libpcscspy.c

/*
    Log PC/SC arguments
    Copyright (C) 2011-2024  Ludovic Rousseau

    This program is free software: you can redistribute it and/or modify
    it under the terms of the GNU General Public License as published by
    the Free Software Foundation, either version 3 of the License, or
    (at your option) any later version.

    This program is distributed in the hope that it will be useful,
    but WITHOUT ANY WARRANTY; without even the implied warranty of
    MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
    GNU General Public License for more details.

    You should have received a copy of the GNU General Public License
    along with this program.  If not, see <http://www.gnu.org/licenses/>.
*/

#include <dlfcn.h>
#include <stdio.h>
#include <stdarg.h>
#include <fcntl.h>
#include <stdlib.h>
#include <errno.h>
#include <string.h>
#include <unistd.h>
#include <sys/time.h>
#include <pthread.h>

#include "misc.h"
#include <winscard.h>
#include "sys_generic.h"

#define DEBUG

#define DLSYM_DECLARE(symbol)          \
        typeof(symbol)* symbol
#define DLSYM_SET_VALUE(symbol)        \
        .symbol = (typeof(symbol)(*))internal_error

/* fake function to just return en error code */
static LONG internal_error(void)
{
    return SCARD_F_INTERNAL_ERROR;
}

#pragma GCC diagnostic push
#pragma GCC diagnostic ignored "-Wcast-function-type"
/* contains pointers to real functions */
static struct
{
    DLSYM_DECLARE(SCardEstablishContext);
    DLSYM_DECLARE(SCardReleaseContext);
    DLSYM_DECLARE(SCardIsValidContext);
    DLSYM_DECLARE(SCardConnect);
    DLSYM_DECLARE(SCardReconnect);
    DLSYM_DECLARE(SCardDisconnect);
    DLSYM_DECLARE(SCardBeginTransaction);
    DLSYM_DECLARE(SCardEndTransaction);
    DLSYM_DECLARE(SCardStatus);
    DLSYM_DECLARE(SCardGetStatusChange);
    DLSYM_DECLARE(SCardControl);
    DLSYM_DECLARE(SCardTransmit);
    DLSYM_DECLARE(SCardListReaderGroups);
    DLSYM_DECLARE(SCardListReaders);
    DLSYM_DECLARE(SCardFreeMemory);
    DLSYM_DECLARE(SCardCancel);
    DLSYM_DECLARE(SCardGetAttrib);
    DLSYM_DECLARE(SCardSetAttrib);
} spy = {
    /* initialized with the fake internal_error() function */
    DLSYM_SET_VALUE(SCardEstablishContext),
    DLSYM_SET_VALUE(SCardReleaseContext),
    DLSYM_SET_VALUE(SCardIsValidContext),
    DLSYM_SET_VALUE(SCardConnect),
    DLSYM_SET_VALUE(SCardReconnect),
    DLSYM_SET_VALUE(SCardDisconnect),
    DLSYM_SET_VALUE(SCardBeginTransaction),
    DLSYM_SET_VALUE(SCardEndTransaction),
    DLSYM_SET_VALUE(SCardStatus),
    DLSYM_SET_VALUE(SCardGetStatusChange),
    DLSYM_SET_VALUE(SCardControl),
    DLSYM_SET_VALUE(SCardTransmit),
    DLSYM_SET_VALUE(SCardListReaderGroups),
    DLSYM_SET_VALUE(SCardListReaders),
    DLSYM_SET_VALUE(SCardFreeMemory),
    DLSYM_SET_VALUE(SCardCancel),
    DLSYM_SET_VALUE(SCardGetAttrib),
    DLSYM_SET_VALUE(SCardSetAttrib)
};
#pragma GCC diagnostic pop

#define LOG log_line("%s:%d", __FILE__, __LINE__)

static int Log_fd = -1;
static void *Lib_handle = NULL;
static pthread_mutex_t Log_fd_mutex = PTHREAD_MUTEX_INITIALIZER;

#ifdef DEBUG
static void log_line(const char *fmt, ...)
{
    va_list args;

    va_start(args, fmt);
    vfprintf(stderr, fmt, args);
    fprintf(stderr, "\n");
    va_end(args);
}
#else
static void log_line(const char *fmt, ...)
{
}
#endif

static void spy_line_direct(char *line)
{
    char threadid[30];
    ssize_t r;

    /* spying disabled */
    if (Log_fd < 0)
        return;

    snprintf(threadid, sizeof threadid, "%lX@", (unsigned long)pthread_self());
    pthread_mutex_lock(&Log_fd_mutex);
    r = write(Log_fd, threadid, strlen(threadid));
    r = write(Log_fd, line, strlen(line));
    r = write(Log_fd, "\n", 1);
    (void)r;
    pthread_mutex_unlock(&Log_fd_mutex);
}

static void spy_line(const char *fmt, ...)
{
    va_list args;
    char line[256];
    int size;
    char threadid[30];
    ssize_t r;

    /* spying disabled */
    if (Log_fd < 0)
        return;

    va_start(args, fmt);
    size = vsnprintf(line, sizeof line, fmt, args);
    va_end(args);
    if ((size_t)size >= sizeof line)
    {
        printf("libpcsc-spy: Buffer is too small!\n");
        return;
    }
    snprintf(threadid, sizeof threadid, "%lX@", (unsigned long)pthread_self());
    pthread_mutex_lock(&Log_fd_mutex);
    r = write(Log_fd, threadid, strlen(threadid));
    r = write(Log_fd, line, size);
    r = write(Log_fd, "\n", 1);
    (void)r;
    pthread_mutex_unlock(&Log_fd_mutex);
}

static void spy_enter(const char *fname)
{
    struct timeval profile_time;

    gettimeofday(&profile_time, NULL);
    spy_line(">|%ld|%ld|%s", profile_time.tv_sec, profile_time.tv_usec, fname);
}

static void spy_quit(const char *fname, LONG rv)
{
    struct timeval profile_time;

    gettimeofday(&profile_time, NULL);
    spy_line("<|%ld|%ld|%s|0x%08lX", profile_time.tv_sec,
        profile_time.tv_usec, fname, rv);
}

#define Enter() spy_enter(__FUNCTION__)
#define Quit() spy_quit(__FUNCTION__, rv)

static void spy_long(long arg)
{
    spy_line("0x%08lX", arg);
}

static void spy_ptr_long(LONG *arg)
{
    if (arg)
        spy_line("0x%08lX", *arg);
    else
        spy_line("NULL");
}

static void spy_ptr_ulong(ULONG *arg)
{
    if (arg)
        spy_line("0x%08lX", *arg);
    else
        spy_line("NULL");
}

static void spy_pvoid(const void *ptr)
{
    spy_line("%p", ptr);
}

static void spy_buffer(const unsigned char *buffer, size_t length)
{
    spy_long(length);

    if (NULL == buffer)
        spy_line("NULL");
    else
    {
        /* "78 79 7A" */
        char log_buffer[length * 3 +1], *p;
        size_t i;

        p = log_buffer;
        log_buffer[0] = '\0';
        for (i=0; i<length; i++)
        {
            snprintf(p, 4, "%02X ", buffer[i]);
            p += 3;
        }
        *p = '\0';

        spy_line_direct(log_buffer);
    }
}

static void spy_str(const char *str)
{
    spy_line("%s", str);
}

static void spy_n_str(const char *str, ULONG *len, int autoallocate)
{
    spy_ptr_ulong(len);
    if (NULL == len)
    {
        spy_line("\"\"");
    }
    else
    {
        if (NULL == str)
        {
            spy_line("NULL");
        }
        else
        {
            const char *s = str;
            unsigned int length = 0;

            if (autoallocate)
                s = *(char **)str;

            do
            {
                spy_line("%s", s);
                length += strlen(s)+1;
                s += strlen(s)+1;
            } while(length < *len);
        }
    }
}


static void spy_readerstate(SCARD_READERSTATE * rgReaderStates, int cReaders)
{
    int i;

    for (i=0; i<cReaders; i++)
    {
        spy_str(rgReaderStates[i].szReader);
        spy_long(rgReaderStates[i].dwCurrentState);
        spy_long(rgReaderStates[i].dwEventState);
        if (rgReaderStates[i].cbAtr <= MAX_ATR_SIZE)
            spy_buffer(rgReaderStates[i].rgbAtr, rgReaderStates[i].cbAtr);
        else
            spy_buffer(NULL, rgReaderStates[i].cbAtr);
    }
}

static LONG load_lib(void)
{

#define LIBPCSC "libpcsclite_real.so.1"

    const char *lib;

    lib = SYS_GetEnv("LIBPCSCLITE_SPY_DELEGATE");
    if (NULL == lib)
        lib = LIBPCSC;

    /* load the normal library */
    Lib_handle = dlopen(lib, RTLD_LAZY);
    if (NULL == Lib_handle)
    {
        log_line("loading \"%s\" failed: %s", lib, dlerror());
        return SCARD_F_INTERNAL_ERROR;
    }

#define get_symbol(s) do { spy.s = dlsym(Lib_handle, #s); if (NULL == spy.s) { log_line("%s", dlerror()); return SCARD_F_INTERNAL_ERROR; } } while (0)

    if (SCardEstablishContext == dlsym(Lib_handle, "SCardEstablishContext"))
    {
        log_line("Symbols dlsym error");
        return SCARD_F_INTERNAL_ERROR;
    }

    get_symbol(SCardEstablishContext);
    get_symbol(SCardReleaseContext);
    get_symbol(SCardIsValidContext);
    get_symbol(SCardConnect);
    get_symbol(SCardReconnect);
    get_symbol(SCardDisconnect);
    get_symbol(SCardBeginTransaction);
    get_symbol(SCardEndTransaction);
    get_symbol(SCardStatus);
    get_symbol(SCardGetStatusChange);
    get_symbol(SCardControl);
    get_symbol(SCardTransmit);
    get_symbol(SCardListReaderGroups);
    get_symbol(SCardListReaders);
    /* Mac OS X do not have SCardFreeMemory() */
    if (dlsym(Lib_handle, "SCardFreeMemory"))
        get_symbol(SCardFreeMemory);
    get_symbol(SCardCancel);
    get_symbol(SCardGetAttrib);
    get_symbol(SCardSetAttrib);

    return SCARD_S_SUCCESS;
}

static void init(void)
{
    const char *home;
    char log_pipe[128];

    /* load the real library */
    if (load_lib() != SCARD_S_SUCCESS)
        return;

    /* check if we can log */
    home = SYS_GetEnv("HOME");
    if (NULL == home)
        home = "/tmp";

    snprintf(log_pipe, sizeof log_pipe, "%s/pcsc-spy", home);
    Log_fd = open(log_pipe, O_WRONLY);
    if (Log_fd < 0)
    {
        log_line("open %s failed: %s", log_pipe, strerror(errno));
    }
}

/* exported functions */
PCSC_API LONG SCardEstablishContext(DWORD dwScope,
    LPCVOID pvReserved1,
    LPCVOID pvReserved2,
    LPSCARDCONTEXT phContext)
{
    LONG rv;
    static pthread_once_t once_control = PTHREAD_ONCE_INIT;

    pthread_once(&once_control, init);

    Enter();
    spy_long(dwScope);
    rv = spy.SCardEstablishContext(dwScope, pvReserved1, pvReserved2,
        phContext);
    spy_ptr_long(phContext);
    Quit();
    return rv;
}

PCSC_API LONG SCardReleaseContext(SCARDCONTEXT hContext)
{
    LONG rv;

    Enter();
    spy_long(hContext);
    rv = spy.SCardReleaseContext(hContext);
    Quit();
    return rv;
}

PCSC_API LONG SCardIsValidContext(SCARDCONTEXT hContext)
{
    LONG rv;

    Enter();
    spy_long(hContext);
    rv = spy.SCardIsValidContext(hContext);
    Quit();
    return rv;
}

PCSC_API LONG SCardConnect(SCARDCONTEXT hContext,
    LPCSTR szReader,
    DWORD dwShareMode,
    DWORD dwPreferredProtocols,
    LPSCARDHANDLE phCard,
    LPDWORD pdwActiveProtocol)
{
    LONG rv;

    Enter();
    spy_long(hContext);
    spy_str(szReader);
    spy_long(dwShareMode);
    spy_long(dwPreferredProtocols);
    spy_ptr_long(phCard);
    spy_ptr_ulong(pdwActiveProtocol);
    rv = spy.SCardConnect(hContext, szReader, dwShareMode,
        dwPreferredProtocols, phCard, pdwActiveProtocol);
    spy_ptr_long(phCard);
    spy_ptr_ulong(pdwActiveProtocol);
    Quit();
    return rv;
}

PCSC_API LONG SCardReconnect(SCARDHANDLE hCard,
    DWORD dwShareMode,
    DWORD dwPreferredProtocols,
    DWORD dwInitialization,
    LPDWORD pdwActiveProtocol)
{
    LONG rv;

    Enter();
    spy_long(hCard);
    spy_long(dwShareMode);
    spy_long(dwPreferredProtocols);
    spy_long(dwInitialization);
    rv = spy.SCardReconnect(hCard, dwShareMode, dwPreferredProtocols,
        dwInitialization, pdwActiveProtocol);
    spy_ptr_ulong(pdwActiveProtocol);
    Quit();
    return rv;
}

PCSC_API LONG SCardDisconnect(SCARDHANDLE hCard,
    DWORD dwDisposition)
{
    LONG rv;

    Enter();
    spy_long(hCard);
    spy_long(dwDisposition);
    rv = spy.SCardDisconnect(hCard, dwDisposition);
    Quit();
    return rv;
}

PCSC_API LONG SCardBeginTransaction(SCARDHANDLE hCard)
{
    LONG rv;

    Enter();
    spy_long(hCard);
    rv = spy.SCardBeginTransaction(hCard);
    Quit();
    return rv;
}

PCSC_API LONG SCardEndTransaction(SCARDHANDLE hCard,
    DWORD dwDisposition)
{
    LONG rv;

    Enter();
    spy_long(hCard);
    spy_long(dwDisposition);
    rv = spy.SCardEndTransaction(hCard, dwDisposition);
    Quit();
    return rv;
}

PCSC_API LONG SCardStatus(SCARDHANDLE hCard,
    LPSTR mszReaderName,
    LPDWORD pcchReaderLen,
    LPDWORD pdwState,
    LPDWORD pdwProtocol,
    LPBYTE pbAtr,
    LPDWORD pcbAtrLen)
{
    LONG rv;
    int autoallocate_ReaderName = 0, autoallocate_Atr = 0;

    if (pcchReaderLen)
        autoallocate_ReaderName = *pcchReaderLen == SCARD_AUTOALLOCATE;

    if (pcbAtrLen)
        autoallocate_Atr = *pcbAtrLen == SCARD_AUTOALLOCATE;

    Enter();
    spy_long(hCard);
    spy_ptr_ulong(pcchReaderLen);
    spy_ptr_ulong(pcbAtrLen);
    rv = spy.SCardStatus(hCard, mszReaderName, pcchReaderLen, pdwState,
        pdwProtocol, pbAtr, pcbAtrLen);
    spy_n_str(mszReaderName, pcchReaderLen, autoallocate_ReaderName);
    spy_ptr_ulong(pdwState);
    spy_ptr_ulong(pdwProtocol);
    if (NULL == pcbAtrLen)
        spy_line("NULL");
    else
    {
        LPBYTE buffer;

        if (autoallocate_Atr)
            buffer = *(LPBYTE *)pbAtr;
        else
            buffer = pbAtr;

        spy_buffer(buffer, *pcbAtrLen);
    }
    Quit();
    return rv;
}

PCSC_API LONG SCardGetStatusChange(SCARDCONTEXT hContext,
    DWORD dwTimeout,
    SCARD_READERSTATE *rgReaderStates,
    DWORD cReaders)
{
    LONG rv;

    Enter();
    spy_long(hContext);
    spy_long(dwTimeout);
    spy_long(cReaders);
    spy_readerstate(rgReaderStates, cReaders);
    rv = spy.SCardGetStatusChange(hContext, dwTimeout, rgReaderStates,
        cReaders);
    spy_readerstate(rgReaderStates, cReaders);
    Quit();
    return rv;
}

PCSC_API LONG SCardControl(SCARDHANDLE hCard,
    DWORD dwControlCode,
    LPCVOID pbSendBuffer,
    DWORD cbSendLength,
    LPVOID pbRecvBuffer,
    DWORD cbRecvLength,
    LPDWORD lpBytesReturned)
{
    LONG rv;

    Enter();
    spy_long(hCard);
    spy_long(dwControlCode);
    spy_buffer(pbSendBuffer, cbSendLength);
    rv = spy.SCardControl(hCard, dwControlCode, pbSendBuffer, cbSendLength,
        pbRecvBuffer, cbRecvLength, lpBytesReturned);
    if (lpBytesReturned)
    {
        if (SCARD_S_SUCCESS == rv)
            spy_buffer(pbRecvBuffer, *lpBytesReturned);
        else
            spy_buffer(NULL, *lpBytesReturned);
    }
    else
        spy_buffer(NULL, 0);
    Quit();
    return rv;
}

PCSC_API LONG SCardTransmit(SCARDHANDLE hCard,
    const SCARD_IO_REQUEST *pioSendPci,
    LPCBYTE pbSendBuffer,
    DWORD cbSendLength,
    SCARD_IO_REQUEST *pioRecvPci,
    LPBYTE pbRecvBuffer,
    LPDWORD pcbRecvLength)
{
    LONG rv;

    Enter();
    spy_long(hCard);
    if (pioSendPci)
    {
        spy_long(pioSendPci->dwProtocol);
        spy_long(pioSendPci->cbPciLength);
    }
    else
    {
        spy_long(-1);
        spy_long(-1);
    }
    spy_buffer(pbSendBuffer, cbSendLength);
    rv = spy.SCardTransmit(hCard, pioSendPci, pbSendBuffer, cbSendLength,
        pioRecvPci, pbRecvBuffer, pcbRecvLength);
    if (pioRecvPci)
    {
        spy_long(pioRecvPci->dwProtocol);
        spy_long(pioRecvPci->cbPciLength);
    }
    else
    {
        spy_long(-1);
        spy_long(-1);
    }
    if (pcbRecvLength)
    {
        if (SCARD_S_SUCCESS == rv)
            spy_buffer(pbRecvBuffer, *pcbRecvLength);
        else
            spy_buffer(NULL, *pcbRecvLength);
    }
    else
        spy_buffer(NULL, 0);
    Quit();
    return rv;
}

PCSC_API LONG SCardListReaderGroups(SCARDCONTEXT hContext,
    LPSTR mszGroups,
    LPDWORD pcchGroups)
{
    LONG rv;
    int autoallocate = 0;

    if (pcchGroups)
        autoallocate = *pcchGroups == SCARD_AUTOALLOCATE;

    Enter();
    spy_long(hContext);
    spy_ptr_ulong(pcchGroups);
    rv = spy.SCardListReaderGroups(hContext, mszGroups, pcchGroups);
    if (SCARD_S_SUCCESS == rv)
        spy_n_str(mszGroups, pcchGroups, autoallocate);
    else
        spy_n_str(NULL, pcchGroups, 0);
    Quit();
    return rv;
}

PCSC_API LONG SCardListReaders(SCARDCONTEXT hContext,
    LPCSTR mszGroups,
    LPSTR mszReaders,
    LPDWORD pcchReaders)
{
    LONG rv;
    int autoallocate = 0;

    if (pcchReaders)
        autoallocate = *pcchReaders == SCARD_AUTOALLOCATE;

    Enter();
    spy_long(hContext);
    spy_str(mszGroups);
    rv = spy.SCardListReaders(hContext, mszGroups, mszReaders, pcchReaders);
    if (SCARD_S_SUCCESS == rv)
        spy_n_str(mszReaders, pcchReaders, autoallocate);
    else
        spy_n_str(NULL, pcchReaders, 0);
    Quit();
    return rv;
}

PCSC_API LONG SCardFreeMemory(SCARDCONTEXT hContext,
    LPCVOID pvMem)
{
    LONG rv;

    Enter();
    spy_long(hContext);
    spy_pvoid(pvMem);
    rv = spy.SCardFreeMemory(hContext, pvMem);
    Quit();
    return rv;
}

PCSC_API LONG SCardCancel(SCARDCONTEXT hContext)
{
    LONG rv;

    Enter();
    spy_long(hContext);
    rv = spy.SCardCancel(hContext);
    Quit();
    return rv;
}

PCSC_API LONG SCardGetAttrib(SCARDHANDLE hCard,
    DWORD dwAttrId,
    LPBYTE pbAttr,
    LPDWORD pcbAttrLen)
{
    LONG rv;
    int autoallocate = 0;

    if (pcbAttrLen)
        autoallocate = *pcbAttrLen == SCARD_AUTOALLOCATE;

    Enter();
    spy_long(hCard);
    spy_long(dwAttrId);
    rv = spy.SCardGetAttrib(hCard, dwAttrId, pbAttr, pcbAttrLen);
    if (NULL == pcbAttrLen)
        spy_buffer(NULL, 0);
    else
        if (rv != SCARD_S_SUCCESS)
            spy_buffer(NULL, *pcbAttrLen);
        else
        {
            LPBYTE buffer;

            if (autoallocate)
                buffer = *(LPBYTE *)pbAttr;
            else
                buffer = pbAttr;

            spy_buffer(buffer, *pcbAttrLen);
        }
    Quit();
    return rv;
}

PCSC_API LONG SCardSetAttrib(SCARDHANDLE hCard,
    DWORD dwAttrId,
    LPCBYTE pbAttr,
    DWORD cbAttrLen)
{
    LONG rv;

    Enter();
    spy_long(hCard);
    spy_long(dwAttrId);
    spy_buffer(pbAttr, cbAttrLen);
    rv = spy.SCardSetAttrib(hCard, dwAttrId, pbAttr, cbAttrLen);
    Quit();
    return rv;
}