diff options
Diffstat (limited to 'usr.sbin/ppp/arp.c')
-rw-r--r-- | usr.sbin/ppp/arp.c | 316 |
1 files changed, 316 insertions, 0 deletions
diff --git a/usr.sbin/ppp/arp.c b/usr.sbin/ppp/arp.c new file mode 100644 index 0000000..b38b97a --- /dev/null +++ b/usr.sbin/ppp/arp.c @@ -0,0 +1,316 @@ +/* + * sys-bsd.c - System-dependent procedures for setting up + * PPP interfaces on bsd-4.4-ish systems (including 386BSD, NetBSD, etc.) + * + * Copyright (c) 1989 Carnegie Mellon University. + * All rights reserved. + * + * Redistribution and use in source and binary forms are permitted + * provided that the above copyright notice and this paragraph are + * duplicated in all such forms and that any documentation, + * advertising materials, and other materials related to such + * distribution and use acknowledge that the software was developed + * by Carnegie Mellon University. The name of the + * University may not be used to endorse or promote products derived + * from this software without specific prior written permission. + * THIS SOFTWARE IS PROVIDED ``AS IS'' AND WITHOUT ANY EXPRESS OR + * IMPLIED WARRANTIES, INCLUDING, WITHOUT LIMITATION, THE IMPLIED + * WARRANTIES OF MERCHANTIBILITY AND FITNESS FOR A PARTICULAR PURPOSE. + * + * $FreeBSD$ + * + */ + +/* + * TODO: + */ + +#include <sys/param.h> +#include <sys/socket.h> +#include <net/if.h> +#include <net/route.h> +#include <net/if_dl.h> +#include <netinet/in.h> +#include <netinet/if_ether.h> +#include <arpa/inet.h> +#include <netinet/in_systm.h> +#include <netinet/ip.h> +#include <sys/un.h> + +#include <errno.h> +#include <stdio.h> +#include <stdlib.h> +#include <string.h> +#include <sys/sysctl.h> +#include <termios.h> +#include <unistd.h> + +#include "layer.h" +#include "mbuf.h" +#include "log.h" +#include "id.h" +#include "timer.h" +#include "fsm.h" +#include "defs.h" +#include "iplist.h" +#include "throughput.h" +#include "slcompress.h" +#include "lqr.h" +#include "hdlc.h" +#include "ncpaddr.h" +#include "ipcp.h" +#include "ipv6cp.h" +#include "descriptor.h" +#include "lcp.h" +#include "ccp.h" +#include "link.h" +#include "mp.h" +#include "ncp.h" +#include "filter.h" +#ifndef NORADIUS +#include "radius.h" +#endif +#include "bundle.h" +#include "iface.h" +#include "arp.h" + +/* + * SET_SA_FAMILY - set the sa_family field of a struct sockaddr, + * if it exists. + */ +#define SET_SA_FAMILY(addr, family) \ + memset((char *) &(addr), '\0', sizeof(addr)); \ + addr.sa_family = (family); \ + addr.sa_len = sizeof(addr); + + +#if RTM_VERSION >= 3 + +/* + * arp_SetProxy - Make a proxy ARP entry for the peer. + */ +static struct { + struct rt_msghdr hdr; + struct sockaddr_in dst; + struct sockaddr_dl hwa; + char extra[128]; +} arpmsg; + +static int +arp_ProxySub(struct bundle *bundle, struct in_addr addr, int add) +{ + int routes; + + /* + * Get the hardware address of an interface on the same subnet as our local + * address. + */ + + memset(&arpmsg, 0, sizeof arpmsg); + if (!arp_EtherAddr(addr, &arpmsg.hwa, 0)) { + log_Printf(LogWARN, "%s: Cannot determine ethernet address for proxy ARP\n", + inet_ntoa(addr)); + return 0; + } + routes = ID0socket(PF_ROUTE, SOCK_RAW, AF_INET); + if (routes < 0) { + log_Printf(LogERROR, "arp_SetProxy: opening routing socket: %s\n", + strerror(errno)); + return 0; + } + arpmsg.hdr.rtm_type = add ? RTM_ADD : RTM_DELETE; + arpmsg.hdr.rtm_flags = RTF_ANNOUNCE | RTF_HOST | RTF_STATIC | RTF_LLDATA; + arpmsg.hdr.rtm_version = RTM_VERSION; + arpmsg.hdr.rtm_seq = ++bundle->routing_seq; + arpmsg.hdr.rtm_addrs = RTA_DST | RTA_GATEWAY; + arpmsg.hdr.rtm_inits = RTV_EXPIRE; + arpmsg.dst.sin_len = sizeof(struct sockaddr_in); + arpmsg.dst.sin_family = AF_INET; + arpmsg.dst.sin_addr.s_addr = addr.s_addr; + + arpmsg.hdr.rtm_msglen = (char *) &arpmsg.hwa - (char *) &arpmsg + + arpmsg.hwa.sdl_len; + + + if (ID0write(routes, &arpmsg, arpmsg.hdr.rtm_msglen) < 0 && + !(!add && errno == ESRCH)) { + log_Printf(LogERROR, "%s proxy arp entry %s: %s\n", + add ? "Add" : "Delete", inet_ntoa(addr), strerror(errno)); + close(routes); + return 0; + } + close(routes); + return 1; +} + +int +arp_SetProxy(struct bundle *bundle, struct in_addr addr) +{ + return (arp_ProxySub(bundle, addr, 1)); +} + +/* + * arp_ClearProxy - Delete the proxy ARP entry for the peer. + */ +int +arp_ClearProxy(struct bundle *bundle, struct in_addr addr) +{ + return (arp_ProxySub(bundle, addr, 0)); +} + +#else /* RTM_VERSION */ + +/* + * arp_SetProxy - Make a proxy ARP entry for the peer. + */ +int +arp_SetProxy(struct bundle *bundle, struct in_addr addr, int s) +{ + struct arpreq arpreq; + struct { + struct sockaddr_dl sdl; + char space[128]; + } dls; + + memset(&arpreq, '\0', sizeof arpreq); + + /* + * Get the hardware address of an interface on the same subnet as our local + * address. + */ + if (!arp_EtherAddr(addr, &dls.sdl, 1)) { + log_Printf(LOG_PHASE_BIT, "Cannot determine ethernet address for " + "proxy ARP\n"); + return 0; + } + arpreq.arp_ha.sa_len = sizeof(struct sockaddr); + arpreq.arp_ha.sa_family = AF_UNSPEC; + memcpy(arpreq.arp_ha.sa_data, LLADDR(&dls.sdl), dls.sdl.sdl_alen); + SET_SA_FAMILY(arpreq.arp_pa, AF_INET); + ((struct sockaddr_in *)&arpreq.arp_pa)->sin_addr.s_addr = addr.s_addr; + arpreq.arp_flags = ATF_PERM | ATF_PUBL; + if (ID0ioctl(s, SIOCSARP, (caddr_t) & arpreq) < 0) { + log_Printf(LogERROR, "arp_SetProxy: ioctl(SIOCSARP): %s\n", + strerror(errno)); + return 0; + } + return 1; +} + +/* + * arp_ClearProxy - Delete the proxy ARP entry for the peer. + */ +int +arp_ClearProxy(struct bundle *bundle, struct in_addr addr, int s) +{ + struct arpreq arpreq; + + memset(&arpreq, '\0', sizeof arpreq); + SET_SA_FAMILY(arpreq.arp_pa, AF_INET); + ((struct sockaddr_in *)&arpreq.arp_pa)->sin_addr.s_addr = addr.s_addr; + if (ID0ioctl(s, SIOCDARP, (caddr_t) & arpreq) < 0) { + log_Printf(LogERROR, "arp_ClearProxy: ioctl(SIOCDARP): %s\n", + strerror(errno)); + return 0; + } + return 1; +} + +#endif /* RTM_VERSION */ + + +/* + * arp_EtherAddr - get the hardware address of an interface on the + * the same subnet as ipaddr. + */ + +int +arp_EtherAddr(struct in_addr ipaddr, struct sockaddr_dl *hwaddr, + int verbose) +{ + int mib[6], skip; + size_t needed; + char *buf, *ptr, *end; + struct if_msghdr *ifm; + struct ifa_msghdr *ifam; + struct sockaddr_dl *dl; + struct sockaddr *sa[RTAX_MAX]; + + mib[0] = CTL_NET; + mib[1] = PF_ROUTE; + mib[2] = 0; + mib[3] = 0; + mib[4] = NET_RT_IFLIST; + mib[5] = 0; + + if (sysctl(mib, 6, NULL, &needed, NULL, 0) < 0) { + log_Printf(LogERROR, "arp_EtherAddr: sysctl: estimate: %s\n", + strerror(errno)); + return 0; + } + + if ((buf = malloc(needed)) == NULL) + return 0; + + if (sysctl(mib, 6, buf, &needed, NULL, 0) < 0) { + free(buf); + return 0; + } + end = buf + needed; + + ptr = buf; + while (ptr < end) { + ifm = (struct if_msghdr *)ptr; /* On if_msghdr */ + if (ifm->ifm_type != RTM_IFINFO) + break; + dl = (struct sockaddr_dl *)(ifm + 1); /* Single _dl at end */ + skip = (ifm->ifm_flags & (IFF_UP | IFF_BROADCAST | IFF_POINTOPOINT | + IFF_NOARP | IFF_LOOPBACK)) != (IFF_UP | IFF_BROADCAST); + ptr += ifm->ifm_msglen; /* First ifa_msghdr */ + while (ptr < end) { + ifam = (struct ifa_msghdr *)ptr; /* Next ifa_msghdr (alias) */ + if (ifam->ifam_type != RTM_NEWADDR) /* finished ? */ + break; + ptr += ifam->ifam_msglen; + if (skip || (ifam->ifam_addrs & (RTA_NETMASK|RTA_IFA)) != + (RTA_NETMASK|RTA_IFA)) + continue; + /* Found a candidate. Do the addresses match ? */ + if (log_IsKept(LogDEBUG) && + ptr == (char *)ifm + ifm->ifm_msglen + ifam->ifam_msglen) + log_Printf(LogDEBUG, "%.*s interface is a candidate for proxy\n", + dl->sdl_nlen, dl->sdl_data); + + iface_ParseHdr(ifam, sa); + + if (sa[RTAX_IFA]->sa_family == AF_INET) { + struct sockaddr_in *ifa, *netmask; + + ifa = (struct sockaddr_in *)sa[RTAX_IFA]; + netmask = (struct sockaddr_in *)sa[RTAX_NETMASK]; + + if (log_IsKept(LogDEBUG)) { + char a[16]; + + strncpy(a, inet_ntoa(netmask->sin_addr), sizeof a - 1); + a[sizeof a - 1] = '\0'; + log_Printf(LogDEBUG, "Check addr %s, mask %s\n", + inet_ntoa(ifa->sin_addr), a); + } + + if ((ifa->sin_addr.s_addr & netmask->sin_addr.s_addr) == + (ipaddr.s_addr & netmask->sin_addr.s_addr)) { + log_Printf(verbose ? LogPHASE : LogDEBUG, + "Found interface %.*s for %s\n", dl->sdl_nlen, + dl->sdl_data, inet_ntoa(ipaddr)); + memcpy(hwaddr, dl, dl->sdl_len); + free(buf); + return 1; + } + } + } + } + free(buf); + + return 0; +} |