From: Theo Buehler <tb@theobuehler.org>
Subject: Re: bgpd: Use 1ULL in shift operations on uint64_t values
To: tech@openbsd.org
Date: Tue, 4 Nov 2025 14:03:44 +0100

On Tue, Nov 04, 2025 at 01:59:03PM +0100, Claudio Jeker wrote:
> When shifting 1 << level into a 64bit value use 1ULL so the shift happens
> on a 64bit value. I doubt we'll see tables with more than 31 levels but
> lets be correct.
> 
> Fix for CID 492339, CID 492340, CID 492357, CID 492363

sigh.

ok tb

> -- 
> :wq Claudio
> 
> Index: chash.c
> ===================================================================
> RCS file: /cvs/src/usr.sbin/bgpd/chash.c,v
> diff -u -p -r1.3 chash.c
> --- chash.c	3 Nov 2025 13:48:19 -0000	1.3
> +++ chash.c	4 Nov 2025 12:48:14 -0000
> @@ -517,8 +517,8 @@ ch_table_resize(struct ch_table *t)
>  {
>  	struct ch_group **tables;
>  	struct ch_meta **metas;
> -	uint64_t oldsize = 1 << t->ch_level;
> -	uint64_t newsize = 1 << (t->ch_level + 1);
> +	uint64_t oldsize = 1ULL << t->ch_level;
> +	uint64_t newsize = 1ULL << (t->ch_level + 1);
>  	int64_t idx;
>  
>  	if (t->ch_level + 1 >= CH_H1_BITS) {
> @@ -566,7 +566,7 @@ ch_table_fill(struct ch_table *t, uint64
>  	uint64_t cnt, i;
>  
>  	idx <<= (t->ch_level - meta->cs_local_level);
> -	cnt = 1 << (t->ch_level - meta->cs_local_level);
> +	cnt = 1ULL << (t->ch_level - meta->cs_local_level);
>  
>  	for (i = 0; i < cnt; i++) {
>  		t->ch_tables[idx + i] = table;
> @@ -722,7 +722,7 @@ _ch_init(const struct ch_type *type, str
>  void
>  _ch_destroy(const struct ch_type *type, struct ch_table *t)
>  {
> -	uint64_t idx, max = 1 << t->ch_level;
> +	uint64_t idx, max = 1ULL << t->ch_level;
>  	struct ch_group *table = NULL;
>  
>  	for (idx = 0; idx < max; idx++) {
> @@ -859,7 +859,7 @@ _ch_next(const struct ch_type *type, str
>  	if (t->ch_tables == NULL)
>  		return NULL;
>  
> -	max = 1 << t->ch_level;
> +	max = 1ULL << t->ch_level;
>  	idx = it->ci_ext_idx;
>  	if (idx >= max)
>  		return NULL;
>