xref: /openbmc/linux/tools/testing/selftests/net/gro.c (revision 0ad53fe3)
1 // SPDX-License-Identifier: GPL-2.0
2 /*
3  * This testsuite provides conformance testing for GRO coalescing.
4  *
5  * Test cases:
6  * 1.data
7  *  Data packets of the same size and same header setup with correct
8  *  sequence numbers coalesce. The one exception being the last data
9  *  packet coalesced: it can be smaller than the rest and coalesced
10  *  as long as it is in the same flow.
11  * 2.ack
12  *  Pure ACK does not coalesce.
13  * 3.flags
14  *  Specific test cases: no packets with PSH, SYN, URG, RST set will
15  *  be coalesced.
16  * 4.tcp
17  *  Packets with incorrect checksum, non-consecutive seqno and
18  *  different TCP header options shouldn't coalesce. Nit: given that
19  *  some extension headers have paddings, such as timestamp, headers
20  *  that are padding differently would not be coalesced.
21  * 5.ip:
22  *  Packets with different (ECN, TTL, TOS) header, ip options or
23  *  ip fragments (ipv6) shouldn't coalesce.
24  * 6.large:
25  *  Packets larger than GRO_MAX_SIZE packets shouldn't coalesce.
26  *
27  * MSS is defined as 4096 - header because if it is too small
28  * (i.e. 1500 MTU - header), it will result in many packets,
29  * increasing the "large" test case's flakiness. This is because
30  * due to time sensitivity in the coalescing window, the receiver
31  * may not coalesce all of the packets.
32  *
33  * Note the timing issue applies to all of the test cases, so some
34  * flakiness is to be expected.
35  *
36  */
37 
38 #define _GNU_SOURCE
39 
40 #include <arpa/inet.h>
41 #include <errno.h>
42 #include <error.h>
43 #include <getopt.h>
44 #include <linux/filter.h>
45 #include <linux/if_packet.h>
46 #include <linux/ipv6.h>
47 #include <net/ethernet.h>
48 #include <net/if.h>
49 #include <netinet/in.h>
50 #include <netinet/ip.h>
51 #include <netinet/ip6.h>
52 #include <netinet/tcp.h>
53 #include <stdbool.h>
54 #include <stddef.h>
55 #include <stdio.h>
56 #include <stdarg.h>
57 #include <string.h>
58 #include <unistd.h>
59 
60 #define DPORT 8000
61 #define SPORT 1500
62 #define PAYLOAD_LEN 100
63 #define ARRAY_SIZE(arr) (sizeof(arr) / sizeof((arr)[0]))
64 #define NUM_PACKETS 4
65 #define START_SEQ 100
66 #define START_ACK 100
67 #define SIP6 "fdaa::2"
68 #define DIP6 "fdaa::1"
69 #define SIP4 "192.168.1.200"
70 #define DIP4 "192.168.1.100"
71 #define ETH_P_NONE 0
72 #define TOTAL_HDR_LEN (ETH_HLEN + sizeof(struct ipv6hdr) + sizeof(struct tcphdr))
73 #define MSS (4096 - sizeof(struct tcphdr) - sizeof(struct ipv6hdr))
74 #define MAX_PAYLOAD (IP_MAXPACKET - sizeof(struct tcphdr) - sizeof(struct ipv6hdr))
75 #define NUM_LARGE_PKT (MAX_PAYLOAD / MSS)
76 #define MAX_HDR_LEN (ETH_HLEN + sizeof(struct ipv6hdr) + sizeof(struct tcphdr))
77 
78 static int proto = -1;
79 static uint8_t src_mac[ETH_ALEN], dst_mac[ETH_ALEN];
80 static char *testname = "data";
81 static char *ifname = "eth0";
82 static char *smac = "aa:00:00:00:00:02";
83 static char *dmac = "aa:00:00:00:00:01";
84 static bool verbose;
85 static bool tx_socket = true;
86 static int tcp_offset = -1;
87 static int total_hdr_len = -1;
88 static int ethhdr_proto = -1;
89 
90 static void vlog(const char *fmt, ...)
91 {
92 	va_list args;
93 
94 	if (verbose) {
95 		va_start(args, fmt);
96 		vfprintf(stderr, fmt, args);
97 		va_end(args);
98 	}
99 }
100 
101 static void setup_sock_filter(int fd)
102 {
103 	const int dport_off = tcp_offset + offsetof(struct tcphdr, dest);
104 	const int ethproto_off = offsetof(struct ethhdr, h_proto);
105 	int optlen = 0;
106 	int ipproto_off;
107 	int next_off;
108 
109 	if (proto == PF_INET)
110 		next_off = offsetof(struct iphdr, protocol);
111 	else
112 		next_off = offsetof(struct ipv6hdr, nexthdr);
113 	ipproto_off = ETH_HLEN + next_off;
114 
115 	if (strcmp(testname, "ip") == 0) {
116 		if (proto == PF_INET)
117 			optlen = sizeof(struct ip_timestamp);
118 		else
119 			optlen = sizeof(struct ip6_frag);
120 	}
121 
122 	struct sock_filter filter[] = {
123 			BPF_STMT(BPF_LD  + BPF_H   + BPF_ABS, ethproto_off),
124 			BPF_JUMP(BPF_JMP + BPF_JEQ + BPF_K, ntohs(ethhdr_proto), 0, 7),
125 			BPF_STMT(BPF_LD  + BPF_B   + BPF_ABS, ipproto_off),
126 			BPF_JUMP(BPF_JMP + BPF_JEQ + BPF_K, IPPROTO_TCP, 0, 5),
127 			BPF_STMT(BPF_LD  + BPF_H   + BPF_ABS, dport_off),
128 			BPF_JUMP(BPF_JMP + BPF_JEQ + BPF_K, DPORT, 2, 0),
129 			BPF_STMT(BPF_LD  + BPF_H   + BPF_ABS, dport_off + optlen),
130 			BPF_JUMP(BPF_JMP + BPF_JEQ + BPF_K, DPORT, 0, 1),
131 			BPF_STMT(BPF_RET + BPF_K, 0xFFFFFFFF),
132 			BPF_STMT(BPF_RET + BPF_K, 0),
133 	};
134 
135 	struct sock_fprog bpf = {
136 		.len = ARRAY_SIZE(filter),
137 		.filter = filter,
138 	};
139 
140 	if (setsockopt(fd, SOL_SOCKET, SO_ATTACH_FILTER, &bpf, sizeof(bpf)) < 0)
141 		error(1, errno, "error setting filter");
142 }
143 
144 static uint32_t checksum_nofold(void *data, size_t len, uint32_t sum)
145 {
146 	uint16_t *words = data;
147 	int i;
148 
149 	for (i = 0; i < len / 2; i++)
150 		sum += words[i];
151 	if (len & 1)
152 		sum += ((char *)data)[len - 1];
153 	return sum;
154 }
155 
156 static uint16_t checksum_fold(void *data, size_t len, uint32_t sum)
157 {
158 	sum = checksum_nofold(data, len, sum);
159 	while (sum > 0xFFFF)
160 		sum = (sum & 0xFFFF) + (sum >> 16);
161 	return ~sum;
162 }
163 
164 static uint16_t tcp_checksum(void *buf, int payload_len)
165 {
166 	struct pseudo_header6 {
167 		struct in6_addr saddr;
168 		struct in6_addr daddr;
169 		uint16_t protocol;
170 		uint16_t payload_len;
171 	} ph6;
172 	struct pseudo_header4 {
173 		struct in_addr saddr;
174 		struct in_addr daddr;
175 		uint16_t protocol;
176 		uint16_t payload_len;
177 	} ph4;
178 	uint32_t sum = 0;
179 
180 	if (proto == PF_INET6) {
181 		if (inet_pton(AF_INET6, SIP6, &ph6.saddr) != 1)
182 			error(1, errno, "inet_pton6 source ip pseudo");
183 		if (inet_pton(AF_INET6, DIP6, &ph6.daddr) != 1)
184 			error(1, errno, "inet_pton6 dest ip pseudo");
185 		ph6.protocol = htons(IPPROTO_TCP);
186 		ph6.payload_len = htons(sizeof(struct tcphdr) + payload_len);
187 
188 		sum = checksum_nofold(&ph6, sizeof(ph6), 0);
189 	} else if (proto == PF_INET) {
190 		if (inet_pton(AF_INET, SIP4, &ph4.saddr) != 1)
191 			error(1, errno, "inet_pton source ip pseudo");
192 		if (inet_pton(AF_INET, DIP4, &ph4.daddr) != 1)
193 			error(1, errno, "inet_pton dest ip pseudo");
194 		ph4.protocol = htons(IPPROTO_TCP);
195 		ph4.payload_len = htons(sizeof(struct tcphdr) + payload_len);
196 
197 		sum = checksum_nofold(&ph4, sizeof(ph4), 0);
198 	}
199 
200 	return checksum_fold(buf, sizeof(struct tcphdr) + payload_len, sum);
201 }
202 
203 static void read_MAC(uint8_t *mac_addr, char *mac)
204 {
205 	if (sscanf(mac, "%hhx:%hhx:%hhx:%hhx:%hhx:%hhx",
206 		   &mac_addr[0], &mac_addr[1], &mac_addr[2],
207 		   &mac_addr[3], &mac_addr[4], &mac_addr[5]) != 6)
208 		error(1, 0, "sscanf");
209 }
210 
211 static void fill_datalinklayer(void *buf)
212 {
213 	struct ethhdr *eth = buf;
214 
215 	memcpy(eth->h_dest, dst_mac, ETH_ALEN);
216 	memcpy(eth->h_source, src_mac, ETH_ALEN);
217 	eth->h_proto = ethhdr_proto;
218 }
219 
220 static void fill_networklayer(void *buf, int payload_len)
221 {
222 	struct ipv6hdr *ip6h = buf;
223 	struct iphdr *iph = buf;
224 
225 	if (proto == PF_INET6) {
226 		memset(ip6h, 0, sizeof(*ip6h));
227 
228 		ip6h->version = 6;
229 		ip6h->payload_len = htons(sizeof(struct tcphdr) + payload_len);
230 		ip6h->nexthdr = IPPROTO_TCP;
231 		ip6h->hop_limit = 8;
232 		if (inet_pton(AF_INET6, SIP6, &ip6h->saddr) != 1)
233 			error(1, errno, "inet_pton source ip6");
234 		if (inet_pton(AF_INET6, DIP6, &ip6h->daddr) != 1)
235 			error(1, errno, "inet_pton dest ip6");
236 	} else if (proto == PF_INET) {
237 		memset(iph, 0, sizeof(*iph));
238 
239 		iph->version = 4;
240 		iph->ihl = 5;
241 		iph->ttl = 8;
242 		iph->protocol	= IPPROTO_TCP;
243 		iph->tot_len = htons(sizeof(struct tcphdr) +
244 				payload_len + sizeof(struct iphdr));
245 		iph->frag_off = htons(0x4000); /* DF = 1, MF = 0 */
246 		if (inet_pton(AF_INET, SIP4, &iph->saddr) != 1)
247 			error(1, errno, "inet_pton source ip");
248 		if (inet_pton(AF_INET, DIP4, &iph->daddr) != 1)
249 			error(1, errno, "inet_pton dest ip");
250 		iph->check = checksum_fold(buf, sizeof(struct iphdr), 0);
251 	}
252 }
253 
254 static void fill_transportlayer(void *buf, int seq_offset, int ack_offset,
255 				int payload_len, int fin)
256 {
257 	struct tcphdr *tcph = buf;
258 
259 	memset(tcph, 0, sizeof(*tcph));
260 
261 	tcph->source = htons(SPORT);
262 	tcph->dest = htons(DPORT);
263 	tcph->seq = ntohl(START_SEQ + seq_offset);
264 	tcph->ack_seq = ntohl(START_ACK + ack_offset);
265 	tcph->ack = 1;
266 	tcph->fin = fin;
267 	tcph->doff = 5;
268 	tcph->window = htons(TCP_MAXWIN);
269 	tcph->urg_ptr = 0;
270 	tcph->check = tcp_checksum(tcph, payload_len);
271 }
272 
273 static void write_packet(int fd, char *buf, int len, struct sockaddr_ll *daddr)
274 {
275 	int ret = -1;
276 
277 	ret = sendto(fd, buf, len, 0, (struct sockaddr *)daddr, sizeof(*daddr));
278 	if (ret == -1)
279 		error(1, errno, "sendto failure");
280 	if (ret != len)
281 		error(1, errno, "sendto wrong length");
282 }
283 
284 static void create_packet(void *buf, int seq_offset, int ack_offset,
285 			  int payload_len, int fin)
286 {
287 	memset(buf, 0, total_hdr_len);
288 	memset(buf + total_hdr_len, 'a', payload_len);
289 	fill_transportlayer(buf + tcp_offset, seq_offset, ack_offset,
290 			    payload_len, fin);
291 	fill_networklayer(buf + ETH_HLEN, payload_len);
292 	fill_datalinklayer(buf);
293 }
294 
295 /* send one extra flag, not first and not last pkt */
296 static void send_flags(int fd, struct sockaddr_ll *daddr, int psh, int syn,
297 		       int rst, int urg)
298 {
299 	static char flag_buf[MAX_HDR_LEN + PAYLOAD_LEN];
300 	static char buf[MAX_HDR_LEN + PAYLOAD_LEN];
301 	int payload_len, pkt_size, flag, i;
302 	struct tcphdr *tcph;
303 
304 	payload_len = PAYLOAD_LEN * psh;
305 	pkt_size = total_hdr_len + payload_len;
306 	flag = NUM_PACKETS / 2;
307 
308 	create_packet(flag_buf, flag * payload_len, 0, payload_len, 0);
309 
310 	tcph = (struct tcphdr *)(flag_buf + tcp_offset);
311 	tcph->psh = psh;
312 	tcph->syn = syn;
313 	tcph->rst = rst;
314 	tcph->urg = urg;
315 	tcph->check = 0;
316 	tcph->check = tcp_checksum(tcph, payload_len);
317 
318 	for (i = 0; i < NUM_PACKETS + 1; i++) {
319 		if (i == flag) {
320 			write_packet(fd, flag_buf, pkt_size, daddr);
321 			continue;
322 		}
323 		create_packet(buf, i * PAYLOAD_LEN, 0, PAYLOAD_LEN, 0);
324 		write_packet(fd, buf, total_hdr_len + PAYLOAD_LEN, daddr);
325 	}
326 }
327 
328 /* Test for data of same length, smaller than previous
329  * and of different lengths
330  */
331 static void send_data_pkts(int fd, struct sockaddr_ll *daddr,
332 			   int payload_len1, int payload_len2)
333 {
334 	static char buf[ETH_HLEN + IP_MAXPACKET];
335 
336 	create_packet(buf, 0, 0, payload_len1, 0);
337 	write_packet(fd, buf, total_hdr_len + payload_len1, daddr);
338 	create_packet(buf, payload_len1, 0, payload_len2, 0);
339 	write_packet(fd, buf, total_hdr_len + payload_len2, daddr);
340 }
341 
342 /* If incoming segments make tracked segment length exceed
343  * legal IP datagram length, do not coalesce
344  */
345 static void send_large(int fd, struct sockaddr_ll *daddr, int remainder)
346 {
347 	static char pkts[NUM_LARGE_PKT][TOTAL_HDR_LEN + MSS];
348 	static char last[TOTAL_HDR_LEN + MSS];
349 	static char new_seg[TOTAL_HDR_LEN + MSS];
350 	int i;
351 
352 	for (i = 0; i < NUM_LARGE_PKT; i++)
353 		create_packet(pkts[i], i * MSS, 0, MSS, 0);
354 	create_packet(last, NUM_LARGE_PKT * MSS, 0, remainder, 0);
355 	create_packet(new_seg, (NUM_LARGE_PKT + 1) * MSS, 0, remainder, 0);
356 
357 	for (i = 0; i < NUM_LARGE_PKT; i++)
358 		write_packet(fd, pkts[i], total_hdr_len + MSS, daddr);
359 	write_packet(fd, last, total_hdr_len + remainder, daddr);
360 	write_packet(fd, new_seg, total_hdr_len + remainder, daddr);
361 }
362 
363 /* Pure acks and dup acks don't coalesce */
364 static void send_ack(int fd, struct sockaddr_ll *daddr)
365 {
366 	static char buf[MAX_HDR_LEN];
367 
368 	create_packet(buf, 0, 0, 0, 0);
369 	write_packet(fd, buf, total_hdr_len, daddr);
370 	write_packet(fd, buf, total_hdr_len, daddr);
371 	create_packet(buf, 0, 1, 0, 0);
372 	write_packet(fd, buf, total_hdr_len, daddr);
373 }
374 
375 static void recompute_packet(char *buf, char *no_ext, int extlen)
376 {
377 	struct tcphdr *tcphdr = (struct tcphdr *)(buf + tcp_offset);
378 	struct ipv6hdr *ip6h = (struct ipv6hdr *)(buf + ETH_HLEN);
379 	struct iphdr *iph = (struct iphdr *)(buf + ETH_HLEN);
380 
381 	memmove(buf, no_ext, total_hdr_len);
382 	memmove(buf + total_hdr_len + extlen,
383 		no_ext + total_hdr_len, PAYLOAD_LEN);
384 
385 	tcphdr->doff = tcphdr->doff + (extlen / 4);
386 	tcphdr->check = 0;
387 	tcphdr->check = tcp_checksum(tcphdr, PAYLOAD_LEN + extlen);
388 	if (proto == PF_INET) {
389 		iph->tot_len = htons(ntohs(iph->tot_len) + extlen);
390 		iph->check = 0;
391 		iph->check = checksum_fold(iph, sizeof(struct iphdr), 0);
392 	} else {
393 		ip6h->payload_len = htons(ntohs(ip6h->payload_len) + extlen);
394 	}
395 }
396 
397 static void tcp_write_options(char *buf, int kind, int ts)
398 {
399 	struct tcp_option_ts {
400 		uint8_t kind;
401 		uint8_t len;
402 		uint32_t tsval;
403 		uint32_t tsecr;
404 	} *opt_ts = (void *)buf;
405 	struct tcp_option_window {
406 		uint8_t kind;
407 		uint8_t len;
408 		uint8_t shift;
409 	} *opt_window = (void *)buf;
410 
411 	switch (kind) {
412 	case TCPOPT_NOP:
413 		buf[0] = TCPOPT_NOP;
414 		break;
415 	case TCPOPT_WINDOW:
416 		memset(opt_window, 0, sizeof(struct tcp_option_window));
417 		opt_window->kind = TCPOPT_WINDOW;
418 		opt_window->len = TCPOLEN_WINDOW;
419 		opt_window->shift = 0;
420 		break;
421 	case TCPOPT_TIMESTAMP:
422 		memset(opt_ts, 0, sizeof(struct tcp_option_ts));
423 		opt_ts->kind = TCPOPT_TIMESTAMP;
424 		opt_ts->len = TCPOLEN_TIMESTAMP;
425 		opt_ts->tsval = ts;
426 		opt_ts->tsecr = 0;
427 		break;
428 	default:
429 		error(1, 0, "unimplemented TCP option");
430 		break;
431 	}
432 }
433 
434 /* TCP with options is always a permutation of {TS, NOP, NOP}.
435  * Implement different orders to verify coalescing stops.
436  */
437 static void add_standard_tcp_options(char *buf, char *no_ext, int ts, int order)
438 {
439 	switch (order) {
440 	case 0:
441 		tcp_write_options(buf + total_hdr_len, TCPOPT_NOP, 0);
442 		tcp_write_options(buf + total_hdr_len + 1, TCPOPT_NOP, 0);
443 		tcp_write_options(buf + total_hdr_len + 2 /* two NOP opts */,
444 				  TCPOPT_TIMESTAMP, ts);
445 		break;
446 	case 1:
447 		tcp_write_options(buf + total_hdr_len, TCPOPT_NOP, 0);
448 		tcp_write_options(buf + total_hdr_len + 1,
449 				  TCPOPT_TIMESTAMP, ts);
450 		tcp_write_options(buf + total_hdr_len + 1 + TCPOLEN_TIMESTAMP,
451 				  TCPOPT_NOP, 0);
452 		break;
453 	case 2:
454 		tcp_write_options(buf + total_hdr_len, TCPOPT_TIMESTAMP, ts);
455 		tcp_write_options(buf + total_hdr_len + TCPOLEN_TIMESTAMP + 1,
456 				  TCPOPT_NOP, 0);
457 		tcp_write_options(buf + total_hdr_len + TCPOLEN_TIMESTAMP + 2,
458 				  TCPOPT_NOP, 0);
459 		break;
460 	default:
461 		error(1, 0, "unknown order");
462 		break;
463 	}
464 	recompute_packet(buf, no_ext, TCPOLEN_TSTAMP_APPA);
465 }
466 
467 /* Packets with invalid checksum don't coalesce. */
468 static void send_changed_checksum(int fd, struct sockaddr_ll *daddr)
469 {
470 	static char buf[MAX_HDR_LEN + PAYLOAD_LEN];
471 	struct tcphdr *tcph = (struct tcphdr *)(buf + tcp_offset);
472 	int pkt_size = total_hdr_len + PAYLOAD_LEN;
473 
474 	create_packet(buf, 0, 0, PAYLOAD_LEN, 0);
475 	write_packet(fd, buf, pkt_size, daddr);
476 
477 	create_packet(buf, PAYLOAD_LEN, 0, PAYLOAD_LEN, 0);
478 	tcph->check = tcph->check - 1;
479 	write_packet(fd, buf, pkt_size, daddr);
480 }
481 
482  /* Packets with non-consecutive sequence number don't coalesce.*/
483 static void send_changed_seq(int fd, struct sockaddr_ll *daddr)
484 {
485 	static char buf[MAX_HDR_LEN + PAYLOAD_LEN];
486 	struct tcphdr *tcph = (struct tcphdr *)(buf + tcp_offset);
487 	int pkt_size = total_hdr_len + PAYLOAD_LEN;
488 
489 	create_packet(buf, 0, 0, PAYLOAD_LEN, 0);
490 	write_packet(fd, buf, pkt_size, daddr);
491 
492 	create_packet(buf, PAYLOAD_LEN, 0, PAYLOAD_LEN, 0);
493 	tcph->seq = ntohl(htonl(tcph->seq) + 1);
494 	tcph->check = 0;
495 	tcph->check = tcp_checksum(tcph, PAYLOAD_LEN);
496 	write_packet(fd, buf, pkt_size, daddr);
497 }
498 
499  /* Packet with different timestamp option or different timestamps
500   * don't coalesce.
501   */
502 static void send_changed_ts(int fd, struct sockaddr_ll *daddr)
503 {
504 	static char buf[MAX_HDR_LEN + PAYLOAD_LEN];
505 	static char extpkt[sizeof(buf) + TCPOLEN_TSTAMP_APPA];
506 	int pkt_size = total_hdr_len + PAYLOAD_LEN + TCPOLEN_TSTAMP_APPA;
507 
508 	create_packet(buf, 0, 0, PAYLOAD_LEN, 0);
509 	add_standard_tcp_options(extpkt, buf, 0, 0);
510 	write_packet(fd, extpkt, pkt_size, daddr);
511 
512 	create_packet(buf, PAYLOAD_LEN, 0, PAYLOAD_LEN, 0);
513 	add_standard_tcp_options(extpkt, buf, 0, 0);
514 	write_packet(fd, extpkt, pkt_size, daddr);
515 
516 	create_packet(buf, PAYLOAD_LEN * 2, 0, PAYLOAD_LEN, 0);
517 	add_standard_tcp_options(extpkt, buf, 100, 0);
518 	write_packet(fd, extpkt, pkt_size, daddr);
519 
520 	create_packet(buf, PAYLOAD_LEN * 3, 0, PAYLOAD_LEN, 0);
521 	add_standard_tcp_options(extpkt, buf, 100, 1);
522 	write_packet(fd, extpkt, pkt_size, daddr);
523 
524 	create_packet(buf, PAYLOAD_LEN * 4, 0, PAYLOAD_LEN, 0);
525 	add_standard_tcp_options(extpkt, buf, 100, 2);
526 	write_packet(fd, extpkt, pkt_size, daddr);
527 }
528 
529 /* Packet with different tcp options don't coalesce. */
530 static void send_diff_opt(int fd, struct sockaddr_ll *daddr)
531 {
532 	static char buf[MAX_HDR_LEN + PAYLOAD_LEN];
533 	static char extpkt1[sizeof(buf) + TCPOLEN_TSTAMP_APPA];
534 	static char extpkt2[sizeof(buf) + TCPOLEN_MAXSEG];
535 	int extpkt1_size = total_hdr_len + PAYLOAD_LEN + TCPOLEN_TSTAMP_APPA;
536 	int extpkt2_size = total_hdr_len + PAYLOAD_LEN + TCPOLEN_MAXSEG;
537 
538 	create_packet(buf, 0, 0, PAYLOAD_LEN, 0);
539 	add_standard_tcp_options(extpkt1, buf, 0, 0);
540 	write_packet(fd, extpkt1, extpkt1_size, daddr);
541 
542 	create_packet(buf, PAYLOAD_LEN, 0, PAYLOAD_LEN, 0);
543 	add_standard_tcp_options(extpkt1, buf, 0, 0);
544 	write_packet(fd, extpkt1, extpkt1_size, daddr);
545 
546 	create_packet(buf, PAYLOAD_LEN * 2, 0, PAYLOAD_LEN, 0);
547 	tcp_write_options(extpkt2 + MAX_HDR_LEN, TCPOPT_NOP, 0);
548 	tcp_write_options(extpkt2 + MAX_HDR_LEN + 1, TCPOPT_WINDOW, 0);
549 	recompute_packet(extpkt2, buf, TCPOLEN_WINDOW + 1);
550 	write_packet(fd, extpkt2, extpkt2_size, daddr);
551 }
552 
553 static void add_ipv4_ts_option(void *buf, void *optpkt)
554 {
555 	struct ip_timestamp *ts = (struct ip_timestamp *)(optpkt + tcp_offset);
556 	int optlen = sizeof(struct ip_timestamp);
557 	struct iphdr *iph;
558 
559 	if (optlen % 4)
560 		error(1, 0, "ipv4 timestamp length is not a multiple of 4B");
561 
562 	ts->ipt_code = IPOPT_TS;
563 	ts->ipt_len = optlen;
564 	ts->ipt_ptr = 5;
565 	ts->ipt_flg = IPOPT_TS_TSONLY;
566 
567 	memcpy(optpkt, buf, tcp_offset);
568 	memcpy(optpkt + tcp_offset + optlen, buf + tcp_offset,
569 	       sizeof(struct tcphdr) + PAYLOAD_LEN);
570 
571 	iph = (struct iphdr *)(optpkt + ETH_HLEN);
572 	iph->ihl = 5 + (optlen / 4);
573 	iph->tot_len = htons(ntohs(iph->tot_len) + optlen);
574 	iph->check = 0;
575 	iph->check = checksum_fold(iph, sizeof(struct iphdr) + optlen, 0);
576 }
577 
578 /* IPv4 options shouldn't coalesce */
579 static void send_ip_options(int fd, struct sockaddr_ll *daddr)
580 {
581 	static char buf[MAX_HDR_LEN + PAYLOAD_LEN];
582 	static char optpkt[sizeof(buf) + sizeof(struct ip_timestamp)];
583 	int optlen = sizeof(struct ip_timestamp);
584 	int pkt_size = total_hdr_len + PAYLOAD_LEN + optlen;
585 
586 	create_packet(buf, 0, 0, PAYLOAD_LEN, 0);
587 	write_packet(fd, buf, total_hdr_len + PAYLOAD_LEN, daddr);
588 
589 	create_packet(buf, PAYLOAD_LEN * 1, 0, PAYLOAD_LEN, 0);
590 	add_ipv4_ts_option(buf, optpkt);
591 	write_packet(fd, optpkt, pkt_size, daddr);
592 
593 	create_packet(buf, PAYLOAD_LEN * 2, 0, PAYLOAD_LEN, 0);
594 	write_packet(fd, buf, total_hdr_len + PAYLOAD_LEN, daddr);
595 }
596 
597 /*  IPv4 fragments shouldn't coalesce */
598 static void send_fragment4(int fd, struct sockaddr_ll *daddr)
599 {
600 	static char buf[IP_MAXPACKET];
601 	struct iphdr *iph = (struct iphdr *)(buf + ETH_HLEN);
602 	int pkt_size = total_hdr_len + PAYLOAD_LEN;
603 
604 	create_packet(buf, 0, 0, PAYLOAD_LEN, 0);
605 	write_packet(fd, buf, pkt_size, daddr);
606 
607 	/* Once fragmented, packet would retain the total_len.
608 	 * Tcp header is prepared as if rest of data is in follow-up frags,
609 	 * but follow up frags aren't actually sent.
610 	 */
611 	memset(buf + total_hdr_len, 'a', PAYLOAD_LEN * 2);
612 	fill_transportlayer(buf + tcp_offset, PAYLOAD_LEN, 0, PAYLOAD_LEN * 2, 0);
613 	fill_networklayer(buf + ETH_HLEN, PAYLOAD_LEN);
614 	fill_datalinklayer(buf);
615 
616 	iph->frag_off = htons(0x6000); // DF = 1, MF = 1
617 	iph->check = 0;
618 	iph->check = checksum_fold(iph, sizeof(struct iphdr), 0);
619 	write_packet(fd, buf, pkt_size, daddr);
620 }
621 
622 /* IPv4 packets with different ttl don't coalesce.*/
623 static void send_changed_ttl(int fd, struct sockaddr_ll *daddr)
624 {
625 	int pkt_size = total_hdr_len + PAYLOAD_LEN;
626 	static char buf[MAX_HDR_LEN + PAYLOAD_LEN];
627 	struct iphdr *iph = (struct iphdr *)(buf + ETH_HLEN);
628 
629 	create_packet(buf, 0, 0, PAYLOAD_LEN, 0);
630 	write_packet(fd, buf, pkt_size, daddr);
631 
632 	create_packet(buf, PAYLOAD_LEN, 0, PAYLOAD_LEN, 0);
633 	iph->ttl = 7;
634 	iph->check = 0;
635 	iph->check = checksum_fold(iph, sizeof(struct iphdr), 0);
636 	write_packet(fd, buf, pkt_size, daddr);
637 }
638 
639 /* Packets with different tos don't coalesce.*/
640 static void send_changed_tos(int fd, struct sockaddr_ll *daddr)
641 {
642 	int pkt_size = total_hdr_len + PAYLOAD_LEN;
643 	static char buf[MAX_HDR_LEN + PAYLOAD_LEN];
644 	struct iphdr *iph = (struct iphdr *)(buf + ETH_HLEN);
645 	struct ipv6hdr *ip6h = (struct ipv6hdr *)(buf + ETH_HLEN);
646 
647 	create_packet(buf, 0, 0, PAYLOAD_LEN, 0);
648 	write_packet(fd, buf, pkt_size, daddr);
649 
650 	create_packet(buf, PAYLOAD_LEN, 0, PAYLOAD_LEN, 0);
651 	if (proto == PF_INET) {
652 		iph->tos = 1;
653 		iph->check = 0;
654 		iph->check = checksum_fold(iph, sizeof(struct iphdr), 0);
655 	} else if (proto == PF_INET6) {
656 		ip6h->priority = 0xf;
657 	}
658 	write_packet(fd, buf, pkt_size, daddr);
659 }
660 
661 /* Packets with different ECN don't coalesce.*/
662 static void send_changed_ECN(int fd, struct sockaddr_ll *daddr)
663 {
664 	int pkt_size = total_hdr_len + PAYLOAD_LEN;
665 	static char buf[MAX_HDR_LEN + PAYLOAD_LEN];
666 	struct iphdr *iph = (struct iphdr *)(buf + ETH_HLEN);
667 
668 	create_packet(buf, 0, 0, PAYLOAD_LEN, 0);
669 	write_packet(fd, buf, pkt_size, daddr);
670 
671 	create_packet(buf, PAYLOAD_LEN, 0, PAYLOAD_LEN, 0);
672 	if (proto == PF_INET) {
673 		buf[ETH_HLEN + 1] ^= 0x2; // ECN set to 10
674 		iph->check = 0;
675 		iph->check = checksum_fold(iph, sizeof(struct iphdr), 0);
676 	} else {
677 		buf[ETH_HLEN + 1] ^= 0x20; // ECN set to 10
678 	}
679 	write_packet(fd, buf, pkt_size, daddr);
680 }
681 
682 /* IPv6 fragments and packets with extensions don't coalesce.*/
683 static void send_fragment6(int fd, struct sockaddr_ll *daddr)
684 {
685 	static char buf[MAX_HDR_LEN + PAYLOAD_LEN];
686 	static char extpkt[MAX_HDR_LEN + PAYLOAD_LEN +
687 			   sizeof(struct ip6_frag)];
688 	struct ipv6hdr *ip6h = (struct ipv6hdr *)(buf + ETH_HLEN);
689 	struct ip6_frag *frag = (void *)(extpkt + tcp_offset);
690 	int extlen = sizeof(struct ip6_frag);
691 	int bufpkt_len = total_hdr_len + PAYLOAD_LEN;
692 	int extpkt_len = bufpkt_len + extlen;
693 	int i;
694 
695 	for (i = 0; i < 2; i++) {
696 		create_packet(buf, PAYLOAD_LEN * i, 0, PAYLOAD_LEN, 0);
697 		write_packet(fd, buf, bufpkt_len, daddr);
698 	}
699 
700 	create_packet(buf, PAYLOAD_LEN * 2, 0, PAYLOAD_LEN, 0);
701 	memset(extpkt, 0, extpkt_len);
702 
703 	ip6h->nexthdr = IPPROTO_FRAGMENT;
704 	ip6h->payload_len = htons(ntohs(ip6h->payload_len) + extlen);
705 	frag->ip6f_nxt = IPPROTO_TCP;
706 
707 	memcpy(extpkt, buf, tcp_offset);
708 	memcpy(extpkt + tcp_offset + extlen, buf + tcp_offset,
709 	       sizeof(struct tcphdr) + PAYLOAD_LEN);
710 	write_packet(fd, extpkt, extpkt_len, daddr);
711 
712 	create_packet(buf, PAYLOAD_LEN * 3, 0, PAYLOAD_LEN, 0);
713 	write_packet(fd, buf, bufpkt_len, daddr);
714 }
715 
716 static void bind_packetsocket(int fd)
717 {
718 	struct sockaddr_ll daddr = {};
719 
720 	daddr.sll_family = AF_PACKET;
721 	daddr.sll_protocol = ethhdr_proto;
722 	daddr.sll_ifindex = if_nametoindex(ifname);
723 	if (daddr.sll_ifindex == 0)
724 		error(1, errno, "if_nametoindex");
725 
726 	if (bind(fd, (void *)&daddr, sizeof(daddr)) < 0)
727 		error(1, errno, "could not bind socket");
728 }
729 
730 static void set_timeout(int fd)
731 {
732 	struct timeval timeout;
733 
734 	timeout.tv_sec = 120;
735 	timeout.tv_usec = 0;
736 	if (setsockopt(fd, SOL_SOCKET, SO_RCVTIMEO, (char *)&timeout,
737 		       sizeof(timeout)) < 0)
738 		error(1, errno, "cannot set timeout, setsockopt failed");
739 }
740 
741 static void check_recv_pkts(int fd, int *correct_payload,
742 			    int correct_num_pkts)
743 {
744 	static char buffer[IP_MAXPACKET + ETH_HLEN + 1];
745 	struct iphdr *iph = (struct iphdr *)(buffer + ETH_HLEN);
746 	struct ipv6hdr *ip6h = (struct ipv6hdr *)(buffer + ETH_HLEN);
747 	struct tcphdr *tcph;
748 	bool bad_packet = false;
749 	int tcp_ext_len = 0;
750 	int ip_ext_len = 0;
751 	int pkt_size = -1;
752 	int data_len = 0;
753 	int num_pkt = 0;
754 	int i;
755 
756 	vlog("Expected {");
757 	for (i = 0; i < correct_num_pkts; i++)
758 		vlog("%d ", correct_payload[i]);
759 	vlog("}, Total %d packets\nReceived {", correct_num_pkts);
760 
761 	while (1) {
762 		pkt_size = recv(fd, buffer, IP_MAXPACKET + ETH_HLEN + 1, 0);
763 		if (pkt_size < 0)
764 			error(1, errno, "could not receive");
765 
766 		if (iph->version == 4)
767 			ip_ext_len = (iph->ihl - 5) * 4;
768 		else if (ip6h->version == 6 && ip6h->nexthdr != IPPROTO_TCP)
769 			ip_ext_len = sizeof(struct ip6_frag);
770 
771 		tcph = (struct tcphdr *)(buffer + tcp_offset + ip_ext_len);
772 
773 		if (tcph->fin)
774 			break;
775 
776 		tcp_ext_len = (tcph->doff - 5) * 4;
777 		data_len = pkt_size - total_hdr_len - tcp_ext_len - ip_ext_len;
778 		/* Min ethernet frame payload is 46(ETH_ZLEN - ETH_HLEN) by RFC 802.3.
779 		 * Ipv4/tcp packets without at least 6 bytes of data will be padded.
780 		 * Packet sockets are protocol agnostic, and will not trim the padding.
781 		 */
782 		if (pkt_size == ETH_ZLEN && iph->version == 4) {
783 			data_len = ntohs(iph->tot_len)
784 				- sizeof(struct tcphdr) - sizeof(struct iphdr);
785 		}
786 		vlog("%d ", data_len);
787 		if (data_len != correct_payload[num_pkt]) {
788 			vlog("[!=%d]", correct_payload[num_pkt]);
789 			bad_packet = true;
790 		}
791 		num_pkt++;
792 	}
793 	vlog("}, Total %d packets.\n", num_pkt);
794 	if (num_pkt != correct_num_pkts)
795 		error(1, 0, "incorrect number of packets");
796 	if (bad_packet)
797 		error(1, 0, "incorrect packet geometry");
798 
799 	printf("Test succeeded\n\n");
800 }
801 
802 static void gro_sender(void)
803 {
804 	static char fin_pkt[MAX_HDR_LEN];
805 	struct sockaddr_ll daddr = {};
806 	int txfd = -1;
807 
808 	txfd = socket(PF_PACKET, SOCK_RAW, IPPROTO_RAW);
809 	if (txfd < 0)
810 		error(1, errno, "socket creation");
811 
812 	memset(&daddr, 0, sizeof(daddr));
813 	daddr.sll_ifindex = if_nametoindex(ifname);
814 	if (daddr.sll_ifindex == 0)
815 		error(1, errno, "if_nametoindex");
816 	daddr.sll_family = AF_PACKET;
817 	memcpy(daddr.sll_addr, dst_mac, ETH_ALEN);
818 	daddr.sll_halen = ETH_ALEN;
819 	create_packet(fin_pkt, PAYLOAD_LEN * 2, 0, 0, 1);
820 
821 	if (strcmp(testname, "data") == 0) {
822 		send_data_pkts(txfd, &daddr, PAYLOAD_LEN, PAYLOAD_LEN);
823 		write_packet(txfd, fin_pkt, total_hdr_len, &daddr);
824 
825 		send_data_pkts(txfd, &daddr, PAYLOAD_LEN, PAYLOAD_LEN / 2);
826 		write_packet(txfd, fin_pkt, total_hdr_len, &daddr);
827 
828 		send_data_pkts(txfd, &daddr, PAYLOAD_LEN / 2, PAYLOAD_LEN);
829 		write_packet(txfd, fin_pkt, total_hdr_len, &daddr);
830 	} else if (strcmp(testname, "ack") == 0) {
831 		send_ack(txfd, &daddr);
832 		write_packet(txfd, fin_pkt, total_hdr_len, &daddr);
833 	} else if (strcmp(testname, "flags") == 0) {
834 		send_flags(txfd, &daddr, 1, 0, 0, 0);
835 		write_packet(txfd, fin_pkt, total_hdr_len, &daddr);
836 
837 		send_flags(txfd, &daddr, 0, 1, 0, 0);
838 		write_packet(txfd, fin_pkt, total_hdr_len, &daddr);
839 
840 		send_flags(txfd, &daddr, 0, 0, 1, 0);
841 		write_packet(txfd, fin_pkt, total_hdr_len, &daddr);
842 
843 		send_flags(txfd, &daddr, 0, 0, 0, 1);
844 		write_packet(txfd, fin_pkt, total_hdr_len, &daddr);
845 	} else if (strcmp(testname, "tcp") == 0) {
846 		send_changed_checksum(txfd, &daddr);
847 		write_packet(txfd, fin_pkt, total_hdr_len, &daddr);
848 
849 		send_changed_seq(txfd, &daddr);
850 		write_packet(txfd, fin_pkt, total_hdr_len, &daddr);
851 
852 		send_changed_ts(txfd, &daddr);
853 		write_packet(txfd, fin_pkt, total_hdr_len, &daddr);
854 
855 		send_diff_opt(txfd, &daddr);
856 		write_packet(txfd, fin_pkt, total_hdr_len, &daddr);
857 	} else if (strcmp(testname, "ip") == 0) {
858 		send_changed_ECN(txfd, &daddr);
859 		write_packet(txfd, fin_pkt, total_hdr_len, &daddr);
860 
861 		send_changed_tos(txfd, &daddr);
862 		write_packet(txfd, fin_pkt, total_hdr_len, &daddr);
863 		if (proto == PF_INET) {
864 			/* Modified packets may be received out of order.
865 			 * Sleep function added to enforce test boundaries
866 			 * so that fin pkts are not received prior to other pkts.
867 			 */
868 			sleep(1);
869 			send_changed_ttl(txfd, &daddr);
870 			write_packet(txfd, fin_pkt, total_hdr_len, &daddr);
871 
872 			sleep(1);
873 			send_ip_options(txfd, &daddr);
874 			sleep(1);
875 			write_packet(txfd, fin_pkt, total_hdr_len, &daddr);
876 
877 			sleep(1);
878 			send_fragment4(txfd, &daddr);
879 			sleep(1);
880 			write_packet(txfd, fin_pkt, total_hdr_len, &daddr);
881 		} else if (proto == PF_INET6) {
882 			send_fragment6(txfd, &daddr);
883 			write_packet(txfd, fin_pkt, total_hdr_len, &daddr);
884 		}
885 	} else if (strcmp(testname, "large") == 0) {
886 		/* 20 is the difference between min iphdr size
887 		 * and min ipv6hdr size. Like MAX_HDR_SIZE,
888 		 * MAX_PAYLOAD is defined with the larger header of the two.
889 		 */
890 		int offset = proto == PF_INET ? 20 : 0;
891 		int remainder = (MAX_PAYLOAD + offset) % MSS;
892 
893 		send_large(txfd, &daddr, remainder);
894 		write_packet(txfd, fin_pkt, total_hdr_len, &daddr);
895 
896 		send_large(txfd, &daddr, remainder + 1);
897 		write_packet(txfd, fin_pkt, total_hdr_len, &daddr);
898 	} else {
899 		error(1, 0, "Unknown testcase");
900 	}
901 
902 	if (close(txfd))
903 		error(1, errno, "socket close");
904 }
905 
906 static void gro_receiver(void)
907 {
908 	static int correct_payload[NUM_PACKETS];
909 	int rxfd = -1;
910 
911 	rxfd = socket(PF_PACKET, SOCK_RAW, htons(ETH_P_NONE));
912 	if (rxfd < 0)
913 		error(1, 0, "socket creation");
914 	setup_sock_filter(rxfd);
915 	set_timeout(rxfd);
916 	bind_packetsocket(rxfd);
917 
918 	memset(correct_payload, 0, sizeof(correct_payload));
919 
920 	if (strcmp(testname, "data") == 0) {
921 		printf("pure data packet of same size: ");
922 		correct_payload[0] = PAYLOAD_LEN * 2;
923 		check_recv_pkts(rxfd, correct_payload, 1);
924 
925 		printf("large data packets followed by a smaller one: ");
926 		correct_payload[0] = PAYLOAD_LEN * 1.5;
927 		check_recv_pkts(rxfd, correct_payload, 1);
928 
929 		printf("small data packets followed by a larger one: ");
930 		correct_payload[0] = PAYLOAD_LEN / 2;
931 		correct_payload[1] = PAYLOAD_LEN;
932 		check_recv_pkts(rxfd, correct_payload, 2);
933 	} else if (strcmp(testname, "ack") == 0) {
934 		printf("duplicate ack and pure ack: ");
935 		check_recv_pkts(rxfd, correct_payload, 3);
936 	} else if (strcmp(testname, "flags") == 0) {
937 		correct_payload[0] = PAYLOAD_LEN * 3;
938 		correct_payload[1] = PAYLOAD_LEN * 2;
939 
940 		printf("psh flag ends coalescing: ");
941 		check_recv_pkts(rxfd, correct_payload, 2);
942 
943 		correct_payload[0] = PAYLOAD_LEN * 2;
944 		correct_payload[1] = 0;
945 		correct_payload[2] = PAYLOAD_LEN * 2;
946 		printf("syn flag ends coalescing: ");
947 		check_recv_pkts(rxfd, correct_payload, 3);
948 
949 		printf("rst flag ends coalescing: ");
950 		check_recv_pkts(rxfd, correct_payload, 3);
951 
952 		printf("urg flag ends coalescing: ");
953 		check_recv_pkts(rxfd, correct_payload, 3);
954 	} else if (strcmp(testname, "tcp") == 0) {
955 		correct_payload[0] = PAYLOAD_LEN;
956 		correct_payload[1] = PAYLOAD_LEN;
957 		correct_payload[2] = PAYLOAD_LEN;
958 		correct_payload[3] = PAYLOAD_LEN;
959 
960 		printf("changed checksum does not coalesce: ");
961 		check_recv_pkts(rxfd, correct_payload, 2);
962 
963 		printf("Wrong Seq number doesn't coalesce: ");
964 		check_recv_pkts(rxfd, correct_payload, 2);
965 
966 		printf("Different timestamp doesn't coalesce: ");
967 		correct_payload[0] = PAYLOAD_LEN * 2;
968 		check_recv_pkts(rxfd, correct_payload, 4);
969 
970 		printf("Different options doesn't coalesce: ");
971 		correct_payload[0] = PAYLOAD_LEN * 2;
972 		check_recv_pkts(rxfd, correct_payload, 2);
973 	} else if (strcmp(testname, "ip") == 0) {
974 		correct_payload[0] = PAYLOAD_LEN;
975 		correct_payload[1] = PAYLOAD_LEN;
976 
977 		printf("different ECN doesn't coalesce: ");
978 		check_recv_pkts(rxfd, correct_payload, 2);
979 
980 		printf("different tos doesn't coalesce: ");
981 		check_recv_pkts(rxfd, correct_payload, 2);
982 
983 		if (proto == PF_INET) {
984 			printf("different ttl doesn't coalesce: ");
985 			check_recv_pkts(rxfd, correct_payload, 2);
986 
987 			printf("ip options doesn't coalesce: ");
988 			correct_payload[2] = PAYLOAD_LEN;
989 			check_recv_pkts(rxfd, correct_payload, 3);
990 
991 			printf("fragmented ip4 doesn't coalesce: ");
992 			check_recv_pkts(rxfd, correct_payload, 2);
993 		} else if (proto == PF_INET6) {
994 			/* GRO doesn't check for ipv6 hop limit when flushing.
995 			 * Hence no corresponding test to the ipv4 case.
996 			 */
997 			printf("fragmented ip6 doesn't coalesce: ");
998 			correct_payload[0] = PAYLOAD_LEN * 2;
999 			check_recv_pkts(rxfd, correct_payload, 2);
1000 		}
1001 	} else if (strcmp(testname, "large") == 0) {
1002 		int offset = proto == PF_INET ? 20 : 0;
1003 		int remainder = (MAX_PAYLOAD + offset) % MSS;
1004 
1005 		correct_payload[0] = (MAX_PAYLOAD + offset);
1006 		correct_payload[1] = remainder;
1007 		printf("Shouldn't coalesce if exceed IP max pkt size: ");
1008 		check_recv_pkts(rxfd, correct_payload, 2);
1009 
1010 		/* last segment sent individually, doesn't start new segment */
1011 		correct_payload[0] = correct_payload[0] - remainder;
1012 		correct_payload[1] = remainder + 1;
1013 		correct_payload[2] = remainder + 1;
1014 		check_recv_pkts(rxfd, correct_payload, 3);
1015 	} else {
1016 		error(1, 0, "Test case error, should never trigger");
1017 	}
1018 
1019 	if (close(rxfd))
1020 		error(1, 0, "socket close");
1021 }
1022 
1023 static void parse_args(int argc, char **argv)
1024 {
1025 	static const struct option opts[] = {
1026 		{ "dmac", required_argument, NULL, 'D' },
1027 		{ "iface", required_argument, NULL, 'i' },
1028 		{ "ipv4", no_argument, NULL, '4' },
1029 		{ "ipv6", no_argument, NULL, '6' },
1030 		{ "rx", no_argument, NULL, 'r' },
1031 		{ "smac", required_argument, NULL, 'S' },
1032 		{ "test", required_argument, NULL, 't' },
1033 		{ "verbose", no_argument, NULL, 'v' },
1034 		{ 0, 0, 0, 0 }
1035 	};
1036 	int c;
1037 
1038 	while ((c = getopt_long(argc, argv, "46D:i:rS:t:v", opts, NULL)) != -1) {
1039 		switch (c) {
1040 		case '4':
1041 			proto = PF_INET;
1042 			ethhdr_proto = htons(ETH_P_IP);
1043 			break;
1044 		case '6':
1045 			proto = PF_INET6;
1046 			ethhdr_proto = htons(ETH_P_IPV6);
1047 			break;
1048 		case 'D':
1049 			dmac = optarg;
1050 			break;
1051 		case 'i':
1052 			ifname = optarg;
1053 			break;
1054 		case 'r':
1055 			tx_socket = false;
1056 			break;
1057 		case 'S':
1058 			smac = optarg;
1059 			break;
1060 		case 't':
1061 			testname = optarg;
1062 			break;
1063 		case 'v':
1064 			verbose = true;
1065 			break;
1066 		default:
1067 			error(1, 0, "%s invalid option %c\n", __func__, c);
1068 			break;
1069 		}
1070 	}
1071 }
1072 
1073 int main(int argc, char **argv)
1074 {
1075 	parse_args(argc, argv);
1076 
1077 	if (proto == PF_INET) {
1078 		tcp_offset = ETH_HLEN + sizeof(struct iphdr);
1079 		total_hdr_len = tcp_offset + sizeof(struct tcphdr);
1080 	} else if (proto == PF_INET6) {
1081 		tcp_offset = ETH_HLEN + sizeof(struct ipv6hdr);
1082 		total_hdr_len = MAX_HDR_LEN;
1083 	} else {
1084 		error(1, 0, "Protocol family is not ipv4 or ipv6");
1085 	}
1086 
1087 	read_MAC(src_mac, smac);
1088 	read_MAC(dst_mac, dmac);
1089 
1090 	if (tx_socket)
1091 		gro_sender();
1092 	else
1093 		gro_receiver();
1094 	return 0;
1095 }
1096