diff options
author | Yang Zhang <yang.z.zhang@intel.com> | 2015-08-28 09:58:54 +0800 |
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committer | Yang Zhang <yang.z.zhang@intel.com> | 2015-09-01 12:44:00 +0800 |
commit | e44e3482bdb4d0ebde2d8b41830ac2cdb07948fb (patch) | |
tree | 66b09f592c55df2878107a468a91d21506104d3f /qemu/net/checksum.c | |
parent | 9ca8dbcc65cfc63d6f5ef3312a33184e1d726e00 (diff) |
Add qemu 2.4.0
Change-Id: Ic99cbad4b61f8b127b7dc74d04576c0bcbaaf4f5
Signed-off-by: Yang Zhang <yang.z.zhang@intel.com>
Diffstat (limited to 'qemu/net/checksum.c')
-rw-r--r-- | qemu/net/checksum.c | 115 |
1 files changed, 115 insertions, 0 deletions
diff --git a/qemu/net/checksum.c b/qemu/net/checksum.c new file mode 100644 index 000000000..14c08550e --- /dev/null +++ b/qemu/net/checksum.c @@ -0,0 +1,115 @@ +/* + * IP checksumming functions. + * (c) 2008 Gerd Hoffmann <kraxel@redhat.com> + * + * This program is free software; you can redistribute it and/or modify + * it under the terms of the GNU General Public License as published by + * the Free Software Foundation; under version 2 or later of the License. + * + * This program is distributed in the hope that it will be useful, + * but WITHOUT ANY WARRANTY; without even the implied warranty of + * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the + * GNU General Public License for more details. + * + * You should have received a copy of the GNU General Public License + * along with this program; if not, see <http://www.gnu.org/licenses/>. + */ + +#include "qemu-common.h" +#include "net/checksum.h" + +#define PROTO_TCP 6 +#define PROTO_UDP 17 + +uint32_t net_checksum_add_cont(int len, uint8_t *buf, int seq) +{ + uint32_t sum = 0; + int i; + + for (i = seq; i < seq + len; i++) { + if (i & 1) { + sum += (uint32_t)buf[i - seq]; + } else { + sum += (uint32_t)buf[i - seq] << 8; + } + } + return sum; +} + +uint16_t net_checksum_finish(uint32_t sum) +{ + while (sum>>16) + sum = (sum & 0xFFFF)+(sum >> 16); + return ~sum; +} + +uint16_t net_checksum_tcpudp(uint16_t length, uint16_t proto, + uint8_t *addrs, uint8_t *buf) +{ + uint32_t sum = 0; + + sum += net_checksum_add(length, buf); // payload + sum += net_checksum_add(8, addrs); // src + dst address + sum += proto + length; // protocol & length + return net_checksum_finish(sum); +} + +void net_checksum_calculate(uint8_t *data, int length) +{ + int hlen, plen, proto, csum_offset; + uint16_t csum; + + if ((data[14] & 0xf0) != 0x40) + return; /* not IPv4 */ + hlen = (data[14] & 0x0f) * 4; + plen = (data[16] << 8 | data[17]) - hlen; + proto = data[23]; + + switch (proto) { + case PROTO_TCP: + csum_offset = 16; + break; + case PROTO_UDP: + csum_offset = 6; + break; + default: + return; + } + + if (plen < csum_offset+2) + return; + + data[14+hlen+csum_offset] = 0; + data[14+hlen+csum_offset+1] = 0; + csum = net_checksum_tcpudp(plen, proto, data+14+12, data+14+hlen); + data[14+hlen+csum_offset] = csum >> 8; + data[14+hlen+csum_offset+1] = csum & 0xff; +} + +uint32_t +net_checksum_add_iov(const struct iovec *iov, const unsigned int iov_cnt, + uint32_t iov_off, uint32_t size) +{ + size_t iovec_off, buf_off; + unsigned int i; + uint32_t res = 0; + uint32_t seq = 0; + + iovec_off = 0; + buf_off = 0; + for (i = 0; i < iov_cnt && size; i++) { + if (iov_off < (iovec_off + iov[i].iov_len)) { + size_t len = MIN((iovec_off + iov[i].iov_len) - iov_off , size); + void *chunk_buf = iov[i].iov_base + (iov_off - iovec_off); + + res += net_checksum_add_cont(len, chunk_buf, seq); + seq += len; + + buf_off += len; + iov_off += len; + size -= len; + } + iovec_off += iov[i].iov_len; + } + return res; +} |