/*
- * Copyright (C) 2004-2006 Andre Noll <maan@systemlinux.org>
+ * Copyright (C) 2004-2009 Andre Noll <maan@systemlinux.org>
*
- * This program is free software; you can redistribute it and/or modify
- * it under the terms of the GNU General Public License as published by
- * the Free Software Foundation; either version 2 of the License, or
- * (at your option) any later version.
- *
- * This program 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 General Public License for more details.
- *
- * You should have received a copy of the GNU General Public License
- * along with this program; if not, write to the Free Software
- * Foundation, Inc., 59 Temple Place - Suite 330, Boston, MA 02111, USA.
+ * Licensed under the GPL v2. For licencing details see COPYING.
*/
-/** \file string.c memory allocation and string handling functions */
+/** \file string.c Memory allocation and string handling functions. */
#include "para.h"
#include "string.h"
#include <sys/time.h> /* gettimeofday */
-#include <regex.h>
#include <pwd.h>
#include <sys/utsname.h> /* uname() */
#include <string.h>
#include "error.h"
/**
- * paraslash's version of realloc()
+ * Paraslash's version of realloc().
*
- * \param p pointer to the memory block, may be NULL
- * \param size desired new size
+ * \param p Pointer to the memory block, may be \p NULL.
+ * \param size The desired new size.
*
* A wrapper for realloc(3). It calls \p exit(\p EXIT_FAILURE) on errors,
* i.e. there is no need to check the return value in the caller.
- * \sa realloc(3)
+ *
+ * \return A pointer to the newly allocated memory, which is suitably aligned
+ * for any kind of variable and may be different from \a p.
+ *
+ * \sa realloc(3).
*/
__must_check __malloc void *para_realloc(void *p, size_t size)
{
/*
- * No need to check for NULL pointers: If p is NULL, the call
+ * No need to check for NULL pointers: If p is NULL, the call
* to realloc is equivalent to malloc(size)
*/
+ assert(size);
if (!(p = realloc(p, size))) {
- PARA_EMERG_LOG("%s", "realloc failed, aborting\n");
+ PARA_EMERG_LOG("realloc failed (size = %zu), aborting\n",
+ size);
exit(EXIT_FAILURE);
}
return p;
}
/**
- * paraslash's version of malloc()
+ * Paraslash's version of malloc().
*
- * \param size desired new size
+ * \param size The desired new size.
*
* A wrapper for malloc(3) which exits on errors.
- * \sa malloc(3)
+ *
+ * \return A pointer to the allocated memory, which is suitably aligned for any
+ * kind of variable.
+ *
+ * \sa malloc(3).
*/
__must_check __malloc void *para_malloc(size_t size)
{
- void *p = malloc(size);
+ void *p;
+ assert(size);
+ p = malloc(size);
if (!p) {
- PARA_EMERG_LOG("%s", "malloc failed, aborting\n");
+ PARA_EMERG_LOG("malloc failed (size = %zu), aborting\n",
+ size);
exit(EXIT_FAILURE);
}
return p;
}
/**
- * paraslash's version of calloc()
+ * Paraslash's version of calloc().
*
- * \param size desired new size
+ * \param size The desired new size.
*
* A wrapper for calloc(3) which exits on errors.
+ *
+ * \return A pointer to the allocated and zeroed-out memory, which is suitably
+ * aligned for any kind of variable.
+ *
* \sa calloc(3)
*/
__must_check __malloc void *para_calloc(size_t size)
}
/**
- * paraslash's version of strdup()
+ * Paraslash's version of strdup().
*
- * \param s: string to be duplicated
+ * \param s The string to be duplicated.
*
- * A wrapper for strdup(3). It calls exit(EXIT_FAILURE) on
- * errors, i.e. there is no need to check the return value in the caller.
- * Moreover, this wrapper checks for \a s being NULL and returns an empty
- * string in this case.
+ * A wrapper for strdup(3). It calls \p exit(EXIT_FAILURE) on errors, i.e.
+ * there is no need to check the return value in the caller.
+ *
+ * \return A pointer to the duplicated string. If \a s was the \p NULL pointer,
+ * an pointer to an empty string is returned.
*
* \sa strdup(3)
*/
if ((ret = strdup(s? s: "")))
return ret;
- PARA_EMERG_LOG("%s", "strdup failed, aborting\n");
+ PARA_EMERG_LOG("strdup failed, aborting\n");
exit(EXIT_FAILURE);
}
/**
- * allocate a sufficiently large string and print into it
+ * Allocate a sufficiently large string and print into it.
+ *
+ * \param fmt A usual format string.
*
- * \param fmt usual format string
+ * Produce output according to \p fmt. No artificial bound on the length of the
+ * resulting string is imposed.
*
- * Produce output according to \a fmt. No artificial bound on the length of the
- * resulting string is imposed. This function either returns a pointer to a
- * string that must be freed by the caller or aborts without returning.
+ * \return This function either returns a pointer to a string that must be
+ * freed by the caller or aborts without returning.
*
- * \sa printf(3)
+ * \sa printf(3).
*/
__must_check __printf_1_2 __malloc char *make_message(const char *fmt, ...)
{
}
/**
- * paraslash's version of strcat()
+ * Paraslash's version of strcat().
*
- * \param a string to be appended to
- * \param b string to append
+ * \param a String to be appended to.
+ * \param b String to append.
*
- * Append \a b to \a a. If \a a is NULL, return a copy of \a b, i.e.
- * para_strcat(NULL, b) is equivalent to para_strdup(b). If \a b is NULL,
+ * Append \p b to \p a.
+ *
+ * \return If \a a is \p NULL, return a pointer to a copy of \a b, i.e.
+ * para_strcat(NULL, b) is equivalent to para_strdup(b). If \a b is \p NULL,
* return \a a without making a copy of \a a. Otherwise, construct the
* concatenation \a c, free \a a (but not \a b) and return \a c.
*
}
/**
- * paraslash's version of dirname()
+ * Paraslash's version of dirname().
+ *
+ * \param name Pointer to the full path.
*
- * \param name pointer to The full path
+ * Compute the directory component of \p name.
*
- * If \a name is \รพ NULL or the empty string, return \p NULL, Otherwise, Make a
- * copy of \a name and return its directory component. Caller is responsible to
- * free the result.
+ * \return If \a name is \p NULL or the empty string, return \p NULL.
+ * Otherwise, Make a copy of \a name and return its directory component. Caller
+ * is responsible to free the result.
*/
__must_check __malloc char *para_dirname(const char *name)
{
}
/**
- * paraslash's version of basename()
+ * Paraslash's version of basename().
*
- * \param name Pointer to the full path
+ * \param name Pointer to the full path.
*
- * If \a name is \p NULL or the empty string, return \p NULL, Otherwise, make a
- * copy of \a name and return its filename component. Caller is responsible to
- * free the result.
+ * Compute the filename component of \a name.
+ *
+ * \return \p NULL if (a) \a name is the empty string or \p NULL, or (b) name
+ * ends with a slash. Otherwise, a pointer within \a name is returned. Caller
+ * must not free the result.
*/
-__must_check __malloc char *para_basename(const char *name)
+__must_check const char *para_basename(const char *name)
{
- char *p;
+ const char *ret;
if (!name || !*name)
return NULL;
- p = strrchr(name, '/');
- if (!p)
- return para_strdup(name);
- p++;
- if (!*p)
- return NULL;
- return para_strdup(p);
-}
-
-/**
- * simple search and replace routine
- *
- * \param src source string
- * \param macro_name the name of the macro
- * \param replacement the replacement format string
- *
- * Replace \a macro_name(arg) by \a replacement. \a replacement is a format
- * string which may contain a single string conversion specifier which gets
- * replaced by 'arg'.
- *
- * \return A string in which all matches in \a src are replaced, or NULL if an
- * syntax error was encountered. Caller must free the result.
- *
- * \sa regcomp(3)
- */
-__must_check __malloc char *s_a_r(const char *src, const char* macro_name,
- const char *replacement)
-{
- regex_t preg;
- size_t nmatch = 1;
- regmatch_t pmatch[1];
- int eflags = 0;
- char *dest = NULL;
- const char *bufptr = src;
-
- if (!macro_name || !replacement || !src)
- return para_strdup(src);
- regcomp(&preg, macro_name, 0);
- while (regexec(&preg, bufptr, nmatch, pmatch, eflags)
- != REG_NOMATCH) {
- char *tmp, *arg, *o_bracket, *c_bracket;
-
- o_bracket = strchr(bufptr + pmatch[0].rm_so, '(');
- c_bracket = o_bracket? strchr(o_bracket, ')') : NULL;
- if (!c_bracket)
- goto out;
- tmp = para_strdup(bufptr);
- tmp[pmatch[0].rm_so] = '\0';
- dest = para_strcat(dest, tmp);
- free(tmp);
-
- arg = para_strdup(o_bracket + 1);
- arg[c_bracket - o_bracket - 1] = '\0';
- tmp = make_message(replacement, arg);
- free(arg);
- dest = para_strcat(dest, tmp);
- free(tmp);
- bufptr = c_bracket;
- bufptr++;
- }
- dest = para_strcat(dest, bufptr);
-// PARA_DEBUG_LOG("%s: returning %s\n", __func__, dest);
-out:
- regfree(&preg);
- return dest;
-}
-
-/**
- * replace a string according to a list of macros
- *
- * \param macro_list the array containing a macro/replacement pairs.
- * \param src the source string
- *
- * This function just calls s_a_r() for each element of \a macro_list.
- */
-__must_check __malloc char *s_a_r_list(struct para_macro *macro_list, char *src)
-{
- struct para_macro *mp = macro_list;
- char *ret = NULL, *tmp = para_strdup(src);
-
- while (mp->name) {
- ret = s_a_r(tmp, mp->name, mp->replacement);
- free(tmp);
- if (!ret) /* syntax error */
- return NULL;
- tmp = ret;
- mp++;
- }
- //PARA_DEBUG_LOG("%s: returning %s\n", __func__, dest);
+ ret = strrchr(name, '/');
+ if (!ret)
+ return name;
+ ret++;
return ret;
}
/**
- * cut trailing newline
+ * Cut trailing newline.
*
- * \param buf the string to be chopped.
+ * \param buf The string to be chopped.
*
- * Replace the last character in \a buf by zero if it is euqal to
+ * Replace the last character in \p buf by zero if it is equal to
* the newline character.
*/
void chop(char *buf)
{
int n = strlen(buf);
+
if (!n)
return;
if (buf[n - 1] == '\n')
}
/**
- * get a random filename
+ * Get a random filename.
*
* This is by no means a secure way to create temporary files in a hostile
- * direcory like /tmp. However, it is OK to use for temp files, fifos, sockets
- * that are created in ~/.paraslash. Result must be freed by the caller.
+ * directory like \p /tmp. However, it is OK to use for temp files, fifos,
+ * sockets that are created in ~/.paraslash. Result must be freed by the
+ * caller.
+ *
+ * \return A pointer to a random filename.
*/
__must_check __malloc char *para_tmpname(void)
{
struct timeval now;
+ unsigned int seed;
+
gettimeofday(&now, NULL);
- srand(now.tv_usec);
+ seed = now.tv_usec;
+ srand(seed);
return make_message("%08i", rand());
}
/**
- * create unique temporary file
+ * Get the logname of the current user.
*
- * \param template the template to be passed to mkstemp()
- * \param mode the desired mode of the tempfile
+ * \return A dynamically allocated string that must be freed by the caller. On
+ * errors, the string "unknown_user" is returned, i.e. this function never
+ * returns \p NULL.
*
- * This wrapper for mkstemp additionally uses fchmod() to
- * set the given mode of the tempfile if mkstemp() returned success.
- * Return value: The file descriptor of the temp file just created on success.
- * On errors, -E_MKSTEMP or -E_FCHMOD is returned.
- */
-__must_check int para_mkstemp(char *template, mode_t mode)
-{
- int tmp, fd = mkstemp(template);
-
- if (fd < 0)
- return -E_MKSTEMP;
- tmp = fchmod(fd, mode);
- if (tmp >= 0)
- return fd;
- close(fd);
- unlink(template);
- return -E_FCHMOD;
-}
-
-/**
- * get the logname of the current user
- *
- * \return A dynammically allocated string that must be freed by the caller. On
- * errors, the string "unknown user" is returned, i.e. this function never
- * returns NULL.
+ * \sa getpwuid(3).
*/
__must_check __malloc char *para_logname(void)
{
}
/**
- * get the home directory of the current user
+ * Get the home directory of the current user.
*
- * \return A dynammically allocated string that must be freed by the caller. If
+ * \return A dynamically allocated string that must be freed by the caller. If
* the home directory could not be found, this function returns "/tmp".
*/
__must_check __malloc char *para_homedir(void)
}
/**
- * split string and return pointers to its parts.
+ * Split string and return pointers to its parts.
*
- * \param args the string to be split
- * \param argv_ptr pointer to the list of substrings
- * \param delim delimiter
+ * \param args The string to be split.
+ * \param argv_ptr Pointer to the list of substrings.
+ * \param delim Delimiter.
*
- * This function modifies \a args by replacing each occurance of \a delim by
- * zero. A NULL-terminated array of pointers to char* is allocated dynamically
+ * This function modifies \a args by replacing each occurrence of \a delim by
+ * zero. A \p NULL-terminated array of pointers to char* is allocated dynamically
* and these pointers are initialized to point to the broken-up substrings
- * within \a args. A pointer to this array is returned via \a argv_ptr. It's OK
- * to call this function with \a args == NULL.
+ * within \a args. A pointer to this array is returned via \a argv_ptr.
*
* \return The number of substrings found in \a args.
*/
-__must_check unsigned split_args(char *args, char ***argv_ptr, int delim)
+unsigned split_args(char *args, char *** const argv_ptr, const char *delim)
{
- char *p = args;
+ char *p;
char **argv;
- ssize_t n = 0, i;
+ size_t n = 0, i, j;
- while (p && (p = strchr(p, delim))) {
- p++;
+ p = args + strspn(args, delim);
+ for (;;) {
+ i = strcspn(p, delim);
+ if (!i)
+ break;
+ p += i;
n++;
+ p += strspn(p, delim);
}
- *argv_ptr = para_calloc((n + 3) * sizeof(char *));
+ *argv_ptr = para_malloc((n + 1) * sizeof(char *));
argv = *argv_ptr;
i = 0;
- p = args;
-// printf("split_args: a:%s\n", p);
+ p = args + strspn(args, delim);
while (p) {
argv[i] = p;
- p = strchr(p, delim);
- if (p) {
-// printf("a:%s\n", p);
+ j = strcspn(p, delim);
+ if (!j)
+ break;
+ p += strcspn(p, delim);
+ if (*p) {
*p = '\0';
-// printf("b:\n");
p++;
- i++;
+ p += strspn(p, delim);
}
+ i++;
}
+ argv[n] = NULL;
return n;
}
/**
- * ensure that file descriptors 0, 1, and 2 are valid
+ * Get the own hostname.
*
- * Common approach that opens /dev/null until it gets a file descriptor greater
- * than two.
+ * \return A dynamically allocated string containing the hostname.
*
- * \sa okir's Black Hats Manual.
+ * \sa uname(2).
*/
-void valid_fd_012(void)
+__malloc char *para_hostname(void)
{
- while (1) {
- int fd;
+ struct utsname u;
+
+ uname(&u);
+ return para_strdup(u.nodename);
+}
+
+/**
+ * Used to distinguish between read-only and read-write mode.
+ *
+ * \sa for_each_line(), for_each_line_ro().
+ */
+enum for_each_line_modes{
+ /** Activate read-only mode. */
+ LINE_MODE_RO,
+ /** Activate read-write mode. */
+ LINE_MODE_RW
+};
+
+static int for_each_complete_line(enum for_each_line_modes mode, char *buf,
+ size_t size, line_handler_t *line_handler, void *private_data)
+{
+ char *start = buf, *end;
+ int ret, i, num_lines = 0;
- fd = open("/dev/null", O_RDWR);
- if (fd < 0)
- exit(EXIT_FAILURE);
- if (fd > 2) {
- close(fd);
+// PARA_NOTICE_LOG("buf: %s\n", buf);
+ while (start < buf + size) {
+ char *next_null;
+ char *next_cr;
+
+ next_cr = memchr(start, '\n', buf + size - start);
+ next_null = memchr(start, '\0', buf + size - start);
+ if (!next_cr && !next_null)
break;
+ if (next_cr && next_null) {
+ end = next_cr < next_null? next_cr : next_null;
+ } else if (next_null) {
+ end = next_null;
+ } else
+ end = next_cr;
+ num_lines++;
+ if (!line_handler) {
+ start = ++end;
+ continue;
+ }
+ if (mode == LINE_MODE_RO) {
+ size_t s = end - start;
+ char *b = para_malloc(s + 1);
+ memcpy(b, start, s);
+ b[s] = '\0';
+// PARA_NOTICE_LOG("b: %s, start: %s\n", b, start);
+ ret = line_handler(b, private_data);
+ free(b);
+ } else {
+ *end = '\0';
+ ret = line_handler(start, private_data);
}
+ if (ret < 0)
+ return ret;
+ start = ++end;
}
+ if (!line_handler || mode == LINE_MODE_RO)
+ return num_lines;
+ i = buf + size - start;
+ if (i && i != size)
+ memmove(buf, start, i);
+ return i;
+}
+
+/**
+ * Call a custom function for each complete line.
+ *
+ * \param buf The buffer containing data separated by newlines.
+ * \param size The number of bytes in \a buf.
+ * \param line_handler The custom function.
+ * \param private_data Pointer passed to \a line_handler.
+ *
+ * If \p line_handler is \p NULL, the function returns the number of complete
+ * lines in \p buf. Otherwise, \p line_handler is called for each complete
+ * line in \p buf. The first argument to \p line_handler is the current line,
+ * and \p private_data is passed as the second argument. The function returns
+ * if \p line_handler returns a negative value or no more lines are in the
+ * buffer. The rest of the buffer (last chunk containing an incomplete line)
+ * is moved to the beginning of the buffer.
+ *
+ * \return If \p line_handler is not \p NULL, this function returns the number
+ * of bytes not handled to \p line_handler on success, or the negative return
+ * value of the \p line_handler on errors.
+ *
+ * \sa for_each_line_ro().
+ */
+int for_each_line(char *buf, size_t size, line_handler_t *line_handler,
+ void *private_data)
+{
+ return for_each_complete_line(LINE_MODE_RW, buf, size, line_handler,
+ private_data);
}
/**
- * get the own hostname
+ * Call a custom function for each complete line.
+ *
+ * \param buf Same meaning as in \p for_each_line().
+ * \param size Same meaning as in \p for_each_line().
+ * \param line_handler Same meaning as in \p for_each_line().
+ * \param private_data Same meaning as in \p for_each_line().
*
- * \return A dynammically allocated string containing the hostname.
+ * This function behaves like \p for_each_line(), but \a buf is left unchanged.
*
- * \sa uname(2)
+ * \return On success, the function returns the number of complete lines in \p
+ * buf, otherwise the (negative) return value of \p line_handler is returned.
+ *
+ * \sa for_each_line().
*/
-__malloc char *para_hostname(void)
+int for_each_line_ro(char *buf, size_t size, line_handler_t *line_handler,
+ void *private_data)
{
- struct utsname u;
+ return for_each_complete_line(LINE_MODE_RO, buf, size, line_handler,
+ private_data);
+}
- uname(&u);
- return para_strdup(u.nodename);
+/**
+ * Safely print into a buffer at a given offset.
+ *
+ * \param b Determines the buffer, its size, and the offset.
+ * \param fmt The format string.
+ *
+ * This function prints into the buffer given by \a b at the offset which is
+ * also given by \a b. If there is not enough space to hold the result, the
+ * buffer size is doubled until the underlying call to vsnprintf() succeeds
+ * or the size of the buffer exceeds the maximal size specified in \a b.
+ *
+ * In the latter case the unmodified \a buf and \a offset values as well as the
+ * private_data pointer of \a b are passed to the \a max_size_handler of \a b.
+ * If this function succeeds, i.e. returns a non-negative value, the offset of
+ * \a b is reset to zero and the given data is written to the beginning of the
+ * buffer.
+ *
+ * Upon return, the offset of \a b is adjusted accordingly so that subsequent
+ * calls to this function append data to what is already contained in the
+ * buffer.
+ *
+ * It's OK to call this function with \p b->buf being \p NULL. In this case, an
+ * initial buffer is allocated.
+ *
+ * \return The number of bytes printed into the buffer (not including the
+ * terminating \p NULL byte).
+ *
+ * \sa make_message(), vsnprintf(3).
+ */
+__printf_2_3 int para_printf(struct para_buffer *b, const char *fmt, ...)
+{
+ int ret;
+
+ if (!b->buf) {
+ b->buf = para_malloc(128);
+ b->size = 128;
+ b->offset = 0;
+ }
+ while (1) {
+ char *p = b->buf + b->offset;
+ size_t size = b->size - b->offset;
+ va_list ap;
+ if (size) {
+ va_start(ap, fmt);
+ ret = vsnprintf(p, size, fmt, ap);
+ va_end(ap);
+ if (ret > -1 && ret < size) { /* success */
+ b->offset += ret;
+ return ret;
+ }
+ }
+ /* check if we may grow the buffer */
+ if (!b->max_size || 2 * b->size < b->max_size) { /* yes */
+ /* try again with more space */
+ b->size *= 2;
+ b->buf = para_realloc(b->buf, b->size);
+ continue;
+ }
+ /* can't grow buffer */
+ if (!b->offset || !b->max_size_handler) /* message too large */
+ return -ERRNO_TO_PARA_ERROR(ENOSPC);
+ ret = b->max_size_handler(b->buf, b->offset, b->private_data);
+ if (ret < 0)
+ return ret;
+ b->offset = 0;
+ }
+}
+
+/** \cond LLONG_MAX and LLONG_LIN might not be defined. */
+#ifndef LLONG_MAX
+#define LLONG_MAX (1 << (sizeof(long) - 1))
+#endif
+#ifndef LLONG_MIN
+#define LLONG_MIN (-LLONG_MAX - 1LL)
+#endif
+/** \endcond */
+
+/**
+ * Convert a string to a 64-bit signed integer value.
+ *
+ * \param str The string to be converted.
+ * \param value Result pointer.
+ *
+ * \return Standard.
+ *
+ * \sa para_atoi32(), strtol(3), atoi(3).
+ */
+int para_atoi64(const char *str, int64_t *value)
+{
+ char *endptr;
+ long long tmp;
+
+ errno = 0; /* To distinguish success/failure after call */
+ tmp = strtoll(str, &endptr, 10);
+ if (errno == ERANGE && (tmp == LLONG_MAX || tmp == LLONG_MIN))
+ return -E_ATOI_OVERFLOW;
+ if (errno != 0 && tmp == 0) /* other error */
+ return -E_STRTOLL;
+ if (endptr == str)
+ return -E_ATOI_NO_DIGITS;
+ if (*endptr != '\0') /* Further characters after number */
+ return -E_ATOI_JUNK_AT_END;
+ *value = tmp;
+ return 1;
+}
+
+/**
+ * Convert a string to a 32-bit signed integer value.
+ *
+ * \param str The string to be converted.
+ * \param value Result pointer.
+ *
+ * \return Standard.
+ *
+ * \sa para_atoi64().
+*/
+int para_atoi32(const char *str, int32_t *value)
+{
+ int64_t tmp;
+ int ret;
+ const int32_t max = 2147483647;
+
+ ret = para_atoi64(str, &tmp);
+ if (ret < 0)
+ return ret;
+ if (tmp > max || tmp < -max - 1)
+ return -E_ATOI_OVERFLOW;
+ *value = tmp;
+ return 1;
+}
+
+static inline int loglevel_equal(const char *arg, const char * const ll)
+{
+ return !strncasecmp(arg, ll, strlen(ll));
+}
+
+/**
+ * Compute the loglevel number from its name.
+ *
+ * \param txt The name of the loglevel (debug, info, ...).
+ *
+ * \return The numeric representation of the loglevel name.
+ */
+int get_loglevel_by_name(const char *txt)
+{
+ if (loglevel_equal(txt, "debug"))
+ return LL_DEBUG;
+ if (loglevel_equal(txt, "info"))
+ return LL_INFO;
+ if (loglevel_equal(txt, "notice"))
+ return LL_NOTICE;
+ if (loglevel_equal(txt, "warning"))
+ return LL_WARNING;
+ if (loglevel_equal(txt, "error"))
+ return LL_ERROR;
+ if (loglevel_equal(txt, "crit"))
+ return LL_CRIT;
+ if (loglevel_equal(txt, "emerg"))
+ return LL_EMERG;
+ return -1;
}
projects / paraslash.git / blobdiff