cosmopolitan/net/http/parsecontentlength.c
2024-07-21 15:54:17 -07:00

48 lines
2.4 KiB
C

/*-*- mode:c;indent-tabs-mode:nil;c-basic-offset:2;tab-width:8;coding:utf-8 -*-│
│ vi: set et ft=c ts=2 sts=2 sw=2 fenc=utf-8 :vi │
╞══════════════════════════════════════════════════════════════════════════════╡
│ Copyright 2020 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/ctype.h"
#include "libc/stdckdint.h"
#include "libc/str/str.h"
#include "net/http/http.h"
/**
* Parses Content-Length header.
*
* @param size is byte length and -1 implies strlen
* @return -1 on invalid or overflow, otherwise >=0 value
*/
int64_t ParseContentLength(const char *s, size_t n) {
size_t i;
int64_t r;
if (n == -1)
n = s ? strlen(s) : 0;
if (!n)
return -1;
for (r = i = 0; i < n; ++i) {
if (s[i] == ',' && i > 0)
break;
if (!isdigit(s[i]))
return -1;
r *= 10;
r += s[i] - '0';
if (r > 0x000000ffffffffff)
return -1;
}
return r;
}