gnunet-android

gnunet_os_lib.h (21266B)

---

 /*
      This file is part of GNUnet.
      Copyright (C) 2001, 2002, 2003, 2004, 2005, 2006, 2011, 2020 GNUnet e.V.
 
      GNUnet is free software: you can redistribute it and/or modify it
      under the terms of the GNU Affero General Public License as published
      by the Free Software Foundation, either version 3 of the License,
      or (at your option) any later version.
 
      GNUnet is distributed in the hope that it will be useful, but
      WITHOUT ANY WARRANTY; without even the implied warranty of
      MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the GNU
      Affero General Public License for more details.
 
      You should have received a copy of the GNU Affero General Public License
      along with this program.  If not, see <http://www.gnu.org/licenses/>.
 
      SPDX-License-Identifier: AGPL3.0-or-later
  */
 
 #if ! defined (__GNUNET_UTIL_LIB_H_INSIDE__)
 #error "Only <gnunet_util_lib.h> can be included directly."
 #endif
 
 /**
  * @addtogroup libgnunetutil
  * Multi-function utilities library for GNUnet programs
  * @{
  *
  * @author Christian Grothoff
  * @author Krista Bennett
  * @author Gerd Knorr <kraxel@bytesex.org>
  * @author Ioana Patrascu
  * @author Tzvetan Horozov
  * @author Milan
  *
  * @file
  * Low level process routines
  *
  * @defgroup os  OS library
  * Low level process routines.
  *
  * This code manages child processes.  We can communicate with child
  * processes using signals.  Because signals are not supported on W32
  * and Java (at least not nicely), we can alternatively use a pipe
  * to send signals to the child processes (if the child process is
  * a full-blown GNUnet process that supports reading signals from
  * a pipe, of course).  Naturally, this also only works for 'normal'
  * termination via signals, and not as a replacement for SIGKILL.
  * Thus using pipes to communicate signals should only be enabled if
  * the child is a Java process OR if we are on Windoze.
  *
  * @{
  */
 
 #ifndef GNUNET_OS_LIB_H
 #define GNUNET_OS_LIB_H
 
 #ifdef __cplusplus
 extern "C"
 {
 #if 0                           /* keep Emacsens' auto-indent happy */
 }
 #endif
 #endif
 
 
 /**
  * Flags that determine which of the standard streams
  * should be inherited by the child process.
  */
 enum GNUNET_OS_InheritStdioFlags
 {
   /**
    * No standard streams should be inherited.
    */
   GNUNET_OS_INHERIT_STD_NONE = 0,
 
   /**
    * When this flag is set, the child process will
    * inherit stdin of the parent.
    */
   GNUNET_OS_INHERIT_STD_IN = 1,
 
   /**
    * When this flag is set, the child process will
    * inherit stdout of the parent.
    */
   GNUNET_OS_INHERIT_STD_OUT = 2,
 
   /**
    * When this flag is set, the child process will
    * inherit stderr of the parent.
    */
   GNUNET_OS_INHERIT_STD_ERR = 4,
 
   /**
    * When these flags are set, the child process will
    * inherit stdout and stderr of the parent.
    */
   GNUNET_OS_INHERIT_STD_OUT_AND_ERR = 6,
 
   /**
    * Use this option to have all of the standard streams
    * (stdin, stdout and stderror) be inherited.
    */
   GNUNET_OS_INHERIT_STD_ALL = 7,
 
   /**
    * Should a pipe be used to send signals to the child?
    */
   GNUNET_OS_USE_PIPE_CONTROL = 8
 };
 
 
 /**
  * Process information (OS-dependent)
  */
 struct GNUNET_OS_Process;
 
 
 /**
  * Possible installation paths to request
  */
 enum GNUNET_OS_InstallationPathKind
 {
   /**
    * Return the "PREFIX" directory given to configure.
    */
   GNUNET_OS_IPK_PREFIX,
 
   /**
    * Return the directory where the program binaries are installed. (bin/)
    */
   GNUNET_OS_IPK_BINDIR,
 
   /**
    * Return the directory where libraries are installed. (lib/gnunet/)
    */
   GNUNET_OS_IPK_LIBDIR,
 
   /**
    * Return the directory where data is installed (share/gnunet/)
    */
   GNUNET_OS_IPK_DATADIR,
 
   /**
    * Return the directory where translations are installed (share/locale/)
    */
   GNUNET_OS_IPK_LOCALEDIR,
 
   /**
    * Return the installation directory of this application, not
    * the one of the overall GNUnet installation (in case they
    * are different).
    */
   GNUNET_OS_IPK_SELF_PREFIX,
 
   /**
    * Return the prefix of the path with application icons (share/icons/).
    */
   GNUNET_OS_IPK_ICONDIR,
 
   /**
    * Return the prefix of the path with documentation files, including the
    * license (share/doc/gnunet/).
    */
   GNUNET_OS_IPK_DOCDIR,
 
   /**
    * Return the directory where helper binaries are installed (lib/gnunet/libexec/)
    */
   GNUNET_OS_IPK_LIBEXECDIR
 };
 
 
 /**
  * Process status types
  */
 enum GNUNET_OS_ProcessStatusType
 {
   /**
    * The process is not known to the OS (or at
    * least not one of our children).
    */
   GNUNET_OS_PROCESS_UNKNOWN,
 
   /**
    * The process is still running.
    */
   GNUNET_OS_PROCESS_RUNNING,
 
   /**
    * The process is paused (but could be resumed).
    */
   GNUNET_OS_PROCESS_STOPPED,
 
   /**
    * The process exited with a return code.
    */
   GNUNET_OS_PROCESS_EXITED,
 
   /**
    * The process was killed by a signal.
    */
   GNUNET_OS_PROCESS_SIGNALED
 };
 
 
 /**
  * Project-specific data used to help the OS subsystem
  * find installation paths.
  */
 struct GNUNET_OS_ProjectData
 {
   /**
    * Name of a library that is installed in the "lib/" directory of
    * the project, such as "libgnunetutil".  Used to locate the
    * installation by scanning dependencies of the current process.
    */
   const char *libname;
 
   /**
    * Name of the project that is used in the "libexec" prefix, For
    * example, "gnunet".  Certain helper binaries are then expected to
    * be installed in "$PREFIX/libexec/gnunet/" and resources in
    * "$PREFIX/share/gnunet/".
    */
   const char *project_dirname;
 
   /**
    * Name of a project-specific binary that should be in "$PREFIX/bin/".
    * Used to determine installation path from $PATH variable.
    * For example "gnunet-arm".  On W32, ".exe" should be omitted.
    */
   const char *binary_name;
 
   /**
    * Name of an environment variable that can be used to override
    * installation path detection, for example "GNUNET_PREFIX".
    */
   const char *env_varname;
 
   /**
    * Alternative name of an environment variable that can be used to
    * override installation path detection, if "env_varname" is not
    * set. Again, for example, "GNUNET_PREFIX".
    */
   const char *env_varname_alt;
 
   /**
    * Name of an environment variable that can be used to override
    * the location from which default configuration files are loaded
    * from, for example "GNUNET_BASE_CONFIG".
    */
   const char *base_config_varname;
 
   /**
    * E-mail address for reporting bugs.
    */
   const char *bug_email;
 
   /**
    * Project homepage.
    */
   const char *homepage;
 
   /**
    * Configuration file name (in $XDG_CONFIG_HOME) to use.
    */
   const char *config_file;
 
   /**
    * Configuration file name to use (if $XDG_CONFIG_HOME is not set).
    */
   const char *user_config_file;
 
   /**
    * String identifying the current project version.
    */
   const char *version;
 
   /**
    * Non-zero means this project is part of GNU.
    */
   int is_gnu;
 
   /**
    * Gettext domain for localisation, e.g. the PACKAGE macro.
    * Setting this field to NULL disables gettext.
    */
   const char *gettext_domain;
 
   /**
    * Gettext directory, e.g. the LOCALEDIR macro.
    * If this field is NULL, the path is automatically inferred.
    */
   const char *gettext_path;
 
   /**
    * URL pointing to the source code of the application.  Required for AGPL.
    * Setting this to NULL disables the built-in mechanism, but you must
    * provide it in some other way.  If non-NULL, message type 1 and 2 are
    * reserved.
    */
   const char *agpl_url;
 
   /**
    * In case we do not have environment variables to determine the install path,
    * the install path can be set explicitly.
    */
   const char *install_path_override;
 };
 
 
 /**
  * Return default project data used by 'libgnunetutil' for GNUnet.
  */
 const struct GNUNET_OS_ProjectData *
 GNUNET_OS_project_data_gnunet (void);
 
 
 /**
  * Setting project data used by 'libgnunetutil' for GNUnet.
  *
  * @param project_data data to set instead of default.
  */
 void
 GNUNET_OS_project_data_gnunet_set (const struct GNUNET_OS_ProjectData *project_data);
 
 
 /**
  * Setup OS subsystem for the given project data and package.
  * Initializes GNU Gettext.
  *
  * @param package_name name of the package for GNU gettext
  * @param pd project data to use to determine paths
  */
 void
 GNUNET_OS_init (const char *package_name,
                 const struct GNUNET_OS_ProjectData *pd);
 
 
 /**
  * Get the path to a specific GNUnet installation directory or, with
  * #GNUNET_OS_IPK_SELF_PREFIX, the current running apps installation
  * directory.
  *
  * @param pd project data to use to determine paths
  * @param dirkind what kind of directory is desired?
  * @return a pointer to the dir path (to be freed by the caller)
  */
 char *
 GNUNET_OS_installation_get_path (const struct GNUNET_OS_ProjectData *pd,
                                  enum GNUNET_OS_InstallationPathKind dirkind);
 
 
 /**
  * Given the name of a gnunet-helper, gnunet-service or gnunet-daemon
  * binary, try to prefix it with the libexec/-directory to get the
  * full path.
  *
  * @param pd project data to use to determine paths
  * @param progname name of the binary
  * @return full path to the binary, if possible, otherwise copy of 'progname'
  */
 char *
 GNUNET_OS_get_libexec_binary_path (const struct GNUNET_OS_ProjectData *pd,
                                    const char *progname);
 
 
 /**
  * Given the name of a helper, service or daemon binary construct the full
  * path to the binary using the SUID_BINARY_PATH in the PATHS section of the
  * configuration. If that option is not present, fall back to
  * GNUNET_OS_get_libexec_binary_path. If @a progname is an absolute path, a
  * copy of this path is returned.
  *
  * @param pd project data to use to determine paths
  * @param cfg configuration to inspect
  * @param progname name of the binary
  * @return full path to the binary, if possible, a copy of @a progname
  *         otherwise
  */
 char *
 GNUNET_OS_get_suid_binary_path (const struct GNUNET_OS_ProjectData *pd,
                                 const struct GNUNET_CONFIGURATION_Handle *cfg,
                                 const char *progname);
 
 
 /**
  * Callback function invoked for each interface found.
  *
  * @param cls closure
  * @param name name of the interface (can be NULL for unknown)
  * @param isDefault is this presumably the default interface
  * @param addr address of this interface (can be NULL for unknown or unassigned)
  * @param broadcast_addr the broadcast address (can be NULL for unknown or unassigned)
  * @param netmask the network mask (can be NULL for unknown or unassigned)
  * @param addrlen length of the address
  * @return #GNUNET_OK to continue iteration, #GNUNET_SYSERR to abort
  */
 typedef enum GNUNET_GenericReturnValue
 (*GNUNET_OS_NetworkInterfaceProcessor)(void *cls,
                                        const char *name,
                                        int isDefault,
                                        const struct sockaddr *addr,
                                        const struct sockaddr *broadcast_addr,
                                        const struct sockaddr *netmask,
                                        socklen_t addrlen);
 
 
 /**
  * @brief Enumerate all network interfaces
  *
  * @param proc the callback function
  * @param proc_cls closure for @a proc
  */
 void
 GNUNET_OS_network_interfaces_list (GNUNET_OS_NetworkInterfaceProcessor proc,
                                    void *proc_cls);
 
 #ifndef HAVE_SYSCONF
 #define HAVE_SYSCONF 0
 #endif
 
 /**
  * @brief Get maximum string length returned by gethostname()
  */
 #if HAVE_SYSCONF && defined(_SC_HOST_NAME_MAX)
 #define GNUNET_OS_get_hostname_max_length() ({ int __sc_tmp = sysconf ( \
                                                  _SC_HOST_NAME_MAX); __sc_tmp <= \
                                                0 ? 255 : __sc_tmp; })
 #elif defined(HOST_NAME_MAX)
 #define GNUNET_OS_get_hostname_max_length() HOST_NAME_MAX
 #else
 #define GNUNET_OS_get_hostname_max_length() 255
 #endif
 
 
 /**
  * Get process structure for current process
  *
  * The pointer it returns points to static memory location and must not be
  * deallocated/closed
  *
  * @return pointer to the process sturcutre for this process
  */
 struct GNUNET_OS_Process *
 GNUNET_OS_process_current (void);
 
 
 /**
  * Sends a signal to the process
  *
  * @param proc pointer to process structure
  * @param sig signal
  * @return 0 on success, -1 on error
  */
 int
 GNUNET_OS_process_kill (struct GNUNET_OS_Process *proc,
                         int sig);
 
 
 /**
  * Cleans up process structure contents (OS-dependent) and deallocates it
  *
  * @param proc pointer to process structure
  */
 void
 GNUNET_OS_process_destroy (struct GNUNET_OS_Process *proc);
 
 
 /**
  * Get the pid of the process in question
  *
  * @param proc the process to get the pid of
  *
  * @return the current process id
  */
 pid_t
 GNUNET_OS_process_get_pid (struct GNUNET_OS_Process *proc);
 
 
 /**
  * Start a process.
  *
  * @param std_inheritance a set of GNUNET_OS_INHERIT_STD_* flags
  * @param pipe_stdin pipe to use to send input to child process (or NULL)
  * @param pipe_stdout pipe to use to get output from child process (or NULL)
  * @param pipe_stderr pipe to use to get error output from child process (or NULL)
  * @param filename name of the binary
  * @param argv NULL-terminated array of arguments to the process
  * @return pointer to process structure of the new process, NULL on error
  */
 struct GNUNET_OS_Process *
 GNUNET_OS_start_process_vap (
   enum GNUNET_OS_InheritStdioFlags std_inheritance,
   struct GNUNET_DISK_PipeHandle *pipe_stdin,
   struct GNUNET_DISK_PipeHandle *pipe_stdout,
   struct GNUNET_DISK_PipeHandle *pipe_stderr,
   const char *filename,
   char *const argv[]);
 
 
 /**
  * Start a process.
  *
  * @param std_inheritance a set of GNUNET_OS_INHERIT_STD_* flags
  * @param pipe_stdin pipe to use to send input to child process (or NULL)
  * @param pipe_stdout pipe to use to get output from child process (or NULL)
  * @param pipe_stderr pipe to use to get error output from child process (or NULL)
  * @param filename name of the binary
  * @param ... NULL-terminated list of arguments to the process
  * @return pointer to process structure of the new process, NULL on error
  */
 struct GNUNET_OS_Process *
 GNUNET_OS_start_process (
   enum GNUNET_OS_InheritStdioFlags std_inheritance,
   struct GNUNET_DISK_PipeHandle *pipe_stdin,
   struct GNUNET_DISK_PipeHandle *pipe_stdout,
   struct GNUNET_DISK_PipeHandle *pipe_stderr,
   const char *filename,
   ...);
 
 
 /**
  * Start a process.
  *
  * @param std_inheritance a set of GNUNET_OS_INHERIT_STD_* flags
  * @param pipe_stdin pipe to use to send input to child process (or NULL)
  * @param pipe_stdout pipe to use to get output from child process (or NULL)
  * @param pipe_stderr pipe to use to get error output from child process (or NULL)
  * @param filename name of the binary
  * @param va NULL-terminated list of arguments to the process
  * @return pointer to process structure of the new process, NULL on error
  */
 struct GNUNET_OS_Process *
 GNUNET_OS_start_process_va (
   enum GNUNET_OS_InheritStdioFlags std_inheritance,
   struct GNUNET_DISK_PipeHandle *pipe_stdin,
   struct GNUNET_DISK_PipeHandle *pipe_stdout,
   struct GNUNET_DISK_PipeHandle *pipe_stderr,
   const char *filename,
   va_list va);
 
 
 /**
  * Start a process.
  *
  * @param std_inheritance a set of GNUNET_OS_INHERIT_STD_* flags
  * @param lsocks array of listen sockets to dup systemd-style (or NULL);
  *         must be NULL on platforms where dup is not supported
  * @param filename name of the binary
  * @param argv NULL-terminated list of arguments to the process,
  *             including the process name as the first argument
  * @return pointer to process structure of the new process, NULL on error
  */
 struct GNUNET_OS_Process *
 GNUNET_OS_start_process_v (
   enum GNUNET_OS_InheritStdioFlags std_inheritance,
   const int *lsocks,
   const char *filename,
   char *const argv[]);
 
 
 /**
  * Start a process.  This function is similar to the GNUNET_OS_start_process_*
  * except that the filename and arguments can have whole strings which contain
  * the arguments.  These arguments are to be separated by spaces and are parsed
  * in the order they appear.  Arguments containing spaces can be used by
  * quoting them with @em ".
  *
  * @param std_inheritance a set of GNUNET_OS_INHERIT_STD_* flags
  * @param lsocks array of listen sockets to dup systemd-style (or NULL);
  *         must be NULL on platforms where dup is not supported
  * @param filename name of the binary.  It is valid to have the arguments
  *         in this string when they are separated by spaces.
  * @param ... more arguments.  Should be of type `char *`.  It is valid
  *         to have the arguments in these strings when they are separated by
  *         spaces.  The last argument MUST be NULL.
  * @return pointer to process structure of the new process, NULL on error
  */
 struct GNUNET_OS_Process *
 GNUNET_OS_start_process_s (
   enum GNUNET_OS_InheritStdioFlags std_inheritance,
   const int *lsocks,
   const char *filename,
   ...);
 
 
 /**
  * Handle to a command action.
  */
 struct GNUNET_OS_CommandHandle;
 
 
 /**
  * Type of a function to process a line of output.
  *
  * @param cls closure
  * @param line line of output from a command, NULL for the end
  */
 typedef void
 (*GNUNET_OS_LineProcessor) (void *cls, const char *line);
 
 
 /**
  * Stop/kill a command.
  *
  * @param cmd handle to the process
  */
 void
 GNUNET_OS_command_stop (struct GNUNET_OS_CommandHandle *cmd);
 
 
 /**
  * Run the given command line and call the given function
  * for each line of the output.
  *
  * @param proc function to call for each line of the output
  * @param proc_cls closure for proc
  * @param timeout when to time out
  * @param binary command to run
  * @param ... arguments to command
  * @return NULL on error
  */
 struct GNUNET_OS_CommandHandle *
 GNUNET_OS_command_run (
   GNUNET_OS_LineProcessor proc,
   void *proc_cls,
   struct GNUNET_TIME_Relative timeout,
   const char *binary,
   ...);
 
 
 /**
  * Retrieve the status of a process.
  * Nonblocking version.
  *
  * @param proc pointer to process structure
  * @param type status type
  * @param code return code/signal number
  * @return #GNUNET_OK on success, #GNUNET_NO if the process is still running, #GNUNET_SYSERR otherwise
  */
 enum GNUNET_GenericReturnValue
 GNUNET_OS_process_status (struct GNUNET_OS_Process *proc,
                           enum GNUNET_OS_ProcessStatusType *type,
                           unsigned long *code);
 
 
 /**
  * Wait for a process to terminate.  The return code is discarded.
  * You must not use #GNUNET_OS_process_status() on the same process
  * after calling this function!  This function is blocking and should
  * thus only be used if the child process is known to have terminated
  * or to terminate very soon.
  *
  * @param proc pointer to process structure of the process to wait for
  * @return #GNUNET_OK on success, #GNUNET_SYSERR otherwise
  */
 enum GNUNET_GenericReturnValue
 GNUNET_OS_process_wait (struct GNUNET_OS_Process *proc);
 
 
 /**
  * Retrieve the status of a process, waiting on it if dead.
  * Blocking version.
  *
  * @param proc pointer to process structure
  * @param type status type
  * @param code return code/signal number
  * @return #GNUNET_OK on success, #GNUNET_NO if the process is still running, #GNUNET_SYSERR otherwise
  */
 enum GNUNET_GenericReturnValue
 GNUNET_OS_process_wait_status (struct GNUNET_OS_Process *proc,
                                enum GNUNET_OS_ProcessStatusType *type,
                                unsigned long *code);
 
 
 /**
  * Connects this process to its parent via pipe;
  * essentially, the parent control handler will read signal numbers
  * from the #GNUNET_OS_CONTROL_PIPE (as given in an environment
  * variable) and raise those signals.
  *
  * @param cls closure (unused)
  */
 void
 GNUNET_OS_install_parent_control_handler (void *cls);
 
 
 /**
  * Check whether an executable exists and possibly
  * if the suid bit is set on the file.
  * Attempts to find the file using the current
  * PATH environment variable as a search path.
  *
  * @param binary the name of the file to check.
  *        W32: must not have an .exe suffix.
  * @param check_suid input true if the binary should be checked for SUID (*nix)
  *        W32: checks if the program has sufficient privileges by executing this
  *             binary with the -d flag. -d omits a programs main loop and only
  *             executes all privileged operations in an binary.
  * @param params parameters used for w32 privilege checking (can be NULL for != w32, or when not checking for suid/permissions )
  * @return #GNUNET_YES if the file is SUID (*nix) or can be executed with current privileges (W32),
  *         #GNUNET_NO if not SUID (but binary exists),
  *         #GNUNET_SYSERR on error (no such binary or not executable)
  */
 enum GNUNET_GenericReturnValue
 GNUNET_OS_check_helper_binary (const char *binary,
                                bool check_suid,
                                const char *params);
 
 
 #if 0                           /* keep Emacsens' auto-indent happy */
 {
 #endif
 #ifdef __cplusplus
 }
 #endif
 
 /* ifndef GNUNET_OS_LIB_H */
 #endif
 
 /** @} */  /* end of group */
 
 /** @} */ /* end of group addition */
 
 /* end of gnunet_os_lib.h */