cosmopolitan/net/http/hascontrolcodes.c
2022-08-11 12:13:18 -07:00

66 lines
3 KiB
C

/*-*- mode:c;indent-tabs-mode:nil;c-basic-offset:2;tab-width:8;coding:utf-8 -*-│
│vi: set net ft=c ts=2 sts=2 sw=2 fenc=utf-8 :vi│
╞══════════════════════════════════════════════════════════════════════════════╡
│ Copyright 2021 Justine Alexandra Roberts Tunney │
│ │
│ Permission to use, copy, modify, and/or distribute this software for │
│ any purpose with or without fee is hereby granted, provided that the │
│ above copyright notice and this permission notice appear in all copies. │
│ │
│ THE SOFTWARE IS PROVIDED "AS IS" AND THE AUTHOR DISCLAIMS ALL │
│ WARRANTIES WITH REGARD TO THIS SOFTWARE INCLUDING ALL IMPLIED │
│ WARRANTIES OF MERCHANTABILITY AND FITNESS. IN NO EVENT SHALL THE │
│ AUTHOR BE LIABLE FOR ANY SPECIAL, DIRECT, INDIRECT, OR CONSEQUENTIAL │
│ DAMAGES OR ANY DAMAGES WHATSOEVER RESULTING FROM LOSS OF USE, DATA OR │
│ PROFITS, WHETHER IN AN ACTION OF CONTRACT, NEGLIGENCE OR OTHER │
│ TORTIOUS ACTION, ARISING OUT OF OR IN CONNECTION WITH THE USE OR │
│ PERFORMANCE OF THIS SOFTWARE. │
╚─────────────────────────────────────────────────────────────────────────────*/
#include "libc/intrin/likely.h"
#include "libc/str/str.h"
#include "libc/str/thompike.h"
#include "net/http/escape.h"
/**
* Returns true if C0 or C1 control codes are present
*
* @param p is input value
* @param n if -1 implies strlen
* @param f can have kControlWs, kControlC0, kControlC1 to forbid
* @return index of first forbidden character or -1
* @see VisualizeControlCodes()
*/
ssize_t HasControlCodes(const char *p, size_t n, int f) {
char t[256];
wint_t x, a, b;
size_t i, j, m, g;
bzero(t, sizeof(t));
if (f & kControlC0) memset(t + 0x00, 1, 0x20 - 0x00), t[0x7F] = 1;
if (f & kControlC1) memset(t + 0x80, 1, 0xA0 - 0x80);
t['\t'] = t['\r'] = t['\n'] = t['\v'] = !!(f & kControlWs);
if (n == -1) n = p ? strlen(p) : 0;
for (i = 0; i < n;) {
g = i;
x = p[i++] & 0xff;
if (UNLIKELY(x >= 0300)) {
a = ThomPikeByte(x);
m = ThomPikeLen(x) - 1;
if (i + m <= n) {
for (j = 0;;) {
b = p[i + j] & 0xff;
if (!ThomPikeCont(b)) break;
a = ThomPikeMerge(a, b);
if (++j == m) {
x = a;
i += j;
break;
}
}
}
}
if (x < 256 && t[x]) {
return g;
}
}
return -1;
}