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authorVijayabhaskar Katamreddy <vkatamre@cisco.com>2022-05-09 14:13:07 +0000
committerOle Tr�an <otroan@employees.org>2022-05-13 07:41:24 +0000
commite0f901a0483f7b10d2409075e694d91cf4fb42c5 (patch)
treec51fd68989615e224872bee83548f426aecd30f8
parent6f5ddf3461906bbc88f679882744afc74a81cae1 (diff)
ip: reassembly - Fixing buffer leaks, corruption
Type: fix *Buffer leaks and corruptions during internal errors, either overriding or missing to add the buffer to the list Signed-off-by: Vijayabhaskar Katamreddy <vkatamre@cisco.com> Change-Id: I6c2406cff53a741e800e2d05593696f3e9fd6ff5
-rw-r--r--src/vnet/ip/reass/ip4_full_reass.c176
1 files changed, 126 insertions, 50 deletions
diff --git a/src/vnet/ip/reass/ip4_full_reass.c b/src/vnet/ip/reass/ip4_full_reass.c
index b0840b1327a..f0e1753cf2d 100644
--- a/src/vnet/ip/reass/ip4_full_reass.c
+++ b/src/vnet/ip/reass/ip4_full_reass.c
@@ -29,10 +29,10 @@
#include <stddef.h>
#define MSEC_PER_SEC 1000
-#define IP4_REASS_TIMEOUT_DEFAULT_MS 100
+#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_MAX_REASSEMBLY_LENGTH_DEFAULT 3
+#define IP4_REASS_MAX_REASSEMBLY_LENGTH_DEFAULT 3
#define IP4_REASS_HT_LOAD_FACTOR (0.75)
#define IP4_REASS_DEBUG_BUFFERS 0
@@ -417,67 +417,65 @@ ip4_full_reass_free (ip4_full_reass_main_t * rm,
return ip4_full_reass_free_ctx (rt, reass);
}
+/* n_left_to_next, and to_next are taken as input params, as this function
+ * could be called from a graphnode, where its managing local copy of these
+ * variables, and ignoring those and still trying to enqueue the buffers
+ * with local variables would cause either buffer leak or corruption */
always_inline void
ip4_full_reass_drop_all (vlib_main_t *vm, vlib_node_runtime_t *node,
- ip4_full_reass_t *reass, u32 offending_bi)
+ ip4_full_reass_t *reass, u32 *n_left_to_next,
+ u32 **to_next)
{
u32 range_bi = reass->first_bi;
vlib_buffer_t *range_b;
vnet_buffer_opaque_t *range_vnb;
u32 *to_free = NULL;
+
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)
+
+ if (~0 != range_bi)
{
- vec_add1 (to_free, bi);
- if (offending_bi == bi)
- {
- offending_bi = ~0;
- }
- 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;
- }
+ vec_add1 (to_free, range_bi);
}
+
range_bi = range_vnb->ip.reass.next_range_bi;
}
- if (~0 != offending_bi)
- {
- vec_add1 (to_free, offending_bi);
- }
+
/* send to next_error_index */
- if (~0 != reass->error_next_index)
+ if (~0 != reass->error_next_index &&
+ reass->error_next_index < node->n_next_nodes)
{
- u32 n_left_to_next, *to_next, next_index;
+ u32 next_index;
next_index = reass->error_next_index;
u32 bi = ~0;
while (vec_len (to_free) > 0)
{
- vlib_get_next_frame (vm, node, next_index, to_next, n_left_to_next);
+ vlib_get_next_frame (vm, node, next_index, *to_next,
+ (*n_left_to_next));
- while (vec_len (to_free) > 0 && n_left_to_next > 0)
+ while (vec_len (to_free) > 0 && (*n_left_to_next) > 0)
{
bi = vec_pop (to_free);
if (~0 != bi)
{
- to_next[0] = bi;
- to_next += 1;
- n_left_to_next -= 1;
+ vlib_buffer_t *b = vlib_get_buffer (vm, bi);
+ if ((b->flags & VLIB_BUFFER_IS_TRACED))
+ {
+ ip4_full_reass_add_trace (vm, node, reass, bi,
+ RANGE_DISCARD, 0, ~0);
+ }
+ *to_next[0] = bi;
+ (*to_next) += 1;
+ (*n_left_to_next) -= 1;
}
}
- vlib_put_next_frame (vm, node, next_index, n_left_to_next);
+ vlib_put_next_frame (vm, node, next_index, (*n_left_to_next));
}
}
else
@@ -488,6 +486,62 @@ ip4_full_reass_drop_all (vlib_main_t *vm, vlib_node_runtime_t *node,
}
always_inline void
+sanitize_reass_buffers_add_missing (vlib_main_t *vm, ip4_full_reass_t *reass,
+ u32 *bi0)
+{
+ 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;
+ if (~0 != bi)
+ {
+ if (bi == *bi0)
+ *bi0 = ~0;
+ if (range_b->flags & VLIB_BUFFER_NEXT_PRESENT)
+ {
+ u32 _bi = bi;
+ vlib_buffer_t *_b = vlib_get_buffer (vm, _bi);
+ while (_b->flags & VLIB_BUFFER_NEXT_PRESENT)
+ {
+ if (_b->next_buffer != range_vnb->ip.reass.next_range_bi)
+ {
+ _bi = _b->next_buffer;
+ _b = vlib_get_buffer (vm, _bi);
+ }
+ else
+ {
+ _b->flags &= ~VLIB_BUFFER_NEXT_PRESENT;
+ break;
+ }
+ }
+ }
+ range_bi = range_vnb->ip.reass.next_range_bi;
+ }
+ }
+ if (*bi0 != ~0)
+ {
+ vlib_buffer_t *fb = vlib_get_buffer (vm, *bi0);
+ vnet_buffer_opaque_t *fvnb = vnet_buffer (fb);
+ if (~0 != reass->first_bi)
+ {
+ fvnb->ip.reass.next_range_bi = reass->first_bi;
+ reass->first_bi = *bi0;
+ }
+ else
+ {
+ reass->first_bi = *bi0;
+ fvnb->ip.reass.next_range_bi = ~0;
+ }
+ *bi0 = ~0;
+ }
+}
+
+always_inline void
ip4_full_reass_init (ip4_full_reass_t * reass)
{
reass->first_bi = ~0;
@@ -498,10 +552,11 @@ ip4_full_reass_init (ip4_full_reass_t * reass)
}
always_inline ip4_full_reass_t *
-ip4_full_reass_find_or_create (vlib_main_t * vm, vlib_node_runtime_t * node,
- ip4_full_reass_main_t * rm,
- ip4_full_reass_per_thread_t * rt,
- ip4_full_reass_kv_t * kv, u8 * do_handoff)
+ip4_full_reass_find_or_create (vlib_main_t *vm, vlib_node_runtime_t *node,
+ ip4_full_reass_main_t *rm,
+ ip4_full_reass_per_thread_t *rt,
+ ip4_full_reass_kv_t *kv, u8 *do_handoff,
+ u32 *n_left_to_next, u32 **to_next)
{
ip4_full_reass_t *reass;
f64 now;
@@ -524,7 +579,7 @@ again:
if (now > reass->last_heard + rm->timeout)
{
- ip4_full_reass_drop_all (vm, node, reass, ~0);
+ ip4_full_reass_drop_all (vm, node, reass, n_left_to_next, to_next);
ip4_full_reass_free (rm, rt, reass);
reass = NULL;
}
@@ -769,6 +824,7 @@ ip4_full_reass_finalize (vlib_main_t * vm, vlib_node_runtime_t * node,
*next0 = reass->next_index;
}
vnet_buffer (first_b)->ip.reass.estimated_mtu = reass->min_fragment_length;
+
*error0 = IP4_ERROR_NONE;
ip4_full_reass_free (rm, rt, reass);
reass = NULL;
@@ -1157,7 +1213,11 @@ ip4_full_reass_inline (vlib_main_t *vm, vlib_node_runtime_t *node,
const u32 fragment_length =
clib_net_to_host_u16 (ip0->length) - ip4_header_bytes (ip0);
const u32 fragment_last = fragment_first + fragment_length - 1;
- if (fragment_first > fragment_last || fragment_first + fragment_length > UINT16_MAX - 20 || (fragment_length < 8 && ip4_get_fragment_more (ip0))) // 8 is minimum frag length per RFC 791
+
+ if (fragment_first > fragment_last ||
+ fragment_first + fragment_length > UINT16_MAX - 20 ||
+ (fragment_length < 8 && // 8 is minimum frag length per RFC 791
+ ip4_get_fragment_more (ip0)))
{
next0 = IP4_FULL_REASS_NEXT_DROP;
error0 = IP4_ERROR_REASS_MALFORMED_PACKET;
@@ -1174,9 +1234,8 @@ ip4_full_reass_inline (vlib_main_t *vm, vlib_node_runtime_t *node,
(u64) ip0->dst_address.
as_u32 | (u64) ip0->fragment_id << 32 | (u64) ip0->protocol << 48;
- ip4_full_reass_t *reass =
- ip4_full_reass_find_or_create (vm, node, rm, rt, &kv,
- &do_handoff);
+ ip4_full_reass_t *reass = ip4_full_reass_find_or_create (
+ vm, node, rm, rt, &kv, &do_handoff, &n_left_to_next, &to_next);
if (reass)
{
@@ -1218,6 +1277,15 @@ ip4_full_reass_inline (vlib_main_t *vm, vlib_node_runtime_t *node,
break;
case IP4_REASS_RC_INTERNAL_ERROR:
counter = IP4_ERROR_REASS_INTERNAL_ERROR;
+ /* Sanitization is needed in internal error cases only, as
+ * the incoming packet is already dropped in other cases,
+ * also adding bi0 back to the reassembly list, fixes the
+ * leaking of buffers during internal errors.
+ *
+ * Also it doesnt make sense to send these buffers custom
+ * app, these fragments are with internal errors */
+ sanitize_reass_buffers_add_missing (vm, reass, &bi0);
+ reass->error_next_index = ~0;
break;
}
@@ -1225,7 +1293,8 @@ ip4_full_reass_inline (vlib_main_t *vm, vlib_node_runtime_t *node,
{
vlib_node_increment_counter (vm, node->node_index, counter,
1);
- ip4_full_reass_drop_all (vm, node, reass, bi0);
+ ip4_full_reass_drop_all (vm, node, reass, &n_left_to_next,
+ &to_next);
ip4_full_reass_free (rm, rt, reass);
goto next_packet;
}
@@ -1265,6 +1334,7 @@ ip4_full_reass_inline (vlib_main_t *vm, vlib_node_runtime_t *node,
{
vnet_feature_next (&next0, b0);
}
+
vlib_validate_buffer_enqueue_x1 (vm, node, next_index,
to_next, n_left_to_next,
bi0, next0);
@@ -1589,6 +1659,8 @@ ip4_full_reass_walk_expired (vlib_main_t *vm, vlib_node_runtime_t *node,
uword thread_index = 0;
int index;
const uword nthreads = vlib_num_workers () + 1;
+ u32 n_left_to_next, *to_next;
+
for (thread_index = 0; thread_index < nthreads; ++thread_index)
{
ip4_full_reass_per_thread_t *rt =
@@ -1596,18 +1668,22 @@ ip4_full_reass_walk_expired (vlib_main_t *vm, vlib_node_runtime_t *node,
clib_spinlock_lock (&rt->lock);
vec_reset_length (pool_indexes_to_free);
- 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);
- }
- }
+
+ 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);
+ }
+ }
+
int *i;
vec_foreach (i, pool_indexes_to_free)
{
ip4_full_reass_t *reass = pool_elt_at_index (rt->pool, i[0]);
- ip4_full_reass_drop_all (vm, node, reass, ~0);
+ ip4_full_reass_drop_all (vm, node, reass, &n_left_to_next,
+ &to_next);
ip4_full_reass_free (rm, rt, reass);
}