/* upf.c Ultrix PacketFilter interface code. /* * Copyright (c) 1995, 1996, 1997 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: upf.c,v 1.1 1998/08/18 03:43:27 deraadt Exp $ Copyright (c) 1995, 1996 The Internet Software Consortium. All rights reserved.\n"; #endif /* not lint */ #include "dhcpd.h" #if defined (USE_UPF_SEND) || defined (USE_UPF_RECEIVE) #include #include #include #include #include "includes/netinet/ip.h" #include "includes/netinet/udp.h" #include "includes/netinet/if_ether.h" /* Reinitializes the specified interface after an address change. This is not required for packet-filter APIs. */ #ifdef USE_UPF_SEND void if_reinitialize_send (info) struct interface_info *info; { } #endif #ifdef USE_UPF_RECEIVE void if_reinitialize_receive (info) struct interface_info *info; { } #endif /* Called by get_interface_list for each interface that's discovered. Opens a packet filter for each interface and adds it to the select mask. */ int if_register_upf (info) struct interface_info *info; { int sock; char filename[50]; int b; struct endevp param; /* Open a UPF device */ for (b = 0; 1; b++) { #ifndef NO_SNPRINTF snprintf(filename, sizeof(filename), "/dev/pf/pfilt%d", b); #else sprintf(filename, "/dev/pf/pfilt%d", b); #endif sock = open (filename, O_RDWR, 0); if (sock < 0) { if (errno == EBUSY) { continue; } else { error ("Can't find free upf: %m"); } } else { break; } } /* Set the UPF device to point at this interface. */ if (ioctl (sock, EIOCSETIF, info -> ifp) < 0) error ("Can't attach interface %s to upf device %s: %m", info -> name, filename); /* Get the hardware address. */ if (ioctl (sock, EIOCDEVP, ¶m) < 0) error ("Can't get interface %s hardware address: %m", info -> name); /* We only know how to do ethernet. */ if (param.end_dev_type != ENDT_10MB) error ("Invalid device type on network interface %s: %d", info -> name, param.end_dev_type); if (param.end_addr_len != 6) error ("Invalid hardware address length on %s: %d", info -> name, param.end_addr_len); info -> hw_address.hlen = 6; info -> hw_address.htype = ARPHRD_ETHER; memcpy (&info -> hw_address.haddr [0], param.end_addr, 6); return sock; } #endif /* USE_UPF_SEND || USE_UPF_RECEIVE */ #ifdef USE_UPF_SEND void if_register_send (info) struct interface_info *info; { /* If we're using the upf API for sending and receiving, we don't need to register this interface twice. */ #ifndef USE_UPF_RECEIVE info -> wfdesc = if_register_upf (info, interface); #else info -> wfdesc = info -> rfdesc; #endif if (!quiet_interface_discovery) note ("Sending on UPF/%s/%s/%s", info -> name, print_hw_addr (info -> hw_address.htype, info -> hw_address.hlen, info -> hw_address.haddr), (info -> shared_network ? info -> shared_network -> name : "unattached")); } #endif /* USE_UPF_SEND */ #ifdef USE_UPF_RECEIVE /* Packet filter program... XXX Changes to the filter program may require changes to the constant offsets used in if_register_send to patch the UPF program! XXX */ void if_register_receive (info) struct interface_info *info; { int flag = 1; u_int32_t addr; struct enfilter pf; u_int32_t bits; /* Open a UPF device and hang it on this interface... */ info -> rfdesc = if_register_upf (info); /* Allow the copyall flag to be set... */ if (ioctl(info -> rfdesc, EIOCALLOWCOPYALL, &flag) < 0) error ("Can't set ALLOWCOPYALL: %m"); /* Clear all the packet filter mode bits first... */ flag = (ENHOLDSIG | ENBATCH | ENTSTAMP | ENPROMISC | ENNONEXCL | ENCOPYALL); if (ioctl (info -> rfdesc, EIOCMBIC, &flag) < 0) error ("Can't clear pfilt bits: %m"); /* Set the ENBATCH and ENCOPYALL bits... */ bits = ENBATCH | ENCOPYALL; if (ioctl (info -> rfdesc, EIOCMBIS, &bits) < 0) error ("Can't set ENBATCH|ENCOPYALL: %m"); /* Set up the UPF filter program. */ /* XXX Unlike the BPF filter program, this one won't work if the XXX IP packet is fragmented or if there are options on the IP XXX header. */ pf.enf_Priority = 0; pf.enf_FilterLen = 0; pf.enf_Filter [pf.enf_FilterLen++] = ENF_PUSHWORD + 6; pf.enf_Filter [pf.enf_FilterLen++] = ENF_PUSHLIT + ENF_CAND; pf.enf_Filter [pf.enf_FilterLen++] = htons (ETHERTYPE_IP); pf.enf_Filter [pf.enf_FilterLen++] = ENF_PUSHLIT; pf.enf_Filter [pf.enf_FilterLen++] = htons (IPPROTO_UDP); pf.enf_Filter [pf.enf_FilterLen++] = ENF_PUSHWORD + 11; pf.enf_Filter [pf.enf_FilterLen++] = ENF_PUSHLIT + ENF_AND; pf.enf_Filter [pf.enf_FilterLen++] = htons (0xFF); pf.enf_Filter [pf.enf_FilterLen++] = ENF_CAND; pf.enf_Filter [pf.enf_FilterLen++] = ENF_PUSHWORD + 18; pf.enf_Filter [pf.enf_FilterLen++] = ENF_PUSHLIT + ENF_CAND; pf.enf_Filter [pf.enf_FilterLen++] = local_port; if (ioctl (info -> rfdesc, EIOCSETF, &pf) < 0) error ("Can't install packet filter program: %m"); if (!quiet_interface_discovery) note ("Listening on UPF/%s/%s/%s", info -> name, print_hw_addr (info -> hw_address.htype, info -> hw_address.hlen, info -> hw_address.haddr), (info -> shared_network ? info -> shared_network -> name : "unattached")); } #endif /* USE_UPF_RECEIVE */ #ifdef USE_UPF_SEND ssize_t send_packet (interface, packet, raw, len, from, to, hto) struct interface_info *interface; struct packet *packet; struct dhcp_packet *raw; size_t len; struct in_addr from; struct sockaddr_in *to; struct hardware *hto; { int bufp = 0; unsigned char buf [256]; struct iovec iov [2]; /* Assemble the headers... */ assemble_hw_header (interface, buf, &bufp, hto); assemble_udp_ip_header (interface, buf, &bufp, from.s_addr, to -> sin_addr.s_addr, to -> sin_port, (unsigned char *)raw, len); /* Fire it off */ iov [0].iov_base = (char *)buf; iov [0].iov_len = bufp; iov [1].iov_base = (char *)raw; iov [1].iov_len = len; return writev(interface -> wfdesc, iov, 2); } #endif /* USE_UPF_SEND */ #ifdef USE_UPF_RECEIVE ssize_t receive_packet (interface, buf, len, from, hfrom) struct interface_info *interface; unsigned char *buf; size_t len; struct sockaddr_in *from; struct hardware *hfrom; { int nread; int length = 0; int offset = 0; unsigned char ibuf [1500 + sizeof (struct enstamp)]; int bufix = 0; length = read (interface -> rfdesc, ibuf, sizeof ibuf); if (length <= 0) return length; bufix = sizeof (struct enstamp); /* Decode the physical header... */ offset = decode_hw_header (interface, ibuf, bufix, hfrom); /* If a physical layer checksum failed (dunno of any physical layer that supports this, but WTH), skip this packet. */ if (offset < 0) { return 0; } bufix += offset; length -= offset; /* Decode the IP and UDP headers... */ offset = decode_udp_ip_header (interface, ibuf, bufix, from, (unsigned char *)0, length); /* If the IP or UDP checksum was bad, skip the packet... */ if (offset < 0) return 0; bufix += offset; length -= offset; /* Copy out the data in the packet... */ memcpy (buf, &ibuf [bufix], length); return length; } #endif