/* * mq_open.c - open a message queue. */ #include <errno.h> #include <stdarg.h> #include <stddef.h> #include <sys/syscall.h> #include <mqueue.h> #ifdef __NR_mq_open #define __NR___syscall_mq_open __NR_mq_open static inline _syscall4(int, __syscall_mq_open, const char *, name, int, oflag, __kernel_mode_t, mode, void *, attr); /* * Establish connection between a process and a message queue and * return message queue descriptor or (mqd_t) -1 on error. * oflag determines the type of access used. If O_CREAT is on oflag, the * third argument is taken as a `mode_t', the mode of the created * message queue, and the fourth argument is taken as `struct mq_attr *', * pointer to message queue attributes. * If the fourth argument is NULL, default attributes are used. */ mqd_t mq_open(const char *name, int oflag, ...) { mode_t mode; struct mq_attr *attr; if (name[0] != '/') { __set_errno(EINVAL); return -1; } mode = 0; attr = NULL; if (oflag & O_CREAT) { va_list ap; va_start(ap, oflag); mode = va_arg(ap, mode_t); attr = va_arg(ap, struct mq_attr *); va_end(ap); } return __syscall_mq_open(name + 1, oflag, mode, attr); } #endif