[linux-2.6-block.git] / net / ipv6 / rpl.c

// SPDX-License-Identifier: GPL-2.0-only
/*
 * Authors:
 * (C) 2020 Alexander Aring <alex.aring@gmail.com>
 */

#include <net/ipv6.h>
#include <net/rpl.h>

#define IPV6_PFXTAIL_LEN(x) (sizeof(struct in6_addr) - (x))
#define IPV6_RPL_BEST_ADDR_COMPRESSION 15

static void ipv6_rpl_addr_decompress(struct in6_addr *dst,
				     const struct in6_addr *daddr,
				     const void *post, unsigned char pfx)
{
	memcpy(dst, daddr, pfx);
	memcpy(&dst->s6_addr[pfx], post, IPV6_PFXTAIL_LEN(pfx));
}

static void ipv6_rpl_addr_compress(void *dst, const struct in6_addr *addr,
				   unsigned char pfx)
{
	memcpy(dst, &addr->s6_addr[pfx], IPV6_PFXTAIL_LEN(pfx));
}

static void *ipv6_rpl_segdata_pos(const struct ipv6_rpl_sr_hdr *hdr, int i)
{
	return (void *)&hdr->rpl_segdata[i * IPV6_PFXTAIL_LEN(hdr->cmpri)];
}

size_t ipv6_rpl_srh_size(unsigned char n, unsigned char cmpri,
			 unsigned char cmpre)
{
	return sizeof(struct ipv6_rpl_sr_hdr) + (n * IPV6_PFXTAIL_LEN(cmpri)) +
		IPV6_PFXTAIL_LEN(cmpre);
}

void ipv6_rpl_srh_decompress(struct ipv6_rpl_sr_hdr *outhdr,
			     const struct ipv6_rpl_sr_hdr *inhdr,
			     const struct in6_addr *daddr, unsigned char n)
{
	int i;

	outhdr->nexthdr = inhdr->nexthdr;
	outhdr->hdrlen = (((n + 1) * sizeof(struct in6_addr)) >> 3);
	outhdr->pad = 0;
	outhdr->type = inhdr->type;
	outhdr->segments_left = inhdr->segments_left;
	outhdr->cmpri = 0;
	outhdr->cmpre = 0;

	for (i = 0; i < n; i++)
		ipv6_rpl_addr_decompress(&outhdr->rpl_segaddr[i], daddr,
					 ipv6_rpl_segdata_pos(inhdr, i),
					 inhdr->cmpri);

	ipv6_rpl_addr_decompress(&outhdr->rpl_segaddr[n], daddr,
				 ipv6_rpl_segdata_pos(inhdr, n),
				 inhdr->cmpre);
}

static unsigned char ipv6_rpl_srh_calc_cmpri(const struct ipv6_rpl_sr_hdr *inhdr,
					     const struct in6_addr *daddr,
					     unsigned char n)
{
	unsigned char plen;
	int i;

	for (plen = 0; plen < sizeof(*daddr); plen++) {
		for (i = 0; i < n; i++) {
			if (daddr->s6_addr[plen] !=
			    inhdr->rpl_segaddr[i].s6_addr[plen])
				return plen;
		}
	}

	return IPV6_RPL_BEST_ADDR_COMPRESSION;
}

static unsigned char ipv6_rpl_srh_calc_cmpre(const struct in6_addr *daddr,
					     const struct in6_addr *last_segment)
{
	unsigned int plen;

	for (plen = 0; plen < sizeof(*daddr); plen++) {
		if (daddr->s6_addr[plen] != last_segment->s6_addr[plen])
			return plen;
	}

	return IPV6_RPL_BEST_ADDR_COMPRESSION;
}

void ipv6_rpl_srh_compress(struct ipv6_rpl_sr_hdr *outhdr,
			   const struct ipv6_rpl_sr_hdr *inhdr,
			   const struct in6_addr *daddr, unsigned char n)
{
	unsigned char cmpri, cmpre;
	size_t seglen;
	int i;

	cmpri = ipv6_rpl_srh_calc_cmpri(inhdr, daddr, n);
	cmpre = ipv6_rpl_srh_calc_cmpre(daddr, &inhdr->rpl_segaddr[n]);

	outhdr->nexthdr = inhdr->nexthdr;
	seglen = (n * IPV6_PFXTAIL_LEN(cmpri)) + IPV6_PFXTAIL_LEN(cmpre);
	outhdr->hdrlen = seglen >> 3;
	if (seglen & 0x7) {
		outhdr->hdrlen++;
		outhdr->pad = 8 - (seglen & 0x7);
	} else {
		outhdr->pad = 0;
	}
	outhdr->type = inhdr->type;
	outhdr->segments_left = inhdr->segments_left;
	outhdr->cmpri = cmpri;
	outhdr->cmpre = cmpre;

	for (i = 0; i < n; i++)
		ipv6_rpl_addr_compress(ipv6_rpl_segdata_pos(outhdr, i),
				       &inhdr->rpl_segaddr[i], cmpri);

	ipv6_rpl_addr_compress(ipv6_rpl_segdata_pos(outhdr, n),
			       &inhdr->rpl_segaddr[n], cmpre);
}
Commit	Line	Data
8610c7c6	1	// SPDX-License-Identifier: GPL-2.0-only
f1f09df1	2	/*
8610c7c6 AA	3	* Authors:
	4	* (C) 2020 Alexander Aring <alex.aring@gmail.com>
	5	*/
	6
	7	#include <net/ipv6.h>
	8	#include <net/rpl.h>
	9
	10	#define IPV6_PFXTAIL_LEN(x) (sizeof(struct in6_addr) - (x))
62e69776	11	#define IPV6_RPL_BEST_ADDR_COMPRESSION 15
8610c7c6 AA	12
	13	static void ipv6_rpl_addr_decompress(struct in6_addr *dst,
	14	const struct in6_addr *daddr,
	15	const void *post, unsigned char pfx)
	16	{
	17	memcpy(dst, daddr, pfx);
	18	memcpy(&dst->s6_addr[pfx], post, IPV6_PFXTAIL_LEN(pfx));
	19	}
	20
	21	static void ipv6_rpl_addr_compress(void dst, const struct in6_addr addr,
	22	unsigned char pfx)
	23	{
	24	memcpy(dst, &addr->s6_addr[pfx], IPV6_PFXTAIL_LEN(pfx));
	25	}
	26
	27	static void ipv6_rpl_segdata_pos(const struct ipv6_rpl_sr_hdr hdr, int i)
	28	{
	29	return (void )&hdr->rpl_segdata[i IPV6_PFXTAIL_LEN(hdr->cmpri)];
	30	}
	31
	32	size_t ipv6_rpl_srh_size(unsigned char n, unsigned char cmpri,
	33	unsigned char cmpre)
	34	{
4e006c7a AA	35	return sizeof(struct ipv6_rpl_sr_hdr) + (n * IPV6_PFXTAIL_LEN(cmpri)) +
4e006c7a AA	36	IPV6_PFXTAIL_LEN(cmpre);
8610c7c6 AA	37	}
	38
	39	void ipv6_rpl_srh_decompress(struct ipv6_rpl_sr_hdr *outhdr,
	40	const struct ipv6_rpl_sr_hdr *inhdr,
	41	const struct in6_addr *daddr, unsigned char n)
	42	{
	43	int i;
	44
	45	outhdr->nexthdr = inhdr->nexthdr;
	46	outhdr->hdrlen = (((n + 1) * sizeof(struct in6_addr)) >> 3);
	47	outhdr->pad = 0;
	48	outhdr->type = inhdr->type;
	49	outhdr->segments_left = inhdr->segments_left;
	50	outhdr->cmpri = 0;
	51	outhdr->cmpre = 0;
	52
a7f9a6f4	53	for (i = 0; i < n; i++)
8610c7c6 AA	54	ipv6_rpl_addr_decompress(&outhdr->rpl_segaddr[i], daddr,
	55	ipv6_rpl_segdata_pos(inhdr, i),
	56	inhdr->cmpri);
	57
	58	ipv6_rpl_addr_decompress(&outhdr->rpl_segaddr[n], daddr,
	59	ipv6_rpl_segdata_pos(inhdr, n),
	60	inhdr->cmpre);
	61	}
	62
	63	static unsigned char ipv6_rpl_srh_calc_cmpri(const struct ipv6_rpl_sr_hdr *inhdr,
	64	const struct in6_addr *daddr,
	65	unsigned char n)
	66	{
	67	unsigned char plen;
	68	int i;
	69
	70	for (plen = 0; plen < sizeof(*daddr); plen++) {
a7f9a6f4	71	for (i = 0; i < n; i++) {
8610c7c6 AA	72	if (daddr->s6_addr[plen] !=
	73	inhdr->rpl_segaddr[i].s6_addr[plen])
	74	return plen;
	75	}
	76	}
	77
62e69776	78	return IPV6_RPL_BEST_ADDR_COMPRESSION;
8610c7c6 AA	79	}
	80
	81	static unsigned char ipv6_rpl_srh_calc_cmpre(const struct in6_addr *daddr,
	82	const struct in6_addr *last_segment)
	83	{
	84	unsigned int plen;
	85
	86	for (plen = 0; plen < sizeof(*daddr); plen++) {
	87	if (daddr->s6_addr[plen] != last_segment->s6_addr[plen])
62e69776	88	return plen;
8610c7c6 AA	89	}
8610c7c6 AA	90
62e69776	91	return IPV6_RPL_BEST_ADDR_COMPRESSION;
8610c7c6 AA	92	}
	93
	94	void ipv6_rpl_srh_compress(struct ipv6_rpl_sr_hdr *outhdr,
	95	const struct ipv6_rpl_sr_hdr *inhdr,
	96	const struct in6_addr *daddr, unsigned char n)
	97	{
	98	unsigned char cmpri, cmpre;
	99	size_t seglen;
	100	int i;
	101
	102	cmpri = ipv6_rpl_srh_calc_cmpri(inhdr, daddr, n);
	103	cmpre = ipv6_rpl_srh_calc_cmpre(daddr, &inhdr->rpl_segaddr[n]);
	104
	105	outhdr->nexthdr = inhdr->nexthdr;
	106	seglen = (n * IPV6_PFXTAIL_LEN(cmpri)) + IPV6_PFXTAIL_LEN(cmpre);
	107	outhdr->hdrlen = seglen >> 3;
	108	if (seglen & 0x7) {
	109	outhdr->hdrlen++;
	110	outhdr->pad = 8 - (seglen & 0x7);
	111	} else {
	112	outhdr->pad = 0;
	113	}
	114	outhdr->type = inhdr->type;
	115	outhdr->segments_left = inhdr->segments_left;
	116	outhdr->cmpri = cmpri;
	117	outhdr->cmpre = cmpre;
	118
a7f9a6f4	119	for (i = 0; i < n; i++)
8610c7c6 AA	120	ipv6_rpl_addr_compress(ipv6_rpl_segdata_pos(outhdr, i),
	121	&inhdr->rpl_segaddr[i], cmpri);
	122
	123	ipv6_rpl_addr_compress(ipv6_rpl_segdata_pos(outhdr, n),
	124	&inhdr->rpl_segaddr[n], cmpre);
	125	}