cosmopolitan/net/http/parsehttpmessage.c
Jōshin 6e6fc38935
Apply clang-format update to repo (#1154)
Commit bc6c183 introduced a bunch of discrepancies between what files
look like in the repo and what clang-format says they should look like.
However, there were already a few discrepancies prior to that. Most of
these discrepancies seemed to be unintentional, but a few of them were
load-bearing (e.g., a #include that violated header ordering needing
something to have been #defined by a 'later' #include.)

I opted to take what I hope is a relatively smooth-brained approach: I
reverted the .clang-format change, ran clang-format on the whole repo,
reapplied the .clang-format change, reran clang-format again, and then
reverted the commit that contained the first run. Thus the full effect
of this PR should only be to apply the changed formatting rules to the
repo, and from skimming the results, this seems to be the case.

My work can be checked by applying the short, manual commits, and then
rerunning the command listed in the autogenerated commits (those whose
messages I have prefixed auto:) and seeing if your results agree.

It might be that the other diffs should be fixed at some point but I'm
leaving that aside for now.

fd '\.c(c|pp)?$' --print0| xargs -0 clang-format -i
2024-04-25 10:38:00 -07:00

300 lines
10 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/assert.h"
#include "libc/limits.h"
#include "libc/macros.internal.h"
#include "libc/mem/alg.h"
#include "libc/mem/arraylist.internal.h"
#include "libc/mem/mem.h"
#include "libc/serialize.h"
#include "libc/stdio/stdio.h"
#include "libc/str/str.h"
#include "libc/str/tab.internal.h"
#include "libc/sysv/errfuns.h"
#include "libc/x/x.h"
#include "net/http/http.h"
#define LIMIT (SHRT_MAX - 2)
/**
* Initializes HTTP message parser.
*/
void InitHttpMessage(struct HttpMessage *r, int type) {
unassert(type == kHttpRequest || type == kHttpResponse);
bzero(r, sizeof(*r));
r->type = type;
}
/**
* Destroys HTTP message parser.
*/
void DestroyHttpMessage(struct HttpMessage *r) {
if (r->xheaders.p) {
free(r->xheaders.p);
r->xheaders.p = NULL;
r->xheaders.n = 0;
}
}
/**
* Parses HTTP request or response.
*
* This parser is responsible for determining the length of a message
* and slicing the strings inside it. Performance is attained using
* perfect hash tables. No memory allocation is performed for normal
* messagesy. Line folding is forbidden. State persists across calls so
* that fragmented messages can be handled efficiently. A limitation on
* message size is imposed to make the header data structures smaller.
*
* This parser assumes ISO-8859-1 and guarantees no C0 or C1 control
* codes are present in message fields, with the exception of tab.
* Please note that fields like kHttpStateUri may use UTF-8 percent encoding.
* This parser doesn't care if you choose ASA X3.4-1963 or MULTICS newlines.
*
* kHttpRepeatable defines which standard header fields are O(1) and
* which ones may have comma entries spilled over into xheaders. For
* most headers it's sufficient to simply check the static slice. If
* r->headers[kHttpFoo].a is zero then the header is totally absent.
*
* This parser has linear complexity. Each character only needs to be
* considered a single time. That's the case even if messages are
* fragmented. If a message is valid but incomplete, this function will
* return zero so that it can be resumed as soon as more data arrives.
*
* This parser takes about 400 nanoseconds to parse a 403 byte Chrome
* HTTP request under MODE=rel on a Core i9 which is about three cycles
* per byte or a gigabyte per second of throughput per core.
*
* @note we assume p points to a buffer that has >=SHRT_MAX bytes
* @see HTTP/1.1 RFC2616 RFC2068
* @see HTTP/1.0 RFC1945
*/
int ParseHttpMessage(struct HttpMessage *r, const char *p, size_t n) {
int c, h, i;
for (n = MIN(n, LIMIT); r->i < n; ++r->i) {
c = p[r->i] & 0xff;
switch (r->t) {
case kHttpStateStart:
if (c == '\r' || c == '\n')
break; // RFC7230 § 3.5
if (!kHttpToken[c])
return ebadmsg();
if (r->type == kHttpRequest) {
r->t = kHttpStateMethod;
r->method = kToUpper[c];
r->a = 8;
} else {
r->t = kHttpStateVersion;
r->a = r->i;
}
break;
case kHttpStateMethod:
for (;;) {
if (c == ' ') {
r->a = r->i + 1;
r->t = kHttpStateUri;
break;
} else if (r->a == 64 || !kHttpToken[c]) {
return ebadmsg();
}
c = kToUpper[c];
r->method |= (uint64_t)c << r->a;
r->a += 8;
if (++r->i == n)
break;
c = p[r->i] & 0xff;
}
break;
case kHttpStateUri:
for (;;) {
if (c == ' ' || c == '\r' || c == '\n') {
if (r->i == r->a)
return ebadmsg();
r->uri.a = r->a;
r->uri.b = r->i;
if (c == ' ') {
r->a = r->i + 1;
r->t = kHttpStateVersion;
} else {
r->version = 9;
r->t = c == '\r' ? kHttpStateCr : kHttpStateLf1;
}
break;
} else if (c < 0x20 || (0x7F <= c && c < 0xA0)) {
return ebadmsg();
}
if (++r->i == n)
break;
c = p[r->i] & 0xff;
}
break;
case kHttpStateVersion:
if (c == ' ' || c == '\r' || c == '\n') {
if (r->i - r->a == 8 &&
(READ64BE(p + r->a) & 0xFFFFFFFFFF00FF00) == 0x485454502F002E00 &&
isdigit(p[r->a + 5]) && isdigit(p[r->a + 7])) {
r->version = (p[r->a + 5] - '0') * 10 + (p[r->a + 7] - '0');
if (r->type == kHttpRequest) {
r->t = c == '\r' ? kHttpStateCr : kHttpStateLf1;
} else {
r->t = kHttpStateStatus;
}
} else {
return ebadmsg();
}
}
break;
case kHttpStateStatus:
for (;;) {
if (c == ' ' || c == '\r' || c == '\n') {
if (r->status < 100)
return ebadmsg();
if (c == ' ') {
r->a = r->i + 1;
r->t = kHttpStateMessage;
} else {
r->t = c == '\r' ? kHttpStateCr : kHttpStateLf1;
}
break;
} else if ('0' <= c && c <= '9') {
r->status *= 10;
r->status += c - '0';
if (r->status > 999)
return ebadmsg();
} else {
return ebadmsg();
}
if (++r->i == n)
break;
c = p[r->i] & 0xff;
}
break;
case kHttpStateMessage:
for (;;) {
if (c == '\r' || c == '\n') {
r->message.a = r->a;
r->message.b = r->i;
r->t = c == '\r' ? kHttpStateCr : kHttpStateLf1;
break;
} else if (c < 0x20 || (0x7F <= c && c < 0xA0)) {
return ebadmsg();
}
if (++r->i == n)
break;
c = p[r->i] & 0xff;
}
break;
case kHttpStateCr:
if (c != '\n')
return ebadmsg();
r->t = kHttpStateLf1;
break;
case kHttpStateLf1:
if (c == '\r') {
r->t = kHttpStateLf2;
break;
} else if (c == '\n') {
return ++r->i;
} else if (!kHttpToken[c]) {
// 1. Forbid empty header name (RFC2616 §2.2)
// 2. Forbid line folding (RFC7230 §3.2.4)
return ebadmsg();
}
r->k.a = r->i;
r->t = kHttpStateName;
break;
case kHttpStateName:
for (;;) {
if (c == ':') {
r->k.b = r->i;
r->t = kHttpStateColon;
break;
} else if (!kHttpToken[c]) {
return ebadmsg();
}
if (++r->i == n)
break;
c = p[r->i] & 0xff;
}
break;
case kHttpStateColon:
if (c == ' ' || c == '\t')
break;
r->a = r->i;
r->t = kHttpStateValue;
// fallthrough
case kHttpStateValue:
for (;;) {
if (c == '\r' || c == '\n') {
i = r->i;
while (i > r->a && (p[i - 1] == ' ' || p[i - 1] == '\t'))
--i;
if ((h = GetHttpHeader(p + r->k.a, r->k.b - r->k.a)) != -1 &&
(!r->headers[h].a || !kHttpRepeatable[h])) {
r->headers[h].a = r->a;
r->headers[h].b = i;
} else {
if (r->xheaders.n == r->xheaders.c) {
unsigned c2;
struct HttpHeader *p1, *p2;
p1 = r->xheaders.p;
c2 = r->xheaders.c;
if (c2 == 0) {
c2 = 1;
} else {
c2 = c2 * 2;
}
if ((p2 = realloc(p1, c2 * sizeof(*p1)))) {
r->xheaders.p = p2;
r->xheaders.c = c2;
}
}
if (r->xheaders.n < r->xheaders.c) {
r->xheaders.p[r->xheaders.n].k = r->k;
r->xheaders.p[r->xheaders.n].v.a = r->a;
r->xheaders.p[r->xheaders.n].v.b = i;
r->xheaders.p = r->xheaders.p;
++r->xheaders.n;
}
}
r->t = c == '\r' ? kHttpStateCr : kHttpStateLf1;
break;
} else if ((c < 0x20 && c != '\t') || (0x7F <= c && c < 0xA0)) {
return ebadmsg();
}
if (++r->i == n)
break;
c = p[r->i] & 0xff;
}
break;
case kHttpStateLf2:
if (c == '\n') {
return ++r->i;
}
return ebadmsg();
default:
__builtin_unreachable();
}
}
if (r->i < LIMIT) {
return 0;
} else {
return ebadmsg();
}
}