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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 |