/* * Copyright (c) 1997-1998 Erez Zadok * Copyright (c) 1990 Jan-Simon Pendry * Copyright (c) 1990 Imperial College of Science, Technology & Medicine * Copyright (c) 1990 The Regents of the University of California. * All rights reserved. * * This code is derived from software contributed to Berkeley by * Jan-Simon Pendry at Imperial College, London. * * Redistribution and use in source and binary forms, with or without * modification, are permitted provided that the following conditions * are met: * 1. Redistributions of source code must retain the above copyright * notice, this list of conditions and the following disclaimer. * 2. 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. * 3. All advertising materials mentioning features or use of this software * must display the following acknowledgement: * This product includes software developed by the University of * California, Berkeley and its contributors. * 4. Neither the name of the University nor the names of its contributors * may be used to endorse or promote products derived from this software * without specific prior written permission. * * THIS SOFTWARE IS PROVIDED BY THE REGENTS 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 REGENTS 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. * * %W% (Berkeley) %G% * * $Id: wire.c,v 5.2.2.2 1992/06/07 18:06:46 jsp Exp jsp $ * */ /* * This function returns the subnet (address&netmask) for the primary network * interface. If the resulting address has an entry in the hosts file, the * corresponding name is retuned, otherwise the address is returned in * standard internet format. * As a side-effect, a list of local IP/net address is recorded for use * by the islocalnet() function. * * Derived from original by Paul Anderson (23/4/90) * Updates from Dirk Grunwald (11/11/91) */ #ifdef HAVE_CONFIG_H # include #endif /* HAVE_CONFIG_H */ #include #include /* * List of locally connected networks */ typedef struct addrlist addrlist; struct addrlist { addrlist *ip_next; u_long ip_addr; /* address of network */ u_long ip_mask; char *ip_net_num; /* number of network */ char *ip_net_name; /* name of network */ }; static addrlist *localnets = NULL; #if defined(IFF_LOCAL_LOOPBACK) && !defined(IFF_LOOPBACK) # define IFF_LOOPBACK IFF_LOCAL_LOOPBACK #endif /* defined(IFF_LOCAL_LOOPBACK) && !defined(IFF_LOOPBACK) */ #if defined(HAVE_FIELD_STRUCT_IFREQ_IFR_ADDR) && defined(HAVE_FIELD_STRUCT_SOCKADDR_SA_LEN) # define SIZE(ifr) (MAX((ifr)->ifr_addr.sa_len, sizeof((ifr)->ifr_addr)) + sizeof(ifr->ifr_name)) #else /* not defined(HAVE_FIELD_STRUCT_IFREQ_IFR_ADDR) && defined(HAVE_FIELD_STRUCT_SOCKADDR_SA_LEN) */ # define SIZE(ifr) sizeof(struct ifreq) #endif /* not defined(HAVE_FIELD_STRUCT_IFREQ_IFR_ADDR) && defined(HAVE_FIELD_STRUCT_SOCKADDR_SA_LEN) */ #define C(x) ((x) & 0xff) #define GFBUFLEN 1024 #define clist (ifc.ifc_ifcu.ifcu_req) #define count (ifc.ifc_len/sizeof(struct ifreq)) /* return malloc'ed buffer. caller must free it */ char * print_wires(void) { addrlist *al; char s[256]; int i; char *buf; int bufcount = 0; int buf_size = 1024; buf = malloc(1024); if (!buf) return NULL; if (!localnets) { sprintf(buf, "No networks.\n"); return buf; } /* check if there's more than one network */ if (!localnets->ip_next) { sprintf(buf, "Network: wire=\"%s\" (netnumber=%s).\n", localnets->ip_net_name, localnets->ip_net_num); return buf; } buf[0] = '\0'; /* null out buffer before appending */ for (i = 1, al = localnets; al; al = al->ip_next, i++) { sprintf(s, "Network %d: wire=\"%s\" (netnumber=%s).\n", i, al->ip_net_name, al->ip_net_num); bufcount += strlen(s); if (bufcount > buf_size) { buf_size *= 2; buf = xrealloc(buf, buf_size); } strcat(buf, s); } return buf; } void getwire(char **name1, char **number1) { struct hostent *hp; struct netent *np; struct ifconf ifc; struct ifreq *ifr; caddr_t cp, cplim; u_long address, netmask, subnet; char buf[GFBUFLEN], *s; int fd = -1; u_long net; u_long mask; u_long subnetshift; char netNumberBuf[64]; addrlist *al = NULL, *tail = NULL; #ifndef SIOCGIFFLAGS /* if cannot get interface flags, return nothing */ plog(XLOG_ERROR, "getwire unable to get interface flags"); localnets = NULL; return; #endif /* not SIOCGIFFLAGS */ /* * Get suitable socket */ if ((fd = socket(AF_INET, SOCK_DGRAM, 0)) < 0) goto out; /* * Fill in ifconf details */ memset(&buf[0], 0, GFBUFLEN); ifc.ifc_len = sizeof(buf); ifc.ifc_buf = buf; /* * Get network interface configurations */ if (ioctl(fd, SIOCGIFCONF, (caddr_t) & ifc) < 0) goto out; /* * Upper bound on array */ cplim = buf + ifc.ifc_len; /* * This is some magic to cope with both "traditional" and the * new 4.4BSD-style struct sockaddrs. The new structure has * variable length and a size field to support longer addresses. * AF_LINK is a new definition for 4.4BSD. */ /* * Scan the list looking for a suitable interface */ for (cp = buf; cp < cplim; cp += SIZE(ifr)) { ifr = (struct ifreq *) cp; if (ifr->ifr_addr.sa_family != AF_INET) continue; else address = ((struct sockaddr_in *) &ifr->ifr_addr)->sin_addr.s_addr; /* * Get interface flags */ if (ioctl(fd, SIOCGIFFLAGS, (caddr_t) ifr) < 0) continue; /* * If the interface is a loopback, or its not running * then ignore it. */ #ifdef IFF_LOOPBACK if ((ifr->ifr_flags & IFF_LOOPBACK) != 0) continue; #endif /* IFF_LOOPBACK */ /* * Fix for 0.0.0.0 loopback on SunOS 3.X which defines IFF_ROUTE * instead of IFF_LOOPBACK. */ #ifdef IFF_ROUTE if (ifr->ifr_flags == (IFF_UP|IFF_RUNNING)) continue; #endif /* IFF_ROUTE */ /* if the interface is not UP or not RUNNING, skip it */ if ((ifr->ifr_flags & IFF_RUNNING) == 0 || (ifr->ifr_flags & IFF_UP) == 0) continue; /* * Get the netmask of this interface */ if (ioctl(fd, SIOCGIFNETMASK, (caddr_t) ifr) < 0) continue; netmask = ((struct sockaddr_in *) &ifr->ifr_addr)->sin_addr.s_addr; /* * Add interface to local network singly linked list */ al = ALLOC(struct addrlist); al->ip_addr = address; al->ip_mask = netmask; al->ip_net_name = NO_SUBNET; /* fill in a bit later */ al->ip_net_num = "0.0.0.0"; /* fill in a bit later */ al->ip_next = NULL; /* append to the end of the list */ if (!localnets) { localnets = tail = al; tail->ip_next = NULL; } else { tail->ip_next = al; tail = al; } /* * Figure out the subnet's network address */ subnet = address & netmask; #ifdef IN_CLASSA subnet = htonl(subnet); if (IN_CLASSA(subnet)) { mask = IN_CLASSA_NET; subnetshift = 8; } else if (IN_CLASSB(subnet)) { mask = IN_CLASSB_NET; subnetshift = 8; } else { mask = IN_CLASSC_NET; subnetshift = 4; } /* * If there are more bits than the standard mask * would suggest, subnets must be in use. * Guess at the subnet mask, assuming reasonable * width subnet fields. * XXX: Or-in at least 1 byte's worth of 1s to make * sure the top bits remain set. */ while (subnet & ~mask) mask = (mask >> subnetshift) | 0xff000000; net = subnet & mask; while ((mask & 1) == 0) mask >>= 1, net >>= 1; /* * Now get a usable name. * First use the network database, * then the host database, * and finally just make a dotted quad. */ np = getnetbyaddr(net, AF_INET); /* the network address has been masked off */ if ((subnet & 0xffffff) == 0) { sprintf(netNumberBuf, "%lu", C(subnet >> 24)); } else if ((subnet & 0xffff) == 0) { sprintf(netNumberBuf, "%lu.%lu", C(subnet >> 24), C(subnet >> 16)); } else if ((subnet & 0xff) == 0) { sprintf(netNumberBuf, "%lu.%lu.%lu", C(subnet >> 24), C(subnet >> 16), C(subnet >> 8)); } else { sprintf(netNumberBuf, "%lu.%lu.%lu.%lu", C(subnet >> 24), C(subnet >> 16), C(subnet >> 8), C(subnet)); } /* fill in network number (string) */ al->ip_net_num = strdup(netNumberBuf); #else /* not IN_CLASSA */ /* This is probably very wrong. */ np = getnetbyaddr(subnet, AF_INET); #endif /* not IN_CLASSA */ if (np) s = np->n_name; else { subnet = address & netmask; hp = gethostbyaddr((char *) &subnet, 4, AF_INET); if (hp) s = (char *) hp->h_name; else s = inet_dquad(buf, subnet); } /* fill in network name (string) */ al->ip_net_name = strdup(s); } out: if (fd >= 0) close(fd); if (localnets) { *name1 = localnets->ip_net_name; *number1 = localnets->ip_net_num; } else { *name1 = NO_SUBNET; *number1 = "0.0.0.0"; } } /* * Make a dotted quad from a 32bit IP address * addr is in network byte order. * sizeof(buf) needs to be at least 16. */ char * inet_dquad(char *buf, u_long addr) { addr = ntohl(addr); sprintf(buf, "%ld.%ld.%ld.%ld", ((addr >> 24) & 0xff), ((addr >> 16) & 0xff), ((addr >> 8) & 0xff), ((addr >> 0) & 0xff)); return buf; } /* * Determine whether a network is on a local network * (addr) is in network byte order. */ int islocalnet(u_long addr) { addrlist *al; #ifdef DEBUG char buf[16]; #endif /* DEBUG */ for (al = localnets; al; al = al->ip_next) if (((addr ^ al->ip_addr) & al->ip_mask) == 0) return TRUE; #ifdef DEBUG plog(XLOG_INFO, "%s is on a remote network", inet_dquad(buf, addr)); #endif /* DEBUG */ return FALSE; } /* * Determine whether a network name is one of the local networks * of a host. */ int is_network_member(const char *net) { addrlist *al; for (al = localnets; al; al = al->ip_next) if (STREQ(net, al->ip_net_name) || STREQ(net, al->ip_net_num)) return TRUE; return FALSE; }