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

[Alon Levy <alevy@redhat.com>]

> Hi,
> 
> review below
> 
> On Mon, Mar 18, 2013 at 2:11 PM, Alon Levy <alevy@redhat.com> wrote:
> > Only because qemu's checkpatch complains about it.
> >
> > Signed-off-by: Alon Levy <alevy@redhat.com>
> > ---
> >  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.

It is purely internal, I could add a private header for this.

> 
> 
> --
> Marc-André Lureau
> 
>