Line data    Source code

       1             : // Copyright (C) 2009 The Android Open Source Project
       2             : //
       3             : // Licensed under the Apache License, Version 2.0 (the "License");
       4             : // you may not use this file except in compliance with the License.
       5             : // You may obtain a copy of the License at
       6             : //
       7             : // http://www.apache.org/licenses/LICENSE-2.0
       8             : //
       9             : // Unless required by applicable law or agreed to in writing, software
      10             : // distributed under the License is distributed on an "AS IS" BASIS,
      11             : // WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
      12             : // See the License for the specific language governing permissions and
      13             : // limitations under the License.
      14             : 
      15             : package com.google.gerrit.httpd.raw;
      16             : 
      17             : import static com.google.gerrit.server.project.ProjectCache.illegalState;
      18             : 
      19             : import com.google.gerrit.entities.Change;
      20             : import com.google.gerrit.entities.Patch;
      21             : import com.google.gerrit.entities.PatchSet;
      22             : import com.google.gerrit.extensions.restapi.AuthException;
      23             : import com.google.gerrit.extensions.restapi.ResourceConflictException;
      24             : import com.google.gerrit.extensions.restapi.Url;
      25             : import com.google.gerrit.server.PatchSetUtil;
      26             : import com.google.gerrit.server.edit.ChangeEdit;
      27             : import com.google.gerrit.server.edit.ChangeEditUtil;
      28             : import com.google.gerrit.server.notedb.ChangeNotes;
      29             : import com.google.gerrit.server.permissions.ChangePermission;
      30             : import com.google.gerrit.server.permissions.PermissionBackend;
      31             : import com.google.gerrit.server.permissions.PermissionBackendException;
      32             : import com.google.gerrit.server.project.NoSuchChangeException;
      33             : import com.google.gerrit.server.project.ProjectCache;
      34             : import com.google.inject.Inject;
      35             : import com.google.inject.Singleton;
      36             : import java.io.IOException;
      37             : import java.util.Optional;
      38             : import javax.servlet.http.HttpServlet;
      39             : import javax.servlet.http.HttpServletRequest;
      40             : import javax.servlet.http.HttpServletResponse;
      41             : import org.eclipse.jgit.lib.ObjectId;
      42             : 
      43             : /**
      44             :  * Exports a single version of a patch as a normal file download.
      45             :  *
      46             :  * <p>This can be relatively unsafe with Microsoft Internet Explorer 6.0 as the browser will (rather
      47             :  * incorrectly) treat an HTML or JavaScript file its supposed to download as though it was served by
      48             :  * this site, and will execute it with the site's own protection domain. This opens a massive
      49             :  * security hole so we package the content into a zip file.
      50             :  */
      51             : @Singleton
      52             : public class CatServlet extends HttpServlet {
      53             :   private static final long serialVersionUID = 1L;
      54             : 
      55             :   private final ChangeEditUtil changeEditUtil;
      56             :   private final PatchSetUtil psUtil;
      57             :   private final ChangeNotes.Factory changeNotesFactory;
      58             :   private final PermissionBackend permissionBackend;
      59             :   private final ProjectCache projectCache;
      60             : 
      61             :   @Inject
      62             :   CatServlet(
      63             :       ChangeEditUtil ceu,
      64             :       PatchSetUtil psu,
      65             :       ChangeNotes.Factory cnf,
      66             :       PermissionBackend pb,
      67          99 :       ProjectCache pc) {
      68          99 :     changeEditUtil = ceu;
      69          99 :     psUtil = psu;
      70          99 :     changeNotesFactory = cnf;
      71          99 :     permissionBackend = pb;
      72          99 :     projectCache = pc;
      73          99 :   }
      74             : 
      75             :   @Override
      76             :   protected void doGet(HttpServletRequest req, HttpServletResponse rsp) throws IOException {
      77           0 :     String keyStr = req.getPathInfo();
      78             : 
      79             :     // We shouldn't have to do this extra decode pass, but somehow we
      80             :     // are now receiving our "^1" suffix as "%5E1", which confuses us
      81             :     // downstream. Other times we get our embedded "," as "%2C", which
      82             :     // is equally bad. And yet when these happen a "%2F" is left as-is,
      83             :     // rather than escaped as "%252F", which makes me feel really really
      84             :     // uncomfortable with a blind decode right here.
      85             :     //
      86           0 :     keyStr = Url.decode(keyStr);
      87             : 
      88           0 :     if (!keyStr.startsWith("/")) {
      89           0 :       rsp.sendError(HttpServletResponse.SC_NOT_FOUND);
      90           0 :       return;
      91             :     }
      92           0 :     keyStr = keyStr.substring(1);
      93             : 
      94             :     final Patch.Key patchKey;
      95             :     final int side;
      96             :     {
      97           0 :       final int c = keyStr.lastIndexOf('^');
      98           0 :       if (c == 0) {
      99           0 :         rsp.sendError(HttpServletResponse.SC_NOT_FOUND);
     100           0 :         return;
     101             :       }
     102             : 
     103           0 :       if (c < 0) {
     104           0 :         side = 0;
     105             :       } else {
     106             :         try {
     107           0 :           side = Integer.parseInt(keyStr.substring(c + 1));
     108           0 :           keyStr = keyStr.substring(0, c);
     109           0 :         } catch (NumberFormatException e) {
     110           0 :           rsp.sendError(HttpServletResponse.SC_NOT_FOUND);
     111           0 :           return;
     112           0 :         }
     113             :       }
     114             : 
     115             :       try {
     116           0 :         patchKey = Patch.Key.parse(keyStr);
     117           0 :       } catch (NumberFormatException e) {
     118           0 :         rsp.sendError(HttpServletResponse.SC_NOT_FOUND);
     119           0 :         return;
     120           0 :       }
     121             :     }
     122             : 
     123           0 :     final Change.Id changeId = patchKey.patchSetId().changeId();
     124             :     String revision;
     125             :     try {
     126           0 :       ChangeNotes notes = changeNotesFactory.createCheckedUsingIndexLookup(changeId);
     127           0 :       permissionBackend.currentUser().change(notes).check(ChangePermission.READ);
     128           0 :       projectCache
     129           0 :           .get(notes.getProjectName())
     130           0 :           .orElseThrow(illegalState(notes.getProjectName()))
     131           0 :           .checkStatePermitsRead();
     132           0 :       if (patchKey.patchSetId().get() == 0) {
     133             :         // change edit
     134           0 :         Optional<ChangeEdit> edit = changeEditUtil.byChange(notes);
     135           0 :         if (edit.isPresent()) {
     136           0 :           revision = ObjectId.toString(edit.get().getEditCommit());
     137             :         } else {
     138           0 :           rsp.sendError(HttpServletResponse.SC_NOT_FOUND);
     139           0 :           return;
     140             :         }
     141           0 :       } else {
     142           0 :         PatchSet patchSet = psUtil.get(notes, patchKey.patchSetId());
     143           0 :         if (patchSet == null) {
     144           0 :           rsp.sendError(HttpServletResponse.SC_NOT_FOUND);
     145           0 :           return;
     146             :         }
     147           0 :         revision = patchSet.commitId().name();
     148             :       }
     149           0 :     } catch (ResourceConflictException | NoSuchChangeException | AuthException e) {
     150           0 :       rsp.sendError(HttpServletResponse.SC_NOT_FOUND);
     151           0 :       return;
     152           0 :     } catch (PermissionBackendException | IOException e) {
     153           0 :       getServletContext().log("Cannot query database", e);
     154           0 :       rsp.sendError(HttpServletResponse.SC_INTERNAL_SERVER_ERROR);
     155           0 :       return;
     156           0 :     }
     157             : 
     158           0 :     String path = patchKey.fileName();
     159           0 :     String restUrl =
     160           0 :         String.format(
     161             :             "%s/changes/%d/revisions/%s/files/%s/download?parent=%d",
     162           0 :             req.getContextPath(), changeId.get(), revision, Url.encode(path), side);
     163           0 :     rsp.sendRedirect(restUrl);
     164           0 :   }
     165             : }