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Diffstat (limited to 'include/protocol.h')
| -rw-r--r-- | include/protocol.h | 190 |
1 files changed, 0 insertions, 190 deletions
diff --git a/include/protocol.h b/include/protocol.h deleted file mode 100644 index 7bfb275..0000000 --- a/include/protocol.h +++ /dev/null @@ -1,190 +0,0 @@ -/* - * Usurpataion --- client-server protocol interface. - * - * Copyright (C) 2019 Ramūnas Mažeikis - * - * This program is free software; you can redistribute it and/or - * modify it under the terms of the GNU Lesser General Public - * License as published by the Free Software Foundation; version 2.1 - * of the License. - * - * 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 - * Lesser General Public License for more details. - * - * You should have received a copy of the GNU Lesser General Public - * License along with this program; if not, write to the Free Software - * Foundation, Inc., 51 Franklin St, Fifth Floor, Boston, MA 02110-1301, USA - */ - -#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> - -#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) - -/** - * Message sequence number since beggining of sesssion. - * - * Mainly used for identifying lost messages. - */ -typedef unsigned int msg_idx_t; - -enum tlv_type { - /** - * NULL-terminated string. To be put in a queue to display on the - * screen. - */ - TEXT, - - /** Fixed point. 1 decimal digit of precision. */ - FPI1, - - /** Literally time_t */ - TIMESTAMP, - - /** Represents a request for lost message. Data is unsigned integer - * that uniquely identifies the message. - */ - REQUEST, - - /** - * Response to request. Begins with unsigned integer that represents - * which message is being repeated and the actual null-terminated - * message after that. - */ - REPLY, - - /** - * UUID that represents a particular device. - */ - 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 -}; - -/** - * Literally type-length-value - * */ -struct tlv { - enum tlv_type type; - size_t length; - void *data; -}; - -/** - * Keeps state of the parsing process. - * - * Related functions return one tlv at a time. - */ -struct tlv_parser { - char *data; - size_t offset; - size_t size; -}; - -/** - * Fills tlv structure to represent the next tlv in the packet. - * - * Returns END_OF_PACKET if all tlv's were read of E_TLV_OVERFLOW, if the last - * tlv, according to its declared size should not fit in a packet. - */ -int tlv_get(struct tlv_parser *parser, struct tlv *ret); - -/** - * Initialises tlv to sane values. - */ -void tlv_init(struct tlv *t, enum tlv_type type); - -/** - * Frees data held in the tlv structure. The structure itself shall be freed as - * needed by calling code. - */ -void tlv_destroy(struct tlv *t); - -/** - * Tells amount of bytes needed to push tlv to a buffer - */ -size_t tlv_raw_size(const struct tlv *t); - -/** - * 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(struct tlv *t, char *buf); - -/** - * 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, size_t size); - -/** - * 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); - -#endif /* USURPATION_PROTOCOL_H_INCLUDED */ |