detail.c

使用最广泛的radius的linux的源码

/*
 * detail.c	Process the detail file
 *
 * Version:	$Id: detail.c,v 1.14 2008/04/26 15:07:43 aland Exp $
 *
 *   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 2 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., 51 Franklin St, Fifth Floor, Boston, MA 02110-1301, USA
 *
 * Copyright 2007  The FreeRADIUS server project
 * Copyright 2007  Alan DeKok <[e-mail]>
 */

#include <freeradius-devel/ident.h>
RCSID("$Id: detail.c,v 1.14 2008/04/26 15:07:43 aland Exp $")

#include <freeradius-devel/radiusd.h>
#include <freeradius-devel/modules.h>
#include <freeradius-devel/detail.h>
#include <freeradius-devel/rad_assert.h>

#ifdef HAVE_SYS_STAT_H
#include <sys/stat.h>
#endif

#ifdef HAVE_GLOB_H
#include <glob.h>
#endif

#include <fcntl.h>

#define USEC (1000000)

typedef struct listen_detail_t {
	int		delay_time; /* should be first entry */
	char		*filename;
	char		*filename_work;
	VALUE_PAIR	*vps;
	FILE		*fp;
	int		state;
	time_t		timestamp;
	fr_ipaddr_t	client_ip;
	int		load_factor; /* 1..100 */
	int		signal;

	int		has_rtt;
	int		srtt;
	int		rttvar;
	struct timeval  last_packet;
	RADCLIENT	detail_client;
} listen_detail_t;


#define STATE_UNOPENED	(0)
#define STATE_UNLOCKED	(1)
#define STATE_HEADER	(2)
#define STATE_READING	(3)
#define STATE_QUEUED	(4)
#define STATE_RUNNING	(5)
#define STATE_NO_REPLY	(6)
#define STATE_REPLIED	(7)

/*
 *	If we're limiting outstanding packets, then mark the response
 *	as being sent.
 */
int detail_send(rad_listen_t *listener, REQUEST *request)
{
	int rtt;
	struct timeval now;
	listen_detail_t *data = listener->data;

	rad_assert(request->listener == listener);
	rad_assert(listener->send == detail_send);

	/*
	 *	This request timed out.  Remember that, and tell the
	 *	caller it's OK to read more "detail" file stuff.
	 */
	if (request->reply->code == 0) {
		data->delay_time = USEC;
		data->signal = 1;
		data->state = STATE_NO_REPLY;
		radius_signal_self(RADIUS_SIGNAL_SELF_DETAIL);
		return 0;
	}

	/*
	 *	We call gettimeofday a lot.  But here it should be OK,
	 *	because there's nothing else to do.
	 */
	gettimeofday(&now, NULL);

	/*
	 *	If we haven't sent a packet in the last second, reset
	 *	the RTT.
	 */
	now.tv_sec -= 1;
	if (timercmp(&data->last_packet, &now, <)) {
		data->has_rtt = FALSE;
	}
	now.tv_sec += 1;

	/*
	 *	Only one detail packet may be outstanding at a time,
	 *	so it's safe to update some entries in the detail
	 *	structure.
	 *
	 *	We keep smoothed round trip time (SRTT), but not round
	 *	trip timeout (RTO).  We use SRTT to calculate a rough
	 *	load factor.
	 */
	rtt = now.tv_sec - request->received.tv_sec;
	rtt *= USEC;
	rtt += now.tv_usec;
	rtt -= request->received.tv_usec;

	/*
	 *	If we're proxying, the RTT is our processing time,
	 *	plus the network delay there and back, plus the time
	 *	on the other end to process the packet.  Ideally, we
	 *	should remove the network delays from the RTT, but we
	 *	don't know what they are.
	 *
	 *	So, to be safe, we over-estimate the total cost of
	 *	processing the packet.
	 */
	if (!data->has_rtt) {
		data->has_rtt = TRUE;
		data->srtt = rtt;
		data->rttvar = rtt / 2;

	} else {
		data->rttvar -= data->rttvar >> 2;
		data->rttvar += (data->srtt - rtt);
		data->srtt -= data->srtt >> 3;
		data->srtt += rtt >> 3;
	}

	/*
	 *	Calculate the time we wait before sending the next
	 *	packet.
	 *
	 *	rtt / (rtt + delay) = load_factor / 100
	 */
	data->delay_time = (data->srtt * (100 - data->load_factor)) / (data->load_factor);
	if (data->delay_time == 0) data->delay_time = USEC / 10;

	/*
	 *	Cap delay at 4 packets/s.  If the end system can't
	 *	handle this, then it's very broken.
	 */
	if (data->delay_time > (USEC / 4)) data->delay_time= USEC / 4;

#if 0
	DEBUG2("RTT %d\tdelay %d", data->srtt, data->delay_time);
#endif

	data->last_packet = now;
	data->signal = 1;
	data->state = STATE_REPLIED;
	radius_signal_self(RADIUS_SIGNAL_SELF_DETAIL);

	return 0;
}

int detail_delay(rad_listen_t *listener)
{
	listen_detail_t *data = listener->data;

	if (!data->signal) return 0;

	data->signal = 0;

	return data->delay_time;
}


/*
 *	Open the detail file, if we can.
 *
 *	FIXME: create it, if it's not already there, so that the main
 *	server select() will wake us up if there's anything to read.
 */
static int detail_open(rad_listen_t *this)
{
	struct stat st;
	listen_detail_t *data = this->data;
	char *filename = data->filename;

	rad_assert(data->state == STATE_UNOPENED);
	data->delay_time = USEC;

	/*
	 *	Open detail.work first, so we don't lose
	 *	accounting packets.  It's probably better to
	 *	duplicate them than to lose them.
	 *
	 *	Note that we're not writing to the file, but
	 *	we've got to open it for writing in order to
	 *	establish the lock, to prevent rlm_detail from
	 *	writing to it.
	 */
	this->fd = open(data->filename_work, O_RDWR);
	if (this->fd < 0) {
		DEBUG2("Polling for detail file %s", filename);

		/*
		 *	Try reading the detail file.  If it
		 *	doesn't exist, we can't do anything.
		 *
		 *	Doing the stat will tell us if the file
		 *	exists, even if we don't have permissions
		 *	to read it.
		 */
		if (stat(filename, &st) < 0) {
#ifdef HAVE_GLOB_H
			int i, found;
			time_t ctime;
			glob_t files;

			memset(&files, 0, sizeof(files));
			if (glob(filename, 0, NULL, &files) != 0) {
				return 0;
			}

			ctime = 0;
			found = -1;
			for (i = 0; i < files.gl_pathc; i++) {
				if (stat(files.gl_pathv[i], &st) < 0) continue;

				if ((i == 0) ||
				    (st.st_ctime < ctime)) {
					ctime = st.st_ctime;
					found = i;
				}
			}

			if (found < 0) {
				globfree(&files);
				return 0;
			}

			filename = strdup(files.gl_pathv[found]);
			globfree(&files);


#else
			return 0;
#endif
		}

		/*
		 *	Open it BEFORE we rename it, just to
		 *	be safe...
		 */
		this->fd = open(filename, O_RDWR);
		if (this->fd < 0) {
			radlog(L_ERR, "Failed to open %s: %s",
			       filename, strerror(errno));
			if (filename != data->filename) free(filename);
			return 0;
		}

		/*
		 *	Rename detail to detail.work
		 */
		DEBUG("detail_recv: Renaming %s -> %s", filename, data->filename_work);
		if (rename(filename, data->filename_work) < 0) {
			if (filename != data->filename) free(filename);
			close(this->fd);
			this->fd = -1;
			return 0;
		}
		if (filename != data->filename) free(filename);
	} /* else detail.work existed, and we opened it */

	rad_assert(data->vps == NULL);
	rad_assert(data->fp == NULL);

	data->state = STATE_UNLOCKED;

	data->client_ip.af = AF_UNSPEC;
	data->timestamp = 0;

	return 1;
}


/*
 *	FIXME: add a configuration "exit when done" so that the detail
 *	file reader can be used as a one-off tool to update stuff.
 *
 *	The time sequence for reading from the detail file is:
 *
 *	t_0		signalled that the server is idle, and we
 *			can read from the detail file.
 *
 *	t_rtt		the packet has been processed successfully,
 *			wait for t_delay to enforce load factor.
 *			
 *	t_rtt + t_delay wait for signal that the server is idle.
 *	
 */
int detail_recv(rad_listen_t *listener,
		RAD_REQUEST_FUNP *pfun, REQUEST **prequest)
{
	char		key[256], value[1024];
	VALUE_PAIR	*vp, **tail;
	RADIUS_PACKET	*packet;
	char		buffer[2048];
	listen_detail_t *data = listener->data;

	switch (data->state) {
		case STATE_UNOPENED:
	open_file:
			rad_assert(listener->fd < 0);
			
			if (!detail_open(listener)) return 0;

			rad_assert(data->state == STATE_UNLOCKED);
			rad_assert(listener->fd >= 0);

			/* FALL-THROUGH */

			/*
			 *	Try to lock fd.  If we can't, return.
			 *	If we can, continue.  This means that
			 *	the server doesn't block while waiting
			 *	for the lock to open...
			 */
		case STATE_UNLOCKED:
			/*
			 *	Note that we do NOT block waiting for
			 *	the lock.  We've re-named the file
			 *	above, so we've already guaranteed
			 *	that any *new* detail writer will not
			 *	be opening this file.  The only
			 *	purpose of the lock is to catch a race
			 *	condition where the execution
			 *	"ping-pongs" between radiusd &
			 *	radrelay.
			 */
			if (rad_lockfd_nonblock(listener->fd, 0) < 0) {
				/*
				 *	Close the FD.  The main loop
				 *	will wake up in a second and
				 *	try again.
				 */
				close(listener->fd);
				listener->fd = -1;
				data->state = STATE_UNOPENED;
				return 0;
			}

			data->fp = fdopen(listener->fd, "r");
			if (!data->fp) {
				radlog(L_ERR, "FATAL: Failed to re-open detail file %s: %s",
				       data->filename, strerror(errno));
				exit(1);
			}

			/*
			 *	Look for the header
			 */
			data->state = STATE_HEADER;
			data->vps = NULL;

			/* FALL-THROUGH */

		case STATE_HEADER:
		do_header:
			if (!data->fp) {
				data->state = STATE_UNOPENED;
				goto open_file;
			}

			{
				struct stat buf;
				
				fstat(listener->fd, &buf);
				if (((off_t) ftell(data->fp)) == buf.st_size) {
					goto cleanup;
				}
			}

			/*
			 *	End of file.  Delete it, and re-set
			 *	everything.
			 */
			if (feof(data->fp)) {
			cleanup:
				unlink(data->filename_work);
				if (data->fp) fclose(data->fp);