From eaba8f34f0dac5e9296df9c2046d9601264c46a4 Mon Sep 17 00:00:00 2001 From: Mark Cave-Ayland Date: Fri, 15 Dec 2017 18:41:43 +0000 Subject: [PATCH] net: move CRC32 calculation from compute_mcast_idx() into its own net_crc32() function MIME-Version: 1.0 Content-Type: text/plain; charset=UTF-8 Content-Transfer-Encoding: 8bit Separate out the standard ethernet CRC32 calculation into a new net_crc32() function, renaming the constant POLYNOMIAL to POLYNOMIAL_BE to make it clear that this is a big-endian CRC32 calculation. As part of the constant rename, remove the duplicate definition of POLYNOMIAL from eepro100.c and use the new POLYNOMIAL_BE constant instead. Once this is complete remove the existing CRC32 implementation from compute_mcast_idx() and call the new net_crc32() function in its place. Signed-off-by: Mark Cave-Ayland Reviewed-by: Philippe Mathieu-Daudé Signed-off-by: Jason Wang --- hw/net/eepro100.c | 4 +--- include/net/net.h | 3 ++- net/net.c | 16 +++++++++++----- 3 files changed, 14 insertions(+), 9 deletions(-) diff --git a/hw/net/eepro100.c b/hw/net/eepro100.c index 1c0def555b..71cddfece4 100644 --- a/hw/net/eepro100.c +++ b/hw/net/eepro100.c @@ -323,8 +323,6 @@ static const uint16_t eepro100_mdi_mask[] = { 0xffff, 0xffff, 0x0000, 0x0000, 0x0000, 0x0000, 0x0000, 0x0000, }; -#define POLYNOMIAL 0x04c11db6 - static E100PCIDeviceInfo *eepro100_get_class(EEPRO100State *s); /* From FreeBSD (locally modified). */ @@ -342,7 +340,7 @@ static unsigned e100_compute_mcast_idx(const uint8_t *ep) crc <<= 1; b >>= 1; if (carry) { - crc = ((crc ^ POLYNOMIAL) | carry); + crc = ((crc ^ POLYNOMIAL_BE) | carry); } } } diff --git a/include/net/net.h b/include/net/net.h index 1c55a93588..586098cb94 100644 --- a/include/net/net.h +++ b/include/net/net.h @@ -227,7 +227,8 @@ NetClientState *net_hub_port_find(int hub_id); void qdev_set_nic_properties(DeviceState *dev, NICInfo *nd); -#define POLYNOMIAL 0x04c11db6 +#define POLYNOMIAL_BE 0x04c11db6 +uint32_t net_crc32(const uint8_t *p, int len); unsigned compute_mcast_idx(const uint8_t *ep); #define vmstate_offset_macaddr(_state, _field) \ diff --git a/net/net.c b/net/net.c index 39ef546708..a14dc9910c 100644 --- a/net/net.c +++ b/net/net.c @@ -1581,25 +1581,31 @@ int net_client_parse(QemuOptsList *opts_list, const char *optarg) /* From FreeBSD */ /* XXX: optimize */ -unsigned compute_mcast_idx(const uint8_t *ep) +uint32_t net_crc32(const uint8_t *p, int len) { uint32_t crc; int carry, i, j; uint8_t b; crc = 0xffffffff; - for (i = 0; i < 6; i++) { - b = *ep++; + for (i = 0; i < len; i++) { + b = *p++; for (j = 0; j < 8; j++) { carry = ((crc & 0x80000000L) ? 1 : 0) ^ (b & 0x01); crc <<= 1; b >>= 1; if (carry) { - crc = ((crc ^ POLYNOMIAL) | carry); + crc = ((crc ^ POLYNOMIAL_BE) | carry); } } } - return crc >> 26; + + return crc; +} + +unsigned compute_mcast_idx(const uint8_t *ep) +{ + return net_crc32(ep, ETH_ALEN) >> 26; } QemuOptsList qemu_netdev_opts = {