storage: Refactor rpmb partition start/size calcs
Make it more explicit which rpmb blocks are used for which data.
Bug: 332762065
Change-Id: Idaa50cc971c1bf93329e7fd85a5a24b9e8aacb9e
diff --git a/block_device_tipc.c b/block_device_tipc.c
index 9bad905..e3eae2e 100644
--- a/block_device_tipc.c
+++ b/block_device_tipc.c
@@ -106,6 +106,19 @@
uint8_t unused[sizeof(struct key)];
};
+struct rpmb_span {
+ uint16_t start;
+ uint16_t block_count;
+};
+
+struct rpmb_spans {
+ struct rpmb_span key;
+ struct rpmb_span ns;
+ struct rpmb_span tdp;
+ /* Start of the rest of the RPMB, which is used for TP and TDEA */
+ uint16_t rpmb_start;
+};
+
static int rpmb_check(struct rpmb_state* rpmb_state, uint16_t block) {
int ret;
uint8_t tmp[RPMB_BUF_SIZE];
@@ -471,31 +484,48 @@
return self->dev_ns.dev.block_count;
}
+/**
+ * rpmb_span_end() - Calculates the first block past the end of @self.
+ */
+static uint16_t rpmb_span_end(struct rpmb_span self) {
+ return self.start + self.block_count;
+}
+
+/**
+ * calculate_rpmb_spans() - Determines the starts and sizes of RPMB partitions.
+ */
+static void calculate_rpmb_spans(struct rpmb_spans* out) {
+ out->key.block_count = 1;
+ /* Used to store superblocks */
+ out->ns.block_count = 2;
+#if HAS_FS_TDP
+ out->tdp.block_count = out->ns.block_count;
+#else
+ out->tdp.block_count = 0;
+#endif
+
+ out->key.start = 0;
+ out->ns.start = rpmb_span_end(out->key);
+ out->tdp.start = rpmb_span_end(out->ns);
+ out->rpmb_start = rpmb_span_end(out->tdp);
+}
+
int block_device_tipc_init(struct block_device_tipc* state,
handle_t ipc_handle,
const struct key* fs_key,
const struct rpmb_key* rpmb_key,
hwkey_session_t hwkey_session) {
- int ret;
- bool alternate_data_partition = false;
- uint32_t ns_init_flags = FS_INIT_FLAGS_NONE;
-#if HAS_FS_TDP
- uint32_t tdp_init_flags = FS_INIT_FLAGS_NONE;
-#endif
- uint8_t probe;
- uint16_t rpmb_key_part_base = 0;
uint32_t rpmb_block_count;
- uint32_t rpmb_part_sb_ns_block_count = 2;
- /*
- * First block is reserved for rpmb key derivation data, whose base is
- * rpmb_key_part_base
- */
- uint16_t rpmb_part1_base = 1;
- uint16_t rpmb_part2_base = rpmb_part1_base + rpmb_part_sb_ns_block_count;
+ bool alternate_data_partition = false;
+ uint8_t probe;
+ uint32_t ns_init_flags = FS_INIT_FLAGS_NONE;
+
+ int ret;
+ struct rpmb_spans partitions;
+ calculate_rpmb_spans(&partitions);
#if HAS_FS_TDP
- uint16_t rpmb_part_sb_tdp_base = rpmb_part2_base;
- rpmb_part2_base += rpmb_part_sb_ns_block_count;
+ uint32_t tdp_init_flags = FS_INIT_FLAGS_NONE;
#endif
state->ipc_handle = ipc_handle;
@@ -507,7 +537,7 @@
}
ret = block_device_tipc_init_rpmb_key(state->rpmb_state, rpmb_key,
- rpmb_key_part_base, hwkey_session);
+ partitions.key.start, hwkey_session);
if (ret < 0) {
SS_ERR("%s: block_device_tipc_init_rpmb_key failed (%d)\n", __func__,
ret);
@@ -528,15 +558,15 @@
0); /* TODO: get hint from ns */
rpmb_block_count /= BLOCK_SIZE_RPMB_BLOCKS;
}
- if (rpmb_block_count < rpmb_part2_base) {
+ if (rpmb_block_count < partitions.rpmb_start) {
ret = -1;
SS_ERR("%s: bad rpmb size, %d\n", __func__, rpmb_block_count);
goto err_bad_rpmb_size;
}
- block_device_tipc_init_dev_rpmb(&state->dev_rpmb, state->rpmb_state,
- rpmb_part2_base,
- rpmb_block_count - rpmb_part2_base, false);
+ block_device_tipc_init_dev_rpmb(
+ &state->dev_rpmb, state->rpmb_state, partitions.rpmb_start,
+ rpmb_block_count - partitions.rpmb_start, false);
/* TODO: allow non-rpmb based tamper proof storage */
ret = fs_init(&state->tr_state_rpmb, file_system_id_tp, fs_key,
@@ -589,8 +619,8 @@
}
block_device_tipc_init_dev_rpmb(&state->dev_ns_tdp_rpmb, state->rpmb_state,
- rpmb_part_sb_tdp_base,
- rpmb_part_sb_ns_block_count, false);
+ partitions.tdp.start,
+ partitions.tdp.block_count, false);
#if STORAGE_TDP_AUTO_CHECKPOINT_ENABLED
if (!system_state_provisioning_allowed()) {
@@ -634,8 +664,8 @@
}
block_device_tipc_init_dev_rpmb(&state->dev_ns_rpmb, state->rpmb_state,
- rpmb_part1_base,
- rpmb_part_sb_ns_block_count, true);
+ partitions.ns.start,
+ partitions.ns.block_count, true);
#if STORAGE_NS_RECOVERY_CLEAR_ALLOWED
ns_init_flags |= FS_INIT_FLAGS_RECOVERY_CLEAR_ALLOWED;
