Crate tds_protocol 

tds-protocol

Pure implementation of the MS-TDS (Tabular Data Stream) protocol used by Microsoft SQL Server.

This crate provides no_std compatible packet structures, token parsing, and serialization for TDS protocol versions 7.4 through 8.0.

Features

• std (default): Enable standard library support
• alloc: Enable allocation without full std (requires alloc crate)
• encoding (default): Enable collation-aware string encoding/decoding via the Collation::encoding() method. Uses the encoding_rs crate.

Collation-Aware VARCHAR Decoding

When the encoding feature is enabled (default), this crate provides comprehensive support for decoding VARCHAR data with locale-specific character encodings. This is essential for databases using non-ASCII collations (e.g., Japanese, Chinese, Korean, Cyrillic, Arabic, etc.).

Supported Encodings

Code Page	Encoding	Languages
874	Windows-874 (TIS-620)	Thai
932	Shift_JIS	Japanese
936	GBK/GB18030	Simplified Chinese
949	EUC-KR	Korean
950	Big5	Traditional Chinese
1250	Windows-1250	Central/Eastern European
1251	Windows-1251	Cyrillic
1252	Windows-1252	Western European (default)
1253	Windows-1253	Greek
1254	Windows-1254	Turkish
1255	Windows-1255	Hebrew
1256	Windows-1256	Arabic
1257	Windows-1257	Baltic
1258	Windows-1258	Vietnamese
UTF-8	UTF-8	SQL Server 2019+ collations

Example

use tds_protocol::Collation;

// Japanese collation (LCID 0x0411 = Japanese_CI_AS)
let collation = Collation { lcid: 0x0411, sort_id: 0 };
if let Some(encoding) = collation.encoding() {
    // encoding is Shift_JIS
    let (decoded, _, _) = encoding.decode(varchar_bytes);
}

// Check if UTF-8 collation (SQL Server 2019+)
let utf8_collation = Collation { lcid: 0x0800_0409, sort_id: 0 };
assert!(utf8_collation.is_utf8()); // true, no transcoding needed

Design Philosophy

This crate is intentionally IO-agnostic. It contains no networking logic and makes no assumptions about the async runtime. Higher-level crates build upon this foundation to provide async I/O capabilities.

Example

use tds_protocol::{PacketHeader, PacketType, PacketStatus};

let header = PacketHeader {
    packet_type: PacketType::SqlBatch,
    status: PacketStatus::END_OF_MESSAGE,
    length: 100,
    spid: 0,
    packet_id: 1,
    window: 0,
};

Re-exports

pub use error::ProtocolError;

pub use login7::FeatureExtension;

pub use login7::FeatureId;

pub use login7::Login7;

pub use login7::OptionFlags1;

pub use login7::OptionFlags2;

pub use login7::OptionFlags3;

pub use login7::TypeFlags;

pub use packet::DEFAULT_PACKET_SIZE;

pub use packet::MAX_PACKET_SIZE;

pub use packet::PACKET_HEADER_SIZE;

pub use packet::PacketHeader;

pub use packet::PacketStatus;

pub use packet::PacketType;

pub use prelogin::EncryptionLevel;

pub use prelogin::PreLogin;

pub use prelogin::PreLoginOption;

pub use rpc::ParamFlags;

pub use rpc::ProcId;

pub use rpc::RpcOptionFlags;

pub use rpc::RpcParam;

pub use rpc::RpcRequest;

pub use rpc::TypeInfo as RpcTypeInfo;

pub use sql_batch::SqlBatch;

pub use sql_batch::encode_sql_batch;

pub use sql_batch::encode_sql_batch_with_transaction;

pub use token::ColMetaData;

pub use token::Collation;

pub use token::ColumnData;

pub use token::Done;

pub use token::DoneInProc;

pub use token::DoneProc;

pub use token::DoneStatus;

pub use token::EnvChange;

pub use token::EnvChangeType;

pub use token::EnvChangeValue;

pub use token::FeatureExtAck;

pub use token::FedAuthInfo;

pub use token::LoginAck;

pub use token::NbcRow;

pub use token::Order;

pub use token::RawRow;

pub use token::ReturnValue;

pub use token::ServerError;

pub use token::ServerInfo;

pub use token::SessionState;

pub use token::SspiToken;

pub use token::Token;

pub use token::TokenParser;

pub use token::TokenType;

pub use token::TypeInfo;

pub use tvp::TVP_END_TOKEN;

pub use tvp::TVP_ROW_TOKEN;

pub use tvp::TVP_TYPE_ID;

pub use tvp::TvpColumnDef as TvpWireColumnDef;

pub use tvp::TvpColumnFlags;

pub use tvp::TvpEncoder;

pub use tvp::TvpWireType;

pub use tvp::encode_tvp_bit;

pub use tvp::encode_tvp_date;

pub use tvp::encode_tvp_datetime2;

pub use tvp::encode_tvp_datetimeoffset;

pub use tvp::encode_tvp_decimal;

pub use tvp::encode_tvp_float;

pub use tvp::encode_tvp_guid;

pub use tvp::encode_tvp_int;

pub use tvp::encode_tvp_null;

pub use tvp::encode_tvp_nvarchar;

pub use tvp::encode_tvp_time;

pub use tvp::encode_tvp_varbinary;

pub use types::ColumnFlags;

pub use types::TypeId;

pub use types::Updateable;

pub use version::SqlServerVersion;

pub use version::TdsVersion;

pub use crypto::ALGORITHM_AEAD_AES_256_CBC_HMAC_SHA256;

pub use crypto::COLUMN_FLAG_ENCRYPTED;

pub use crypto::CekTable;

pub use crypto::CekTableEntry;

pub use crypto::CekValue;

pub use crypto::ColumnCryptoInfo;

pub use crypto::CryptoMetadata;

pub use crypto::ENCRYPTION_TYPE_DETERMINISTIC;

pub use crypto::ENCRYPTION_TYPE_RANDOMIZED;

pub use crypto::EncryptionTypeWire;

pub use crypto::NORMALIZATION_RULE_VERSION;

pub use crypto::is_column_encrypted;

Modules

codec

Codec utilities for TDS protocol encoding and decoding.

collation

Collation encoding support for SQL Server VARCHAR decoding.

crypto

Always Encrypted cryptography metadata for TDS protocol.

error

Protocol-level error types.

login7

TDS LOGIN7 packet construction.

packet

TDS packet header definitions.

prelogin

TDS pre-login packet handling.

rpc

RPC (Remote Procedure Call) request encoding.

sql_batch

SQL batch request encoding.

token

TDS token stream definitions.

tvp

Table-Valued Parameter (TVP) wire format encoding.

types

TDS data type definitions.

version

TDS protocol version definitions.