diff options
Diffstat (limited to 'qga/commands-posix.c')
| -rw-r--r-- | qga/commands-posix.c | 528 |
1 files changed, 528 insertions, 0 deletions
diff --git a/qga/commands-posix.c b/qga/commands-posix.c new file mode 100644 index 0000000000..126127aae4 --- /dev/null +++ b/qga/commands-posix.c @@ -0,0 +1,528 @@ +/* + * QEMU Guest Agent POSIX-specific command implementations + * + * Copyright IBM Corp. 2011 + * + * Authors: + * 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 <glib.h> + +#if defined(__linux__) +#include <mntent.h> +#include <linux/fs.h> + +#if defined(__linux__) && defined(FIFREEZE) +#define CONFIG_FSFREEZE +#endif +#endif + +#include <sys/types.h> +#include <sys/ioctl.h> +#include "qga/guest-agent-core.h" +#include "qga-qmp-commands.h" +#include "qerror.h" +#include "qemu-queue.h" + +static GAState *ga_state; + +void qmp_guest_shutdown(bool has_mode, const char *mode, Error **err) +{ + int ret; + const char *shutdown_flag; + + slog("guest-shutdown called, mode: %s", mode); + if (!has_mode || strcmp(mode, "powerdown") == 0) { + shutdown_flag = "-P"; + } else if (strcmp(mode, "halt") == 0) { + shutdown_flag = "-H"; + } else if (strcmp(mode, "reboot") == 0) { + shutdown_flag = "-r"; + } else { + error_set(err, QERR_INVALID_PARAMETER_VALUE, "mode", + "halt|powerdown|reboot"); + return; + } + + ret = fork(); + if (ret == 0) { + /* child, start the shutdown */ + setsid(); + fclose(stdin); + fclose(stdout); + fclose(stderr); + + ret = execl("/sbin/shutdown", "shutdown", shutdown_flag, "+0", + "hypervisor initiated shutdown", (char*)NULL); + if (ret) { + slog("guest-shutdown failed: %s", strerror(errno)); + } + exit(!!ret); + } else if (ret < 0) { + error_set(err, QERR_UNDEFINED_ERROR); + } +} + +typedef struct GuestFileHandle { + uint64_t id; + FILE *fh; + QTAILQ_ENTRY(GuestFileHandle) next; +} GuestFileHandle; + +static struct { + QTAILQ_HEAD(, GuestFileHandle) filehandles; +} guest_file_state; + +static void guest_file_handle_add(FILE *fh) +{ + GuestFileHandle *gfh; + + gfh = g_malloc0(sizeof(GuestFileHandle)); + gfh->id = fileno(fh); + gfh->fh = fh; + QTAILQ_INSERT_TAIL(&guest_file_state.filehandles, gfh, next); +} + +static GuestFileHandle *guest_file_handle_find(int64_t id) +{ + GuestFileHandle *gfh; + + QTAILQ_FOREACH(gfh, &guest_file_state.filehandles, next) + { + if (gfh->id == id) { + return gfh; + } + } + + return NULL; +} + +int64_t qmp_guest_file_open(const char *path, bool has_mode, const char *mode, Error **err) +{ + FILE *fh; + int fd; + int64_t ret = -1; + + if (!has_mode) { + mode = "r"; + } + slog("guest-file-open called, filepath: %s, mode: %s", path, mode); + fh = fopen(path, mode); + if (!fh) { + error_set(err, QERR_OPEN_FILE_FAILED, path); + return -1; + } + + /* set fd non-blocking to avoid common use cases (like reading from a + * named pipe) from hanging the agent + */ + fd = fileno(fh); + ret = fcntl(fd, F_GETFL); + ret = fcntl(fd, F_SETFL, ret | O_NONBLOCK); + if (ret == -1) { + error_set(err, QERR_QGA_COMMAND_FAILED, "fcntl() failed"); + fclose(fh); + return -1; + } + + guest_file_handle_add(fh); + slog("guest-file-open, handle: %d", fd); + return fd; +} + +void qmp_guest_file_close(int64_t handle, Error **err) +{ + GuestFileHandle *gfh = guest_file_handle_find(handle); + int ret; + + slog("guest-file-close called, handle: %ld", handle); + if (!gfh) { + error_set(err, QERR_FD_NOT_FOUND, "handle"); + return; + } + + ret = fclose(gfh->fh); + if (ret == -1) { + error_set(err, QERR_QGA_COMMAND_FAILED, "fclose() failed"); + return; + } + + QTAILQ_REMOVE(&guest_file_state.filehandles, gfh, next); + g_free(gfh); +} + +struct GuestFileRead *qmp_guest_file_read(int64_t handle, bool has_count, + int64_t count, Error **err) +{ + GuestFileHandle *gfh = guest_file_handle_find(handle); + GuestFileRead *read_data = NULL; + guchar *buf; + FILE *fh; + size_t read_count; + + if (!gfh) { + error_set(err, QERR_FD_NOT_FOUND, "handle"); + return NULL; + } + + if (!has_count) { + count = QGA_READ_COUNT_DEFAULT; + } else if (count < 0) { + error_set(err, QERR_INVALID_PARAMETER, "count"); + return NULL; + } + + fh = gfh->fh; + buf = g_malloc0(count+1); + read_count = fread(buf, 1, count, fh); + if (ferror(fh)) { + slog("guest-file-read failed, handle: %ld", handle); + error_set(err, QERR_QGA_COMMAND_FAILED, "fread() failed"); + } else { + buf[read_count] = 0; + read_data = g_malloc0(sizeof(GuestFileRead)); + read_data->count = read_count; + read_data->eof = feof(fh); + if (read_count) { + read_data->buf_b64 = g_base64_encode(buf, read_count); + } + } + g_free(buf); + clearerr(fh); + + return read_data; +} + +GuestFileWrite *qmp_guest_file_write(int64_t handle, const char *buf_b64, + bool has_count, int64_t count, Error **err) +{ + GuestFileWrite *write_data = NULL; + guchar *buf; + gsize buf_len; + int write_count; + GuestFileHandle *gfh = guest_file_handle_find(handle); + FILE *fh; + + if (!gfh) { + error_set(err, QERR_FD_NOT_FOUND, "handle"); + return NULL; + } + + fh = gfh->fh; + buf = g_base64_decode(buf_b64, &buf_len); + + if (!has_count) { + count = buf_len; + } else if (count < 0 || count > buf_len) { + g_free(buf); + error_set(err, QERR_INVALID_PARAMETER, "count"); + return NULL; + } + + write_count = fwrite(buf, 1, count, fh); + if (ferror(fh)) { + slog("guest-file-write failed, handle: %ld", handle); + error_set(err, QERR_QGA_COMMAND_FAILED, "fwrite() error"); + } else { + write_data = g_malloc0(sizeof(GuestFileWrite)); + write_data->count = write_count; + write_data->eof = feof(fh); + } + g_free(buf); + clearerr(fh); + + return write_data; +} + +struct GuestFileSeek *qmp_guest_file_seek(int64_t handle, int64_t offset, + int64_t whence, Error **err) +{ + GuestFileHandle *gfh = guest_file_handle_find(handle); + GuestFileSeek *seek_data = NULL; + FILE *fh; + int ret; + + if (!gfh) { + error_set(err, QERR_FD_NOT_FOUND, "handle"); + return NULL; + } + + fh = gfh->fh; + ret = fseek(fh, offset, whence); + if (ret == -1) { + error_set(err, QERR_QGA_COMMAND_FAILED, strerror(errno)); + } else { + seek_data = g_malloc0(sizeof(GuestFileRead)); + seek_data->position = ftell(fh); + seek_data->eof = feof(fh); + } + clearerr(fh); + + return seek_data; +} + +void qmp_guest_file_flush(int64_t handle, Error **err) +{ + GuestFileHandle *gfh = guest_file_handle_find(handle); + FILE *fh; + int ret; + + if (!gfh) { + error_set(err, QERR_FD_NOT_FOUND, "handle"); + return; + } + + fh = gfh->fh; + ret = fflush(fh); + if (ret == EOF) { + error_set(err, QERR_QGA_COMMAND_FAILED, strerror(errno)); + } +} + +static void guest_file_init(void) +{ + QTAILQ_INIT(&guest_file_state.filehandles); +} + +#if defined(CONFIG_FSFREEZE) +static void disable_logging(void) +{ + ga_disable_logging(ga_state); +} + +static void enable_logging(void) +{ + ga_enable_logging(ga_state); +} + +typedef struct GuestFsfreezeMount { + char *dirname; + char *devtype; + QTAILQ_ENTRY(GuestFsfreezeMount) next; +} GuestFsfreezeMount; + +struct { + GuestFsfreezeStatus status; + QTAILQ_HEAD(, GuestFsfreezeMount) mount_list; +} guest_fsfreeze_state; + +/* + * Walk the mount table and build a list of local file systems + */ +static int guest_fsfreeze_build_mount_list(void) +{ + struct mntent *ment; + GuestFsfreezeMount *mount, *temp; + char const *mtab = MOUNTED; + FILE *fp; + + QTAILQ_FOREACH_SAFE(mount, &guest_fsfreeze_state.mount_list, next, temp) { + QTAILQ_REMOVE(&guest_fsfreeze_state.mount_list, mount, next); + g_free(mount->dirname); + g_free(mount->devtype); + g_free(mount); + } + + fp = setmntent(mtab, "r"); + if (!fp) { + g_warning("fsfreeze: unable to read mtab"); + return -1; + } + + while ((ment = getmntent(fp))) { + /* + * An entry which device name doesn't start with a '/' is + * either a dummy file system or a network file system. + * Add special handling for smbfs and cifs as is done by + * coreutils as well. + */ + if ((ment->mnt_fsname[0] != '/') || + (strcmp(ment->mnt_type, "smbfs") == 0) || + (strcmp(ment->mnt_type, "cifs") == 0)) { + continue; + } + + mount = g_malloc0(sizeof(GuestFsfreezeMount)); + mount->dirname = g_strdup(ment->mnt_dir); + mount->devtype = g_strdup(ment->mnt_type); + + QTAILQ_INSERT_TAIL(&guest_fsfreeze_state.mount_list, mount, next); + } + + endmntent(fp); + + return 0; +} + +/* + * Return status of freeze/thaw + */ +GuestFsfreezeStatus qmp_guest_fsfreeze_status(Error **err) +{ + return guest_fsfreeze_state.status; +} + +/* + * Walk list of mounted file systems in the guest, and freeze the ones which + * are real local file systems. + */ +int64_t qmp_guest_fsfreeze_freeze(Error **err) +{ + int ret = 0, i = 0; + struct GuestFsfreezeMount *mount, *temp; + int fd; + char err_msg[512]; + + slog("guest-fsfreeze called"); + + if (guest_fsfreeze_state.status == GUEST_FSFREEZE_STATUS_FROZEN) { + return 0; + } + + ret = guest_fsfreeze_build_mount_list(); + if (ret < 0) { + return ret; + } + + /* cannot risk guest agent blocking itself on a write in this state */ + disable_logging(); + + QTAILQ_FOREACH_SAFE(mount, &guest_fsfreeze_state.mount_list, next, temp) { + fd = qemu_open(mount->dirname, O_RDONLY); + if (fd == -1) { + sprintf(err_msg, "failed to open %s, %s", mount->dirname, strerror(errno)); + error_set(err, QERR_QGA_COMMAND_FAILED, err_msg); + goto error; + } + + /* we try to cull filesytems we know won't work in advance, but other + * filesytems may not implement fsfreeze for less obvious reasons. + * these will report EOPNOTSUPP, so we simply ignore them. when + * thawing, these filesystems will return an EINVAL instead, due to + * not being in a frozen state. Other filesystem-specific + * errors may result in EINVAL, however, so the user should check the + * number * of filesystems returned here against those returned by the + * thaw operation to determine whether everything completed + * successfully + */ + ret = ioctl(fd, FIFREEZE); + if (ret < 0 && errno != EOPNOTSUPP) { + sprintf(err_msg, "failed to freeze %s, %s", mount->dirname, strerror(errno)); + error_set(err, QERR_QGA_COMMAND_FAILED, err_msg); + close(fd); + goto error; + } + close(fd); + + i++; + } + + guest_fsfreeze_state.status = GUEST_FSFREEZE_STATUS_FROZEN; + return i; + +error: + if (i > 0) { + qmp_guest_fsfreeze_thaw(NULL); + } + return 0; +} + +/* + * Walk list of frozen file systems in the guest, and thaw them. + */ +int64_t qmp_guest_fsfreeze_thaw(Error **err) +{ + int ret; + GuestFsfreezeMount *mount, *temp; + int fd, i = 0; + bool has_error = false; + + QTAILQ_FOREACH_SAFE(mount, &guest_fsfreeze_state.mount_list, next, temp) { + fd = qemu_open(mount->dirname, O_RDONLY); + if (fd == -1) { + has_error = true; + continue; + } + ret = ioctl(fd, FITHAW); + if (ret < 0 && errno != EOPNOTSUPP && errno != EINVAL) { + has_error = true; + close(fd); + continue; + } + close(fd); + i++; + } + + if (has_error) { + guest_fsfreeze_state.status = GUEST_FSFREEZE_STATUS_ERROR; + } else { + guest_fsfreeze_state.status = GUEST_FSFREEZE_STATUS_THAWED; + } + enable_logging(); + return i; +} + +static void guest_fsfreeze_init(void) +{ + guest_fsfreeze_state.status = GUEST_FSFREEZE_STATUS_THAWED; + QTAILQ_INIT(&guest_fsfreeze_state.mount_list); +} + +static void guest_fsfreeze_cleanup(void) +{ + int64_t ret; + Error *err = NULL; + + if (guest_fsfreeze_state.status == GUEST_FSFREEZE_STATUS_FROZEN) { + ret = qmp_guest_fsfreeze_thaw(&err); + if (ret < 0 || err) { + slog("failed to clean up frozen filesystems"); + } + } +} +#else +/* + * Return status of freeze/thaw + */ +GuestFsfreezeStatus qmp_guest_fsfreeze_status(Error **err) +{ + error_set(err, QERR_UNSUPPORTED); + + return 0; +} + +/* + * Walk list of mounted file systems in the guest, and freeze the ones which + * are real local file systems. + */ +int64_t qmp_guest_fsfreeze_freeze(Error **err) +{ + error_set(err, QERR_UNSUPPORTED); + + return 0; +} + +/* + * Walk list of frozen file systems in the guest, and thaw them. + */ +int64_t qmp_guest_fsfreeze_thaw(Error **err) +{ + error_set(err, QERR_UNSUPPORTED); + + return 0; +} +#endif + +/* register init/cleanup routines for stateful command groups */ +void ga_command_state_init(GAState *s, GACommandState *cs) +{ + ga_state = s; +#if defined(CONFIG_FSFREEZE) + ga_command_state_add(cs, guest_fsfreeze_init, guest_fsfreeze_cleanup); +#endif + ga_command_state_add(cs, guest_file_init, NULL); +} |