ceph/src/common/admin_socket.h

   1 // -*- mode:C++; tab-width:8; c-basic-offset:2; indent-tabs-mode:t -*-
   2 // vim: ts=8 sw=2 smarttab
   3 /*
   4  * Ceph - scalable distributed file system
   5  *
   6  * Copyright (C) 2011 New Dream Network
   7  *
   8  * This is free software; you can redistribute it and/or
   9  * modify it under the terms of the GNU Lesser General Public
  10  * License version 2.1, as published by the Free Software
  11  * Foundation.  See file COPYING.
  12  *
  13  */
  14
  15 #ifndef CEPH_COMMON_ADMIN_SOCKET_H
  16 #define CEPH_COMMON_ADMIN_SOCKET_H
  17
  18 #include <condition_variable>
  19 #include <mutex>
  20 #include <string>
  21 #include <string_view>
  22 #include <thread>
  23
  24 #include "include/buffer.h"
  25 #include "common/cmdparse.h"
  26
  27 class AdminSocket;
  28 class CephContext;
  29
  30 using namespace std::literals;
  31
  32 inline constexpr auto CEPH_ADMIN_SOCK_VERSION = "2"sv;
  33
  34 class AdminSocketHook {
  35 public:
  36   virtual bool call(std::string_view command, const cmdmap_t& cmdmap,
  37                     std::string_view format, bufferlist& out) = 0;
  38   virtual ~AdminSocketHook() {}
  39 };
  40
  41 class AdminSocket
  42 {
  43 public:
  44   AdminSocket(CephContext *cct);
  45   ~AdminSocket();
  46
  47   AdminSocket(const AdminSocket&) = delete;
  48   AdminSocket& operator =(const AdminSocket&) = delete;
  49   AdminSocket(AdminSocket&&) = delete;
  50   AdminSocket& operator =(AdminSocket&&) = delete;
  51
  52   /**
  53    * register an admin socket command
  54    *
  55    * The command is registered under a command string.  Incoming
  56    * commands are split by space and matched against the longest
  57    * registered command.  For example, if 'foo' and 'foo bar' are
  58    * registered, and an incoming command is 'foo bar baz', it is
  59    * matched with 'foo bar', while 'foo fud' will match 'foo'.
  60    *
  61    * The entire incoming command string is passed to the registered
  62    * hook.
  63    *
  64    * @param command command string
  65    * @param cmddesc command syntax descriptor
  66    * @param hook implementation
  67    * @param help help text.  if empty, command will not be included in 'help' output.
  68    *
  69    * @return 0 for success, -EEXIST if command already registered.
  70    */
  71   int register_command(std::string_view command,
  72                        std::string_view cmddesc,
  73                        AdminSocketHook *hook,
  74                        std::string_view help);
  75
  76   /**
  77    * unregister an admin socket command.
  78    *
  79    * If a command is currently in progress, this will block until it
  80    * is done.  For that reason, you must not hold any locks required
  81    * by your hook while you call this.
  82    *
  83    * @param command command string
  84    * @return 0 on succest, -ENOENT if command dne.
  85    */
  86   int unregister_command(std::string_view command);
  87
  88   /*
  89    * unregister all commands belong to hook.
  90    */
  91   void unregister_commands(const AdminSocketHook *hook);
  92
  93   bool init(const std::string& path);
  94
  95   void chown(uid_t uid, gid_t gid);
  96   void chmod(mode_t mode);
  97   int execute_command(const std::string& cmd, ceph::bufferlist& out);
  98
  99 private:
 100
 101   void shutdown();
 102
 103   std::string create_shutdown_pipe(int *pipe_rd, int *pipe_wr);
 104   std::string destroy_shutdown_pipe();
 105   std::string bind_and_listen(const std::string &sock_path, int *fd);
 106
 107   std::thread th;
 108   void entry() noexcept;
 109   bool do_accept();
 110   bool validate(const std::string& command,
 111                 const cmdmap_t& cmdmap,
 112                 bufferlist& out) const;
 113
 114   CephContext *m_cct;
 115   std::string m_path;
 116   int m_sock_fd = -1;
 117   int m_shutdown_rd_fd = -1;
 118   int m_shutdown_wr_fd = -1;
 119
 120   bool in_hook = false;
 121   std::condition_variable in_hook_cond;
 122   std::mutex lock;  // protects `hooks`
 123   std::unique_ptr<AdminSocketHook> version_hook;
 124   std::unique_ptr<AdminSocketHook> help_hook;
 125   std::unique_ptr<AdminSocketHook> getdescs_hook;
 126
 127   struct hook_info {
 128     AdminSocketHook* hook;
 129     std::string desc;
 130     std::string help;
 131
 132     hook_info(AdminSocketHook* hook, std::string_view desc,
 133               std::string_view help)
 134       : hook(hook), desc(desc), help(help) {}
 135   };
 136
 137   std::map<std::string, hook_info, std::less<>> hooks;
 138
 139   friend class AdminSocketTest;
 140   friend class HelpHook;
 141   friend class GetdescsHook;
 142 };
 143
 144 #endif