xref: /dpdk/lib/net/rte_ip.h (revision 8d54b1ec4a8be40975ae6978535bcc1431caad02)
1 /* SPDX-License-Identifier: BSD-3-Clause
2  * Copyright(c) 1982, 1986, 1990, 1993
3  *      The Regents of the University of California.
4  * Copyright(c) 2010-2014 Intel Corporation.
5  * Copyright(c) 2014 6WIND S.A.
6  * All rights reserved.
7  */
8 
9 #ifndef _RTE_IP_H_
10 #define _RTE_IP_H_
11 
12 /**
13  * @file
14  *
15  * IP-related defines
16  */
17 
18 #include <stdint.h>
19 
20 #ifdef RTE_EXEC_ENV_WINDOWS
21 #include <ws2tcpip.h>
22 #else
23 #include <sys/socket.h>
24 #include <sys/types.h>
25 #include <netinet/in.h>
26 #include <arpa/inet.h>
27 #include <netinet/ip.h>
28 #include <netinet/ip6.h>
29 #endif
30 
31 #include <rte_byteorder.h>
32 #include <rte_mbuf.h>
33 
34 #ifdef __cplusplus
35 extern "C" {
36 #endif
37 
38 /**
39  * IPv4 Header
40  */
41 struct rte_ipv4_hdr {
42 	__extension__
43 	union {
44 		uint8_t version_ihl;    /**< version and header length */
45 		struct {
46 #if RTE_BYTE_ORDER == RTE_LITTLE_ENDIAN
47 			uint8_t ihl:4;     /**< header length */
48 			uint8_t version:4; /**< version */
49 #elif RTE_BYTE_ORDER == RTE_BIG_ENDIAN
50 			uint8_t version:4; /**< version */
51 			uint8_t ihl:4;     /**< header length */
52 #endif
53 		};
54 	};
55 	uint8_t  type_of_service;	/**< type of service */
56 	rte_be16_t total_length;	/**< length of packet */
57 	rte_be16_t packet_id;		/**< packet ID */
58 	rte_be16_t fragment_offset;	/**< fragmentation offset */
59 	uint8_t  time_to_live;		/**< time to live */
60 	uint8_t  next_proto_id;		/**< protocol ID */
61 	rte_be16_t hdr_checksum;	/**< header checksum */
62 	rte_be32_t src_addr;		/**< source address */
63 	rte_be32_t dst_addr;		/**< destination address */
64 } __rte_packed;
65 
66 /** Create IPv4 address */
67 #define RTE_IPV4(a, b, c, d) ((uint32_t)(((a) & 0xff) << 24) | \
68 					   (((b) & 0xff) << 16) | \
69 					   (((c) & 0xff) << 8)  | \
70 					   ((d) & 0xff))
71 
72 /** Maximal IPv4 packet length (including a header) */
73 #define RTE_IPV4_MAX_PKT_LEN        65535
74 
75 /** Internet header length mask for version_ihl field */
76 #define RTE_IPV4_HDR_IHL_MASK	(0x0f)
77 /**
78  * Internet header length field multiplier (IHL field specifies overall header
79  * length in number of 4-byte words)
80  */
81 #define RTE_IPV4_IHL_MULTIPLIER	(4)
82 
83 /* Type of Service fields */
84 #define RTE_IPV4_HDR_DSCP_MASK	(0xfc)
85 #define RTE_IPV4_HDR_ECN_MASK	(0x03)
86 #define RTE_IPV4_HDR_ECN_CE	RTE_IPV4_HDR_ECN_MASK
87 
88 /* Fragment Offset * Flags. */
89 #define	RTE_IPV4_HDR_DF_SHIFT	14
90 #define	RTE_IPV4_HDR_MF_SHIFT	13
91 #define	RTE_IPV4_HDR_FO_SHIFT	3
92 
93 #define	RTE_IPV4_HDR_DF_FLAG	(1 << RTE_IPV4_HDR_DF_SHIFT)
94 #define	RTE_IPV4_HDR_MF_FLAG	(1 << RTE_IPV4_HDR_MF_SHIFT)
95 
96 #define	RTE_IPV4_HDR_OFFSET_MASK	((1 << RTE_IPV4_HDR_MF_SHIFT) - 1)
97 
98 #define	RTE_IPV4_HDR_OFFSET_UNITS	8
99 
100 /* IPv4 options */
101 #define RTE_IPV4_HDR_OPT_EOL       0
102 #define RTE_IPV4_HDR_OPT_NOP       1
103 #define RTE_IPV4_HDR_OPT_COPIED(v) ((v) & 0x80)
104 #define RTE_IPV4_HDR_OPT_MAX_LEN   40
105 
106 /*
107  * IPv4 address types
108  */
109 #define RTE_IPV4_ANY              ((uint32_t)0x00000000) /**< 0.0.0.0 */
110 #define RTE_IPV4_LOOPBACK         ((uint32_t)0x7f000001) /**< 127.0.0.1 */
111 #define RTE_IPV4_BROADCAST        ((uint32_t)0xe0000000) /**< 224.0.0.0 */
112 #define RTE_IPV4_ALLHOSTS_GROUP   ((uint32_t)0xe0000001) /**< 224.0.0.1 */
113 #define RTE_IPV4_ALLRTRS_GROUP    ((uint32_t)0xe0000002) /**< 224.0.0.2 */
114 #define RTE_IPV4_MAX_LOCAL_GROUP  ((uint32_t)0xe00000ff) /**< 224.0.0.255 */
115 
116 /*
117  * IPv4 Multicast-related macros
118  */
119 #define RTE_IPV4_MIN_MCAST \
120 	RTE_IPV4(224, 0, 0, 0)          /**< Minimal IPv4-multicast address */
121 #define RTE_IPV4_MAX_MCAST \
122 	RTE_IPV4(239, 255, 255, 255)    /**< Maximum IPv4 multicast address */
123 
124 #define RTE_IS_IPV4_MCAST(x) \
125 	((x) >= RTE_IPV4_MIN_MCAST && (x) <= RTE_IPV4_MAX_MCAST)
126 	/**< check if IPv4 address is multicast */
127 
128 /* IPv4 default fields values */
129 #define RTE_IPV4_MIN_IHL    (0x5)
130 #define RTE_IPV4_VHL_DEF    ((IPVERSION << 4) | RTE_IPV4_MIN_IHL)
131 
132 /**
133  * Get the length of an IPv4 header.
134  *
135  * @param ipv4_hdr
136  *   Pointer to the IPv4 header.
137  * @return
138  *   The length of the IPv4 header (with options if present) in bytes.
139  */
140 static inline uint8_t
141 rte_ipv4_hdr_len(const struct rte_ipv4_hdr *ipv4_hdr)
142 {
143 	return (uint8_t)((ipv4_hdr->version_ihl & RTE_IPV4_HDR_IHL_MASK) *
144 		RTE_IPV4_IHL_MULTIPLIER);
145 }
146 
147 /**
148  * @internal Calculate a sum of all words in the buffer.
149  * Helper routine for the rte_raw_cksum().
150  *
151  * @param buf
152  *   Pointer to the buffer.
153  * @param len
154  *   Length of the buffer.
155  * @param sum
156  *   Initial value of the sum.
157  * @return
158  *   sum += Sum of all words in the buffer.
159  */
160 static inline uint32_t
161 __rte_raw_cksum(const void *buf, size_t len, uint32_t sum)
162 {
163 	const void *end;
164 
165 	for (end = RTE_PTR_ADD(buf, RTE_ALIGN_FLOOR(len, sizeof(uint16_t)));
166 	     buf != end; buf = RTE_PTR_ADD(buf, sizeof(uint16_t))) {
167 		uint16_t v;
168 
169 		memcpy(&v, buf, sizeof(uint16_t));
170 		sum += v;
171 	}
172 
173 	/* if length is odd, keeping it byte order independent */
174 	if (unlikely(len % 2)) {
175 		uint16_t left = 0;
176 
177 		memcpy(&left, end, 1);
178 		sum += left;
179 	}
180 
181 	return sum;
182 }
183 
184 /**
185  * @internal Reduce a sum to the non-complemented checksum.
186  * Helper routine for the rte_raw_cksum().
187  *
188  * @param sum
189  *   Value of the sum.
190  * @return
191  *   The non-complemented checksum.
192  */
193 static inline uint16_t
194 __rte_raw_cksum_reduce(uint32_t sum)
195 {
196 	sum = ((sum & 0xffff0000) >> 16) + (sum & 0xffff);
197 	sum = ((sum & 0xffff0000) >> 16) + (sum & 0xffff);
198 	return (uint16_t)sum;
199 }
200 
201 /**
202  * Process the non-complemented checksum of a buffer.
203  *
204  * @param buf
205  *   Pointer to the buffer.
206  * @param len
207  *   Length of the buffer.
208  * @return
209  *   The non-complemented checksum.
210  */
211 static inline uint16_t
212 rte_raw_cksum(const void *buf, size_t len)
213 {
214 	uint32_t sum;
215 
216 	sum = __rte_raw_cksum(buf, len, 0);
217 	return __rte_raw_cksum_reduce(sum);
218 }
219 
220 /**
221  * Compute the raw (non complemented) checksum of a packet.
222  *
223  * @param m
224  *   The pointer to the mbuf.
225  * @param off
226  *   The offset in bytes to start the checksum.
227  * @param len
228  *   The length in bytes of the data to checksum.
229  * @param cksum
230  *   A pointer to the checksum, filled on success.
231  * @return
232  *   0 on success, -1 on error (bad length or offset).
233  */
234 static inline int
235 rte_raw_cksum_mbuf(const struct rte_mbuf *m, uint32_t off, uint32_t len,
236 	uint16_t *cksum)
237 {
238 	const struct rte_mbuf *seg;
239 	const char *buf;
240 	uint32_t sum, tmp;
241 	uint32_t seglen, done;
242 
243 	/* easy case: all data in the first segment */
244 	if (off + len <= rte_pktmbuf_data_len(m)) {
245 		*cksum = rte_raw_cksum(rte_pktmbuf_mtod_offset(m,
246 				const char *, off), len);
247 		return 0;
248 	}
249 
250 	if (unlikely(off + len > rte_pktmbuf_pkt_len(m)))
251 		return -1; /* invalid params, return a dummy value */
252 
253 	/* else browse the segment to find offset */
254 	seglen = 0;
255 	for (seg = m; seg != NULL; seg = seg->next) {
256 		seglen = rte_pktmbuf_data_len(seg);
257 		if (off < seglen)
258 			break;
259 		off -= seglen;
260 	}
261 	RTE_ASSERT(seg != NULL);
262 	if (seg == NULL)
263 		return -1;
264 	seglen -= off;
265 	buf = rte_pktmbuf_mtod_offset(seg, const char *, off);
266 	if (seglen >= len) {
267 		/* all in one segment */
268 		*cksum = rte_raw_cksum(buf, len);
269 		return 0;
270 	}
271 
272 	/* hard case: process checksum of several segments */
273 	sum = 0;
274 	done = 0;
275 	for (;;) {
276 		tmp = __rte_raw_cksum(buf, seglen, 0);
277 		if (done & 1)
278 			tmp = rte_bswap16((uint16_t)tmp);
279 		sum += tmp;
280 		done += seglen;
281 		if (done == len)
282 			break;
283 		seg = seg->next;
284 		buf = rte_pktmbuf_mtod(seg, const char *);
285 		seglen = rte_pktmbuf_data_len(seg);
286 		if (seglen > len - done)
287 			seglen = len - done;
288 	}
289 
290 	*cksum = __rte_raw_cksum_reduce(sum);
291 	return 0;
292 }
293 
294 /**
295  * Process the IPv4 checksum of an IPv4 header.
296  *
297  * The checksum field must be set to 0 by the caller.
298  *
299  * @param ipv4_hdr
300  *   The pointer to the contiguous IPv4 header.
301  * @return
302  *   The complemented checksum to set in the IP packet.
303  */
304 static inline uint16_t
305 rte_ipv4_cksum(const struct rte_ipv4_hdr *ipv4_hdr)
306 {
307 	uint16_t cksum;
308 	cksum = rte_raw_cksum(ipv4_hdr, rte_ipv4_hdr_len(ipv4_hdr));
309 	return (uint16_t)~cksum;
310 }
311 
312 /**
313  * Process the pseudo-header checksum of an IPv4 header.
314  *
315  * The checksum field must be set to 0 by the caller.
316  *
317  * Depending on the ol_flags, the pseudo-header checksum expected by the
318  * drivers is not the same. For instance, when TSO is enabled, the IP
319  * payload length must not be included in the packet.
320  *
321  * When ol_flags is 0, it computes the standard pseudo-header checksum.
322  *
323  * @param ipv4_hdr
324  *   The pointer to the contiguous IPv4 header.
325  * @param ol_flags
326  *   The ol_flags of the associated mbuf.
327  * @return
328  *   The non-complemented checksum to set in the L4 header.
329  */
330 static inline uint16_t
331 rte_ipv4_phdr_cksum(const struct rte_ipv4_hdr *ipv4_hdr, uint64_t ol_flags)
332 {
333 	struct ipv4_psd_header {
334 		uint32_t src_addr; /* IP address of source host. */
335 		uint32_t dst_addr; /* IP address of destination host. */
336 		uint8_t  zero;     /* zero. */
337 		uint8_t  proto;    /* L4 protocol type. */
338 		uint16_t len;      /* L4 length. */
339 	} psd_hdr;
340 
341 	uint32_t l3_len;
342 
343 	psd_hdr.src_addr = ipv4_hdr->src_addr;
344 	psd_hdr.dst_addr = ipv4_hdr->dst_addr;
345 	psd_hdr.zero = 0;
346 	psd_hdr.proto = ipv4_hdr->next_proto_id;
347 	if (ol_flags & RTE_MBUF_F_TX_TCP_SEG) {
348 		psd_hdr.len = 0;
349 	} else {
350 		l3_len = rte_be_to_cpu_16(ipv4_hdr->total_length);
351 		psd_hdr.len = rte_cpu_to_be_16((uint16_t)(l3_len -
352 			rte_ipv4_hdr_len(ipv4_hdr)));
353 	}
354 	return rte_raw_cksum(&psd_hdr, sizeof(psd_hdr));
355 }
356 
357 /**
358  * @internal Calculate the non-complemented IPv4 L4 checksum
359  */
360 static inline uint16_t
361 __rte_ipv4_udptcp_cksum(const struct rte_ipv4_hdr *ipv4_hdr, const void *l4_hdr)
362 {
363 	uint32_t cksum;
364 	uint32_t l3_len, l4_len;
365 	uint8_t ip_hdr_len;
366 
367 	ip_hdr_len = rte_ipv4_hdr_len(ipv4_hdr);
368 	l3_len = rte_be_to_cpu_16(ipv4_hdr->total_length);
369 	if (l3_len < ip_hdr_len)
370 		return 0;
371 
372 	l4_len = l3_len - ip_hdr_len;
373 
374 	cksum = rte_raw_cksum(l4_hdr, l4_len);
375 	cksum += rte_ipv4_phdr_cksum(ipv4_hdr, 0);
376 
377 	cksum = ((cksum & 0xffff0000) >> 16) + (cksum & 0xffff);
378 
379 	return (uint16_t)cksum;
380 }
381 
382 /**
383  * Process the IPv4 UDP or TCP checksum.
384  *
385  * The layer 4 checksum must be set to 0 in the L4 header by the caller.
386  *
387  * @param ipv4_hdr
388  *   The pointer to the contiguous IPv4 header.
389  * @param l4_hdr
390  *   The pointer to the beginning of the L4 header.
391  * @return
392  *   The complemented checksum to set in the L4 header.
393  */
394 static inline uint16_t
395 rte_ipv4_udptcp_cksum(const struct rte_ipv4_hdr *ipv4_hdr, const void *l4_hdr)
396 {
397 	uint16_t cksum = __rte_ipv4_udptcp_cksum(ipv4_hdr, l4_hdr);
398 
399 	cksum = ~cksum;
400 
401 	/*
402 	 * Per RFC 768: If the computed checksum is zero for UDP,
403 	 * it is transmitted as all ones
404 	 * (the equivalent in one's complement arithmetic).
405 	 */
406 	if (cksum == 0 && ipv4_hdr->next_proto_id == IPPROTO_UDP)
407 		cksum = 0xffff;
408 
409 	return cksum;
410 }
411 
412 /**
413  * @internal Calculate the non-complemented IPv4 L4 checksum of a packet
414  */
415 static inline uint16_t
416 __rte_ipv4_udptcp_cksum_mbuf(const struct rte_mbuf *m,
417 			     const struct rte_ipv4_hdr *ipv4_hdr,
418 			     uint16_t l4_off)
419 {
420 	uint16_t raw_cksum;
421 	uint32_t cksum;
422 
423 	if (l4_off > m->pkt_len)
424 		return 0;
425 
426 	if (rte_raw_cksum_mbuf(m, l4_off, m->pkt_len - l4_off, &raw_cksum))
427 		return 0;
428 
429 	cksum = raw_cksum + rte_ipv4_phdr_cksum(ipv4_hdr, 0);
430 
431 	cksum = ((cksum & 0xffff0000) >> 16) + (cksum & 0xffff);
432 
433 	return (uint16_t)cksum;
434 }
435 
436 /**
437  * @warning
438  * @b EXPERIMENTAL: this API may change without prior notice.
439  *
440  * Compute the IPv4 UDP/TCP checksum of a packet.
441  *
442  * @param m
443  *   The pointer to the mbuf.
444  * @param ipv4_hdr
445  *   The pointer to the contiguous IPv4 header.
446  * @param l4_off
447  *   The offset in bytes to start L4 checksum.
448  * @return
449  *   The complemented checksum to set in the L4 header.
450  */
451 __rte_experimental
452 static inline uint16_t
453 rte_ipv4_udptcp_cksum_mbuf(const struct rte_mbuf *m,
454 			   const struct rte_ipv4_hdr *ipv4_hdr, uint16_t l4_off)
455 {
456 	uint16_t cksum = __rte_ipv4_udptcp_cksum_mbuf(m, ipv4_hdr, l4_off);
457 
458 	cksum = ~cksum;
459 
460 	/*
461 	 * Per RFC 768: If the computed checksum is zero for UDP,
462 	 * it is transmitted as all ones
463 	 * (the equivalent in one's complement arithmetic).
464 	 */
465 	if (cksum == 0 && ipv4_hdr->next_proto_id == IPPROTO_UDP)
466 		cksum = 0xffff;
467 
468 	return cksum;
469 }
470 
471 /**
472  * Validate the IPv4 UDP or TCP checksum.
473  *
474  * In case of UDP, the caller must first check if udp_hdr->dgram_cksum is 0
475  * (i.e. no checksum).
476  *
477  * @param ipv4_hdr
478  *   The pointer to the contiguous IPv4 header.
479  * @param l4_hdr
480  *   The pointer to the beginning of the L4 header.
481  * @return
482  *   Return 0 if the checksum is correct, else -1.
483  */
484 __rte_experimental
485 static inline int
486 rte_ipv4_udptcp_cksum_verify(const struct rte_ipv4_hdr *ipv4_hdr,
487 			     const void *l4_hdr)
488 {
489 	uint16_t cksum = __rte_ipv4_udptcp_cksum(ipv4_hdr, l4_hdr);
490 
491 	if (cksum != 0xffff)
492 		return -1;
493 
494 	return 0;
495 }
496 
497 /**
498  * @warning
499  * @b EXPERIMENTAL: this API may change without prior notice.
500  *
501  * Verify the IPv4 UDP/TCP checksum of a packet.
502  *
503  * In case of UDP, the caller must first check if udp_hdr->dgram_cksum is 0
504  * (i.e. no checksum).
505  *
506  * @param m
507  *   The pointer to the mbuf.
508  * @param ipv4_hdr
509  *   The pointer to the contiguous IPv4 header.
510  * @param l4_off
511  *   The offset in bytes to start L4 checksum.
512  * @return
513  *   Return 0 if the checksum is correct, else -1.
514  */
515 __rte_experimental
516 static inline uint16_t
517 rte_ipv4_udptcp_cksum_mbuf_verify(const struct rte_mbuf *m,
518 				  const struct rte_ipv4_hdr *ipv4_hdr,
519 				  uint16_t l4_off)
520 {
521 	uint16_t cksum = __rte_ipv4_udptcp_cksum_mbuf(m, ipv4_hdr, l4_off);
522 
523 	if (cksum != 0xffff)
524 		return -1;
525 
526 	return 0;
527 }
528 
529 /**
530  * IPv6 Header
531  */
532 struct rte_ipv6_hdr {
533 	rte_be32_t vtc_flow;	/**< IP version, traffic class & flow label. */
534 	rte_be16_t payload_len;	/**< IP payload size, including ext. headers */
535 	uint8_t  proto;		/**< Protocol, next header. */
536 	uint8_t  hop_limits;	/**< Hop limits. */
537 	uint8_t  src_addr[16];	/**< IP address of source host. */
538 	uint8_t  dst_addr[16];	/**< IP address of destination host(s). */
539 } __rte_packed;
540 
541 /* IPv6 vtc_flow: IPv / TC / flow_label */
542 #define RTE_IPV6_HDR_FL_SHIFT 0
543 #define RTE_IPV6_HDR_TC_SHIFT 20
544 #define RTE_IPV6_HDR_FL_MASK	((1u << RTE_IPV6_HDR_TC_SHIFT) - 1)
545 #define RTE_IPV6_HDR_TC_MASK	(0xff << RTE_IPV6_HDR_TC_SHIFT)
546 #define RTE_IPV6_HDR_DSCP_MASK	(0xfc << RTE_IPV6_HDR_TC_SHIFT)
547 #define RTE_IPV6_HDR_ECN_MASK	(0x03 << RTE_IPV6_HDR_TC_SHIFT)
548 #define RTE_IPV6_HDR_ECN_CE	RTE_IPV6_HDR_ECN_MASK
549 
550 #define RTE_IPV6_MIN_MTU 1280 /**< Minimum MTU for IPv6, see RFC 8200. */
551 
552 /**
553  * Process the pseudo-header checksum of an IPv6 header.
554  *
555  * Depending on the ol_flags, the pseudo-header checksum expected by the
556  * drivers is not the same. For instance, when TSO is enabled, the IPv6
557  * payload length must not be included in the packet.
558  *
559  * When ol_flags is 0, it computes the standard pseudo-header checksum.
560  *
561  * @param ipv6_hdr
562  *   The pointer to the contiguous IPv6 header.
563  * @param ol_flags
564  *   The ol_flags of the associated mbuf.
565  * @return
566  *   The non-complemented checksum to set in the L4 header.
567  */
568 static inline uint16_t
569 rte_ipv6_phdr_cksum(const struct rte_ipv6_hdr *ipv6_hdr, uint64_t ol_flags)
570 {
571 	uint32_t sum;
572 	struct {
573 		rte_be32_t len;   /* L4 length. */
574 		rte_be32_t proto; /* L4 protocol - top 3 bytes must be zero */
575 	} psd_hdr;
576 
577 	psd_hdr.proto = (uint32_t)(ipv6_hdr->proto << 24);
578 	if (ol_flags & RTE_MBUF_F_TX_TCP_SEG) {
579 		psd_hdr.len = 0;
580 	} else {
581 		psd_hdr.len = ipv6_hdr->payload_len;
582 	}
583 
584 	sum = __rte_raw_cksum(ipv6_hdr->src_addr,
585 		sizeof(ipv6_hdr->src_addr) + sizeof(ipv6_hdr->dst_addr),
586 		0);
587 	sum = __rte_raw_cksum(&psd_hdr, sizeof(psd_hdr), sum);
588 	return __rte_raw_cksum_reduce(sum);
589 }
590 
591 /**
592  * @internal Calculate the non-complemented IPv6 L4 checksum
593  */
594 static inline uint16_t
595 __rte_ipv6_udptcp_cksum(const struct rte_ipv6_hdr *ipv6_hdr, const void *l4_hdr)
596 {
597 	uint32_t cksum;
598 	uint32_t l4_len;
599 
600 	l4_len = rte_be_to_cpu_16(ipv6_hdr->payload_len);
601 
602 	cksum = rte_raw_cksum(l4_hdr, l4_len);
603 	cksum += rte_ipv6_phdr_cksum(ipv6_hdr, 0);
604 
605 	cksum = ((cksum & 0xffff0000) >> 16) + (cksum & 0xffff);
606 
607 	return (uint16_t)cksum;
608 }
609 
610 /**
611  * Process the IPv6 UDP or TCP checksum.
612  *
613  * The IPv6 header must not be followed by extension headers. The layer 4
614  * checksum must be set to 0 in the L4 header by the caller.
615  *
616  * @param ipv6_hdr
617  *   The pointer to the contiguous IPv6 header.
618  * @param l4_hdr
619  *   The pointer to the beginning of the L4 header.
620  * @return
621  *   The complemented checksum to set in the L4 header.
622  */
623 static inline uint16_t
624 rte_ipv6_udptcp_cksum(const struct rte_ipv6_hdr *ipv6_hdr, const void *l4_hdr)
625 {
626 	uint16_t cksum = __rte_ipv6_udptcp_cksum(ipv6_hdr, l4_hdr);
627 
628 	cksum = ~cksum;
629 
630 	/*
631 	 * Per RFC 768: If the computed checksum is zero for UDP,
632 	 * it is transmitted as all ones
633 	 * (the equivalent in one's complement arithmetic).
634 	 */
635 	if (cksum == 0 && ipv6_hdr->proto == IPPROTO_UDP)
636 		cksum = 0xffff;
637 
638 	return cksum;
639 }
640 
641 /**
642  * @internal Calculate the non-complemented IPv6 L4 checksum of a packet
643  */
644 static inline uint16_t
645 __rte_ipv6_udptcp_cksum_mbuf(const struct rte_mbuf *m,
646 			     const struct rte_ipv6_hdr *ipv6_hdr,
647 			     uint16_t l4_off)
648 {
649 	uint16_t raw_cksum;
650 	uint32_t cksum;
651 
652 	if (l4_off > m->pkt_len)
653 		return 0;
654 
655 	if (rte_raw_cksum_mbuf(m, l4_off, m->pkt_len - l4_off, &raw_cksum))
656 		return 0;
657 
658 	cksum = raw_cksum + rte_ipv6_phdr_cksum(ipv6_hdr, 0);
659 
660 	cksum = ((cksum & 0xffff0000) >> 16) + (cksum & 0xffff);
661 
662 	return (uint16_t)cksum;
663 }
664 
665 /**
666  * @warning
667  * @b EXPERIMENTAL: this API may change without prior notice.
668  *
669  * Process the IPv6 UDP or TCP checksum of a packet.
670  *
671  * The IPv6 header must not be followed by extension headers. The layer 4
672  * checksum must be set to 0 in the L4 header by the caller.
673  *
674  * @param m
675  *   The pointer to the mbuf.
676  * @param ipv6_hdr
677  *   The pointer to the contiguous IPv6 header.
678  * @param l4_off
679  *   The offset in bytes to start L4 checksum.
680  * @return
681  *   The complemented checksum to set in the L4 header.
682  */
683 __rte_experimental
684 static inline uint16_t
685 rte_ipv6_udptcp_cksum_mbuf(const struct rte_mbuf *m,
686 			   const struct rte_ipv6_hdr *ipv6_hdr, uint16_t l4_off)
687 {
688 	uint16_t cksum = __rte_ipv6_udptcp_cksum_mbuf(m, ipv6_hdr, l4_off);
689 
690 	cksum = ~cksum;
691 
692 	/*
693 	 * Per RFC 768: If the computed checksum is zero for UDP,
694 	 * it is transmitted as all ones
695 	 * (the equivalent in one's complement arithmetic).
696 	 */
697 	if (cksum == 0 && ipv6_hdr->proto == IPPROTO_UDP)
698 		cksum = 0xffff;
699 
700 	return cksum;
701 }
702 
703 /**
704  * Validate the IPv6 UDP or TCP checksum.
705  *
706  * In case of UDP, the caller must first check if udp_hdr->dgram_cksum is 0:
707  * this is either invalid or means no checksum in some situations. See 8.1
708  * (Upper-Layer Checksums) in RFC 8200.
709  *
710  * @param ipv6_hdr
711  *   The pointer to the contiguous IPv6 header.
712  * @param l4_hdr
713  *   The pointer to the beginning of the L4 header.
714  * @return
715  *   Return 0 if the checksum is correct, else -1.
716  */
717 __rte_experimental
718 static inline int
719 rte_ipv6_udptcp_cksum_verify(const struct rte_ipv6_hdr *ipv6_hdr,
720 			     const void *l4_hdr)
721 {
722 	uint16_t cksum = __rte_ipv6_udptcp_cksum(ipv6_hdr, l4_hdr);
723 
724 	if (cksum != 0xffff)
725 		return -1;
726 
727 	return 0;
728 }
729 
730 /**
731  * @warning
732  * @b EXPERIMENTAL: this API may change without prior notice.
733  *
734  * Validate the IPv6 UDP or TCP checksum of a packet.
735  *
736  * In case of UDP, the caller must first check if udp_hdr->dgram_cksum is 0:
737  * this is either invalid or means no checksum in some situations. See 8.1
738  * (Upper-Layer Checksums) in RFC 8200.
739  *
740  * @param m
741  *   The pointer to the mbuf.
742  * @param ipv6_hdr
743  *   The pointer to the contiguous IPv6 header.
744  * @param l4_off
745  *   The offset in bytes to start L4 checksum.
746  * @return
747  *   Return 0 if the checksum is correct, else -1.
748  */
749 __rte_experimental
750 static inline int
751 rte_ipv6_udptcp_cksum_mbuf_verify(const struct rte_mbuf *m,
752 				  const struct rte_ipv6_hdr *ipv6_hdr,
753 				  uint16_t l4_off)
754 {
755 	uint16_t cksum = __rte_ipv6_udptcp_cksum_mbuf(m, ipv6_hdr, l4_off);
756 
757 	if (cksum != 0xffff)
758 		return -1;
759 
760 	return 0;
761 }
762 
763 /** IPv6 fragment extension header. */
764 #define	RTE_IPV6_EHDR_MF_SHIFT	0
765 #define	RTE_IPV6_EHDR_MF_MASK	1
766 #define	RTE_IPV6_EHDR_FO_SHIFT	3
767 #define	RTE_IPV6_EHDR_FO_MASK	(~((1 << RTE_IPV6_EHDR_FO_SHIFT) - 1))
768 #define	RTE_IPV6_EHDR_FO_ALIGN	(1 << RTE_IPV6_EHDR_FO_SHIFT)
769 
770 #define RTE_IPV6_FRAG_USED_MASK	(RTE_IPV6_EHDR_MF_MASK | RTE_IPV6_EHDR_FO_MASK)
771 
772 #define RTE_IPV6_GET_MF(x)	((x) & RTE_IPV6_EHDR_MF_MASK)
773 #define RTE_IPV6_GET_FO(x)	((x) >> RTE_IPV6_EHDR_FO_SHIFT)
774 
775 #define RTE_IPV6_SET_FRAG_DATA(fo, mf)	\
776 	(((fo) & RTE_IPV6_EHDR_FO_MASK) | ((mf) & RTE_IPV6_EHDR_MF_MASK))
777 
778 struct rte_ipv6_fragment_ext {
779 	uint8_t next_header;	/**< Next header type */
780 	uint8_t reserved;	/**< Reserved */
781 	rte_be16_t frag_data;	/**< All fragmentation data */
782 	rte_be32_t id;		/**< Packet ID */
783 } __rte_packed;
784 
785 /* IPv6 fragment extension header size */
786 #define RTE_IPV6_FRAG_HDR_SIZE	sizeof(struct rte_ipv6_fragment_ext)
787 
788 /**
789  * Parse next IPv6 header extension
790  *
791  * This function checks if proto number is an IPv6 extensions and parses its
792  * data if so, providing information on next header and extension length.
793  *
794  * @param p
795  *   Pointer to an extension raw data.
796  * @param proto
797  *   Protocol number extracted from the "next header" field from
798  *   the IPv6 header or the previous extension.
799  * @param ext_len
800  *   Extension data length.
801  * @return
802  *   next protocol number if proto is an IPv6 extension, -EINVAL otherwise
803  */
804 __rte_experimental
805 static inline int
806 rte_ipv6_get_next_ext(const uint8_t *p, int proto, size_t *ext_len)
807 {
808 	int next_proto;
809 
810 	switch (proto) {
811 	case IPPROTO_AH:
812 		next_proto = *p++;
813 		*ext_len = (*p + 2) * sizeof(uint32_t);
814 		break;
815 
816 	case IPPROTO_HOPOPTS:
817 	case IPPROTO_ROUTING:
818 	case IPPROTO_DSTOPTS:
819 		next_proto = *p++;
820 		*ext_len = (*p + 1) * sizeof(uint64_t);
821 		break;
822 
823 	case IPPROTO_FRAGMENT:
824 		next_proto = *p;
825 		*ext_len = RTE_IPV6_FRAG_HDR_SIZE;
826 		break;
827 
828 	default:
829 		return -EINVAL;
830 	}
831 
832 	return next_proto;
833 }
834 
835 #ifdef __cplusplus
836 }
837 #endif
838 
839 #endif /* _RTE_IP_H_ */
840