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,
376 const char *slash = strrchr(argv0, '/');
378 assert_single_threaded();
380 program_name = slash ? slash + 1 : argv0;
382 free(program_version);
384 if (!strcmp(version, VERSION)) {
385 program_version = xasprintf("%s (Open vSwitch) "VERSION"\n"
387 program_name, date, time);
389 program_version = xasprintf("%s %s\n"
390 "Open vSwitch Library "VERSION"\n"
392 program_name, version, date, time);
396 /* Returns the name of the currently running thread or process. */
398 get_subprogram_name(void)
400 const char *name = subprogram_name_get();
401 return name ? name : "";
404 /* Sets the formatted value of 'format' as the name of the currently running
405 * thread or process. (This appears in log messages and may also be visible in
406 * system process listings and debuggers.) */
408 set_subprogram_name(const char *format, ...)
415 va_start(args, format);
416 pname = xvasprintf(format, args);
419 pname = xstrdup(program_name);
422 free(subprogram_name_set(pname));
424 #if HAVE_GLIBC_PTHREAD_SETNAME_NP
425 pthread_setname_np(pthread_self(), pname);
426 #elif HAVE_NETBSD_PTHREAD_SETNAME_NP
427 pthread_setname_np(pthread_self(), "%s", pname);
428 #elif HAVE_PTHREAD_SET_NAME_NP
429 pthread_set_name_np(pthread_self(), pname);
433 /* Returns a pointer to a string describing the program version. The
434 * caller must not modify or free the returned string.
437 get_program_version(void)
439 return program_version;
442 /* Print the version information for the program. */
444 ovs_print_version(uint8_t min_ofp, uint8_t max_ofp)
446 printf("%s", program_version);
447 if (min_ofp || max_ofp) {
448 printf("OpenFlow versions %#x:%#x\n", min_ofp, max_ofp);
452 /* Writes the 'size' bytes in 'buf' to 'stream' as hex bytes arranged 16 per
453 * line. Numeric offsets are also included, starting at 'ofs' for the first
454 * byte in 'buf'. If 'ascii' is true then the corresponding ASCII characters
455 * are also rendered alongside. */
457 ovs_hex_dump(FILE *stream, const void *buf_, size_t size,
458 uintptr_t ofs, bool ascii)
460 const uint8_t *buf = buf_;
461 const size_t per_line = 16; /* Maximum bytes per line. */
465 size_t start, end, n;
468 /* Number of bytes on this line. */
469 start = ofs % per_line;
471 if (end - start > size)
476 fprintf(stream, "%08"PRIxMAX" ", (uintmax_t) ROUND_DOWN(ofs, per_line));
477 for (i = 0; i < start; i++)
478 fprintf(stream, " ");
480 fprintf(stream, "%02x%c",
481 buf[i - start], i == per_line / 2 - 1? '-' : ' ');
484 for (; i < per_line; i++)
485 fprintf(stream, " ");
486 fprintf(stream, "|");
487 for (i = 0; i < start; i++)
488 fprintf(stream, " ");
489 for (; i < end; i++) {
490 int c = buf[i - start];
491 putc(c >= 32 && c < 127 ? c : '.', stream);
493 for (; i < per_line; i++)
494 fprintf(stream, " ");
495 fprintf(stream, "|");
497 fprintf(stream, "\n");
506 str_to_int(const char *s, int base, int *i)
509 bool ok = str_to_llong(s, base, &ll);
515 str_to_long(const char *s, int base, long *li)
518 bool ok = str_to_llong(s, base, &ll);
524 str_to_llong(const char *s, int base, long long *x)
526 int save_errno = errno;
529 *x = strtoll(s, &tail, base);
530 if (errno == EINVAL || errno == ERANGE || tail == s || *tail != '\0') {
541 str_to_uint(const char *s, int base, unsigned int *u)
543 return str_to_int(s, base, (int *) u);
547 str_to_ulong(const char *s, int base, unsigned long *ul)
549 return str_to_long(s, base, (long *) ul);
553 str_to_ullong(const char *s, int base, unsigned long long *ull)
555 return str_to_llong(s, base, (long long *) ull);
558 /* Converts floating-point string 's' into a double. If successful, stores
559 * the double in '*d' and returns true; on failure, stores 0 in '*d' and
562 * Underflow (e.g. "1e-9999") is not considered an error, but overflow
563 * (e.g. "1e9999)" is. */
565 str_to_double(const char *s, double *d)
567 int save_errno = errno;
570 *d = strtod(s, &tail);
571 if (errno == EINVAL || (errno == ERANGE && *d != 0)
572 || tail == s || *tail != '\0') {
582 /* Returns the value of 'c' as a hexadecimal digit. */
587 case '0': case '1': case '2': case '3': case '4':
588 case '5': case '6': case '7': case '8': case '9':
614 /* Returns the integer value of the 'n' hexadecimal digits starting at 's', or
615 * UINT_MAX if one of those "digits" is not really a hex digit. If 'ok' is
616 * nonnull, '*ok' is set to true if the conversion succeeds or to false if a
617 * non-hex digit is detected. */
619 hexits_value(const char *s, size_t n, bool *ok)
625 for (i = 0; i < n; i++) {
626 int hexit = hexit_value(s[i]);
633 value = (value << 4) + hexit;
641 /* Returns the current working directory as a malloc()'d string, or a null
642 * pointer if the current working directory cannot be determined. */
649 /* Get maximum path length or at least a reasonable estimate. */
650 path_max = pathconf(".", _PC_PATH_MAX);
651 size = (path_max < 0 ? 1024
652 : path_max > 10240 ? 10240
655 /* Get current working directory. */
657 char *buf = xmalloc(size);
658 if (getcwd(buf, size)) {
659 return xrealloc(buf, strlen(buf) + 1);
663 if (error != ERANGE) {
664 VLOG_WARN("getcwd failed (%s)", ovs_strerror(error));
673 all_slashes_name(const char *s)
675 return xstrdup(s[0] == '/' && s[1] == '/' && s[2] != '/' ? "//"
680 /* Returns the directory name portion of 'file_name' as a malloc()'d string,
681 * similar to the POSIX dirname() function but thread-safe. */
683 dir_name(const char *file_name)
685 size_t len = strlen(file_name);
686 while (len > 0 && file_name[len - 1] == '/') {
689 while (len > 0 && file_name[len - 1] != '/') {
692 while (len > 0 && file_name[len - 1] == '/') {
695 return len ? xmemdup0(file_name, len) : all_slashes_name(file_name);
698 /* Returns the file name portion of 'file_name' as a malloc()'d string,
699 * similar to the POSIX basename() function but thread-safe. */
701 base_name(const char *file_name)
705 end = strlen(file_name);
706 while (end > 0 && file_name[end - 1] == '/') {
711 return all_slashes_name(file_name);
715 while (start > 0 && file_name[start - 1] != '/') {
719 return xmemdup0(file_name + start, end - start);
722 /* If 'file_name' starts with '/', returns a copy of 'file_name'. Otherwise,
723 * returns an absolute path to 'file_name' considering it relative to 'dir',
724 * which itself must be absolute. 'dir' may be null or the empty string, in
725 * which case the current working directory is used.
727 * Returns a null pointer if 'dir' is null and getcwd() fails. */
729 abs_file_name(const char *dir, const char *file_name)
731 if (file_name[0] == '/') {
732 return xstrdup(file_name);
733 } else if (dir && dir[0]) {
734 char *separator = dir[strlen(dir) - 1] == '/' ? "" : "/";
735 return xasprintf("%s%s%s", dir, separator, file_name);
737 char *cwd = get_cwd();
739 char *abs_name = xasprintf("%s/%s", cwd, file_name);
748 /* Like readlink(), but returns the link name as a null-terminated string in
749 * allocated memory that the caller must eventually free (with free()).
750 * Returns NULL on error, in which case errno is set appropriately. */
752 xreadlink(const char *filename)
756 for (size = 64; ; size *= 2) {
757 char *buf = xmalloc(size);
758 ssize_t retval = readlink(filename, buf, size);
761 if (retval >= 0 && retval < size) {
774 /* Returns a version of 'filename' with symlinks in the final component
775 * dereferenced. This differs from realpath() in that:
777 * - 'filename' need not exist.
779 * - If 'filename' does exist as a symlink, its referent need not exist.
781 * - Only symlinks in the final component of 'filename' are dereferenced.
783 * The caller must eventually free the returned string (with free()). */
785 follow_symlinks(const char *filename)
791 fn = xstrdup(filename);
792 for (i = 0; i < 10; i++) {
796 if (lstat(fn, &s) != 0 || !S_ISLNK(s.st_mode)) {
800 linkname = xreadlink(fn);
802 VLOG_WARN("%s: readlink failed (%s)",
803 filename, ovs_strerror(errno));
807 if (linkname[0] == '/') {
808 /* Target of symlink is absolute so use it raw. */
811 /* Target of symlink is relative so add to 'fn''s directory. */
812 char *dir = dir_name(fn);
814 if (!strcmp(dir, ".")) {
817 char *separator = dir[strlen(dir) - 1] == '/' ? "" : "/";
818 next_fn = xasprintf("%s%s%s", dir, separator, linkname);
829 VLOG_WARN("%s: too many levels of symlinks", filename);
831 return xstrdup(filename);
834 /* Pass a value to this function if it is marked with
835 * __attribute__((warn_unused_result)) and you genuinely want to ignore
836 * its return value. (Note that every scalar type can be implicitly
837 * converted to bool.) */
838 void ignore(bool x OVS_UNUSED) { }
840 /* Returns an appropriate delimiter for inserting just before the 0-based item
841 * 'index' in a list that has 'total' items in it. */
843 english_list_delimiter(size_t index, size_t total)
845 return (index == 0 ? ""
846 : index < total - 1 ? ", "
847 : total > 2 ? ", and "
851 /* Returns the number of trailing 0-bits in 'n'. Undefined if 'n' == 0. */
853 /* Defined inline in util.h. */
855 /* Returns the number of trailing 0-bits in 'n'. Undefined if 'n' == 0. */
862 #define CTZ_STEP(X) \
879 /* Returns the number of leading 0-bits in 'n'. Undefined if 'n' == 0. */
881 raw_clz64(uint64_t n)
886 #define CLZ_STEP(X) \
904 #if NEED_COUNT_1BITS_8
906 ((((X) & (1 << 0)) != 0) + \
907 (((X) & (1 << 1)) != 0) + \
908 (((X) & (1 << 2)) != 0) + \
909 (((X) & (1 << 3)) != 0) + \
910 (((X) & (1 << 4)) != 0) + \
911 (((X) & (1 << 5)) != 0) + \
912 (((X) & (1 << 6)) != 0) + \
913 (((X) & (1 << 7)) != 0))
914 #define INIT2(X) INIT1(X), INIT1((X) + 1)
915 #define INIT4(X) INIT2(X), INIT2((X) + 2)
916 #define INIT8(X) INIT4(X), INIT4((X) + 4)
917 #define INIT16(X) INIT8(X), INIT8((X) + 8)
918 #define INIT32(X) INIT16(X), INIT16((X) + 16)
919 #define INIT64(X) INIT32(X), INIT32((X) + 32)
921 const uint8_t count_1bits_8[256] = {
922 INIT64(0), INIT64(64), INIT64(128), INIT64(192)
926 /* Returns true if the 'n' bytes starting at 'p' are zeros. */
928 is_all_zeros(const uint8_t *p, size_t n)
932 for (i = 0; i < n; i++) {
940 /* Returns true if the 'n' bytes starting at 'p' are 0xff. */
942 is_all_ones(const uint8_t *p, size_t n)
946 for (i = 0; i < n; i++) {
954 /* Copies 'n_bits' bits starting from bit 'src_ofs' in 'src' to the 'n_bits'
955 * starting from bit 'dst_ofs' in 'dst'. 'src' is 'src_len' bytes long and
956 * 'dst' is 'dst_len' bytes long.
958 * If you consider all of 'src' to be a single unsigned integer in network byte
959 * order, then bit N is the bit with value 2**N. That is, bit 0 is the bit
960 * with value 1 in src[src_len - 1], bit 1 is the bit with value 2, bit 2 is
961 * the bit with value 4, ..., bit 8 is the bit with value 1 in src[src_len -
962 * 2], and so on. Similarly for 'dst'.
964 * Required invariants:
965 * src_ofs + n_bits <= src_len * 8
966 * dst_ofs + n_bits <= dst_len * 8
967 * 'src' and 'dst' must not overlap.
970 bitwise_copy(const void *src_, unsigned int src_len, unsigned int src_ofs,
971 void *dst_, unsigned int dst_len, unsigned int dst_ofs,
974 const uint8_t *src = src_;
977 src += src_len - (src_ofs / 8 + 1);
980 dst += dst_len - (dst_ofs / 8 + 1);
983 if (src_ofs == 0 && dst_ofs == 0) {
984 unsigned int n_bytes = n_bits / 8;
988 memcpy(dst, src, n_bytes);
995 uint8_t mask = (1 << n_bits) - 1;
996 *dst = (*dst & ~mask) | (*src & mask);
1000 unsigned int max_copy = 8 - MAX(src_ofs, dst_ofs);
1001 unsigned int chunk = MIN(n_bits, max_copy);
1002 uint8_t mask = ((1 << chunk) - 1) << dst_ofs;
1005 *dst |= ((*src >> src_ofs) << dst_ofs) & mask;
1022 /* Zeros the 'n_bits' bits starting from bit 'dst_ofs' in 'dst'. 'dst' is
1023 * 'dst_len' bytes long.
1025 * If you consider all of 'dst' to be a single unsigned integer in network byte
1026 * order, then bit N is the bit with value 2**N. That is, bit 0 is the bit
1027 * with value 1 in dst[dst_len - 1], bit 1 is the bit with value 2, bit 2 is
1028 * the bit with value 4, ..., bit 8 is the bit with value 1 in dst[dst_len -
1031 * Required invariant:
1032 * dst_ofs + n_bits <= dst_len * 8
1035 bitwise_zero(void *dst_, unsigned int dst_len, unsigned dst_ofs,
1036 unsigned int n_bits)
1038 uint8_t *dst = dst_;
1044 dst += dst_len - (dst_ofs / 8 + 1);
1048 unsigned int chunk = MIN(n_bits, 8 - dst_ofs);
1050 *dst &= ~(((1 << chunk) - 1) << dst_ofs);
1060 while (n_bits >= 8) {
1066 *dst &= ~((1 << n_bits) - 1);
1070 /* Sets to 1 all of the 'n_bits' bits starting from bit 'dst_ofs' in 'dst'.
1071 * 'dst' is 'dst_len' bytes long.
1073 * If you consider all of 'dst' to be a single unsigned integer in network byte
1074 * order, then bit N is the bit with value 2**N. That is, bit 0 is the bit
1075 * with value 1 in dst[dst_len - 1], bit 1 is the bit with value 2, bit 2 is
1076 * the bit with value 4, ..., bit 8 is the bit with value 1 in dst[dst_len -
1079 * Required invariant:
1080 * dst_ofs + n_bits <= dst_len * 8
1083 bitwise_one(void *dst_, unsigned int dst_len, unsigned dst_ofs,
1084 unsigned int n_bits)
1086 uint8_t *dst = dst_;
1092 dst += dst_len - (dst_ofs / 8 + 1);
1096 unsigned int chunk = MIN(n_bits, 8 - dst_ofs);
1098 *dst |= ((1 << chunk) - 1) << dst_ofs;
1108 while (n_bits >= 8) {
1114 *dst |= (1 << n_bits) - 1;
1118 /* Scans the 'n_bits' bits starting from bit 'dst_ofs' in 'dst' for 1-bits.
1119 * Returns false if any 1-bits are found, otherwise true. 'dst' is 'dst_len'
1122 * If you consider all of 'dst' to be a single unsigned integer in network byte
1123 * order, then bit N is the bit with value 2**N. That is, bit 0 is the bit
1124 * with value 1 in dst[dst_len - 1], bit 1 is the bit with value 2, bit 2 is
1125 * the bit with value 4, ..., bit 8 is the bit with value 1 in dst[dst_len -
1128 * Required invariant:
1129 * dst_ofs + n_bits <= dst_len * 8
1132 bitwise_is_all_zeros(const void *p_, unsigned int len, unsigned int ofs,
1133 unsigned int n_bits)
1135 const uint8_t *p = p_;
1141 p += len - (ofs / 8 + 1);
1145 unsigned int chunk = MIN(n_bits, 8 - ofs);
1147 if (*p & (((1 << chunk) - 1) << ofs)) {
1159 while (n_bits >= 8) {
1167 if (n_bits && *p & ((1 << n_bits) - 1)) {
1174 /* Copies the 'n_bits' low-order bits of 'value' into the 'n_bits' bits
1175 * starting at bit 'dst_ofs' in 'dst', which is 'dst_len' bytes long.
1177 * If you consider all of 'dst' to be a single unsigned integer in network byte
1178 * order, then bit N is the bit with value 2**N. That is, bit 0 is the bit
1179 * with value 1 in dst[dst_len - 1], bit 1 is the bit with value 2, bit 2 is
1180 * the bit with value 4, ..., bit 8 is the bit with value 1 in dst[dst_len -
1183 * Required invariants:
1184 * dst_ofs + n_bits <= dst_len * 8
1188 bitwise_put(uint64_t value,
1189 void *dst, unsigned int dst_len, unsigned int dst_ofs,
1190 unsigned int n_bits)
1192 ovs_be64 n_value = htonll(value);
1193 bitwise_copy(&n_value, sizeof n_value, 0,
1194 dst, dst_len, dst_ofs,
1198 /* Returns the value of the 'n_bits' bits starting at bit 'src_ofs' in 'src',
1199 * which is 'src_len' bytes long.
1201 * If you consider all of 'src' to be a single unsigned integer in network byte
1202 * order, then bit N is the bit with value 2**N. That is, bit 0 is the bit
1203 * with value 1 in src[src_len - 1], bit 1 is the bit with value 2, bit 2 is
1204 * the bit with value 4, ..., bit 8 is the bit with value 1 in src[src_len -
1207 * Required invariants:
1208 * src_ofs + n_bits <= src_len * 8
1212 bitwise_get(const void *src, unsigned int src_len,
1213 unsigned int src_ofs, unsigned int n_bits)
1215 ovs_be64 value = htonll(0);
1217 bitwise_copy(src, src_len, src_ofs,
1218 &value, sizeof value, 0,
1220 return ntohll(value);
1241 skip_spaces(const char *s)
1243 while (isspace((unsigned char) *s)) {
1250 scan_int(const char *s, const struct scan_spec *spec, int base, va_list *args)
1252 const char *start = s;
1257 negative = *s == '-';
1258 s += *s == '-' || *s == '+';
1260 if ((!base || base == 16) && *s == '0' && (s[1] == 'x' || s[1] == 'X')) {
1264 base = *s == '0' ? 8 : 10;
1267 if (s - start >= spec->width) {
1273 while (s - start < spec->width) {
1274 int digit = hexit_value(*s);
1276 if (digit < 0 || digit >= base) {
1279 value = value * base + digit;
1291 switch (spec->type) {
1295 *va_arg(*args, char *) = value;
1298 *va_arg(*args, short int *) = value;
1301 *va_arg(*args, int *) = value;
1304 *va_arg(*args, long int *) = value;
1307 *va_arg(*args, long long int *) = value;
1310 *va_arg(*args, intmax_t *) = value;
1312 case SCAN_PTRDIFF_T:
1313 *va_arg(*args, ptrdiff_t *) = value;
1316 *va_arg(*args, size_t *) = value;
1323 skip_digits(const char *s)
1325 while (*s >= '0' && *s <= '9') {
1332 scan_float(const char *s, const struct scan_spec *spec, va_list *args)
1334 const char *start = s;
1340 s += *s == '+' || *s == '-';
1343 s = skip_digits(s + 1);
1345 if (*s == 'e' || *s == 'E') {
1347 s += *s == '+' || *s == '-';
1351 if (s - start > spec->width) {
1352 s = start + spec->width;
1355 copy = xmemdup0(start, s - start);
1356 value = strtold(copy, &tail);
1363 switch (spec->type) {
1367 *va_arg(*args, float *) = value;
1370 *va_arg(*args, double *) = value;
1373 *va_arg(*args, long double *) = value;
1379 case SCAN_PTRDIFF_T:
1387 scan_output_string(const struct scan_spec *spec,
1388 const char *s, size_t n,
1391 if (spec->type != SCAN_DISCARD) {
1392 char *out = va_arg(*args, char *);
1399 scan_string(const char *s, const struct scan_spec *spec, va_list *args)
1403 for (n = 0; n < spec->width; n++) {
1404 if (!s[n] || isspace((unsigned char) s[n])) {
1412 scan_output_string(spec, s, n, args);
1417 parse_scanset(const char *p_, unsigned long *set, bool *complemented)
1419 const uint8_t *p = (const uint8_t *) p_;
1421 *complemented = *p == '^';
1425 bitmap_set1(set, ']');
1429 while (*p && *p != ']') {
1430 if (p[1] == '-' && p[2] != ']' && p[2] > *p) {
1431 bitmap_set_multiple(set, *p, p[2] - *p + 1, true);
1434 bitmap_set1(set, *p++);
1440 return (const char *) p;
1444 scan_set(const char *s, const struct scan_spec *spec, const char **pp,
1447 unsigned long set[BITMAP_N_LONGS(UCHAR_MAX + 1)];
1451 /* Parse the scan set. */
1452 memset(set, 0, sizeof set);
1453 *pp = parse_scanset(*pp, set, &complemented);
1455 /* Parse the data. */
1458 && bitmap_is_set(set, (unsigned char) s[n]) == !complemented
1459 && n < spec->width) {
1465 scan_output_string(spec, s, n, args);
1470 scan_chars(const char *s, const struct scan_spec *spec, va_list *args)
1472 unsigned int n = spec->width == UINT_MAX ? 1 : spec->width;
1474 if (strlen(s) < n) {
1477 if (spec->type != SCAN_DISCARD) {
1478 memcpy(va_arg(*args, char *), s, n);
1483 /* This is an implementation of the standard sscanf() function, with the
1484 * following exceptions:
1486 * - It returns true if the entire template was successfully scanned and
1487 * converted, false if any conversion failed.
1489 * - The standard doesn't define sscanf() behavior when an out-of-range value
1490 * is scanned, e.g. if a "%"PRIi8 conversion scans "-1" or "0x1ff". Some
1491 * implementations consider this an error and stop scanning. This
1492 * implementation never considers an out-of-range value an error; instead,
1493 * it stores the least-significant bits of the converted value in the
1494 * destination, e.g. the value 255 for both examples earlier.
1496 * - Only single-byte characters are supported, that is, the 'l' modifier
1497 * on %s, %[, and %c is not supported. The GNU extension 'a' modifier is
1498 * also not supported.
1500 * - %p is not supported.
1503 ovs_scan(const char *s, const char *template, ...)
1505 const char *const start = s;
1510 va_start(args, template);
1512 while (*p != '\0') {
1513 struct scan_spec spec;
1514 unsigned char c = *p++;
1520 } else if (c != '%') {
1526 } else if (*p == '%') {
1534 /* Parse '*' flag. */
1535 discard = *p == '*';
1538 /* Parse field width. */
1540 while (*p >= '0' && *p <= '9') {
1541 spec.width = spec.width * 10 + (*p++ - '0');
1543 if (spec.width == 0) {
1544 spec.width = UINT_MAX;
1547 /* Parse type modifier. */
1551 spec.type = SCAN_CHAR;
1554 spec.type = SCAN_SHORT;
1560 spec.type = SCAN_INTMAX_T;
1566 spec.type = SCAN_LLONG;
1569 spec.type = SCAN_LONG;
1576 spec.type = SCAN_LLONG;
1581 spec.type = SCAN_PTRDIFF_T;
1586 spec.type = SCAN_SIZE_T;
1591 spec.type = SCAN_INT;
1596 spec.type = SCAN_DISCARD;
1600 if (c != 'c' && c != 'n' && c != '[') {
1605 s = scan_int(s, &spec, 10, &args);
1609 s = scan_int(s, &spec, 0, &args);
1613 s = scan_int(s, &spec, 8, &args);
1617 s = scan_int(s, &spec, 10, &args);
1622 s = scan_int(s, &spec, 16, &args);
1630 s = scan_float(s, &spec, &args);
1634 s = scan_string(s, &spec, &args);
1638 s = scan_set(s, &spec, &p, &args);
1642 s = scan_chars(s, &spec, &args);
1646 if (spec.type != SCAN_DISCARD) {
1647 *va_arg(args, int *) = s - start;