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Diffstat (limited to 'src/contrib/net.h')
| -rw-r--r-- | src/contrib/net.h | 264 |
1 files changed, 264 insertions, 0 deletions
diff --git a/src/contrib/net.h b/src/contrib/net.h new file mode 100644 index 0000000..698c66b --- /dev/null +++ b/src/contrib/net.h @@ -0,0 +1,264 @@ +/* Copyright (C) 2023 CZ.NIC, z.s.p.o. <knot-dns@labs.nic.cz> + + This program is free software: you can redistribute it and/or modify + it under the terms of the GNU General Public License as published by + the Free Software Foundation, either version 3 of the License, or + (at your option) any later version. + + This program is distributed in the hope that it will be useful, + but WITHOUT ANY WARRANTY; without even the implied warranty of + MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the + GNU General Public License for more details. + + You should have received a copy of the GNU General Public License + along with this program. If not, see <https://www.gnu.org/licenses/>. + */ + +#pragma once + +#include <stdbool.h> +#include <stdint.h> +#include <sys/socket.h> +#include <sys/stat.h> + +// 1280 (IPv6 minimum link MTU) - 40 (IPv6 fixed header) - 20 (TCP fixed header) +#define KNOT_TCP_MSS 1220 + +/*! + * \brief Network interface flags. + */ +typedef enum { + NET_BIND_NONLOCAL = (1 << 0), //!< Allow to bind unavailable address. + NET_BIND_MULTIPLE = (1 << 1), //!< Allow to bind address multiple times. +} net_bind_flag_t; + +/*! + * \brief Create unbound socket of given family and type. + * + * \note The socket is set to non-blocking mode. + * + * \param type Socket transport type (SOCK_STREAM, SOCK_DGRAM). + * \param addr Socket address. + * + * \return socket or error code + */ +int net_unbound_socket(int type, const struct sockaddr_storage *addr); + +/*! + * \brief Create socket bound to given address. + * + * The socket is set to non-blocking mode. + * + * \param type Socket transport type (SOCK_STREAM, SOCK_DGRAM). + * \param addr Socket address. + * \param flags Socket binding options. + * \param unix_mode Socket file mode (UNIX socket only). 0 means don't set mode. + * + * \return socket or error code + */ +int net_bound_socket(int type, const struct sockaddr_storage *addr, + net_bind_flag_t flags, mode_t unix_mode); + +/*! + * \brief Create socket connected (asynchronously) to destination address. + * + * \note The socket is set to non-blocking mode. + * + * \param type Socket transport type (SOCK_STREAM, SOCK_DGRAM). + * \param dst_addr Destination address. + * \param src_addr Source address (can be NULL). + * \param tfo Enable TCP Fast Open. + * + * \return socket or error code + */ +int net_connected_socket(int type, const struct sockaddr_storage *dst_addr, + const struct sockaddr_storage *src_addr, bool tfo); + +/*! + * \brief Enables TCP Fast Open on a bound socket. + * + * \param sock Socket. + * + * \return KNOT_EOK or error code + */ +int net_bound_tfo(int sock, int backlog); + +/*! + * \brief Tell kernel to send ECN bits thru CMSG on packet receival. + * + * \param sock Socket to enable receiving ECN bits. + * \param family Address family on that socket. + * + * \return KNOT_E* + */ +int net_cmsg_ecn_enable(int sock, int family); + +/*! + * \brief Return pointer to possible ECN value in cmsg. + * + * \note The function also updates cmsg_type for outgoing use. + * + * \param cmsg Received control message. + * + * \return Pointer to ECN value or NULL. + */ +int *net_cmsg_ecn_ptr(struct cmsghdr *cmsg); + +/*! + * \brief Get ECN bits of packets received by recv(m)msg. + * + * \param msg Received message header. + * + * \return 0..3 + */ +uint8_t net_cmsg_ecn(struct msghdr *msg); + +/*! + * \brief Set ECN for outgoing packets on this socket. + * + * \param sock Socket file descriptor. + * \param family Address family for outgoing packets. + * \param ecn ECN bits to be set. + * + * \return KNOT_E* + */ +int net_ecn_set(int sock, int family, uint8_t ecn); + +/*! + * \brief Return true if the socket is fully connected. + * + * \param sock Socket. + * + * \return true if connected + */ +bool net_is_connected(int sock); + +/*! + * \brief Get socket type (e.g. \a SOCK_STREAM). + * + * \param sock Socket. + */ +int net_socktype(int sock); + +/*! + * \brief Check if socket is a SOCK_STREAM socket. + */ +bool net_is_stream(int sock); + +/*! + * \brief Accept a connection on a listening socket. + * + * \brief The socket is set to non-blocking mode. + * + * \param sock Socket + * \param addr Remote address (can be NULL). + * + * \return socket or error code + */ +int net_accept(int sock, struct sockaddr_storage *addr); + +/*! + * \brief Reset a TCP connection (with a RST packet). + */ +void net_reset(int sock); + +/*! + * \brief Send a message on a socket. + * + * The socket can be SOCK_STREAM or SOCK_DGRAM. + * + * The implementation handles partial-writes automatically. + * + * \param[in] sock Socket. + * \param[in] buffer Message buffer. + * \param[in] size Size of the message. + * \param[in] addr Remote address (ignored for SOCK_STREAM). + * \param[in] timeout_ms Write timeout in milliseconds (-1 for infinity, + * not valid for SOCK_DGRAM). + * + * \return Number of bytes sent or negative error code. + */ +ssize_t net_base_send(int sock, const uint8_t *buffer, size_t size, + const struct sockaddr_storage *addr, int timeout_ms); + +/*! + * \brief Receive a message from a socket. + * + * \param[in] sock Socket. + * \param[out] buffer Receiving buffer. + * \param[in] size Capacity of the receiving buffer. + * \param[out] addr Remote address (can be NULL). + * \param[in] timeout_ms Read timeout in milliseconds (-1 for infinity). + * + * \return Number of bytes read or negative error code. + */ +ssize_t net_base_recv(int sock, uint8_t *buffer, size_t size, + struct sockaddr_storage *addr, int timeout_ms); + +/*! + * \brief Send a message with prepared msghdr structure. + * + * \see net_base_send + */ +ssize_t net_msg_send(int sock, struct msghdr *msg, int timeout_ms); + +/*! + * \brief Receive a message into msghdr structure. + * + * \see net_base_send + */ +ssize_t net_msg_recv(int sock, struct msghdr *msg, int timeout_ms); + +/*! + * \brief Send a message on a SOCK_DGRAM socket. + * + * \see net_base_send + */ +ssize_t net_dgram_send(int sock, const uint8_t *buffer, size_t size, + const struct sockaddr_storage *addr); + +/*! + * \brief Receive a message from a SOCK_DGRAM socket. + * + * \see net_base_recv + */ +ssize_t net_dgram_recv(int sock, uint8_t *buffer, size_t size, int timeout_ms); + +/*! + * \brief Send a message on a SOCK_STREAM socket. + * + * \see net_base_send + */ +ssize_t net_stream_send(int sock, const uint8_t *buffer, size_t size, int timeout_ms); + +/*! + * \brief Receive a message from a SOCK_STREAM socket. + * + * \see net_base_recv + */ +ssize_t net_stream_recv(int sock, uint8_t *buffer, size_t size, int timeout_ms); + +/*! + * \brief Send a DNS message on a TCP socket. + * + * The outgoing message is prefixed with a two-byte value carrying the DNS + * message size according to the specification. These two bytes are not + * reflected in the return value. + * + * \param[in] tfo_addr If not NULL, send using TCP Fast Open to this address. + * + * \see net_base_send + */ +ssize_t net_dns_tcp_send(int sock, const uint8_t *buffer, size_t size, int timeout_ms, + struct sockaddr_storage *tfo_addr); + +/*! + * \brief Receive a DNS message from a TCP socket. + * + * The first two bytes of the incoming message are interpreted as a DNS message + * size according to the specification. These two bytes are not included in + * the returned size. Only a complete DNS message is retrieved. + * + * \see net_base_recv + */ +ssize_t net_dns_tcp_recv(int sock, uint8_t *buffer, size_t size, int timeout_ms); |