From 9382ad9b390e17c8bfd8229342656348d059becb Mon Sep 17 00:00:00 2001 From: Dave Barach Date: Mon, 23 Sep 2019 16:03:49 -0400 Subject: misc: improve pcap drop trace output Append : to pcap drop traces. The data displays perfectly fine in [vanilla] wireshark, and makes it 100% obvious which node dropped the packet, and why. Type: feature Ticket: VPP-1776 Signed-off-by: Dave Barach Change-Id: I9b964b99da4011b93723354db6ef0b128fca20cb --- src/vnet/interface_output.c | 54 +++++++++++++++++++++++++++++++++++++++++++++ 1 file changed, 54 insertions(+) diff --git a/src/vnet/interface_output.c b/src/vnet/interface_output.c index 8eb2e67b1bd..8e257014789 100644 --- a/src/vnet/interface_output.c +++ b/src/vnet/interface_output.c @@ -1177,6 +1177,7 @@ pcap_drop_trace (vlib_main_t * vm, u32 bi0; i16 save_current_data; u16 save_current_length; + vlib_error_main_t *em = &vm->error_main; from = vlib_frame_vector_args (f); @@ -1222,6 +1223,59 @@ pcap_drop_trace (vlib_main_t * vm, else if (b0->current_data > 0) vlib_buffer_advance (b0, (word) - b0->current_data); + { + vlib_buffer_t *last = b0; + u32 error_node_index; + int drop_string_len; + vlib_node_t *n; + /* Length of the error string */ + int error_string_len = + clib_strnlen (em->error_strings_heap[b0->error], 128); + + /* Dig up the drop node */ + error_node_index = vm->node_main.node_by_error[b0->error]; + n = vlib_get_node (vm, error_node_index); + + /* Length of full drop string, w/ "nodename: " prepended */ + drop_string_len = error_string_len + vec_len (n->name) + 2; + + /* Find the last buffer in the chain */ + while (last->flags & VLIB_BUFFER_NEXT_PRESENT) + last = vlib_get_buffer (vm, last->next_buffer); + + /* + * Append : to the capture, + * only if we can do that without allocating a new buffer. + */ + if (PREDICT_TRUE ((last->current_data + last->current_length) + < (VLIB_BUFFER_DEFAULT_DATA_SIZE + - drop_string_len))) + { + clib_memcpy_fast (last->data + last->current_data + + last->current_length, n->name, + vec_len (n->name)); + clib_memcpy_fast (last->data + last->current_data + + last->current_length + vec_len (n->name), + ": ", 2); + clib_memcpy_fast (last->data + last->current_data + + last->current_length + vec_len (n->name) + + 2, em->error_strings_heap[b0->error], + error_string_len); + last->current_length += drop_string_len; + b0->flags &= ~(VLIB_BUFFER_TOTAL_LENGTH_VALID); + pcap_add_buffer (&pp->pcap_main, vm, bi0, + pp->max_bytes_per_pkt); + last->current_length -= drop_string_len; + b0->current_data = save_current_data; + b0->current_length = save_current_length; + continue; + } + } + + /* + * Didn't have space in the last buffer, here's the dropped + * packet as-is + */ pcap_add_buffer (&pp->pcap_main, vm, bi0, pp->max_bytes_per_pkt); b0->current_data = save_current_data; -- cgit 1.2.3-korg