1 /* $NetBSD: cons.c,v 1.3 2013/09/08 04:37:17 pooka Exp $ */ 2 3 /* 4 * Copyright (c) 2013 Antti Kantee. All Rights Reserved. 5 * 6 * Redistribution and use in source and binary forms, with or without 7 * modification, are permitted provided that the following conditions 8 * are met: 9 * 1. Redistributions of source code must retain the above copyright 10 * notice, this list of conditions and the following disclaimer. 11 * 2. Redistributions in binary form must reproduce the above copyright 12 * notice, this list of conditions and the following disclaimer in the 13 * documentation and/or other materials provided with the distribution. 14 * 15 * THIS SOFTWARE IS PROVIDED BY THE AUTHOR ``AS IS'' AND ANY EXPRESS 16 * OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE IMPLIED 17 * WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE ARE 18 * DISCLAIMED. IN NO EVENT SHALL THE AUTHOR OR CONTRIBUTORS BE LIABLE 19 * FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL 20 * DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS OR 21 * SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION) 22 * HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT 23 * LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY 24 * OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF 25 * SUCH DAMAGE. 26 */ 27 28 /* 29 * rumpcons, a (very) simple console-type device which relays output 30 * to the rumpuser_putchar() hypercall. This is most useful in 31 * environments where there is no Unix-like host (e.g. Xen DomU). 32 * It's currently a truly half duplex console since there is support 33 * only for writing to the console (there is no hypercall for reading 34 * the host console). The driver attempts to look like a tty just 35 * enough to fool isatty(). Let's see how far that gets us. 36 */ 37 38 #include <sys/cdefs.h> 39 __KERNEL_RCSID(0, "$NetBSD: cons.c,v 1.3 2013/09/08 04:37:17 pooka Exp $"); 40 41 #include <sys/param.h> 42 #include <sys/file.h> 43 #include <sys/filedesc.h> 44 #include <sys/ioctl.h> 45 #include <sys/kernel.h> 46 #include <sys/kmem.h> 47 #include <sys/proc.h> 48 #include <sys/stat.h> 49 #include <sys/termios.h> 50 51 #include <rump/rumpuser.h> 52 53 #include "rump_private.h" 54 55 static int rumpcons_write(struct file *, off_t *, struct uio *, 56 kauth_cred_t, int); 57 static int rumpcons_ioctl(struct file *, u_long, void *); 58 static int rumpcons_stat(struct file *, struct stat *); 59 60 static const struct fileops rumpcons_fileops = { 61 .fo_read = (void *)nullop, 62 .fo_write = rumpcons_write, 63 .fo_ioctl = rumpcons_ioctl, 64 .fo_fcntl = fnullop_fcntl, 65 .fo_poll = fnullop_poll, 66 .fo_stat = rumpcons_stat, 67 .fo_close = (void *)nullop, 68 .fo_kqfilter = fnullop_kqfilter, 69 .fo_restart = fnullop_restart, 70 }; 71 72 void 73 rump_consdev_init(void) 74 { 75 struct file *fp; 76 int fd, error; 77 78 /* 79 * We want to open the descriptors for the implicit proc 80 * so that they get inherited by default to all processes. 81 */ 82 KASSERT(curproc->p_pid == 1); 83 KASSERT(fd_getfile(0) == NULL); 84 85 /* then, map a file descriptor to the device */ 86 if ((error = fd_allocfile(&fp, &fd)) != 0) 87 panic("cons fd_allocfile failed: %d", error); 88 89 fp->f_flag = FWRITE; 90 fp->f_type = DTYPE_MISC; 91 fp->f_ops = &rumpcons_fileops; 92 fp->f_data = NULL; 93 fd_affix(curproc, fp, fd); 94 95 KASSERT(fd == 0); 96 error += fd_dup2(fp, 1, 0); 97 error += fd_dup2(fp, 2, 0); 98 99 if (error) 100 panic("failed to dup fd 0/1/2"); 101 } 102 103 static int 104 rumpcons_write(struct file *fp, off_t *off, struct uio *uio, 105 kauth_cred_t cred, int flags) 106 { 107 char *buf; 108 size_t len, n; 109 int error = 0; 110 111 buf = kmem_alloc(PAGE_SIZE, KM_SLEEP); 112 while (uio->uio_resid > 0) { 113 len = min(PAGE_SIZE, uio->uio_resid); 114 error = uiomove(buf, len, uio); 115 if (error) 116 break; 117 118 for (n = 0; n < len; n++) { 119 rumpuser_putchar(*(buf+n)); 120 } 121 } 122 kmem_free(buf, PAGE_SIZE); 123 124 return error; 125 } 126 127 static int 128 rumpcons_ioctl(struct file *fp, u_long cmd, void *data) 129 { 130 131 if (cmd == TIOCGETA) 132 return 0; 133 134 return ENOTTY; /* considering how we are cheating, lol */ 135 } 136 137 static int 138 rumpcons_stat(struct file *fp, struct stat *sb) 139 { 140 141 memset(sb, 0, sizeof(*sb)); 142 sb->st_mode = 0600 | _S_IFCHR; 143 sb->st_atimespec = sb->st_mtimespec = sb->st_ctimespec = boottime; 144 sb->st_birthtimespec = boottime; 145 146 return 0; 147 } 148