2 * Copyright (c) 2008, 2009, 2010, 2011, 2012, 2013 Nicira, Inc.
4 * Licensed under the Apache License, Version 2.0 (the "License");
5 * you may not use this file except in compliance with the License.
6 * You may obtain a copy of the License at:
8 * http://www.apache.org/licenses/LICENSE-2.0
10 * Unless required by applicable law or agreed to in writing, software
11 * distributed under the License is distributed on an "AS IS" BASIS,
12 * WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
13 * See the License for the specific language governing permissions and
14 * limitations under the License.
31 #include "byte-order.h"
33 #include "ovs-thread.h"
35 #ifdef HAVE_PTHREAD_SET_NAME_NP
36 #include <pthread_np.h>
39 VLOG_DEFINE_THIS_MODULE(util);
41 COVERAGE_DEFINE(util_xalloc);
43 /* argv[0] without directory names. */
44 const char *program_name;
46 /* Name for the currently running thread or process, for log messages, process
47 * listings, and debuggers. */
48 DEFINE_PER_THREAD_MALLOCED_DATA(char *, subprogram_name);
50 /* --version option output. */
51 static char *program_version;
53 /* Buffer used by ovs_strerror(). */
54 DEFINE_STATIC_PER_THREAD_DATA(struct { char s[128]; },
59 ovs_assert_failure(const char *where, const char *function,
60 const char *condition)
62 /* Prevent an infinite loop (or stack overflow) in case VLOG_ABORT happens
63 * to trigger an assertion failure of its own. */
64 static int reentry = 0;
68 VLOG_ABORT("%s: assertion %s failed in %s()",
69 where, condition, function);
73 fprintf(stderr, "%s: assertion %s failed in %s()",
74 where, condition, function);
85 ovs_abort(0, "virtual memory exhausted");
89 xcalloc(size_t count, size_t size)
91 void *p = count && size ? calloc(count, size) : malloc(1);
92 COVERAGE_INC(util_xalloc);
102 return xcalloc(1, size);
108 void *p = malloc(size ? size : 1);
109 COVERAGE_INC(util_xalloc);
117 xrealloc(void *p, size_t size)
119 p = realloc(p, size ? size : 1);
120 COVERAGE_INC(util_xalloc);
128 xmemdup(const void *p_, size_t size)
130 void *p = xmalloc(size);
136 xmemdup0(const char *p_, size_t length)
138 char *p = xmalloc(length + 1);
139 memcpy(p, p_, length);
145 xstrdup(const char *s)
147 return xmemdup0(s, strlen(s));
151 xvasprintf(const char *format, va_list args)
157 va_copy(args2, args);
158 needed = vsnprintf(NULL, 0, format, args);
160 s = xmalloc(needed + 1);
162 vsnprintf(s, needed + 1, format, args2);
169 x2nrealloc(void *p, size_t *n, size_t s)
171 *n = *n == 0 ? 1 : 2 * *n;
172 return xrealloc(p, *n * s);
176 xasprintf(const char *format, ...)
181 va_start(args, format);
182 s = xvasprintf(format, args);
188 /* Similar to strlcpy() from OpenBSD, but it never reads more than 'size - 1'
189 * bytes from 'src' and doesn't return anything. */
191 ovs_strlcpy(char *dst, const char *src, size_t size)
194 size_t len = strnlen(src, size - 1);
195 memcpy(dst, src, len);
200 /* Copies 'src' to 'dst'. Reads no more than 'size - 1' bytes from 'src'.
201 * Always null-terminates 'dst' (if 'size' is nonzero), and writes a zero byte
202 * to every otherwise unused byte in 'dst'.
204 * Except for performance, the following call:
205 * ovs_strzcpy(dst, src, size);
206 * is equivalent to these two calls:
207 * memset(dst, '\0', size);
208 * ovs_strlcpy(dst, src, size);
210 * (Thus, ovs_strzcpy() is similar to strncpy() without some of the pitfalls.)
213 ovs_strzcpy(char *dst, const char *src, size_t size)
216 size_t len = strnlen(src, size - 1);
217 memcpy(dst, src, len);
218 memset(dst + len, '\0', size - len);
222 /* Prints 'format' on stderr, formatting it like printf() does. If 'err_no' is
223 * nonzero, then it is formatted with ovs_retval_to_string() and appended to
224 * the message inside parentheses. Then, terminates with abort().
226 * This function is preferred to ovs_fatal() in a situation where it would make
227 * sense for a monitoring process to restart the daemon.
229 * 'format' should not end with a new-line, because this function will add one
232 ovs_abort(int err_no, const char *format, ...)
236 va_start(args, format);
237 ovs_abort_valist(err_no, format, args);
240 /* Same as ovs_abort() except that the arguments are supplied as a va_list. */
242 ovs_abort_valist(int err_no, const char *format, va_list args)
244 ovs_error_valist(err_no, format, args);
248 /* Prints 'format' on stderr, formatting it like printf() does. If 'err_no' is
249 * nonzero, then it is formatted with ovs_retval_to_string() and appended to
250 * the message inside parentheses. Then, terminates with EXIT_FAILURE.
252 * 'format' should not end with a new-line, because this function will add one
255 ovs_fatal(int err_no, const char *format, ...)
259 va_start(args, format);
260 ovs_fatal_valist(err_no, format, args);
263 /* Same as ovs_fatal() except that the arguments are supplied as a va_list. */
265 ovs_fatal_valist(int err_no, const char *format, va_list args)
267 ovs_error_valist(err_no, format, args);
271 /* Prints 'format' on stderr, formatting it like printf() does. If 'err_no' is
272 * nonzero, then it is formatted with ovs_retval_to_string() and appended to
273 * the message inside parentheses.
275 * 'format' should not end with a new-line, because this function will add one
278 ovs_error(int err_no, const char *format, ...)
282 va_start(args, format);
283 ovs_error_valist(err_no, format, args);
287 /* Same as ovs_error() except that the arguments are supplied as a va_list. */
289 ovs_error_valist(int err_no, const char *format, va_list args)
291 const char *subprogram_name = get_subprogram_name();
292 int save_errno = errno;
294 if (subprogram_name[0]) {
295 fprintf(stderr, "%s(%s): ", program_name, subprogram_name);
297 fprintf(stderr, "%s: ", program_name);
300 vfprintf(stderr, format, args);
302 fprintf(stderr, " (%s)", ovs_retval_to_string(err_no));
309 /* Many OVS functions return an int which is one of:
312 * - EOF: end of file (not necessarily an error; depends on the function called)
314 * Returns the appropriate human-readable string. The caller must copy the
315 * string if it wants to hold onto it, as the storage may be overwritten on
316 * subsequent function calls.
319 ovs_retval_to_string(int retval)
322 : retval == EOF ? "End of file"
323 : ovs_strerror(retval));
327 ovs_strerror(int error)
329 enum { BUFSIZE = sizeof strerror_buffer_get()->s };
335 buffer = strerror_buffer_get()->s;
337 #if STRERROR_R_CHAR_P
338 /* GNU style strerror_r() might return an immutable static string, or it
339 * might write and return 'buffer', but in either case we can pass the
340 * returned string directly to the caller. */
341 s = strerror_r(error, buffer, BUFSIZE);
342 #else /* strerror_r() returns an int. */
344 if (strerror_r(error, buffer, BUFSIZE)) {
345 /* strerror_r() is only allowed to fail on ERANGE (because the buffer
346 * is too short). We don't check the actual failure reason because
347 * POSIX requires strerror_r() to return the error but old glibc
348 * (before 2.13) returns -1 and sets errno. */
349 snprintf(buffer, BUFSIZE, "Unknown error %d", error);
358 /* Sets global "program_name" and "program_version" variables. Should
359 * be called at the beginning of main() with "argv[0]" as the argument
362 * 'version' should contain the version of the caller's program. If 'version'
363 * is the same as the VERSION #define, the caller is assumed to be part of Open
364 * vSwitch. Otherwise, it is assumed to be an external program linking against
365 * the Open vSwitch libraries.
367 * The 'date' and 'time' arguments should likely be called with
368 * "__DATE__" and "__TIME__" to use the time the binary was built.
369 * Alternatively, the "set_program_name" macro may be called to do this
373 set_program_name__(const char *argv0, const char *version, const char *date,
378 size_t max_len = strlen(argv0) + 1;
379 basename = xmalloc(max_len);
380 _splitpath_s(argv0, NULL, 0, NULL, 0, basename, max_len, NULL, 0);
381 assert_single_threaded();
382 program_name = basename;
384 const char *slash = strrchr(argv0, '/');
385 assert_single_threaded();
386 program_name = slash ? slash + 1 : argv0;
389 free(program_version);
391 if (!strcmp(version, VERSION)) {
392 program_version = xasprintf("%s (Open vSwitch) "VERSION"\n"
394 program_name, date, time);
396 program_version = xasprintf("%s %s\n"
397 "Open vSwitch Library "VERSION"\n"
399 program_name, version, date, time);
403 /* Returns the name of the currently running thread or process. */
405 get_subprogram_name(void)
407 const char *name = subprogram_name_get();
408 return name ? name : "";
411 /* Sets the formatted value of 'format' as the name of the currently running
412 * thread or process. (This appears in log messages and may also be visible in
413 * system process listings and debuggers.) */
415 set_subprogram_name(const char *format, ...)
422 va_start(args, format);
423 pname = xvasprintf(format, args);
426 pname = xstrdup(program_name);
429 free(subprogram_name_set(pname));
431 #if HAVE_GLIBC_PTHREAD_SETNAME_NP
432 pthread_setname_np(pthread_self(), pname);
433 #elif HAVE_NETBSD_PTHREAD_SETNAME_NP
434 pthread_setname_np(pthread_self(), "%s", pname);
435 #elif HAVE_PTHREAD_SET_NAME_NP
436 pthread_set_name_np(pthread_self(), pname);
440 /* Returns a pointer to a string describing the program version. The
441 * caller must not modify or free the returned string.
444 get_program_version(void)
446 return program_version;
449 /* Print the version information for the program. */
451 ovs_print_version(uint8_t min_ofp, uint8_t max_ofp)
453 printf("%s", program_version);
454 if (min_ofp || max_ofp) {
455 printf("OpenFlow versions %#x:%#x\n", min_ofp, max_ofp);
459 /* Writes the 'size' bytes in 'buf' to 'stream' as hex bytes arranged 16 per
460 * line. Numeric offsets are also included, starting at 'ofs' for the first
461 * byte in 'buf'. If 'ascii' is true then the corresponding ASCII characters
462 * are also rendered alongside. */
464 ovs_hex_dump(FILE *stream, const void *buf_, size_t size,
465 uintptr_t ofs, bool ascii)
467 const uint8_t *buf = buf_;
468 const size_t per_line = 16; /* Maximum bytes per line. */
472 size_t start, end, n;
475 /* Number of bytes on this line. */
476 start = ofs % per_line;
478 if (end - start > size)
483 fprintf(stream, "%08"PRIxMAX" ", (uintmax_t) ROUND_DOWN(ofs, per_line));
484 for (i = 0; i < start; i++)
485 fprintf(stream, " ");
487 fprintf(stream, "%02x%c",
488 buf[i - start], i == per_line / 2 - 1? '-' : ' ');
491 for (; i < per_line; i++)
492 fprintf(stream, " ");
493 fprintf(stream, "|");
494 for (i = 0; i < start; i++)
495 fprintf(stream, " ");
496 for (; i < end; i++) {
497 int c = buf[i - start];
498 putc(c >= 32 && c < 127 ? c : '.', stream);
500 for (; i < per_line; i++)
501 fprintf(stream, " ");
502 fprintf(stream, "|");
504 fprintf(stream, "\n");
513 str_to_int(const char *s, int base, int *i)
516 bool ok = str_to_llong(s, base, &ll);
522 str_to_long(const char *s, int base, long *li)
525 bool ok = str_to_llong(s, base, &ll);
531 str_to_llong(const char *s, int base, long long *x)
533 int save_errno = errno;
536 *x = strtoll(s, &tail, base);
537 if (errno == EINVAL || errno == ERANGE || tail == s || *tail != '\0') {
547 /* Converts floating-point string 's' into a double. If successful, stores
548 * the double in '*d' and returns true; on failure, stores 0 in '*d' and
551 * Underflow (e.g. "1e-9999") is not considered an error, but overflow
552 * (e.g. "1e9999)" is. */
554 str_to_double(const char *s, double *d)
556 int save_errno = errno;
559 *d = strtod(s, &tail);
560 if (errno == EINVAL || (errno == ERANGE && *d != 0)
561 || tail == s || *tail != '\0') {
571 /* Returns the value of 'c' as a hexadecimal digit. */
576 case '0': case '1': case '2': case '3': case '4':
577 case '5': case '6': case '7': case '8': case '9':
603 /* Returns the integer value of the 'n' hexadecimal digits starting at 's', or
604 * UINT_MAX if one of those "digits" is not really a hex digit. If 'ok' is
605 * nonnull, '*ok' is set to true if the conversion succeeds or to false if a
606 * non-hex digit is detected. */
608 hexits_value(const char *s, size_t n, bool *ok)
614 for (i = 0; i < n; i++) {
615 int hexit = hexit_value(s[i]);
622 value = (value << 4) + hexit;
630 /* Returns the current working directory as a malloc()'d string, or a null
631 * pointer if the current working directory cannot be determined. */
638 /* Get maximum path length or at least a reasonable estimate. */
639 path_max = pathconf(".", _PC_PATH_MAX);
640 size = (path_max < 0 ? 1024
641 : path_max > 10240 ? 10240
644 /* Get current working directory. */
646 char *buf = xmalloc(size);
647 if (getcwd(buf, size)) {
648 return xrealloc(buf, strlen(buf) + 1);
652 if (error != ERANGE) {
653 VLOG_WARN("getcwd failed (%s)", ovs_strerror(error));
662 all_slashes_name(const char *s)
664 return xstrdup(s[0] == '/' && s[1] == '/' && s[2] != '/' ? "//"
669 /* Returns the directory name portion of 'file_name' as a malloc()'d string,
670 * similar to the POSIX dirname() function but thread-safe. */
672 dir_name(const char *file_name)
674 size_t len = strlen(file_name);
675 while (len > 0 && file_name[len - 1] == '/') {
678 while (len > 0 && file_name[len - 1] != '/') {
681 while (len > 0 && file_name[len - 1] == '/') {
684 return len ? xmemdup0(file_name, len) : all_slashes_name(file_name);
687 /* Returns the file name portion of 'file_name' as a malloc()'d string,
688 * similar to the POSIX basename() function but thread-safe. */
690 base_name(const char *file_name)
694 end = strlen(file_name);
695 while (end > 0 && file_name[end - 1] == '/') {
700 return all_slashes_name(file_name);
704 while (start > 0 && file_name[start - 1] != '/') {
708 return xmemdup0(file_name + start, end - start);
711 /* If 'file_name' starts with '/', returns a copy of 'file_name'. Otherwise,
712 * returns an absolute path to 'file_name' considering it relative to 'dir',
713 * which itself must be absolute. 'dir' may be null or the empty string, in
714 * which case the current working directory is used.
716 * Returns a null pointer if 'dir' is null and getcwd() fails. */
718 abs_file_name(const char *dir, const char *file_name)
720 if (file_name[0] == '/') {
721 return xstrdup(file_name);
722 } else if (dir && dir[0]) {
723 char *separator = dir[strlen(dir) - 1] == '/' ? "" : "/";
724 return xasprintf("%s%s%s", dir, separator, file_name);
726 char *cwd = get_cwd();
728 char *abs_name = xasprintf("%s/%s", cwd, file_name);
737 /* Like readlink(), but returns the link name as a null-terminated string in
738 * allocated memory that the caller must eventually free (with free()).
739 * Returns NULL on error, in which case errno is set appropriately. */
741 xreadlink(const char *filename)
745 for (size = 64; ; size *= 2) {
746 char *buf = xmalloc(size);
747 ssize_t retval = readlink(filename, buf, size);
750 if (retval >= 0 && retval < size) {
763 /* Returns a version of 'filename' with symlinks in the final component
764 * dereferenced. This differs from realpath() in that:
766 * - 'filename' need not exist.
768 * - If 'filename' does exist as a symlink, its referent need not exist.
770 * - Only symlinks in the final component of 'filename' are dereferenced.
772 * The caller must eventually free the returned string (with free()). */
774 follow_symlinks(const char *filename)
780 fn = xstrdup(filename);
781 for (i = 0; i < 10; i++) {
785 if (lstat(fn, &s) != 0 || !S_ISLNK(s.st_mode)) {
789 linkname = xreadlink(fn);
791 VLOG_WARN("%s: readlink failed (%s)",
792 filename, ovs_strerror(errno));
796 if (linkname[0] == '/') {
797 /* Target of symlink is absolute so use it raw. */
800 /* Target of symlink is relative so add to 'fn''s directory. */
801 char *dir = dir_name(fn);
803 if (!strcmp(dir, ".")) {
806 char *separator = dir[strlen(dir) - 1] == '/' ? "" : "/";
807 next_fn = xasprintf("%s%s%s", dir, separator, linkname);
818 VLOG_WARN("%s: too many levels of symlinks", filename);
820 return xstrdup(filename);
823 /* Pass a value to this function if it is marked with
824 * __attribute__((warn_unused_result)) and you genuinely want to ignore
825 * its return value. (Note that every scalar type can be implicitly
826 * converted to bool.) */
827 void ignore(bool x OVS_UNUSED) { }
829 /* Returns an appropriate delimiter for inserting just before the 0-based item
830 * 'index' in a list that has 'total' items in it. */
832 english_list_delimiter(size_t index, size_t total)
834 return (index == 0 ? ""
835 : index < total - 1 ? ", "
836 : total > 2 ? ", and "
840 /* Returns the number of trailing 0-bits in 'n'. Undefined if 'n' == 0. */
842 /* Defined inline in util.h. */
844 /* Returns the number of trailing 0-bits in 'n'. Undefined if 'n' == 0. */
851 #define CTZ_STEP(X) \
868 /* Returns the number of leading 0-bits in 'n'. Undefined if 'n' == 0. */
870 raw_clz64(uint64_t n)
875 #define CLZ_STEP(X) \
893 #if NEED_COUNT_1BITS_8
895 ((((X) & (1 << 0)) != 0) + \
896 (((X) & (1 << 1)) != 0) + \
897 (((X) & (1 << 2)) != 0) + \
898 (((X) & (1 << 3)) != 0) + \
899 (((X) & (1 << 4)) != 0) + \
900 (((X) & (1 << 5)) != 0) + \
901 (((X) & (1 << 6)) != 0) + \
902 (((X) & (1 << 7)) != 0))
903 #define INIT2(X) INIT1(X), INIT1((X) + 1)
904 #define INIT4(X) INIT2(X), INIT2((X) + 2)
905 #define INIT8(X) INIT4(X), INIT4((X) + 4)
906 #define INIT16(X) INIT8(X), INIT8((X) + 8)
907 #define INIT32(X) INIT16(X), INIT16((X) + 16)
908 #define INIT64(X) INIT32(X), INIT32((X) + 32)
910 const uint8_t count_1bits_8[256] = {
911 INIT64(0), INIT64(64), INIT64(128), INIT64(192)
915 /* Returns true if the 'n' bytes starting at 'p' are zeros. */
917 is_all_zeros(const uint8_t *p, size_t n)
921 for (i = 0; i < n; i++) {
929 /* Returns true if the 'n' bytes starting at 'p' are 0xff. */
931 is_all_ones(const uint8_t *p, size_t n)
935 for (i = 0; i < n; i++) {
943 /* Copies 'n_bits' bits starting from bit 'src_ofs' in 'src' to the 'n_bits'
944 * starting from bit 'dst_ofs' in 'dst'. 'src' is 'src_len' bytes long and
945 * 'dst' is 'dst_len' bytes long.
947 * If you consider all of 'src' to be a single unsigned integer in network byte
948 * order, then bit N is the bit with value 2**N. That is, bit 0 is the bit
949 * with value 1 in src[src_len - 1], bit 1 is the bit with value 2, bit 2 is
950 * the bit with value 4, ..., bit 8 is the bit with value 1 in src[src_len -
951 * 2], and so on. Similarly for 'dst'.
953 * Required invariants:
954 * src_ofs + n_bits <= src_len * 8
955 * dst_ofs + n_bits <= dst_len * 8
956 * 'src' and 'dst' must not overlap.
959 bitwise_copy(const void *src_, unsigned int src_len, unsigned int src_ofs,
960 void *dst_, unsigned int dst_len, unsigned int dst_ofs,
963 const uint8_t *src = src_;
966 src += src_len - (src_ofs / 8 + 1);
969 dst += dst_len - (dst_ofs / 8 + 1);
972 if (src_ofs == 0 && dst_ofs == 0) {
973 unsigned int n_bytes = n_bits / 8;
977 memcpy(dst, src, n_bytes);
984 uint8_t mask = (1 << n_bits) - 1;
985 *dst = (*dst & ~mask) | (*src & mask);
989 unsigned int max_copy = 8 - MAX(src_ofs, dst_ofs);
990 unsigned int chunk = MIN(n_bits, max_copy);
991 uint8_t mask = ((1 << chunk) - 1) << dst_ofs;
994 *dst |= ((*src >> src_ofs) << dst_ofs) & mask;
1011 /* Zeros the 'n_bits' bits starting from bit 'dst_ofs' in 'dst'. 'dst' is
1012 * 'dst_len' bytes long.
1014 * If you consider all of 'dst' to be a single unsigned integer in network byte
1015 * order, then bit N is the bit with value 2**N. That is, bit 0 is the bit
1016 * with value 1 in dst[dst_len - 1], bit 1 is the bit with value 2, bit 2 is
1017 * the bit with value 4, ..., bit 8 is the bit with value 1 in dst[dst_len -
1020 * Required invariant:
1021 * dst_ofs + n_bits <= dst_len * 8
1024 bitwise_zero(void *dst_, unsigned int dst_len, unsigned dst_ofs,
1025 unsigned int n_bits)
1027 uint8_t *dst = dst_;
1033 dst += dst_len - (dst_ofs / 8 + 1);
1037 unsigned int chunk = MIN(n_bits, 8 - dst_ofs);
1039 *dst &= ~(((1 << chunk) - 1) << dst_ofs);
1049 while (n_bits >= 8) {
1055 *dst &= ~((1 << n_bits) - 1);
1059 /* Sets to 1 all of the 'n_bits' bits starting from bit 'dst_ofs' in 'dst'.
1060 * 'dst' is 'dst_len' bytes long.
1062 * If you consider all of 'dst' to be a single unsigned integer in network byte
1063 * order, then bit N is the bit with value 2**N. That is, bit 0 is the bit
1064 * with value 1 in dst[dst_len - 1], bit 1 is the bit with value 2, bit 2 is
1065 * the bit with value 4, ..., bit 8 is the bit with value 1 in dst[dst_len -
1068 * Required invariant:
1069 * dst_ofs + n_bits <= dst_len * 8
1072 bitwise_one(void *dst_, unsigned int dst_len, unsigned dst_ofs,
1073 unsigned int n_bits)
1075 uint8_t *dst = dst_;
1081 dst += dst_len - (dst_ofs / 8 + 1);
1085 unsigned int chunk = MIN(n_bits, 8 - dst_ofs);
1087 *dst |= ((1 << chunk) - 1) << dst_ofs;
1097 while (n_bits >= 8) {
1103 *dst |= (1 << n_bits) - 1;
1107 /* Scans the 'n_bits' bits starting from bit 'dst_ofs' in 'dst' for 1-bits.
1108 * Returns false if any 1-bits are found, otherwise true. 'dst' is 'dst_len'
1111 * If you consider all of 'dst' to be a single unsigned integer in network byte
1112 * order, then bit N is the bit with value 2**N. That is, bit 0 is the bit
1113 * with value 1 in dst[dst_len - 1], bit 1 is the bit with value 2, bit 2 is
1114 * the bit with value 4, ..., bit 8 is the bit with value 1 in dst[dst_len -
1117 * Required invariant:
1118 * dst_ofs + n_bits <= dst_len * 8
1121 bitwise_is_all_zeros(const void *p_, unsigned int len, unsigned int ofs,
1122 unsigned int n_bits)
1124 const uint8_t *p = p_;
1130 p += len - (ofs / 8 + 1);
1134 unsigned int chunk = MIN(n_bits, 8 - ofs);
1136 if (*p & (((1 << chunk) - 1) << ofs)) {
1148 while (n_bits >= 8) {
1156 if (n_bits && *p & ((1 << n_bits) - 1)) {
1163 /* Copies the 'n_bits' low-order bits of 'value' into the 'n_bits' bits
1164 * starting at bit 'dst_ofs' in 'dst', which is 'dst_len' bytes long.
1166 * If you consider all of 'dst' to be a single unsigned integer in network byte
1167 * order, then bit N is the bit with value 2**N. That is, bit 0 is the bit
1168 * with value 1 in dst[dst_len - 1], bit 1 is the bit with value 2, bit 2 is
1169 * the bit with value 4, ..., bit 8 is the bit with value 1 in dst[dst_len -
1172 * Required invariants:
1173 * dst_ofs + n_bits <= dst_len * 8
1177 bitwise_put(uint64_t value,
1178 void *dst, unsigned int dst_len, unsigned int dst_ofs,
1179 unsigned int n_bits)
1181 ovs_be64 n_value = htonll(value);
1182 bitwise_copy(&n_value, sizeof n_value, 0,
1183 dst, dst_len, dst_ofs,
1187 /* Returns the value of the 'n_bits' bits starting at bit 'src_ofs' in 'src',
1188 * which is 'src_len' bytes long.
1190 * If you consider all of 'src' to be a single unsigned integer in network byte
1191 * order, then bit N is the bit with value 2**N. That is, bit 0 is the bit
1192 * with value 1 in src[src_len - 1], bit 1 is the bit with value 2, bit 2 is
1193 * the bit with value 4, ..., bit 8 is the bit with value 1 in src[src_len -
1196 * Required invariants:
1197 * src_ofs + n_bits <= src_len * 8
1201 bitwise_get(const void *src, unsigned int src_len,
1202 unsigned int src_ofs, unsigned int n_bits)
1204 ovs_be64 value = htonll(0);
1206 bitwise_copy(src, src_len, src_ofs,
1207 &value, sizeof value, 0,
1209 return ntohll(value);
1230 skip_spaces(const char *s)
1232 while (isspace((unsigned char) *s)) {
1239 scan_int(const char *s, const struct scan_spec *spec, int base, va_list *args)
1241 const char *start = s;
1246 negative = *s == '-';
1247 s += *s == '-' || *s == '+';
1249 if ((!base || base == 16) && *s == '0' && (s[1] == 'x' || s[1] == 'X')) {
1253 base = *s == '0' ? 8 : 10;
1256 if (s - start >= spec->width) {
1262 while (s - start < spec->width) {
1263 int digit = hexit_value(*s);
1265 if (digit < 0 || digit >= base) {
1268 value = value * base + digit;
1280 switch (spec->type) {
1284 *va_arg(*args, char *) = value;
1287 *va_arg(*args, short int *) = value;
1290 *va_arg(*args, int *) = value;
1293 *va_arg(*args, long int *) = value;
1296 *va_arg(*args, long long int *) = value;
1299 *va_arg(*args, intmax_t *) = value;
1301 case SCAN_PTRDIFF_T:
1302 *va_arg(*args, ptrdiff_t *) = value;
1305 *va_arg(*args, size_t *) = value;
1312 skip_digits(const char *s)
1314 while (*s >= '0' && *s <= '9') {
1321 scan_float(const char *s, const struct scan_spec *spec, va_list *args)
1323 const char *start = s;
1329 s += *s == '+' || *s == '-';
1332 s = skip_digits(s + 1);
1334 if (*s == 'e' || *s == 'E') {
1336 s += *s == '+' || *s == '-';
1340 if (s - start > spec->width) {
1341 s = start + spec->width;
1344 copy = xmemdup0(start, s - start);
1345 value = strtold(copy, &tail);
1352 switch (spec->type) {
1356 *va_arg(*args, float *) = value;
1359 *va_arg(*args, double *) = value;
1362 *va_arg(*args, long double *) = value;
1368 case SCAN_PTRDIFF_T:
1376 scan_output_string(const struct scan_spec *spec,
1377 const char *s, size_t n,
1380 if (spec->type != SCAN_DISCARD) {
1381 char *out = va_arg(*args, char *);
1388 scan_string(const char *s, const struct scan_spec *spec, va_list *args)
1392 for (n = 0; n < spec->width; n++) {
1393 if (!s[n] || isspace((unsigned char) s[n])) {
1401 scan_output_string(spec, s, n, args);
1406 parse_scanset(const char *p_, unsigned long *set, bool *complemented)
1408 const uint8_t *p = (const uint8_t *) p_;
1410 *complemented = *p == '^';
1414 bitmap_set1(set, ']');
1418 while (*p && *p != ']') {
1419 if (p[1] == '-' && p[2] != ']' && p[2] > *p) {
1420 bitmap_set_multiple(set, *p, p[2] - *p + 1, true);
1423 bitmap_set1(set, *p++);
1429 return (const char *) p;
1433 scan_set(const char *s, const struct scan_spec *spec, const char **pp,
1436 unsigned long set[BITMAP_N_LONGS(UCHAR_MAX + 1)];
1440 /* Parse the scan set. */
1441 memset(set, 0, sizeof set);
1442 *pp = parse_scanset(*pp, set, &complemented);
1444 /* Parse the data. */
1447 && bitmap_is_set(set, (unsigned char) s[n]) == !complemented
1448 && n < spec->width) {
1454 scan_output_string(spec, s, n, args);
1459 scan_chars(const char *s, const struct scan_spec *spec, va_list *args)
1461 unsigned int n = spec->width == UINT_MAX ? 1 : spec->width;
1463 if (strlen(s) < n) {
1466 if (spec->type != SCAN_DISCARD) {
1467 memcpy(va_arg(*args, char *), s, n);
1472 /* This is an implementation of the standard sscanf() function, with the
1473 * following exceptions:
1475 * - It returns true if the entire format was successfully scanned and
1476 * converted, false if any conversion failed.
1478 * - The standard doesn't define sscanf() behavior when an out-of-range value
1479 * is scanned, e.g. if a "%"PRIi8 conversion scans "-1" or "0x1ff". Some
1480 * implementations consider this an error and stop scanning. This
1481 * implementation never considers an out-of-range value an error; instead,
1482 * it stores the least-significant bits of the converted value in the
1483 * destination, e.g. the value 255 for both examples earlier.
1485 * - Only single-byte characters are supported, that is, the 'l' modifier
1486 * on %s, %[, and %c is not supported. The GNU extension 'a' modifier is
1487 * also not supported.
1489 * - %p is not supported.
1492 ovs_scan(const char *s, const char *format, ...)
1494 const char *const start = s;
1499 va_start(args, format);
1501 while (*p != '\0') {
1502 struct scan_spec spec;
1503 unsigned char c = *p++;
1509 } else if (c != '%') {
1515 } else if (*p == '%') {
1523 /* Parse '*' flag. */
1524 discard = *p == '*';
1527 /* Parse field width. */
1529 while (*p >= '0' && *p <= '9') {
1530 spec.width = spec.width * 10 + (*p++ - '0');
1532 if (spec.width == 0) {
1533 spec.width = UINT_MAX;
1536 /* Parse type modifier. */
1540 spec.type = SCAN_CHAR;
1543 spec.type = SCAN_SHORT;
1549 spec.type = SCAN_INTMAX_T;
1555 spec.type = SCAN_LLONG;
1558 spec.type = SCAN_LONG;
1565 spec.type = SCAN_LLONG;
1570 spec.type = SCAN_PTRDIFF_T;
1575 spec.type = SCAN_SIZE_T;
1580 spec.type = SCAN_INT;
1585 spec.type = SCAN_DISCARD;
1589 if (c != 'c' && c != 'n' && c != '[') {
1594 s = scan_int(s, &spec, 10, &args);
1598 s = scan_int(s, &spec, 0, &args);
1602 s = scan_int(s, &spec, 8, &args);
1606 s = scan_int(s, &spec, 10, &args);
1611 s = scan_int(s, &spec, 16, &args);
1619 s = scan_float(s, &spec, &args);
1623 s = scan_string(s, &spec, &args);
1627 s = scan_set(s, &spec, &p, &args);
1631 s = scan_chars(s, &spec, &args);
1635 if (spec.type != SCAN_DISCARD) {
1636 *va_arg(args, int *) = s - start;