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Diffstat (limited to 'common/upf.c')
-rw-r--r-- | common/upf.c | 373 |
1 files changed, 373 insertions, 0 deletions
diff --git a/common/upf.c b/common/upf.c new file mode 100644 index 0000000..feb82a2 --- /dev/null +++ b/common/upf.c @@ -0,0 +1,373 @@ +/* upf.c + + Ultrix PacketFilter interface code. */ + +/* + * Copyright (c) 2004,2007,2009 by Internet Systems Consortium, Inc. ("ISC") + * Copyright (c) 1996-2003 by Internet Software Consortium + * + * Permission to use, copy, modify, and distribute this software for any + * purpose with or without fee is hereby granted, provided that the above + * copyright notice and this permission notice appear in all copies. + * + * THE SOFTWARE IS PROVIDED "AS IS" AND ISC DISCLAIMS ALL WARRANTIES + * WITH REGARD TO THIS SOFTWARE INCLUDING ALL IMPLIED WARRANTIES OF + * MERCHANTABILITY AND FITNESS. IN NO EVENT SHALL ISC BE LIABLE FOR + * ANY SPECIAL, DIRECT, INDIRECT, OR CONSEQUENTIAL DAMAGES OR ANY DAMAGES + * WHATSOEVER RESULTING FROM LOSS OF USE, DATA OR PROFITS, WHETHER IN AN + * ACTION OF CONTRACT, NEGLIGENCE OR OTHER TORTIOUS ACTION, ARISING OUT + * OF OR IN CONNECTION WITH THE USE OR PERFORMANCE OF THIS SOFTWARE. + * + * Internet Systems Consortium, Inc. + * 950 Charter Street + * Redwood City, CA 94063 + * <info@isc.org> + * https://www.isc.org/ + * + * This software has been written for Internet Systems Consortium + * by Ted Lemon in cooperation with Vixie Enterprises and Nominum, Inc. + * To learn more about Internet Systems Consortium, see + * ``https://www.isc.org/''. To learn more about Vixie Enterprises, + * see ``http://www.vix.com''. To learn more about Nominum, Inc., see + * ``http://www.nominum.com''. + */ + +#include "dhcpd.h" +#if defined (USE_UPF_SEND) || defined (USE_UPF_RECEIVE) +#include <sys/ioctl.h> +#include <sys/uio.h> + +#include <net/pfilt.h> +#include <netinet/in_systm.h> +#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++) { + /* %Audit% Cannot exceed 36 bytes. %2004.06.17,Safe% */ + sprintf(filename, "/dev/pf/pfilt%d", b); + + sock = open (filename, O_RDWR, 0); + if (sock < 0) { + if (errno == EBUSY) { + continue; + } else { + log_fatal ("Can't find free upf: %m"); + } + } else { + break; + } + } + + /* Set the UPF device to point at this interface. */ + if (ioctl (sock, EIOCSETIF, info -> ifp) < 0) + log_fatal ("Can't attach interface %s to upf device %s: %m", + info -> name, filename); + + /* Get the hardware address. */ + if (ioctl (sock, EIOCDEVP, ¶m) < 0) + log_fatal ("Can't get interface %s hardware address: %m", + info -> name); + + /* We only know how to do ethernet. */ + if (param.end_dev_type != ENDT_10MB) + log_fatal ("Invalid device type on network interface %s: %d", + info -> name, param.end_dev_type); + + if (param.end_addr_len != 6) + log_fatal ("Invalid hardware address length on %s: %d", + info -> name, param.end_addr_len); + + info -> hw_address.hlen = 7; + info -> hw_address.hbuf [0] = ARPHRD_ETHER; + memcpy (&info -> hw_address.hbuf [1], 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) + log_info ("Sending on UPF/%s/%s%s%s", + info -> name, + print_hw_addr (info -> hw_address.hbuf [0], + info -> hw_address.hlen - 1, + &info -> hw_address.hbuf [1]), + (info -> shared_network ? "/" : ""), + (info -> shared_network ? + info -> shared_network -> name : "")); +} + +void if_deregister_send (info) + struct interface_info *info; +{ +#ifndef USE_UPF_RECEIVE + close (info -> wfdesc); +#endif + info -> wfdesc = -1; + if (!quiet_interface_discovery) + log_info ("Disabling output on UPF/%s/%s%s%s", + info -> name, + print_hw_addr (info -> hw_address.hbuf [0], + info -> hw_address.hlen - 1, + &info -> hw_address.hbuf [1]), + (info -> shared_network ? "/" : ""), + (info -> shared_network ? + info -> shared_network -> name : "")); +} +#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) + log_fatal ("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) + log_fatal ("Can't clear pfilt bits: %m"); + + /* Set the ENBATCH and ENCOPYALL bits... */ + bits = ENBATCH | ENCOPYALL; + if (ioctl (info -> rfdesc, EIOCMBIS, &bits) < 0) + log_fatal ("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) + log_fatal ("Can't install packet filter program: %m"); + if (!quiet_interface_discovery) + log_info ("Listening on UPF/%s/%s%s%s", + info -> name, + print_hw_addr (info -> hw_address.hbuf [0], + info -> hw_address.hlen - 1, + &info -> hw_address.hbuf [1]), + (info -> shared_network ? "/" : ""), + (info -> shared_network ? + info -> shared_network -> name : "")); +} + +void if_deregister_receive (info) + struct interface_info *info; +{ + close (info -> rfdesc); + info -> rfdesc = -1; + if (!quiet_interface_discovery) + log_info ("Disabling input on UPF/%s/%s%s%s", + info -> name, + print_hw_addr (info -> hw_address.hbuf [0], + info -> hw_address.hlen - 1, + &info -> hw_address.hbuf [1]), + (info -> shared_network ? "/" : ""), + (info -> shared_network ? + info -> shared_network -> name : "")); +} +#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; +{ + unsigned hbufp = 0, ibufp = 0; + double hw [4]; + double ip [32]; + struct iovec iov [3]; + int result; + int fudge; + + if (!strcmp (interface -> name, "fallback")) + return send_fallback (interface, packet, raw, + len, from, to, hto); + + if (hto == NULL && interface->anycast_mac_addr.hlen) + hto = &interface->anycast_mac_addr; + + /* Assemble the headers... */ + assemble_hw_header (interface, (unsigned char *)hw, &hbufp, hto); + assemble_udp_ip_header (interface, + (unsigned char *)ip, &ibufp, from.s_addr, + to -> sin_addr.s_addr, to -> sin_port, + (unsigned char *)raw, len); + + /* Fire it off */ + iov [0].iov_base = ((char *)hw); + iov [0].iov_len = hbufp; + iov [1].iov_base = ((char *)ip); + iov [1].iov_len = ibufp; + iov [2].iov_base = (char *)raw; + iov [2].iov_len = len; + + result = writev(interface -> wfdesc, iov, 3); + if (result < 0) + log_error ("send_packet: %m"); + return result; +} +#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; + unsigned paylen; + + 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, length, &paylen); + + /* If the IP or UDP checksum was bad, skip the packet... */ + if (offset < 0) + return 0; + + bufix += offset; + length -= offset; + + if (length < paylen) + log_fatal("Internal inconsistency at %s:%d.", MDL); + + /* Copy out the data in the packet... */ + memcpy (buf, &ibuf[bufix], paylen); + return paylen; +} + +int can_unicast_without_arp (ip) + struct interface_info *ip; +{ + return 1; +} + +int can_receive_unicast_unconfigured (ip) + struct interface_info *ip; +{ + return 1; +} + +int supports_multiple_interfaces (ip) + struct interface_info *ip; +{ + return 1; +} + +void maybe_setup_fallback () +{ + isc_result_t status; + struct interface_info *fbi = (struct interface_info *)0; + if (setup_fallback (&fbi, MDL)) { + if_register_fallback (fbi); + status = omapi_register_io_object ((omapi_object_t *)fbi, + if_readsocket, 0, + fallback_discard, 0, 0); + if (status != ISC_R_SUCCESS) + log_fatal ("Can't register I/O handle for %s: %s", + fbi -> name, isc_result_totext (status)); + interface_dereference (&fbi, MDL); + } +} +#endif |