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authorJuraj Sloboda <jsloboda@cisco.com>2018-07-23 12:22:54 +0200
committerOle Trøan <otroan@employees.org>2018-09-20 07:15:03 +0000
commitfe0aa7648703f63159be8362836b39d4727fbb0c (patch)
tree623ae6470eba01b87ed41a94da14c8f7dbb31930 /src/plugins/nat/nat.c
parent6e06d66795a3948bb75cf5fd1cfc5745fec29505 (diff)
NAT44 virtual fragmentation reassembly for endpoint-dependent mode (VPP-1325)
Change-Id: I36ece2ef2eaef9fa559d69ec7f7f07e7c16a7a9d Signed-off-by: Juraj Sloboda <jsloboda@cisco.com>
Diffstat (limited to 'src/plugins/nat/nat.c')
-rwxr-xr-xsrc/plugins/nat/nat.c265
1 files changed, 240 insertions, 25 deletions
diff --git a/src/plugins/nat/nat.c b/src/plugins/nat/nat.c
index c3583cabc21..d4c266a2b16 100755
--- a/src/plugins/nat/nat.c
+++ b/src/plugins/nat/nat.c
@@ -178,9 +178,27 @@ vlib_node_registration_t nat44_ed_classify_node;
vlib_node_registration_t nat44_det_classify_node;
vlib_node_registration_t nat44_handoff_classify_node;
+#define foreach_nat44_classify_error \
+_(MAX_REASS, "Maximum reassemblies exceeded") \
+_(MAX_FRAG, "Maximum fragments per reassembly exceeded")
+
+typedef enum {
+#define _(sym,str) NAT44_CLASSIFY_ERROR_##sym,
+ foreach_nat44_classify_error
+#undef _
+ NAT44_CLASSIFY_N_ERROR,
+} nat44_classify_error_t;
+
+static char * nat44_classify_error_strings[] = {
+#define _(sym,string) string,
+ foreach_nat44_classify_error
+#undef _
+};
+
typedef enum {
NAT44_CLASSIFY_NEXT_IN2OUT,
NAT44_CLASSIFY_NEXT_OUT2IN,
+ NAT44_CLASSIFY_NEXT_DROP,
NAT44_CLASSIFY_N_NEXT,
} nat44_classify_next_t;
@@ -438,6 +456,7 @@ nat_ed_session_alloc (snat_main_t *sm, snat_user_t *u, u32 thread_index)
typedef struct {
u8 next_in2out;
+ u8 cached;
} nat44_classify_trace_t;
static u8 * format_nat44_classify_trace (u8 * s, va_list * args)
@@ -447,9 +466,13 @@ static u8 * format_nat44_classify_trace (u8 * s, va_list * args)
nat44_classify_trace_t *t = va_arg (*args, nat44_classify_trace_t *);
char *next;
- next = t->next_in2out ? "nat44-in2out" : "nat44-out2in";
-
- s = format (s, "nat44-classify: next %s", next);
+ if (t->cached)
+ s = format (s, "nat44-classify: fragment cached");
+ else
+ {
+ next = t->next_in2out ? "nat44-in2out" : "nat44-out2in";
+ s = format (s, "nat44-classify: next %s", next);
+ }
return s;
}
@@ -466,6 +489,8 @@ nat44_classify_node_fn_inline (vlib_main_t * vm,
snat_static_mapping_t *m;
u32 thread_index = vm->thread_index;
snat_main_per_thread_data_t *tsm = &sm->per_thread_data[thread_index];
+ u32 *fragments_to_drop = 0;
+ u32 *fragments_to_loopback = 0;
from = vlib_frame_vector_args (frame);
n_left_from = frame->n_vectors;
@@ -489,6 +514,8 @@ nat44_classify_node_fn_inline (vlib_main_t * vm,
clib_bihash_kv_8_8_t kv0, value0;
clib_bihash_kv_16_8_t ed_kv0, ed_value0;
udp_header_t *udp0;
+ nat_reass_ip4_t *reass0;
+ u8 cached0 = 0;
/* speculatively enqueue b0 to the current next frame */
bi0 = from[0];
@@ -502,17 +529,102 @@ nat44_classify_node_fn_inline (vlib_main_t * vm,
ip0 = vlib_buffer_get_current (b0);
udp0 = ip4_next_header (ip0);
- if (is_ed)
+ if (is_ed && ip0->protocol != IP_PROTOCOL_ICMP)
{
- sw_if_index0 = vnet_buffer(b0)->sw_if_index[VLIB_RX];
- rx_fib_index0 =
- fib_table_get_index_for_sw_if_index (FIB_PROTOCOL_IP4,
- sw_if_index0);
- make_ed_kv (&ed_kv0, &ip0->src_address, &ip0->dst_address,
- ip0->protocol, rx_fib_index0, udp0->src_port,
- udp0->dst_port);
- if (!clib_bihash_search_16_8 (&tsm->in2out_ed, &ed_kv0, &ed_value0))
- goto enqueue0;
+ if (!ip4_is_fragment (ip0) || ip4_is_first_fragment (ip0))
+ {
+ /* process leading fragment/whole packet (with L4 header) */
+ sw_if_index0 = vnet_buffer(b0)->sw_if_index[VLIB_RX];
+ rx_fib_index0 =
+ fib_table_get_index_for_sw_if_index (FIB_PROTOCOL_IP4,
+ sw_if_index0);
+ make_ed_kv (&ed_kv0, &ip0->src_address, &ip0->dst_address,
+ ip0->protocol, rx_fib_index0, udp0->src_port,
+ udp0->dst_port);
+ if (ip4_is_fragment (ip0))
+ {
+ reass0 = nat_ip4_reass_find_or_create (ip0->src_address,
+ ip0->dst_address,
+ ip0->fragment_id,
+ ip0->protocol,
+ 1,
+ &fragments_to_drop);
+ if (PREDICT_FALSE (!reass0))
+ {
+ next0 = NAT44_CLASSIFY_NEXT_DROP;
+ b0->error = node->errors[NAT44_CLASSIFY_ERROR_MAX_REASS];
+ nat_log_notice ("maximum reassemblies exceeded");
+ goto enqueue0;
+ }
+ if (!clib_bihash_search_16_8 (&tsm->in2out_ed, &ed_kv0,
+ &ed_value0))
+ {
+ /* session exists so classify as IN2OUT,
+ * save this information for future fragments and set
+ * past fragments to be looped over and reprocessed */
+ reass0->sess_index = ed_value0.value;
+ reass0->classify_next = NAT_REASS_IP4_CLASSIFY_NEXT_IN2OUT;
+ nat_ip4_reass_get_frags (reass0,
+ &fragments_to_loopback);
+ goto enqueue0;
+ }
+ else
+ {
+ /* session doesn't exist so continue in the code,
+ * save this information for future fragments and set
+ * past fragments to be looped over and reprocessed */
+ reass0->flags |= NAT_REASS_FLAG_CLASSIFY_ED_CONTINUE;
+ nat_ip4_reass_get_frags (reass0,
+ &fragments_to_loopback);
+ }
+ }
+ else
+ {
+ /* process whole packet */
+ if (!clib_bihash_search_16_8 (&tsm->in2out_ed, &ed_kv0,
+ &ed_value0))
+ goto enqueue0;
+ /* session doesn't exist so continue in code */
+ }
+ }
+ else
+ {
+ /* process non-first fragment */
+ reass0 = nat_ip4_reass_find_or_create (ip0->src_address,
+ ip0->dst_address,
+ ip0->fragment_id,
+ ip0->protocol,
+ 1,
+ &fragments_to_drop);
+ if (PREDICT_FALSE (!reass0))
+ {
+ next0 = NAT44_CLASSIFY_NEXT_DROP;
+ b0->error = node->errors[NAT44_CLASSIFY_ERROR_MAX_REASS];
+ nat_log_notice ("maximum reassemblies exceeded");
+ goto enqueue0;
+ }
+ /* check if first fragment has arrived */
+ if (reass0->classify_next == NAT_REASS_IP4_CLASSIFY_NONE &&
+ !(reass0->flags & NAT_REASS_FLAG_CLASSIFY_ED_CONTINUE))
+ {
+ /* first fragment still hasn't arrived, cache this fragment */
+ if (nat_ip4_reass_add_fragment (reass0, bi0,
+ &fragments_to_drop))
+ {
+ b0->error = node->errors[NAT44_CLASSIFY_ERROR_MAX_FRAG];
+ nat_log_notice ("maximum fragments per reassembly exceeded");
+ next0 = NAT44_CLASSIFY_NEXT_DROP;
+ goto enqueue0;
+ }
+ cached0 = 1;
+ goto enqueue0;
+ }
+ if (reass0->classify_next == NAT_REASS_IP4_CLASSIFY_NEXT_IN2OUT)
+ goto enqueue0;
+ /* flag NAT_REASS_FLAG_CLASSIFY_ED_CONTINUE is set
+ * so keep the default next0 and continue in code to
+ * potentially find other classification for this packet */
+ }
}
vec_foreach (ap, sm->addresses)
@@ -531,21 +643,86 @@ nat44_classify_node_fn_inline (vlib_main_t * vm,
m_key0.protocol = 0;
m_key0.fib_index = 0;
kv0.key = m_key0.as_u64;
- if (!clib_bihash_search_8_8 (&sm->static_mapping_by_external, &kv0, &value0))
+ /* try to classify the fragment based on IP header alone */
+ if (!clib_bihash_search_8_8 (&sm->static_mapping_by_external,
+ &kv0, &value0))
{
m = pool_elt_at_index (sm->static_mappings, value0.value);
if (m->local_addr.as_u32 != m->external_addr.as_u32)
next0 = NAT44_CLASSIFY_NEXT_OUT2IN;
goto enqueue0;
}
- m_key0.port = clib_net_to_host_u16 (udp0->dst_port);
- m_key0.protocol = ip_proto_to_snat_proto (ip0->protocol);
- kv0.key = m_key0.as_u64;
- if (!clib_bihash_search_8_8 (&sm->static_mapping_by_external, &kv0, &value0))
+ if (!ip4_is_fragment (ip0) || ip4_is_first_fragment (ip0))
{
- m = pool_elt_at_index (sm->static_mappings, value0.value);
- if (m->local_addr.as_u32 != m->external_addr.as_u32)
+ /* process leading fragment/whole packet (with L4 header) */
+ m_key0.port = clib_net_to_host_u16 (udp0->dst_port);
+ m_key0.protocol = ip_proto_to_snat_proto (ip0->protocol);
+ kv0.key = m_key0.as_u64;
+ if (!clib_bihash_search_8_8 (&sm->static_mapping_by_external,
+ &kv0, &value0))
+ {
+ m = pool_elt_at_index (sm->static_mappings, value0.value);
+ if (m->local_addr.as_u32 != m->external_addr.as_u32)
+ next0 = NAT44_CLASSIFY_NEXT_OUT2IN;
+ }
+ if (ip4_is_fragment (ip0))
+ {
+ reass0 = nat_ip4_reass_find_or_create (ip0->src_address,
+ ip0->dst_address,
+ ip0->fragment_id,
+ ip0->protocol,
+ 1,
+ &fragments_to_drop);
+ if (PREDICT_FALSE (!reass0))
+ {
+ next0 = NAT44_CLASSIFY_NEXT_DROP;
+ b0->error = node->errors[NAT44_CLASSIFY_ERROR_MAX_REASS];
+ nat_log_notice ("maximum reassemblies exceeded");
+ goto enqueue0;
+ }
+ /* save classification for future fragments and set past
+ * fragments to be looped over and reprocessed */
+ if (next0 == NAT44_CLASSIFY_NEXT_OUT2IN)
+ reass0->classify_next = NAT_REASS_IP4_CLASSIFY_NEXT_OUT2IN;
+ else
+ reass0->classify_next = NAT_REASS_IP4_CLASSIFY_NEXT_IN2OUT;
+ nat_ip4_reass_get_frags (reass0, &fragments_to_loopback);
+ }
+ }
+ else
+ {
+ /* process non-first fragment */
+ reass0 = nat_ip4_reass_find_or_create (ip0->src_address,
+ ip0->dst_address,
+ ip0->fragment_id,
+ ip0->protocol,
+ 1,
+ &fragments_to_drop);
+ if (PREDICT_FALSE (!reass0))
+ {
+ next0 = NAT44_CLASSIFY_NEXT_DROP;
+ b0->error = node->errors[NAT44_CLASSIFY_ERROR_MAX_REASS];
+ nat_log_notice ("maximum reassemblies exceeded");
+ goto enqueue0;
+ }
+ if (reass0->classify_next == NAT_REASS_IP4_CLASSIFY_NONE)
+ /* first fragment still hasn't arrived */
+ {
+ if (nat_ip4_reass_add_fragment (reass0, bi0,
+ &fragments_to_drop))
+ {
+ b0->error = node->errors[NAT44_CLASSIFY_ERROR_MAX_FRAG];
+ nat_log_notice ("maximum fragments per reassembly exceeded");
+ next0 = NAT44_CLASSIFY_NEXT_DROP;
+ goto enqueue0;
+ }
+ cached0 = 1;
+ goto enqueue0;
+ }
+ else if (reass0->classify_next == NAT_REASS_IP4_CLASSIFY_NEXT_OUT2IN)
next0 = NAT44_CLASSIFY_NEXT_OUT2IN;
+ else if (reass0->classify_next == NAT_REASS_IP4_CLASSIFY_NEXT_IN2OUT)
+ next0 = NAT44_CLASSIFY_NEXT_IN2OUT;
}
}
@@ -555,18 +732,50 @@ nat44_classify_node_fn_inline (vlib_main_t * vm,
{
nat44_classify_trace_t *t =
vlib_add_trace (vm, node, b0, sizeof (*t));
- t->next_in2out = next0 == NAT44_CLASSIFY_NEXT_IN2OUT ? 1 : 0;
+ t->cached = cached0;
+ if (!cached0)
+ t->next_in2out = next0 == NAT44_CLASSIFY_NEXT_IN2OUT ? 1 : 0;
}
- /* verify speculative enqueue, maybe switch current next frame */
- vlib_validate_buffer_enqueue_x1 (vm, node, next_index,
- to_next, n_left_to_next,
- bi0, next0);
+ if (cached0)
+ {
+ n_left_to_next++;
+ to_next--;
+ }
+ else
+ /* verify speculative enqueue, maybe switch current next frame */
+ vlib_validate_buffer_enqueue_x1 (vm, node, next_index,
+ to_next, n_left_to_next,
+ bi0, next0);
+
+ if (n_left_from == 0 && vec_len (fragments_to_loopback))
+ {
+ from = vlib_frame_vector_args (frame);
+ u32 len = vec_len (fragments_to_loopback);
+ if (len <= VLIB_FRAME_SIZE)
+ {
+ clib_memcpy (from, fragments_to_loopback, sizeof (u32) * len);
+ n_left_from = len;
+ vec_reset_length (fragments_to_loopback);
+ }
+ else
+ {
+ clib_memcpy (from,
+ fragments_to_loopback + (len - VLIB_FRAME_SIZE),
+ sizeof (u32) * VLIB_FRAME_SIZE);
+ n_left_from = VLIB_FRAME_SIZE;
+ _vec_len (fragments_to_loopback) = len - VLIB_FRAME_SIZE;
+ }
+ }
}
vlib_put_next_frame (vm, node, next_index, n_left_to_next);
}
+ nat_send_all_to_node (vm, fragments_to_drop, node, 0, NAT44_CLASSIFY_NEXT_DROP);
+
+ vec_free (fragments_to_drop);
+
return frame->n_vectors;
}
@@ -584,10 +793,13 @@ VLIB_REGISTER_NODE (nat44_classify_node) = {
.vector_size = sizeof (u32),
.format_trace = format_nat44_classify_trace,
.type = VLIB_NODE_TYPE_INTERNAL,
+ .n_errors = ARRAY_LEN(nat44_classify_error_strings),
+ .error_strings = nat44_classify_error_strings,
.n_next_nodes = NAT44_CLASSIFY_N_NEXT,
.next_nodes = {
[NAT44_CLASSIFY_NEXT_IN2OUT] = "nat44-in2out",
[NAT44_CLASSIFY_NEXT_OUT2IN] = "nat44-out2in",
+ [NAT44_CLASSIFY_NEXT_DROP] = "error-drop",
},
};
@@ -611,6 +823,7 @@ VLIB_REGISTER_NODE (nat44_ed_classify_node) = {
.next_nodes = {
[NAT44_CLASSIFY_NEXT_IN2OUT] = "nat44-ed-in2out",
[NAT44_CLASSIFY_NEXT_OUT2IN] = "nat44-ed-out2in",
+ [NAT44_CLASSIFY_NEXT_DROP] = "error-drop",
},
};
@@ -635,6 +848,7 @@ VLIB_REGISTER_NODE (nat44_det_classify_node) = {
.next_nodes = {
[NAT44_CLASSIFY_NEXT_IN2OUT] = "nat44-det-in2out",
[NAT44_CLASSIFY_NEXT_OUT2IN] = "nat44-det-out2in",
+ [NAT44_CLASSIFY_NEXT_DROP] = "error-drop",
},
};
@@ -659,6 +873,7 @@ VLIB_REGISTER_NODE (nat44_handoff_classify_node) = {
.next_nodes = {
[NAT44_CLASSIFY_NEXT_IN2OUT] = "nat44-in2out-worker-handoff",
[NAT44_CLASSIFY_NEXT_OUT2IN] = "nat44-out2in-worker-handoff",
+ [NAT44_CLASSIFY_NEXT_DROP] = "error-drop",
},
};