diff --git a/sys/include/net/gnrc/rpl/srh.h b/sys/include/net/gnrc/rpl/srh.h
index ab7248d2308f78690d77e27763c303e725d9993b..21fce7fe123e4af8b9d0a94c4d4370f067fb2f8d 100644
--- a/sys/include/net/gnrc/rpl/srh.h
+++ b/sys/include/net/gnrc/rpl/srh.h
@@ -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.
*
diff --git a/sys/net/gnrc/routing/rpl/srh/gnrc_rpl_srh.c b/sys/net/gnrc/routing/rpl/srh/gnrc_rpl_srh.c
index 753d5bf65e0b9255e0808e7a433c1f119d3b5d92..618d749a1a3ae106f863cbc869e76ace9db9c191 100644
--- a/sys/net/gnrc/routing/rpl/srh/gnrc_rpl_srh.c
+++ b/sys/net/gnrc/routing/rpl/srh/gnrc_rpl_srh.c
@@ -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;
+ 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;
+
+ 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;
+}
- 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;
+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);
- bool found = false;
+ 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;
- DEBUG("RPL SRH: %u addresses in the routing header\n", (unsigned) n);
+ 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;
- if (rh->seg_left > n) {
- DEBUG("RPL SRH: number of segments left > number of addresses - discard\n");
+ 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;
}