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http: try to avoid lowercasing incoming headers
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PR-URL: #10558
Reviewed-By: Matteo Collina <[email protected]>
Reviewed-By: James M Snell <[email protected]>
Reviewed-By: Evan Lucas <[email protected]>
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@mscdex
mscdex committed Jan 11, 2017
1 parent c77ed32 commit 73d9445
Showing 1 changed file with 161 additions and 45 deletions.
206 changes: 161 additions & 45 deletions lib/_http_incoming.js
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Original file line number Diff line number Diff line change
Expand Up @@ -119,6 +119,146 @@ function _addHeaderLines(headers, n) {
}


// This function is used to help avoid the lowercasing of a field name if it
// matches a 'traditional cased' version of a field name. It then returns the
// lowercased name to both avoid calling toLowerCase() a second time and to
// indicate whether the field was a 'no duplicates' field. If a field is not a
// 'no duplicates' field, a `0` byte is prepended as a flag. The one exception
// to this is the Set-Cookie header which is indicated by a `1` byte flag, since
// it is an 'array' field and thus is treated differently in _addHeaderLines().
// TODO: perhaps http_parser could be returning both raw and lowercased versions
// of known header names to avoid us having to call toLowerCase() for those
// headers.
/* eslint-disable max-len */
// 'array' header list is taken from:
// https://mxr.mozilla.org/mozilla/source/netwerk/protocol/http/src/nsHttpHeaderArray.cpp
/* eslint-enable max-len */
function matchKnownFields(field) {
var low = false;
while (true) {
switch (field) {
case 'Content-Type':
case 'content-type':
return 'content-type';
case 'Content-Length':
case 'content-length':
return 'content-length';
case 'User-Agent':
case 'user-agent':
return 'user-agent';
case 'Referer':
case 'referer':
return 'referer';
case 'Host':
case 'host':
return 'host';
case 'Authorization':
case 'authorization':
return 'authorization';
case 'Proxy-Authorization':
case 'proxy-authorization':
return 'proxy-authorization';
case 'If-Modified-Since':
case 'if-modified-since':
return 'if-modified-since';
case 'If-Unmodified-Since':
case 'if-unmodified-since':
return 'if-unmodified-since';
case 'From':
case 'from':
return 'from';
case 'Location':
case 'location':
return 'location';
case 'Max-Forwards':
case 'max-forwards':
return 'max-forwards';
case 'Retry-After':
case 'retry-after':
return 'retry-after';
case 'ETag':
case 'etag':
return 'etag';
case 'Last-Modified':
case 'last-modified':
return 'last-modified';
case 'Server':
case 'server':
return 'server';
case 'Age':
case 'age':
return 'age';
case 'Expires':
case 'expires':
return 'expires';
case 'Set-Cookie':
case 'set-cookie':
return '\u0001';
// The fields below are not used in _addHeaderLine(), but they are common
// headers where we can avoid toLowerCase() if the mixed or lower case
// versions match the first time through.
case 'Transfer-Encoding':
case 'transfer-encoding':
return '\u0000transfer-encoding';
case 'Date':
case 'date':
return '\u0000date';
case 'Connection':
case 'connection':
return '\u0000connection';
case 'Cache-Control':
case 'cache-control':
return '\u0000cache-control';
case 'Vary':
case 'vary':
return '\u0000vary';
case 'Content-Encoding':
case 'content-encoding':
return '\u0000content-encoding';
case 'Cookie':
case 'cookie':
return '\u0000cookie';
case 'Origin':
case 'origin':
return '\u0000origin';
case 'Upgrade':
case 'upgrade':
return '\u0000upgrade';
case 'Expect':
case 'expect':
return '\u0000expect';
case 'If-Match':
case 'if-match':
return '\u0000if-match';
case 'If-None-Match':
case 'if-none-match':
return '\u0000if-none-match';
case 'Accept':
case 'accept':
return '\u0000accept';
case 'Accept-Encoding':
case 'accept-encoding':
return '\u0000accept-encoding';
case 'Accept-Language':
case 'accept-language':
return '\u0000accept-language';
case 'X-Forwarded-For':
case 'x-forwarded-for':
return '\u0000x-forwarded-for';
case 'X-Forwarded-Host':
case 'x-forwarded-host':
return '\u0000x-forwarded-host';
case 'X-Forwarded-Proto':
case 'x-forwarded-proto':
return '\u0000x-forwarded-proto';
default:
if (low)
return '\u0000' + field;
field = field.toLowerCase();
low = true;
}
}
}
// Add the given (field, value) pair to the message
//
// Per RFC2616, section 4.2 it is acceptable to join multiple instances of the
Expand All @@ -128,51 +268,27 @@ function _addHeaderLines(headers, n) {
// always joined.
IncomingMessage.prototype._addHeaderLine = _addHeaderLine;
function _addHeaderLine(field, value, dest) {
field = field.toLowerCase();
switch (field) {
// Array headers:
case 'set-cookie':
if (dest[field] !== undefined) {
dest[field].push(value);
} else {
dest[field] = [value];
}
break;

/* eslint-disable max-len */
// list is taken from:
// https://mxr.mozilla.org/mozilla/source/netwerk/protocol/http/src/nsHttpHeaderArray.cpp
/* eslint-enable max-len */
case 'content-type':
case 'content-length':
case 'user-agent':
case 'referer':
case 'host':
case 'authorization':
case 'proxy-authorization':
case 'if-modified-since':
case 'if-unmodified-since':
case 'from':
case 'location':
case 'max-forwards':
case 'retry-after':
case 'etag':
case 'last-modified':
case 'server':
case 'age':
case 'expires':
// drop duplicates
if (dest[field] === undefined)
dest[field] = value;
break;

default:
// make comma-separated list
if (typeof dest[field] === 'string') {
dest[field] += ', ' + value;
} else {
dest[field] = value;
}
field = matchKnownFields(field);
var flag = field.charCodeAt(0);
if (flag === 0) {
field = field.slice(1);
// Make comma-separated list
if (typeof dest[field] === 'string') {
dest[field] += ', ' + value;
} else {
dest[field] = value;
}
} else if (flag === 1) {
// Array header -- only Set-Cookie at the moment
if (dest['set-cookie'] !== undefined) {
dest['set-cookie'].push(value);
} else {
dest['set-cookie'] = [value];
}
} else {
// Drop duplicates
if (dest[field] === undefined)
dest[field] = value;
}
}

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