From mboxrd@z Thu Jan 1 00:00:00 1970 Received: from eggs.gnu.org ([208.118.235.92]:39254) by lists.gnu.org with esmtp (Exim 4.71) (envelope-from ) id 1Tu3tX-0003iN-PA for qemu-devel@nongnu.org; Sat, 12 Jan 2013 11:25:24 -0500 Received: from Debian-exim by eggs.gnu.org with spam-scanned (Exim 4.71) (envelope-from ) id 1Tu3tR-0007UT-2p for qemu-devel@nongnu.org; Sat, 12 Jan 2013 11:25:19 -0500 Received: from mail-wg0-f51.google.com ([74.125.82.51]:46805) by eggs.gnu.org with esmtp (Exim 4.71) (envelope-from ) id 1Tu3tQ-0007UH-Sr for qemu-devel@nongnu.org; Sat, 12 Jan 2013 11:25:13 -0500 Received: by mail-wg0-f51.google.com with SMTP id gg4so1348961wgb.30 for ; Sat, 12 Jan 2013 08:25:12 -0800 (PST) From: Dmitry Fleytman Date: Sat, 12 Jan 2013 18:09:43 +0200 Message-Id: <1358006986-7248-3-git-send-email-dmitry@daynix.com> In-Reply-To: <1358006986-7248-1-git-send-email-dmitry@daynix.com> References: <1358006986-7248-1-git-send-email-dmitry@daynix.com> Subject: [Qemu-devel] [PATCH v9 2/5] Adding utility function net_checksum_add_iov() for iovec checksum calculation List-Id: List-Unsubscribe: , List-Archive: List-Post: List-Help: List-Subscribe: , To: qemu-devel@nongnu.org Cc: Dmitry Fleytman , Yan Vugenfirer , Anthony Liguori , Gerhard Wiesinger , Paolo Bonzini Signed-off-by: Dmitry Fleytman Signed-off-by: Yan Vugenfirer --- include/net/checksum.h | 8 ++++++++ net/checksum.c | 28 ++++++++++++++++++++++++++++ 2 files changed, 36 insertions(+) diff --git a/include/net/checksum.h b/include/net/checksum.h index 171924c..289c16c 100644 --- a/include/net/checksum.h +++ b/include/net/checksum.h @@ -19,6 +19,7 @@ #define QEMU_NET_CHECKSUM_H #include +#include "qemu-common.h" uint32_t net_checksum_add_cont(int len, uint8_t *buf, int seq); uint16_t net_checksum_finish(uint32_t sum); @@ -38,4 +39,11 @@ net_raw_checksum(uint8_t *data, int length) return net_checksum_finish(net_checksum_add(length, data)); } +/** + * Checksum calculation for scatter-gather vector + */ +uint32_t net_checksum_add_iov(const struct iovec *iov, + const unsigned int iov_cnt, + uint32_t iov_off, uint32_t size); + #endif /* QEMU_NET_CHECKSUM_H */ diff --git a/net/checksum.c b/net/checksum.c index 4fa5563..9c813ff 100644 --- a/net/checksum.c +++ b/net/checksum.c @@ -84,3 +84,31 @@ void net_checksum_calculate(uint8_t *data, int length) 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; +} -- 1.7.11.7