diff options
Diffstat (limited to 'accel-pppd')
| -rw-r--r-- | accel-pppd/ipdb.c | 5 |
1 files changed, 4 insertions, 1 deletions
diff --git a/accel-pppd/ipdb.c b/accel-pppd/ipdb.c index dd8c61c9..8fc08063 100644 --- a/accel-pppd/ipdb.c +++ b/accel-pppd/ipdb.c @@ -83,7 +83,10 @@ void __export build_ip6_addr(struct ipv6db_addr_t *a, uint64_t intf_id, struct i if (a->prefix_len <= 64) *(uint64_t *)(addr->s6_addr + 8) = intf_id; else - *(uint64_t *)(addr->s6_addr + 8) |= intf_id & htobe64((1 << (128 - a->prefix_len)) - 1); + /* prefix_len 65..127 means a shift of up to 63 bits: a plain + * int literal 1 is undefined behavior for shifts >= 31, so the + * host bits mask must be built from a 64-bit constant */ + *(uint64_t *)(addr->s6_addr + 8) |= intf_id & htobe64((UINT64_C(1) << (128 - a->prefix_len)) - 1); } |