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      1 // Copyright (c) 2012 The Chromium Authors. All rights reserved.
      2 // Use of this source code is governed by a BSD-style license that can be
      3 // found in the LICENSE file.
      4 #ifndef EXTENSIONS_COMMON_URL_PATTERN_H_
      5 #define EXTENSIONS_COMMON_URL_PATTERN_H_
      6 
      7 #include <functional>
      8 #include <iosfwd>
      9 #include <string>
     10 #include <vector>
     11 
     12 class GURL;
     13 
     14 // A pattern that can be used to match URLs. A URLPattern is a very restricted
     15 // subset of URL syntax:
     16 //
     17 // <url-pattern> := <scheme>://<host><port><path> | '<all_urls>'
     18 // <scheme> := '*' | 'http' | 'https' | 'file' | 'ftp' | 'chrome' |
     19 //             'chrome-extension' | 'filesystem'
     20 // <host> := '*' | '*.' <anychar except '/' and '*'>+
     21 // <port> := [':' ('*' | <port number between 0 and 65535>)]
     22 // <path> := '/' <any chars>
     23 //
     24 // * Host is not used when the scheme is 'file'.
     25 // * The path can have embedded '*' characters which act as glob wildcards.
     26 // * '<all_urls>' is a special pattern that matches any URL that contains a
     27 //   valid scheme (as specified by valid_schemes_).
     28 // * The '*' scheme pattern excludes file URLs.
     29 //
     30 // Examples of valid patterns:
     31 // - http://*/*
     32 // - http://*/foo*
     33 // - https://*.google.com/foo*bar
     34 // - file://monkey*
     35 // - http://127.0.0.1/*
     36 //
     37 // Examples of invalid patterns:
     38 // - http://* -- path not specified
     39 // - http://*foo/bar -- * not allowed as substring of host component
     40 // - http://foo.*.bar/baz -- * must be first component
     41 // - http:/bar -- scheme separator not found
     42 // - foo://* -- invalid scheme
     43 // - chrome:// -- we don't support chrome internal URLs
     44 class URLPattern {
     45  public:
     46   // A collection of scheme bitmasks for use with valid_schemes.
     47   enum SchemeMasks {
     48     SCHEME_NONE       = 0,
     49     SCHEME_HTTP       = 1 << 0,
     50     SCHEME_HTTPS      = 1 << 1,
     51     SCHEME_FILE       = 1 << 2,
     52     SCHEME_FTP        = 1 << 3,
     53     SCHEME_CHROMEUI   = 1 << 4,
     54     SCHEME_EXTENSION  = 1 << 5,
     55     SCHEME_FILESYSTEM = 1 << 6,
     56 
     57     // IMPORTANT!
     58     // SCHEME_ALL will match every scheme, including chrome://, chrome-
     59     // extension://, about:, etc. Because this has lots of security
     60     // implications, third-party extensions should usually not be able to get
     61     // access to URL patterns initialized this way. If there is a reason
     62     // for violating this general rule, document why this it safe.
     63     SCHEME_ALL      = -1,
     64   };
     65 
     66   // Error codes returned from Parse().
     67   enum ParseResult {
     68     PARSE_SUCCESS = 0,
     69     PARSE_ERROR_MISSING_SCHEME_SEPARATOR,
     70     PARSE_ERROR_INVALID_SCHEME,
     71     PARSE_ERROR_WRONG_SCHEME_SEPARATOR,
     72     PARSE_ERROR_EMPTY_HOST,
     73     PARSE_ERROR_INVALID_HOST_WILDCARD,
     74     PARSE_ERROR_EMPTY_PATH,
     75     PARSE_ERROR_INVALID_PORT,
     76     PARSE_ERROR_INVALID_HOST,
     77     NUM_PARSE_RESULTS
     78   };
     79 
     80   // The <all_urls> string pattern.
     81   static const char kAllUrlsPattern[];
     82 
     83   // Returns true if the given |scheme| is considered valid for extensions.
     84   static bool IsValidSchemeForExtensions(const std::string& scheme);
     85 
     86   explicit URLPattern(int valid_schemes);
     87 
     88   // Convenience to construct a URLPattern from a string. If the string is not
     89   // known ahead of time, use Parse() instead, which returns success or failure.
     90   URLPattern(int valid_schemes, const std::string& pattern);
     91 
     92   URLPattern();
     93   ~URLPattern();
     94 
     95   bool operator<(const URLPattern& other) const;
     96   bool operator>(const URLPattern& other) const;
     97   bool operator==(const URLPattern& other) const;
     98 
     99   // Initializes this instance by parsing the provided string. Returns
    100   // URLPattern::PARSE_SUCCESS on success, or an error code otherwise. On
    101   // failure, this instance will have some intermediate values and is in an
    102   // invalid state.
    103   ParseResult Parse(const std::string& pattern_str);
    104 
    105   // Gets the bitmask of valid schemes.
    106   int valid_schemes() const { return valid_schemes_; }
    107   void SetValidSchemes(int valid_schemes);
    108 
    109   // Gets the host the pattern matches. This can be an empty string if the
    110   // pattern matches all hosts (the input was <scheme>://*/<whatever>).
    111   const std::string& host() const { return host_; }
    112   void SetHost(const std::string& host);
    113 
    114   // Gets whether to match subdomains of host().
    115   bool match_subdomains() const { return match_subdomains_; }
    116   void SetMatchSubdomains(bool val);
    117 
    118   // Gets the path the pattern matches with the leading slash. This can have
    119   // embedded asterisks which are interpreted using glob rules.
    120   const std::string& path() const { return path_; }
    121   void SetPath(const std::string& path);
    122 
    123   // Returns true if this pattern matches all urls.
    124   bool match_all_urls() const { return match_all_urls_; }
    125   void SetMatchAllURLs(bool val);
    126 
    127   // Sets the scheme for pattern matches. This can be a single '*' if the
    128   // pattern matches all valid schemes (as defined by the valid_schemes_
    129   // property). Returns false on failure (if the scheme is not valid).
    130   bool SetScheme(const std::string& scheme);
    131   // Note: You should use MatchesScheme() instead of this getter unless you
    132   // absolutely need the exact scheme. This is exposed for testing.
    133   const std::string& scheme() const { return scheme_; }
    134 
    135   // Returns true if the specified scheme can be used in this URL pattern, and
    136   // false otherwise. Uses valid_schemes_ to determine validity.
    137   bool IsValidScheme(const std::string& scheme) const;
    138 
    139   // Returns true if this instance matches the specified URL.
    140   bool MatchesURL(const GURL& test) const;
    141 
    142   // Returns true if this instance matches the specified security origin.
    143   bool MatchesSecurityOrigin(const GURL& test) const;
    144 
    145   // Returns true if |test| matches our scheme.
    146   // Note that if test is "filesystem", this may fail whereas MatchesURL
    147   // may succeed.  MatchesURL is smart enough to look at the inner_url instead
    148   // of the outer "filesystem:" part.
    149   bool MatchesScheme(const std::string& test) const;
    150 
    151   // Returns true if |test| matches our host.
    152   bool MatchesHost(const std::string& test) const;
    153   bool MatchesHost(const GURL& test) const;
    154 
    155   // Returns true if |test| matches our path.
    156   bool MatchesPath(const std::string& test) const;
    157 
    158   // Returns true if the pattern is vague enough that it implies all hosts,
    159   // such as *://*/*.
    160   // This is an expensive method, and should be used sparingly!
    161   // You should probably use URLPatternSet::ShouldWarnAllHosts(), which is
    162   // cached.
    163   bool ImpliesAllHosts() const;
    164 
    165   // Returns true if the pattern only matches a single origin. The pattern may
    166   // include a path.
    167   bool MatchesSingleOrigin() const;
    168 
    169   // Sets the port. Returns false if the port is invalid.
    170   bool SetPort(const std::string& port);
    171   const std::string& port() const { return port_; }
    172 
    173   // Returns a string representing this instance.
    174   const std::string& GetAsString() const;
    175 
    176   // Determines whether there is a URL that would match this instance and
    177   // another instance. This method is symmetrical: Calling
    178   // other.OverlapsWith(this) would result in the same answer.
    179   bool OverlapsWith(const URLPattern& other) const;
    180 
    181   // Returns true if this pattern matches all possible URLs that |other| can
    182   // match. For example, http://*.google.com encompasses http://www.google.com.
    183   bool Contains(const URLPattern& other) const;
    184 
    185   // Converts this URLPattern into an equivalent set of URLPatterns that don't
    186   // use a wildcard in the scheme component. If this URLPattern doesn't use a
    187   // wildcard scheme, then the returned set will contain one element that is
    188   // equivalent to this instance.
    189   std::vector<URLPattern> ConvertToExplicitSchemes() const;
    190 
    191   static bool EffectiveHostCompare(const URLPattern& a, const URLPattern& b) {
    192     if (a.match_all_urls_ && b.match_all_urls_)
    193       return false;
    194     return a.host_.compare(b.host_) < 0;
    195   }
    196 
    197   // Used for origin comparisons in a std::set.
    198   class EffectiveHostCompareFunctor {
    199    public:
    200     bool operator()(const URLPattern& a, const URLPattern& b) const {
    201       return EffectiveHostCompare(a, b);
    202     }
    203   };
    204 
    205   // Get an error string for a ParseResult.
    206   static const char* GetParseResultString(URLPattern::ParseResult parse_result);
    207 
    208  private:
    209   // Returns true if any of the |schemes| items matches our scheme.
    210   bool MatchesAnyScheme(const std::vector<std::string>& schemes) const;
    211 
    212   // Returns true if all of the |schemes| items matches our scheme.
    213   bool MatchesAllSchemes(const std::vector<std::string>& schemes) const;
    214 
    215   bool MatchesSecurityOriginHelper(const GURL& test) const;
    216 
    217   // Returns true if our port matches the |port| pattern (it may be "*").
    218   bool MatchesPortPattern(const std::string& port) const;
    219 
    220   // If the URLPattern contains a wildcard scheme, returns a list of
    221   // equivalent literal schemes, otherwise returns the current scheme.
    222   std::vector<std::string> GetExplicitSchemes() const;
    223 
    224   // A bitmask containing the schemes which are considered valid for this
    225   // pattern. Parse() uses this to decide whether a pattern contains a valid
    226   // scheme.
    227   int valid_schemes_;
    228 
    229   // True if this is a special-case "<all_urls>" pattern.
    230   bool match_all_urls_;
    231 
    232   // The scheme for the pattern.
    233   std::string scheme_;
    234 
    235   // The host without any leading "*" components.
    236   std::string host_;
    237 
    238   // Whether we should match subdomains of the host. This is true if the first
    239   // component of the pattern's host was "*".
    240   bool match_subdomains_;
    241 
    242   // The port.
    243   std::string port_;
    244 
    245   // The path to match. This is everything after the host of the URL, or
    246   // everything after the scheme in the case of file:// URLs.
    247   std::string path_;
    248 
    249   // The path with "?" and "\" characters escaped for use with the
    250   // MatchPattern() function.
    251   std::string path_escaped_;
    252 
    253   // A string representing this URLPattern.
    254   mutable std::string spec_;
    255 };
    256 
    257 std::ostream& operator<<(std::ostream& out, const URLPattern& url_pattern);
    258 
    259 typedef std::vector<URLPattern> URLPatternList;
    260 
    261 #endif  // EXTENSIONS_COMMON_URL_PATTERN_H_
    262