diff options
| -rw-r--r-- | sys/include/sys/filedesc.h | 2 | ||||
| -rw-r--r-- | sys/kern/kern_descrip.c | 23 |
2 files changed, 25 insertions, 0 deletions
diff --git a/sys/include/sys/filedesc.h b/sys/include/sys/filedesc.h index f5f24db..94946a0 100644 --- a/sys/include/sys/filedesc.h +++ b/sys/include/sys/filedesc.h @@ -48,6 +48,8 @@ int fd_read(unsigned int fd, void *buf, size_t count); int fd_alloc(struct filedesc **fd_out); int fd_open(const char *pathname, int flags); + +int fd_dup(int fd); struct filedesc *fd_get(unsigned int fdno); #endif /* !_SYS_FILEDESC_H_ */ diff --git a/sys/kern/kern_descrip.c b/sys/kern/kern_descrip.c index c3d9b5c..da10f89 100644 --- a/sys/kern/kern_descrip.c +++ b/sys/kern/kern_descrip.c @@ -226,3 +226,26 @@ fd_open(const char *pathname, int flags) filedes->vp = nd.vp; return filedes->fdno; } + +/* + * Duplicate a file descriptor. New file descriptor + * points to the same vnode. + */ +int +fd_dup(int fd) +{ + int error; + struct filedesc *new_desc, *tmp; + + tmp = fd_get(fd); + if (tmp == NULL) + return -EBADF; + + if ((error = fd_alloc(&new_desc)) != 0) + return error; + + /* Ref that vnode before we point to it */ + vfs_vref(tmp->vp); + new_desc->vp = tmp->vp; + return new_desc->fdno; +} |