icp_v2.c

-

/*
 * $Id: icp_v2.c,v 1.58 1999/01/29 21:28:13 wessels Exp $
 *
 * DEBUG: section 12    Internet Cache Protocol
 * AUTHOR: Duane Wessels
 *
 * SQUID Internet Object Cache  http://squid.nlanr.net/Squid/
 * ----------------------------------------------------------
 *
 *  Squid is the result of efforts by numerous individuals from the
 *  Internet community.  Development is led by Duane Wessels of the
 *  National Laboratory for Applied Network Research and funded by the
 *  National Science Foundation.  Squid is Copyrighted (C) 1998 by
 *  Duane Wessels and the University of California San Diego.  Please
 *  see the COPYRIGHT file for full details.  Squid incorporates
 *  software developed and/or copyrighted by other sources.  Please see
 *  the CREDITS file for full details.
 *
 *  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., 59 Temple Place, Suite 330, Boston, MA 02111, USA.
 *
 */

#include "squid.h"

static void icpLogIcp(struct in_addr, log_type, int, const char *, int);
static void icpHandleIcpV2(int, struct sockaddr_in, char *, int);
static void icpCount(void *, int, size_t, int);

/*
 * IcpQueueHead is global so comm_incoming() knows whether or not
 * to call icpUdpSendQueue.
 */
static icpUdpData *IcpQueueTail = NULL;

static void
icpLogIcp(struct in_addr caddr, log_type logcode, int len, const char *url, int delay)
{
    AccessLogEntry al;
    if (LOG_TAG_NONE == logcode)
	return;
    if (LOG_ICP_QUERY == logcode)
	return;
    clientdbUpdate(caddr, logcode, PROTO_ICP, len);
    if (!Config.onoff.log_udp)
	return;
    memset(&al, '\0', sizeof(al));
    al.icp.opcode = ICP_QUERY;
    al.url = url;
    al.cache.caddr = caddr;
    al.cache.size = len;
    al.cache.code = logcode;
    al.cache.msec = delay;
    accessLogLog(&al);
}

void
icpUdpSendQueue(int fd, void *unused)
{
    icpUdpData *q;
    int x;
    int delay;
    while ((q = IcpQueueHead) != NULL) {
	delay = tvSubUsec(q->queue_time, current_time);
	/* increment delay to prevent looping */
	x = icpUdpSend(fd, &q->address, q->msg, q->logcode, ++delay);
	IcpQueueHead = q->next;
	safe_free(q);
	if (x < 0)
	    break;
    }
}

void *
icpCreateMessage(
    icp_opcode opcode,
    int flags,
    const char *url,
    int reqnum,
    int pad)
{
    char *buf = NULL;
    icp_common_t *headerp = NULL;
    char *urloffset = NULL;
    int buf_len;
    buf_len = sizeof(icp_common_t) + strlen(url) + 1;
    if (opcode == ICP_QUERY)
	buf_len += sizeof(u_num32);
    buf = xcalloc(buf_len, 1);
    headerp = (icp_common_t *) (void *) buf;
    headerp->opcode = (char) opcode;
    headerp->version = ICP_VERSION_CURRENT;
    headerp->length = (u_short) htons(buf_len);
    headerp->reqnum = htonl(reqnum);
    headerp->flags = htonl(flags);
    headerp->pad = htonl(pad);
    headerp->shostid = theOutICPAddr.s_addr;
    urloffset = buf + sizeof(icp_common_t);
    if (opcode == ICP_QUERY)
	urloffset += sizeof(u_num32);
    xmemcpy(urloffset, url, strlen(url));
    return buf;
}

int
icpUdpSend(int fd,
    const struct sockaddr_in *to,
    icp_common_t * msg,
    log_type logcode,
    int delay)
{
    icpUdpData *queue;
    int x;
    int len;
    len = (int) ntohs(msg->length);
    debug(12, 5) ("icpUdpSend: FD %d sending %s, %d bytes to %s:%d\n",
	fd,
	icp_opcode_str[msg->opcode],
	len,
	inet_ntoa(to->sin_addr),
	ntohs(to->sin_port));
    x = comm_udp_sendto(fd, to, sizeof(*to), msg, len);
    if (x >= 0) {
	/* successfully written */
	icpLogIcp(to->sin_addr, logcode, len, (char *) (msg + 1), delay);
	icpCount(msg, SENT, (size_t) len, delay);
	safe_free(msg);
    } else if (0 == delay) {
	/* send failed, but queue it */
	queue = xcalloc(1, sizeof(icpUdpData));
	queue->address = *to;
	queue->msg = msg;
	queue->len = (int) ntohs(msg->length);
	queue->queue_time = current_time;
	queue->logcode = logcode;
	if (IcpQueueHead == NULL) {
	    IcpQueueHead = queue;
	    IcpQueueTail = queue;
	} else if (IcpQueueTail == IcpQueueHead) {
	    IcpQueueTail = queue;
	    IcpQueueHead->next = queue;
	} else {
	    IcpQueueTail->next = queue;
	    IcpQueueTail = queue;
	}
	commSetSelect(fd, COMM_SELECT_WRITE, icpUdpSendQueue, NULL, 0);
	Counter.icp.replies_queued++;
    } else {
	/* don't queue it */
	Counter.icp.replies_dropped++;
    }
    return x;
}

int
icpCheckUdpHit(StoreEntry * e, request_t * request)
{
    if (e == NULL)
	return 0;
    if (!storeEntryValidToSend(e))
	return 0;
    if (Config.onoff.icp_hit_stale)
	return 1;
    if (refreshCheckICP(e, request))
	return 0;
    return 1;
}

static void
icpHandleIcpV2(int fd, struct sockaddr_in from, char *buf, int len)
{
    icp_common_t header;
    StoreEntry *entry = NULL;
    char *url = NULL;
    const cache_key *key;
    request_t *icp_request = NULL;
    int allow = 0;
    aclCheck_t checklist;
    icp_common_t *reply;
    int src_rtt = 0;
    u_num32 flags = 0;
    int rtt = 0;
    int hops = 0;
    xmemcpy(&header, buf, sizeof(icp_common_t));
    /*
     * Only these fields need to be converted
     */
    header.length = ntohs(header.length);
    header.reqnum = ntohl(header.reqnum);
    header.flags = ntohl(header.flags);
    header.pad = ntohl(header.pad);

    switch (header.opcode) {
    case ICP_QUERY:
	/* We have a valid packet */
	url = buf + sizeof(icp_common_t) + sizeof(u_num32);
	if (strpbrk(url, w_space)) {
	    url = rfc1738_escape(url);
	    reply = icpCreateMessage(ICP_ERR, 0, url, header.reqnum, 0);
	    icpUdpSend(fd, &from, reply, LOG_UDP_INVALID, 0);
	    break;
	}
	if ((icp_request = urlParse(METHOD_GET, url)) == NULL) {
	    reply = icpCreateMessage(ICP_ERR, 0, url, header.reqnum, 0);
	    icpUdpSend(fd, &from, reply, LOG_UDP_INVALID, 0);
	    break;
	}
	checklist.src_addr = from.sin_addr;
	checklist.my_addr = no_addr;
	checklist.request = icp_request;
	allow = aclCheckFast(Config.accessList.icp, &checklist);
	if (!allow) {
	    debug(12, 2) ("icpHandleIcpV2: Access Denied for %s by %s.\n",
		inet_ntoa(from.sin_addr), AclMatchedName);
	    if (clientdbCutoffDenied(from.sin_addr)) {
		/*
		 * count this DENIED query in the clientdb, even though
		 * we're not sending an ICP reply...
		 */
		clientdbUpdate(from.sin_addr, LOG_UDP_DENIED, PROTO_ICP, 0);
	    } else {
		reply = icpCreateMessage(ICP_DENIED, 0, url, header.reqnum, 0);
		icpUdpSend(fd, &from, reply, LOG_UDP_DENIED, 0);
	    }
	    break;
	}
	if (header.flags & ICP_FLAG_SRC_RTT) {
	    rtt = netdbHostRtt(icp_request->host);
	    hops = netdbHostHops(icp_request->host);
	    src_rtt = ((hops & 0xFFFF) << 16) | (rtt & 0xFFFF);
	    if (rtt)
		flags |= ICP_FLAG_SRC_RTT;
	}
	/* The peer is allowed to use this cache */
	entry = storeGetPublic(url, METHOD_GET);
	debug(12, 5) ("icpHandleIcpV2: OPCODE %s\n", icp_opcode_str[header.opcode]);
	if (icpCheckUdpHit(entry, icp_request)) {
	    reply = icpCreateMessage(ICP_HIT, flags, url, header.reqnum, src_rtt);
	    icpUdpSend(fd, &from, reply, LOG_UDP_HIT, 0);
	    break;
	}
	if (Config.onoff.test_reachability && rtt == 0) {
	    if ((rtt = netdbHostRtt(icp_request->host)) == 0)
		netdbPingSite(icp_request->host);
	}
	/* if store is rebuilding, return a UDP_HIT, but not a MISS */
	if (store_rebuilding && opt_reload_hit_only) {
	    reply = icpCreateMessage(ICP_MISS_NOFETCH, flags, url, header.reqnum, src_rtt);
	    icpUdpSend(fd, &from, reply, LOG_UDP_MISS_NOFETCH, 0);
	} else if (hit_only_mode_until > squid_curtime) {
	    reply = icpCreateMessage(ICP_MISS_NOFETCH, flags, url, header.reqnum, src_rtt);
	    icpUdpSend(fd, &from, reply, LOG_UDP_MISS_NOFETCH, 0);
	} else if (Config.onoff.test_reachability && rtt == 0) {
	    reply = icpCreateMessage(ICP_MISS_NOFETCH, flags, url, header.reqnum, src_rtt);
	    icpUdpSend(fd, &from, reply, LOG_UDP_MISS_NOFETCH, 0);
	} else {
	    reply = icpCreateMessage(ICP_MISS, flags, url, header.reqnum, src_rtt);
	    icpUdpSend(fd, &from, reply, LOG_UDP_MISS, 0);
	}
	break;

    case ICP_HIT:
#if ALLOW_SOURCE_PING
    case ICP_SECHO:
#endif
    case ICP_DECHO:
    case ICP_MISS:
    case ICP_DENIED: