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authorDave Barach <dave@barachs.net>2019-10-24 18:10:10 -0400
committerDave Barach <openvpp@barachs.net>2019-10-25 14:36:13 +0000
commitd7b306657d205fddd781e982aec5f3c3dc69fa88 (patch)
tree20f61a92fb05cfcc727bb4a95977a306a8d7a614 /src/plugins/mdata/mdata.c
parent94afc9391d0588608d67de717a927e9a50349d3a (diff)
mdata: buffer metadata change tracker plugin
A handy tool in case you need to know which metadata will be changed when a packet visits a certain node. Reflect metadata changes into format functions used by the vpp-specific wireshark dissector. Type: feature Signed-off-by: Dave Barach <dave@barachs.net> Change-Id: I96fe8a24db4082bb29fe2a33cc522e8616a3a1bb
Diffstat (limited to 'src/plugins/mdata/mdata.c')
-rw-r--r--src/plugins/mdata/mdata.c493
1 files changed, 493 insertions, 0 deletions
diff --git a/src/plugins/mdata/mdata.c b/src/plugins/mdata/mdata.c
new file mode 100644
index 00000000000..830673edeb8
--- /dev/null
+++ b/src/plugins/mdata/mdata.c
@@ -0,0 +1,493 @@
+/*
+ * mdata.c - Buffer metadata change tracker
+ *
+ * Copyright (c) 2019 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.
+ */
+
+#include <vnet/vnet.h>
+#include <vnet/plugin/plugin.h>
+#include <mdata/mdata.h>
+
+#include <vlibapi/api.h>
+#include <vlibmemory/api.h>
+#include <vpp/app/version.h>
+#include <stdbool.h>
+
+#include <mdata/mdata.api_enum.h>
+#include <mdata/mdata.api_types.h>
+
+#define REPLY_MSG_ID_BASE mmp->msg_id_base
+#include <vlibapi/api_helper_macros.h>
+
+mdata_main_t mdata_main;
+
+/** @file buffer metadata change tracker
+ */
+
+static mdata_t mdata_none;
+
+/** Metadata tracking callback
+ before_or_after: 0 => before, 1=> after
+*/
+static void
+mdata_trace_callback (vlib_main_t * vm, u64 * c0, u64 * c1,
+ vlib_node_runtime_t * node,
+ vlib_frame_t * frame, int before_or_after)
+{
+ int i;
+ mdata_main_t *mm = &mdata_main;
+ vlib_buffer_t *bufs[VLIB_FRAME_SIZE], **b;
+ u32 *from;
+ u32 n_left_from;
+ mdata_t *before, *modifies;
+ u8 *after;
+
+ /* Input nodes don't have frames, etc. */
+ if (frame == 0)
+ return;
+
+ n_left_from = frame->n_vectors;
+
+ if (n_left_from == 0)
+ return;
+
+ from = vlib_frame_vector_args (frame);
+
+ vlib_get_buffers (vm, from, bufs, n_left_from);
+ b = bufs;
+
+ if (before_or_after == 1 /* after */ )
+ goto after_pass;
+
+ /* Resize the per-thread "before" vector to cover the current frame */
+ vec_reset_length (mm->before_per_thread[vm->thread_index]);
+ vec_validate (mm->before_per_thread[vm->thread_index], n_left_from - 1);
+ before = mm->before_per_thread[vm->thread_index];
+ before->node_index = ~0;
+
+ /* Before we call the dispatch fn, copy metadata. */
+ while (n_left_from > 0)
+ {
+ clib_memcpy_fast (before->mdata, b[0], sizeof (before->mdata));
+ b++;
+ before++;
+ n_left_from--;
+ }
+ return;
+
+after_pass:
+
+ /* Recover the metadata copy we saved a moment ago */
+ before = mm->before_per_thread[vm->thread_index];
+
+ /* We'd better have the same number of buffers... */
+ ASSERT (n_left_from == vec_len (before));
+ ASSERT (node->node_index);
+
+ clib_spinlock_lock_if_init (&mm->modify_lock);
+
+ /*
+ * Resize the per-node accumulator vector as needed
+ * Paint the "no data" patter across any nodes we haven't seen yet
+ */
+ vec_validate_init_empty (mm->modifies, node->node_index, mdata_none);
+ modifies = vec_elt_at_index (mm->modifies, node->node_index);
+ modifies->node_index = node->node_index;
+ before = mm->before_per_thread[vm->thread_index];
+
+ /* Walk the frame */
+ while (n_left_from > 0)
+ {
+ after = (u8 *) b[0];
+
+ /* Compare metadata before and after node dispatch fn */
+ for (i = 0; i < ARRAY_LEN (before->mdata); i++)
+ {
+ /* Mark mdata octet changed */
+ if (before->mdata[i] != after[i])
+ modifies->mdata[i] = 0xff;
+ }
+
+ b++;
+ before++;
+ n_left_from--;
+ }
+
+ clib_spinlock_unlock_if_init (&mm->modify_lock);
+}
+
+int
+mdata_enable_disable (mdata_main_t * mmp, int enable_disable)
+{
+ int rv = 0;
+ vlib_thread_main_t *thread_main = vlib_get_thread_main ();
+ int i;
+
+ if (mmp->modify_lock == 0 && thread_main->n_vlib_mains > 1)
+ clib_spinlock_init (&mmp->modify_lock);
+
+ if (vec_len (mmp->before_per_thread) == 0)
+ {
+ mdata_none.node_index = ~0;
+ vec_validate (mmp->before_per_thread, vec_len (vlib_mains) - 1);
+ }
+
+ /* Reset the per-node accumulator, see vec_validate_init_empty above */
+ vec_reset_length (mmp->modifies);
+
+ for (i = 0; i < vec_len (vlib_mains); i++)
+ {
+ if (vlib_mains[i] == 0)
+ continue;
+
+ clib_callback_enable_disable
+ (vlib_mains[i]->vlib_node_runtime_perf_counter_cbs,
+ vlib_mains[i]->vlib_node_runtime_perf_counter_cb_tmp,
+ vlib_mains[i]->worker_thread_main_loop_callback_lock,
+ (void *) mdata_trace_callback, enable_disable);
+ }
+
+ return rv;
+}
+
+static clib_error_t *
+mdata_enable_disable_command_fn (vlib_main_t * vm,
+ unformat_input_t * input,
+ vlib_cli_command_t * cmd)
+{
+ mdata_main_t *mmp = &mdata_main;
+ int enable_disable = 1;
+
+ int rv;
+
+ while (unformat_check_input (input) != UNFORMAT_END_OF_INPUT)
+ {
+ if (unformat (input, "disable") || unformat (input, "off"))
+ enable_disable = 0;
+ if (unformat (input, "enable") || unformat (input, "on"))
+ enable_disable = 1;
+ else
+ break;
+ }
+
+ rv = mdata_enable_disable (mmp, enable_disable);
+
+ switch (rv)
+ {
+ case 0:
+ break;
+
+ default:
+ return clib_error_return (0, "mdata_enable_disable returned %d", rv);
+ }
+ return 0;
+}
+
+/*?
+ * This command enables or disables buffer metadata change tracking
+ *
+ *@cliexpar
+ * To enable buffer metadata change tracking:
+ *@cliexstart{buffer metadata tracking on}
+ * Tracking enabled
+ *@cliexend
+ *
+ *@cliexstart{buffer metadata tracking off}
+ * Tracking disabled
+ *@cliexend
+?*/
+
+/* *INDENT-OFF* */
+VLIB_CLI_COMMAND (mdata_enable_disable_command, static) =
+{
+ .path = "buffer metadata tracking",
+ .short_help = "buffer metadata tracking [on][off]",
+ .function = mdata_enable_disable_command_fn,
+};
+/* *INDENT-ON* */
+
+/* API message handler */
+static void vl_api_mdata_enable_disable_t_handler
+ (vl_api_mdata_enable_disable_t * mp)
+{
+ vl_api_mdata_enable_disable_reply_t *rmp;
+ mdata_main_t *mmp = &mdata_main;
+ int rv;
+
+ rv = mdata_enable_disable (mmp, (int) (mp->enable_disable));
+
+ REPLY_MACRO (VL_API_MDATA_ENABLE_DISABLE_REPLY);
+}
+
+/* API definitions */
+#include <mdata/mdata.api.c>
+
+static clib_error_t *
+mdata_init (vlib_main_t * vm)
+{
+ mdata_main_t *mmp = &mdata_main;
+ clib_error_t *error = 0;
+
+ mmp->vlib_main = vm;
+ mmp->vnet_main = vnet_get_main ();
+
+ /* Add our API messages to the global name_crc hash table */
+ mmp->msg_id_base = setup_message_id_table ();
+
+ return error;
+}
+
+VLIB_INIT_FUNCTION (mdata_init);
+
+/* *INDENT-OFF* */
+VLIB_PLUGIN_REGISTER () =
+{
+ .version = VPP_BUILD_VER,
+ .description = "Buffer metadata change tracker."
+};
+/* *INDENT-ON* */
+
+
+#define foreach_primary_metadata_field \
+_(current_data) \
+_(current_length) \
+_(flags) \
+_(flow_id) \
+_(ref_count) \
+_(buffer_pool_index) \
+_(error) \
+_(next_buffer) \
+_(current_config_index) \
+_(punt_reason)
+
+#define foreach_opaque_metadata_field \
+_(sw_if_index[0]) \
+_(sw_if_index[1]) \
+_(l2_hdr_offset) \
+_(l3_hdr_offset) \
+_(l4_hdr_offset) \
+_(feature_arc_index) \
+_(ip.adj_index[0]) \
+_(ip.adj_index[1]) \
+_(ip.flow_hash) \
+_(ip.save_protocol) \
+_(ip.fib_index) \
+_(ip.icmp.type) \
+_(ip.icmp.code) \
+_(ip.icmp.data) \
+_(ip.reass.next_index) \
+_(ip.reass.error_next_index) \
+_(ip.reass.owner_thread_index) \
+_(ip.reass.ip_proto) \
+_(ip.reass.l4_src_port) \
+_(ip.reass.l4_dst_port) \
+_(ip.reass.estimated_mtu) \
+_(ip.reass.fragment_first) \
+_(ip.reass.fragment_last) \
+_(ip.reass.range_first) \
+_(ip.reass.range_last) \
+_(ip.reass.next_range_bi) \
+_(ip.reass.ip6_frag_hdr_offset) \
+_(mpls.ttl) \
+_(mpls.exp) \
+_(mpls.first) \
+_(mpls.save_rewrite_length) \
+_(mpls.mpls_hdr_length) \
+_(mpls.bier.n_bytes) \
+_(l2.feature_bitmap) \
+_(l2.bd_index) \
+_(l2.l2fib_sn) \
+_(l2.l2_len) \
+_(l2.shg) \
+_(l2.bd_age) \
+_(l2t.next_index) \
+_(l2t.session_index) \
+_(l2_classify.table_index) \
+_(l2_classify.opaque_index) \
+_(l2_classify.hash) \
+_(policer.index) \
+_(ipsec.sad_index) \
+_(ipsec.protect_index) \
+_(map.mtu) \
+_(map_t.map_domain_index) \
+_(map_t.v6.saddr) \
+_(map_t.v6.daddr) \
+_(map_t.v6.frag_offset) \
+_(map_t.v6.l4_offset) \
+_(map_t.v6.l4_protocol) \
+_(map_t.checksum_offset) \
+_(map_t.mtu) \
+_(ip_frag.mtu) \
+_(ip_frag.next_index) \
+_(ip_frag.flags) \
+_(cop.current_config_index) \
+_(lisp.overlay_afi) \
+_(tcp.connection_index) \
+_(tcp.seq_number) \
+_(tcp.next_node_opaque) \
+_(tcp.seq_end) \
+_(tcp.ack_number) \
+_(tcp.hdr_offset) \
+_(tcp.data_offset) \
+_(tcp.data_len) \
+_(tcp.flags) \
+_(snat.flags)
+
+#define foreach_opaque2_metadata_field \
+_(qos.bits) \
+_(qos.source) \
+_(loop_counter) \
+_(gbp.flags) \
+_(gbp.sclass) \
+_(gso_size) \
+_(gso_l4_hdr_sz) \
+_(pg_replay_timestamp)
+
+static u8 *
+format_buffer_metadata_changes (u8 * s, va_list * args)
+{
+ mdata_main_t *mm = va_arg (*args, mdata_main_t *);
+ int verbose = va_arg (*args, int);
+ mdata_t *modifies;
+ vlib_buffer_t *b;
+ vnet_buffer_opaque_t *o;
+ vnet_buffer_opaque2_t *o2;
+ vlib_node_t *node;
+ int i, j;
+ int printed;
+
+ clib_spinlock_lock_if_init (&mm->modify_lock);
+
+ for (i = 0; i < vec_len (mm->modifies); i++)
+ {
+ modifies = vec_elt_at_index (mm->modifies, i);
+ node = vlib_get_node (mm->vlib_main, i);
+
+ /* No data for this node? */
+ if (modifies->node_index == ~0)
+ {
+ if (verbose)
+ s = format (s, "\n%v: no data\n", node->name);
+ continue;
+ }
+
+ /* We visited the node, but it may not have changed any metadata... */
+ for (j = 0; j < ARRAY_LEN (modifies->mdata); j++)
+ {
+ if (modifies->mdata[j])
+ goto found;
+ }
+ s = format (s, "\n%v: no metadata changes\n", node->name);
+ continue;
+
+ found:
+ /* Fields which the node modifies will be non-zero */
+ b = (vlib_buffer_t *) (modifies->mdata);
+
+ /* Dump primary metadata changes */
+ s = format (s, "\n%v: ", node->name);
+
+ printed = 0;
+#define _(n) if (b->n) {s = format (s, "%s ", #n); printed = 1;}
+ foreach_primary_metadata_field;
+#undef _
+
+ if (printed == 0)
+ s = format (s, "no vlib_buffer_t metadata changes");
+
+ vec_add1 (s, '\n');
+
+ /*
+ * Dump opaque union changes.
+ * Hopefully this will give folks a clue about opaque
+ * union data conflicts. That's the point of the exercise...
+ */
+ o = vnet_buffer (b);
+ printed = 0;
+ s = format (s, " vnet_buffer_t: ");
+
+#define _(n) if (o->n) {s = format (s, "%s ", #n); printed = 1;}
+ foreach_opaque_metadata_field;
+#undef _
+
+ if (printed == 0)
+ s = format (s, "no changes");
+
+ vec_add1 (s, '\n');
+
+ o2 = vnet_buffer2 (b);
+ printed = 0;
+ s = format (s, " vnet_buffer2_t: ");
+
+#define _(n) if (o2->n) {s = format (s, "%s ", #n); printed = 1;}
+ foreach_opaque2_metadata_field;
+#undef _
+ if (printed == 0)
+ s = format (s, "no changes");
+
+ vec_add1 (s, '\n');
+
+ }
+
+ clib_spinlock_unlock_if_init (&mm->modify_lock);
+
+ return s;
+}
+
+static clib_error_t *
+show_metadata_command_fn (vlib_main_t * vm,
+ unformat_input_t * input, vlib_cli_command_t * cmd)
+{
+ int verbose = 0;
+
+ while (unformat_check_input (input) != UNFORMAT_END_OF_INPUT)
+ {
+ if (unformat (input, "verbose %=", &verbose, 1))
+ ;
+ else
+ break;
+ }
+
+ vlib_cli_output (vm, "%U", format_buffer_metadata_changes, &mdata_main,
+ verbose);
+ return 0;
+}
+
+/*?
+ * This command displays buffer metadata change information
+ *@cliexpar
+ * How to display buffer metadata change information
+ *@cliexstart{show buffer metadata}
+ * ethernet-input: current_data current_length flags error
+ * vnet_buffer_t: l2_hdr_offset l3_hdr_offset
+ * vnet_buffer2_t: no changes
+ *@cliexend
+?*/
+
+/* *INDENT-OFF* */
+VLIB_CLI_COMMAND (show_metadata_command, static) =
+{
+ .path = "show buffer metadata",
+ .short_help = "show buffer metadata",
+ .function = show_metadata_command_fn,
+};
+/* *INDENT-OFF* */
+
+/*
+ * fd.io coding-style-patch-verification: ON
+ *
+ * Local Variables:
+ * eval: (c-set-style "gnu")
+ * End:
+ */