From ace9429bb58fd418f0c81d4c2835699bddf6bde6 Mon Sep 17 00:00:00 2001 From: Daniel Baumann Date: Thu, 11 Apr 2024 10:27:49 +0200 Subject: Adding upstream version 6.6.15. Signed-off-by: Daniel Baumann --- net/ipv6/rpl.c | 118 +++++++++++++++++++++++++++++++++++++++++++++++++++++++++ 1 file changed, 118 insertions(+) create mode 100644 net/ipv6/rpl.c (limited to 'net/ipv6/rpl.c') diff --git a/net/ipv6/rpl.c b/net/ipv6/rpl.c new file mode 100644 index 0000000000..e186998bfb --- /dev/null +++ b/net/ipv6/rpl.c @@ -0,0 +1,118 @@ +// SPDX-License-Identifier: GPL-2.0-only +/* + * Authors: + * (C) 2020 Alexander Aring + */ + +#include +#include + +#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)]; +} + +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); +} -- cgit v1.2.3