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gerrit.nordix.org / fdio / vpp / 17ddc0fee1bc20d0da84dd70bb579c8844a48ef4 / . / src / vnet / ip / ip4_reassembly.c
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/*
* Copyright (c) 2017 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 IPv4 Reassembly.
*
* This file contains the source code for IPv4 reassembly.
*/
#include <vppinfra/vec.h>
#include <vnet/vnet.h>
#include <vnet/ip/ip.h>
#include <vppinfra/bihash_24_8.h>
#include <vnet/ip/ip4_reassembly.h>
#define MSEC_PER_SEC 1000
#define IP4_REASS_TIMEOUT_DEFAULT_MS 100
#define IP4_REASS_EXPIRE_WALK_INTERVAL_DEFAULT_MS 10000 // 10 seconds default
#define IP4_REASS_MAX_REASSEMBLIES_DEFAULT 1024
#define IP4_REASS_HT_LOAD_FACTOR (0.75)
#define IP4_REASS_DEBUG_BUFFERS 0
#if IP4_REASS_DEBUG_BUFFERS
#define IP4_REASS_DEBUG_BUFFER(bi, what) \
do \
{ \
u32 _bi = bi; \
printf (#what "buffer %u", _bi); \
vlib_buffer_t *_b = vlib_get_buffer (vm, _bi); \
while (_b->flags & VLIB_BUFFER_NEXT_PRESENT) \
{ \
_bi = _b->next_buffer; \
printf ("[%u]", _bi); \
_b = vlib_get_buffer (vm, _bi); \
} \
printf ("\n"); \
fflush (stdout); \
} \
while (0)
#else
#define IP4_REASS_DEBUG_BUFFER(...)
#endif
static vlib_node_registration_t ip4_reass_node;
typedef struct
{
union
{
struct
{
// align by making this 4 octets even though its a 2 octets field
u32 xx_id;
ip4_address_t src;
ip4_address_t dst;
// align by making this 4 octets even though its a 2 octets field
u32 frag_id;
// align by making this 4 octets even though its a 1 octet field
u32 proto;
u32 unused;
};
u64 as_u64[3];
};
} ip4_reass_key_t;
always_inline u32
ip4_reass_buffer_get_data_offset_no_check (vlib_buffer_t * b)
{
vnet_buffer_opaque_t *vnb = vnet_buffer (b);
return vnb->ip.reass.range_first - vnb->ip.reass.fragment_first;
}
always_inline u32
ip4_reass_buffer_get_data_offset (vlib_buffer_t * b)
{
vnet_buffer_opaque_t *vnb = vnet_buffer (b);
ASSERT (vnb->ip.reass.range_first >= vnb->ip.reass.fragment_first);
return ip4_reass_buffer_get_data_offset_no_check (b);
}
always_inline u16
ip4_reass_buffer_get_data_len_no_check (vlib_buffer_t * b)
{
vnet_buffer_opaque_t *vnb = vnet_buffer (b);
return clib_min (vnb->ip.reass.range_last, vnb->ip.reass.fragment_last) -
(vnb->ip.reass.fragment_first + ip4_reass_buffer_get_data_offset (b)) + 1;
}
always_inline u16
ip4_reass_buffer_get_data_len (vlib_buffer_t * b)
{
vnet_buffer_opaque_t *vnb = vnet_buffer (b);
ASSERT (vnb->ip.reass.range_last > vnb->ip.reass.fragment_first);
return ip4_reass_buffer_get_data_len_no_check (b);
}
typedef struct
{
// hash table key
ip4_reass_key_t key;
// time when last packet was received
f64 last_heard;
// internal id of this reassembly
u64 id;
// buffer index of first buffer in this reassembly context
u32 first_bi;
// last octet of packet, ~0 until fragment without more_fragments arrives
u32 last_packet_octet;
// length of data collected so far
u32 data_len;
// trace operation counter
u32 trace_op_counter;
// next index - used by non-feature node
u8 next_index;
// minimum fragment length for this reassembly - used to estimate MTU
u16 min_fragment_length;
} ip4_reass_t;
typedef struct
{
ip4_reass_t *pool;
u32 reass_n;
u32 buffers_n;
u32 id_counter;
clib_spinlock_t lock;
} ip4_reass_per_thread_t;
typedef struct
{
// IPv4 config
u32 timeout_ms;
f64 timeout;
u32 expire_walk_interval_ms;
u32 max_reass_n;
// IPv4 runtime
clib_bihash_24_8_t hash;
// per-thread data
ip4_reass_per_thread_t *per_thread_data;
// convenience
vlib_main_t *vlib_main;
vnet_main_t *vnet_main;
// node index of ip4-drop node
u32 ip4_drop_idx;
u32 ip4_reass_expire_node_idx;
} ip4_reass_main_t;
ip4_reass_main_t ip4_reass_main;
typedef enum
{
IP4_REASSEMBLY_NEXT_INPUT,
IP4_REASSEMBLY_NEXT_DROP,
IP4_REASSEMBLY_N_NEXT,
} ip4_reass_next_t;
typedef enum
{
RANGE_NEW,
RANGE_SHRINK,
RANGE_DISCARD,
RANGE_OVERLAP,
FINALIZE,
} ip4_reass_trace_operation_e;
typedef struct
{
u16 range_first;
u16 range_last;
u32 range_bi;
i32 data_offset;
u32 data_len;
u32 first_bi;
} ip4_reass_range_trace_t;
typedef struct
{
ip4_reass_trace_operation_e action;
u32 reass_id;
ip4_reass_range_trace_t trace_range;
u32 size_diff;
u32 op_id;
u32 fragment_first;
u32 fragment_last;
u32 total_data_len;
} ip4_reass_trace_t;
static void
ip4_reass_trace_details (vlib_main_t * vm, u32 bi,
ip4_reass_range_trace_t * trace)
{
vlib_buffer_t *b = vlib_get_buffer (vm, bi);
vnet_buffer_opaque_t *vnb = vnet_buffer (b);
trace->range_first = vnb->ip.reass.range_first;
trace->range_last = vnb->ip.reass.range_last;
trace->data_offset = ip4_reass_buffer_get_data_offset_no_check (b);
trace->data_len = ip4_reass_buffer_get_data_len_no_check (b);
trace->range_bi = bi;
}
static u8 *
format_ip4_reass_range_trace (u8 * s, va_list * args)
{
ip4_reass_range_trace_t *trace = va_arg (*args, ip4_reass_range_trace_t *);
s = format (s, "range: [%u, %u], off %d, len %u, bi %u", trace->range_first,
trace->range_last, trace->data_offset, trace->data_len,
trace->range_bi);
return s;
}
u8 *
format_ip4_reass_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 *);
ip4_reass_trace_t *t = va_arg (*args, ip4_reass_trace_t *);
s = format (s, "reass id: %u, op id: %u ", t->reass_id, t->op_id);
u32 indent = format_get_indent (s);
s = format (s, "first bi: %u, data len: %u, ip/fragment[%u, %u]",
t->trace_range.first_bi, t->total_data_len, t->fragment_first,
t->fragment_last);
switch (t->action)
{
case RANGE_SHRINK:
s = format (s, "\n%Ushrink %U by %u", format_white_space, indent,
format_ip4_reass_range_trace, &t->trace_range,
t->size_diff);
break;
case RANGE_DISCARD:
s = format (s, "\n%Udiscard %U", format_white_space, indent,
format_ip4_reass_range_trace, &t->trace_range);
break;
case RANGE_NEW:
s = format (s, "\n%Unew %U", format_white_space, indent,
format_ip4_reass_range_trace, &t->trace_range);
break;
case RANGE_OVERLAP:
s = format (s, "\n%Uoverlapping/ignored %U", format_white_space, indent,
format_ip4_reass_range_trace, &t->trace_range);
break;
case FINALIZE:
s = format (s, "\n%Ufinalize reassembly", format_white_space, indent);
break;
}
return s;
}
static void
ip4_reass_add_trace (vlib_main_t * vm, vlib_node_runtime_t * node,
ip4_reass_main_t * rm, ip4_reass_t * reass, u32 bi,
ip4_reass_trace_operation_e action, u32 size_diff)
{
vlib_buffer_t *b = vlib_get_buffer (vm, bi);
vnet_buffer_opaque_t *vnb = vnet_buffer (b);
if (pool_is_free_index (vm->trace_main.trace_buffer_pool, b->trace_index))
{
// this buffer's trace is gone
b->flags &= ~VLIB_BUFFER_IS_TRACED;
return;
}
ip4_reass_trace_t *t = vlib_add_trace (vm, node, b, sizeof (t[0]));
t->reass_id = reass->id;
t->action = action;
ip4_reass_trace_details (vm, bi, &t->trace_range);
t->size_diff = size_diff;
t->op_id = reass->trace_op_counter;
++reass->trace_op_counter;
t->fragment_first = vnb->ip.reass.fragment_first;
t->fragment_last = vnb->ip.reass.fragment_last;
t->trace_range.first_bi = reass->first_bi;
t->total_data_len = reass->data_len;
#if 0
static u8 *s = NULL;
s = format (s, "%U", format_ip4_reass_trace, NULL, NULL, t);
printf ("%.*s\n", vec_len (s), s);
fflush (stdout);
vec_reset_length (s);
#endif
}
always_inline void
ip4_reass_free (ip4_reass_main_t * rm, ip4_reass_per_thread_t * rt,
ip4_reass_t * reass)
{
clib_bihash_kv_24_8_t kv;
kv.key[0] = reass->key.as_u64[0];
kv.key[1] = reass->key.as_u64[1];
kv.key[2] = reass->key.as_u64[2];
clib_bihash_add_del_24_8 (&rm->hash, &kv, 0);
pool_put (rt->pool, reass);
--rt->reass_n;
}
always_inline void
ip4_reass_on_timeout (vlib_main_t * vm, ip4_reass_main_t * rm,
ip4_reass_t * reass, u32 ** vec_drop_timeout)
{
u32 range_bi = reass->first_bi;
vlib_buffer_t *range_b;
vnet_buffer_opaque_t *range_vnb;
while (~0 != range_bi)
{
range_b = vlib_get_buffer (vm, range_bi);
range_vnb = vnet_buffer (range_b);
u32 bi = range_bi;
while (~0 != bi)
{
vec_add1 (*vec_drop_timeout, bi);
vlib_buffer_t *b = vlib_get_buffer (vm, bi);
if (b->flags & VLIB_BUFFER_NEXT_PRESENT)
{
bi = b->next_buffer;
b->flags &= ~VLIB_BUFFER_NEXT_PRESENT;
}
else
{
bi = ~0;
}
}
range_bi = range_vnb->ip.reass.next_range_bi;
}
}
ip4_reass_t *
ip4_reass_find_or_create (vlib_main_t * vm, ip4_reass_main_t * rm,
ip4_reass_per_thread_t * rt,
ip4_reass_key_t * k, u32 ** vec_drop_timeout)
{
ip4_reass_t *reass = NULL;
f64 now = vlib_time_now (rm->vlib_main);
clib_bihash_kv_24_8_t kv, value;
kv.key[0] = k->as_u64[0];
kv.key[1] = k->as_u64[1];
kv.key[2] = k->as_u64[2];
if (!clib_bihash_search_24_8 (&rm->hash, &kv, &value))
{
reass = pool_elt_at_index (rt->pool, value.value);
if (now > reass->last_heard + rm->timeout)
{
ip4_reass_on_timeout (vm, rm, reass, vec_drop_timeout);
ip4_reass_free (rm, rt, reass);
reass = NULL;
}
}
if (reass)
{
reass->last_heard = now;
return reass;
}
if (rt->reass_n >= rm->max_reass_n)
{
reass = NULL;
return reass;
}
else
{
pool_get (rt->pool, reass);
memset (reass, 0, sizeof (*reass));
reass->id =
((u64) os_get_thread_index () * 1000000000) + rt->id_counter;
++rt->id_counter;
reass->first_bi = ~0;
reass->last_packet_octet = ~0;
reass->data_len = 0;
++rt->reass_n;
}
reass->key.as_u64[0] = kv.key[0] = k->as_u64[0];
reass->key.as_u64[1] = kv.key[1] = k->as_u64[1];
reass->key.as_u64[2] = kv.key[2] = k->as_u64[2];
kv.value = reass - rt->pool;
reass->last_heard = now;
if (clib_bihash_add_del_24_8 (&rm->hash, &kv, 1))
{
ip4_reass_free (rm, rt, reass);
reass = NULL;
}
return reass;
}
always_inline void
ip4_reass_finalize (vlib_main_t * vm, vlib_node_runtime_t * node,
ip4_reass_main_t * rm, ip4_reass_per_thread_t * rt,
ip4_reass_t * reass, u32 * bi0, u32 * next0,
vlib_error_t * error0, u32 ** vec_drop_compress,
u32 ** vec_drop_overlap, bool is_feature)
{
ASSERT (~0 != reass->first_bi);
vlib_buffer_t *first_b = vlib_get_buffer (vm, reass->first_bi);
vlib_buffer_t *last_b = NULL;
u32 sub_chain_bi = reass->first_bi;
u32 total_length = 0;
u32 buf_cnt = 0;
u32 dropped_cnt = 0;
do
{
u32 tmp_bi = sub_chain_bi;
vlib_buffer_t *tmp = vlib_get_buffer (vm, tmp_bi);
ip4_header_t *ip = vlib_buffer_get_current (tmp);
u32 data_len = ip4_reass_buffer_get_data_len (tmp);
u32 trim_front =
ip4_header_bytes (ip) + ip4_reass_buffer_get_data_offset (tmp);
u32 trim_end =
vlib_buffer_length_in_chain (vm, tmp) - trim_front - data_len;
if (tmp_bi == reass->first_bi)
{
/* first buffer - keep ip4 header */
ASSERT (0 == ip4_reass_buffer_get_data_offset (tmp));
trim_front = 0;
trim_end = vlib_buffer_length_in_chain (vm, tmp) - data_len -
ip4_header_bytes (ip);
ASSERT (vlib_buffer_length_in_chain (vm, tmp) - trim_end > 0);
}
u32 keep_data =
vlib_buffer_length_in_chain (vm, tmp) - trim_front - trim_end;
while (1)
{
++buf_cnt;
if (trim_front)
{
if (trim_front > tmp->current_length)
{
/* drop whole buffer */
vec_add1 (*vec_drop_compress, tmp_bi);
++dropped_cnt;
trim_front -= tmp->current_length;
ASSERT (tmp->flags & VLIB_BUFFER_NEXT_PRESENT);
tmp->flags &= ~VLIB_BUFFER_NEXT_PRESENT;
tmp_bi = tmp->next_buffer;
tmp = vlib_get_buffer (vm, tmp_bi);
continue;
}
else
{
vlib_buffer_advance (tmp, trim_front);
trim_front = 0;
}
}
if (keep_data)
{
if (last_b)
{
last_b->flags |= VLIB_BUFFER_NEXT_PRESENT;
last_b->next_buffer = tmp_bi;
}
last_b = tmp;
if (keep_data <= tmp->current_length)
{
tmp->current_length = keep_data;
keep_data = 0;
}
else
{
keep_data -= tmp->current_length;
ASSERT (tmp->flags & VLIB_BUFFER_NEXT_PRESENT);
}
total_length += tmp->current_length;
}
else
{
vec_add1 (*vec_drop_overlap, tmp_bi);
ASSERT (reass->first_bi != tmp_bi);
++dropped_cnt;
}
if (tmp->flags & VLIB_BUFFER_NEXT_PRESENT)
{
tmp_bi = tmp->next_buffer;
tmp = vlib_get_buffer (vm, tmp->next_buffer);
}
else
{
break;
}
}
sub_chain_bi =
vnet_buffer (vlib_get_buffer (vm, sub_chain_bi))->ip.
reass.next_range_bi;
}
while (~0 != sub_chain_bi);
ASSERT (last_b != NULL);
last_b->flags &= ~VLIB_BUFFER_NEXT_PRESENT;
ASSERT (rt->buffers_n >= (buf_cnt - dropped_cnt));
rt->buffers_n -= buf_cnt - dropped_cnt;
ASSERT (total_length >= first_b->current_length);
total_length -= first_b->current_length;
first_b->flags |= VLIB_BUFFER_TOTAL_LENGTH_VALID;
first_b->total_length_not_including_first_buffer = total_length;
ip4_header_t *ip = vlib_buffer_get_current (first_b);
ip->flags_and_fragment_offset = 0;
ip->length = clib_host_to_net_u16 (first_b->current_length + total_length);
ip->checksum = ip4_header_checksum (ip);
vlib_buffer_chain_compress (vm, first_b, vec_drop_compress);
if (PREDICT_FALSE (first_b->flags & VLIB_BUFFER_IS_TRACED))
{
ip4_reass_add_trace (vm, node, rm, reass, reass->first_bi, FINALIZE, 0);
#if 0
// following code does a hexdump of packet fragments to stdout ...
do
{
u32 bi = reass->first_bi;
u8 *s = NULL;
while (~0 != bi)
{
vlib_buffer_t *b = vlib_get_buffer (vm, bi);
s = format (s, "%u: %U\n", bi, format_hexdump,
vlib_buffer_get_current (b), b->current_length);
if (b->flags & VLIB_BUFFER_NEXT_PRESENT)
{
bi = b->next_buffer;
}
else
{
break;
}
}
printf ("%.*s\n", vec_len (s), s);
fflush (stdout);
vec_free (s);
}
while (0);
#endif
}
*bi0 = reass->first_bi;
if (is_feature)
{
*next0 = IP4_REASSEMBLY_NEXT_INPUT;
}
else
{
*next0 = reass->next_index;
}
vnet_buffer (first_b)->ip.reass.estimated_mtu = reass->min_fragment_length;
*error0 = IP4_ERROR_NONE;
ip4_reass_free (rm, rt, reass);
reass = NULL;
}
always_inline u32
ip4_reass_get_buffer_chain_length (vlib_main_t * vm, vlib_buffer_t * b)
{
u32 len = 0;
while (b)
{
++len;
if (PREDICT_FALSE (b->flags & VLIB_BUFFER_NEXT_PRESENT))
{
b = vlib_get_buffer (vm, b->next_buffer);
}
else
{
break;
}
}
return len;
}
always_inline void
ip4_reass_insert_range_in_chain (vlib_main_t * vm,
ip4_reass_main_t * rm,
ip4_reass_per_thread_t * rt,
ip4_reass_t * reass,
u32 prev_range_bi, u32 new_next_bi)
{
vlib_buffer_t *new_next_b = vlib_get_buffer (vm, new_next_bi);
vnet_buffer_opaque_t *new_next_vnb = vnet_buffer (new_next_b);
if (~0 != prev_range_bi)
{
vlib_buffer_t *prev_b = vlib_get_buffer (vm, prev_range_bi);
vnet_buffer_opaque_t *prev_vnb = vnet_buffer (prev_b);
new_next_vnb->ip.reass.next_range_bi = prev_vnb->ip.reass.next_range_bi;
prev_vnb->ip.reass.next_range_bi = new_next_bi;
}
else
{
if (~0 != reass->first_bi)
{
new_next_vnb->ip.reass.next_range_bi = reass->first_bi;
}
reass->first_bi = new_next_bi;
}
reass->data_len += ip4_reass_buffer_get_data_len (new_next_b);
rt->buffers_n += ip4_reass_get_buffer_chain_length (vm, new_next_b);
}
always_inline void
ip4_reass_remove_range_from_chain (vlib_main_t * vm,
vlib_node_runtime_t * node,
ip4_reass_main_t * rm,
u32 ** vec_drop_overlap,
ip4_reass_t * reass, u32 prev_range_bi,
u32 discard_bi)
{
vlib_buffer_t *discard_b = vlib_get_buffer (vm, discard_bi);
vnet_buffer_opaque_t *discard_vnb = vnet_buffer (discard_b);
if (~0 != prev_range_bi)
{
vlib_buffer_t *prev_b = vlib_get_buffer (vm, prev_range_bi);
vnet_buffer_opaque_t *prev_vnb = vnet_buffer (prev_b);
ASSERT (prev_vnb->ip.reass.next_range_bi == discard_bi);
prev_vnb->ip.reass.next_range_bi = discard_vnb->ip.reass.next_range_bi;
}
else
{
reass->first_bi = discard_vnb->ip.reass.next_range_bi;
}
reass->data_len -= ip4_reass_buffer_get_data_len (discard_b);
while (1)
{
vec_add1 (*vec_drop_overlap, discard_bi);
if (PREDICT_FALSE (discard_b->flags & VLIB_BUFFER_IS_TRACED))
{
ip4_reass_add_trace (vm, node, rm, reass, discard_bi, RANGE_DISCARD,
0);
}
if (discard_b->flags & VLIB_BUFFER_NEXT_PRESENT)
{
discard_b->flags &= ~VLIB_BUFFER_NEXT_PRESENT;
discard_bi = discard_b->next_buffer;
discard_b = vlib_get_buffer (vm, discard_bi);
}
else
{
break;
}
}
}
always_inline void
ip4_reass_update (vlib_main_t * vm, vlib_node_runtime_t * node,
ip4_reass_main_t * rm, ip4_reass_per_thread_t * rt,
ip4_reass_t * reass, u32 * bi0, u32 * next0,
vlib_error_t * error0, u32 ** vec_drop_overlap,
u32 ** vec_drop_compress, bool is_feature)
{
int consumed = 0;
vlib_buffer_t *fb = vlib_get_buffer (vm, *bi0);
ip4_header_t *fip = vlib_buffer_get_current (fb);
ASSERT (fb->current_length >= sizeof (*fip));
vnet_buffer_opaque_t *fvnb = vnet_buffer (fb);
u32 fragment_first = fvnb->ip.reass.fragment_first =
ip4_get_fragment_offset_bytes (fip);
u32 fragment_length =
clib_net_to_host_u16 (fip->length) - ip4_header_bytes (fip);
u32 fragment_last = fvnb->ip.reass.fragment_last =
fragment_first + fragment_length - 1;
int more_fragments = ip4_get_fragment_more (fip);
u32 candidate_range_bi = reass->first_bi;
u32 prev_range_bi = ~0;
reass->next_index = fvnb->ip.reass.next_index; // store next_index before it's overwritten
fvnb->ip.reass.range_first = fragment_first;
fvnb->ip.reass.range_last = fragment_last;
fvnb->ip.reass.next_range_bi = ~0;
if (!more_fragments)
{
reass->last_packet_octet = fragment_last;
}
if (~0 == reass->first_bi)
{
// starting a new reassembly
ip4_reass_insert_range_in_chain (vm, rm, rt, reass, prev_range_bi,
*bi0);
if (PREDICT_FALSE (fb->flags & VLIB_BUFFER_IS_TRACED))
{
ip4_reass_add_trace (vm, node, rm, reass, *bi0, RANGE_NEW, 0);
}
*bi0 = ~0;
reass->min_fragment_length = clib_net_to_host_u16 (fip->length);
return;
}
reass->min_fragment_length = clib_min (clib_net_to_host_u16 (fip->length),
fvnb->ip.reass.estimated_mtu);
while (~0 != candidate_range_bi)
{
vlib_buffer_t *candidate_b = vlib_get_buffer (vm, candidate_range_bi);
vnet_buffer_opaque_t *candidate_vnb = vnet_buffer (candidate_b);
if (fragment_first > candidate_vnb->ip.reass.range_last)
{
// this fragments starts after candidate range
prev_range_bi = candidate_range_bi;
candidate_range_bi = candidate_vnb->ip.reass.next_range_bi;
if (candidate_vnb->ip.reass.range_last < fragment_last &&
~0 == candidate_range_bi)
{
// special case - this fragment falls beyond all known ranges
ip4_reass_insert_range_in_chain (vm, rm, rt, reass,
prev_range_bi, *bi0);
consumed = 1;
break;
}
continue;
}
if (fragment_last < candidate_vnb->ip.reass.range_first)
{
// this fragment ends before candidate range without any overlap
ip4_reass_insert_range_in_chain (vm, rm, rt, reass, prev_range_bi,
*bi0);
consumed = 1;
}
else
{
if (fragment_first >= candidate_vnb->ip.reass.range_first &&
fragment_last <= candidate_vnb->ip.reass.range_last)
{
// this fragment is a (sub)part of existing range, ignore it
if (PREDICT_FALSE (fb->flags & VLIB_BUFFER_IS_TRACED))
{
ip4_reass_add_trace (vm, node, rm, reass, *bi0,
RANGE_OVERLAP, 0);
}
break;
}
int discard_candidate = 0;
if (fragment_first < candidate_vnb->ip.reass.range_first)
{
u32 overlap =
fragment_last - candidate_vnb->ip.reass.range_first + 1;
if (overlap < ip4_reass_buffer_get_data_len (candidate_b))
{
candidate_vnb->ip.reass.range_first += overlap;
ASSERT (reass->data_len >= overlap);
reass->data_len -= overlap;
if (PREDICT_FALSE (fb->flags & VLIB_BUFFER_IS_TRACED))
{
ip4_reass_add_trace (vm, node, rm, reass,
candidate_range_bi, RANGE_SHRINK,
overlap);
}
ip4_reass_insert_range_in_chain (vm, rm, rt, reass,
prev_range_bi, *bi0);
consumed = 1;
}
else
{
discard_candidate = 1;
}
}
else if (fragment_last > candidate_vnb->ip.reass.range_last)
{
u32 overlap =
candidate_vnb->ip.reass.range_last - fragment_first + 1;
if (overlap < ip4_reass_buffer_get_data_len (candidate_b))
{
fvnb->ip.reass.range_first += overlap;
if (~0 != candidate_vnb->ip.reass.next_range_bi)
{
prev_range_bi = candidate_range_bi;
candidate_range_bi =
candidate_vnb->ip.reass.next_range_bi;
continue;
}
else
{
// special case - last range discarded
ip4_reass_insert_range_in_chain (vm, rm, rt, reass,
candidate_range_bi,
*bi0);
consumed = 1;
}
}
else
{
discard_candidate = 1;
}
}
else
{
discard_candidate = 1;
}
if (discard_candidate)
{
u32 next_range_bi = candidate_vnb->ip.reass.next_range_bi;
// discard candidate range, probe next range
ip4_reass_remove_range_from_chain (vm, node, rm,
vec_drop_overlap, reass,
prev_range_bi,
candidate_range_bi);
if (~0 != next_range_bi)
{
candidate_range_bi = next_range_bi;
continue;
}
else
{
// special case - last range discarded
ip4_reass_insert_range_in_chain (vm, rm, rt, reass,
prev_range_bi, *bi0);
consumed = 1;
}
}
}
break;
}
if (consumed)
{
if (PREDICT_FALSE (fb->flags & VLIB_BUFFER_IS_TRACED))
{
ip4_reass_add_trace (vm, node, rm, reass, *bi0, RANGE_NEW, 0);
}
}
if (~0 != reass->last_packet_octet &&
reass->data_len == reass->last_packet_octet + 1)
{
ip4_reass_finalize (vm, node, rm, rt, reass, bi0, next0, error0,
vec_drop_compress, vec_drop_overlap, is_feature);
}
else
{
if (consumed)
{
*bi0 = ~0;
}
else
{
*next0 = IP4_REASSEMBLY_NEXT_DROP;
*error0 = IP4_ERROR_REASS_DUPLICATE_FRAGMENT;
}
}
}
always_inline uword
ip4_reassembly_inline (vlib_main_t * vm,
vlib_node_runtime_t * node,
vlib_frame_t * frame, bool is_feature)
{
u32 *from = vlib_frame_vector_args (frame);
u32 n_left_from, n_left_to_next, *to_next, next_index;
ip4_reass_main_t *rm = &ip4_reass_main;
ip4_reass_per_thread_t *rt = &rm->per_thread_data[os_get_thread_index ()];
clib_spinlock_lock (&rt->lock);
n_left_from = frame->n_vectors;
next_index = node->cached_next_index;
static u32 *vec_drop_timeout = NULL; // indexes of buffers which timed out
static u32 *vec_drop_overlap = NULL; // indexes of buffers which were discarded due to overlap
static u32 *vec_drop_compress = NULL; // indexes of buffers dicarded due to buffer compression
while (n_left_from > 0 || vec_len (vec_drop_timeout) > 0 ||
vec_len (vec_drop_overlap) > 0 || vec_len (vec_drop_compress) > 0)
{
vlib_get_next_frame (vm, node, next_index, to_next, n_left_to_next);
while (vec_len (vec_drop_timeout) > 0 && n_left_to_next > 0)
{
u32 bi = vec_pop (vec_drop_timeout);
vlib_buffer_t *b = vlib_get_buffer (vm, bi);
b->error = node->errors[IP4_ERROR_REASS_TIMEOUT];
to_next[0] = bi;
to_next += 1;
n_left_to_next -= 1;
vlib_validate_buffer_enqueue_x1 (vm, node, next_index, to_next,
n_left_to_next, bi,
IP4_REASSEMBLY_NEXT_DROP);
IP4_REASS_DEBUG_BUFFER (bi, enqueue_drop_timeout);
ASSERT (rt->buffers_n > 0);
--rt->buffers_n;
}
while (vec_len (vec_drop_overlap) > 0 && n_left_to_next > 0)
{
u32 bi = vec_pop (vec_drop_overlap);
vlib_buffer_t *b = vlib_get_buffer (vm, bi);
b->error = node->errors[IP4_ERROR_REASS_DUPLICATE_FRAGMENT];
to_next[0] = bi;
to_next += 1;
n_left_to_next -= 1;
vlib_validate_buffer_enqueue_x1 (vm, node, next_index, to_next,
n_left_to_next, bi,
IP4_REASSEMBLY_NEXT_DROP);
IP4_REASS_DEBUG_BUFFER (bi, enqueue_drop_duplicate_fragment);
ASSERT (rt->buffers_n > 0);
--rt->buffers_n;
}
while (vec_len (vec_drop_compress) > 0 && n_left_to_next > 0)
{
u32 bi = vec_pop (vec_drop_compress);
vlib_buffer_t *b = vlib_get_buffer (vm, bi);
b->error = node->errors[IP4_ERROR_NONE];
to_next[0] = bi;
to_next += 1;
n_left_to_next -= 1;
vlib_validate_buffer_enqueue_x1 (vm, node, next_index, to_next,
n_left_to_next, bi,
IP4_REASSEMBLY_NEXT_DROP);
IP4_REASS_DEBUG_BUFFER (bi, enqueue_drop_compress);
ASSERT (rt->buffers_n > 0);
--rt->buffers_n;
}
while (n_left_from > 0 && n_left_to_next > 0)
{
u32 bi0;
vlib_buffer_t *b0;
u32 next0;
u32 error0 = IP4_ERROR_NONE;
bi0 = from[0];
b0 = vlib_get_buffer (vm, bi0);
ip4_header_t *ip0 = vlib_buffer_get_current (b0);
if (!ip4_get_fragment_more (ip0) && !ip4_get_fragment_offset (ip0))
{
// this is a whole packet - no fragmentation
if (is_feature)
{
next0 = IP4_REASSEMBLY_NEXT_INPUT;
}
else
{
next0 = vnet_buffer (b0)->ip.reass.next_index;
}
}
else
{
ip4_reass_key_t k;
k.src.as_u32 = ip0->src_address.as_u32;
k.dst.as_u32 = ip0->dst_address.as_u32;
k.xx_id = vnet_buffer (b0)->sw_if_index[VLIB_RX];
k.frag_id = ip0->fragment_id;
k.proto = ip0->protocol;
k.unused = 0;
ip4_reass_t *reass =
ip4_reass_find_or_create (vm, rm, rt, &k, &vec_drop_timeout);
if (reass)
{
ip4_reass_update (vm, node, rm, rt, reass, &bi0, &next0,
&error0, &vec_drop_overlap,
&vec_drop_compress, is_feature);
}
else
{
next0 = IP4_REASSEMBLY_NEXT_DROP;
error0 = IP4_ERROR_REASS_LIMIT_REACHED;
}
b0->error = node->errors[error0];
}
if (bi0 != ~0)
{
to_next[0] = bi0;
to_next += 1;
n_left_to_next -= 1;
if (is_feature && IP4_ERROR_NONE == error0)
{
vnet_feature_next (vnet_buffer (b0)->sw_if_index[VLIB_RX],
&next0, b0);
}
vlib_validate_buffer_enqueue_x1 (vm, node, next_index, to_next,
n_left_to_next, bi0, next0);
IP4_REASS_DEBUG_BUFFER (bi0, enqueue_next);
}
from += 1;
n_left_from -= 1;
}
vlib_put_next_frame (vm, node, next_index, n_left_to_next);
}
clib_spinlock_unlock (&rt->lock);
return frame->n_vectors;
}
static char *ip4_reassembly_error_strings[] = {
#define _(sym, string) string,
foreach_ip4_error
#undef _
};
always_inline uword
ip4_reassembly (vlib_main_t * vm, vlib_node_runtime_t * node,
vlib_frame_t * frame)
{
return ip4_reassembly_inline (vm, node, frame, false /* is_feature */ );
}
/* *INDENT-OFF* */
VLIB_REGISTER_NODE (ip4_reass_node, static) = {
.function = ip4_reassembly,
.name = "ip4-reassembly",
.vector_size = sizeof (u32),
.format_trace = format_ip4_reass_trace,
.n_errors = ARRAY_LEN (ip4_reassembly_error_strings),
.error_strings = ip4_reassembly_error_strings,
.n_next_nodes = IP4_REASSEMBLY_N_NEXT,
.next_nodes =
{
[IP4_REASSEMBLY_NEXT_INPUT] = "ip4-input",
[IP4_REASSEMBLY_NEXT_DROP] = "ip4-drop",
},
};
/* *INDENT-ON* */
VLIB_NODE_FUNCTION_MULTIARCH (ip4_reass_node, ip4_reassembly);
always_inline uword
ip4_reassembly_feature (vlib_main_t * vm,
vlib_node_runtime_t * node, vlib_frame_t * frame)
{
return ip4_reassembly_inline (vm, node, frame, true /* is_feature */ );
}
/* *INDENT-OFF* */
VLIB_REGISTER_NODE (ip4_reass_node_feature, static) = {
.function = ip4_reassembly_feature,
.name = "ip4-reassembly-feature",
.vector_size = sizeof (u32),
.format_trace = format_ip4_reass_trace,
.n_errors = ARRAY_LEN (ip4_reassembly_error_strings),
.error_strings = ip4_reassembly_error_strings,
.n_next_nodes = IP4_REASSEMBLY_N_NEXT,
.next_nodes =
{
[IP4_REASSEMBLY_NEXT_INPUT] = "ip4-input",
[IP4_REASSEMBLY_NEXT_DROP] = "ip4-drop",
},
};
/* *INDENT-ON* */
VLIB_NODE_FUNCTION_MULTIARCH (ip4_reass_node_feature, ip4_reassembly_feature);
/* *INDENT-OFF* */
VNET_FEATURE_INIT (ip4_reassembly_feature, static) = {
.arc_name = "ip4-unicast",
.node_name = "ip4-reassembly-feature",
.runs_before = VNET_FEATURES ("ip4-lookup"),
.runs_after = 0,
};
/* *INDENT-ON* */
always_inline u32
ip4_reass_get_nbuckets ()
{
ip4_reass_main_t *rm = &ip4_reass_main;
u32 nbuckets;
u8 i;
nbuckets = (u32) (rm->max_reass_n / IP4_REASS_HT_LOAD_FACTOR);
for (i = 0; i < 31; i++)
if ((1 << i) >= nbuckets)
break;
nbuckets = 1 << i;
return nbuckets;
}
typedef enum
{
IP4_EVENT_CONFIG_CHANGED = 1,
} ip4_reass_event_t;
typedef struct
{
int failure;
clib_bihash_24_8_t *new_hash;
} ip4_rehash_cb_ctx;
static void
ip4_rehash_cb (clib_bihash_kv_24_8_t * kv, void *_ctx)
{
ip4_rehash_cb_ctx *ctx = _ctx;
if (clib_bihash_add_del_24_8 (ctx->new_hash, kv, 1))
{
ctx->failure = 1;
}
}
static void
ip4_reass_set_params (u32 timeout_ms, u32 max_reassemblies,
u32 expire_walk_interval_ms)
{
ip4_reass_main.timeout_ms = timeout_ms;
ip4_reass_main.timeout = (f64) timeout_ms / (f64) MSEC_PER_SEC;
ip4_reass_main.max_reass_n = max_reassemblies;
ip4_reass_main.expire_walk_interval_ms = expire_walk_interval_ms;
}
vnet_api_error_t
ip4_reass_set (u32 timeout_ms, u32 max_reassemblies,
u32 expire_walk_interval_ms)
{
u32 old_nbuckets = ip4_reass_get_nbuckets ();
ip4_reass_set_params (timeout_ms, max_reassemblies,
expire_walk_interval_ms);
vlib_process_signal_event (ip4_reass_main.vlib_main,
ip4_reass_main.ip4_reass_expire_node_idx,
IP4_EVENT_CONFIG_CHANGED, 0);
u32 new_nbuckets = ip4_reass_get_nbuckets ();
if (ip4_reass_main.max_reass_n > 0 && new_nbuckets > 1 &&
new_nbuckets != old_nbuckets)
{
clib_bihash_24_8_t new_hash;
memset (&new_hash, 0, sizeof (new_hash));
ip4_rehash_cb_ctx ctx;
ctx.failure = 0;
ctx.new_hash = &new_hash;
clib_bihash_init_24_8 (&new_hash, "ip4-reass", new_nbuckets,
new_nbuckets * 1024);
clib_bihash_foreach_key_value_pair_24_8 (&ip4_reass_main.hash,
ip4_rehash_cb, &ctx);
if (ctx.failure)
{
clib_bihash_free_24_8 (&new_hash);
return -1;
}
else
{
clib_bihash_free_24_8 (&ip4_reass_main.hash);
clib_memcpy (&ip4_reass_main.hash, &new_hash,
sizeof (ip4_reass_main.hash));
}
}
return 0;
}
vnet_api_error_t
ip4_reass_get (u32 * timeout_ms, u32 * max_reassemblies,
u32 * expire_walk_interval_ms)
{
*timeout_ms = ip4_reass_main.timeout_ms;
*max_reassemblies = ip4_reass_main.max_reass_n;
*expire_walk_interval_ms = ip4_reass_main.expire_walk_interval_ms;
return 0;
}
static clib_error_t *
ip4_reass_init_function (vlib_main_t * vm)
{
ip4_reass_main_t *rm = &ip4_reass_main;
clib_error_t *error = 0;
u32 nbuckets;
vlib_node_t *node;
rm->vlib_main = vm;
rm->vnet_main = vnet_get_main ();
vec_validate (rm->per_thread_data, vlib_num_workers () + 1);
ip4_reass_per_thread_t *rt;
vec_foreach (rt, rm->per_thread_data)
{
clib_spinlock_init (&rt->lock);
pool_alloc (rt->pool, rm->max_reass_n);
}
node = vlib_get_node_by_name (vm, (u8 *) "ip4-reassembly-expire-walk");
ASSERT (node);
rm->ip4_reass_expire_node_idx = node->index;
nbuckets = ip4_reass_get_nbuckets ();
clib_bihash_init_24_8 (&rm->hash, "ip4-reass", nbuckets, nbuckets * 1024);
node = vlib_get_node_by_name (vm, (u8 *) "ip4-drop");
ASSERT (node);
rm->ip4_drop_idx = node->index;
ip4_reass_set_params (IP4_REASS_TIMEOUT_DEFAULT_MS,
IP4_REASS_MAX_REASSEMBLIES_DEFAULT,
IP4_REASS_EXPIRE_WALK_INTERVAL_DEFAULT_MS);
return error;
}
VLIB_INIT_FUNCTION (ip4_reass_init_function);
static uword
ip4_reass_walk_expired (vlib_main_t * vm,
vlib_node_runtime_t * node, vlib_frame_t * f)
{
ip4_reass_main_t *rm = &ip4_reass_main;
uword event_type, *event_data = 0;
while (true)
{
vlib_process_wait_for_event_or_clock (vm,
(f64) rm->expire_walk_interval_ms
/ (f64) MSEC_PER_SEC);
event_type = vlib_process_get_events (vm, &event_data);
switch (event_type)
{
case ~0: /* no events => timeout */
/* nothing to do here */
break;
case IP4_EVENT_CONFIG_CHANGED:
break;
default:
clib_warning ("BUG: event type 0x%wx", event_type);
break;
}
f64 now = vlib_time_now (vm);
ip4_reass_t *reass;
u32 *vec_drop_timeout = NULL;
int *pool_indexes_to_free = NULL;
uword thread_index = 0;
int index;
const uword nthreads = os_get_nthreads ();
for (thread_index = 0; thread_index < nthreads; ++thread_index)
{
ip4_reass_per_thread_t *rt = &rm->per_thread_data[thread_index];
clib_spinlock_lock (&rt->lock);
vec_reset_length (pool_indexes_to_free);
/* *INDENT-OFF* */
pool_foreach_index (index, rt->pool, ({
reass = pool_elt_at_index (rt->pool, index);
if (now > reass->last_heard + rm->timeout)
{
vec_add1 (pool_indexes_to_free, index);
}
}));
/* *INDENT-ON* */
int *i;
/* *INDENT-OFF* */
vec_foreach (i, pool_indexes_to_free)
{
ip4_reass_t *reass = pool_elt_at_index (rt->pool, i[0]);
u32 before = vec_len (vec_drop_timeout);
vlib_buffer_t *b = vlib_get_buffer (vm, reass->first_bi);
if (PREDICT_FALSE (b->flags & VLIB_BUFFER_IS_TRACED))
{
if (pool_is_free_index (vm->trace_main.trace_buffer_pool,
b->trace_index))
{
/* the trace is gone, don't trace this buffer anymore */
b->flags &= ~VLIB_BUFFER_IS_TRACED;
}
}
ip4_reass_on_timeout (vm, rm, reass, &vec_drop_timeout);
u32 after = vec_len (vec_drop_timeout);
ASSERT (rt->buffers_n >= (after - before));
rt->buffers_n -= (after - before);
ip4_reass_free (rm, rt, reass);
}
/* *INDENT-ON* */
clib_spinlock_unlock (&rt->lock);
}
while (vec_len (vec_drop_timeout) > 0)
{
vlib_frame_t *f = vlib_get_frame_to_node (vm, rm->ip4_drop_idx);
u32 *to_next = vlib_frame_vector_args (f);
u32 n_left_to_next = VLIB_FRAME_SIZE - f->n_vectors;
int trace_frame = 0;
while (vec_len (vec_drop_timeout) > 0 && n_left_to_next > 0)
{
u32 bi = vec_pop (vec_drop_timeout);
vlib_buffer_t *b = vlib_get_buffer (vm, bi);
if (PREDICT_FALSE (b->flags & VLIB_BUFFER_IS_TRACED))
{
if (pool_is_free_index (vm->trace_main.trace_buffer_pool,
b->trace_index))
{
/* the trace is gone, don't trace this buffer anymore */
b->flags &= ~VLIB_BUFFER_IS_TRACED;
}
else
{
trace_frame = 1;
}
}
b->error = node->errors[IP4_ERROR_REASS_TIMEOUT];
to_next[0] = bi;
++f->n_vectors;
to_next += 1;
n_left_to_next -= 1;
IP4_REASS_DEBUG_BUFFER (bi, enqueue_drop_timeout_walk);
}
f->flags |= (trace_frame * VLIB_FRAME_TRACE);
vlib_put_frame_to_node (vm, rm->ip4_drop_idx, f);
}
vec_free (pool_indexes_to_free);
vec_free (vec_drop_timeout);
if (event_data)
{
_vec_len (event_data) = 0;
}
}
return 0;
}
static vlib_node_registration_t ip4_reass_expire_node;
/* *INDENT-OFF* */
VLIB_REGISTER_NODE (ip4_reass_expire_node, static) = {
.function = ip4_reass_walk_expired,
.type = VLIB_NODE_TYPE_PROCESS,
.name = "ip4-reassembly-expire-walk",
.format_trace = format_ip4_reass_trace,
.n_errors = ARRAY_LEN (ip4_reassembly_error_strings),
.error_strings = ip4_reassembly_error_strings,
};
/* *INDENT-ON* */
static u8 *
format_ip4_reass_key (u8 * s, va_list * args)
{
ip4_reass_key_t *key = va_arg (*args, ip4_reass_key_t *);
s = format (s, "xx_id: %u, src: %U, dst: %U, frag_id: %u, proto: %u",
key->xx_id, format_ip4_address, &key->src, format_ip4_address,
&key->dst, clib_net_to_host_u16 (key->frag_id), key->proto);
return s;
}
static u8 *
format_ip4_reass (u8 * s, va_list * args)
{
vlib_main_t *vm = va_arg (*args, vlib_main_t *);
ip4_reass_t *reass = va_arg (*args, ip4_reass_t *);
s = format (s, "ID: %lu, key: %U\n first_bi: %u, data_len: %u, "
"last_packet_octet: %u, trace_op_counter: %u\n",
reass->id, format_ip4_reass_key, &reass->key, reass->first_bi,
reass->data_len, reass->last_packet_octet,
reass->trace_op_counter);
u32 bi = reass->first_bi;
u32 counter = 0;
while (~0 != bi)
{
vlib_buffer_t *b = vlib_get_buffer (vm, bi);
vnet_buffer_opaque_t *vnb = vnet_buffer (b);
s = format (s, " #%03u: range: [%u, %u], bi: %u, off: %d, len: %u, "
"fragment[%u, %u]\n",
counter, vnb->ip.reass.range_first,
vnb->ip.reass.range_last, bi,
ip4_reass_buffer_get_data_offset_no_check (b),
ip4_reass_buffer_get_data_len_no_check (b),
vnb->ip.reass.fragment_first, vnb->ip.reass.fragment_last);
if (b->flags & VLIB_BUFFER_NEXT_PRESENT)
{
bi = b->next_buffer;
}
else
{
bi = ~0;
}
}
return s;
}
static clib_error_t *
show_ip4_reass (vlib_main_t * vm, unformat_input_t * input,
CLIB_UNUSED (vlib_cli_command_t * lmd))
{
ip4_reass_main_t *rm = &ip4_reass_main;
vlib_cli_output (vm, "---------------------");
vlib_cli_output (vm, "IP4 reassembly status");
vlib_cli_output (vm, "---------------------");
bool details = false;
if (unformat (input, "details"))
{
details = true;
}
u32 sum_reass_n = 0;
u64 sum_buffers_n = 0;
ip4_reass_t *reass;
uword thread_index;
const uword nthreads = os_get_nthreads ();
for (thread_index = 0; thread_index < nthreads; ++thread_index)
{
ip4_reass_per_thread_t *rt = &rm->per_thread_data[thread_index];
clib_spinlock_lock (&rt->lock);
if (details)
{
/* *INDENT-OFF* */
pool_foreach (reass, rt->pool, {
vlib_cli_output (vm, "%U", format_ip4_reass, vm, reass);
});
/* *INDENT-ON* */
}
sum_reass_n += rt->reass_n;
sum_buffers_n += rt->buffers_n;
clib_spinlock_unlock (&rt->lock);
}
vlib_cli_output (vm, "---------------------");
vlib_cli_output (vm, "Current IP4 reassemblies count: %lu\n",
(long unsigned) sum_reass_n);
vlib_cli_output (vm,
"Maximum configured concurrent IP4 reassemblies per worker-thread: %lu\n",
(long unsigned) rm->max_reass_n);
vlib_cli_output (vm, "Buffers in use: %lu\n",
(long unsigned) sum_buffers_n);
return 0;
}
/* *INDENT-OFF* */
VLIB_CLI_COMMAND (show_ip4_reassembly_cmd, static) = {
.path = "show ip4-reassembly",
.short_help = "show ip4-reassembly [details]",
.function = show_ip4_reass,
};
/* *INDENT-ON* */
vnet_api_error_t
ip4_reass_enable_disable (u32 sw_if_index, u8 enable_disable)
{
return vnet_feature_enable_disable ("ip4-unicast", "ip4-reassembly-feature",
sw_if_index, enable_disable, 0, 0);
}
/*
* fd.io coding-style-patch-verification: ON
*
* Local Variables:
* eval: (c-set-style "gnu")
* End:
*/