/*
 * Tester for VSCARD protocol, client side.
 *
 * Can be used with ccid-card-passthru.
 *
 * Copyright (c) 2011 Red Hat.
 * Written by Alon Levy.
 *
 * This work is licensed under the terms of the GNU LGPL, version 2.1 or later.
 * See the COPYING.LIB file in the top-level directory.
 */

#include <netdb.h>

#include "qemu-common.h"
#include "qemu/thread.h"
#include "qemu/sockets.h"

#include "vscard_common.h"

#include "vreader.h"
#include "vcard_emul.h"
#include "vevent.h"

int verbose;

int sock;

static void
print_byte_array(
    uint8_t *arrBytes,
    unsigned int nSize
) {
    int i;
    for (i = 0; i < nSize; i++) {
        printf("%02X ", arrBytes[i]);
    }
    printf("\n");
}

static void
print_usage(void) {
    printf("vscclient [-c <certname> .. -e <emul_args> -d <level>%s] "
            "<host> <port>\n",
#ifdef USE_PASSTHRU
    " -p");
    printf(" -p use passthrough mode\n");
#else
   "");
#endif
    vcard_emul_usage();
}

static QemuMutex write_lock;

static int
send_msg(
    VSCMsgType type,
    uint32_t reader_id,
    const void *msg,
    unsigned int length
) {
    int rv;
    VSCMsgHeader mhHeader;

    qemu_mutex_lock(&write_lock);

    if (verbose > 10) {
        printf("sending type=%d id=%u, len =%u (0x%x)\n",
               type, reader_id, length, length);
    }

    mhHeader.type = htonl(type);
    mhHeader.reader_id = 0;
    mhHeader.length = htonl(length);
    rv = write(sock, &mhHeader, sizeof(mhHeader));
    if (rv < 0) {
        /* Error */
        fprintf(stderr, "write header error\n");
        close(sock);
        qemu_mutex_unlock(&write_lock);
        return 16;
    }
    rv = write(sock, msg, length);
    if (rv < 0) {
        /* Error */
        fprintf(stderr, "write error\n");
        close(sock);
        qemu_mutex_unlock(&write_lock);
        return 16;
    }
    qemu_mutex_unlock(&write_lock);

    return 0;
}

static VReader *pending_reader;
static QemuMutex pending_reader_lock;
static QemuCond pending_reader_condition;

#define MAX_ATR_LEN 40
static void *
event_thread(void *arg)
{
    unsigned char atr[MAX_ATR_LEN];
    int atr_len = MAX_ATR_LEN;
    VEvent *event = NULL;
    unsigned int reader_id;


    while (1) {
        const char *reader_name;

        event = vevent_wait_next_vevent();
        if (event == NULL) {
            break;
        }
        reader_id = vreader_get_id(event->reader);
        if (reader_id == VSCARD_UNDEFINED_READER_ID &&
            event->type != VEVENT_READER_INSERT) {
            /* ignore events from readers qemu has rejected */
            /* if qemu is still deciding on this reader, wait to see if need to
             * forward this event */
            qemu_mutex_lock(&pending_reader_lock);
            if (!pending_reader || (pending_reader != event->reader)) {
                /* wasn't for a pending reader, this reader has already been
                 * rejected by qemu */
                qemu_mutex_unlock(&pending_reader_lock);
                vevent_delete(event);
                continue;
            }
            /* this reader hasn't been told its status from qemu yet, wait for
             * that status */
            while (pending_reader != NULL) {
                qemu_cond_wait(&pending_reader_condition, &pending_reader_lock);
            }
            qemu_mutex_unlock(&pending_reader_lock);
            /* now recheck the id */
            reader_id = vreader_get_id(event->reader);
            if (reader_id == VSCARD_UNDEFINED_READER_ID) {
                /* this reader was rejected */
                vevent_delete(event);
                continue;
            }
            /* reader was accepted, now forward the event */
        }
        switch (event->type) {
        case VEVENT_READER_INSERT:
            /* tell qemu to insert a new CCID reader */
            /* wait until qemu has responded to our first reader insert
             * before we send a second. That way we won't confuse the responses
             * */
            qemu_mutex_lock(&pending_reader_lock);
            while (pending_reader != NULL) {
                qemu_cond_wait(&pending_reader_condition, &pending_reader_lock);
            }
            pending_reader = vreader_reference(event->reader);
            qemu_mutex_unlock(&pending_reader_lock);
            reader_name = vreader_get_name(event->reader);
            if (verbose > 10) {
                printf(" READER INSERT: %s\n", reader_name);
            }
            send_msg(VSC_ReaderAdd,
                reader_id, /* currerntly VSCARD_UNDEFINED_READER_ID */
                NULL, 0 /* TODO reader_name, strlen(reader_name) */);
            break;
        case VEVENT_READER_REMOVE:
            /* future, tell qemu that an old CCID reader has been removed */
            if (verbose > 10) {
                printf(" READER REMOVE: %u\n", reader_id);
            }
            send_msg(VSC_ReaderRemove, reader_id, NULL, 0);
            break;
        case VEVENT_CARD_INSERT:
            /* get the ATR (intended as a response to a power on from the
             * reader */
            atr_len = MAX_ATR_LEN;
            vreader_power_on(event->reader, atr, &atr_len);
            /* ATR call functions as a Card Insert event */
            if (verbose > 10) {
                printf(" CARD INSERT %u: ", reader_id);
                print_byte_array(atr, atr_len);
            }
            send_msg(VSC_ATR, reader_id, atr, atr_len);
            break;
        case VEVENT_CARD_REMOVE:
            /* Card removed */
            if (verbose > 10) {
                printf(" CARD REMOVE %u:\n", reader_id);
            }
            send_msg(VSC_CardRemove, reader_id, NULL, 0);
            break;
        default:
            break;
        }
        vevent_delete(event);
    }
    return NULL;
}


static unsigned int
get_id_from_string(char *string, unsigned int default_id)
{
    unsigned int id = atoi(string);

    /* don't accidentally swith to zero because no numbers have been supplied */
    if ((id == 0) && *string != '0') {
        return default_id;
    }
    return id;
}

static int
on_host_init(VSCMsgHeader *mhHeader, VSCMsgInit *incoming)
{
    uint32_t *capabilities = (incoming->capabilities);
    int num_capabilities =
        1 + ((mhHeader->length - sizeof(VSCMsgInit)) / sizeof(uint32_t));
    int i;
    QemuThread thread_id;

    incoming->version = ntohl(incoming->version);
    if (incoming->version != VSCARD_VERSION) {
        if (verbose > 0) {
            printf("warning: host has version %d, we have %d\n",
                verbose, VSCARD_VERSION);
        }
    }
    if (incoming->magic != VSCARD_MAGIC) {
        printf("unexpected magic: got %d, expected %d\n",
            incoming->magic, VSCARD_MAGIC);
        return -1;
    }
    for (i = 0 ; i < num_capabilities; ++i) {
        capabilities[i] = ntohl(capabilities[i]);
    }
    /* Future: check capabilities */
    /* remove whatever reader might be left in qemu,
     * in case of an unclean previous exit. */
    send_msg(VSC_ReaderRemove, VSCARD_MINIMAL_READER_ID, NULL, 0);
    /* launch the event_thread. This will trigger reader adds for all the
     * existing readers */
    qemu_thread_create(&thread_id, event_thread, NULL, 0);
    return 0;
}

#define APDUBufSize 270

static int
do_socket_read(void)
{
    int rv;
    int dwSendLength;
    int dwRecvLength;
    uint8_t pbRecvBuffer[APDUBufSize];
    uint8_t pbSendBuffer[APDUBufSize];
    VReaderStatus reader_status;
    VReader *reader = NULL;
    VSCMsgHeader mhHeader;
    VSCMsgError *error_msg;

    rv = read(sock, &mhHeader, sizeof(mhHeader));
    if (rv < sizeof(mhHeader)) {
        /* Error */
        if (rv < 0) {
            perror("header read error\n");
        } else {
            fprintf(stderr, "header short read %d\n", rv);
        }
        return -1;
    }
    mhHeader.type = ntohl(mhHeader.type);
    mhHeader.reader_id = ntohl(mhHeader.reader_id);
    mhHeader.length = ntohl(mhHeader.length);
    if (verbose) {
        printf("Header: type=%d, reader_id=%u length=%d (0x%x)\n",
               mhHeader.type, mhHeader.reader_id, mhHeader.length,
               mhHeader.length);
    }
    switch (mhHeader.type) {
    case VSC_APDU:
    case VSC_Flush:
    case VSC_Error:
    case VSC_Init:
        rv = read(sock, pbSendBuffer, mhHeader.length);
        break;
    default:
        fprintf(stderr, "Unexpected message of type 0x%X\n", mhHeader.type);
        return -1;
    }
    switch (mhHeader.type) {
    case VSC_APDU:
        if (rv < 0) {
            /* Error */
            fprintf(stderr, "read error\n");
            close(sock);
            return -1;
        }
        if (verbose) {
            printf(" recv APDU: ");
            print_byte_array(pbSendBuffer, mhHeader.length);
        }
        /* Transmit received APDU */
        dwSendLength = mhHeader.length;
        dwRecvLength = sizeof(pbRecvBuffer);
        reader = vreader_get_reader_by_id(mhHeader.reader_id);
        reader_status = vreader_xfr_bytes(reader,
                                          pbSendBuffer, dwSendLength,
                                          pbRecvBuffer, &dwRecvLength);
        if (reader_status == VREADER_OK) {
            mhHeader.length = dwRecvLength;
            if (verbose) {
                printf(" send response: ");
                print_byte_array(pbRecvBuffer, mhHeader.length);
            }
            send_msg(VSC_APDU, mhHeader.reader_id,
                     pbRecvBuffer, dwRecvLength);
        } else {
            rv = reader_status; /* warning: not meaningful */
            send_msg(VSC_Error, mhHeader.reader_id, &rv, sizeof(uint32_t));
        }
        vreader_free(reader);
        reader = NULL; /* we've freed it, don't use it by accident
                          again */
        break;
    case VSC_Flush:
        /* TODO: actually flush */
        send_msg(VSC_FlushComplete, mhHeader.reader_id, NULL, 0);
        break;
    case VSC_Error:
        error_msg = (VSCMsgError *) pbSendBuffer;
        if (error_msg->code == VSC_SUCCESS) {
            qemu_mutex_lock(&pending_reader_lock);
            if (pending_reader) {
                vreader_set_id(pending_reader, mhHeader.reader_id);
                vreader_free(pending_reader);
                pending_reader = NULL;
                qemu_cond_signal(&pending_reader_condition);
            }
            qemu_mutex_unlock(&pending_reader_lock);
            break;
        }
        printf("warning: qemu refused to add reader\n");
        if (error_msg->code == VSC_CANNOT_ADD_MORE_READERS) {
            /* clear pending reader, qemu can't handle any more */
            qemu_mutex_lock(&pending_reader_lock);
            if (pending_reader) {
                pending_reader = NULL;
                /* make sure the event loop doesn't hang */
                qemu_cond_signal(&pending_reader_condition);
            }
            qemu_mutex_unlock(&pending_reader_lock);
        }
        break;
    case VSC_Init:
        if (on_host_init(&mhHeader, (VSCMsgInit *)pbSendBuffer) < 0) {
            return -1;
        }
        break;
    default:
        printf("Default\n");
        return -1;
    }

    return 0;
}

static void
do_command(void)
{
    char inbuf[255];
    char *string;
    VCardEmulError error;
    static unsigned int default_reader_id;
    unsigned int reader_id;
    VReader *reader = NULL;

    reader_id = default_reader_id;
    string = fgets(inbuf, sizeof(inbuf), stdin);
    if (string != NULL) {
        if (strncmp(string, "exit", 4) == 0) {
            /* remove all the readers */
            VReaderList *list = vreader_get_reader_list();
            VReaderListEntry *reader_entry;
            printf("Active Readers:\n");
            for (reader_entry = vreader_list_get_first(list); reader_entry;
                 reader_entry = vreader_list_get_next(reader_entry)) {
                VReader *reader = vreader_list_get_reader(reader_entry);
                vreader_id_t reader_id;
                reader_id = vreader_get_id(reader);
                if (reader_id == -1) {
                    continue;
                }
                /* be nice and signal card removal first (qemu probably should
                 * do this itself) */
                if (vreader_card_is_present(reader) == VREADER_OK) {
                    send_msg(VSC_CardRemove, reader_id, NULL, 0);
                }
                send_msg(VSC_ReaderRemove, reader_id, NULL, 0);
            }
            exit(0);
        } else if (strncmp(string, "insert", 6) == 0) {
            if (string[6] == ' ') {
                reader_id = get_id_from_string(&string[7], reader_id);
            }
            reader = vreader_get_reader_by_id(reader_id);
            if (reader != NULL) {
                error = vcard_emul_force_card_insert(reader);
                printf("insert %s, returned %d\n",
                       reader ? vreader_get_name(reader)
                       : "invalid reader", error);
            } else {
                printf("no reader by id %u found\n", reader_id);
            }
        } else if (strncmp(string, "remove", 6) == 0) {
            if (string[6] == ' ') {
                reader_id = get_id_from_string(&string[7], reader_id);
            }
            reader = vreader_get_reader_by_id(reader_id);
            if (reader != NULL) {
                error = vcard_emul_force_card_remove(reader);
                printf("remove %s, returned %d\n",
                        reader ? vreader_get_name(reader)
                        : "invalid reader", error);
            } else {
                printf("no reader by id %u found\n", reader_id);
            }
        } else if (strncmp(string, "select", 6) == 0) {
            if (string[6] == ' ') {
                reader_id = get_id_from_string(&string[7],
                                               VSCARD_UNDEFINED_READER_ID);
            }
            if (reader_id != VSCARD_UNDEFINED_READER_ID) {
                reader = vreader_get_reader_by_id(reader_id);
            }
            if (reader) {
                printf("Selecting reader %u, %s\n", reader_id,
                        vreader_get_name(reader));
                default_reader_id = reader_id;
            } else {
                printf("Reader with id %u not found\n", reader_id);
            }
        } else if (strncmp(string, "debug", 5) == 0) {
            if (string[5] == ' ') {
                verbose = get_id_from_string(&string[6], 0);
            }
            printf("debug level = %d\n", verbose);
        } else if (strncmp(string, "list", 4) == 0) {
            VReaderList *list = vreader_get_reader_list();
            VReaderListEntry *reader_entry;
            printf("Active Readers:\n");
            for (reader_entry = vreader_list_get_first(list); reader_entry;
                 reader_entry = vreader_list_get_next(reader_entry)) {
                VReader *reader = vreader_list_get_reader(reader_entry);
                vreader_id_t reader_id;
                reader_id = vreader_get_id(reader);
                if (reader_id == -1) {
                    continue;
                }
                printf("%3u %s %s\n", reader_id,
                       vreader_card_is_present(reader) == VREADER_OK ?
                       "CARD_PRESENT" : "            ",
                       vreader_get_name(reader));
            }
            printf("Inactive Readers:\n");
            for (reader_entry = vreader_list_get_first(list); reader_entry;
                 reader_entry = vreader_list_get_next(reader_entry)) {
                VReader *reader = vreader_list_get_reader(reader_entry);
                vreader_id_t reader_id;
                reader_id = vreader_get_id(reader);
                if (reader_id != -1) {
                    continue;
                }

                printf("INA %s %s\n",
                       vreader_card_is_present(reader) == VREADER_OK ?
                       "CARD_PRESENT" : "            ",
                       vreader_get_name(reader));
            }
        } else if (*string != 0) {
            printf("valid commands:\n");
            printf("insert [reader_id]\n");
            printf("remove [reader_id]\n");
            printf("select reader_id\n");
            printf("list\n");
            printf("debug [level]\n");
            printf("exit\n");
        }
    }
    vreader_free(reader);
    printf("> ");
    fflush(stdout);
}


/* just for ease of parsing command line arguments. */
#define MAX_CERTS 100

static int
connect_to_qemu(
    const char *host,
    const char *port
) {
    struct addrinfo hints;
    struct addrinfo *server;
    int ret;

    sock = qemu_socket(AF_INET, SOCK_STREAM, 0);
    if (sock < 0) {
        /* Error */
        fprintf(stderr, "Error opening socket!\n");
        return -1;
    }

    memset(&hints, 0, sizeof(struct addrinfo));
    hints.ai_family = AF_UNSPEC;
    hints.ai_socktype = SOCK_STREAM;
    hints.ai_flags = 0;
    hints.ai_protocol = 0;          /* Any protocol */

    ret = getaddrinfo(host, port, &hints, &server);

    if (ret != 0) {
        /* Error */
        fprintf(stderr, "getaddrinfo failed\n");
        return -1;
    }

    if (connect(sock, server->ai_addr, server->ai_addrlen) < 0) {
        /* Error */
        fprintf(stderr, "Could not connect\n");
        return -1;
    }
    if (verbose) {
        printf("Connected (sizeof Header=%zd)!\n", sizeof(VSCMsgHeader));
    }
    return sock;
}

int
main(
    int argc,
    char *argv[]
) {
    char *qemu_host;
    char *qemu_port;
    VSCMsgHeader mhHeader;

    VCardEmulOptions *command_line_options = NULL;

    char *cert_names[MAX_CERTS];
    char *emul_args = NULL;
    int cert_count = 0;
    int c, rv;

    while ((c = getopt(argc, argv, "c:e:pd:")) != -1) {
        switch (c) {
        case 'c':
            if (cert_count >= MAX_CERTS) {
                printf("too many certificates (max = %d)\n", MAX_CERTS);
                exit(5);
            }
            cert_names[cert_count++] = optarg;
            break;
        case 'e':
            emul_args = optarg;
            break;
        case 'p':
            print_usage();
            exit(4);
            break;
        case 'd':
            verbose = get_id_from_string(optarg, 1);
            break;
        }
    }

    if (argc - optind != 2) {
        print_usage();
        exit(4);
    }

    if (cert_count > 0) {
        char *new_args;
        int len, i;
        /* if we've given some -c options, we clearly we want do so some
         * software emulation.  add that emulation now. this is NSS Emulator
         * specific */
        if (emul_args == NULL) {
            emul_args = (char *)"db=\"/etc/pki/nssdb\"";
        }
#define SOFT_STRING ",soft=(,Virtual Reader,CAC,,"
             /* 2 == close paren & null */
        len = strlen(emul_args) + strlen(SOFT_STRING) + 2;
        for (i = 0; i < cert_count; i++) {
            len += strlen(cert_names[i])+1; /* 1 == comma */
        }
        new_args = g_malloc(len);
        strcpy(new_args, emul_args);
        strcat(new_args, SOFT_STRING);
        for (i = 0; i < cert_count; i++) {
            strcat(new_args, cert_names[i]);
            strcat(new_args, ",");
        }
        strcat(new_args, ")");
        emul_args = new_args;
    }
    if (emul_args) {
        command_line_options = vcard_emul_options(emul_args);
    }

    qemu_host = g_strdup(argv[argc - 2]);
    qemu_port = g_strdup(argv[argc - 1]);
    sock = connect_to_qemu(qemu_host, qemu_port);
    if (sock == -1) {
        fprintf(stderr, "error opening socket, exiting.\n");
        exit(5);
    }

    qemu_mutex_init(&write_lock);
    qemu_mutex_init(&pending_reader_lock);
    qemu_cond_init(&pending_reader_condition);

    vcard_emul_init(command_line_options);

    printf("> ");
    fflush(stdout);

    /* Send init message, Host responds (and then we send reader attachments) */
    VSCMsgInit init = {
        .version = htonl(VSCARD_VERSION),
        .magic = VSCARD_MAGIC,
        .capabilities = {0}
    };
    send_msg(VSC_Init, mhHeader.reader_id, &init, sizeof(init));

    do {
        fd_set fds;

        FD_ZERO(&fds);
        FD_SET(1, &fds);
        FD_SET(sock, &fds);

        /* waiting on input from the socket */
        rv = select(sock+1, &fds, NULL, NULL, NULL);
        if (rv < 0) {
            /* handle error */
            perror("select");
            return 7;
        }
        if (FD_ISSET(1, &fds)) {
            do_command();
        }
        if (!FD_ISSET(sock, &fds)) {
            continue;
        }
        rv = do_socket_read();
    } while (rv >= 0);

    return 0;
}