1 /* $OpenBSD: diskmap.c,v 1.27 2023/04/13 02:19:05 jsg Exp $ */ 2 3 /* 4 * Copyright (c) 2009, 2010 Joel Sing <jsing@openbsd.org> 5 * 6 * Permission to use, copy, modify, and distribute this software for any 7 * purpose with or without fee is hereby granted, provided that the above 8 * copyright notice and this permission notice appear in all copies. 9 * 10 * THE SOFTWARE IS PROVIDED "AS IS" AND THE AUTHOR DISCLAIMS ALL WARRANTIES 11 * WITH REGARD TO THIS SOFTWARE INCLUDING ALL IMPLIED WARRANTIES OF 12 * MERCHANTABILITY AND FITNESS. IN NO EVENT SHALL THE AUTHOR BE LIABLE FOR 13 * ANY SPECIAL, DIRECT, INDIRECT, OR CONSEQUENTIAL DAMAGES OR ANY DAMAGES 14 * WHATSOEVER RESULTING FROM LOSS OF USE, DATA OR PROFITS, WHETHER IN AN 15 * ACTION OF CONTRACT, NEGLIGENCE OR OTHER TORTIOUS ACTION, ARISING OUT OF 16 * OR IN CONNECTION WITH THE USE OR PERFORMANCE OF THIS SOFTWARE. 17 */ 18 19 /* 20 * Disk mapper. 21 */ 22 23 #include <sys/param.h> 24 #include <sys/systm.h> 25 #include <sys/device.h> 26 #include <sys/errno.h> 27 #include <sys/conf.h> 28 #include <sys/dkio.h> 29 #include <sys/disk.h> 30 #include <sys/disklabel.h> 31 #include <sys/fcntl.h> 32 #include <sys/file.h> 33 #include <sys/filedesc.h> 34 #include <sys/lock.h> 35 #include <sys/malloc.h> 36 #include <sys/namei.h> 37 #include <sys/proc.h> 38 #include <sys/vnode.h> 39 #include <sys/pledge.h> 40 41 int 42 diskmapopen(dev_t dev, int flag, int fmt, struct proc *p) 43 { 44 return 0; 45 } 46 47 int 48 diskmapclose(dev_t dev, int flag, int fmt, struct proc *p) 49 { 50 return 0; 51 } 52 53 int 54 diskmapioctl(dev_t dev, u_long cmd, caddr_t addr, int flag, struct proc *p) 55 { 56 struct dk_diskmap *dm; 57 struct nameidata ndp; 58 struct filedesc *fdp = p->p_fd; 59 struct file *fp0 = NULL, *fp = NULL; 60 struct vnode *vp = NULL; 61 char *devname, flags; 62 int error, fd; 63 64 if (cmd != DIOCMAP) 65 return ENOTTY; 66 67 /* 68 * Map a request for a disk to the correct device. We should be 69 * supplied with either a diskname or a disklabel UID. 70 */ 71 72 dm = (struct dk_diskmap *)addr; 73 fd = dm->fd; 74 devname = malloc(PATH_MAX, M_DEVBUF, M_WAITOK); 75 if ((error = copyinstr(dm->device, devname, PATH_MAX, NULL)) != 0) 76 goto invalid; 77 if (disk_map(devname, devname, PATH_MAX, dm->flags) == 0) { 78 error = copyoutstr(devname, dm->device, PATH_MAX, NULL); 79 if (error != 0) 80 goto invalid; 81 } 82 83 /* Attempt to open actual device. */ 84 if ((error = getvnode(p, fd, &fp0)) != 0) 85 goto invalid; 86 87 NDINIT(&ndp, 0, 0, UIO_SYSSPACE, devname, p); 88 ndp.ni_pledge = PLEDGE_RPATH; 89 ndp.ni_unveil = UNVEIL_READ; 90 if ((error = vn_open(&ndp, fp0->f_flag, 0)) != 0) 91 goto invalid; 92 93 vp = ndp.ni_vp; 94 VOP_UNLOCK(vp); 95 96 fdplock(fdp); 97 /* 98 * Stop here if the 'struct file *' has been replaced, 99 * for example by another thread calling dup2(2), while 100 * this thread was sleeping in vn_open(). 101 * 102 * Note that this would not happen for correct usages of 103 * "/dev/diskmap". 104 */ 105 if (fdp->fd_ofiles[fd] != fp0) { 106 error = EAGAIN; 107 goto bad; 108 } 109 110 fp = fnew(p); 111 if (fp == NULL) { 112 error = ENFILE; 113 goto bad; 114 } 115 116 /* Zap old file. */ 117 mtx_enter(&fdp->fd_fplock); 118 KASSERT(fdp->fd_ofiles[fd] == fp0); 119 flags = fdp->fd_ofileflags[fd]; 120 fdp->fd_ofiles[fd] = NULL; 121 fdp->fd_ofileflags[fd] = 0; 122 mtx_leave(&fdp->fd_fplock); 123 124 /* Insert new file. */ 125 fp->f_flag = fp0->f_flag; 126 fp->f_type = DTYPE_VNODE; 127 fp->f_ops = &vnops; 128 fp->f_data = (caddr_t)vp; 129 fdinsert(fdp, fd, flags, fp); 130 fdpunlock(fdp); 131 132 closef(fp0, p); 133 free(devname, M_DEVBUF, PATH_MAX); 134 135 return 0; 136 137 bad: 138 fdpunlock(fdp); 139 (void)vn_close(vp, fp0->f_flag, p->p_ucred, p); 140 invalid: 141 if (fp0) 142 FRELE(fp0, p); 143 144 free(devname, M_DEVBUF, PATH_MAX); 145 146 return error; 147 } 148 149 int 150 diskmapread(dev_t dev, struct uio *uio, int flag) 151 { 152 return ENXIO; 153 } 154 155 int 156 diskmapwrite(dev_t dev, struct uio *uio, int flag) 157 { 158 return ENXIO; 159 } 160