/* $NetBSD: wire.c,v 1.12 2006/03/18 21:14:09 christos Exp $ */ /* * Copyright (c) 1997-2005 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 acknowledgment: * 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. * * * File: am-utils/libamu/wire.c * */ /* * 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 returned, 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 #ifdef HAVE_IFADDRS_H #include #endif /* HAVE_IFADDRS_H */ #ifdef HAVE_IRS_H # include #endif /* HAVE_IRS_H */ /* * 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) */ #define C(x) ((x) & 0xff) #define GFBUFLEN 1024 #define S2IN(s) (((struct sockaddr_in *)(s))->sin_addr.s_addr) /* 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 = SALLOC(buf_size); /* initial allocation (may grow!) */ if (!buf) return NULL; if (!localnets) { xstrlcpy(buf, "No networks\n", buf_size); return buf; } /* check if there's more than one network */ if (!localnets->ip_next) { /* use buf_size for sizeof(buf) because of the realloc() below */ xsnprintf(buf, buf_size, "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++) { xsnprintf(s, sizeof(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); } xstrlcat(buf, s, buf_size); } return buf; } static struct addrlist * getwire_lookup(u_long address, u_long netmask, int ishost) { struct addrlist *al; u_long subnet; char netNumberBuf[64]; char buf[GFBUFLEN], *s; #ifdef HAVE_IRS_H struct nwent *np; #else /* not HAVE_IRS_H */ struct netent *np; #endif /* not HAVE_IRS_H */ /* * 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; subnet = ntohl(address) & ntohl(netmask); if (ishost) np = NULL; else { #ifdef HAVE_IRS_H u_long mask = ntohl(netmask); static struct irs_acc *irs_gen; static struct irs_nw *irs_nw; u_long net; int maskbits; u_char addr[4]; if (irs_gen == NULL) #ifdef irs_irp_acc /* * bsdi4 added another argument to this function, without changing * its name. The irs_irp_acc is the one (hacky) distinguishing * feature found in that can differentiate between bsdi3 and * bsdi4. */ irs_gen = irs_gen_acc("", NULL); #else /* not irs_irp_acc */ irs_gen = irs_gen_acc(""); #endif /* not irs_irp_acc */ if (irs_gen && irs_nw == NULL) irs_nw = (*irs_gen->nw_map)(irs_gen); net = ntohl(address) & (mask = ntohl(netmask)); addr[0] = (0xFF000000 & net) >> 24; addr[1] = (0x00FF0000 & net) >> 16; addr[2] = (0x0000FF00 & net) >> 8; addr[3] = (0x000000FF & net); for (maskbits = 32; !(mask & 1); mask >>= 1) maskbits--; np = (*irs_nw->byaddr)(irs_nw, addr, maskbits, AF_INET); #else /* not HAVE_IRS_H */ np = getnetbyaddr(subnet, AF_INET); /* * Some systems (IRIX 6.4) cannot getnetbyaddr on networks such as * "128.59.16.0". Instead, they need to look for the short form of * the network, "128.59.16". So if the first getnetbyaddr failed, we * shift the subnet way from zeros and try again. */ if (!np) { u_long short_subnet = subnet; while (short_subnet && (short_subnet & 0x000000ff) == 0) short_subnet >>= 8; np = getnetbyaddr(short_subnet, AF_INET); if (np) plog(XLOG_WARNING, "getnetbyaddr failed on 0x%x, succeeded on 0x%x", (u_int) subnet, (u_int) short_subnet); } #endif /* not HAVE_IRS_H */ } if ((subnet & 0xffffff) == 0) { xsnprintf(netNumberBuf, sizeof(netNumberBuf), "%lu", C(subnet >> 24)); } else if ((subnet & 0xffff) == 0) { xsnprintf(netNumberBuf, sizeof(netNumberBuf), "%lu.%lu", C(subnet >> 24), C(subnet >> 16)); } else if ((subnet & 0xff) == 0) { xsnprintf(netNumberBuf, sizeof(netNumberBuf), "%lu.%lu.%lu", C(subnet >> 24), C(subnet >> 16), C(subnet >> 8)); } else { xsnprintf(netNumberBuf, sizeof(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); if (np != NULL) s = np->n_name; else { struct hostent *hp; subnet = address & netmask; hp = gethostbyaddr((char *) &subnet, 4, AF_INET); if (hp != NULL) s = (char *) hp->h_name; else s = inet_dquad(buf, sizeof(buf), subnet); } /* fill in network name (string) */ al->ip_net_name = strdup(s); /* Let's be cautious here about buffer overflows -Ion */ if (strlen(s) > MAXHOSTNAMELEN) { al->ip_net_name[MAXHOSTNAMELEN] = '\0'; plog(XLOG_WARNING, "Long hostname %s truncated to %d characters", s, MAXHOSTNAMELEN); } return (al); } /* * 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, size_t l, u_long addr) { addr = ntohl(addr); xsnprintf(buf, l, "%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; for (al = localnets; al; al = al->ip_next) if (((addr ^ al->ip_addr) & al->ip_mask) == 0) return TRUE; #ifdef DEBUG { char buf[16]; plog(XLOG_INFO, "%s is on a remote network", inet_dquad(buf, sizeof(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; /* * If the network name string does not contain a '/', use old behavior. * If it does contain a '/' then interpret the string as a network/netmask * pair. If "netmask" doesn't exist, use the interface's own netmask. * Also support fully explicit netmasks such as 255.255.255.0 as well as * bit-length netmask such as /24 (hex formats such 0xffffff00 work too). */ if (strchr(net, '/') == NULL) { for (al = localnets; al; al = al->ip_next) if (STREQ(net, al->ip_net_name) || STREQ(net, al->ip_net_num)) return TRUE; } else { char *netstr = strdup(net), *maskstr; u_long netnum, masknum = 0; maskstr = strchr(netstr, '/'); maskstr[0] = '\0'; /* null terminate netstr */ maskstr++; if (*maskstr == '\0') /* if empty string, make it NULL */ maskstr = NULL; /* check if netmask uses a dotted-quad or bit-length, or not defined at all */ if (maskstr) { if (strchr(maskstr, '.')) { /* XXX: inet_addr is obsolste, convert to inet_aton() */ masknum = inet_addr(maskstr); if (masknum == INADDR_NONE) /* can be invalid (-1) or all-1s */ masknum = 0xffffffff; } else if (NSTRCEQ(maskstr, "0x", 2)) { masknum = strtoul(maskstr, NULL, 16); } else { int bits = atoi(maskstr); if (bits < 0) bits = 0; if (bits > 32) bits = 32; masknum = 0xffffffff << (32-bits); } } netnum = inet_addr(netstr); /* not checking return value, b/c -1 (0xffffffff) is valid */ XFREE(netstr); /* netstr not needed any longer */ /* now check against each local interface */ for (al = localnets; al; al = al->ip_next) { if ((al->ip_addr & (maskstr ? masknum : al->ip_mask)) == netnum) return TRUE; } } return FALSE; } #ifdef HAVE_GETIFADDRS void getwire(char **name1, char **number1) { addrlist *al = NULL, *tail = NULL; struct ifaddrs *ifaddrs, *ifap; #ifndef HAVE_STRUCT_IFADDRS_IFA_NEXT int count = 0, i; #endif /* not HAVE_STRUCT_IFADDRS_IFA_NEXT */ ifaddrs = NULL; #ifdef HAVE_STRUCT_IFADDRS_IFA_NEXT if (getifaddrs(&ifaddrs) < 0) goto out; for (ifap = ifaddrs; ifap != NULL; ifap = ifap->ifa_next) { #else /* not HAVE_STRUCT_IFADDRS_IFA_NEXT */ if (getifaddrs(&ifaddrs, &count) < 0) goto out; for (i = 0,ifap = ifaddrs; i < count; ifap++, i++) { #endif /* HAVE_STRUCT_IFADDRS_IFA_NEXT */ if (!ifap || !ifap->ifa_addr || ifap->ifa_addr->sa_family != AF_INET) continue; /* * If the interface is a loopback, or its not running * then ignore it. */ if ((ifap->ifa_flags & IFF_LOOPBACK) != 0) continue; if ((ifap->ifa_flags & IFF_RUNNING) == 0) continue; if ((ifap->ifa_flags & IFF_POINTOPOINT) == 0) al = getwire_lookup(S2IN(ifap->ifa_addr), S2IN(ifap->ifa_netmask), 0); else al = getwire_lookup(S2IN(ifap->ifa_dstaddr), 0xffffffff, 1); /* append to the end of the list */ if (!localnets || tail == NULL) { localnets = tail = al; tail->ip_next = NULL; } else { tail->ip_next = al; tail = al; } } out: if (ifaddrs) XFREE(ifaddrs); if (localnets) { *name1 = localnets->ip_net_name; *number1 = localnets->ip_net_num; } else { *name1 = NO_SUBNET; *number1 = "0.0.0.0"; } } #else /* not HAVE_GETIFADDRS */ #if defined(HAVE_STRUCT_IFREQ_IFR_ADDR) && defined(HAVE_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_STRUCT_IFREQ_IFR_ADDR) && defined(HAVE_STRUCT_SOCKADDR_SA_LEN) */ # define SIZE(ifr) sizeof(struct ifreq) #endif /* not defined(HAVE_STRUCT_IFREQ_IFR_ADDR) && defined(HAVE_STRUCT_SOCKADDR_SA_LEN) */ #define clist (ifc.ifc_ifcu.ifcu_req) #define count (ifc.ifc_len/sizeof(struct ifreq)) void getwire(char **name1, char **number1) { struct ifconf ifc; struct ifreq *ifr, ifrpool; caddr_t cp, cplim; int fd = -1; u_long address; addrlist *al = NULL, *tail = NULL; char buf[GFBUFLEN]; #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; /* increment in the loop body */) { memcpy(&ifrpool, cp, sizeof(ifrpool)); ifr = &ifrpool; cp += SIZE(ifr); if (ifr->ifr_addr.sa_family != AF_INET) continue; 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; if ((ifr->ifr_flags & IFF_POINTOPOINT) == 0) { /* * Get the netmask of this interface */ if (ioctl(fd, SIOCGIFNETMASK, (caddr_t) ifr) < 0) continue; al = getwire_lookup(address, S2IN(&ifr->ifr_addr), 0); } else al = getwire_lookup(address, 0xffffffff, 1); /* append to the end of the list */ if (!localnets) { localnets = tail = al; tail->ip_next = NULL; } else { tail->ip_next = al; tail = al; } } 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"; } } #endif /* not HAVE_GETIFADDRS */