Stephen Smalley | 2dd4e51 | 2012-01-04 12:33:27 -0500 | [diff] [blame] | 1 | ######################################### |
| 2 | # MLS declarations |
| 3 | # |
| 4 | |
| 5 | # Generate the desired number of sensitivities and categories. |
| 6 | gen_sens(mls_num_sens) |
| 7 | gen_cats(mls_num_cats) |
| 8 | |
| 9 | # Generate level definitions for each sensitivity and category. |
| 10 | gen_levels(mls_num_sens,mls_num_cats) |
| 11 | |
| 12 | |
| 13 | ################################################# |
| 14 | # MLS policy constraints |
| 15 | # |
| 16 | |
| 17 | # |
| 18 | # Process constraints |
| 19 | # |
| 20 | |
| 21 | # Process transition: Require equivalence unless the subject is trusted. |
| 22 | mlsconstrain process { transition dyntransition } |
| 23 | ((h1 eq h2 and l1 eq l2) or t1 == mlstrustedsubject); |
| 24 | |
| 25 | # Process read operations: No read up unless trusted. |
| 26 | mlsconstrain process { getsched getsession getpgid getcap getattr ptrace share } |
| 27 | (l1 dom l2 or t1 == mlstrustedsubject); |
| 28 | |
| 29 | # Process write operations: No write down unless trusted. |
| 30 | mlsconstrain process { sigkill sigstop signal setsched setpgid setcap setrlimit ptrace share } |
| 31 | (l1 domby l2 or t1 == mlstrustedsubject); |
| 32 | |
| 33 | # |
| 34 | # Socket constraints |
| 35 | # |
| 36 | |
Stephen Smalley | e884872 | 2012-11-13 13:00:05 -0500 | [diff] [blame] | 37 | # Create/relabel operations: Subject must be equivalent to object unless |
| 38 | # the subject is trusted. Sockets inherit the range of their creator. |
| 39 | mlsconstrain socket_class_set { create relabelfrom relabelto } |
| 40 | ((h1 eq h2 and l1 eq l2) or t1 == mlstrustedsubject); |
Stephen Smalley | 2dd4e51 | 2012-01-04 12:33:27 -0500 | [diff] [blame] | 41 | |
| 42 | # Datagram send: Sender must be dominated by receiver unless one of them is |
| 43 | # trusted. |
| 44 | mlsconstrain unix_dgram_socket { sendto } |
| 45 | (l1 domby l2 or t1 == mlstrustedsubject or t2 == mlstrustedsubject); |
| 46 | |
| 47 | # Stream connect: Client must be equivalent to server unless one of them |
| 48 | # is trusted. |
| 49 | mlsconstrain unix_stream_socket { connectto } |
| 50 | (l1 eq l2 or t1 == mlstrustedsubject or t2 == mlstrustedsubject); |
| 51 | |
| 52 | # |
| 53 | # Directory/file constraints |
| 54 | # |
| 55 | |
| 56 | # Create/relabel operations: Subject must be equivalent to object unless |
| 57 | # the subject is trusted. Also, files should always be single-level. |
| 58 | # Do NOT exempt mlstrustedobject types from this constraint. |
| 59 | mlsconstrain dir_file_class_set { create relabelfrom relabelto } |
| 60 | (l2 eq h2 and (l1 eq l2 or t1 == mlstrustedsubject)); |
| 61 | |
Stephen Smalley | 0e85c17 | 2012-03-19 10:32:24 -0400 | [diff] [blame] | 62 | # |
| 63 | # Constraints for app data files only. |
| 64 | # |
| 65 | |
| 66 | # Only constrain open, not read/write. |
| 67 | # Also constrain other forms of manipulation, e.g. chmod/chown, unlink, rename, etc. |
| 68 | # Subject must be equivalent to object unless the subject is trusted. |
| 69 | mlsconstrain dir { open search setattr rename add_name remove_name reparent rmdir } |
| 70 | (t2 != app_data_file or l1 eq l2 or t1 == mlstrustedsubject); |
| 71 | mlsconstrain { file lnk_file sock_file } { open setattr unlink link rename } |
| 72 | (t2 != app_data_file or l1 eq l2 or t1 == mlstrustedsubject); |
| 73 | |
| 74 | # |
| 75 | # Constraints for file types other than app data files. |
| 76 | # |
| 77 | |
Stephen Smalley | 2dd4e51 | 2012-01-04 12:33:27 -0500 | [diff] [blame] | 78 | # Read operations: Subject must dominate object unless the subject |
| 79 | # or the object is trusted. |
| 80 | mlsconstrain dir { read getattr search } |
Stephen Smalley | 0e85c17 | 2012-03-19 10:32:24 -0400 | [diff] [blame] | 81 | (t2 == app_data_file or l1 dom l2 or t1 == mlstrustedsubject or t2 == mlstrustedobject); |
Stephen Smalley | 2dd4e51 | 2012-01-04 12:33:27 -0500 | [diff] [blame] | 82 | |
| 83 | mlsconstrain { file lnk_file sock_file chr_file blk_file } { read getattr execute } |
Stephen Smalley | 0e85c17 | 2012-03-19 10:32:24 -0400 | [diff] [blame] | 84 | (t2 == app_data_file or l1 dom l2 or t1 == mlstrustedsubject or t2 == mlstrustedobject); |
Stephen Smalley | 2dd4e51 | 2012-01-04 12:33:27 -0500 | [diff] [blame] | 85 | |
| 86 | # Write operations: Subject must be dominated by the object unless the |
| 87 | # subject or the object is trusted. |
| 88 | mlsconstrain dir { write setattr rename add_name remove_name reparent rmdir } |
Stephen Smalley | 0e85c17 | 2012-03-19 10:32:24 -0400 | [diff] [blame] | 89 | (t2 == app_data_file or l1 domby l2 or t1 == mlstrustedsubject or t2 == mlstrustedobject); |
Stephen Smalley | 2dd4e51 | 2012-01-04 12:33:27 -0500 | [diff] [blame] | 90 | |
| 91 | mlsconstrain { file lnk_file sock_file chr_file blk_file } { write setattr append unlink link rename } |
Stephen Smalley | 0e85c17 | 2012-03-19 10:32:24 -0400 | [diff] [blame] | 92 | (t2 == app_data_file or l1 domby l2 or t1 == mlstrustedsubject or t2 == mlstrustedobject); |
Stephen Smalley | 2dd4e51 | 2012-01-04 12:33:27 -0500 | [diff] [blame] | 93 | |
| 94 | # Special case for FIFOs. |
| 95 | # These can be unnamed pipes, in which case they will be labeled with the |
| 96 | # creating process' label. Thus we also have an exemption when the "object" |
| 97 | # is a MLS trusted subject and can receive data at any level. |
| 98 | mlsconstrain fifo_file { read getattr } |
| 99 | (l1 dom l2 or t1 == mlstrustedsubject or t2 == mlstrustedobject or t2 == mlstrustedsubject); |
| 100 | |
| 101 | mlsconstrain fifo_file { write setattr append unlink link rename } |
| 102 | (l1 domby l2 or t1 == mlstrustedsubject or t2 == mlstrustedobject or t2 == mlstrustedsubject); |
| 103 | |
| 104 | # |
| 105 | # IPC constraints |
| 106 | # |
| 107 | |
| 108 | # Create/destroy: equivalence or trusted. |
| 109 | mlsconstrain ipc_class_set { create destroy } |
| 110 | (l2 eq h2 and (l1 eq l2 or t1 == mlstrustedsubject)); |
| 111 | |
| 112 | # Read ops: No read up unless trusted. |
| 113 | mlsconstrain ipc_class_set r_ipc_perms |
| 114 | (l1 dom l2 or t1 == mlstrustedsubject); |
| 115 | |
| 116 | # Write ops: No write down unless trusted. |
| 117 | mlsconstrain ipc_class_set w_ipc_perms |
| 118 | (l1 domby l2 or t1 == mlstrustedsubject); |
| 119 | |
| 120 | # |
| 121 | # Binder IPC constraints |
| 122 | # |
| 123 | # Presently commented out, as apps are expected to call one another. |
| 124 | # This would only make sense if apps were assigned categories |
| 125 | # based on allowable communications rather than per-app categories. |
| 126 | #mlsconstrain binder call |
| 127 | # (l1 eq l2 or t1 == mlstrustedsubject or t2 == mlstrustedsubject); |