ntopng/src/FlowHash.cpp
Alfredo Cardigliano 9352d0cdcd Update copyright
2025-01-02 09:09:56 +01:00

116 lines
3.7 KiB
C++

/*
*
* (C) 2013-25 - ntop.org
*
*
* 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, write to the Free Software Foundation,
* Inc., 59 Temple Place - Suite 330, Boston, MA 02111-1307, USA.
*
*/
#include "ntop_includes.h"
/* ************************************ */
FlowHash::FlowHash(NetworkInterface *_iface, u_int _num_hashes,
u_int _max_hash_size)
: GenericHash(_iface, _num_hashes, _max_hash_size, "FlowHash") {
if(trace_new_delete) ntop->getTrace()->traceEvent(TRACE_NORMAL, "[new] %s", __FILE__);
};
/* ************************************ */
static u_int16_t max_num_loops = 0;
Flow *FlowHash::find(Mac *src_mac, Mac *dst_mac, IpAddress *src_ip,
IpAddress *dst_ip, u_int16_t src_port, u_int16_t dst_port,
u_int16_t vlanId, u_int16_t observation_point_id,
u_int32_t private_flow_id, u_int8_t protocol,
const ICMPinfo *const icmp_info, bool *src2dst_direction,
bool is_inline_call, Flow **unswapped_flow) {
u_int32_t hash = ((src_ip->key() + dst_ip->key() + (icmp_info ? icmp_info->key() : 0) +
private_flow_id + src_port + dst_port + vlanId + protocol) %
num_hashes);
Flow *head = (Flow *)table[hash];
u_int16_t num_loops = 0;
*unswapped_flow = NULL;
#if 0
ntop->getTrace()->traceEvent(TRACE_NORMAL, "%u:%u / %u:%u [icmp: %u][key: %u][icmp info key: %u][head: 0x%x]",
src_ip->key(), src_port, dst_ip->key(), dst_port, icmp_info ? 1 : 0, hash, icmp_info ? icmp_info->key() : 0, head);
#endif
if (!head) return (NULL);
if (!is_inline_call) locks[hash]->rdlock(__FILE__, __LINE__);
while (head) {
if (!head->idle() &&
head->equal(src_mac, dst_mac, src_ip, dst_ip, src_port, dst_port,
vlanId, observation_point_id, private_flow_id, protocol,
icmp_info, src2dst_direction)) {
if (num_loops > max_num_loops) {
ntop->getTrace()->traceEvent(
TRACE_INFO, "DEBUG: [Num loops: %u][hashId: %u]", num_loops, hash);
max_num_loops = num_loops;
}
if (head->is_swap_requested()) {
/*
This is a good flow but in the wrong direction
hence we remember the flow unswapped but merge
data with the flow with the correct direction
*/
*unswapped_flow = head;
head = NULL;
}
break;
} else
head = (Flow *)head->next(), num_loops++;
}
if (num_loops > max_num_loops) {
ntop->getTrace()->traceEvent(
TRACE_INFO, "DEBUG: [Num loops: %u][hashId: %u]", num_loops, hash);
max_num_loops = num_loops;
}
if (!is_inline_call) locks[hash]->unlock(__FILE__, __LINE__);
return (head);
}
/* ************************************ */
Flow *FlowHash::findByKeyAndHashId(u_int32_t key, u_int32_t hash_id) {
u_int32_t hash = key % num_hashes;
Flow *head = (Flow *)table[hash];
if (head == NULL) return (NULL);
locks[hash]->rdlock(__FILE__, __LINE__);
while (head) {
if ((!head->idle()) && (head->get_hash_entry_id() == hash_id))
break;
else
head = (Flow *)head->next();
}
locks[hash]->unlock(__FILE__, __LINE__);
return ((Flow *)head);
}