module/krate-builder.cpp

   1 /*
   2  *  Copyright (c) 2015 Samsung Electronics Co., Ltd All Rights Reserved
   3  *
   4  *  Licensed under the Apache License, Version 2.0 (the "License");
   5  *  you may not use this file except in compliance with the License.
   6  *  You may obtain a copy of the License at
   7  *
   8  *      http://www.apache.org/licenses/LICENSE-2.0
   9  *
  10  *  Unless required by applicable law or agreed to in writing, software
  11  *  distributed under the License is distributed on an "AS IS" BASIS,
  12  *  WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
  13  *  See the License for the specific language governing permissions and
  14  *  limitations under the License
  15  */
  16 #include <fcntl.h>
  17 #include <unistd.h>
  18 #include <sys/stat.h>
  19 #include <sys/types.h>
  20 #include <sys/mount.h>
  21
  22 #include "krate-builder.h"
  23
  24 #include <klay/exception.h>
  25 #include <klay/namespace.h>
  26 #include <klay/filesystem.h>
  27
  28 #define CGROUP_SUBSYSTEM "krate"
  29
  30 KrateBuilder::KrateBuilder(const runtime::User& user) :
  31         user(user)
  32 {
  33         runtime::File data(getManifestPath());
  34         if (data.exists()) {
  35                 manifest.reset(xml::Parser::parseFile(data.getPath()));
  36         }
  37 }
  38
  39 KrateBuilder::~KrateBuilder()
  40 {
  41 }
  42
  43 std::string KrateBuilder::getManifestPath()
  44 {
  45         return "/home/" + user.getName() + "/.config/krate/krate.xml";
  46 }
  47
  48 void KrateBuilder::bindFilesystemNode(const std::string& source, const std::string& target,
  49                                                                          const std::string& type, const std::string& options,
  50                                                                          bool create)
  51 {
  52         if (create) {
  53                 runtime::File dir(target);
  54                 if (!dir.exists()) {
  55                         dir.makeDirectory(true, user.getUid(), user.getGid());
  56                 }
  57         }
  58
  59         runtime::Mount::mountEntry(source, target, type, options);
  60 }
  61
  62 void KrateBuilder::mountOwnFilesystem()
  63 {
  64         if (manifest.get()) {
  65                 xml::Node::NodeList entries = manifest->evaluate("/manifest/filesystem/entry");
  66                 for (const xml::Node& entry : entries) {
  67                         bindFilesystemNode(entry.getProp("source"), entry.getProp("target"),
  68                                                            entry.getProp("type"), entry.getProp("options"));
  69                 }
  70         }
  71
  72         bindFilesystemNode("/home/" + user.getName(),
  73                                            "/home/" + user.getName() + "/.krate/" + user.getName(),
  74                                            "none", "rw,bind");
  75
  76         bindFilesystemNode("/home/" + user.getName() + "/.krate", "/home",
  77                                            "none", "rw,rbind");
  78 }
  79
  80 void KrateBuilder::enterKrate()
  81 {
  82         std::string path = CGROUP_SUBSYSTEM "/" + user.getName();
  83         pid_t pid = 0;
  84
  85         if (runtime::Cgroup::exist(CGROUP_SUBSYSTEM, path)) {
  86                 auto pids = runtime::Cgroup::getProcessList(CGROUP_SUBSYSTEM, path);
  87                 if (pids.size() > 0) {
  88                         pid  = pids[0];
  89                 }
  90         } else {
  91                 runtime::Cgroup::create(CGROUP_SUBSYSTEM, path);
  92         }
  93
  94         if (pid == 0) {
  95                 runtime::Cgroup::addProcess(CGROUP_SUBSYSTEM, path, ::getpid());
  96                 runtime::Namespace::unshare(CLONE_NEWNS | CLONE_NEWIPC);
  97         } else {
  98                 runtime::Namespace::attach(pid);
  99         }
 100 }
 101
 102 void KrateBuilder::exitKrate()
 103 {
 104         std::string path =  CGROUP_SUBSYSTEM "/" + user.getName();
 105         auto pids = runtime::Cgroup::getProcessList(CGROUP_SUBSYSTEM, path);
 106         if (pids.size() <= 1) {
 107                 runtime::Cgroup::destroy(CGROUP_SUBSYSTEM, path);
 108         }
 109 }