#include #include #include #include #include #include #include #include #include #include #include "utils.h" typedef char pid_str[16]; static int daemonize = 0; void daemonize_enable(void) { daemonize = 1; } static int is_daemon_running(char const * const pidfile, pid_str ps) { int pfd = open(pidfile, O_RDONLY, 0); char proc_path[32]; if (pfd < 0) { return 0; } if (read(pfd, ps, sizeof(pid_str)) <= 0) { close(pfd); return 1; } close(pfd); if (snprintf(proc_path, sizeof(pid_str), "/proc/%s", ps) <= 0) { return 1; } if (access(proc_path, F_OK) == 0) { return 1; } return 0; } static int create_pidfile(char const * const pidfile) { int pfd; if (is_path_absolute("Pidfile", pidfile) != 0) { return 1; } pfd = open(pidfile, O_WRONLY | O_CREAT | O_TRUNC, S_IRUSR | S_IWUSR | S_IRGRP | S_IROTH); if (pfd < 0) { syslog(LOG_DAEMON | LOG_ERR, "Could open pidfile %s for writing: %s", pidfile, strerror(errno)); return 1; } if (dprintf(pfd, "%d", getpid()) <= 0) { close(pfd); return 1; } close(pfd); return 0; } int is_path_absolute(char const * const prefix, char const * const path) { if (path[0] != '/') { syslog(LOG_DAEMON | LOG_ERR, "%s path must be absolut i.e. starting with a `/', path given: `%s'", prefix, path); return 1; } return 0; } int daemonize_with_pidfile(char const * const pidfile) { pid_str ps = {}; if (daemonize != 0) { if (is_daemon_running(pidfile, ps) != 0) { syslog(LOG_DAEMON | LOG_ERR, "Pidfile %s found and daemon %s still running", pidfile, ps); return 1; } if (daemon(0, 0) != 0) { syslog(LOG_DAEMON | LOG_ERR, "daemon: %s", strerror(errno)); return 1; } if (create_pidfile(pidfile) != 0) { return 1; } } return 0; } int daemonize_shutdown(char const * const pidfile) { if (daemonize != 0) { if (unlink(pidfile) != 0) { syslog(LOG_DAEMON | LOG_ERR, "Could not unlink pidfile %s: %s", pidfile, strerror(errno)); return 1; } } return 0; } int change_user_group(char const * const user, char const * const group, char const * const pidfile, char const * const uds_collector_path, char const * const uds_distributor_path) { struct passwd * pwd; struct group * grp; gid_t gid; if (getuid() != 0) { return 0; } if (user == NULL) { return 1; } pwd = getpwnam(user); if (pwd == NULL) { return 1; } if (group != NULL) { grp = getgrnam(group); if (grp == NULL) { return 1; } gid = grp->gr_gid; } else { gid = pwd->pw_gid; } if (uds_collector_path != NULL) { chmod(uds_collector_path, S_IRUSR | S_IWUSR); chown(uds_collector_path, pwd->pw_uid, gid); } if (uds_distributor_path != NULL) { chmod(uds_distributor_path, S_IRUSR | S_IWUSR | S_IRGRP); chown(uds_distributor_path, pwd->pw_uid, gid); } if (pidfile != NULL) { chown(pidfile, pwd->pw_uid, gid); } return setregid(gid, gid) != 0 || setreuid(pwd->pw_uid, pwd->pw_uid); }