Re: [Qemu-devel] [PATCH] util: Improved qemu_hexmap() to include an ascii dump of the buffer

[Thomas Huth <thuth@redhat.com>]

 Hi Isaac,

thanks for taking care of this!
Comments below...

On 22.03.2016 08:41, Isaac Lozano wrote:
> qemu_hexdump() in util/hexdump.c has been changed to give also include a
> ascii dump of the buffer. Also, calls to hex_dump() in net/net.c have
> been replaced with calls to qemu_hexdump(). This takes care of two misc
> BiteSized Tasks.
> 
> Signed-off-by: Isaac Lozano <109lozanoi@gmail.com>
> ---
>  net/net.c      | 31 +------------------------------
>  util/hexdump.c | 35 ++++++++++++++++++++++++-----------
>  2 files changed, 25 insertions(+), 41 deletions(-)
> 
> diff --git a/net/net.c b/net/net.c
> index 1a78edf..8d51ffb 100644
> --- a/net/net.c
> +++ b/net/net.c
> @@ -79,34 +79,6 @@ int default_net = 1;
>  /***********************************************************/
>  /* network device redirectors */
>  
> -#if defined(DEBUG_NET)
> -static void hex_dump(FILE *f, const uint8_t *buf, int size)
> -{
> -    int len, i, j, c;
> -
> -    for(i=0;i<size;i+=16) {
> -        len = size - i;
> -        if (len > 16)
> -            len = 16;
> -        fprintf(f, "%08x ", i);
> -        for(j=0;j<16;j++) {
> -            if (j < len)
> -                fprintf(f, " %02x", buf[i+j]);
> -            else
> -                fprintf(f, "   ");
> -        }
> -        fprintf(f, " ");
> -        for(j=0;j<len;j++) {
> -            c = buf[i+j];
> -            if (c < ' ' || c > '~')
> -                c = '.';
> -            fprintf(f, "%c", c);
> -        }
> -        fprintf(f, "\n");
> -    }
> -}
> -#endif
> -
>  static int get_str_sep(char *buf, int buf_size, const char **pp, int sep)
>  {
>      const char *p, *p1;
> @@ -661,8 +633,7 @@ static ssize_t qemu_send_packet_async_with_flags(NetClientState *sender,
>      int ret;
>  
>  #ifdef DEBUG_NET
> -    printf("qemu_send_packet_async:\n");
> -    hex_dump(stdout, buf, size);
> +    qemu_hexdump((const char*)buf, stdout, "qemu_send_packet_async", size);

Since the third parameter of qemu_hexdump() is used as a prefix for
each line, I'd maybe use a shorter string here instead, like "net",
and keep the printf("qemu_send_packet_async:\n") in front of it.

>  #endif
>  
>      if (sender->link_down || !sender->peer) {
> diff --git a/util/hexdump.c b/util/hexdump.c
> index 1d9c129..886e53c 100644
> --- a/util/hexdump.c
> +++ b/util/hexdump.c
> @@ -18,21 +18,34 @@
>  
>  void qemu_hexdump(const char *buf, FILE *fp, const char *prefix, size_t size)
>  {
> -    unsigned int b;
> +    unsigned int b, len, i, c;
>  
> -    for (b = 0; b < size; b++) {
> -        if ((b % 16) == 0) {
> -            fprintf(fp, "%s: %04x:", prefix, b);
> +    for (b = 0; b < size; b += 16) {
> +        len = size - b;
> +        if (len > 16) {
> +            len = 16;
>          }
> -        if ((b % 4) == 0) {
> -            fprintf(fp, " ");
> +        fprintf(fp, "%s: %04x:", prefix, b);
> +        for (i = 0; i < 16; i++) {
> +            if ((i % 4) == 0) {
> +                fprintf(fp, " ");
> +            }
> +            if (i < len) {
> +                fprintf(fp, " %02x", (unsigned char)buf[b + i]);
> +            }
> +            else
> +            {
> +                fprintf(fp, "   ");
> +            }
>          }
> -        fprintf(fp, " %02x", (unsigned char)buf[b]);
> -        if ((b % 16) == 15) {
> -            fprintf(fp, "\n");
> +        fprintf(fp, " ");
> +        for (i = 0; i < len; i++) {
> +            c = buf[b+i];
> +            if (c < ' ' || c > '~') {
> +                c = '.';
> +            }
> +            fprintf(fp, "%c", c);
>          }
> -    }
> -    if ((b % 16) != 0) {
>          fprintf(fp, "\n");
>      }
>  }
> 

The code looks basically fine to me, but scripts/checkpatch.pl
complains about some style issues:

ERROR: "(foo*)" should be "(foo *)"
#59: FILE: net/net.c:636:
+    qemu_hexdump((const char*)buf, stdout, "qemu_send_packet_async", size);

ERROR: that open brace { should be on the previous line
#92: FILE: util/hexdump.c:36:
+            else
+            {

ERROR: else should follow close brace '}'
#92: FILE: util/hexdump.c:36:
+            }
+            else

ERROR: spaces required around that '+' (ctx:VxV)
#102: FILE: util/hexdump.c:43:
+            c = buf[b+i];
                      ^

 Thomas