/* $OpenBSD: inet.c,v 1.28 2024/08/28 11:41:42 op Exp $ */ /* * Copyright (c) 1994, 1995, 1996, 1997, 1998 * The Regents of the University of California. All rights reserved. * * 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 Computer Systems * Engineering Group at Lawrence Berkeley Laboratory. * 4. Neither the name of the University nor of the Laboratory 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. */ #include #include #include #ifdef HAVE_SYS_SOCKIO_H #include #endif #include /* concession to AIX */ #include #include #include #include #include #include #include #include #include #ifdef HAVE_IFADDRS_H #include #endif #include "pcap-int.h" #ifdef HAVE_OS_PROTO_H #include "os-proto.h" #endif /* * Free a list of interfaces. */ void pcap_freealldevs(pcap_if_t *alldevs) { pcap_if_t *curdev, *nextdev; pcap_addr_t *curaddr, *nextaddr; for (curdev = alldevs; curdev != NULL; curdev = nextdev) { nextdev = curdev->next; /* * Free all addresses. */ for (curaddr = curdev->addresses; curaddr != NULL; curaddr = nextaddr) { nextaddr = curaddr->next; free(curaddr->addr); free(curaddr->netmask); free(curaddr->broadaddr); free(curaddr->dstaddr); free(curaddr); } /* * Free the name string. */ free(curdev->name); /* * Free the description string, if any. */ free(curdev->description); /* * Free the interface. */ free(curdev); } } /* * Return the name of a network interface attached to the system, or NULL * if none can be found. The interface must be configured up; the * lowest unit number is preferred; loopback is ignored. */ char * pcap_lookupdev(char *errbuf) { #ifdef HAVE_IFADDRS_H struct ifaddrs *ifap, *ifa, *mp; int n, minunit; char *cp; const char *errstr; static char device[IF_NAMESIZE + 1]; if (getifaddrs(&ifap) != 0) { (void)snprintf(errbuf, PCAP_ERRBUF_SIZE, "getifaddrs: %s", pcap_strerror(errno)); return NULL; } mp = NULL; minunit = 666; for (ifa = ifap; ifa; ifa = ifa->ifa_next) { if ((ifa->ifa_flags & IFF_UP) == 0) continue; if (ISLOOPBACK(ifa->ifa_name, ifa->ifa_flags)) continue; for (cp = ifa->ifa_name; !isdigit((unsigned char)*cp); ++cp) continue; n = strtonum(cp, 0, INT_MAX, &errstr); if (errstr != NULL) continue; if (n < minunit) { minunit = n; mp = ifa; } } if (mp == NULL) { (void)strlcpy(errbuf, "no suitable device found", PCAP_ERRBUF_SIZE); freeifaddrs(ifap); return (NULL); } (void)strlcpy(device, mp->ifa_name, sizeof(device)); freeifaddrs(ifap); return (device); #else int fd, minunit, n; char *cp; const char *errstr; struct ifreq *ifrp, *ifend, *ifnext, *mp; struct ifconf ifc; struct ifreq ibuf[16], ifr; static char device[sizeof(ifrp->ifr_name) + 1]; fd = socket(AF_INET, SOCK_DGRAM, 0); if (fd == -1) { (void)snprintf(errbuf, PCAP_ERRBUF_SIZE, "socket: %s", pcap_strerror(errno)); return (NULL); } ifc.ifc_len = sizeof ibuf; ifc.ifc_buf = (caddr_t)ibuf; memset((char *)ibuf, 0, sizeof(ibuf)); if (ioctl(fd, SIOCGIFCONF, (char *)&ifc) == -1 || ifc.ifc_len < sizeof(struct ifreq)) { (void)snprintf(errbuf, PCAP_ERRBUF_SIZE, "SIOCGIFCONF: %s", pcap_strerror(errno)); (void)close(fd); return (NULL); } ifrp = ibuf; ifend = (struct ifreq *)((char *)ibuf + ifc.ifc_len); mp = NULL; minunit = 666; for (; ifrp < ifend; ifrp = ifnext) { #ifdef HAVE_SOCKADDR_SA_LEN n = ifrp->ifr_addr.sa_len + sizeof(ifrp->ifr_name); if (n < sizeof(*ifrp)) ifnext = ifrp + 1; else ifnext = (struct ifreq *)((char *)ifrp + n); if (ifrp->ifr_addr.sa_family != AF_INET) continue; #else ifnext = ifrp + 1; #endif /* * Need a template to preserve address info that is * used below to locate the next entry. (Otherwise, * SIOCGIFFLAGS stomps over it because the requests * are returned in a union.) */ (void)strlcpy(ifr.ifr_name, ifrp->ifr_name, sizeof(ifr.ifr_name)); if (ioctl(fd, SIOCGIFFLAGS, (char *)&ifr) == -1) { if (errno == ENXIO) continue; (void)snprintf(errbuf, PCAP_ERRBUF_SIZE, "SIOCGIFFLAGS: %.*s: %s", (int)sizeof(ifr.ifr_name), ifr.ifr_name, pcap_strerror(errno)); (void)close(fd); return (NULL); } /* Must be up and not the loopback */ if ((ifr.ifr_flags & IFF_UP) == 0 || ISLOOPBACK(ifr.ifr_name, ifr.ifr_flags)) continue; for (cp = ifrp->ifr_name; !isdigit((unsigned char)*cp); ++cp) continue; n = strtonum(cp, 0, INT_MAX, &errstr); if (errstr != NULL) continue; if (n < minunit) { minunit = n; mp = ifrp; } } (void)close(fd); if (mp == NULL) { (void)strlcpy(errbuf, "no suitable device found", PCAP_ERRBUF_SIZE); return (NULL); } (void)strlcpy(device, mp->ifr_name, sizeof(device)); return (device); #endif } int pcap_lookupnet(const char *device, bpf_u_int32 *netp, bpf_u_int32 *maskp, char *errbuf) { int fd; struct sockaddr_in *sin; struct ifreq ifr; fd = socket(AF_INET, SOCK_DGRAM, 0); if (fd == -1) { (void)snprintf(errbuf, PCAP_ERRBUF_SIZE, "socket: %s", pcap_strerror(errno)); return (-1); } memset(&ifr, 0, sizeof(ifr)); #ifdef linux /* XXX Work around Linux kernel bug */ ifr.ifr_addr.sa_family = AF_INET; #endif (void)strlcpy(ifr.ifr_name, device, sizeof(ifr.ifr_name)); if (ioctl(fd, SIOCGIFADDR, (char *)&ifr) == -1) { if (errno == EADDRNOTAVAIL) { (void)snprintf(errbuf, PCAP_ERRBUF_SIZE, "%s: no IPv4 address assigned", device); } else { (void)snprintf(errbuf, PCAP_ERRBUF_SIZE, "SIOCGIFADDR: %s: %s", device, pcap_strerror(errno)); } (void)close(fd); return (-1); } sin = (struct sockaddr_in *)&ifr.ifr_addr; *netp = sin->sin_addr.s_addr; if (ioctl(fd, SIOCGIFNETMASK, (char *)&ifr) == -1) { (void)snprintf(errbuf, PCAP_ERRBUF_SIZE, "SIOCGIFNETMASK: %s: %s", device, pcap_strerror(errno)); (void)close(fd); return (-1); } (void)close(fd); *maskp = sin->sin_addr.s_addr; if (*maskp == 0) { if (IN_CLASSA(*netp)) *maskp = IN_CLASSA_NET; else if (IN_CLASSB(*netp)) *maskp = IN_CLASSB_NET; else if (IN_CLASSC(*netp)) *maskp = IN_CLASSC_NET; else { (void)snprintf(errbuf, PCAP_ERRBUF_SIZE, "inet class for 0x%x unknown", *netp); return (-1); } } *netp &= *maskp; return (0); }