Commit | Line | Data |
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5485e062 | 1 | /* vfs_vnops.c 4.22 82/02/27 */ |
fc96c615 BJ |
2 | |
3 | #include "../h/param.h" | |
4 | #include "../h/systm.h" | |
5 | #include "../h/dir.h" | |
6 | #include "../h/user.h" | |
7 | #include "../h/filsys.h" | |
8 | #include "../h/file.h" | |
9 | #include "../h/conf.h" | |
10 | #include "../h/inode.h" | |
11 | #include "../h/reg.h" | |
12 | #include "../h/acct.h" | |
f5b8937b | 13 | #include "../h/mount.h" |
ae921915 BJ |
14 | #include "../h/socket.h" |
15 | #include "../h/socketvar.h" | |
f3156a73 | 16 | #include "../h/proc.h" |
fc96c615 BJ |
17 | |
18 | /* | |
fdd90ee3 BJ |
19 | * Convert a user supplied file descriptor into a pointer |
20 | * to a file structure. Only task is to check range of the descriptor. | |
21 | * Critical paths should use the GETF macro, defined in inline.h. | |
fc96c615 BJ |
22 | */ |
23 | struct file * | |
24 | getf(f) | |
fdd90ee3 | 25 | register int f; |
fc96c615 BJ |
26 | { |
27 | register struct file *fp; | |
28 | ||
75a44ba5 BJ |
29 | if ((unsigned)f >= NOFILE || (fp = u.u_ofile[f]) == NULL) { |
30 | u.u_error = EBADF; | |
31 | return (NULL); | |
fc96c615 | 32 | } |
75a44ba5 | 33 | return (fp); |
fc96c615 BJ |
34 | } |
35 | ||
36 | /* | |
37 | * Internal form of close. | |
38 | * Decrement reference count on | |
39 | * file structure. | |
40 | * Also make sure the pipe protocol | |
41 | * does not constipate. | |
42 | * | |
43 | * Decrement reference count on the inode following | |
44 | * removal to the referencing file structure. | |
45 | * Call device handler on last close. | |
f3156a73 BJ |
46 | * Nouser indicates that the user isn't available to present |
47 | * errors to. | |
fc96c615 | 48 | */ |
f3156a73 | 49 | closef(fp, nouser) |
fdd90ee3 | 50 | register struct file *fp; |
fc96c615 BJ |
51 | { |
52 | register struct inode *ip; | |
f5b8937b | 53 | register struct mount *mp; |
fc96c615 BJ |
54 | int flag, mode; |
55 | dev_t dev; | |
56 | register int (*cfunc)(); | |
fc96c615 | 57 | |
fdd90ee3 | 58 | if (fp == NULL) |
fc96c615 BJ |
59 | return; |
60 | if (fp->f_count > 1) { | |
61 | fp->f_count--; | |
62 | return; | |
63 | } | |
fc96c615 | 64 | flag = fp->f_flag; |
fdd90ee3 | 65 | if (flag & FSOCKET) { |
8f4851aa | 66 | u.u_error = 0; /* XXX */ |
f3156a73 | 67 | soclose(fp->f_socket, nouser); |
8f4851aa | 68 | if (nouser == 0 && u.u_error) |
f3156a73 | 69 | return; |
fdd90ee3 | 70 | fp->f_socket = 0; |
eb681afb BJ |
71 | fp->f_count = 0; |
72 | return; | |
73 | } | |
74 | ip = fp->f_inode; | |
fc96c615 | 75 | dev = (dev_t)ip->i_un.i_rdev; |
f5b8937b | 76 | mode = ip->i_mode & IFMT; |
fdd90ee3 | 77 | ilock(ip); |
fc96c615 | 78 | iput(ip); |
eb681afb | 79 | fp->f_count = 0; |
fc96c615 | 80 | |
eb681afb | 81 | switch (mode) { |
fc96c615 BJ |
82 | |
83 | case IFCHR: | |
fc96c615 BJ |
84 | cfunc = cdevsw[major(dev)].d_close; |
85 | break; | |
86 | ||
87 | case IFBLK: | |
f5b8937b RE |
88 | /* |
89 | * We don't want to really close the device if it is mounted | |
90 | */ | |
91 | for (mp = mount; mp < &mount[NMOUNT]; mp++) | |
92 | if (mp->m_bufp != NULL && mp->m_dev == dev) | |
93 | return; | |
fc96c615 BJ |
94 | cfunc = bdevsw[major(dev)].d_close; |
95 | break; | |
fdd90ee3 | 96 | |
fc96c615 BJ |
97 | default: |
98 | return; | |
99 | } | |
fdd90ee3 BJ |
100 | for (fp = file; fp < fileNFILE; fp++) { |
101 | if (fp->f_flag & FSOCKET) | |
102 | continue; | |
231ed58b | 103 | if (fp->f_count && (ip = fp->f_inode) && |
fdd90ee3 | 104 | ip->i_un.i_rdev == dev && (ip->i_mode&IFMT) == mode) |
231ed58b BJ |
105 | return; |
106 | } | |
107 | if (mode == IFBLK) { | |
108 | /* | |
fdd90ee3 | 109 | * On last close of a block device (that isn't mounted) |
231ed58b BJ |
110 | * we must invalidate any in core blocks |
111 | */ | |
112 | bflush(dev); | |
113 | binval(dev); | |
f5b8937b | 114 | } |
e6aa77eb | 115 | (*cfunc)(dev, flag, fp); |
fc96c615 BJ |
116 | } |
117 | ||
118 | /* | |
fdd90ee3 | 119 | * Openi called to allow handler |
fc96c615 BJ |
120 | * of special files to initialize and |
121 | * validate before actual IO. | |
122 | */ | |
123 | openi(ip, rw) | |
fdd90ee3 | 124 | register struct inode *ip; |
fc96c615 BJ |
125 | { |
126 | dev_t dev; | |
127 | register unsigned int maj; | |
128 | ||
129 | dev = (dev_t)ip->i_un.i_rdev; | |
130 | maj = major(dev); | |
fdd90ee3 | 131 | switch (ip->i_mode&IFMT) { |
fc96c615 BJ |
132 | |
133 | case IFCHR: | |
fdd90ee3 | 134 | if (maj >= nchrdev) |
fc96c615 BJ |
135 | goto bad; |
136 | (*cdevsw[maj].d_open)(dev, rw); | |
137 | break; | |
138 | ||
139 | case IFBLK: | |
fdd90ee3 | 140 | if (maj >= nblkdev) |
fc96c615 BJ |
141 | goto bad; |
142 | (*bdevsw[maj].d_open)(dev, rw); | |
143 | } | |
144 | return; | |
145 | ||
146 | bad: | |
147 | u.u_error = ENXIO; | |
148 | } | |
149 | ||
150 | /* | |
151 | * Check mode permission on inode pointer. | |
152 | * Mode is READ, WRITE or EXEC. | |
153 | * In the case of WRITE, the | |
154 | * read-only status of the file | |
155 | * system is checked. | |
156 | * Also in WRITE, prototype text | |
157 | * segments cannot be written. | |
158 | * The mode is shifted to select | |
159 | * the owner/group/other fields. | |
160 | * The super user is granted all | |
161 | * permissions. | |
162 | */ | |
163 | access(ip, mode) | |
fdd90ee3 BJ |
164 | register struct inode *ip; |
165 | int mode; | |
fc96c615 BJ |
166 | { |
167 | register m; | |
168 | ||
169 | m = mode; | |
fdd90ee3 BJ |
170 | if (m == IWRITE) { |
171 | if (getfs(ip->i_dev)->s_ronly != 0) { | |
fc96c615 | 172 | u.u_error = EROFS; |
fdd90ee3 | 173 | return (1); |
fc96c615 BJ |
174 | } |
175 | if (ip->i_flag&ITEXT) /* try to free text */ | |
176 | xrele(ip); | |
fdd90ee3 | 177 | if (ip->i_flag & ITEXT) { |
fc96c615 | 178 | u.u_error = ETXTBSY; |
fdd90ee3 | 179 | return (1); |
fc96c615 BJ |
180 | } |
181 | } | |
fdd90ee3 BJ |
182 | if (u.u_uid == 0) |
183 | return (0); | |
184 | if (u.u_uid != ip->i_uid) { | |
fc96c615 | 185 | m >>= 3; |
4f4caf05 BJ |
186 | if (ip->i_gid >= NGRPS || |
187 | (u.u_grps[ip->i_gid/(sizeof(int)*8)] & | |
188 | (1 << ip->i_gid%(sizeof(int)*8)) == 0)) | |
fc96c615 BJ |
189 | m >>= 3; |
190 | } | |
fdd90ee3 BJ |
191 | if ((ip->i_mode&m) != 0) |
192 | return (0); | |
fc96c615 | 193 | u.u_error = EACCES; |
fdd90ee3 | 194 | return (1); |
fc96c615 BJ |
195 | } |
196 | ||
197 | /* | |
198 | * Look up a pathname and test if | |
199 | * the resultant inode is owned by the | |
200 | * current user. | |
201 | * If not, try for super-user. | |
202 | * If permission is granted, | |
203 | * return inode pointer. | |
204 | */ | |
205 | struct inode * | |
5485e062 BJ |
206 | owner(follow) |
207 | int follow; | |
fc96c615 BJ |
208 | { |
209 | register struct inode *ip; | |
210 | ||
5485e062 | 211 | ip = namei(uchar, 0, follow); |
fdd90ee3 BJ |
212 | if (ip == NULL) |
213 | return (NULL); | |
214 | if (u.u_uid == ip->i_uid) | |
215 | return (ip); | |
216 | if (suser()) | |
217 | return (ip); | |
fc96c615 | 218 | iput(ip); |
fdd90ee3 | 219 | return (NULL); |
fc96c615 BJ |
220 | } |
221 | ||
222 | /* | |
223 | * Test if the current user is the | |
224 | * super user. | |
225 | */ | |
226 | suser() | |
227 | { | |
228 | ||
fdd90ee3 | 229 | if (u.u_uid == 0) { |
fc96c615 | 230 | u.u_acflag |= ASU; |
fdd90ee3 | 231 | return (1); |
fc96c615 BJ |
232 | } |
233 | u.u_error = EPERM; | |
fdd90ee3 | 234 | return (0); |
fc96c615 BJ |
235 | } |
236 | ||
237 | /* | |
238 | * Allocate a user file descriptor. | |
239 | */ | |
240 | ufalloc() | |
241 | { | |
242 | register i; | |
243 | ||
fdd90ee3 BJ |
244 | for (i=0; i<NOFILE; i++) |
245 | if (u.u_ofile[i] == NULL) { | |
fc96c615 BJ |
246 | u.u_r.r_val1 = i; |
247 | u.u_pofile[i] = 0; | |
fdd90ee3 | 248 | return (i); |
fc96c615 BJ |
249 | } |
250 | u.u_error = EMFILE; | |
fdd90ee3 | 251 | return (-1); |
fc96c615 BJ |
252 | } |
253 | ||
0a34b6fd | 254 | struct file *lastf; |
fc96c615 BJ |
255 | /* |
256 | * Allocate a user file descriptor | |
257 | * and a file structure. | |
258 | * Initialize the descriptor | |
259 | * to point at the file structure. | |
fc96c615 BJ |
260 | */ |
261 | struct file * | |
262 | falloc() | |
263 | { | |
264 | register struct file *fp; | |
265 | register i; | |
266 | ||
267 | i = ufalloc(); | |
0a34b6fd | 268 | if (i < 0) |
fdd90ee3 | 269 | return (NULL); |
0a34b6fd BJ |
270 | if (lastf == 0) |
271 | lastf = file; | |
272 | for (fp = lastf; fp < fileNFILE; fp++) | |
273 | if (fp->f_count == 0) | |
9c98386a | 274 | goto slot; |
0a34b6fd BJ |
275 | for (fp = file; fp < lastf; fp++) |
276 | if (fp->f_count == 0) | |
9c98386a | 277 | goto slot; |
73317613 | 278 | tablefull("file"); |
fc96c615 | 279 | u.u_error = ENFILE; |
0a34b6fd | 280 | return (NULL); |
9c98386a BJ |
281 | slot: |
282 | u.u_ofile[i] = fp; | |
283 | fp->f_count++; | |
fdd90ee3 | 284 | fp->f_offset = 0; |
eede782b | 285 | fp->f_inode = 0; |
9c98386a | 286 | lastf = fp + 1; |
0a34b6fd | 287 | return (fp); |
fc96c615 | 288 | } |