cafe-grader-judge-scripts

Commit r76:4469d653fe5f public

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Description:
added /dev/urandom to file allowed to be accessed, probably needed after ubuntu 9.04 git-svn-id: http://theory.cpe.ku.ac.th/grader/judge/trunk/scripts@417 6386c4cd-e34a-4fa8-8920-d93eb39b512e
Commit status:
[Not Reviewed]
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r76:4469d653fe5f - - 1 file changed: 1 inserted, 0 deleted

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@@ -142,96 +142,97
142 142 if (file_access >= 9)
143 143 return;
144 144
145 145 if (!mem_fd)
146 146 {
147 147 sprintf(namebuf, "/proc/%d/mem", (int) box_pid);
148 148 mem_fd = open(namebuf, O_RDONLY);
149 149 if (mem_fd < 0)
150 150 die("open(%s): %m", namebuf);
151 151 }
152 152 p = end = namebuf;
153 153 do
154 154 {
155 155 if (p >= end)
156 156 {
157 157 int remains = PAGE_SIZE - (addr & (PAGE_SIZE-1));
158 158 int l = namebuf + sizeof(namebuf) - end;
159 159 if (l > remains)
160 160 l = remains;
161 161 if (!l)
162 162 die("Access to file with name too long.");
163 163 if (long_seek(mem_fd, addr, SEEK_SET) < 0)
164 164 die("long_seek(mem): %m");
165 165 remains = read(mem_fd, end, l);
166 166 if (remains < 0)
167 167 die("read(mem): %m");
168 168 if (!remains)
169 169 die("Access to file with name out of memory.");
170 170 end += l;
171 171 addr += l;
172 172 }
173 173 }
174 174 while (*p++);
175 175
176 176 log("[%s] ", namebuf);
177 177 if (file_access >= 3)
178 178 return;
179 179 if (!strchr(namebuf, '/') && strcmp(namebuf, ".."))
180 180 return;
181 181 if (file_access >= 2)
182 182 {
183 183 if ((!strncmp(namebuf, "/etc/", 5) ||
184 184 !strncmp(namebuf, "/lib/", 5) ||
185 185 !strncmp(namebuf, "/usr/lib/", 9))
186 186 && !strstr(namebuf, ".."))
187 187 return;
188 188 if (!strcmp(namebuf, "/dev/null") ||
189 189 !strcmp(namebuf, "/dev/zero") ||
190 + !strcmp(namebuf, "/dev/urandom") ||
190 191 !strcmp(namebuf, "/proc/meminfo") ||
191 192 !strcmp(namebuf, "/proc/self/stat") ||
192 193 !strncmp(namebuf, "/usr/share/zoneinfo/", 20))
193 194 return;
194 195 }
195 196 die("Forbidden access to file `%s'.", namebuf);
196 197 }
197 198
198 199 static int
199 200 valid_syscall(struct user *u)
200 201 {
201 202 switch (u->regs.orig_eax)
202 203 {
203 204 case __NR_execve:
204 205 {
205 206 static int exec_counter;
206 207 return !exec_counter++;
207 208 }
208 209 case __NR_open:
209 210 case __NR_creat:
210 211 case __NR_unlink:
211 212 case __NR_oldstat:
212 213 case __NR_access:
213 214 case __NR_oldlstat:
214 215 case __NR_truncate:
215 216 case __NR_stat:
216 217 case __NR_lstat:
217 218 case __NR_truncate64:
218 219 case __NR_stat64:
219 220 case __NR_lstat64:
220 221 valid_filename(u->regs.ebx);
221 222 return 1;
222 223 case __NR_exit:
223 224 case __NR_read:
224 225 case __NR_write:
225 226 case __NR_close:
226 227 case __NR_lseek:
227 228 case __NR_getpid:
228 229 case __NR_getuid:
229 230 case __NR_oldfstat:
230 231 case __NR_dup:
231 232 case __NR_brk:
232 233 case __NR_getgid:
233 234 case __NR_geteuid:
234 235 case __NR_getegid:
235 236 case __NR_dup2:
236 237 case __NR_ftruncate:
237 238 case __NR_fstat:
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