/*
 * Copyright (c) 2008 Damien Miller <djm@mindrot.org>
 * Copyright (c) 2011 Christiano F. Haesbaert <haesbaert@haesbaert.org>
 *
 * Permission to use, copy, modify, and distribute this software for any
 * purpose with or without fee is hereby granted, provided that the above
 * copyright notice and this permission notice appear in all copies.
 *
 * THE SOFTWARE IS PROVIDED "AS IS" AND THE AUTHOR DISCLAIMS ALL WARRANTIES
 * WITH REGARD TO THIS SOFTWARE INCLUDING ALL IMPLIED WARRANTIES OF
 * MERCHANTABILITY AND FITNESS. IN NO EVENT SHALL THE AUTHOR BE LIABLE FOR
 * ANY SPECIAL, DIRECT, INDIRECT, OR CONSEQUENTIAL DAMAGES OR ANY DAMAGES
 * WHATSOEVER RESULTING FROM LOSS OF USE, DATA OR PROFITS, WHETHER IN AN
 * ACTION OF CONTRACT, NEGLIGENCE OR OTHER TORTIOUS ACTION, ARISING OUT OF
 * OR IN CONNECTION WITH THE USE OR PERFORMANCE OF THIS SOFTWARE.
 */

#include <sys/types.h>
#include <sys/time.h>
#include <sys/socket.h>
#include <sys/socketvar.h>
#include <sys/resource.h>
#include <sys/queue.h>

#include <net/route.h>

#include <netinet/in.h>
#include <netinet/in_systm.h>
#include <netinet/ip.h>
#include <netinet/tcp.h>
#include <netinet/tcp_timer.h>
#include <netinet/tcp_fsm.h>
#include <netinet/in_pcb.h>
#include <netinet/tcp_var.h>

#include <arpa/inet.h>

#include <unistd.h>
#include <limits.h>
#include <stdlib.h>
#include <stdio.h>
#include <string.h>
#include <errno.h>
#include <event.h>
#include <netdb.h>
#include <signal.h>
#include <err.h>
#include <fcntl.h>
#include <poll.h>

#include <kvm.h>
#include <nlist.h>

#define DEFAULT_PORT "12345"
#define DEFAULT_STATS_INTERVAL 1000 /* ms */
#define DEFAULT_BUF (256 * 1024)
#define DEFAULT_UDP_PKT (1500 - 28) /* TODO don't hardcode this */
#define TCP_MODE !ptb->uflag
#define UDP_MODE ptb->uflag
#define MAX_FD 1024

/* Our tcpbench globals */
struct {
	u_int	  Vflag;	/* rtableid */
	int	  Sflag;	/* Socket buffer size (tcp mode) */
	u_int	  rflag;	/* Report rate (ms) */
	int	  sflag;	/* True if server */
	int	  vflag;	/* Verbose */
	int	  uflag;	/* UDP mode */
	kvm_t	 *kvmh;		/* Kvm handler */
	char	**kvars;	/* Kvm enabled vars */
	u_long	  ktcbtab;	/* Ktcb */
	char	 *dummybuf;	/* IO buffer */
	size_t	  dummybuf_len;	/* IO buffer len */
} tcpbench, *ptb;

/* stats for a single tcp connection, udp uses only one  */
struct statctx {
	TAILQ_ENTRY(statctx) entry;
	struct timeval t_start, t_last;
	unsigned long long bytes;
	int fd;
	char *buf;
	size_t buflen;
	struct event ev;
	/* TCP only */
	u_long tcp_tcbaddr;
	/* UDP only */
	u_long udp_slice_pkts;
};

static void	signal_handler(int, short, void *);
static void	saddr_ntop(const struct sockaddr *, socklen_t, char *, size_t);
static void	drop_gid(void);
static void	set_slice_timer(int);
static void 	print_tcp_header(void);
static void	kget(u_long, void *, size_t);
static u_long	kfind_tcb(int);
static void	kupdate_stats(u_long, struct inpcb *, struct tcpcb *,
    struct socket *);
static void	list_kvars(void);
static void	check_kvar(const char *);
static char **	check_prepare_kvars(char *);
static void	stats_prepare(struct statctx *);
static void	tcp_stats_display(unsigned long long, long double, float,
    struct statctx *, struct inpcb *, struct tcpcb *, struct socket *);
static void	tcp_process_slice(int, short, void *);
static void	tcp_server_handle_sc(int, short, void *);
static void	tcp_server_accept(int, short, void *);
static void	server_init(struct addrinfo *, struct statctx *);
static void	client_handle_sc(int, short, void *);
static void	client_init(struct addrinfo *, int, struct statctx *);
static int	clock_gettime_tv(clockid_t, struct timeval *);
static void	udp_server_handle_sc(int, short, void *);
static void	udp_process_slice(int, short, void *);

/*
 * We account the mainstats here, that is the stats
 * for all connections, all variables starting with slice
 * are used to account information for the timeslice
 * between each output. Peak variables record the highest
 * between all slices so far.
 */
static struct {
	unsigned long long slice_bytes; /* bytes for last slice */
	long double peak_mbps;		/* peak mbps so far */
	int nconns; 		        /* connected clients */
	struct event timer;		/* process timer */
} mainstats;

/* When adding variables, also add to tcp_stats_display() */
static const char *allowed_kvars[] = {
	"inpcb.inp_flags",
	"sockb.so_rcv.sb_cc",
	"sockb.so_rcv.sb_wat",
	"sockb.so_rcv.sb_hiwat",
	"sockb.so_snd.sb_cc",
	"sockb.so_snd.sb_wat",
	"sockb.so_snd.sb_hiwat",
	"tcpcb.snd_una",
	"tcpcb.snd_nxt",
	"tcpcb.snd_wl1",
	"tcpcb.snd_wl2",
	"tcpcb.snd_wnd",
	"tcpcb.rcv_wnd",
	"tcpcb.rcv_nxt",
	"tcpcb.rcv_adv",
	"tcpcb.snd_max",
	"tcpcb.snd_cwnd",
	"tcpcb.snd_ssthresh",
	"tcpcb.t_rcvtime",
	"tcpcb.t_rtttime",
	"tcpcb.t_rtseq",
	"tcpcb.t_srtt",
	"tcpcb.t_rttvar",
	"tcpcb.t_rttmin",
	"tcpcb.max_sndwnd",
	"tcpcb.snd_scale",
	"tcpcb.rcv_scale",
	"tcpcb.last_ack_sent",
	"tcpcb.rfbuf_cnt",
	"tcpcb.rfbuf_ts",
	"tcpcb.ts_recent_age",
	"tcpcb.ts_recent",
	NULL
};

TAILQ_HEAD(, statctx) sc_queue;

static void __dead
usage(void)
{
	fprintf(stderr,
	    "usage: tcpbench -l\n"
	    "       tcpbench [-uv] [-B buf] [-k kvars] [-n connections] [-p port]\n"
	    "                [-r interval] [-S space] [-V rtable] hostname\n"
	    "       tcpbench -s [-uv] [-B buf] [-k kvars] [-p port]\n"
	    "                [-r interval] [-S space] [-V rtable]\n");
	exit(1);
}

static void
signal_handler(int sig, short event, void *bula)
{
	/*
	 * signal handler rules don't apply, libevent decouples for us
	 */
	switch (sig) {
	case SIGINT:
	case SIGTERM:
	case SIGHUP:
		warnx("Terminated by signal %d", sig);
		exit(0);
		break;		/* NOTREACHED */
	default:
		errx(1, "unexpected signal %d", sig);
		break;		/* NOTREACHED */
	}
}

static void
saddr_ntop(const struct sockaddr *addr, socklen_t alen, char *buf, size_t len)
{
	char hbuf[NI_MAXHOST], pbuf[NI_MAXSERV];
	int herr;

	if ((herr = getnameinfo(addr, alen, hbuf, sizeof(hbuf),
	    pbuf, sizeof(pbuf), NI_NUMERICHOST|NI_NUMERICSERV)) != 0) {
		if (herr == EAI_SYSTEM)
			err(1, "getnameinfo");
		else
			errx(1, "getnameinfo: %s", gai_strerror(herr));
	}
	snprintf(buf, len, "[%s]:%s", hbuf, pbuf);
}

static void
drop_gid(void)
{
	gid_t gid;

	gid = getgid();
	if (setresgid(gid, gid, gid) == -1)
		err(1, "setresgid");
}

static void
set_slice_timer(int on)
{
	struct timeval tv;

	if (ptb->rflag == 0)
		return;

	if (on) {
		if (evtimer_pending(&mainstats.timer, NULL))
			return;
		timerclear(&tv);
		/* XXX Is there a better way to do this ? */
		tv.tv_sec = ptb->rflag / 1000;
		tv.tv_usec = (ptb->rflag % 1000) * 1000;
		
		evtimer_add(&mainstats.timer, &tv);
	} else if (evtimer_pending(&mainstats.timer, NULL))
		evtimer_del(&mainstats.timer);
}
		
static int
clock_gettime_tv(clockid_t clock_id, struct timeval *tv)
{
	struct timespec ts;

	if (clock_gettime(clock_id, &ts) == -1)
		return (-1);
	
	TIMESPEC_TO_TIMEVAL(tv, &ts);
	
	return (0);
}

static void
print_tcp_header(void)
{
	char **kv;

	printf("%12s %14s %12s %8s ", "elapsed_ms", "bytes", "mbps",
	    "bwidth");
	for (kv = ptb->kvars;  ptb->kvars != NULL && *kv != NULL; kv++) 
		printf("%s%s", kv != ptb->kvars ? "," : "", *kv);
	printf("\n");
}

static void
kget(u_long addr, void *buf, size_t size)
{
	if (kvm_read(ptb->kvmh, addr, buf, size) != (ssize_t)size)
		errx(1, "kvm_read: %s", kvm_geterr(ptb->kvmh));
}

static u_long
kfind_tcb(int sock)
{
	struct inpcbtable tcbtab;
	struct inpcb *head, *next, *prev;
	struct inpcb inpcb;
	struct tcpcb tcpcb;

	struct sockaddr_storage me, them;
	socklen_t melen, themlen;
	struct sockaddr_in *in4;
	struct sockaddr_in6 *in6;
	char tmp1[64], tmp2[64];
	int nretry;

	nretry = 10;
	melen = themlen = sizeof(struct sockaddr_storage);
	if (getsockname(sock, (struct sockaddr *)&me, &melen) == -1)
		err(1, "getsockname");
	if (getpeername(sock, (struct sockaddr *)&them, &themlen) == -1)
		err(1, "getpeername");
	if (me.ss_family != them.ss_family)
		errx(1, "%s: me.ss_family != them.ss_family", __func__);
	if (me.ss_family != AF_INET && me.ss_family != AF_INET6)
		errx(1, "%s: unknown socket family", __func__);
	if (ptb->vflag >= 2) {
		saddr_ntop((struct sockaddr *)&me, me.ss_len,
		    tmp1, sizeof(tmp1));
		saddr_ntop((struct sockaddr *)&them, them.ss_len,
		    tmp2, sizeof(tmp2));
		fprintf(stderr, "Our socket local %s remote %s\n", tmp1, tmp2);
	}
	if (ptb->vflag >= 2)
		fprintf(stderr, "Using PCB table at %lu\n", ptb->ktcbtab);
retry:
	kget(ptb->ktcbtab, &tcbtab, sizeof(tcbtab));
	prev = head = (struct inpcb *)&CIRCLEQ_FIRST(
	    &((struct inpcbtable *)ptb->ktcbtab)->inpt_queue);
	next = CIRCLEQ_FIRST(&tcbtab.inpt_queue);

	if (ptb->vflag >= 2)
		fprintf(stderr, "PCB head at %p\n", head);
	while (next != head) {
		if (ptb->vflag >= 2)
			fprintf(stderr, "Checking PCB %p\n", next);
		kget((u_long)next, &inpcb, sizeof(inpcb));
		if (CIRCLEQ_PREV(&inpcb, inp_queue) != prev) {
			if (nretry--) {
				warnx("pcb prev pointer insane");
				goto retry;
			}
			else
				errx(1, "pcb prev pointer insane,"
				     " all attempts exausted");
		}
		prev = next;
		next = CIRCLEQ_NEXT(&inpcb, inp_queue);

		if (me.ss_family == AF_INET) {
			if ((inpcb.inp_flags & INP_IPV6) != 0) {
				if (ptb->vflag >= 2)
					fprintf(stderr, "Skip: INP_IPV6");
				continue;
			}
			if (ptb->vflag >= 2) {
				inet_ntop(AF_INET, &inpcb.inp_laddr,
				    tmp1, sizeof(tmp1));
				inet_ntop(AF_INET, &inpcb.inp_faddr,
				    tmp2, sizeof(tmp2));
				fprintf(stderr, "PCB %p local: [%s]:%d "
				    "remote: [%s]:%d\n", prev,
				    tmp1, inpcb.inp_lport,
				    tmp2, inpcb.inp_fport);
			}
			in4 = (struct sockaddr_in *)&me;
			if (memcmp(&in4->sin_addr, &inpcb.inp_laddr,
			    sizeof(struct in_addr)) != 0 ||
			    in4->sin_port != inpcb.inp_lport)
				continue;
			in4 = (struct sockaddr_in *)&them;
			if (memcmp(&in4->sin_addr, &inpcb.inp_faddr,
			    sizeof(struct in_addr)) != 0 ||
			    in4->sin_port != inpcb.inp_fport)
				continue;
		} else {
			if ((inpcb.inp_flags & INP_IPV6) == 0)
				continue;
			if (ptb->vflag >= 2) {
				inet_ntop(AF_INET6, &inpcb.inp_laddr6,
				    tmp1, sizeof(tmp1));
				inet_ntop(AF_INET6, &inpcb.inp_faddr6,
				    tmp2, sizeof(tmp2));
				fprintf(stderr, "PCB %p local: [%s]:%d "
				    "remote: [%s]:%d\n", prev,
				    tmp1, inpcb.inp_lport,
				    tmp2, inpcb.inp_fport);
			}
			in6 = (struct sockaddr_in6 *)&me;
			if (memcmp(&in6->sin6_addr, &inpcb.inp_laddr6,
			    sizeof(struct in6_addr)) != 0 ||
			    in6->sin6_port != inpcb.inp_lport)
				continue;
			in6 = (struct sockaddr_in6 *)&them;
			if (memcmp(&in6->sin6_addr, &inpcb.inp_faddr6,
			    sizeof(struct in6_addr)) != 0 ||
			    in6->sin6_port != inpcb.inp_fport)
				continue;
		}
		kget((u_long)inpcb.inp_ppcb, &tcpcb, sizeof(tcpcb));
		if (tcpcb.t_state != TCPS_ESTABLISHED) {
			if (ptb->vflag >= 2)
				fprintf(stderr, "Not established\n");
			continue;
		}
		if (ptb->vflag >= 2)
			fprintf(stderr, "Found PCB at %p\n", prev);
		return ((u_long)prev);
	}

	errx(1, "No matching PCB found");
}

static void
kupdate_stats(u_long tcbaddr, struct inpcb *inpcb,
    struct tcpcb *tcpcb, struct socket *sockb)
{
	kget(tcbaddr, inpcb, sizeof(*inpcb));
	kget((u_long)inpcb->inp_ppcb, tcpcb, sizeof(*tcpcb));
	kget((u_long)inpcb->inp_socket, sockb, sizeof(*sockb));
}

static void
check_kvar(const char *var)
{
	u_int i;

	for (i = 0; allowed_kvars[i] != NULL; i++)
		if (strcmp(allowed_kvars[i], var) == 0)
			return;
	errx(1, "Unrecognised kvar: %s", var);
}

static void
list_kvars(void)
{
	u_int i;

	fprintf(stderr, "Supported kernel variables:\n");
	for (i = 0; allowed_kvars[i] != NULL; i++)
		fprintf(stderr, "\t%s\n", allowed_kvars[i]);
}

static char **
check_prepare_kvars(char *list)
{
	char *item, **ret = NULL;
	u_int n = 0;

	while ((item = strsep(&list, ", \t\n")) != NULL) {
		check_kvar(item);
		if ((ret = realloc(ret, sizeof(*ret) * (++n + 1))) == NULL)
			errx(1, "realloc(kvars)");
		if ((ret[n - 1] = strdup(item)) == NULL)
			errx(1, "strdup");
		ret[n] = NULL;
	}
	return (ret);
}

static void
stats_prepare(struct statctx *sc)
{
	sc->buf = ptb->dummybuf;
	sc->buflen = ptb->dummybuf_len;

	if (ptb->kvars)
		sc->tcp_tcbaddr = kfind_tcb(sc->fd);
	if (clock_gettime_tv(CLOCK_MONOTONIC, &sc->t_start) == -1)
		err(1, "clock_gettime_tv");
	sc->t_last = sc->t_start;

}

static void
tcp_stats_display(unsigned long long total_elapsed, long double mbps,
    float bwperc, struct statctx *sc, struct inpcb *inpcb,
    struct tcpcb *tcpcb, struct socket *sockb)
{
	int j;
	
	printf("%12llu %14llu %12.3Lf %7.2f%% ", total_elapsed, sc->bytes,
	    mbps, bwperc);
	
	if (ptb->kvars != NULL) {
		kupdate_stats(sc->tcp_tcbaddr, inpcb, tcpcb,
		    sockb);

		for (j = 0; ptb->kvars[j] != NULL; j++) {
#define S(a) #a
#define P(b, v, f)							\
			if (strcmp(ptb->kvars[j], S(b.v)) == 0) {	\
				printf("%s"f, j > 0 ? "," : "", b->v);	\
				continue;				\
			}
			P(inpcb, inp_flags, "0x%08x")
			P(sockb, so_rcv.sb_cc, "%lu")
			P(sockb, so_rcv.sb_wat, "%lu")
			P(sockb, so_rcv.sb_hiwat, "%lu")
			P(sockb, so_snd.sb_cc, "%lu")
			P(sockb, so_snd.sb_wat, "%lu")
			P(sockb, so_snd.sb_hiwat, "%lu")
			P(tcpcb, snd_una, "%u")
			P(tcpcb, snd_nxt, "%u")
			P(tcpcb, snd_wl1, "%u")
			P(tcpcb, snd_wl2, "%u")
			P(tcpcb, snd_wnd, "%lu")
			P(tcpcb, rcv_wnd, "%lu")
			P(tcpcb, rcv_nxt, "%u")
			P(tcpcb, rcv_adv, "%u")
			P(tcpcb, snd_max, "%u")
			P(tcpcb, snd_cwnd, "%lu")
			P(tcpcb, snd_ssthresh, "%lu")
			P(tcpcb, t_rcvtime, "%u")
			P(tcpcb, t_rtttime, "%u")
			P(tcpcb, t_rtseq, "%u")
			P(tcpcb, t_srtt, "%hu")
			P(tcpcb, t_rttvar, "%hu")
			P(tcpcb, t_rttmin, "%hu")
			P(tcpcb, max_sndwnd, "%lu")
			P(tcpcb, snd_scale, "%u")
			P(tcpcb, rcv_scale, "%u")
			P(tcpcb, last_ack_sent, "%u")
			P(tcpcb, rfbuf_cnt, "%u")
			P(tcpcb, rfbuf_ts, "%u")
			P(tcpcb, ts_recent_age, "%u")
			P(tcpcb, ts_recent, "%u")
#undef S			    
#undef P
		}
	}
	printf("\n");
}

static void
tcp_process_slice(int fd, short event, void *bula)
{
	unsigned long long total_elapsed, since_last;
	long double mbps, slice_mbps = 0;
	float bwperc;
	struct statctx *sc;
	struct timeval t_cur, t_diff;
	struct inpcb inpcb;
	struct tcpcb tcpcb;
	struct socket sockb;
	
	TAILQ_FOREACH(sc, &sc_queue, entry) {
		if (clock_gettime_tv(CLOCK_MONOTONIC, &t_cur) == -1)
			err(1, "clock_gettime_tv");
		if (ptb->kvars != NULL) /* process kernel stats */
			kupdate_stats(sc->tcp_tcbaddr, &inpcb, &tcpcb,
			    &sockb);
		
		timersub(&t_cur, &sc->t_start, &t_diff);
		total_elapsed = t_diff.tv_sec * 1000 + t_diff.tv_usec / 1000;
		timersub(&t_cur, &sc->t_last, &t_diff);
		since_last = t_diff.tv_sec * 1000 + t_diff.tv_usec / 1000;
		bwperc = (sc->bytes * 100.0) / mainstats.slice_bytes;
		mbps = (sc->bytes * 8) / (since_last * 1000.0);
		slice_mbps += mbps;
		
		tcp_stats_display(total_elapsed, mbps, bwperc, sc,
		    &inpcb, &tcpcb, &sockb);
		
		sc->t_last = t_cur;
		sc->bytes = 0;
	}

	/* process stats for this slice */
	if (slice_mbps > mainstats.peak_mbps)
		mainstats.peak_mbps = slice_mbps;
	printf("Conn: %3d Mbps: %12.3Lf Peak Mbps: %12.3Lf Avg Mbps: %12.3Lf\n",
	    mainstats.nconns, slice_mbps, mainstats.peak_mbps,
	    slice_mbps / mainstats.nconns); 
	mainstats.slice_bytes = 0;

	set_slice_timer(mainstats.nconns > 0);
}

static void
udp_process_slice(int fd, short event, void *v_sc)
{
	struct statctx *sc = v_sc;
	unsigned long long total_elapsed, since_last;
	long double slice_mbps, pps;
	struct timeval t_cur, t_diff;

	if (clock_gettime_tv(CLOCK_MONOTONIC, &t_cur) == -1)
		err(1, "clock_gettime_tv");
	/* Calculate pps */
	timersub(&t_cur, &sc->t_start, &t_diff);
	total_elapsed = t_diff.tv_sec * 1000 + t_diff.tv_usec / 1000;
	timersub(&t_cur, &sc->t_last, &t_diff);
	since_last = t_diff.tv_sec * 1000 + t_diff.tv_usec / 1000;
	slice_mbps = (sc->bytes * 8) / (since_last * 1000.0);
	pps = (sc->udp_slice_pkts * 1000) / since_last;
	if (slice_mbps > mainstats.peak_mbps)
		mainstats.peak_mbps = slice_mbps;
	printf("Elapsed: %11llu Mbps: %11.3Lf Peak Mbps: %11.3Lf %s PPS: %10.3Lf\n",
	    total_elapsed, slice_mbps, mainstats.peak_mbps,
	    ptb->sflag ? "Rx" : "Tx", pps);

	/* Clean up this slice time */
	sc->t_last = t_cur;
	sc->bytes = 0;
	sc->udp_slice_pkts = 0;
	set_slice_timer(1);
}

static void
udp_server_handle_sc(int fd, short event, void *v_sc)
{
	ssize_t n;
	struct statctx *sc = v_sc;

again:
	n = read(fd, ptb->dummybuf, ptb->dummybuf_len);
	if (n == 0)
		return;
	else if (n == -1) {
		if (errno == EINTR)
			goto again;
		else if (errno == EWOULDBLOCK) 
			return;
		warn("fd %d read error", fd);
		return;
	}
		
	if (ptb->vflag >= 3)
		fprintf(stderr, "read: %zd bytes\n", n);
	/* If this was our first packet, start slice timer */
	if (mainstats.peak_mbps == 0)
		set_slice_timer(1);
	/* Account packet */
	sc->udp_slice_pkts++;
	sc->bytes += n;
}

static void
tcp_server_handle_sc(int fd, short event, void *v_sc)
{
	struct statctx *sc = v_sc;
	ssize_t n;

again:
	n = read(sc->fd, sc->buf, sc->buflen);
	if (n == -1) {
		if (errno == EINTR)
			goto again;
		else if (errno == EWOULDBLOCK) 
			return;
		warn("fd %d read error", sc->fd);
		return;
	} else if (n == 0) {
		if (ptb->vflag)
			fprintf(stderr, "%8d closed by remote end\n", sc->fd);
		close(sc->fd);
		TAILQ_REMOVE(&sc_queue, sc, entry);
		free(sc);
		mainstats.nconns--;
		set_slice_timer(mainstats.nconns > 0);
		return;
	}
	if (ptb->vflag >= 3)
		fprintf(stderr, "read: %zd bytes\n", n);
	sc->bytes += n;
	mainstats.slice_bytes += n;
}
	
static void
tcp_server_accept(int fd, short event, void *bula)
{
	int sock, r;
	struct statctx *sc;
	struct sockaddr_storage ss;
	socklen_t sslen;
	char tmp[128];
	
	sslen = sizeof(ss);
again:	
	if ((sock = accept(fd, (struct sockaddr *)&ss, &sslen)) == -1) {
		if (errno == EINTR)
			goto again;
		warn("accept");
		return;
	}
	saddr_ntop((struct sockaddr *)&ss, sslen,
	    tmp, sizeof(tmp));
	if ((r = fcntl(sock, F_GETFL, 0)) == -1)
		err(1, "fcntl(F_GETFL)");
	r |= O_NONBLOCK;
	if (fcntl(sock, F_SETFL, r) == -1)
		err(1, "fcntl(F_SETFL, O_NONBLOCK)");
	/* Alloc client structure and register reading callback */
	if ((sc = calloc(1, sizeof(*sc))) == NULL)
		err(1, "calloc");
	sc->fd = sock;
	stats_prepare(sc);
	event_set(&sc->ev, sc->fd, EV_READ | EV_PERSIST,
	    tcp_server_handle_sc, sc);
	event_add(&sc->ev, NULL);
	TAILQ_INSERT_TAIL(&sc_queue, sc, entry);
	mainstats.nconns++;
	set_slice_timer(mainstats.nconns > 0);
	if (ptb->vflag)
		warnx("Accepted connection from %s, fd = %d\n", tmp, sc->fd);
}

static void
server_init(struct addrinfo *aitop, struct statctx *udp_sc)
{
	char tmp[128];
	int sock, on = 1;
	struct addrinfo *ai;
	struct event *ev;
	nfds_t lnfds;

	if (setpgid(0, 0) == -1)
		err(1, "setpgid");

	lnfds = 0;
	for (ai = aitop; ai != NULL; ai = ai->ai_next) {
		saddr_ntop(ai->ai_addr, ai->ai_addrlen, tmp, sizeof(tmp));
		if (ptb->vflag)
			fprintf(stderr, "Try to bind to %s\n", tmp);
		if ((sock = socket(ai->ai_family, ai->ai_socktype,
		    ai->ai_protocol)) == -1) {
			if (ai->ai_next == NULL)
				err(1, "socket");
			if (ptb->vflag)
				warn("socket");
			continue;
		}
		if (ptb->Vflag) {
			if (setsockopt(sock, SOL_SOCKET, SO_RTABLE,
			    &ptb->Vflag, sizeof(ptb->Vflag)) == -1) {
				if (errno == ENOPROTOOPT)
					warn("set rtable");
				else
					err(1, "setsockopt SO_RTABLE");
			}
		}
		if (setsockopt(sock, SOL_SOCKET, SO_REUSEADDR,
		    &on, sizeof(on)) == -1)
			warn("reuse port");
		if (bind(sock, ai->ai_addr, ai->ai_addrlen) != 0) {
			if (ai->ai_next == NULL)
				err(1, "bind");
			if (ptb->vflag)
				warn("bind");
			close(sock);
			continue;
		}
		if (ptb->Sflag) {
			if (setsockopt(sock, SOL_SOCKET, SO_RCVBUF,
			    &ptb->Sflag, sizeof(ptb->Sflag)) == -1)
				warn("set receive buffer size");
		}
		if (TCP_MODE) {
			if (listen(sock, 64) == -1) {
				if (ai->ai_next == NULL)
					err(1, "listen");
				if (ptb->vflag)
					warn("listen");
				close(sock);
				continue;
			}
		}
		if ((ev = calloc(1, sizeof(*ev))) == NULL)
			err(1, "calloc");
		if (UDP_MODE)
			event_set(ev, sock, EV_READ | EV_PERSIST,
			    udp_server_handle_sc, udp_sc);
		else
			event_set(ev, sock, EV_READ | EV_PERSIST,
			    tcp_server_accept, NULL);
		event_add(ev, NULL);
		if (ptb->vflag >= 3)
			fprintf(stderr, "bound to fd %d\n", sock);
		lnfds++;
	}
	freeaddrinfo(aitop);
	if (lnfds == 0)
		errx(1, "No working listen addresses found");
}	

static void
client_handle_sc(int fd, short event, void *v_sc)
{
	struct statctx *sc = v_sc;
	ssize_t n;

again:
	if ((n = write(sc->fd, sc->buf, sc->buflen)) == -1) {
		if (errno == EINTR || errno == EAGAIN ||
		    (UDP_MODE && errno == ENOBUFS))
			goto again;
		err(1, "write");
	}
	if (TCP_MODE && n == 0) {	
		warnx("Remote end closed connection");
		exit(1);
	}
	if (ptb->vflag >= 3)
		warnx("write: %zd bytes\n", n);
	sc->bytes += n;
	mainstats.slice_bytes += n;
	if (UDP_MODE)
		sc->udp_slice_pkts++;
}

static void
client_init(struct addrinfo *aitop, int nconn, struct statctx *udp_sc)
{
	struct statctx *sc;
	struct addrinfo *ai;
	char tmp[128];
	int i, r, sock;

	sc = udp_sc;
	for (i = 0; i < nconn; i++) {
		for (sock = -1, ai = aitop; ai != NULL; ai = ai->ai_next) {
			saddr_ntop(ai->ai_addr, ai->ai_addrlen, tmp,
			    sizeof(tmp));
			if (ptb->vflag && i == 0)
				fprintf(stderr, "Trying %s\n", tmp);
			if ((sock = socket(ai->ai_family, ai->ai_socktype,
			    ai->ai_protocol)) == -1) {
				if (ai->ai_next == NULL)
					err(1, "socket");
				if (ptb->vflag)
					warn("socket");
				continue;
			}
			if (ptb->Vflag) {
				if (setsockopt(sock, SOL_SOCKET, SO_RTABLE,
				    &ptb->Vflag, sizeof(ptb->Vflag)) == -1) {
					if (errno == ENOPROTOOPT)
						warn("set rtable");
					else
						err(1, "setsockopt SO_RTABLE");
				}
			}
			if (ptb->Sflag) {
				if (setsockopt(sock, SOL_SOCKET, SO_SNDBUF,
				    &ptb->Sflag, sizeof(ptb->Sflag)) == -1)
					warn("set TCP send buffer size");
			}
			if (connect(sock, ai->ai_addr, ai->ai_addrlen) != 0) {
				if (ai->ai_next == NULL)
					err(1, "connect");
				if (ptb->vflag)
					warn("connect");
				close(sock);
				sock = -1;
				continue;
			}
			break;
		}
		if (sock == -1)
			errx(1, "No host found");
		if ((r = fcntl(sock, F_GETFL, 0)) == -1)
			err(1, "fcntl(F_GETFL)");
		r |= O_NONBLOCK;
		if (fcntl(sock, F_SETFL, r) == -1)
			err(1, "fcntl(F_SETFL, O_NONBLOCK)");
		/* Alloc and prepare stats */
		if (TCP_MODE) {
			if ((sc = calloc(1, sizeof(*sc))) == NULL)
				err(1, "calloc");
		}
		sc->fd = sock;
		stats_prepare(sc);
		event_set(&sc->ev, sc->fd, EV_WRITE | EV_PERSIST,
		    client_handle_sc, sc);
		event_add(&sc->ev, NULL);
		TAILQ_INSERT_TAIL(&sc_queue, sc, entry);
		mainstats.nconns++;
		set_slice_timer(mainstats.nconns > 0);
		if (UDP_MODE)
			break;
	}
	freeaddrinfo(aitop);

	if (ptb->vflag && nconn > 1)
		fprintf(stderr, "%u connections established\n", nconn);
}

int
main(int argc, char **argv)
{
	extern int optind;
	extern char *optarg;

	char kerr[_POSIX2_LINE_MAX], *tmp;
	struct addrinfo *aitop, hints;
	const char *errstr;
	struct rlimit rl;
	int ch, herr, nconn;
	struct nlist nl[] = { { "_tcbtable" }, { "" } };
	const char *host = NULL, *port = DEFAULT_PORT;
	struct event ev_sigint, ev_sigterm, ev_sighup;
	struct statctx *udp_sc = NULL;

	/* Init world */
	ptb = &tcpbench;
	ptb->dummybuf_len = 0;
	ptb->Sflag = ptb->sflag = ptb->vflag = ptb->Vflag = 0;
	ptb->kvmh  = NULL;
	ptb->kvars = NULL;
	ptb->rflag = DEFAULT_STATS_INTERVAL;
	nconn = 1;

	while ((ch = getopt(argc, argv, "B:hlk:n:p:r:sS:uvV:")) != -1) {
		switch (ch) {
		case 'l':
			list_kvars();
			exit(0);
		case 'k':
			if ((tmp = strdup(optarg)) == NULL)
				errx(1, "strdup");
			ptb->kvars = check_prepare_kvars(tmp);
			free(tmp);
			break;
		case 'r':
			ptb->rflag = strtonum(optarg, 0, 60 * 60 * 24 * 1000,
			    &errstr);
			if (errstr != NULL)
				errx(1, "statistics interval is %s: %s",
				    errstr, optarg);
			break;
		case 'p':
			port = optarg;
			break;
		case 's':
			ptb->sflag = 1;
			break;
		case 'S':
			ptb->Sflag = strtonum(optarg, 0, 1024*1024*1024,
			    &errstr);
			if (errstr != NULL)
				errx(1, "receive space interval is %s: %s",
				    errstr, optarg);
			break;
		case 'B':
			ptb->dummybuf_len = strtonum(optarg, 0, 1024*1024*1024,
			    &errstr);
			if (errstr != NULL)
				errx(1, "read/write buffer size is %s: %s",
				    errstr, optarg);
			break;
		case 'v':
			ptb->vflag++;
			break;
		case 'V':
			ptb->Vflag = (unsigned int)strtonum(optarg, 0,
			    RT_TABLEID_MAX, &errstr);
			if (errstr)
				errx(1, "rtable value is %s: %s",
				    errstr, optarg);
			break;
		case 'n':
			nconn = strtonum(optarg, 0, 65535, &errstr);
			if (errstr != NULL)
				errx(1, "number of connections is %s: %s",
				    errstr, optarg);
			break;
		case 'u':
			ptb->uflag = 1;
			break;
		case 'h':
		default:
			usage();
		}
	}

	argv += optind;
	argc -= optind;
	if ((argc != (ptb->sflag ? 0 : 1)) ||
	    (UDP_MODE && (ptb->kvars || nconn != 1)))
		usage();

	if (!ptb->sflag)
		host = argv[0];
	/*
	 * Rationale,
	 * If TCP, use a big buffer with big reads/writes.
	 * If UDP, use a big buffer in server and a buffer the size of a
	 * ethernet packet.
	 */
	if (!ptb->dummybuf_len) {
		if (ptb->sflag || TCP_MODE) 
			ptb->dummybuf_len = DEFAULT_BUF;
		else
			ptb->dummybuf_len = DEFAULT_UDP_PKT;
	}

	bzero(&hints, sizeof(hints));
	if (UDP_MODE)
		hints.ai_socktype = SOCK_DGRAM;
	else
		hints.ai_socktype = SOCK_STREAM;
	if (ptb->sflag)
		hints.ai_flags = AI_PASSIVE;
	if ((herr = getaddrinfo(host, port, &hints, &aitop)) != 0) {
		if (herr == EAI_SYSTEM)
			err(1, "getaddrinfo");
		else
			errx(1, "getaddrinfo: %s", gai_strerror(herr));
	}
	if (ptb->kvars) {
		if ((ptb->kvmh = kvm_openfiles(NULL, NULL, NULL,
		    O_RDONLY, kerr)) == NULL)
			errx(1, "kvm_open: %s", kerr);
		drop_gid();
		if (kvm_nlist(ptb->kvmh, nl) < 0 || nl[0].n_type == 0)
			errx(1, "kvm: no namelist");
		ptb->ktcbtab = nl[0].n_value;
	} else
		drop_gid();

	if (getrlimit(RLIMIT_NOFILE, &rl) == -1)
		err(1, "getrlimit");
	if (rl.rlim_cur < MAX_FD)
		rl.rlim_cur = MAX_FD;
	if (setrlimit(RLIMIT_NOFILE, &rl))
		err(1, "setrlimit");
	if (getrlimit(RLIMIT_NOFILE, &rl) == -1)
		err(1, "getrlimit");
	
	/* Init world */
	TAILQ_INIT(&sc_queue);
	if ((ptb->dummybuf = malloc(ptb->dummybuf_len)) == NULL)
		err(1, "malloc");
	arc4random_buf(ptb->dummybuf, ptb->dummybuf_len);

	if (UDP_MODE) {
		if ((udp_sc = calloc(1, sizeof(*udp_sc))) == NULL)
			err(1, "calloc");
		udp_sc->fd = -1;
		stats_prepare(udp_sc);
	}

	/* Setup libevent and signals */
	event_init();
	signal_set(&ev_sigterm, SIGTERM, signal_handler, NULL);
	signal_set(&ev_sighup, SIGHUP, signal_handler, NULL);
	signal_set(&ev_sigint, SIGINT, signal_handler, NULL);
	signal_add(&ev_sigint, NULL);
	signal_add(&ev_sigterm, NULL);
	signal_add(&ev_sighup, NULL);
	signal(SIGPIPE, SIG_IGN);
	
	if (TCP_MODE)
		print_tcp_header();
	
	if (UDP_MODE)
		evtimer_set(&mainstats.timer, udp_process_slice, udp_sc);
	else
		evtimer_set(&mainstats.timer, tcp_process_slice, NULL);

	if (ptb->sflag) {
		server_init(aitop, udp_sc);
	} else
		client_init(aitop, nconn, udp_sc);
	
	/* libevent main loop*/
	event_dispatch();

	return (0);
}