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/home/brennan/n-sim/Vaike/linux/system-addons/networking/mesh_on_demand.c Go to the documentation of this file. /* * Copyright 2007. Los Alamos National Security, LLC. This material * was produced under U.S. Government contract DE-AC52-06NA25396 for * Los Alamos National Laboratory (LANL), which is operated by Los * Alamos National Security, LLC, for the Department of Energy. The * U.S. Government has rights to use, reproduce, and distribute this * software. NEITHER THE GOVERNMENT NOR LOS ALAMOS NATIONAL SECURITY, * LLC, MAKES ANY WARRANTY, EXPRESS OR IMPLIED, OR ASSUMES ANY LEGAL * LIABILITY FOR THE USE OF THIS SOFTWARE. If software is modified to * produce derivative works, such modified software should be clearly * marked, so as not to confuse it with the version available from LANL. * * Additionally, 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; version 2 of * the License. Accordingly, this program is distributed in the hope * 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. */ #define _BSD_SOURCE #include <stdio.h> #include <stdlib.h> #include <string.h> #include <syslog.h> #include <sys/types.h> #include <sys/socket.h> #include <sys/stat.h> #include <sys/time.h> #include <sys/ioctl.h> #include <fcntl.h> #include <unistd.h> #include <net/if.h> #include <netinet/in.h> #include <netinet/ip.h> #include <netinet/udp.h> #include <net/ethernet.h> #include <net/if_arp.h> #include <arpa/inet.h> #include <linux/if_tun.h> #include <linux/netfilter.h> #include "libipq.h" #define MISC_MAJOR 10 #define TUN_MINOR 200 /******************************************/ #include "sensor_self.h" #include "mesh_link.h" #include "mesh_route.h" #include "mesh_on_demand.h" #define DIVERT_DEV_IP "127.0.0.2" #define DIVERT_DEV_NAME "tun" /* callback */ int route_discovery_done(u_int32_t daddr, protocol_t *proto, discovery_result_t reachable) { link_entry_t *entry; msg_queue_t *pkt; if (proto == NULL) { errno = EINVAL; return -1; } if ((entry = retrieve_entry(proto, daddr)) == NULL) { errno = ENOLINK; return -1; } pkt = entry->routing_backlog; entry->routing_pending = 0; if (reachable == ROUTE_FOUND) { while (pkt != NULL) { msg_queue_t *cur = pkt; struct sockaddr_in to; to.sin_family = AF_INET; to.sin_port = pkt->port; to.sin_addr = entry->link.node; mesh_sendmsg(proto->sensor->interface, proto->sensor->mac_addr, proto->queue_sd, pkt->data, pkt->len, &to); free(pkt->data); pkt = pkt->next; free(cur); } } else if (reachable == NO_ROUTE) { // TODO: search other protocols for a route?? while (pkt != NULL) { msg_queue_t *cur = pkt; pkt = pkt->next; free(pkt->data); free(cur); } } return 0; } /* 1 if discovery is pending, 0 otherwise, -1 on error */ static int route_discovery_pending(u_int32_t daddr, protocol_t *proto) { link_entry_t *entry; if (proto == NULL) return -1; if ((entry = retrieve_entry(proto, daddr)) == NULL) return entry->routing_pending; return 0; } static int divert_init(void) { struct ifreq ifr; int fd, error; char cmd[256]; unsigned char dev[IFNAMSIZ]; char *dev_name = "/dev/net/tun"; umask(0); mkdir("/dev/net", 0755); mknod(dev_name, S_IFCHR|S_IREAD|S_IWRITE, makedev(MISC_MAJOR, TUN_MINOR)); system("modprobe tun"); if ((fd = open(dev_name, O_RDWR)) < 0) { syslog(LOG_ERR, "open %s: %m", dev_name); return -1; } memset(&ifr, 0, sizeof(ifr)); ifr.ifr_flags = IFF_TUN | IFF_NO_PI; /* i.e. no ethernet hdr, no pkt info */ strcpy(ifr.ifr_name, DIVERT_DEV_NAME); if ((error = ioctl(fd, TUNSETIFF, (void *) &ifr)) < 0) { syslog(LOG_ERR, "ioctl (TUNSETIFF): %m"); close(fd); return error; } strcpy(dev, ifr.ifr_name); sprintf(cmd, "/sbin/ifconfig %s %s netmask 255.255.255.255 up", dev, DIVERT_DEV_IP); system(cmd); /* no checksum */ if ((error = ioctl(fd, TUNSETNOCSUM, 1)) < 0) { syslog(LOG_ERR, "ioctl (TUNSETNOCSUM): %m"); close(fd); return error; } return fd; } /*************************************/ static int read_route_request(self_t *self, int fd, u_int32_t *dest_addr, protocol_t *proto) { unsigned int buflen = MAX_MTU; unsigned char buf[buflen], *iphdr; ssize_t rlen; link_entry_t *entry; msg_queue_t *pkt; u_int32_t src_addr; struct ether_header eh; struct ip ip; struct udphdr udp; struct mesh_hdr mh; unsigned int header_size = ETHER_HDR_LEN + sizeof(ip) + sizeof(udp); if ((rlen = read(fd, buf, buflen)) <= 0) { if (rlen < 0) syslog(LOG_ERR, "read: %m"); return rlen; } if (header_size > rlen) { syslog(LOG_ERR, "read_route_request: invalid packet"); return -1; } iphdr = buf + ETHER_HDR_LEN; pkt = malloc(sizeof(msg_queue_t)); pkt->data = malloc(rlen * sizeof(unsigned char)); pkt->len = rlen; memcpy(pkt->data, buf + header_size, rlen); memcpy(&eh, buf, ETHER_HDR_LEN); memcpy(&ip, iphdr, sizeof(ip)); memcpy(&udp, iphdr + sizeof(ip), sizeof(udp)); memcpy(&mh, iphdr + sizeof(ip) + sizeof(udp), sizeof(mh)); *dest_addr = ip.ip_dst.s_addr; src_addr = ip.ip_src.s_addr; pkt->port = udp.uh_sport; proto = protocol_by_id(self, mh.protocol_id); if ((entry = retrieve_entry(proto, *dest_addr)) == NULL) { int error = 0; entry = new_link_entry(proto); entry->node_id = *dest_addr; entry->link.node.s_addr = *dest_addr; entry->requester = src_addr; if ((error = add_entry(proto, *dest_addr, entry)) < 0) return error; entry->routing_backlog = entry->last_packet = pkt; } else { if (entry->last_packet == NULL) { entry->routing_backlog = entry->last_packet = pkt; } else { entry->last_packet->next = pkt; entry->last_packet = pkt; } } if (retrieve_entry(proto, src_addr) == NULL) { int sd, error = 0; struct arpreq ar; link_entry_t *sentry = new_link_entry(proto); sentry->node_id = src_addr; sentry->link.node.s_addr = src_addr; sentry->requester = 0; ar.arp_ha.sa_family = AF_INET; strncpy(ar.arp_ha.sa_data, eh.ether_shost, sizeof(ar.arp_ha.sa_data)); strncpy(ar.arp_dev, proto->sensor->interface, sizeof(ar.arp_dev)); if ((sd = socket(PF_INET, SOCK_DGRAM, 0)) < 0) { syslog(LOG_ERR, "read_route_request: source backtrack socket %m"); return -1; } if ((error = ioctl(sd, SIOCGRARP, &ar)) < 0) { syslog(LOG_ERR, "read_route_request: ioctl SIOCGRARP %m"); return error; } sentry->link.next_hop = ((struct sockaddr_in*)(&ar.arp_pa))->sin_addr; if ((error = add_entry(proto, src_addr, sentry)) < 0) return error; } return 0; } int route_idle_time(u_int32_t dest, protocol_t *proto) { link_entry_t *entry = retrieve_entry(proto, dest); if (entry == NULL) { errno = ENOLINK; return -1; } return (int)(get_current_time() - entry->time_last_used); } static int init_on_demand(void) { int fd, error = 0; link_entry_t deflt; system("sysctl -w net/ipv4/ip_forward=1"); system("sysctl -w net/ipv4/conf/all/accept_redirects=0"); system("sysctl -w net/ipv4/conf/all/send_redirects=0"); system("sysctl -w net/ipv4/route/min_delay=0"); if ((fd = divert_init()) < 0) { syslog(LOG_ERR, "tun_init"); return fd; } /* default route to divert device */ inet_aton("0.0.0.0", &deflt.link.node); inet_aton("0.0.0.0", &deflt.link.next_hop); deflt.iface = DIVERT_DEV_NAME; if ((error = add_kernel_route(&deflt)) < 0) return error; return fd; } /* thread */ int on_demand(self_t *self) { int fd; if (self == NULL) { errno = EINVAL; return -1; } if ((fd = init_on_demand()) < 0) return fd; while (1) { int error; u_int32_t dest_addr; protocol_t *proto = NULL; if ((error = read_route_request(self, fd, &dest_addr, proto)) <= 0) { if (error < 0) syslog(LOG_ERR, "read_route_request: %m"); continue; } if ((error = route_discovery_pending(dest_addr, proto)) <= 0) { if (error < 0) syslog(LOG_ERR, "route_discovery_pending: %m"); continue; } proto->mesh_init_discovery(proto, dest_addr); } } /* thread for tracking */ int packet_usage(self_t *self) { int error; struct ipq_handle *qh; if ((qh = ipq_create_handle(0, PF_INET)) < 0) { syslog(LOG_ERR, "ipq_create_handle %m"); return -1; } if ((error = ipq_set_mode(qh, IPQ_COPY_META, 0)) < 0) { syslog(LOG_ERR, "ipq_set_mode (IPQ_COPY_META): %m"); return -1; } while (1) { unsigned int bufsize = sizeof(struct ip) + sizeof(struct udphdr); unsigned char buf[bufsize]; if ((error = ipq_read(qh, buf, bufsize, 0)) < 0) { syslog(LOG_ERR, "ipq_read %m"); continue; } switch (ipq_message_type(buf)) { case NLMSG_ERROR: syslog(LOG_ERR, "NLMSG_ERROR: %s", strerror(ipq_get_msgerr(buf))); break; case IPQM_PACKET: { ipq_packet_msg_t *pkt; struct iphdr *iph; link_entry_t *entry; protocol_t *proto = self->protocols; if ((pkt = ipq_get_packet(buf)) == NULL) { syslog(LOG_ERR, "ipq_get_packet %m"); break; } iph = (struct iphdr*)pkt->payload; while (proto != NULL) { if ((entry = retrieve_entry(proto, iph->daddr)) == NULL) { syslog(LOG_ERR, "no entry for %s: %m", ip_to_dot(iph->daddr)); continue; } entry->time_last_used = get_current_time(); if ((entry = retrieve_entry(proto, iph->saddr)) == NULL) { syslog(LOG_ERR, "no entry for %s: %m", ip_to_dot(iph->saddr)); continue; } entry->time_last_used = get_current_time(); proto = proto->next; } if ((error = ipq_set_verdict(qh, pkt->packet_id, NF_ACCEPT, 0, NULL)) < 0) syslog(LOG_ERR, "ipq_set_verdict %m"); break; } } } ipq_destroy_handle(qh); return 0; }

© 2007, Los Alamos National Security, LLC.