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diff --git a/bfdd/bfddp_packet.h b/bfdd/bfddp_packet.h new file mode 100644 index 0000000..4ece94f --- /dev/null +++ b/bfdd/bfddp_packet.h @@ -0,0 +1,386 @@ +/* + * BFD Data Plane protocol messages header. + * + * Copyright (C) 2020 Network Device Education Foundation, Inc. ("NetDEF") + * Rafael F. Zalamena + * + * Permission is hereby granted, free of charge, to any person obtaining a copy + * of this software and associated documentation files (the “Software”), to + * deal in the Software without restriction, including without limitation the + * rights to use, copy, modify, merge, publish, distribute, sublicense, and/or + * sell copies of the Software, and to permit persons to whom the Software is + * furnished to do so, subject to the following conditions: + * + * The above copyright notice and this permission notice shall be included in + * all copies or substantial portions of the Software. + * + * THE SOFTWARE IS PROVIDED “AS IS”, WITHOUT WARRANTY OF ANY KIND, EXPRESS OR + * IMPLIED, INCLUDING BUT NOT LIMITED TO THE WARRANTIES OF MERCHANTABILITY, + * FITNESS FOR A PARTICULAR PURPOSE AND NONINFRINGEMENT. IN NO EVENT SHALL THE + * AUTHORS OR COPYRIGHT HOLDERS BE LIABLE FOR ANY CLAIM, DAMAGES OR OTHER + * LIABILITY, WHETHER IN AN ACTION OF CONTRACT, TORT OR OTHERWISE, ARISING + * FROM, OUT OF OR IN CONNECTION WITH THE SOFTWARE OR THE USE OR OTHER DEALINGS + * IN THE SOFTWARE. + */ + +/** + * \file bfddp_packet.h + */ +#ifndef BFD_DP_PACKET_H +#define BFD_DP_PACKET_H + +#include <netinet/in.h> + +#include <stdint.h> + +/* + * Protocol definitions. + */ + +/** + * BFD protocol version as defined in RFC5880 Section 4.1 Generic BFD Control + * Packet Format. + */ +#define BFD_PROTOCOL_VERSION 1 + +/** Default data plane port. */ +#define BFD_DATA_PLANE_DEFAULT_PORT 50700 + +/** BFD single hop UDP port, as defined in RFC 5881 Section 4. Encapsulation. */ +#define BFD_SINGLE_HOP_PORT 3784 + +/** BFD multi hop UDP port, as defined in RFC 5883 Section 5. Encapsulation. */ +#define BFD_MULTI_HOP_PORT 4784 + +/** Default slow start multiplier. */ +#define SLOWSTART_DMULT 3 +/** Default slow start transmission speed. */ +#define SLOWSTART_TX 1000000u +/** Default slow start receive speed. */ +#define SLOWSTART_RX 1000000u +/** Default slow start echo receive speed. */ +#define SLOWSTART_ERX 0u + +/* + * BFD single hop source UDP ports. As defined in RFC 5881 Section 4. + * Encapsulation. + */ +#define BFD_SOURCE_PORT_BEGIN 49152 +#define BFD_SOURCE_PORT_END 65535 + +/** BFD data plane protocol version. */ +#define BFD_DP_VERSION 1 + +/** BFD data plane message types. */ +enum bfddp_message_type { + /** Ask for BFD daemon or data plane for echo packet. */ + ECHO_REQUEST = 0, + /** Answer a ECHO_REQUEST packet. */ + ECHO_REPLY = 1, + /** Add or update BFD peer session. */ + DP_ADD_SESSION = 2, + /** Delete BFD peer session. */ + DP_DELETE_SESSION = 3, + /** Tell BFD daemon state changed: timer expired or session down. */ + BFD_STATE_CHANGE = 4, + + /** Ask for BFD session counters. */ + DP_REQUEST_SESSION_COUNTERS = 5, + /** Tell BFD daemon about counters values. */ + BFD_SESSION_COUNTERS = 6, +}; + +/** + * `ECHO_REQUEST`/`ECHO_REPLY` data payload. + * + * Data plane might use whatever precision it wants for `dp_time` + * field, however if you want to be able to tell the delay between + * data plane packet send and BFD daemon packet processing you should + * use `gettimeofday()` and have the data plane clock synchronized with + * BFD daemon (not a problem if data plane runs in the same system). + * + * Normally data plane will only check the time stamp it sent to determine + * the whole packet trip time. + */ +struct bfddp_echo { + /** Filled by data plane. */ + uint64_t dp_time; + /** Filled by BFD daemon. */ + uint64_t bfdd_time; +}; + + +/** BFD session flags. */ +enum bfddp_session_flag { + /** Set when using multi hop. */ + SESSION_MULTIHOP = (1 << 0), + /** Set when using demand mode. */ + SESSION_DEMAND = (1 << 1), + /** Set when using cbit (Control Plane Independent). */ + SESSION_CBIT = (1 << 2), + /** Set when using echo mode. */ + SESSION_ECHO = (1 << 3), + /** Set when using IPv6. */ + SESSION_IPV6 = (1 << 4), + /** Set when using passive mode. */ + SESSION_PASSIVE = (1 << 5), + /** Set when session is administrative down. */ + SESSION_SHUTDOWN = (1 << 6), +}; + +/** + * `DP_ADD_SESSION`/`DP_DELETE_SESSION` data payload. + * + * `lid` is unique in BFD daemon so it might be used as key for data + * structures lookup. + */ +struct bfddp_session { + /** Important session flags. \see bfddp_session_flag. */ + uint32_t flags; + /** + * Session source address. + * + * Check `flags` field for `SESSION_IPV6` before using as IPv6. + */ + struct in6_addr src; + /** + * Session destination address. + * + * Check `flags` field for `SESSION_IPV6` before using as IPv6. + */ + struct in6_addr dst; + + /** Local discriminator. */ + uint32_t lid; + /** + * Minimum desired transmission interval (in microseconds) without + * jitter. + */ + uint32_t min_tx; + /** + * Required minimum receive interval rate (in microseconds) without + * jitter. + */ + uint32_t min_rx; + /** + * Minimum desired echo transmission interval (in microseconds) + * without jitter. + */ + uint32_t min_echo_tx; + /** + * Required minimum echo receive interval rate (in microseconds) + * without jitter. + */ + uint32_t min_echo_rx; + /** Amount of milliseconds to wait before starting the session */ + uint32_t hold_time; + + /** Minimum TTL. */ + uint8_t ttl; + /** Detection multiplier. */ + uint8_t detect_mult; + /** Reserved / zeroed. */ + uint16_t zero; + + /** Interface index (set to `0` when unavailable). */ + uint32_t ifindex; + /** Interface name (empty when unavailable). */ + char ifname[64]; + + /* TODO: missing authentication. */ +}; + +/** BFD packet state values as defined in RFC 5880, Section 4.1. */ +enum bfd_state_value { + /** Session is administratively down. */ + STATE_ADMINDOWN = 0, + /** Session is down or went down. */ + STATE_DOWN = 1, + /** Session is initializing. */ + STATE_INIT = 2, + /** Session is up. */ + STATE_UP = 3, +}; + +/** BFD diagnostic field values as defined in RFC 5880, Section 4.1. */ +enum bfd_diagnostic_value { + /** Nothing was diagnosed. */ + DIAG_NOTHING = 0, + /** Control detection time expired. */ + DIAG_CONTROL_EXPIRED = 1, + /** Echo function failed. */ + DIAG_ECHO_FAILED = 2, + /** Neighbor signaled down. */ + DIAG_DOWN = 3, + /** Forwarding plane reset. */ + DIAG_FP_RESET = 4, + /** Path down. */ + DIAG_PATH_DOWN = 5, + /** Concatenated path down. */ + DIAG_CONCAT_PATH_DOWN = 6, + /** Administratively down. */ + DIAG_ADMIN_DOWN = 7, + /** Reverse concatenated path down. */ + DIAG_REV_CONCAT_PATH_DOWN = 8, +}; + +/** BFD remote state flags. */ +enum bfd_remote_flags { + /** Control Plane Independent bit. */ + RBIT_CPI = (1 << 0), + /** Demand mode bit. */ + RBIT_DEMAND = (1 << 1), + /** Multipoint bit. */ + RBIT_MP = (1 << 2), +}; + +/** + * `BFD_STATE_CHANGE` data payload. + */ +struct bfddp_state_change { + /** Local discriminator. */ + uint32_t lid; + /** Remote discriminator. */ + uint32_t rid; + /** Remote configurations/bits set. \see bfd_remote_flags. */ + uint32_t remote_flags; + /** Remote minimum desired transmission interval. */ + uint32_t desired_tx; + /** Remote minimum receive interval. */ + uint32_t required_rx; + /** Remote minimum echo receive interval. */ + uint32_t required_echo_rx; + /** Remote state. \see bfd_state_values.*/ + uint8_t state; + /** Remote diagnostics (if any) */ + uint8_t diagnostics; + /** Remote detection multiplier. */ + uint8_t detection_multiplier; +}; + +/** + * BFD control packet state bits definition. + */ +enum bfddp_control_state_bits { + /** Used to request connection establishment signal. */ + STATE_POLL_BIT = (1 << 5), + /** Finalizes the connection establishment signal. */ + STATE_FINAL_BIT = (1 << 4), + /** Signalizes that forward plane doesn't depend on control plane. */ + STATE_CPI_BIT = (1 << 3), + /** Signalizes the use of authentication. */ + STATE_AUTH_BIT = (1 << 2), + /** Signalizes that peer is using demand mode. */ + STATE_DEMAND_BIT = (1 << 1), + /** Used in RFC 8562 implementation. */ + STATE_MULTI_BIT = (1 << 0), +}; + +/** + * BFD control packet. + * + * As defined in 'RFC 5880 Section 4.1 Generic BFD Control Packet Format'. + */ +struct bfddp_control_packet { + /** (3 bits version << 5) | (5 bits diag). */ + uint8_t version_diag; + /** + * (2 bits state << 6) | (6 bits flags) + * + * \see bfd_state_value, bfddp_control_state_bits. + */ + uint8_t state_bits; + /** Detection multiplier. */ + uint8_t detection_multiplier; + /** Packet length in bytes. */ + uint8_t length; + /** Our discriminator. */ + uint32_t local_id; + /** Remote system discriminator. */ + uint32_t remote_id; + /** Desired minimum send interval in microseconds. */ + uint32_t desired_tx; + /** Desired minimum receive interval in microseconds. */ + uint32_t required_rx; + /** Desired minimum echo receive interval in microseconds. */ + uint32_t required_echo_rx; +}; + +/** + * The protocol wire message header structure. + */ +struct bfddp_message_header { + /** Protocol version format. \see BFD_DP_VERSION. */ + uint8_t version; + /** Reserved / zero field. */ + uint8_t zero; + /** Message contents type. \see bfddp_message_type. */ + uint16_t type; + /** + * Message identification (to pair request/response). + * + * The ID `0` is reserved for asynchronous messages (e.g. unrequested + * messages). + */ + uint16_t id; + /** Message length. */ + uint16_t length; +}; + +/** + * Data plane session counters request. + * + * Message type: `DP_REQUEST_SESSION_COUNTERS`. + */ +struct bfddp_request_counters { + /** Session local discriminator. */ + uint32_t lid; +}; + +/** + * BFD session counters reply. + * + * Message type: `BFD_SESSION_COUNTERS`. + */ +struct bfddp_session_counters { + /** Session local discriminator. */ + uint32_t lid; + + /** Control packet bytes input. */ + uint64_t control_input_bytes; + /** Control packets input. */ + uint64_t control_input_packets; + /** Control packet bytes output. */ + uint64_t control_output_bytes; + /** Control packets output. */ + uint64_t control_output_packets; + + /** Echo packet bytes input. */ + uint64_t echo_input_bytes; + /** Echo packets input. */ + uint64_t echo_input_packets; + /** Echo packet bytes output. */ + uint64_t echo_output_bytes; + /** Echo packets output. */ + uint64_t echo_output_packets; +}; + +/** + * The protocol wire messages structure. + */ +struct bfddp_message { + /** Message header. \see bfddp_message_header. */ + struct bfddp_message_header header; + + /** Message payload. \see bfddp_message_type. */ + union { + struct bfddp_echo echo; + struct bfddp_session session; + struct bfddp_state_change state; + struct bfddp_control_packet control; + struct bfddp_request_counters counters_req; + struct bfddp_session_counters session_counters; + } data; +}; + +#endif /* BFD_DP_PACKET_H */ |