RIOT-OS/RIOT
RIOT-OS/RIOT
1
0
Fork 0
mirror of https://github.com/RIOT-OS/RIOT.git synced 2025-01-17 05:12:57 +01:00
Code Releases Activity

Merge pull request #4772 from Yonezawa-T2/rbuf_overlap_improvement

Browse Source 
rbuf: drop overlapped fragment only if offset or size differs from previous one
This commit is contained in:
Oleg Hahm 2016-02-09 10:26:39 +01:00
commit bafda20664
1 changed files with 18 additions and 8 deletions
Show Stats Download Patch File Download Diff File Expand all files Collapse all files

26
sys/net/gnrc/network_layer/sixlowpan/frag/rbuf.c
View File

@ -44,8 +44,8 @@ static char l2addr_str[3 * RBUF_L2ADDR_MAX_LEN];
/* ------------------------------------
* internal function definitions
* ------------------------------------*/
/* checks whether start and end are in given interval i */
static inline bool _rbuf_int_in(rbuf_int_t *i, uint16_t start, uint16_t end);
/* checks whether start and end overlaps, but not identical to, given interval i */
static inline bool _rbuf_int_overlap_partially(rbuf_int_t *i, uint16_t start, uint16_t end);
/* gets a free entry from interval buffer */
static rbuf_int_t *_rbuf_int_get_free(void);
/* remove entry from reassembly buffer */
@ -66,6 +66,7 @@ void rbuf_add(gnrc_netif_hdr_t *netif_hdr, gnrc_pktsnip_t *pkt,
/* cppcheck is clearly wrong here */
/* cppcheck-suppress variableScope */
unsigned int data_offset = 0;
size_t original_size = frag_size;
sixlowpan_frag_t *frag = pkt->data;
rbuf_int_t *ptr;
uint8_t *data = ((uint8_t *)pkt->data) + sizeof(sixlowpan_frag_t);
@ -118,11 +119,20 @@ void rbuf_add(gnrc_netif_hdr_t *netif_hdr, gnrc_pktsnip_t *pkt,
return;
}
/* If the fragment overlaps another fragment and differs in either the size
* or the offset of the overlapped fragment, discards the datagram
* https://tools.ietf.org/html/rfc4944#section-5.3 */
while (ptr != NULL) {
if (_rbuf_int_in(ptr, offset, offset + frag_size - 1)) {
DEBUG("6lo rfrag: overlapping or same intervals, discarding datagram\n");
if (_rbuf_int_overlap_partially(ptr, offset, offset + frag_size - 1)) {
DEBUG("6lo rfrag: overlapping intervals, discarding datagram\n");
gnrc_pktbuf_release(entry->pkt);
_rbuf_rem(entry);
/* "A fresh reassembly may be commenced with the most recently
* received link fragment"
* https://tools.ietf.org/html/rfc4944#section-5.3 */
rbuf_add(netif_hdr, pkt, original_size, offset);
return;
}
@ -168,11 +178,11 @@ void rbuf_add(gnrc_netif_hdr_t *netif_hdr, gnrc_pktsnip_t *pkt,
}
}
static inline bool _rbuf_int_in(rbuf_int_t *i, uint16_t start, uint16_t end)
static inline bool _rbuf_int_overlap_partially(rbuf_int_t *i, uint16_t start, uint16_t end)
{
return (((i->start < start) && (start <= i->end)) ||
((start < i->start) && (i->start <= end)) ||
((i->start == start) && (i->end == end)));
/* start and ends are both inclusive, so using <= for both */
return ((i->start <= end) && (start <= i->end)) && /* overlaps */
((start != i->start) || (end != i->end)); /* not identical */
}
static rbuf_int_t *_rbuf_int_get_free(void)