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https://github.com/RIOT-OS/RIOT.git
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98 lines
3.2 KiB
C
98 lines
3.2 KiB
C
/*
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* Copyright (C) 2015 Martine Lenders <mlenders@inf.fu-berlin.de>
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*
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* This file is subject to the terms and conditions of the GNU Lesser
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* General Public License v2.1. See the file LICENSE in the top level
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* directory for more details.
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*/
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/**
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* @{
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*
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* @file
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*/
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#include <string.h>
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#include "net/gnrc/ipv6/netif.h"
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#include "net/gnrc/rpl/srh.h"
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#define ENABLE_DEBUG (0)
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#include "debug.h"
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#if ENABLE_DEBUG
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static char addr_str[IPV6_ADDR_MAX_STR_LEN];
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#endif
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#define GNRC_RPL_SRH_PADDING(X) ((X & 0xF0) >> 4)
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#define GNRC_RPL_SRH_COMPRE(X) (X & 0x0F)
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#define GNRC_RPL_SRH_COMPRI(X) ((X & 0xF0) >> 4)
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int gnrc_rpl_srh_process(ipv6_hdr_t *ipv6, gnrc_rpl_srh_t *rh)
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{
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if (rh->seg_left == 0) {
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return EXT_RH_CODE_OK;
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}
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uint8_t n = (((rh->len * 8) - GNRC_RPL_SRH_PADDING(rh->pad_resv) -
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(16 - GNRC_RPL_SRH_COMPRE(rh->compr))) /
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(16 - GNRC_RPL_SRH_COMPRI(rh->compr))) + 1;
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ipv6_addr_t addr = ipv6->dst, tmp;
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uint8_t i, pref_elided, tmp_pref_elided, addr_len, compri_addr_len, tmp_addr_len, found_pos = 0;
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uint8_t *addr_vec = (uint8_t *) (rh + 1);
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bool found = false;
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DEBUG("RPL SRH: %u addresses in the routing header\n", (unsigned) n);
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if (rh->seg_left > n) {
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DEBUG("RPL SRH: number of segments left > number of addresses - discard\n");
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/* TODO ICMP Parameter Problem - Code 0 */
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return EXT_RH_CODE_ERROR;
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}
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rh->seg_left--;
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i = n - rh->seg_left;
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pref_elided = rh->seg_left ? GNRC_RPL_SRH_COMPRI(rh->compr) : GNRC_RPL_SRH_COMPRE(rh->compr);
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compri_addr_len = sizeof(ipv6_addr_t) - GNRC_RPL_SRH_COMPRI(rh->compr);
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addr_len = sizeof(ipv6_addr_t) - pref_elided;
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memcpy(&addr.u8[pref_elided], &addr_vec[(i - 1) * compri_addr_len], addr_len);
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if (ipv6_addr_is_multicast(&ipv6->dst) || ipv6_addr_is_multicast(&addr)) {
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DEBUG("RPL SRH: found a multicast address - discard\n");
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/* TODO discard the packet */
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return EXT_RH_CODE_ERROR;
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}
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/* check if multiple addresses of my interface exist */
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tmp_pref_elided = GNRC_RPL_SRH_COMPRI(rh->compr);
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tmp_addr_len = sizeof(ipv6_addr_t) - tmp_pref_elided;
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tmp = ipv6->dst;
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for (uint8_t k = 0; k < n; k++) {
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if (k == n - 1) {
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tmp_pref_elided = GNRC_RPL_SRH_COMPRE(rh->compr);
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tmp_addr_len = sizeof(ipv6_addr_t) - tmp_pref_elided;
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tmp = ipv6->dst;
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}
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memcpy(&tmp.u8[tmp_pref_elided], &addr_vec[k * compri_addr_len], tmp_addr_len);
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if (gnrc_ipv6_netif_find_by_addr(NULL, &tmp) != KERNEL_PID_UNDEF) {
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if (found && ((k - found_pos) > 1)) {
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DEBUG("RPL SRH: found multiple addresses that belong to me - discard\n");
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/* TODO send an ICMP Parameter Problem (Code 0) and discard the packet */
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return EXT_RH_CODE_ERROR;
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}
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found_pos = k;
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found = true;
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}
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}
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memcpy(&addr_vec[(i - 1) * compri_addr_len], &ipv6->dst.u8[pref_elided], addr_len);
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DEBUG("RPL SRH: Next hop: %s at position %d\n",
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ipv6_addr_to_str(addr_str, &addr, sizeof(addr_str)), i);
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ipv6->dst = addr;
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return EXT_RH_CODE_FORWARD;
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}
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/** @} */
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