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// 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 <string>
#include <unordered_set>
#include <vector>
#include "base/macros.h"
#include "base/memory/ref_counted.h"
#include "base/strings/string_piece.h"
#include "base/time/time.h"
#include "net/base/net_export.h"
#include "net/http/http_version.h"
#include "starboard/types.h"
namespace base {
class Pickle;
class PickleIterator;
class Time;
class TimeDelta;
class Value;
namespace net {
class HttpByteRange;
class NetLogCaptureMode;
enum ValidationType {
VALIDATION_NONE, // The resource is fresh.
VALIDATION_ASYNCHRONOUS, // The resource requires async revalidation.
VALIDATION_SYNCHRONOUS // The resource requires sync revalidation.
// HttpResponseHeaders: parses and holds HTTP response headers.
class NET_EXPORT HttpResponseHeaders
: public base::RefCountedThreadSafe<HttpResponseHeaders> {
// Persist options.
typedef int PersistOptions;
static const PersistOptions PERSIST_RAW = -1; // Raw, unparsed headers.
static const PersistOptions PERSIST_ALL = 0; // Parsed headers.
static const PersistOptions PERSIST_SANS_COOKIES = 1 << 0;
static const PersistOptions PERSIST_SANS_CHALLENGES = 1 << 1;
static const PersistOptions PERSIST_SANS_HOP_BY_HOP = 1 << 2;
static const PersistOptions PERSIST_SANS_NON_CACHEABLE = 1 << 3;
static const PersistOptions PERSIST_SANS_RANGES = 1 << 4;
static const PersistOptions PERSIST_SANS_SECURITY_STATE = 1 << 5;
struct FreshnessLifetimes {
// How long the resource will be fresh for.
base::TimeDelta freshness;
// How long after becoming not fresh that the resource will be stale but
// usable (if async revalidation is enabled).
base::TimeDelta staleness;
static const char kContentRange[];
HttpResponseHeaders() = delete;
// Parses the given raw_headers. raw_headers should be formatted thus:
// includes the http status response line, each line is \0-terminated, and
// it's terminated by an empty line (ie, 2 \0s in a row).
// (Note that line continuations should have already been joined;
// see HttpUtil::AssembleRawHeaders)
// HttpResponseHeaders does not perform any encoding changes on the input.
explicit HttpResponseHeaders(const std::string& raw_headers);
// Initializes from the representation stored in the given pickle. The data
// for this object is found relative to the given pickle_iter, which should
// be passed to the pickle's various Read* methods.
explicit HttpResponseHeaders(base::PickleIterator* pickle_iter);
// Appends a representation of this object to the given pickle.
// The options argument can be a combination of PersistOptions.
void Persist(base::Pickle* pickle, PersistOptions options);
// Performs header merging as described in 13.5.3 of RFC 2616.
void Update(const HttpResponseHeaders& new_headers);
// Removes all instances of a particular header.
void RemoveHeader(const std::string& name);
// Removes all instances of particular headers.
void RemoveHeaders(const std::unordered_set<std::string>& header_names);
// Removes a particular header line. The header name is compared
// case-insensitively.
void RemoveHeaderLine(const std::string& name, const std::string& value);
// Adds a particular header. |header| has to be a single header without any
// EOL termination, just [<header-name>: <header-values>]
// If a header with the same name is already stored, the two headers are not
// merged together by this method; the one provided is simply put at the
// end of the list.
void AddHeader(const std::string& header);
// Adds a cookie header. |cookie_string| should be the header value without
// the header name (Set-Cookie).
void AddCookie(const std::string& cookie_string);
// Replaces the current status line with the provided one (|new_status| should
// not have any EOL).
void ReplaceStatusLine(const std::string& new_status);
// Updates headers (Content-Length and Content-Range) in the |headers| to
// include the right content length and range for |byte_range|. This also
// updates HTTP status line if |replace_status_line| is true.
// |byte_range| must have a valid, bounded range (i.e. coming from a valid
// response or should be usable for a response).
void UpdateWithNewRange(const HttpByteRange& byte_range,
int64_t resource_size,
bool replace_status_line);
// Fetch the "normalized" value of a single header, where all values for the
// header name are separated by commas. See the GetNormalizedHeaders for
// format details. Returns false if this header wasn't found.
// NOTE: Do not make any assumptions about the encoding of this output
// string. It may be non-ASCII, and the encoding used by the server is not
// necessarily known to us. Do not assume that this output is UTF-8!
bool GetNormalizedHeader(const std::string& name, std::string* value) const;
// Returns the normalized status line.
std::string GetStatusLine() const;
// Get the HTTP version of the normalized status line.
HttpVersion GetHttpVersion() const {
return http_version_;
// Get the HTTP status text of the normalized status line.
std::string GetStatusText() const;
// Enumerate the "lines" of the response headers. This skips over the status
// line. Use GetStatusLine if you are interested in that. Note that this
// method returns the un-coalesced response header lines, so if a response
// header appears on multiple lines, then it will appear multiple times in
// this enumeration (in the order the header lines were received from the
// server). Also, a given header might have an empty value. Initialize a
// 'size_t' variable to 0 and pass it by address to EnumerateHeaderLines.
// Call EnumerateHeaderLines repeatedly until it returns false. The
// out-params 'name' and 'value' are set upon success.
bool EnumerateHeaderLines(size_t* iter,
std::string* name,
std::string* value) const;
// Enumerate the values of the specified header. If you are only interested
// in the first header, then you can pass nullptr for the 'iter' parameter.
// Otherwise, to iterate across all values for the specified header,
// initialize a 'size_t' variable to 0 and pass it by address to
// EnumerateHeader. Note that a header might have an empty value. Call
// EnumerateHeader repeatedly until it returns false.
// Unless a header is explicitly marked as non-coalescing (see
// HttpUtil::IsNonCoalescingHeader), headers that contain
// comma-separated lists are treated "as if" they had been sent as
// distinct headers. That is, a header of "Foo: a, b, c" would
// enumerate into distinct values of "a", "b", and "c". This is also
// true for headers that occur multiple times in a response; unless
// they are marked non-coalescing, "Foo: a, b" followed by "Foo: c"
// will enumerate to "a", "b", "c". Commas inside quoted strings are ignored,
// for example a header of 'Foo: "a, b", "c"' would enumerate as '"a, b"',
// '"c"'.
// This can cause issues for headers that might have commas in fields that
// aren't quoted strings, for example a header of "Foo: <a, b>, <c>" would
// enumerate as '<a', 'b>', '<c>', rather than as '<a, b>', '<c>'.
// To handle cases such as this, use GetNormalizedHeader to return the full
// concatenated header, and then parse manually.
bool EnumerateHeader(size_t* iter,
const base::StringPiece& name,
std::string* value) const;
// Returns true if the response contains the specified header-value pair.
// Both name and value are compared case insensitively.
bool HasHeaderValue(const base::StringPiece& name,
const base::StringPiece& value) const;
// Returns true if the response contains the specified header.
// The name is compared case insensitively.
bool HasHeader(const base::StringPiece& name) const;
// Get the mime type and charset values in lower case form from the headers.
// Empty strings are returned if the values are not present.
void GetMimeTypeAndCharset(std::string* mime_type,
std::string* charset) const;
// Get the mime type in lower case from the headers. If there's no mime
// type, returns false.
bool GetMimeType(std::string* mime_type) const;
// Get the charset in lower case from the headers. If there's no charset,
// returns false.
bool GetCharset(std::string* charset) const;
// Returns true if this response corresponds to a redirect. The target
// location of the redirect is optionally returned if location is non-null.
bool IsRedirect(std::string* location) const;
// Returns true if the HTTP response code passed in corresponds to a
// redirect.
static bool IsRedirectResponseCode(int response_code);
// Returns VALIDATION_NONE if the response can be reused without
// validation. VALIDATION_ASYNCHRONOUS means the response can be re-used, but
// asynchronous revalidation must be performed. VALIDATION_SYNCHRONOUS means
// that the result cannot be reused without revalidation.
// The result is relative to the current_time parameter, which is
// a parameter to support unit testing. The request_time parameter indicates
// the time at which the request was made that resulted in this response,
// which was received at response_time.
ValidationType RequiresValidation(const base::Time& request_time,
const base::Time& response_time,
const base::Time& current_time) const;
// Calculates the amount of time the server claims the response is fresh from
// the time the response was generated. See section 13.2.4 of RFC 2616. See
// RequiresValidation for a description of the response_time parameter. See
// the definition of FreshnessLifetimes above for the meaning of the return
// value. See RFC 5861 section 3 for the definition of
// stale-while-revalidate.
FreshnessLifetimes GetFreshnessLifetimes(
const base::Time& response_time) const;
// Returns the age of the response. See section 13.2.3 of RFC 2616.
// See RequiresValidation for a description of this method's parameters.
base::TimeDelta GetCurrentAge(const base::Time& request_time,
const base::Time& response_time,
const base::Time& current_time) const;
// The following methods extract values from the response headers. If a
// value is not present, or is invalid, then false is returned. Otherwise,
// true is returned and the out param is assigned to the corresponding value.
bool GetMaxAgeValue(base::TimeDelta* value) const;
bool GetAgeValue(base::TimeDelta* value) const;
bool GetDateValue(base::Time* value) const;
bool GetLastModifiedValue(base::Time* value) const;
bool GetExpiresValue(base::Time* value) const;
bool GetStaleWhileRevalidateValue(base::TimeDelta* value) const;
// Extracts the time value of a particular header. This method looks for the
// first matching header value and parses its value as a HTTP-date.
bool GetTimeValuedHeader(const std::string& name, base::Time* result) const;
// Determines if this response indicates a keep-alive connection.
bool IsKeepAlive() const;
// Returns true if this response has a strong etag or last-modified header.
// See section 13.3.3 of RFC 2616.
bool HasStrongValidators() const;
// Returns true if this response has any validator (either a Last-Modified or
// an ETag) regardless of whether it is strong or weak. See section 13.3.3 of
// RFC 2616.
bool HasValidators() const;
// Extracts the value of the Content-Length header or returns -1 if there is
// no such header in the response.
int64_t GetContentLength() const;
// Extracts the value of the specified header or returns -1 if there is no
// such header in the response.
int64_t GetInt64HeaderValue(const std::string& header) const;
// Extracts the values in a Content-Range header and returns true if all three
// values are present and valid for a 206 response; otherwise returns false.
// The following values will be outputted:
// |*first_byte_position| = inclusive position of the first byte of the range
// |*last_byte_position| = inclusive position of the last byte of the range
// |*instance_length| = size in bytes of the object requested
// If this method returns false, then all of the outputs will be -1.
bool GetContentRangeFor206(int64_t* first_byte_position,
int64_t* last_byte_position,
int64_t* instance_length) const;
// Returns true if the response is chunk-encoded.
bool IsChunkEncoded() const;
// Creates a Value for use with the NetLog containing the response headers.
std::unique_ptr<base::Value> NetLogCallback(
NetLogCaptureMode capture_mode) const;
// Returns the HTTP response code. This is 0 if the response code text seems
// to exist but could not be parsed. Otherwise, it defaults to 200 if the
// response code is not found in the raw headers.
int response_code() const { return response_code_; }
// Returns the raw header string.
const std::string& raw_headers() const { return raw_headers_; }
// Returns true if |name| is a cookie related header name. This is consistent
static bool IsCookieResponseHeader(base::StringPiece name);
friend class base::RefCountedThreadSafe<HttpResponseHeaders>;
using HeaderSet = std::unordered_set<std::string>;
// The members of this structure point into raw_headers_.
struct ParsedHeader;
typedef std::vector<ParsedHeader> HeaderList;
// Initializes from the given raw headers.
void Parse(const std::string& raw_input);
// Helper function for ParseStatusLine.
// Tries to extract the "HTTP/X.Y" from a status line formatted like:
// HTTP/1.1 200 OK
// with line_begin and end pointing at the begin and end of this line. If the
// status line is malformed, returns HttpVersion(0,0).
static HttpVersion ParseVersion(std::string::const_iterator line_begin,
std::string::const_iterator line_end);
// Tries to extract the status line from a header block, given the first
// line of said header block. If the status line is malformed, we'll
// construct a valid one. Example input:
// HTTP/1.1 200 OK
// with line_begin and end pointing at the begin and end of this line.
// Output will be a normalized version of this.
void ParseStatusLine(std::string::const_iterator line_begin,
std::string::const_iterator line_end,
bool has_headers);
// Find the header in our list (case-insensitive) starting with parsed_ at
// index |from|. Returns string::npos if not found.
size_t FindHeader(size_t from, const base::StringPiece& name) const;
// Search the Cache-Control header for a directive matching |directive|. If
// present, treat its value as a time offset in seconds, write it to |result|,
// and return true.
bool GetCacheControlDirective(const base::StringPiece& directive,
base::TimeDelta* result) const;
// Add a header->value pair to our list. If we already have header in our
// list, append the value to it.
void AddHeader(std::string::const_iterator name_begin,
std::string::const_iterator name_end,
std::string::const_iterator value_begin,
std::string::const_iterator value_end);
// Add to parsed_ given the fields of a ParsedHeader object.
void AddToParsed(std::string::const_iterator name_begin,
std::string::const_iterator name_end,
std::string::const_iterator value_begin,
std::string::const_iterator value_end);
// Replaces the current headers with the merged version of |raw_headers| and
// the current headers without the headers in |headers_to_remove|. Note that
// |headers_to_remove| are removed from the current headers (before the
// merge), not after the merge.
void MergeWithHeaders(const std::string& raw_headers,
const HeaderSet& headers_to_remove);
// Adds the values from any 'cache-control: no-cache="foo,bar"' headers.
void AddNonCacheableHeaders(HeaderSet* header_names) const;
// Adds the set of header names that contain cookie values.
static void AddSensitiveHeaders(HeaderSet* header_names);
// Adds the set of rfc2616 hop-by-hop response headers.
static void AddHopByHopHeaders(HeaderSet* header_names);
// Adds the set of challenge response headers.
static void AddChallengeHeaders(HeaderSet* header_names);
// Adds the set of cookie response headers.
static void AddCookieHeaders(HeaderSet* header_names);
// Adds the set of content range response headers.
static void AddHopContentRangeHeaders(HeaderSet* header_names);
// Adds the set of transport security state headers.
static void AddSecurityStateHeaders(HeaderSet* header_names);
// We keep a list of ParsedHeader objects. These tell us where to locate the
// header-value pairs within raw_headers_.
HeaderList parsed_;
// The raw_headers_ consists of the normalized status line (terminated with a
// null byte) and then followed by the raw null-terminated headers from the
// input that was passed to our constructor. We preserve the input [*] to
// maintain as much ancillary fidelity as possible (since it is sometimes
// hard to tell what may matter down-stream to a consumer of XMLHttpRequest).
// [*] The status line may be modified.
std::string raw_headers_;
// This is the parsed HTTP response code.
int response_code_;
// The normalized http version (consistent with what GetStatusLine() returns).
HttpVersion http_version_;
using ResponseHeadersCallback =
base::Callback<void(scoped_refptr<const HttpResponseHeaders>)>;
} // namespace net