1 files changed, 314 insertions, 0 deletions

diff --git a/usr.sbin/ppp/arp.c b/usr.sbin/ppp/arp.c
new file mode 100644
index 00000000000..bed1cd879aa
--- /dev/null
+++ b/usr.sbin/ppp/arp.c
@@ -0,0 +1,314 @@
+/*
+ * 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.
+ *
+ * $Id: arp.c,v 1.1 1997/11/23 20:27:32 brian Exp $
+ *
+ */
+
+/*
+ * TODO:
+ */
+
+#include <sys/types.h>
+#include <sys/time.h>
+#include <sys/socket.h>
+#include <net/if.h>
+#ifdef __FreeBSD__
+#include <net/if_var.h>
+#endif
+#include <net/route.h>
+#include <net/if_dl.h>
+#include <netinet/in.h>
+#include <net/if_types.h>
+#include <netinet/in_var.h>
+#include <netinet/if_ether.h>
+
+#include <fcntl.h>
+#include <stdio.h>
+#include <string.h>
+#include <sys/errno.h>
+#include <sys/ioctl.h>
+#include <sys/uio.h>
+#include <unistd.h>
+
+#include "command.h"
+#include "mbuf.h"
+#include "log.h"
+#include "id.h"
+#include "arp.h"
+
+static int rtm_seq;
+
+static int get_ether_addr(int, u_long, struct sockaddr_dl *);
+
+/*
+ * 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
+
+/*
+ * sifproxyarp - Make a proxy ARP entry for the peer.
+ */
+static struct {
+  struct rt_msghdr hdr;
+  struct sockaddr_inarp dst;
+  struct sockaddr_dl hwa;
+  char extra[128];
+} arpmsg;
+
+static int arpmsg_valid;
+
+int
+sifproxyarp(int unit, u_long hisaddr)
+{
+  int routes;
+
+  /*
+   * Get the hardware address of an interface on the same subnet as our local
+   * address.
+   */
+  memset(&arpmsg, 0, sizeof(arpmsg));
+  if (!get_ether_addr(unit, hisaddr, &arpmsg.hwa)) {
+    LogPrintf(LogERROR, "Cannot determine ethernet address for proxy ARP\n");
+    return 0;
+  }
+  routes = ID0socket(PF_ROUTE, SOCK_RAW, AF_INET);
+  if (routes < 0) {
+    LogPrintf(LogERROR, "sifproxyarp: opening routing socket: %s\n",
+	      strerror(errno));
+    return 0;
+  }
+  arpmsg.hdr.rtm_type = RTM_ADD;
+  arpmsg.hdr.rtm_flags = RTF_ANNOUNCE | RTF_HOST | RTF_STATIC;
+  arpmsg.hdr.rtm_version = RTM_VERSION;
+  arpmsg.hdr.rtm_seq = ++rtm_seq;
+  arpmsg.hdr.rtm_addrs = RTA_DST | RTA_GATEWAY;
+  arpmsg.hdr.rtm_inits = RTV_EXPIRE;
+  arpmsg.dst.sin_len = sizeof(struct sockaddr_inarp);
+  arpmsg.dst.sin_family = AF_INET;
+  arpmsg.dst.sin_addr.s_addr = hisaddr;
+  arpmsg.dst.sin_other = SIN_PROXY;
+
+  arpmsg.hdr.rtm_msglen = (char *) &arpmsg.hwa - (char *) &arpmsg
+    + arpmsg.hwa.sdl_len;
+  if (write(routes, &arpmsg, arpmsg.hdr.rtm_msglen) < 0) {
+    LogPrintf(LogERROR, "Add proxy arp entry: %s\n", strerror(errno));
+    close(routes);
+    return 0;
+  }
+  close(routes);
+  arpmsg_valid = 1;
+  return 1;
+}
+
+/*
+ * cifproxyarp - Delete the proxy ARP entry for the peer.
+ */
+int
+cifproxyarp(int unit, u_long hisaddr)
+{
+  int routes;
+
+  if (!arpmsg_valid)
+    return 0;
+  arpmsg_valid = 0;
+
+  arpmsg.hdr.rtm_type = RTM_DELETE;
+  arpmsg.hdr.rtm_seq = ++rtm_seq;
+
+  routes = ID0socket(PF_ROUTE, SOCK_RAW, AF_INET);
+  if (routes < 0) {
+    LogPrintf(LogERROR, "sifproxyarp: opening routing socket: %s\n",
+	      strerror(errno));
+    return 0;
+  }
+  if (write(routes, &arpmsg, arpmsg.hdr.rtm_msglen) < 0) {
+    LogPrintf(LogERROR, "Delete proxy arp entry: %s\n", strerror(errno));
+    close(routes);
+    return 0;
+  }
+  close(routes);
+  return 1;
+}
+
+#else				/* RTM_VERSION */
+
+/*
+ * sifproxyarp - Make a proxy ARP entry for the peer.
+ */
+int
+sifproxyarp(int unit, u_long hisaddr)
+{
+  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 (!get_ether_addr(unit, hisaddr, &dls.sdl)) {
+    LogPrintf(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 = hisaddr;
+  arpreq.arp_flags = ATF_PERM | ATF_PUBL;
+  if (ID0ioctl(unit, SIOCSARP, (caddr_t) & arpreq) < 0) {
+    LogPrintf(LogERROR, "sifproxyarp: ioctl(SIOCSARP): %s\n", strerror(errno));
+    return 0;
+  }
+  return 1;
+}
+
+/*
+ * cifproxyarp - Delete the proxy ARP entry for the peer.
+ */
+int
+cifproxyarp(int unit, u_long hisaddr)
+{
+  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 = hisaddr;
+  if (ID0ioctl(unit, SIOCDARP, (caddr_t) & arpreq) < 0) {
+    LogPrintf(LogERROR, "cifproxyarp: ioctl(SIOCDARP): %s\n", strerror(errno));
+    return 0;
+  }
+  return 1;
+}
+
+#endif				/* RTM_VERSION */
+
+
+/*
+ * get_ether_addr - get the hardware address of an interface on the
+ * the same subnet as ipaddr.
+ */
+#define MAX_IFS		32
+
+static int
+get_ether_addr(int s, u_long ipaddr, struct sockaddr_dl *hwaddr)
+{
+  struct ifreq *ifr, *ifend, *ifp;
+  u_long ina, mask;
+  struct sockaddr_dl *dla;
+  struct ifreq ifreq;
+  struct ifconf ifc;
+  struct ifreq ifs[MAX_IFS];
+
+  ifc.ifc_len = sizeof(ifs);
+  ifc.ifc_req = ifs;
+  if (ioctl(s, SIOCGIFCONF, &ifc) < 0) {
+    LogPrintf(LogERROR, "get_ether_addr: ioctl(SIOCGIFCONF): %s\n",
+	      strerror(errno));
+    return 0;
+  }
+
+  /*
+   * Scan through looking for an interface with an Internet address on the
+   * same subnet as `ipaddr'.
+   */
+  ifend = (struct ifreq *) (ifc.ifc_buf + ifc.ifc_len);
+  for (ifr = ifc.ifc_req; ifr < ifend;) {
+    if (ifr->ifr_addr.sa_family == AF_INET) {
+      ina = ((struct sockaddr_in *) & ifr->ifr_addr)->sin_addr.s_addr;
+      strncpy(ifreq.ifr_name, ifr->ifr_name, sizeof(ifreq.ifr_name));
+      ifreq.ifr_name[sizeof(ifreq.ifr_name) - 1] = '\0';
+
+      /*
+       * Check that the interface is up, and not point-to-point or loopback.
+       */
+      if (ioctl(s, SIOCGIFFLAGS, &ifreq) < 0)
+	continue;
+      if ((ifreq.ifr_flags &
+      (IFF_UP | IFF_BROADCAST | IFF_POINTOPOINT | IFF_LOOPBACK | IFF_NOARP))
+	  != (IFF_UP | IFF_BROADCAST))
+	goto nextif;
+
+      /*
+       * Get its netmask and check that it's on the right subnet.
+       */
+      if (ioctl(s, SIOCGIFNETMASK, &ifreq) < 0)
+	continue;
+      mask = ((struct sockaddr_in *) & ifreq.ifr_addr)->sin_addr.s_addr;
+      if ((ipaddr & mask) != (ina & mask))
+	goto nextif;
+
+      break;
+    }
+nextif:
+    ifr = (struct ifreq *) ((char *) &ifr->ifr_addr + ifr->ifr_addr.sa_len);
+  }
+
+  if (ifr >= ifend)
+    return 0;
+  LogPrintf(LogPHASE, "Found interface %s for proxy arp\n", ifr->ifr_name);
+
+  /*
+   * Now scan through again looking for a link-level address for this
+   * interface.
+   */
+  ifp = ifr;
+  for (ifr = ifc.ifc_req; ifr < ifend;) {
+    if (strcmp(ifp->ifr_name, ifr->ifr_name) == 0
+	&& ifr->ifr_addr.sa_family == AF_LINK) {
+
+      /*
+       * Found the link-level address - copy it out
+       */
+      dla = (struct sockaddr_dl *) & ifr->ifr_addr;
+      memcpy(hwaddr, dla, dla->sdl_len);
+      return 1;
+    }
+    ifr = (struct ifreq *) ((char *) &ifr->ifr_addr + ifr->ifr_addr.sa_len);
+  }
+
+  return 0;
+}
+
+
+#ifdef DEBUG
+int
+main()
+{
+  u_long ipaddr;
+  int s;
+
+  s = socket(AF_INET, SOCK_DGRAM, 0);
+  ipaddr = inet_addr("192.168.1.32");
+  sifproxyarp(s, ipaddr);
+  close(s);
+}
+#endif