diff options
Diffstat (limited to 'src/inet.h')
| -rw-r--r-- | src/inet.h | 73 |
1 files changed, 71 insertions, 2 deletions
@@ -1,3 +1,8 @@ +/** \file + * \brief The utility functions for the internet protocol. + * \note The header includes functions which are required when using raw TCP/IP + * sockets. + */ /* * Copyright (c) 2019-2021 David Timber <mieabby@gmail.com> * @@ -27,10 +32,21 @@ #include "protocol.h" -// Workaround for header issues in uClibc +/* Alias declarations */ typedef struct prne_iphdr4 prne_iphdr4_t; typedef struct prne_iphdr6 prne_iphdr6_t; +/** \struct prne_iphdr4 \struct prne_iphdr6 + * \brief The workaround for the issues in uClibc headers. + * \note At the time of writing the code, the IPv6 support of uClibc was not + * complete and there were some problems using the IP headers provided by + * uClibc. These structures are exactly the same as the counterparts in the + * standard IP headers. + * \note The values must be in the host byte order. Unlike the standard + * functions, the serialisation and deserialisation functions are responsible + * for byte order conversion. + */ + struct prne_iphdr4 { uint8_t saddr[4]; uint8_t daddr[4]; @@ -50,13 +66,45 @@ struct prne_iphdr6 { uint8_t hop_limit; }; +/** + * \brief Set bits to represent the CIDR + * \param out The byte array used to represent the netmask. + * \param cidr The CIDR value. + * \note The number of elements modified is calculated by dividing \p cidr by 8. + * For example, if the \p cidr is passed as 24, only the first 3 elements of + * \p out are modified to set the first 24 bits. + * \warning The behaviour is undefined if \p cidr divided by 8 is larger than + * the size of \p out (buffer overflow). + */ void prne_netmask_from_cidr (uint8_t *out, size_t cidr); +/** + * \brief Calculate the checksum of the IPv4 TCP packet. + * \param ih The pointer to the IPv4 header structure. + * \param th The pointer to the TCP header data. + * \param th_len The byte length of the TCP header data. + * \param data The pointer to the payload data. + * \param data_len The byte length of the payload data. + * \return The calculated checksum value in the host byte order. The value must + * be converted to the network byte order. + */ uint16_t prne_calc_tcp_chksum4 ( const prne_iphdr4_t *ih, const uint8_t *th, size_t th_len, const uint8_t *data, size_t data_len); +/** + * \brief Calculate the checksum of the IPv6 TCP packet. + * \param ih The pointer to the IPv6 header structure. + * \param th The pointer to the TCP header data. + * \param th_len The byte length of the TCP header data. + * \param data The pointer to the payload data. + * \param data_len The byte length of the payload data. + * \return The calculated checksum value in the host byte order. The value must + * be converted to the network byte order. + * \note The same algorithm(the function) can be used to calculate the checksum + * values of ICMP packets. + */ uint16_t prne_calc_tcp_chksum6 ( const prne_iphdr6_t *ih, const uint8_t *th, @@ -64,8 +112,29 @@ uint16_t prne_calc_tcp_chksum6 ( const uint8_t *data, size_t data_len); +/** + * \brief Serialise the IPv4 header structure for transmission. + * \param mem The destination buffer. The length of the buffer must be at least + * 20 bytes. + * \param in The pointer to the IPv4 header structure. + */ void prne_ser_iphdr4 (uint8_t *mem, const prne_iphdr4_t *in); +/** + * \brief Serialise the IPv6 header structure for transmission. + * \param mem The destination buffer. The length of the buffer must be at least + * 40 bytes. + * \param in The pointer to the IPv6 header structure. + */ void prne_ser_iphdr6 (uint8_t *mem, const prne_iphdr6_t *in); - +/** + * \brief Deserialise the IPv4 header from the binary data. + * \param data The binary data. The length must be at least 20 bytes. + * \param out The pointer to the IPv4 header structure. + */ void prne_dser_iphdr4 (const uint8_t *data, prne_iphdr4_t *out); +/** + * \brief Deserialise the IPv6 header from the binary data. + * \param data The binary data. The length must be at least 40 bytes. + * \param out The pointer to the IPv6 header structure. + */ void prne_dser_iphdr6 (const uint8_t *data, prne_iphdr6_t *out); |