Introduce exception filter rules.

Allow for patterns to start with a - to mark exceptions. A URL matches a
filter, if it matches at least one pattern and no exception.

BUG=16932
TEST=covered by unit_tests

Review URL: http://codereview.chromium.org/541009

git-svn-id: svn://svn.chromium.org/chrome/trunk/src@35999 0039d316-1c4b-4281-b951-d872f2087c98

6 files changed, 41 insertions, 8 deletions

diff --git a/chrome/browser/privacy_blacklist/blacklist.cc b/chrome/browser/privacy_blacklist/blacklist.cc
index 1bec742..581f65a 100644
--- a/chrome/browser/privacy_blacklist/blacklist.cc
+++ b/chrome/browser/privacy_blacklist/blacklist.cc
@@ -112,8 +112,12 @@ bool Blacklist::Entry::IsBlocked(const GURL& url) const {
     ((attributes_ & kBlockUnsecure) && !url.SchemeIsSecure());
 }
 
-Blacklist::Entry::Entry(const std::string& pattern, const Provider* provider)
-    : pattern_(pattern), attributes_(0), provider_(provider) {}
+Blacklist::Entry::Entry(const std::string& pattern, const Provider* provider,
+                        bool is_exception)
+    : attributes_(0),
+      is_exception_(is_exception),
+      pattern_(pattern),
+      provider_(provider) {}
 
 void Blacklist::Entry::AddAttributes(unsigned int attributes) {
   attributes_ |= attributes;
diff --git a/chrome/browser/privacy_blacklist/blacklist.h b/chrome/browser/privacy_blacklist/blacklist.h
index 2fba5fb..b4d26d0 100644
--- a/chrome/browser/privacy_blacklist/blacklist.h
+++ b/chrome/browser/privacy_blacklist/blacklist.h
@@ -75,7 +75,8 @@ class Blacklist {
   class Entry {
    public:
     // Construct with given pattern.
-    Entry(const std::string& pattern, const Provider* provider);
+    Entry(const std::string& pattern, const Provider* provider,
+          bool is_exception);
 
     // Returns the pattern which this entry matches.
     const std::string& pattern() const { return pattern_; }
@@ -108,8 +109,11 @@ class Blacklist {
     // Merge the attributes and types of the given entry with this one.
     void Merge(const Entry& entry);
 
-    std::string pattern_;
     unsigned int attributes_;
+
+    // True if this entry is an exception to the blacklist.
+    bool is_exception_;
+    std::string pattern_;
     std::vector<std::string> types_;
 
     // Points to the provider of this entry, the providers are all
diff --git a/chrome/browser/privacy_blacklist/blacklist_io.cc b/chrome/browser/privacy_blacklist/blacklist_io.cc
index 10f09dc..5567202 100644
--- a/chrome/browser/privacy_blacklist/blacklist_io.cc
+++ b/chrome/browser/privacy_blacklist/blacklist_io.cc
@@ -18,6 +18,7 @@ namespace {
 const char header[] = "[Chromium::PrivacyBlacklist]";
 const char name_tag[] = "Name:";
 const char url_tag[] = "URL:";
+const char whitelist_tag[] = "-";
 const char arrow_tag[] = "=>";
 const char eol[] = "\n\r";
 
@@ -106,6 +107,16 @@ bool BlacklistIO::ReadText(Blacklist* blacklist,
       continue;
     }
 
+    bool is_exception = false;
+    if (StartsWith(cur, end, whitelist_tag, arraysize(whitelist_tag))) {
+      is_exception = true;
+      cur++;
+      if (IsAsciiWhitespace(*cur)) {
+        *error_string = "Dash followed by white space.";
+        return false;
+      }
+    }
+
     const char* skip = std::find_if(cur, end, IsWhiteSpace());
     std::string pattern(cur, skip);
 
@@ -115,7 +126,8 @@ bool BlacklistIO::ReadText(Blacklist* blacklist,
       return false;
     }
 
-    linked_ptr<Blacklist::Entry> entry(new Blacklist::Entry(pattern, provider));
+    linked_ptr<Blacklist::Entry> entry(new Blacklist::Entry(pattern, provider,
+                                       is_exception));
 
     cur = std::find_if(cur + arraysize(arrow_tag), end, IsNotWhiteSpace());
     skip = std::find_first_of(cur, end, eol, eol + 2);
@@ -211,13 +223,15 @@ bool BlacklistIO::ReadBinary(Blacklist* blacklist, const FilePath& path) {
 
   std::string pattern;
   unsigned int attributes, provider;
+  bool is_exception;
   std::vector<std::string> types;
   for (size_t i = 0; i < num_entries; ++i) {
-    if (!input.ReadEntry(&pattern, &attributes, &types, &provider))
+    if (!input.ReadEntry(&pattern, &attributes, &types, &is_exception,
+                         &provider))
       return false;
 
     Blacklist::Entry* entry =
-        new Blacklist::Entry(pattern, provider_map[provider]);
+        new Blacklist::Entry(pattern, provider_map[provider], is_exception);
     entry->AddAttributes(attributes);
     entry->SwapTypes(&types);
     entries.push_back(linked_ptr<Blacklist::Entry>(entry));
@@ -269,6 +283,7 @@ bool BlacklistIO::WriteBinary(const Blacklist* blacklist,
     if (!output.StoreEntry((*i)->pattern_,
                            (*i)->attributes_,
                            (*i)->types_,
+                           (*i)->is_exception_,
                            index[(*i)->provider_])) {
       return false;
     }
diff --git a/chrome/browser/privacy_blacklist/blacklist_store.cc b/chrome/browser/privacy_blacklist/blacklist_store.cc
index 327b255..87f5f1d 100644
--- a/chrome/browser/privacy_blacklist/blacklist_store.cc
+++ b/chrome/browser/privacy_blacklist/blacklist_store.cc
@@ -13,7 +13,7 @@
 
 namespace {
 
-const char cookie[] = "GCPBL100";
+const char cookie[] = "GCPBL200";
 
 const size_t kMaxBlockedTypes = 256;
 const size_t kMaxStringSize = 8192;
@@ -55,9 +55,11 @@ bool BlacklistStoreOutput::ReserveEntries(uint32 num) {
 bool BlacklistStoreOutput::StoreEntry(const std::string& pattern,
                                       uint32 attributes,
                                       const std::vector<std::string>& types,
+                                      bool is_exception,
                                       uint32 provider) {
   if (WriteString(pattern) &&
       WriteUInt(attributes) &&
+      WriteUInt(is_exception ? 1 : 0) &&
       WriteUInt(types.size())) {
     for (uint32 i = 0; i < types.size(); ++i) {
       if (!WriteString(types[i]))
@@ -117,6 +119,7 @@ uint32 BlacklistStoreInput::ReadNumEntries() {
 bool BlacklistStoreInput::ReadEntry(std::string* pattern,
                                     uint32* attributes,
                                     std::vector<std::string>* types,
+                                    bool* is_exception,
                                     uint32* provider) {
   *pattern = ReadString();
   if (pattern->empty())
@@ -126,6 +129,11 @@ bool BlacklistStoreInput::ReadEntry(std::string* pattern,
   if (*attributes == std::numeric_limits<uint32>::max())
     return false;
 
+  uint32 exception = ReadUInt();
+  if (exception == std::numeric_limits<uint32>::max())
+    return false;
+  *is_exception = (exception == 1);
+
   if (uint32 n = ReadUInt()) {
     if (n >= kMaxBlockedTypes)
       return false;
diff --git a/chrome/browser/privacy_blacklist/blacklist_store.h b/chrome/browser/privacy_blacklist/blacklist_store.h
index 5907fb7..63f7c12 100644
--- a/chrome/browser/privacy_blacklist/blacklist_store.h
+++ b/chrome/browser/privacy_blacklist/blacklist_store.h
@@ -44,6 +44,7 @@ class BlacklistStoreOutput {
   bool StoreEntry(const std::string& pattern,
                   uint32 attributes,
                   const std::vector<std::string>& types,
+                  bool is_exception,
                   uint32 provider);
 
  private:
@@ -87,6 +88,7 @@ class BlacklistStoreInput {
   bool ReadEntry(std::string* pattern,
                  uint32* attributes,
                  std::vector<std::string>* types,
+                 bool* is_exception,
                  uint32* provider);
 
  private:
diff --git a/chrome/test/data/blacklist_small.pbr b/chrome/test/data/blacklist_small.pbr
index c3f8571..2c0417a 100644
--- a/chrome/test/data/blacklist_small.pbr
+++ b/chrome/test/data/blacklist_small.pbr