blob: e26c7d78b7d379dd010ba6ac6afdf494ecd5c563 [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.
// The rules for parsing content-types were borrowed from Firefox:
// http://lxr.mozilla.org/mozilla/source/netwerk/base/src/nsURLHelper.cpp#834
#include "net/http/http_util.h"
#include <algorithm>
#include "base/logging.h"
#include "base/stl_util.h"
#include "base/strings/string_number_conversions.h"
#include "base/strings/string_piece.h"
#include "base/strings/string_tokenizer.h"
#include "base/strings/string_util.h"
#include "base/strings/stringprintf.h"
#include "base/time/time.h"
#include "net/base/url_util.h"
namespace net {
namespace {
template <typename ConstIterator>
void TrimLWSImplementation(ConstIterator* begin, ConstIterator* end) {
// leading whitespace
while (*begin < *end && HttpUtil::IsLWS((*begin)[0]))
++(*begin);
// trailing whitespace
while (*begin < *end && HttpUtil::IsLWS((*end)[-1]))
--(*end);
}
} // namespace
// HttpUtil -------------------------------------------------------------------
// static
std::string HttpUtil::SpecForRequest(const GURL& url) {
// We may get ftp scheme when fetching ftp resources through proxy.
DCHECK(url.is_valid() && (url.SchemeIsHTTPOrHTTPS() || url.SchemeIs("ftp") ||
url.SchemeIsWSOrWSS()));
return SimplifyUrlForRequest(url).spec();
}
// static
void HttpUtil::ParseContentType(const std::string& content_type_str,
std::string* mime_type,
std::string* charset,
bool* had_charset,
std::string* boundary) {
const std::string::const_iterator begin = content_type_str.begin();
// Trim leading and trailing whitespace from type. We include '(' in
// the trailing trim set to catch media-type comments, which are not at all
// standard, but may occur in rare cases.
size_t type_val = content_type_str.find_first_not_of(HTTP_LWS);
type_val = std::min(type_val, content_type_str.length());
size_t type_end = content_type_str.find_first_of(HTTP_LWS ";(", type_val);
if (type_end == std::string::npos)
type_end = content_type_str.length();
std::string charset_value;
bool type_has_charset = false;
// Iterate over parameters. Can't split the string around semicolons
// preemptively because quoted strings may include semicolons. Matches logic
// in https://mimesniff.spec.whatwg.org/.
std::string::size_type offset = content_type_str.find_first_of(';', type_end);
while (offset < content_type_str.size()) {
DCHECK_EQ(';', content_type_str[offset]);
// Trim off the semicolon.
++offset;
// Trim off any following spaces.
offset = content_type_str.find_first_not_of(HTTP_LWS, offset);
std::string::size_type param_name_start = offset;
// Extend parameter name until run into a semicolon or equals sign. Per
// spec, trailing spaces are not removed.
offset = content_type_str.find_first_of(";=", offset);
// Nothing more to do if at end of string, or if there's no parameter
// value, since names without values aren't allowed.
if (offset == std::string::npos || content_type_str[offset] == ';')
continue;
base::StringPiece param_name(content_type_str.begin() + param_name_start,
content_type_str.begin() + offset);
// Now parse the value.
DCHECK_EQ('=', content_type_str[offset]);
// Trim off the '='.
offset++;
// Remove leading spaces. This violates the spec, though it matches
// pre-existing behavior.
//
// TODO(mmenke): Consider doing this (only?) after parsing quotes, which
// seems to align more with the spec - not the content-type spec, but the
// GET spec's way of getting an encoding, and the spec for handling
// boundary values as well.
// See https://encoding.spec.whatwg.org/#names-and-labels.
offset = content_type_str.find_first_not_of(HTTP_LWS, offset);
std::string param_value;
if (offset == std::string::npos) {
// Nothing to do here - an unquoted string of only whitespace is
// considered to have an empty value.
} else if (content_type_str[offset] != '"') {
// If the first character is not a quotation mark, copy data directly.
std::string::size_type value_start = offset;
offset = content_type_str.find_first_of(';', offset);
std::string::size_type value_end = offset;
// Remove terminal whitespace. If ran off the end of the string, have to
// update |value_end| first.
if (value_end == std::string::npos)
value_end = content_type_str.size();
while (value_end > value_start &&
IsLWS(content_type_str[value_end - 1])) {
--value_end;
}
param_value =
content_type_str.substr(value_start, value_end - value_start);
} else {
// Otherwise, append data, with special handling for backslashes, until
// a close quote.
// Skip open quote.
DCHECK_EQ('"', content_type_str[offset]);
++offset;
while (offset < content_type_str.size() &&
content_type_str[offset] != '"') {
// Skip over backslash and append the next character, when not at
// the end of the string. Otherwise, copy the next character (Which may
// be a backslash).
if (content_type_str[offset] == '\\' &&
offset + 1 < content_type_str.size()) {
++offset;
}
param_value += content_type_str[offset];
++offset;
}
offset = content_type_str.find_first_of(';', offset);
}
// 0-length parameter values are not considered valid.
if (!param_value.size())
continue;
// TODO(mmenke): Take first, rather than last, value in the case of
// duplicates.
// TODO(mmenke): Check that name has only valid characters.
if (base::LowerCaseEqualsASCII(param_name, "charset")) {
// Ignore the part after '('. This is not in the standard, but may
// occur in rare cases.
// TODO(bnc): Do not ignore the part after '('.
// See https://crbug.com/772343.
charset_value = param_value.substr(0, param_value.find("("));
type_has_charset = true;
} else if (base::LowerCaseEqualsASCII(param_name, "boundary")) {
if (boundary)
boundary->assign(std::move(param_value));
}
}
// If the server sent "*/*", it is meaningless, so do not store it.
// Also, reject a mime-type if it does not include a slash.
// Some servers give junk after the charset parameter, which may
// include a comma, so this check makes us a bit more tolerant.
if (content_type_str.length() == 0 || content_type_str == "*/*" ||
content_type_str.find_first_of('/') == std::string::npos) {
return;
}
// If type_val is the same as mime_type, then just update the charset.
// However, if charset is empty and mime_type hasn't changed, then don't
// wipe-out an existing charset.
// It is common that mime_type is empty.
bool eq = !mime_type->empty() &&
base::LowerCaseEqualsASCII(
base::StringPiece(begin + type_val, begin + type_end),
mime_type->data());
if (!eq) {
*mime_type = base::ToLowerASCII(
base::StringPiece(begin + type_val, begin + type_end));
}
if ((!eq && *had_charset) || type_has_charset) {
*had_charset = true;
*charset = base::ToLowerASCII(charset_value);
}
}
// static
bool HttpUtil::ParseRangeHeader(const std::string& ranges_specifier,
std::vector<HttpByteRange>* ranges) {
size_t equal_char_offset = ranges_specifier.find('=');
if (equal_char_offset == std::string::npos)
return false;
// Try to extract bytes-unit part.
std::string::const_iterator bytes_unit_begin = ranges_specifier.begin();
std::string::const_iterator bytes_unit_end = bytes_unit_begin +
equal_char_offset;
std::string::const_iterator byte_range_set_begin = bytes_unit_end + 1;
std::string::const_iterator byte_range_set_end = ranges_specifier.end();
TrimLWS(&bytes_unit_begin, &bytes_unit_end);
// "bytes" unit identifier is not found.
if (!base::LowerCaseEqualsASCII(
base::StringPiece(bytes_unit_begin, bytes_unit_end), "bytes")) {
return false;
}
ValuesIterator byte_range_set_iterator(byte_range_set_begin,
byte_range_set_end, ',');
while (byte_range_set_iterator.GetNext()) {
size_t minus_char_offset = byte_range_set_iterator.value().find('-');
// If '-' character is not found, reports failure.
if (minus_char_offset == std::string::npos)
return false;
std::string::const_iterator first_byte_pos_begin =
byte_range_set_iterator.value_begin();
std::string::const_iterator first_byte_pos_end =
first_byte_pos_begin + minus_char_offset;
TrimLWS(&first_byte_pos_begin, &first_byte_pos_end);
std::string first_byte_pos(first_byte_pos_begin, first_byte_pos_end);
HttpByteRange range;
// Try to obtain first-byte-pos.
if (!first_byte_pos.empty()) {
int64_t first_byte_position = -1;
if (!base::StringToInt64(first_byte_pos, &first_byte_position))
return false;
range.set_first_byte_position(first_byte_position);
}
std::string::const_iterator last_byte_pos_begin =
byte_range_set_iterator.value_begin() + minus_char_offset + 1;
std::string::const_iterator last_byte_pos_end =
byte_range_set_iterator.value_end();
TrimLWS(&last_byte_pos_begin, &last_byte_pos_end);
std::string last_byte_pos(last_byte_pos_begin, last_byte_pos_end);
// We have last-byte-pos or suffix-byte-range-spec in this case.
if (!last_byte_pos.empty()) {
int64_t last_byte_position;
if (!base::StringToInt64(last_byte_pos, &last_byte_position))
return false;
if (range.HasFirstBytePosition())
range.set_last_byte_position(last_byte_position);
else
range.set_suffix_length(last_byte_position);
} else if (!range.HasFirstBytePosition()) {
return false;
}
// Do a final check on the HttpByteRange object.
if (!range.IsValid())
return false;
ranges->push_back(range);
}
return !ranges->empty();
}
// static
// From RFC 2616 14.16:
// content-range-spec =
// bytes-unit SP byte-range-resp-spec "/" ( instance-length | "*" )
// byte-range-resp-spec = (first-byte-pos "-" last-byte-pos) | "*"
// instance-length = 1*DIGIT
// bytes-unit = "bytes"
bool HttpUtil::ParseContentRangeHeaderFor206(
base::StringPiece content_range_spec,
int64_t* first_byte_position,
int64_t* last_byte_position,
int64_t* instance_length) {
*first_byte_position = *last_byte_position = *instance_length = -1;
content_range_spec = TrimLWS(content_range_spec);
size_t space_position = content_range_spec.find(' ');
if (space_position == base::StringPiece::npos)
return false;
// Invalid header if it doesn't contain "bytes-unit".
if (!base::LowerCaseEqualsASCII(
TrimLWS(content_range_spec.substr(0, space_position)), "bytes")) {
return false;
}
size_t minus_position = content_range_spec.find('-', space_position + 1);
if (minus_position == base::StringPiece::npos)
return false;
size_t slash_position = content_range_spec.find('/', minus_position + 1);
if (slash_position == base::StringPiece::npos)
return false;
if (base::StringToInt64(
TrimLWS(content_range_spec.substr(
space_position + 1, minus_position - (space_position + 1))),
first_byte_position) &&
*first_byte_position >= 0 &&
base::StringToInt64(
TrimLWS(content_range_spec.substr(
minus_position + 1, slash_position - (minus_position + 1))),
last_byte_position) &&
*last_byte_position >= *first_byte_position &&
base::StringToInt64(
TrimLWS(content_range_spec.substr(slash_position + 1)),
instance_length) &&
*instance_length > *last_byte_position) {
return true;
}
*first_byte_position = *last_byte_position = *instance_length = -1;
return false;
}
// static
bool HttpUtil::ParseRetryAfterHeader(const std::string& retry_after_string,
base::Time now,
base::TimeDelta* retry_after) {
int seconds;
base::Time time;
base::TimeDelta interval;
if (base::StringToInt(retry_after_string, &seconds)) {
interval = base::TimeDelta::FromSeconds(seconds);
} else if (base::Time::FromUTCString(retry_after_string.c_str(), &time)) {
interval = time - now;
} else {
return false;
}
if (interval < base::TimeDelta::FromSeconds(0))
return false;
*retry_after = interval;
return true;
}
namespace {
// A header string containing any of the following fields will cause
// an error. The list comes from the XMLHttpRequest standard.
// http://www.w3.org/TR/XMLHttpRequest/#the-setrequestheader-method
const char* const kForbiddenHeaderFields[] = {
"accept-charset",
"accept-encoding",
"access-control-request-headers",
"access-control-request-method",
"connection",
"content-length",
"cookie",
"cookie2",
"content-transfer-encoding",
"date",
"expect",
"host",
"keep-alive",
"origin",
"referer",
"te",
"trailer",
"transfer-encoding",
"upgrade",
"user-agent",
"via",
};
} // namespace
// static
bool HttpUtil::IsMethodSafe(const std::string& method) {
return method == "GET" || method == "HEAD" || method == "OPTIONS" ||
method == "TRACE";
}
// static
bool HttpUtil::IsMethodIdempotent(const std::string& method) {
return IsMethodSafe(method) || method == "PUT" || method == "DELETE";
}
// static
bool HttpUtil::IsSafeHeader(const std::string& name) {
std::string lower_name(base::ToLowerASCII(name));
if (base::StartsWith(lower_name, "proxy-", base::CompareCase::SENSITIVE) ||
base::StartsWith(lower_name, "sec-", base::CompareCase::SENSITIVE))
return false;
for (const char* field : kForbiddenHeaderFields) {
if (lower_name == field)
return false;
}
return true;
}
// static
bool HttpUtil::IsValidHeaderName(const base::StringPiece& name) {
// Check whether the header name is RFC 2616-compliant.
return HttpUtil::IsToken(name);
}
// static
bool HttpUtil::IsValidHeaderValue(const base::StringPiece& value) {
// Just a sanity check: disallow NUL, CR and LF.
for (char c : value) {
if (c == '\0' || c == '\r' || c == '\n')
return false;
}
return true;
}
// static
bool HttpUtil::IsNonCoalescingHeader(std::string::const_iterator name_begin,
std::string::const_iterator name_end) {
// NOTE: "set-cookie2" headers do not support expires attributes, so we don't
// have to list them here.
const char* const kNonCoalescingHeaders[] = {
"date",
"expires",
"last-modified",
"location", // See bug 1050541 for details
"retry-after",
"set-cookie",
// The format of auth-challenges mixes both space separated tokens and
// comma separated properties, so coalescing on comma won't work.
"www-authenticate",
"proxy-authenticate",
// STS specifies that UAs must not process any STS headers after the first
// one.
"strict-transport-security"
};
for (const char* header : kNonCoalescingHeaders) {
if (base::LowerCaseEqualsASCII(base::StringPiece(name_begin, name_end),
header)) {
return true;
}
}
return false;
}
bool HttpUtil::IsLWS(char c) {
const base::StringPiece kWhiteSpaceCharacters(HTTP_LWS);
return kWhiteSpaceCharacters.find(c) != base::StringPiece::npos;
}
// static
void HttpUtil::TrimLWS(std::string::const_iterator* begin,
std::string::const_iterator* end) {
TrimLWSImplementation(begin, end);
}
// static
base::StringPiece HttpUtil::TrimLWS(const base::StringPiece& string) {
const char* begin = string.data();
const char* end = string.data() + string.size();
TrimLWSImplementation(&begin, &end);
return base::StringPiece(begin, end - begin);
}
bool HttpUtil::IsTokenChar(char c) {
return !(c >= 0x7F || c <= 0x20 || c == '(' || c == ')' || c == '<' ||
c == '>' || c == '@' || c == ',' || c == ';' || c == ':' ||
c == '\\' || c == '"' || c == '/' || c == '[' || c == ']' ||
c == '?' || c == '=' || c == '{' || c == '}');
}
// See RFC 7230 Sec 3.2.6 for the definition of |token|.
bool HttpUtil::IsToken(const base::StringPiece& string) {
if (string.empty())
return false;
for (char c : string) {
if (!IsTokenChar(c))
return false;
}
return true;
}
// See RFC 5987 Sec 3.2.1 for the definition of |parmname|.
bool HttpUtil::IsParmName(std::string::const_iterator begin,
std::string::const_iterator end) {
if (begin == end)
return false;
for (std::string::const_iterator iter = begin; iter != end; ++iter) {
unsigned char c = *iter;
if (!IsTokenChar(c) || c == '*' || c == '\'' || c == '%')
return false;
}
return true;
}
namespace {
bool IsQuote(char c) {
// Single quote mark isn't actually part of quoted-text production,
// but apparently some servers rely on this.
return c == '"' || c == '\'';
}
bool UnquoteImpl(std::string::const_iterator begin,
std::string::const_iterator end,
bool strict_quotes,
std::string* out) {
// Empty string
if (begin == end)
return false;
// Nothing to unquote.
if (!IsQuote(*begin))
return false;
// Anything other than double quotes in strict mode.
if (strict_quotes && *begin != '"')
return false;
// No terminal quote mark.
if (end - begin < 2 || *begin != *(end - 1))
return false;
char quote = *begin;
// Strip quotemarks
++begin;
--end;
// Unescape quoted-pair (defined in RFC 2616 section 2.2)
bool prev_escape = false;
std::string unescaped;
for (; begin != end; ++begin) {
char c = *begin;
if (c == '\\' && !prev_escape) {
prev_escape = true;
continue;
}
if (strict_quotes && !prev_escape && c == quote)
return false;
prev_escape = false;
unescaped.push_back(c);
}
// Terminal quote is escaped.
if (strict_quotes && prev_escape)
return false;
*out = std::move(unescaped);
return true;
}
} // anonymous namespace
std::string HttpUtil::Unquote(std::string::const_iterator begin,
std::string::const_iterator end) {
std::string result;
if (!UnquoteImpl(begin, end, false, &result))
return std::string(begin, end);
return result;
}
// static
std::string HttpUtil::Unquote(const std::string& str) {
return Unquote(str.begin(), str.end());
}
// static
bool HttpUtil::StrictUnquote(std::string::const_iterator begin,
std::string::const_iterator end,
std::string* out) {
return UnquoteImpl(begin, end, true, out);
}
// static
bool HttpUtil::StrictUnquote(const std::string& str, std::string* out) {
return StrictUnquote(str.begin(), str.end(), out);
}
// static
std::string HttpUtil::Quote(const std::string& str) {
std::string escaped;
escaped.reserve(2 + str.size());
std::string::const_iterator begin = str.begin();
std::string::const_iterator end = str.end();
// Esape any backslashes or quotemarks within the string, and
// then surround with quotes.
escaped.push_back('"');
for (; begin != end; ++begin) {
char c = *begin;
if (c == '"' || c == '\\')
escaped.push_back('\\');
escaped.push_back(c);
}
escaped.push_back('"');
return escaped;
}
// Find the "http" substring in a status line. This allows for
// some slop at the start. If the "http" string could not be found
// then returns -1.
// static
int HttpUtil::LocateStartOfStatusLine(const char* buf, int buf_len) {
const int slop = 4;
const int http_len = 4;
if (buf_len >= http_len) {
int i_max = std::min(buf_len - http_len, slop);
for (int i = 0; i <= i_max; ++i) {
if (base::LowerCaseEqualsASCII(base::StringPiece(buf + i, http_len),
"http"))
return i;
}
}
return -1; // Not found
}
static int LocateEndOfHeadersHelper(const char* buf,
int buf_len,
int i,
bool accept_empty_header_list) {
char last_c = '\0';
bool was_lf = false;
if (accept_empty_header_list) {
// Normally two line breaks signal the end of a header list. An empty header
// list ends with a single line break at the start of the buffer.
last_c = '\n';
was_lf = true;
}
for (; i < buf_len; ++i) {
char c = buf[i];
if (c == '\n') {
if (was_lf)
return i + 1;
was_lf = true;
} else if (c != '\r' || last_c != '\n') {
was_lf = false;
}
last_c = c;
}
return -1;
}
int HttpUtil::LocateEndOfAdditionalHeaders(const char* buf,
int buf_len,
int i) {
return LocateEndOfHeadersHelper(buf, buf_len, i, true);
}
int HttpUtil::LocateEndOfHeaders(const char* buf, int buf_len, int i) {
return LocateEndOfHeadersHelper(buf, buf_len, i, false);
}
// In order for a line to be continuable, it must specify a
// non-blank header-name. Line continuations are specifically for
// header values -- do not allow headers names to span lines.
static bool IsLineSegmentContinuable(const char* begin, const char* end) {
if (begin == end)
return false;
const char* colon = std::find(begin, end, ':');
if (colon == end)
return false;
const char* name_begin = begin;
const char* name_end = colon;
// Name can't be empty.
if (name_begin == name_end)
return false;
// Can't start with LWS (this would imply the segment is a continuation)
if (HttpUtil::IsLWS(*name_begin))
return false;
return true;
}
// Helper used by AssembleRawHeaders, to find the end of the status line.
static const char* FindStatusLineEnd(const char* begin, const char* end) {
size_t i = base::StringPiece(begin, end - begin).find_first_of("\r\n");
if (i == base::StringPiece::npos)
return end;
return begin + i;
}
// Helper used by AssembleRawHeaders, to skip past leading LWS.
static const char* FindFirstNonLWS(const char* begin, const char* end) {
for (const char* cur = begin; cur != end; ++cur) {
if (!HttpUtil::IsLWS(*cur))
return cur;
}
return end; // Not found.
}
std::string HttpUtil::AssembleRawHeaders(const char* input_begin,
int input_len) {
std::string raw_headers;
raw_headers.reserve(input_len);
const char* input_end = input_begin + input_len;
// Skip any leading slop, since the consumers of this output
// (HttpResponseHeaders) don't deal with it.
int status_begin_offset = LocateStartOfStatusLine(input_begin, input_len);
if (status_begin_offset != -1)
input_begin += status_begin_offset;
// Copy the status line.
const char* status_line_end = FindStatusLineEnd(input_begin, input_end);
raw_headers.append(input_begin, status_line_end);
// After the status line, every subsequent line is a header line segment.
// Should a segment start with LWS, it is a continuation of the previous
// line's field-value.
// TODO(ericroman): is this too permissive? (delimits on [\r\n]+)
base::CStringTokenizer lines(status_line_end, input_end, "\r\n");
// This variable is true when the previous line was continuable.
bool prev_line_continuable = false;
while (lines.GetNext()) {
const char* line_begin = lines.token_begin();
const char* line_end = lines.token_end();
if (prev_line_continuable && IsLWS(*line_begin)) {
// Join continuation; reduce the leading LWS to a single SP.
raw_headers.push_back(' ');
raw_headers.append(FindFirstNonLWS(line_begin, line_end), line_end);
} else {
// Terminate the previous line.
raw_headers.push_back('\n');
// Copy the raw data to output.
raw_headers.append(line_begin, line_end);
// Check if the current line can be continued.
prev_line_continuable = IsLineSegmentContinuable(line_begin, line_end);
}
}
raw_headers.append("\n\n", 2);
// Use '\0' as the canonical line terminator. If the input already contained
// any embeded '\0' characters we will strip them first to avoid interpreting
// them as line breaks.
base::Erase(raw_headers, '\0');
std::replace(raw_headers.begin(), raw_headers.end(), '\n', '\0');
return raw_headers;
}
std::string HttpUtil::ConvertHeadersBackToHTTPResponse(const std::string& str) {
std::string disassembled_headers;
base::StringTokenizer tokenizer(str, std::string(1, '\0'));
while (tokenizer.GetNext()) {
disassembled_headers.append(tokenizer.token_begin(), tokenizer.token_end());
disassembled_headers.append("\r\n");
}
disassembled_headers.append("\r\n");
return disassembled_headers;
}
// TODO(jungshik): This function assumes that the input is a comma separated
// list without any whitespace. As long as it comes from the preference and
// a user does not manually edit the preference file, it's the case. Still,
// we may have to make it more robust.
std::string HttpUtil::GenerateAcceptLanguageHeader(
const std::string& raw_language_list) {
// We use integers for qvalue and qvalue decrement that are 10 times
// larger than actual values to avoid a problem with comparing
// two floating point numbers.
const unsigned int kQvalueDecrement10 = 1;
unsigned int qvalue10 = 10;
base::StringTokenizer t(raw_language_list, ",");
std::string lang_list_with_q;
while (t.GetNext()) {
std::string language = t.token();
if (qvalue10 == 10) {
// q=1.0 is implicit.
lang_list_with_q = language;
} else {
DCHECK_LT(qvalue10, 10U);
base::StringAppendF(&lang_list_with_q, ",%s;q=0.%d", language.c_str(),
qvalue10);
}
// It does not make sense to have 'q=0'.
if (qvalue10 > kQvalueDecrement10)
qvalue10 -= kQvalueDecrement10;
}
return lang_list_with_q;
}
bool HttpUtil::HasStrongValidators(HttpVersion version,
const std::string& etag_header,
const std::string& last_modified_header,
const std::string& date_header) {
if (!HasValidators(version, etag_header, last_modified_header))
return false;
if (version < HttpVersion(1, 1))
return false;
if (!etag_header.empty()) {
size_t slash = etag_header.find('/');
if (slash == std::string::npos || slash == 0)
return true;
std::string::const_iterator i = etag_header.begin();
std::string::const_iterator j = etag_header.begin() + slash;
TrimLWS(&i, &j);
if (!base::LowerCaseEqualsASCII(base::StringPiece(i, j), "w"))
return true;
}
base::Time last_modified;
if (!base::Time::FromString(last_modified_header.c_str(), &last_modified))
return false;
base::Time date;
if (!base::Time::FromString(date_header.c_str(), &date))
return false;
// Last-Modified is implicitly weak unless it is at least 60 seconds before
// the Date value.
return ((date - last_modified).InSeconds() >= 60);
}
bool HttpUtil::HasValidators(HttpVersion version,
const std::string& etag_header,
const std::string& last_modified_header) {
if (version < HttpVersion(1, 0))
return false;
base::Time last_modified;
if (base::Time::FromString(last_modified_header.c_str(), &last_modified))
return true;
// It is OK to consider an empty string in etag_header to be a missing header
// since valid ETags are always quoted-strings (see RFC 2616 3.11) and thus
// empty ETags aren't empty strings (i.e., an empty ETag might be "\"\"").
return version >= HttpVersion(1, 1) && !etag_header.empty();
}
// Functions for histogram initialization. The code 0 is put in the map to
// track status codes that are invalid.
// TODO(gavinp): Greatly prune the collected codes once we learn which
// ones are not sent in practice, to reduce upload size & memory use.
enum {
HISTOGRAM_MIN_HTTP_STATUS_CODE = 100,
HISTOGRAM_MAX_HTTP_STATUS_CODE = 599,
};
// static
std::vector<int> HttpUtil::GetStatusCodesForHistogram() {
std::vector<int> codes;
codes.reserve(
HISTOGRAM_MAX_HTTP_STATUS_CODE - HISTOGRAM_MIN_HTTP_STATUS_CODE + 2);
codes.push_back(0);
for (int i = HISTOGRAM_MIN_HTTP_STATUS_CODE;
i <= HISTOGRAM_MAX_HTTP_STATUS_CODE; ++i)
codes.push_back(i);
return codes;
}
// static
int HttpUtil::MapStatusCodeForHistogram(int code) {
if (HISTOGRAM_MIN_HTTP_STATUS_CODE <= code &&
code <= HISTOGRAM_MAX_HTTP_STATUS_CODE)
return code;
return 0;
}
// BNF from section 4.2 of RFC 2616:
//
// message-header = field-name ":" [ field-value ]
// field-name = token
// field-value = *( field-content | LWS )
// field-content = <the OCTETs making up the field-value
// and consisting of either *TEXT or combinations
// of token, separators, and quoted-string>
//
HttpUtil::HeadersIterator::HeadersIterator(
std::string::const_iterator headers_begin,
std::string::const_iterator headers_end,
const std::string& line_delimiter)
: lines_(headers_begin, headers_end, line_delimiter) {
}
HttpUtil::HeadersIterator::~HeadersIterator() = default;
bool HttpUtil::HeadersIterator::GetNext() {
while (lines_.GetNext()) {
name_begin_ = lines_.token_begin();
values_end_ = lines_.token_end();
std::string::const_iterator colon(std::find(name_begin_, values_end_, ':'));
if (colon == values_end_)
continue; // skip malformed header
name_end_ = colon;
// If the name starts with LWS, it is an invalid line.
// Leading LWS implies a line continuation, and these should have
// already been joined by AssembleRawHeaders().
if (name_begin_ == name_end_ || IsLWS(*name_begin_))
continue;
TrimLWS(&name_begin_, &name_end_);
DCHECK(name_begin_ < name_end_);
if (!IsToken(base::StringPiece(name_begin_, name_end_)))
continue; // skip malformed header
values_begin_ = colon + 1;
TrimLWS(&values_begin_, &values_end_);
// if we got a header name, then we are done.
return true;
}
return false;
}
bool HttpUtil::HeadersIterator::AdvanceTo(const char* name) {
DCHECK(name != NULL);
DCHECK_EQ(0, base::ToLowerASCII(name).compare(name))
<< "the header name must be in all lower case";
while (GetNext()) {
if (base::LowerCaseEqualsASCII(base::StringPiece(name_begin_, name_end_),
name)) {
return true;
}
}
return false;
}
HttpUtil::ValuesIterator::ValuesIterator(
std::string::const_iterator values_begin,
std::string::const_iterator values_end,
char delimiter)
: values_(values_begin, values_end, std::string(1, delimiter)) {
values_.set_quote_chars("\'\"");
}
HttpUtil::ValuesIterator::ValuesIterator(const ValuesIterator& other) = default;
HttpUtil::ValuesIterator::~ValuesIterator() = default;
bool HttpUtil::ValuesIterator::GetNext() {
while (values_.GetNext()) {
value_begin_ = values_.token_begin();
value_end_ = values_.token_end();
TrimLWS(&value_begin_, &value_end_);
// bypass empty values.
if (value_begin_ != value_end_)
return true;
}
return false;
}
HttpUtil::NameValuePairsIterator::NameValuePairsIterator(
std::string::const_iterator begin,
std::string::const_iterator end,
char delimiter,
Values optional_values,
Quotes strict_quotes)
: props_(begin, end, delimiter),
valid_(true),
name_begin_(end),
name_end_(end),
value_begin_(end),
value_end_(end),
value_is_quoted_(false),
values_optional_(optional_values == Values::NOT_REQUIRED),
strict_quotes_(strict_quotes == Quotes::STRICT_QUOTES) {
if (strict_quotes_)
props_.set_quote_chars("\"");
}
HttpUtil::NameValuePairsIterator::NameValuePairsIterator(
std::string::const_iterator begin,
std::string::const_iterator end,
char delimiter)
: NameValuePairsIterator(begin,
end,
delimiter,
Values::REQUIRED,
Quotes::NOT_STRICT) {}
HttpUtil::NameValuePairsIterator::NameValuePairsIterator(
const NameValuePairsIterator& other) = default;
HttpUtil::NameValuePairsIterator::~NameValuePairsIterator() = default;
// We expect properties to be formatted as one of:
// name="value"
// name='value'
// name='\'value\''
// name=value
// name = value
// name (if values_optional_ is true)
// Due to buggy implementations found in some embedded devices, we also
// accept values with missing close quotemark (http://crbug.com/39836):
// name="value
bool HttpUtil::NameValuePairsIterator::GetNext() {
if (!props_.GetNext())
return false;
// Set the value as everything. Next we will split out the name.
value_begin_ = props_.value_begin();
value_end_ = props_.value_end();
name_begin_ = name_end_ = value_end_;
// Scan for the equals sign.
std::string::const_iterator equals = std::find(value_begin_, value_end_, '=');
if (equals == value_begin_)
return valid_ = false; // Malformed, no name
if (equals == value_end_ && !values_optional_)
return valid_ = false; // Malformed, no equals sign and values are required
// If an equals sign was found, verify that it wasn't inside of quote marks.
if (equals != value_end_) {
for (std::string::const_iterator it = value_begin_; it != equals; ++it) {
if (IsQuote(*it))
return valid_ = false; // Malformed, quote appears before equals sign
}
}
name_begin_ = value_begin_;
name_end_ = equals;
value_begin_ = (equals == value_end_) ? value_end_ : equals + 1;
TrimLWS(&name_begin_, &name_end_);
TrimLWS(&value_begin_, &value_end_);
value_is_quoted_ = false;
unquoted_value_.clear();
if (equals != value_end_ && value_begin_ == value_end_) {
// Malformed; value is empty
return valid_ = false;
}
if (value_begin_ != value_end_ && IsQuote(*value_begin_)) {
value_is_quoted_ = true;
if (strict_quotes_) {
if (!HttpUtil::StrictUnquote(value_begin_, value_end_, &unquoted_value_))
return valid_ = false;
return true;
}
// Trim surrounding quotemarks off the value
if (*value_begin_ != *(value_end_ - 1) || value_begin_ + 1 == value_end_) {
// NOTE: This is not as graceful as it sounds:
// * quoted-pairs will no longer be unquoted
// (["\"hello] should give ["hello]).
// * Does not detect when the final quote is escaped
// (["value\"] should give [value"])
value_is_quoted_ = false;
++value_begin_; // Gracefully recover from mismatching quotes.
} else {
// Do not store iterators into this. See declaration of unquoted_value_.
unquoted_value_ = HttpUtil::Unquote(value_begin_, value_end_);
}
}
return true;
}
bool HttpUtil::NameValuePairsIterator::IsQuote(char c) const {
if (strict_quotes_)
return c == '"';
// The call to the file-scoped IsQuote must be qualified to avoid re-entrantly
// calling NameValuePairsIterator::IsQuote again.
return net::IsQuote(c);
}
bool HttpUtil::ParseAcceptEncoding(const std::string& accept_encoding,
std::set<std::string>* allowed_encodings) {
DCHECK(allowed_encodings);
if (accept_encoding.find_first_of("\"") != std::string::npos)
return false;
allowed_encodings->clear();
base::StringTokenizer tokenizer(accept_encoding.begin(),
accept_encoding.end(), ",");
while (tokenizer.GetNext()) {
base::StringPiece entry = tokenizer.token_piece();
entry = TrimLWS(entry);
size_t semicolon_pos = entry.find(';');
if (semicolon_pos == base::StringPiece::npos) {
if (entry.find_first_of(HTTP_LWS) != base::StringPiece::npos)
return false;
allowed_encodings->insert(base::ToLowerASCII(entry));
continue;
}
base::StringPiece encoding = entry.substr(0, semicolon_pos);
encoding = TrimLWS(encoding);
if (encoding.find_first_of(HTTP_LWS) != base::StringPiece::npos)
return false;
base::StringPiece params = entry.substr(semicolon_pos + 1);
params = TrimLWS(params);
size_t equals_pos = params.find('=');
if (equals_pos == base::StringPiece::npos)
return false;
base::StringPiece param_name = params.substr(0, equals_pos);
param_name = TrimLWS(param_name);
if (!base::LowerCaseEqualsASCII(param_name, "q"))
return false;
base::StringPiece qvalue = params.substr(equals_pos + 1);
qvalue = TrimLWS(qvalue);
if (qvalue.empty())
return false;
if (qvalue[0] == '1') {
if (base::StringPiece("1.000").starts_with(qvalue)) {
allowed_encodings->insert(base::ToLowerASCII(encoding));
continue;
}
return false;
}
if (qvalue[0] != '0')
return false;
if (qvalue.length() == 1)
continue;
if (qvalue.length() <= 2 || qvalue.length() > 5)
return false;
if (qvalue[1] != '.')
return false;
bool nonzero_number = false;
for (size_t i = 2; i < qvalue.length(); ++i) {
if (!base::IsAsciiDigit(qvalue[i]))
return false;
if (qvalue[i] != '0')
nonzero_number = true;
}
if (nonzero_number)
allowed_encodings->insert(base::ToLowerASCII(encoding));
}
// RFC 7231 5.3.4 "A request without an Accept-Encoding header field implies
// that the user agent has no preferences regarding content-codings."
if (allowed_encodings->empty()) {
allowed_encodings->insert("*");
return true;
}
// Any browser must support "identity".
allowed_encodings->insert("identity");
// RFC says gzip == x-gzip; mirror it here for easier matching.
if (allowed_encodings->find("gzip") != allowed_encodings->end())
allowed_encodings->insert("x-gzip");
if (allowed_encodings->find("x-gzip") != allowed_encodings->end())
allowed_encodings->insert("gzip");
// RFC says compress == x-compress; mirror it here for easier matching.
if (allowed_encodings->find("compress") != allowed_encodings->end())
allowed_encodings->insert("x-compress");
if (allowed_encodings->find("x-compress") != allowed_encodings->end())
allowed_encodings->insert("compress");
return true;
}
bool HttpUtil::ParseContentEncoding(const std::string& content_encoding,
std::set<std::string>* used_encodings) {
DCHECK(used_encodings);
if (content_encoding.find_first_of("\"=;*") != std::string::npos)
return false;
used_encodings->clear();
base::StringTokenizer encoding_tokenizer(content_encoding.begin(),
content_encoding.end(), ",");
while (encoding_tokenizer.GetNext()) {
base::StringPiece encoding = TrimLWS(encoding_tokenizer.token_piece());
if (encoding.find_first_of(HTTP_LWS) != base::StringPiece::npos)
return false;
used_encodings->insert(base::ToLowerASCII(encoding));
}
return true;
}
} // namespace net