blob: 3f816b9b447e3d0556cfa8c582cd149992dfebf3 [file] [log] [blame]
// Copyright (c) 2012 The Chromium Authors. All rights reserved.
// Use of this source code is governed by a BSD-style license that can be
// found in the LICENSE file.
//
#include "chrome_frame/html_utils.h"
#include <atlbase.h>
#include <urlmon.h>
#include "base/string_util.h"
#include "base/stringprintf.h"
#include "base/strings/string_tokenizer.h"
#include "chrome/common/chrome_version_info.h"
#include "chrome_frame/utils.h"
#include "net/base/net_util.h"
#include "webkit/common/user_agent/user_agent_util.h"
const wchar_t kQuotes[] = L"\"'";
const char kXFrameOptionsHeader[] = "X-Frame-Options";
const char kXFrameOptionsValueAllowAll[] = "allowall";
HTMLScanner::StringRange::StringRange() {
}
HTMLScanner::StringRange::StringRange(StrPos start, StrPos end)
: start_(start), end_(end) {
}
bool HTMLScanner::StringRange::LowerCaseEqualsASCII(const char* other) const {
return ::LowerCaseEqualsASCII(start_, end_, other);
}
bool HTMLScanner::StringRange::Equals(const wchar_t* other) const {
int ret = wcsncmp(&start_[0], other, end_ - start_);
if (ret == 0)
ret = (other[end_ - start_] == L'\0') ? 0 : -1;
return ret == 0;
}
std::wstring HTMLScanner::StringRange::Copy() const {
return std::wstring(start_, end_);
}
bool HTMLScanner::StringRange::GetTagName(std::wstring* tag_name) const {
if (*start_ != L'<') {
LOG(ERROR) << "Badly formatted tag found";
return false;
}
StrPos name_start = start_;
name_start++;
while (name_start < end_ && IsWhitespace(*name_start))
name_start++;
if (name_start >= end_) {
// We seem to have a degenerate tag (i.e. < >). Return false here.
return false;
}
StrPos name_end = name_start + 1;
while (name_end < end_ && !IsWhitespace(*name_end))
name_end++;
if (name_end > end_) {
// This looks like an improperly formatted tab ('<foo'). Return false here.
return false;
}
tag_name->assign(name_start, name_end);
return true;
}
bool HTMLScanner::StringRange::GetTagAttribute(const wchar_t* attribute_name,
StringRange* attribute_value) const {
if (NULL == attribute_name || NULL == attribute_value) {
NOTREACHED();
return false;
}
// Use this so we can use the convenience method LowerCaseEqualsASCII()
// from string_util.h.
std::string search_name_ascii(WideToASCII(attribute_name));
base::WStringTokenizer tokenizer(start_, end_, L" =/");
tokenizer.set_options(base::WStringTokenizer::RETURN_DELIMS);
// Set up the quote chars so that we get quoted attribute values as single
// tokens.
tokenizer.set_quote_chars(L"\"'");
const bool PARSE_STATE_NAME = true;
const bool PARSE_STATE_VALUE = false;
bool parse_state = PARSE_STATE_NAME;
// Used to skip the first token, which is the tag name.
bool first_token_skipped = false;
// This is set during a loop iteration in which an '=' sign was spotted.
// It is used to filter out degenerate tags such as:
// <meta foo==bar>
bool last_token_was_delim = false;
// Set this if the attribute name has been found that we might then
// pick up the value in the next loop iteration.
bool attribute_name_found = false;
while (tokenizer.GetNext()) {
// If we have a whitespace delimiter, just keep going. Cases of this should
// be reduced by the CollapseWhitespace call. If we have an '=' character,
// we update our state and reiterate.
if (tokenizer.token_is_delim()) {
if (*tokenizer.token_begin() == L'=') {
if (last_token_was_delim) {
// Looks like we have a badly formed tag, just stop parsing now.
return false;
}
parse_state = !parse_state;
last_token_was_delim = true;
}
continue;
}
last_token_was_delim = false;
// The first non-delimiter token is the tag name, which we don't want.
if (!first_token_skipped) {
first_token_skipped = true;
continue;
}
if (PARSE_STATE_NAME == parse_state) {
// We have a tag name, check to see if it matches our target name:
if (::LowerCaseEqualsASCII(tokenizer.token_begin(), tokenizer.token_end(),
search_name_ascii.c_str())) {
attribute_name_found = true;
continue;
}
} else if (PARSE_STATE_VALUE == parse_state && attribute_name_found) {
attribute_value->start_ = tokenizer.token_begin();
attribute_value->end_ = tokenizer.token_end();
// Unquote the attribute value if need be.
attribute_value->UnQuote();
return true;
} else if (PARSE_STATE_VALUE == parse_state) {
// If we haven't found the attribute name we want yet, ignore this token
// and go back to looking for our name.
parse_state = PARSE_STATE_NAME;
}
}
return false;
}
bool HTMLScanner::StringRange::UnQuote() {
if (start_ + 2 > end_) {
// String's too short to be quoted, bail.
return false;
}
if ((*start_ == L'\'' && *(end_ - 1) == L'\'') ||
(*start_ == L'"' && *(end_ - 1) == L'"')) {
start_ = start_ + 1;
end_ = end_ - 1;
return true;
}
return false;
}
HTMLScanner::HTMLScanner(const wchar_t* html_string)
: html_string_(CollapseWhitespace(html_string, true)),
quotes_(kQuotes) {
}
void HTMLScanner::GetTagsByName(const wchar_t* name, StringRangeList* tag_list,
const wchar_t* stop_tag) {
DCHECK(NULL != name);
DCHECK(NULL != tag_list);
DCHECK(NULL != stop_tag);
StringRange remaining_html(html_string_.begin(), html_string_.end());
std::wstring search_name(name);
TrimWhitespace(search_name, TRIM_ALL, &search_name);
// Use this so we can use the convenience method LowerCaseEqualsASCII()
// from string_util.h.
std::string search_name_ascii(WideToASCII(search_name));
std::string stop_tag_ascii(WideToASCII(stop_tag));
StringRange current_tag;
std::wstring current_name;
while (NextTag(&remaining_html, &current_tag)) {
if (current_tag.GetTagName(&current_name)) {
if (LowerCaseEqualsASCII(current_name, search_name_ascii.c_str())) {
tag_list->push_back(current_tag);
} else if (LowerCaseEqualsASCII(current_name, stop_tag_ascii.c_str())) {
// We hit the stop tag so it's time to go home.
break;
}
}
}
}
struct ScanState {
bool in_quote;
bool in_escape;
wchar_t quote_char;
ScanState() : in_quote(false), in_escape(false) {}
};
bool HTMLScanner::IsQuote(wchar_t c) {
return quotes_.find(c) != std::wstring::npos;
}
bool HTMLScanner::IsHTMLCommentClose(const StringRange* html_string,
StrPos pos) {
if (pos < html_string->end_ && pos > html_string->start_ + 2 &&
*pos == L'>') {
return *(pos-1) == L'-' && *(pos-2) == L'-';
}
return false;
}
bool HTMLScanner::IsIEConditionalCommentClose(const StringRange* html_string,
StrPos pos) {
if (pos < html_string->end_ && pos > html_string->start_ + 2 &&
*pos == L'>') {
return *(pos-1) == L']';
}
return false;
}
bool HTMLScanner::NextTag(StringRange* html_string, StringRange* tag) {
DCHECK(NULL != html_string);
DCHECK(NULL != tag);
tag->start_ = html_string->start_;
while (tag->start_ < html_string->end_ && *tag->start_ != L'<') {
tag->start_++;
}
// we went past the end of the string.
if (tag->start_ >= html_string->end_) {
return false;
}
tag->end_ = tag->start_ + 1;
// Get the tag name to see if we are in an HTML comment. If we are, then
// don't consider quotes. This should work for example:
// <!-- foo ' --> <meta foo='bar'>
std::wstring tag_name;
StringRange start_range(tag->start_, html_string->end_);
start_range.GetTagName(&tag_name);
if (StartsWith(tag_name, L"!--[if", true)) {
// This looks like the beginning of an IE conditional comment, scan until
// we hit the end which always looks like ']>'. For now we disregard the
// contents of the condition, and always assume true.
// TODO(robertshield): Optionally support the grammar defined by
// http://msdn.microsoft.com/en-us/library/ms537512(VS.85).aspx#syntax.
while (tag->end_ < html_string->end_ &&
!IsIEConditionalCommentClose(html_string, tag->end_)) {
tag->end_++;
}
} else if (StartsWith(tag_name, L"!--", true)) {
// We're inside a comment tag which ends in '-->'. Keep going until we
// reach the end.
while (tag->end_ < html_string->end_ &&
!IsHTMLCommentClose(html_string, tag->end_)) {
tag->end_++;
}
} else if (StartsWith(tag_name, L"![endif", true)) {
// We're inside the closing tag of an IE conditional comment which ends in
// either '-->' of ']>'. Keep going until we reach the end.
while (tag->end_ < html_string->end_ &&
!IsIEConditionalCommentClose(html_string, tag->end_) &&
!IsHTMLCommentClose(html_string, tag->end_)) {
tag->end_++;
}
} else {
// Properly handle quoted strings within non-comment tags by maintaining
// some state while scanning. Specifically, we have to maintain state on
// whether we are inside a string, what the string terminating character
// will be and whether we are inside an escape sequence.
ScanState state;
while (tag->end_ < html_string->end_) {
if (state.in_quote) {
if (state.in_escape) {
state.in_escape = false;
} else if (*tag->end_ == '\\') {
state.in_escape = true;
} else if (*tag->end_ == state.quote_char) {
state.in_quote = false;
}
} else {
state.in_quote = IsQuote(state.quote_char = *tag->end_);
}
if (!state.in_quote && *tag->end_ == L'>') {
break;
}
tag->end_++;
}
}
// We hit the end_ but found no matching tag closure. Consider this an
// incomplete tag and do not report it.
if (tag->end_ >= html_string->end_)
return false;
// Modify html_string to point to just beyond the end_ of the current tag.
html_string->start_ = tag->end_ + 1;
return true;
}
namespace http_utils {
const char kChromeFrameUserAgent[] = "chromeframe";
static char g_cf_user_agent[100] = {0};
static char g_chrome_user_agent[255] = {0};
const char* GetChromeFrameUserAgent() {
if (!g_cf_user_agent[0]) {
_pAtlModule->m_csStaticDataInitAndTypeInfo.Lock();
if (!g_cf_user_agent[0]) {
uint32 high_version = 0, low_version = 0;
GetModuleVersion(reinterpret_cast<HMODULE>(&__ImageBase), &high_version,
&low_version);
wsprintfA(g_cf_user_agent, "%s/%i.%i.%i.%i", kChromeFrameUserAgent,
HIWORD(high_version), LOWORD(high_version),
HIWORD(low_version), LOWORD(low_version));
}
_pAtlModule->m_csStaticDataInitAndTypeInfo.Unlock();
}
return g_cf_user_agent;
}
std::string AddChromeFrameToUserAgentValue(const std::string& value) {
if (value.empty()) {
return value;
}
if (value.find(kChromeFrameUserAgent) != std::string::npos) {
// Our user agent has already been added.
return value;
}
std::string ret(value);
size_t insert_position = ret.find(')');
if (insert_position != std::string::npos) {
if (insert_position > 1 && isalnum(ret[insert_position - 1]))
ret.insert(insert_position++, ";");
ret.insert(insert_position++, " ");
ret.insert(insert_position, GetChromeFrameUserAgent());
} else {
ret += " ";
ret += GetChromeFrameUserAgent();
}
return ret;
}
std::string RemoveChromeFrameFromUserAgentValue(const std::string& value) {
size_t cf_start = value.find(kChromeFrameUserAgent);
if (cf_start == std::string::npos) {
// The user agent is not present.
return value;
}
size_t offset = 0;
// If we prepended a '; ' or a ' ' then remove that in the output.
if (cf_start > 1 && value[cf_start - 1] == ' ')
++offset;
if (cf_start > 3 &&
value[cf_start - 2] == ';' &&
isalnum(value[cf_start - 3])) {
++offset;
}
std::string ret(value, 0, std::max(cf_start - offset, 0U));
cf_start += strlen(kChromeFrameUserAgent);
while (cf_start < value.length() &&
((value[cf_start] >= '0' && value[cf_start] <= '9') ||
value[cf_start] == '.' ||
value[cf_start] == '/')) {
++cf_start;
}
if (cf_start < value.length())
ret.append(value, cf_start, std::string::npos);
return ret;
}
std::string GetDefaultUserAgentHeaderWithCFTag() {
std::string ua(GetDefaultUserAgent());
return "User-Agent: " + AddChromeFrameToUserAgentValue(ua);
}
const char* GetChromeUserAgent() {
if (!g_chrome_user_agent[0]) {
_pAtlModule->m_csStaticDataInitAndTypeInfo.Lock();
if (!g_chrome_user_agent[0]) {
std::string ua;
chrome::VersionInfo version_info;
std::string product("Chrome/");
product += version_info.is_valid() ? version_info.Version()
: "0.0.0.0";
ua = webkit_glue::BuildUserAgentFromProduct(product);
DCHECK(ua.length() < arraysize(g_chrome_user_agent));
lstrcpynA(g_chrome_user_agent, ua.c_str(),
arraysize(g_chrome_user_agent) - 1);
}
_pAtlModule->m_csStaticDataInitAndTypeInfo.Unlock();
}
return g_chrome_user_agent;
}
std::string GetDefaultUserAgent() {
std::string ret;
DWORD size = MAX_PATH;
HRESULT hr = E_OUTOFMEMORY;
for (int retries = 1; hr == E_OUTOFMEMORY && retries <= 10; ++retries) {
hr = ::ObtainUserAgentString(0, WriteInto(&ret, size + 1), &size);
if (hr == E_OUTOFMEMORY) {
size = MAX_PATH * retries;
} else if (SUCCEEDED(hr)) {
// Truncate the extra allocation.
DCHECK_GT(size, 0U);
ret.resize(size - 1);
}
}
if (FAILED(hr)) {
NOTREACHED() << base::StringPrintf("ObtainUserAgentString==0x%08X", hr);
return std::string();
}
return ret;
}
bool HasFrameBustingHeader(const std::string& http_headers) {
// NOTE: We cannot use net::GetSpecificHeader() here since when there are
// multiple instances of a header that returns the first value seen, and we
// need to look at all instances.
net::HttpUtil::HeadersIterator it(http_headers.begin(), http_headers.end(),
"\r\n");
while (it.GetNext()) {
if (!lstrcmpiA(it.name().c_str(), kXFrameOptionsHeader) &&
lstrcmpiA(it.values().c_str(), kXFrameOptionsValueAllowAll))
return true;
}
return false;
}
std::string GetHttpHeaderFromHeaderList(const std::string& header,
const std::string& headers) {
net::HttpUtil::HeadersIterator it(headers.begin(), headers.end(), "\r\n");
while (it.GetNext()) {
if (!lstrcmpiA(it.name().c_str(), header.c_str()))
return std::string(it.values_begin(), it.values_end());
}
return std::string();
}
} // namespace http_utils