Rev 1063 | Details | Compare with Previous | Last modification | View Log | RSS feed
| Rev | Author | Line No. | Line |
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| 2 | pj | 1 | |
| 1063 | tullio | 2 | /* |
| 3 | * This program is free software; you can redistribute it and/or modify |
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| 4 | * it under the terms of the GNU General Public License as published by |
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| 5 | * the Free Software Foundation; either version 2 of the License, or |
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| 6 | * (at your option) any later version. |
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| 7 | * |
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| 8 | * This program is distributed in the hope that it will be useful, |
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| 9 | * but WITHOUT ANY WARRANTY; without even the implied warranty of |
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| 10 | * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the |
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| 11 | * GNU General Public License for more details. |
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| 12 | * |
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| 13 | * You should have received a copy of the GNU General Public License |
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| 14 | * along with this program; if not, write to the Free Software |
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| 15 | * Foundation, Inc., 59 Temple Place, Suite 330, Boston, MA 02111-1307 USA |
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| 16 | * |
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| 17 | */ |
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| 18 | |||
| 2 | pj | 19 | #include <fs/types.h> |
| 20 | #include <fs/errno.h> |
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| 21 | #include <fs/task.h> |
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| 22 | #include <fs/maccess.h> |
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| 23 | #include <fs/stat.h> |
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| 24 | #include <fs/fcntl.h> |
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| 25 | #include <fs/mount.h> |
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| 26 | |||
| 27 | #include "fsconst.h" |
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| 28 | #include "file.h" |
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| 29 | #include "dentry.h" |
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| 30 | #include "inode.h" |
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| 31 | #include "fileop.h" |
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| 32 | #include "inodeop.h" |
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| 33 | #include "super.h" |
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| 34 | #include "fs.h" |
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| 35 | |||
| 36 | #include "debug.h" |
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| 37 | |||
| 38 | |||
| 39 | /* |
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| 40 | Example of how the code is expanded in system with/without |
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| 41 | memory protection. |
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| 42 | |||
| 43 | If DUMMY_MACCESS is defined: |
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| 44 | |||
| 45 | char *pathname; |
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| 46 | int len; |
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| 47 | |||
| 48 | len=1; |
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| 49 | if ((!len)||len>MAXSIZE) return -EVERIFY; |
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| 50 | pathname=userpathname; |
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| 51 | ... |
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| 52 | |||
| 53 | |||
| 54 | if DUMMY_MACCESS is NOT defined: |
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| 55 | |||
| 56 | char pathname[MAXSIZE]; |
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| 57 | int len; |
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| 58 | |||
| 59 | len=verifyreadnolen(userpathanme); |
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| 60 | if ((!len)||len>MAXSIZE) return -EVERIFY; |
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| 61 | memcpyfromuser(pathname,userpathname); |
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| 62 | ... |
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| 63 | |||
| 64 | */ |
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| 65 | |||
| 66 | /* PS: open() e opendir() potrebbero condividere codice! */ |
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| 67 | |||
| 68 | int k_open(char *upathname, int oflag, int mode) |
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| 69 | { |
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| 70 | declare_buffer(char,pathname,MAXPATHNAME); |
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| 71 | int len; |
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| 72 | struct file *f; |
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| 73 | struct dentry *d; |
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| 74 | int ret,res,createflag; |
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| 75 | __pid_t pid; |
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| 76 | |||
| 77 | call_to_fs(); |
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| 78 | |||
| 79 | printk0("k_open: START"); |
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| 80 | pid=__get_pid(); |
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| 81 | |||
| 82 | len=__verify_read_nolen((char*)upathname); |
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| 83 | if ((!len)||(len>MAXPATHNAMELEN)) return_from_fs(-EVERIFY); |
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| 84 | __copy_from_user(pathname,upathname,len+1); |
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| 85 | |||
| 86 | printk0("k_open: verifing memory... done"); |
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| 87 | |||
| 88 | /* flags not supported */ |
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| 89 | /* O_NOCTTY is ignored */ |
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| 90 | if (oflag&O_DSYNC|| |
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| 91 | oflag&O_NOCTTY|| |
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| 92 | oflag&O_NONBLOCK|| |
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| 93 | oflag&O_RSYNC|| |
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| 94 | oflag&O_SYNC) { |
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| 95 | return_from_fs(-EACCES); |
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| 96 | } |
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| 97 | |||
| 98 | /* O_TRUNC wiht O_RDONLY not permitted! */ |
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| 99 | if ((oflag&O_RDONLY)&&(oflag&O_TRUNC)) return_from_fs(-EACCES); |
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| 100 | |||
| 101 | printk0("k_open: checking flags... done"); |
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| 102 | |||
| 103 | if (oflag&O_CREAT) { |
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| 104 | if (oflag&O_EXCL) createflag=DENTRY_MUSTCREATE; |
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| 105 | else createflag=DENTRY_CANCREATE; |
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| 106 | } else createflag=DENTRY_NOCREATE; |
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| 107 | |||
| 108 | |||
| 109 | d=find_dentry_from_ext(cwden_ptr(pid),(char *)pathname,&createflag); |
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| 110 | if (d==NULL) { |
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| 111 | printk0("k_open: can't find/create directory entry"); |
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| 112 | if (createflag&DENTRY_EXIST) return_from_fs(-EEXIST); |
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| 113 | return_from_fs(-ENOENT); |
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| 114 | } |
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| 115 | |||
| 116 | if (__S_ISDIR(d->d_inode->i_st.st_mode)) { |
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| 117 | if (oflag&O_WRONLY||oflag&O_RDWR) |
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| 118 | /* can't write on a directory */ |
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| 119 | return_from_fs(-EISDIR); |
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| 120 | } |
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| 121 | |||
| 122 | /* check for read-only filesystem */ |
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| 123 | if (!(d->d_sb->sb_mopts.flags&MOUNT_FLAG_RW)) { |
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| 124 | if (oflag&O_WRONLY||oflag&O_RDWR||oflag&O_TRUNC) { |
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| 125 | /* NB: O_CREAT va testata prima della find_dentry() */ |
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| 126 | unlock_dentry(d); |
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| 127 | return_from_fs(-EROFS); |
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| 128 | } |
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| 129 | } |
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| 130 | |||
| 131 | printk0("k_open: find dir entry... done"); |
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| 132 | |||
| 133 | f=get_file(d->d_inode); |
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| 134 | if (f==NULL) { |
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| 135 | unlock_dentry(d); |
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| 136 | return_from_fs(-ENFILE); |
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| 137 | } |
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| 138 | |||
| 139 | printk0("k_open: getting system file entry... done"); |
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| 140 | |||
| 141 | if (createflag&DENTRY_CREATED) |
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| 142 | d->d_inode->i_st.st_mode=(mode&__ALLPERMS)|__S_IFREG; |
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| 143 | |||
| 144 | f->f_dentry=d; |
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| 145 | f->f_op=d->d_inode->i_op->default_file_ops; |
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| 146 | f->f_pos=0; |
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| 147 | f->f_flag_isdir=__S_ISDIR(d->d_inode->i_st.st_mode); |
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| 148 | |||
| 149 | ret=get_fd(pid,f); |
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| 150 | if (ret==-1) { |
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| 151 | free_file(f); |
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| 152 | unlock_dentry(d); |
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| 153 | return_from_fs(-EMFILE); |
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| 154 | } |
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| 155 | *fildesfflags_ptr(pid,ret)=oflag; |
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| 156 | |||
| 157 | printk0("k_open: getting file descriptor... done"); |
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| 158 | |||
| 159 | if (oflag&O_TRUNC&&!(createflag&DENTRY_CREATED)) { |
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| 160 | struct inode *in=file_ptr(pid,ret)->f_dentry->d_inode; |
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| 161 | /* acquire write lock on inode's file */ |
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| 162 | __rwlock_wrlock(&in->i_lock); |
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| 163 | /* truncate the file */ |
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| 164 | in->i_op->truncate(in,0); |
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| 165 | /* release write lock on inode's file */ |
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| 166 | __rwlock_wrunlock(&in->i_lock); |
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| 167 | printk0("k_open: file truncation... done"); |
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| 168 | } |
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| 169 | |||
| 170 | res=f->f_op->open(f->f_dentry->d_inode,f); |
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| 171 | if (res!=0) { |
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| 172 | free_fd(pid,ret); |
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| 173 | free_file(f); |
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| 174 | unlock_dentry(d); |
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| 175 | return_from_fs(res); |
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| 176 | } |
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| 177 | |||
| 178 | printk0("k_open: called proper filesystem open... done"); |
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| 179 | |||
| 180 | printk0("k_open: END"); |
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| 181 | return_from_fs(ret); |
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| 182 | } |
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| 183 |