sr: SRv6 Path Tracing Midpoint behaviour
Type: feature
Signed-off-by: Julian Klaiber <julian@klaiber.me>
Change-Id: I866a2d2e06013380309c98a54078c1b3f6ad76fc
diff --git a/src/vnet/CMakeLists.txt b/src/vnet/CMakeLists.txt
index f4394ac..32ff39a 100644
--- a/src/vnet/CMakeLists.txt
+++ b/src/vnet/CMakeLists.txt
@@ -820,6 +820,7 @@
srv6/sr_steering.c
srv6/sr_api.c
srv6/sr_pt.c
+ srv6/sr_pt_node.c
)
list(APPEND VNET_HEADERS
diff --git a/src/vnet/srv6/sr_pt.c b/src/vnet/srv6/sr_pt.c
index 5d907ea..6299faa 100644
--- a/src/vnet/srv6/sr_pt.c
+++ b/src/vnet/srv6/sr_pt.c
@@ -69,6 +69,8 @@
if (tts_template > SR_PT_TTS_TEMPLATE_MAX)
return SR_PT_ERR_TTS_TEMPLATE_INVALID;
+ vnet_feature_enable_disable ("ip6-output", "pt", iface, 1, 0, 0);
+
/* Create a new sr_pt_iface */
pool_get_zero (sr_pt->sr_pt_iface, ls);
ls->iface = iface;
@@ -101,6 +103,7 @@
{
/* Retrieve sr_pt_iface */
ls = pool_elt_at_index (sr_pt->sr_pt_iface, p[0]);
+ vnet_feature_enable_disable ("ip6-output", "pt", iface, 0, 0, 0);
/* Delete sr_pt_iface */
pool_put (sr_pt->sr_pt_iface, ls);
mhash_unset (&sr_pt->sr_pt_iface_index_hash, &iface, NULL);
diff --git a/src/vnet/srv6/sr_pt.h b/src/vnet/srv6/sr_pt.h
index 87fdb68..cd70cd0 100644
--- a/src/vnet/srv6/sr_pt.h
+++ b/src/vnet/srv6/sr_pt.h
@@ -11,6 +11,8 @@
#ifndef included_vnet_sr_pt_h
#define included_vnet_sr_pt_h
+#define IP6_HBH_PT_TYPE 50
+
/*SR PT error codes*/
#define SR_PT_ERR_NOENT -1 /* No such entry*/
#define SR_PT_ERR_EXIST -2 /* Entry exists */
@@ -37,6 +39,11 @@
#define SR_PT_TTS_SHIFT_TEMPLATE_2 16
#define SR_PT_TTS_SHIFT_TEMPLATE_3 20
+/*PT node behaviors*/
+#define PT_BEHAVIOR_SRC 0
+#define PT_BEHAVIOR_MID 1
+#define PT_BEHAVIOR_SNK 2
+
typedef struct
{
u32 iface; /**< Interface */
@@ -46,6 +53,17 @@
u8 tts_template; /**< Interface TTS Template */
} sr_pt_iface_t;
+typedef struct
+{
+ u16 oif_oil;
+ u8 tts;
+} __clib_packed sr_pt_cmd_t;
+
+typedef struct
+{
+ sr_pt_cmd_t cmd_stack[12];
+} __clib_packed ip6_hop_by_hop_option_pt_t;
+
/**
* @brief SR Path Tracing main datastructure
*/
@@ -60,6 +78,7 @@
} sr_pt_main_t;
extern sr_pt_main_t sr_pt_main;
+extern vlib_node_registration_t sr_pt_node;
extern int sr_pt_add_iface (u32 iface, u16 id, u8 ingress_load, u8 egress_load,
u8 tts_template);
extern int sr_pt_del_iface (u32 iface);
diff --git a/src/vnet/srv6/sr_pt_node.c b/src/vnet/srv6/sr_pt_node.c
new file mode 100644
index 0000000..3921019
--- /dev/null
+++ b/src/vnet/srv6/sr_pt_node.c
@@ -0,0 +1,173 @@
+/* SPDX-License-Identifier: Apache-2.0
+ * Copyright(c) 2022 Cisco Systems, Inc.
+ */
+
+#include <vnet/fib/ip6_fib.h>
+#include <vnet/dpo/load_balance.h>
+#include <vnet/l2/feat_bitmap.h>
+#include <vnet/fib/fib_table.h>
+#include <vnet/srv6/sr.h>
+#include <vnet/srv6/sr_pt.h>
+
+/**
+ * @brief PT node trace
+ */
+typedef struct
+{
+ u32 iface;
+ u16 id;
+ u8 load;
+ timestamp_64_t t64;
+ u8 tts_template;
+ u8 tts;
+ u8 behavior;
+} pt_trace_t;
+
+static u8 *
+format_pt_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 *);
+ pt_trace_t *t = va_arg (*args, pt_trace_t *);
+ switch (t->behavior)
+ {
+ case PT_BEHAVIOR_MID:
+ s = format (
+ s,
+ "Behavior Midpoint, outgoing interface %U, outgoing interface id %u, "
+ "outgoing interface load %u, t64_sec %u, t64_nsec %u, tts_template "
+ "%u, tts %u",
+ format_vnet_sw_if_index_name, vnet_get_main (), t->iface, t->id,
+ t->load, htobe32 (t->t64.sec), htobe32 (t->t64.nsec), t->tts_template,
+ t->tts);
+ break;
+ default:
+ break;
+ }
+ return s;
+}
+
+static_always_inline void
+pt_midpoint_processing (vlib_main_t *vm, vlib_node_runtime_t *node,
+ vlib_buffer_t *b0, ip6_header_t *ip0,
+ sr_pt_iface_t *ls, timestamp_64_t t64)
+{
+ ip6_hop_by_hop_header_t *hbh;
+ ip6_hop_by_hop_option_t *hbh_opt;
+ ip6_hop_by_hop_option_pt_t *hbh_opt_pt;
+
+ if (ip0->protocol == IP_PROTOCOL_IP6_HOP_BY_HOP_OPTIONS)
+ {
+ hbh = (void *) (ip0 + 1);
+ hbh_opt = (void *) (hbh + 1);
+ if (hbh_opt->type == IP6_HBH_PT_TYPE)
+ {
+ hbh_opt_pt = (void *) (hbh_opt + 1);
+ clib_memcpy_fast (&hbh_opt_pt->cmd_stack[1],
+ &hbh_opt_pt->cmd_stack[0], 33);
+ hbh_opt_pt->cmd_stack[0].oif_oil = htobe16 (ls->id << 4);
+ hbh_opt_pt->cmd_stack[0].oif_oil |= ls->egress_load;
+ switch (ls->tts_template)
+ {
+ case SR_PT_TTS_TEMPLATE_0:
+ hbh_opt_pt->cmd_stack[0].tts =
+ t64.nsec >> SR_PT_TTS_SHIFT_TEMPLATE_0;
+ break;
+ case SR_PT_TTS_TEMPLATE_1:
+ hbh_opt_pt->cmd_stack[0].tts =
+ t64.nsec >> SR_PT_TTS_SHIFT_TEMPLATE_1;
+ break;
+ case SR_PT_TTS_TEMPLATE_2:
+ hbh_opt_pt->cmd_stack[0].tts =
+ t64.nsec >> SR_PT_TTS_SHIFT_TEMPLATE_2;
+ break;
+ case SR_PT_TTS_TEMPLATE_3:
+ hbh_opt_pt->cmd_stack[0].tts =
+ t64.nsec >> SR_PT_TTS_SHIFT_TEMPLATE_0;
+ break;
+ default:
+ break;
+ }
+ }
+ }
+ return;
+}
+
+VLIB_NODE_FN (sr_pt_node)
+(vlib_main_t *vm, vlib_node_runtime_t *node, vlib_frame_t *from_frame)
+{
+ u32 n_left_from, next_index, *from, *to_next;
+ from = vlib_frame_vector_args (from_frame);
+ n_left_from = from_frame->n_vectors;
+ next_index = node->cached_next_index;
+ u8 pt_behavior = ~(u8) 0;
+ sr_pt_iface_t *ls = 0;
+ while (n_left_from > 0)
+ {
+ u32 n_left_to_next;
+ vlib_get_next_frame (vm, node, next_index, to_next, n_left_to_next);
+
+ // Single loop for potentially the last three packets
+ while (n_left_from > 0 && n_left_to_next > 0)
+ {
+ u32 bi0;
+ u32 iface;
+ vlib_buffer_t *b0;
+ u32 next0 = 0;
+ ethernet_header_t *en0;
+ ip6_header_t *ip0 = 0;
+ bi0 = from[0];
+ to_next[0] = bi0;
+ from += 1;
+ to_next += 1;
+ n_left_from -= 1;
+ n_left_to_next -= 1;
+ timestamp_64_t t64;
+
+ b0 = vlib_get_buffer (vm, bi0);
+ iface = vnet_buffer (b0)->sw_if_index[VLIB_TX];
+ ls = sr_pt_find_iface (iface);
+ if (ls)
+ {
+ en0 = vlib_buffer_get_current (b0);
+ ip0 = (void *) (en0 + 1);
+ unix_time_now_nsec_fraction (&t64.sec, &t64.nsec);
+ pt_midpoint_processing (vm, node, b0, ip0, ls, t64);
+ pt_behavior = PT_BEHAVIOR_MID;
+ }
+ if (PREDICT_FALSE (b0->flags & VLIB_BUFFER_IS_TRACED))
+ {
+ pt_trace_t *tr = vlib_add_trace (vm, node, b0, sizeof (*tr));
+ tr->iface = iface;
+ tr->id = ls->id;
+ tr->load = ls->egress_load;
+ tr->tts_template = ls->tts_template;
+ tr->t64.sec = t64.sec;
+ tr->t64.nsec = t64.nsec;
+ tr->tts = t64.nsec >> 20;
+ tr->behavior = pt_behavior;
+ }
+ vlib_validate_buffer_enqueue_x1 (vm, node, next_index, to_next,
+ n_left_to_next, bi0, next0);
+ }
+ vlib_put_next_frame (vm, node, next_index, n_left_to_next);
+ }
+
+ return from_frame->n_vectors;
+}
+
+VLIB_REGISTER_NODE (sr_pt_node) = {
+ .name = "pt",
+ .vector_size = sizeof (u32),
+ .format_trace = format_pt_trace,
+ .type = VLIB_NODE_TYPE_INTERNAL,
+ .n_errors = 0,
+ .n_next_nodes = 1,
+ .next_nodes = { [0] = "interface-output" },
+};
+
+VNET_FEATURE_INIT (sr_pt_node, static) = {
+ .arc_name = "ip6-output",
+ .node_name = "pt",
+ .runs_after = VNET_FEATURES ("ip6-lookup"),
+};
\ No newline at end of file