/* * QEMU Guest Agent common/cross-platform command implementations * * Copyright IBM Corp. 2012 * * 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 "qemu/osdep.h" #include <glib.h> #include "qga/guest-agent-core.h" #include "qga-qmp-commands.h" #include "qapi/qmp/qerror.h" #include "qemu/base64.h" /* Maximum captured guest-exec out_data/err_data - 16MB */ #define GUEST_EXEC_MAX_OUTPUT (16*1024*1024) /* Allocation and I/O buffer for reading guest-exec out_data/err_data - 4KB */ #define GUEST_EXEC_IO_SIZE (4*1024) /* Note: in some situations, like with the fsfreeze, logging may be * temporarilly disabled. if it is necessary that a command be able * to log for accounting purposes, check ga_logging_enabled() beforehand, * and use the QERR_QGA_LOGGING_DISABLED to generate an error */ void slog(const gchar *fmt, ...) { va_list ap; va_start(ap, fmt); g_logv("syslog", G_LOG_LEVEL_INFO, fmt, ap); va_end(ap); } int64_t qmp_guest_sync_delimited(int64_t id, Error **errp) { ga_set_response_delimited(ga_state); return id; } int64_t qmp_guest_sync(int64_t id, Error **errp) { return id; } void qmp_guest_ping(Error **errp) { slog("guest-ping called"); } static void qmp_command_info(QmpCommand *cmd, void *opaque) { GuestAgentInfo *info = opaque; GuestAgentCommandInfo *cmd_info; GuestAgentCommandInfoList *cmd_info_list; cmd_info = g_new0(GuestAgentCommandInfo, 1); cmd_info->name = g_strdup(qmp_command_name(cmd)); cmd_info->enabled = qmp_command_is_enabled(cmd); cmd_info->success_response = qmp_has_success_response(cmd); cmd_info_list = g_new0(GuestAgentCommandInfoList, 1); cmd_info_list->value = cmd_info; cmd_info_list->next = info->supported_commands; info->supported_commands = cmd_info_list; } struct GuestAgentInfo *qmp_guest_info(Error **errp) { GuestAgentInfo *info = g_new0(GuestAgentInfo, 1); info->version = g_strdup(QEMU_VERSION); qmp_for_each_command(qmp_command_info, info); return info; } struct GuestExecIOData { guchar *data; gsize size; gsize length; gint closed; bool truncated; const char *name; }; typedef struct GuestExecIOData GuestExecIOData; struct GuestExecInfo { GPid pid; int64_t pid_numeric; gint status; bool has_output; gint finished; GuestExecIOData in; GuestExecIOData out; GuestExecIOData err; QTAILQ_ENTRY(GuestExecInfo) next; }; typedef struct GuestExecInfo GuestExecInfo; static struct { QTAILQ_HEAD(, GuestExecInfo) processes; } guest_exec_state = { .processes = QTAILQ_HEAD_INITIALIZER(guest_exec_state.processes), }; static int64_t gpid_to_int64(GPid pid) { #ifdef G_OS_WIN32 return GetProcessId(pid); #else return (int64_t)pid; #endif } static GuestExecInfo *guest_exec_info_add(GPid pid) { GuestExecInfo *gei; gei = g_new0(GuestExecInfo, 1); gei->pid = pid; gei->pid_numeric = gpid_to_int64(pid); QTAILQ_INSERT_TAIL(&guest_exec_state.processes, gei, next); return gei; } static GuestExecInfo *guest_exec_info_find(int64_t pid_numeric) { GuestExecInfo *gei; QTAILQ_FOREACH(gei, &guest_exec_state.processes, next) { if (gei->pid_numeric == pid_numeric) { return gei; } } return NULL; } GuestExecStatus *qmp_guest_exec_status(int64_t pid, Error **err) { GuestExecInfo *gei; GuestExecStatus *ges; slog("guest-exec-status called, pid: %u", (uint32_t)pid); gei = guest_exec_info_find(pid); if (gei == NULL) { error_setg(err, QERR_INVALID_PARAMETER, "pid"); return NULL; } ges = g_new0(GuestExecStatus, 1); bool finished = g_atomic_int_get(&gei->finished); /* need to wait till output channels are closed * to be sure we captured all output at this point */ if (gei->has_output) { finished = finished && g_atomic_int_get(&gei->out.closed); finished = finished && g_atomic_int_get(&gei->err.closed); } ges->exited = finished; if (finished) { /* Glib has no portable way to parse exit status. * On UNIX, we can get either exit code from normal termination * or signal number. * On Windows, it is either the same exit code or the exception * value for an unhandled exception that caused the process * to terminate. * See MSDN for GetExitCodeProcess() and ntstatus.h for possible * well-known codes, e.g. C0000005 ACCESS_DENIED - analog of SIGSEGV * References: * https://msdn.microsoft.com/en-us/library/windows/desktop/ms683189(v=vs.85).aspx * https://msdn.microsoft.com/en-us/library/aa260331(v=vs.60).aspx */ #ifdef G_OS_WIN32 /* Additionally WIN32 does not provide any additional information * on whetherthe child exited or terminated via signal. * We use this simple range check to distingish application exit code * (usually value less then 256) and unhandled exception code with * ntstatus (always value greater then 0xC0000005). */ if ((uint32_t)gei->status < 0xC0000000U) { ges->has_exitcode = true; ges->exitcode = gei->status; } else { ges->has_signal = true; ges->signal = gei->status; } #else if (WIFEXITED(gei->status)) { ges->has_exitcode = true; ges->exitcode = WEXITSTATUS(gei->status); } else if (WIFSIGNALED(gei->status)) { ges->has_signal = true; ges->signal = WTERMSIG(gei->status); } #endif if (gei->out.length > 0) { ges->has_out_data = true; ges->out_data = g_base64_encode(gei->out.data, gei->out.length); g_free(gei->out.data); ges->has_out_truncated = gei->out.truncated; } if (gei->err.length > 0) { ges->has_err_data = true; ges->err_data = g_base64_encode(gei->err.data, gei->err.length); g_free(gei->err.data); ges->has_err_truncated = gei->err.truncated; } QTAILQ_REMOVE(&guest_exec_state.processes, gei, next); g_free(gei); } return ges; } /* Get environment variables or arguments array for execve(). */ static char **guest_exec_get_args(const strList *entry, bool log) { const strList *it; int count = 1, i = 0; /* reserve for NULL terminator */ char **args; char *str; /* for logging array of arguments */ size_t str_size = 1; for (it = entry; it != NULL; it = it->next) { count++; str_size += 1 + strlen(it->value); } str = g_malloc(str_size); *str = 0; args = g_malloc(count * sizeof(char *)); for (it = entry; it != NULL; it = it->next) { args[i++] = it->value; pstrcat(str, str_size, it->value); if (it->next) { pstrcat(str, str_size, " "); } } args[i] = NULL; if (log) { slog("guest-exec called: \"%s\"", str); } g_free(str); return args; } static void guest_exec_child_watch(GPid pid, gint status, gpointer data) { GuestExecInfo *gei = (GuestExecInfo *)data; g_debug("guest_exec_child_watch called, pid: %d, status: %u", (int32_t)gpid_to_int64(pid), (uint32_t)status); gei->status = status; gei->finished = true; g_spawn_close_pid(pid); } /** Reset ignored signals back to default. */ static void guest_exec_task_setup(gpointer data) { #if !defined(G_OS_WIN32) struct sigaction sigact; memset(&sigact, 0, sizeof(struct sigaction)); sigact.sa_handler = SIG_DFL; if (sigaction(SIGPIPE, &sigact, NULL) != 0) { slog("sigaction() failed to reset child process's SIGPIPE: %s", strerror(errno)); } #endif } static gboolean guest_exec_input_watch(GIOChannel *ch, GIOCondition cond, gpointer p_) { GuestExecIOData *p = (GuestExecIOData *)p_; gsize bytes_written = 0; GIOStatus status; GError *gerr = NULL; /* nothing left to write */ if (p->size == p->length) { goto done; } status = g_io_channel_write_chars(ch, (gchar *)p->data + p->length, p->size - p->length, &bytes_written, &gerr); /* can be not 0 even if not G_IO_STATUS_NORMAL */ if (bytes_written != 0) { p->length += bytes_written; } /* continue write, our callback will be called again */ if (status == G_IO_STATUS_NORMAL || status == G_IO_STATUS_AGAIN) { return true; } if (gerr) { g_warning("qga: i/o error writing to input_data channel: %s", gerr->message); g_error_free(gerr); } done: g_io_channel_shutdown(ch, true, NULL); g_io_channel_unref(ch); g_atomic_int_set(&p->closed, 1); g_free(p->data); return false; } static gboolean guest_exec_output_watch(GIOChannel *ch, GIOCondition cond, gpointer p_) { GuestExecIOData *p = (GuestExecIOData *)p_; gsize bytes_read; GIOStatus gstatus; if (cond == G_IO_HUP || cond == G_IO_ERR) { goto close; } if (p->size == p->length) { gpointer t = NULL; if (!p->truncated && p->size < GUEST_EXEC_MAX_OUTPUT) { t = g_try_realloc(p->data, p->size + GUEST_EXEC_IO_SIZE); } if (t == NULL) { /* ignore truncated output */ gchar buf[GUEST_EXEC_IO_SIZE]; p->truncated = true; gstatus = g_io_channel_read_chars(ch, buf, sizeof(buf), &bytes_read, NULL); if (gstatus == G_IO_STATUS_EOF || gstatus == G_IO_STATUS_ERROR) { goto close; } return true; } p->size += GUEST_EXEC_IO_SIZE; p->data = t; } /* Calling read API once. * On next available data our callback will be called again */ gstatus = g_io_channel_read_chars(ch, (gchar *)p->data + p->length, p->size - p->length, &bytes_read, NULL); if (gstatus == G_IO_STATUS_EOF || gstatus == G_IO_STATUS_ERROR) { goto close; } p->length += bytes_read; return true; close: g_io_channel_unref(ch); g_atomic_int_set(&p->closed, 1); return false; } GuestExec *qmp_guest_exec(const char *path, bool has_arg, strList *arg, bool has_env, strList *env, bool has_input_data, const char *input_data, bool has_capture_output, bool capture_output, Error **err) { GPid pid; GuestExec *ge = NULL; GuestExecInfo *gei; char **argv, **envp; strList arglist; gboolean ret; GError *gerr = NULL; gint in_fd, out_fd, err_fd; GIOChannel *in_ch, *out_ch, *err_ch; GSpawnFlags flags; bool has_output = (has_capture_output && capture_output); uint8_t *input = NULL; size_t ninput = 0; arglist.value = (char *)path; arglist.next = has_arg ? arg : NULL; if (has_input_data) { input = qbase64_decode(input_data, -1, &ninput, err); if (!input) { return NULL; } } argv = guest_exec_get_args(&arglist, true); envp = has_env ? guest_exec_get_args(env, false) : NULL; flags = G_SPAWN_SEARCH_PATH | G_SPAWN_DO_NOT_REAP_CHILD; #if GLIB_CHECK_VERSION(2, 33, 2) flags |= G_SPAWN_SEARCH_PATH_FROM_ENVP; #endif if (!has_output) { flags |= G_SPAWN_STDOUT_TO_DEV_NULL | G_SPAWN_STDERR_TO_DEV_NULL; } ret = g_spawn_async_with_pipes(NULL, argv, envp, flags, guest_exec_task_setup, NULL, &pid, has_input_data ? &in_fd : NULL, has_output ? &out_fd : NULL, has_output ? &err_fd : NULL, &gerr); if (!ret) { error_setg(err, QERR_QGA_COMMAND_FAILED, gerr->message); g_error_free(gerr); goto done; } ge = g_new0(GuestExec, 1); ge->pid = gpid_to_int64(pid); gei = guest_exec_info_add(pid); gei->has_output = has_output; g_child_watch_add(pid, guest_exec_child_watch, gei); if (has_input_data) { gei->in.data = input; gei->in.size = ninput; #ifdef G_OS_WIN32 in_ch = g_io_channel_win32_new_fd(in_fd); #else in_ch = g_io_channel_unix_new(in_fd); #endif g_io_channel_set_encoding(in_ch, NULL, NULL); g_io_channel_set_buffered(in_ch, false); g_io_channel_set_flags(in_ch, G_IO_FLAG_NONBLOCK, NULL); g_io_add_watch(in_ch, G_IO_OUT, guest_exec_input_watch, &gei->in); } if (has_output) { #ifdef G_OS_WIN32 out_ch = g_io_channel_win32_new_fd(out_fd); err_ch = g_io_channel_win32_new_fd(err_fd); #else out_ch = g_io_channel_unix_new(out_fd); err_ch = g_io_channel_unix_new(err_fd); #endif g_io_channel_set_encoding(out_ch, NULL, NULL); g_io_channel_set_encoding(err_ch, NULL, NULL); g_io_channel_set_buffered(out_ch, false); g_io_channel_set_buffered(err_ch, false); g_io_add_watch(out_ch, G_IO_IN | G_IO_HUP, guest_exec_output_watch, &gei->out); g_io_add_watch(err_ch, G_IO_IN | G_IO_HUP, guest_exec_output_watch, &gei->err); } done: g_free(argv); g_free(envp); return ge; }