Commit | Line | Data |
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231ed58b | 1 | /* vfs_vnops.c 4.13 81/10/11 */ |
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" |
fc96c615 BJ |
14 | |
15 | /* | |
16 | * Convert a user supplied | |
17 | * file descriptor into a pointer | |
18 | * to a file structure. | |
19 | * Only task is to check range | |
20 | * of the descriptor. | |
21 | */ | |
22 | struct file * | |
23 | getf(f) | |
24 | register int f; | |
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) | |
47 | register struct file *fp; | |
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 BJ |
54 | |
55 | if(fp == NULL) | |
56 | return; | |
57 | if (fp->f_count > 1) { | |
58 | fp->f_count--; | |
59 | return; | |
60 | } | |
fc96c615 | 61 | flag = fp->f_flag; |
fc814008 BJ |
62 | #ifdef BBNNET |
63 | if (flag&FNET) { | |
64 | netclose(fp); | |
65 | return; | |
66 | } | |
67 | #endif | |
eb681afb BJ |
68 | if (flag & FPORT) { |
69 | ptclose(fp); | |
70 | fp->f_count = 0; | |
71 | return; | |
72 | } | |
73 | ip = fp->f_inode; | |
fc96c615 | 74 | dev = (dev_t)ip->i_un.i_rdev; |
f5b8937b | 75 | mode = ip->i_mode & IFMT; |
fc96c615 | 76 | plock(ip); |
fc96c615 | 77 | iput(ip); |
eb681afb | 78 | fp->f_count = 0; |
fc96c615 | 79 | |
eb681afb | 80 | switch (mode) { |
fc96c615 BJ |
81 | |
82 | case IFCHR: | |
fc96c615 BJ |
83 | cfunc = cdevsw[major(dev)].d_close; |
84 | break; | |
85 | ||
86 | case IFBLK: | |
f5b8937b RE |
87 | /* |
88 | * We don't want to really close the device if it is mounted | |
89 | */ | |
90 | for (mp = mount; mp < &mount[NMOUNT]; mp++) | |
91 | if (mp->m_bufp != NULL && mp->m_dev == dev) | |
92 | return; | |
fc96c615 BJ |
93 | cfunc = bdevsw[major(dev)].d_close; |
94 | break; | |
95 | default: | |
96 | return; | |
97 | } | |
98 | ||
231ed58b | 99 | for(fp=file; fp < fileNFILE; fp++) { |
7cdbcf53 EC |
100 | #ifdef BBNNET |
101 | if (fp->f_flag & FNET) | |
102 | continue; | |
103 | #endif | |
231ed58b BJ |
104 | if (fp->f_count && (ip = fp->f_inode) && |
105 | ip->i_un.i_rdev == dev && | |
106 | (ip->i_mode&IFMT) == mode) | |
107 | return; | |
108 | } | |
109 | if (mode == IFBLK) { | |
110 | /* | |
111 | * on last close of a block device (that isn't mounted) | |
112 | * we must invalidate any in core blocks | |
113 | */ | |
114 | bflush(dev); | |
115 | binval(dev); | |
f5b8937b | 116 | } |
e6aa77eb | 117 | (*cfunc)(dev, flag, fp); |
fc96c615 BJ |
118 | } |
119 | ||
120 | /* | |
121 | * openi called to allow handler | |
122 | * of special files to initialize and | |
123 | * validate before actual IO. | |
124 | */ | |
125 | openi(ip, rw) | |
126 | register struct inode *ip; | |
127 | { | |
128 | dev_t dev; | |
129 | register unsigned int maj; | |
130 | ||
131 | dev = (dev_t)ip->i_un.i_rdev; | |
132 | maj = major(dev); | |
133 | switch(ip->i_mode&IFMT) { | |
134 | ||
135 | case IFCHR: | |
fc96c615 BJ |
136 | if(maj >= nchrdev) |
137 | goto bad; | |
138 | (*cdevsw[maj].d_open)(dev, rw); | |
139 | break; | |
140 | ||
141 | case IFBLK: | |
fc96c615 BJ |
142 | if(maj >= nblkdev) |
143 | goto bad; | |
144 | (*bdevsw[maj].d_open)(dev, rw); | |
145 | } | |
146 | return; | |
147 | ||
148 | bad: | |
149 | u.u_error = ENXIO; | |
150 | } | |
151 | ||
152 | /* | |
153 | * Check mode permission on inode pointer. | |
154 | * Mode is READ, WRITE or EXEC. | |
155 | * In the case of WRITE, the | |
156 | * read-only status of the file | |
157 | * system is checked. | |
158 | * Also in WRITE, prototype text | |
159 | * segments cannot be written. | |
160 | * The mode is shifted to select | |
161 | * the owner/group/other fields. | |
162 | * The super user is granted all | |
163 | * permissions. | |
164 | */ | |
165 | access(ip, mode) | |
166 | register struct inode *ip; | |
167 | { | |
168 | register m; | |
169 | ||
170 | m = mode; | |
171 | if(m == IWRITE) { | |
172 | if(getfs(ip->i_dev)->s_ronly != 0) { | |
173 | u.u_error = EROFS; | |
174 | return(1); | |
175 | } | |
176 | if (ip->i_flag&ITEXT) /* try to free text */ | |
177 | xrele(ip); | |
178 | if(ip->i_flag & ITEXT) { | |
179 | u.u_error = ETXTBSY; | |
180 | return(1); | |
181 | } | |
182 | } | |
183 | if(u.u_uid == 0) | |
184 | return(0); | |
185 | if(u.u_uid != ip->i_uid) { | |
186 | m >>= 3; | |
187 | if(u.u_gid != ip->i_gid) | |
188 | m >>= 3; | |
189 | } | |
190 | if((ip->i_mode&m) != 0) | |
191 | return(0); | |
192 | ||
193 | u.u_error = EACCES; | |
194 | return(1); | |
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 * | |
206 | owner() | |
207 | { | |
208 | register struct inode *ip; | |
209 | ||
210 | ip = namei(uchar, 0); | |
211 | if(ip == NULL) | |
212 | return(NULL); | |
213 | if(u.u_uid == ip->i_uid) | |
214 | return(ip); | |
215 | if(suser()) | |
216 | return(ip); | |
217 | iput(ip); | |
218 | return(NULL); | |
219 | } | |
220 | ||
221 | /* | |
222 | * Test if the current user is the | |
223 | * super user. | |
224 | */ | |
225 | suser() | |
226 | { | |
227 | ||
228 | if(u.u_uid == 0) { | |
229 | u.u_acflag |= ASU; | |
230 | return(1); | |
231 | } | |
232 | u.u_error = EPERM; | |
233 | return(0); | |
234 | } | |
235 | ||
236 | /* | |
237 | * Allocate a user file descriptor. | |
238 | */ | |
239 | ufalloc() | |
240 | { | |
241 | register i; | |
242 | ||
243 | for(i=0; i<NOFILE; i++) | |
244 | if(u.u_ofile[i] == NULL) { | |
245 | u.u_r.r_val1 = i; | |
246 | u.u_pofile[i] = 0; | |
247 | return(i); | |
248 | } | |
249 | u.u_error = EMFILE; | |
250 | return(-1); | |
251 | } | |
252 | ||
0a34b6fd | 253 | struct file *lastf; |
fc96c615 BJ |
254 | /* |
255 | * Allocate a user file descriptor | |
256 | * and a file structure. | |
257 | * Initialize the descriptor | |
258 | * to point at the file structure. | |
fc96c615 BJ |
259 | */ |
260 | struct file * | |
261 | falloc() | |
262 | { | |
263 | register struct file *fp; | |
264 | register i; | |
265 | ||
266 | i = ufalloc(); | |
0a34b6fd | 267 | if (i < 0) |
fc96c615 | 268 | return(NULL); |
0a34b6fd BJ |
269 | if (lastf == 0) |
270 | lastf = file; | |
271 | for (fp = lastf; fp < fileNFILE; fp++) | |
272 | if (fp->f_count == 0) | |
9c98386a | 273 | goto slot; |
0a34b6fd BJ |
274 | for (fp = file; fp < lastf; fp++) |
275 | if (fp->f_count == 0) | |
9c98386a | 276 | goto slot; |
73317613 | 277 | tablefull("file"); |
fc96c615 | 278 | u.u_error = ENFILE; |
0a34b6fd | 279 | return (NULL); |
9c98386a BJ |
280 | slot: |
281 | u.u_ofile[i] = fp; | |
282 | fp->f_count++; | |
283 | fp->f_un.f_offset = 0; | |
eede782b | 284 | fp->f_inode = 0; |
9c98386a | 285 | lastf = fp + 1; |
0a34b6fd | 286 | return (fp); |
fc96c615 | 287 | } |