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Merge pull request #10227 from miri64/gnrc_rpl_srh/enh/cleanup-handler

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gnrc_rpl_srh: cleanup and optimize SRH processing function
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Martine Lenders 2018-11-27 16:41:44 +01:00 committed by GitHub
commit 310ef3c29e
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2 changed files with 73 additions and 40 deletions
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4
sys/include/net/gnrc/rpl/srh.h
View File

@ -52,6 +52,10 @@ typedef struct __attribute__((packed)) {
/**
* @brief Process the RPL source routing header.
*
* @pre `rh->seq_left > 0`; The 0 case means the destination is reached and
* common among all routing headers, so it should be handled by an
* external routing header handler.
*
* @param[in,out] ipv6 The IPv6 header of the incoming packet.
* @param[in] rh A RPL source routing header.
*

109
sys/net/gnrc/routing/rpl/srh/gnrc_rpl_srh.c
View File

@ -1,5 +1,6 @@
/*
* Copyright (C) 2015 Martine Lenders <mlenders@inf.fu-berlin.de>
* Copyright (C) 2015 Cenk Gündoğan <cnkgndgn@gmail.com>
* Copyright (C) 2018 Freie Universität Berlin
*
* This file is subject to the terms and conditions of the GNU Lesser
* General Public License v2.1. See the file LICENSE in the top level
@ -10,6 +11,8 @@
* @{
*
* @file
* @author Cenk Gündoğan <cnkgndgn@gmail.com>
* @author Martine Lenders <m.lenders@fu-berlin.de>
*/
#include <string.h>
@ -26,34 +29,74 @@ static char addr_str[IPV6_ADDR_MAX_STR_LEN];
#define GNRC_RPL_SRH_COMPRE(X) (X & 0x0F)
#define GNRC_RPL_SRH_COMPRI(X) ((X & 0xF0) >> 4)
int gnrc_rpl_srh_process(ipv6_hdr_t *ipv6, gnrc_rpl_srh_t *rh)
/* checks if multiple addresses within the source routing header exist on my
* interfaces */
static bool _contains_multiple_of_my_addr(const ipv6_addr_t *dst,
const gnrc_rpl_srh_t *rh,
unsigned num_addr,
unsigned compri_addr_len)
{
if (rh->seg_left == 0) {
return GNRC_IPV6_EXT_RH_AT_DST;
}
uint8_t n = (((rh->len * 8) - GNRC_RPL_SRH_PADDING(rh->pad_resv) -
(16 - GNRC_RPL_SRH_COMPRE(rh->compr))) /
(16 - GNRC_RPL_SRH_COMPRI(rh->compr))) + 1;
ipv6_addr_t addr = ipv6->dst, tmp;
uint8_t i, pref_elided, tmp_pref_elided, addr_len, compri_addr_len, tmp_addr_len, found_pos = 0;
ipv6_addr_t addr;
uint8_t *addr_vec = (uint8_t *) (rh + 1);
bool found = false;
uint8_t pref_elided = GNRC_RPL_SRH_COMPRI(rh->compr);
uint8_t addr_len = compri_addr_len;
uint8_t found_pos = 0;
DEBUG("RPL SRH: %u addresses in the routing header\n", (unsigned) n);
memcpy(&addr, dst, pref_elided);
for (unsigned i = 0; i < num_addr; i++) {
if (i == num_addr - 1) {
pref_elided = GNRC_RPL_SRH_COMPRE(rh->compr);
addr_len = sizeof(ipv6_addr_t) - pref_elided;
}
memcpy(&addr.u8[pref_elided], &addr_vec[i * compri_addr_len], addr_len);
if (gnrc_netif_get_by_ipv6_addr(&addr) != NULL) {
if (found && ((i - found_pos) > 1)) {
DEBUG("RPL SRH: found multiple addresses that belong to me - "
"discard\n");
/* TODO send an ICMP Parameter Problem (Code 0) and
* discard the packet */
return true;
}
found_pos = i;
found = true;
}
}
return false;
}
if (rh->seg_left > n) {
DEBUG("RPL SRH: number of segments left > number of addresses - discard\n");
int gnrc_rpl_srh_process(ipv6_hdr_t *ipv6, gnrc_rpl_srh_t *rh)
{
ipv6_addr_t addr;
uint8_t *addr_vec = (uint8_t *) (rh + 1);
uint8_t num_addr;
uint8_t current_pos, pref_elided, addr_len, compri_addr_len;
const uint8_t new_seg_left = rh->seg_left - 1;
assert(rh->seg_left > 0);
num_addr = (((rh->len * 8) - GNRC_RPL_SRH_PADDING(rh->pad_resv) -
(16 - GNRC_RPL_SRH_COMPRE(rh->compr))) /
(16 - GNRC_RPL_SRH_COMPRI(rh->compr))) + 1;
DEBUG("RPL SRH: %u addresses in the routing header\n", (unsigned) num_addr);
if (rh->seg_left > num_addr) {
DEBUG("RPL SRH: number of segments left > number of addresses - "
"discard\n");
/* TODO ICMP Parameter Problem - Code 0 */
return GNRC_IPV6_EXT_RH_ERROR;
}
rh->seg_left--;
i = n - rh->seg_left;
pref_elided = rh->seg_left ? GNRC_RPL_SRH_COMPRI(rh->compr) : GNRC_RPL_SRH_COMPRE(rh->compr);
current_pos = num_addr - new_seg_left;
pref_elided = (new_seg_left)
? GNRC_RPL_SRH_COMPRI(rh->compr)
: GNRC_RPL_SRH_COMPRE(rh->compr);
compri_addr_len = sizeof(ipv6_addr_t) - GNRC_RPL_SRH_COMPRI(rh->compr);
addr_len = sizeof(ipv6_addr_t) - pref_elided;
memcpy(&addr.u8[pref_elided], &addr_vec[(i - 1) * compri_addr_len], addr_len);
memcpy(&addr, &ipv6->dst, pref_elided);
memcpy(&addr.u8[pref_elided],
&addr_vec[(current_pos - 1) * compri_addr_len],
addr_len);
if (ipv6_addr_is_multicast(&ipv6->dst) || ipv6_addr_is_multicast(&addr)) {
DEBUG("RPL SRH: found a multicast address - discard\n");
@ -62,32 +105,18 @@ int gnrc_rpl_srh_process(ipv6_hdr_t *ipv6, gnrc_rpl_srh_t *rh)
}
/* check if multiple addresses of my interface exist */
tmp_pref_elided = GNRC_RPL_SRH_COMPRI(rh->compr);
tmp_addr_len = sizeof(ipv6_addr_t) - tmp_pref_elided;
tmp = ipv6->dst;
for (uint8_t k = 0; k < n; k++) {
if (k == n - 1) {
tmp_pref_elided = GNRC_RPL_SRH_COMPRE(rh->compr);
tmp_addr_len = sizeof(ipv6_addr_t) - tmp_pref_elided;
}
memcpy(&tmp.u8[tmp_pref_elided], &addr_vec[k * compri_addr_len], tmp_addr_len);
if (gnrc_netif_get_by_ipv6_addr(&tmp) != NULL) {
if (found && ((k - found_pos) > 1)) {
DEBUG("RPL SRH: found multiple addresses that belong to me - discard\n");
/* TODO send an ICMP Parameter Problem (Code 0) and discard the packet */
return GNRC_IPV6_EXT_RH_ERROR;
}
found_pos = k;
found = true;
}
if (_contains_multiple_of_my_addr(&ipv6->dst, rh, num_addr,
compri_addr_len)) {
return GNRC_IPV6_EXT_RH_ERROR;
}
memcpy(&addr_vec[(i - 1) * compri_addr_len], &ipv6->dst.u8[pref_elided], addr_len);
rh->seg_left = new_seg_left;
memcpy(&addr_vec[(current_pos - 1) * compri_addr_len],
&ipv6->dst.u8[pref_elided], addr_len);
DEBUG("RPL SRH: Next hop: %s at position %d\n",
ipv6_addr_to_str(addr_str, &addr, sizeof(addr_str)), i);
ipv6_addr_to_str(addr_str, &addr, sizeof(addr_str)), current_pos);
ipv6->dst = addr;
memcpy(&ipv6->dst, &addr, sizeof(ipv6->dst));
return GNRC_IPV6_EXT_RH_FORWARDED;
}