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+/*
+ * include/import/ist.h
+ * Very simple indirect string manipulation functions.
+ *
+ * Copyright (C) 2014-2020 Willy Tarreau - w@1wt.eu
+ *
+ * Permission is hereby granted, free of charge, to any person obtaining
+ * a copy of this software and associated documentation files (the
+ * "Software"), to deal in the Software without restriction, including
+ * without limitation the rights to use, copy, modify, merge, publish,
+ * distribute, sublicense, and/or sell copies of the Software, and to
+ * permit persons to whom the Software is furnished to do so, subject to
+ * the following conditions:
+ *
+ * The above copyright notice and this permission notice shall be
+ * included in all copies or substantial portions of the Software.
+ *
+ * THE SOFTWARE IS PROVIDED "AS IS", WITHOUT WARRANTY OF ANY KIND,
+ * EXPRESS OR IMPLIED, INCLUDING BUT NOT LIMITED TO THE WARRANTIES
+ * OF MERCHANTABILITY, FITNESS FOR A PARTICULAR PURPOSE AND
+ * NONINFRINGEMENT. IN NO EVENT SHALL THE AUTHORS OR COPYRIGHT
+ * HOLDERS BE LIABLE FOR ANY CLAIM, DAMAGES OR OTHER LIABILITY,
+ * WHETHER IN AN ACTION OF CONTRACT, TORT OR OTHERWISE, ARISING
+ * FROM, OUT OF OR IN CONNECTION WITH THE SOFTWARE OR THE USE OR
+ * OTHER DEALINGS IN THE SOFTWARE.
+ */
+
+#ifndef _IMPORT_IST_H
+#define _IMPORT_IST_H
+
+#include <sys/types.h>
+#include <ctype.h>
+#include <stddef.h>
+#include <string.h>
+
+#ifndef IST_FREESTANDING
+#include <stdlib.h>
+#endif
+
+/* ASCII to lower case conversion table */
+#define _IST_LC { \
+ 0x00, 0x01, 0x02, 0x03, 0x04, 0x05, 0x06, 0x07, \
+ 0x08, 0x09, 0x0a, 0x0b, 0x0c, 0x0d, 0x0e, 0x0f, \
+ 0x10, 0x11, 0x12, 0x13, 0x14, 0x15, 0x16, 0x17, \
+ 0x18, 0x19, 0x1a, 0x1b, 0x1c, 0x1d, 0x1e, 0x1f, \
+ 0x20, 0x21, 0x22, 0x23, 0x24, 0x25, 0x26, 0x27, \
+ 0x28, 0x29, 0x2a, 0x2b, 0x2c, 0x2d, 0x2e, 0x2f, \
+ 0x30, 0x31, 0x32, 0x33, 0x34, 0x35, 0x36, 0x37, \
+ 0x38, 0x39, 0x3a, 0x3b, 0x3c, 0x3d, 0x3e, 0x3f, \
+ 0x40, 0x61, 0x62, 0x63, 0x64, 0x65, 0x66, 0x67, \
+ 0x68, 0x69, 0x6a, 0x6b, 0x6c, 0x6d, 0x6e, 0x6f, \
+ 0x70, 0x71, 0x72, 0x73, 0x74, 0x75, 0x76, 0x77, \
+ 0x78, 0x79, 0x7a, 0x5b, 0x5c, 0x5d, 0x5e, 0x5f, \
+ 0x60, 0x61, 0x62, 0x63, 0x64, 0x65, 0x66, 0x67, \
+ 0x68, 0x69, 0x6a, 0x6b, 0x6c, 0x6d, 0x6e, 0x6f, \
+ 0x70, 0x71, 0x72, 0x73, 0x74, 0x75, 0x76, 0x77, \
+ 0x78, 0x79, 0x7a, 0x7b, 0x7c, 0x7d, 0x7e, 0x7f, \
+ 0x80, 0x81, 0x82, 0x83, 0x84, 0x85, 0x86, 0x87, \
+ 0x88, 0x89, 0x8a, 0x8b, 0x8c, 0x8d, 0x8e, 0x8f, \
+ 0x90, 0x91, 0x92, 0x93, 0x94, 0x95, 0x96, 0x97, \
+ 0x98, 0x99, 0x9a, 0x9b, 0x9c, 0x9d, 0x9e, 0x9f, \
+ 0xa0, 0xa1, 0xa2, 0xa3, 0xa4, 0xa5, 0xa6, 0xa7, \
+ 0xa8, 0xa9, 0xaa, 0xab, 0xac, 0xad, 0xae, 0xaf, \
+ 0xb0, 0xb1, 0xb2, 0xb3, 0xb4, 0xb5, 0xb6, 0xb7, \
+ 0xb8, 0xb9, 0xba, 0xbb, 0xbc, 0xbd, 0xbe, 0xbf, \
+ 0xc0, 0xc1, 0xc2, 0xc3, 0xc4, 0xc5, 0xc6, 0xc7, \
+ 0xc8, 0xc9, 0xca, 0xcb, 0xcc, 0xcd, 0xce, 0xcf, \
+ 0xd0, 0xd1, 0xd2, 0xd3, 0xd4, 0xd5, 0xd6, 0xd7, \
+ 0xd8, 0xd9, 0xda, 0xdb, 0xdc, 0xdd, 0xde, 0xdf, \
+ 0xe0, 0xe1, 0xe2, 0xe3, 0xe4, 0xe5, 0xe6, 0xe7, \
+ 0xe8, 0xe9, 0xea, 0xeb, 0xec, 0xed, 0xee, 0xef, \
+ 0xf0, 0xf1, 0xf2, 0xf3, 0xf4, 0xf5, 0xf6, 0xf7, \
+ 0xf8, 0xf9, 0xfa, 0xfb, 0xfc, 0xfd, 0xfe, 0xff, \
+}
+
+/* ASCII to upper case conversion table */
+#define _IST_UC { \
+ 0x00, 0x01, 0x02, 0x03, 0x04, 0x05, 0x06, 0x07, \
+ 0x08, 0x09, 0x0a, 0x0b, 0x0c, 0x0d, 0x0e, 0x0f, \
+ 0x10, 0x11, 0x12, 0x13, 0x14, 0x15, 0x16, 0x17, \
+ 0x18, 0x19, 0x1a, 0x1b, 0x1c, 0x1d, 0x1e, 0x1f, \
+ 0x20, 0x21, 0x22, 0x23, 0x24, 0x25, 0x26, 0x27, \
+ 0x28, 0x29, 0x2a, 0x2b, 0x2c, 0x2d, 0x2e, 0x2f, \
+ 0x30, 0x31, 0x32, 0x33, 0x34, 0x35, 0x36, 0x37, \
+ 0x38, 0x39, 0x3a, 0x3b, 0x3c, 0x3d, 0x3e, 0x3f, \
+ 0x40, 0x41, 0x42, 0x43, 0x44, 0x45, 0x46, 0x47, \
+ 0x48, 0x49, 0x4a, 0x4b, 0x4c, 0x4d, 0x4e, 0x4f, \
+ 0x50, 0x51, 0x52, 0x53, 0x54, 0x55, 0x56, 0x57, \
+ 0x58, 0x59, 0x5a, 0x5b, 0x5c, 0x5d, 0x5e, 0x5f, \
+ 0x60, 0x41, 0x42, 0x43, 0x44, 0x45, 0x46, 0x47, \
+ 0x48, 0x49, 0x4a, 0x4b, 0x4c, 0x4d, 0x4e, 0x4f, \
+ 0x50, 0x51, 0x52, 0x53, 0x54, 0x55, 0x56, 0x57, \
+ 0x58, 0x59, 0x5a, 0x7b, 0x7c, 0x7d, 0x7e, 0x7f, \
+ 0x80, 0x81, 0x82, 0x83, 0x84, 0x85, 0x86, 0x87, \
+ 0x88, 0x89, 0x8a, 0x8b, 0x8c, 0x8d, 0x8e, 0x8f, \
+ 0x90, 0x91, 0x92, 0x93, 0x94, 0x95, 0x96, 0x97, \
+ 0x98, 0x99, 0x9a, 0x9b, 0x9c, 0x9d, 0x9e, 0x9f, \
+ 0xa0, 0xa1, 0xa2, 0xa3, 0xa4, 0xa5, 0xa6, 0xa7, \
+ 0xa8, 0xa9, 0xaa, 0xab, 0xac, 0xad, 0xae, 0xaf, \
+ 0xb0, 0xb1, 0xb2, 0xb3, 0xb4, 0xb5, 0xb6, 0xb7, \
+ 0xb8, 0xb9, 0xba, 0xbb, 0xbc, 0xbd, 0xbe, 0xbf, \
+ 0xc0, 0xc1, 0xc2, 0xc3, 0xc4, 0xc5, 0xc6, 0xc7, \
+ 0xc8, 0xc9, 0xca, 0xcb, 0xcc, 0xcd, 0xce, 0xcf, \
+ 0xd0, 0xd1, 0xd2, 0xd3, 0xd4, 0xd5, 0xd6, 0xd7, \
+ 0xd8, 0xd9, 0xda, 0xdb, 0xdc, 0xdd, 0xde, 0xdf, \
+ 0xe0, 0xe1, 0xe2, 0xe3, 0xe4, 0xe5, 0xe6, 0xe7, \
+ 0xe8, 0xe9, 0xea, 0xeb, 0xec, 0xed, 0xee, 0xef, \
+ 0xf0, 0xf1, 0xf2, 0xf3, 0xf4, 0xf5, 0xf6, 0xf7, \
+ 0xf8, 0xf9, 0xfa, 0xfb, 0xfc, 0xfd, 0xfe, 0xff, \
+}
+
+#if defined(USE_OBSOLETE_LINKER) || defined(__TINYC__)
+/* some old linkers and some non-ELF platforms have issues with the weak
+ * attribute so we turn these arrays to literals there. TCC silently ignores
+ * it so we switch to literal as well.
+ */
+#define ist_lc ((const unsigned char[256])_IST_LC)
+#define ist_uc ((const unsigned char[256])_IST_UC)
+#else
+const unsigned char ist_lc[256] __attribute__((weak)) = _IST_LC;
+const unsigned char ist_uc[256] __attribute__((weak)) = _IST_UC;
+#endif
+
+/* This string definition will most often be used to represent a read-only
+ * string returned from a function, based on the starting point and its length
+ * in bytes. No storage is provided, only a pointer and a length. The types
+ * here are important as we only want to have 2 native machine words there so
+ * that on modern architectures the compiler is capable of efficiently
+ * returning a register pair without having to allocate stack room from the
+ * caller. This is done with -freg-struct which is often enabled by default.
+ */
+struct ist {
+ char *ptr;
+ size_t len;
+};
+
+/* makes a constant ist from a constant string, for use in array declarations */
+#define IST(str) { .ptr = str "", .len = (sizeof str "") - 1 }
+
+/* IST_NULL is equivalent to an `ist` with `.ptr = NULL` and `.len = 0` */
+#define IST_NULL ((const struct ist){ .ptr = 0, .len = 0 })
+
+/* makes an ist from a regular zero terminated string. Null has length 0.
+ * Constants are detected and replaced with constant initializers. Other values
+ * are measured by hand without strlen() as it's much cheaper and inlinable on
+ * small strings. The construct is complex because we must never call
+ * __builtin_strlen() with an expression otherwise it involves a real
+ * measurement.
+ */
+#if __GNUC__ >= 4
+// gcc >= 4 detects constant propagation of str through __x and resolves the
+// length of constant strings easily.
+#define ist(str) ({ \
+ char *__x = (void *)(str); \
+ (struct ist){ \
+ .ptr = __x, \
+ .len = __builtin_constant_p(str) ? \
+ ((void *)str == (void *)0) ? 0 : \
+ __builtin_strlen(__x) : \
+ ({ \
+ size_t __l = 0; \
+ if (__x) for (__l--; __x[++__l]; ) ; \
+ __l; \
+ }) \
+ }; \
+})
+#else
+// gcc < 4 can't do this, and the side effect is a warning each time a NULL is
+// passed to ist() due to the check on __builtin_strlen(). It doesn't have the
+// ability to know that this code is never called.
+#define ist(str) ({ \
+ char *__x = (void *)(str); \
+ (struct ist){ \
+ .ptr = __x, \
+ .len = __builtin_constant_p(str) ? \
+ ((void *)str == (void *)0) ? 0 : \
+ __builtin_strlen(str) : \
+ ({ \
+ size_t __l = 0; \
+ if (__x) for (__l--; __x[++__l]; ) ; \
+ __l; \
+ }) \
+ }; \
+})
+#endif
+
+/* makes an ist struct from a string and a length */
+static inline struct ist ist2(const void *ptr, size_t len)
+{
+ return (struct ist){ .ptr = (char *)ptr, .len = len };
+}
+
+/* returns the result of `ist.ptr != NULL` */
+static inline int isttest(const struct ist ist)
+{
+ return ist.ptr != NULL;
+}
+
+/* This function MODIFIES the string to add a zero AFTER the end, and returns
+ * the start pointer. The purpose is to use it on strings extracted by parsers
+ * from larger strings cut with delimiters that are not important and can be
+ * destroyed. It allows any such string to be used with regular string
+ * functions. It's also convenient to use with printf() to show data extracted
+ * from writable areas. The caller is obviously responsible for ensuring that
+ * the string is valid and that the first byte past the end is writable. If
+ * these conditions cannot be satisfied, use istpad() below instead.
+ */
+static inline char *ist0(struct ist ist)
+{
+ ist.ptr[ist.len] = 0;
+ return ist.ptr;
+}
+
+/* returns the pointer of the string */
+static inline char *istptr(const struct ist ist)
+{
+ return ist.ptr;
+}
+
+/* returns the length of the string */
+static inline size_t istlen(const struct ist ist)
+{
+ return ist.len;
+}
+
+/* returns the pointer to the end the string */
+static inline char *istend(const struct ist ist)
+{
+ return (ist.ptr + ist.len);
+}
+
+/* skips to next character in the string, always stops at the end */
+static inline struct ist istnext(const struct ist ist)
+{
+ struct ist ret = ist;
+
+ if (ret.len) {
+ ret.len--;
+ ret.ptr++;
+ }
+ return ret;
+}
+
+/* Returns the first character of the <ist> and advances the <ist> by 1.
+ * If the <ist> is empty the result is undefined.
+ */
+static inline char istshift(struct ist *ist)
+{
+ if (ist->len) {
+ char c = *ist->ptr;
+ *ist = istnext(*ist);
+
+ return c;
+ }
+
+ return 0;
+}
+
+/* copies the contents from string <ist> to buffer <buf> and adds a trailing
+ * zero. The caller must ensure <buf> is large enough.
+ */
+static inline struct ist istpad(void *buf, const struct ist ist)
+{
+ struct ist ret = { .ptr = buf, .len = ist.len };
+
+ for (ret.len = 0; ret.len < ist.len; ret.len++)
+ ret.ptr[ret.len] = ist.ptr[ret.len];
+
+ ret.ptr[ret.len] = 0;
+ return ret;
+}
+
+/* trims string <ist> to no more than <size> characters. The string is
+ * returned.
+ */
+static inline struct ist isttrim(const struct ist ist, size_t size)
+{
+ struct ist ret = ist;
+
+ if (ret.len > size)
+ ret.len = size;
+ return ret;
+}
+
+/* Sets the <len> of the <ist> to zero and returns the previous length.
+ *
+ * This function is meant to be used in functions that receive an ist containing
+ * the destination buffer and the buffer's size. The returned size must be stored
+ * to prevent an overflow of such a destination buffer.
+ *
+ * If you simply want to clear an ist and do not care about the previous length
+ * then you should use `isttrim(ist, 0)`.
+ *
+ * Example Usage (fill the complete buffer with 'x'):
+ *
+ * void my_func(struct ist* dst)
+ * {
+ * size_t dst_size = istclear(dst);
+ * size_t i;
+ *
+ * for (i = 0; i < dst_size; i++)
+ * *dst = __istappend(*dst, 'x');
+ * }
+ */
+__attribute__((warn_unused_result))
+static inline size_t istclear(struct ist* ist)
+{
+ size_t len = ist->len;
+
+ ist->len = 0;
+
+ return len;
+}
+
+/* trims string <ist> to no more than <size>-1 characters and ensures that a
+ * zero is placed after <ist.len> (possibly reduced by one) and before <size>,
+ * unless <size> is already zero. The string is returned. This is mostly aimed
+ * at building printable strings that need to be zero-terminated.
+ */
+static inline struct ist istzero(const struct ist ist, size_t size)
+{
+ struct ist ret = ist;
+
+ if (!size)
+ ret.len = 0;
+ else {
+ if (ret.len > size - 1)
+ ret.len = size - 1;
+ ret.ptr[ret.len] = 0;
+ }
+ return ret;
+}
+
+/* returns the ordinal difference between two strings :
+ * < 0 if ist1 < ist2
+ * = 0 if ist1 == ist2
+ * > 0 if ist1 > ist2
+ */
+static inline int istdiff(const struct ist ist1, const struct ist ist2)
+{
+ struct ist l = ist1;
+ struct ist r = ist2;
+
+ do {
+ if (!l.len--)
+ return -r.len;
+ if (!r.len--)
+ return 1;
+ } while (*l.ptr++ == *r.ptr++);
+
+ return *(unsigned char *)(l.ptr - 1) - *(unsigned char *)(r.ptr - 1);
+}
+
+/* returns non-zero if <ist1> starts like <ist2> (empty strings do match) */
+static inline int istmatch(const struct ist ist1, const struct ist ist2)
+{
+ struct ist l = ist1;
+ struct ist r = ist2;
+
+ if (l.len < r.len)
+ return 0;
+
+ while (r.len--) {
+ if (*l.ptr++ != *r.ptr++)
+ return 0;
+ }
+ return 1;
+}
+
+/* returns non-zero if <ist1> starts like <ist2>, ignoring the case (empty strings do match) */
+static inline int istmatchi(const struct ist ist1, const struct ist ist2)
+{
+ struct ist l = ist1;
+ struct ist r = ist2;
+
+ if (l.len < r.len)
+ return 0;
+
+ while (r.len--) {
+ if (*l.ptr != *r.ptr &&
+ ist_lc[(unsigned char)*l.ptr] != ist_lc[(unsigned char)*r.ptr])
+ return 0;
+
+ l.ptr++;
+ r.ptr++;
+ }
+ return 1;
+}
+
+/* returns non-zero if <ist1> starts like <ist2> on the first <count>
+ * characters (empty strings do match).
+ */
+static inline int istnmatch(const struct ist ist1, const struct ist ist2, size_t count)
+{
+ struct ist l = ist1;
+ struct ist r = ist2;
+
+ if (l.len > count)
+ l.len = count;
+ if (r.len > count)
+ r.len = count;
+ return istmatch(l, r);
+}
+
+/* returns non-zero if <ist1> equals <ist2> (empty strings are equal) */
+static inline int isteq(const struct ist ist1, const struct ist ist2)
+{
+ struct ist l = ist1;
+ struct ist r = ist2;
+
+ if (l.len != r.len)
+ return 0;
+
+ while (l.len--) {
+ if (*l.ptr++ != *r.ptr++)
+ return 0;
+ }
+ return 1;
+}
+
+/* returns non-zero if <ist1> equals <ist2>, ignoring the case (empty strings are equal) */
+static inline int isteqi(const struct ist ist1, const struct ist ist2)
+{
+ struct ist l = ist1;
+ struct ist r = ist2;
+
+ if (l.len != r.len)
+ return 0;
+
+ while (l.len--) {
+ if (*l.ptr != *r.ptr &&
+ ist_lc[(unsigned char)*l.ptr] != ist_lc[(unsigned char)*r.ptr])
+ return 0;
+
+ l.ptr++;
+ r.ptr++;
+ }
+ return 1;
+}
+
+/* returns non-zero if <ist1> equals <ist2> on the first <count> characters
+ * (empty strings are equal).
+ */
+static inline int istneq(const struct ist ist1, const struct ist ist2, size_t count)
+{
+ struct ist l = ist1;
+ struct ist r = ist2;
+
+ if (l.len > count)
+ l.len = count;
+ if (r.len > count)
+ r.len = count;
+ return isteq(l, r);
+}
+
+/* appends <src> after <dst>. The caller must ensure that the underlying buffer
+ * is large enough to fit the character.
+ */
+static inline struct ist __istappend(struct ist dst, const char src)
+{
+ dst.ptr[dst.len++] = src;
+
+ return dst;
+}
+
+/* copies <src> over <dst> for a maximum of <count> bytes. Returns the number
+ * of characters copied (src.len), or -1 if it does not fit. In all cases, the
+ * contents are copied prior to reporting an error, so that the destination
+ * at least contains a valid but truncated string.
+ */
+static inline ssize_t istcpy(struct ist *dst, const struct ist src, size_t count)
+{
+ dst->len = 0;
+
+ if (count > src.len)
+ count = src.len;
+
+ while (dst->len < count) {
+ dst->ptr[dst->len] = src.ptr[dst->len];
+ dst->len++;
+ }
+
+ if (dst->len == src.len)
+ return src.len;
+
+ return -1;
+}
+
+/* copies <src> over <dst> for a maximum of <count> bytes. Returns the number
+ * of characters copied, or -1 if it does not fit. A (possibly truncated) valid
+ * copy of <src> is always left into <dst>, and a trailing \0 is appended as
+ * long as <count> is not null, even if that results in reducing the string by
+ * one character.
+ */
+static inline ssize_t istscpy(struct ist *dst, const struct ist src, size_t count)
+{
+ dst->len = 0;
+
+ if (!count)
+ goto fail;
+
+ if (count > src.len)
+ count = src.len + 1;
+
+ while (dst->len < count - 1) {
+ dst->ptr[dst->len] = src.ptr[dst->len];
+ dst->len++;
+ }
+
+ dst->ptr[dst->len] = 0;
+ if (dst->len == src.len)
+ return src.len;
+ fail:
+ return -1;
+}
+
+/* appends <src> after <dst> for a maximum of <count> total bytes in <dst> after
+ * the copy. <dst> is assumed to be <count> or less before the call. The new
+ * string's length is returned, or -1 if a truncation happened. In all cases,
+ * the contents are copied prior to reporting an error, so that the destination
+ * at least contains a valid but truncated string.
+ */
+static inline ssize_t istcat(struct ist *dst, const struct ist src, size_t count)
+{
+ const char *s = src.ptr;
+
+ while (dst->len < count && s != src.ptr + src.len)
+ dst->ptr[dst->len++] = *s++;
+
+ if (s == src.ptr + src.len)
+ return dst->len;
+
+ return -1;
+}
+
+/* appends <src> after <dst> for a maximum of <count> total bytes in <dst> after
+ * the copy. <dst> is assumed to be <count> or less before the call. The new
+ * string's length is returned, or -1 if a truncation happened. In all cases,
+ * the contents are copied prior to reporting an error, so that the destination
+ * at least contains a valid but truncated string.
+ */
+static inline ssize_t istscat(struct ist *dst, const struct ist src, size_t count)
+{
+ const char *s = src.ptr;
+
+ if (!count)
+ goto fail;
+
+ while (dst->len < count - 1 && s != src.ptr + src.len) {
+ dst->ptr[dst->len++] = *s++;
+ }
+
+ dst->ptr[dst->len] = 0;
+ if (s == src.ptr + src.len)
+ return dst->len;
+ fail:
+ return -1;
+}
+
+/* copies the entire <src> over <dst>, which must be allocated large enough to
+ * hold the whole contents. No trailing zero is appended, this is mainly used
+ * for protocol processing where the frame length has already been checked. An
+ * ist made of the output and its length are returned. The destination is not
+ * touched if src.len is null.
+ */
+static inline struct ist ist2bin(char *dst, const struct ist src)
+{
+ size_t ofs = 0;
+
+ /* discourage the compiler from trying to optimize for large strings,
+ * but tell it that most of our strings are not empty.
+ */
+ if (__builtin_expect(ofs < src.len, 1)) {
+ do {
+ dst[ofs] = src.ptr[ofs];
+ ofs++;
+ } while (__builtin_expect(ofs < src.len, 0));
+ }
+ return ist2(dst, ofs);
+}
+
+/* copies the entire <src> over <dst>, which must be allocated large enough to
+ * hold the whole contents as well as a trailing zero which is always appended.
+ * This is mainly used for protocol conversions where the frame length has
+ * already been checked. An ist made of the output and its length (not counting
+ * the trailing zero) are returned.
+ */
+static inline struct ist ist2str(char *dst, const struct ist src)
+{
+ size_t ofs = 0;
+
+ /* discourage the compiler from trying to optimize for large strings,
+ * but tell it that most of our strings are not empty.
+ */
+ if (__builtin_expect(ofs < src.len, 1)) {
+ do {
+ dst[ofs] = src.ptr[ofs];
+ ofs++;
+ } while (__builtin_expect(ofs < src.len, 0));
+ }
+ dst[ofs] = 0;
+ return ist2(dst, ofs);
+}
+
+/* makes a lower case copy of the entire <src> into <dst>, which must have been
+ * allocated large enough to hold the whole contents. No trailing zero is
+ * appended, this is mainly used for protocol processing where the frame length
+ * has already been checked. An ist made of the output and its length are
+ * returned. The destination is not touched if src.len is null.
+ */
+static inline struct ist ist2bin_lc(char *dst, const struct ist src)
+{
+ size_t ofs = 0;
+
+ /* discourage the compiler from trying to optimize for large strings,
+ * but tell it that most of our strings are not empty.
+ */
+ if (__builtin_expect(ofs < src.len, 1)) {
+ do {
+ dst[ofs] = ist_lc[(unsigned char)src.ptr[ofs]];
+ ofs++;
+ } while (__builtin_expect(ofs < src.len, 0));
+ }
+ return ist2(dst, ofs);
+}
+
+/* makes a lower case copy of the entire <src> into <dst>, which must have been
+ * allocated large enough to hold the whole contents as well as a trailing zero
+ * which is always appended. This is mainly used for protocol conversions where
+ * the frame length has already been checked. An ist made of the output and its
+ * length (not counting the trailing zero) are returned.
+ */
+static inline struct ist ist2str_lc(char *dst, const struct ist src)
+{
+ size_t ofs = 0;
+
+ /* discourage the compiler from trying to optimize for large strings,
+ * but tell it that most of our strings are not empty.
+ */
+ if (__builtin_expect(ofs < src.len, 1)) {
+ do {
+ dst[ofs] = ist_lc[(unsigned char)src.ptr[ofs]];
+ ofs++;
+ } while (__builtin_expect(ofs < src.len, 0));
+ }
+ dst[ofs] = 0;
+ return ist2(dst, ofs);
+}
+
+/* makes an upper case copy of the entire <src> into <dst>, which must have
+ * been allocated large enough to hold the whole contents. No trailing zero is
+ * appended, this is mainly used for protocol processing where the frame length
+ * has already been checked. An ist made of the output and its length are
+ * returned. The destination is not touched if src.len is null.
+ */
+static inline struct ist ist2bin_uc(char *dst, const struct ist src)
+{
+ size_t ofs = 0;
+
+ /* discourage the compiler from trying to optimize for large strings,
+ * but tell it that most of our strings are not empty.
+ */
+ if (__builtin_expect(ofs < src.len, 1)) {
+ do {
+ dst[ofs] = ist_uc[(unsigned char)src.ptr[ofs]];
+ ofs++;
+ } while (__builtin_expect(ofs < src.len, 0));
+ }
+ return ist2(dst, ofs);
+}
+
+/* makes an upper case copy of the entire <src> into <dst>, which must have been
+ * allocated large enough to hold the whole contents as well as a trailing zero
+ * which is always appended. This is mainly used for protocol conversions where
+ * the frame length has already been checked. An ist made of the output and its
+ * length (not counting the trailing zero) are returned.
+ */
+static inline struct ist ist2str_uc(char *dst, const struct ist src)
+{
+ size_t ofs = 0;
+
+ /* discourage the compiler from trying to optimize for large strings,
+ * but tell it that most of our strings are not empty.
+ */
+ if (__builtin_expect(ofs < src.len, 1)) {
+ do {
+ dst[ofs] = ist_uc[(unsigned char)src.ptr[ofs]];
+ ofs++;
+ } while (__builtin_expect(ofs < src.len, 0));
+ }
+ dst[ofs] = 0;
+ return ist2(dst, ofs);
+}
+
+/* looks for first occurrence of character <chr> in string <ist>. Returns the
+ * pointer if found, or NULL if not found.
+ */
+static inline char *istchr(const struct ist ist, char chr)
+{
+ char *s = ist.ptr;
+
+ do {
+ if (s >= ist.ptr + ist.len)
+ return NULL;
+ } while (*s++ != chr);
+ return s - 1;
+}
+
+/* Returns a pointer to the first control character found in <ist>, or NULL if
+ * none is present. A control character is defined as a byte whose value is
+ * between 0x00 and 0x1F included. The function is optimized for strings having
+ * no CTL chars by processing up to sizeof(long) bytes at once on architectures
+ * supporting efficient unaligned accesses. Despite this it is not very fast
+ * (~0.43 byte/cycle) and should mostly be used on low match probability when
+ * it can save a call to a much slower function.
+ */
+static inline const char *ist_find_ctl(const struct ist ist)
+{
+ const union { unsigned long v; } __attribute__((packed)) *u;
+ const char *curr = (void *)ist.ptr - sizeof(long);
+ const char *last = curr + ist.len;
+ unsigned long l1, l2;
+
+ do {
+ curr += sizeof(long);
+ if (curr > last)
+ break;
+ u = (void *)curr;
+ /* subtract 0x202020...20 to the value to generate a carry in
+ * the lower byte if the byte contains a lower value. If we
+ * generate a bit 7 that was not there, it means the byte was
+ * within 0x00..0x1F.
+ */
+ l2 = u->v;
+ l1 = ~l2 & ((~0UL / 255) * 0x80); /* 0x808080...80 */
+ l2 -= (~0UL / 255) * 0x20; /* 0x202020...20 */
+ } while ((l1 & l2) == 0);
+
+ last += sizeof(long);
+ if (__builtin_expect(curr < last, 0)) {
+ do {
+ if ((unsigned char)*curr < 0x20)
+ return curr;
+ curr++;
+ } while (curr < last);
+ }
+ return NULL;
+}
+
+/* Returns a pointer to the first character found <ist> that belongs to the
+ * range [min:max] inclusive, or NULL if none is present. The function is
+ * optimized for strings having no such chars by processing up to sizeof(long)
+ * bytes at once on architectures supporting efficient unaligned accesses.
+ * Despite this it is not very fast (~0.43 byte/cycle) and should mostly be
+ * used on low match probability when it can save a call to a much slower
+ * function. Will not work for characters 0x80 and above. It's optimized for
+ * min and max to be known at build time.
+ */
+static inline const char *ist_find_range(const struct ist ist, unsigned char min, unsigned char max)
+{
+ const union { unsigned long v; } __attribute__((packed)) *u;
+ const char *curr = (void *)ist.ptr - sizeof(long);
+ const char *last = curr + ist.len;
+ unsigned long l1, l2;
+
+ /* easier with an exclusive boundary */
+ max++;
+
+ do {
+ curr += sizeof(long);
+ if (curr > last)
+ break;
+ u = (void *)curr;
+ /* add 0x<min><min><min><min>..<min> then subtract
+ * 0x<max><max><max><max>..<max> to the value to generate a
+ * carry in the lower byte if the byte contains a lower value.
+ * If we generate a bit 7 that was not there, it means the byte
+ * was min..max.
+ */
+ l2 = u->v;
+ l1 = ~l2 & ((~0UL / 255) * 0x80); /* 0x808080...80 */
+ l2 += (~0UL / 255) * min; /* 0x<min><min>..<min> */
+ l2 -= (~0UL / 255) * max; /* 0x<max><max>..<max> */
+ } while ((l1 & l2) == 0);
+
+ last += sizeof(long);
+ if (__builtin_expect(curr < last, 0)) {
+ do {
+ if ((unsigned char)(*curr - min) < (unsigned char)(max - min))
+ return curr;
+ curr++;
+ } while (curr < last);
+ }
+ return NULL;
+}
+
+/* looks for first occurrence of character <chr> in string <ist> and returns
+ * the tail of the string starting with this character, or (ist.end,0) if not
+ * found.
+ */
+static inline struct ist istfind(const struct ist ist, char chr)
+{
+ struct ist ret = ist;
+
+ while (ret.len--) {
+ if (*ret.ptr++ == chr)
+ return ist2(ret.ptr - 1, ret.len + 1);
+ }
+ return ist2(ret.ptr, 0);
+}
+
+/* looks for first occurrence of character different from <chr> in string <ist>
+ * and returns the tail of the string starting at this character, or (ist_end,0)
+ * if not found.
+ */
+static inline struct ist istskip(const struct ist ist, char chr)
+{
+ struct ist ret = ist;
+
+ while (ret.len--) {
+ if (*ret.ptr++ != chr)
+ return ist2(ret.ptr - 1, ret.len + 1);
+ }
+ return ist2(ret.ptr, 0);
+}
+
+/* looks for first occurrence of string <pat> in string <ist> and returns the
+ * tail of the string starting at this position, or (NULL,0) if not found. The
+ * empty pattern is found everywhere.
+ */
+static inline struct ist istist(const struct ist ist, const struct ist pat)
+{
+ struct ist ret = ist;
+ size_t pos;
+
+ if (!pat.len)
+ return ret;
+
+ while (1) {
+ loop:
+ ret = istfind(ret, *pat.ptr);
+ if (ret.len < pat.len)
+ break;
+
+ /* ret.len >= 1, pat.len >= 1 and *ret.ptr == *pat.ptr */
+
+ ret = istnext(ret);
+ for (pos = 0; pos < pat.len - 1; ) {
+ ++pos;
+ if (ret.ptr[pos - 1] != pat.ptr[pos])
+ goto loop;
+ }
+ return ist2(ret.ptr - 1, ret.len + 1);
+ }
+ return IST_NULL;
+}
+
+/*
+ * looks for the first occurrence of <chr> in string <ist> and returns a shorter
+ * ist if char is found.
+ */
+static inline struct ist iststop(const struct ist ist, char chr)
+{
+ size_t len = 0;
+
+ while (len++ < ist.len && ist.ptr[len - 1] != chr)
+ ;
+ return ist2(ist.ptr, len - 1);
+}
+
+/*
+ * advance <.ptr> by <nb> characters.
+ * If <ist> is too short, (ist.end,0) is returned.
+ */
+static inline struct ist istadv(const struct ist ist, const size_t nb)
+{
+ if (ist.len < nb)
+ return ist2(ist.ptr + ist.len, 0);
+ return ist2(ist.ptr + nb, ist.len - nb);
+}
+
+/* Splits the given <ist> at the given character. The returned ist is
+ * equivalent to iststop(ist, delim). The passed <ist> will contain the
+ * remainder of the string, not including the delimiter. In other words
+ * it will be advanced by the length of the returned string plus 1.
+ */
+static inline struct ist istsplit(struct ist *ist, char delim)
+{
+ const struct ist result = iststop(*ist, delim);
+
+ *ist = istadv(*ist, result.len + 1);
+
+ return result;
+}
+
+/*
+ * compare 2 ists and return non-zero if they are the same
+ */
+static inline int istissame(const struct ist ist1, const struct ist ist2)
+{
+ return ((ist1.ptr == ist2.ptr) && (ist1.len == ist2.len));
+}
+
+#ifndef IST_FREESTANDING
+/* This function allocates <size> bytes and returns an `ist` pointing to
+ * the allocated area with size `0`.
+ *
+ * If this function fails to allocate memory the return value is equivalent
+ * to IST_NULL.
+ */
+static inline struct ist istalloc(const size_t size)
+{
+ /* Note: do not use ist2 here, as it triggers a gcc11 warning.
+ * €˜<unknown>€™ may be used uninitialized [-Werror=maybe-uninitialized]
+ *
+ * This warning is reported because the uninitialized memory block
+ * allocated by malloc should not be passed to a const argument as in
+ * ist2.
+ * See https://gcc.gnu.org/onlinedocs/gcc-11.1.0/gcc/Warning-Options.html#index-Wmaybe-uninitialized
+ */
+ return (struct ist){ .ptr = malloc(size), .len = 0 };
+}
+
+/* This function performs the equivalent of free() on the given <ist>.
+ *
+ * After this function returns the value of the given <ist> will be
+ * modified to be equivalent to IST_NULL.
+ */
+static inline void istfree(struct ist *ist)
+{
+ free(ist->ptr);
+ *ist = IST_NULL;
+}
+
+/* This function performs the equivalent of strdup() on the given <src>.
+ *
+ * If this function fails to allocate memory the return value is equivalent
+ * to IST_NULL.
+ */
+static inline struct ist istdup(const struct ist src)
+{
+ const size_t src_size = src.len;
+
+ /* Allocate at least 1 byte to allow duplicating an empty string with
+ * malloc implementations that return NULL for a 0-size allocation.
+ */
+ struct ist dst = istalloc(src_size ? src_size : 1);
+
+ if (isttest(dst)) {
+ istcpy(&dst, src, src_size);
+ }
+
+ return dst;
+}
+#endif
+
+#endif
generated by cgit v1.2.3 (git 2.39.1) at 2024-05-20 10:54:31 +0000