Commit | Line | Data |
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eede782b | 1 | /* vfs_vnops.c 4.11 81/05/15 */ |
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: | |
83 | case IFMPC: | |
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 | case IFMPB: |
95 | cfunc = bdevsw[major(dev)].d_close; | |
96 | break; | |
97 | default: | |
98 | return; | |
99 | } | |
100 | ||
f5b8937b | 101 | if ((flag & FMP) == 0) { |
fb21923a | 102 | for(fp=file; fp < fileNFILE; fp++) |
eb681afb BJ |
103 | if (fp->f_count && (ip = fp->f_inode) && |
104 | ip->i_un.i_rdev == dev && | |
f5b8937b RE |
105 | (ip->i_mode&IFMT) == mode) |
106 | return; | |
f5b8937b RE |
107 | if (mode == IFBLK) { |
108 | /* | |
109 | * on last close of a block device (that isn't mounted) | |
110 | * we must invalidate any in core blocks | |
111 | */ | |
112 | bflush(dev); | |
113 | binval(dev); | |
114 | } | |
115 | } | |
e6aa77eb | 116 | (*cfunc)(dev, flag, fp); |
fc96c615 BJ |
117 | } |
118 | ||
119 | /* | |
120 | * openi called to allow handler | |
121 | * of special files to initialize and | |
122 | * validate before actual IO. | |
123 | */ | |
124 | openi(ip, rw) | |
125 | register struct inode *ip; | |
126 | { | |
127 | dev_t dev; | |
128 | register unsigned int maj; | |
129 | ||
130 | dev = (dev_t)ip->i_un.i_rdev; | |
131 | maj = major(dev); | |
132 | switch(ip->i_mode&IFMT) { | |
133 | ||
134 | case IFCHR: | |
135 | case IFMPC: | |
136 | if(maj >= nchrdev) | |
137 | goto bad; | |
138 | (*cdevsw[maj].d_open)(dev, rw); | |
139 | break; | |
140 | ||
141 | case IFBLK: | |
142 | case IFMPB: | |
143 | if(maj >= nblkdev) | |
144 | goto bad; | |
145 | (*bdevsw[maj].d_open)(dev, rw); | |
146 | } | |
147 | return; | |
148 | ||
149 | bad: | |
150 | u.u_error = ENXIO; | |
151 | } | |
152 | ||
153 | /* | |
154 | * Check mode permission on inode pointer. | |
155 | * Mode is READ, WRITE or EXEC. | |
156 | * In the case of WRITE, the | |
157 | * read-only status of the file | |
158 | * system is checked. | |
159 | * Also in WRITE, prototype text | |
160 | * segments cannot be written. | |
161 | * The mode is shifted to select | |
162 | * the owner/group/other fields. | |
163 | * The super user is granted all | |
164 | * permissions. | |
165 | */ | |
166 | access(ip, mode) | |
167 | register struct inode *ip; | |
168 | { | |
169 | register m; | |
170 | ||
171 | m = mode; | |
172 | if(m == IWRITE) { | |
173 | if(getfs(ip->i_dev)->s_ronly != 0) { | |
174 | u.u_error = EROFS; | |
175 | return(1); | |
176 | } | |
177 | if (ip->i_flag&ITEXT) /* try to free text */ | |
178 | xrele(ip); | |
179 | if(ip->i_flag & ITEXT) { | |
180 | u.u_error = ETXTBSY; | |
181 | return(1); | |
182 | } | |
183 | } | |
184 | if(u.u_uid == 0) | |
185 | return(0); | |
186 | if(u.u_uid != ip->i_uid) { | |
187 | m >>= 3; | |
188 | if(u.u_gid != ip->i_gid) | |
189 | m >>= 3; | |
190 | } | |
191 | if((ip->i_mode&m) != 0) | |
192 | return(0); | |
193 | ||
194 | u.u_error = EACCES; | |
195 | return(1); | |
196 | } | |
197 | ||
198 | /* | |
199 | * Look up a pathname and test if | |
200 | * the resultant inode is owned by the | |
201 | * current user. | |
202 | * If not, try for super-user. | |
203 | * If permission is granted, | |
204 | * return inode pointer. | |
205 | */ | |
206 | struct inode * | |
207 | owner() | |
208 | { | |
209 | register struct inode *ip; | |
210 | ||
211 | ip = namei(uchar, 0); | |
212 | if(ip == NULL) | |
213 | return(NULL); | |
214 | if(u.u_uid == ip->i_uid) | |
215 | return(ip); | |
216 | if(suser()) | |
217 | return(ip); | |
218 | iput(ip); | |
219 | return(NULL); | |
220 | } | |
221 | ||
222 | /* | |
223 | * Test if the current user is the | |
224 | * super user. | |
225 | */ | |
226 | suser() | |
227 | { | |
228 | ||
229 | if(u.u_uid == 0) { | |
230 | u.u_acflag |= ASU; | |
231 | return(1); | |
232 | } | |
233 | u.u_error = EPERM; | |
234 | return(0); | |
235 | } | |
236 | ||
237 | /* | |
238 | * Allocate a user file descriptor. | |
239 | */ | |
240 | ufalloc() | |
241 | { | |
242 | register i; | |
243 | ||
244 | for(i=0; i<NOFILE; i++) | |
245 | if(u.u_ofile[i] == NULL) { | |
246 | u.u_r.r_val1 = i; | |
247 | u.u_pofile[i] = 0; | |
248 | return(i); | |
249 | } | |
250 | u.u_error = EMFILE; | |
251 | return(-1); | |
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) |
fc96c615 | 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++; | |
284 | fp->f_un.f_offset = 0; | |
eede782b | 285 | fp->f_inode = 0; |
9c98386a | 286 | lastf = fp + 1; |
0a34b6fd | 287 | return (fp); |
fc96c615 | 288 | } |