sbosse/basekernel
1
0
Fork 0
Code Issues Pull Requests Actions Packages Projects Releases Wiki Activity

Mon 14 Oct 23:06:38 CEST 2024

Browse Source
This commit is contained in:
sbosse 2024-10-14 23:07:58 +02:00
parent 78e12f4a56
commit c307abcaee
1 changed files with 162 additions and 0 deletions
Show Stats Download Patch File Download Diff File Expand all files Collapse all files

162
kernel/is_valid.c Normal file
View File

@ -0,0 +1,162 @@
/*
Copyright (C) 2016-2019 The University of Notre Dame
This software is distributed under the GNU General Public License.
See the file LICENSE for details.
*/
#include "is_valid.h"
#include "string.h"
#include "kobject.h"
#include "process.h"
#include "kmalloc.h"
// Does this string comprise a valid path?
// Valid paths are comprised of the following characters:
// CHARS | ASCII CODE
// '-' | 45
// '.' | 46
// '/' | 47
// [0-9] | [48-57]
// [a-z] | [65-90]
// '_' | 95
// [A-Z] | [97-122]
int is_valid_path(const char * s)
{
int length = strlen(s);
for (int i = 0; i < length; i++) {
if (s[i] < 45) return 0;
if (s[i] > 57 && s[i] < 65) return 0;
if (s[i] > 90 && s[i] < 95) return 0;
if (s[i] > 95 && s[i] < 97) return 0;
if (s[i] > 122) return 0;
}
return 1;
}
// Does this string comprise a valid tag?
// CHARS | ASCII CODE
// [0-9] | [48-57]
// [a-z] | [65-90]
// [A-Z] | [97-122]
int is_valid_tag(const char * s)
{
int length = strlen(s);
for (int i = 0; i < length; i++) {
if (s[i] < 48) return 0;
if (s[i] > 57 && s[i] < 65) return 0;
if (s[i] > 90 && s[i] < 95) return 0;
if (s[i] > 95 && s[i] < 97) return 0;
if (s[i] > 122) return 0;
}
return 1;
}
// Does this string point to a valid resource (i.e. is it a legitimate
// tag-path concatenation)?
// CHARS | ASCII CODE
// ':' | 58
int is_valid_location(const char * s)
{
int length = strlen(s);
char * mutable_test = kmalloc(sizeof(char) * (length+1));
strcpy(mutable_test, s);
int path_index = 0;
while (path_index < length && s[path_index] != 58) {
path_index += 1;
}
mutable_test[path_index++] = 0;
if (is_valid_tag(mutable_test)
&& is_valid_path(mutable_test + path_index)) {
return 1;
}
return 0;
}
// Return true if file desciptor is in range and refers to a live object.
int is_valid_object( int fd )
{
return fd>=0 && fd<PROCESS_MAX_OBJECTS && current->ktable[fd];
}
// Return true if fd valid and object is also of indicated type.
int is_valid_object_type( int fd, kobject_type_t type )
{
return is_valid_object(fd) && kobject_get_type(current->ktable[fd])==type;
}
// Return true if (ptr,length) describes a valid area in user space.
// XXX Needs to be implemented!
int is_valid_pointer( void *ptr, int length )
{
return 1;
}
// Return true if string points to a valid area in user space.
// XXX Needs to be implemented!
int is_valid_string( const char *str )
{
return 1;
}
#ifdef TEST
void is_valid_test()
{
printf("Testing PATH validations...\n");
char * s = "/root/is-valid.path";
if (!is_valid_path(s))
printf("ERROR: Did not validate %s\n", s);
s = "abcdefghijklmnopqrstuvwxyz";
if (!is_valid_path(s))
printf("ERROR: Did not validate %s\n", s);
s = "ABCDEFGHIJKLMNOPQRSTUVWXYZ";
if (!is_valid_path(s))
printf("ERROR: Did not validate %s\n", s);
s = "0123456789";
if (!is_valid_path(s))
printf("ERROR: Did not validate %s\n", s);
s = "/root/isn't/valid:";
if (is_valid_path(s))
printf("ERROR: Did not invalidate %s\n", s);
printf("Testing Tag Validations...\n");
s = "TAG";
if (!is_valid_tag(s))
printf("ERROR: Did not validate %s\n", s);
s = "abcdefghijklmnopqrstuvwxyz";
if (!is_valid_tag(s))
printf("ERROR: Did not validate %s\n", s);
s = "ABCDEFGHIJKLMNOPQRSTUVWXYZ";
if (!is_valid_tag(s))
printf("ERROR: Did not validate %s\n", s);
s = "0123456789";
if (!is_valid_tag(s))
printf("ERROR: Did not validate %s\n", s);
s = ":NOT-A-TAG";
if (is_valid_tag(s))
printf("ERROR: Did not invalidate %s\n", s);
printf("Testing Location Validations...\n");
s = "HOME:path/to/root/dir";
if (!is_valid_location(s))
printf("ERROR: Did not validate %s\n", s);
s = "TAG";
if (!is_valid_tag(s))
printf("ERROR: Did not validate %s\n", s);
s = "/root/is-valid.path";
if (!is_valid_path(s))
printf("ERROR: Did not validate %s\n", s);
s = "BAD-TAG:p@th/:/root/dir";
if (is_valid_location(s))
printf("ERROR: Did not invalidate %s\n", s);
}
#endif