xref: /dpdk/app/test-pmd/csumonly.c (revision 3bb3ebb51b789d4ecb417cbdb1dce5c7211f6f18)
1 /* SPDX-License-Identifier: BSD-3-Clause
2  * Copyright(c) 2010-2014 Intel Corporation.
3  * Copyright 2014 6WIND S.A.
4  */
5 
6 #include <stdarg.h>
7 #include <stdio.h>
8 #include <errno.h>
9 #include <stdint.h>
10 #include <unistd.h>
11 #include <inttypes.h>
12 
13 #include <sys/queue.h>
14 #include <sys/stat.h>
15 
16 #include <rte_common.h>
17 #include <rte_byteorder.h>
18 #include <rte_log.h>
19 #include <rte_debug.h>
20 #include <rte_cycles.h>
21 #include <rte_memory.h>
22 #include <rte_memcpy.h>
23 #include <rte_launch.h>
24 #include <rte_eal.h>
25 #include <rte_per_lcore.h>
26 #include <rte_lcore.h>
27 #include <rte_atomic.h>
28 #include <rte_branch_prediction.h>
29 #include <rte_mempool.h>
30 #include <rte_mbuf.h>
31 #include <rte_interrupts.h>
32 #include <rte_pci.h>
33 #include <rte_ether.h>
34 #include <rte_ethdev.h>
35 #include <rte_ip.h>
36 #include <rte_tcp.h>
37 #include <rte_udp.h>
38 #include <rte_vxlan.h>
39 #include <rte_sctp.h>
40 #include <rte_gtp.h>
41 #include <rte_prefetch.h>
42 #include <rte_string_fns.h>
43 #include <rte_flow.h>
44 #include <rte_gro.h>
45 #include <rte_gso.h>
46 #include <rte_geneve.h>
47 
48 #include "testpmd.h"
49 
50 #define IP_DEFTTL  64   /* from RFC 1340. */
51 
52 #define GRE_CHECKSUM_PRESENT	0x8000
53 #define GRE_KEY_PRESENT		0x2000
54 #define GRE_SEQUENCE_PRESENT	0x1000
55 #define GRE_EXT_LEN		4
56 #define GRE_SUPPORTED_FIELDS	(GRE_CHECKSUM_PRESENT | GRE_KEY_PRESENT |\
57 				 GRE_SEQUENCE_PRESENT)
58 
59 /* We cannot use rte_cpu_to_be_16() on a constant in a switch/case */
60 #if RTE_BYTE_ORDER == RTE_LITTLE_ENDIAN
61 #define _htons(x) ((uint16_t)((((x) & 0x00ffU) << 8) | (((x) & 0xff00U) >> 8)))
62 #else
63 #define _htons(x) (x)
64 #endif
65 
66 uint16_t vxlan_gpe_udp_port = RTE_VXLAN_GPE_DEFAULT_PORT;
67 uint16_t geneve_udp_port = RTE_GENEVE_DEFAULT_PORT;
68 
69 /* structure that caches offload info for the current packet */
70 struct testpmd_offload_info {
71 	uint16_t ethertype;
72 	uint8_t gso_enable;
73 	uint16_t l2_len;
74 	uint16_t l3_len;
75 	uint16_t l4_len;
76 	uint8_t l4_proto;
77 	uint8_t is_tunnel;
78 	uint16_t outer_ethertype;
79 	uint16_t outer_l2_len;
80 	uint16_t outer_l3_len;
81 	uint8_t outer_l4_proto;
82 	uint16_t tso_segsz;
83 	uint16_t tunnel_tso_segsz;
84 	uint32_t pkt_len;
85 };
86 
87 /* simplified GRE header */
88 struct simple_gre_hdr {
89 	uint16_t flags;
90 	uint16_t proto;
91 } __rte_packed;
92 
93 static uint16_t
94 get_udptcp_checksum(void *l3_hdr, void *l4_hdr, uint16_t ethertype)
95 {
96 	if (ethertype == _htons(RTE_ETHER_TYPE_IPV4))
97 		return rte_ipv4_udptcp_cksum(l3_hdr, l4_hdr);
98 	else /* assume ethertype == RTE_ETHER_TYPE_IPV6 */
99 		return rte_ipv6_udptcp_cksum(l3_hdr, l4_hdr);
100 }
101 
102 /* Parse an IPv4 header to fill l3_len, l4_len, and l4_proto */
103 static void
104 parse_ipv4(struct rte_ipv4_hdr *ipv4_hdr, struct testpmd_offload_info *info)
105 {
106 	struct rte_tcp_hdr *tcp_hdr;
107 
108 	info->l3_len = rte_ipv4_hdr_len(ipv4_hdr);
109 	info->l4_proto = ipv4_hdr->next_proto_id;
110 
111 	/* only fill l4_len for TCP, it's useful for TSO */
112 	if (info->l4_proto == IPPROTO_TCP) {
113 		tcp_hdr = (struct rte_tcp_hdr *)
114 			((char *)ipv4_hdr + info->l3_len);
115 		info->l4_len = (tcp_hdr->data_off & 0xf0) >> 2;
116 	} else if (info->l4_proto == IPPROTO_UDP)
117 		info->l4_len = sizeof(struct rte_udp_hdr);
118 	else
119 		info->l4_len = 0;
120 }
121 
122 /* Parse an IPv6 header to fill l3_len, l4_len, and l4_proto */
123 static void
124 parse_ipv6(struct rte_ipv6_hdr *ipv6_hdr, struct testpmd_offload_info *info)
125 {
126 	struct rte_tcp_hdr *tcp_hdr;
127 
128 	info->l3_len = sizeof(struct rte_ipv6_hdr);
129 	info->l4_proto = ipv6_hdr->proto;
130 
131 	/* only fill l4_len for TCP, it's useful for TSO */
132 	if (info->l4_proto == IPPROTO_TCP) {
133 		tcp_hdr = (struct rte_tcp_hdr *)
134 			((char *)ipv6_hdr + info->l3_len);
135 		info->l4_len = (tcp_hdr->data_off & 0xf0) >> 2;
136 	} else if (info->l4_proto == IPPROTO_UDP)
137 		info->l4_len = sizeof(struct rte_udp_hdr);
138 	else
139 		info->l4_len = 0;
140 }
141 
142 /*
143  * Parse an ethernet header to fill the ethertype, l2_len, l3_len and
144  * ipproto. This function is able to recognize IPv4/IPv6 with optional VLAN
145  * headers. The l4_len argument is only set in case of TCP (useful for TSO).
146  */
147 static void
148 parse_ethernet(struct rte_ether_hdr *eth_hdr, struct testpmd_offload_info *info)
149 {
150 	struct rte_ipv4_hdr *ipv4_hdr;
151 	struct rte_ipv6_hdr *ipv6_hdr;
152 	struct rte_vlan_hdr *vlan_hdr;
153 
154 	info->l2_len = sizeof(struct rte_ether_hdr);
155 	info->ethertype = eth_hdr->ether_type;
156 
157 	while (info->ethertype == _htons(RTE_ETHER_TYPE_VLAN) ||
158 	       info->ethertype == _htons(RTE_ETHER_TYPE_QINQ)) {
159 		vlan_hdr = (struct rte_vlan_hdr *)
160 			((char *)eth_hdr + info->l2_len);
161 		info->l2_len  += sizeof(struct rte_vlan_hdr);
162 		info->ethertype = vlan_hdr->eth_proto;
163 	}
164 
165 	switch (info->ethertype) {
166 	case _htons(RTE_ETHER_TYPE_IPV4):
167 		ipv4_hdr = (struct rte_ipv4_hdr *)
168 			((char *)eth_hdr + info->l2_len);
169 		parse_ipv4(ipv4_hdr, info);
170 		break;
171 	case _htons(RTE_ETHER_TYPE_IPV6):
172 		ipv6_hdr = (struct rte_ipv6_hdr *)
173 			((char *)eth_hdr + info->l2_len);
174 		parse_ipv6(ipv6_hdr, info);
175 		break;
176 	default:
177 		info->l4_len = 0;
178 		info->l3_len = 0;
179 		info->l4_proto = 0;
180 		break;
181 	}
182 }
183 
184 /* Fill in outer layers length */
185 static void
186 update_tunnel_outer(struct testpmd_offload_info *info)
187 {
188 	info->is_tunnel = 1;
189 	info->outer_ethertype = info->ethertype;
190 	info->outer_l2_len = info->l2_len;
191 	info->outer_l3_len = info->l3_len;
192 	info->outer_l4_proto = info->l4_proto;
193 }
194 
195 /*
196  * Parse a GTP protocol header.
197  * No optional fields and next extension header type.
198  */
199 static void
200 parse_gtp(struct rte_udp_hdr *udp_hdr,
201 	  struct testpmd_offload_info *info)
202 {
203 	struct rte_ipv4_hdr *ipv4_hdr;
204 	struct rte_ipv6_hdr *ipv6_hdr;
205 	struct rte_gtp_hdr *gtp_hdr;
206 	uint8_t gtp_len = sizeof(*gtp_hdr);
207 	uint8_t ip_ver;
208 
209 	/* Check udp destination port. */
210 	if (udp_hdr->dst_port != _htons(RTE_GTPC_UDP_PORT) &&
211 	    udp_hdr->src_port != _htons(RTE_GTPC_UDP_PORT) &&
212 	    udp_hdr->dst_port != _htons(RTE_GTPU_UDP_PORT))
213 		return;
214 
215 	update_tunnel_outer(info);
216 	info->l2_len = 0;
217 
218 	gtp_hdr = (struct rte_gtp_hdr *)((char *)udp_hdr +
219 		  sizeof(struct rte_udp_hdr));
220 
221 	/*
222 	 * Check message type. If message type is 0xff, it is
223 	 * a GTP data packet. If not, it is a GTP control packet
224 	 */
225 	if (gtp_hdr->msg_type == 0xff) {
226 		ip_ver = *(uint8_t *)((char *)udp_hdr +
227 			 sizeof(struct rte_udp_hdr) +
228 			 sizeof(struct rte_gtp_hdr));
229 		ip_ver = (ip_ver) & 0xf0;
230 
231 		if (ip_ver == RTE_GTP_TYPE_IPV4) {
232 			ipv4_hdr = (struct rte_ipv4_hdr *)((char *)gtp_hdr +
233 				   gtp_len);
234 			info->ethertype = _htons(RTE_ETHER_TYPE_IPV4);
235 			parse_ipv4(ipv4_hdr, info);
236 		} else if (ip_ver == RTE_GTP_TYPE_IPV6) {
237 			ipv6_hdr = (struct rte_ipv6_hdr *)((char *)gtp_hdr +
238 				   gtp_len);
239 			info->ethertype = _htons(RTE_ETHER_TYPE_IPV6);
240 			parse_ipv6(ipv6_hdr, info);
241 		}
242 	} else {
243 		info->ethertype = 0;
244 		info->l4_len = 0;
245 		info->l3_len = 0;
246 		info->l4_proto = 0;
247 	}
248 
249 	info->l2_len += RTE_ETHER_GTP_HLEN;
250 }
251 
252 /* Parse a vxlan header */
253 static void
254 parse_vxlan(struct rte_udp_hdr *udp_hdr,
255 	    struct testpmd_offload_info *info,
256 	    uint32_t pkt_type)
257 {
258 	struct rte_ether_hdr *eth_hdr;
259 
260 	/* check udp destination port, RTE_VXLAN_DEFAULT_PORT (4789) is the
261 	 * default vxlan port (rfc7348) or that the rx offload flag is set
262 	 * (i40e only currently)
263 	 */
264 	if (udp_hdr->dst_port != _htons(RTE_VXLAN_DEFAULT_PORT) &&
265 		RTE_ETH_IS_TUNNEL_PKT(pkt_type) == 0)
266 		return;
267 
268 	update_tunnel_outer(info);
269 
270 	eth_hdr = (struct rte_ether_hdr *)((char *)udp_hdr +
271 		sizeof(struct rte_udp_hdr) +
272 		sizeof(struct rte_vxlan_hdr));
273 
274 	parse_ethernet(eth_hdr, info);
275 	info->l2_len += RTE_ETHER_VXLAN_HLEN; /* add udp + vxlan */
276 }
277 
278 /* Parse a vxlan-gpe header */
279 static void
280 parse_vxlan_gpe(struct rte_udp_hdr *udp_hdr,
281 	    struct testpmd_offload_info *info)
282 {
283 	struct rte_ether_hdr *eth_hdr;
284 	struct rte_ipv4_hdr *ipv4_hdr;
285 	struct rte_ipv6_hdr *ipv6_hdr;
286 	struct rte_vxlan_gpe_hdr *vxlan_gpe_hdr;
287 	uint8_t vxlan_gpe_len = sizeof(*vxlan_gpe_hdr);
288 
289 	/* Check udp destination port. */
290 	if (udp_hdr->dst_port != _htons(vxlan_gpe_udp_port))
291 		return;
292 
293 	vxlan_gpe_hdr = (struct rte_vxlan_gpe_hdr *)((char *)udp_hdr +
294 				sizeof(struct rte_udp_hdr));
295 
296 	if (!vxlan_gpe_hdr->proto || vxlan_gpe_hdr->proto ==
297 	    RTE_VXLAN_GPE_TYPE_IPV4) {
298 		update_tunnel_outer(info);
299 
300 		ipv4_hdr = (struct rte_ipv4_hdr *)((char *)vxlan_gpe_hdr +
301 			   vxlan_gpe_len);
302 
303 		parse_ipv4(ipv4_hdr, info);
304 		info->ethertype = _htons(RTE_ETHER_TYPE_IPV4);
305 		info->l2_len = 0;
306 
307 	} else if (vxlan_gpe_hdr->proto == RTE_VXLAN_GPE_TYPE_IPV6) {
308 		update_tunnel_outer(info);
309 
310 		ipv6_hdr = (struct rte_ipv6_hdr *)((char *)vxlan_gpe_hdr +
311 			   vxlan_gpe_len);
312 
313 		info->ethertype = _htons(RTE_ETHER_TYPE_IPV6);
314 		parse_ipv6(ipv6_hdr, info);
315 		info->l2_len = 0;
316 
317 	} else if (vxlan_gpe_hdr->proto == RTE_VXLAN_GPE_TYPE_ETH) {
318 		update_tunnel_outer(info);
319 
320 		eth_hdr = (struct rte_ether_hdr *)((char *)vxlan_gpe_hdr +
321 			  vxlan_gpe_len);
322 
323 		parse_ethernet(eth_hdr, info);
324 	} else
325 		return;
326 
327 	info->l2_len += RTE_ETHER_VXLAN_GPE_HLEN;
328 }
329 
330 /* Parse a geneve header */
331 static void
332 parse_geneve(struct rte_udp_hdr *udp_hdr,
333 	    struct testpmd_offload_info *info)
334 {
335 	struct rte_ether_hdr *eth_hdr;
336 	struct rte_ipv4_hdr *ipv4_hdr;
337 	struct rte_ipv6_hdr *ipv6_hdr;
338 	struct rte_geneve_hdr *geneve_hdr;
339 	uint16_t geneve_len;
340 
341 	/* Check udp destination port. */
342 	if (udp_hdr->dst_port != _htons(geneve_udp_port))
343 		return;
344 
345 	geneve_hdr = (struct rte_geneve_hdr *)((char *)udp_hdr +
346 				sizeof(struct rte_udp_hdr));
347 	geneve_len = sizeof(struct rte_geneve_hdr) + geneve_hdr->opt_len * 4;
348 	if (!geneve_hdr->proto || geneve_hdr->proto ==
349 	    _htons(RTE_ETHER_TYPE_IPV4)) {
350 		update_tunnel_outer(info);
351 		ipv4_hdr = (struct rte_ipv4_hdr *)((char *)geneve_hdr +
352 			   geneve_len);
353 		parse_ipv4(ipv4_hdr, info);
354 		info->ethertype = _htons(RTE_ETHER_TYPE_IPV4);
355 		info->l2_len = 0;
356 	} else if (geneve_hdr->proto == _htons(RTE_ETHER_TYPE_IPV6)) {
357 		update_tunnel_outer(info);
358 		ipv6_hdr = (struct rte_ipv6_hdr *)((char *)geneve_hdr +
359 			   geneve_len);
360 		info->ethertype = _htons(RTE_ETHER_TYPE_IPV6);
361 		parse_ipv6(ipv6_hdr, info);
362 		info->l2_len = 0;
363 
364 	} else if (geneve_hdr->proto == _htons(RTE_GENEVE_TYPE_ETH)) {
365 		update_tunnel_outer(info);
366 		eth_hdr = (struct rte_ether_hdr *)((char *)geneve_hdr +
367 			  geneve_len);
368 		parse_ethernet(eth_hdr, info);
369 	} else
370 		return;
371 
372 	info->l2_len +=
373 		(sizeof(struct rte_udp_hdr) + sizeof(struct rte_geneve_hdr) +
374 		((struct rte_geneve_hdr *)geneve_hdr)->opt_len * 4);
375 }
376 
377 /* Parse a gre header */
378 static void
379 parse_gre(struct simple_gre_hdr *gre_hdr, struct testpmd_offload_info *info)
380 {
381 	struct rte_ether_hdr *eth_hdr;
382 	struct rte_ipv4_hdr *ipv4_hdr;
383 	struct rte_ipv6_hdr *ipv6_hdr;
384 	uint8_t gre_len = 0;
385 
386 	gre_len += sizeof(struct simple_gre_hdr);
387 
388 	if (gre_hdr->flags & _htons(GRE_KEY_PRESENT))
389 		gre_len += GRE_EXT_LEN;
390 	if (gre_hdr->flags & _htons(GRE_SEQUENCE_PRESENT))
391 		gre_len += GRE_EXT_LEN;
392 	if (gre_hdr->flags & _htons(GRE_CHECKSUM_PRESENT))
393 		gre_len += GRE_EXT_LEN;
394 
395 	if (gre_hdr->proto == _htons(RTE_ETHER_TYPE_IPV4)) {
396 		update_tunnel_outer(info);
397 
398 		ipv4_hdr = (struct rte_ipv4_hdr *)((char *)gre_hdr + gre_len);
399 
400 		parse_ipv4(ipv4_hdr, info);
401 		info->ethertype = _htons(RTE_ETHER_TYPE_IPV4);
402 		info->l2_len = 0;
403 
404 	} else if (gre_hdr->proto == _htons(RTE_ETHER_TYPE_IPV6)) {
405 		update_tunnel_outer(info);
406 
407 		ipv6_hdr = (struct rte_ipv6_hdr *)((char *)gre_hdr + gre_len);
408 
409 		info->ethertype = _htons(RTE_ETHER_TYPE_IPV6);
410 		parse_ipv6(ipv6_hdr, info);
411 		info->l2_len = 0;
412 
413 	} else if (gre_hdr->proto == _htons(RTE_ETHER_TYPE_TEB)) {
414 		update_tunnel_outer(info);
415 
416 		eth_hdr = (struct rte_ether_hdr *)((char *)gre_hdr + gre_len);
417 
418 		parse_ethernet(eth_hdr, info);
419 	} else
420 		return;
421 
422 	info->l2_len += gre_len;
423 }
424 
425 
426 /* Parse an encapsulated ip or ipv6 header */
427 static void
428 parse_encap_ip(void *encap_ip, struct testpmd_offload_info *info)
429 {
430 	struct rte_ipv4_hdr *ipv4_hdr = encap_ip;
431 	struct rte_ipv6_hdr *ipv6_hdr = encap_ip;
432 	uint8_t ip_version;
433 
434 	ip_version = (ipv4_hdr->version_ihl & 0xf0) >> 4;
435 
436 	if (ip_version != 4 && ip_version != 6)
437 		return;
438 
439 	info->is_tunnel = 1;
440 	info->outer_ethertype = info->ethertype;
441 	info->outer_l2_len = info->l2_len;
442 	info->outer_l3_len = info->l3_len;
443 
444 	if (ip_version == 4) {
445 		parse_ipv4(ipv4_hdr, info);
446 		info->ethertype = _htons(RTE_ETHER_TYPE_IPV4);
447 	} else {
448 		parse_ipv6(ipv6_hdr, info);
449 		info->ethertype = _htons(RTE_ETHER_TYPE_IPV6);
450 	}
451 	info->l2_len = 0;
452 }
453 
454 /* if possible, calculate the checksum of a packet in hw or sw,
455  * depending on the testpmd command line configuration */
456 static uint64_t
457 process_inner_cksums(void *l3_hdr, const struct testpmd_offload_info *info,
458 	uint64_t tx_offloads)
459 {
460 	struct rte_ipv4_hdr *ipv4_hdr = l3_hdr;
461 	struct rte_udp_hdr *udp_hdr;
462 	struct rte_tcp_hdr *tcp_hdr;
463 	struct rte_sctp_hdr *sctp_hdr;
464 	uint64_t ol_flags = 0;
465 	uint32_t max_pkt_len, tso_segsz = 0;
466 
467 	/* ensure packet is large enough to require tso */
468 	if (!info->is_tunnel) {
469 		max_pkt_len = info->l2_len + info->l3_len + info->l4_len +
470 			info->tso_segsz;
471 		if (info->tso_segsz != 0 && info->pkt_len > max_pkt_len)
472 			tso_segsz = info->tso_segsz;
473 	} else {
474 		max_pkt_len = info->outer_l2_len + info->outer_l3_len +
475 			info->l2_len + info->l3_len + info->l4_len +
476 			info->tunnel_tso_segsz;
477 		if (info->tunnel_tso_segsz != 0 && info->pkt_len > max_pkt_len)
478 			tso_segsz = info->tunnel_tso_segsz;
479 	}
480 
481 	if (info->ethertype == _htons(RTE_ETHER_TYPE_IPV4)) {
482 		ipv4_hdr = l3_hdr;
483 		ipv4_hdr->hdr_checksum = 0;
484 
485 		ol_flags |= PKT_TX_IPV4;
486 		if (info->l4_proto == IPPROTO_TCP && tso_segsz) {
487 			ol_flags |= PKT_TX_IP_CKSUM;
488 		} else {
489 			if (tx_offloads & DEV_TX_OFFLOAD_IPV4_CKSUM)
490 				ol_flags |= PKT_TX_IP_CKSUM;
491 			else
492 				ipv4_hdr->hdr_checksum =
493 					rte_ipv4_cksum(ipv4_hdr);
494 		}
495 	} else if (info->ethertype == _htons(RTE_ETHER_TYPE_IPV6))
496 		ol_flags |= PKT_TX_IPV6;
497 	else
498 		return 0; /* packet type not supported, nothing to do */
499 
500 	if (info->l4_proto == IPPROTO_UDP) {
501 		udp_hdr = (struct rte_udp_hdr *)((char *)l3_hdr + info->l3_len);
502 		/* do not recalculate udp cksum if it was 0 */
503 		if (udp_hdr->dgram_cksum != 0) {
504 			udp_hdr->dgram_cksum = 0;
505 			if (tx_offloads & DEV_TX_OFFLOAD_UDP_CKSUM)
506 				ol_flags |= PKT_TX_UDP_CKSUM;
507 			else {
508 				udp_hdr->dgram_cksum =
509 					get_udptcp_checksum(l3_hdr, udp_hdr,
510 						info->ethertype);
511 			}
512 		}
513 		if (info->gso_enable)
514 			ol_flags |= PKT_TX_UDP_SEG;
515 	} else if (info->l4_proto == IPPROTO_TCP) {
516 		tcp_hdr = (struct rte_tcp_hdr *)((char *)l3_hdr + info->l3_len);
517 		tcp_hdr->cksum = 0;
518 		if (tso_segsz)
519 			ol_flags |= PKT_TX_TCP_SEG;
520 		else if (tx_offloads & DEV_TX_OFFLOAD_TCP_CKSUM)
521 			ol_flags |= PKT_TX_TCP_CKSUM;
522 		else {
523 			tcp_hdr->cksum =
524 				get_udptcp_checksum(l3_hdr, tcp_hdr,
525 					info->ethertype);
526 		}
527 		if (info->gso_enable)
528 			ol_flags |= PKT_TX_TCP_SEG;
529 	} else if (info->l4_proto == IPPROTO_SCTP) {
530 		sctp_hdr = (struct rte_sctp_hdr *)
531 			((char *)l3_hdr + info->l3_len);
532 		sctp_hdr->cksum = 0;
533 		/* sctp payload must be a multiple of 4 to be
534 		 * offloaded */
535 		if ((tx_offloads & DEV_TX_OFFLOAD_SCTP_CKSUM) &&
536 			((ipv4_hdr->total_length & 0x3) == 0)) {
537 			ol_flags |= PKT_TX_SCTP_CKSUM;
538 		} else {
539 			/* XXX implement CRC32c, example available in
540 			 * RFC3309 */
541 		}
542 	}
543 
544 	return ol_flags;
545 }
546 
547 /* Calculate the checksum of outer header */
548 static uint64_t
549 process_outer_cksums(void *outer_l3_hdr, struct testpmd_offload_info *info,
550 	uint64_t tx_offloads, int tso_enabled)
551 {
552 	struct rte_ipv4_hdr *ipv4_hdr = outer_l3_hdr;
553 	struct rte_ipv6_hdr *ipv6_hdr = outer_l3_hdr;
554 	struct rte_udp_hdr *udp_hdr;
555 	uint64_t ol_flags = 0;
556 
557 	if (info->outer_ethertype == _htons(RTE_ETHER_TYPE_IPV4)) {
558 		ipv4_hdr->hdr_checksum = 0;
559 		ol_flags |= PKT_TX_OUTER_IPV4;
560 
561 		if (tx_offloads	& DEV_TX_OFFLOAD_OUTER_IPV4_CKSUM)
562 			ol_flags |= PKT_TX_OUTER_IP_CKSUM;
563 		else
564 			ipv4_hdr->hdr_checksum = rte_ipv4_cksum(ipv4_hdr);
565 	} else
566 		ol_flags |= PKT_TX_OUTER_IPV6;
567 
568 	if (info->outer_l4_proto != IPPROTO_UDP)
569 		return ol_flags;
570 
571 	udp_hdr = (struct rte_udp_hdr *)
572 		((char *)outer_l3_hdr + info->outer_l3_len);
573 
574 	if (tso_enabled)
575 		ol_flags |= PKT_TX_TCP_SEG;
576 
577 	/* Skip SW outer UDP checksum generation if HW supports it */
578 	if (tx_offloads & DEV_TX_OFFLOAD_OUTER_UDP_CKSUM) {
579 		if (info->outer_ethertype == _htons(RTE_ETHER_TYPE_IPV4))
580 			udp_hdr->dgram_cksum
581 				= rte_ipv4_phdr_cksum(ipv4_hdr, ol_flags);
582 		else
583 			udp_hdr->dgram_cksum
584 				= rte_ipv6_phdr_cksum(ipv6_hdr, ol_flags);
585 
586 		ol_flags |= PKT_TX_OUTER_UDP_CKSUM;
587 		return ol_flags;
588 	}
589 
590 	/* outer UDP checksum is done in software. In the other side, for
591 	 * UDP tunneling, like VXLAN or Geneve, outer UDP checksum can be
592 	 * set to zero.
593 	 *
594 	 * If a packet will be TSOed into small packets by NIC, we cannot
595 	 * set/calculate a non-zero checksum, because it will be a wrong
596 	 * value after the packet be split into several small packets.
597 	 */
598 	if (tso_enabled)
599 		udp_hdr->dgram_cksum = 0;
600 
601 	/* do not recalculate udp cksum if it was 0 */
602 	if (udp_hdr->dgram_cksum != 0) {
603 		udp_hdr->dgram_cksum = 0;
604 		if (info->outer_ethertype == _htons(RTE_ETHER_TYPE_IPV4))
605 			udp_hdr->dgram_cksum =
606 				rte_ipv4_udptcp_cksum(ipv4_hdr, udp_hdr);
607 		else
608 			udp_hdr->dgram_cksum =
609 				rte_ipv6_udptcp_cksum(ipv6_hdr, udp_hdr);
610 	}
611 
612 	return ol_flags;
613 }
614 
615 /*
616  * Helper function.
617  * Performs actual copying.
618  * Returns number of segments in the destination mbuf on success,
619  * or negative error code on failure.
620  */
621 static int
622 mbuf_copy_split(const struct rte_mbuf *ms, struct rte_mbuf *md[],
623 	uint16_t seglen[], uint8_t nb_seg)
624 {
625 	uint32_t dlen, slen, tlen;
626 	uint32_t i, len;
627 	const struct rte_mbuf *m;
628 	const uint8_t *src;
629 	uint8_t *dst;
630 
631 	dlen = 0;
632 	slen = 0;
633 	tlen = 0;
634 
635 	dst = NULL;
636 	src = NULL;
637 
638 	m = ms;
639 	i = 0;
640 	while (ms != NULL && i != nb_seg) {
641 
642 		if (slen == 0) {
643 			slen = rte_pktmbuf_data_len(ms);
644 			src = rte_pktmbuf_mtod(ms, const uint8_t *);
645 		}
646 
647 		if (dlen == 0) {
648 			dlen = RTE_MIN(seglen[i], slen);
649 			md[i]->data_len = dlen;
650 			md[i]->next = (i + 1 == nb_seg) ? NULL : md[i + 1];
651 			dst = rte_pktmbuf_mtod(md[i], uint8_t *);
652 		}
653 
654 		len = RTE_MIN(slen, dlen);
655 		memcpy(dst, src, len);
656 		tlen += len;
657 		slen -= len;
658 		dlen -= len;
659 		src += len;
660 		dst += len;
661 
662 		if (slen == 0)
663 			ms = ms->next;
664 		if (dlen == 0)
665 			i++;
666 	}
667 
668 	if (ms != NULL)
669 		return -ENOBUFS;
670 	else if (tlen != m->pkt_len)
671 		return -EINVAL;
672 
673 	md[0]->nb_segs = nb_seg;
674 	md[0]->pkt_len = tlen;
675 	md[0]->vlan_tci = m->vlan_tci;
676 	md[0]->vlan_tci_outer = m->vlan_tci_outer;
677 	md[0]->ol_flags = m->ol_flags;
678 	md[0]->tx_offload = m->tx_offload;
679 
680 	return nb_seg;
681 }
682 
683 /*
684  * Allocate a new mbuf with up to tx_pkt_nb_segs segments.
685  * Copy packet contents and offload information into the new segmented mbuf.
686  */
687 static struct rte_mbuf *
688 pkt_copy_split(const struct rte_mbuf *pkt)
689 {
690 	int32_t n, rc;
691 	uint32_t i, len, nb_seg;
692 	struct rte_mempool *mp;
693 	uint16_t seglen[RTE_MAX_SEGS_PER_PKT];
694 	struct rte_mbuf *p, *md[RTE_MAX_SEGS_PER_PKT];
695 
696 	mp = current_fwd_lcore()->mbp;
697 
698 	if (tx_pkt_split == TX_PKT_SPLIT_RND)
699 		nb_seg = random() % tx_pkt_nb_segs + 1;
700 	else
701 		nb_seg = tx_pkt_nb_segs;
702 
703 	memcpy(seglen, tx_pkt_seg_lengths, nb_seg * sizeof(seglen[0]));
704 
705 	/* calculate number of segments to use and their length. */
706 	len = 0;
707 	for (i = 0; i != nb_seg && len < pkt->pkt_len; i++) {
708 		len += seglen[i];
709 		md[i] = NULL;
710 	}
711 
712 	n = pkt->pkt_len - len;
713 
714 	/* update size of the last segment to fit rest of the packet */
715 	if (n >= 0) {
716 		seglen[i - 1] += n;
717 		len += n;
718 	}
719 
720 	nb_seg = i;
721 	while (i != 0) {
722 		p = rte_pktmbuf_alloc(mp);
723 		if (p == NULL) {
724 			TESTPMD_LOG(ERR,
725 				"failed to allocate %u-th of %u mbuf "
726 				"from mempool: %s\n",
727 				nb_seg - i, nb_seg, mp->name);
728 			break;
729 		}
730 
731 		md[--i] = p;
732 		if (rte_pktmbuf_tailroom(md[i]) < seglen[i]) {
733 			TESTPMD_LOG(ERR, "mempool %s, %u-th segment: "
734 				"expected seglen: %u, "
735 				"actual mbuf tailroom: %u\n",
736 				mp->name, i, seglen[i],
737 				rte_pktmbuf_tailroom(md[i]));
738 			break;
739 		}
740 	}
741 
742 	/* all mbufs successfully allocated, do copy */
743 	if (i == 0) {
744 		rc = mbuf_copy_split(pkt, md, seglen, nb_seg);
745 		if (rc < 0)
746 			TESTPMD_LOG(ERR,
747 				"mbuf_copy_split for %p(len=%u, nb_seg=%u) "
748 				"into %u segments failed with error code: %d\n",
749 				pkt, pkt->pkt_len, pkt->nb_segs, nb_seg, rc);
750 
751 		/* figure out how many mbufs to free. */
752 		i = RTE_MAX(rc, 0);
753 	}
754 
755 	/* free unused mbufs */
756 	for (; i != nb_seg; i++) {
757 		rte_pktmbuf_free_seg(md[i]);
758 		md[i] = NULL;
759 	}
760 
761 	return md[0];
762 }
763 
764 /*
765  * Receive a burst of packets, and for each packet:
766  *  - parse packet, and try to recognize a supported packet type (1)
767  *  - if it's not a supported packet type, don't touch the packet, else:
768  *  - reprocess the checksum of all supported layers. This is done in SW
769  *    or HW, depending on testpmd command line configuration
770  *  - if TSO is enabled in testpmd command line, also flag the mbuf for TCP
771  *    segmentation offload (this implies HW TCP checksum)
772  * Then transmit packets on the output port.
773  *
774  * (1) Supported packets are:
775  *   Ether / (vlan) / IP|IP6 / UDP|TCP|SCTP .
776  *   Ether / (vlan) / outer IP|IP6 / outer UDP / VxLAN / Ether / IP|IP6 /
777  *           UDP|TCP|SCTP
778  *   Ether / (vlan) / outer IP|IP6 / outer UDP / VXLAN-GPE / Ether / IP|IP6 /
779  *           UDP|TCP|SCTP
780  *   Ether / (vlan) / outer IP|IP6 / outer UDP / VXLAN-GPE / IP|IP6 /
781  *           UDP|TCP|SCTP
782  *   Ether / (vlan) / outer IP / outer UDP / GTP / IP|IP6 / UDP|TCP|SCTP
783  *   Ether / (vlan) / outer IP|IP6 / GRE / Ether / IP|IP6 / UDP|TCP|SCTP
784  *   Ether / (vlan) / outer IP|IP6 / GRE / IP|IP6 / UDP|TCP|SCTP
785  *   Ether / (vlan) / outer IP|IP6 / IP|IP6 / UDP|TCP|SCTP
786  *
787  * The testpmd command line for this forward engine sets the flags
788  * TESTPMD_TX_OFFLOAD_* in ports[tx_port].tx_ol_flags. They control
789  * wether a checksum must be calculated in software or in hardware. The
790  * IP, UDP, TCP and SCTP flags always concern the inner layer. The
791  * OUTER_IP is only useful for tunnel packets.
792  */
793 static void
794 pkt_burst_checksum_forward(struct fwd_stream *fs)
795 {
796 	struct rte_mbuf *pkts_burst[MAX_PKT_BURST];
797 	struct rte_mbuf *gso_segments[GSO_MAX_PKT_BURST];
798 	struct rte_gso_ctx *gso_ctx;
799 	struct rte_mbuf **tx_pkts_burst;
800 	struct rte_port *txp;
801 	struct rte_mbuf *m, *p;
802 	struct rte_ether_hdr *eth_hdr;
803 	void *l3_hdr = NULL, *outer_l3_hdr = NULL; /* can be IPv4 or IPv6 */
804 	void **gro_ctx;
805 	uint16_t gro_pkts_num;
806 	uint8_t gro_enable;
807 	uint16_t nb_rx;
808 	uint16_t nb_tx;
809 	uint16_t nb_prep;
810 	uint16_t i;
811 	uint64_t rx_ol_flags, tx_ol_flags;
812 	uint64_t tx_offloads;
813 	uint32_t retry;
814 	uint32_t rx_bad_ip_csum;
815 	uint32_t rx_bad_l4_csum;
816 	uint32_t rx_bad_outer_l4_csum;
817 	uint32_t rx_bad_outer_ip_csum;
818 	struct testpmd_offload_info info;
819 	uint16_t nb_segments = 0;
820 	int ret;
821 
822 	uint64_t start_tsc = 0;
823 
824 	get_start_cycles(&start_tsc);
825 
826 	/* receive a burst of packet */
827 	nb_rx = rte_eth_rx_burst(fs->rx_port, fs->rx_queue, pkts_burst,
828 				 nb_pkt_per_burst);
829 	inc_rx_burst_stats(fs, nb_rx);
830 	if (unlikely(nb_rx == 0))
831 		return;
832 
833 	fs->rx_packets += nb_rx;
834 	rx_bad_ip_csum = 0;
835 	rx_bad_l4_csum = 0;
836 	rx_bad_outer_l4_csum = 0;
837 	rx_bad_outer_ip_csum = 0;
838 	gro_enable = gro_ports[fs->rx_port].enable;
839 
840 	txp = &ports[fs->tx_port];
841 	tx_offloads = txp->dev_conf.txmode.offloads;
842 	memset(&info, 0, sizeof(info));
843 	info.tso_segsz = txp->tso_segsz;
844 	info.tunnel_tso_segsz = txp->tunnel_tso_segsz;
845 	if (gso_ports[fs->tx_port].enable)
846 		info.gso_enable = 1;
847 
848 	for (i = 0; i < nb_rx; i++) {
849 		if (likely(i < nb_rx - 1))
850 			rte_prefetch0(rte_pktmbuf_mtod(pkts_burst[i + 1],
851 						       void *));
852 
853 		m = pkts_burst[i];
854 		info.is_tunnel = 0;
855 		info.pkt_len = rte_pktmbuf_pkt_len(m);
856 		tx_ol_flags = m->ol_flags &
857 			      (IND_ATTACHED_MBUF | EXT_ATTACHED_MBUF);
858 		rx_ol_flags = m->ol_flags;
859 
860 		/* Update the L3/L4 checksum error packet statistics */
861 		if ((rx_ol_flags & PKT_RX_IP_CKSUM_MASK) == PKT_RX_IP_CKSUM_BAD)
862 			rx_bad_ip_csum += 1;
863 		if ((rx_ol_flags & PKT_RX_L4_CKSUM_MASK) == PKT_RX_L4_CKSUM_BAD)
864 			rx_bad_l4_csum += 1;
865 		if (rx_ol_flags & PKT_RX_OUTER_L4_CKSUM_BAD)
866 			rx_bad_outer_l4_csum += 1;
867 		if (rx_ol_flags & PKT_RX_OUTER_IP_CKSUM_BAD)
868 			rx_bad_outer_ip_csum += 1;
869 
870 		/* step 1: dissect packet, parsing optional vlan, ip4/ip6, vxlan
871 		 * and inner headers */
872 
873 		eth_hdr = rte_pktmbuf_mtod(m, struct rte_ether_hdr *);
874 		rte_ether_addr_copy(&peer_eth_addrs[fs->peer_addr],
875 				&eth_hdr->d_addr);
876 		rte_ether_addr_copy(&ports[fs->tx_port].eth_addr,
877 				&eth_hdr->s_addr);
878 		parse_ethernet(eth_hdr, &info);
879 		l3_hdr = (char *)eth_hdr + info.l2_len;
880 
881 		/* check if it's a supported tunnel */
882 		if (txp->parse_tunnel) {
883 			if (info.l4_proto == IPPROTO_UDP) {
884 				struct rte_udp_hdr *udp_hdr;
885 
886 				udp_hdr = (struct rte_udp_hdr *)
887 					((char *)l3_hdr + info.l3_len);
888 				parse_gtp(udp_hdr, &info);
889 				if (info.is_tunnel) {
890 					tx_ol_flags |= PKT_TX_TUNNEL_GTP;
891 					goto tunnel_update;
892 				}
893 				parse_vxlan_gpe(udp_hdr, &info);
894 				if (info.is_tunnel) {
895 					tx_ol_flags |=
896 						PKT_TX_TUNNEL_VXLAN_GPE;
897 					goto tunnel_update;
898 				}
899 				parse_vxlan(udp_hdr, &info,
900 					    m->packet_type);
901 				if (info.is_tunnel) {
902 					tx_ol_flags |=
903 						PKT_TX_TUNNEL_VXLAN;
904 					goto tunnel_update;
905 				}
906 				parse_geneve(udp_hdr, &info);
907 				if (info.is_tunnel) {
908 					tx_ol_flags |=
909 						PKT_TX_TUNNEL_GENEVE;
910 					goto tunnel_update;
911 				}
912 			} else if (info.l4_proto == IPPROTO_GRE) {
913 				struct simple_gre_hdr *gre_hdr;
914 
915 				gre_hdr = (struct simple_gre_hdr *)
916 					((char *)l3_hdr + info.l3_len);
917 				parse_gre(gre_hdr, &info);
918 				if (info.is_tunnel)
919 					tx_ol_flags |= PKT_TX_TUNNEL_GRE;
920 			} else if (info.l4_proto == IPPROTO_IPIP) {
921 				void *encap_ip_hdr;
922 
923 				encap_ip_hdr = (char *)l3_hdr + info.l3_len;
924 				parse_encap_ip(encap_ip_hdr, &info);
925 				if (info.is_tunnel)
926 					tx_ol_flags |= PKT_TX_TUNNEL_IPIP;
927 			}
928 		}
929 
930 tunnel_update:
931 		/* update l3_hdr and outer_l3_hdr if a tunnel was parsed */
932 		if (info.is_tunnel) {
933 			outer_l3_hdr = l3_hdr;
934 			l3_hdr = (char *)l3_hdr + info.outer_l3_len + info.l2_len;
935 		}
936 
937 		/* step 2: depending on user command line configuration,
938 		 * recompute checksum either in software or flag the
939 		 * mbuf to offload the calculation to the NIC. If TSO
940 		 * is configured, prepare the mbuf for TCP segmentation. */
941 
942 		/* process checksums of inner headers first */
943 		tx_ol_flags |= process_inner_cksums(l3_hdr, &info,
944 			tx_offloads);
945 
946 		/* Then process outer headers if any. Note that the software
947 		 * checksum will be wrong if one of the inner checksums is
948 		 * processed in hardware. */
949 		if (info.is_tunnel == 1) {
950 			tx_ol_flags |= process_outer_cksums(outer_l3_hdr, &info,
951 					tx_offloads,
952 					!!(tx_ol_flags & PKT_TX_TCP_SEG));
953 		}
954 
955 		/* step 3: fill the mbuf meta data (flags and header lengths) */
956 
957 		m->tx_offload = 0;
958 		if (info.is_tunnel == 1) {
959 			if (info.tunnel_tso_segsz ||
960 			    (tx_offloads &
961 			     DEV_TX_OFFLOAD_OUTER_IPV4_CKSUM) ||
962 			    (tx_offloads &
963 			     DEV_TX_OFFLOAD_OUTER_UDP_CKSUM) ||
964 			    (tx_ol_flags & PKT_TX_OUTER_IPV6)) {
965 				m->outer_l2_len = info.outer_l2_len;
966 				m->outer_l3_len = info.outer_l3_len;
967 				m->l2_len = info.l2_len;
968 				m->l3_len = info.l3_len;
969 				m->l4_len = info.l4_len;
970 				m->tso_segsz = info.tunnel_tso_segsz;
971 			}
972 			else {
973 				/* if there is a outer UDP cksum
974 				   processed in sw and the inner in hw,
975 				   the outer checksum will be wrong as
976 				   the payload will be modified by the
977 				   hardware */
978 				m->l2_len = info.outer_l2_len +
979 					info.outer_l3_len + info.l2_len;
980 				m->l3_len = info.l3_len;
981 				m->l4_len = info.l4_len;
982 			}
983 		} else {
984 			/* this is only useful if an offload flag is
985 			 * set, but it does not hurt to fill it in any
986 			 * case */
987 			m->l2_len = info.l2_len;
988 			m->l3_len = info.l3_len;
989 			m->l4_len = info.l4_len;
990 			m->tso_segsz = info.tso_segsz;
991 		}
992 		m->ol_flags = tx_ol_flags;
993 
994 		/* Do split & copy for the packet. */
995 		if (tx_pkt_split != TX_PKT_SPLIT_OFF) {
996 			p = pkt_copy_split(m);
997 			if (p != NULL) {
998 				rte_pktmbuf_free(m);
999 				m = p;
1000 				pkts_burst[i] = m;
1001 			}
1002 		}
1003 
1004 		/* if verbose mode is enabled, dump debug info */
1005 		if (verbose_level > 0) {
1006 			char buf[256];
1007 
1008 			printf("-----------------\n");
1009 			printf("port=%u, mbuf=%p, pkt_len=%u, nb_segs=%u:\n",
1010 				fs->rx_port, m, m->pkt_len, m->nb_segs);
1011 			/* dump rx parsed packet info */
1012 			rte_get_rx_ol_flag_list(rx_ol_flags, buf, sizeof(buf));
1013 			printf("rx: l2_len=%d ethertype=%x l3_len=%d "
1014 				"l4_proto=%d l4_len=%d flags=%s\n",
1015 				info.l2_len, rte_be_to_cpu_16(info.ethertype),
1016 				info.l3_len, info.l4_proto, info.l4_len, buf);
1017 			if (rx_ol_flags & PKT_RX_LRO)
1018 				printf("rx: m->lro_segsz=%u\n", m->tso_segsz);
1019 			if (info.is_tunnel == 1)
1020 				printf("rx: outer_l2_len=%d outer_ethertype=%x "
1021 					"outer_l3_len=%d\n", info.outer_l2_len,
1022 					rte_be_to_cpu_16(info.outer_ethertype),
1023 					info.outer_l3_len);
1024 			/* dump tx packet info */
1025 			if ((tx_offloads & (DEV_TX_OFFLOAD_IPV4_CKSUM |
1026 					    DEV_TX_OFFLOAD_UDP_CKSUM |
1027 					    DEV_TX_OFFLOAD_TCP_CKSUM |
1028 					    DEV_TX_OFFLOAD_SCTP_CKSUM)) ||
1029 				info.tso_segsz != 0)
1030 				printf("tx: m->l2_len=%d m->l3_len=%d "
1031 					"m->l4_len=%d\n",
1032 					m->l2_len, m->l3_len, m->l4_len);
1033 			if (info.is_tunnel == 1) {
1034 				if ((tx_offloads &
1035 				    DEV_TX_OFFLOAD_OUTER_IPV4_CKSUM) ||
1036 				    (tx_offloads &
1037 				    DEV_TX_OFFLOAD_OUTER_UDP_CKSUM) ||
1038 				    (tx_ol_flags & PKT_TX_OUTER_IPV6))
1039 					printf("tx: m->outer_l2_len=%d "
1040 						"m->outer_l3_len=%d\n",
1041 						m->outer_l2_len,
1042 						m->outer_l3_len);
1043 				if (info.tunnel_tso_segsz != 0 &&
1044 						(m->ol_flags & PKT_TX_TCP_SEG))
1045 					printf("tx: m->tso_segsz=%d\n",
1046 						m->tso_segsz);
1047 			} else if (info.tso_segsz != 0 &&
1048 					(m->ol_flags & PKT_TX_TCP_SEG))
1049 				printf("tx: m->tso_segsz=%d\n", m->tso_segsz);
1050 			rte_get_tx_ol_flag_list(m->ol_flags, buf, sizeof(buf));
1051 			printf("tx: flags=%s", buf);
1052 			printf("\n");
1053 		}
1054 	}
1055 
1056 	if (unlikely(gro_enable)) {
1057 		if (gro_flush_cycles == GRO_DEFAULT_FLUSH_CYCLES) {
1058 			nb_rx = rte_gro_reassemble_burst(pkts_burst, nb_rx,
1059 					&(gro_ports[fs->rx_port].param));
1060 		} else {
1061 			gro_ctx = current_fwd_lcore()->gro_ctx;
1062 			nb_rx = rte_gro_reassemble(pkts_burst, nb_rx, gro_ctx);
1063 
1064 			if (++fs->gro_times >= gro_flush_cycles) {
1065 				gro_pkts_num = rte_gro_get_pkt_count(gro_ctx);
1066 				if (gro_pkts_num > MAX_PKT_BURST - nb_rx)
1067 					gro_pkts_num = MAX_PKT_BURST - nb_rx;
1068 
1069 				nb_rx += rte_gro_timeout_flush(gro_ctx, 0,
1070 						RTE_GRO_TCP_IPV4,
1071 						&pkts_burst[nb_rx],
1072 						gro_pkts_num);
1073 				fs->gro_times = 0;
1074 			}
1075 		}
1076 	}
1077 
1078 	if (gso_ports[fs->tx_port].enable == 0)
1079 		tx_pkts_burst = pkts_burst;
1080 	else {
1081 		gso_ctx = &(current_fwd_lcore()->gso_ctx);
1082 		gso_ctx->gso_size = gso_max_segment_size;
1083 		for (i = 0; i < nb_rx; i++) {
1084 			ret = rte_gso_segment(pkts_burst[i], gso_ctx,
1085 					&gso_segments[nb_segments],
1086 					GSO_MAX_PKT_BURST - nb_segments);
1087 			if (ret >= 1) {
1088 				/* pkts_burst[i] can be freed safely here. */
1089 				rte_pktmbuf_free(pkts_burst[i]);
1090 				nb_segments += ret;
1091 			} else if (ret == 0) {
1092 				/* 0 means it can be transmitted directly
1093 				 * without gso.
1094 				 */
1095 				gso_segments[nb_segments] = pkts_burst[i];
1096 				nb_segments += 1;
1097 			} else {
1098 				TESTPMD_LOG(DEBUG, "Unable to segment packet");
1099 				rte_pktmbuf_free(pkts_burst[i]);
1100 			}
1101 		}
1102 
1103 		tx_pkts_burst = gso_segments;
1104 		nb_rx = nb_segments;
1105 	}
1106 
1107 	nb_prep = rte_eth_tx_prepare(fs->tx_port, fs->tx_queue,
1108 			tx_pkts_burst, nb_rx);
1109 	if (nb_prep != nb_rx)
1110 		printf("Preparing packet burst to transmit failed: %s\n",
1111 				rte_strerror(rte_errno));
1112 
1113 	nb_tx = rte_eth_tx_burst(fs->tx_port, fs->tx_queue, tx_pkts_burst,
1114 			nb_prep);
1115 
1116 	/*
1117 	 * Retry if necessary
1118 	 */
1119 	if (unlikely(nb_tx < nb_rx) && fs->retry_enabled) {
1120 		retry = 0;
1121 		while (nb_tx < nb_rx && retry++ < burst_tx_retry_num) {
1122 			rte_delay_us(burst_tx_delay_time);
1123 			nb_tx += rte_eth_tx_burst(fs->tx_port, fs->tx_queue,
1124 					&tx_pkts_burst[nb_tx], nb_rx - nb_tx);
1125 		}
1126 	}
1127 	fs->tx_packets += nb_tx;
1128 	fs->rx_bad_ip_csum += rx_bad_ip_csum;
1129 	fs->rx_bad_l4_csum += rx_bad_l4_csum;
1130 	fs->rx_bad_outer_l4_csum += rx_bad_outer_l4_csum;
1131 	fs->rx_bad_outer_ip_csum += rx_bad_outer_ip_csum;
1132 
1133 	inc_tx_burst_stats(fs, nb_tx);
1134 	if (unlikely(nb_tx < nb_rx)) {
1135 		fs->fwd_dropped += (nb_rx - nb_tx);
1136 		do {
1137 			rte_pktmbuf_free(tx_pkts_burst[nb_tx]);
1138 		} while (++nb_tx < nb_rx);
1139 	}
1140 
1141 	get_end_cycles(fs, start_tsc);
1142 }
1143 
1144 struct fwd_engine csum_fwd_engine = {
1145 	.fwd_mode_name  = "csum",
1146 	.port_fwd_begin = NULL,
1147 	.port_fwd_end   = NULL,
1148 	.packet_fwd     = pkt_burst_checksum_forward,
1149 };
1150