Archipelago » qemu

/*

 * QEMU Guest Agent

 *

 * Copyright IBM Corp. 2011

 *

 * Authors:

 *  Adam Litke        <aglitke@linux.vnet.ibm.com>

 *  Michael Roth      <mdroth@linux.vnet.ibm.com>

 *

 * This work is licensed under the terms of the GNU GPL, version 2 or later.

 * See the COPYING file in the top-level directory.

 */

#include <stdlib.h>

#include <stdio.h>

#include <stdbool.h>

#include <glib.h>

#include <getopt.h>

#include <termios.h>

#include <syslog.h>

#include "qemu_socket.h"

#include "json-streamer.h"

#include "json-parser.h"

#include "qint.h"

#include "qjson.h"

#include "qga/guest-agent-core.h"

#include "module.h"

#include "signal.h"

#include "qerror.h"

#include "error_int.h"

#include "qapi/qmp-core.h"

#define QGA_VIRTIO_PATH_DEFAULT "/dev/virtio-ports/org.qemu.guest_agent.0"

#define QGA_PIDFILE_DEFAULT "/var/run/qemu-ga.pid"

#define QGA_BAUDRATE_DEFAULT B38400 /* for isa-serial channels */

#define QGA_TIMEOUT_DEFAULT 30*1000 /* ms */

struct GAState {

    JSONMessageParser parser;

    GMainLoop *main_loop;

    GIOChannel *conn_channel;

    GIOChannel *listen_channel;

    const char *path;

    const char *method;

    bool virtio; /* fastpath to check for virtio to deal with poll() quirks */

    GACommandState *command_state;

    GLogLevelFlags log_level;

    FILE *log_file;

    bool logging_enabled;

};

static struct GAState *ga_state;

static void quit_handler(int sig)

{

    g_debug("received signal num %d, quitting", sig);

    if (g_main_loop_is_running(ga_state->main_loop)) {

        g_main_loop_quit(ga_state->main_loop);

    }

}

static void register_signal_handlers(void)

{

    struct sigaction sigact;

    int ret;

    memset(&sigact, 0, sizeof(struct sigaction));

    sigact.sa_handler = quit_handler;

    ret = sigaction(SIGINT, &sigact, NULL);

    if (ret == -1) {

        g_error("error configuring signal handler: %s", strerror(errno));

        exit(EXIT_FAILURE);

    }

    ret = sigaction(SIGTERM, &sigact, NULL);

    if (ret == -1) {

        g_error("error configuring signal handler: %s", strerror(errno));

    }

}

static void usage(const char *cmd)

{

    printf(

"Usage: %s -c <channel_opts>\n"

"QEMU Guest Agent %s\n"

"\n"

"  -m, --method      transport method: one of unix-listen, virtio-serial, or\n"

"                    isa-serial (virtio-serial is the default)\n"

"  -p, --path        device/socket path (%s is the default for virtio-serial)\n"

"  -l, --logfile     set logfile path, logs to stderr by default\n"

"  -f, --pidfile     specify pidfile (default is %s)\n"

"  -v, --verbose     log extra debugging information\n"

"  -V, --version     print version information and exit\n"

"  -d, --daemonize   become a daemon\n"

"  -b, --blacklist   comma-separated list of RPCs to disable (no spaces, \"?\""

"                    to list available RPCs)\n"

"  -h, --help        display this help and exit\n"

"\n"

"Report bugs to <mdroth@linux.vnet.ibm.com>\n"

    , cmd, QGA_VERSION, QGA_VIRTIO_PATH_DEFAULT, QGA_PIDFILE_DEFAULT);

}

static void conn_channel_close(GAState *s);

static const char *ga_log_level_str(GLogLevelFlags level)

{

    switch (level & G_LOG_LEVEL_MASK) {

        case G_LOG_LEVEL_ERROR:

            return "error";

        case G_LOG_LEVEL_CRITICAL:

            return "critical";

        case G_LOG_LEVEL_WARNING:

            return "warning";

        case G_LOG_LEVEL_MESSAGE:

            return "message";

        case G_LOG_LEVEL_INFO:

            return "info";

        case G_LOG_LEVEL_DEBUG:

            return "debug";

        default:

            return "user";

    }

}

bool ga_logging_enabled(GAState *s)

{

    return s->logging_enabled;

}

void ga_disable_logging(GAState *s)

{

    s->logging_enabled = false;

}

void ga_enable_logging(GAState *s)

{

    s->logging_enabled = true;

}

static void ga_log(const gchar *domain, GLogLevelFlags level,

                   const gchar *msg, gpointer opaque)

{

    GAState *s = opaque;

    GTimeVal time;

    const char *level_str = ga_log_level_str(level);

    if (!ga_logging_enabled(s)) {

        return;

    }

    level &= G_LOG_LEVEL_MASK;

    if (domain && strcmp(domain, "syslog") == 0) {

        syslog(LOG_INFO, "%s: %s", level_str, msg);

    } else if (level & s->log_level) {

        g_get_current_time(&time);

        fprintf(s->log_file,

                "%lu.%lu: %s: %s\n", time.tv_sec, time.tv_usec, level_str, msg);

        fflush(s->log_file);

    }

}

static void become_daemon(const char *pidfile)

{

    pid_t pid, sid;

    int pidfd;

    char *pidstr = NULL;

    pid = fork();

    if (pid < 0) {

        exit(EXIT_FAILURE);

    }

    if (pid > 0) {

        exit(EXIT_SUCCESS);

    }

    pidfd = open(pidfile, O_CREAT|O_WRONLY|O_EXCL, S_IRUSR|S_IWUSR);

    if (pidfd == -1) {

        g_critical("Cannot create pid file, %s", strerror(errno));

        exit(EXIT_FAILURE);

    }

    if (asprintf(&pidstr, "%d", getpid()) == -1) {

        g_critical("Cannot allocate memory");

        goto fail;

    }

    if (write(pidfd, pidstr, strlen(pidstr)) != strlen(pidstr)) {

        free(pidstr);

        g_critical("Failed to write pid file");

        goto fail;

    }

    umask(0);

    sid = setsid();

    if (sid < 0) {

        goto fail;

    }

    if ((chdir("/")) < 0) {

        goto fail;

    }

    close(STDIN_FILENO);

    close(STDOUT_FILENO);

    close(STDERR_FILENO);

    free(pidstr);

    return;

fail:

    unlink(pidfile);

    g_critical("failed to daemonize");

    exit(EXIT_FAILURE);

}

static int conn_channel_send_buf(GIOChannel *channel, const char *buf,

                                 gsize count)

{

    GError *err = NULL;

    gsize written = 0;

    GIOStatus status;

    while (count) {

        status = g_io_channel_write_chars(channel, buf, count, &written, &err);

        g_debug("sending data, count: %d", (int)count);

        if (err != NULL) {

            g_warning("error sending newline: %s", err->message);

            return err->code;

        }

        if (status == G_IO_STATUS_ERROR || status == G_IO_STATUS_EOF) {

            return -EPIPE;

        }

        if (status == G_IO_STATUS_NORMAL) {

            count -= written;

        }

    }

    return 0;

}

static int conn_channel_send_payload(GIOChannel *channel, QObject *payload)

{

    int ret = 0;

    const char *buf;

    QString *payload_qstr;

    GError *err = NULL;

    g_assert(payload && channel);

    payload_qstr = qobject_to_json(payload);

    if (!payload_qstr) {

        return -EINVAL;

    }

    qstring_append_chr(payload_qstr, '\n');

    buf = qstring_get_str(payload_qstr);

    ret = conn_channel_send_buf(channel, buf, strlen(buf));

    if (ret) {

        goto out_free;

    }

    g_io_channel_flush(channel, &err);

    if (err != NULL) {

        g_warning("error flushing payload: %s", err->message);

        ret = err->code;

        goto out_free;

    }

out_free:

    QDECREF(payload_qstr);

    if (err) {

        g_error_free(err);

    }

    return ret;

}

static void process_command(GAState *s, QDict *req)

{

    QObject *rsp = NULL;

    int ret;

    g_assert(req);

    g_debug("processing command");

    rsp = qmp_dispatch(QOBJECT(req));

    if (rsp) {

        ret = conn_channel_send_payload(s->conn_channel, rsp);

        if (ret) {

            g_warning("error sending payload: %s", strerror(ret));

        }

        qobject_decref(rsp);

    } else {

        g_warning("error getting response");

    }

}

/* handle requests/control events coming in over the channel */

static void process_event(JSONMessageParser *parser, QList *tokens)

{

    GAState *s = container_of(parser, GAState, parser);

    QObject *obj;

    QDict *qdict;

    Error *err = NULL;

    int ret;

    g_assert(s && parser);

    g_debug("process_event: called");

    obj = json_parser_parse_err(tokens, NULL, &err);

    if (err || !obj || qobject_type(obj) != QTYPE_QDICT) {

        qobject_decref(obj);

        qdict = qdict_new();

        if (!err) {

            g_warning("failed to parse event: unknown error");

            error_set(&err, QERR_JSON_PARSING);

        } else {

            g_warning("failed to parse event: %s", error_get_pretty(err));

        }

        qdict_put_obj(qdict, "error", error_get_qobject(err));

        error_free(err);

    } else {

        qdict = qobject_to_qdict(obj);

    }

    g_assert(qdict);

    /* handle host->guest commands */

    if (qdict_haskey(qdict, "execute")) {

        process_command(s, qdict);

    } else {

        if (!qdict_haskey(qdict, "error")) {

            QDECREF(qdict);

            qdict = qdict_new();

            g_warning("unrecognized payload format");

            error_set(&err, QERR_UNSUPPORTED);

            qdict_put_obj(qdict, "error", error_get_qobject(err));

            error_free(err);

        }

        ret = conn_channel_send_payload(s->conn_channel, QOBJECT(qdict));

        if (ret) {

            g_warning("error sending payload: %s", strerror(ret));

        }

    }

    QDECREF(qdict);

}

static gboolean conn_channel_read(GIOChannel *channel, GIOCondition condition,

                                  gpointer data)

{

    GAState *s = data;

    gchar buf[1024];

    gsize count;

    GError *err = NULL;

    memset(buf, 0, 1024);

    GIOStatus status = g_io_channel_read_chars(channel, buf, 1024,

                                               &count, &err);

    if (err != NULL) {

        g_warning("error reading channel: %s", err->message);

        conn_channel_close(s);

        g_error_free(err);

        return false;

    }

    switch (status) {

    case G_IO_STATUS_ERROR:

        g_warning("problem");

        return false;

    case G_IO_STATUS_NORMAL:

        g_debug("read data, count: %d, data: %s", (int)count, buf);

        json_message_parser_feed(&s->parser, (char *)buf, (int)count);

    case G_IO_STATUS_AGAIN:

        /* virtio causes us to spin here when no process is attached to

         * host-side chardev. sleep a bit to mitigate this

         */

        if (s->virtio) {

            usleep(100*1000);

        }

        return true;

    case G_IO_STATUS_EOF:

        g_debug("received EOF");

        conn_channel_close(s);

        if (s->virtio) {

            return true;

        }

        return false;

    default:

        g_warning("unknown channel read status, closing");

        conn_channel_close(s);

        return false;

    }

    return true;

}

static int conn_channel_add(GAState *s, int fd)

{

    GIOChannel *conn_channel;

    GError *err = NULL;

    g_assert(s && !s->conn_channel);

    conn_channel = g_io_channel_unix_new(fd);

    g_assert(conn_channel);

    g_io_channel_set_encoding(conn_channel, NULL, &err);

    if (err != NULL) {

        g_warning("error setting channel encoding to binary");

        g_error_free(err);

        return -1;

    }

    g_io_add_watch(conn_channel, G_IO_IN | G_IO_HUP,

                   conn_channel_read, s);

    s->conn_channel = conn_channel;

    return 0;

}

static gboolean listen_channel_accept(GIOChannel *channel,

                                      GIOCondition condition, gpointer data)

{

    GAState *s = data;

    g_assert(channel != NULL);

    int ret, conn_fd;

    bool accepted = false;

    struct sockaddr_un addr;

    socklen_t addrlen = sizeof(addr);

    conn_fd = qemu_accept(g_io_channel_unix_get_fd(s->listen_channel),

                             (struct sockaddr *)&addr, &addrlen);

    if (conn_fd == -1) {

        g_warning("error converting fd to gsocket: %s", strerror(errno));

        goto out;

    }

    fcntl(conn_fd, F_SETFL, O_NONBLOCK);

    ret = conn_channel_add(s, conn_fd);

    if (ret) {

        g_warning("error setting up connection");

        goto out;

    }

    accepted = true;

out:

    /* only accept 1 connection at a time */

    return !accepted;

}

/* start polling for readable events on listen fd, new==true

 * indicates we should use the existing s->listen_channel

 */

static int listen_channel_add(GAState *s, int listen_fd, bool new)

{

    if (new) {

        s->listen_channel = g_io_channel_unix_new(listen_fd);

    }

    g_io_add_watch(s->listen_channel, G_IO_IN,

                   listen_channel_accept, s);

    return 0;

}

/* cleanup state for closed connection/session, start accepting new

 * connections if we're in listening mode

 */

static void conn_channel_close(GAState *s)

{

    if (strcmp(s->method, "unix-listen") == 0) {

        g_io_channel_shutdown(s->conn_channel, true, NULL);

        listen_channel_add(s, 0, false);

    } else if (strcmp(s->method, "virtio-serial") == 0) {

        /* we spin on EOF for virtio-serial, so back off a bit. also,

         * dont close the connection in this case, it'll resume normal

         * operation when another process connects to host chardev

         */

        usleep(100*1000);

        goto out_noclose;

    }

    g_io_channel_unref(s->conn_channel);

    s->conn_channel = NULL;

out_noclose:

    return;

}

static void init_guest_agent(GAState *s)

{

    struct termios tio;

    int ret, fd;

    if (s->method == NULL) {

        /* try virtio-serial as our default */

        s->method = "virtio-serial";

    }

    if (s->path == NULL) {

        if (strcmp(s->method, "virtio-serial") != 0) {

            g_critical("must specify a path for this channel");

            exit(EXIT_FAILURE);

        }

        /* try the default path for the virtio-serial port */

        s->path = QGA_VIRTIO_PATH_DEFAULT;

    }

    if (strcmp(s->method, "virtio-serial") == 0) {

        s->virtio = true;

        fd = qemu_open(s->path, O_RDWR | O_NONBLOCK | O_ASYNC);

        if (fd == -1) {

            g_critical("error opening channel: %s", strerror(errno));

            exit(EXIT_FAILURE);

        }

        ret = conn_channel_add(s, fd);

        if (ret) {

            g_critical("error adding channel to main loop");

            exit(EXIT_FAILURE);

        }

    } else if (strcmp(s->method, "isa-serial") == 0) {

        fd = qemu_open(s->path, O_RDWR | O_NOCTTY);

        if (fd == -1) {

            g_critical("error opening channel: %s", strerror(errno));

            exit(EXIT_FAILURE);

        }

        tcgetattr(fd, &tio);

        /* set up serial port for non-canonical, dumb byte streaming */

        tio.c_iflag &= ~(IGNBRK | BRKINT | IGNPAR | PARMRK | INPCK | ISTRIP |

                         INLCR | IGNCR | ICRNL | IXON | IXOFF | IXANY |

                         IMAXBEL);

        tio.c_oflag = 0;

        tio.c_lflag = 0;

        tio.c_cflag |= QGA_BAUDRATE_DEFAULT;

        /* 1 available byte min or reads will block (we'll set non-blocking

         * elsewhere, else we have to deal with read()=0 instead)

         */

        tio.c_cc[VMIN] = 1;

        tio.c_cc[VTIME] = 0;

        /* flush everything waiting for read/xmit, it's garbage at this point */

        tcflush(fd, TCIFLUSH);

        tcsetattr(fd, TCSANOW, &tio);

        ret = conn_channel_add(s, fd);

        if (ret) {

            g_error("error adding channel to main loop");

        }

    } else if (strcmp(s->method, "unix-listen") == 0) {

        fd = unix_listen(s->path, NULL, strlen(s->path));

        if (fd == -1) {

            g_critical("error opening path: %s", strerror(errno));

            exit(EXIT_FAILURE);

        }

        ret = listen_channel_add(s, fd, true);

        if (ret) {

            g_critical("error binding/listening to specified socket");

            exit(EXIT_FAILURE);

        }

    } else {

        g_critical("unsupported channel method/type: %s", s->method);

        exit(EXIT_FAILURE);

    }

    json_message_parser_init(&s->parser, process_event);

    s->main_loop = g_main_loop_new(NULL, false);

}

int main(int argc, char **argv)

{

    const char *sopt = "hVvdm:p:l:f:b:";

    const char *method = NULL, *path = NULL, *pidfile = QGA_PIDFILE_DEFAULT;

    const struct option lopt[] = {

        { "help", 0, NULL, 'h' },

        { "version", 0, NULL, 'V' },

        { "logfile", 0, NULL, 'l' },

        { "pidfile", 0, NULL, 'f' },

        { "verbose", 0, NULL, 'v' },

        { "method", 0, NULL, 'm' },

        { "path", 0, NULL, 'p' },

        { "daemonize", 0, NULL, 'd' },

        { "blacklist", 0, NULL, 'b' },

        { NULL, 0, NULL, 0 }

    };

    int opt_ind = 0, ch, daemonize = 0, i, j, len;

    GLogLevelFlags log_level = G_LOG_LEVEL_ERROR | G_LOG_LEVEL_CRITICAL;

    FILE *log_file = stderr;

    GAState *s;

    module_call_init(MODULE_INIT_QAPI);

    while ((ch = getopt_long(argc, argv, sopt, lopt, &opt_ind)) != -1) {

        switch (ch) {

        case 'm':

            method = optarg;

            break;

        case 'p':

            path = optarg;

            break;

        case 'l':

            log_file = fopen(optarg, "a");

            if (!log_file) {

                g_critical("unable to open specified log file: %s",

                           strerror(errno));

                return EXIT_FAILURE;

            }

            break;

        case 'f':

            pidfile = optarg;

            break;

        case 'v':

            /* enable all log levels */

            log_level = G_LOG_LEVEL_MASK;

            break;

        case 'V':

            printf("QEMU Guest Agent %s\n", QGA_VERSION);

            return 0;

        case 'd':

            daemonize = 1;

            break;

        case 'b': {

            char **list_head, **list;

            if (*optarg == '?') {

                list_head = list = qmp_get_command_list();

                while (*list != NULL) {

                    printf("%s\n", *list);

                    g_free(*list);

                    list++;

                }

                g_free(list_head);

                return 0;

            }

            for (j = 0, i = 0, len = strlen(optarg); i < len; i++) {

                if (optarg[i] == ',') {

                    optarg[i] = 0;

                    qmp_disable_command(&optarg[j]);

                    g_debug("disabling command: %s", &optarg[j]);

                    j = i + 1;

                }

            }

            if (j < i) {

                qmp_disable_command(&optarg[j]);

                g_debug("disabling command: %s", &optarg[j]);

            }

            break;

        }

        case 'h':

            usage(argv[0]);

            return 0;

        case '?':

            g_print("Unknown option, try '%s --help' for more information.\n",

                    argv[0]);

            return EXIT_FAILURE;

        }

    }

    if (daemonize) {

        g_debug("starting daemon");

        become_daemon(pidfile);

    }

    s = g_malloc0(sizeof(GAState));

    s->conn_channel = NULL;

    s->path = path;

    s->method = method;

    s->log_file = log_file;

    s->log_level = log_level;

    g_log_set_default_handler(ga_log, s);

    g_log_set_fatal_mask(NULL, G_LOG_LEVEL_ERROR);

    s->logging_enabled = true;

    s->command_state = ga_command_state_new();

    ga_command_state_init(s, s->command_state);

    ga_command_state_init_all(s->command_state);

    ga_state = s;

    init_guest_agent(ga_state);

    register_signal_handlers();

    g_main_loop_run(ga_state->main_loop);

    ga_command_state_cleanup_all(ga_state->command_state);

    unlink(pidfile);

    return 0;

}