1 /* $NetBSD: cons.c,v 1.5 2015/05/26 15:29:39 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 1.5 2015/05/26 15:29:39 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/poll.h> 48 #include <sys/proc.h> 49 #include <sys/stat.h> 50 #include <sys/termios.h> 51 52 #include <rump/rumpuser.h> 53 54 #include "rump_private.h" 55 56 static int rumpcons_write(struct file *, off_t *, struct uio *, 57 kauth_cred_t, int); 58 static int rumpcons_ioctl(struct file *, u_long, void *); 59 static int rumpcons_stat(struct file *, struct stat *); 60 static int rumpcons_poll(struct file *, int events); 61 62 static const struct fileops rumpcons_fileops = { 63 .fo_read = (void *)nullop, 64 .fo_write = rumpcons_write, 65 .fo_ioctl = rumpcons_ioctl, 66 .fo_fcntl = fnullop_fcntl, 67 .fo_poll = rumpcons_poll, 68 .fo_stat = rumpcons_stat, 69 .fo_close = (void *)nullop, 70 .fo_kqfilter = fnullop_kqfilter, 71 .fo_restart = fnullop_restart, 72 }; 73 74 void 75 rump_consdev_init(void) 76 { 77 struct file *fp; 78 int fd, error; 79 80 KASSERT(fd_getfile(0) == NULL); 81 KASSERT(fd_getfile(1) == NULL); 82 KASSERT(fd_getfile(2) == NULL); 83 84 /* then, map a file descriptor to the device */ 85 if ((error = fd_allocfile(&fp, &fd)) != 0) 86 panic("cons fd_allocfile failed: %d", error); 87 88 fp->f_flag = FWRITE; 89 fp->f_type = DTYPE_MISC; 90 fp->f_ops = &rumpcons_fileops; 91 fp->f_data = NULL; 92 fd_affix(curproc, fp, fd); 93 94 KASSERT(fd == 0); 95 error += fd_dup2(fp, 1, 0); 96 error += fd_dup2(fp, 2, 0); 97 98 if (error) 99 panic("failed to dup fd 0/1/2"); 100 } 101 102 static int 103 rumpcons_write(struct file *fp, off_t *off, struct uio *uio, 104 kauth_cred_t cred, int flags) 105 { 106 char *buf; 107 size_t len, n; 108 int error = 0; 109 110 buf = kmem_alloc(PAGE_SIZE, KM_SLEEP); 111 while (uio->uio_resid > 0) { 112 len = min(PAGE_SIZE, uio->uio_resid); 113 error = uiomove(buf, len, uio); 114 if (error) 115 break; 116 117 for (n = 0; n < len; n++) { 118 rumpuser_putchar(*(buf+n)); 119 } 120 } 121 kmem_free(buf, PAGE_SIZE); 122 123 return error; 124 } 125 126 static int 127 rumpcons_ioctl(struct file *fp, u_long cmd, void *data) 128 { 129 130 if (cmd == TIOCGETA) 131 return 0; 132 133 return ENOTTY; /* considering how we are cheating, lol */ 134 } 135 136 static int 137 rumpcons_stat(struct file *fp, struct stat *sb) 138 { 139 140 memset(sb, 0, sizeof(*sb)); 141 sb->st_mode = 0600 | _S_IFCHR; 142 sb->st_atimespec = sb->st_mtimespec = sb->st_ctimespec = boottime; 143 sb->st_birthtimespec = boottime; 144 145 return 0; 146 } 147 148 static int 149 rumpcons_poll(struct file *fp, int events) 150 { 151 int revents = 0; 152 153 if (events & (POLLOUT | POLLWRNORM)) 154 revents |= events & (POLLOUT | POLLWRNORM); 155 156 return revents; 157 } 158