12.6 Payload-bearing responses

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Five operations return data on success. Each takes the result as flat arrays and encodes the frame for you.

12.6.0.1 LOOKUP #

struct rsi_path_entry {
    const void *layer;  uint32_t layer_len;
    uint8_t     target_type;   /* RSI_PATH_TARGET_GUID (0) / RSI_PATH_TARGET_HIDDEN (1) */
    uint8_t     target_guid[16];
    uint64_t    sequence;
};
struct rsi_key_metadata {
    uint8_t     guid[16];
    const void *sd;  uint32_t sd_len;
    uint8_t     volatile_key;
    uint8_t     symlink;
    uint64_t    last_write_time;
};

int rsi_respond_lookup(int fd, const struct rsi_request *req,
                       const struct rsi_path_entry *entries, uint32_t entry_count,
                       const struct rsi_key_metadata *metadata, uint32_t metadata_count);

Answers a LOOKUP with the resolved path entries for the child — one per layer that has a view of it, each either a GUID target or a HIDDEN (tombstone) target — plus the metadata for every key the entries reference. A RSI_PATH_TARGET_HIDDEN entry must carry an all-zero target_guid; the metadata must exactly cover the GUID targets. EINVAL if req is not a LOOKUP, a nonzero count has a NULL array, or an entry has invalid target/boolean fields, missing/duplicate metadata, or unreferenced metadata.

12.6.0.2 ENUM_CHILDREN #

struct rsi_child_entry {
    const void            *child_name;  uint32_t child_name_len;
    const struct rsi_path_entry *entries;  uint32_t entry_count;
};

int rsi_respond_enum_children(int fd, const struct rsi_request *req,
                              const struct rsi_child_entry *children, uint32_t child_count,
                              const struct rsi_key_metadata *metadata, uint32_t metadata_count);

Answers an ENUM_CHILDREN with each child — its name and the path entries that resolve it — plus the metadata for every referenced key. The same target/boolean/metadata-coverage rules as LOOKUP apply. EINVAL on the same conditions, scoped to ENUM_CHILDREN.

12.6.0.3 READ_KEY #

int rsi_respond_read_key(int fd, const struct rsi_request *req, const void *name,
                         uint32_t name_len, const uint8_t *parent_guid, const void *sd,
                         uint32_t sd_len, uint8_t volatile_key, uint8_t symlink,
                         uint64_t last_write_time);

Answers a READ_KEY with the key's non-layered metadata: its name, parent_guid, security descriptor (sd), the volatile_key/symlink flags, and last_write_time. EINVAL if req is not a READ_KEY, parent_guid is NULL, or a boolean field is invalid.

12.6.0.4 QUERY_VALUES #

struct rsi_value_entry {
    const void *value_name;  uint32_t value_name_len;
    const void *layer_name;  uint32_t layer_name_len;
    uint32_t    value_type;
    const void *data;  uint32_t data_len;
    uint64_t    sequence;
};
struct rsi_blanket_entry {
    const void *layer_name;  uint32_t layer_name_len;
    uint64_t    sequence;
};

int rsi_respond_query_values(int fd, const struct rsi_request *req,
                             const struct rsi_value_entry *entries, uint32_t entry_count,
                             const struct rsi_blanket_entry *blankets, uint32_t blanket_count);

Answers a QUERY_VALUES with the value entries — each value's name, the layer it lives in, its type, data, and sequence — plus the blankets (the blanket tombstones on this key, each a layer and sequence). The kernel resolves precedence across the layers you report. EINVAL if req is not a QUERY_VALUES or a nonzero count has a NULL array.

12.6.0.5 DELETE_LAYER #

int rsi_respond_delete_layer(int fd, const struct rsi_request *req,
                             const uint8_t *orphaned_guids, uint32_t orphaned_count);

Answers a DELETE_LAYER with the GUIDs of the keys the deleted layer orphaned — a flat orphaned_count * 16-byte array. The GUIDs must be nonzero and unique. EINVAL if req is not a DELETE_LAYER or a nonzero count has a NULL array, a nil GUID, or a duplicate.

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