From patchwork Fri Dec 7 11:15:06 2012 Content-Type: text/plain; charset="utf-8" MIME-Version: 1.0 Content-Transfer-Encoding: 7bit Subject: [V8, 2/5] Adding utility function net_checksum_add_iov() for iovec checksum calculation Date: Fri, 07 Dec 2012 01:15:06 -0000 From: Dmitry Fleytman X-Patchwork-Id: 204454 Message-Id: <1354878909-21369-3-git-send-email-dmitry@daynix.com> 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 --- iov.h | 5 +++++ net/checksum.c | 28 ++++++++++++++++++++++++++++ net/checksum.h | 8 ++++++++ 3 files changed, 41 insertions(+) diff --git a/iov.h b/iov.h index 34c8ec9..c184a80 100644 --- a/iov.h +++ b/iov.h @@ -11,6 +11,9 @@ * the COPYING file in the top-level directory. */ +#ifndef QEMU_IOV_H +#define QEMU_IOV_H + #include "qemu-common.h" /** @@ -95,3 +98,5 @@ void iov_hexdump(const struct iovec *iov, const unsigned int iov_cnt, unsigned iov_copy(struct iovec *dst_iov, unsigned int dst_iov_cnt, const struct iovec *iov, unsigned int iov_cnt, size_t offset, size_t bytes); + +#endif /* QEMU_IOV_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; +} diff --git a/net/checksum.h b/net/checksum.h index 171924c..e63c482 100644 --- a/net/checksum.h +++ b/net/checksum.h @@ -19,6 +19,7 @@ #define QEMU_NET_CHECKSUM_H #include +#include "iov.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 */