xref: /dpdk/lib/gro/gro_tcp4.c (revision daa02b5cddbb8e11b31d41e2bf7bb1ae64dcae2f)
1 /* SPDX-License-Identifier: BSD-3-Clause
2  * Copyright(c) 2017 Intel Corporation
3  */
4 
5 #include <rte_malloc.h>
6 #include <rte_mbuf.h>
7 #include <rte_cycles.h>
8 #include <rte_ethdev.h>
9 
10 #include "gro_tcp4.h"
11 
12 void *
13 gro_tcp4_tbl_create(uint16_t socket_id,
14 		uint16_t max_flow_num,
15 		uint16_t max_item_per_flow)
16 {
17 	struct gro_tcp4_tbl *tbl;
18 	size_t size;
19 	uint32_t entries_num, i;
20 
21 	entries_num = max_flow_num * max_item_per_flow;
22 	entries_num = RTE_MIN(entries_num, GRO_TCP4_TBL_MAX_ITEM_NUM);
23 
24 	if (entries_num == 0)
25 		return NULL;
26 
27 	tbl = rte_zmalloc_socket(__func__,
28 			sizeof(struct gro_tcp4_tbl),
29 			RTE_CACHE_LINE_SIZE,
30 			socket_id);
31 	if (tbl == NULL)
32 		return NULL;
33 
34 	size = sizeof(struct gro_tcp4_item) * entries_num;
35 	tbl->items = rte_zmalloc_socket(__func__,
36 			size,
37 			RTE_CACHE_LINE_SIZE,
38 			socket_id);
39 	if (tbl->items == NULL) {
40 		rte_free(tbl);
41 		return NULL;
42 	}
43 	tbl->max_item_num = entries_num;
44 
45 	size = sizeof(struct gro_tcp4_flow) * entries_num;
46 	tbl->flows = rte_zmalloc_socket(__func__,
47 			size,
48 			RTE_CACHE_LINE_SIZE,
49 			socket_id);
50 	if (tbl->flows == NULL) {
51 		rte_free(tbl->items);
52 		rte_free(tbl);
53 		return NULL;
54 	}
55 	/* INVALID_ARRAY_INDEX indicates an empty flow */
56 	for (i = 0; i < entries_num; i++)
57 		tbl->flows[i].start_index = INVALID_ARRAY_INDEX;
58 	tbl->max_flow_num = entries_num;
59 
60 	return tbl;
61 }
62 
63 void
64 gro_tcp4_tbl_destroy(void *tbl)
65 {
66 	struct gro_tcp4_tbl *tcp_tbl = tbl;
67 
68 	if (tcp_tbl) {
69 		rte_free(tcp_tbl->items);
70 		rte_free(tcp_tbl->flows);
71 	}
72 	rte_free(tcp_tbl);
73 }
74 
75 static inline uint32_t
76 find_an_empty_item(struct gro_tcp4_tbl *tbl)
77 {
78 	uint32_t i;
79 	uint32_t max_item_num = tbl->max_item_num;
80 
81 	for (i = 0; i < max_item_num; i++)
82 		if (tbl->items[i].firstseg == NULL)
83 			return i;
84 	return INVALID_ARRAY_INDEX;
85 }
86 
87 static inline uint32_t
88 find_an_empty_flow(struct gro_tcp4_tbl *tbl)
89 {
90 	uint32_t i;
91 	uint32_t max_flow_num = tbl->max_flow_num;
92 
93 	for (i = 0; i < max_flow_num; i++)
94 		if (tbl->flows[i].start_index == INVALID_ARRAY_INDEX)
95 			return i;
96 	return INVALID_ARRAY_INDEX;
97 }
98 
99 static inline uint32_t
100 insert_new_item(struct gro_tcp4_tbl *tbl,
101 		struct rte_mbuf *pkt,
102 		uint64_t start_time,
103 		uint32_t prev_idx,
104 		uint32_t sent_seq,
105 		uint16_t ip_id,
106 		uint8_t is_atomic)
107 {
108 	uint32_t item_idx;
109 
110 	item_idx = find_an_empty_item(tbl);
111 	if (item_idx == INVALID_ARRAY_INDEX)
112 		return INVALID_ARRAY_INDEX;
113 
114 	tbl->items[item_idx].firstseg = pkt;
115 	tbl->items[item_idx].lastseg = rte_pktmbuf_lastseg(pkt);
116 	tbl->items[item_idx].start_time = start_time;
117 	tbl->items[item_idx].next_pkt_idx = INVALID_ARRAY_INDEX;
118 	tbl->items[item_idx].sent_seq = sent_seq;
119 	tbl->items[item_idx].ip_id = ip_id;
120 	tbl->items[item_idx].nb_merged = 1;
121 	tbl->items[item_idx].is_atomic = is_atomic;
122 	tbl->item_num++;
123 
124 	/* if the previous packet exists, chain them together. */
125 	if (prev_idx != INVALID_ARRAY_INDEX) {
126 		tbl->items[item_idx].next_pkt_idx =
127 			tbl->items[prev_idx].next_pkt_idx;
128 		tbl->items[prev_idx].next_pkt_idx = item_idx;
129 	}
130 
131 	return item_idx;
132 }
133 
134 static inline uint32_t
135 delete_item(struct gro_tcp4_tbl *tbl, uint32_t item_idx,
136 		uint32_t prev_item_idx)
137 {
138 	uint32_t next_idx = tbl->items[item_idx].next_pkt_idx;
139 
140 	/* NULL indicates an empty item */
141 	tbl->items[item_idx].firstseg = NULL;
142 	tbl->item_num--;
143 	if (prev_item_idx != INVALID_ARRAY_INDEX)
144 		tbl->items[prev_item_idx].next_pkt_idx = next_idx;
145 
146 	return next_idx;
147 }
148 
149 static inline uint32_t
150 insert_new_flow(struct gro_tcp4_tbl *tbl,
151 		struct tcp4_flow_key *src,
152 		uint32_t item_idx)
153 {
154 	struct tcp4_flow_key *dst;
155 	uint32_t flow_idx;
156 
157 	flow_idx = find_an_empty_flow(tbl);
158 	if (unlikely(flow_idx == INVALID_ARRAY_INDEX))
159 		return INVALID_ARRAY_INDEX;
160 
161 	dst = &(tbl->flows[flow_idx].key);
162 
163 	rte_ether_addr_copy(&(src->eth_saddr), &(dst->eth_saddr));
164 	rte_ether_addr_copy(&(src->eth_daddr), &(dst->eth_daddr));
165 	dst->ip_src_addr = src->ip_src_addr;
166 	dst->ip_dst_addr = src->ip_dst_addr;
167 	dst->recv_ack = src->recv_ack;
168 	dst->src_port = src->src_port;
169 	dst->dst_port = src->dst_port;
170 
171 	tbl->flows[flow_idx].start_index = item_idx;
172 	tbl->flow_num++;
173 
174 	return flow_idx;
175 }
176 
177 /*
178  * update the packet length for the flushed packet.
179  */
180 static inline void
181 update_header(struct gro_tcp4_item *item)
182 {
183 	struct rte_ipv4_hdr *ipv4_hdr;
184 	struct rte_mbuf *pkt = item->firstseg;
185 
186 	ipv4_hdr = (struct rte_ipv4_hdr *)(rte_pktmbuf_mtod(pkt, char *) +
187 			pkt->l2_len);
188 	ipv4_hdr->total_length = rte_cpu_to_be_16(pkt->pkt_len -
189 			pkt->l2_len);
190 }
191 
192 int32_t
193 gro_tcp4_reassemble(struct rte_mbuf *pkt,
194 		struct gro_tcp4_tbl *tbl,
195 		uint64_t start_time)
196 {
197 	struct rte_ether_hdr *eth_hdr;
198 	struct rte_ipv4_hdr *ipv4_hdr;
199 	struct rte_tcp_hdr *tcp_hdr;
200 	uint32_t sent_seq;
201 	int32_t tcp_dl;
202 	uint16_t ip_id, hdr_len, frag_off;
203 	uint8_t is_atomic;
204 
205 	struct tcp4_flow_key key;
206 	uint32_t cur_idx, prev_idx, item_idx;
207 	uint32_t i, max_flow_num, remaining_flow_num;
208 	int cmp;
209 	uint8_t find;
210 
211 	/*
212 	 * Don't process the packet whose TCP header length is greater
213 	 * than 60 bytes or less than 20 bytes.
214 	 */
215 	if (unlikely(INVALID_TCP_HDRLEN(pkt->l4_len)))
216 		return -1;
217 
218 	eth_hdr = rte_pktmbuf_mtod(pkt, struct rte_ether_hdr *);
219 	ipv4_hdr = (struct rte_ipv4_hdr *)((char *)eth_hdr + pkt->l2_len);
220 	tcp_hdr = (struct rte_tcp_hdr *)((char *)ipv4_hdr + pkt->l3_len);
221 	hdr_len = pkt->l2_len + pkt->l3_len + pkt->l4_len;
222 
223 	/*
224 	 * Don't process the packet which has FIN, SYN, RST, PSH, URG, ECE
225 	 * or CWR set.
226 	 */
227 	if (tcp_hdr->tcp_flags != RTE_TCP_ACK_FLAG)
228 		return -1;
229 	/*
230 	 * Don't process the packet whose payload length is less than or
231 	 * equal to 0.
232 	 */
233 	tcp_dl = pkt->pkt_len - hdr_len;
234 	if (tcp_dl <= 0)
235 		return -1;
236 
237 	/*
238 	 * Save IPv4 ID for the packet whose DF bit is 0. For the packet
239 	 * whose DF bit is 1, IPv4 ID is ignored.
240 	 */
241 	frag_off = rte_be_to_cpu_16(ipv4_hdr->fragment_offset);
242 	is_atomic = (frag_off & RTE_IPV4_HDR_DF_FLAG) == RTE_IPV4_HDR_DF_FLAG;
243 	ip_id = is_atomic ? 0 : rte_be_to_cpu_16(ipv4_hdr->packet_id);
244 	sent_seq = rte_be_to_cpu_32(tcp_hdr->sent_seq);
245 
246 	rte_ether_addr_copy(&(eth_hdr->src_addr), &(key.eth_saddr));
247 	rte_ether_addr_copy(&(eth_hdr->dst_addr), &(key.eth_daddr));
248 	key.ip_src_addr = ipv4_hdr->src_addr;
249 	key.ip_dst_addr = ipv4_hdr->dst_addr;
250 	key.src_port = tcp_hdr->src_port;
251 	key.dst_port = tcp_hdr->dst_port;
252 	key.recv_ack = tcp_hdr->recv_ack;
253 
254 	/* Search for a matched flow. */
255 	max_flow_num = tbl->max_flow_num;
256 	remaining_flow_num = tbl->flow_num;
257 	find = 0;
258 	for (i = 0; i < max_flow_num && remaining_flow_num; i++) {
259 		if (tbl->flows[i].start_index != INVALID_ARRAY_INDEX) {
260 			if (is_same_tcp4_flow(tbl->flows[i].key, key)) {
261 				find = 1;
262 				break;
263 			}
264 			remaining_flow_num--;
265 		}
266 	}
267 
268 	/*
269 	 * Fail to find a matched flow. Insert a new flow and store the
270 	 * packet into the flow.
271 	 */
272 	if (find == 0) {
273 		item_idx = insert_new_item(tbl, pkt, start_time,
274 				INVALID_ARRAY_INDEX, sent_seq, ip_id,
275 				is_atomic);
276 		if (item_idx == INVALID_ARRAY_INDEX)
277 			return -1;
278 		if (insert_new_flow(tbl, &key, item_idx) ==
279 				INVALID_ARRAY_INDEX) {
280 			/*
281 			 * Fail to insert a new flow, so delete the
282 			 * stored packet.
283 			 */
284 			delete_item(tbl, item_idx, INVALID_ARRAY_INDEX);
285 			return -1;
286 		}
287 		return 0;
288 	}
289 
290 	/*
291 	 * Check all packets in the flow and try to find a neighbor for
292 	 * the input packet.
293 	 */
294 	cur_idx = tbl->flows[i].start_index;
295 	prev_idx = cur_idx;
296 	do {
297 		cmp = check_seq_option(&(tbl->items[cur_idx]), tcp_hdr,
298 				sent_seq, ip_id, pkt->l4_len, tcp_dl, 0,
299 				is_atomic);
300 		if (cmp) {
301 			if (merge_two_tcp4_packets(&(tbl->items[cur_idx]),
302 						pkt, cmp, sent_seq, ip_id, 0))
303 				return 1;
304 			/*
305 			 * Fail to merge the two packets, as the packet
306 			 * length is greater than the max value. Store
307 			 * the packet into the flow.
308 			 */
309 			if (insert_new_item(tbl, pkt, start_time, prev_idx,
310 						sent_seq, ip_id, is_atomic) ==
311 					INVALID_ARRAY_INDEX)
312 				return -1;
313 			return 0;
314 		}
315 		prev_idx = cur_idx;
316 		cur_idx = tbl->items[cur_idx].next_pkt_idx;
317 	} while (cur_idx != INVALID_ARRAY_INDEX);
318 
319 	/* Fail to find a neighbor, so store the packet into the flow. */
320 	if (insert_new_item(tbl, pkt, start_time, prev_idx, sent_seq,
321 				ip_id, is_atomic) == INVALID_ARRAY_INDEX)
322 		return -1;
323 
324 	return 0;
325 }
326 
327 uint16_t
328 gro_tcp4_tbl_timeout_flush(struct gro_tcp4_tbl *tbl,
329 		uint64_t flush_timestamp,
330 		struct rte_mbuf **out,
331 		uint16_t nb_out)
332 {
333 	uint16_t k = 0;
334 	uint32_t i, j;
335 	uint32_t max_flow_num = tbl->max_flow_num;
336 
337 	for (i = 0; i < max_flow_num; i++) {
338 		if (unlikely(tbl->flow_num == 0))
339 			return k;
340 
341 		j = tbl->flows[i].start_index;
342 		while (j != INVALID_ARRAY_INDEX) {
343 			if (tbl->items[j].start_time <= flush_timestamp) {
344 				out[k++] = tbl->items[j].firstseg;
345 				if (tbl->items[j].nb_merged > 1)
346 					update_header(&(tbl->items[j]));
347 				/*
348 				 * Delete the packet and get the next
349 				 * packet in the flow.
350 				 */
351 				j = delete_item(tbl, j, INVALID_ARRAY_INDEX);
352 				tbl->flows[i].start_index = j;
353 				if (j == INVALID_ARRAY_INDEX)
354 					tbl->flow_num--;
355 
356 				if (unlikely(k == nb_out))
357 					return k;
358 			} else
359 				/*
360 				 * The left packets in this flow won't be
361 				 * timeout. Go to check other flows.
362 				 */
363 				break;
364 		}
365 	}
366 	return k;
367 }
368 
369 uint32_t
370 gro_tcp4_tbl_pkt_count(void *tbl)
371 {
372 	struct gro_tcp4_tbl *gro_tbl = tbl;
373 
374 	if (gro_tbl)
375 		return gro_tbl->item_num;
376 
377 	return 0;
378 }
379