diff options
Diffstat (limited to 'include')
| -rw-r--r-- | include/net.h | 17 | ||||
| -rw-r--r-- | include/tlv.h | 153 | ||||
| -rw-r--r-- | include/utils.h | 17 |
3 files changed, 58 insertions, 129 deletions
diff --git a/include/net.h b/include/net.h index 8385943..3fbaf5c 100644 --- a/include/net.h +++ b/include/net.h @@ -22,22 +22,11 @@ #ifndef USURPATION_NET_H_INCLUDED #define USURPATION_NET_H_INCLUDED -#ifdef unix #include <sys/socket.h> #include <netinet/in.h> -#endif #include <stddef.h> -#define MTU 1500 - -enum response { - ERROR = -1, - A_OK = 0, /* would be "OK", but clashes with some lib definitions */ - NONEWDATA, - DEAD, -}; - /** * Initialises a listening socket and returns the associated network descriptor. */ @@ -52,12 +41,12 @@ int net_close(int nd); * Get last data received from connection associated with network descriptor. * If the pointer pointed by data is NULL, a buffer is allocated by the function * and needs to be free()'d later. Otherwise, the supplied buffer is reused. + * Returns the amount of data acually fetched through recvsize pointer. */ -int net_getlastdata(int nd, char ** const data); +int net_getlastdata(int nd, char ** const data, size_t *recvsize); int net_send(int nd, const char * const buf, size_t buf_size); -#ifdef unix int net_send_addr(int nd, const char * const buf, size_t buf_size, const struct sockaddr_in * const addr); -#endif +void net_flush_read_buffer(int nd); #endif /* USURPATION_NET_H_INCLUDED */ diff --git a/include/tlv.h b/include/tlv.h index 75aa133..43b7a11 100644 --- a/include/tlv.h +++ b/include/tlv.h @@ -1,7 +1,8 @@ /* - * Usurpataion --- client-server protocol interface. + * Usurpation – clinet-server protocol implementation. * * Copyright (C) 2019 Ramūnas Mažeikis + * Copyright (C) 2019 Gediminas Jakutis * * This program is free software; you can redistribute it and/or * modify it under the terms of the GNU Lesser General Public @@ -21,55 +22,12 @@ #ifndef USURPATION_PROTOCOL_H_INCLUDED #define USURPATION_PROTOCOL_H_INCLUDED -#if 0 - -How do we use this API(?), I hear you say. Well, here is a self-contained -example complete with tedious comments, allocation of buffers and cleanup: - -------------------------------------------------------------------------------- - 1 | void functy_the_function(void) - 2 | { - 3 | struct tlv tlv_packet; /* A packet made of tlv's */ - 4 | struct tlv text; /* Actually useful data */ - 5 | char *packet; /* Raw bytes to be pushed via UDP */ - 6 | size_t packet_size; /* Raw packet size */ - 7 | char message[] = "Get jacked!"; /* Duh! */ - 9 | - 10 | tlv_init(&tlv_packet, REGURAL); /* Initialise tlv_packet to regular */ - 11 | tlv_init(&text, TEXT); /* Initialise text packet */ - 12 | tlv_push_data(&text, message, sizeof(message)); /* Push text to appropriate tlv */ - 13 | tlv_push_tlv(&tlv_packet, &text); /* Push the tlv into tlv packet */ - 14 | - 15 | packet_size = tlv_raw_size(&tlv_packet); /* Get raw size required to push entire tlv_packet as bytes */ - 16 | packet = (char *)malloc(packet_size); /* Allocate buffer for outgoing packet */ - 17 | tlv_get_raw(&tlv_packet, packet); /* Flash tlv_packet to buffer */ - 19 | udp_push(packet, packet_size); /* Push packet via UDP */ - 20 | udp_flush(); /* Flush to the other side*/ - 21 | - 22 | tlv_destroy(&tlv_packet); /* Free tlv_packet */ - 23 | free(packet); /* Free packet itself */ - 24 | return; /* GTFO and save stack space */ - 25 | } -------------------------------------------------------------------------------- - -A few things to note: - * Calling tlv_destroy() on a tlv of type REGURAL or HEARTBEAT destorys - all sub-tlv's too. - * Tlv's get copies of data, which means the original buffer can be - freed immediately. - -#endif - - #include <errno.h> #include <stdint.h> +#include <stddef.h> #include <limits.h> -#define E_TLV_OVERFLOW (1 << 0) -#define E_UNKNOWN_TYPE (1 << 1) -#define END_OF_PACKET (1 << 2) - -#define TLV_SZ_MAX_RAW (MTU - 64) +#define TLV_SZ_MAX (MTU - 64) #ifdef __cplusplus extern "C" { @@ -81,12 +39,6 @@ extern "C" { */ typedef unsigned int msg_idx_t; -#if INT32_MAX == INT_MAX -#define READ_ENUM(data) htonl((data)) -#else INT_MAX == INT16_MAX -#define READ_ENUM(data) htons((data)) -#endif - enum tlv_type { /** * Explicitly states that this tlv is no longer valid for reading. @@ -122,93 +74,66 @@ enum tlv_type { */ UUID, -/* Data of the following types are other tlv's! */ - - /** - * Just a TLV container. - */ - REGURAL, - /** * Says "I'm not dead yet.". */ HEARTBEAT, +}; - /** - * Says "Bring out yer dead!". - */ - DISCOVERY +struct tlv_header { + int32_t type; + uint32_t size; }; -/** - * Literally type-length-value - * */ struct tlv { - enum tlv_type type; - uint16_t length; - const void *data; + struct tlv_header head; + char *data; }; -/** - * Keeps state of the parsing process. - * - * Related functions return one tlv at a time. - */ -struct tlv_parser { - const char *data; - uint16_t offset; +/* for tlv to "raw" conversion */ +struct tlv_packet { + size_t size; + ptrdiff_t cursor; + char *data; }; -/** - * Initialises parser to begin parsing the data. - * - * Returns the first tlv which should be a meta-tlv. If it is not --- you got - * problems. - */ -int tlv_parser_init(struct tlv_parser *parser, char *data, struct tlv *ret); +/* used as a termninator */ +#define tlv_none ((struct tlv) {{INVALID, 0}, NULL}) /** * Fills tlv structure to represent the next tlv in the packet. + * If saveptr is non-NULL, saves the offset to the next field in saveptr. + * Returns NONEWDATA if once all tlvs were read. * - * Returns END_OF_PACKET if all tlv's were read or E_TLV_OVERFLOW, if the last - * tlv, according to its declared size should not fit in a packet. + * tlv data fields obtained through this function MUST NOT be given + * to free(), as they point to the offsets in the "in" buffer. */ -int tlv_get(struct tlv_parser *parser, struct tlv *ret); +int tlv_get(char *in, struct tlv *tlv, char **saveptr); -/** - * Initialises tlv to sane values. - */ -void tlv_init(struct tlv *t, enum tlv_type type); +/* host<->network endianess conversion for the header */ +struct tlv_header ntoh_tlvh(const struct tlv_header * const in); +struct tlv_header hton_tlvh(const struct tlv_header * const in); /** - * Frees data held in the tlv structure. The structure itself shall be freed as - * needed by calling code. + * Forms (packs up) a raw data packet from the given tlv by appending it to the + * packet. Returns E_TLV_OVERFLOW if pushing data would cause the final size + * (including the terminator tlv) to be greater than TLV_SZ_MAX_RAW. In case of + * such error the data is left untouched. */ -void tlv_destroy(struct tlv *t); +int tlv_pack(struct tlv_packet *pack, struct tlv *tlv); -/** - * Tells amount of bytes needed to push tlv to a buffer - */ -size_t tlv_raw_size(const struct tlv *t); +/* finalized the packet by placing tlv_none at the end */ +int tlv_packet_finalize(struct tlv_packet *pack); -/** - * Pushes tlv to buffer as contiguous data. Check tlv size with tlv_raw_size - * beforehand. If you don't do that and overflow --- tough tiddy. - */ -int tlv_get_raw(const struct tlv *t, char *buf); +struct tlv *tlv_init(struct tlv *in, enum tlv_type type); +void tlv_destroy(struct tlv *in); -/** - * Pushes data to tlv. Returns E_TLV_OVERFLOW if pushing data would cause the - * final size to be greater than TLV_SZ_MAX_RAW. In case of such error the data is left - * untouched. - */ -int tlv_push_data(struct tlv *t, const char *data, uint16_t size); +struct tlv_packet *tlv_packet_init(struct tlv_packet *in); +void tlv_packet_destroy(struct tlv_packet *in); + +/* resets the packet to form a new one, without deallocating buffers */ +struct tlv_packet *tlv_packet_reset(struct tlv_packet *in); -/** - * Pushes a sub-tlv into the packet. 't' can only be REGURAL, HEARTBEAT or - * DISCOVERY. - */ -int tlv_push_tlv(struct tlv *t, const struct tlv *other); #ifdef __cplusplus } diff --git a/include/utils.h b/include/utils.h index ba726ec..e1364c5 100644 --- a/include/utils.h +++ b/include/utils.h @@ -2,6 +2,7 @@ * Usurpation – utility functions. * * Copyright (C) 2019 Ramūnas Mažeikis + * Copyright (C) 2019 Gediminas Jakutis * * This program is free software; you can redistribute it and/or * modify it under the terms of the GNU Lesser General Public @@ -23,8 +24,22 @@ #include <stdint.h> +#define MTU 1500 + +static const char heartbeat_device[] = "hey, hey!"; +static const char heartbeat_server[] = "cover this area."; + +/* standard status responses */ +enum response { + ERROR = -1, + A_OK = 0, /* would be "OK", but clashes with some lib definitions */ + NONEWDATA, + DEAD, + EMPTY, +}; + typedef struct uuid_s { - char bytes[16]; + char bytes[16]; } uuid_t; int cmp_uuid(uuid_t *first, uuid_t *second); |