/* libguestfs * Copyright (C) 2009 Red Hat Inc. * * This library is free software; you can redistribute it and/or * modify it under the terms of the GNU Lesser General Public * License as published by the Free Software Foundation; either * version 2 of the License, or (at your option) any later version. * * This library is distributed in the hope that it will be useful, * but WITHOUT ANY WARRANTY; without even the implied warranty of * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the GNU * Lesser General Public License for more details. * * You should have received a copy of the GNU Lesser General Public * License along with this library; if not, write to the Free Software * Foundation, Inc., 51 Franklin Street, Fifth Floor, Boston, MA 02110-1301 USA */ #include #define _BSD_SOURCE /* for mkdtemp, usleep */ #include #include #include #include #include #include #include #include #include #include #include #include #include #include #ifdef HAVE_ERRNO_H #include #endif #ifdef HAVE_SYS_TYPES_H #include #endif #ifdef HAVE_SYS_WAIT_H #include #endif #ifdef HAVE_SYS_SOCKET_H #include #endif #ifdef HAVE_SYS_UN_H #include #endif #include "guestfs.h" #include "guestfs_protocol.h" #include "ignore-value.h" #ifdef HAVE_GETTEXT #include "gettext.h" #define _(str) dgettext(PACKAGE, (str)) //#define N_(str) dgettext(PACKAGE, (str)) #else #define _(str) str //#define N_(str) str #endif #define error guestfs_error #define perrorf guestfs_perrorf #define safe_malloc guestfs_safe_malloc #define safe_realloc guestfs_safe_realloc #define safe_strdup guestfs_safe_strdup //#define safe_memdup guestfs_safe_memdup static void default_error_cb (guestfs_h *g, void *data, const char *msg); static void stdout_event (struct guestfs_main_loop *ml, guestfs_h *g, void *data, int watch, int fd, int events); static void sock_read_event (struct guestfs_main_loop *ml, guestfs_h *g, void *data, int watch, int fd, int events); static void sock_write_event (struct guestfs_main_loop *ml, guestfs_h *g, void *data, int watch, int fd, int events); static void close_handles (void); static int select_add_handle (guestfs_main_loop *ml, guestfs_h *g, int fd, int events, guestfs_handle_event_cb cb, void *data); static int select_remove_handle (guestfs_main_loop *ml, guestfs_h *g, int watch); static int select_add_timeout (guestfs_main_loop *ml, guestfs_h *g, int interval, guestfs_handle_timeout_cb cb, void *data); static int select_remove_timeout (guestfs_main_loop *ml, guestfs_h *g, int timer); static int select_main_loop_run (guestfs_main_loop *ml, guestfs_h *g); static int select_main_loop_quit (guestfs_main_loop *ml, guestfs_h *g); /* Default select-based main loop. */ struct select_handle_cb_data { guestfs_handle_event_cb cb; guestfs_h *g; void *data; }; struct select_main_loop { /* NB. These fields must be the same as in struct guestfs_main_loop: */ guestfs_add_handle_cb add_handle; guestfs_remove_handle_cb remove_handle; guestfs_add_timeout_cb add_timeout; guestfs_remove_timeout_cb remove_timeout; guestfs_main_loop_run_cb main_loop_run; guestfs_main_loop_quit_cb main_loop_quit; /* Additional private data: */ int is_running; fd_set rset; fd_set wset; fd_set xset; int max_fd; int nr_fds; struct select_handle_cb_data *handle_cb_data; }; /* Default main loop. */ static struct select_main_loop default_main_loop = { .add_handle = select_add_handle, .remove_handle = select_remove_handle, .add_timeout = select_add_timeout, .remove_timeout = select_remove_timeout, .main_loop_run = select_main_loop_run, .main_loop_quit = select_main_loop_quit, /* XXX hopefully .rset, .wset, .xset are initialized to the empty * set by the normal action of everything being initialized to zero. */ .is_running = 0, .max_fd = -1, .nr_fds = 0, .handle_cb_data = NULL, }; #define UNIX_PATH_MAX 108 /* Also in guestfsd.c */ #define VMCHANNEL_PORT 6666 #define VMCHANNEL_ADDR "10.0.2.4" /* GuestFS handle and connection. */ enum state { CONFIG, LAUNCHING, READY, BUSY, NO_HANDLE }; struct guestfs_h { struct guestfs_h *next; /* Linked list of open handles. */ /* State: see the state machine diagram in the man page guestfs(3). */ enum state state; int fd[2]; /* Stdin/stdout of qemu. */ int sock; /* Daemon communications socket. */ pid_t pid; /* Qemu PID. */ pid_t recoverypid; /* Recovery process PID. */ time_t start_t; /* The time when we started qemu. */ int stdout_watch; /* Watches qemu stdout for log messages. */ int sock_watch; /* Watches daemon comm socket. */ char *tmpdir; /* Temporary directory containing socket. */ char *qemu_help, *qemu_version; /* Output of qemu -help, qemu -version. */ char **cmdline; /* Qemu command line. */ int cmdline_size; int verbose; int autosync; char *path; /* Path to kernel, initrd. */ char *qemu; /* Qemu binary. */ char *append; /* Append to kernel command line. */ int memsize; /* Size of RAM (megabytes). */ int selinux; /* selinux enabled? */ char *last_error; /* Callbacks. */ guestfs_abort_cb abort_cb; guestfs_error_handler_cb error_cb; void * error_cb_data; guestfs_send_cb send_cb; void * send_cb_data; guestfs_reply_cb reply_cb; void * reply_cb_data; guestfs_log_message_cb log_message_cb; void * log_message_cb_data; guestfs_subprocess_quit_cb subprocess_quit_cb; void * subprocess_quit_cb_data; guestfs_launch_done_cb launch_done_cb; void * launch_done_cb_data; /* Main loop used by this handle. */ guestfs_main_loop *main_loop; /* Messages sent and received from the daemon. */ char *msg_in; unsigned int msg_in_size, msg_in_allocated; char *msg_out; unsigned int msg_out_size, msg_out_pos; int msg_next_serial; }; static guestfs_h *handles = NULL; static int atexit_handler_set = 0; guestfs_h * guestfs_create (void) { guestfs_h *g; const char *str; g = malloc (sizeof (*g)); if (!g) return NULL; memset (g, 0, sizeof (*g)); g->state = CONFIG; g->fd[0] = -1; g->fd[1] = -1; g->sock = -1; g->stdout_watch = -1; g->sock_watch = -1; g->abort_cb = abort; g->error_cb = default_error_cb; g->error_cb_data = NULL; str = getenv ("LIBGUESTFS_DEBUG"); g->verbose = str != NULL && strcmp (str, "1") == 0; str = getenv ("LIBGUESTFS_PATH"); g->path = str != NULL ? strdup (str) : strdup (GUESTFS_DEFAULT_PATH); if (!g->path) goto error; str = getenv ("LIBGUESTFS_QEMU"); g->qemu = str != NULL ? strdup (str) : strdup (QEMU); if (!g->qemu) goto error; str = getenv ("LIBGUESTFS_APPEND"); if (str) { g->append = strdup (str); if (!g->append) goto error; } /* Choose a suitable memory size. Previously we tried to choose * a minimal memory size, but this isn't really necessary since * recent QEMU and KVM don't do anything nasty like locking * memory into core any more. Thus we can safely choose a * large, generous amount of memory, and it'll just get swapped * on smaller systems. */ str = getenv ("LIBGUESTFS_MEMSIZE"); if (str) { if (sscanf (str, "%d", &g->memsize) != 1 || g->memsize <= 256) { fprintf (stderr, "libguestfs: non-numeric or too small value for LIBGUESTFS_MEMSIZE\n"); goto error; } } else g->memsize = 500; g->main_loop = guestfs_get_default_main_loop (); /* Start with large serial numbers so they are easy to spot * inside the protocol. */ g->msg_next_serial = 0x00123400; /* Link the handles onto a global list. This is the one area * where the library needs to be made thread-safe. (XXX) */ /* acquire mutex (XXX) */ g->next = handles; handles = g; if (!atexit_handler_set) { atexit (close_handles); atexit_handler_set = 1; } /* release mutex (XXX) */ if (g->verbose) fprintf (stderr, "new guestfs handle %p\n", g); return g; error: free (g->path); free (g->qemu); free (g->append); free (g); return NULL; } void guestfs_close (guestfs_h *g) { int i; char filename[256]; guestfs_h *gg; if (g->state == NO_HANDLE) { /* Not safe to call 'error' here, so ... */ fprintf (stderr, _("guestfs_close: called twice on the same handle\n")); return; } if (g->verbose) fprintf (stderr, "closing guestfs handle %p (state %d)\n", g, g->state); /* Try to sync if autosync flag is set. */ if (g->autosync && g->state == READY) { guestfs_umount_all (g); guestfs_sync (g); } /* Remove any handlers that might be called back before we kill the * subprocess. */ g->log_message_cb = NULL; if (g->state != CONFIG) guestfs_kill_subprocess (g); /* Close any sockets and deregister any handlers. */ if (g->stdout_watch >= 0) g->main_loop->remove_handle (g->main_loop, g, g->stdout_watch); if (g->sock_watch >= 0) g->main_loop->remove_handle (g->main_loop, g, g->sock_watch); g->stdout_watch = -1; g->sock_watch = -1; if (g->fd[0] >= 0) close (g->fd[0]); if (g->fd[1] >= 0) close (g->fd[1]); if (g->sock >= 0) close (g->sock); g->fd[0] = -1; g->fd[1] = -1; g->sock = -1; /* Wait for subprocess(es) to exit. */ waitpid (g->pid, NULL, 0); if (g->recoverypid > 0) waitpid (g->recoverypid, NULL, 0); /* Remove tmpfiles. */ if (g->tmpdir) { snprintf (filename, sizeof filename, "%s/sock", g->tmpdir); unlink (filename); snprintf (filename, sizeof filename, "%s/initrd", g->tmpdir); unlink (filename); snprintf (filename, sizeof filename, "%s/kernel", g->tmpdir); unlink (filename); rmdir (g->tmpdir); free (g->tmpdir); } if (g->cmdline) { for (i = 0; i < g->cmdline_size; ++i) free (g->cmdline[i]); free (g->cmdline); } /* Mark the handle as dead before freeing it. */ g->state = NO_HANDLE; /* acquire mutex (XXX) */ if (handles == g) handles = g->next; else { for (gg = handles; gg->next != g; gg = gg->next) ; gg->next = g->next; } /* release mutex (XXX) */ free (g->msg_in); free (g->msg_out); free (g->last_error); free (g->path); free (g->qemu); free (g->append); free (g->qemu_help); free (g->qemu_version); free (g); } /* Close all open handles (called from atexit(3)). */ static void close_handles (void) { while (handles) guestfs_close (handles); } const char * guestfs_last_error (guestfs_h *g) { return g->last_error; } static void set_last_error (guestfs_h *g, const char *msg) { free (g->last_error); g->last_error = strdup (msg); } static void default_error_cb (guestfs_h *g, void *data, const char *msg) { fprintf (stderr, _("libguestfs: error: %s\n"), msg); } void guestfs_error (guestfs_h *g, const char *fs, ...) { va_list args; char *msg; va_start (args, fs); int err = vasprintf (&msg, fs, args); va_end (args); if (err < 0) return; if (g->error_cb) g->error_cb (g, g->error_cb_data, msg); set_last_error (g, msg); free (msg); } void guestfs_perrorf (guestfs_h *g, const char *fs, ...) { va_list args; char *msg; int errnum = errno; va_start (args, fs); int err = vasprintf (&msg, fs, args); va_end (args); if (err < 0) return; #ifndef _GNU_SOURCE char buf[256]; strerror_r (errnum, buf, sizeof buf); #else char _buf[256]; char *buf; buf = strerror_r (errnum, _buf, sizeof _buf); #endif msg = safe_realloc (g, msg, strlen (msg) + 2 + strlen (buf) + 1); strcat (msg, ": "); strcat (msg, buf); if (g->error_cb) g->error_cb (g, g->error_cb_data, msg); set_last_error (g, msg); free (msg); } void * guestfs_safe_malloc (guestfs_h *g, size_t nbytes) { void *ptr = malloc (nbytes); if (nbytes > 0 && !ptr) g->abort_cb (); return ptr; } /* Return 1 if an array of N objects, each of size S, cannot exist due to size arithmetic overflow. S must be positive and N must be nonnegative. This is a macro, not an inline function, so that it works correctly even when SIZE_MAX < N. By gnulib convention, SIZE_MAX represents overflow in size calculations, so the conservative dividend to use here is SIZE_MAX - 1, since SIZE_MAX might represent an overflowed value. However, malloc (SIZE_MAX) fails on all known hosts where sizeof (ptrdiff_t) <= sizeof (size_t), so do not bother to test for exactly-SIZE_MAX allocations on such hosts; this avoids a test and branch when S is known to be 1. */ # define xalloc_oversized(n, s) \ ((size_t) (sizeof (ptrdiff_t) <= sizeof (size_t) ? -1 : -2) / (s) < (n)) /* Technically we should add an autoconf test for this, testing for the desired functionality, like what's done in gnulib, but for now, this is fine. */ #define HAVE_GNU_CALLOC (__GLIBC__ >= 2) /* Allocate zeroed memory for N elements of S bytes, with error checking. S must be nonzero. */ void * guestfs_safe_calloc (guestfs_h *g, size_t n, size_t s) { /* From gnulib's calloc function in xmalloc.c. */ void *p; /* Test for overflow, since some calloc implementations don't have proper overflow checks. But omit overflow and size-zero tests if HAVE_GNU_CALLOC, since GNU calloc catches overflow and never returns NULL if successful. */ if ((! HAVE_GNU_CALLOC && xalloc_oversized (n, s)) || (! (p = calloc (n, s)) && (HAVE_GNU_CALLOC || n != 0))) g->abort_cb (); return p; } void * guestfs_safe_realloc (guestfs_h *g, void *ptr, int nbytes) { void *p = realloc (ptr, nbytes); if (nbytes > 0 && !p) g->abort_cb (); return p; } char * guestfs_safe_strdup (guestfs_h *g, const char *str) { char *s = strdup (str); if (!s) g->abort_cb (); return s; } void * guestfs_safe_memdup (guestfs_h *g, void *ptr, size_t size) { void *p = malloc (size); if (!p) g->abort_cb (); memcpy (p, ptr, size); return p; } static int xwrite (int fd, const void *v_buf, size_t len) { const char *buf = v_buf; int r; while (len > 0) { r = write (fd, buf, len); if (r == -1) return -1; buf += r; len -= r; } return 0; } static int xread (int fd, void *v_buf, size_t len) { char *buf = v_buf; int r; while (len > 0) { r = read (fd, buf, len); if (r == -1) { if (errno == EINTR || errno == EAGAIN) continue; return -1; } buf += r; len -= r; } return 0; } void guestfs_set_out_of_memory_handler (guestfs_h *g, guestfs_abort_cb cb) { g->abort_cb = cb; } guestfs_abort_cb guestfs_get_out_of_memory_handler (guestfs_h *g) { return g->abort_cb; } void guestfs_set_error_handler (guestfs_h *g, guestfs_error_handler_cb cb, void *data) { g->error_cb = cb; g->error_cb_data = data; } guestfs_error_handler_cb guestfs_get_error_handler (guestfs_h *g, void **data_rtn) { if (data_rtn) *data_rtn = g->error_cb_data; return g->error_cb; } int guestfs_set_verbose (guestfs_h *g, int v) { g->verbose = !!v; return 0; } int guestfs_get_verbose (guestfs_h *g) { return g->verbose; } int guestfs_set_autosync (guestfs_h *g, int a) { g->autosync = !!a; return 0; } int guestfs_get_autosync (guestfs_h *g) { return g->autosync; } int guestfs_set_path (guestfs_h *g, const char *path) { free (g->path); g->path = NULL; g->path = path == NULL ? safe_strdup (g, GUESTFS_DEFAULT_PATH) : safe_strdup (g, path); return 0; } const char * guestfs_get_path (guestfs_h *g) { return g->path; } int guestfs_set_qemu (guestfs_h *g, const char *qemu) { free (g->qemu); g->qemu = NULL; g->qemu = qemu == NULL ? safe_strdup (g, QEMU) : safe_strdup (g, qemu); return 0; } const char * guestfs_get_qemu (guestfs_h *g) { return g->qemu; } int guestfs_set_append (guestfs_h *g, const char *append) { free (g->append); g->append = NULL; g->append = append ? safe_strdup (g, append) : NULL; return 0; } const char * guestfs_get_append (guestfs_h *g) { return g->append; } int guestfs_set_memsize (guestfs_h *g, int memsize) { g->memsize = memsize; return 0; } int guestfs_get_memsize (guestfs_h *g) { return g->memsize; } int guestfs_set_selinux (guestfs_h *g, int selinux) { g->selinux = selinux; return 0; } int guestfs_get_selinux (guestfs_h *g) { return g->selinux; } int guestfs_get_pid (guestfs_h *g) { if (g->pid > 0) return g->pid; else { error (g, "get_pid: no qemu subprocess"); return -1; } } struct guestfs_version * guestfs_version (guestfs_h *g) { struct guestfs_version *r; r = safe_malloc (g, sizeof *r); r->major = PACKAGE_VERSION_MAJOR; r->minor = PACKAGE_VERSION_MINOR; r->release = PACKAGE_VERSION_RELEASE; r->extra = safe_strdup (g, PACKAGE_VERSION_EXTRA); return r; } /* Add a string to the current command line. */ static void incr_cmdline_size (guestfs_h *g) { if (g->cmdline == NULL) { /* g->cmdline[0] is reserved for argv[0], set in guestfs_launch. */ g->cmdline_size = 1; g->cmdline = safe_malloc (g, sizeof (char *)); g->cmdline[0] = NULL; } g->cmdline_size++; g->cmdline = safe_realloc (g, g->cmdline, sizeof (char *) * g->cmdline_size); } static int add_cmdline (guestfs_h *g, const char *str) { if (g->state != CONFIG) { error (g, _("command line cannot be altered after qemu subprocess launched")); return -1; } incr_cmdline_size (g); g->cmdline[g->cmdline_size-1] = safe_strdup (g, str); return 0; } int guestfs_config (guestfs_h *g, const char *qemu_param, const char *qemu_value) { if (qemu_param[0] != '-') { error (g, _("guestfs_config: parameter must begin with '-' character")); return -1; } /* A bit fascist, but the user will probably break the extra * parameters that we add if they try to set any of these. */ if (strcmp (qemu_param, "-kernel") == 0 || strcmp (qemu_param, "-initrd") == 0 || strcmp (qemu_param, "-nographic") == 0 || strcmp (qemu_param, "-serial") == 0 || strcmp (qemu_param, "-full-screen") == 0 || strcmp (qemu_param, "-std-vga") == 0 || strcmp (qemu_param, "-vnc") == 0) { error (g, _("guestfs_config: parameter '%s' isn't allowed"), qemu_param); return -1; } if (add_cmdline (g, qemu_param) != 0) return -1; if (qemu_value != NULL) { if (add_cmdline (g, qemu_value) != 0) return -1; } return 0; } int guestfs_add_drive (guestfs_h *g, const char *filename) { size_t len = strlen (filename) + 64; char buf[len]; if (strchr (filename, ',') != NULL) { error (g, _("filename cannot contain ',' (comma) character")); return -1; } /* cache=off improves reliability in the event of a host crash. * * However this option causes qemu to try to open the file with * O_DIRECT. This fails on some filesystem types (notably tmpfs). * So we check if we can open the file with or without O_DIRECT, * and use cache=off (or not) accordingly. * * This test also checks for the presence of the file, which * is a documented semantic of this interface. */ int fd = open (filename, O_RDONLY|O_DIRECT); if (fd >= 0) { close (fd); snprintf (buf, len, "file=%s,cache=off,if=" DRIVE_IF, filename); } else { fd = open (filename, O_RDONLY); if (fd >= 0) { close (fd); snprintf (buf, len, "file=%s,if=" DRIVE_IF, filename); } else { perrorf (g, "%s", filename); return -1; } } return guestfs_config (g, "-drive", buf); } int guestfs_add_drive_ro (guestfs_h *g, const char *filename) { size_t len = strlen (filename) + 64; char buf[len]; if (strchr (filename, ',') != NULL) { error (g, _("filename cannot contain ',' (comma) character")); return -1; } if (access (filename, F_OK) == -1) { perrorf (g, "%s", filename); return -1; } snprintf (buf, len, "file=%s,snapshot=on,if=%s", filename, DRIVE_IF); return guestfs_config (g, "-drive", buf); } int guestfs_add_cdrom (guestfs_h *g, const char *filename) { if (strchr (filename, ',') != NULL) { error (g, _("filename cannot contain ',' (comma) character")); return -1; } if (access (filename, F_OK) == -1) { perrorf (g, "%s", filename); return -1; } return guestfs_config (g, "-cdrom", filename); } /* Returns true iff file is contained in dir. */ static int dir_contains_file (const char *dir, const char *file) { int dirlen = strlen (dir); int filelen = strlen (file); int len = dirlen+filelen+2; char path[len]; snprintf (path, len, "%s/%s", dir, file); return access (path, F_OK) == 0; } /* Returns true iff every listed file is contained in 'dir'. */ static int dir_contains_files (const char *dir, ...) { va_list args; const char *file; va_start (args, dir); while ((file = va_arg (args, const char *)) != NULL) { if (!dir_contains_file (dir, file)) { va_end (args); return 0; } } va_end (args); return 1; } static int build_supermin_appliance (guestfs_h *g, const char *path, char **kernel, char **initrd); static int test_qemu (guestfs_h *g); static int qemu_supports (guestfs_h *g, const char *option); static void print_cmdline (guestfs_h *g); static const char *kernel_name = "vmlinuz." REPO "." host_cpu; static const char *initrd_name = "initramfs." REPO "." host_cpu ".img"; static const char *supermin_name = "initramfs." REPO "." host_cpu ".supermin.img"; static const char *supermin_hostfiles_name = "initramfs." REPO "." host_cpu ".supermin.hostfiles"; int guestfs_launch (guestfs_h *g) { const char *tmpdir; char dir_template[PATH_MAX]; int r, pmore; size_t len; int wfd[2], rfd[2]; int tries; char *path, *pelem, *pend; char *kernel = NULL, *initrd = NULL; char unixsock[256]; struct sockaddr_un addr; #ifdef P_tmpdir tmpdir = P_tmpdir; #else tmpdir = "/tmp"; #endif tmpdir = getenv ("TMPDIR") ? : tmpdir; snprintf (dir_template, sizeof dir_template, "%s/libguestfsXXXXXX", tmpdir); /* Configured? */ if (!g->cmdline) { error (g, _("you must call guestfs_add_drive before guestfs_launch")); return -1; } if (g->state != CONFIG) { error (g, _("qemu has already been launched")); return -1; } /* Make the temporary directory. */ if (!g->tmpdir) { g->tmpdir = safe_strdup (g, dir_template); if (mkdtemp (g->tmpdir) == NULL) { perrorf (g, _("%s: cannot create temporary directory"), dir_template); goto cleanup0; } } /* First search g->path for the supermin appliance, and try to * synthesize a kernel and initrd from that. If it fails, we * try the path search again looking for a backup ordinary * appliance. */ pelem = path = safe_strdup (g, g->path); do { pend = strchrnul (pelem, ':'); pmore = *pend == ':'; *pend = '\0'; len = pend - pelem; /* Empty element of "." means cwd. */ if (len == 0 || (len == 1 && *pelem == '.')) { if (g->verbose) fprintf (stderr, "looking for supermin appliance in current directory\n"); if (dir_contains_files (".", supermin_name, supermin_hostfiles_name, "kmod.whitelist", NULL)) { if (build_supermin_appliance (g, ".", &kernel, &initrd) == -1) return -1; break; } } /* Look at /supermin* etc. */ else { if (g->verbose) fprintf (stderr, "looking for supermin appliance in %s\n", pelem); if (dir_contains_files (pelem, supermin_name, supermin_hostfiles_name, "kmod.whitelist", NULL)) { if (build_supermin_appliance (g, pelem, &kernel, &initrd) == -1) return -1; break; } } pelem = pend + 1; } while (pmore); free (path); if (kernel == NULL || initrd == NULL) { /* Search g->path for the kernel and initrd. */ pelem = path = safe_strdup (g, g->path); do { pend = strchrnul (pelem, ':'); pmore = *pend == ':'; *pend = '\0'; len = pend - pelem; /* Empty element or "." means cwd. */ if (len == 0 || (len == 1 && *pelem == '.')) { if (g->verbose) fprintf (stderr, "looking for appliance in current directory\n"); if (dir_contains_files (".", kernel_name, initrd_name, NULL)) { kernel = safe_strdup (g, kernel_name); initrd = safe_strdup (g, initrd_name); break; } } /* Look at /kernel etc. */ else { if (g->verbose) fprintf (stderr, "looking for appliance in %s\n", pelem); if (dir_contains_files (pelem, kernel_name, initrd_name, NULL)) { kernel = safe_malloc (g, len + strlen (kernel_name) + 2); initrd = safe_malloc (g, len + strlen (initrd_name) + 2); sprintf (kernel, "%s/%s", pelem, kernel_name); sprintf (initrd, "%s/%s", pelem, initrd_name); break; } } pelem = pend + 1; } while (pmore); free (path); } if (kernel == NULL || initrd == NULL) { error (g, _("cannot find %s or %s on LIBGUESTFS_PATH (current path = %s)"), kernel_name, initrd_name, g->path); goto cleanup0; } /* Get qemu help text and version. */ if (test_qemu (g) == -1) goto cleanup0; /* Make the vmchannel socket. */ snprintf (unixsock, sizeof unixsock, "%s/sock", g->tmpdir); unlink (unixsock); if (pipe (wfd) == -1 || pipe (rfd) == -1) { perrorf (g, "pipe"); goto cleanup0; } r = fork (); if (r == -1) { perrorf (g, "fork"); close (wfd[0]); close (wfd[1]); close (rfd[0]); close (rfd[1]); goto cleanup0; } if (r == 0) { /* Child (qemu). */ char vmchannel[256]; char append[256]; char memsize_str[256]; /* Set up the full command line. Do this in the subprocess so we * don't need to worry about cleaning up. */ g->cmdline[0] = g->qemu; #define LINUX_CMDLINE \ "panic=1 " /* force kernel to panic if daemon exits */ \ "console=ttyS0 " /* serial console */ \ "udevtimeout=300 " /* good for very slow systems (RHBZ#480319) */ \ "noapic " /* workaround for RHBZ#502058 - ok if not SMP */ \ "acpi=off " /* we don't need ACPI, turn it off */ \ "cgroup_disable=memory " /* saves us about 5 MB of RAM */ /* Linux kernel command line. */ snprintf (append, sizeof append, LINUX_CMDLINE "guestfs=%s:%d " "%s" /* (selinux) */ "%s" /* (verbose) */ "%s", /* (append) */ VMCHANNEL_ADDR, VMCHANNEL_PORT, g->selinux ? "selinux=1 enforcing=0 " : "selinux=0 ", g->verbose ? "guestfs_verbose=1 " : " ", g->append ? g->append : ""); snprintf (memsize_str, sizeof memsize_str, "%d", g->memsize); add_cmdline (g, "-m"); add_cmdline (g, memsize_str); add_cmdline (g, "-no-reboot"); /* Force exit instead of reboot on panic */ add_cmdline (g, "-kernel"); add_cmdline (g, (char *) kernel); add_cmdline (g, "-initrd"); add_cmdline (g, (char *) initrd); add_cmdline (g, "-append"); add_cmdline (g, append); add_cmdline (g, "-nographic"); add_cmdline (g, "-serial"); add_cmdline (g, "stdio"); #if 0 /* Doesn't work. See: * http://lists.gnu.org/archive/html/qemu-devel/2009-07/threads.html * Subject "guestfwd option doesn't allow supplementary ,server,nowait" */ if (qemu_supports (g, "guestfwd")) { /* New-style -net user,guestfwd=... syntax for vmchannel. See: * http://git.savannah.gnu.org/cgit/qemu.git/commit/?id=c92ef6a22d3c71538fcc48fb61ad353f7ba03b62 */ snprintf (vmchannel, sizeof vmchannel, "user,vlan=0,net=10.0.2.0/8,guestfwd=tcp:%s:%d-unix:%s,server,nowait", VMCHANNEL_ADDR, VMCHANNEL_PORT, unixsock); add_cmdline (g, "-net"); add_cmdline (g, vmchannel); } else { #endif /* Not guestfwd. HOPEFULLY this qemu uses the older -net channel * syntax, or if not then we'll get a quick failure. */ snprintf (vmchannel, sizeof vmchannel, "channel,%d:unix:%s,server,nowait", VMCHANNEL_PORT, unixsock); add_cmdline (g, "-net"); add_cmdline (g, vmchannel); add_cmdline (g, "-net"); add_cmdline (g, "user,vlan=0,net=10.0.2.0/8"); #if 0 } #endif add_cmdline (g, "-net"); add_cmdline (g, "nic,model=" NET_IF ",vlan=0"); /* These options recommended by KVM developers to improve reliability. */ if (qemu_supports (g, "-no-hpet")) add_cmdline (g, "-no-hpet"); if (qemu_supports (g, "-rtc-td-hack")) add_cmdline (g, "-rtc-td-hack"); /* Finish off the command line. */ incr_cmdline_size (g); g->cmdline[g->cmdline_size-1] = NULL; if (g->verbose) print_cmdline (g); /* Set up stdin, stdout. */ close (0); close (1); close (wfd[1]); close (rfd[0]); if (dup (wfd[0]) == -1) { dup_failed: perror ("dup failed"); _exit (1); } if (dup (rfd[1]) == -1) goto dup_failed; close (wfd[0]); close (rfd[1]); #if 0 /* Set up a new process group, so we can signal this process * and all subprocesses (eg. if qemu is really a shell script). */ setpgid (0, 0); #endif execv (g->qemu, g->cmdline); /* Run qemu. */ perror (g->qemu); _exit (1); } /* Parent (library). */ g->pid = r; free (kernel); kernel = NULL; free (initrd); initrd = NULL; /* Fork the recovery process off which will kill qemu if the parent * process fails to do so (eg. if the parent segfaults). */ r = fork (); if (r == 0) { pid_t qemu_pid = g->pid; pid_t parent_pid = getppid (); /* Writing to argv is hideously complicated and error prone. See: * http://anoncvs.postgresql.org/cvsweb.cgi/pgsql/src/backend/utils/misc/ps_status.c?rev=1.33.2.1;content-type=text%2Fplain */ /* Loop around waiting for one or both of the other processes to * disappear. It's fair to say this is very hairy. The PIDs that * we are looking at might be reused by another process. We are * effectively polling. Is the cure worse than the disease? */ for (;;) { if (kill (qemu_pid, 0) == -1) /* qemu's gone away, we aren't needed */ _exit (0); if (kill (parent_pid, 0) == -1) { /* Parent's gone away, qemu still around, so kill qemu. */ kill (qemu_pid, 9); _exit (0); } sleep (2); } } /* Don't worry, if the fork failed, this will be -1. The recovery * process isn't essential. */ g->recoverypid = r; /* Start the clock ... */ time (&g->start_t); /* Close the other ends of the pipe. */ close (wfd[0]); close (rfd[1]); if (fcntl (wfd[1], F_SETFL, O_NONBLOCK) == -1 || fcntl (rfd[0], F_SETFL, O_NONBLOCK) == -1) { perrorf (g, "fcntl"); goto cleanup1; } g->fd[0] = wfd[1]; /* stdin of child */ g->fd[1] = rfd[0]; /* stdout of child */ /* Open the Unix socket. The vmchannel implementation that got * merged with qemu sucks in a number of ways. Both ends do * connect(2), which means that no one knows what, if anything, is * connected to the other end, or if it becomes disconnected. Even * worse, we have to wait some indeterminate time for qemu to create * the socket and connect to it (which happens very early in qemu's * start-up), so any code that uses vmchannel is inherently racy. * Hence this silly loop. */ g->sock = socket (AF_UNIX, SOCK_STREAM, 0); if (g->sock == -1) { perrorf (g, "socket"); goto cleanup1; } if (fcntl (g->sock, F_SETFL, O_NONBLOCK) == -1) { perrorf (g, "fcntl"); goto cleanup2; } addr.sun_family = AF_UNIX; strncpy (addr.sun_path, unixsock, UNIX_PATH_MAX); addr.sun_path[UNIX_PATH_MAX-1] = '\0'; tries = 100; /* Always sleep at least once to give qemu a small chance to start up. */ usleep (10000); while (tries > 0) { r = connect (g->sock, (struct sockaddr *) &addr, sizeof addr); if ((r == -1 && errno == EINPROGRESS) || r == 0) goto connected; if (errno != ENOENT) perrorf (g, "connect"); tries--; usleep (100000); } error (g, _("failed to connect to vmchannel socket")); goto cleanup2; connected: /* Watch the file descriptors. */ free (g->msg_in); g->msg_in = NULL; g->msg_in_size = g->msg_in_allocated = 0; free (g->msg_out); g->msg_out = NULL; g->msg_out_size = 0; g->msg_out_pos = 0; g->stdout_watch = g->main_loop->add_handle (g->main_loop, g, g->fd[1], GUESTFS_HANDLE_READABLE, stdout_event, NULL); if (g->stdout_watch == -1) { error (g, _("could not watch qemu stdout")); goto cleanup3; } if (guestfs__switch_to_receiving (g) == -1) goto cleanup3; g->state = LAUNCHING; return 0; cleanup3: if (g->stdout_watch >= 0) g->main_loop->remove_handle (g->main_loop, g, g->stdout_watch); if (g->sock_watch >= 0) g->main_loop->remove_handle (g->main_loop, g, g->sock_watch); cleanup2: close (g->sock); cleanup1: close (wfd[1]); close (rfd[0]); kill (g->pid, 9); if (g->recoverypid > 0) kill (g->recoverypid, 9); waitpid (g->pid, NULL, 0); if (g->recoverypid > 0) waitpid (g->recoverypid, NULL, 0); g->fd[0] = -1; g->fd[1] = -1; g->sock = -1; g->pid = 0; g->recoverypid = 0; g->start_t = 0; g->stdout_watch = -1; g->sock_watch = -1; cleanup0: free (kernel); free (initrd); return -1; } /* This function is used to print the qemu command line before it gets * executed, when in verbose mode. */ static void print_cmdline (guestfs_h *g) { int i = 0; int needs_quote; while (g->cmdline[i]) { if (g->cmdline[i][0] == '-') /* -option starts a new line */ fprintf (stderr, " \\\n "); if (i > 0) fputc (' ', stderr); /* Does it need shell quoting? This only deals with simple cases. */ needs_quote = strcspn (g->cmdline[i], " ") != strlen (g->cmdline[i]); if (needs_quote) fputc ('\'', stderr); fprintf (stderr, "%s", g->cmdline[i]); if (needs_quote) fputc ('\'', stderr); i++; } fputc ('\n', stderr); } /* This function does the hard work of building the supermin appliance * on the fly. 'path' is the directory containing the control files. * 'kernel' and 'initrd' are where we will return the names of the * kernel and initrd (only initrd is built). The work is done by * an external script. We just tell it where to put the result. */ static int build_supermin_appliance (guestfs_h *g, const char *path, char **kernel, char **initrd) { char cmd[4096]; int r, len; len = strlen (g->tmpdir); *kernel = safe_malloc (g, len + 8); snprintf (*kernel, len+8, "%s/kernel", g->tmpdir); *initrd = safe_malloc (g, len + 8); snprintf (*initrd, len+8, "%s/initrd", g->tmpdir); snprintf (cmd, sizeof cmd, "PATH='%s':$PATH " "libguestfs-supermin-helper '%s' %s %s", path, path, *kernel, *initrd); r = system (cmd); if (r == -1 || WEXITSTATUS(r) != 0) { error (g, _("external command failed: %s"), cmd); free (*kernel); free (*initrd); *kernel = *initrd = NULL; return -1; } return 0; } static int read_all (guestfs_h *g, FILE *fp, char **ret); /* Test qemu binary (or wrapper) runs, and do 'qemu -help' and * 'qemu -version' so we know what options this qemu supports and * the version. */ static int test_qemu (guestfs_h *g) { char cmd[1024]; FILE *fp; free (g->qemu_help); free (g->qemu_version); g->qemu_help = NULL; g->qemu_version = NULL; snprintf (cmd, sizeof cmd, "'%s' -help", g->qemu); fp = popen (cmd, "r"); /* qemu -help should always work (qemu -version OTOH wasn't * supported by qemu 0.9). If this command doesn't work then it * probably indicates that the qemu binary is missing. */ if (!fp) { /* XXX This error is never printed, even if the qemu binary * doesn't exist. Why? */ error: perrorf (g, _("%s: command failed: If qemu is located on a non-standard path, try setting the LIBGUESTFS_QEMU environment variable."), cmd); return -1; } if (read_all (g, fp, &g->qemu_help) == -1) goto error; if (pclose (fp) == -1) goto error; snprintf (cmd, sizeof cmd, "'%s' -version 2>/dev/null", g->qemu); fp = popen (cmd, "r"); if (fp) { /* Intentionally ignore errors. */ read_all (g, fp, &g->qemu_version); pclose (fp); } return 0; } static int read_all (guestfs_h *g, FILE *fp, char **ret) { int r, n = 0; char *p; again: if (feof (fp)) { *ret = safe_realloc (g, *ret, n + 1); (*ret)[n] = '\0'; return n; } *ret = safe_realloc (g, *ret, n + BUFSIZ); p = &(*ret)[n]; r = fread (p, 1, BUFSIZ, fp); if (ferror (fp)) { perrorf (g, "read"); return -1; } n += r; goto again; } /* Test if option is supported by qemu command line (just by grepping * the help text). */ static int qemu_supports (guestfs_h *g, const char *option) { return g->qemu_help && strstr (g->qemu_help, option) != NULL; } static void finish_wait_ready (guestfs_h *g, void *vp) { if (g->verbose) fprintf (stderr, "finish_wait_ready called, %p, vp = %p\n", g, vp); *((int *)vp) = 1; g->main_loop->main_loop_quit (g->main_loop, g); } int guestfs_wait_ready (guestfs_h *g) { int finished = 0, r; if (g->state == READY) return 0; if (g->state == BUSY) { error (g, _("qemu has finished launching already")); return -1; } if (g->state != LAUNCHING) { error (g, _("qemu has not been launched yet")); return -1; } g->launch_done_cb = finish_wait_ready; g->launch_done_cb_data = &finished; r = g->main_loop->main_loop_run (g->main_loop, g); g->launch_done_cb = NULL; g->launch_done_cb_data = NULL; if (r == -1) return -1; if (finished != 1) { error (g, _("guestfs_wait_ready failed, see earlier error messages")); return -1; } /* This is possible in some really strange situations, such as * guestfsd starts up OK but then qemu immediately exits. Check for * it because the caller is probably expecting to be able to send * commands after this function returns. */ if (g->state != READY) { error (g, _("qemu launched and contacted daemon, but state != READY")); return -1; } return 0; } int guestfs_kill_subprocess (guestfs_h *g) { if (g->state == CONFIG) { error (g, _("no subprocess to kill")); return -1; } if (g->verbose) fprintf (stderr, "sending SIGTERM to process %d\n", g->pid); kill (g->pid, SIGTERM); if (g->recoverypid > 0) kill (g->recoverypid, 9); return 0; } /* Access current state. */ int guestfs_is_config (guestfs_h *g) { return g->state == CONFIG; } int guestfs_is_launching (guestfs_h *g) { return g->state == LAUNCHING; } int guestfs_is_ready (guestfs_h *g) { return g->state == READY; } int guestfs_is_busy (guestfs_h *g) { return g->state == BUSY; } int guestfs_get_state (guestfs_h *g) { return g->state; } int guestfs_set_ready (guestfs_h *g) { if (g->state != BUSY) { error (g, _("guestfs_set_ready: called when in state %d != BUSY"), g->state); return -1; } g->state = READY; return 0; } int guestfs_set_busy (guestfs_h *g) { if (g->state != READY) { error (g, _("guestfs_set_busy: called when in state %d != READY"), g->state); return -1; } g->state = BUSY; return 0; } int guestfs_end_busy (guestfs_h *g) { switch (g->state) { case BUSY: g->state = READY; break; case CONFIG: case READY: break; case LAUNCHING: case NO_HANDLE: default: error (g, _("guestfs_end_busy: called when in state %d"), g->state); return -1; } return 0; } /* We don't know if stdout_event or sock_read_event will be the * first to receive EOF if the qemu process dies. This function * has the common cleanup code for both. */ static void child_cleanup (guestfs_h *g) { if (g->verbose) fprintf (stderr, "stdout_event: %p: child process died\n", g); /*kill (g->pid, SIGTERM);*/ if (g->recoverypid > 0) kill (g->recoverypid, 9); waitpid (g->pid, NULL, 0); if (g->recoverypid > 0) waitpid (g->recoverypid, NULL, 0); if (g->stdout_watch >= 0) g->main_loop->remove_handle (g->main_loop, g, g->stdout_watch); if (g->sock_watch >= 0) g->main_loop->remove_handle (g->main_loop, g, g->sock_watch); close (g->fd[0]); close (g->fd[1]); close (g->sock); g->fd[0] = -1; g->fd[1] = -1; g->sock = -1; g->pid = 0; g->recoverypid = 0; g->start_t = 0; g->stdout_watch = -1; g->sock_watch = -1; g->state = CONFIG; if (g->subprocess_quit_cb) g->subprocess_quit_cb (g, g->subprocess_quit_cb_data); } /* This function is called whenever qemu prints something on stdout. * Qemu's stdout is also connected to the guest's serial console, so * we see kernel messages here too. */ static void stdout_event (struct guestfs_main_loop *ml, guestfs_h *g, void *data, int watch, int fd, int events) { char buf[4096]; int n; #if 0 if (g->verbose) fprintf (stderr, "stdout_event: %p g->state = %d, fd = %d, events = 0x%x\n", g, g->state, fd, events); #endif if (g->fd[1] != fd) { error (g, _("stdout_event: internal error: %d != %d"), g->fd[1], fd); return; } n = read (fd, buf, sizeof buf); if (n == 0) { /* Hopefully this indicates the qemu child process has died. */ child_cleanup (g); return; } if (n == -1) { if (errno != EINTR && errno != EAGAIN) perrorf (g, "read"); return; } /* In verbose mode, copy all log messages to stderr. */ if (g->verbose) ignore_value (write (STDERR_FILENO, buf, n)); /* It's an actual log message, send it upwards if anyone is listening. */ if (g->log_message_cb) g->log_message_cb (g, g->log_message_cb_data, buf, n); } /* The function is called whenever we can read something on the * guestfsd (daemon inside the guest) communication socket. */ static void sock_read_event (struct guestfs_main_loop *ml, guestfs_h *g, void *data, int watch, int fd, int events) { XDR xdr; u_int32_t len; int n; if (g->verbose) fprintf (stderr, "sock_read_event: %p g->state = %d, fd = %d, events = 0x%x\n", g, g->state, fd, events); if (g->sock != fd) { error (g, _("sock_read_event: internal error: %d != %d"), g->sock, fd); return; } if (g->msg_in_size <= g->msg_in_allocated) { g->msg_in_allocated += 4096; g->msg_in = safe_realloc (g, g->msg_in, g->msg_in_allocated); } n = read (g->sock, g->msg_in + g->msg_in_size, g->msg_in_allocated - g->msg_in_size); if (n == 0) { /* Disconnected. */ child_cleanup (g); return; } if (n == -1) { if (errno != EINTR && errno != EAGAIN) perrorf (g, "read"); return; } g->msg_in_size += n; /* Have we got enough of a message to be able to process it yet? */ again: if (g->msg_in_size < 4) return; xdrmem_create (&xdr, g->msg_in, g->msg_in_size, XDR_DECODE); if (!xdr_uint32_t (&xdr, &len)) { error (g, _("can't decode length word")); goto cleanup; } /* Length is normally the length of the message, but when guestfsd * starts up it sends a "magic" value (longer than any possible * message). Check for this. */ if (len == GUESTFS_LAUNCH_FLAG) { if (g->state != LAUNCHING) error (g, _("received magic signature from guestfsd, but in state %d"), g->state); else if (g->msg_in_size != 4) error (g, _("received magic signature from guestfsd, but msg size is %d"), g->msg_in_size); else { g->state = READY; if (g->launch_done_cb) g->launch_done_cb (g, g->launch_done_cb_data); } goto cleanup; } /* This can happen if a cancellation happens right at the end * of us sending a FileIn parameter to the daemon. Discard. The * daemon should send us an error message next. */ if (len == GUESTFS_CANCEL_FLAG) { g->msg_in_size -= 4; memmove (g->msg_in, g->msg_in+4, g->msg_in_size); goto again; } /* If this happens, it's pretty bad and we've probably lost * synchronization. */ if (len > GUESTFS_MESSAGE_MAX) { error (g, _("message length (%u) > maximum possible size (%d)"), len, GUESTFS_MESSAGE_MAX); goto cleanup; } if (g->msg_in_size-4 < len) return; /* Need more of this message. */ /* Got the full message, begin processing it. */ #if 0 if (g->verbose) { int i, j; for (i = 0; i < g->msg_in_size; i += 16) { printf ("%04x: ", i); for (j = i; j < MIN (i+16, g->msg_in_size); ++j) printf ("%02x ", (unsigned char) g->msg_in[j]); for (; j < i+16; ++j) printf (" "); printf ("|"); for (j = i; j < MIN (i+16, g->msg_in_size); ++j) if (isprint (g->msg_in[j])) printf ("%c", g->msg_in[j]); else printf ("."); for (; j < i+16; ++j) printf (" "); printf ("|\n"); } } #endif /* Not in the expected state. */ if (g->state != BUSY) error (g, _("state %d != BUSY"), g->state); /* Push the message up to the higher layer. */ if (g->reply_cb) g->reply_cb (g, g->reply_cb_data, &xdr); else /* This message (probably) should never be printed. */ fprintf (stderr, "libguesfs: sock_read_event: !!! dropped message !!!\n"); g->msg_in_size -= len + 4; memmove (g->msg_in, g->msg_in+len+4, g->msg_in_size); if (g->msg_in_size > 0) goto again; cleanup: /* Free the message buffer if it's grown excessively large. */ if (g->msg_in_allocated > 65536) { free (g->msg_in); g->msg_in = NULL; g->msg_in_size = g->msg_in_allocated = 0; } else g->msg_in_size = 0; xdr_destroy (&xdr); } /* The function is called whenever we can write something on the * guestfsd (daemon inside the guest) communication socket. */ static void sock_write_event (struct guestfs_main_loop *ml, guestfs_h *g, void *data, int watch, int fd, int events) { int n, err; if (g->verbose) fprintf (stderr, "sock_write_event: %p g->state = %d, fd = %d, events = 0x%x\n", g, g->state, fd, events); if (g->sock != fd) { error (g, _("sock_write_event: internal error: %d != %d"), g->sock, fd); return; } if (g->state != BUSY) { error (g, _("sock_write_event: state %d != BUSY"), g->state); return; } if (g->verbose) fprintf (stderr, "sock_write_event: writing %d bytes ...\n", g->msg_out_size - g->msg_out_pos); n = write (g->sock, g->msg_out + g->msg_out_pos, g->msg_out_size - g->msg_out_pos); if (n == -1) { err = errno; if (err != EAGAIN) perrorf (g, "write"); if (err == EPIPE) /* Disconnected from guest (RHBZ#508713). */ child_cleanup (g); return; } if (g->verbose) fprintf (stderr, "sock_write_event: wrote %d bytes\n", n); g->msg_out_pos += n; /* More to write? */ if (g->msg_out_pos < g->msg_out_size) return; if (g->verbose) fprintf (stderr, "sock_write_event: done writing, calling send_cb\n"); free (g->msg_out); g->msg_out = NULL; g->msg_out_pos = g->msg_out_size = 0; /* Done writing, call the higher layer. */ if (g->send_cb) g->send_cb (g, g->send_cb_data); } void guestfs_set_send_callback (guestfs_h *g, guestfs_send_cb cb, void *opaque) { g->send_cb = cb; g->send_cb_data = opaque; } void guestfs_set_reply_callback (guestfs_h *g, guestfs_reply_cb cb, void *opaque) { g->reply_cb = cb; g->reply_cb_data = opaque; } void guestfs_set_log_message_callback (guestfs_h *g, guestfs_log_message_cb cb, void *opaque) { g->log_message_cb = cb; g->log_message_cb_data = opaque; } void guestfs_set_subprocess_quit_callback (guestfs_h *g, guestfs_subprocess_quit_cb cb, void *opaque) { g->subprocess_quit_cb = cb; g->subprocess_quit_cb_data = opaque; } void guestfs_set_launch_done_callback (guestfs_h *g, guestfs_launch_done_cb cb, void *opaque) { g->launch_done_cb = cb; g->launch_done_cb_data = opaque; } /* Access to the handle's main loop and the default main loop. */ void guestfs_set_main_loop (guestfs_h *g, guestfs_main_loop *main_loop) { g->main_loop = main_loop; } guestfs_main_loop * guestfs_get_main_loop (guestfs_h *g) { return g->main_loop; } guestfs_main_loop * guestfs_get_default_main_loop (void) { return (guestfs_main_loop *) &default_main_loop; } /* Change the daemon socket handler so that we are now writing. * This sets the handle to sock_write_event. */ int guestfs__switch_to_sending (guestfs_h *g) { if (g->sock_watch >= 0) { if (g->main_loop->remove_handle (g->main_loop, g, g->sock_watch) == -1) { error (g, _("remove_handle failed")); g->sock_watch = -1; return -1; } } g->sock_watch = g->main_loop->add_handle (g->main_loop, g, g->sock, GUESTFS_HANDLE_WRITABLE, sock_write_event, NULL); if (g->sock_watch == -1) { error (g, _("add_handle failed")); return -1; } return 0; } int guestfs__switch_to_receiving (guestfs_h *g) { if (g->sock_watch >= 0) { if (g->main_loop->remove_handle (g->main_loop, g, g->sock_watch) == -1) { error (g, _("remove_handle failed")); g->sock_watch = -1; return -1; } } g->sock_watch = g->main_loop->add_handle (g->main_loop, g, g->sock, GUESTFS_HANDLE_READABLE, sock_read_event, NULL); if (g->sock_watch == -1) { error (g, _("add_handle failed")); return -1; } return 0; } /* Dispatch a call (len + header + args) to the remote daemon, * synchronously (ie. using the guest's main loop to wait until * it has been sent). Returns -1 for error, or the serial * number of the message. */ static void send_cb (guestfs_h *g, void *data) { guestfs_main_loop *ml = guestfs_get_main_loop (g); *((int *)data) = 1; ml->main_loop_quit (ml, g); } int guestfs__send_sync (guestfs_h *g, int proc_nr, xdrproc_t xdrp, char *args) { struct guestfs_message_header hdr; XDR xdr; u_int32_t len; int serial = g->msg_next_serial++; int sent; guestfs_main_loop *ml = guestfs_get_main_loop (g); if (g->state != BUSY) { error (g, _("guestfs__send_sync: state %d != BUSY"), g->state); return -1; } /* This is probably an internal error. Or perhaps we should just * free the buffer anyway? */ if (g->msg_out != NULL) { error (g, _("guestfs__send_sync: msg_out should be NULL")); return -1; } /* We have to allocate this message buffer on the heap because * it is quite large (although will be mostly unused). We * can't allocate it on the stack because in some environments * we have quite limited stack space available, notably when * running in the JVM. */ g->msg_out = safe_malloc (g, GUESTFS_MESSAGE_MAX + 4); xdrmem_create (&xdr, g->msg_out + 4, GUESTFS_MESSAGE_MAX, XDR_ENCODE); /* Serialize the header. */ hdr.prog = GUESTFS_PROGRAM; hdr.vers = GUESTFS_PROTOCOL_VERSION; hdr.proc = proc_nr; hdr.direction = GUESTFS_DIRECTION_CALL; hdr.serial = serial; hdr.status = GUESTFS_STATUS_OK; if (!xdr_guestfs_message_header (&xdr, &hdr)) { error (g, _("xdr_guestfs_message_header failed")); goto cleanup1; } /* Serialize the args. If any, because some message types * have no parameters. */ if (xdrp) { if (!(*xdrp) (&xdr, args)) { error (g, _("dispatch failed to marshal args")); goto cleanup1; } } /* Get the actual length of the message, resize the buffer to match * the actual length, and write the length word at the beginning. */ len = xdr_getpos (&xdr); xdr_destroy (&xdr); g->msg_out = safe_realloc (g, g->msg_out, len + 4); g->msg_out_size = len + 4; g->msg_out_pos = 0; xdrmem_create (&xdr, g->msg_out, 4, XDR_ENCODE); xdr_uint32_t (&xdr, &len); if (guestfs__switch_to_sending (g) == -1) goto cleanup1; sent = 0; guestfs_set_send_callback (g, send_cb, &sent); if (ml->main_loop_run (ml, g) == -1) goto cleanup1; if (sent != 1) { error (g, _("send failed, see earlier error messages")); goto cleanup1; } return serial; cleanup1: free (g->msg_out); g->msg_out = NULL; g->msg_out_size = 0; return -1; } static int cancel = 0; /* XXX Implement file cancellation. */ static int send_file_chunk_sync (guestfs_h *g, int cancel, const char *buf, size_t len); static int send_file_data_sync (guestfs_h *g, const char *buf, size_t len); static int send_file_cancellation_sync (guestfs_h *g); static int send_file_complete_sync (guestfs_h *g); /* Synchronously send a file. * Returns: * 0 OK * -1 error * -2 daemon cancelled (we must read the error message) */ int guestfs__send_file_sync (guestfs_h *g, const char *filename) { char buf[GUESTFS_MAX_CHUNK_SIZE]; int fd, r, err; fd = open (filename, O_RDONLY); if (fd == -1) { perrorf (g, "open: %s", filename); send_file_cancellation_sync (g); /* Daemon sees cancellation and won't reply, so caller can * just return here. */ return -1; } /* Send file in chunked encoding. */ while (!cancel) { r = read (fd, buf, sizeof buf); if (r == -1 && (errno == EINTR || errno == EAGAIN)) continue; if (r <= 0) break; err = send_file_data_sync (g, buf, r); if (err < 0) { if (err == -2) /* daemon sent cancellation */ send_file_cancellation_sync (g); return err; } } if (cancel) { /* cancel from either end */ send_file_cancellation_sync (g); return -1; } if (r == -1) { perrorf (g, "read: %s", filename); send_file_cancellation_sync (g); return -1; } /* End of file, but before we send that, we need to close * the file and check for errors. */ if (close (fd) == -1) { perrorf (g, "close: %s", filename); send_file_cancellation_sync (g); return -1; } return send_file_complete_sync (g); } /* Send a chunk of file data. */ static int send_file_data_sync (guestfs_h *g, const char *buf, size_t len) { return send_file_chunk_sync (g, 0, buf, len); } /* Send a cancellation message. */ static int send_file_cancellation_sync (guestfs_h *g) { return send_file_chunk_sync (g, 1, NULL, 0); } /* Send a file complete chunk. */ static int send_file_complete_sync (guestfs_h *g) { char buf[1]; return send_file_chunk_sync (g, 0, buf, 0); } /* Send a chunk, cancellation or end of file, synchronously (ie. wait * for it to go). */ static int check_for_daemon_cancellation (guestfs_h *g); static int send_file_chunk_sync (guestfs_h *g, int cancel, const char *buf, size_t buflen) { u_int32_t len; int sent; guestfs_chunk chunk; XDR xdr; guestfs_main_loop *ml = guestfs_get_main_loop (g); if (g->state != BUSY) { error (g, _("send_file_chunk_sync: state %d != READY"), g->state); return -1; } /* This is probably an internal error. Or perhaps we should just * free the buffer anyway? */ if (g->msg_out != NULL) { error (g, _("guestfs__send_sync: msg_out should be NULL")); return -1; } /* Did the daemon send a cancellation message? */ if (check_for_daemon_cancellation (g)) { if (g->verbose) fprintf (stderr, "got daemon cancellation\n"); return -2; } /* Allocate the chunk buffer. Don't use the stack to avoid * excessive stack usage and unnecessary copies. */ g->msg_out = safe_malloc (g, GUESTFS_MAX_CHUNK_SIZE + 4 + 48); xdrmem_create (&xdr, g->msg_out + 4, GUESTFS_MAX_CHUNK_SIZE + 48, XDR_ENCODE); /* Serialize the chunk. */ chunk.cancel = cancel; chunk.data.data_len = buflen; chunk.data.data_val = (char *) buf; if (!xdr_guestfs_chunk (&xdr, &chunk)) { error (g, _("xdr_guestfs_chunk failed (buf = %p, buflen = %zu)"), buf, buflen); xdr_destroy (&xdr); goto cleanup1; } len = xdr_getpos (&xdr); xdr_destroy (&xdr); /* Reduce the size of the outgoing message buffer to the real length. */ g->msg_out = safe_realloc (g, g->msg_out, len + 4); g->msg_out_size = len + 4; g->msg_out_pos = 0; xdrmem_create (&xdr, g->msg_out, 4, XDR_ENCODE); xdr_uint32_t (&xdr, &len); if (guestfs__switch_to_sending (g) == -1) goto cleanup1; sent = 0; guestfs_set_send_callback (g, send_cb, &sent); if (ml->main_loop_run (ml, g) == -1) goto cleanup1; if (sent != 1) { error (g, _("send file chunk failed, see earlier error messages")); goto cleanup1; } return 0; cleanup1: free (g->msg_out); g->msg_out = NULL; g->msg_out_size = 0; return -1; } /* At this point we are sending FileIn file(s) to the guest, and not * expecting to read anything, so if we do read anything, it must be * a cancellation message. This checks for this case without blocking. */ static int check_for_daemon_cancellation (guestfs_h *g) { fd_set rset; struct timeval tv; int r; char buf[4]; uint32_t flag; XDR xdr; FD_ZERO (&rset); FD_SET (g->sock, &rset); tv.tv_sec = 0; tv.tv_usec = 0; r = select (g->sock+1, &rset, NULL, NULL, &tv); if (r == -1) { perrorf (g, "select"); return 0; } if (r == 0) return 0; /* Read the message from the daemon. */ r = xread (g->sock, buf, sizeof buf); if (r == -1) { perrorf (g, "read"); return 0; } xdrmem_create (&xdr, buf, sizeof buf, XDR_DECODE); xdr_uint32_t (&xdr, &flag); xdr_destroy (&xdr); if (flag != GUESTFS_CANCEL_FLAG) { error (g, _("check_for_daemon_cancellation: read 0x%x from daemon, expected 0x%x\n"), flag, GUESTFS_CANCEL_FLAG); return 0; } return 1; } /* Synchronously receive a file. */ /* Returns -1 = error, 0 = EOF, 1 = more data */ static int receive_file_data_sync (guestfs_h *g, void **buf, size_t *len); int guestfs__receive_file_sync (guestfs_h *g, const char *filename) { void *buf; int fd, r; size_t len; fd = open (filename, O_WRONLY|O_CREAT|O_TRUNC|O_NOCTTY, 0666); if (fd == -1) { perrorf (g, "open: %s", filename); goto cancel; } /* Receive the file in chunked encoding. */ while ((r = receive_file_data_sync (g, &buf, &len)) >= 0) { if (xwrite (fd, buf, len) == -1) { perrorf (g, "%s: write", filename); free (buf); goto cancel; } free (buf); if (r == 0) break; /* End of file. */ } if (r == -1) { error (g, _("%s: error in chunked encoding"), filename); return -1; } if (close (fd) == -1) { perrorf (g, "close: %s", filename); return -1; } return 0; cancel: ; /* Send cancellation message to daemon, then wait until it * cancels (just throwing away data). */ XDR xdr; char fbuf[4]; uint32_t flag = GUESTFS_CANCEL_FLAG; if (g->verbose) fprintf (stderr, "%s: waiting for daemon to acknowledge cancellation\n", __func__); xdrmem_create (&xdr, fbuf, sizeof fbuf, XDR_ENCODE); xdr_uint32_t (&xdr, &flag); xdr_destroy (&xdr); if (xwrite (g->sock, fbuf, sizeof fbuf) == -1) { perrorf (g, _("write to daemon socket")); return -1; } while (receive_file_data_sync (g, NULL, NULL) > 0) ; /* just discard it */ return -1; } /* Note that the reply callback can be called multiple times before * the main loop quits and we get back to the synchronous code. So * we have to be prepared to save multiple chunks on a list here. */ struct receive_file_ctx { int count; /* 0 if receive_file_cb not called, or * else count number of chunks. */ guestfs_chunk *chunks; /* Array of chunks. */ }; static void free_chunks (struct receive_file_ctx *ctx) { int i; for (i = 0; i < ctx->count; ++i) free (ctx->chunks[i].data.data_val); free (ctx->chunks); } static void receive_file_cb (guestfs_h *g, void *data, XDR *xdr) { guestfs_main_loop *ml = guestfs_get_main_loop (g); struct receive_file_ctx *ctx = (struct receive_file_ctx *) data; guestfs_chunk chunk; if (ctx->count == -1) /* Parse error occurred previously. */ return; ml->main_loop_quit (ml, g); memset (&chunk, 0, sizeof chunk); if (!xdr_guestfs_chunk (xdr, &chunk)) { error (g, _("failed to parse file chunk")); free_chunks (ctx); ctx->chunks = NULL; ctx->count = -1; return; } /* Copy the chunk to the list. */ ctx->chunks = safe_realloc (g, ctx->chunks, sizeof (guestfs_chunk) * (ctx->count+1)); ctx->chunks[ctx->count] = chunk; ctx->count++; } /* Receive a chunk of file data. */ /* Returns -1 = error, 0 = EOF, 1 = more data */ static int receive_file_data_sync (guestfs_h *g, void **buf, size_t *len_r) { struct receive_file_ctx ctx; guestfs_main_loop *ml = guestfs_get_main_loop (g); int i; size_t len; ctx.count = 0; ctx.chunks = NULL; guestfs_set_reply_callback (g, receive_file_cb, &ctx); (void) ml->main_loop_run (ml, g); guestfs_set_reply_callback (g, NULL, NULL); if (ctx.count == 0) { error (g, _("receive_file_data_sync: reply callback not called\n")); return -1; } if (ctx.count == -1) { error (g, _("receive_file_data_sync: parse error in reply callback\n")); /* callback already freed the chunks */ return -1; } if (g->verbose) fprintf (stderr, "receive_file_data_sync: got %d chunks\n", ctx.count); /* Process each chunk in the list. */ if (buf) *buf = NULL; /* Accumulate data in this buffer. */ len = 0; for (i = 0; i < ctx.count; ++i) { if (ctx.chunks[i].cancel) { error (g, _("file receive cancelled by daemon")); free_chunks (&ctx); if (buf) free (*buf); if (len_r) *len_r = 0; return -1; } if (ctx.chunks[i].data.data_len == 0) { /* end of transfer */ free_chunks (&ctx); if (len_r) *len_r = len; return 0; } if (buf) { *buf = safe_realloc (g, *buf, len + ctx.chunks[i].data.data_len); memcpy (((char *)*buf)+len, ctx.chunks[i].data.data_val, ctx.chunks[i].data.data_len); } len += ctx.chunks[i].data.data_len; } if (len_r) *len_r = len; free_chunks (&ctx); return 1; } /* This is the default main loop implementation, using select(2). */ static int select_add_handle (guestfs_main_loop *mlv, guestfs_h *g, int fd, int events, guestfs_handle_event_cb cb, void *data) { struct select_main_loop *ml = (struct select_main_loop *) mlv; if (fd < 0 || fd >= FD_SETSIZE) { error (g, _("fd %d is out of range"), fd); return -1; } if ((events & ~(GUESTFS_HANDLE_READABLE | GUESTFS_HANDLE_WRITABLE | GUESTFS_HANDLE_HANGUP | GUESTFS_HANDLE_ERROR)) != 0) { error (g, _("set of events (0x%x) contains unknown events"), events); return -1; } if (events == 0) { error (g, _("set of events is empty")); return -1; } if (FD_ISSET (fd, &ml->rset) || FD_ISSET (fd, &ml->wset) || FD_ISSET (fd, &ml->xset)) { error (g, _("fd %d is already registered"), fd); return -1; } if (cb == NULL) { error (g, _("callback is NULL")); return -1; } if ((events & GUESTFS_HANDLE_READABLE)) FD_SET (fd, &ml->rset); if ((events & GUESTFS_HANDLE_WRITABLE)) FD_SET (fd, &ml->wset); if ((events & GUESTFS_HANDLE_HANGUP) || (events & GUESTFS_HANDLE_ERROR)) FD_SET (fd, &ml->xset); if (fd > ml->max_fd) { ml->max_fd = fd; ml->handle_cb_data = safe_realloc (g, ml->handle_cb_data, sizeof (struct select_handle_cb_data) * (ml->max_fd+1)); } ml->handle_cb_data[fd].cb = cb; ml->handle_cb_data[fd].g = g; ml->handle_cb_data[fd].data = data; ml->nr_fds++; /* Any integer >= 0 can be the handle, and this is as good as any ... */ return fd; } static int select_remove_handle (guestfs_main_loop *mlv, guestfs_h *g, int fd) { struct select_main_loop *ml = (struct select_main_loop *) mlv; if (fd < 0 || fd >= FD_SETSIZE) { error (g, _("fd %d is out of range"), fd); return -1; } if (!FD_ISSET (fd, &ml->rset) && !FD_ISSET (fd, &ml->wset) && !FD_ISSET (fd, &ml->xset)) { error (g, _("fd %d was not registered"), fd); return -1; } FD_CLR (fd, &ml->rset); FD_CLR (fd, &ml->wset); FD_CLR (fd, &ml->xset); if (fd == ml->max_fd) { ml->max_fd--; ml->handle_cb_data = safe_realloc (g, ml->handle_cb_data, sizeof (struct select_handle_cb_data) * (ml->max_fd+1)); } ml->nr_fds--; return 0; } static int __attribute__((noreturn)) select_add_timeout (guestfs_main_loop *mlv, guestfs_h *g, int interval, guestfs_handle_timeout_cb cb, void *data) { //struct select_main_loop *ml = (struct select_main_loop *) mlv; abort (); /* XXX not implemented yet */ } static int __attribute__((noreturn)) select_remove_timeout (guestfs_main_loop *mlv, guestfs_h *g, int timer) { //struct select_main_loop *ml = (struct select_main_loop *) mlv; abort (); /* XXX not implemented yet */ } /* The 'g' parameter is just used for error reporting. Events * for multiple handles can be dispatched by running the main * loop. */ static int select_main_loop_run (guestfs_main_loop *mlv, guestfs_h *g) { struct select_main_loop *ml = (struct select_main_loop *) mlv; int fd, r, events; fd_set rset2, wset2, xset2; if (ml->is_running) { error (g, _("select_main_loop_run: this cannot be called recursively")); return -1; } ml->is_running = 1; while (ml->is_running) { if (ml->nr_fds == 0) break; rset2 = ml->rset; wset2 = ml->wset; xset2 = ml->xset; r = select (ml->max_fd+1, &rset2, &wset2, &xset2, NULL); if (r == -1) { if (errno == EINTR || errno == EAGAIN) continue; perrorf (g, "select"); ml->is_running = 0; return -1; } for (fd = 0; r > 0 && fd <= ml->max_fd; ++fd) { events = 0; if (FD_ISSET (fd, &rset2)) events |= GUESTFS_HANDLE_READABLE; if (FD_ISSET (fd, &wset2)) events |= GUESTFS_HANDLE_WRITABLE; if (FD_ISSET (fd, &xset2)) events |= GUESTFS_HANDLE_ERROR | GUESTFS_HANDLE_HANGUP; if (events) { r--; ml->handle_cb_data[fd].cb ((guestfs_main_loop *) ml, ml->handle_cb_data[fd].g, ml->handle_cb_data[fd].data, fd, fd, events); } } } ml->is_running = 0; return 0; } static int select_main_loop_quit (guestfs_main_loop *mlv, guestfs_h *g) { struct select_main_loop *ml = (struct select_main_loop *) mlv; /* Note that legitimately ml->is_running can be zero when * this function is called. */ ml->is_running = 0; return 0; }