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 000000000000..5613b345c116
--- /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.)
+ *
+ * SPDX-License-Identifier: BSD-4.3TAHOE
+ *
+ * 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.
+ *
+ */
+
+/*
+ * 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
+ * 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;
+}