Implement event logging for intent firewall

# ConfigUpdateInstallReceiver.java

# ---------------------------

51300 config_install_failed (dir|3)

# ---------------------------

# IntentFirewall.java

# ---------------------------

51400 ifw_intent_matched (Intent Type|1|5),(Component Name|3),(Caller Uid|1|5),(Caller Pkg Count|1|1),(Caller Pkgs|3),(Action|3),(MIME Type|3),(URI|3),(Flags|1|5)

package com.android.server.firewall;

import android.app.AppGlobals;

import android.content.ComponentName;

import android.content.Intent;

import android.content.IntentFilter;

import android.content.pm.ActivityInfo;

import android.content.pm.ApplicationInfo;

import android.content.pm.IPackageManager;

import android.content.pm.PackageManager;

import android.os.Environment;

import android.os.ServiceManager;

import android.os.RemoteException;

import android.util.Slog;

import android.util.Xml;

import com.android.internal.util.XmlUtils;

import com.android.server.EventLogTags;

import com.android.server.IntentResolver;

import com.android.server.pm.PackageManagerService;

import org.xmlpull.v1.XmlPullParser;

import org.xmlpull.v1.XmlPullParserException;

    private static final File RULES_FILE =

            new File(Environment.getSystemSecureDirectory(), "ifw/ifw.xml");

    private static final int LOG_PACKAGES_MAX_LENGTH = 150;

    private static final int LOG_PACKAGES_SUFFICIENT_LENGTH = 125;

    private static final String TAG_RULES = "rules";

    private static final String TAG_ACTIVITY = "activity";

    private static final String TAG_SERVICE = "service";

    private static final String TAG_BROADCAST = "broadcast";

    private static final int TYPE_ACTIVITY = 0;

    private static final int TYPE_SERVICE = 1;

    private static final int TYPE_BROADCAST = 2;

    private static final HashMap<String, FilterFactory> factoryMap;

    private final AMSInterface mAms;

        }

        if (log) {

            // TODO: log info about intent to event log

            logIntent(TYPE_ACTIVITY, intent, callerUid, resolvedType);

        }

        return !block;

    }

    private static void logIntent(int intentType, Intent intent, int callerUid,

            String resolvedType) {

        // The component shouldn't be null, but let's double check just to be safe

        ComponentName cn = intent.getComponent();

        String shortComponent = null;

        if (cn != null) {

            shortComponent = cn.flattenToShortString();

        }

        String callerPackages = null;

        int callerPackageCount = 0;

        IPackageManager pm = AppGlobals.getPackageManager();

        if (pm != null) {

            try {

                String[] callerPackagesArray = pm.getPackagesForUid(callerUid);

                if (callerPackagesArray != null) {

                    callerPackageCount = callerPackagesArray.length;

                    callerPackages = joinPackages(callerPackagesArray);

                }

            } catch (RemoteException ex) {

                Slog.e(TAG, "Remote exception while retrieving packages", ex);

            }

        }

        EventLogTags.writeIfwIntentMatched(intentType, shortComponent, callerUid,

                callerPackageCount, callerPackages, intent.getAction(), resolvedType,

                intent.getDataString(), intent.getFlags());

    }

    /**

     * Joins a list of package names such that the resulting string is no more than

     * LOG_PACKAGES_MAX_LENGTH.

     *

     * Only full package names will be added to the result, unless every package is longer than the

     * limit, in which case one of the packages will be truncated and added. In this case, an

     * additional '-' character will be added to the end of the string, to denote the truncation.

     *

     * If it encounters a package that won't fit in the remaining space, it will continue on to the

     * next package, unless the total length of the built string so far is greater than

     * LOG_PACKAGES_SUFFICIENT_LENGTH, in which case it will stop and return what it has.

     */

    private static String joinPackages(String[] packages) {

        boolean first = true;

        StringBuilder sb = new StringBuilder();

        for (int i=0; i<packages.length; i++) {

            String pkg = packages[i];

            // + 1 length for the comma. This logic technically isn't correct for the first entry,

            // but it's not critical.

            if (sb.length() + pkg.length() + 1 < LOG_PACKAGES_MAX_LENGTH) {

                if (!first) {

                    sb.append(',');

                } else {

                    first = false;

                }

                sb.append(pkg);

            } else if (sb.length() >= LOG_PACKAGES_SUFFICIENT_LENGTH) {

                return sb.toString();

            }

        }

        if (sb.length() == 0 && packages.length > 0) {

            String pkg = packages[0];

            // truncating from the end - the last part of the package name is more likely to be

            // interesting/unique

            return pkg.substring(pkg.length() - LOG_PACKAGES_MAX_LENGTH + 1) + '-';

        }

        return null;

    }

    public static File getRulesFile() {

        return RULES_FILE;

    }

    }

    boolean signaturesMatch(int uid1, int uid2) {

        PackageManagerService pm = (PackageManagerService)ServiceManager.getService("package");

        try {

            IPackageManager pm = AppGlobals.getPackageManager();

            return pm.checkUidSignatures(uid1, uid2) == PackageManager.SIGNATURE_MATCH;

        } catch (RemoteException ex) {

            Slog.e(TAG, "Remote exception while checking signatures", ex);

            return false;

        }

    }

}