Commit | Line | Data |
---|---|---|
73317613 | 1 | /* vfs_vnops.c 4.7 %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 | ||
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 | } | |
61 | ip = fp->f_inode; | |
62 | flag = fp->f_flag; | |
fc96c615 | 63 | dev = (dev_t)ip->i_un.i_rdev; |
f5b8937b | 64 | mode = ip->i_mode & IFMT; |
fc96c615 BJ |
65 | |
66 | plock(ip); | |
67 | fp->f_count = 0; | |
68 | if(flag & FPIPE) { | |
69 | ip->i_mode &= ~(IREAD|IWRITE); | |
70 | wakeup((caddr_t)ip+1); | |
71 | wakeup((caddr_t)ip+2); | |
72 | } | |
73 | iput(ip); | |
74 | ||
f5b8937b | 75 | switch(mode) { |
fc96c615 BJ |
76 | |
77 | case IFCHR: | |
78 | case IFMPC: | |
79 | cfunc = cdevsw[major(dev)].d_close; | |
80 | break; | |
81 | ||
82 | case IFBLK: | |
f5b8937b RE |
83 | /* |
84 | * We don't want to really close the device if it is mounted | |
85 | */ | |
86 | for (mp = mount; mp < &mount[NMOUNT]; mp++) | |
87 | if (mp->m_bufp != NULL && mp->m_dev == dev) | |
88 | return; | |
fc96c615 BJ |
89 | case IFMPB: |
90 | cfunc = bdevsw[major(dev)].d_close; | |
91 | break; | |
92 | default: | |
93 | return; | |
94 | } | |
95 | ||
f5b8937b | 96 | if ((flag & FMP) == 0) { |
fb21923a | 97 | for(fp=file; fp < fileNFILE; fp++) |
f5b8937b RE |
98 | if (fp->f_count && (ip=fp->f_inode)->i_un.i_rdev==dev && |
99 | (ip->i_mode&IFMT) == mode) | |
100 | return; | |
f5b8937b RE |
101 | if (mode == IFBLK) { |
102 | /* | |
103 | * on last close of a block device (that isn't mounted) | |
104 | * we must invalidate any in core blocks | |
105 | */ | |
106 | bflush(dev); | |
107 | binval(dev); | |
108 | } | |
109 | } | |
e6aa77eb | 110 | (*cfunc)(dev, flag, fp); |
fc96c615 BJ |
111 | } |
112 | ||
113 | /* | |
114 | * openi called to allow handler | |
115 | * of special files to initialize and | |
116 | * validate before actual IO. | |
117 | */ | |
118 | openi(ip, rw) | |
119 | register struct inode *ip; | |
120 | { | |
121 | dev_t dev; | |
122 | register unsigned int maj; | |
123 | ||
124 | dev = (dev_t)ip->i_un.i_rdev; | |
125 | maj = major(dev); | |
126 | switch(ip->i_mode&IFMT) { | |
127 | ||
128 | case IFCHR: | |
129 | case IFMPC: | |
130 | if(maj >= nchrdev) | |
131 | goto bad; | |
132 | (*cdevsw[maj].d_open)(dev, rw); | |
133 | break; | |
134 | ||
135 | case IFBLK: | |
136 | case IFMPB: | |
137 | if(maj >= nblkdev) | |
138 | goto bad; | |
139 | (*bdevsw[maj].d_open)(dev, rw); | |
140 | } | |
141 | return; | |
142 | ||
143 | bad: | |
144 | u.u_error = ENXIO; | |
145 | } | |
146 | ||
147 | /* | |
148 | * Check mode permission on inode pointer. | |
149 | * Mode is READ, WRITE or EXEC. | |
150 | * In the case of WRITE, the | |
151 | * read-only status of the file | |
152 | * system is checked. | |
153 | * Also in WRITE, prototype text | |
154 | * segments cannot be written. | |
155 | * The mode is shifted to select | |
156 | * the owner/group/other fields. | |
157 | * The super user is granted all | |
158 | * permissions. | |
159 | */ | |
160 | access(ip, mode) | |
161 | register struct inode *ip; | |
162 | { | |
163 | register m; | |
164 | ||
165 | m = mode; | |
166 | if(m == IWRITE) { | |
167 | if(getfs(ip->i_dev)->s_ronly != 0) { | |
168 | u.u_error = EROFS; | |
169 | return(1); | |
170 | } | |
171 | if (ip->i_flag&ITEXT) /* try to free text */ | |
172 | xrele(ip); | |
173 | if(ip->i_flag & ITEXT) { | |
174 | u.u_error = ETXTBSY; | |
175 | return(1); | |
176 | } | |
177 | } | |
178 | if(u.u_uid == 0) | |
179 | return(0); | |
180 | if(u.u_uid != ip->i_uid) { | |
181 | m >>= 3; | |
182 | if(u.u_gid != ip->i_gid) | |
183 | m >>= 3; | |
184 | } | |
185 | if((ip->i_mode&m) != 0) | |
186 | return(0); | |
187 | ||
188 | u.u_error = EACCES; | |
189 | return(1); | |
190 | } | |
191 | ||
192 | /* | |
193 | * Look up a pathname and test if | |
194 | * the resultant inode is owned by the | |
195 | * current user. | |
196 | * If not, try for super-user. | |
197 | * If permission is granted, | |
198 | * return inode pointer. | |
199 | */ | |
200 | struct inode * | |
201 | owner() | |
202 | { | |
203 | register struct inode *ip; | |
204 | ||
205 | ip = namei(uchar, 0); | |
206 | if(ip == NULL) | |
207 | return(NULL); | |
208 | if(u.u_uid == ip->i_uid) | |
209 | return(ip); | |
210 | if(suser()) | |
211 | return(ip); | |
212 | iput(ip); | |
213 | return(NULL); | |
214 | } | |
215 | ||
216 | /* | |
217 | * Test if the current user is the | |
218 | * super user. | |
219 | */ | |
220 | suser() | |
221 | { | |
222 | ||
223 | if(u.u_uid == 0) { | |
224 | u.u_acflag |= ASU; | |
225 | return(1); | |
226 | } | |
227 | u.u_error = EPERM; | |
228 | return(0); | |
229 | } | |
230 | ||
231 | /* | |
232 | * Allocate a user file descriptor. | |
233 | */ | |
234 | ufalloc() | |
235 | { | |
236 | register i; | |
237 | ||
238 | for(i=0; i<NOFILE; i++) | |
239 | if(u.u_ofile[i] == NULL) { | |
240 | u.u_r.r_val1 = i; | |
241 | u.u_pofile[i] = 0; | |
242 | return(i); | |
243 | } | |
244 | u.u_error = EMFILE; | |
245 | return(-1); | |
246 | } | |
247 | ||
0a34b6fd | 248 | struct file *lastf; |
fc96c615 BJ |
249 | /* |
250 | * Allocate a user file descriptor | |
251 | * and a file structure. | |
252 | * Initialize the descriptor | |
253 | * to point at the file structure. | |
fc96c615 BJ |
254 | */ |
255 | struct file * | |
256 | falloc() | |
257 | { | |
258 | register struct file *fp; | |
259 | register i; | |
260 | ||
261 | i = ufalloc(); | |
0a34b6fd | 262 | if (i < 0) |
fc96c615 | 263 | return(NULL); |
0a34b6fd BJ |
264 | if (lastf == 0) |
265 | lastf = file; | |
266 | for (fp = lastf; fp < fileNFILE; fp++) | |
267 | if (fp->f_count == 0) | |
9c98386a | 268 | goto slot; |
0a34b6fd BJ |
269 | for (fp = file; fp < lastf; fp++) |
270 | if (fp->f_count == 0) | |
9c98386a | 271 | goto slot; |
73317613 | 272 | tablefull("file"); |
fc96c615 | 273 | u.u_error = ENFILE; |
0a34b6fd | 274 | return (NULL); |
9c98386a BJ |
275 | slot: |
276 | u.u_ofile[i] = fp; | |
277 | fp->f_count++; | |
278 | fp->f_un.f_offset = 0; | |
279 | lastf = fp + 1; | |
0a34b6fd | 280 | return (fp); |
fc96c615 | 281 | } |