commit 6bd23bc373a372b010d5bdfb659ca3e17fcf864c Author: Mike Perry <mikeperry-git@fscked.org> Date: Wed Dec 28 22:12:08 2011 -0600 Add patch for font limiting. --- ...13-Limit-the-number-of-fonts-per-document.patch | 228 ++++++++++++++++++++ 1 files changed, 228 insertions(+), 0 deletions(-) diff --git a/src/current-patches/firefox/0013-Limit-the-number-of-fonts-per-document.patch b/src/current-patches/firefox/0013-Limit-the-number-of-fonts-per-document.patch new file mode 100644 index 0000000..989d072 --- /dev/null +++ b/src/current-patches/firefox/0013-Limit-the-number-of-fonts-per-document.patch @@ -0,0 +1,228 @@ +From 27c2a4a72504fe9a08cbfdf2210b05263bd693dd Mon Sep 17 00:00:00 2001 +From: Mike Perry <mikeperry-git@fscked.org> +Date: Tue, 27 Dec 2011 15:28:22 -0600 +Subject: [PATCH 13/13] Limit the number of fonts per document. + +We create two prefs: +browser.display.max_font_count and browser.display.max_font_attempts. +max_font_count sets a limit on the number of fonts actually used in the +document, and max_font_attempts sets a limit on the total number of CSS +queries that a document is allowed to perform. + +Once either limit is reached, the browser behaves as if +browser.display.use_document_fonts was set to 0 for subsequent font queries. + +If a pref is not set or is negative, that limit does not apply. + +This is done to address: +https://www.torproject.org/projects/torbrowser/design/#fingerprinting-linkab... +--- + layout/base/nsPresContext.cpp | 100 +++++++++++++++++++++++++++++++++++++++++ + layout/base/nsPresContext.h | 9 ++++ + layout/style/nsRuleNode.cpp | 13 ++++- + 3 files changed, 119 insertions(+), 3 deletions(-) + +diff --git a/layout/base/nsPresContext.cpp b/layout/base/nsPresContext.cpp +index 0d5b1ce..ab9a7ba 100644 +--- a/layout/base/nsPresContext.cpp ++++ b/layout/base/nsPresContext.cpp +@@ -98,6 +98,8 @@ + #include "nsIFrameMessageManager.h" + #include "FrameLayerBuilder.h" + #include "nsDOMMediaQueryList.h" ++#include "nsString.h" ++#include "nsUnicharUtils.h" + + #ifdef MOZ_SMIL + #include "nsSMILAnimationController.h" +@@ -707,6 +709,10 @@ nsPresContext::GetUserPreferences() + // * use fonts? + mUseDocumentFonts = + Preferences::GetInt("browser.display.use_document_fonts") != 0; ++ mMaxFonts = ++ Preferences::GetInt("browser.display.max_font_count", -1); ++ mMaxFontAttempts = ++ Preferences::GetInt("browser.display.max_font_attempts", -1); + + // * replace backslashes with Yen signs? (bug 245770) + mEnableJapaneseTransform = +@@ -1306,6 +1312,100 @@ nsPresContext::GetDefaultFont(PRUint8 aFontID) const + return font; + } + ++PRBool ++nsPresContext::FontUseCountReached(const nsFont &font) { ++ if (mMaxFonts < 0) { ++ return PR_FALSE; ++ } ++ ++ for (PRUint32 i = 0; i < mFontsUsed.Length(); i++) { ++ if (mFontsUsed[i].name.Equals(font.name, ++ nsCaseInsensitiveStringComparator()) ++ // XXX: Style is sometimes filled with garbage?? ++ /*&& mFontsUsed[i].style == font.style*/) { ++ // seen it before: OK ++ return PR_FALSE; ++ } ++ } ++ ++ if (mFontsUsed.Length() >= mMaxFonts) { ++ return PR_TRUE; ++ } ++ ++ return PR_FALSE; ++} ++ ++PRBool ++nsPresContext::FontAttemptCountReached(const nsFont &font) { ++ if (mMaxFontAttempts < 0) { ++ return PR_FALSE; ++ } ++ ++ for (PRUint32 i = 0; i < mFontsTried.Length(); i++) { ++ if (mFontsTried[i].name.Equals(font.name, ++ nsCaseInsensitiveStringComparator()) ++ // XXX: Style is sometimes filled with garbage?? ++ /*&& mFontsTried[i].style == font.style*/) { ++ // seen it before: OK ++ return PR_FALSE; ++ } ++ } ++ ++ if (mFontsTried.Length() >= mMaxFontAttempts) { ++ return PR_TRUE; ++ } ++ ++ return PR_FALSE; ++} ++ ++void ++nsPresContext::AddFontUse(const nsFont &font) { ++ if (mMaxFonts < 0) { ++ return; ++ } ++ ++ for (PRUint32 i = 0; i < mFontsUsed.Length(); i++) { ++ if (mFontsUsed[i].name.Equals(font.name, ++ nsCaseInsensitiveStringComparator()) ++ // XXX: Style is sometimes filled with garbage?? ++ /*&& mFontsUsed[i].style == font.style*/) { ++ // seen it before: OK ++ return; ++ } ++ } ++ ++ if (mFontsUsed.Length() >= mMaxFonts) { ++ return; ++ } ++ ++ mFontsUsed.AppendElement(font); ++ return; ++} ++ ++void ++nsPresContext::AddFontAttempt(const nsFont &font) { ++ if (mMaxFontAttempts < 0) { ++ return; ++ } ++ ++ for (PRUint32 i = 0; i < mFontsTried.Length(); i++) { ++ if (mFontsTried[i].name.Equals(font.name, ++ nsCaseInsensitiveStringComparator()) ++ // XXX: Style is sometimes filled with garbage?? ++ /*&& mFontsTried[i].style == font.style*/) { ++ // seen it before: OK ++ return; ++ } ++ } ++ ++ if (mFontsTried.Length() >= mMaxFontAttempts) { ++ return; ++ } ++ ++ mFontsTried.AppendElement(font); ++ return; ++} ++ + void + nsPresContext::SetFullZoom(float aZoom) + { +diff --git a/layout/base/nsPresContext.h b/layout/base/nsPresContext.h +index 2b09cc0..fe8a926 100644 +--- a/layout/base/nsPresContext.h ++++ b/layout/base/nsPresContext.h +@@ -548,6 +548,13 @@ public: + } + } + ++ nsTArray<nsFont> mFontsUsed; // currently for font-count limiting only ++ nsTArray<nsFont> mFontsTried; // currently for font-count limiting only ++ void AddFontUse(const nsFont &font); ++ void AddFontAttempt(const nsFont &font); ++ PRBool FontUseCountReached(const nsFont &font); ++ PRBool FontAttemptCountReached(const nsFont &font); ++ + PRInt32 MinFontSize() const { + return NS_MAX(mMinFontSize, mMinimumFontSizePref); + } +@@ -1123,6 +1130,8 @@ protected: + PRUint32 mInterruptChecksToSkip; + + mozilla::TimeStamp mReflowStartTime; ++ PRInt32 mMaxFontAttempts; ++ PRInt32 mMaxFonts; + + unsigned mHasPendingInterrupt : 1; + unsigned mInterruptsEnabled : 1; +diff --git a/layout/style/nsRuleNode.cpp b/layout/style/nsRuleNode.cpp +index a791723..5d65984 100644 +--- a/layout/style/nsRuleNode.cpp ++++ b/layout/style/nsRuleNode.cpp +@@ -3087,6 +3087,7 @@ nsRuleNode::ComputeFontData(void* aStartStruct, + + // See if there is a minimum font-size constraint to honor + nscoord minimumFontSize = mPresContext->MinFontSize(); ++ PRBool isXUL = PR_FALSE; + + if (minimumFontSize < 0) + minimumFontSize = 0; +@@ -3098,10 +3099,10 @@ nsRuleNode::ComputeFontData(void* aStartStruct, + // We only need to know this to determine if we have to use the + // document fonts (overriding the useDocumentFonts flag), or to + // determine if we have to override the minimum font-size constraint. +- if ((!useDocumentFonts || minimumFontSize > 0) && mPresContext->IsChrome()) { ++ if (mPresContext->IsChrome()) { + // if we are not using document fonts, but this is a XUL document, + // then we use the document fonts anyway +- useDocumentFonts = PR_TRUE; ++ isXUL = PR_TRUE; + minimumFontSize = 0; + } + +@@ -3116,9 +3117,13 @@ nsRuleNode::ComputeFontData(void* aStartStruct, + // generic? + nsFont::GetGenericID(font->mFont.name, &generic); + ++ mPresContext->AddFontAttempt(font->mFont); ++ + // If we aren't allowed to use document fonts, then we are only entitled + // to use the user's default variable-width font and fixed-width font +- if (!useDocumentFonts) { ++ if (!isXUL && (!useDocumentFonts || ++ mPresContext->FontAttemptCountReached(font->mFont) || ++ mPresContext->FontUseCountReached(font->mFont))) { + // Extract the generic from the specified font family... + nsAutoString genericName; + if (!font->mFont.EnumerateFamilies(ExtractGeneric, &genericName)) { +@@ -3154,6 +3159,8 @@ nsRuleNode::ComputeFontData(void* aStartStruct, + minimumFontSize, font); + } + ++ if (font->mGenericID == kGenericFont_NONE) ++ mPresContext->AddFontUse(font->mFont); + COMPUTE_END_INHERITED(Font, font) + } + +-- +1.7.3.4 +