Commit | Line | Data |
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2b4b57cd | 1 | /* vfs_vnops.c 4.17 81/11/18 */ |
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" | |
fc96c615 BJ |
16 | |
17 | /* | |
fdd90ee3 BJ |
18 | * Convert a user supplied file descriptor into a pointer |
19 | * to a file structure. Only task is to check range of the descriptor. | |
20 | * Critical paths should use the GETF macro, defined in inline.h. | |
fc96c615 BJ |
21 | */ |
22 | struct file * | |
23 | getf(f) | |
fdd90ee3 | 24 | register int f; |
fc96c615 BJ |
25 | { |
26 | register struct file *fp; | |
27 | ||
75a44ba5 BJ |
28 | if ((unsigned)f >= NOFILE || (fp = u.u_ofile[f]) == NULL) { |
29 | u.u_error = EBADF; | |
30 | return (NULL); | |
fc96c615 | 31 | } |
75a44ba5 | 32 | return (fp); |
fc96c615 BJ |
33 | } |
34 | ||
35 | /* | |
36 | * Internal form of close. | |
37 | * Decrement reference count on | |
38 | * file structure. | |
39 | * Also make sure the pipe protocol | |
40 | * does not constipate. | |
41 | * | |
42 | * Decrement reference count on the inode following | |
43 | * removal to the referencing file structure. | |
44 | * Call device handler on last close. | |
45 | */ | |
46 | closef(fp) | |
fdd90ee3 | 47 | register struct file *fp; |
fc96c615 BJ |
48 | { |
49 | register struct inode *ip; | |
f5b8937b | 50 | register struct mount *mp; |
fc96c615 BJ |
51 | int flag, mode; |
52 | dev_t dev; | |
53 | register int (*cfunc)(); | |
fc96c615 | 54 | |
fdd90ee3 | 55 | if (fp == NULL) |
fc96c615 BJ |
56 | return; |
57 | if (fp->f_count > 1) { | |
58 | fp->f_count--; | |
59 | return; | |
60 | } | |
fc96c615 | 61 | flag = fp->f_flag; |
fdd90ee3 | 62 | if (flag & FSOCKET) { |
cc15ab5d | 63 | soclose(fp->f_socket); |
fdd90ee3 | 64 | fp->f_socket = 0; |
eb681afb BJ |
65 | fp->f_count = 0; |
66 | return; | |
67 | } | |
68 | ip = fp->f_inode; | |
fc96c615 | 69 | dev = (dev_t)ip->i_un.i_rdev; |
f5b8937b | 70 | mode = ip->i_mode & IFMT; |
fdd90ee3 | 71 | ilock(ip); |
fc96c615 | 72 | iput(ip); |
eb681afb | 73 | fp->f_count = 0; |
fc96c615 | 74 | |
eb681afb | 75 | switch (mode) { |
fc96c615 BJ |
76 | |
77 | case IFCHR: | |
fc96c615 BJ |
78 | cfunc = cdevsw[major(dev)].d_close; |
79 | break; | |
80 | ||
81 | case IFBLK: | |
f5b8937b RE |
82 | /* |
83 | * We don't want to really close the device if it is mounted | |
84 | */ | |
85 | for (mp = mount; mp < &mount[NMOUNT]; mp++) | |
86 | if (mp->m_bufp != NULL && mp->m_dev == dev) | |
87 | return; | |
fc96c615 BJ |
88 | cfunc = bdevsw[major(dev)].d_close; |
89 | break; | |
fdd90ee3 | 90 | |
fc96c615 BJ |
91 | default: |
92 | return; | |
93 | } | |
fdd90ee3 BJ |
94 | for (fp = file; fp < fileNFILE; fp++) { |
95 | if (fp->f_flag & FSOCKET) | |
96 | continue; | |
231ed58b | 97 | if (fp->f_count && (ip = fp->f_inode) && |
fdd90ee3 | 98 | ip->i_un.i_rdev == dev && (ip->i_mode&IFMT) == mode) |
231ed58b BJ |
99 | return; |
100 | } | |
101 | if (mode == IFBLK) { | |
102 | /* | |
fdd90ee3 | 103 | * On last close of a block device (that isn't mounted) |
231ed58b BJ |
104 | * we must invalidate any in core blocks |
105 | */ | |
106 | bflush(dev); | |
107 | binval(dev); | |
f5b8937b | 108 | } |
e6aa77eb | 109 | (*cfunc)(dev, flag, fp); |
fc96c615 BJ |
110 | } |
111 | ||
112 | /* | |
fdd90ee3 | 113 | * Openi called to allow handler |
fc96c615 BJ |
114 | * of special files to initialize and |
115 | * validate before actual IO. | |
116 | */ | |
117 | openi(ip, rw) | |
fdd90ee3 | 118 | register struct inode *ip; |
fc96c615 BJ |
119 | { |
120 | dev_t dev; | |
121 | register unsigned int maj; | |
122 | ||
123 | dev = (dev_t)ip->i_un.i_rdev; | |
124 | maj = major(dev); | |
fdd90ee3 | 125 | switch (ip->i_mode&IFMT) { |
fc96c615 BJ |
126 | |
127 | case IFCHR: | |
fdd90ee3 | 128 | if (maj >= nchrdev) |
fc96c615 BJ |
129 | goto bad; |
130 | (*cdevsw[maj].d_open)(dev, rw); | |
131 | break; | |
132 | ||
133 | case IFBLK: | |
fdd90ee3 | 134 | if (maj >= nblkdev) |
fc96c615 BJ |
135 | goto bad; |
136 | (*bdevsw[maj].d_open)(dev, rw); | |
137 | } | |
138 | return; | |
139 | ||
140 | bad: | |
141 | u.u_error = ENXIO; | |
142 | } | |
143 | ||
144 | /* | |
145 | * Check mode permission on inode pointer. | |
146 | * Mode is READ, WRITE or EXEC. | |
147 | * In the case of WRITE, the | |
148 | * read-only status of the file | |
149 | * system is checked. | |
150 | * Also in WRITE, prototype text | |
151 | * segments cannot be written. | |
152 | * The mode is shifted to select | |
153 | * the owner/group/other fields. | |
154 | * The super user is granted all | |
155 | * permissions. | |
156 | */ | |
157 | access(ip, mode) | |
fdd90ee3 BJ |
158 | register struct inode *ip; |
159 | int mode; | |
fc96c615 BJ |
160 | { |
161 | register m; | |
162 | ||
163 | m = mode; | |
fdd90ee3 BJ |
164 | if (m == IWRITE) { |
165 | if (getfs(ip->i_dev)->s_ronly != 0) { | |
fc96c615 | 166 | u.u_error = EROFS; |
fdd90ee3 | 167 | return (1); |
fc96c615 BJ |
168 | } |
169 | if (ip->i_flag&ITEXT) /* try to free text */ | |
170 | xrele(ip); | |
fdd90ee3 | 171 | if (ip->i_flag & ITEXT) { |
fc96c615 | 172 | u.u_error = ETXTBSY; |
fdd90ee3 | 173 | return (1); |
fc96c615 BJ |
174 | } |
175 | } | |
fdd90ee3 BJ |
176 | if (u.u_uid == 0) |
177 | return (0); | |
178 | if (u.u_uid != ip->i_uid) { | |
fc96c615 | 179 | m >>= 3; |
fdd90ee3 | 180 | if (u.u_gid != ip->i_gid) |
fc96c615 BJ |
181 | m >>= 3; |
182 | } | |
fdd90ee3 BJ |
183 | if ((ip->i_mode&m) != 0) |
184 | return (0); | |
fc96c615 | 185 | u.u_error = EACCES; |
fdd90ee3 | 186 | return (1); |
fc96c615 BJ |
187 | } |
188 | ||
189 | /* | |
190 | * Look up a pathname and test if | |
191 | * the resultant inode is owned by the | |
192 | * current user. | |
193 | * If not, try for super-user. | |
194 | * If permission is granted, | |
195 | * return inode pointer. | |
196 | */ | |
197 | struct inode * | |
198 | owner() | |
199 | { | |
200 | register struct inode *ip; | |
201 | ||
202 | ip = namei(uchar, 0); | |
fdd90ee3 BJ |
203 | if (ip == NULL) |
204 | return (NULL); | |
205 | if (u.u_uid == ip->i_uid) | |
206 | return (ip); | |
207 | if (suser()) | |
208 | return (ip); | |
fc96c615 | 209 | iput(ip); |
fdd90ee3 | 210 | return (NULL); |
fc96c615 BJ |
211 | } |
212 | ||
213 | /* | |
214 | * Test if the current user is the | |
215 | * super user. | |
216 | */ | |
217 | suser() | |
218 | { | |
219 | ||
fdd90ee3 | 220 | if (u.u_uid == 0) { |
fc96c615 | 221 | u.u_acflag |= ASU; |
fdd90ee3 | 222 | return (1); |
fc96c615 BJ |
223 | } |
224 | u.u_error = EPERM; | |
fdd90ee3 | 225 | return (0); |
fc96c615 BJ |
226 | } |
227 | ||
228 | /* | |
229 | * Allocate a user file descriptor. | |
230 | */ | |
231 | ufalloc() | |
232 | { | |
233 | register i; | |
234 | ||
fdd90ee3 BJ |
235 | for (i=0; i<NOFILE; i++) |
236 | if (u.u_ofile[i] == NULL) { | |
fc96c615 BJ |
237 | u.u_r.r_val1 = i; |
238 | u.u_pofile[i] = 0; | |
fdd90ee3 | 239 | return (i); |
fc96c615 BJ |
240 | } |
241 | u.u_error = EMFILE; | |
fdd90ee3 | 242 | return (-1); |
fc96c615 BJ |
243 | } |
244 | ||
0a34b6fd | 245 | struct file *lastf; |
fc96c615 BJ |
246 | /* |
247 | * Allocate a user file descriptor | |
248 | * and a file structure. | |
249 | * Initialize the descriptor | |
250 | * to point at the file structure. | |
fc96c615 BJ |
251 | */ |
252 | struct file * | |
253 | falloc() | |
254 | { | |
255 | register struct file *fp; | |
256 | register i; | |
257 | ||
258 | i = ufalloc(); | |
0a34b6fd | 259 | if (i < 0) |
fdd90ee3 | 260 | return (NULL); |
0a34b6fd BJ |
261 | if (lastf == 0) |
262 | lastf = file; | |
263 | for (fp = lastf; fp < fileNFILE; fp++) | |
264 | if (fp->f_count == 0) | |
9c98386a | 265 | goto slot; |
0a34b6fd BJ |
266 | for (fp = file; fp < lastf; fp++) |
267 | if (fp->f_count == 0) | |
9c98386a | 268 | goto slot; |
73317613 | 269 | tablefull("file"); |
fc96c615 | 270 | u.u_error = ENFILE; |
0a34b6fd | 271 | return (NULL); |
9c98386a BJ |
272 | slot: |
273 | u.u_ofile[i] = fp; | |
274 | fp->f_count++; | |
fdd90ee3 | 275 | fp->f_offset = 0; |
eede782b | 276 | fp->f_inode = 0; |
9c98386a | 277 | lastf = fp + 1; |
0a34b6fd | 278 | return (fp); |
fc96c615 | 279 | } |