diff options
| -rw-r--r-- | bgpd/bgp_mplsvpn.c | 24 |
1 files changed, 21 insertions, 3 deletions
diff --git a/bgpd/bgp_mplsvpn.c b/bgpd/bgp_mplsvpn.c index b3d8d1b82d..4d8c4ac2ac 100644 --- a/bgpd/bgp_mplsvpn.c +++ b/bgpd/bgp_mplsvpn.c @@ -532,6 +532,7 @@ static uint32_t alloc_new_sid(struct bgp *bgp, uint32_t index, bool alloced = false; int label = 0; uint8_t offset = 0; + uint8_t len = 0; if (!bgp || !sid_locator || !sid) return false; @@ -540,10 +541,11 @@ static uint32_t alloc_new_sid(struct bgp *bgp, uint32_t index, *sid_locator = chunk->prefix.prefix; *sid = chunk->prefix.prefix; offset = chunk->block_bits_length + chunk->node_bits_length; + len = chunk->function_bits_length ?: 16; if (index != 0) { label = index << 12; - transpose_sid(sid, label, offset, 16); + transpose_sid(sid, label, offset, len); if (sid_exist(bgp, sid)) return false; alloced = true; @@ -552,7 +554,7 @@ static uint32_t alloc_new_sid(struct bgp *bgp, uint32_t index, for (size_t i = 1; i < 255; i++) { label = i << 12; - transpose_sid(sid, label, offset, 16); + transpose_sid(sid, label, offset, len); if (sid_exist(bgp, sid)) continue; alloced = true; @@ -633,13 +635,29 @@ void ensure_vrf_tovpn_sid(struct bgp *bgp_vpn, struct bgp *bgp_vrf, afi_t afi) tovpn_sid_transpose_label; } +/* + * This function shifts "label" 4 bits to the right and + * embeds it by length "len", starting at offset "offset" + * as seen from the MSB (Most Significant Bit) of "sid". + * + * e.g. if "label" is 0x1000 and "len" is 16, "label" is + * embedded in "sid" as follows: + * + * <---- len -----> + * label: 0000 0001 0000 0000 0000 + * sid: .... 0000 0001 0000 0000 + * <---- len -----> + * ^ + * | + * offset from MSB + */ void transpose_sid(struct in6_addr *sid, uint32_t label, uint8_t offset, uint8_t len) { for (uint8_t idx = 0; idx < len; idx++) { uint8_t tidx = offset + idx; sid->s6_addr[tidx / 8] &= ~(0x1 << (7 - tidx % 8)); - if (label >> (19 - idx) & 0x1) + if (label >> (len + 3 - idx) & 0x1) sid->s6_addr[tidx / 8] |= 0x1 << (7 - tidx % 8); } } |