On Mon, Feb 27, 2023 at 11:00:03AM +0100, Stefano Brivio wrote:...and, given that I keep getting this wrong, add a convenience macro, MAX_FROM_BITS(). Signed-off-by: Stefano Brivio <sbrivio(a)redhat.com>Reviewed-by: David Gibson <david(a)gibson.dropbear.id.au>--- passt.h | 4 ++-- tcp.h | 4 ++-- tcp_conn.h | 2 +- util.h | 2 ++ 4 files changed, 7 insertions(+), 5 deletions(-) diff --git a/passt.h b/passt.h index 3d7e567..e0383eb 100644 --- a/passt.h +++ b/passt.h @@ -42,7 +42,7 @@ union epoll_ref; /** * union epoll_ref - Breakdown of reference for epoll socket bookkeeping * @proto: IP protocol number - * @s: Socket number (implies 2^24 limit on number of descriptors) + * @s: Socket number (implies 2^24-1 limit on number of descriptors) * @tcp: TCP-specific reference part * @udp: UDP-specific reference part * @icmp: ICMP-specific reference part @@ -53,7 +53,7 @@ union epoll_ref { struct { int32_t proto:8, #define SOCKET_REF_BITS 24 -#define SOCKET_MAX (1 << SOCKET_REF_BITS) +#define SOCKET_MAX MAX_FROM_BITS(SOCKET_REF_BITS) s:SOCKET_REF_BITS; union { union tcp_epoll_ref tcp; diff --git a/tcp.h b/tcp.h index 5527c5b..36e5391 100644 --- a/tcp.h +++ b/tcp.h @@ -8,8 +8,8 @@ #define TCP_TIMER_INTERVAL 1000 /* ms */ -#define TCP_CONN_INDEX_BITS 17 /* 128k */ -#define TCP_MAX_CONNS (1 << TCP_CONN_INDEX_BITS) +#define TCP_CONN_INDEX_BITS 17 /* 128k - 1 */ +#define TCP_MAX_CONNS MAX_FROM_BITS(TCP_CONN_INDEX_BITS) struct ctx; diff --git a/tcp_conn.h b/tcp_conn.h index a499f34..c22632b 100644 --- a/tcp_conn.h +++ b/tcp_conn.h @@ -54,7 +54,7 @@ struct tcp_tap_conn { #define TCP_RETRANS_BITS 3 unsigned int retrans :TCP_RETRANS_BITS; -#define TCP_MAX_RETRANS ((1U << TCP_RETRANS_BITS) - 1) +#define TCP_MAX_RETRANS MAX_FROM_BITS(TCP_RETRANS_BITS) #define TCP_WS_BITS 4 /* RFC 7323 */ #define TCP_WS_MAX 14 diff --git a/util.h b/util.h index 6303c17..570094c 100644 --- a/util.h +++ b/util.h @@ -40,6 +40,8 @@ #define ROUND_DOWN(x, y) ((x) & ~((y) - 1)) #define ROUND_UP(x, y) (((x) + (y) - 1) & ~((y) - 1)) +#define MAX_FROM_BITS(n) ((int)((1U << (n)) - 1)) + #define BIT(n) (1UL << (n)) #define BITMAP_BIT(n) (BIT((n) % (sizeof(long) * 8))) #define BITMAP_WORD(n) (n / (sizeof(long) * 8))-- David Gibson | I'll have my music baroque, and my code david AT gibson.dropbear.id.au | minimalist, thank you. NOT _the_ _other_ | _way_ _around_! http://www.ozlabs.org/~dgibson