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Code Activity

scd: Remove context reference counting from pc/sc

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* scd/apdu.c (pcsc): Add flag context_valid, remove count.
(close_pcsc_reader): Use new flag instead of looking at magic context
value.
(pcsc_init): Set new flag.
(open_pcsc_reader): Use new flag.
(apdu_init): Clear new flag.

* scd/apdu.c: Remove assert.h.  Replace all assert by log_assert.
--

The previous fix 192113552faa98f40cc91fe014ec55861474626c did not
help, thus the new hypothesis is that PC/SC might return a valid
context with the value -1.  We now use a dedicated flag to track the
validity of the context.

The reference counting seems to be superfluous and is a relict due to
backporting from 2.3.  Removed.
This commit is contained in:
Werner Koch 2021-09-14 13:04:59 +02:00
parent 117afec018
commit 67e1834ad4
No known key found for this signature in database
GPG Key ID: E3FDFF218E45B72B
1 changed files with 16 additions and 22 deletions
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38
scd/apdu.c
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@ -27,7 +27,6 @@
#include <stdio.h>
#include <stdlib.h>
#include <string.h>
#include <assert.h>
#include <signal.h>
#ifdef USE_NPTH
# include <unistd.h>
@ -91,7 +90,7 @@ typedef unsigned long pcsc_dword_t;
/* PC/SC context to access readers. Shared among all readers. */
static struct pcsc {
int count; /* Reference count - valid if .context != -1 */
unsigned int context_valid:1;
long context;
char *reader_list; /* List of detected readers. */
} pcsc;
@ -817,16 +816,10 @@ close_pcsc_reader (int slot)
{
(void)slot;
/* Note that we might be called via apdu_close_reader and we can't
* guarantee that we have not yet been called. */
if (pcsc.context != -1)
if (pcsc.context_valid)
{
log_assert (pcsc.count > 0);
if (--pcsc.count == 0)
{
pcsc_release_context (pcsc.context);
pcsc.context = -1;
}
pcsc_release_context (pcsc.context);
pcsc.context_valid = 0;
}
return 0;
}
@ -838,7 +831,7 @@ connect_pcsc_card (int slot)
{
long err;
assert (slot >= 0 && slot < MAX_READER);
log_assert (slot >= 0 && slot < MAX_READER);
if (reader_table[slot].pcsc.card)
return SW_HOST_ALREADY_CONNECTED;
@ -905,7 +898,7 @@ disconnect_pcsc_card (int slot)
{
long err;
assert (slot >= 0 && slot < MAX_READER);
log_assert (slot >= 0 && slot < MAX_READER);
if (!reader_table[slot].pcsc.card)
return 0;
@ -1182,6 +1175,7 @@ pcsc_init (void)
pcsc_api_loaded = 1;
}
pcsc.context_valid = 0;
err = pcsc_establish_context (PCSC_SCOPE_SYSTEM, NULL, NULL, &pcsc.context);
if (err)
{
@ -1189,7 +1183,7 @@ pcsc_init (void)
pcsc_error_string (err), err);
return -1;
}
pcsc.count++;
pcsc.context_valid = 1;
return 0;
}
@ -1211,7 +1205,7 @@ open_pcsc_reader (const char *portstr)
xfree (pcsc.reader_list);
pcsc.reader_list = NULL;
if (pcsc.context == -1)
if (!pcsc.context_valid)
if (pcsc_init () < 0)
return -1;
@ -1553,7 +1547,7 @@ reset_ccid_reader (int slot)
if (err)
return err;
/* If the reset was successful, update the ATR. */
assert (sizeof slotp->atr >= sizeof atr);
log_assert (sizeof slotp->atr >= sizeof atr);
slotp->atrlen = atrlen;
memcpy (slotp->atr, atr, atrlen);
dump_reader_status (slot);
@ -2875,7 +2869,7 @@ send_le (int slot, int class, int ins, int p0, int p1,
if (use_chaining && lc > 255)
{
apdu[apdulen] |= 0x10;
assert (use_chaining < 256);
log_assert (use_chaining < 256);
lc_chunk = use_chaining;
lc -= use_chaining;
}
@ -2905,7 +2899,7 @@ send_le (int slot, int class, int ins, int p0, int p1,
exact_length_hack:
/* As a safeguard don't pass any garbage to the driver. */
assert (apdulen <= apdu_buffer_size);
log_assert (apdulen <= apdu_buffer_size);
memset (apdu+apdulen, 0, apdu_buffer_size - apdulen);
resultlen = result_buffer_size;
rc = send_apdu (slot, apdu, apdulen, result, &resultlen, pininfo);
@ -2976,7 +2970,7 @@ send_le (int slot, int class, int ins, int p0, int p1,
xfree (result_buffer);
return SW_HOST_OUT_OF_CORE;
}
assert (resultlen < bufsize);
log_assert (resultlen < bufsize);
memcpy (p, result, resultlen);
p += resultlen;
}
@ -2996,7 +2990,7 @@ send_le (int slot, int class, int ins, int p0, int p1,
apdu[apdulen++] = 0;
apdu[apdulen++] = 0;
apdu[apdulen++] = len;
assert (apdulen <= apdu_buffer_size);
log_assert (apdulen <= apdu_buffer_size);
memset (apdu+apdulen, 0, apdu_buffer_size - apdulen);
resultlen = result_buffer_size;
rc = send_apdu (slot, apdu, apdulen, result, &resultlen, NULL);
@ -3246,7 +3240,7 @@ apdu_send_direct (int slot, size_t extended_length,
xfree (result_buffer);
return SW_HOST_OUT_OF_CORE;
}
assert (resultlen < bufsize);
log_assert (resultlen < bufsize);
memcpy (p, result, resultlen);
p += resultlen;
}
@ -3404,8 +3398,8 @@ apdu_init (void)
gpg_error_t err;
int i;
pcsc.count = 0;
pcsc.context = -1;
pcsc.context_valid = 0;
pcsc.reader_list = NULL;
if (npth_mutex_init (&reader_table_lock, NULL))