From c307abcaee9355475e517b19699d22341a1e4e7a Mon Sep 17 00:00:00 2001 From: sbosse Date: Mon, 14 Oct 2024 23:07:58 +0200 Subject: [PATCH] Mon 14 Oct 23:06:38 CEST 2024 --- kernel/is_valid.c | 162 ++++++++++++++++++++++++++++++++++++++++++++++ 1 file changed, 162 insertions(+) create mode 100644 kernel/is_valid.c diff --git a/kernel/is_valid.c b/kernel/is_valid.c new file mode 100644 index 0000000..69f592a --- /dev/null +++ b/kernel/is_valid.c @@ -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 && fdktable[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 +