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Vector Packet Processing
adj_l2.c
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1 /*
2  * Copyright (c) 2016 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 
16 #include <vnet/vnet.h>
17 #include <vnet/adj/adj_l2.h>
18 #include <vnet/ethernet/ethernet.h>
19 #include <vnet/ip/ip.h>
20 
21 /**
22  * @brief Trace data for a L2 Midchain
23  */
24 typedef struct adj_l2_trace_t_ {
25  /** Adjacency index taken. */
28 
29 static u8 *
30 format_adj_l2_trace (u8 * s, va_list * args)
31 {
32  CLIB_UNUSED (vlib_main_t * vm) = va_arg (*args, vlib_main_t *);
33  CLIB_UNUSED (vlib_node_t * node) = va_arg (*args, vlib_node_t *);
34  adj_l2_trace_t * t = va_arg (*args, adj_l2_trace_t *);
35 
36  s = format (s, "adj-idx %d : %U",
37  t->adj_index,
39  return s;
40 }
41 
43 {
46 
49  vlib_node_runtime_t * node,
50  vlib_frame_t * frame,
51  int is_midchain)
52 {
53  u32 * from = vlib_frame_vector_args (frame);
54  u32 n_left_from, n_left_to_next, * to_next, next_index;
55  u32 cpu_index = os_get_cpu_number();
57 
58  n_left_from = frame->n_vectors;
59  next_index = node->cached_next_index;
60 
61  while (n_left_from > 0)
62  {
63  vlib_get_next_frame (vm, node, next_index, to_next, n_left_to_next);
64 
65  while (n_left_from > 0 && n_left_to_next > 0)
66  {
67  ip_adjacency_t * adj0;
68  vlib_buffer_t * p0;
69  char *h0;
70  u32 pi0, rw_len0, adj_index0, next0 = 0;
71  u32 tx_sw_if_index0;
72 
73  pi0 = to_next[0] = from[0];
74  from += 1;
75  n_left_from -= 1;
76  to_next += 1;
77  n_left_to_next -= 1;
78 
79  p0 = vlib_get_buffer (vm, pi0);
80  h0 = vlib_buffer_get_current (p0);
81 
82  adj_index0 = vnet_buffer (p0)->ip.adj_index[VLIB_TX];
83 
84  /* We should never rewrite a pkt using the MISS adjacency */
85  ASSERT(adj_index0);
86 
87  adj0 = adj_get (adj_index0);
88 
89  /* Guess we are only writing on simple Ethernet header. */
90  vnet_rewrite_one_header (adj0[0], h0,
91  sizeof (ethernet_header_t));
92 
93  /* Update packet buffer attributes/set output interface. */
94  rw_len0 = adj0[0].rewrite_header.data_bytes;
95  vnet_buffer(p0)->ip.save_rewrite_length = rw_len0;
96 
99  cpu_index, adj_index0,
100  /* packet increment */ 0,
101  /* byte increment */ rw_len0-sizeof(ethernet_header_t));
102 
103  /* Check MTU of outgoing interface. */
105  adj0[0].rewrite_header.max_l3_packet_bytes)))
106  {
107  /* Don't adjust the buffer for ttl issue; icmp-error node wants
108  * to see the IP headerr */
109  p0->current_data -= rw_len0;
110  p0->current_length += rw_len0;
111  tx_sw_if_index0 = adj0[0].rewrite_header.sw_if_index;
112 
113  if (is_midchain)
114  {
115  adj0->sub_type.midchain.fixup_func(vm, adj0, p0);
116  }
117 
118  vnet_buffer (p0)->sw_if_index[VLIB_TX] = tx_sw_if_index0;
119 
120  /*
121  * Follow the feature ARC. this will result eventually in
122  * the midchain-tx node
123  */
124  vnet_feature_arc_start(em->output_feature_arc_index, tx_sw_if_index0, &next0, p0);
125  }
126  else
127  {
128  /* can't fragment L2 */
129  next0 = ADJ_L2_REWRITE_NEXT_DROP;
130  }
131 
133  {
134  adj_l2_trace_t *tr = vlib_add_trace (vm, node,
135  p0, sizeof (*tr));
136  tr->adj_index = vnet_buffer(p0)->ip.adj_index[VLIB_TX];
137  }
138 
139  vlib_validate_buffer_enqueue_x1 (vm, node, next_index,
140  to_next, n_left_to_next,
141  pi0, next0);
142  }
143 
144  vlib_put_next_frame (vm, node, next_index, n_left_to_next);
145  }
146 
147  return frame->n_vectors;
148 }
149 
150 static uword
152  vlib_node_runtime_t * node,
153  vlib_frame_t * frame)
154 {
155  return adj_l2_rewrite_inline (vm, node, frame, 0);
156 }
157 
158 static uword
160  vlib_node_runtime_t * node,
161  vlib_frame_t * frame)
162 {
163  return adj_l2_rewrite_inline (vm, node, frame, 1);
164 }
165 
167  .function = adj_l2_rewrite,
168  .name = "adj-l2-rewrite",
169  .vector_size = sizeof (u32),
170 
171  .format_trace = format_adj_l2_trace,
172 
173  .n_next_nodes = 1,
174  .next_nodes = {
175  [ADJ_L2_REWRITE_NEXT_DROP] = "error-drop",
176  },
177 };
178 
180 
182  .function = adj_l2_midchain,
183  .name = "adj-l2-midchain",
184  .vector_size = sizeof (u32),
185 
186  .format_trace = format_adj_l2_trace,
187 
188  .n_next_nodes = 1,
189  .next_nodes = {
190  [ADJ_L2_REWRITE_NEXT_DROP] = "error-drop",
191  },
192 };
193 
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:459
#define vnet_rewrite_one_header(rw0, p0, most_likely_size)
Definition: rewrite.h:253
#define CLIB_UNUSED(x)
Definition: clib.h:79
#define PREDICT_TRUE(x)
Definition: clib.h:98
IP unicast adjacency.
Definition: lookup.h:188
static uword vlib_buffer_length_in_chain(vlib_main_t *vm, vlib_buffer_t *b)
Get length in bytes of the buffer chain.
Definition: buffer_funcs.h:100
union ip_adjacency_t_::@175 sub_type
ethernet_main_t ethernet_main
Definition: ethernet.h:270
static ip_adjacency_t * adj_get(adj_index_t adj_index)
Get a pointer to an adjacency object from its index.
Definition: adj.h:117
i16 current_data
signed offset in data[], pre_data[] that we are currently processing.
Definition: buffer.h:78
#define always_inline
Definition: clib.h:84
static void * vlib_buffer_get_current(vlib_buffer_t *b)
Get pointer to current data to process.
Definition: buffer.h:194
u8 output_feature_arc_index
Definition: ethernet.h:267
vlib_node_registration_t adj_l2_midchain_node
(constructor) VLIB_REGISTER_NODE (adj_l2_midchain_node)
Definition: adj_l2.c:181
u16 current_length
Nbytes between current data and the end of this buffer.
Definition: buffer.h:82
uword os_get_cpu_number(void)
Definition: unix-misc.c:224
#define PREDICT_FALSE(x)
Definition: clib.h:97
static u8 * format_adj_l2_trace(u8 *s, va_list *args)
Definition: adj_l2.c:30
#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:216
#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:350
adj_l2_rewrite_next_t_
Definition: adj_l2.c:42
vlib_combined_counter_main_t adjacency_counters
Adjacency packet counters.
Definition: adj.c:30
static uword adj_l2_rewrite(vlib_main_t *vm, vlib_node_runtime_t *node, vlib_frame_t *frame)
Definition: adj_l2.c:151
u16 n_vectors
Definition: node.h:344
struct adj_l2_trace_t_ adj_l2_trace_t
Trace data for a L2 Midchain.
u16 cached_next_index
Definition: node.h:463
static void vlib_increment_combined_counter(vlib_combined_counter_main_t *cm, u32 cpu_index, u32 index, u32 packet_increment, u32 byte_increment)
Increment a combined counter.
Definition: counter.h:241
#define ASSERT(truth)
unsigned int u32
Definition: types.h:88
#define vnet_buffer(b)
Definition: buffer.h:361
static uword adj_l2_rewrite_inline(vlib_main_t *vm, vlib_node_runtime_t *node, vlib_frame_t *frame, int is_midchain)
Definition: adj_l2.c:48
#define VLIB_BUFFER_IS_TRACED
Definition: buffer.h:95
u64 uword
Definition: types.h:112
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
Definition: defs.h:47
unsigned char u8
Definition: types.h:56
static uword adj_l2_midchain(vlib_main_t *vm, vlib_node_runtime_t *node, vlib_frame_t *frame)
Definition: adj_l2.c:159
static void * vlib_frame_vector_args(vlib_frame_t *f)
Get pointer to frame vector data.
Definition: node_funcs.h:253
Trace data for a L2 Midchain.
Definition: adj_l2.c:24
#define VLIB_NODE_FUNCTION_MULTIARCH(node, fn)
Definition: node.h:158
#define VLIB_REGISTER_NODE(x,...)
Definition: node.h:143
u8 * format(u8 *s, const char *fmt,...)
Definition: format.c:418
u32 adj_index
Adjacency index taken.
Definition: adj_l2.c:26
vlib_node_registration_t adj_l2_rewrite_node
(constructor) VLIB_REGISTER_NODE (adj_l2_rewrite_node)
Definition: adj_l2.c:166
u32 flags
buffer flags: VLIB_BUFFER_IS_TRACED: trace this buffer.
Definition: buffer.h:85
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
enum adj_l2_rewrite_next_t_ adj_l2_rewrite_next_t
format_function_t format_ip_adjacency
Definition: format.h:58
struct ip_adjacency_t_::@175::@177 midchain
IP_LOOKUP_NEXT_MIDCHAIN.
static_always_inline void vnet_feature_arc_start(u8 arc, u32 sw_if_index, u32 *next0, vlib_buffer_t *b0)
Definition: feature.h:203