1 /* $NetBSD: devnodes.c,v 1.10 2014/06/20 11:27:25 pooka Exp $ */ 2 3 /* 4 * Copyright (c) 2009 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 #include <sys/cdefs.h> 29 __KERNEL_RCSID(0, "$NetBSD: devnodes.c,v 1.10 2014/06/20 11:27:25 pooka Exp $"); 30 31 #include <sys/param.h> 32 #include <sys/device.h> 33 #include <sys/filedesc.h> 34 #include <sys/kmem.h> 35 #include <sys/lwp.h> 36 #include <sys/namei.h> 37 #include <sys/stat.h> 38 #include <sys/vfs_syscalls.h> 39 40 #include "rump_vfs_private.h" 41 42 /* realqvik(tm) "devfs" */ 43 static int 44 makeonedevnode(dev_t devtype, const char *devname, 45 devmajor_t majnum, devminor_t minnum) 46 { 47 register_t retval; 48 int error; 49 50 error = do_sys_mknod(curlwp, devname, 0666 | devtype, 51 makedev(majnum, minnum), &retval, UIO_SYSSPACE); 52 if (error == EEXIST) /* XXX: should check it's actually the same */ 53 error = 0; 54 55 return error; 56 } 57 58 static int 59 makedevnodes(dev_t devtype, const char *basename, char minchar, 60 devmajor_t maj, devminor_t minnum, int nnodes) 61 { 62 int error = 0; 63 char *devname, *p; 64 size_t devlen; 65 register_t retval; 66 67 devlen = strlen(basename) + 1 + 1; /* +letter +0 */ 68 devname = kmem_zalloc(devlen, KM_SLEEP); 69 strlcpy(devname, basename, devlen); 70 p = devname + devlen-2; 71 72 for (; nnodes > 0; nnodes--, minchar++, minnum++) { 73 KASSERT(minchar <= 'z'); 74 *p = minchar; 75 76 if ((error = do_sys_mknod(curlwp, devname, 0666 | devtype, 77 makedev(maj, minnum), &retval, UIO_SYSSPACE))) { 78 if (error == EEXIST) 79 error = 0; 80 else 81 goto out; 82 } 83 } 84 85 out: 86 kmem_free(devname, devlen); 87 return error; 88 } 89 90 enum { NOTEXIST, SAME, DIFFERENT }; 91 static int 92 doesitexist(const char *path, bool isblk, devmajor_t dmaj, devminor_t dmin) 93 { 94 struct stat sb; 95 int error; 96 97 error = do_sys_stat(path, 0, &sb); 98 /* even if not ENOENT, we might be able to create it */ 99 if (error) 100 return NOTEXIST; 101 102 if (major(sb.st_rdev) != dmaj || minor(sb.st_rdev) != dmin) 103 return DIFFERENT; 104 if (isblk && !S_ISBLK(sb.st_mode)) 105 return DIFFERENT; 106 if (!isblk && !S_ISCHR(sb.st_mode)) 107 return DIFFERENT; 108 109 return SAME; 110 } 111 112 static void 113 makeonenode(char *buf, size_t len, devmajor_t blk, devmajor_t chr, 114 devminor_t dmin, const char *base, int c1, int c2) 115 { 116 char cstr1[2] = {0,0}, cstr2[2] = {0,0}; 117 register_t rv; 118 int error; 119 120 if (c1 != -1) { 121 cstr1[0] = '0' + c1; 122 cstr1[1] = '\0'; 123 } 124 125 if (c2 != -1) { 126 cstr2[0] = 'a' + c2; 127 cstr2[1] = '\0'; 128 129 } 130 131 /* block device */ 132 snprintf(buf, len, "/dev/%s%s%s", base, cstr1, cstr2); 133 if (blk != NODEVMAJOR) { 134 switch (doesitexist(buf, true, blk, dmin)) { 135 case DIFFERENT: 136 aprint_verbose("mkdevnodes: block device %s " 137 "already exists\n", buf); 138 break; 139 case NOTEXIST: 140 if ((error = do_sys_mknod(curlwp, buf, 0600 | S_IFBLK, 141 makedev(blk, dmin), &rv, UIO_SYSSPACE)) != 0) 142 aprint_verbose("mkdevnodes: failed to " 143 "create %s: %d\n", buf, error); 144 break; 145 case SAME: 146 /* done */ 147 break; 148 } 149 snprintf(buf, len, "/dev/r%s%s%s", base, cstr1, cstr2); 150 } 151 152 switch (doesitexist(buf, true, chr, dmin)) { 153 case DIFFERENT: 154 aprint_verbose("mkdevnodes: character device %s " 155 "already exists\n", buf); 156 break; 157 case NOTEXIST: 158 if ((error = do_sys_mknod(curlwp, buf, 0600 | S_IFCHR, 159 makedev(chr, dmin), &rv, UIO_SYSSPACE)) != 0) 160 aprint_verbose("mkdevnodes: failed to " 161 "create %s: %d\n", buf, error); 162 break; 163 case SAME: 164 /* yeehaa */ 165 break; 166 } 167 } 168 169 void 170 rump_vfs_builddevs(struct devsw_conv *dcvec, size_t dcvecsize) 171 { 172 char *pnbuf = PNBUF_GET(); 173 devminor_t themin; 174 struct devsw_conv *dc; 175 size_t i; 176 int v1, v2; 177 178 rump_vfs_makeonedevnode = makeonedevnode; 179 rump_vfs_makedevnodes = makedevnodes; 180 181 for (i = 0; i < dcvecsize; i++) { 182 dc = &dcvec[i]; 183 184 switch (dc->d_class) { 185 case DEVNODE_DONTBOTHER: 186 break; 187 case DEVNODE_SINGLE: 188 if (dc->d_flags & DEVNODE_FLAG_ISMINOR0) { 189 themin = dc->d_vectdim[0]; 190 } else { 191 themin = 0; 192 } 193 makeonenode(pnbuf, MAXPATHLEN, 194 dc->d_bmajor, dc->d_cmajor, themin, 195 dc->d_name, -1, -1); 196 break; 197 case DEVNODE_VECTOR: 198 for (v1 = 0; v1 < dc->d_vectdim[0]; v1++) { 199 if (dc->d_vectdim[1] == 0) { 200 makeonenode(pnbuf, MAXPATHLEN, 201 dc->d_bmajor, dc->d_cmajor, 202 v1, dc->d_name, v1, -1); 203 } else { 204 for (v2 = 0; 205 v2 < dc->d_vectdim[1]; v2++) { 206 makeonenode(pnbuf, MAXPATHLEN, 207 dc->d_bmajor, dc->d_cmajor, 208 v1 * dc->d_vectdim[1] + v2, 209 dc->d_name, v1, v2); 210 } 211 } 212 } 213 214 /* add some extra sanity checks here */ 215 if (dc->d_flags & DEVNODE_FLAG_LINKZERO) { 216 /* 217 * ok, so we cheat a bit since 218 * symlink isn't supported on rumpfs ... 219 */ 220 makeonenode(pnbuf, MAXPATHLEN, 221 -1, dc->d_cmajor, 0, dc->d_name, -1, -1); 222 223 } 224 break; 225 } 226 } 227 228 PNBUF_PUT(pnbuf); 229 } 230