (tlv))
+    {
+      return LLDP_ERROR_BAD_TLV;
+    }
+  l = lldp_tlv_get_length (tlv);
+  if (l != STRUCT_SIZE_OF (lldp_ttl_tlv_t, ttl))
+    {
+      return LLDP_ERROR_BAD_TLV;
+    }
+  u16 ttl = ntohs (((lldp_ttl_tlv_t *) tlv)->ttl);
+  tlv = (lldp_tlv_t *) ((u8 *) tlv + STRUCT_SIZE_OF (lldp_tlv_t, head) + l);
+  while (!TLV_VIOLATES_PKT_BOUNDARY (pkt, tlv) &&
+	 LLDP_TLV_NAME (pdu_end) != lldp_tlv_get_code (tlv))
+    {
+      switch (lldp_tlv_get_code (tlv))
+	{
+#define F(num, type, str)         \
+    case LLDP_TLV_NAME(type):     \
+        /* ignore optional TLV */ \
+        break;
+	  foreach_lldp_optional_tlv_type (F);
+#undef F
+	default:
+	  return LLDP_ERROR_BAD_TLV;
+	}
+      if (e)
+	{
+	  return e;
+	}
+      tlv = (lldp_tlv_t *) ((u8 *) tlv + STRUCT_SIZE_OF (lldp_tlv_t, head) +
+			    lldp_tlv_get_length (tlv));
+    }
+  /* last tlv is pdu_end */
+  if (TLV_VIOLATES_PKT_BOUNDARY (pkt, tlv) ||
+      LLDP_TLV_NAME (pdu_end) != lldp_tlv_get_code (tlv) ||
+      0 != lldp_tlv_get_length (tlv))
+    {
+      return LLDP_ERROR_BAD_TLV;
+    }
+  /* LLDP PDU validated, now store data */
+  if (n->chassis_id)
+    {
+      _vec_len (n->chassis_id) = 0;
+    }
+  vec_add (n->chassis_id, chid, chid_len);
+  n->chassis_id_subtype = chid_subtype;
+  if (n->port_id)
+    {
+      _vec_len (n->port_id) = 0;
+    }
+  vec_add (n->port_id, portid, portid_len);
+  n->port_id_subtype = portid_subtype;
+  n->ttl = ttl;
+  return LLDP_ERROR_NONE;
+}
+
+lldp_intf_t *
+lldp_get_intf (lldp_main_t * lm, u32 hw_if_index)
+{
+  uword *p = hash_get (lm->intf_by_hw_if_index, hw_if_index);
+
+  if (p)
+    {
+      return pool_elt_at_index (lm->intfs, p[0]);
+    }
+  return NULL;
+}
+
+lldp_intf_t *
+lldp_create_intf (lldp_main_t * lm, u32 hw_if_index)
+{
+
+  uword *p;
+  lldp_intf_t *n;
+  p = hash_get (lm->intf_by_hw_if_index, hw_if_index);
+
+  if (p == 0)
+    {
+      pool_get (lm->intfs, n);
+      memset (n, 0, sizeof (*n));
+      n->hw_if_index = hw_if_index;
+      hash_set (lm->intf_by_hw_if_index, n->hw_if_index, n - lm->intfs);
+    }
+  else
+    {
+      n = pool_elt_at_index (lm->intfs, p[0]);
+    }
+  return n;
+}
+
+/*
+ * lldp input routine
+ */
+lldp_error_t
+lldp_input (vlib_main_t * vm, vlib_buffer_t * b0, u32 bi0)
+{
+  lldp_main_t *lm = &lldp_main;
+  lldp_error_t e;
+
+  /* find our interface */
+  lldp_intf_t *n = lldp_get_intf (lm, vnet_buffer (b0)->sw_if_index[VLIB_RX]);
+
+  if (!n)
+    {
+      /* lldp disabled on this interface, we're done */
+      return LLDP_ERROR_DISABLED;
+    }
+
+  /* Actually scan the packet */
+  e = lldp_packet_scan (lm, n, vlib_buffer_get_current (b0));
+
+  if (LLDP_ERROR_NONE == e)
+    {
+      n->last_heard = vlib_time_now (vm);
+    }
+
+  return e;
+}
+
+/*
+ * setup function
+ */
+static clib_error_t *
+lldp_init (vlib_main_t * vm)
+{
+  clib_error_t *error;
+  lldp_main_t *lm = &lldp_main;
+
+  if ((error = vlib_call_init_function (vm, lldp_template_init)))
+    return error;
+
+  lm->vlib_main = vm;
+  lm->vnet_main = vnet_get_main ();
+  lm->msg_tx_hold = 4;		/* default value per IEEE 802.1AB-2009 */
+  lm->msg_tx_interval = 30;	/* default value per IEEE 802.1AB-2009 */
+
+  return 0;
+}
+
+VLIB_INIT_FUNCTION (lldp_init);
+
+/*
+ * fd.io coding-style-patch-verification: ON
+ *
+ * Local Variables:
+ * eval: (c-set-style "gnu")
+ * End:
+ */