FD.io VPP  v18.07.1-19-g511ce25
Vector Packet Processing
cdp_node.c
Go to the documentation of this file.
1 /*
2  * Copyright (c) 2011-2018 Cisco and/or its affiliates.
3  * Licensed under the Apache License, Version 2.0 (the "License");
4  * you may not use this file except in compliance with the License.
5  * You may obtain a copy of the License at:
6  *
7  * http://www.apache.org/licenses/LICENSE-2.0
8  *
9  * Unless required by applicable law or agreed to in writing, software
10  * distributed under the License is distributed on an "AS IS" BASIS,
11  * WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
12  * See the License for the specific language governing permissions and
13  * limitations under the License.
14  */
15 #include <cdp/cdp.h>
16 #include <vnet/ethernet/packet.h>
17 
18 /** \file
19 
20  2 x CDP graph nodes: an "interior" node to process
21  incoming announcements, and a "process" node to periodically
22  send announcements.
23 
24  The interior node is neither pipelined nor dual-looped, because
25  it would be very unusual to see more than one CDP packet in
26  a given input frame. So, it's a very simple / straighforward
27  example.
28 */
29 
30 /*
31  * packet counter strings
32  * Dump these counters via the "show error" CLI command
33  */
34 static char *cdp_error_strings[] = {
35 #define _(sym,string) string,
37 #undef _
38 };
39 
40 /*
41  * We actually send all cdp pkts to the "error" node after scanning
42  * them, so the graph node has only one next-index. The "error-drop"
43  * node automatically bumps our per-node packet counters for us.
44  */
45 typedef enum
46 {
49 } cdp_next_t;
50 
51 /*
52  * Process a frame of cdp packets
53  * Expect 1 packet / frame
54  */
55 static uword
57  vlib_node_runtime_t * node, vlib_frame_t * frame)
58 {
59  u32 n_left_from, *from;
61 
62  from = vlib_frame_vector_args (frame); /* array of buffer indices */
63  n_left_from = frame->n_vectors; /* number of buffer indices */
64 
65  while (n_left_from > 0)
66  {
67  u32 bi0;
68  vlib_buffer_t *b0;
69  u32 next0, error0;
70 
71  bi0 = from[0];
72  b0 = vlib_get_buffer (vm, bi0);
73 
74  next0 = CDP_INPUT_NEXT_NORMAL;
75 
76  /* scan this cdp pkt. error0 is the counter index to bump */
77  error0 = cdp_input (vm, b0, bi0);
78  b0->error = node->errors[error0];
79 
80  /* If this pkt is traced, snapshoot the data */
81  if (b0->flags & VLIB_BUFFER_IS_TRACED)
82  {
83  int len;
84  t0 = vlib_add_trace (vm, node, b0, sizeof (*t0));
85  len = (b0->current_length < sizeof (t0->data))
86  ? b0->current_length : sizeof (t0->data);
87  t0->len = len;
88  clib_memcpy (t0->data, vlib_buffer_get_current (b0), len);
89  }
90  /* push this pkt to the next graph node, always error-drop */
91  vlib_set_next_frame_buffer (vm, node, next0, bi0);
92 
93  from += 1;
94  n_left_from -= 1;
95  }
96 
97  return frame->n_vectors;
98 }
99 
100 /*
101  * cdp input graph node declaration
102  */
103 /* *INDENT-OFF* */
105  .function = cdp_node_fn,
106  .name = "cdp-input",
107  .vector_size = sizeof (u32),
108  .type = VLIB_NODE_TYPE_INTERNAL,
109 
110  .n_errors = CDP_N_ERROR,
111  .error_strings = cdp_error_strings,
112 
113  .format_trace = cdp_input_format_trace,
114 
115  .n_next_nodes = CDP_INPUT_N_NEXT,
116  .next_nodes = {
117  [CDP_INPUT_NEXT_NORMAL] = "error-drop",
118  },
119 };
120 /* *INDENT-ON* */
121 
122 /*
123  * cdp periodic function
124  */
125 static uword
127 {
128  cdp_main_t *cm = &cdp_main;
129  f64 poll_time_remaining;
130  uword event_type, *event_data = 0;
131 
132  /* So we can send events to the cdp process */
134 
135  /* Dynamically register the cdp input node with the snap classifier */
136  snap_register_input_protocol (vm, "cdp-input", 0xC /* ieee_oui, Cisco */ ,
137  0x2000 /* protocol CDP */ ,
138  cdp_input_node.index);
139 
140  snap_register_input_protocol (vm, "cdp-input", 0xC /* ieee_oui, Cisco */ ,
141  0x2004 /* protocol CDP */ ,
142  cdp_input_node.index);
143 
144 #if 0 /* retain for reference */
145  /* with the hdlc classifier */
146  hdlc_register_input_protocol (vm, HDLC_PROTOCOL_cdp, cdp_input_node.index);
147 #endif
148 
149  /* with ethernet input (for SRP) */
150  ethernet_register_input_type (vm, ETHERNET_TYPE_CDP /* CDP */ ,
151  cdp_input_node.index);
152 
153  /* Start w/ cdp effectively disabled */
154  poll_time_remaining = 86400.0;
155 
156  while (1)
157  {
158  /* sleep until next poll time, or msg serialize event occurs */
159  poll_time_remaining =
160  vlib_process_wait_for_event_or_clock (vm, poll_time_remaining);
161 
162  event_type = vlib_process_get_events (vm, &event_data);
163  switch (event_type)
164  {
165  case ~0: /* no events => timeout */
166  break;
167 
168  case CDP_EVENT_ENABLE:
169  poll_time_remaining = 10.0;
170  break;
171 
172  case CDP_EVENT_DISABLE:
173  poll_time_remaining = 86400.0;
174  break;
175 
176  default:
177  clib_warning ("BUG: event type 0x%wx", event_type);
178  break;
179  }
180  vec_reset_length (event_data);
181 
182  /* peer timeout scan, send announcements */
183  if (vlib_process_suspend_time_is_zero (poll_time_remaining))
184  {
185  cdp_periodic (vm);
186  poll_time_remaining = 10.0;
187  }
188  }
189 
190  return 0;
191 }
192 
193 /*
194  * cdp periodic node declaration
195  */
196 /* *INDENT-OFF* */
198  .function = cdp_process,
199  .type = VLIB_NODE_TYPE_PROCESS,
200  .name = "cdp-process",
201 };
202 /* *INDENT-ON* */
203 
204 void
206 {
207 }
208 
209 /*
210  * fd.io coding-style-patch-verification: ON
211  *
212  * Local Variables:
213  * eval: (c-set-style "gnu")
214  * End:
215  */
static f64 vlib_process_wait_for_event_or_clock(vlib_main_t *vm, f64 dt)
Suspend a cooperative multi-tasking thread Waits for an event, or for the indicated number of seconds...
Definition: node_funcs.h:699
static void vlib_set_next_frame_buffer(vlib_main_t *vm, vlib_node_runtime_t *node, u32 next_index, u32 buffer_index)
Definition: node_funcs.h:397
static uword cdp_node_fn(vlib_main_t *vm, vlib_node_runtime_t *node, vlib_frame_t *frame)
Definition: cdp_node.c:56
cdp_error_t cdp_input(vlib_main_t *vm, vlib_buffer_t *b0, u32 bi0)
Definition: cdp_input.c:297
cdp_main_t cdp_main
Definition: cdp_input.c:17
u32 cdp_process_node_index
Definition: cdp.h:94
vlib_error_t * errors
Vector of errors for this node.
Definition: node.h:451
static uword vlib_process_suspend_time_is_zero(f64 dt)
Returns TRUE if a process suspend time is less than 10us.
Definition: node_funcs.h:436
#define vec_reset_length(v)
Reset vector length to zero NULL-pointer tolerant.
cdp_next_t
Definition: cdp_node.c:45
double f64
Definition: types.h:142
void cdp_periodic(vlib_main_t *vm)
Definition: cdp_periodic.c:350
static uword vlib_process_get_events(vlib_main_t *vm, uword **data_vector)
Return the first event type which has occurred and a vector of per-event data of that type...
Definition: node_funcs.h:542
u8 data[400]
Definition: cdp.h:131
static vlib_node_registration_t cdp_input_node
(constructor) VLIB_REGISTER_NODE (cdp_input_node)
Definition: cdp_node.c:104
unsigned int u32
Definition: types.h:88
u8 * cdp_input_format_trace(u8 *s, va_list *args)
Definition: cdp_input.c:460
u16 current_length
Nbytes between current data and the end of this buffer.
Definition: buffer.h:108
static void * vlib_buffer_get_current(vlib_buffer_t *b)
Get pointer to current data to process.
Definition: buffer.h:202
static char * cdp_error_strings[]
Definition: cdp_node.c:34
#define foreach_cdp_error
Definition: cdp.h:111
vlib_error_t error
Error code for buffers to be enqueued to error handler.
Definition: buffer.h:135
void vnet_cdp_node_reference(void)
Definition: cdp_node.c:205
#define VLIB_REGISTER_NODE(x,...)
Definition: node.h:153
u16 n_vectors
Definition: node.h:380
vlib_main_t * vm
Definition: buffer.c:294
#define clib_warning(format, args...)
Definition: error.h:59
#define clib_memcpy(a, b, c)
Definition: string.h:75
void hdlc_register_input_protocol(vlib_main_t *vm, hdlc_protocol_t protocol, u32 node_index)
Definition: node.c:351
vlib_node_registration_t cdp_process_node
(constructor) VLIB_REGISTER_NODE (cdp_process_node)
Definition: cdp_node.c:197
void ethernet_register_input_type(vlib_main_t *vm, ethernet_type_t type, u32 node_index)
Definition: node.c:1342
static void * vlib_add_trace(vlib_main_t *vm, vlib_node_runtime_t *r, vlib_buffer_t *b, u32 n_data_bytes)
Definition: trace_funcs.h:55
u64 uword
Definition: types.h:112
static void * vlib_frame_vector_args(vlib_frame_t *f)
Get pointer to frame vector data.
Definition: node_funcs.h:267
Definition: cdp.h:79
u32 flags
buffer flags: VLIB_BUFFER_FREE_LIST_INDEX_MASK: bits used to store free list index, VLIB_BUFFER_IS_TRACED: trace this buffer.
Definition: buffer.h:111
static uword cdp_process(vlib_main_t *vm, vlib_node_runtime_t *rt, vlib_frame_t *f)
Definition: cdp_node.c:126
static vlib_buffer_t * vlib_get_buffer(vlib_main_t *vm, u32 buffer_index)
Translate buffer index into buffer pointer.
Definition: buffer_funcs.h:57
void snap_register_input_protocol(vlib_main_t *vm, char *name, u32 ieee_oui, u16 protocol, u32 node_index)
Definition: node.c:311