diff options
Diffstat (limited to 'src/login/elogind.c')
| -rw-r--r-- | src/login/elogind.c | 123 |
1 files changed, 108 insertions, 15 deletions
diff --git a/src/login/elogind.c b/src/login/elogind.c index 73e2a52b3..0dace0eff 100644 --- a/src/login/elogind.c +++ b/src/login/elogind.c @@ -25,6 +25,7 @@ #include "fileio.h" #include "fs-util.h" #include "mount-setup.h" +#include "parse-util.h" #include "process-util.h" #include "socket-util.h" #include "stdio-util.h" @@ -44,13 +45,33 @@ static void remove_pid_file(void) { } -/* daemonize elogind by double forking. - The grand child returns 0. - The parent and child return their forks PID. - On error, a value < 0 is returned. -*/ -int elogind_daemonize(void) { +static void write_pid_file(void) { char c[DECIMAL_STR_MAX(pid_t) + 2]; + pid_t pid; + int r; + + pid = getpid_cached(); + + xsprintf(c, PID_FMT "\n", pid); + + r = write_string_file(ELOGIND_PID_FILE, c, + WRITE_STRING_FILE_CREATE | + WRITE_STRING_FILE_VERIFY_ON_FAILURE); + if (r < 0) + log_error_errno(-r, "Failed to write PID file %s: %m", + ELOGIND_PID_FILE); + + /* Make sure the PID file gets cleaned up on exit! */ + atexit(remove_pid_file); +} + + +/** daemonize elogind by double forking. + * The grand child returns 0. + * The parent and child return their forks PID. + * On error, a value < 0 is returned. +**/ +static int elogind_daemonize(void) { pid_t child; pid_t grandchild; pid_t SID; @@ -92,19 +113,37 @@ int elogind_daemonize(void) { umask(0022); /* Take care of our PID-file now */ - grandchild = getpid_cached(); + write_pid_file(); - xsprintf(c, PID_FMT "\n", grandchild); + return 0; +} + + +/// Simple tool to see, if elogind is already running +static pid_t elogind_is_already_running(void) { + _cleanup_free_ char *s = NULL; + pid_t pid; + int r; + + r = read_one_line_file(ELOGIND_PID_FILE, &s); - r = write_string_file(ELOGIND_PID_FILE, c, - WRITE_STRING_FILE_CREATE | - WRITE_STRING_FILE_VERIFY_ON_FAILURE); if (r < 0) - log_error_errno(-r, "Failed to write PID file %s: %m", - ELOGIND_PID_FILE); + goto we_are_alone; - /* Make sure the PID file gets cleaned up on exit! */ - atexit(remove_pid_file); + r = safe_atoi32(s, &pid); + + if (r < 0) + goto we_are_alone; + + if ( (pid != getpid_cached()) && pid_is_alive(pid)) + return pid; + +we_are_alone: + + /* Take care of our PID-file now. + If the user is going to fork elogind, the PID file + will be overwritten. */ + write_pid_file(); return 0; } @@ -138,6 +177,7 @@ static int manager_dispatch_cgroups_agent_fd(sd_event_source *source, int fd, ui return 0; } + /// Add-On for manager_connect_bus() /// Original: src/core/manager.c:manager_setup_cgroups_agent() int elogind_setup_cgroups_agent(Manager *m) { @@ -216,6 +256,57 @@ int elogind_setup_cgroups_agent(Manager *m) { return 0; } + +/** Extra functionality at startup, exclusive to elogind + * return < 0 on error, exit with failure. + * return = 0 on success, continue normal operation. + * return > 0 if elogind is already running or forked, exit with success. +**/ +int elogind_startup(int argc, char *argv[]) { + bool daemonize = false; + pid_t pid; + int r = 0; + bool show_help = false; + bool wrong_arg = false; + + /* add a -h/--help and a -d/--daemon argument. */ + if ( (argc == 2) && argv[1] && strlen(argv[1]) ) { + if ( streq(argv[1], "-D") || streq(argv[1], "--daemon") ) + daemonize = true; + else if ( streq(argv[1], "-h") || streq(argv[1], "--help") ) { + show_help = true; + r = 1; + } else + wrong_arg = true; + } else if (argc > 2) + wrong_arg = true; + + /* try to get some meaningful output in case of an error */ + if (wrong_arg) { + fprintf(stderr, "ERROR: Unknown arguments\n"); + show_help = true; + r = -EINVAL; + } + if (show_help) { + fprintf(stderr, "%s [<-D|--daemon>|<-h|--help>]\n", argv[0]); + return r; + } + + /* Do not continue if elogind is already running */ + pid = elogind_is_already_running(); + if (pid) { + fprintf(stderr, "elogind is already running:" PID_FMT "\n", pid); + return pid; + } + + /* elogind allows to be daemonized using one argument "-D" / "--daemon" */ + if (daemonize) + r = elogind_daemonize(); + + return r; +} + + /// Add-On for manager_free() void elogind_manager_free(Manager* m) { @@ -233,6 +324,7 @@ void elogind_manager_free(Manager* m) { strv_free(m->hybrid_sleep_state); } + /// Add-On for manager_new() int elogind_manager_new(Manager* m) { int r = 0; @@ -263,6 +355,7 @@ int elogind_manager_new(Manager* m) { return r; } + /// Add-On for manager_reset_config() void elogind_manager_reset_config(Manager* m) { |