cosmopolitan/net/http/parsehttprequest.c

126 lines
4.2 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/alg/alg.h"
#include "libc/alg/arraylist.internal.h"
#include "libc/limits.h"
#include "libc/stdio/stdio.h"
#include "libc/str/str.h"
#include "libc/sysv/errfuns.h"
#include "libc/x/x.h"
#include "net/http/http.h"
enum ParseHttpRequestState {
METHOD,
URI,
VERSION,
HKEY,
HSEP,
HVAL,
CR1,
LF1,
LF2
};
/**
* Parses HTTP request header.
*/
int ParseHttpRequest(struct HttpRequest *req, const char *p, size_t n) {
int a, h, c, i, x;
enum ParseHttpRequestState t;
memset(req, 0, sizeof(*req));
a = h = 0;
t = METHOD;
if (n > SHRT_MAX - 1) n = SHRT_MAX - 1;
for (i = 0; i < n; ++i) {
c = p[i] & 0xFF;
switch (t) {
case METHOD:
if (c == '\r' || c == '\n') break; /* RFC7230 § 3.5 */
if (c == ' ') {
if (!i) return ebadmsg();
if ((x = GetHttpMethod(p, i)) == -1) return ebadmsg();
req->method = x;
req->uri.a = i + 1;
t = URI;
}
break;
case URI:
if (c == ' ') {
req->uri.b = i;
req->version.a = i + 1;
if (req->uri.a == req->uri.b) return ebadmsg();
t = VERSION;
}
break;
case VERSION:
if (c == '\r' || c == '\n') {
req->version.b = i;
t = c == '\r' ? CR1 : LF1;
}
break;
case CR1:
if (c != '\n') return ebadmsg();
t = LF1;
break;
case LF1:
if (c == '\r') {
t = LF2;
break;
} else if (c == '\n') {
return 0;
} else if (c == ' ' || c == '\t') { /* line folding!!! */
return eprotonosupport(); /* RFC7230 § 3.2.4 */
}
a = i;
t = HKEY;
/* εpsilon transition */
case HKEY:
if (c == ':') {
h = GetHttpHeader(p + a, i - a);
t = HSEP;
}
break;
case HSEP:
if (c == ' ' || c == '\t') break;
a = i;
t = HVAL;
/* εpsilon transition */
case HVAL:
if (c == '\r' || c == '\n') {
if (h != -1) {
req->headers[h].a = a;
req->headers[h].b = i;
}
t = c == '\r' ? CR1 : LF1;
}
break;
case LF2:
if (c == '\n') {
req->length = i + 1;
return i + 1;
}
return ebadmsg();
default:
unreachable;
}
}
return 0;
}