gecko/netwerk/protocol/http/nsHttpResponseHead.cpp

651 lines
19 KiB
C++

/* -*- Mode: C++; tab-width: 4; indent-tabs-mode: nil; c-basic-offset: 4 -*- */
/* vim:set ts=4 sw=4 sts=4 et cin: */
/* This Source Code Form is subject to the terms of the Mozilla Public
* License, v. 2.0. If a copy of the MPL was not distributed with this
* file, You can obtain one at http://mozilla.org/MPL/2.0/. */
#include <stdlib.h>
#include "nsHttpResponseHead.h"
#include "nsPrintfCString.h"
#include "prprf.h"
#include "prtime.h"
#include "nsCRT.h"
//-----------------------------------------------------------------------------
// nsHttpResponseHead <public>
//-----------------------------------------------------------------------------
nsresult
nsHttpResponseHead::SetHeader(nsHttpAtom hdr,
const nsACString &val,
bool merge)
{
nsresult rv = mHeaders.SetHeader(hdr, val, merge);
if (NS_FAILED(rv)) return rv;
// respond to changes in these headers. we need to reparse the entire
// header since the change may have merged in additional values.
if (hdr == nsHttp::Cache_Control)
ParseCacheControl(mHeaders.PeekHeader(hdr));
else if (hdr == nsHttp::Pragma)
ParsePragma(mHeaders.PeekHeader(hdr));
return NS_OK;
}
void
nsHttpResponseHead::SetContentLength(PRInt64 len)
{
mContentLength = len;
if (!LL_GE_ZERO(len)) // < 0
mHeaders.ClearHeader(nsHttp::Content_Length);
else
mHeaders.SetHeader(nsHttp::Content_Length, nsPrintfCString("%lld", len));
}
void
nsHttpResponseHead::Flatten(nsACString &buf, bool pruneTransients)
{
if (mVersion == NS_HTTP_VERSION_0_9)
return;
buf.AppendLiteral("HTTP/");
if (mVersion == NS_HTTP_VERSION_1_1)
buf.AppendLiteral("1.1 ");
else
buf.AppendLiteral("1.0 ");
buf.Append(nsPrintfCString("%u", PRUintn(mStatus)) +
NS_LITERAL_CSTRING(" ") +
mStatusText +
NS_LITERAL_CSTRING("\r\n"));
if (!pruneTransients) {
mHeaders.Flatten(buf, false);
return;
}
// otherwise, we need to iterate over the headers and only flatten
// those that are appropriate.
PRUint32 i, count = mHeaders.Count();
for (i=0; i<count; ++i) {
nsHttpAtom header;
const char *value = mHeaders.PeekHeaderAt(i, header);
if (!value || header == nsHttp::Connection
|| header == nsHttp::Proxy_Connection
|| header == nsHttp::Keep_Alive
|| header == nsHttp::WWW_Authenticate
|| header == nsHttp::Proxy_Authenticate
|| header == nsHttp::Trailer
|| header == nsHttp::Transfer_Encoding
|| header == nsHttp::Upgrade
// XXX this will cause problems when we start honoring
// Cache-Control: no-cache="set-cookie", what to do?
|| header == nsHttp::Set_Cookie)
continue;
// otherwise, write out the "header: value\r\n" line
buf.Append(nsDependentCString(header.get()) +
NS_LITERAL_CSTRING(": ") +
nsDependentCString(value) +
NS_LITERAL_CSTRING("\r\n"));
}
}
nsresult
nsHttpResponseHead::Parse(char *block)
{
LOG(("nsHttpResponseHead::Parse [this=%x]\n", this));
// this command works on a buffer as prepared by Flatten, as such it is
// not very forgiving ;-)
char *p = PL_strstr(block, "\r\n");
if (!p)
return NS_ERROR_UNEXPECTED;
*p = 0;
ParseStatusLine(block);
do {
block = p + 2;
if (*block == 0)
break;
p = PL_strstr(block, "\r\n");
if (!p)
return NS_ERROR_UNEXPECTED;
*p = 0;
ParseHeaderLine(block);
} while (1);
return NS_OK;
}
void
nsHttpResponseHead::ParseStatusLine(const char *line)
{
//
// Parse Status-Line:: HTTP-Version SP Status-Code SP Reason-Phrase CRLF
//
// HTTP-Version
ParseVersion(line);
if ((mVersion == NS_HTTP_VERSION_0_9) || !(line = PL_strchr(line, ' '))) {
mStatus = 200;
mStatusText.AssignLiteral("OK");
}
else {
// Status-Code
mStatus = (PRUint16) atoi(++line);
if (mStatus == 0) {
LOG(("mal-formed response status; assuming status = 200\n"));
mStatus = 200;
}
// Reason-Phrase is whatever is remaining of the line
if (!(line = PL_strchr(line, ' '))) {
LOG(("mal-formed response status line; assuming statusText = 'OK'\n"));
mStatusText.AssignLiteral("OK");
}
else
mStatusText = nsDependentCString(++line);
}
LOG(("Have status line [version=%u status=%u statusText=%s]\n",
PRUintn(mVersion), PRUintn(mStatus), mStatusText.get()));
}
nsresult
nsHttpResponseHead::ParseHeaderLine(const char *line)
{
nsHttpAtom hdr = {0};
char *val;
nsresult rv;
rv = mHeaders.ParseHeaderLine(line, &hdr, &val);
if (NS_FAILED(rv))
return rv;
// leading and trailing LWS has been removed from |val|
// handle some special case headers...
if (hdr == nsHttp::Content_Length) {
PRInt64 len;
const char *ignored;
// permit only a single value here.
if (nsHttp::ParseInt64(val, &ignored, &len)) {
mContentLength = len;
}
else {
// If this is a negative content length then just ignore it
LOG(("invalid content-length! %s\n", val));
}
}
else if (hdr == nsHttp::Content_Type) {
LOG(("ParseContentType [type=%s]\n", val));
bool dummy;
net_ParseContentType(nsDependentCString(val),
mContentType, mContentCharset, &dummy);
}
else if (hdr == nsHttp::Cache_Control)
ParseCacheControl(val);
else if (hdr == nsHttp::Pragma)
ParsePragma(val);
return NS_OK;
}
// From section 13.2.3 of RFC2616, we compute the current age of a cached
// response as follows:
//
// currentAge = max(max(0, responseTime - dateValue), ageValue)
// + now - requestTime
//
// where responseTime == now
//
// This is typically a very small number.
//
nsresult
nsHttpResponseHead::ComputeCurrentAge(PRUint32 now,
PRUint32 requestTime,
PRUint32 *result) const
{
PRUint32 dateValue;
PRUint32 ageValue;
*result = 0;
if (NS_FAILED(GetDateValue(&dateValue))) {
LOG(("nsHttpResponseHead::ComputeCurrentAge [this=%x] "
"Date response header not set!\n", this));
// Assume we have a fast connection and that our clock
// is in sync with the server.
dateValue = now;
}
// Compute apparent age
if (now > dateValue)
*result = now - dateValue;
// Compute corrected received age
if (NS_SUCCEEDED(GetAgeValue(&ageValue)))
*result = NS_MAX(*result, ageValue);
NS_ASSERTION(now >= requestTime, "bogus request time");
// Compute current age
*result += (now - requestTime);
return NS_OK;
}
// From section 13.2.4 of RFC2616, we compute the freshness lifetime of a cached
// response as follows:
//
// freshnessLifetime = max_age_value
// <or>
// freshnessLifetime = expires_value - date_value
// <or>
// freshnessLifetime = (date_value - last_modified_value) * 0.10
// <or>
// freshnessLifetime = 0
//
nsresult
nsHttpResponseHead::ComputeFreshnessLifetime(PRUint32 *result) const
{
*result = 0;
// Try HTTP/1.1 style max-age directive...
if (NS_SUCCEEDED(GetMaxAgeValue(result)))
return NS_OK;
*result = 0;
PRUint32 date = 0, date2 = 0;
if (NS_FAILED(GetDateValue(&date)))
date = NowInSeconds(); // synthesize a date header if none exists
// Try HTTP/1.0 style expires header...
if (NS_SUCCEEDED(GetExpiresValue(&date2))) {
if (date2 > date)
*result = date2 - date;
// the Expires header can specify a date in the past.
return NS_OK;
}
// Fallback on heuristic using last modified header...
if (NS_SUCCEEDED(GetLastModifiedValue(&date2))) {
LOG(("using last-modified to determine freshness-lifetime\n"));
LOG(("last-modified = %u, date = %u\n", date2, date));
if (date2 <= date) {
// this only makes sense if last-modified is actually in the past
*result = (date - date2) / 10;
return NS_OK;
}
}
// These responses can be cached indefinitely.
if ((mStatus == 300) || (mStatus == 301)) {
*result = PRUint32(-1);
return NS_OK;
}
LOG(("nsHttpResponseHead::ComputeFreshnessLifetime [this = %x] "
"Insufficient information to compute a non-zero freshness "
"lifetime!\n", this));
return NS_OK;
}
bool
nsHttpResponseHead::MustValidate() const
{
LOG(("nsHttpResponseHead::MustValidate ??\n"));
// Some response codes are cacheable, but the rest are not. This switch
// should stay in sync with the list in nsHttpChannel::ProcessResponse
switch (mStatus) {
// Success codes
case 200:
case 203:
case 206:
// Cacheable redirects
case 300:
case 301:
case 302:
case 304:
case 307:
case 308:
break;
// Uncacheable redirects
case 303:
case 305:
// Other known errors
case 401:
case 407:
case 412:
case 416:
default: // revalidate unknown error pages
LOG(("Must validate since response is an uncacheable error page\n"));
return true;
}
// The no-cache response header indicates that we must validate this
// cached response before reusing.
if (NoCache()) {
LOG(("Must validate since response contains 'no-cache' header\n"));
return true;
}
// Likewise, if the response is no-store, then we must validate this
// cached response before reusing. NOTE: it may seem odd that a no-store
// response may be cached, but indeed all responses are cached in order
// to support File->SaveAs, View->PageSource, and other browser features.
if (NoStore()) {
LOG(("Must validate since response contains 'no-store' header\n"));
return true;
}
// Compare the Expires header to the Date header. If the server sent an
// Expires header with a timestamp in the past, then we must validate this
// cached response before reusing.
if (ExpiresInPast()) {
LOG(("Must validate since Expires < Date\n"));
return true;
}
LOG(("no mandatory validation requirement\n"));
return false;
}
bool
nsHttpResponseHead::MustValidateIfExpired() const
{
// according to RFC2616, section 14.9.4:
//
// When the must-revalidate directive is present in a response received by a
// cache, that cache MUST NOT use the entry after it becomes stale to respond to
// a subsequent request without first revalidating it with the origin server.
//
return HasHeaderValue(nsHttp::Cache_Control, "must-revalidate");
}
bool
nsHttpResponseHead::IsResumable() const
{
// even though some HTTP/1.0 servers may support byte range requests, we're not
// going to bother with them, since those servers wouldn't understand If-Range.
// Also, while in theory it may be possible to resume when the status code
// is not 200, it is unlikely to be worth the trouble, especially for
// non-2xx responses.
return mStatus == 200 &&
mVersion >= NS_HTTP_VERSION_1_1 &&
PeekHeader(nsHttp::Content_Length) &&
(PeekHeader(nsHttp::ETag) || PeekHeader(nsHttp::Last_Modified)) &&
HasHeaderValue(nsHttp::Accept_Ranges, "bytes");
}
bool
nsHttpResponseHead::ExpiresInPast() const
{
PRUint32 maxAgeVal, expiresVal, dateVal;
// Bug #203271. Ensure max-age directive takes precedence over Expires
if (NS_SUCCEEDED(GetMaxAgeValue(&maxAgeVal))) {
return false;
}
return NS_SUCCEEDED(GetExpiresValue(&expiresVal)) &&
NS_SUCCEEDED(GetDateValue(&dateVal)) &&
expiresVal < dateVal;
}
nsresult
nsHttpResponseHead::UpdateHeaders(const nsHttpHeaderArray &headers)
{
LOG(("nsHttpResponseHead::UpdateHeaders [this=%x]\n", this));
PRUint32 i, count = headers.Count();
for (i=0; i<count; ++i) {
nsHttpAtom header;
const char *val = headers.PeekHeaderAt(i, header);
if (!val) {
continue;
}
// Ignore any hop-by-hop headers...
if (header == nsHttp::Connection ||
header == nsHttp::Proxy_Connection ||
header == nsHttp::Keep_Alive ||
header == nsHttp::Proxy_Authenticate ||
header == nsHttp::Proxy_Authorization || // not a response header!
header == nsHttp::TE ||
header == nsHttp::Trailer ||
header == nsHttp::Transfer_Encoding ||
header == nsHttp::Upgrade ||
// Ignore any non-modifiable headers...
header == nsHttp::Content_Location ||
header == nsHttp::Content_MD5 ||
header == nsHttp::ETag ||
// Assume Cache-Control: "no-transform"
header == nsHttp::Content_Encoding ||
header == nsHttp::Content_Range ||
header == nsHttp::Content_Type ||
// Ignore wacky headers too...
// this one is for MS servers that send "Content-Length: 0"
// on 304 responses
header == nsHttp::Content_Length) {
LOG(("ignoring response header [%s: %s]\n", header.get(), val));
}
else {
LOG(("new response header [%s: %s]\n", header.get(), val));
// overwrite the current header value with the new value...
SetHeader(header, nsDependentCString(val));
}
}
return NS_OK;
}
void
nsHttpResponseHead::Reset()
{
LOG(("nsHttpResponseHead::Reset\n"));
ClearHeaders();
mVersion = NS_HTTP_VERSION_1_1;
mStatus = 200;
mContentLength = LL_MAXUINT;
mCacheControlNoStore = false;
mCacheControlNoCache = false;
mPragmaNoCache = false;
mStatusText.Truncate();
mContentType.Truncate();
mContentCharset.Truncate();
}
nsresult
nsHttpResponseHead::ParseDateHeader(nsHttpAtom header, PRUint32 *result) const
{
const char *val = PeekHeader(header);
if (!val)
return NS_ERROR_NOT_AVAILABLE;
PRTime time;
PRStatus st = PR_ParseTimeString(val, true, &time);
if (st != PR_SUCCESS)
return NS_ERROR_NOT_AVAILABLE;
*result = PRTimeToSeconds(time);
return NS_OK;
}
nsresult
nsHttpResponseHead::GetAgeValue(PRUint32 *result) const
{
const char *val = PeekHeader(nsHttp::Age);
if (!val)
return NS_ERROR_NOT_AVAILABLE;
*result = (PRUint32) atoi(val);
return NS_OK;
}
// Return the value of the (HTTP 1.1) max-age directive, which itself is a
// component of the Cache-Control response header
nsresult
nsHttpResponseHead::GetMaxAgeValue(PRUint32 *result) const
{
const char *val = PeekHeader(nsHttp::Cache_Control);
if (!val)
return NS_ERROR_NOT_AVAILABLE;
const char *p = PL_strcasestr(val, "max-age=");
if (!p)
return NS_ERROR_NOT_AVAILABLE;
int maxAgeValue = atoi(p + 8);
if (maxAgeValue < 0)
maxAgeValue = 0;
*result = PRUint32(maxAgeValue);
return NS_OK;
}
nsresult
nsHttpResponseHead::GetExpiresValue(PRUint32 *result) const
{
const char *val = PeekHeader(nsHttp::Expires);
if (!val)
return NS_ERROR_NOT_AVAILABLE;
PRTime time;
PRStatus st = PR_ParseTimeString(val, true, &time);
if (st != PR_SUCCESS) {
// parsing failed... RFC 2616 section 14.21 says we should treat this
// as an expiration time in the past.
*result = 0;
return NS_OK;
}
if (LL_CMP(time, <, LL_Zero()))
*result = 0;
else
*result = PRTimeToSeconds(time);
return NS_OK;
}
PRInt64
nsHttpResponseHead::TotalEntitySize() const
{
const char* contentRange = PeekHeader(nsHttp::Content_Range);
if (!contentRange)
return ContentLength();
// Total length is after a slash
const char* slash = strrchr(contentRange, '/');
if (!slash)
return -1; // No idea what the length is
slash++;
if (*slash == '*') // Server doesn't know the length
return -1;
PRInt64 size;
if (!nsHttp::ParseInt64(slash, &size))
size = LL_MAXUINT;
return size;
}
//-----------------------------------------------------------------------------
// nsHttpResponseHead <private>
//-----------------------------------------------------------------------------
void
nsHttpResponseHead::ParseVersion(const char *str)
{
// Parse HTTP-Version:: "HTTP" "/" 1*DIGIT "." 1*DIGIT
LOG(("nsHttpResponseHead::ParseVersion [version=%s]\n", str));
// make sure we have HTTP at the beginning
if (PL_strncasecmp(str, "HTTP", 4) != 0) {
LOG(("looks like a HTTP/0.9 response\n"));
mVersion = NS_HTTP_VERSION_0_9;
return;
}
str += 4;
if (*str != '/') {
LOG(("server did not send a version number; assuming HTTP/1.0\n"));
// NCSA/1.5.2 has a bug in which it fails to send a version number
// if the request version is HTTP/1.1, so we fall back on HTTP/1.0
mVersion = NS_HTTP_VERSION_1_0;
return;
}
char *p = PL_strchr(str, '.');
if (p == nsnull) {
LOG(("mal-formed server version; assuming HTTP/1.0\n"));
mVersion = NS_HTTP_VERSION_1_0;
return;
}
++p; // let b point to the minor version
int major = atoi(str + 1);
int minor = atoi(p);
if ((major > 1) || ((major == 1) && (minor >= 1)))
// at least HTTP/1.1
mVersion = NS_HTTP_VERSION_1_1;
else
// treat anything else as version 1.0
mVersion = NS_HTTP_VERSION_1_0;
}
void
nsHttpResponseHead::ParseCacheControl(const char *val)
{
if (!(val && *val)) {
// clear flags
mCacheControlNoCache = false;
mCacheControlNoStore = false;
return;
}
// search header value for occurrence(s) of "no-cache" but ignore
// occurrence(s) of "no-cache=blah"
if (nsHttp::FindToken(val, "no-cache", HTTP_HEADER_VALUE_SEPS))
mCacheControlNoCache = true;
// search header value for occurrence of "no-store"
if (nsHttp::FindToken(val, "no-store", HTTP_HEADER_VALUE_SEPS))
mCacheControlNoStore = true;
}
void
nsHttpResponseHead::ParsePragma(const char *val)
{
LOG(("nsHttpResponseHead::ParsePragma [val=%s]\n", val));
if (!(val && *val)) {
// clear no-cache flag
mPragmaNoCache = false;
return;
}
// Although 'Pragma: no-cache' is not a standard HTTP response header (it's
// a request header), caching is inhibited when this header is present so
// as to match existing Navigator behavior.
if (nsHttp::FindToken(val, "no-cache", HTTP_HEADER_VALUE_SEPS))
mPragmaNoCache = true;
}