pkt2flow.h

/* pkt2flow
 * Xiaming Chen (chen_xm@sjtu.edu.cn)
 *
 * Copyright (c) 2012
 * Copyright (c) 2014 Sven Eckelmann <sven@narfation.org>
 *
 * 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 names and trademarks of copyright holders may not be used in
 * advertising or publicity pertaining to the software without specific
 * prior permission. Title to copyright in this software and any
 * associated documentation will at all times remain with the copyright
 * holders.
 *
 * 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.
 */

#include <stdint.h>
#include <netinet/in.h>
#include <netinet/ip6.h>

#define __SOURCE_VERSION__              "1.2"
#define __AUTHOR__                      "X. Chen (chenxm35@gmail.com)"
#define __GLOBAL_NAME__                 "pkt2flow"
#define FLOW_TIMEOUT                    1800    // seconds
#define HASH_MULTIPLIER                 37
#define HASH_TBL_SIZE                   48611

#define BIT(bitnr) (1ULL << (bitnr))
#define isset_bits(x, bitmask) ({ typeof(bitmask) _bitmask = (bitmask); \
				  (_bitmask & (x)) == _bitmask; })

enum dump_allow_flags {
	DUMP_OTHER_ALLOWED = BIT(0),
	DUMP_TCP_NOSYN_ALLOWED = BIT(1),
	DUMP_UDP_ALLOWED = BIT(2),
};

enum pkt_dump_file_status {
	STS_UNSET,
	STS_TCP_SYN,
	STS_TCP_NOSYN,
	STS_UDP,
};

struct pkt_dump_file {
	char *file_name;
	unsigned long pkts;

	enum pkt_dump_file_status status;
	unsigned long start_time;
};

/* VLAN header, IEEE 802.1Q */
struct vlan_header {
	uint16_t tci;   /* Priority 3bits, CFI 1bit, ID 12bits */
	uint16_t tpid;
};

union ip_address {
	struct in_addr v4;
	struct in6_addr v6;
};

struct af_6tuple {
	int af_family;
	int protocol;
	union ip_address ip1, ip2;
	uint16_t port1, port2;
	uint8_t is_vlan;
};

struct ip_pair {
	struct af_6tuple af_6tuple;
	struct pkt_dump_file pdf;
	struct ip_pair *next;
};

/* pkt2flow.c */
extern struct ip_pair *pairs[];

/* utilities.c */

/*
 * Generate a new file name for flow with 4-tuple and timestamp
 */
char *new_file_name(struct af_6tuple af_6tuple, unsigned long timestamp);

/* flow_db.c */

/*
 * Initialize the flow hash table to store registered flow items
 */
void init_hash_table(void);

/*
 * Free the flow has table
 */
void free_hash_table(void);

/*
 * Search for the flow in the flow hash table with specific 4-tuple;
 * If the flow item exists in the hash table, the pointer to the ip_pair will be
 * returned.
 * Otherwise, NULL returned;
 */
struct ip_pair *find_ip_pair(struct af_6tuple af_6tuple);

/*
 * To register a new flow item in the flow hash table. This is uaually called
 * after finding the flow item with NULL returned.
 * The pointer to the new registerd ip_pair will be returned; and the pdf will
 * be reset as empty.
 */
struct ip_pair *register_ip_pair(struct af_6tuple af_6tuple);

/*
 * Reset the packet dump file (pdf) for: 1) a new ip_pair created;
 * 2) a timeout flow with new status.
 * The pdf will be reset with: zero packets, zero timestamp,
 * and file name bytes all set to be '\0'
 */
void reset_pdf(struct pkt_dump_file *f);