xref: /linux/tools/testing/selftests/net/gro.c (revision cbc7afffc5ec581d3781c49fe9c8e8c661e5217b)
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 #include "../kselftest.h"
61 
62 #define DPORT 8000
63 #define SPORT 1500
64 #define PAYLOAD_LEN 100
65 #define NUM_PACKETS 4
66 #define START_SEQ 100
67 #define START_ACK 100
68 #define ETH_P_NONE 0
69 #define TOTAL_HDR_LEN (ETH_HLEN + sizeof(struct ipv6hdr) + sizeof(struct tcphdr))
70 #define MSS (4096 - sizeof(struct tcphdr) - sizeof(struct ipv6hdr))
71 #define MAX_PAYLOAD (IP_MAXPACKET - sizeof(struct tcphdr) - sizeof(struct ipv6hdr))
72 #define NUM_LARGE_PKT (MAX_PAYLOAD / MSS)
73 #define MAX_HDR_LEN (ETH_HLEN + sizeof(struct ipv6hdr) + sizeof(struct tcphdr))
74 #define MIN_EXTHDR_SIZE 8
75 #define EXT_PAYLOAD_1 "\x00\x00\x00\x00\x00\x00"
76 #define EXT_PAYLOAD_2 "\x11\x11\x11\x11\x11\x11"
77 
78 #define ipv6_optlen(p)  (((p)->hdrlen+1) << 3) /* calculate IPv6 extension header len */
79 #define BUILD_BUG_ON(condition) ((void)sizeof(char[1 - 2*!!(condition)]))
80 
81 static const char *addr6_src = "fdaa::2";
82 static const char *addr6_dst = "fdaa::1";
83 static const char *addr4_src = "192.168.1.200";
84 static const char *addr4_dst = "192.168.1.100";
85 static int proto = -1;
86 static uint8_t src_mac[ETH_ALEN], dst_mac[ETH_ALEN];
87 static char *testname = "data";
88 static char *ifname = "eth0";
89 static char *smac = "aa:00:00:00:00:02";
90 static char *dmac = "aa:00:00:00:00:01";
91 static bool verbose;
92 static bool tx_socket = true;
93 static int tcp_offset = -1;
94 static int total_hdr_len = -1;
95 static int ethhdr_proto = -1;
96 
97 static void vlog(const char *fmt, ...)
98 {
99 	va_list args;
100 
101 	if (verbose) {
102 		va_start(args, fmt);
103 		vfprintf(stderr, fmt, args);
104 		va_end(args);
105 	}
106 }
107 
108 static void setup_sock_filter(int fd)
109 {
110 	const int dport_off = tcp_offset + offsetof(struct tcphdr, dest);
111 	const int ethproto_off = offsetof(struct ethhdr, h_proto);
112 	int optlen = 0;
113 	int ipproto_off, opt_ipproto_off;
114 	int next_off;
115 
116 	if (proto == PF_INET)
117 		next_off = offsetof(struct iphdr, protocol);
118 	else
119 		next_off = offsetof(struct ipv6hdr, nexthdr);
120 	ipproto_off = ETH_HLEN + next_off;
121 
122 	/* Overridden later if exthdrs are used: */
123 	opt_ipproto_off = ipproto_off;
124 
125 	if (strcmp(testname, "ip") == 0) {
126 		if (proto == PF_INET)
127 			optlen = sizeof(struct ip_timestamp);
128 		else {
129 			BUILD_BUG_ON(sizeof(struct ip6_hbh) > MIN_EXTHDR_SIZE);
130 			BUILD_BUG_ON(sizeof(struct ip6_dest) > MIN_EXTHDR_SIZE);
131 			BUILD_BUG_ON(sizeof(struct ip6_frag) > MIN_EXTHDR_SIZE);
132 
133 			/* same size for HBH and Fragment extension header types */
134 			optlen = MIN_EXTHDR_SIZE;
135 			opt_ipproto_off = ETH_HLEN + sizeof(struct ipv6hdr)
136 				+ offsetof(struct ip6_ext, ip6e_nxt);
137 		}
138 	}
139 
140 	/* this filter validates the following:
141 	 *	- packet is IPv4/IPv6 according to the running test.
142 	 *	- packet is TCP. Also handles the case of one extension header and then TCP.
143 	 *	- checks the packet tcp dport equals to DPORT. Also handles the case of one
144 	 *	  extension header and then TCP.
145 	 */
146 	struct sock_filter filter[] = {
147 			BPF_STMT(BPF_LD  + BPF_H   + BPF_ABS, ethproto_off),
148 			BPF_JUMP(BPF_JMP + BPF_JEQ + BPF_K, ntohs(ethhdr_proto), 0, 9),
149 			BPF_STMT(BPF_LD  + BPF_B   + BPF_ABS, ipproto_off),
150 			BPF_JUMP(BPF_JMP + BPF_JEQ + BPF_K, IPPROTO_TCP, 2, 0),
151 			BPF_STMT(BPF_LD  + BPF_B   + BPF_ABS, opt_ipproto_off),
152 			BPF_JUMP(BPF_JMP + BPF_JEQ + BPF_K, IPPROTO_TCP, 0, 5),
153 			BPF_STMT(BPF_LD  + BPF_H   + BPF_ABS, dport_off),
154 			BPF_JUMP(BPF_JMP + BPF_JEQ + BPF_K, DPORT, 2, 0),
155 			BPF_STMT(BPF_LD  + BPF_H   + BPF_ABS, dport_off + optlen),
156 			BPF_JUMP(BPF_JMP + BPF_JEQ + BPF_K, DPORT, 0, 1),
157 			BPF_STMT(BPF_RET + BPF_K, 0xFFFFFFFF),
158 			BPF_STMT(BPF_RET + BPF_K, 0),
159 	};
160 
161 	struct sock_fprog bpf = {
162 		.len = ARRAY_SIZE(filter),
163 		.filter = filter,
164 	};
165 
166 	if (setsockopt(fd, SOL_SOCKET, SO_ATTACH_FILTER, &bpf, sizeof(bpf)) < 0)
167 		error(1, errno, "error setting filter");
168 }
169 
170 static uint32_t checksum_nofold(void *data, size_t len, uint32_t sum)
171 {
172 	uint16_t *words = data;
173 	int i;
174 
175 	for (i = 0; i < len / 2; i++)
176 		sum += words[i];
177 	if (len & 1)
178 		sum += ((char *)data)[len - 1];
179 	return sum;
180 }
181 
182 static uint16_t checksum_fold(void *data, size_t len, uint32_t sum)
183 {
184 	sum = checksum_nofold(data, len, sum);
185 	while (sum > 0xFFFF)
186 		sum = (sum & 0xFFFF) + (sum >> 16);
187 	return ~sum;
188 }
189 
190 static uint16_t tcp_checksum(void *buf, int payload_len)
191 {
192 	struct pseudo_header6 {
193 		struct in6_addr saddr;
194 		struct in6_addr daddr;
195 		uint16_t protocol;
196 		uint16_t payload_len;
197 	} ph6;
198 	struct pseudo_header4 {
199 		struct in_addr saddr;
200 		struct in_addr daddr;
201 		uint16_t protocol;
202 		uint16_t payload_len;
203 	} ph4;
204 	uint32_t sum = 0;
205 
206 	if (proto == PF_INET6) {
207 		if (inet_pton(AF_INET6, addr6_src, &ph6.saddr) != 1)
208 			error(1, errno, "inet_pton6 source ip pseudo");
209 		if (inet_pton(AF_INET6, addr6_dst, &ph6.daddr) != 1)
210 			error(1, errno, "inet_pton6 dest ip pseudo");
211 		ph6.protocol = htons(IPPROTO_TCP);
212 		ph6.payload_len = htons(sizeof(struct tcphdr) + payload_len);
213 
214 		sum = checksum_nofold(&ph6, sizeof(ph6), 0);
215 	} else if (proto == PF_INET) {
216 		if (inet_pton(AF_INET, addr4_src, &ph4.saddr) != 1)
217 			error(1, errno, "inet_pton source ip pseudo");
218 		if (inet_pton(AF_INET, addr4_dst, &ph4.daddr) != 1)
219 			error(1, errno, "inet_pton dest ip pseudo");
220 		ph4.protocol = htons(IPPROTO_TCP);
221 		ph4.payload_len = htons(sizeof(struct tcphdr) + payload_len);
222 
223 		sum = checksum_nofold(&ph4, sizeof(ph4), 0);
224 	}
225 
226 	return checksum_fold(buf, sizeof(struct tcphdr) + payload_len, sum);
227 }
228 
229 static void read_MAC(uint8_t *mac_addr, char *mac)
230 {
231 	if (sscanf(mac, "%hhx:%hhx:%hhx:%hhx:%hhx:%hhx",
232 		   &mac_addr[0], &mac_addr[1], &mac_addr[2],
233 		   &mac_addr[3], &mac_addr[4], &mac_addr[5]) != 6)
234 		error(1, 0, "sscanf");
235 }
236 
237 static void fill_datalinklayer(void *buf)
238 {
239 	struct ethhdr *eth = buf;
240 
241 	memcpy(eth->h_dest, dst_mac, ETH_ALEN);
242 	memcpy(eth->h_source, src_mac, ETH_ALEN);
243 	eth->h_proto = ethhdr_proto;
244 }
245 
246 static void fill_networklayer(void *buf, int payload_len)
247 {
248 	struct ipv6hdr *ip6h = buf;
249 	struct iphdr *iph = buf;
250 
251 	if (proto == PF_INET6) {
252 		memset(ip6h, 0, sizeof(*ip6h));
253 
254 		ip6h->version = 6;
255 		ip6h->payload_len = htons(sizeof(struct tcphdr) + payload_len);
256 		ip6h->nexthdr = IPPROTO_TCP;
257 		ip6h->hop_limit = 8;
258 		if (inet_pton(AF_INET6, addr6_src, &ip6h->saddr) != 1)
259 			error(1, errno, "inet_pton source ip6");
260 		if (inet_pton(AF_INET6, addr6_dst, &ip6h->daddr) != 1)
261 			error(1, errno, "inet_pton dest ip6");
262 	} else if (proto == PF_INET) {
263 		memset(iph, 0, sizeof(*iph));
264 
265 		iph->version = 4;
266 		iph->ihl = 5;
267 		iph->ttl = 8;
268 		iph->protocol	= IPPROTO_TCP;
269 		iph->tot_len = htons(sizeof(struct tcphdr) +
270 				payload_len + sizeof(struct iphdr));
271 		iph->frag_off = htons(0x4000); /* DF = 1, MF = 0 */
272 		if (inet_pton(AF_INET, addr4_src, &iph->saddr) != 1)
273 			error(1, errno, "inet_pton source ip");
274 		if (inet_pton(AF_INET, addr4_dst, &iph->daddr) != 1)
275 			error(1, errno, "inet_pton dest ip");
276 		iph->check = checksum_fold(buf, sizeof(struct iphdr), 0);
277 	}
278 }
279 
280 static void fill_transportlayer(void *buf, int seq_offset, int ack_offset,
281 				int payload_len, int fin)
282 {
283 	struct tcphdr *tcph = buf;
284 
285 	memset(tcph, 0, sizeof(*tcph));
286 
287 	tcph->source = htons(SPORT);
288 	tcph->dest = htons(DPORT);
289 	tcph->seq = ntohl(START_SEQ + seq_offset);
290 	tcph->ack_seq = ntohl(START_ACK + ack_offset);
291 	tcph->ack = 1;
292 	tcph->fin = fin;
293 	tcph->doff = 5;
294 	tcph->window = htons(TCP_MAXWIN);
295 	tcph->urg_ptr = 0;
296 	tcph->check = tcp_checksum(tcph, payload_len);
297 }
298 
299 static void write_packet(int fd, char *buf, int len, struct sockaddr_ll *daddr)
300 {
301 	int ret = -1;
302 
303 	ret = sendto(fd, buf, len, 0, (struct sockaddr *)daddr, sizeof(*daddr));
304 	if (ret == -1)
305 		error(1, errno, "sendto failure");
306 	if (ret != len)
307 		error(1, errno, "sendto wrong length");
308 }
309 
310 static void create_packet(void *buf, int seq_offset, int ack_offset,
311 			  int payload_len, int fin)
312 {
313 	memset(buf, 0, total_hdr_len);
314 	memset(buf + total_hdr_len, 'a', payload_len);
315 	fill_transportlayer(buf + tcp_offset, seq_offset, ack_offset,
316 			    payload_len, fin);
317 	fill_networklayer(buf + ETH_HLEN, payload_len);
318 	fill_datalinklayer(buf);
319 }
320 
321 /* send one extra flag, not first and not last pkt */
322 static void send_flags(int fd, struct sockaddr_ll *daddr, int psh, int syn,
323 		       int rst, int urg)
324 {
325 	static char flag_buf[MAX_HDR_LEN + PAYLOAD_LEN];
326 	static char buf[MAX_HDR_LEN + PAYLOAD_LEN];
327 	int payload_len, pkt_size, flag, i;
328 	struct tcphdr *tcph;
329 
330 	payload_len = PAYLOAD_LEN * psh;
331 	pkt_size = total_hdr_len + payload_len;
332 	flag = NUM_PACKETS / 2;
333 
334 	create_packet(flag_buf, flag * payload_len, 0, payload_len, 0);
335 
336 	tcph = (struct tcphdr *)(flag_buf + tcp_offset);
337 	tcph->psh = psh;
338 	tcph->syn = syn;
339 	tcph->rst = rst;
340 	tcph->urg = urg;
341 	tcph->check = 0;
342 	tcph->check = tcp_checksum(tcph, payload_len);
343 
344 	for (i = 0; i < NUM_PACKETS + 1; i++) {
345 		if (i == flag) {
346 			write_packet(fd, flag_buf, pkt_size, daddr);
347 			continue;
348 		}
349 		create_packet(buf, i * PAYLOAD_LEN, 0, PAYLOAD_LEN, 0);
350 		write_packet(fd, buf, total_hdr_len + PAYLOAD_LEN, daddr);
351 	}
352 }
353 
354 /* Test for data of same length, smaller than previous
355  * and of different lengths
356  */
357 static void send_data_pkts(int fd, struct sockaddr_ll *daddr,
358 			   int payload_len1, int payload_len2)
359 {
360 	static char buf[ETH_HLEN + IP_MAXPACKET];
361 
362 	create_packet(buf, 0, 0, payload_len1, 0);
363 	write_packet(fd, buf, total_hdr_len + payload_len1, daddr);
364 	create_packet(buf, payload_len1, 0, payload_len2, 0);
365 	write_packet(fd, buf, total_hdr_len + payload_len2, daddr);
366 }
367 
368 /* If incoming segments make tracked segment length exceed
369  * legal IP datagram length, do not coalesce
370  */
371 static void send_large(int fd, struct sockaddr_ll *daddr, int remainder)
372 {
373 	static char pkts[NUM_LARGE_PKT][TOTAL_HDR_LEN + MSS];
374 	static char last[TOTAL_HDR_LEN + MSS];
375 	static char new_seg[TOTAL_HDR_LEN + MSS];
376 	int i;
377 
378 	for (i = 0; i < NUM_LARGE_PKT; i++)
379 		create_packet(pkts[i], i * MSS, 0, MSS, 0);
380 	create_packet(last, NUM_LARGE_PKT * MSS, 0, remainder, 0);
381 	create_packet(new_seg, (NUM_LARGE_PKT + 1) * MSS, 0, remainder, 0);
382 
383 	for (i = 0; i < NUM_LARGE_PKT; i++)
384 		write_packet(fd, pkts[i], total_hdr_len + MSS, daddr);
385 	write_packet(fd, last, total_hdr_len + remainder, daddr);
386 	write_packet(fd, new_seg, total_hdr_len + remainder, daddr);
387 }
388 
389 /* Pure acks and dup acks don't coalesce */
390 static void send_ack(int fd, struct sockaddr_ll *daddr)
391 {
392 	static char buf[MAX_HDR_LEN];
393 
394 	create_packet(buf, 0, 0, 0, 0);
395 	write_packet(fd, buf, total_hdr_len, daddr);
396 	write_packet(fd, buf, total_hdr_len, daddr);
397 	create_packet(buf, 0, 1, 0, 0);
398 	write_packet(fd, buf, total_hdr_len, daddr);
399 }
400 
401 static void recompute_packet(char *buf, char *no_ext, int extlen)
402 {
403 	struct tcphdr *tcphdr = (struct tcphdr *)(buf + tcp_offset);
404 	struct ipv6hdr *ip6h = (struct ipv6hdr *)(buf + ETH_HLEN);
405 	struct iphdr *iph = (struct iphdr *)(buf + ETH_HLEN);
406 
407 	memmove(buf, no_ext, total_hdr_len);
408 	memmove(buf + total_hdr_len + extlen,
409 		no_ext + total_hdr_len, PAYLOAD_LEN);
410 
411 	tcphdr->doff = tcphdr->doff + (extlen / 4);
412 	tcphdr->check = 0;
413 	tcphdr->check = tcp_checksum(tcphdr, PAYLOAD_LEN + extlen);
414 	if (proto == PF_INET) {
415 		iph->tot_len = htons(ntohs(iph->tot_len) + extlen);
416 		iph->check = 0;
417 		iph->check = checksum_fold(iph, sizeof(struct iphdr), 0);
418 	} else {
419 		ip6h->payload_len = htons(ntohs(ip6h->payload_len) + extlen);
420 	}
421 }
422 
423 static void tcp_write_options(char *buf, int kind, int ts)
424 {
425 	struct tcp_option_ts {
426 		uint8_t kind;
427 		uint8_t len;
428 		uint32_t tsval;
429 		uint32_t tsecr;
430 	} *opt_ts = (void *)buf;
431 	struct tcp_option_window {
432 		uint8_t kind;
433 		uint8_t len;
434 		uint8_t shift;
435 	} *opt_window = (void *)buf;
436 
437 	switch (kind) {
438 	case TCPOPT_NOP:
439 		buf[0] = TCPOPT_NOP;
440 		break;
441 	case TCPOPT_WINDOW:
442 		memset(opt_window, 0, sizeof(struct tcp_option_window));
443 		opt_window->kind = TCPOPT_WINDOW;
444 		opt_window->len = TCPOLEN_WINDOW;
445 		opt_window->shift = 0;
446 		break;
447 	case TCPOPT_TIMESTAMP:
448 		memset(opt_ts, 0, sizeof(struct tcp_option_ts));
449 		opt_ts->kind = TCPOPT_TIMESTAMP;
450 		opt_ts->len = TCPOLEN_TIMESTAMP;
451 		opt_ts->tsval = ts;
452 		opt_ts->tsecr = 0;
453 		break;
454 	default:
455 		error(1, 0, "unimplemented TCP option");
456 		break;
457 	}
458 }
459 
460 /* TCP with options is always a permutation of {TS, NOP, NOP}.
461  * Implement different orders to verify coalescing stops.
462  */
463 static void add_standard_tcp_options(char *buf, char *no_ext, int ts, int order)
464 {
465 	switch (order) {
466 	case 0:
467 		tcp_write_options(buf + total_hdr_len, TCPOPT_NOP, 0);
468 		tcp_write_options(buf + total_hdr_len + 1, TCPOPT_NOP, 0);
469 		tcp_write_options(buf + total_hdr_len + 2 /* two NOP opts */,
470 				  TCPOPT_TIMESTAMP, ts);
471 		break;
472 	case 1:
473 		tcp_write_options(buf + total_hdr_len, TCPOPT_NOP, 0);
474 		tcp_write_options(buf + total_hdr_len + 1,
475 				  TCPOPT_TIMESTAMP, ts);
476 		tcp_write_options(buf + total_hdr_len + 1 + TCPOLEN_TIMESTAMP,
477 				  TCPOPT_NOP, 0);
478 		break;
479 	case 2:
480 		tcp_write_options(buf + total_hdr_len, TCPOPT_TIMESTAMP, ts);
481 		tcp_write_options(buf + total_hdr_len + TCPOLEN_TIMESTAMP + 1,
482 				  TCPOPT_NOP, 0);
483 		tcp_write_options(buf + total_hdr_len + TCPOLEN_TIMESTAMP + 2,
484 				  TCPOPT_NOP, 0);
485 		break;
486 	default:
487 		error(1, 0, "unknown order");
488 		break;
489 	}
490 	recompute_packet(buf, no_ext, TCPOLEN_TSTAMP_APPA);
491 }
492 
493 /* Packets with invalid checksum don't coalesce. */
494 static void send_changed_checksum(int fd, struct sockaddr_ll *daddr)
495 {
496 	static char buf[MAX_HDR_LEN + PAYLOAD_LEN];
497 	struct tcphdr *tcph = (struct tcphdr *)(buf + tcp_offset);
498 	int pkt_size = total_hdr_len + PAYLOAD_LEN;
499 
500 	create_packet(buf, 0, 0, PAYLOAD_LEN, 0);
501 	write_packet(fd, buf, pkt_size, daddr);
502 
503 	create_packet(buf, PAYLOAD_LEN, 0, PAYLOAD_LEN, 0);
504 	tcph->check = tcph->check - 1;
505 	write_packet(fd, buf, pkt_size, daddr);
506 }
507 
508  /* Packets with non-consecutive sequence number don't coalesce.*/
509 static void send_changed_seq(int fd, struct sockaddr_ll *daddr)
510 {
511 	static char buf[MAX_HDR_LEN + PAYLOAD_LEN];
512 	struct tcphdr *tcph = (struct tcphdr *)(buf + tcp_offset);
513 	int pkt_size = total_hdr_len + PAYLOAD_LEN;
514 
515 	create_packet(buf, 0, 0, PAYLOAD_LEN, 0);
516 	write_packet(fd, buf, pkt_size, daddr);
517 
518 	create_packet(buf, PAYLOAD_LEN, 0, PAYLOAD_LEN, 0);
519 	tcph->seq = ntohl(htonl(tcph->seq) + 1);
520 	tcph->check = 0;
521 	tcph->check = tcp_checksum(tcph, PAYLOAD_LEN);
522 	write_packet(fd, buf, pkt_size, daddr);
523 }
524 
525  /* Packet with different timestamp option or different timestamps
526   * don't coalesce.
527   */
528 static void send_changed_ts(int fd, struct sockaddr_ll *daddr)
529 {
530 	static char buf[MAX_HDR_LEN + PAYLOAD_LEN];
531 	static char extpkt[sizeof(buf) + TCPOLEN_TSTAMP_APPA];
532 	int pkt_size = total_hdr_len + PAYLOAD_LEN + TCPOLEN_TSTAMP_APPA;
533 
534 	create_packet(buf, 0, 0, PAYLOAD_LEN, 0);
535 	add_standard_tcp_options(extpkt, buf, 0, 0);
536 	write_packet(fd, extpkt, pkt_size, daddr);
537 
538 	create_packet(buf, PAYLOAD_LEN, 0, PAYLOAD_LEN, 0);
539 	add_standard_tcp_options(extpkt, buf, 0, 0);
540 	write_packet(fd, extpkt, pkt_size, daddr);
541 
542 	create_packet(buf, PAYLOAD_LEN * 2, 0, PAYLOAD_LEN, 0);
543 	add_standard_tcp_options(extpkt, buf, 100, 0);
544 	write_packet(fd, extpkt, pkt_size, daddr);
545 
546 	create_packet(buf, PAYLOAD_LEN * 3, 0, PAYLOAD_LEN, 0);
547 	add_standard_tcp_options(extpkt, buf, 100, 1);
548 	write_packet(fd, extpkt, pkt_size, daddr);
549 
550 	create_packet(buf, PAYLOAD_LEN * 4, 0, PAYLOAD_LEN, 0);
551 	add_standard_tcp_options(extpkt, buf, 100, 2);
552 	write_packet(fd, extpkt, pkt_size, daddr);
553 }
554 
555 /* Packet with different tcp options don't coalesce. */
556 static void send_diff_opt(int fd, struct sockaddr_ll *daddr)
557 {
558 	static char buf[MAX_HDR_LEN + PAYLOAD_LEN];
559 	static char extpkt1[sizeof(buf) + TCPOLEN_TSTAMP_APPA];
560 	static char extpkt2[sizeof(buf) + TCPOLEN_MAXSEG];
561 	int extpkt1_size = total_hdr_len + PAYLOAD_LEN + TCPOLEN_TSTAMP_APPA;
562 	int extpkt2_size = total_hdr_len + PAYLOAD_LEN + TCPOLEN_MAXSEG;
563 
564 	create_packet(buf, 0, 0, PAYLOAD_LEN, 0);
565 	add_standard_tcp_options(extpkt1, buf, 0, 0);
566 	write_packet(fd, extpkt1, extpkt1_size, daddr);
567 
568 	create_packet(buf, PAYLOAD_LEN, 0, PAYLOAD_LEN, 0);
569 	add_standard_tcp_options(extpkt1, buf, 0, 0);
570 	write_packet(fd, extpkt1, extpkt1_size, daddr);
571 
572 	create_packet(buf, PAYLOAD_LEN * 2, 0, PAYLOAD_LEN, 0);
573 	tcp_write_options(extpkt2 + MAX_HDR_LEN, TCPOPT_NOP, 0);
574 	tcp_write_options(extpkt2 + MAX_HDR_LEN + 1, TCPOPT_WINDOW, 0);
575 	recompute_packet(extpkt2, buf, TCPOLEN_WINDOW + 1);
576 	write_packet(fd, extpkt2, extpkt2_size, daddr);
577 }
578 
579 static void add_ipv4_ts_option(void *buf, void *optpkt)
580 {
581 	struct ip_timestamp *ts = (struct ip_timestamp *)(optpkt + tcp_offset);
582 	int optlen = sizeof(struct ip_timestamp);
583 	struct iphdr *iph;
584 
585 	if (optlen % 4)
586 		error(1, 0, "ipv4 timestamp length is not a multiple of 4B");
587 
588 	ts->ipt_code = IPOPT_TS;
589 	ts->ipt_len = optlen;
590 	ts->ipt_ptr = 5;
591 	ts->ipt_flg = IPOPT_TS_TSONLY;
592 
593 	memcpy(optpkt, buf, tcp_offset);
594 	memcpy(optpkt + tcp_offset + optlen, buf + tcp_offset,
595 	       sizeof(struct tcphdr) + PAYLOAD_LEN);
596 
597 	iph = (struct iphdr *)(optpkt + ETH_HLEN);
598 	iph->ihl = 5 + (optlen / 4);
599 	iph->tot_len = htons(ntohs(iph->tot_len) + optlen);
600 	iph->check = 0;
601 	iph->check = checksum_fold(iph, sizeof(struct iphdr) + optlen, 0);
602 }
603 
604 static void add_ipv6_exthdr(void *buf, void *optpkt, __u8 exthdr_type, char *ext_payload)
605 {
606 	struct ipv6_opt_hdr *exthdr = (struct ipv6_opt_hdr *)(optpkt + tcp_offset);
607 	struct ipv6hdr *iph = (struct ipv6hdr *)(optpkt + ETH_HLEN);
608 	char *exthdr_payload_start = (char *)(exthdr + 1);
609 
610 	exthdr->hdrlen = 0;
611 	exthdr->nexthdr = IPPROTO_TCP;
612 
613 	memcpy(exthdr_payload_start, ext_payload, MIN_EXTHDR_SIZE - sizeof(*exthdr));
614 
615 	memcpy(optpkt, buf, tcp_offset);
616 	memcpy(optpkt + tcp_offset + MIN_EXTHDR_SIZE, buf + tcp_offset,
617 		sizeof(struct tcphdr) + PAYLOAD_LEN);
618 
619 	iph->nexthdr = exthdr_type;
620 	iph->payload_len = htons(ntohs(iph->payload_len) + MIN_EXTHDR_SIZE);
621 }
622 
623 static void send_ipv6_exthdr(int fd, struct sockaddr_ll *daddr, char *ext_data1, char *ext_data2)
624 {
625 	static char buf[MAX_HDR_LEN + PAYLOAD_LEN];
626 	static char exthdr_pck[sizeof(buf) + MIN_EXTHDR_SIZE];
627 
628 	create_packet(buf, 0, 0, PAYLOAD_LEN, 0);
629 	add_ipv6_exthdr(buf, exthdr_pck, IPPROTO_HOPOPTS, ext_data1);
630 	write_packet(fd, exthdr_pck, total_hdr_len + PAYLOAD_LEN + MIN_EXTHDR_SIZE, daddr);
631 
632 	create_packet(buf, PAYLOAD_LEN * 1, 0, PAYLOAD_LEN, 0);
633 	add_ipv6_exthdr(buf, exthdr_pck, IPPROTO_HOPOPTS, ext_data2);
634 	write_packet(fd, exthdr_pck, total_hdr_len + PAYLOAD_LEN + MIN_EXTHDR_SIZE, daddr);
635 }
636 
637 /* IPv4 options shouldn't coalesce */
638 static void send_ip_options(int fd, struct sockaddr_ll *daddr)
639 {
640 	static char buf[MAX_HDR_LEN + PAYLOAD_LEN];
641 	static char optpkt[sizeof(buf) + sizeof(struct ip_timestamp)];
642 	int optlen = sizeof(struct ip_timestamp);
643 	int pkt_size = total_hdr_len + PAYLOAD_LEN + optlen;
644 
645 	create_packet(buf, 0, 0, PAYLOAD_LEN, 0);
646 	write_packet(fd, buf, total_hdr_len + PAYLOAD_LEN, daddr);
647 
648 	create_packet(buf, PAYLOAD_LEN * 1, 0, PAYLOAD_LEN, 0);
649 	add_ipv4_ts_option(buf, optpkt);
650 	write_packet(fd, optpkt, pkt_size, daddr);
651 
652 	create_packet(buf, PAYLOAD_LEN * 2, 0, PAYLOAD_LEN, 0);
653 	write_packet(fd, buf, total_hdr_len + PAYLOAD_LEN, daddr);
654 }
655 
656 /*  IPv4 fragments shouldn't coalesce */
657 static void send_fragment4(int fd, struct sockaddr_ll *daddr)
658 {
659 	static char buf[IP_MAXPACKET];
660 	struct iphdr *iph = (struct iphdr *)(buf + ETH_HLEN);
661 	int pkt_size = total_hdr_len + PAYLOAD_LEN;
662 
663 	create_packet(buf, 0, 0, PAYLOAD_LEN, 0);
664 	write_packet(fd, buf, pkt_size, daddr);
665 
666 	/* Once fragmented, packet would retain the total_len.
667 	 * Tcp header is prepared as if rest of data is in follow-up frags,
668 	 * but follow up frags aren't actually sent.
669 	 */
670 	memset(buf + total_hdr_len, 'a', PAYLOAD_LEN * 2);
671 	fill_transportlayer(buf + tcp_offset, PAYLOAD_LEN, 0, PAYLOAD_LEN * 2, 0);
672 	fill_networklayer(buf + ETH_HLEN, PAYLOAD_LEN);
673 	fill_datalinklayer(buf);
674 
675 	iph->frag_off = htons(0x6000); // DF = 1, MF = 1
676 	iph->check = 0;
677 	iph->check = checksum_fold(iph, sizeof(struct iphdr), 0);
678 	write_packet(fd, buf, pkt_size, daddr);
679 }
680 
681 /* IPv4 packets with different ttl don't coalesce.*/
682 static void send_changed_ttl(int fd, struct sockaddr_ll *daddr)
683 {
684 	int pkt_size = total_hdr_len + PAYLOAD_LEN;
685 	static char buf[MAX_HDR_LEN + PAYLOAD_LEN];
686 	struct iphdr *iph = (struct iphdr *)(buf + ETH_HLEN);
687 
688 	create_packet(buf, 0, 0, PAYLOAD_LEN, 0);
689 	write_packet(fd, buf, pkt_size, daddr);
690 
691 	create_packet(buf, PAYLOAD_LEN, 0, PAYLOAD_LEN, 0);
692 	iph->ttl = 7;
693 	iph->check = 0;
694 	iph->check = checksum_fold(iph, sizeof(struct iphdr), 0);
695 	write_packet(fd, buf, pkt_size, daddr);
696 }
697 
698 /* Packets with different tos don't coalesce.*/
699 static void send_changed_tos(int fd, struct sockaddr_ll *daddr)
700 {
701 	int pkt_size = total_hdr_len + PAYLOAD_LEN;
702 	static char buf[MAX_HDR_LEN + PAYLOAD_LEN];
703 	struct iphdr *iph = (struct iphdr *)(buf + ETH_HLEN);
704 	struct ipv6hdr *ip6h = (struct ipv6hdr *)(buf + ETH_HLEN);
705 
706 	create_packet(buf, 0, 0, PAYLOAD_LEN, 0);
707 	write_packet(fd, buf, pkt_size, daddr);
708 
709 	create_packet(buf, PAYLOAD_LEN, 0, PAYLOAD_LEN, 0);
710 	if (proto == PF_INET) {
711 		iph->tos = 1;
712 		iph->check = 0;
713 		iph->check = checksum_fold(iph, sizeof(struct iphdr), 0);
714 	} else if (proto == PF_INET6) {
715 		ip6h->priority = 0xf;
716 	}
717 	write_packet(fd, buf, pkt_size, daddr);
718 }
719 
720 /* Packets with different ECN don't coalesce.*/
721 static void send_changed_ECN(int fd, struct sockaddr_ll *daddr)
722 {
723 	int pkt_size = total_hdr_len + PAYLOAD_LEN;
724 	static char buf[MAX_HDR_LEN + PAYLOAD_LEN];
725 	struct iphdr *iph = (struct iphdr *)(buf + ETH_HLEN);
726 
727 	create_packet(buf, 0, 0, PAYLOAD_LEN, 0);
728 	write_packet(fd, buf, pkt_size, daddr);
729 
730 	create_packet(buf, PAYLOAD_LEN, 0, PAYLOAD_LEN, 0);
731 	if (proto == PF_INET) {
732 		buf[ETH_HLEN + 1] ^= 0x2; // ECN set to 10
733 		iph->check = 0;
734 		iph->check = checksum_fold(iph, sizeof(struct iphdr), 0);
735 	} else {
736 		buf[ETH_HLEN + 1] ^= 0x20; // ECN set to 10
737 	}
738 	write_packet(fd, buf, pkt_size, daddr);
739 }
740 
741 /* IPv6 fragments and packets with extensions don't coalesce.*/
742 static void send_fragment6(int fd, struct sockaddr_ll *daddr)
743 {
744 	static char buf[MAX_HDR_LEN + PAYLOAD_LEN];
745 	static char extpkt[MAX_HDR_LEN + PAYLOAD_LEN +
746 			   sizeof(struct ip6_frag)];
747 	struct ipv6hdr *ip6h = (struct ipv6hdr *)(buf + ETH_HLEN);
748 	struct ip6_frag *frag = (void *)(extpkt + tcp_offset);
749 	int extlen = sizeof(struct ip6_frag);
750 	int bufpkt_len = total_hdr_len + PAYLOAD_LEN;
751 	int extpkt_len = bufpkt_len + extlen;
752 	int i;
753 
754 	for (i = 0; i < 2; i++) {
755 		create_packet(buf, PAYLOAD_LEN * i, 0, PAYLOAD_LEN, 0);
756 		write_packet(fd, buf, bufpkt_len, daddr);
757 	}
758 	sleep(1);
759 	create_packet(buf, PAYLOAD_LEN * 2, 0, PAYLOAD_LEN, 0);
760 	memset(extpkt, 0, extpkt_len);
761 
762 	ip6h->nexthdr = IPPROTO_FRAGMENT;
763 	ip6h->payload_len = htons(ntohs(ip6h->payload_len) + extlen);
764 	frag->ip6f_nxt = IPPROTO_TCP;
765 
766 	memcpy(extpkt, buf, tcp_offset);
767 	memcpy(extpkt + tcp_offset + extlen, buf + tcp_offset,
768 	       sizeof(struct tcphdr) + PAYLOAD_LEN);
769 	write_packet(fd, extpkt, extpkt_len, daddr);
770 
771 	create_packet(buf, PAYLOAD_LEN * 3, 0, PAYLOAD_LEN, 0);
772 	write_packet(fd, buf, bufpkt_len, daddr);
773 }
774 
775 static void bind_packetsocket(int fd)
776 {
777 	struct sockaddr_ll daddr = {};
778 
779 	daddr.sll_family = AF_PACKET;
780 	daddr.sll_protocol = ethhdr_proto;
781 	daddr.sll_ifindex = if_nametoindex(ifname);
782 	if (daddr.sll_ifindex == 0)
783 		error(1, errno, "if_nametoindex");
784 
785 	if (bind(fd, (void *)&daddr, sizeof(daddr)) < 0)
786 		error(1, errno, "could not bind socket");
787 }
788 
789 static void set_timeout(int fd)
790 {
791 	struct timeval timeout;
792 
793 	timeout.tv_sec = 3;
794 	timeout.tv_usec = 0;
795 	if (setsockopt(fd, SOL_SOCKET, SO_RCVTIMEO, (char *)&timeout,
796 		       sizeof(timeout)) < 0)
797 		error(1, errno, "cannot set timeout, setsockopt failed");
798 }
799 
800 static void check_recv_pkts(int fd, int *correct_payload,
801 			    int correct_num_pkts)
802 {
803 	static char buffer[IP_MAXPACKET + ETH_HLEN + 1];
804 	struct iphdr *iph = (struct iphdr *)(buffer + ETH_HLEN);
805 	struct ipv6hdr *ip6h = (struct ipv6hdr *)(buffer + ETH_HLEN);
806 	struct tcphdr *tcph;
807 	bool bad_packet = false;
808 	int tcp_ext_len = 0;
809 	int ip_ext_len = 0;
810 	int pkt_size = -1;
811 	int data_len = 0;
812 	int num_pkt = 0;
813 	int i;
814 
815 	vlog("Expected {");
816 	for (i = 0; i < correct_num_pkts; i++)
817 		vlog("%d ", correct_payload[i]);
818 	vlog("}, Total %d packets\nReceived {", correct_num_pkts);
819 
820 	while (1) {
821 		ip_ext_len = 0;
822 		pkt_size = recv(fd, buffer, IP_MAXPACKET + ETH_HLEN + 1, 0);
823 		if (pkt_size < 0)
824 			error(1, errno, "could not receive");
825 
826 		if (iph->version == 4)
827 			ip_ext_len = (iph->ihl - 5) * 4;
828 		else if (ip6h->version == 6 && ip6h->nexthdr != IPPROTO_TCP)
829 			ip_ext_len = MIN_EXTHDR_SIZE;
830 
831 		tcph = (struct tcphdr *)(buffer + tcp_offset + ip_ext_len);
832 
833 		if (tcph->fin)
834 			break;
835 
836 		tcp_ext_len = (tcph->doff - 5) * 4;
837 		data_len = pkt_size - total_hdr_len - tcp_ext_len - ip_ext_len;
838 		/* Min ethernet frame payload is 46(ETH_ZLEN - ETH_HLEN) by RFC 802.3.
839 		 * Ipv4/tcp packets without at least 6 bytes of data will be padded.
840 		 * Packet sockets are protocol agnostic, and will not trim the padding.
841 		 */
842 		if (pkt_size == ETH_ZLEN && iph->version == 4) {
843 			data_len = ntohs(iph->tot_len)
844 				- sizeof(struct tcphdr) - sizeof(struct iphdr);
845 		}
846 		vlog("%d ", data_len);
847 		if (data_len != correct_payload[num_pkt]) {
848 			vlog("[!=%d]", correct_payload[num_pkt]);
849 			bad_packet = true;
850 		}
851 		num_pkt++;
852 	}
853 	vlog("}, Total %d packets.\n", num_pkt);
854 	if (num_pkt != correct_num_pkts)
855 		error(1, 0, "incorrect number of packets");
856 	if (bad_packet)
857 		error(1, 0, "incorrect packet geometry");
858 
859 	printf("Test succeeded\n\n");
860 }
861 
862 static void gro_sender(void)
863 {
864 	static char fin_pkt[MAX_HDR_LEN];
865 	struct sockaddr_ll daddr = {};
866 	int txfd = -1;
867 
868 	txfd = socket(PF_PACKET, SOCK_RAW, IPPROTO_RAW);
869 	if (txfd < 0)
870 		error(1, errno, "socket creation");
871 
872 	memset(&daddr, 0, sizeof(daddr));
873 	daddr.sll_ifindex = if_nametoindex(ifname);
874 	if (daddr.sll_ifindex == 0)
875 		error(1, errno, "if_nametoindex");
876 	daddr.sll_family = AF_PACKET;
877 	memcpy(daddr.sll_addr, dst_mac, ETH_ALEN);
878 	daddr.sll_halen = ETH_ALEN;
879 	create_packet(fin_pkt, PAYLOAD_LEN * 2, 0, 0, 1);
880 
881 	if (strcmp(testname, "data") == 0) {
882 		send_data_pkts(txfd, &daddr, PAYLOAD_LEN, PAYLOAD_LEN);
883 		write_packet(txfd, fin_pkt, total_hdr_len, &daddr);
884 
885 		send_data_pkts(txfd, &daddr, PAYLOAD_LEN, PAYLOAD_LEN / 2);
886 		write_packet(txfd, fin_pkt, total_hdr_len, &daddr);
887 
888 		send_data_pkts(txfd, &daddr, PAYLOAD_LEN / 2, PAYLOAD_LEN);
889 		write_packet(txfd, fin_pkt, total_hdr_len, &daddr);
890 	} else if (strcmp(testname, "ack") == 0) {
891 		send_ack(txfd, &daddr);
892 		write_packet(txfd, fin_pkt, total_hdr_len, &daddr);
893 	} else if (strcmp(testname, "flags") == 0) {
894 		send_flags(txfd, &daddr, 1, 0, 0, 0);
895 		write_packet(txfd, fin_pkt, total_hdr_len, &daddr);
896 
897 		send_flags(txfd, &daddr, 0, 1, 0, 0);
898 		write_packet(txfd, fin_pkt, total_hdr_len, &daddr);
899 
900 		send_flags(txfd, &daddr, 0, 0, 1, 0);
901 		write_packet(txfd, fin_pkt, total_hdr_len, &daddr);
902 
903 		send_flags(txfd, &daddr, 0, 0, 0, 1);
904 		write_packet(txfd, fin_pkt, total_hdr_len, &daddr);
905 	} else if (strcmp(testname, "tcp") == 0) {
906 		send_changed_checksum(txfd, &daddr);
907 		write_packet(txfd, fin_pkt, total_hdr_len, &daddr);
908 
909 		send_changed_seq(txfd, &daddr);
910 		write_packet(txfd, fin_pkt, total_hdr_len, &daddr);
911 
912 		send_changed_ts(txfd, &daddr);
913 		write_packet(txfd, fin_pkt, total_hdr_len, &daddr);
914 
915 		send_diff_opt(txfd, &daddr);
916 		write_packet(txfd, fin_pkt, total_hdr_len, &daddr);
917 	} else if (strcmp(testname, "ip") == 0) {
918 		send_changed_ECN(txfd, &daddr);
919 		write_packet(txfd, fin_pkt, total_hdr_len, &daddr);
920 
921 		send_changed_tos(txfd, &daddr);
922 		write_packet(txfd, fin_pkt, total_hdr_len, &daddr);
923 		if (proto == PF_INET) {
924 			/* Modified packets may be received out of order.
925 			 * Sleep function added to enforce test boundaries
926 			 * so that fin pkts are not received prior to other pkts.
927 			 */
928 			sleep(1);
929 			send_changed_ttl(txfd, &daddr);
930 			write_packet(txfd, fin_pkt, total_hdr_len, &daddr);
931 
932 			sleep(1);
933 			send_ip_options(txfd, &daddr);
934 			sleep(1);
935 			write_packet(txfd, fin_pkt, total_hdr_len, &daddr);
936 
937 			sleep(1);
938 			send_fragment4(txfd, &daddr);
939 			sleep(1);
940 			write_packet(txfd, fin_pkt, total_hdr_len, &daddr);
941 		} else if (proto == PF_INET6) {
942 			sleep(1);
943 			send_fragment6(txfd, &daddr);
944 			sleep(1);
945 			write_packet(txfd, fin_pkt, total_hdr_len, &daddr);
946 
947 			sleep(1);
948 			/* send IPv6 packets with ext header with same payload */
949 			send_ipv6_exthdr(txfd, &daddr, EXT_PAYLOAD_1, EXT_PAYLOAD_1);
950 			sleep(1);
951 			write_packet(txfd, fin_pkt, total_hdr_len, &daddr);
952 
953 			sleep(1);
954 			/* send IPv6 packets with ext header with different payload */
955 			send_ipv6_exthdr(txfd, &daddr, EXT_PAYLOAD_1, EXT_PAYLOAD_2);
956 			sleep(1);
957 			write_packet(txfd, fin_pkt, total_hdr_len, &daddr);
958 		}
959 	} else if (strcmp(testname, "large") == 0) {
960 		/* 20 is the difference between min iphdr size
961 		 * and min ipv6hdr size. Like MAX_HDR_SIZE,
962 		 * MAX_PAYLOAD is defined with the larger header of the two.
963 		 */
964 		int offset = proto == PF_INET ? 20 : 0;
965 		int remainder = (MAX_PAYLOAD + offset) % MSS;
966 
967 		send_large(txfd, &daddr, remainder);
968 		write_packet(txfd, fin_pkt, total_hdr_len, &daddr);
969 
970 		send_large(txfd, &daddr, remainder + 1);
971 		write_packet(txfd, fin_pkt, total_hdr_len, &daddr);
972 	} else {
973 		error(1, 0, "Unknown testcase");
974 	}
975 
976 	if (close(txfd))
977 		error(1, errno, "socket close");
978 }
979 
980 static void gro_receiver(void)
981 {
982 	static int correct_payload[NUM_PACKETS];
983 	int rxfd = -1;
984 
985 	rxfd = socket(PF_PACKET, SOCK_RAW, htons(ETH_P_NONE));
986 	if (rxfd < 0)
987 		error(1, 0, "socket creation");
988 	setup_sock_filter(rxfd);
989 	set_timeout(rxfd);
990 	bind_packetsocket(rxfd);
991 
992 	memset(correct_payload, 0, sizeof(correct_payload));
993 
994 	if (strcmp(testname, "data") == 0) {
995 		printf("pure data packet of same size: ");
996 		correct_payload[0] = PAYLOAD_LEN * 2;
997 		check_recv_pkts(rxfd, correct_payload, 1);
998 
999 		printf("large data packets followed by a smaller one: ");
1000 		correct_payload[0] = PAYLOAD_LEN * 1.5;
1001 		check_recv_pkts(rxfd, correct_payload, 1);
1002 
1003 		printf("small data packets followed by a larger one: ");
1004 		correct_payload[0] = PAYLOAD_LEN / 2;
1005 		correct_payload[1] = PAYLOAD_LEN;
1006 		check_recv_pkts(rxfd, correct_payload, 2);
1007 	} else if (strcmp(testname, "ack") == 0) {
1008 		printf("duplicate ack and pure ack: ");
1009 		check_recv_pkts(rxfd, correct_payload, 3);
1010 	} else if (strcmp(testname, "flags") == 0) {
1011 		correct_payload[0] = PAYLOAD_LEN * 3;
1012 		correct_payload[1] = PAYLOAD_LEN * 2;
1013 
1014 		printf("psh flag ends coalescing: ");
1015 		check_recv_pkts(rxfd, correct_payload, 2);
1016 
1017 		correct_payload[0] = PAYLOAD_LEN * 2;
1018 		correct_payload[1] = 0;
1019 		correct_payload[2] = PAYLOAD_LEN * 2;
1020 		printf("syn flag ends coalescing: ");
1021 		check_recv_pkts(rxfd, correct_payload, 3);
1022 
1023 		printf("rst flag ends coalescing: ");
1024 		check_recv_pkts(rxfd, correct_payload, 3);
1025 
1026 		printf("urg flag ends coalescing: ");
1027 		check_recv_pkts(rxfd, correct_payload, 3);
1028 	} else if (strcmp(testname, "tcp") == 0) {
1029 		correct_payload[0] = PAYLOAD_LEN;
1030 		correct_payload[1] = PAYLOAD_LEN;
1031 		correct_payload[2] = PAYLOAD_LEN;
1032 		correct_payload[3] = PAYLOAD_LEN;
1033 
1034 		printf("changed checksum does not coalesce: ");
1035 		check_recv_pkts(rxfd, correct_payload, 2);
1036 
1037 		printf("Wrong Seq number doesn't coalesce: ");
1038 		check_recv_pkts(rxfd, correct_payload, 2);
1039 
1040 		printf("Different timestamp doesn't coalesce: ");
1041 		correct_payload[0] = PAYLOAD_LEN * 2;
1042 		check_recv_pkts(rxfd, correct_payload, 4);
1043 
1044 		printf("Different options doesn't coalesce: ");
1045 		correct_payload[0] = PAYLOAD_LEN * 2;
1046 		check_recv_pkts(rxfd, correct_payload, 2);
1047 	} else if (strcmp(testname, "ip") == 0) {
1048 		correct_payload[0] = PAYLOAD_LEN;
1049 		correct_payload[1] = PAYLOAD_LEN;
1050 
1051 		printf("different ECN doesn't coalesce: ");
1052 		check_recv_pkts(rxfd, correct_payload, 2);
1053 
1054 		printf("different tos doesn't coalesce: ");
1055 		check_recv_pkts(rxfd, correct_payload, 2);
1056 
1057 		if (proto == PF_INET) {
1058 			printf("different ttl doesn't coalesce: ");
1059 			check_recv_pkts(rxfd, correct_payload, 2);
1060 
1061 			printf("ip options doesn't coalesce: ");
1062 			correct_payload[2] = PAYLOAD_LEN;
1063 			check_recv_pkts(rxfd, correct_payload, 3);
1064 
1065 			printf("fragmented ip4 doesn't coalesce: ");
1066 			check_recv_pkts(rxfd, correct_payload, 2);
1067 		} else if (proto == PF_INET6) {
1068 			/* GRO doesn't check for ipv6 hop limit when flushing.
1069 			 * Hence no corresponding test to the ipv4 case.
1070 			 */
1071 			printf("fragmented ip6 doesn't coalesce: ");
1072 			correct_payload[0] = PAYLOAD_LEN * 2;
1073 			correct_payload[1] = PAYLOAD_LEN;
1074 			correct_payload[2] = PAYLOAD_LEN;
1075 			check_recv_pkts(rxfd, correct_payload, 3);
1076 
1077 			printf("ipv6 with ext header does coalesce: ");
1078 			correct_payload[0] = PAYLOAD_LEN * 2;
1079 			check_recv_pkts(rxfd, correct_payload, 1);
1080 
1081 			printf("ipv6 with ext header with different payloads doesn't coalesce: ");
1082 			correct_payload[0] = PAYLOAD_LEN;
1083 			correct_payload[1] = PAYLOAD_LEN;
1084 			check_recv_pkts(rxfd, correct_payload, 2);
1085 		}
1086 	} else if (strcmp(testname, "large") == 0) {
1087 		int offset = proto == PF_INET ? 20 : 0;
1088 		int remainder = (MAX_PAYLOAD + offset) % MSS;
1089 
1090 		correct_payload[0] = (MAX_PAYLOAD + offset);
1091 		correct_payload[1] = remainder;
1092 		printf("Shouldn't coalesce if exceed IP max pkt size: ");
1093 		check_recv_pkts(rxfd, correct_payload, 2);
1094 
1095 		/* last segment sent individually, doesn't start new segment */
1096 		correct_payload[0] = correct_payload[0] - remainder;
1097 		correct_payload[1] = remainder + 1;
1098 		correct_payload[2] = remainder + 1;
1099 		check_recv_pkts(rxfd, correct_payload, 3);
1100 	} else {
1101 		error(1, 0, "Test case error, should never trigger");
1102 	}
1103 
1104 	if (close(rxfd))
1105 		error(1, 0, "socket close");
1106 }
1107 
1108 static void parse_args(int argc, char **argv)
1109 {
1110 	static const struct option opts[] = {
1111 		{ "daddr", required_argument, NULL, 'd' },
1112 		{ "dmac", required_argument, NULL, 'D' },
1113 		{ "iface", required_argument, NULL, 'i' },
1114 		{ "ipv4", no_argument, NULL, '4' },
1115 		{ "ipv6", no_argument, NULL, '6' },
1116 		{ "rx", no_argument, NULL, 'r' },
1117 		{ "saddr", required_argument, NULL, 's' },
1118 		{ "smac", required_argument, NULL, 'S' },
1119 		{ "test", required_argument, NULL, 't' },
1120 		{ "verbose", no_argument, NULL, 'v' },
1121 		{ 0, 0, 0, 0 }
1122 	};
1123 	int c;
1124 
1125 	while ((c = getopt_long(argc, argv, "46d:D:i:rs:S:t:v", opts, NULL)) != -1) {
1126 		switch (c) {
1127 		case '4':
1128 			proto = PF_INET;
1129 			ethhdr_proto = htons(ETH_P_IP);
1130 			break;
1131 		case '6':
1132 			proto = PF_INET6;
1133 			ethhdr_proto = htons(ETH_P_IPV6);
1134 			break;
1135 		case 'd':
1136 			addr4_dst = addr6_dst = optarg;
1137 			break;
1138 		case 'D':
1139 			dmac = optarg;
1140 			break;
1141 		case 'i':
1142 			ifname = optarg;
1143 			break;
1144 		case 'r':
1145 			tx_socket = false;
1146 			break;
1147 		case 's':
1148 			addr4_src = addr6_src = optarg;
1149 			break;
1150 		case 'S':
1151 			smac = optarg;
1152 			break;
1153 		case 't':
1154 			testname = optarg;
1155 			break;
1156 		case 'v':
1157 			verbose = true;
1158 			break;
1159 		default:
1160 			error(1, 0, "%s invalid option %c\n", __func__, c);
1161 			break;
1162 		}
1163 	}
1164 }
1165 
1166 int main(int argc, char **argv)
1167 {
1168 	parse_args(argc, argv);
1169 
1170 	if (proto == PF_INET) {
1171 		tcp_offset = ETH_HLEN + sizeof(struct iphdr);
1172 		total_hdr_len = tcp_offset + sizeof(struct tcphdr);
1173 	} else if (proto == PF_INET6) {
1174 		tcp_offset = ETH_HLEN + sizeof(struct ipv6hdr);
1175 		total_hdr_len = MAX_HDR_LEN;
1176 	} else {
1177 		error(1, 0, "Protocol family is not ipv4 or ipv6");
1178 	}
1179 
1180 	read_MAC(src_mac, smac);
1181 	read_MAC(dst_mac, dmac);
1182 
1183 	if (tx_socket)
1184 		gro_sender();
1185 	else
1186 		gro_receiver();
1187 
1188 	fprintf(stderr, "Gro::%s test passed.\n", testname);
1189 	return 0;
1190 }
1191