/* assuan.c - Definitions for the Assuan IPC library * Copyright (C) 2001, 2002, 2003, 2005 Free Software Foundation, Inc. * * This file is part of Assuan. * * Assuan is free software; you can redistribute it and/or modify it * under the terms of the GNU Lesser General Public License as * published by the Free Software Foundation; either version 2.1 of * the License, or (at your option) any later version. * * Assuan 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 * Lesser General Public License for more details. * * You should have received a copy of the GNU Lesser General Public * License along with this program; if not, write to the Free Software * Foundation, Inc., 51 Franklin Street, Fifth Floor, Boston, MA 02110-1301, * USA. */ #ifndef ASSUAN_H #define ASSUAN_H #include #include #include /* To use this file with libraries the following macros are useful: #define _ASSUAN_EXT_SYM_PREFIX _foo_ This prefixes all external symbols with "_foo_". #define _ASSUAN_ONLY_GPG_ERRORS If this is defined all old-style Assuan error codes are made inactive as well as other dereacted stuff. The follwing macros are used internally in the implementation of libassuan: #define _ASSUAN_NO_PTH This avoids inclusion of special GNU Pth hacks. #define _ASSUAN_NO_FIXED_SIGNALS This disables changing of certain signal handler; i.e. SIGPIPE. #define _ASSUAN_USE_DOUBLE_FORK Use a double fork approach when connecting to a server through a pipe. */ /**** Begin GPGME specific modifications. ******/ #define _ASSUAN_EXT_SYM_PREFIX _gpgme_ #define _ASSUAN_NO_PTH #define _ASSUAN_NO_FIXED_SIGNALS #define _ASSUAN_USE_DOUBLE_FORK #ifdef _ASSUAN_IN_GPGME_BUILD_ASSUAN int _gpgme_io_read (int fd, void *buffer, size_t count); int _gpgme_io_write (int fd, const void *buffer, size_t count); ssize_t _gpgme_ath_waitpid (pid_t pid, int *status, int options); #ifdef HAVE_W32_SYSTEM int _gpgme_ath_accept (int s, void *addr, int *length_ptr); #else /*!HAVE_W32_SYSTEM*/ struct sockaddr; struct msghdr; ssize_t _gpgme_ath_select (int nfd, fd_set *rset, fd_set *wset, fd_set *eset, struct timeval *timeout); int _gpgme_ath_accept (int s, struct sockaddr *addr, socklen_t *length_ptr); int _gpgme_ath_connect (int s, struct sockaddr *addr, socklen_t length); int _gpgme_ath_sendmsg (int s, const struct msghdr *msg, int flags); int _gpgme_ath_recvmsg (int s, struct msghdr *msg, int flags); int _gpgme_io_sendmsg (int sock, const struct msghdr *msg, int flags); int _gpgme_io_recvmsg (int sock, struct msghdr *msg, int flags); #endif /*!HAVE_W32_SYSTEM*/ #define read _gpgme_io_read #define write _gpgme_io_write #define waitpid _gpgme_ath_waitpid #define select _gpgme_ath_select #define accept _gpgme_ath_accept #define connect _gpgme_ath_connect #define sendmsg _gpgme_io_sendmsg #define recvmsg _gpgme_io_recvmsg #endif /*_ASSUAN_IN_GPGME_BUILD_ASSUAN*/ /**** End GPGME specific modifications. ******/ #ifdef _ASSUAN_EXT_SYM_PREFIX #define _ASSUAN_PREFIX1(x,y) x ## y #define _ASSUAN_PREFIX2(x,y) _ASSUAN_PREFIX1(x,y) #define _ASSUAN_PREFIX(x) _ASSUAN_PREFIX2(_ASSUAN_EXT_SYM_PREFIX,x) #define assuan_ _ASSUAN_PREFIX(assuan_) #define assuan_register_command _ASSUAN_PREFIX(assuan_register_command) #define assuan_register_post_cmd_notify \ _ASSUAN_PREFIX(assuan_register_post_cmd_notify) #define assuan_register_bye_notify _ASSUAN_PREFIX(assuan_register_bye_notify) #define assuan_register_reset_notify \ _ASSUAN_PREFIX(assuan_register_reset_notify) #define assuan_register_cancel_notify \ _ASSUAN_PREFIX(assuan_register_cancel_notify) #define assuan_register_input_notify \ _ASSUAN_PREFIX(assuan_register_input_notify) #define assuan_register_output_notify \ _ASSUAN_PREFIX(assuan_register_output_notify) #define assuan_register_option_handler \ _ASSUAN_PREFIX(assuan_register_option_handler) #define assuan_process _ASSUAN_PREFIX(assuan_process) #define assuan_process_next _ASSUAN_PREFIX(assuan_process_next) #define assuan_get_active_fds _ASSUAN_PREFIX(assuan_get_active_fds) #define assuan_get_data_fp _ASSUAN_PREFIX(assuan_get_data_fp) #define assuan_set_okay_line _ASSUAN_PREFIX(assuan_set_okay_line) #define assuan_write_status _ASSUAN_PREFIX(assuan_write_status) #define assuan_command_parse_fd _ASSUAN_PREFIX(assuan_command_parse_fd) #define assuan_set_hello_line _ASSUAN_PREFIX(assuan_set_hello_line) #define assuan_accept _ASSUAN_PREFIX(assuan_accept) #define assuan_get_input_fd _ASSUAN_PREFIX(assuan_get_input_fd) #define assuan_get_output_fd _ASSUAN_PREFIX(assuan_get_output_fd) #define assuan_close_input_fd _ASSUAN_PREFIX(assuan_close_input_fd) #define assuan_close_output_fd _ASSUAN_PREFIX(assuan_close_output_fd) #define assuan_init_pipe_server _ASSUAN_PREFIX(assuan_init_pipe_server) #define assuan_deinit_server _ASSUAN_PREFIX(assuan_deinit_server) #define assuan_init_socket_server _ASSUAN_PREFIX(assuan_init_socket_server) #define assuan_init_connected_socket_server \ _ASSUAN_PREFIX(assuan_init_connected_socket_server) #define assuan_init_socket_server_ext \ _ASSUAN_PREFIX(assuan_init_socket_server_ext) #define assuan_pipe_connect _ASSUAN_PREFIX(assuan_pipe_connect) #define assuan_pipe_connect_ext _ASSUAN_PREFIX(assuan_pipe_connect_ext) #define assuan_socket_connect _ASSUAN_PREFIX(assuan_socket_connect) #define assuan_socket_connect_ext _ASSUAN_PREFIX(assuan_socket_connect_ext) #define assuan_disconnect _ASSUAN_PREFIX(assuan_disconnect) #define assuan_get_pid _ASSUAN_PREFIX(assuan_get_pid) #define assuan_get_peercred _ASSUAN_PREFIX(assuan_get_peercred) #define assuan_transact _ASSUAN_PREFIX(assuan_transact) #define assuan_inquire _ASSUAN_PREFIX(assuan_inquire) #define assuan_read_line _ASSUAN_PREFIX(assuan_read_line) #define assuan_pending_line _ASSUAN_PREFIX(assuan_pending_line) #define assuan_write_line _ASSUAN_PREFIX(assuan_write_line) #define assuan_send_data _ASSUAN_PREFIX(assuan_send_data) #define assuan_sendfd _ASSUAN_PREFIX(assuan_sendfd) #define assuan_receivefd _ASSUAN_PREFIX(assuan_receivefd) #define assuan_set_malloc_hooks _ASSUAN_PREFIX(assuan_set_malloc_hooks) #define assuan_set_log_stream _ASSUAN_PREFIX(assuan_set_log_stream) #define assuan_set_error _ASSUAN_PREFIX(assuan_set_error) #define assuan_set_pointer _ASSUAN_PREFIX(assuan_set_pointer) #define assuan_get_pointer _ASSUAN_PREFIX(assuan_get_pointer) #define assuan_set_io_monitor _ASSUAN_PREFIX(assuan_set_io_monitor) #define assuan_begin_confidential _ASSUAN_PREFIX(assuan_begin_confidential) #define assuan_end_confidential _ASSUAN_PREFIX(assuan_end_confidential) #define assuan_strerror _ASSUAN_PREFIX(assuan_strerror) #define assuan_set_assuan_err_source \ _ASSUAN_PREFIX(assuan_set_assuan_err_source) #define assuan_set_assuan_log_stream \ _ASSUAN_PREFIX(assuan_set_assuan_log_stream) #define assuan_get_assuan_log_stream \ _ASSUAN_PREFIX(assuan_get_assuan_log_stream) #define assuan_get_assuan_log_prefix \ _ASSUAN_PREFIX(assuan_get_assuan_log_prefix) #define assuan_set_flag _ASSUAN_PREFIX(assuan_set_flag) #define assuan_get_flag _ASSUAN_PREFIX(assuan_get_flag) /* And now the internal functions, argh... */ #define _assuan_read_line _ASSUAN_PREFIX(_assuan_read_line) #define _assuan_cookie_write_data _ASSUAN_PREFIX(_assuan_cookie_write_data) #define _assuan_cookie_write_flush _ASSUAN_PREFIX(_assuan_cookie_write_flush) #define _assuan_read_from_server _ASSUAN_PREFIX(_assuan_read_from_server) #define _assuan_domain_init _ASSUAN_PREFIX(_assuan_domain_init) #define _assuan_register_std_commands \ _ASSUAN_PREFIX(_assuan_register_std_commands) #define _assuan_simple_read _ASSUAN_PREFIX(_assuan_simple_read) #define _assuan_simple_write _ASSUAN_PREFIX(_assuan_simple_write) #define _assuan_simple_read _ASSUAN_PREFIX(_assuan_simple_read) #define _assuan_simple_write _ASSUAN_PREFIX(_assuan_simple_write) #define _assuan_new_context _ASSUAN_PREFIX(_assuan_new_context) #define _assuan_release_context _ASSUAN_PREFIX(_assuan_release_context) #define _assuan_malloc _ASSUAN_PREFIX(_assuan_malloc) #define _assuan_realloc _ASSUAN_PREFIX(_assuan_realloc) #define _assuan_calloc _ASSUAN_PREFIX(_assuan_calloc) #define _assuan_free _ASSUAN_PREFIX(_assuan_free) #define _assuan_log_print_buffer _ASSUAN_PREFIX(_assuan_log_print_buffer) #define _assuan_log_sanitized_string \ _ASSUAN_PREFIX(_assuan_log_sanitized_string) #define _assuan_log_printf _ASSUAN_PREFIX(_assuan_log_printf) #define _assuan_set_default_log_stream \ _ASSUAN_PREFIX(_assuan_set_default_log_stream) #define _assuan_w32_strerror _ASSUAN_PREFIX(_assuan_w32_strerror) #define _assuan_write_line _ASSUAN_PREFIX(_assuan_write_line) #define _assuan_close _ASSUAN_PREFIX(_assuan_close) #define _assuan_sock_new _ASSUAN_PREFIX(_assuan_sock_new) #define _assuan_sock_bind _ASSUAN_PREFIX(_assuan_sock_bind) #define _assuan_sock_connect _ASSUAN_PREFIX(_assuan_sock_connect) #endif /*_ASSUAN_EXT_SYM_PREFIX*/ #ifdef __cplusplus extern "C" { #if 0 } #endif #endif /* Check for compiler features. */ #if __GNUC__ #define _ASSUAN_GCC_VERSION (__GNUC__ * 10000 \ + __GNUC_MINOR__ * 100 \ + __GNUC_PATCHLEVEL__) #if _ASSUAN_GCC_VERSION > 30100 #define _ASSUAN_DEPRECATED __attribute__ ((__deprecated__)) #endif #endif #ifndef _ASSUAN_DEPRECATED #define _ASSUAN_DEPRECATED #endif /* Assuan error codes. These are only used by old applications or those applications which won't make use of libgpg-error. */ #ifndef _ASSUAN_ONLY_GPG_ERRORS #ifndef _ASSUAN_IN_LIBASSUAN #define ASSUAN_No_Error 0 #endif #define ASSUAN_General_Error 1 #define ASSUAN_Out_Of_Core 2 #define ASSUAN_Invalid_Value 3 #ifndef _ASSUAN_IN_LIBASSUAN #define ASSUAN_Timeout 4 #endif #define ASSUAN_Read_Error 5 #define ASSUAN_Write_Error 6 #define ASSUAN_Problem_Starting_Server 7 #define ASSUAN_Not_A_Server 8 #ifndef _ASSUAN_IN_LIBASSUAN #define ASSUAN_Not_A_Client 9 #endif #define ASSUAN_Nested_Commands 10 #define ASSUAN_Invalid_Response 11 #define ASSUAN_No_Data_Callback 12 #define ASSUAN_No_Inquire_Callback 13 #define ASSUAN_Connect_Failed 14 #define ASSUAN_Accept_Failed 15 /* Error codes above 99 are meant as status codes */ #define ASSUAN_Not_Implemented 100 #define ASSUAN_Server_Fault 101 #ifndef _ASSUAN_IN_LIBASSUAN #define ASSUAN_Invalid_Command 102 #endif #define ASSUAN_Unknown_Command 103 #define ASSUAN_Syntax_Error 104 #ifndef _ASSUAN_IN_LIBASSUAN #define ASSUAN_Parameter_Error 105 #endif #define ASSUAN_Parameter_Conflict 106 #define ASSUAN_Line_Too_Long 107 #define ASSUAN_Line_Not_Terminated 108 #ifndef _ASSUAN_IN_LIBASSUAN #define ASSUAN_No_Input 109 #define ASSUAN_No_Output 110 #endif #define ASSUAN_Canceled 111 #ifndef _ASSUAN_IN_LIBASSUAN #define ASSUAN_Unsupported_Algorithm 112 #define ASSUAN_Server_Resource_Problem 113 #define ASSUAN_Server_IO_Error 114 #define ASSUAN_Server_Bug 115 #define ASSUAN_No_Data_Available 116 #define ASSUAN_Invalid_Data 117 #endif #define ASSUAN_Unexpected_Command 118 #define ASSUAN_Too_Much_Data 119 #ifndef _ASSUAN_IN_LIBASSUAN #define ASSUAN_Inquire_Unknown 120 #define ASSUAN_Inquire_Error 121 #define ASSUAN_Invalid_Option 122 #define ASSUAN_Invalid_Index 123 #define ASSUAN_Unexpected_Status 124 #define ASSUAN_Unexpected_Data 125 #define ASSUAN_Invalid_Status 126 #define ASSUAN_Locale_Problem 127 #endif #define ASSUAN_Not_Confirmed 128 /* Warning: Don't use the Error codes, below they are deprecated. */ #ifndef _ASSUAN_IN_LIBASSUAN #define ASSUAN_Bad_Certificate 201 #define ASSUAN_Bad_Certificate_Chain 202 #define ASSUAN_Missing_Certificate 203 #define ASSUAN_Bad_Signature 204 #define ASSUAN_No_Agent 205 #define ASSUAN_Agent_Error 206 #define ASSUAN_No_Public_Key 207 #define ASSUAN_No_Secret_Key 208 #define ASSUAN_Invalid_Name 209 #define ASSUAN_Cert_Revoked 301 #define ASSUAN_No_CRL_For_Cert 302 #define ASSUAN_CRL_Too_Old 303 #define ASSUAN_Not_Trusted 304 #define ASSUAN_Card_Error 401 #define ASSUAN_Invalid_Card 402 #define ASSUAN_No_PKCS15_App 403 #define ASSUAN_Card_Not_Present 404 #define ASSUAN_Invalid_Id 405 /* Error codes in the range 1000 to 9999 may be used by applications at their own discretion. */ #define ASSUAN_USER_ERROR_FIRST 1000 #define ASSUAN_USER_ERROR_LAST 9999 #endif typedef int assuan_error_t; typedef assuan_error_t AssuanError _ASSUAN_DEPRECATED; /* This is a list of pre-registered ASSUAN commands */ /* Note, these command IDs are now deprectated and solely exists for compatibility reasons. */ typedef enum { ASSUAN_CMD_NOP = 0, ASSUAN_CMD_CANCEL, /* cancel the current request */ ASSUAN_CMD_BYE, ASSUAN_CMD_AUTH, ASSUAN_CMD_RESET, ASSUAN_CMD_OPTION, ASSUAN_CMD_DATA, ASSUAN_CMD_END, ASSUAN_CMD_INPUT, ASSUAN_CMD_OUTPUT, ASSUAN_CMD_USER = 256 /* Other commands should be used with this offset*/ } AssuanCommand; #else /*!_ASSUAN_ONLY_GPG_ERRORS*/ typedef int assuan_error_t; #endif /*!_ASSUAN_ONLY_GPG_ERRORS*/ /* Definitions of flags for assuan_set_flag(). */ typedef enum { /* When using a pipe server, by default Assuan will wait for the forked process to die in assuan_disconnect. In certain cases this is not desirable. By setting this flag, the waitpid will be skipped and the caller is responsible to cleanup a forked process. */ ASSUAN_NO_WAITPID = 1 } assuan_flag_t; #define ASSUAN_LINELENGTH 1002 /* 1000 + [CR,]LF */ struct assuan_context_s; typedef struct assuan_context_s *assuan_context_t; #ifndef _ASSUAN_ONLY_GPG_ERRORS typedef struct assuan_context_s *ASSUAN_CONTEXT _ASSUAN_DEPRECATED; #endif /*_ASSUAN_ONLY_GPG_ERRORS*/ /*-- assuan-handler.c --*/ int assuan_register_command (assuan_context_t ctx, const char *cmd_string, int (*handler)(assuan_context_t, char *)); int assuan_register_post_cmd_notify (assuan_context_t ctx, void (*fnc)(assuan_context_t, int)); int assuan_register_bye_notify (assuan_context_t ctx, void (*fnc)(assuan_context_t)); int assuan_register_reset_notify (assuan_context_t ctx, void (*fnc)(assuan_context_t)); int assuan_register_cancel_notify (assuan_context_t ctx, void (*fnc)(assuan_context_t)); int assuan_register_input_notify (assuan_context_t ctx, void (*fnc)(assuan_context_t, const char *)); int assuan_register_output_notify (assuan_context_t ctx, void (*fnc)(assuan_context_t, const char *)); int assuan_register_option_handler (assuan_context_t ctx, int (*fnc)(assuan_context_t, const char*, const char*)); int assuan_process (assuan_context_t ctx); int assuan_process_next (assuan_context_t ctx); int assuan_get_active_fds (assuan_context_t ctx, int what, int *fdarray, int fdarraysize); FILE *assuan_get_data_fp (assuan_context_t ctx); assuan_error_t assuan_set_okay_line (assuan_context_t ctx, const char *line); assuan_error_t assuan_write_status (assuan_context_t ctx, const char *keyword, const char *text); /* Negotiate a file descriptor. If LINE contains "FD=N", returns N assuming a local file descriptor. If LINE contains "FD" reads a file descriptor via CTX and stores it in *RDF (the CTX must be capable of passing file descriptors). */ assuan_error_t assuan_command_parse_fd (assuan_context_t ctx, char *line, int *rfd); /*-- assuan-listen.c --*/ assuan_error_t assuan_set_hello_line (assuan_context_t ctx, const char *line); assuan_error_t assuan_accept (assuan_context_t ctx); int assuan_get_input_fd (assuan_context_t ctx); int assuan_get_output_fd (assuan_context_t ctx); assuan_error_t assuan_close_input_fd (assuan_context_t ctx); assuan_error_t assuan_close_output_fd (assuan_context_t ctx); /*-- assuan-pipe-server.c --*/ int assuan_init_pipe_server (assuan_context_t *r_ctx, int filedes[2]); void assuan_deinit_server (assuan_context_t ctx); /*-- assuan-socket-server.c --*/ int assuan_init_socket_server (assuan_context_t *r_ctx, int listen_fd); int assuan_init_connected_socket_server (assuan_context_t *r_ctx, int fd) _ASSUAN_DEPRECATED; int assuan_init_socket_server_ext (assuan_context_t *r_ctx, int fd, unsigned int flags); /*-- assuan-pipe-connect.c --*/ assuan_error_t assuan_pipe_connect (assuan_context_t *ctx, const char *name, const char *const argv[], int *fd_child_list); assuan_error_t assuan_pipe_connect2 (assuan_context_t *ctx, const char *name, const char *const argv[], int *fd_child_list, void (*atfork) (void*, int), void *atforkvalue) _ASSUAN_DEPRECATED; assuan_error_t assuan_pipe_connect_ext (assuan_context_t *ctx, const char *name, const char *const argv[], int *fd_child_list, void (*atfork) (void *, int), void *atforkvalue, unsigned int flags); /*-- assuan-socket-connect.c --*/ assuan_error_t assuan_socket_connect (assuan_context_t *ctx, const char *name, pid_t server_pid); assuan_error_t assuan_socket_connect_ext (assuan_context_t *ctx, const char *name, pid_t server_pid, unsigned int flags); /*-- assuan-connect.c --*/ void assuan_disconnect (assuan_context_t ctx); pid_t assuan_get_pid (assuan_context_t ctx); #ifndef HAVE_W32_SYSTEM assuan_error_t assuan_get_peercred (assuan_context_t ctx, pid_t *pid, uid_t *uid, gid_t *gid); #endif /*-- assuan-client.c --*/ assuan_error_t assuan_transact (assuan_context_t ctx, const char *command, int (*data_cb)(void *, const void *, size_t), void *data_cb_arg, int (*inquire_cb)(void*, const char *), void *inquire_cb_arg, int (*status_cb)(void*, const char *), void *status_cb_arg); /*-- assuan-inquire.c --*/ assuan_error_t assuan_inquire (assuan_context_t ctx, const char *keyword, unsigned char **r_buffer, size_t *r_length, size_t maxlen); /*-- assuan-buffer.c --*/ assuan_error_t assuan_read_line (assuan_context_t ctx, char **line, size_t *linelen); int assuan_pending_line (assuan_context_t ctx); assuan_error_t assuan_write_line (assuan_context_t ctx, const char *line ); assuan_error_t assuan_send_data (assuan_context_t ctx, const void *buffer, size_t length); /* The file descriptor must be pending before assuan_receivefd is called. This means that assuan_sendfd should be called *before* the trigger is sent (normally via assuan_write_line ("INPUT FD")). */ assuan_error_t assuan_sendfd (assuan_context_t ctx, int fd); assuan_error_t assuan_receivefd (assuan_context_t ctx, int *fd); /*-- assuan-util.c --*/ void assuan_set_malloc_hooks ( void *(*new_alloc_func)(size_t n), void *(*new_realloc_func)(void *p, size_t n), void (*new_free_func)(void*) ); void assuan_set_log_stream (assuan_context_t ctx, FILE *fp); int assuan_set_error (assuan_context_t ctx, int err, const char *text); void assuan_set_pointer (assuan_context_t ctx, void *pointer); void *assuan_get_pointer (assuan_context_t ctx); void assuan_begin_confidential (assuan_context_t ctx); void assuan_end_confidential (assuan_context_t ctx); void assuan_set_io_monitor (assuan_context_t ctx, unsigned int (*monitor)(assuan_context_t ctx, int direction, const char *line, size_t linelen)); /* For context CTX, set the flag FLAG to VALUE. Values for flags are usually 1 or 0 but certain flags might allow for other values; see the description of the type assuan_flag_t for details. */ void assuan_set_flag (assuan_context_t ctx, assuan_flag_t flag, int value); /* Return the VALUE of FLAG in context CTX. */ int assuan_get_flag (assuan_context_t ctx, assuan_flag_t flag); /*-- assuan-errors.c --*/ #ifndef _ASSUAN_ONLY_GPG_ERRORS /* Return a string describing the assuan error. The use of this function is deprecated; it is better to call assuan_set_assuan_err_source once and then make use libgpg-error. */ const char *assuan_strerror (assuan_error_t err); #endif /*_ASSUAN_ONLY_GPG_ERRORS*/ /* Enable gpg-error style error codes. ERRSOURCE is one of gpg-error sources. Note, that this function is not thread-safe and should be used right at startup. Switching back to the old style mode is not supported. */ void assuan_set_assuan_err_source (int errsource); /*-- assuan-logging.c --*/ /* Set the stream to which assuan should log message not associated with a context. By default, this is stderr. The default value will be changed when the first log stream is associated with a context. Note, that this function is not thread-safe and should in general be used right at startup. */ extern void assuan_set_assuan_log_stream (FILE *fp); /* Return the stream which is currently being using for global logging. */ extern FILE *assuan_get_assuan_log_stream (void); /* Set the prefix to be used at the start of a line emitted by assuan on the log stream. The default is the empty string. Note, that this function is not thread-safe and should in general be used right at startup. */ void assuan_set_assuan_log_prefix (const char *text); /* Return a prefix to be used at the start of a line emitted by assuan on the log stream. The default implementation returns the empty string, i.e. "" */ const char *assuan_get_assuan_log_prefix (void); #ifdef __cplusplus } #endif #endif /* ASSUAN_H */