winscard_msg_srv.c

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/*
 * MUSCLE SmartCard Development ( https://pcsclite.apdu.fr/ )
 *
 * Copyright (C) 2001-2004
 *  David Corcoran <corcoran@musclecard.com>
 * Copyright (C) 2003-2004
 *  Damien Sauveron <damien.sauveron@labri.fr>
 * Copyright (C) 2002-2023
 *  Ludovic Rousseau <ludovic.rousseau@free.fr>
 *
Redistribution and use in source and binary forms, with or without
modification, are permitted provided that the following conditions
are met:

1. Redistributions of source code must retain the above copyright
   notice, this list of conditions and the following disclaimer.
2. Redistributions in binary form must reproduce the above copyright
   notice, this list of conditions and the following disclaimer in the
   documentation and/or other materials provided with the distribution.
3. The name of the author may not be used to endorse or promote products
   derived from this software without specific prior written permission.

THIS SOFTWARE IS PROVIDED BY THE AUTHOR ``AS IS'' AND ANY EXPRESS OR
IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE IMPLIED WARRANTIES
OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE ARE DISCLAIMED.
IN NO EVENT SHALL THE AUTHOR BE LIABLE FOR ANY DIRECT, INDIRECT,
INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL DAMAGES (INCLUDING, BUT
NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS OR SERVICES; LOSS OF USE,
DATA, OR PROFITS; OR BUSINESS INTERRUPTION) HOWEVER CAUSED AND ON ANY
THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT LIABILITY, OR TORT
(INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY OUT OF THE USE OF
THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF SUCH DAMAGE.
 */

#include "config.h"
#include <fcntl.h>
#include <unistd.h>
#include <sys/types.h>
#include <sys/stat.h>
#include <sys/socket.h>
#include <sys/time.h>
#include <sys/un.h>
#include <sys/ioctl.h>
#include <errno.h>
#include <stdio.h>
#include <time.h>
#include <string.h>
#ifdef USE_LIBSYSTEMD
#include <systemd/sd-daemon.h>
#endif

#include "misc.h"
#include "pcscd.h"
#include "winscard.h"
#include "debuglog.h"
#include "winscard_msg.h"

static int commonSocket = 0;

static int ProcessCommonChannelRequest(/*@out@*/ uint32_t *pdwClientID)
{
    socklen_t clnt_len;
    int new_sock;
    struct sockaddr_un clnt_addr;

    clnt_len = sizeof(clnt_addr);

    if ((new_sock = accept(commonSocket, (struct sockaddr *) &clnt_addr,
                &clnt_len)) < 0)
    {
        Log2(PCSC_LOG_CRITICAL, "Accept on common socket: %s",
            strerror(errno));
        return -1;
    }

    *pdwClientID = new_sock;

    return 0;
}

INTERNAL int32_t InitializeSocket(void)
{
    union
    {
        struct sockaddr sa;
        struct sockaddr_un un;
    } sa;

    /*
     * Create the common shared connection socket
     */
    if ((commonSocket = socket(PF_UNIX, SOCK_STREAM, 0)) < 0)
    {
        Log2(PCSC_LOG_CRITICAL, "Unable to create common socket: %s",
            strerror(errno));
        return -1;
    }

    memset(&sa, 0, sizeof sa);
    sa.un.sun_family = AF_UNIX;
    strncpy(sa.un.sun_path, PCSCLITE_CSOCK_NAME, sizeof sa.un.sun_path);
    (void)remove(PCSCLITE_CSOCK_NAME);

    if (bind(commonSocket, &sa.sa, sizeof sa) < 0)
    {
        Log2(PCSC_LOG_CRITICAL, "Unable to bind common socket: %s",
            strerror(errno));
        return -1;
    }

    if (listen(commonSocket, 1) < 0)
    {
        Log2(PCSC_LOG_CRITICAL, "Unable to listen common socket: %s",
            strerror(errno));
        return -1;
    }

    /*
     * Chmod the public entry channel
     */
    (void)chmod(PCSCLITE_CSOCK_NAME, S_IRUSR | S_IWUSR | S_IRGRP | S_IWGRP | S_IROTH | S_IWOTH);

    return 0;
}

#ifdef USE_LIBSYSTEMD

INTERNAL int32_t ListenExistingSocket(int fd)
{
    if (!sd_is_socket(fd, AF_UNIX, SOCK_STREAM, -1))
    {
        Log1(PCSC_LOG_CRITICAL, "Passed FD is not an UNIX socket");
        return -1;
    }

    commonSocket = fd;
    return 0;
}
#endif

#if defined(__NetBSD__) || defined(__FreeBSD__) || defined(__OpenBSD__) || defined(__DragonFly__)
#define DO_TIMEOUT
#endif
INTERNAL int32_t ProcessEventsServer(uint32_t *pdwClientID)
{
    fd_set read_fd;
    int selret;
#ifdef DO_TIMEOUT
    struct timeval tv;

    tv.tv_sec = 1;
    tv.tv_usec = 0;
#endif

    FD_ZERO(&read_fd);

    /*
     * Set up the bit masks for select
     */
    FD_SET(commonSocket, &read_fd);

    selret = select(commonSocket + 1, &read_fd, (fd_set *) NULL,
        (fd_set *) NULL,
#ifdef DO_TIMEOUT
        &tv
#else
        NULL
#endif
        );

    if (selret < 0)
    {
        if (EINTR == errno)
            return -2;

        Log2(PCSC_LOG_CRITICAL, "Select returns with failure: %s",
            strerror(errno));
        return -1;
    }

    if (selret == 0)
        /* timeout. On *BSD only */
        return 2;

    /*
     * A common pipe packet has arrived - it could be a new application
     */
    if (FD_ISSET(commonSocket, &read_fd))
    {
        Log1(PCSC_LOG_DEBUG, "Common channel packet arrival");
        if (ProcessCommonChannelRequest(pdwClientID) == -1)
        {
            Log2(PCSC_LOG_ERROR,
                "error in ProcessCommonChannelRequest: %d", *pdwClientID);
            return -1;
        }
    }
    else
        return -1;

    Log2(PCSC_LOG_DEBUG,
        "ProcessCommonChannelRequest detects: %d", *pdwClientID);

    return 0;
}