GRE_HASH_SIZE
hash = malloc(sizeof(struct gre_list) * GRE_HASH_SIZE,
for (i = 0; i < GRE_HASH_SIZE; i++)
#ifndef GRE_HASH_SIZE
in_gre_hashval((src), (dst)) & (GRE_HASH_SIZE - 1)])
fnv_32_buf(&(src), sizeof(src), FNV1_32_INIT) & (GRE_HASH_SIZE - 1)])
fnv_32_buf(&(src), sizeof(src), FNV1_32_INIT) & (GRE_HASH_SIZE - 1)])
in6_gre_hashval((src), (dst)) & (GRE_HASH_SIZE - 1)])
fnv_32_buf((src), sizeof(*src), FNV1_32_INIT) & (GRE_HASH_SIZE - 1)])
fnv_32_buf((src), sizeof(*src), FNV1_32_INIT) & (GRE_HASH_SIZE - 1)])