From fa226d8ff58ca6bc93ad4ff82f09853f32d31273 Mon Sep 17 00:00:00 2001 From: Ted Lemon Date: Fri, 6 Nov 1998 00:19:56 +0000 Subject: [PATCH] Interface discovery code. --- common/discover.c | 450 ++++++++++++++++++++++++++++++++++++++++++++++ 1 file changed, 450 insertions(+) create mode 100644 common/discover.c diff --git a/common/discover.c b/common/discover.c new file mode 100644 index 000000000..81d06a208 --- /dev/null +++ b/common/discover.c @@ -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 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 + +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); + } +} + -- 2.47.3