This is the actual guest daemon, it listens for requests over a virtio-serial/isa-serial/unix socket channel and routes them through to dispatch routines, and writes the results back to the channel in a manner similar to Qmp.
This is currently horribly broken, only the unix-listen channel method is working at the moment (likely due to mis-use of gio channel interfaces), and the code is in overall rough shape. Signed-off-by: Michael Roth <mdr...@linux.vnet.ibm.com> --- qemu-ga.c | 522 +++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++ 1 files changed, 522 insertions(+), 0 deletions(-) create mode 100644 qemu-ga.c diff --git a/qemu-ga.c b/qemu-ga.c new file mode 100644 index 0000000..435a1fc --- /dev/null +++ b/qemu-ga.c @@ -0,0 +1,522 @@ +/* + * QEMU Guest Agent + * + * Copyright IBM Corp. 2011 + * + * Authors: + * Adam Litke <agli...@linux.vnet.ibm.com> + * Michael Roth <mdr...@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 <gio/gio.h> +#include <getopt.h> +#include <termios.h> +#include "qemu_socket.h" +#include "json-streamer.h" +#include "json-parser.h" +#include "guest-agent.h" + +#define QGA_VERSION "1.0" +#define QGA_GUEST_PATH_VIRTIO_DEFAULT "/dev/virtio-ports/va" +#define QGA_PIDFILE_DEFAULT "/var/run/qemu-va.pid" +#define QGA_BAUDRATE_DEFAULT B38400 /* for isa-serial channels */ + +bool verbose_enabled = false; + +typedef struct GAState { + bool active; + int session_id; + const char *proxy_path; + JSONMessageParser parser; + GMainLoop *main_loop; + guint conn_id; + GSocket *conn_sock; + GIOChannel *conn_channel; + guint listen_id; + GSocket *listen_sock; + GIOChannel *listen_channel; + const char *path; + const char *method; +} GAState; + +static void usage(const char *cmd) +{ + printf( +"Usage: %s -c <channel_opts>\n" +"QEMU virtagent guest agent %s\n" +"\n" +" -c, --channel channel method: one of unix-connect, virtio-serial, or\n" +" isa-serial\n" +" -p, --path channel path\n" +" -v, --verbose display extra debugging information\n" +" -d, --daemonize become a daemon\n" +" -h, --help display this help and exit\n" +"\n" +"Report bugs to <mdr...@linux.vnet.ibm.com>\n" + , cmd, QGA_VERSION); +} + +static void conn_channel_close(GAState *s); + +static void become_daemon(void) +{ + pid_t pid, sid; + int pidfd; + char *pidstr; + + pid = fork(); + if (pid < 0) + exit(EXIT_FAILURE); + if (pid > 0) { + exit(EXIT_SUCCESS); + } + + pidfd = open(QGA_PIDFILE_DEFAULT, O_CREAT|O_RDWR, S_IRUSR|S_IWUSR); + if (!pidfd || lockf(pidfd, F_TLOCK, 0)) + g_error("Cannot lock pid file"); + + if (ftruncate(pidfd, 0) || lseek(pidfd, 0, SEEK_SET)) + g_error("Cannot truncate pid file"); + if (asprintf(&pidstr, "%d", getpid()) == -1) + g_error("Cannot allocate memory"); + if (write(pidfd, pidstr, strlen(pidstr)) != strlen(pidstr)) + g_error("Failed to write pid file"); + free(pidstr); + + umask(0); + sid = setsid(); + if (sid < 0) + goto fail; + if ((chdir("/")) < 0) + goto fail; + + close(STDIN_FILENO); + close(STDOUT_FILENO); + close(STDERR_FILENO); + return; + +fail: + unlink(QGA_PIDFILE_DEFAULT); + g_error("failed to daemonize"); +} + +static int conn_channel_send_payload(GIOChannel *channel, QObject *payload) +{ + gsize count, written=0; + const char *buf; + QString *payload_qstr; + GIOStatus status; + GError *err = NULL; + + if (!payload || !channel) { + return -EINVAL; + } + + payload_qstr = qobject_to_json(payload); + if (!payload_qstr) { + return -EINVAL; + } + + buf = qstring_get_str(payload_qstr); + count = strlen(buf); + + while (count) { + g_warning("sending, count: %d", (int)count); + status = g_io_channel_write_chars(channel, buf, count, &written, &err); + if (err != NULL) { + g_warning("error sending payload: %s", err->message); + return err->code; + } + if (status == G_IO_STATUS_NORMAL) { + count -= written; + } else if (status == G_IO_STATUS_ERROR || status == G_IO_STATUS_EOF) { + return -EPIPE; + } + } + g_io_channel_flush(channel, &err); + if (err != NULL) { + g_warning("error flushing payload: %s", err->message); + return err->code; + } + return 0; +} + +/* keep reading channel, but ignore all data until we see an appropriate + * ack from the host + */ +static void start_negotiation(GAState *s) +{ + QDict *payload = qdict_new(); + int ret; + + g_debug("[re]negotiating connection"); + + g_assert(s && s->conn_channel); + s->active = false; + s->session_id = g_random_int_range(1, G_MAXINT32); + + qdict_put_obj(payload, "_xport_event", + QOBJECT(qstring_from_str("guest_init"))); + qdict_put_obj(payload, "_xport_arg_sid", + QOBJECT(qint_from_int(s->session_id))); + + ret = conn_channel_send_payload(s->conn_channel, QOBJECT(payload)); + if (ret) { + g_warning("failed to send guest init, resetting connection"); + conn_channel_close(s); + } +} + +static void complete_negotiation(GAState *s) +{ + g_debug("connection negotiation complete"); + s->active = true; +} + +static void process_event(JSONMessageParser *parser, QList *tokens) +{ + GAState *s = container_of(parser, GAState, parser); + QObject *obj, *rsp; + QDict *qdict; + Error *err = NULL; + const char *cmd; + int session_id, ret; + + g_assert(s && parser); + + g_debug("process_event: called\n"); + obj = json_parser_parse_err(tokens, NULL, &err); + if (!obj || qobject_type(obj) != QTYPE_QDICT) { + g_warning("failed to parse event"); + return; + } else { + g_debug("parse successful"); + qdict = qobject_to_qdict(obj); + } + + /* check for transport-only commands/events */ + if (qdict_haskey(qdict, "_xport_event")) { + cmd = qdict_get_try_str(qdict, "_xport_event"); + if (cmd && strcmp(cmd, "host_ack") == 0) { + session_id = qdict_get_try_int(qdict, "_xport_arg_sid", 0); + if (session_id == s->session_id) { + /* host acknowledged us, begin normal operation */ + complete_negotiation(s); + } + return; + } + } + + /* ignore any non-xport-related events/objects */ + if (!s->active) { + return; + } + + if (qdict_haskey(qdict, "execute")) { + g_debug("received command"); + rsp = qga_dispatch(QOBJECT(qdict), &err); + g_debug("done handling command"); + if (err == NULL && rsp) { + g_debug("response:\n%s", qstring_get_str(qobject_to_json(rsp))); + ret = conn_channel_send_payload(s->conn_channel, rsp); + if (ret) { + g_warning("error sending payload: %s", strerror(ret)); + /* reset/renegotiate connection, since we may be in + * unrecoverable state + */ + start_negotiation(s); + } + qobject_decref(rsp); + } else { + g_warning("error getting response"); + } + } else { + g_warning("unrecognized payload format, ignoring"); + } +} + +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); + return false; + } + switch (status) { + case G_IO_STATUS_ERROR: + g_warning("problem"); + return false; + case G_IO_STATUS_NORMAL: + json_message_parser_feed(&s->parser, (char *)buf, (int)count); + g_warning("count: %d, data: %s", (int)count, buf); + case G_IO_STATUS_AGAIN: + return true; + case G_IO_STATUS_EOF: + g_debug("received EOF"); + conn_channel_close(s); + 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; + guint conn_id; + GError *err = NULL; + + g_assert(s && fd > 0 && !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"); + return -1; + } + conn_id = g_io_add_watch(conn_channel, G_IO_IN, conn_channel_read, s); + if (err != NULL) { + g_warning("error adding io watch: %s", err->message); + return -1; + } + s->conn_channel = conn_channel; + s->conn_id = conn_id; + start_negotiation(s); + return 0; +} + +static gboolean listen_channel_accept(GIOChannel *channel, + GIOCondition condition, gpointer data) +{ + GAState *s = data; + GError *err = NULL; + g_assert(channel != NULL); + int ret; + bool accepted = false; + + s->conn_sock = g_socket_accept(s->listen_sock, NULL, &err); + if (err != NULL) { + g_warning("error converting fd to gsocket: %s", err->message); + goto out; + } + ret = conn_channel_add(s, g_socket_get_fd(s->conn_sock)); + 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, listen_fd=0 + * indicates we should use the existing s->listen_channel + */ +static int listen_channel_add(GAState *s, int listen_fd) +{ + GError *err = NULL; + guint listen_id; + + if (listen_fd) { + s->listen_channel = g_io_channel_unix_new(listen_fd); + if (s->listen_sock) { + g_object_unref(s->listen_sock); + } + s->listen_sock = g_socket_new_from_fd(listen_fd, &err); + if (err != NULL) { + g_warning("error converting fd to gsocket: %s", err->message); + return -1; + } + } + listen_id = g_io_add_watch(s->listen_channel, G_IO_IN, + listen_channel_accept, s); + if (err != NULL) { + g_warning("error adding io watch: %s", err->message); + return -1; + } + 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_object_unref(s->conn_sock); + s->conn_sock = NULL; + listen_channel_add(s, 0); + } 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); + return; + } + g_io_channel_shutdown(s->conn_channel, true, NULL); + g_io_channel_unref(s->conn_channel); + s->conn_channel = NULL; + s->conn_id = 0; +} + +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_error("must specify a path for this channel"); + } + /* try the default path for the virtio-serial port */ + s->path = QGA_GUEST_PATH_VIRTIO_DEFAULT; + } + + if (strcmp(s->method, "virtio-serial") == 0) { + fd = qemu_open(s->path, O_RDWR); + if (fd == -1) { + g_error("error opening channel: %s", strerror(errno)); + } + ret = fcntl(fd, F_GETFL); + if (ret < 0) { + g_error("error getting channel flags: %s", strerror(errno)); + } + ret = fcntl(fd, F_SETFL, ret | O_NONBLOCK | O_ASYNC); + if (ret < 0) { + g_error("error setting channel flags: %s", strerror(errno)); + } + ret = conn_channel_add(s, fd); + if (ret) { + g_error("error adding channel to main loop"); + } + } else if (strcmp(s->method, "isa-serial") == 0) { + fd = qemu_open(s->path, O_RDWR | O_NOCTTY); + if (fd == -1) { + g_error("error opening channel: %s", strerror(errno)); + } + 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 <= 0) { + g_error("error opening path: %s", strerror(errno)); + } + ret = listen_channel_add(s, fd); + if (ret) { + g_error("error binding/listening to specified socket"); + } + } else { + g_error("unsupported channel method/type: %s", s->method); + } + + 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 = "hVvdc:p:", *method = NULL, *path = NULL; + struct option lopt[] = { + { "help", 0, NULL, 'h' }, + { "version", 0, NULL, 'V' }, + { "verbose", 0, NULL, 'v' }, + { "channel", 0, NULL, 'c' }, + { "path", 0, NULL, 'p' }, + { "daemonize", 0, NULL, 'd' }, + { NULL, 0, NULL, 0 } + }; + int opt_ind = 0, ch, daemonize=0; + GAState *s; + + g_type_init(); + + while ((ch = getopt_long(argc, argv, sopt, lopt, &opt_ind)) != -1) { + switch (ch) { + case 'c': + method = optarg; + break; + case 'p': + path = optarg; + break; + case 'v': + /* TODO: set appropriate log level */ + verbose_enabled = true; + break; + case 'V': + printf("QEMU Guest Agent %s\n", QGA_VERSION); + return 0; + case 'd': + daemonize = 1; + break; + case 'h': + usage(argv[0]); + return 0; + case '?': + g_error("Unknown option, try '%s --help' for more information.", + argv[0]); + } + } + + if (daemonize) { + g_debug("starting daemon"); + become_daemon(); + } + + qga_init_marshal(); + + s = g_malloc(sizeof(GAState)); + s->active = false; + s->session_id = 0; + s->conn_id = 0; + s->conn_channel = NULL; + s->path = path; + s->method = method; + + init_guest_agent(s); + g_main_loop_run(s->main_loop); + + return 0; +} -- 1.7.0.4