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;
383 basename = xmalloc(max_len);
384 _splitpath_s(argv0, NULL, 0, NULL, 0, basename, max_len, NULL, 0);
385 assert_single_threaded();
386 program_name = basename;
388 const char *slash = strrchr(argv0, '/');
389 assert_single_threaded();
390 program_name = slash ? slash + 1 : argv0;
393 free(program_version);
395 if (!strcmp(version, VERSION)) {
396 program_version = xasprintf("%s (Open vSwitch) "VERSION"\n"
398 program_name, date, time);
400 program_version = xasprintf("%s %s\n"
401 "Open vSwitch Library "VERSION"\n"
403 program_name, version, date, time);
407 /* Returns the name of the currently running thread or process. */
409 get_subprogram_name(void)
411 const char *name = subprogram_name_get();
412 return name ? name : "";
415 /* Sets the formatted value of 'format' as the name of the currently running
416 * thread or process. (This appears in log messages and may also be visible in
417 * system process listings and debuggers.) */
419 set_subprogram_name(const char *format, ...)
426 va_start(args, format);
427 pname = xvasprintf(format, args);
430 pname = xstrdup(program_name);
433 free(subprogram_name_set(pname));
435 #if HAVE_GLIBC_PTHREAD_SETNAME_NP
436 pthread_setname_np(pthread_self(), pname);
437 #elif HAVE_NETBSD_PTHREAD_SETNAME_NP
438 pthread_setname_np(pthread_self(), "%s", pname);
439 #elif HAVE_PTHREAD_SET_NAME_NP
440 pthread_set_name_np(pthread_self(), pname);
444 /* Returns a pointer to a string describing the program version. The
445 * caller must not modify or free the returned string.
448 get_program_version(void)
450 return program_version;
453 /* Print the version information for the program. */
455 ovs_print_version(uint8_t min_ofp, uint8_t max_ofp)
457 printf("%s", program_version);
458 if (min_ofp || max_ofp) {
459 printf("OpenFlow versions %#x:%#x\n", min_ofp, max_ofp);
463 /* Writes the 'size' bytes in 'buf' to 'stream' as hex bytes arranged 16 per
464 * line. Numeric offsets are also included, starting at 'ofs' for the first
465 * byte in 'buf'. If 'ascii' is true then the corresponding ASCII characters
466 * are also rendered alongside. */
468 ovs_hex_dump(FILE *stream, const void *buf_, size_t size,
469 uintptr_t ofs, bool ascii)
471 const uint8_t *buf = buf_;
472 const size_t per_line = 16; /* Maximum bytes per line. */
476 size_t start, end, n;
479 /* Number of bytes on this line. */
480 start = ofs % per_line;
482 if (end - start > size)
487 fprintf(stream, "%08"PRIxMAX" ", (uintmax_t) ROUND_DOWN(ofs, per_line));
488 for (i = 0; i < start; i++)
489 fprintf(stream, " ");
491 fprintf(stream, "%02x%c",
492 buf[i - start], i == per_line / 2 - 1? '-' : ' ');
495 for (; i < per_line; i++)
496 fprintf(stream, " ");
497 fprintf(stream, "|");
498 for (i = 0; i < start; i++)
499 fprintf(stream, " ");
500 for (; i < end; i++) {
501 int c = buf[i - start];
502 putc(c >= 32 && c < 127 ? c : '.', stream);
504 for (; i < per_line; i++)
505 fprintf(stream, " ");
506 fprintf(stream, "|");
508 fprintf(stream, "\n");
517 str_to_int(const char *s, int base, int *i)
520 bool ok = str_to_llong(s, base, &ll);
526 str_to_long(const char *s, int base, long *li)
529 bool ok = str_to_llong(s, base, &ll);
535 str_to_llong(const char *s, int base, long long *x)
537 int save_errno = errno;
540 *x = strtoll(s, &tail, base);
541 if (errno == EINVAL || errno == ERANGE || tail == s || *tail != '\0') {
551 /* Converts floating-point string 's' into a double. If successful, stores
552 * the double in '*d' and returns true; on failure, stores 0 in '*d' and
555 * Underflow (e.g. "1e-9999") is not considered an error, but overflow
556 * (e.g. "1e9999)" is. */
558 str_to_double(const char *s, double *d)
560 int save_errno = errno;
563 *d = strtod(s, &tail);
564 if (errno == EINVAL || (errno == ERANGE && *d != 0)
565 || tail == s || *tail != '\0') {
575 /* Returns the value of 'c' as a hexadecimal digit. */
580 case '0': case '1': case '2': case '3': case '4':
581 case '5': case '6': case '7': case '8': case '9':
607 /* Returns the integer value of the 'n' hexadecimal digits starting at 's', or
608 * UINT_MAX if one of those "digits" is not really a hex digit. If 'ok' is
609 * nonnull, '*ok' is set to true if the conversion succeeds or to false if a
610 * non-hex digit is detected. */
612 hexits_value(const char *s, size_t n, bool *ok)
618 for (i = 0; i < n; i++) {
619 int hexit = hexit_value(s[i]);
626 value = (value << 4) + hexit;
634 /* Returns the current working directory as a malloc()'d string, or a null
635 * pointer if the current working directory cannot be determined. */
642 /* Get maximum path length or at least a reasonable estimate. */
643 path_max = pathconf(".", _PC_PATH_MAX);
644 size = (path_max < 0 ? 1024
645 : path_max > 10240 ? 10240
648 /* Get current working directory. */
650 char *buf = xmalloc(size);
651 if (getcwd(buf, size)) {
652 return xrealloc(buf, strlen(buf) + 1);
656 if (error != ERANGE) {
657 VLOG_WARN("getcwd failed (%s)", ovs_strerror(error));
666 all_slashes_name(const char *s)
668 return xstrdup(s[0] == '/' && s[1] == '/' && s[2] != '/' ? "//"
673 /* Returns the directory name portion of 'file_name' as a malloc()'d string,
674 * similar to the POSIX dirname() function but thread-safe. */
676 dir_name(const char *file_name)
678 size_t len = strlen(file_name);
679 while (len > 0 && file_name[len - 1] == '/') {
682 while (len > 0 && file_name[len - 1] != '/') {
685 while (len > 0 && file_name[len - 1] == '/') {
688 return len ? xmemdup0(file_name, len) : all_slashes_name(file_name);
691 /* Returns the file name portion of 'file_name' as a malloc()'d string,
692 * similar to the POSIX basename() function but thread-safe. */
694 base_name(const char *file_name)
698 end = strlen(file_name);
699 while (end > 0 && file_name[end - 1] == '/') {
704 return all_slashes_name(file_name);
708 while (start > 0 && file_name[start - 1] != '/') {
712 return xmemdup0(file_name + start, end - start);
715 /* If 'file_name' starts with '/', returns a copy of 'file_name'. Otherwise,
716 * returns an absolute path to 'file_name' considering it relative to 'dir',
717 * which itself must be absolute. 'dir' may be null or the empty string, in
718 * which case the current working directory is used.
720 * Returns a null pointer if 'dir' is null and getcwd() fails. */
722 abs_file_name(const char *dir, const char *file_name)
724 if (file_name[0] == '/') {
725 return xstrdup(file_name);
726 } else if (dir && dir[0]) {
727 char *separator = dir[strlen(dir) - 1] == '/' ? "" : "/";
728 return xasprintf("%s%s%s", dir, separator, file_name);
730 char *cwd = get_cwd();
732 char *abs_name = xasprintf("%s/%s", cwd, file_name);
741 /* Like readlink(), but returns the link name as a null-terminated string in
742 * allocated memory that the caller must eventually free (with free()).
743 * Returns NULL on error, in which case errno is set appropriately. */
745 xreadlink(const char *filename)
749 for (size = 64; ; size *= 2) {
750 char *buf = xmalloc(size);
751 ssize_t retval = readlink(filename, buf, size);
754 if (retval >= 0 && retval < size) {
767 /* Returns a version of 'filename' with symlinks in the final component
768 * dereferenced. This differs from realpath() in that:
770 * - 'filename' need not exist.
772 * - If 'filename' does exist as a symlink, its referent need not exist.
774 * - Only symlinks in the final component of 'filename' are dereferenced.
776 * The caller must eventually free the returned string (with free()). */
778 follow_symlinks(const char *filename)
784 fn = xstrdup(filename);
785 for (i = 0; i < 10; i++) {
789 if (lstat(fn, &s) != 0 || !S_ISLNK(s.st_mode)) {
793 linkname = xreadlink(fn);
795 VLOG_WARN("%s: readlink failed (%s)",
796 filename, ovs_strerror(errno));
800 if (linkname[0] == '/') {
801 /* Target of symlink is absolute so use it raw. */
804 /* Target of symlink is relative so add to 'fn''s directory. */
805 char *dir = dir_name(fn);
807 if (!strcmp(dir, ".")) {
810 char *separator = dir[strlen(dir) - 1] == '/' ? "" : "/";
811 next_fn = xasprintf("%s%s%s", dir, separator, linkname);
822 VLOG_WARN("%s: too many levels of symlinks", filename);
824 return xstrdup(filename);
827 /* Pass a value to this function if it is marked with
828 * __attribute__((warn_unused_result)) and you genuinely want to ignore
829 * its return value. (Note that every scalar type can be implicitly
830 * converted to bool.) */
831 void ignore(bool x OVS_UNUSED) { }
833 /* Returns an appropriate delimiter for inserting just before the 0-based item
834 * 'index' in a list that has 'total' items in it. */
836 english_list_delimiter(size_t index, size_t total)
838 return (index == 0 ? ""
839 : index < total - 1 ? ", "
840 : total > 2 ? ", and "
844 /* Returns the number of trailing 0-bits in 'n'. Undefined if 'n' == 0. */
846 /* Defined inline in util.h. */
848 /* Returns the number of trailing 0-bits in 'n'. Undefined if 'n' == 0. */
855 #define CTZ_STEP(X) \
872 /* Returns the number of leading 0-bits in 'n'. Undefined if 'n' == 0. */
874 raw_clz64(uint64_t n)
879 #define CLZ_STEP(X) \
897 #if NEED_COUNT_1BITS_8
899 ((((X) & (1 << 0)) != 0) + \
900 (((X) & (1 << 1)) != 0) + \
901 (((X) & (1 << 2)) != 0) + \
902 (((X) & (1 << 3)) != 0) + \
903 (((X) & (1 << 4)) != 0) + \
904 (((X) & (1 << 5)) != 0) + \
905 (((X) & (1 << 6)) != 0) + \
906 (((X) & (1 << 7)) != 0))
907 #define INIT2(X) INIT1(X), INIT1((X) + 1)
908 #define INIT4(X) INIT2(X), INIT2((X) + 2)
909 #define INIT8(X) INIT4(X), INIT4((X) + 4)
910 #define INIT16(X) INIT8(X), INIT8((X) + 8)
911 #define INIT32(X) INIT16(X), INIT16((X) + 16)
912 #define INIT64(X) INIT32(X), INIT32((X) + 32)
914 const uint8_t count_1bits_8[256] = {
915 INIT64(0), INIT64(64), INIT64(128), INIT64(192)
919 /* Returns true if the 'n' bytes starting at 'p' are zeros. */
921 is_all_zeros(const uint8_t *p, size_t n)
925 for (i = 0; i < n; i++) {
933 /* Returns true if the 'n' bytes starting at 'p' are 0xff. */
935 is_all_ones(const uint8_t *p, size_t n)
939 for (i = 0; i < n; i++) {
947 /* Copies 'n_bits' bits starting from bit 'src_ofs' in 'src' to the 'n_bits'
948 * starting from bit 'dst_ofs' in 'dst'. 'src' is 'src_len' bytes long and
949 * 'dst' is 'dst_len' bytes long.
951 * If you consider all of 'src' to be a single unsigned integer in network byte
952 * order, then bit N is the bit with value 2**N. That is, bit 0 is the bit
953 * with value 1 in src[src_len - 1], bit 1 is the bit with value 2, bit 2 is
954 * the bit with value 4, ..., bit 8 is the bit with value 1 in src[src_len -
955 * 2], and so on. Similarly for 'dst'.
957 * Required invariants:
958 * src_ofs + n_bits <= src_len * 8
959 * dst_ofs + n_bits <= dst_len * 8
960 * 'src' and 'dst' must not overlap.
963 bitwise_copy(const void *src_, unsigned int src_len, unsigned int src_ofs,
964 void *dst_, unsigned int dst_len, unsigned int dst_ofs,
967 const uint8_t *src = src_;
970 src += src_len - (src_ofs / 8 + 1);
973 dst += dst_len - (dst_ofs / 8 + 1);
976 if (src_ofs == 0 && dst_ofs == 0) {
977 unsigned int n_bytes = n_bits / 8;
981 memcpy(dst, src, n_bytes);
988 uint8_t mask = (1 << n_bits) - 1;
989 *dst = (*dst & ~mask) | (*src & mask);
993 unsigned int max_copy = 8 - MAX(src_ofs, dst_ofs);
994 unsigned int chunk = MIN(n_bits, max_copy);
995 uint8_t mask = ((1 << chunk) - 1) << dst_ofs;
998 *dst |= ((*src >> src_ofs) << dst_ofs) & mask;
1015 /* Zeros the 'n_bits' bits starting from bit 'dst_ofs' in 'dst'. 'dst' is
1016 * 'dst_len' bytes long.
1018 * If you consider all of 'dst' to be a single unsigned integer in network byte
1019 * order, then bit N is the bit with value 2**N. That is, bit 0 is the bit
1020 * with value 1 in dst[dst_len - 1], bit 1 is the bit with value 2, bit 2 is
1021 * the bit with value 4, ..., bit 8 is the bit with value 1 in dst[dst_len -
1024 * Required invariant:
1025 * dst_ofs + n_bits <= dst_len * 8
1028 bitwise_zero(void *dst_, unsigned int dst_len, unsigned dst_ofs,
1029 unsigned int n_bits)
1031 uint8_t *dst = dst_;
1037 dst += dst_len - (dst_ofs / 8 + 1);
1041 unsigned int chunk = MIN(n_bits, 8 - dst_ofs);
1043 *dst &= ~(((1 << chunk) - 1) << dst_ofs);
1053 while (n_bits >= 8) {
1059 *dst &= ~((1 << n_bits) - 1);
1063 /* Sets to 1 all of the 'n_bits' bits starting from bit 'dst_ofs' in 'dst'.
1064 * 'dst' is 'dst_len' bytes long.
1066 * If you consider all of 'dst' to be a single unsigned integer in network byte
1067 * order, then bit N is the bit with value 2**N. That is, bit 0 is the bit
1068 * with value 1 in dst[dst_len - 1], bit 1 is the bit with value 2, bit 2 is
1069 * the bit with value 4, ..., bit 8 is the bit with value 1 in dst[dst_len -
1072 * Required invariant:
1073 * dst_ofs + n_bits <= dst_len * 8
1076 bitwise_one(void *dst_, unsigned int dst_len, unsigned dst_ofs,
1077 unsigned int n_bits)
1079 uint8_t *dst = dst_;
1085 dst += dst_len - (dst_ofs / 8 + 1);
1089 unsigned int chunk = MIN(n_bits, 8 - dst_ofs);
1091 *dst |= ((1 << chunk) - 1) << dst_ofs;
1101 while (n_bits >= 8) {
1107 *dst |= (1 << n_bits) - 1;
1111 /* Scans the 'n_bits' bits starting from bit 'dst_ofs' in 'dst' for 1-bits.
1112 * Returns false if any 1-bits are found, otherwise true. 'dst' is 'dst_len'
1115 * If you consider all of 'dst' to be a single unsigned integer in network byte
1116 * order, then bit N is the bit with value 2**N. That is, bit 0 is the bit
1117 * with value 1 in dst[dst_len - 1], bit 1 is the bit with value 2, bit 2 is
1118 * the bit with value 4, ..., bit 8 is the bit with value 1 in dst[dst_len -
1121 * Required invariant:
1122 * dst_ofs + n_bits <= dst_len * 8
1125 bitwise_is_all_zeros(const void *p_, unsigned int len, unsigned int ofs,
1126 unsigned int n_bits)
1128 const uint8_t *p = p_;
1134 p += len - (ofs / 8 + 1);
1138 unsigned int chunk = MIN(n_bits, 8 - ofs);
1140 if (*p & (((1 << chunk) - 1) << ofs)) {
1152 while (n_bits >= 8) {
1160 if (n_bits && *p & ((1 << n_bits) - 1)) {
1167 /* Copies the 'n_bits' low-order bits of 'value' into the 'n_bits' bits
1168 * starting at bit 'dst_ofs' in 'dst', which is 'dst_len' bytes long.
1170 * If you consider all of 'dst' to be a single unsigned integer in network byte
1171 * order, then bit N is the bit with value 2**N. That is, bit 0 is the bit
1172 * with value 1 in dst[dst_len - 1], bit 1 is the bit with value 2, bit 2 is
1173 * the bit with value 4, ..., bit 8 is the bit with value 1 in dst[dst_len -
1176 * Required invariants:
1177 * dst_ofs + n_bits <= dst_len * 8
1181 bitwise_put(uint64_t value,
1182 void *dst, unsigned int dst_len, unsigned int dst_ofs,
1183 unsigned int n_bits)
1185 ovs_be64 n_value = htonll(value);
1186 bitwise_copy(&n_value, sizeof n_value, 0,
1187 dst, dst_len, dst_ofs,
1191 /* Returns the value of the 'n_bits' bits starting at bit 'src_ofs' in 'src',
1192 * which is 'src_len' bytes long.
1194 * If you consider all of 'src' to be a single unsigned integer in network byte
1195 * order, then bit N is the bit with value 2**N. That is, bit 0 is the bit
1196 * with value 1 in src[src_len - 1], bit 1 is the bit with value 2, bit 2 is
1197 * the bit with value 4, ..., bit 8 is the bit with value 1 in src[src_len -
1200 * Required invariants:
1201 * src_ofs + n_bits <= src_len * 8
1205 bitwise_get(const void *src, unsigned int src_len,
1206 unsigned int src_ofs, unsigned int n_bits)
1208 ovs_be64 value = htonll(0);
1210 bitwise_copy(src, src_len, src_ofs,
1211 &value, sizeof value, 0,
1213 return ntohll(value);
1234 skip_spaces(const char *s)
1236 while (isspace((unsigned char) *s)) {
1243 scan_int(const char *s, const struct scan_spec *spec, int base, va_list *args)
1245 const char *start = s;
1250 negative = *s == '-';
1251 s += *s == '-' || *s == '+';
1253 if ((!base || base == 16) && *s == '0' && (s[1] == 'x' || s[1] == 'X')) {
1257 base = *s == '0' ? 8 : 10;
1260 if (s - start >= spec->width) {
1266 while (s - start < spec->width) {
1267 int digit = hexit_value(*s);
1269 if (digit < 0 || digit >= base) {
1272 value = value * base + digit;
1284 switch (spec->type) {
1288 *va_arg(*args, char *) = value;
1291 *va_arg(*args, short int *) = value;
1294 *va_arg(*args, int *) = value;
1297 *va_arg(*args, long int *) = value;
1300 *va_arg(*args, long long int *) = value;
1303 *va_arg(*args, intmax_t *) = value;
1305 case SCAN_PTRDIFF_T:
1306 *va_arg(*args, ptrdiff_t *) = value;
1309 *va_arg(*args, size_t *) = value;
1316 skip_digits(const char *s)
1318 while (*s >= '0' && *s <= '9') {
1325 scan_float(const char *s, const struct scan_spec *spec, va_list *args)
1327 const char *start = s;
1333 s += *s == '+' || *s == '-';
1336 s = skip_digits(s + 1);
1338 if (*s == 'e' || *s == 'E') {
1340 s += *s == '+' || *s == '-';
1344 if (s - start > spec->width) {
1345 s = start + spec->width;
1348 copy = xmemdup0(start, s - start);
1349 value = strtold(copy, &tail);
1356 switch (spec->type) {
1360 *va_arg(*args, float *) = value;
1363 *va_arg(*args, double *) = value;
1366 *va_arg(*args, long double *) = value;
1372 case SCAN_PTRDIFF_T:
1380 scan_output_string(const struct scan_spec *spec,
1381 const char *s, size_t n,
1384 if (spec->type != SCAN_DISCARD) {
1385 char *out = va_arg(*args, char *);
1392 scan_string(const char *s, const struct scan_spec *spec, va_list *args)
1396 for (n = 0; n < spec->width; n++) {
1397 if (!s[n] || isspace((unsigned char) s[n])) {
1405 scan_output_string(spec, s, n, args);
1410 parse_scanset(const char *p_, unsigned long *set, bool *complemented)
1412 const uint8_t *p = (const uint8_t *) p_;
1414 *complemented = *p == '^';
1418 bitmap_set1(set, ']');
1422 while (*p && *p != ']') {
1423 if (p[1] == '-' && p[2] != ']' && p[2] > *p) {
1424 bitmap_set_multiple(set, *p, p[2] - *p + 1, true);
1427 bitmap_set1(set, *p++);
1433 return (const char *) p;
1437 scan_set(const char *s, const struct scan_spec *spec, const char **pp,
1440 unsigned long set[BITMAP_N_LONGS(UCHAR_MAX + 1)];
1444 /* Parse the scan set. */
1445 memset(set, 0, sizeof set);
1446 *pp = parse_scanset(*pp, set, &complemented);
1448 /* Parse the data. */
1451 && bitmap_is_set(set, (unsigned char) s[n]) == !complemented
1452 && n < spec->width) {
1458 scan_output_string(spec, s, n, args);
1463 scan_chars(const char *s, const struct scan_spec *spec, va_list *args)
1465 unsigned int n = spec->width == UINT_MAX ? 1 : spec->width;
1467 if (strlen(s) < n) {
1470 if (spec->type != SCAN_DISCARD) {
1471 memcpy(va_arg(*args, char *), s, n);
1476 /* This is an implementation of the standard sscanf() function, with the
1477 * following exceptions:
1479 * - It returns true if the entire format was successfully scanned and
1480 * converted, false if any conversion failed.
1482 * - The standard doesn't define sscanf() behavior when an out-of-range value
1483 * is scanned, e.g. if a "%"PRIi8 conversion scans "-1" or "0x1ff". Some
1484 * implementations consider this an error and stop scanning. This
1485 * implementation never considers an out-of-range value an error; instead,
1486 * it stores the least-significant bits of the converted value in the
1487 * destination, e.g. the value 255 for both examples earlier.
1489 * - Only single-byte characters are supported, that is, the 'l' modifier
1490 * on %s, %[, and %c is not supported. The GNU extension 'a' modifier is
1491 * also not supported.
1493 * - %p is not supported.
1496 ovs_scan(const char *s, const char *format, ...)
1498 const char *const start = s;
1503 va_start(args, format);
1505 while (*p != '\0') {
1506 struct scan_spec spec;
1507 unsigned char c = *p++;
1513 } else if (c != '%') {
1519 } else if (*p == '%') {
1527 /* Parse '*' flag. */
1528 discard = *p == '*';
1531 /* Parse field width. */
1533 while (*p >= '0' && *p <= '9') {
1534 spec.width = spec.width * 10 + (*p++ - '0');
1536 if (spec.width == 0) {
1537 spec.width = UINT_MAX;
1540 /* Parse type modifier. */
1544 spec.type = SCAN_CHAR;
1547 spec.type = SCAN_SHORT;
1553 spec.type = SCAN_INTMAX_T;
1559 spec.type = SCAN_LLONG;
1562 spec.type = SCAN_LONG;
1569 spec.type = SCAN_LLONG;
1574 spec.type = SCAN_PTRDIFF_T;
1579 spec.type = SCAN_SIZE_T;
1584 spec.type = SCAN_INT;
1589 spec.type = SCAN_DISCARD;
1593 if (c != 'c' && c != 'n' && c != '[') {
1598 s = scan_int(s, &spec, 10, &args);
1602 s = scan_int(s, &spec, 0, &args);
1606 s = scan_int(s, &spec, 8, &args);
1610 s = scan_int(s, &spec, 10, &args);
1615 s = scan_int(s, &spec, 16, &args);
1623 s = scan_float(s, &spec, &args);
1627 s = scan_string(s, &spec, &args);
1631 s = scan_set(s, &spec, &p, &args);
1635 s = scan_chars(s, &spec, &args);
1639 if (spec.type != SCAN_DISCARD) {
1640 *va_arg(args, int *) = s - start;
1658 /* Calls FormatMessage() with GetLastError() as an argument. Returns
1659 * pointer to a buffer that receives the null-terminated string that specifies
1660 * the formatted message and that has to be freed by the caller with
1663 ovs_lasterror_to_string(void)
1666 FormatMessage(FORMAT_MESSAGE_ALLOCATE_BUFFER | FORMAT_MESSAGE_FROM_SYSTEM
1667 | FORMAT_MESSAGE_IGNORE_INSERTS, NULL, GetLastError(), 0,
1668 (char *)&buffer, 0, NULL);