*/
#ifndef lint
-static char rcsid[] = "$Id: main.c,v 1.5 1994/01/10 00:18:59 paulus Exp $";
+static char rcsid[] = "$Id: main.c,v 1.10 1994/05/18 06:00:48 paulus Exp $";
#endif
#define SETSID
#include <syslog.h>
#include <netdb.h>
#include <utmp.h>
+#include <pwd.h>
+#include <sys/wait.h>
/*
* If REQ_SYSOPTIONS is defined to 1, pppd will not run unless
* /etc/ppp/options exists.
*/
#ifndef REQ_SYSOPTIONS
-#define REQ_SYSOPTIONS 0
-#endif
-
-#ifdef STREAMS
-#undef SGTTY
+#define REQ_SYSOPTIONS 1
#endif
#ifdef SGTTY
char hostname[MAXNAMELEN]; /* Our hostname */
char our_name[MAXNAMELEN];
char remote_name[MAXNAMELEN];
+static char pidfilename[MAXPATHLEN];
static pid_t pid; /* Our pid */
static pid_t pgrpid; /* Process Group ID */
-static char pidfilename[MAXPATHLEN];
+uid_t uid; /* Our real user-id */
char devname[MAXPATHLEN] = "/dev/tty"; /* Device name */
int default_device = TRUE; /* use default device (stdin/out) */
-int fd; /* Device file descriptor */
+int fd = -1; /* Device file descriptor */
int s; /* Socket file descriptor */
+int phase; /* where the link is at */
+
#ifdef SGTTY
static struct sgttyb initsgttyb; /* Initial TTY sgttyb */
#else
static u_char inpacket_buf[MTU+DLLHEADERLEN]; /* buffer for incoming packet */
int hungup; /* terminal has been hung up */
+static int n_children; /* # child processes still running */
/* configured variables */
int debug = 0; /* Debug flag */
+int kdebugflag = 0; /* Kernel debugging flag */
char user[MAXNAMELEN]; /* username for PAP */
char passwd[MAXSECRETLEN]; /* password for PAP */
char *connector = NULL; /* "connect" command */
-int inspeed = 0; /* Input/Output speed */
+char *disconnector = NULL; /* "disconnect" command */
+int inspeed = 0; /* Input/Output speed requested */
+int baud_rate; /* bits/sec currently used */
u_long netmask = 0; /* netmask to use on ppp interface */
int crtscts = 0; /* use h/w flow control */
int nodetach = 0; /* don't fork */
int persist = 0; /* re-initiate on termination */
int answer = 0; /* wait for incoming call */
int uselogin = 0; /* check PAP info against /etc/passwd */
+int lockflag = 0; /* lock the serial device */
/* prototypes */
static void nodebug __ARGS((int));
void establish_ppp __ARGS((void));
+void reap_kids __ARGS((void));
void cleanup __ARGS((int, caddr_t));
void die __ARGS((int));
-void dumpbuffer __ARGS((unsigned char *, int, int));
+void novm __ARGS((char *));
+
+void log_packet __ARGS((u_char *, int, char *));
+void format_packet __ARGS((u_char *, int,
+ void (*) (void *, char *, ...), void *));
+void pr_log __ARGS((void *, char *, ...));
-#ifdef STREAMS
extern char *ttyname __ARGS((int));
-#endif
extern char *getlogin __ARGS((void));
/*
void (*init)();
void (*input)();
void (*protrej)();
+ int (*printpkt)();
+ char *name;
} prottbl[] = {
- { LCP, lcp_init, lcp_input, lcp_protrej },
- { IPCP, ipcp_init, ipcp_input, ipcp_protrej },
- { UPAP, upap_init, upap_input, upap_protrej },
- { CHAP, ChapInit, ChapInput, ChapProtocolReject },
+ { LCP, lcp_init, lcp_input, lcp_protrej, lcp_printpkt, "LCP" },
+ { IPCP, ipcp_init, ipcp_input, ipcp_protrej, ipcp_printpkt, "IPCP" },
+ { UPAP, upap_init, upap_input, upap_protrej, upap_printpkt, "PAP" },
+ { CHAP, ChapInit, ChapInput, ChapProtocolReject, ChapPrintPkt, "CHAP" },
};
+#define N_PROTO (sizeof(prottbl) / sizeof(prottbl[0]))
main(argc, argv)
int argc;
struct cmd *cmdp;
FILE *pidfile;
char *p;
+ struct passwd *pw;
- /*
- * Initialize syslog system and magic number package.
- */
-#if BSD >= 43 || defined(sun)
- openlog("pppd", LOG_PID | LOG_NDELAY, LOG_PPP);
- setlogmask(LOG_UPTO(LOG_INFO));
-#else
- openlog("pppd", LOG_PID);
-#define LOG_UPTO(x) (x)
-#define setlogmask(x) (x)
-#endif
-
-#ifdef STREAMS
- p = ttyname(fileno(stdin));
+ p = ttyname(0);
if (p)
strcpy(devname, p);
-#endif
- magic_init();
-
if (gethostname(hostname, MAXNAMELEN) < 0 ) {
- syslog(LOG_ERR, "couldn't get hostname: %m");
+ perror("couldn't get hostname");
die(1);
}
hostname[MAXNAMELEN-1] = 0;
pid = getpid();
+ uid = getuid();
if (!ppp_available()) {
fprintf(stderr, "Sorry - PPP is not available on this system\n");
* the system options file, the user's options file, and the command
* line arguments.
*/
- for (i = 0; i < sizeof (prottbl) / sizeof (struct protent); i++)
+ for (i = 0; i < N_PROTO; i++)
(*prottbl[i].init)(0);
progname = *argv;
- if (!options_from_file(_PATH_SYSOPTIONS, REQ_SYSOPTIONS) ||
+ if (!options_from_file(_PATH_SYSOPTIONS, REQ_SYSOPTIONS, 0) ||
!options_from_user() ||
- !parse_args(argc-1, argv+1))
+ !parse_args(argc-1, argv+1) ||
+ !options_for_tty())
die(1);
check_auth_options();
setipdefault();
+ if (lockflag && !default_device)
+ if (lock(devname) < 0)
+ die(1);
+
+ /*
+ * Initialize syslog system and magic number package.
+ */
+#if (BSD >= 43 || defined(sun)) && !defined(ultrix)
+ openlog("pppd", LOG_PID | LOG_NDELAY, LOG_PPP);
+ setlogmask(LOG_UPTO(LOG_INFO));
+#else
+ openlog("pppd", LOG_PID);
+#define LOG_UPTO(x) (x)
+#define setlogmask(x) (x)
+#endif
+ if (debug)
+ setlogmask(LOG_UPTO(LOG_DEBUG));
+
+ magic_init();
+
p = getlogin();
- if (p == NULL)
- p = "(unknown)";
+ if (p == NULL) {
+ pw = getpwuid(uid);
+ if (pw != NULL && pw->pw_name != NULL)
+ p = pw->pw_name;
+ else
+ p = "(unknown)";
+ }
syslog(LOG_NOTICE, "pppd %s.%d started by %s, uid %d",
- VERSION, PATCHLEVEL, p, getuid());
+ VERSION, PATCHLEVEL, p, uid);
#ifdef SETSID
/*
}
hungup = 0;
+#ifdef TIOCSCTTY
/* set device to be controlling tty */
if (!default_device && ioctl(fd, TIOCSCTTY) < 0) {
syslog(LOG_ERR, "ioctl(TIOCSCTTY): %m");
die(1);
}
-
- /* set line speed, flow control, etc. */
- set_up_tty(fd);
+#endif /* TIOCSCTTY */
/* run connection script */
if (connector) {
- syslog(LOG_INFO, "Connecting with <%s>", connector);
+ MAINDEBUG((LOG_INFO, "Connecting with <%s>", connector));
+
+ /* set line speed, flow control, etc.; set CLOCAL for now */
+ set_up_tty(fd, 1);
/* drop dtr to hang up in case modem is off hook */
if (!default_device && modem) {
setdtr(fd, TRUE);
}
- if (set_up_connection(connector, fd, fd) < 0) {
+ if (device_script(connector, fd, fd) < 0) {
syslog(LOG_ERR, "could not set up connection");
setdtr(fd, FALSE);
die(1);
sleep(1); /* give it time to set up its terminal */
}
+ /* set line speed, flow control, etc.; clear CLOCAL if modem option */
+ set_up_tty(fd, 0);
+
/* set up the serial device as a ppp interface */
establish_ppp();
*/
syslog(LOG_NOTICE, "Connect: %s <--> %s", ifname, devname);
sigprocmask(SIG_BLOCK, &mask, NULL); /* Block signals now */
- lcp_lowerup(0); /* XXX Well, sort of... */
- lcp_open(0); /* Start protocol */
- for (;;) {
- sigpause(0); /* Wait for next signal */
+ lcp_lowerup(0); /* XXX Well, sort of... */
+ lcp_open(0); /* Start protocol */
+ for (phase = PHASE_ESTABLISH; phase != PHASE_DEAD; ) {
+ sigpause(0); /* Wait for next signal */
+ reap_kids(); /* Don't leave dead kids lying around */
}
+
+ /*
+ * Run disconnector script, if requested
+ */
+ if (disconnector) {
+ if (device_script(disconnector, fd, fd) < 0) {
+ syslog(LOG_WARNING, "disconnect script failed");
+ die(1);
+ }
+
+ syslog(LOG_INFO, "Disconnected...");
+ }
+
+ quit();
}
#if B9600 == 9600
* (so we can ask for any speed).
*/
#define translate_speed(bps) (bps)
+#define baud_rate_of(speed) (speed)
#else
/*
syslog(LOG_WARNING, "speed %d not supported", bps);
return 0;
}
+
+/*
+ * Translate from a speed_t to bits/second.
+ */
+int
+baud_rate_of(speed)
+ int speed;
+{
+ struct speed *speedp;
+
+ if (speed == 0)
+ return 0;
+ for (speedp = speeds; speedp->speed_int; speedp++)
+ if (speed == speedp->speed_val)
+ return speedp->speed_int;
+ return 0;
+}
#endif
/*
* set_up_tty: Set up the serial port on `fd' for 8 bits, no parity,
- * at the requested speed, etc.
+ * at the requested speed, etc. If `local' is true, set CLOCAL
+ * regardless of whether the modem option was specified.
*/
-set_up_tty(fd)
- int fd;
+set_up_tty(fd, local)
+ int fd, local;
{
#ifndef SGTTY
- int speed;
+ int speed, x;
struct termios tios;
if (tcgetattr(fd, &tios) < 0) {
if (!restore_term)
inittermios = tios;
+#ifdef CRTSCTS
tios.c_cflag &= ~(CSIZE | CSTOPB | PARENB | CLOCAL | CRTSCTS);
- tios.c_cflag |= CS8 | CREAD | HUPCL;
if (crtscts)
tios.c_cflag |= CRTSCTS;
- if (!modem)
+#else
+ tios.c_cflag &= ~(CSIZE | CSTOPB | PARENB | CLOCAL);
+#endif /* CRTSCTS */
+
+ tios.c_cflag |= CS8 | CREAD | HUPCL;
+ if (local || !modem)
tios.c_cflag |= CLOCAL;
tios.c_iflag = IGNBRK | IGNPAR;
tios.c_oflag = 0;
if (speed) {
cfsetospeed(&tios, speed);
cfsetispeed(&tios, speed);
+ } else {
+ speed = cfgetospeed(&tios);
}
if (tcsetattr(fd, TCSAFLUSH, &tios) < 0) {
syslog(LOG_ERR, "tcsetattr: %m");
die(1);
}
+
+#ifdef ultrix
+ x = 0;
+ if (ioctl(fd, (crtscts || modem)? TIOCMODEM: TIOCNMODEM, &x) < 0)
+ syslog(LOG_WARNING, "TIOC(N)MODEM: %m");
+ if (ioctl(fd, (local || !modem)? TIOCNCAR: TIOCCAR) < 0)
+ syslog(LOG_WARNING, "TIOC(N)CAR: %m");
+#endif
+
#else /* SGTTY */
int speed;
struct sgttyb sgttyb;
speed = translate_speed(inspeed);
if (speed)
sgttyb.sg_ispeed = speed;
+ else
+ speed = sgttyb.sg_ispeed;
if (ioctl(fd, TIOCSETP, &sgttyb) < 0) {
syslog(LOG_ERR, "ioctl(TIOCSETP): %m");
die(1);
}
#endif
+
+ baud_rate = baud_rate_of(speed);
restore_term = TRUE;
}
+/*
+ * setdtr - control the DTR line on the serial port.
+ * This is called from die(), so it shouldn't call die().
+ */
+setdtr(fd, on)
+int fd, on;
+{
+ int modembits = TIOCM_DTR;
+
+ ioctl(fd, (on? TIOCMBIS: TIOCMBIC), &modembits);
+}
+
/*
* quit - Clean up state and exit.
int status;
caddr_t arg;
{
- if (fd != 0) {
+ if (fd >= 0) {
/* drop dtr to hang up */
if (modem)
setdtr(fd, FALSE);
- if (fcntl(fd, F_SETFL, initfdflags) < 0)
- syslog(LOG_ERR, "fcntl(F_SETFL, fdflags): %m");
+ if (initfdflags != -1 && fcntl(fd, F_SETFL, initfdflags) < 0)
+ syslog(LOG_WARNING, "fcntl(F_SETFL, fdflags): %m");
disestablish_ppp();
if (restore_term) {
#ifndef SGTTY
if (tcsetattr(fd, TCSAFLUSH, &inittermios) < 0)
- syslog(LOG_ERR, "tcsetattr: %m");
+ syslog(LOG_WARNING, "tcsetattr: %m");
#else
if (ioctl(fd, TIOCSETP, &initsgttyb) < 0)
- syslog(LOG_ERR, "ioctl(TIOCSETP): %m");
+ syslog(LOG_WARNING, "ioctl(TIOCSETP): %m");
#endif
}
if (pidfilename[0] != 0 && unlink(pidfilename) < 0)
syslog(LOG_WARNING, "unable to unlink pid file: %m");
pidfilename[0] = 0;
+
+ if (lockflag && !default_device)
+ unlock();
}
itv.it_interval.tv_sec = itv.it_interval.tv_usec =
itv.it_value.tv_usec = 0;
itv.it_value.tv_sec = callout->c_time;
- MAINDEBUG((LOG_DEBUG, "Setting itimer for %d seconds.",
+ MAINDEBUG((LOG_DEBUG, "Setting itimer for %d seconds in timeout.",
itv.it_value.tv_sec));
if (setitimer(ITIMER_REAL, &itv, NULL)) {
syslog(LOG_ERR, "setitimer(ITIMER_REAL): %m");
itv.it_interval.tv_sec = itv.it_interval.tv_usec =
itv.it_value.tv_usec = 0;
itv.it_value.tv_sec = callout ? callout->c_time : 0;
- MAINDEBUG((LOG_DEBUG, "Setting itimer for %d seconds.",
+ MAINDEBUG((LOG_DEBUG, "Setting itimer for %d seconds in untimeout.",
itv.it_value.tv_sec));
if (setitimer(ITIMER_REAL, &itv, NULL)) {
syslog(LOG_ERR, "setitimer(ITIMER_REAL): %m");
char *addr;
{
struct itimerval itv;
- struct callout *freep;
+ struct callout *freep, *list, *last;
MAINDEBUG((LOG_DEBUG, "Alarm"));
+ if (callout == NULL)
+ return;
/*
- * Call and free first scheduled timeout and any that were scheduled
- * for the same time.
+ * Get the first scheduled timeout and any that were scheduled
+ * for the same time as a list, and remove them all from callout
+ * list.
*/
- while (callout) {
- freep = callout; /* Remove entry before calling */
- callout = freep->c_next;
- (*freep->c_func)(freep->c_arg);
- (void) free((char *) freep);
- if (callout && callout->c_time)
- break;
- }
-
+ list = last = callout;
+ while (last->c_next != NULL && last->c_next->c_time == 0)
+ last = last->c_next;
+ callout = last->c_next;
+ last->c_next = NULL;
+
/*
* Set a new itimer if there are more timeouts scheduled.
*/
itv.it_interval.tv_sec = itv.it_interval.tv_usec = 0;
itv.it_value.tv_usec = 0;
itv.it_value.tv_sec = callout->c_time;
- MAINDEBUG((LOG_DEBUG, "Setting itimer for %d seconds.",
+ MAINDEBUG((LOG_DEBUG, "Setting itimer for %d seconds in alrm.",
itv.it_value.tv_sec));
if (setitimer(ITIMER_REAL, &itv, NULL)) {
syslog(LOG_ERR, "setitimer(ITIMER_REAL): %m");
die(1);
}
}
+
+ /*
+ * Now call all the timeout routines scheduled for this time.
+ */
+ while (list) {
+ (*list->c_func)(list->c_arg);
+ freep = list;
+ list = list->c_next;
+ (void) free((char *) freep);
+ }
+
}
return;
if (len == 0) {
- syslog(LOG_ERR, "End of file on fd!");
+ syslog(LOG_WARNING, "End of file on fd!");
die(1);
}
+ if (debug /*&& (debugflags & DBG_INPACKET)*/)
+ log_packet(p, len, "rcvd ");
+
if (len < DLLHEADERLEN) {
MAINDEBUG((LOG_INFO, "io(): Received short packet."));
return;
if (protocol != LCP && lcp_fsm[0].state != OPENED) {
MAINDEBUG((LOG_INFO,
"io(): Received non-LCP packet when LCP not open."));
- if (debug)
- dumpbuffer(inpacket_buf, len + DLLHEADERLEN, LOG_INFO);
return;
}
/*
- * set_up_connection - run a program to initialize the serial connector
+ * device_script - run a program to connect or disconnect the
+ * serial device.
*/
int
-set_up_connection(program, in, out)
+device_script(program, in, out)
char *program;
int in, out;
{
sigprocmask(SIG_BLOCK, &mask, &mask);
pid = fork();
-
+
if (pid < 0) {
syslog(LOG_ERR, "fork: %m");
die(1);
}
-
+
if (pid == 0) {
setreuid(getuid(), getuid());
setregid(getgid(), getgid());
/* NOTREACHED */
}
- while (waitpid(pid, &status, 0) != pid) {
+ while (waitpid(pid, &status, 0) < 0) {
if (errno == EINTR)
continue;
- syslog(LOG_ERR, "waiting for connection process: %m");
+ syslog(LOG_ERR, "waiting for (dis)connection process: %m");
die(1);
}
sigprocmask(SIG_SETMASK, &mask, NULL);
/*
- * Return user specified netmask. A value of zero means no netmask has
- * been set.
+ * run-program - execute a program with given arguments,
+ * but don't wait for it.
+ * If the program can't be executed, logs an error unless
+ * must_exist is 0 and the program file doesn't exist.
*/
-/* ARGSUSED */
-u_long
-GetMask(addr)
- u_long addr;
+int
+run_program(prog, args, must_exist)
+ char *prog;
+ char **args;
+ int must_exist;
{
- return(netmask);
+ int pid;
+
+ pid = fork();
+ if (pid == -1) {
+ syslog(LOG_ERR, "can't fork to run %s: %m", prog);
+ return -1;
+ }
+ if (pid == 0) {
+ execv(prog, args);
+ if (must_exist || errno != ENOENT)
+ syslog(LOG_WARNING, "can't execute %s: %m", prog);
+ _exit(-1);
+ }
+ MAINDEBUG((LOG_DEBUG, "Script %s started; pid = %d", prog, pid));
+ ++n_children;
+ return 0;
}
+
/*
- * dumpbuffer - print contents of a buffer in hex to standard output.
+ * reap_kids - get status from any dead child processes,
+ * and log a message for abnormal terminations.
*/
void
-dumpbuffer(buffer, size, level)
- unsigned char *buffer;
- int size;
- int level;
+reap_kids()
{
- register int i;
- char line[256], *p;
-
- printf("%d bytes:\n", size);
- while (size > 0)
- {
- p = line;
- sprintf(p, "%08lx: ", buffer);
- p += 10;
-
- for (i = 0; i < 8; i++, p += 3)
- if (size - i <= 0)
- sprintf(p, "xx ");
- else
- sprintf(p, "%02x ", buffer[i]);
-
- for (i = 0; i < 8; i++)
- if (size - i <= 0)
- *p++ = 'x';
- else
- *p++ = (' ' <= buffer[i] && buffer[i] <= '~') ?
- buffer[i] : '.';
-
- *p++ = 0;
- buffer += 8;
- size -= 8;
-
-/* syslog(level, "%s\n", line); */
- printf("%s\n", line);
- fflush(stdout);
+ int pid, status;
+
+ if (n_children == 0)
+ return;
+ if ((pid = waitpid(-1, &status, WNOHANG)) == -1) {
+ if (errno != ECHILD)
+ syslog(LOG_ERR, "waitpid: %m");
+ return;
+ }
+ if (pid > 0) {
+ --n_children;
+ if (WIFSIGNALED(status)) {
+ syslog(LOG_WARNING, "child process %d terminated with signal %d",
+ pid, WTERMSIG(status));
+ }
}
}
/*
- * setdtr - control the DTR line on the serial port.
- * This is called from die(), so it shouldn't call die().
+ * log_packet - format a packet and log it.
*/
-setdtr(fd, on)
-int fd, on;
+
+char line[256]; /* line to be logged accumulated here */
+char *linep;
+
+void
+log_packet(p, len, prefix)
+ u_char *p;
+ int len;
+ char *prefix;
{
- int modembits = TIOCM_DTR;
+ strcpy(line, prefix);
+ linep = line + strlen(line);
+ format_packet(p, len, pr_log, NULL);
+ if (linep != line)
+ syslog(LOG_DEBUG, "%s", line);
+}
- ioctl(fd, (on? TIOCMBIS: TIOCMBIC), &modembits);
+/*
+ * format_packet - make a readable representation of a packet,
+ * calling `printer(arg, format, ...)' to output it.
+ */
+void
+format_packet(p, len, printer, arg)
+ u_char *p;
+ int len;
+ void (*printer) __ARGS((void *, char *, ...));
+ void *arg;
+{
+ int i, n;
+ u_short proto;
+ u_char x;
+
+ if (len >= DLLHEADERLEN && p[0] == ALLSTATIONS && p[1] == UI) {
+ p += 2;
+ GETSHORT(proto, p);
+ len -= DLLHEADERLEN;
+ for (i = 0; i < N_PROTO; ++i)
+ if (proto == prottbl[i].protocol)
+ break;
+ if (i < N_PROTO) {
+ printer(arg, "[%s", prottbl[i].name);
+ n = (*prottbl[i].printpkt)(p, len, printer, arg);
+ printer(arg, "]");
+ p += n;
+ len -= n;
+ } else {
+ printer(arg, "[proto=0x%x]", proto);
+ }
+ }
+
+ for (; len > 0; --len) {
+ GETCHAR(x, p);
+ printer(arg, " %.2x", x);
+ }
}
-#include <varargs.h>
+#ifdef __STDC__
+#include <stdarg.h>
-char line[256];
-char *p;
+void
+pr_log(void *arg, char *fmt, ...)
+{
+ int n;
+ va_list pvar;
+ char buf[256];
+
+ va_start(pvar, fmt);
+ vsprintf(buf, fmt, pvar);
+ va_end(pvar);
+
+ n = strlen(buf);
+ if (linep + n + 1 > line + sizeof(line)) {
+ syslog(LOG_DEBUG, "%s", line);
+ linep = line;
+ }
+ strcpy(linep, buf);
+ linep += n;
+}
-logf(level, fmt, va_alist)
-int level;
+#else /* __STDC__ */
+#include <varargs.h>
+
+void
+pr_log(arg, fmt, va_alist)
+void *arg;
char *fmt;
va_dcl
{
+ int n;
va_list pvar;
char buf[256];
vsprintf(buf, fmt, pvar);
va_end(pvar);
- p = line + strlen(line);
- strcat(p, buf);
+ n = strlen(buf);
+ if (linep + n + 1 > line + sizeof(line)) {
+ syslog(LOG_DEBUG, "%s", line);
+ linep = line;
+ }
+ strcpy(linep, buf);
+ linep += n;
+}
+#endif
- if (buf[strlen(buf)-1] == '\n') {
- syslog(level, "%s", line);
- line[0] = 0;
+/*
+ * print_string - print a readable representation of a string using
+ * printer.
+ */
+void
+print_string(p, len, printer, arg)
+ char *p;
+ int len;
+ void (*printer) __ARGS((void *, char *, ...));
+ void *arg;
+{
+ int c;
+
+ printer(arg, "\"");
+ for (; len > 0; --len) {
+ c = *p++;
+ if (' ' <= c && c <= '~')
+ printer(arg, "%c", c);
+ else
+ printer(arg, "\\%.3o", c);
}
+ printer(arg, "\"");
}
+/*
+ * novm - log an error message saying we ran out of memory, and die.
+ */
void
novm(msg)
char *msg;
projects / ppp.git / blobdiff