1 /* $NetBSD: devnodes.c,v 1.13 2019/06/18 22:34:26 kamil 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 1.13 2019/06/18 22:34:26 kamil 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-sys/vfs.h>
41
42 /* realqvik(tm) "devfs" */
43 static int
makeonedevnode(dev_t devtype,const char * devname,devmajor_t majnum,devminor_t minnum)44 makeonedevnode(dev_t devtype, const char *devname,
45 devmajor_t majnum, devminor_t minnum)
46 {
47 int error;
48
49 error = do_sys_mknod(curlwp, devname, 0666 | devtype,
50 makedev(majnum, minnum), UIO_SYSSPACE);
51 if (error == EEXIST) /* XXX: should check it's actually the same */
52 error = 0;
53
54 return error;
55 }
56
57 static int
makedevnodes(dev_t devtype,const char * basename,char minchar,devmajor_t maj,devminor_t minnum,int nnodes)58 makedevnodes(dev_t devtype, const char *basename, char minchar,
59 devmajor_t maj, devminor_t minnum, int nnodes)
60 {
61 int error = 0;
62 char *devname, *p;
63 size_t devlen;
64
65 devlen = strlen(basename) + 1 + 1; /* +letter +0 */
66 devname = kmem_zalloc(devlen, KM_SLEEP);
67 strlcpy(devname, basename, devlen);
68 p = devname + devlen-2;
69
70 for (; nnodes > 0; nnodes--, minchar++, minnum++) {
71 KASSERT(minchar <= 'z');
72 *p = minchar;
73
74 if ((error = do_sys_mknod(curlwp, devname, 0666 | devtype,
75 makedev(maj, minnum), UIO_SYSSPACE))) {
76 if (error == EEXIST)
77 error = 0;
78 else
79 goto out;
80 }
81 }
82
83 out:
84 kmem_free(devname, devlen);
85 return error;
86 }
87
88 static int
makesymlink(const char * dst,const char * src)89 makesymlink(const char *dst, const char *src)
90 {
91
92 return do_sys_symlink(dst, src, UIO_SYSSPACE);
93 }
94
95 enum { NOTEXIST, SAME, DIFFERENT };
96 static int
doesitexist(const char * path,bool isblk,devmajor_t dmaj,devminor_t dmin)97 doesitexist(const char *path, bool isblk, devmajor_t dmaj, devminor_t dmin)
98 {
99 struct stat sb;
100 int error;
101
102 error = do_sys_stat(path, 0, &sb);
103 /* even if not ENOENT, we might be able to create it */
104 if (error)
105 return NOTEXIST;
106
107 if (major(sb.st_rdev) != dmaj || minor(sb.st_rdev) != dmin)
108 return DIFFERENT;
109 if (isblk && !S_ISBLK(sb.st_mode))
110 return DIFFERENT;
111 if (!isblk && !S_ISCHR(sb.st_mode))
112 return DIFFERENT;
113
114 return SAME;
115 }
116
117 static void
makeonenode(char * buf,size_t len,devmajor_t blk,devmajor_t chr,devminor_t dmin,const char * base,int c1,int c2)118 makeonenode(char *buf, size_t len, devmajor_t blk, devmajor_t chr,
119 devminor_t dmin, const char *base, int c1, int c2)
120 {
121 char cstr1[2] = {0,0}, cstr2[2] = {0,0};
122 int error;
123
124 if (c1 != -1) {
125 cstr1[0] = '0' + c1;
126 cstr1[1] = '\0';
127 }
128
129 if (c2 != -1) {
130 cstr2[0] = 'a' + c2;
131 cstr2[1] = '\0';
132
133 }
134
135 /* block device */
136 snprintf(buf, len, "/dev/%s%s%s", base, cstr1, cstr2);
137 if (blk != NODEVMAJOR) {
138 switch (doesitexist(buf, true, blk, dmin)) {
139 case DIFFERENT:
140 aprint_verbose("mkdevnodes: block device %s "
141 "already exists\n", buf);
142 break;
143 case NOTEXIST:
144 if ((error = do_sys_mknod(curlwp, buf, 0600 | S_IFBLK,
145 makedev(blk, dmin), UIO_SYSSPACE)) != 0)
146 aprint_verbose("mkdevnodes: failed to "
147 "create %s: %d\n", buf, error);
148 break;
149 case SAME:
150 /* done */
151 break;
152 }
153 snprintf(buf, len, "/dev/r%s%s%s", base, cstr1, cstr2);
154 }
155
156 switch (doesitexist(buf, true, chr, dmin)) {
157 case DIFFERENT:
158 aprint_verbose("mkdevnodes: character device %s "
159 "already exists\n", buf);
160 break;
161 case NOTEXIST:
162 if ((error = do_sys_mknod(curlwp, buf, 0600 | S_IFCHR,
163 makedev(chr, dmin), UIO_SYSSPACE)) != 0)
164 aprint_verbose("mkdevnodes: failed to "
165 "create %s: %d\n", buf, error);
166 break;
167 case SAME:
168 /* yeehaa */
169 break;
170 }
171 }
172
173 void
rump_vfs_builddevs(struct devsw_conv * dcvec,size_t dcvecsize)174 rump_vfs_builddevs(struct devsw_conv *dcvec, size_t dcvecsize)
175 {
176 char *pnbuf = PNBUF_GET();
177 devminor_t themin;
178 struct devsw_conv *dc;
179 size_t i;
180 int v1, v2;
181
182 rump_vfs_makeonedevnode = makeonedevnode;
183 rump_vfs_makedevnodes = makedevnodes;
184 rump_vfs_makesymlink = makesymlink;
185
186 for (i = 0; i < dcvecsize; i++) {
187 dc = &dcvec[i];
188
189 switch (dc->d_class) {
190 case DEVNODE_DONTBOTHER:
191 break;
192 case DEVNODE_SINGLE:
193 if (dc->d_flags & DEVNODE_FLAG_ISMINOR0) {
194 themin = dc->d_vectdim[0];
195 } else {
196 themin = 0;
197 }
198 makeonenode(pnbuf, MAXPATHLEN,
199 dc->d_bmajor, dc->d_cmajor, themin,
200 dc->d_name, -1, -1);
201 break;
202 case DEVNODE_VECTOR:
203 for (v1 = 0; v1 < dc->d_vectdim[0]; v1++) {
204 if (dc->d_vectdim[1] == 0) {
205 makeonenode(pnbuf, MAXPATHLEN,
206 dc->d_bmajor, dc->d_cmajor,
207 v1, dc->d_name, v1, -1);
208 } else {
209 for (v2 = 0;
210 v2 < dc->d_vectdim[1]; v2++) {
211 makeonenode(pnbuf, MAXPATHLEN,
212 dc->d_bmajor, dc->d_cmajor,
213 v1 * dc->d_vectdim[1] + v2,
214 dc->d_name, v1, v2);
215 }
216 }
217 }
218
219 /* add some extra sanity checks here */
220 if (dc->d_flags & DEVNODE_FLAG_LINKZERO) {
221 /*
222 * ok, so we cheat a bit since
223 * symlink isn't supported on rumpfs ...
224 */
225 makeonenode(pnbuf, MAXPATHLEN,
226 -1, dc->d_cmajor, 0, dc->d_name, -1, -1);
227
228 }
229 break;
230 }
231 }
232
233 PNBUF_PUT(pnbuf);
234 }
235