FD.io VPP  v18.10-34-gcce845e
Vector Packet Processing
nsim_input.c
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1 /*
2  * nsim.c - skeleton vpp engine plug-in
3  *
4  * Copyright (c) <current-year> <your-organization>
5  * Licensed under the Apache License, Version 2.0 (the "License");
6  * you may not use this file except in compliance with the License.
7  * You may obtain a copy of the License at:
8  *
9  * http://www.apache.org/licenses/LICENSE-2.0
10  *
11  * Unless required by applicable law or agreed to in writing, software
12  * distributed under the License is distributed on an "AS IS" BASIS,
13  * WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
14  * See the License for the specific language governing permissions and
15  * limitations under the License.
16  */
17 
18 #include <vlib/vlib.h>
19 #include <vnet/vnet.h>
20 #include <vnet/pg/pg.h>
21 #include <vppinfra/error.h>
22 #include <nsim/nsim.h>
23 
24 typedef struct
25 {
29 
30 #ifndef CLIB_MARCH_VARIANT
31 /* packet trace format function */
32 static u8 *
33 format_nsim_tx_trace (u8 * s, va_list * args)
34 {
35  CLIB_UNUSED (vlib_main_t * vm) = va_arg (*args, vlib_main_t *);
36  CLIB_UNUSED (vlib_node_t * node) = va_arg (*args, vlib_node_t *);
37  nsim_tx_trace_t *t = va_arg (*args, nsim_tx_trace_t *);
38 
39  s = format (s, "NSIM: tx at %.6f sw_if_index %d",
40  t->expired, t->tx_sw_if_index);
41  return s;
42 }
43 #endif /* CLIB_MARCH_VARIANT */
44 
45 #define foreach_nsim_tx_error \
46 _(TX, "Packets transmitted") \
47 _(DROPPED, "No buffer drops")
48 
49 typedef enum
50 {
51 #define _(sym,str) NSIM_TX_ERROR_##sym,
53 #undef _
56 
57 #ifndef CLIB_MARCH_VARIANT
58 static char *nsim_tx_error_strings[] = {
59 #define _(sym,string) string,
61 #undef _
62 };
63 #endif /* CLIB_MARCH_VARIANT */
64 
65 typedef enum
66 {
69 } nsim_next_t;
70 
73  vlib_frame_t * f, int is_trace)
74 {
75  nsim_main_t *nsm = &nsim_main;
76  u32 my_thread_index = vm->thread_index;
77  u32 *my_buffer_cache = nsm->buffer_indices_by_thread[my_thread_index];
78  nsim_wheel_t *wp = nsm->wheel_by_thread[my_thread_index];
79  f64 now = vlib_time_now (vm);
80  uword n_rx_packets = 0;
81  vlib_buffer_t *b0;
82  u32 bi0, next0;
84  u32 *to_next;
85  u32 next_index;
86  u32 n_left_to_next;
88 
89  /* Nothing on the scheduler wheel? */
90  if (wp->cursize == 0)
91  return 0;
92 
93  /* First entry on the wheel isn't expired? */
94  ep = wp->entries + wp->head;
95  if (ep->tx_time > now)
96  return n_rx_packets;
97 
98  /*
99  * We use per-thread buffer caches, so we need the freelist to
100  * initialize them...
101  */
103  next_index = node->cached_next_index;
104 
105  while (wp->cursize)
106  {
107  /* Be aware: this is not the usual coding pattern */
108  vlib_get_next_frame (vm, node, next_index, to_next, n_left_to_next);
109 
110  while (n_left_to_next > 0 && ep->tx_time <= now)
111  {
112  /* Out of local buffer cache? */
113  if (PREDICT_FALSE (_vec_len (my_buffer_cache) == 0))
114  {
115  u32 n =
116  vlib_buffer_alloc (vm, my_buffer_cache, VLIB_FRAME_SIZE);
117  _vec_len (my_buffer_cache) = n;
118 
119  /* Ugh, drop the rest of the expired entries */
120  if (n == 0)
121  {
122  u32 drops = 0;
123  while (ep->tx_time <= now && wp->cursize)
124  {
125  wp->head++;
126  if (wp->head == wp->wheel_size)
127  wp->head = 0;
128  ep = wp->entries + wp->head;
129  wp->cursize--;
130  drops++;
131  }
132  /* Count the drops */
134  NSIM_TX_ERROR_DROPPED, drops);
135  /* Ship any pkts we already processed */
136  vlib_put_next_frame (vm, node, next_index, n_left_to_next);
137  return n_rx_packets + drops;
138  }
139  }
140 
141  /* Allocate a buffer */
142  bi0 = my_buffer_cache[_vec_len (my_buffer_cache) - 1];
143  _vec_len (my_buffer_cache) -= 1;
144 
145  to_next[0] = bi0;
146  to_next += 1;
147  n_left_to_next -= 1;
148 
149  b0 = vlib_get_buffer (vm, bi0);
150  /* Initialize the buffer */
152 
153  b0->current_data = 0;
154  b0->current_length = ep->current_length;
155 
156  /* Copy data from the ring */
157  clib_memcpy (b0->data, ep->data, ep->current_length);
158  b0->flags |= VLIB_BUFFER_TOTAL_LENGTH_VALID;
159  vnet_buffer (b0)->sw_if_index[VLIB_TX] = ep->tx_sw_if_index;
160  vnet_buffer (b0)->sw_if_index[VLIB_RX] =
161  (ep->tx_sw_if_index == nsm->sw_if_index0) ? nsm->sw_if_index1 :
162  nsm->sw_if_index0;
163  next0 = (ep->tx_sw_if_index == nsm->sw_if_index0) ?
165 
166  /* verify speculative enqueue, maybe switch current next frame */
167  vlib_validate_buffer_enqueue_x1 (vm, node, next_index,
168  to_next, n_left_to_next,
169  bi0, next0);
170  /* Advance to the next ring entry */
171  wp->head++;
172  if (wp->head == wp->wheel_size)
173  wp->head = 0;
174  wp->cursize--;
175  ep = wp->entries + wp->head;
176  n_rx_packets++;
177 
178  /* Out of ring entries? */
179  if (PREDICT_FALSE (wp->cursize == 0))
180  break;
181  }
182 
183  vlib_put_next_frame (vm, node, next_index, n_left_to_next);
184 
185  /* If the current entry hasn't expired, we're done */
186  if (ep->tx_time > now)
187  break;
188  }
189  return n_rx_packets;
190 }
191 
193  vlib_frame_t * frame)
194 {
195  if (PREDICT_FALSE (node->flags & VLIB_NODE_FLAG_TRACE))
196  return nsim_input_inline (vm, node, frame, 1 /* is_trace */ );
197  else
198  return nsim_input_inline (vm, node, frame, 0 /* is_trace */ );
199 
200 }
201 
202 /* *INDENT-OFF* */
203 #ifndef CLIB_MARCH_VARIANT
205 {
206  .type = VLIB_NODE_TYPE_INPUT,
207  .name = "nsim-wheel",
208 
209  /* Will be enabled if/when the feature is configured */
210  .state = VLIB_NODE_STATE_DISABLED,
211 
212  .format_trace = format_nsim_tx_trace,
213 
214  .n_errors = NSIM_N_ERROR,
215  .error_strings = nsim_tx_error_strings,
216 };
217 #endif /* CLIB_MARCH_VARIANT */
218 /* *INDENT-ON* */
219 
220 /*
221  * fd.io coding-style-patch-verification: ON
222  *
223  * Local Variables:
224  * eval: (c-set-style "gnu")
225  * End:
226  */
static char * nsim_tx_error_strings[]
Definition: nsim_input.c:58
#define CLIB_UNUSED(x)
Definition: clib.h:81
Definition: nsim.h:30
static f64 vlib_time_now(vlib_main_t *vm)
Definition: main.h:227
u32 thread_index
Definition: main.h:179
u8 * format(u8 *s, const char *fmt,...)
Definition: format.c:419
#define VLIB_NODE_FN(node)
Definition: node.h:187
u32 output_next_index0
Definition: nsim.h:56
unsigned char u8
Definition: types.h:56
u32 current_length
Definition: nsim.h:34
double f64
Definition: types.h:142
static u8 * format_nsim_tx_trace(u8 *s, va_list *args)
Definition: nsim_input.c:33
u32 tx_sw_if_index
Definition: nsim.h:33
u32 cursize
Definition: nsim.h:42
i16 current_data
signed offset in data[], pre_data[] that we are currently processing.
Definition: buffer.h:109
#define always_inline
Definition: clib.h:94
unsigned int u32
Definition: types.h:88
nsim_tx_error_t
Definition: nsim_input.c:49
#define VLIB_FRAME_SIZE
Definition: node.h:382
#define fl(x, y)
#define foreach_nsim_tx_error
Definition: nsim_input.c:45
u16 current_length
Nbytes between current data and the end of this buffer.
Definition: buffer.h:113
u8 data[WHEEL_ENTRY_DATA_SIZE]
Definition: nsim.h:36
#define VLIB_BUFFER_DEFAULT_FREE_LIST_INDEX
Definition: buffer.h:440
nsim_next_t
Definition: nsim_input.c:65
#define PREDICT_FALSE(x)
Definition: clib.h:107
u32 node_index
Node index.
Definition: node.h:494
#define vlib_validate_buffer_enqueue_x1(vm, node, next_index, to_next, n_left_to_next, bi0, next0)
Finish enqueueing one buffer forward in the graph.
Definition: buffer_node.h:218
#define vlib_get_next_frame(vm, node, next_index, vectors, n_vectors_left)
Get pointer to next frame vector data by (vlib_node_runtime_t, next_index).
Definition: node_funcs.h:364
static void vlib_node_increment_counter(vlib_main_t *vm, u32 node_index, u32 counter_index, u64 increment)
Definition: node_funcs.h:1176
u32 sw_if_index1
Definition: nsim.h:55
#define VLIB_REGISTER_NODE(x,...)
Definition: node.h:155
vlib_main_t * vm
Definition: buffer.c:294
static uword nsim_input_inline(vlib_main_t *vm, vlib_node_runtime_t *node, vlib_frame_t *f, int is_trace)
Definition: nsim_input.c:72
nsim_wheel_entry_t * entries
Definition: nsim.h:45
#define clib_memcpy(a, b, c)
Definition: string.h:75
void vlib_put_next_frame(vlib_main_t *vm, vlib_node_runtime_t *r, u32 next_index, u32 n_vectors_left)
Release pointer to next frame vector data.
Definition: main.c:455
u32 head
Definition: nsim.h:43
u16 cached_next_index
Next frame index that vector arguments were last enqueued to last time this node ran.
Definition: node.h:513
nsim_wheel_t ** wheel_by_thread
Definition: nsim.h:59
vlib_node_registration_t nsim_input_node
(constructor) VLIB_REGISTER_NODE (nsim_input_node)
Definition: nsim_input.c:204
Definition: defs.h:47
u32 sw_if_index0
Definition: nsim.h:55
f64 tx_time
Definition: nsim.h:32
u64 uword
Definition: types.h:112
u32 ** buffer_indices_by_thread
Definition: nsim.h:60
static void vlib_buffer_init_for_free_list(vlib_buffer_t *dst, vlib_buffer_free_list_t *fl)
#define vnet_buffer(b)
Definition: buffer.h:344
u8 data[0]
Packet data.
Definition: buffer.h:175
static vlib_buffer_free_list_t * vlib_buffer_get_free_list(vlib_main_t *vm, vlib_buffer_free_list_index_t free_list_index)
Definition: buffer_funcs.h:675
#define VLIB_NODE_FLAG_TRACE
Definition: node.h:310
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:116
static u32 vlib_buffer_alloc(vlib_main_t *vm, u32 *buffers, u32 n_buffers)
Allocate buffers into supplied array.
Definition: buffer_funcs.h:503
u32 wheel_size
Definition: nsim.h:41
u32 output_next_index1
Definition: nsim.h:56
nsim_main_t nsim_main
Definition: nsim.c:59
static vlib_buffer_t * vlib_get_buffer(vlib_main_t *vm, u32 buffer_index)
Translate buffer index into buffer pointer.
Definition: buffer_funcs.h:58
Definition: defs.h:46