cosmopolitan/net/http/parsecontentlength.c

36 lines
2.3 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 2020 Justine Alexandra Roberts Tunney │
│ │
│ This program is free software; you can redistribute it and/or modify │
│ it under the terms of the GNU General Public License as published by │
│ the Free Software Foundation; version 2 of the License. │
│ │
│ This program is distributed in the hope that it will be useful, but │
│ WITHOUT ANY WARRANTY; without even the implied warranty of │
│ MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the GNU │
│ General Public License for more details. │
│ │
│ You should have received a copy of the GNU General Public License │
│ along with this program; if not, write to the Free Software │
│ Foundation, Inc., 51 Franklin Street, Fifth Floor, Boston, MA │
│ 02110-1301 USA │
╚─────────────────────────────────────────────────────────────────────────────*/
#include "libc/str/str.h"
#include "net/http/http.h"
long ParseContentLength(const struct HttpRequest *req, const char *p) {
long i, r, n = 0;
for (i = req->headers[kHttpContentLength].a;
i < req->headers[kHttpContentLength].b; ++i) {
if (isdigit(p[i])) {
if (!__builtin_mul_overflow(n, 10, &r) &&
!__builtin_add_overflow(r, p[i] - '0', &r)) {
n = r;
}
}
}
return n;
}