mirror of
https://github.com/jart/cosmopolitan.git
synced 2025-01-31 03:27:39 +00:00
105 lines
4.1 KiB
C
105 lines
4.1 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/macros.h"
|
|
#include "libc/stdckdint.h"
|
|
#include "libc/str/str.h"
|
|
#include "net/http/http.h"
|
|
|
|
/**
|
|
* Parses HTTP Range request header.
|
|
*
|
|
* Here are some example values:
|
|
*
|
|
* Range: bytes=0- (everything)
|
|
* Range: bytes=0-499 (first 500 bytes)
|
|
* Range: bytes=500-999 (second 500 bytes)
|
|
* Range: bytes=-500 (final 500 bytes)
|
|
* Range: bytes=0-0,-1 (first and last and always)
|
|
* Range: bytes=500-600,601-999 (overlong but legal)
|
|
*/
|
|
bool ParseHttpRange(const char *p, size_t n, long resourcelength,
|
|
long *out_start, long *out_length) {
|
|
long start, length, ending;
|
|
*out_start = 0;
|
|
*out_length = 0;
|
|
if (memchr(p, ',', n))
|
|
return false;
|
|
if (n < 7 || memcmp(p, "bytes=", 6) != 0)
|
|
return false;
|
|
p += 6, n -= 6;
|
|
if (n && *p == '-') {
|
|
++p, --n;
|
|
length = 0;
|
|
while (n && '0' <= *p && *p <= '9') {
|
|
if (ckd_mul(&length, length, 10))
|
|
return false;
|
|
if (ckd_add(&length, length, *p - '0'))
|
|
return false;
|
|
++p, --n;
|
|
}
|
|
if (ckd_sub(&start, resourcelength, length))
|
|
return false;
|
|
} else {
|
|
start = 0;
|
|
while (n && '0' <= *p && *p <= '9') {
|
|
if (ckd_mul(&start, start, 10))
|
|
return false;
|
|
if (ckd_add(&start, start, *p - '0'))
|
|
return false;
|
|
++p, --n;
|
|
}
|
|
if (n && *p == '-') {
|
|
++p, --n;
|
|
if (!n) {
|
|
length = MAX(start, resourcelength) - start;
|
|
} else {
|
|
length = 0;
|
|
while (n && '0' <= *p && *p <= '9') {
|
|
if (ckd_mul(&length, length, 10))
|
|
return false;
|
|
if (ckd_add(&length, length, *p - '0'))
|
|
return false;
|
|
++p, --n;
|
|
}
|
|
if (ckd_add(&length, length, 1))
|
|
return false;
|
|
if (ckd_sub(&length, length, start))
|
|
return false;
|
|
}
|
|
} else if (ckd_sub(&length, resourcelength, start)) {
|
|
return false;
|
|
}
|
|
}
|
|
if (n)
|
|
return false;
|
|
if (start < 0)
|
|
return false;
|
|
if (length < 1)
|
|
return false;
|
|
if (start > resourcelength)
|
|
return false;
|
|
if (ckd_add(&ending, start, length))
|
|
return false;
|
|
if (ending > resourcelength) {
|
|
length = resourcelength - start;
|
|
}
|
|
*out_start = start;
|
|
*out_length = length;
|
|
return true;
|
|
}
|