]> git.ipfire.org Git - thirdparty/dhcp.git/commitdiff
Interface discovery code.
authorTed Lemon <source@isc.org>
Fri, 6 Nov 1998 00:19:56 +0000 (00:19 +0000)
committerTed Lemon <source@isc.org>
Fri, 6 Nov 1998 00:19:56 +0000 (00:19 +0000)
common/discover.c [new file with mode: 0644]

diff --git a/common/discover.c b/common/discover.c
new file mode 100644 (file)
index 0000000..81d06a2
--- /dev/null
@@ -0,0 +1,450 @@
+/* dispatch.c
+
+   Network input dispatcher... */
+
+/*
+ * Copyright (c) 1995, 1996, 1998 The Internet Software Consortium.
+ * 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. Neither the name of The Internet Software Consortium nor the names
+ *    of its contributors may be used to endorse or promote products derived
+ *    from this software without specific prior written permission.
+ *
+ * THIS SOFTWARE IS PROVIDED BY THE INTERNET SOFTWARE CONSORTIUM 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 INTERNET SOFTWARE CONSORTIUM 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.
+ *
+ * This software has been written for the Internet Software Consortium
+ * by Ted Lemon <mellon@fugue.com> in cooperation with Vixie
+ * Enterprises.  To learn more about the Internet Software Consortium,
+ * see ``http://www.vix.com/isc''.  To learn more about Vixie
+ * Enterprises, see ``http://www.vix.com''.
+ */
+
+#ifndef lint
+static char copyright[] =
+"$Id: discover.c,v 1.1 1998/11/06 00:19:56 mellon Exp $ Copyright (c) 1995, 1996 The Internet Software Consortium.  All rights reserved.\n";
+#endif /* not lint */
+
+#include "dhcpd.h"
+#include <sys/ioctl.h>
+
+struct interface_info *interfaces, *dummy_interfaces;
+extern int interfaces_invalidated;
+int quiet_interface_discovery;
+
+void (*bootp_packet_handler) PROTO ((struct interface_info *,
+                                    struct dhcp_packet *, int, unsigned int,
+                                    struct iaddr, struct hardware *));
+
+static void got_one PROTO ((struct protocol *));
+
+/* Use the SIOCGIFCONF ioctl to get a list of all the attached interfaces.
+   For each interface that's of type INET and not the loopback interface,
+   register that interface with the network I/O software, figure out what
+   subnet it's on, and add it to the list of interfaces. */
+
+void discover_interfaces (state)
+       int state;
+{
+       struct interface_info *tmp;
+       struct interface_info *last, *next;
+       char buf [8192];
+       struct ifconf ic;
+       struct ifreq ifr;
+       int i;
+       int sock;
+       int address_count = 0;
+       struct subnet *subnet;
+       struct shared_network *share;
+       struct sockaddr_in foo;
+       int ir;
+#ifdef ALIAS_NAMES_PERMUTED
+       char *s;
+#endif
+#ifdef USE_FALLBACK
+       static struct shared_network fallback_network;
+#endif
+
+       /* Create an unbound datagram socket to do the SIOCGIFADDR ioctl on. */
+       if ((sock = socket (AF_INET, SOCK_DGRAM, IPPROTO_UDP)) < 0)
+               error ("Can't create addrlist socket");
+
+       /* Get the interface configuration information... */
+       ic.ifc_len = sizeof buf;
+       ic.ifc_ifcu.ifcu_buf = (caddr_t)buf;
+       i = ioctl(sock, SIOCGIFCONF, &ic);
+
+       if (i < 0)
+               error ("ioctl: SIOCGIFCONF: %m");
+
+       /* If we already have a list of interfaces, and we're running as
+          a DHCP server, the interfaces were requested. */
+       if (interfaces && (state == DISCOVER_SERVER ||
+                          state == DISCOVER_RELAY ||
+                          state == DISCOVER_REQUESTED))
+               ir = 0;
+       else if (state == DISCOVER_UNCONFIGURED)
+               ir = INTERFACE_REQUESTED | INTERFACE_AUTOMATIC;
+       else
+               ir = INTERFACE_REQUESTED;
+
+       /* Cycle through the list of interfaces looking for IP addresses.
+          Go through twice; once to count the number of addresses, and a
+          second time to copy them into an array of addresses. */
+       for (i = 0; i < ic.ifc_len;) {
+               struct ifreq *ifp = (struct ifreq *)((caddr_t)ic.ifc_req + i);
+#ifdef HAVE_SA_LEN
+               if (ifp -> ifr_addr.sa_len)
+                       i += (sizeof ifp -> ifr_name) + ifp -> ifr_addr.sa_len;
+               else
+#endif
+                       i += sizeof *ifp;
+
+#ifdef ALIAS_NAMES_PERMUTED
+               if ((s = strrchr (ifp -> ifr_name, ':'))) {
+                       *s = 0;
+               }
+#endif
+
+#ifdef SKIP_DUMMY_INTERFACES
+               if (!strncmp (ifp -> ifr_name, "dummy", 5))
+                       continue;
+#endif
+
+
+               /* See if this is the sort of interface we want to
+                  deal with. */
+               strcpy (ifr.ifr_name, ifp -> ifr_name);
+               if (ioctl (sock, SIOCGIFFLAGS, &ifr) < 0)
+                       error ("Can't get interface flags for %s: %m",
+                              ifr.ifr_name);
+
+               /* Skip loopback, point-to-point and down interfaces,
+                  except don't skip down interfaces if we're trying to
+                  get a list of configurable interfaces. */
+               if ((ifr.ifr_flags & IFF_LOOPBACK) ||
+#ifdef IFF_POINTOPOINT
+                   (ifr.ifr_flags & IFF_POINTOPOINT) ||
+#endif
+                   (!(ifr.ifr_flags & IFF_UP) &&
+                    state != DISCOVER_UNCONFIGURED))
+                       continue;
+               
+               /* See if we've seen an interface that matches this one. */
+               for (tmp = interfaces; tmp; tmp = tmp -> next)
+                       if (!strcmp (tmp -> name, ifp -> ifr_name))
+                               break;
+
+               /* If there isn't already an interface by this name,
+                  allocate one. */
+               if (!tmp) {
+                       tmp = ((struct interface_info *)
+                              dmalloc (sizeof *tmp, "discover_interfaces"));
+                       if (!tmp)
+                               error ("Insufficient memory to %s %s",
+                                      "record interface", ifp -> ifr_name);
+                       strcpy (tmp -> name, ifp -> ifr_name);
+                       tmp -> circuit_id = (u_int8_t *)tmp -> name;
+                       tmp -> circuit_id_len = strlen (tmp -> name);
+                       tmp -> remote_id = 0;
+                       tmp -> remote_id_len = 0;
+                       tmp -> next = interfaces;
+                       tmp -> flags = ir;
+                       interfaces = tmp;
+               }
+
+               /* If we have the capability, extract link information
+                  and record it in a linked list. */
+#ifdef AF_LINK
+               if (ifp -> ifr_addr.sa_family == AF_LINK) {
+                       struct sockaddr_dl *foo = ((struct sockaddr_dl *)
+                                                  (&ifp -> ifr_addr));
+#if defined (HAVE_SIN_LEN)
+                       tmp -> hw_address.hlen = foo -> sdl_alen;
+#else
+                       tmp -> hw_address.hlen = 6; /* XXX!!! */
+#endif
+                       tmp -> hw_address.htype = HTYPE_ETHER; /* XXX */
+                       memcpy (tmp -> hw_address.haddr,
+                               LLADDR (foo), tmp -> hw_address.hlen);
+               } else
+#endif /* AF_LINK */
+
+               if (ifp -> ifr_addr.sa_family == AF_INET) {
+                       struct iaddr addr;
+
+#if defined (SIOCGIFHWADDR) && !defined (AF_LINK)
+                       struct ifreq ifr;
+                       struct sockaddr sa;
+                       int b, sk;
+                       
+                       /* Read the hardware address from this interface. */
+                       ifr = *ifp;
+                       if (ioctl (sock, SIOCGIFHWADDR, &ifr) < 0)
+                               error ("Can't get hardware address for %s: %m",
+                                      ifr.ifr_name);
+
+                       sa = *(struct sockaddr *)&ifr.ifr_hwaddr;
+                                       
+                       switch (sa.sa_family) {
+#ifdef ARPHRD_LOOPBACK
+                             case ARPHRD_LOOPBACK:
+                               /* ignore loopback interface */
+                               break;
+#endif
+
+                             case ARPHRD_ETHER:
+                               tmp -> hw_address.hlen = 6;
+                               tmp -> hw_address.htype = ARPHRD_ETHER;
+                               memcpy (tmp -> hw_address.haddr,
+                                       sa.sa_data, 6);
+                               break;
+
+#ifndef ARPHRD_IEEE802
+# define ARPHRD_IEEE802 HTYPE_IEEE802
+#endif
+                             case ARPHRD_IEEE802:
+                               tmp -> hw_address.hlen = 6;
+                               tmp -> hw_address.htype = ARPHRD_IEEE802;
+                               memcpy (tmp -> hw_address.haddr,
+                                       sa.sa_data, 6);
+                               break;
+
+#ifdef ARPHRD_FDDI
+                             case ARPHRD_FDDI:
+                               tmp -> hw_address.hlen = 16;
+                               tmp -> hw_address.htype = ARPHRD_FDDI;
+                               memcpy (tmp -> hw_address.haddr,
+                                       sa.sa_data, 16);
+
+                               break;
+#endif
+
+#ifdef ARPHRD_METRICOM
+                             case ARPHRD_METRICOM:
+                               tmp -> hw_address.hlen = 6;
+                               tmp -> hw_address.htype = ARPHRD_METRICOM;
+                               memcpy (tmp -> hw_address.haddr,
+                                       sa.sa_data, 6);
+
+                               break;
+#endif
+
+                             default:
+                               error ("%s: unknown hardware address type %d",
+                                      ifr.ifr_name, sa.sa_family);
+                       }
+#endif /* defined (SIOCGIFHWADDR) && !defined (AF_LINK) */
+
+                       /* Get a pointer to the address... */
+                       memcpy (&foo, &ifp -> ifr_addr,
+                               sizeof ifp -> ifr_addr);
+
+                       /* We don't want the loopback interface. */
+                       if (foo.sin_addr.s_addr == htonl (INADDR_LOOPBACK))
+                               continue;
+
+
+                       /* If this is the first real IP address we've
+                          found, keep a pointer to ifreq structure in
+                          which we found it. */
+                       if (!tmp -> ifp) {
+                               struct ifreq *tif;
+#ifdef HAVE_SA_LEN
+                               int len = ((sizeof ifp -> ifr_name) +
+                                          ifp -> ifr_addr.sa_len);
+#else
+                               int len = sizeof *ifp;
+#endif
+                               tif = (struct ifreq *)malloc (len);
+                               if (!tif)
+                                       error ("no space to remember ifp.");
+                               memcpy (tif, ifp, len);
+                               tmp -> ifp = tif;
+                               tmp -> primary_address = foo.sin_addr;
+                       }
+
+                       /* Grab the address... */
+                       addr.len = 4;
+                       memcpy (addr.iabuf, &foo.sin_addr.s_addr,
+                               addr.len);
+
+                       /* If there's a registered subnet for this address,
+                          connect it together... */
+                       if ((subnet = find_subnet (addr))) {
+                               /* If this interface has multiple aliases
+                                  on the same subnet, ignore all but the
+                                  first we encounter. */
+                               if (!subnet -> interface) {
+                                       subnet -> interface = tmp;
+                                       subnet -> interface_address = addr;
+                               } else if (subnet -> interface != tmp) {
+                                       warn ("Multiple %s %s: %s %s", 
+                                             "interfaces match the",
+                                             "same subnet",
+                                             subnet -> interface -> name,
+                                             tmp -> name);
+                               }
+                               share = subnet -> shared_network;
+                               if (tmp -> shared_network &&
+                                   tmp -> shared_network != share) {
+                                       warn ("Interface %s matches %s",
+                                             tmp -> name,
+                                             "multiple shared networks");
+                               } else {
+                                       tmp -> shared_network = share;
+                               }
+
+                               if (!share -> interface) {
+                                       share -> interface = tmp;
+                               } else if (share -> interface != tmp) {
+                                       warn ("Multiple %s %s: %s %s", 
+                                             "interfaces match the",
+                                             "same shared network",
+                                             share -> interface -> name,
+                                             tmp -> name);
+                               }
+                       }
+               }
+       }
+
+       /* If we're just trying to get a list of interfaces that we might
+          be able to configure, we can quit now. */
+       if (state == DISCOVER_UNCONFIGURED)
+               return;
+
+       /* Weed out the interfaces that did not have IP addresses. */
+       last = (struct interface_info *)0;
+       for (tmp = interfaces; tmp; tmp = next) {
+               next = tmp -> next;
+               if ((tmp -> flags & INTERFACE_AUTOMATIC) &&
+                   state == DISCOVER_REQUESTED)
+                       tmp -> flags &= ~(INTERFACE_AUTOMATIC |
+                                         INTERFACE_REQUESTED);
+               if (!tmp -> ifp || !(tmp -> flags & INTERFACE_REQUESTED)) {
+                       if ((tmp -> flags & INTERFACE_REQUESTED) != ir)
+                               error ("%s: not found", tmp -> name);
+                       if (!last)
+                               interfaces = interfaces -> next;
+                       else
+                               last -> next = tmp -> next;
+
+                       /* Remember the interface in case we need to know
+                          about it later. */
+                       tmp -> next = dummy_interfaces;
+                       dummy_interfaces = tmp;
+                       continue;
+               }
+               last = tmp;
+
+               memcpy (&foo, &tmp -> ifp -> ifr_addr,
+                       sizeof tmp -> ifp -> ifr_addr);
+
+               /* We must have a subnet declaration for each interface. */
+               if (!tmp -> shared_network && (state == DISCOVER_SERVER))
+                       error ("No subnet declaration for %s (%s).",
+                              tmp -> name, inet_ntoa (foo.sin_addr));
+
+               /* Find subnets that don't have valid interface
+                  addresses... */
+               for (subnet = (tmp -> shared_network
+                              ? tmp -> shared_network -> subnets
+                              : (struct subnet *)0);
+                    subnet; subnet = subnet -> next_sibling) {
+                       if (!subnet -> interface_address.len) {
+                               /* Set the interface address for this subnet
+                                  to the first address we found. */
+                               subnet -> interface_address.len = 4;
+                               memcpy (subnet -> interface_address.iabuf,
+                                       &foo.sin_addr.s_addr, 4);
+                       }
+               }
+
+               /* Register the interface... */
+               if_register_receive (tmp);
+               if_register_send (tmp);
+       }
+
+       /* Now register all the remaining interfaces as protocols. */
+       for (tmp = interfaces; tmp; tmp = tmp -> next)
+               add_protocol (tmp -> name, tmp -> rfdesc, got_one, tmp);
+
+       close (sock);
+
+#ifdef USE_FALLBACK
+       strcpy (fallback_interface.name, "fallback");   
+       fallback_interface.shared_network = &fallback_network;
+       fallback_network.name = "fallback-net";
+       if_register_fallback (&fallback_interface);
+       add_protocol ("fallback", fallback_interface.wfdesc,
+                     fallback_discard, &fallback_interface);
+#endif
+}
+
+void reinitialize_interfaces ()
+{
+       struct interface_info *ip;
+
+       for (ip = interfaces; ip; ip = ip -> next) {
+               if_reinitialize_receive (ip);
+               if_reinitialize_send (ip);
+       }
+
+#ifdef USE_FALLBACK
+       if_reinitialize_fallback (&fallback_interface);
+#endif
+
+       interfaces_invalidated = 1;
+}
+static void got_one (l)
+       struct protocol *l;
+{
+       struct sockaddr_in from;
+       struct hardware hfrom;
+       struct iaddr ifrom;
+       int result;
+       union {
+               unsigned char packbuf [4095]; /* Packet input buffer.
+                                                Must be as large as largest
+                                                possible MTU. */
+               struct dhcp_packet packet;
+       } u;
+       struct interface_info *ip = l -> local;
+
+       if ((result =
+            receive_packet (ip, u.packbuf, sizeof u, &from, &hfrom)) < 0) {
+               warn ("receive_packet failed on %s: %m", ip -> name);
+               return;
+       }
+       if (result == 0)
+               return;
+
+       if (bootp_packet_handler) {
+               ifrom.len = 4;
+               memcpy (ifrom.iabuf, &from.sin_addr, ifrom.len);
+
+               (*bootp_packet_handler) (ip, &u.packet, result,
+                                        from.sin_port, ifrom, &hfrom);
+       }
+}
+