/* libguestfs
- * Copyright (C) 2009 Red Hat Inc.
+ * 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
#include <stdio.h>
#include <stdlib.h>
#include <stdarg.h>
+#include <stddef.h>
#include <unistd.h>
#include <ctype.h>
#include <string.h>
#include <time.h>
#include <sys/stat.h>
#include <sys/select.h>
+#include <dirent.h>
#include <rpc/types.h>
#include <rpc/xdr.h>
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;
char *qemu; /* Qemu binary. */
char *append; /* Append to kernel command line. */
+ int memsize; /* Size of RAM (megabytes). */
+
char *last_error;
/* Callbacks. */
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
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;
+
+ /* 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);
free (g->path);
free (g->qemu);
free (g->append);
+ free (g->qemu_help);
+ free (g->qemu_version);
free (g);
}
char *msg;
va_start (args, fs);
- vasprintf (&msg, fs, args);
+ 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);
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)
{
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_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)
strcmp (qemu_param, "-initrd") == 0 ||
strcmp (qemu_param, "-nographic") == 0 ||
strcmp (qemu_param, "-serial") == 0 ||
- strcmp (qemu_param, "-vnc") == 0 ||
strcmp (qemu_param, "-full-screen") == 0 ||
strcmp (qemu_param, "-std-vga") == 0 ||
strcmp (qemu_param, "-vnc") == 0) {
return -1;
}
- snprintf (buf, len, "file=%s", filename);
+ /* cache=off improves reliability in the event of a host crash. */
+ snprintf (buf, len, "file=%s,cache=off,if=%s", filename, DRIVE_IF);
+
+ 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);
}
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 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)
{
- static const char *dir_template = "/tmp/libguestfsXXXXXX";
- int r, i, pmore, memsize;
+ const char *tmpdir;
+ char dir_template[PATH_MAX];
+ int r, i, pmore;
size_t len;
int wfd[2], rfd[2];
int tries;
- const char *kernel_name = "vmlinuz." REPO "." host_cpu;
- const char *initrd_name = "initramfs." REPO "." host_cpu ".img";
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;
}
- /* Search g->path for the kernel and initrd. */
+ /* 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, ':');
*pend = '\0';
len = pend - pelem;
- /* Empty element or "." means cwd. */
+ /* Empty element of "." means cwd. */
if (len == 0 || (len == 1 && *pelem == '.')) {
if (g->verbose)
fprintf (stderr,
- "looking for kernel and initrd in current directory\n");
- if (access (kernel_name, F_OK) == 0 && access (initrd_name, F_OK) == 0) {
- kernel = safe_strdup (g, kernel_name);
- initrd = safe_strdup (g, initrd_name);
+ "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 <path>/kernel etc. */
+ /* Look at <path>/supermin* etc. */
else {
- 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);
-
if (g->verbose)
- fprintf (stderr, "looking for %s and %s\n", kernel, initrd);
+ fprintf (stderr, "looking for supermin appliance in %s\n", pelem);
- if (access (kernel, F_OK) == 0 && access (initrd, F_OK) == 0)
+ 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;
- free (kernel);
- free (initrd);
- kernel = initrd = NULL;
+ }
}
pelem = pend + 1;
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 <path>/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;
}
- /* 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. This we can safely choose a
- * large, generous amount of memory, and it'll just get swapped
- * on smaller systems.
- */
- memsize = 384;
-
- /* Make the temporary directory containing the socket. */
- 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;
- }
- }
+ /* 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);
*/
g->cmdline[0] = g->qemu;
- /* Construct the -net channel parameter for qemu. */
- snprintf (vmchannel, sizeof vmchannel,
- "channel,%d:unix:%s,server,nowait",
- VMCHANNEL_PORT, unixsock);
+#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,
- "panic=1 console=ttyS0 guestfs=%s:%d%s%s%s",
+ LINUX_CMDLINE "guestfs=%s:%d%s%s%s",
VMCHANNEL_ADDR, VMCHANNEL_PORT,
g->verbose ? " guestfs_verbose=1" : "",
g->append ? " " : "", g->append ? g->append : "");
- snprintf (memsize_str, sizeof memsize_str, "%d", memsize);
+ snprintf (memsize_str, sizeof memsize_str, "%d", g->memsize);
add_cmdline (g, "-m");
add_cmdline (g, memsize_str);
-#if 0
- add_cmdline (g, "-no-kqemu"); /* Avoids a warning. */
-#endif
add_cmdline (g, "-no-reboot"); /* Force exit instead of reboot on panic */
add_cmdline (g, "-kernel");
add_cmdline (g, (char *) kernel);
add_cmdline (g, "-nographic");
add_cmdline (g, "-serial");
add_cmdline (g, "stdio");
- add_cmdline (g, "-net");
- add_cmdline (g, vmchannel);
- add_cmdline (g, "-net");
- add_cmdline (g, "user,vlan=0");
+
+#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,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");
+#if 0
+ }
+#endif
add_cmdline (g, "-net");
add_cmdline (g, "nic,model=virtio,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;
return -1;
}
+/* 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)
{
return 0;
}
-/* Structure-freeing functions. These rely on the fact that the
- * structure format is identical to the XDR format. See note in
- * generator.ml.
- */
-void
-guestfs_free_int_bool (struct guestfs_int_bool *x)
-{
- free (x);
-}
-
-void
-guestfs_free_lvm_pv_list (struct guestfs_lvm_pv_list *x)
-{
- xdr_free ((xdrproc_t) xdr_guestfs_lvm_int_pv_list, (char *) x);
- free (x);
-}
-
-void
-guestfs_free_lvm_vg_list (struct guestfs_lvm_vg_list *x)
-{
- xdr_free ((xdrproc_t) xdr_guestfs_lvm_int_vg_list, (char *) x);
- free (x);
-}
-
-void
-guestfs_free_lvm_lv_list (struct guestfs_lvm_lv_list *x)
-{
- xdr_free ((xdrproc_t) xdr_guestfs_lvm_int_lv_list, (char *) x);
- free (x);
-}
-
/* 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.
sock_write_event (struct guestfs_main_loop *ml, guestfs_h *g, void *data,
int watch, int fd, int events)
{
- int n;
+ int n, err;
if (g->verbose)
fprintf (stderr,
n = write (g->sock, g->msg_out + g->msg_out_pos,
g->msg_out_size - g->msg_out_pos);
if (n == -1) {
- if (errno != EAGAIN)
+ err = errno;
+ if (err != EAGAIN)
perrorf (g, "write");
+ if (err == EPIPE) /* Disconnected from guest (RHBZ#508713). */
+ child_cleanup (g);
return;
}
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);
git.annexia.org / libguestfs.git / blobdiff