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file_vault: fix locking issue
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The File Vault used to sporadically fail to complete Extend or Rekey operations
when it was locked during the operation. The cause was an insufficient state
model that has been fixed with this commit.

Ref #5190
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@m-stein @chelmuth
m-stein authored and chelmuth committed Apr 25, 2024
1 parent 969469e commit 2bcc85b
Showing 1 changed file with 141 additions and 117 deletions.
258 changes: 141 additions & 117 deletions repos/gems/src/app/file_vault/main.cc
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Expand Up @@ -147,7 +147,7 @@ struct Main : Sandbox::Local_service_base::Wakeup, Sandbox::State_handler
enum State {
INVALID, UNINITIALIZED, SETUP_CREATE_IMAGE, SETUP_INIT_TRUST_ANCHOR, SETUP_TRESOR_INIT,
SETUP_START_TRESOR, SETUP_MKE2FS, SETUP_READ_FS_SIZE, LOCKED, UNLOCK_INIT_TRUST_ANCHOR,
UNLOCK_START_TRESOR, UNLOCK_READ_FS_SIZE, UNLOCKED, LOCK_SEND_REQUEST, LOCK_REQUEST_IN_PROGRESS };
UNLOCK_START_TRESOR, UNLOCK_READ_FS_SIZE, UNLOCKED, LOCK_PENDING, START_LOCKING, LOCKING };

struct Extend { enum State {
INACTIVE, ADAPT_IMAGE_SIZE, WAIT_FOR_TRESOR, SEND_REQUEST, REQUEST_IN_PROGRESS, READ_FS_SIZE, RESIZE2FS }; };
Expand Down Expand Up @@ -207,8 +207,12 @@ struct Main : Sandbox::Local_service_base::Wakeup, Sandbox::State_handler
Signal_transmitter(state_handler).submit();
}

void handle_sandbox_state_extend_and_rekey(Xml_node const &, bool &, bool &);

void generate_sandbox_config(Xml_generator &) const;

void gen_sandbox_cfg_extend_and_rekey(Xml_generator &) const;

void handle_image_fs_query_listing(Xml_node const &);

void handle_client_fs_query_listing(Xml_node const &);
Expand All @@ -219,7 +223,7 @@ struct Main : Sandbox::Local_service_base::Wakeup, Sandbox::State_handler

void handle_lock_fs_query_listing(Xml_node const &node)
{
if (state != LOCK_REQUEST_IN_PROGRESS)
if (state != LOCKING)
return;
if (file_starts_with(node, "deinitialize", String<10>("succeeded"))) {
set_state(LOCKED);
Expand Down Expand Up @@ -314,16 +318,17 @@ Ui_report::State Main::state_to_ui_report_state(State state)
case UNLOCK_INIT_TRUST_ANCHOR:
case UNLOCK_START_TRESOR:
case UNLOCK_READ_FS_SIZE: return Ui_report::UNLOCKING;
case LOCK_SEND_REQUEST:
case LOCK_REQUEST_IN_PROGRESS: return Ui_report::LOCKING;
case LOCK_PENDING:
case START_LOCKING:
case LOCKING: return Ui_report::LOCKING;
}
ASSERT_NEVER_REACHED;
}


void Main::handle_extend_fs_query_listing(Xml_node const &node)
{
if (state != UNLOCKED)
if (state != UNLOCKED && state != LOCK_PENDING)
return;

switch (extend_state) {
Expand Down Expand Up @@ -354,7 +359,7 @@ void Main::handle_extend_fs_query_listing(Xml_node const &node)

void Main::handle_rekey_fs_query_listing(Xml_node const &node)
{
if (state != UNLOCKED)
if (state != UNLOCKED && state != LOCK_PENDING)
return;

bool ui_report_changed = false;
Expand Down Expand Up @@ -404,6 +409,7 @@ void Main::handle_client_fs_query_listing(Xml_node const &listing)
break;

case UNLOCKED:
case LOCK_PENDING:

if (extend_state != Extend::READ_FS_SIZE)
break;
Expand Down Expand Up @@ -448,6 +454,7 @@ void Main::handle_image_fs_query_listing(Xml_node const &listing)
break;
}
case UNLOCKED:
case LOCK_PENDING:
{
size_t size { 0 };
with_file(listing, image_name, [&] (Xml_node const &file) { size = file.attribute_value("size", 0UL); });
Expand Down Expand Up @@ -490,11 +497,6 @@ void Main::handle_ui_config()

case UNLOCKED:

if (!ui_config->passphrase_long_enough()) {
set_state(LOCK_SEND_REQUEST);
update_sandbox_cfg = true;
break;
}
if (rekey_state == Rekey::INACTIVE && rekey_operation_pending()) {
ui_report.rekey.construct(ui_config->rekey->id, false);
rekey_state = Rekey::WAIT_FOR_TRESOR;
Expand All @@ -506,6 +508,11 @@ void Main::handle_ui_config()
extend_state = Extend::ADAPT_IMAGE_SIZE;
update_sandbox_cfg = true;
}
if (!ui_config->passphrase_long_enough()) {
set_state(LOCK_PENDING);
update_sandbox_cfg = true;
break;
}
break;

default: break;
Expand All @@ -516,6 +523,50 @@ void Main::handle_ui_config()
update_sandbox_config();
}

void Main::handle_sandbox_state_extend_and_rekey(Xml_node const &sandbox_state, bool &update_sandbox_cfg, bool &ui_report_changed)
{
switch (extend_state) {
case Extend::ADAPT_IMAGE_SIZE:

if (child_succeeded(truncate_file, sandbox_state)) {
extend_state = Extend::WAIT_FOR_TRESOR;
update_sandbox_cfg = true;
}
break;

case Extend::SEND_REQUEST:

if (child_succeeded(extend_fs_tool, sandbox_state)) {
extend_state = Extend::REQUEST_IN_PROGRESS;
update_sandbox_cfg = true;
}
break;

case Extend::RESIZE2FS:

if (child_succeeded(resize2fs, sandbox_state)) {
extend_state = Extend::INACTIVE;
ui_report.extend->finished = true;
ui_report_changed = true;
update_sandbox_cfg = true;
}
break;

default: break;
}
switch (rekey_state) {
case Rekey::SEND_REQUEST:

if (child_succeeded(rekey_fs_tool, sandbox_state)) {
rekey_state = Rekey::REQUEST_IN_PROGRESS;
update_sandbox_cfg = true;
}
break;

default: break;
}
}


void Main::handle_sandbox_state()
{
Expand Down Expand Up @@ -588,68 +639,27 @@ void Main::handle_sandbox_state()

case UNLOCKED:

handle_sandbox_state_extend_and_rekey(sandbox_state, update_sandbox_cfg, ui_report_changed);
with_child(sandbox_state, rump_vfs, [&] (Xml_node const &child) {
child.with_optional_sub_node("provided", [&] (Xml_node const &provided) {
provided.for_each_sub_node("session", [&] (Xml_node const &session) {
if (session.attribute_value("service", Service_name()) == "File_system")
num_clients.value++; }); }); });
break;

switch (extend_state) {
case Extend::ADAPT_IMAGE_SIZE:

if (child_succeeded(truncate_file, sandbox_state)) {
extend_state = Extend::WAIT_FOR_TRESOR;
update_sandbox_cfg = true;
}
break;

case Extend::SEND_REQUEST:

if (child_succeeded(extend_fs_tool, sandbox_state)) {
extend_state = Extend::REQUEST_IN_PROGRESS;
update_sandbox_cfg = true;
}
break;

case Extend::RESIZE2FS:

if (child_succeeded(resize2fs, sandbox_state)) {
extend_state = Extend::INACTIVE;
ui_report.extend->finished = true;
ui_report_changed = true;
update_sandbox_cfg = true;
}
break;

default: break;
}
switch (rekey_state) {
case Rekey::SEND_REQUEST:

if (child_succeeded(rekey_fs_tool, sandbox_state)) {
rekey_state = Rekey::REQUEST_IN_PROGRESS;
update_sandbox_cfg = true;
}
break;
case LOCK_PENDING:

default: break;
handle_sandbox_state_extend_and_rekey(sandbox_state, update_sandbox_cfg, ui_report_changed);
if (extend_state == Extend::INACTIVE && rekey_state == Rekey::INACTIVE) {
set_state(START_LOCKING);
update_sandbox_cfg = true;
}
break;

case LOCK_SEND_REQUEST:
case START_LOCKING:

if (child_succeeded(lock_fs_tool, sandbox_state)) {
if (ui_report.rekey.constructed()) {
ui_report.rekey->finished = true;
rekey_state = Rekey::INACTIVE;
ui_report_changed = true;
}
if (ui_report.extend.constructed()) {
ui_report.extend->finished = true;
extend_state = Extend::INACTIVE;
ui_report_changed = true;
}
set_state(LOCK_REQUEST_IN_PROGRESS);
set_state(LOCKING);
update_sandbox_cfg = true;
}
break;
Expand Down Expand Up @@ -693,6 +703,61 @@ void Main::wakeup_local_service()
}


void Main::gen_sandbox_cfg_extend_and_rekey(Xml_generator &xml) const
{
switch (extend_state) {
case Extend::INACTIVE: break;
case Extend::ADAPT_IMAGE_SIZE:

switch (ui_config->extend->tree) {
case Ui_config::Extend::VIRTUAL_BLOCK_DEVICE:
{
size_t bytes = ui_config->extend->num_bytes;
size_t effective_bytes = bytes - (bytes % BLOCK_SIZE);
gen_truncate_file_start_node(
xml, truncate_file, File_path("/tresor/", image_name).string(), ui_report.image_size + effective_bytes);
break;
}
case Ui_config::Extend::FREE_TREE:
{
size_t bytes = ui_config->extend->num_bytes;
size_t effective_bytes = bytes - (bytes % BLOCK_SIZE);
gen_truncate_file_start_node(
xml, truncate_file, File_path("/tresor/", image_name).string(), ui_report.image_size + effective_bytes);
break;
} }
break;

case Extend::WAIT_FOR_TRESOR: gen_extend_fs_query_start_node(xml, extend_fs_query); break;
case Extend::SEND_REQUEST:

switch (ui_config->extend->tree) {
case Ui_config::Extend::VIRTUAL_BLOCK_DEVICE:
gen_extend_fs_tool_start_node(xml, extend_fs_tool, "vbd", ui_config->extend->num_bytes / BLOCK_SIZE);
break;
case Ui_config::Extend::FREE_TREE:
gen_extend_fs_tool_start_node(xml, extend_fs_tool, "ft", ui_config->extend->num_bytes / BLOCK_SIZE);
break;
}
break;

case Extend::REQUEST_IN_PROGRESS: gen_extend_fs_query_start_node(xml, extend_fs_query); break;
case Extend::READ_FS_SIZE:

gen_client_fs_query_start_node(xml, client_fs_query);
break;

case Extend::RESIZE2FS: gen_resize2fs_start_node(xml, resize2fs); break;
}
switch(rekey_state) {
case Rekey::INACTIVE: break;
case Rekey::WAIT_FOR_TRESOR: gen_rekey_fs_query_start_node(xml, rekey_fs_query); break;
case Rekey::SEND_REQUEST: gen_rekey_fs_tool_start_node(xml, rekey_fs_tool); break;
case Rekey::REQUEST_IN_PROGRESS: gen_rekey_fs_query_start_node(xml, rekey_fs_query); break;
}
}


void Main::generate_sandbox_config(Xml_generator &xml) const
{
switch (state) {
Expand Down Expand Up @@ -777,71 +842,30 @@ void Main::generate_sandbox_config(Xml_generator &xml) const
break;

case UNLOCKED:
{

gen_parent_provides_and_report_nodes(xml);
gen_tresor_trust_anchor_vfs_start_node(xml, tresor_trust_anchor_vfs, jent_avail);
gen_tresor_vfs_start_node(xml, tresor_vfs, image_name);
gen_tresor_vfs_block_start_node(xml, tresor_vfs_block);
gen_image_fs_query_start_node(xml, image_fs_query);
switch(extend_state) {
case Extend::INACTIVE: break;
case Extend::ADAPT_IMAGE_SIZE:

switch (ui_config->extend->tree) {
case Ui_config::Extend::VIRTUAL_BLOCK_DEVICE:
{
size_t bytes = ui_config->extend->num_bytes;
size_t effective_bytes = bytes - (bytes % BLOCK_SIZE);
gen_truncate_file_start_node(
xml, truncate_file, File_path("/tresor/", image_name).string(), ui_report.image_size + effective_bytes);
break;
}
case Ui_config::Extend::FREE_TREE:
{
size_t bytes = ui_config->extend->num_bytes;
size_t effective_bytes = bytes - (bytes % BLOCK_SIZE);
gen_truncate_file_start_node(
xml, truncate_file, File_path("/tresor/", image_name).string(), ui_report.image_size + effective_bytes);
break;
} }
break;

case Extend::WAIT_FOR_TRESOR: gen_extend_fs_query_start_node(xml, extend_fs_query); break;
case Extend::SEND_REQUEST:

switch (ui_config->extend->tree) {
case Ui_config::Extend::VIRTUAL_BLOCK_DEVICE:
gen_extend_fs_tool_start_node(xml, extend_fs_tool, "vbd", ui_config->extend->num_bytes / BLOCK_SIZE);
break;
case Ui_config::Extend::FREE_TREE:
gen_extend_fs_tool_start_node(xml, extend_fs_tool, "ft", ui_config->extend->num_bytes / BLOCK_SIZE);
break;
}
gen_sandbox_cfg_extend_and_rekey(xml);
if (extend_state != Extend::INACTIVE && ui_config->extend->tree == Ui_config::Extend::VIRTUAL_BLOCK_DEVICE)
break;

case Extend::REQUEST_IN_PROGRESS: gen_extend_fs_query_start_node(xml, extend_fs_query); break;
case Extend::READ_FS_SIZE:
gen_child_service_policy(xml, "File_system", rump_vfs);
gen_rump_vfs_start_node(xml, rump_vfs);
break;

gen_client_fs_query_start_node(xml, client_fs_query);
break;
case LOCK_PENDING:

case Extend::RESIZE2FS: gen_resize2fs_start_node(xml, resize2fs); break;
}
switch(rekey_state) {
case Rekey::INACTIVE: break;
case Rekey::WAIT_FOR_TRESOR: gen_rekey_fs_query_start_node(xml, rekey_fs_query); break;
case Rekey::SEND_REQUEST: gen_rekey_fs_tool_start_node(xml, rekey_fs_tool); break;
case Rekey::REQUEST_IN_PROGRESS: gen_rekey_fs_query_start_node(xml, rekey_fs_query); break;
}
if (extend_state == Extend::INACTIVE ||
ui_config->extend->tree != Ui_config::Extend::VIRTUAL_BLOCK_DEVICE) {

gen_child_service_policy(xml, "File_system", rump_vfs);
gen_rump_vfs_start_node(xml, rump_vfs);
}
gen_parent_provides_and_report_nodes(xml);
gen_tresor_trust_anchor_vfs_start_node(xml, tresor_trust_anchor_vfs, jent_avail);
gen_tresor_vfs_start_node(xml, tresor_vfs, image_name);
gen_tresor_vfs_block_start_node(xml, tresor_vfs_block);
gen_sandbox_cfg_extend_and_rekey(xml);
break;
}
case LOCK_SEND_REQUEST:

case START_LOCKING:

gen_parent_provides_and_report_nodes(xml);
gen_child_service_policy(xml, "File_system", rump_vfs);
Expand All @@ -851,7 +875,7 @@ void Main::generate_sandbox_config(Xml_generator &xml) const
gen_lock_fs_tool_start_node(xml, lock_fs_tool);
break;

case LOCK_REQUEST_IN_PROGRESS:
case LOCKING:

gen_parent_provides_and_report_nodes(xml);
gen_child_service_policy(xml, "File_system", rump_vfs);
Expand Down

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