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| Rev | Author | Line No. | Line |
|---|---|---|---|
| 2 | pj | 1 | |
| 2 | #include <fs/types.h> |
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| 3 | #include <fs/errno.h> |
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| 4 | #include <fs/task.h> |
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| 5 | #include <fs/maccess.h> |
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| 6 | #include <fs/stat.h> |
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| 7 | #include <fs/fcntl.h> |
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| 8 | #include <fs/mount.h> |
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| 9 | |||
| 10 | #include "fsconst.h" |
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| 11 | #include "file.h" |
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| 12 | #include "dentry.h" |
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| 13 | #include "inode.h" |
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| 14 | #include "fileop.h" |
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| 15 | #include "inodeop.h" |
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| 16 | #include "super.h" |
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| 17 | #include "fs.h" |
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| 18 | |||
| 19 | #include "debug.h" |
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| 20 | |||
| 21 | |||
| 22 | /* |
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| 23 | Example of how the code is expanded in system with/without |
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| 24 | memory protection. |
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| 25 | |||
| 26 | If DUMMY_MACCESS is defined: |
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| 27 | |||
| 28 | char *pathname; |
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| 29 | int len; |
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| 30 | |||
| 31 | len=1; |
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| 32 | if ((!len)||len>MAXSIZE) return -EVERIFY; |
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| 33 | pathname=userpathname; |
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| 34 | ... |
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| 35 | |||
| 36 | |||
| 37 | if DUMMY_MACCESS is NOT defined: |
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| 38 | |||
| 39 | char pathname[MAXSIZE]; |
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| 40 | int len; |
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| 41 | |||
| 42 | len=verifyreadnolen(userpathanme); |
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| 43 | if ((!len)||len>MAXSIZE) return -EVERIFY; |
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| 44 | memcpyfromuser(pathname,userpathname); |
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| 45 | ... |
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| 46 | |||
| 47 | */ |
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| 48 | |||
| 49 | /* PS: open() e opendir() potrebbero condividere codice! */ |
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| 50 | |||
| 51 | int k_open(char *upathname, int oflag, int mode) |
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| 52 | { |
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| 53 | declare_buffer(char,pathname,MAXPATHNAME); |
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| 54 | int len; |
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| 55 | struct file *f; |
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| 56 | struct dentry *d; |
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| 57 | int ret,res,createflag; |
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| 58 | __pid_t pid; |
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| 59 | |||
| 60 | call_to_fs(); |
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| 61 | |||
| 62 | printk0("k_open: START"); |
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| 63 | pid=__get_pid(); |
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| 64 | |||
| 65 | len=__verify_read_nolen((char*)upathname); |
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| 66 | if ((!len)||(len>MAXPATHNAMELEN)) return_from_fs(-EVERIFY); |
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| 67 | __copy_from_user(pathname,upathname,len+1); |
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| 68 | |||
| 69 | printk0("k_open: verifing memory... done"); |
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| 70 | |||
| 71 | /* flags not supported */ |
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| 72 | /* O_NOCTTY is ignored */ |
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| 73 | if (oflag&O_DSYNC|| |
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| 74 | oflag&O_NOCTTY|| |
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| 75 | oflag&O_NONBLOCK|| |
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| 76 | oflag&O_RSYNC|| |
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| 77 | oflag&O_SYNC) { |
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| 78 | return_from_fs(-EACCES); |
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| 79 | } |
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| 80 | |||
| 81 | /* O_TRUNC wiht O_RDONLY not permitted! */ |
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| 82 | if ((oflag&O_RDONLY)&&(oflag&O_TRUNC)) return_from_fs(-EACCES); |
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| 83 | |||
| 84 | printk0("k_open: checking flags... done"); |
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| 85 | |||
| 86 | if (oflag&O_CREAT) { |
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| 87 | if (oflag&O_EXCL) createflag=DENTRY_MUSTCREATE; |
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| 88 | else createflag=DENTRY_CANCREATE; |
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| 89 | } else createflag=DENTRY_NOCREATE; |
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| 90 | |||
| 91 | |||
| 92 | d=find_dentry_from_ext(cwden_ptr(pid),(char *)pathname,&createflag); |
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| 93 | if (d==NULL) { |
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| 94 | printk0("k_open: can't find/create directory entry"); |
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| 95 | if (createflag&DENTRY_EXIST) return_from_fs(-EEXIST); |
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| 96 | return_from_fs(-ENOENT); |
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| 97 | } |
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| 98 | |||
| 99 | if (__S_ISDIR(d->d_inode->i_st.st_mode)) { |
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| 100 | if (oflag&O_WRONLY||oflag&O_RDWR) |
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| 101 | /* can't write on a directory */ |
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| 102 | return_from_fs(-EISDIR); |
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| 103 | } |
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| 104 | |||
| 105 | /* check for read-only filesystem */ |
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| 106 | if (!(d->d_sb->sb_mopts.flags&MOUNT_FLAG_RW)) { |
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| 107 | if (oflag&O_WRONLY||oflag&O_RDWR||oflag&O_TRUNC) { |
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| 108 | /* NB: O_CREAT va testata prima della find_dentry() */ |
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| 109 | unlock_dentry(d); |
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| 110 | return_from_fs(-EROFS); |
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| 111 | } |
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| 112 | } |
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| 113 | |||
| 114 | printk0("k_open: find dir entry... done"); |
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| 115 | |||
| 116 | f=get_file(d->d_inode); |
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| 117 | if (f==NULL) { |
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| 118 | unlock_dentry(d); |
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| 119 | return_from_fs(-ENFILE); |
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| 120 | } |
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| 121 | |||
| 122 | printk0("k_open: getting system file entry... done"); |
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| 123 | |||
| 124 | if (createflag&DENTRY_CREATED) |
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| 125 | d->d_inode->i_st.st_mode=(mode&__ALLPERMS)|__S_IFREG; |
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| 126 | |||
| 127 | f->f_dentry=d; |
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| 128 | f->f_op=d->d_inode->i_op->default_file_ops; |
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| 129 | f->f_pos=0; |
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| 130 | f->f_flag_isdir=__S_ISDIR(d->d_inode->i_st.st_mode); |
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| 131 | |||
| 132 | ret=get_fd(pid,f); |
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| 133 | if (ret==-1) { |
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| 134 | free_file(f); |
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| 135 | unlock_dentry(d); |
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| 136 | return_from_fs(-EMFILE); |
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| 137 | } |
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| 138 | *fildesfflags_ptr(pid,ret)=oflag; |
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| 139 | |||
| 140 | printk0("k_open: getting file descriptor... done"); |
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| 141 | |||
| 142 | if (oflag&O_TRUNC&&!(createflag&DENTRY_CREATED)) { |
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| 143 | struct inode *in=file_ptr(pid,ret)->f_dentry->d_inode; |
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| 144 | /* acquire write lock on inode's file */ |
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| 145 | __rwlock_wrlock(&in->i_lock); |
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| 146 | /* truncate the file */ |
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| 147 | in->i_op->truncate(in,0); |
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| 148 | /* release write lock on inode's file */ |
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| 149 | __rwlock_wrunlock(&in->i_lock); |
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| 150 | printk0("k_open: file truncation... done"); |
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| 151 | } |
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| 152 | |||
| 153 | res=f->f_op->open(f->f_dentry->d_inode,f); |
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| 154 | if (res!=0) { |
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| 155 | free_fd(pid,ret); |
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| 156 | free_file(f); |
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| 157 | unlock_dentry(d); |
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| 158 | return_from_fs(res); |
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| 159 | } |
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| 160 | |||
| 161 | printk0("k_open: called proper filesystem open... done"); |
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| 162 | |||
| 163 | printk0("k_open: END"); |
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| 164 | return_from_fs(ret); |
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| 165 | } |
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| 166 |