/* Unix SMB/Netbios implementation. Version 1.9. code to query kernel netmask Copyright (C) Andrew Tridgell 1998 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., 675 Mass Ave, Cambridge, MA 02139, USA. */ /* working out the netmask for an interface is an incredibly non-portable thing. We have several possible implementations below, and autoconf tries each of them to see what works Note that this file does _not_ include includes.h. That is so this code can be called directly from the autoconf tests. That also means this code cannot use any of the normal Samba debug stuff or defines. This is standalone code. */ #ifndef AUTOCONF #include "config.h" #endif #ifdef HAVE_NETMASK_IFCONF #include <stdio.h> #include <unistd.h> #include <sys/types.h> #include <sys/socket.h> #include <netinet/in.h> #include <arpa/inet.h> #include <netdb.h> #include <sys/ioctl.h> #include <net/if.h> #ifndef SIOCGIFCONF #include <sys/sockio.h> #endif /**************************************************************************** get the netmask address for a local interface ****************************************************************************/ int get_netmask(struct in_addr *ipaddr, struct in_addr *nmask) { struct ifconf ifc; char buff[2048]; int fd, i, n; struct ifreq *ifr=NULL; if ((fd = socket(AF_INET, SOCK_DGRAM, 0)) == -1) { #ifdef DEBUG fprintf(stderr,"socket failed\n"); #endif return -1; } ifc.ifc_len = sizeof(buff); ifc.ifc_buf = buff; if (ioctl(fd, SIOCGIFCONF, &ifc) != 0) { #ifdef DEBUG fprintf(stderr,"SIOCGIFCONF failed\n"); #endif close(fd); return -1; } ifr = ifc.ifc_req; n = ifc.ifc_len / sizeof(struct ifreq); #ifdef DEBUG fprintf(stderr,"%d interfaces - looking for %s\n", n, inet_ntoa(*ipaddr)); #endif /* Loop through interfaces, looking for given IP address */ for (i=n-1;i>=0;i--) { if (ioctl(fd, SIOCGIFADDR, &ifr[i]) != 0) { #ifdef DEBUG fprintf(stderr,"SIOCGIFADDR failed\n"); #endif continue; } #ifdef DEBUG fprintf(stderr,"interface %s\n", inet_ntoa((*(struct sockaddr_in *)&ifr[i].ifr_addr).sin_addr)); #endif if (ipaddr->s_addr != (*(struct sockaddr_in *)&ifr[i].ifr_addr).sin_addr.s_addr) { continue; } if (ioctl(fd, SIOCGIFNETMASK, &ifr[i]) != 0) { #ifdef DEBUG fprintf(stderr,"SIOCGIFNETMASK failed\n"); #endif close(fd); return -1; } close(fd); (*nmask) = ((struct sockaddr_in *)&ifr[i].ifr_addr)->sin_addr; #ifdef DEBUG fprintf(stderr,"netmask %s\n", inet_ntoa(*nmask)); #endif return 0; } #ifdef DEBUG fprintf(stderr,"interface not found\n"); #endif close(fd); return -1; } #elif defined(HAVE_NETMASK_IFREQ) #include <stdio.h> #include <sys/types.h> #include <sys/socket.h> #include <netinet/in.h> #include <arpa/inet.h> #include <netdb.h> #include <sys/ioctl.h> #include <net/if.h> #ifndef SIOCGIFCONF #include <sys/sockio.h> #endif #ifndef I_STR #include <sys/stropts.h> #endif /**************************************************************************** this should cover most of the rest of systems ****************************************************************************/ int get_netmask(struct in_addr *ipaddr, struct in_addr *nmask) { struct ifreq ifreq; struct strioctl strioctl; struct ifconf *ifc; char buff[2048]; int fd, i, n; struct ifreq *ifr=NULL; if ((fd = socket(AF_INET, SOCK_DGRAM, 0)) == -1) { #ifdef DEBUG fprintf(stderr,"socket failed\n"); #endif return -1; } ifc = (struct ifconf *)buff; ifc->ifc_len = BUFSIZ - sizeof(struct ifconf); strioctl.ic_cmd = SIOCGIFCONF; strioctl.ic_dp = (char *)ifc; strioctl.ic_len = sizeof(buff); if (ioctl(fd, I_STR, &strioctl) < 0) { #ifdef DEBUG fprintf(stderr,"SIOCGIFCONF failed\n"); #endif close(fd); return -1; } ifr = (struct ifreq *)ifc->ifc_req; /* Loop through interfaces, looking for given IP address */ n = ifc->ifc_len / sizeof(struct ifreq); for (i = 0; i<n; i++, ifr++) { #ifdef DEBUG fprintf(stderr,"interface %s\n", inet_ntoa((*(struct sockaddr_in *)&ifr->ifr_addr).sin_addr.s_addr)); #endif if (ipaddr->s_addr == (*(struct sockaddr_in *) &ifr->ifr_addr).sin_addr.s_addr) { break; } } #ifdef DEBUG if (i == n) { fprintf(stderr,"interface not found\n"); close(fd); return -1; } #endif ifreq = *ifr; strioctl.ic_cmd = SIOCGIFNETMASK; strioctl.ic_dp = (char *)&ifreq; strioctl.ic_len = sizeof(struct ifreq); if (ioctl(fd, I_STR, &strioctl) != 0) { #ifdef DEBUG fprintf(stderr,"Failed SIOCGIFNETMASK\n"); #endif close(fd); return -1; } close(fd); *nmask = ((struct sockaddr_in *)&ifreq.ifr_addr)->sin_addr; #ifdef DEBUG fprintf(stderr,"netmask %s\n", inet_ntoa(*nmask)); #endif return 0; } #elif defined(HAVE_NETMASK_AIX) #include <stdio.h> #include <sys/types.h> #include <sys/socket.h> #include <netinet/in.h> #include <arpa/inet.h> #include <netdb.h> #include <sys/ioctl.h> #include <net/if.h> #ifndef SIOCGIFCONF #include <sys/sockio.h> #endif /**************************************************************************** this one is for AIX ****************************************************************************/ int get_netmask(struct in_addr *ipaddr, struct in_addr *nmask) { char buff[2048]; int fd, i, n; struct ifconf ifc; struct ifreq *ifr=NULL; if ((fd = socket(AF_INET, SOCK_DGRAM, 0)) == -1) { #ifdef DEBUG fprintf(stderr,"socket failed\n"); #endif return -1; } ifc.ifc_len = sizeof(buff); ifc.ifc_buf = buff; if (ioctl(fd, SIOCGIFCONF, &ifc) != 0) { #ifdef DEBUG fprintf(stderr,"SIOCGIFCONF failed\n"); #endif close(fd); return -1; } ifr = ifc.ifc_req; /* Loop through interfaces, looking for given IP address */ i = ifc.ifc_len; while (i > 0) { #ifdef DEBUG fprintf(stderr,"interface %s\n", inet_ntoa((*(struct sockaddr_in *)&ifr->ifr_addr).sin_addr)); #endif if (ipaddr->s_addr == (*(struct sockaddr_in *) &ifr->ifr_addr).sin_addr.s_addr) { break; } i -= ifr->ifr_addr.sa_len + IFNAMSIZ; ifr = (struct ifreq*) ((char*) ifr + ifr->ifr_addr.sa_len + IFNAMSIZ); } #ifdef DEBUG if (i <= 0) { fprintf(stderr,"interface not found\n"); close(fd); return -1; } #endif if (ioctl(fd, SIOCGIFNETMASK, ifr) != 0) { #ifdef DEBUG fprintf(stderr,"SIOCGIFNETMASK failed\n"); #endif close(fd); return -1; } close(fd); (*nmask) = ((struct sockaddr_in *)&ifr->ifr_addr)->sin_addr; #ifdef DEBUG fprintf(stderr,"netmask %s\n", inet_ntoa(*nmask)); #endif return 0; } #else /* a dummy version */ struct in_addr; /* it may not have been declared before */ int get_netmask(struct in_addr *ipaddr, struct in_addr *nmask) { return -1; } #endif #ifdef AUTOCONF /* this is the autoconf driver to test get_netmask() */ main() { char buf[1024]; struct hostent *hp; struct in_addr ip, nmask; if (gethostname(buf, sizeof(buf)-1) != 0) { fprintf(stderr,"gethostname failed\n"); exit(1); } hp = gethostbyname(buf); if (!hp) { fprintf(stderr,"gethostbyname failed\n"); exit(1); } memcpy((char *)&ip, (char *)hp->h_addr, hp->h_length); if (get_netmask(&ip, &nmask) == 0) exit(0); fprintf(stderr,"get_netmask failed\n"); exit(1); } #endif