Patchwork [V8,2/5] Adding utility function net_checksum_add_iov() for iovec checksum calculation

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Submitter Dmitry Fleytman
Date Dec. 7, 2012, 11:15 a.m.
Message ID <1354878909-21369-3-git-send-email-dmitry@daynix.com>
Download mbox | patch
Permalink /patch/204454/
State New
Headers show

Comments

Dmitry Fleytman - Dec. 7, 2012, 11:15 a.m.
Signed-off-by: Dmitry Fleytman <dmitry@daynix.com>
Signed-off-by: Yan Vugenfirer <yan@daynix.com>
---
 iov.h          |  5 +++++
 net/checksum.c | 28 ++++++++++++++++++++++++++++
 net/checksum.h |  8 ++++++++
 3 files changed, 41 insertions(+)
Stefan Hajnoczi - Jan. 7, 2013, 2:04 p.m.
On Fri, Dec 07, 2012 at 01:15:06PM +0200, Dmitry Fleytman wrote:
> Signed-off-by: Dmitry Fleytman <dmitry@daynix.com>
> Signed-off-by: Yan Vugenfirer <yan@daynix.com>
> ---
>  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 @@

This file has been moved in qemu.git/master.  It is now
include/qemu/iov.h.

>   * the COPYING file in the top-level directory.
>   */
>  
> +#ifndef QEMU_IOV_H
> +#define QEMU_IOV_H
> +

This is already present in qemu.git/master.

>  #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 */

Same here.  Just pointing out expected rebase conflicts you'll see for
the next revision of this series.

> 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 <stdint.h>
> +#include "iov.h"

iov.h is the wrong header file, you need struct iovec from
qemu-common.h.
Dmitry Fleytman - Jan. 11, 2013, 1:33 p.m.
Thanks for pointing out, Stefan.
I've rebased the code and fixed these issues.


On Mon, Jan 7, 2013 at 4:04 PM, Stefan Hajnoczi <stefanha@gmail.com> wrote:

> On Fri, Dec 07, 2012 at 01:15:06PM +0200, Dmitry Fleytman wrote:
> > Signed-off-by: Dmitry Fleytman <dmitry@daynix.com>
> > Signed-off-by: Yan Vugenfirer <yan@daynix.com>
> > ---
> >  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 @@
>
> This file has been moved in qemu.git/master.  It is now
> include/qemu/iov.h.
>
> >   * the COPYING file in the top-level directory.
> >   */
> >
> > +#ifndef QEMU_IOV_H
> > +#define QEMU_IOV_H
> > +
>
> This is already present in qemu.git/master.
>
> >  #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 */
>
> Same here.  Just pointing out expected rebase conflicts you'll see for
> the next revision of this series.
>
> > 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 <stdint.h>
> > +#include "iov.h"
>
> iov.h is the wrong header file, you need struct iovec from
> qemu-common.h.
>

Patch

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 <stdint.h>
+#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 */