Re: [Qemu-devel] [PATCH 24/26] libcacard: move atr setting from macro to function

[Marc-André Lureau]

Hi,

review below

On Mon, Mar 18, 2013 at 2:11 PM, Alon Levy <address@hidden> wrote:
> Only because qemu's checkpatch complains about it.
>
> Signed-off-by: Alon Levy <address@hidden>
> ---
>  Makefile.objs              |  1 +
>  libcacard/vcard_emul_nss.c | 11 ++++++++---
>  libcacard/vcardt.c         | 40 ++++++++++++++++++++++++++++++++++++++++
>  libcacard/vcardt.h         | 15 ++-------------
>  4 files changed, 51 insertions(+), 16 deletions(-)
>  create mode 100644 libcacard/vcardt.c
>
> diff --git a/Makefile.objs b/Makefile.objs
> index f99841c..6d47567 100644
> --- a/Makefile.objs
> +++ b/Makefile.objs
> @@ -41,6 +41,7 @@ libcacard-y += libcacard/vcard.o libcacard/vreader.o
>  libcacard-y += libcacard/vcard_emul_nss.o
>  libcacard-y += libcacard/vcard_emul_type.o
>  libcacard-y += libcacard/card_7816.o
> +libcacard-y += libcacard/vcardt.o
>
>  ######################################################################
>  # Target independent part of system emulation. The long term path is to
> diff --git a/libcacard/vcard_emul_nss.c b/libcacard/vcard_emul_nss.c
> index 21d4689..6bad0b9 100644
> --- a/libcacard/vcard_emul_nss.c
> +++ b/libcacard/vcard_emul_nss.c
> @@ -519,18 +519,23 @@ vcard_emul_reader_get_slot(VReader *vreader)
>  }
>
>  /*
> - *  Card ATR's map to physical cards. VCARD_ATR_PREFIX will set appropriate
> + *  Card ATR's map to physical cards. vcard_alloc_atr will set appropriate
>   *  historical bytes for any software emulated card. The remaining bytes can 
> be
>   *  used to indicate the actual emulator
>   */
> -static const unsigned char nss_atr[] = { VCARD_ATR_PREFIX(3), 'N', 'S', 'S' 
> };
> +static unsigned char *nss_atr;
> +static int nss_atr_len;
>
>  void
>  vcard_emul_get_atr(VCard *card, unsigned char *atr, int *atr_len)
>  {
> -    int len = MIN(sizeof(nss_atr), *atr_len);
> +    int len;
>      assert(atr != NULL);
>
> +    if (nss_atr == NULL) {
> +        nss_atr = vcard_alloc_atr("NSS", &nss_atr_len);
> +    }
> +    len = MIN(nss_atr_len, *atr_len);
>      memcpy(atr, nss_atr, len);
>      *atr_len = len;
>  }
> diff --git a/libcacard/vcardt.c b/libcacard/vcardt.c
> new file mode 100644
> index 0000000..f64c343
> --- /dev/null
> +++ b/libcacard/vcardt.c
> @@ -0,0 +1,40 @@
> +#include <stdlib.h>
> +#include <string.h>
> +#include <glib.h>
> +
> +#include "libcacard/vcardt.h"
> +
> +/* create an ATR with appropriate historical bytes */
> +#define ATR_TS_DIRECT_CONVENTION 0x3b
> +#define ATR_TA_PRESENT 0x10
> +#define ATR_TB_PRESENT 0x20
> +#define ATR_TC_PRESENT 0x40
> +#define ATR_TD_PRESENT 0x80
> +
> +unsigned char *vcard_alloc_atr(const char *postfix, int *atr_len)
> +{
> +    int postfix_len;
> +    const char prefix[] = "VCARD_";
> +    const int prefix_len = strlen(prefix);

or sizeof(prefix) -1

> +    int total_len;
> +    unsigned char *atr;
> +
> +    if (postfix == NULL) {

I would make postfix mandatory.

> +        postfix_len = 0;
> +    } else {
> +        postfix_len = strlen(postfix);
> +    }
> +    total_len = 3 + prefix_len + postfix_len;
> +    atr = g_malloc(total_len);
> +    atr[0] = ATR_TS_DIRECT_CONVENTION;
> +    atr[1] = ATR_TD_PRESENT + prefix_len + postfix_len;
> +    atr[2] = 0x00;
> +    memcpy(&atr[3], prefix, prefix_len);
> +    if (postfix) {
> +        memcpy(&atr[3 + prefix_len], postfix, postfix_len);
> +    }
> +    if (atr_len) {
> +        *atr_len = total_len;
> +    }
> +    return atr;
> +}
> diff --git a/libcacard/vcardt.h b/libcacard/vcardt.h
> index 3b9a619..e8e651f 100644
> --- a/libcacard/vcardt.h
> +++ b/libcacard/vcardt.h
> @@ -25,19 +25,6 @@ typedef struct VCardEmulStruct VCardEmul;
>
>  #define MAX_CHANNEL 4
>
> -/* create an ATR with appropriate historical bytes */
> -#define TS_DIRECT_CONVENTION 0x3b
> -#define TA_PRESENT 0x10
> -#define TB_PRESENT 0x20
> -#define TC_PRESENT 0x40
> -#define TD_PRESENT 0x80
> -
> -#define VCARD_ATR_PREFIX(size) \
> -    TS_DIRECT_CONVENTION, \
> -    TD_PRESENT + (6 + size), \
> -    0x00, \
> -    'V', 'C', 'A', 'R', 'D', '_'
> -
>  typedef enum {
>      VCARD_DONE,
>      VCARD_NEXT,
> @@ -69,4 +56,6 @@ struct VCardBufferResponseStruct {
>      int len;
>  };
>
> +unsigned char *vcard_alloc_atr(const char *postfix, int *atr_len);
> +

If the function is exposed in public header, it should also be
exported (in libcacard.syms), but I am not sure it's useful for
libcacard user.


-- 
Marc-André Lureau