Commit | Line | Data |
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f5b8937b | 1 | /* vfs_vnops.c 4.3 %G% */ |
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 | ||
28 | if(0 <= f && f < NOFILE) { | |
29 | fp = u.u_ofile[f]; | |
30 | if(fp != NULL) | |
31 | return(fp); | |
32 | } | |
33 | u.u_error = EBADF; | |
34 | return(NULL); | |
35 | } | |
36 | ||
37 | /* | |
38 | * Internal form of close. | |
39 | * Decrement reference count on | |
40 | * file structure. | |
41 | * Also make sure the pipe protocol | |
42 | * does not constipate. | |
43 | * | |
44 | * Decrement reference count on the inode following | |
45 | * removal to the referencing file structure. | |
46 | * Call device handler on last close. | |
47 | */ | |
48 | closef(fp) | |
49 | register struct file *fp; | |
50 | { | |
51 | register struct inode *ip; | |
f5b8937b | 52 | register struct mount *mp; |
fc96c615 BJ |
53 | int flag, mode; |
54 | dev_t dev; | |
55 | register int (*cfunc)(); | |
fc96c615 BJ |
56 | |
57 | if(fp == NULL) | |
58 | return; | |
59 | if (fp->f_count > 1) { | |
60 | fp->f_count--; | |
61 | return; | |
62 | } | |
63 | ip = fp->f_inode; | |
64 | flag = fp->f_flag; | |
fc96c615 | 65 | dev = (dev_t)ip->i_un.i_rdev; |
f5b8937b | 66 | mode = ip->i_mode & IFMT; |
fc96c615 BJ |
67 | |
68 | plock(ip); | |
69 | fp->f_count = 0; | |
70 | if(flag & FPIPE) { | |
71 | ip->i_mode &= ~(IREAD|IWRITE); | |
72 | wakeup((caddr_t)ip+1); | |
73 | wakeup((caddr_t)ip+2); | |
74 | } | |
75 | iput(ip); | |
76 | ||
f5b8937b | 77 | switch(mode) { |
fc96c615 BJ |
78 | |
79 | case IFCHR: | |
80 | case IFMPC: | |
81 | cfunc = cdevsw[major(dev)].d_close; | |
82 | break; | |
83 | ||
84 | case IFBLK: | |
f5b8937b RE |
85 | /* |
86 | * We don't want to really close the device if it is mounted | |
87 | */ | |
88 | for (mp = mount; mp < &mount[NMOUNT]; mp++) | |
89 | if (mp->m_bufp != NULL && mp->m_dev == dev) | |
90 | return; | |
fc96c615 BJ |
91 | case IFMPB: |
92 | cfunc = bdevsw[major(dev)].d_close; | |
93 | break; | |
94 | default: | |
95 | return; | |
96 | } | |
97 | ||
f5b8937b RE |
98 | if ((flag & FMP) == 0) { |
99 | for(fp=file; fp < &file[NFILE]; fp++) | |
100 | if (fp->f_count && (ip=fp->f_inode)->i_un.i_rdev==dev && | |
101 | (ip->i_mode&IFMT) == mode) | |
102 | return; | |
103 | ||
104 | if (mode == IFBLK) { | |
105 | /* | |
106 | * on last close of a block device (that isn't mounted) | |
107 | * we must invalidate any in core blocks | |
108 | */ | |
109 | bflush(dev); | |
110 | binval(dev); | |
111 | } | |
112 | } | |
fc96c615 | 113 | |
e6aa77eb | 114 | (*cfunc)(dev, flag, fp); |
fc96c615 BJ |
115 | } |
116 | ||
117 | /* | |
118 | * openi called to allow handler | |
119 | * of special files to initialize and | |
120 | * validate before actual IO. | |
121 | */ | |
122 | openi(ip, rw) | |
123 | register struct inode *ip; | |
124 | { | |
125 | dev_t dev; | |
126 | register unsigned int maj; | |
127 | ||
128 | dev = (dev_t)ip->i_un.i_rdev; | |
129 | maj = major(dev); | |
130 | switch(ip->i_mode&IFMT) { | |
131 | ||
132 | case IFCHR: | |
133 | case IFMPC: | |
134 | if(maj >= nchrdev) | |
135 | goto bad; | |
136 | (*cdevsw[maj].d_open)(dev, rw); | |
137 | break; | |
138 | ||
139 | case IFBLK: | |
140 | case IFMPB: | |
141 | if(maj >= nblkdev) | |
142 | goto bad; | |
143 | (*bdevsw[maj].d_open)(dev, rw); | |
144 | } | |
145 | return; | |
146 | ||
147 | bad: | |
148 | u.u_error = ENXIO; | |
149 | } | |
150 | ||
151 | /* | |
152 | * Check mode permission on inode pointer. | |
153 | * Mode is READ, WRITE or EXEC. | |
154 | * In the case of WRITE, the | |
155 | * read-only status of the file | |
156 | * system is checked. | |
157 | * Also in WRITE, prototype text | |
158 | * segments cannot be written. | |
159 | * The mode is shifted to select | |
160 | * the owner/group/other fields. | |
161 | * The super user is granted all | |
162 | * permissions. | |
163 | */ | |
164 | access(ip, mode) | |
165 | register struct inode *ip; | |
166 | { | |
167 | register m; | |
168 | ||
169 | m = mode; | |
170 | if(m == IWRITE) { | |
171 | if(getfs(ip->i_dev)->s_ronly != 0) { | |
172 | u.u_error = EROFS; | |
173 | return(1); | |
174 | } | |
175 | if (ip->i_flag&ITEXT) /* try to free text */ | |
176 | xrele(ip); | |
177 | if(ip->i_flag & ITEXT) { | |
178 | u.u_error = ETXTBSY; | |
179 | return(1); | |
180 | } | |
181 | } | |
182 | if(u.u_uid == 0) | |
183 | return(0); | |
184 | if(u.u_uid != ip->i_uid) { | |
185 | m >>= 3; | |
186 | if(u.u_gid != ip->i_gid) | |
187 | m >>= 3; | |
188 | } | |
189 | if((ip->i_mode&m) != 0) | |
190 | return(0); | |
191 | ||
192 | u.u_error = EACCES; | |
193 | return(1); | |
194 | } | |
195 | ||
196 | /* | |
197 | * Look up a pathname and test if | |
198 | * the resultant inode is owned by the | |
199 | * current user. | |
200 | * If not, try for super-user. | |
201 | * If permission is granted, | |
202 | * return inode pointer. | |
203 | */ | |
204 | struct inode * | |
205 | owner() | |
206 | { | |
207 | register struct inode *ip; | |
208 | ||
209 | ip = namei(uchar, 0); | |
210 | if(ip == NULL) | |
211 | return(NULL); | |
212 | if(u.u_uid == ip->i_uid) | |
213 | return(ip); | |
214 | if(suser()) | |
215 | return(ip); | |
216 | iput(ip); | |
217 | return(NULL); | |
218 | } | |
219 | ||
220 | /* | |
221 | * Test if the current user is the | |
222 | * super user. | |
223 | */ | |
224 | suser() | |
225 | { | |
226 | ||
227 | if(u.u_uid == 0) { | |
228 | u.u_acflag |= ASU; | |
229 | return(1); | |
230 | } | |
231 | u.u_error = EPERM; | |
232 | return(0); | |
233 | } | |
234 | ||
235 | /* | |
236 | * Allocate a user file descriptor. | |
237 | */ | |
238 | ufalloc() | |
239 | { | |
240 | register i; | |
241 | ||
242 | for(i=0; i<NOFILE; i++) | |
243 | if(u.u_ofile[i] == NULL) { | |
244 | u.u_r.r_val1 = i; | |
245 | u.u_pofile[i] = 0; | |
246 | return(i); | |
247 | } | |
248 | u.u_error = EMFILE; | |
249 | return(-1); | |
250 | } | |
251 | ||
9c98386a | 252 | struct file *lastf = &file[0]; |
fc96c615 BJ |
253 | /* |
254 | * Allocate a user file descriptor | |
255 | * and a file structure. | |
256 | * Initialize the descriptor | |
257 | * to point at the file structure. | |
258 | * | |
259 | * no file -- if there are no available | |
260 | * file structures. | |
261 | */ | |
262 | struct file * | |
263 | falloc() | |
264 | { | |
265 | register struct file *fp; | |
266 | register i; | |
267 | ||
268 | i = ufalloc(); | |
269 | if(i < 0) | |
270 | return(NULL); | |
9c98386a BJ |
271 | for(fp = lastf; fp < &file[NFILE]; fp++) |
272 | if(fp->f_count == 0) | |
273 | goto slot; | |
274 | for(fp = &file[0]; fp < lastf; fp++) | |
275 | if(fp->f_count == 0) | |
276 | goto slot; | |
fc96c615 BJ |
277 | printf("no file\n"); |
278 | u.u_error = ENFILE; | |
279 | return(NULL); | |
9c98386a BJ |
280 | slot: |
281 | u.u_ofile[i] = fp; | |
282 | fp->f_count++; | |
283 | fp->f_un.f_offset = 0; | |
284 | lastf = fp + 1; | |
285 | return(fp); | |
fc96c615 | 286 | } |