code wiki / _hdl_build / nx_warden_paths.nx
`nx_warden_paths.nx` source

1// nx_warden_paths.nx -- the WARDEN's real teeth: classify whether an autonomous
2// action on a PATH is additive-safe or must be DENIED. Gives the crew council's
3// Warden leg actual protected-path safety (vs a hand-set flag), so the loop can
4// self-heal/build but can NEVER overwrite the canonical assets.
5//
6// Protected (OVERWRITE / DELETE = HARD DENY):
7//   - the known-good compiler  _offc/nx_cc_known_good.elf  (the canonical root of
8//     trust everything is proven against -- the operator's #1 asset)
9//   - any *.nx SOURCE  (autonomous overwrite-in-place forbidden; real edits land
10//     ADDITIVELY + via a gate + review, never an in-place clobber)
11// Safe:
12//   - CREATE a new file (additive), APPEND (journals), READ
13//   - OVERWRITE of a regenerable build artifact (_offc/*.s, *.o, *.elf scratch, /tmp/*)
14// license_tier: ORIGINAL
15
16import "nx_syscalls.nx"
17
18const WP_SAFE: i64 = 1
19const WP_DENY: i64 = 0
20
21const WP_READ:      i64 = 0
22const WP_APPEND:    i64 = 1
23const WP_CREATE:    i64 = 2    // create a NEW path (additive)
24const WP_OVERWRITE: i64 = 3    // write over an EXISTING path
25const WP_DELETE:    i64 = 4
26
27func wp_slen(s: *u8) -> i64 { var n: i64 = 0; while s[n] != (0 as u8) { n = n + 1 } return n }
28
29// does `hay` contain the NUL-terminated substring `needle`?
30func wp_contains(hay: *u8, needle: *u8) -> i64 {
31    let hn: i64 = wp_slen(hay)
32    let nn: i64 = wp_slen(needle)
33    if nn == 0 { return 1 }
34    var i: i64 = 0
35    while i + nn <= hn {
36        var j: i64 = 0
37        var hit: i64 = 1
38        while j < nn {
39            if hay[i + j] != needle[j] { hit = 0 }
40            j = j + 1
41        }
42        if hit == 1 { return 1 }
43        i = i + 1
44    }
45    return 0
46}
47
48// does `s` end with `suf`?
49func wp_endswith(s: *u8, suf: *u8) -> i64 {
50    let sn: i64 = wp_slen(s)
51    let fn: i64 = wp_slen(suf)
52    if fn > sn { return 0 }
53    var i: i64 = 0
54    while i < fn {
55        if s[sn - fn + i] != suf[i] { return 0 }
56        i = i + 1
57    }
58    return 1
59}
60
61// Is this path PROTECTED from autonomous overwrite/delete?
62func wp_is_protected(path: *u8) -> i64 {
63    if wp_contains(path, "nx_cc_known_good" as *u8) == 1 { return 1 }   // the canonical compiler
64    if wp_endswith(path, ".nx" as *u8) == 1 { return 1 }                // a language source
65    return 0
66}
67
68// The Warden's verdict on (action, path).
69func nx_warden_path_safe(action: i64, path: *u8) -> i64 {
70    if action == WP_READ   { return WP_SAFE }
71    if action == WP_APPEND { return WP_SAFE }
72    if action == WP_CREATE { return WP_SAFE }                 // additive: a new file
73    // OVERWRITE / DELETE: DENY iff the target is protected.
74    if wp_is_protected(path) == 1 { return WP_DENY }
75    return WP_SAFE                                            // regenerable artifact -> ok
76}
nx_warden_paths.nx source

`nx_warden_paths.nx` source
