mirror of
https://github.com/kuhyx/testsAndMisc.git
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Krzysztof kuhy Rudnicki
0a07684cca
The bind-mount logic goes to hosts_mount.sh, the Magisk-module and
cache-invalidation logic to hosts_magisk.sh. Both flat siblings, both in
both deploy lists; the two lists were then checked to correspond exactly
in both directions, since a push with no matching cp stages a file that
never lands and the enforcer would fail to source it.
Audited for stdin-draining `while read` loops BEFORE extracting, because
piping one would change behaviour in a way stubs cannot catch. There are
none here. Also confirmed no function writes a global, so there was no
cross-half hazard of the kind that kept NET_BUILT in curfew_enforcer.sh.
69 assertions, 43/43 and 62/62 lines, 17 mutations all killed. Two survived
the first run and both were real findings:
- the unmount give-up threshold was not pinned. Raising it from 5 to 500
changed nothing observable, so the enforcer could have spun 500 times
per poll against a mount that was never going to clear. Now asserted as
a call count.
- the `[ ! -f $HOSTS_TARGET ] && return 1` guard in
is_bind_mounted_correctly is PROVABLY EQUIVALENT: sha256_of returns
empty for a missing file, so the existing -n check already rejects that
case. No test can distinguish it. Equivalent code is a claim of a check
that is not being made, so it is deleted rather than covered by a test
that would pass either way. Old and new bodies were compared across all
four input states -- both-missing, target-missing, match, mismatch --
and agree on every one.
That deletion is the only non-verbatim function; the other 19 moved
untouched, making this the first fully verbatim extraction of the session.
Ordering is asserted where it is load-bearing: /system must go back to ro
after rw, and +i must be restored after being dropped. Presence assertions
alone would pass with either pair reversed.
UNVERIFIED ON DEVICE -- the highest-stakes of the four enforcer splits now
outstanding, since a failure to source leaves nothing blocking while the
phone looks normal. Over-cap count 20 -> 19.
Co-Authored-By: Claude Opus 5 (1M context) <noreply@anthropic.com>
Claude-Session: https://claude.ai/code/session_011w2Pj4Ek3ZNMQVYcFHgXDY
92 lines
3.8 KiB
Bash
Executable File
92 lines
3.8 KiB
Bash
Executable File
#!/system/bin/sh
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# shellcheck shell=ash
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# hosts_mount.sh — the bind-mount half of hosts_enforcer.sh: proving the
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# blocklist is actually mounted over $HOSTS_TARGET, clearing a stale or wrong
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# mount, and making the target writable once on ROMs that ship it read-only.
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#
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# A flat sibling, not lib/, for the same reason as hosts_magisk.sh: deploy.sh
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# pushes phone scripts into one directory.
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#
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# Sourced by hosts_enforcer.sh, which owns log() and $HOSTS_TARGET, the only
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# config.sh global these read. Nothing is assigned here.
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is_bind_mounted_correctly() {
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# Android devices often already have /system/etc/hosts as its own mount
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# point (OEM overlay / f2fs block). A mere "path is in /proc/self/mounts"
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# check is not enough - we must verify the mounted content matches our
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# currently-active canonical by hash (which depends on workout state).
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# No early -f guard on the target: sha256_of returns empty for a file
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# that does not exist, so the -n check below already rejects that case.
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# The guard was provably equivalent — a mutation removing it could not be
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# distinguished by any test — and equivalent code is a claim of a check
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# that is not actually being made.
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local target_hash canonical_hash canonical
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canonical="$(current_canonical)"
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target_hash="$(sha256_of "$HOSTS_TARGET")"
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canonical_hash="$(sha256_of "$canonical")"
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[ -n "$target_hash" ] && [ "$target_hash" = "$canonical_hash" ]
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}
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unmount_existing_hosts_mount() {
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# If anything else is already mounted on /system/etc/hosts (OEM overlay
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# or a previous failed bind), unmount it so we can take its place.
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local attempts=0
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while grep -qE "[[:space:]]${HOSTS_TARGET}[[:space:]]" /proc/self/mounts 2>/dev/null; do
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if [ "$attempts" -ge 5 ]; then
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log "Could not fully unmount $HOSTS_TARGET after 5 attempts"
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return 1
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fi
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umount "$HOSTS_TARGET" 2>/dev/null \
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|| umount -l "$HOSTS_TARGET" 2>/dev/null \
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|| break
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attempts=$((attempts + 1))
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done
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return 0
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}
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make_target_writable_once() {
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# /system is usually mounted read-only. Make it rw just long enough
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# to overwrite HOSTS_TARGET with the canonical content, then remount ro.
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local system_mount canonical
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canonical="$(current_canonical)"
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system_mount="$(awk '$2=="/system"{print $2; exit}' /proc/self/mounts)"
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if [ -z "$system_mount" ]; then
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system_mount="/system"
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fi
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mount -o remount,rw "$system_mount" 2>/dev/null || true
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chattr -i "$HOSTS_TARGET" 2>/dev/null || true
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cp "$canonical" "$HOSTS_TARGET" 2>/dev/null || true
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chmod 644 "$HOSTS_TARGET" 2>/dev/null || true
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chattr +i "$HOSTS_TARGET" 2>/dev/null || true
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mount -o remount,ro "$system_mount" 2>/dev/null || true
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}
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assert_bind_mount() {
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if is_bind_mounted_correctly; then
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return 0
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fi
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# Something is in the way (OEM overlay or previous partial mount).
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unmount_existing_hosts_mount
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local canonical
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canonical="$(current_canonical)"
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# Try plain bind mount - no remount-rw of /system needed.
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if mount --bind "$canonical" "$HOSTS_TARGET" 2>/dev/null; then
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mount -o remount,ro,bind "$HOSTS_TARGET" 2>/dev/null || true
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if is_bind_mounted_correctly; then
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log "Bind-mounted $canonical over $HOSTS_TARGET"
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sync_magisk_module "$canonical"
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return 0
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fi
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log "Bind mount reported success but target still mismatches - unmounting"
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umount "$HOSTS_TARGET" 2>/dev/null || true
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fi
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# Bind failed - fall back to direct overwrite of /system/etc/hosts.
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log "Bind mount failed - falling back to direct overwrite"
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make_target_writable_once
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if is_bind_mounted_correctly; then
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sync_magisk_module "$canonical"
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return 0
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fi
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return 1
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}
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