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softflowd.c
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softflowd.c
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/*
* Copyright 2002 Damien Miller <[email protected]> All rights reserved.
*
* Redistribution and use in source and binary forms, with or without
* modification, are permitted provided that the following conditions
* are met:
* 1. Redistributions of source code must retain the above copyright
* notice, this list of conditions and the following disclaimer.
* 2. Redistributions in binary form must reproduce the above copyright
* notice, this list of conditions and the following disclaimer in the
* documentation and/or other materials provided with the distribution.
*
* THIS SOFTWARE IS PROVIDED BY THE AUTHOR ``AS IS'' AND ANY EXPRESS OR
* IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE IMPLIED WARRANTIES
* OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE ARE DISCLAIMED.
* IN NO EVENT SHALL THE AUTHOR BE LIABLE FOR ANY DIRECT, INDIRECT,
* INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL DAMAGES (INCLUDING, BUT
* NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS OR SERVICES; LOSS OF USE,
* DATA, OR PROFITS; OR BUSINESS INTERRUPTION) HOWEVER CAUSED AND ON ANY
* THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT LIABILITY, OR TORT
* (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY OUT OF THE USE OF
* THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF SUCH DAMAGE.
*/
/*
* This is software implementation of Cisco's NetFlow(tm) traffic
* reporting system. It operates by listening (via libpcap) on a
* promiscuous interface and tracking traffic flows.
*
* Traffic flows are recorded by source/destination/protocol
* IP address or, in the case of TCP and UDP, by
* src_addr:src_port/dest_addr:dest_port/protocol
*
* Flows expire automatically after a period of inactivity (default: 1
* hour) They may also be evicted (in order of age) in situations where
* there are more flows than slots available.
*
* Netflow compatible packets are sent to a specified target host upon
* flow expiry.
*
* As this implementation watches traffic promiscuously, it is likely to
* place significant load on hosts or gateways on which it is installed.
*/
#include "common.h"
#include "sys-tree.h"
#include "convtime.h"
#include "softflowd.h"
#include "treetype.h"
#include "freelist.h"
#include "log.h"
#include <pcap.h>
/* Global variables */
static int verbose_flag = 0; /* Debugging flag */
static u_int16_t if_index = 0; /* "manual" interface index */
/* Signal handler flags */
static volatile sig_atomic_t graceful_shutdown_request = 0;
/* Context for libpcap callback functions */
struct CB_CTXT {
struct FLOWTRACK *ft;
int linktype;
int fatal;
int want_v6;
};
/* Describes a datalink header and how to extract v4/v6 frames from it */
struct DATALINK {
int dlt; /* BPF datalink type */
int skiplen; /* Number of bytes to skip datalink header */
int ft_off; /* Datalink frametype offset */
int ft_len; /* Datalink frametype length */
int ft_is_be; /* Set if frametype is big-endian */
u_int32_t ft_mask; /* Mask applied to frametype */
u_int32_t ft_v4; /* IPv4 frametype */
u_int32_t ft_v6; /* IPv6 frametype */
};
/* Datalink types that we know about */
static const struct DATALINK lt[] = {
{ DLT_EN10MB, 14, 12, 2, 1, 0xffffffff, 0x0800, 0x86dd },
{ DLT_PPP, 5, 3, 2, 1, 0xffffffff, 0x0021, 0x0057 },
#ifdef DLT_LINUX_SLL
{ DLT_LINUX_SLL,16, 14, 2, 1, 0xffffffff, 0x0800, 0x86dd },
#endif
{ DLT_RAW, 0, 0, 1, 1, 0x000000f0, 0x0040, 0x0060 },
{ DLT_NULL, 4, 0, 4, 0, 0xffffffff, AF_INET, AF_INET6 },
#ifdef DLT_LOOP
{ DLT_LOOP, 4, 0, 4, 1, 0xffffffff, AF_INET, AF_INET6 },
#endif
{ -1, -1, -1, -1, -1, 0x00000000, 0xffff, 0xffff },
};
/* Netflow send functions */
typedef int (netflow_send_func_t)(struct FLOW **, int, int, u_int16_t,
struct FLOWTRACKPARAMETERS *, int);
struct NETFLOW_SENDER {
int version;
netflow_send_func_t *func;
netflow_send_func_t *bidir_func;
int v6_capable;
};
/* Array of NetFlow export function that we know of. NB. nf[0] is default */
static const struct NETFLOW_SENDER nf[] = {
{ 5, send_netflow_v5, NULL, 0 },
{ 1, send_netflow_v1, NULL, 0 },
{ 9, send_netflow_v9, NULL, 1 },
{ 10, send_ipfix, send_ipfix_bidirection, 1 },
{ -1, NULL, NULL, 0 },
};
/* Describes a location where we send NetFlow packets to */
struct NETFLOW_TARGET {
int fd;
const struct NETFLOW_SENDER *dialect;
};
/* Signal handlers */
static void sighand_graceful_shutdown(int signum)
{
graceful_shutdown_request = signum;
}
static void sighand_other(int signum)
{
/* XXX: this may not be completely safe */
logit(LOG_WARNING, "Exiting immediately on unexpected signal %d",
signum);
_exit(0);
}
/*
* This is the flow comparison function.
*/
static int
flow_compare(struct FLOW *a, struct FLOW *b)
{
/* Be careful to avoid signed vs unsigned issues here */
int r;
if (a->vlanid != b->vlanid)
return (a->vlanid > b->vlanid ? 1 : -1);
if (a->af != b->af)
return (a->af > b->af ? 1 : -1);
if ((r = memcmp(&a->addr[0], &b->addr[0], sizeof(a->addr[0]))) != 0)
return (r > 0 ? 1 : -1);
if ((r = memcmp(&a->addr[1], &b->addr[1], sizeof(a->addr[1]))) != 0)
return (r > 0 ? 1 : -1);
#ifdef notyet
if (a->ip6_flowlabel[0] != 0 && b->ip6_flowlabel[0] != 0 &&
a->ip6_flowlabel[0] != b->ip6_flowlabel[0])
return (a->ip6_flowlabel[0] > b->ip6_flowlabel[0] ? 1 : -1);
if (a->ip6_flowlabel[1] != 0 && b->ip6_flowlabel[1] != 0 &&
a->ip6_flowlabel[1] != b->ip6_flowlabel[1])
return (a->ip6_flowlabel[1] > b->ip6_flowlabel[1] ? 1 : -1);
#endif
if (a->protocol != b->protocol)
return (a->protocol > b->protocol ? 1 : -1);
if (a->port[0] != b->port[0])
return (ntohs(a->port[0]) > ntohs(b->port[0]) ? 1 : -1);
if (a->port[1] != b->port[1])
return (ntohs(a->port[1]) > ntohs(b->port[1]) ? 1 : -1);
return (0);
}
/* Generate functions for flow tree */
FLOW_PROTOTYPE(FLOWS, FLOW, trp, flow_compare);
FLOW_GENERATE(FLOWS, FLOW, trp, flow_compare);
/*
* This is the expiry comparison function.
*/
static int
expiry_compare(struct EXPIRY *a, struct EXPIRY *b)
{
if (a->expires_at != b->expires_at)
return (a->expires_at > b->expires_at ? 1 : -1);
/* Make expiry entries unique by comparing flow sequence */
if (a->flow->flow_seq != b->flow->flow_seq)
return (a->flow->flow_seq > b->flow->flow_seq ? 1 : -1);
return (0);
}
/* Generate functions for flow tree */
EXPIRY_PROTOTYPE(EXPIRIES, EXPIRY, trp, expiry_compare);
EXPIRY_GENERATE(EXPIRIES, EXPIRY, trp, expiry_compare);
static struct FLOW *
flow_get(struct FLOWTRACK *ft)
{
return freelist_get(&ft->flow_freelist);
}
static void
flow_put(struct FLOWTRACK *ft, struct FLOW *flow)
{
return freelist_put(&ft->flow_freelist, flow);
}
static struct EXPIRY *
expiry_get(struct FLOWTRACK *ft)
{
return freelist_get(&ft->expiry_freelist);
}
static void
expiry_put(struct FLOWTRACK *ft, struct EXPIRY *expiry)
{
return freelist_put(&ft->expiry_freelist, expiry);
}
#if 0
/* Dump a packet */
static void
dump_packet(const u_int8_t *p, int len)
{
char buf[1024], tmp[3];
int i;
for (*buf = '\0', i = 0; i < len; i++) {
snprintf(tmp, sizeof(tmp), "%02x%s", p[i], i % 2 ? " " : "");
if (strlcat(buf, tmp, sizeof(buf) - 4) >= sizeof(buf) - 4) {
strlcat(buf, "...", sizeof(buf));
break;
}
}
logit(LOG_INFO, "packet len %d: %s", len, buf);
}
#endif
/* Format a time in an ISOish format */
static const char *
format_time(time_t t)
{
struct tm *tm;
static char buf[32];
tm = gmtime(&t);
strftime(buf, sizeof(buf), "%Y-%m-%dT%H:%M:%S", tm);
return (buf);
}
/* Format a flow in a verbose and ugly way */
static const char *
format_flow(struct FLOW *flow)
{
char addr1[64], addr2[64], start_time[32], fin_time[32];
static char buf[1024];
inet_ntop(flow->af, &flow->addr[0], addr1, sizeof(addr1));
inet_ntop(flow->af, &flow->addr[1], addr2, sizeof(addr2));
snprintf(start_time, sizeof(start_time), "%s",
format_time(flow->flow_start.tv_sec));
snprintf(fin_time, sizeof(fin_time), "%s",
format_time(flow->flow_last.tv_sec));
snprintf(buf, sizeof(buf), "seq:%"PRIu64" [%s]:%hu <> [%s]:%hu proto:%u "
"octets>:%u packets>:%u octets<:%u packets<:%u "
"start:%s.%03ld finish:%s.%03ld tcp>:%02x tcp<:%02x "
"flowlabel>:%08x flowlabel<:%08x ",
flow->flow_seq,
addr1, ntohs(flow->port[0]), addr2, ntohs(flow->port[1]),
(int)flow->protocol,
flow->octets[0], flow->packets[0],
flow->octets[1], flow->packets[1],
start_time, (flow->flow_start.tv_usec + 500) / 1000,
fin_time, (flow->flow_last.tv_usec + 500) / 1000,
flow->tcp_flags[0], flow->tcp_flags[1],
flow->ip6_flowlabel[0], flow->ip6_flowlabel[1]);
return (buf);
}
/* Format a flow in a brief way */
static const char *
format_flow_brief(struct FLOW *flow)
{
char addr1[64], addr2[64];
static char buf[1024];
inet_ntop(flow->af, &flow->addr[0], addr1, sizeof(addr1));
inet_ntop(flow->af, &flow->addr[1], addr2, sizeof(addr2));
snprintf(buf, sizeof(buf),
"seq:%"PRIu64" [%s]:%hu <> [%s]:%hu proto:%u",
flow->flow_seq,
addr1, ntohs(flow->port[0]), addr2, ntohs(flow->port[1]),
(int)flow->protocol);
return (buf);
}
/* Fill in transport-layer (tcp/udp) portions of flow record */
static int
transport_to_flowrec(struct FLOW *flow, const u_int8_t *pkt,
const size_t caplen, int isfrag, int protocol, int ndx)
{
const struct tcphdr *tcp = (const struct tcphdr *)pkt;
const struct udphdr *udp = (const struct udphdr *)pkt;
const struct icmp *icmp = (const struct icmp *)pkt;
/*
* XXX to keep flow in proper canonical format, it may be necessary to
* swap the array slots based on the order of the port numbers does
* this matter in practice??? I don't think so - return flows will
* always match, because of their symmetrical addr/ports
*/
switch (protocol) {
case IPPROTO_TCP:
/* Check for runt packet, but don't error out on short frags */
if (caplen < sizeof(*tcp))
return (isfrag ? 0 : 1);
flow->port[ndx] = tcp->th_sport;
flow->port[ndx ^ 1] = tcp->th_dport;
flow->tcp_flags[ndx] |= tcp->th_flags;
break;
case IPPROTO_UDP:
/* Check for runt packet, but don't error out on short frags */
if (caplen < sizeof(*udp))
return (isfrag ? 0 : 1);
flow->port[ndx] = udp->uh_sport;
flow->port[ndx ^ 1] = udp->uh_dport;
break;
case IPPROTO_ICMP:
case IPPROTO_ICMPV6:
/*
* Encode ICMP type * 256 + code into dest port like
* Cisco routers
*/
flow->port[ndx] = 0;
flow->port[ndx ^ 1] = htons(icmp->icmp_type * 256 +
icmp->icmp_code);
break;
}
return (0);
}
/* Convert a IPv4 packet to a partial flow record (used for comparison) */
static int
ipv4_to_flowrec(struct FLOW *flow, const u_int8_t *pkt, size_t caplen,
size_t len, int *isfrag, int af, u_int16_t vlanid)
{
const struct ip *ip = (const struct ip *)pkt;
int ndx;
if (caplen < 20 || caplen < ip->ip_hl * 4)
return (-1); /* Runt packet */
if (ip->ip_v != 4)
return (-1); /* Unsupported IP version */
/* Prepare to store flow in canonical format */
ndx = memcmp(&ip->ip_src, &ip->ip_dst, sizeof(ip->ip_src)) > 0 ? 1 : 0;
flow->af = af;
flow->addr[ndx].v4 = ip->ip_src;
flow->addr[ndx ^ 1].v4 = ip->ip_dst;
flow->protocol = ip->ip_p;
flow->octets[ndx] = len;
flow->packets[ndx] = 1;
flow->vlanid = vlanid;
*isfrag = (ntohs(ip->ip_off) & (IP_OFFMASK|IP_MF)) ? 1 : 0;
/* Don't try to examine higher level headers if not first fragment */
if (*isfrag && (ntohs(ip->ip_off) & IP_OFFMASK) != 0)
return (0);
return (transport_to_flowrec(flow, pkt + (ip->ip_hl * 4),
caplen - (ip->ip_hl * 4), *isfrag, ip->ip_p, ndx));
}
/* Convert a IPv6 packet to a partial flow record (used for comparison) */
static int
ipv6_to_flowrec(struct FLOW *flow, const u_int8_t *pkt, size_t caplen,
size_t len, int *isfrag, int af, u_int16_t vlanid)
{
const struct ip6_hdr *ip6 = (const struct ip6_hdr *)pkt;
const struct ip6_ext *eh6;
const struct ip6_frag *fh6;
int ndx, nxt;
if (caplen < sizeof(*ip6))
return (-1); /* Runt packet */
if ((ip6->ip6_vfc & IPV6_VERSION_MASK) != IPV6_VERSION)
return (-1); /* Unsupported IPv6 version */
/* Prepare to store flow in canonical format */
ndx = memcmp(&ip6->ip6_src, &ip6->ip6_dst,
sizeof(ip6->ip6_src)) > 0 ? 1 : 0;
flow->af = af;
flow->ip6_flowlabel[ndx] = ip6->ip6_flow & IPV6_FLOWLABEL_MASK;
flow->addr[ndx].v6 = ip6->ip6_src;
flow->addr[ndx ^ 1].v6 = ip6->ip6_dst;
flow->octets[ndx] = len;
flow->packets[ndx] = 1;
flow->vlanid = vlanid;
*isfrag = 0;
nxt = ip6->ip6_nxt;
pkt += sizeof(*ip6);
caplen -= sizeof(*ip6);
/* Now loop through headers, looking for transport header */
for (;;) {
eh6 = (const struct ip6_ext *)pkt;
if (nxt == IPPROTO_HOPOPTS ||
nxt == IPPROTO_ROUTING ||
nxt == IPPROTO_DSTOPTS) {
if (caplen < sizeof(*eh6) ||
caplen < (eh6->ip6e_len + 1) << 3)
return (1); /* Runt */
nxt = eh6->ip6e_nxt;
pkt += (eh6->ip6e_len + 1) << 3;
caplen -= (eh6->ip6e_len + 1) << 3;
} else if (nxt == IPPROTO_FRAGMENT) {
*isfrag = 1;
fh6 = (const struct ip6_frag *)eh6;
if (caplen < sizeof(*fh6))
return (1); /* Runt */
/*
* Don't try to examine higher level headers if
* not first fragment
*/
if ((fh6->ip6f_offlg & IP6F_OFF_MASK) != 0)
return (0);
nxt = fh6->ip6f_nxt;
pkt += sizeof(*fh6);
caplen -= sizeof(*fh6);
} else
break;
}
flow->protocol = nxt;
return (transport_to_flowrec(flow, pkt, caplen, *isfrag, nxt, ndx));
}
static void
flow_update_expiry(struct FLOWTRACK *ft, struct FLOW *flow)
{
EXPIRY_REMOVE(EXPIRIES, &ft->expiries, flow->expiry);
/* Flows over 2 GiB traffic */
if (flow->octets[0] > (1U << 31) || flow->octets[1] > (1U << 31)) {
flow->expiry->expires_at = 0;
flow->expiry->reason = R_OVERBYTES;
goto out;
}
/* Flows over maximum life seconds */
if (ft->param.maximum_lifetime != 0 &&
flow->flow_last.tv_sec - flow->flow_start.tv_sec >
ft->param.maximum_lifetime) {
flow->expiry->expires_at = 0;
flow->expiry->reason = R_MAXLIFE;
goto out;
}
if (flow->protocol == IPPROTO_TCP) {
/* Reset TCP flows */
if (ft->param.tcp_rst_timeout != 0 &&
((flow->tcp_flags[0] & TH_RST) ||
(flow->tcp_flags[1] & TH_RST))) {
flow->expiry->expires_at = flow->flow_last.tv_sec +
ft->param.tcp_rst_timeout;
flow->expiry->reason = R_TCP_RST;
goto out;
}
/* Finished TCP flows */
if (ft->param.tcp_fin_timeout != 0 &&
((flow->tcp_flags[0] & TH_FIN) &&
(flow->tcp_flags[1] & TH_FIN))) {
flow->expiry->expires_at = flow->flow_last.tv_sec +
ft->param.tcp_fin_timeout;
flow->expiry->reason = R_TCP_FIN;
goto out;
}
/* TCP flows */
if (ft->param.tcp_timeout != 0) {
flow->expiry->expires_at = flow->flow_last.tv_sec +
ft->param.tcp_timeout;
flow->expiry->reason = R_TCP;
goto out;
}
}
if (ft->param.udp_timeout != 0 && flow->protocol == IPPROTO_UDP) {
/* UDP flows */
flow->expiry->expires_at = flow->flow_last.tv_sec +
ft->param.udp_timeout;
flow->expiry->reason = R_UDP;
goto out;
}
if (ft->param.icmp_timeout != 0 &&
((flow->af == AF_INET && flow->protocol == IPPROTO_ICMP) ||
((flow->af == AF_INET6 && flow->protocol == IPPROTO_ICMPV6)))) {
/* ICMP flows */
flow->expiry->expires_at = flow->flow_last.tv_sec +
ft->param.icmp_timeout;
flow->expiry->reason = R_ICMP;
goto out;
}
/* Everything else */
flow->expiry->expires_at = flow->flow_last.tv_sec +
ft->param.general_timeout;
flow->expiry->reason = R_GENERAL;
out:
if (ft->param.maximum_lifetime != 0 && flow->expiry->expires_at != 0) {
flow->expiry->expires_at = MIN(flow->expiry->expires_at,
flow->flow_start.tv_sec + ft->param.maximum_lifetime);
}
EXPIRY_INSERT(EXPIRIES, &ft->expiries, flow->expiry);
}
/* Return values from process_packet */
#define PP_OK 0
#define PP_BAD_PACKET -2
#define PP_MALLOC_FAIL -3
/*
* Main per-packet processing function. Take a packet (provided by
* libpcap) and attempt to find a matching flow. If no such flow exists,
* then create one.
*
* Also marks flows for fast expiry, based on flow or packet attributes
* (the actual expiry is performed elsewhere)
*/
static int
process_packet(struct FLOWTRACK *ft, const u_int8_t *pkt, int af,
const u_int32_t caplen, const u_int32_t len, u_int16_t vlanid,
const struct timeval *received_time)
{
struct FLOW tmp, *flow;
int frag;
ft->param.total_packets++;
/* Convert the IP packet to a flow identity */
memset(&tmp, 0, sizeof(tmp));
switch (af) {
case AF_INET:
if (ipv4_to_flowrec(&tmp, pkt, caplen, len, &frag, af, vlanid) == -1)
goto bad;
break;
case AF_INET6:
if (ipv6_to_flowrec(&tmp, pkt, caplen, len, &frag, af, vlanid) == -1)
goto bad;
break;
default:
bad:
ft->param.bad_packets++;
return (PP_BAD_PACKET);
}
if (frag)
ft->param.frag_packets++;
/* Zero out bits of the flow that aren't relevant to tracking level */
switch (ft->param.track_level) {
case TRACK_IP_ONLY:
tmp.protocol = 0;
/* FALLTHROUGH */
case TRACK_IP_PROTO:
tmp.port[0] = tmp.port[1] = 0;
tmp.tcp_flags[0] = tmp.tcp_flags[1] = 0;
/* FALLTHROUGH */
case TRACK_FULL:
tmp.vlanid = 0;
case TRACK_FULL_VLAN:
break;
}
/* If a matching flow does not exist, create and insert one */
if ((flow = FLOW_FIND(FLOWS, &ft->flows, &tmp)) == NULL) {
/* Allocate and fill in the flow */
if ((flow = flow_get(ft)) == NULL) {
logit(LOG_ERR, "process_packet: flow_get failed",
sizeof(*flow));
return (PP_MALLOC_FAIL);
}
memcpy(flow, &tmp, sizeof(*flow));
memcpy(&flow->flow_start, received_time,
sizeof(flow->flow_start));
flow->flow_seq = ft->param.next_flow_seq++;
FLOW_INSERT(FLOWS, &ft->flows, flow);
/* Allocate and fill in the associated expiry event */
if ((flow->expiry = expiry_get(ft)) == NULL) {
logit(LOG_ERR, "process_packet: expiry_get failed",
sizeof(*flow->expiry));
return (PP_MALLOC_FAIL);
}
flow->expiry->flow = flow;
/* Must be non-zero (0 means expire immediately) */
flow->expiry->expires_at = 1;
flow->expiry->reason = R_GENERAL;
EXPIRY_INSERT(EXPIRIES, &ft->expiries, flow->expiry);
ft->param.num_flows++;
if (verbose_flag)
logit(LOG_DEBUG, "ADD FLOW %s",
format_flow_brief(flow));
} else {
/* Update flow statistics */
flow->packets[0] += tmp.packets[0];
flow->octets[0] += tmp.octets[0];
flow->tcp_flags[0] |= tmp.tcp_flags[0];
flow->packets[1] += tmp.packets[1];
flow->octets[1] += tmp.octets[1];
flow->tcp_flags[1] |= tmp.tcp_flags[1];
}
memcpy(&flow->flow_last, received_time, sizeof(flow->flow_last));
if (flow->expiry->expires_at != 0)
flow_update_expiry(ft, flow);
return (PP_OK);
}
/*
* Subtract two timevals. Returns (t1 - t2) in milliseconds.
*/
u_int32_t
timeval_sub_ms(const struct timeval *t1, const struct timeval *t2)
{
struct timeval res;
res.tv_sec = t1->tv_sec - t2->tv_sec;
res.tv_usec = t1->tv_usec - t2->tv_usec;
if (res.tv_usec < 0) {
res.tv_usec += 1000000L;
res.tv_sec--;
}
return ((u_int32_t)res.tv_sec * 1000 + (u_int32_t)res.tv_usec / 1000);
}
static void
update_statistic(struct STATISTIC *s, double new, double n)
{
if (n == 1.0) {
s->min = s->mean = s->max = new;
return;
}
s->min = MIN(s->min, new);
s->max = MAX(s->max, new);
s->mean = s->mean + ((new - s->mean) / n);
}
/* Update global statistics */
static void
update_statistics(struct FLOWTRACK *ft, struct FLOW *flow)
{
double tmp;
static double n = 1.0;
ft->param.flows_expired++;
ft->param.flows_pp[flow->protocol % 256]++;
tmp = (double)flow->flow_last.tv_sec +
((double)flow->flow_last.tv_usec / 1000000.0);
tmp -= (double)flow->flow_start.tv_sec +
((double)flow->flow_start.tv_usec / 1000000.0);
if (tmp < 0.0)
tmp = 0.0;
update_statistic(&ft->param.duration, tmp, n);
update_statistic(&ft->param.duration_pp[flow->protocol], tmp,
(double)ft->param.flows_pp[flow->protocol % 256]);
tmp = flow->octets[0] + flow->octets[1];
update_statistic(&ft->param.octets, tmp, n);
ft->param.octets_pp[flow->protocol % 256] += tmp;
tmp = flow->packets[0] + flow->packets[1];
update_statistic(&ft->param.packets, tmp, n);
ft->param.packets_pp[flow->protocol % 256] += tmp;
n++;
}
static void
update_expiry_stats(struct FLOWTRACK *ft, struct EXPIRY *e)
{
switch (e->reason) {
case R_GENERAL:
ft->param.expired_general++;
break;
case R_TCP:
ft->param.expired_tcp++;
break;
case R_TCP_RST:
ft->param.expired_tcp_rst++;
break;
case R_TCP_FIN:
ft->param.expired_tcp_fin++;
break;
case R_UDP:
ft->param.expired_udp++;
break;
case R_ICMP:
ft->param.expired_icmp++;
break;
case R_MAXLIFE:
ft->param.expired_maxlife++;
break;
case R_OVERBYTES:
ft->param.expired_overbytes++;
break;
case R_OVERFLOWS:
ft->param.expired_maxflows++;
break;
case R_FLUSH:
ft->param.expired_flush++;
break;
}
}
/* How long before the next expiry event in millisecond */
static int
next_expire(struct FLOWTRACK *ft)
{
struct EXPIRY *expiry;
struct timeval now;
u_int32_t expires_at, ret, fudge;
gettimeofday(&now, NULL);
if ((expiry = EXPIRY_MIN(EXPIRIES, &ft->expiries)) == NULL)
return (-1); /* indefinite */
expires_at = expiry->expires_at;
/* Don't cluster urgent expiries */
if (expires_at == 0 && (expiry->reason == R_OVERBYTES ||
expiry->reason == R_OVERFLOWS || expiry->reason == R_FLUSH))
return (0); /* Now */
/* Cluster expiries by expiry_interval */
if (ft->param.expiry_interval > 1) {
if ((fudge = expires_at % ft->param.expiry_interval) > 0)
expires_at += ft->param.expiry_interval - fudge;
}
if (expires_at < now.tv_sec)
return (0); /* Now */
ret = 999 + (expires_at - now.tv_sec) * 1000;
return (ret);
}
/*
* Scan the tree of expiry events and process expired flows. If zap_all
* is set, then forcibly expire all flows.
*/
#define CE_EXPIRE_NORMAL 0 /* Normal expiry processing */
#define CE_EXPIRE_ALL -1 /* Expire all flows immediately */
#define CE_EXPIRE_FORCED 1 /* Only expire force-expired flows */
static int
check_expired(struct FLOWTRACK *ft, struct NETFLOW_TARGET *target, int ex)
{
struct FLOW **expired_flows, **oldexp;
int num_expired, i, r;
struct timeval now;
struct EXPIRY *expiry, *nexpiry;
gettimeofday(&now, NULL);
r = 0;
num_expired = 0;
expired_flows = NULL;
if (verbose_flag)
logit(LOG_DEBUG, "Starting expiry scan: mode %d", ex);
for(expiry = EXPIRY_MIN(EXPIRIES, &ft->expiries);
expiry != NULL;
expiry = nexpiry) {
nexpiry = EXPIRY_NEXT(EXPIRIES, &ft->expiries, expiry);
if ((expiry->expires_at == 0) || (ex == CE_EXPIRE_ALL) ||
(ex != CE_EXPIRE_FORCED &&
(expiry->expires_at < now.tv_sec))) {
/* Flow has expired */
if (ft->param.maximum_lifetime != 0 &&
expiry->flow->flow_last.tv_sec -
expiry->flow->flow_start.tv_sec >=
ft->param.maximum_lifetime)
expiry->reason = R_MAXLIFE;
if (verbose_flag)
logit(LOG_DEBUG,
"Queuing flow seq:%"PRIu64" (%p) for expiry "
"reason %d", expiry->flow->flow_seq,
expiry->flow, expiry->reason);
/* Add to array of expired flows */
oldexp = expired_flows;
expired_flows = realloc(expired_flows,
sizeof(*expired_flows) * (num_expired + 1));
/* Don't fatal on realloc failures */
if (expired_flows == NULL)
expired_flows = oldexp;
else {
expired_flows[num_expired] = expiry->flow;
num_expired++;
}
if (ex == CE_EXPIRE_ALL)
expiry->reason = R_FLUSH;
update_expiry_stats(ft, expiry);
/* Remove from flow tree, destroy expiry event */
FLOW_REMOVE(FLOWS, &ft->flows, expiry->flow);
EXPIRY_REMOVE(EXPIRIES, &ft->expiries, expiry);
expiry->flow->expiry = NULL;
expiry_put(ft, expiry);
ft->param.num_flows--;
}
}
if (verbose_flag)
logit(LOG_DEBUG, "Finished scan %d flow(s) to be evicted",
num_expired);
/* Processing for expired flows */
if (num_expired > 0) {
if (target != NULL && target->fd != -1) {
netflow_send_func_t *func =
ft->param.bidirection == 1 ?
target->dialect->bidir_func :
target->dialect->func;
if (func == NULL) {
func = target->dialect->func;
}
r = func(expired_flows, num_expired,
target->fd, if_index, &ft->param, verbose_flag);
if (verbose_flag)
logit(LOG_DEBUG, "sent %d netflow packets", r);
if (r > 0) {
ft->param.packets_sent += r;
/* XXX what if r < num_expired * 2 ? */
} else {
ft->param.flows_dropped += num_expired * 2;
}
}
for (i = 0; i < num_expired; i++) {
if (verbose_flag) {
logit(LOG_DEBUG, "EXPIRED: %s (%p)",
format_flow(expired_flows[i]),
expired_flows[i]);
}
update_statistics(ft, expired_flows[i]);
flow_put(ft, expired_flows[i]);
}
free(expired_flows);
}
return (r == -1 ? -1 : num_expired);
}
/*
* Force expiry of num_to_expire flows (e.g. when flow table overfull)
*/
static void
force_expire(struct FLOWTRACK *ft, u_int32_t num_to_expire)
{
struct EXPIRY *expiry, **expiryv;
int i;
/* XXX move all overflow processing here (maybe) */
if (verbose_flag)
logit(LOG_INFO, "Forcing expiry of %d flows",
num_to_expire);
/*
* Do this in two steps, as it is dangerous to change a key on
* a tree entry without first removing it and then re-adding it.
* It is even worse when this has to be done during a FOREACH :)
* To get around this, we make a list of expired flows and _then_
* alter them
*/
if ((expiryv = calloc(num_to_expire, sizeof(*expiryv))) == NULL) {
/*
* On malloc failure, expire ALL flows. I assume that
* setting all the keys in a tree to the same value is
* safe.
*/
logit(LOG_ERR, "Out of memory while expiring flows - "
"all flows expired");
EXPIRY_FOREACH(expiry, EXPIRIES, &ft->expiries) {
expiry->expires_at = 0;
expiry->reason = R_OVERFLOWS;
ft->param.flows_force_expired++;
}
return;
}
/* Make the list of flows to expire */
i = 0;
EXPIRY_FOREACH(expiry, EXPIRIES, &ft->expiries) {
if (i >= num_to_expire)
break;
expiryv[i++] = expiry;
}
if (i < num_to_expire) {
logit(LOG_ERR, "Needed to expire %d flows, "
"but only %d active", num_to_expire, i);
num_to_expire = i;
}
for(i = 0; i < num_to_expire; i++) {
EXPIRY_REMOVE(EXPIRIES, &ft->expiries, expiryv[i]);
expiryv[i]->expires_at = 0;
expiryv[i]->reason = R_OVERFLOWS;
EXPIRY_INSERT(EXPIRIES, &ft->expiries, expiryv[i]);
}
ft->param.flows_force_expired += num_to_expire;
free(expiryv);
/* XXX - this is overcomplicated, perhaps use a separate queue */
}
/* Delete all flows that we know about without processing */
static int
delete_all_flows(struct FLOWTRACK *ft)
{
struct FLOW *flow, *nflow;
int i;
i = 0;
for(flow = FLOW_MIN(FLOWS, &ft->flows); flow != NULL; flow = nflow) {
nflow = FLOW_NEXT(FLOWS, &ft->flows, flow);
FLOW_REMOVE(FLOWS, &ft->flows, flow);
EXPIRY_REMOVE(EXPIRIES, &ft->expiries, flow->expiry);
expiry_put(ft, flow->expiry);
ft->param.num_flows--;
flow_put(ft, flow);
i++;
}
return (i);
}
/*
* Log our current status.
* Includes summary counters and (in verbose mode) the list of current flows
* and the tree of expiry events.
*/
static int
statistics(struct FLOWTRACK *ft, FILE *out, pcap_t *pcap)
{
int i;
struct protoent *pe;
char proto[32];
struct pcap_stat ps;
fprintf(out, "Number of active flows: %d\n", ft->param.num_flows);
fprintf(out, "Packets processed: %"PRIu64"\n", ft->param.total_packets);
if (ft->param.non_sampled_packets)
fprintf(out, "Packets non-sampled: %"PRIu64"\n",
ft->param.non_sampled_packets);
fprintf(out, "Fragments: %"PRIu64"\n", ft->param.frag_packets);
fprintf(out, "Ignored packets: %"PRIu64" (%"PRIu64" non-IP, %"PRIu64" too short)\n",
ft->param.non_ip_packets + ft->param.bad_packets, ft->param.non_ip_packets, ft->param.bad_packets);
fprintf(out, "Flows expired: %"PRIu64" (%"PRIu64" forced)\n",
ft->param.flows_expired, ft->param.flows_force_expired);
fprintf(out, "Flows exported: %"PRIu64" (%"PRIu64" records) in %"PRIu64" packets (%"PRIu64" failures)\n",