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Diffstat (limited to 'src/vnet/ipfix-export/ipfix_doc.md')
| -rw-r--r-- | src/vnet/ipfix-export/ipfix_doc.md | 355 |
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diff --git a/src/vnet/ipfix-export/ipfix_doc.md b/src/vnet/ipfix-export/ipfix_doc.md deleted file mode 100644 index edae3f73660..00000000000 --- a/src/vnet/ipfix-export/ipfix_doc.md +++ /dev/null @@ -1,355 +0,0 @@ -# IPFIX support {#ipfix_doc} - -VPP includes a high-performance IPFIX record exporter. This note -explains how to use the internal APIs to export IPFIX data, and how to -configure and send the required IPFIX templates. - -As you'll see, a bit of typing is required. - -## First: create an ipfix "report" - -Include the flow report header file, fill out a @ref -vnet_flow_report_add_del_args_t structure, and call vnet_flow_report_add_del. - -```{.c} - #include <vnet/ipfix-export/flow_report.h> - /* Defined in flow_report.h, of interest when constructing reports */ - - /* ipfix field definitions for a particular report */ - typedef struct - { - u32 info_element; - u32 size; - } ipfix_report_element_t; - - /* Report add/del argument structure */ - typedef struct - { - /* Callback to flush current ipfix packet / frame */ - vnet_flow_data_callback_t *flow_data_callback; - - /* Callback to build the template packet rewrite string */ - vnet_flow_rewrite_callback_t *rewrite_callback; - - /* List of ipfix elements in the report */ - ipfix_report_element_t *report_elements; - u32 n_report_elements; - /* Kept in flow report, used e.g. by flow classifier */ - opaque_t opaque; - /* Add / delete a report */ - int is_add; - /* Ipfix "domain-ID", see RFC, set as desired */ - u32 domain_id; - /* ipfix packet source port, often set to UDP_DST_PORT_ipfix */ - u16 src_port; - /* Set by ipfix infra, needed to send data packets */ - u32 *stream_indexp; - } vnet_flow_report_add_del_args_t; - - /* Private header file contents */ - - /* Report ipfix element definition */ - #define foreach_simple_report_ipfix_element \ - _(sourceIPv4Address, 4) \ - _(destinationIPv4Address, 4) \ - _(sourceTransportPort, 2) \ - _(destinationTransportPort, 2) \ - _(protocolIdentifier, 1) \ - _(flowStartMicroseconds, 8) \ - _(flowEndMicroseconds, 8) - - static ipfix_report_element_t simple_report_elements[] = { - #define _(a,b) {a,b}, - foreach_simple_report_ipfix_element - #undef _ - }; - - typedef struct - { - /** Buffers and frames, per thread */ - vlib_buffer_t **buffers_by_thread; - vlib_frame_t **frames_by_thread; - u32 *next_record_offset_by_thread; - - /** Template ID's */ - u16 *template_ids; - - /** Time reference pair */ - u64 usec_time_0; - f64 vlib_time_0; - - /** Stream index */ - u32 stream_index; - - /* Convenience */ - flow_report_main_t *flow_report_main; - vlib_main_t *vlib_main; - vnet_main_t *vnet_main; - } my_logging_main_t; - - extern my_logging_main_t my_logging_main; - - ... - - /* Recitations */ - flow_report_main_t *frm = &flow_report_main; - my_logging_main_t *mlm = &my_logging_main; - vnet_flow_report_add_del_args_t a; - int rv; - u16 template_id; - - ... - - /* Init function: set up time reference pair */ - mlm->vlib_time_0 = vlib_time_now (vm); - mlm->milisecond_time_0 = unix_time_now_nsec () * 1e-6; - - ... - - /* Create a report */ - memset (&a, 0, sizeof (a)); - a.is_add = 1 /* to enable the report */; - a.domain_id = 1 /* pick a domain ID */; - a.src_port = UDP_DST_PORT_ipfix /* src port for reports */; - - /* Use the generic template packet rewrite string generator */ - a.rewrite_callback = vnet_flow_rewrite_generic_callback; - - /* Supply a list of ipfix report elements */ - a.report_elements = simple_report_elements; - a.n_report_elements = ARRAY_LEN (simple_report_elements); - - /* Pointer to the ipfix stream index, set by the report infra */ - a.stream_indexp = &mlm->stream_index; - a.flow_data_callback = my_flow_data_callback; - - /* Create the report */ - rv = vnet_flow_report_add_del (frm, &a, &template_id); - if (rv) - oops... - - /* Save the template-ID for later use */ - mlm->template_id = template_id; - -``` - -Several things are worth describing in more detail. - -### vnet_flow_rewrite_generic_callback programming - -This generic callback helps build ipfix template packets. When -registering an ipfix report, pass an (array, count) -of ipfix elements as shown above. - -### my_flow_data_callback - -The ipfix flow export infrastructure calls this callback to flush the -current ipfix packet; to make sure that ipfix data is not retained for -an unreasonably long period of time. - -We typically code it as shown below, to call an application-specific -function with (uninteresting arguments), and "do_flush = 1": - - -```{.c} - - vlib_frame_t *my_flow_data_callback - (flow_report_main_t * frm, - flow_report_t * fr, - vlib_frame_t * f, - u32 * to_next, u32 node_index) - { - - my_buffer_flow_record (0, ... , 0, 1 /* do_flush */); - return f; - } -``` - -### my_flow_data_header - -This function creates the packet header for an ipfix data packet - -```{.c} - - static inline void - my_flow_report_header (flow_report_main_t * frm, - vlib_buffer_t * b0, u32 * offset) - { - my_logging_main_t *mlm = &my_logging_main; - flow_report_stream_t *stream; - ip4_ipfix_template_packet_t *tp; - ipfix_message_header_t *h = 0; - - - ipfix_set_header_t *s = 0; - ip4_header_t *ip; - udp_header_t *udp; - - stream = &frm->streams[mlm->stream_index]; - - b0->current_data = 0; - b0->current_length = sizeof (*ip) + sizeof (*udp) + sizeof (*h) + - sizeof (*s); - b0->flags |= (VLIB_BUFFER_TOTAL_LENGTH_VALID | VNET_BUFFER_F_FLOW_REPORT); - vnet_buffer (b0)->sw_if_index[VLIB_RX] = 0; - vnet_buffer (b0)->sw_if_index[VLIB_TX] = frm->fib_index; - tp = vlib_buffer_get_current (b0); - ip = (ip4_header_t *) & tp->ip4; - udp = (udp_header_t *) (ip + 1); - h = (ipfix_message_header_t *) (udp + 1); - s = (ipfix_set_header_t *) (h + 1); - - ip->ip_version_and_header_length = 0x45; - ip->ttl = 254; - ip->protocol = IP_PROTOCOL_UDP; - ip->flags_and_fragment_offset = 0; - ip->src_address.as_u32 = frm->src_address.as_u32; - ip->dst_address.as_u32 = frm->ipfix_collector.as_u32; - udp->src_port = clib_host_to_net_u16 (stream->src_port); - udp->dst_port = clib_host_to_net_u16 (frm->collector_port); - udp->checksum = 0; - - h->export_time = clib_host_to_net_u32 ((u32) - (((f64) frm->unix_time_0) + - (vlib_time_now (frm->vlib_main) - - frm->vlib_time_0))); - h->sequence_number = clib_host_to_net_u32 (stream->sequence_number++); - h->domain_id = clib_host_to_net_u32 (stream->domain_id); - - *offset = (u32) (((u8 *) (s + 1)) - (u8 *) tp); - } - ``` - - ### fixup and transmit a flow record - - ```{.c} - - static inline void - my_send_ipfix_pkt (flow_report_main_t * frm, - vlib_frame_t * f, vlib_buffer_t * b0, u16 template_id) - { - ip4_ipfix_template_packet_t *tp; - ipfix_message_header_t *h = 0; - ipfix_set_header_t *s = 0; - ip4_header_t *ip; - udp_header_t *udp; - vlib_main_t *vm = frm->vlib_main; - - tp = vlib_buffer_get_current (b0); - ip = (ip4_header_t *) & tp->ip4; - udp = (udp_header_t *) (ip + 1); - h = (ipfix_message_header_t *) (udp + 1); - s = (ipfix_set_header_t *) (h + 1); - - s->set_id_length = ipfix_set_id_length (template_id, - b0->current_length - - (sizeof (*ip) + sizeof (*udp) + - sizeof (*h))); - h->version_length = version_length (b0->current_length - - (sizeof (*ip) + sizeof (*udp))); - - ip->length = clib_host_to_net_u16 (b0->current_length); - ip->checksum = ip4_header_checksum (ip); - udp->length = clib_host_to_net_u16 (b0->current_length - sizeof (*ip)); - - if (frm->udp_checksum) - { - udp->checksum = ip4_tcp_udp_compute_checksum (vm, b0, ip); - if (udp->checksum == 0) - udp->checksum = 0xffff; - } - - ASSERT (ip4_header_checksum_is_valid (ip)); - - vlib_put_frame_to_node (vm, ip4_lookup_node.index, f); - } - ``` - - ### my_buffer_flow_record - - This is the key routine which paints individual flow records into - an ipfix packet under construction. It's pretty straightforward - (albeit stateful) vpp data-plane code. The code shown below is - thread-safe by construction. - - ```{.c} - static inline void - my_buffer_flow_record_internal (my_flow_record_t * rp, int do_flush, - u32 thread_index) - { - vlib_main_t *vm = vlib_mains[thread_index]; - my_logging_main_t *mlm = &jvp_ipfix_main; - flow_report_main_t *frm = &flow_report_main; - vlib_frame_t *f; - vlib_buffer_t *b0 = 0; - u32 bi0 = ~0; - u32 offset; - - b0 = mlm->buffers_by_thread[thread_index]; - - if (PREDICT_FALSE (b0 == 0)) - { - if (do_flush) - return; - - if (vlib_buffer_alloc (vm, &bi0, 1) != 1) - { - clib_warning ("can't allocate ipfix data buffer"); - return; - } - - b0 = vlib_get_buffer (vm, bi0); - offset = 0; - mlm->buffers_by_thread[thread_index] = b0; - } - else - { - bi0 = vlib_get_buffer_index (vm, b0); - offset = mlm->next_record_offset_by_thread[thread_index]; - } - - f = mlm->frames_by_thread[thread_index]; - if (PREDICT_FALSE (f == 0)) - { - u32 *to_next; - f = vlib_get_frame_to_node (vm, ip4_lookup_node.index); - mlm->frames_by_thread[thread_index] = f; - to_next = vlib_frame_vector_args (f); - to_next[0] = bi0; - f->n_vectors = 1; - mlm->frames_by_thread[thread_index] = f; - } - - if (PREDICT_FALSE (offset == 0)) - my_flow_report_header (frm, b0, &offset); - - if (PREDICT_TRUE (do_flush == 0)) - { - /* Paint the new ipfix data record into the buffer */ - clib_memcpy (b0->data + offset, rp, sizeof (*rp)); - offset += sizeof (*rp); - b0->current_length += sizeof (*rp); - } - - if (PREDICT_FALSE (do_flush || (offset + sizeof (*rp)) > frm->path_mtu)) - { - /* Nothing to send? */ - if (offset == 0) - return; - - send_ipfix_pkt (frm, f, b0, mlm->template_ids[0]); - mlm->buffers_by_thread[thread_index] = 0; - mlm->frames_by_thread[thread_index] = 0; - offset = 0; - } - mlm->next_record_offset_by_thread[thread_index] = offset; - } - - static void - my_buffer_flow_record (my_flow_record_t * rp, int do_flush) - { - u32 thread_index = vlib_get_thread_index(); - my_buffer_flow_record_internal (rp, do_flush, thread_index); - } - -``` |