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- /* $Id: muxnet.c,v 1.8 2002/08/11 20:00:41 dijkstra Exp $ */
- /*
- * Copyright (c) 2001-2002 Willem Dijkstra
- * All rights reserved.
- *
- * Redistribution and use in source and binary forms, with or without
- * modification, are permitted provided that the following conditions
- * are met:
- *
- * - Redistributions of source code must retain the above copyright
- * notice, this list of conditions and the following disclaimer.
- * - 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 COPYRIGHT HOLDERS AND CONTRIBUTORS
- * "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
- * COPYRIGHT HOLDERS OR CONTRIBUTORS 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.
- *
- */
- #include <sys/types.h>
- #include <sys/socket.h>
- #include <netinet/in.h>
- #include <errno.h>
- #include <fcntl.h>
- #include <string.h>
- #include <unistd.h>
- #include "data.h"
- #include "error.h"
- #include "monmux.h"
- #include "muxnet.h"
- #include "net.h"
- #include "xmalloc.h"
- #include "share.h"
- /* Obtain a udp socket for incoming mon traffic */
- int
- getmonsocket(struct mux *mux)
- {
- struct sockaddr_in sockaddr;
- int sock;
-
- if ((sock = socket(AF_INET, SOCK_DGRAM, 0)) == -1)
- fatal("could not obtain socket: %.200s", strerror(errno));
- sockaddr.sin_family = AF_INET;
- sockaddr.sin_port = htons(mux->port);
- sockaddr.sin_addr.s_addr = htonl(mux->ip);
- bzero(&sockaddr.sin_zero, sizeof(sockaddr.sin_zero));
- if (bind(sock, (struct sockaddr *) &sockaddr,
- sizeof(struct sockaddr)) == -1)
- fatal("could not bind socket: %.200s", strerror(errno));
- mux->monsocket = sock;
- info("listening for incoming mon traffic on udp:%s:%d",
- mux->name, mux->port);
- return sock;
- }
- /* Obtain a listen socket for new clients */
- int
- getclientsocket(struct mux *mux)
- {
- struct sockaddr_in sockaddr;
- int sock;
-
- if ((sock = socket(AF_INET, SOCK_STREAM, 0)) == -1)
- fatal("could not obtain socket: %.200s", strerror(errno));
- sockaddr.sin_family = AF_INET;
- sockaddr.sin_port = htons(mux->port);
- sockaddr.sin_addr.s_addr = htonl(mux->ip);
- bzero(&sockaddr.sin_zero, sizeof(sockaddr.sin_zero));
- if (bind(sock, (struct sockaddr *) &sockaddr,
- sizeof(struct sockaddr)) == -1)
- fatal("could not bind socket: %.200s", strerror(errno));
- if (listen(sock, MONMUX_TCPBACKLOG) == -1)
- fatal("could not listen to socket: %.200s", strerror(errno));
- fcntl(sock, O_NONBLOCK);
- mux->clientsocket = sock;
- info("listening for incoming connections on tcp:%s:%d",
- mux->name, mux->port);
- return sock;
- }
- /*
- * Wait for traffic (mon reports from a source in sourclist | clients trying to connect
- * Returns the <source> and <packet>
- * Silently forks off clienthandlers
- */
- void
- waitfortraffic(struct mux *mux, struct sourcelist *sourcelist,
- struct source **source, struct monpacket *packet)
- {
- fd_set readset;
- int socksactive;
- int maxsock;
- maxsock = ((mux->clientsocket > mux->monsocket) ?
- mux->clientsocket :
- mux->monsocket);
- maxsock++;
- for (;;) { /* FOREVER - until a valid mon packet is received */
- FD_ZERO(&readset);
- FD_SET(mux->clientsocket, &readset);
- FD_SET(mux->monsocket, &readset);
-
- socksactive = select(maxsock, &readset, NULL, NULL, NULL);
-
- if (socksactive != -1) {
- if (FD_ISSET(mux->clientsocket, &readset)) {
- spawn_client(mux->clientsocket);
- }
- if (FD_ISSET(mux->monsocket, &readset)) {
- if (recvmonpacket(mux, sourcelist, source, packet))
- return;
- }
- } else {
- if (errno == EINTR)
- return; /* signal received while waiting, bail out */
- }
- }
- }
- /* Receive a mon packet for mux. Checks if the source is allowed and returns the source found.
- * return 0 if no valid packet found
- */
- int
- recvmonpacket(struct mux *mux, struct sourcelist *sourcelist,
- struct source **source, struct monpacket *packet)
- {
- struct sockaddr_in sind;
- u_int32_t sourceaddr;
- int size;
- unsigned int received;
- socklen_t sl;
- int tries;
- u_int32_t crc;
- received = 0;
- tries = 0;
- do {
- sl = sizeof(sind);
- size = recvfrom(mux->monsocket, (void *)packet + received,
- sizeof(struct monpacket) - received,
- 0, (struct sockaddr *)&sind, &sl);
- if (size > 0)
- received += size;
- tries++;
- } while ((size == -1) &&
- (errno == EAGAIN || errno == EINTR) &&
- (tries < MONMUX_MAXREADTRIES) &&
- (received < sizeof(struct monpacket)));
- if ((size == -1) &&
- errno)
- warning("recvfrom failed: %s", strerror(errno));
- sourceaddr = ntohl((u_int32_t)sind.sin_addr.s_addr);
- *source = find_source_ip(sourcelist, sourceaddr);
-
- if (*source == NULL) {
- debug("ignored data from %u.%u.%u.%u",
- IPAS4BYTES(sourceaddr));
- return 0;
- } else {
- /* check crc */
- crc = ntohl(packet->header.crc);
- packet->header.crc = 0;
- crc ^= crc32(packet, received);
- if ( crc != 0 ) {
- warning("ignored packet with bad crc from %u.%u.%u.%u",
- IPAS4BYTES(sourceaddr));
- return 0;
- }
- /* check packet version */
- if (packet->header.mon_version != MON_PACKET_VER) {
- warning("ignored packet with illegal type %d",
- packet->header.mon_version);
- return 0;
- } else {
- /* rewrite structs to host order */
- packet->header.length = ntohs(packet->header.length);
- packet->header.crc = ntohs(packet->header.crc);
- packet->header.timestamp = ntohq(packet->header.timestamp);
-
- if (flag_debug)
- debug("good data received from %u.%u.%u.%u",
- IPAS4BYTES(sourceaddr));
- return 1; /* good packet received */
- }
- }
- }
- int
- acceptconnection(int sock)
- {
- struct sockaddr_in sind;
- socklen_t len;
- u_int32_t clientaddr;
- int clientsock;
- if ((clientsock = accept(sock, (struct sockaddr *)&sind, &len)) < 0)
- fatal("Failed to accept an incoming connection. (.200%s)",
- strerror(errno));
- clientaddr = ntohl((u_int32_t)sind.sin_addr.s_addr);
- info("Accepted incoming client connection from %u.%u.%u.%u",
- IPAS4BYTES(clientaddr));
- return clientsock;
- }
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