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/*
*------------------------------------------------------------------
* ip_path_mtu.c
*
* Copyright (c) 2020 Graphiant.
* 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 <vnet/ip/ip_path_mtu.h>
#include <vnet/ip/ip_frag.h>
typedef enum
{
IP_PMTU_DROP,
IP_PMTU_N_NEXT,
} ip_pmtu_next_t;
typedef struct ip_pmtu_trace_t_
{
u16 pmtu;
u16 packet_size;
} ip_pmtu_trace_t;
static u8 *
format_ip_pmtu_trace (u8 *s, va_list *args)
{
CLIB_UNUSED (vlib_main_t * vm) = va_arg (*args, vlib_main_t *);
CLIB_UNUSED (vlib_node_t * node) = va_arg (*args, vlib_node_t *);
ip_pmtu_trace_t *t = va_arg (*args, ip_pmtu_trace_t *);
s = format (s, "path mtu:%d packet size:%d", t->pmtu, t->packet_size);
return s;
}
static inline uword
ip_pmtu_dpo_inline (vlib_main_t *vm, vlib_node_runtime_t *node,
vlib_frame_t *frame, ip_address_family_t af)
{
u32 n_left_from, *from, next_index, *to_next, n_left_to_next;
from = vlib_frame_vector_args (frame);
n_left_from = frame->n_vectors;
next_index = node->cached_next_index;
u32 *buffer = 0;
while (n_left_from > 0)
{
vlib_get_next_frame (vm, node, next_index, to_next, n_left_to_next);
while (n_left_from > 0 && n_left_to_next > 0)
{
const ip_pmtu_dpo_t *ipm0;
u32 pi0, *frag_from, frag_left;
vlib_buffer_t *p0;
ip_frag_error_t error0;
u16 next0;
/*
* Note: The packet is not enqueued now. It is instead put
* in a vector where other fragments will be put as well.
*/
pi0 = from[0];
from += 1;
n_left_from -= 1;
p0 = vlib_get_buffer (vm, pi0);
ipm0 = ip_pmtu_dpo_get (vnet_buffer (p0)->ip.adj_index[VLIB_TX]);
vnet_buffer (p0)->ip.adj_index[VLIB_TX] = ipm0->ipm_dpo.dpoi_index;
next0 = ipm0->ipm_dpo.dpoi_next_node;
if (PREDICT_FALSE (p0->flags & VLIB_BUFFER_IS_TRACED))
{
ip_pmtu_trace_t *t;
t = vlib_add_trace (vm, node, p0, sizeof (*t));
t->pmtu = ipm0->ipm_pmtu;
t->packet_size = vlib_buffer_length_in_chain (vm, p0);
}
if (AF_IP6 == af)
error0 =
ip6_frag_do_fragment (vm, pi0, ipm0->ipm_pmtu, 0, &buffer);
else
error0 =
ip4_frag_do_fragment (vm, pi0, ipm0->ipm_pmtu, 0, &buffer);
if (AF_IP4 == af && error0 == IP_FRAG_ERROR_DONT_FRAGMENT_SET)
{
icmp4_error_set_vnet_buffer (
p0, ICMP4_destination_unreachable,
ICMP4_destination_unreachable_fragmentation_needed_and_dont_fragment_set,
ipm0->ipm_pmtu);
next0 = IP_FRAG_NEXT_ICMP_ERROR;
}
else
{
next0 =
(error0 == IP_FRAG_ERROR_NONE ? next0 : IP_FRAG_NEXT_DROP);
}
if (error0 == IP_FRAG_ERROR_NONE)
{
/* Free original buffer chain */
vlib_buffer_free_one (vm, pi0); /* Free original packet */
}
else
{
vlib_error_count (vm, node->node_index, error0, 1);
vec_add1 (buffer, pi0); /* Get rid of the original buffer */
}
/* Send fragments that were added in the frame */
frag_from = buffer;
frag_left = vec_len (buffer);
while (frag_left > 0)
{
while (frag_left > 0 && n_left_to_next > 0)
{
u32 i;
i = to_next[0] = frag_from[0];
frag_from += 1;
frag_left -= 1;
to_next += 1;
n_left_to_next -= 1;
vlib_get_buffer (vm, i)->error = node->errors[error0];
vlib_validate_buffer_enqueue_x1 (
vm, node, next_index, to_next, n_left_to_next, i, next0);
}
vlib_put_next_frame (vm, node, next_index, n_left_to_next);
vlib_get_next_frame (vm, node, next_index, to_next,
n_left_to_next);
}
vec_reset_length (buffer);
}
vlib_put_next_frame (vm, node, next_index, n_left_to_next);
}
vec_free (buffer);
return frame->n_vectors;
}
// clang-format off
VLIB_NODE_FN (ip4_ip_pmtu_dpo_node) (vlib_main_t *vm,
vlib_node_runtime_t *node,
vlib_frame_t *from_frame)
{
return (ip_pmtu_dpo_inline (vm, node, from_frame, 0));
}
VLIB_NODE_FN (ip6_ip_pmtu_dpo_node) (vlib_main_t *vm,
vlib_node_runtime_t *node,
vlib_frame_t *from_frame)
{
return (ip_pmtu_dpo_inline (vm, node, from_frame, 1));
}
VLIB_REGISTER_NODE (ip4_ip_pmtu_dpo_node) = {
.name = "ip4-pmtu-dpo",
.vector_size = sizeof (u32),
.format_trace = format_ip_pmtu_trace,
.n_errors = IP_FRAG_N_ERROR,
.error_counters = ip_frag_error_counters,
.n_next_nodes = IP_PMTU_N_NEXT,
.next_nodes =
{
[IP_PMTU_DROP] = "ip4-drop",
}
};
VLIB_REGISTER_NODE (ip6_ip_pmtu_dpo_node) = {
.name = "ip6-pmtu-dpo",
.vector_size = sizeof (u32),
.format_trace = format_ip_pmtu_trace,
.n_errors = IP_FRAG_N_ERROR,
.error_counters = ip_frag_error_counters,
.n_next_nodes = IP_PMTU_N_NEXT,
.next_nodes =
{
[IP_PMTU_DROP] = "ip6-drop",
}
};
// clang-format on
/*
* fd.io coding-style-patch-verification: ON
*
* Local Variables:
* eval: (c-set-style "gnu")
* End:
*/
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