diff options
Diffstat (limited to 'src/plugins/bpf_trace_filter/bpf_trace_filter.c')
-rw-r--r-- | src/plugins/bpf_trace_filter/bpf_trace_filter.c | 96 |
1 files changed, 96 insertions, 0 deletions
diff --git a/src/plugins/bpf_trace_filter/bpf_trace_filter.c b/src/plugins/bpf_trace_filter/bpf_trace_filter.c new file mode 100644 index 00000000000..ff08d2cdb80 --- /dev/null +++ b/src/plugins/bpf_trace_filter/bpf_trace_filter.c @@ -0,0 +1,96 @@ +/* + *------------------------------------------------------------------ + * Copyright (c) 2023 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 <vlib/vlib.h> +#include <bpf_trace_filter/bpf_trace_filter.h> + +clib_error_t * +bpf_trace_filter_init (vlib_main_t *vm) +{ + bpf_trace_filter_main_t *btm = &bpf_trace_filter_main; + btm->pcap = pcap_open_dead (DLT_EN10MB, 65535); + + return 0; +} + +int vnet_is_packet_traced (vlib_buffer_t *b, u32 classify_table_index, + int func); + +clib_error_t * +bpf_trace_filter_set_unset (const char *bpf_expr, u8 is_del) +{ + bpf_trace_filter_main_t *btm = &bpf_trace_filter_main; + if (is_del) + { + if (btm->prog_set) + { + btm->prog_set = 0; + pcap_freecode (&btm->prog); + } + } + else if (bpf_expr) + { + if (btm->prog_set) + pcap_freecode (&btm->prog); + btm->prog_set = 0; + if (pcap_compile (btm->pcap, &btm->prog, (char *) bpf_expr, 0, + PCAP_NETMASK_UNKNOWN)) + { + return clib_error_return (0, "Failed pcap_compile of %s", bpf_expr); + } + btm->prog_set = 1; + } + return 0; +}; + +int +bpf_is_packed_traced (vlib_buffer_t *b, u32 classify_table_index, int func) +{ + bpf_trace_filter_main_t *bfm = &bpf_trace_filter_main; + struct pcap_pkthdr phdr = { 0 }; + int res; + int res1; + res1 = vnet_is_packet_traced (b, classify_table_index, 0); + + if (res1 != 1) + return res1; + + if (!bfm->prog_set) + return 1; + + phdr.caplen = b->current_length; + phdr.len = b->current_length; + res = pcap_offline_filter (&bfm->prog, &phdr, vlib_buffer_get_current (b)); + return res != 0; +} + +VLIB_REGISTER_TRACE_FILTER_FUNCTION (bpf_trace_filter_fn, static) = { + .name = "bpf_trace_filter", + .description = "bpf based trace filter", + .priority = 10, + .function = bpf_is_packed_traced +}; + +VLIB_INIT_FUNCTION (bpf_trace_filter_init); +bpf_trace_filter_main_t bpf_trace_filter_main; +/* + * fd.io coding-style-patch-verification: ON + * + * Local Variables: + * eval: (c-set-style "gnu") + * End: + */ |