diff options
Diffstat (limited to 'common/bpf.c')
| -rw-r--r-- | common/bpf.c | 384 |
1 files changed, 0 insertions, 384 deletions
diff --git a/common/bpf.c b/common/bpf.c deleted file mode 100644 index d223a9f8..00000000 --- a/common/bpf.c +++ /dev/null @@ -1,384 +0,0 @@ -/* bpf.c - - BPF socket interface code, originally contributed by Archie Cobbs. */ - -/* - * Copyright (c) 1995, 1996 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: bpf.c,v 1.17 1997/02/26 05:20:52 mellon Exp $ Copyright (c) 1995, 1996 The Internet Software Consortium. All rights reserved.\n"; -#endif /* not lint */ - -#include "dhcpd.h" -#if defined (USE_BPF_SEND) || defined (USE_BPF_RECEIVE) -#include <sys/ioctl.h> -#include <sys/uio.h> - -#include <net/bpf.h> -#ifdef NEED_OSF_PFILT_HACKS -#include <net/pfilt.h> -#endif -#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_BPF_SEND -void if_reinitialize_send (info) - struct interface_info *info; -{ -} -#endif - -#ifdef USE_BPF_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_bpf (info) - struct interface_info *info; -{ - int sock; - char filename[50]; - int b; - - /* Open a BPF device */ - for (b = 0; 1; b++) { -#ifndef NO_SNPRINTF - snprintf(filename, sizeof(filename), BPF_FORMAT, b); -#else - sprintf(filename, BPF_FORMAT, b); -#endif - sock = open (filename, O_RDWR, 0); - if (sock < 0) { - if (errno == EBUSY) { - continue; - } else { - error ("Can't find free bpf: %m"); - } - } else { - break; - } - } - - /* Set the BPF device to point at this interface. */ - if (ioctl (sock, BIOCSETIF, info -> ifp) < 0) - error ("Can't attach interface %s to bpf device %s: %m", - info -> name, filename); - - return sock; -} -#endif /* USE_BPF_SEND || USE_BPF_RECEIVE */ - -#ifdef USE_BPF_SEND -void if_register_send (info) - struct interface_info *info; -{ - /* If we're using the bpf API for sending and receiving, - we don't need to register this interface twice. */ -#ifndef USE_BPF_RECEIVE - info -> wfdesc = if_register_bpf (info, interface); -#else - info -> wfdesc = info -> rfdesc; -#endif - note ("Sending on BPF/%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_BPF_SEND */ - -#ifdef USE_BPF_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 BPF program! XXX */ - -struct bpf_insn filter [] = { - /* Make sure this is an IP packet... */ - BPF_STMT (BPF_LD + BPF_H + BPF_ABS, 12), - BPF_JUMP (BPF_JMP + BPF_JEQ + BPF_K, ETHERTYPE_IP, 0, 8), - - /* Make sure it's a UDP packet... */ - BPF_STMT (BPF_LD + BPF_B + BPF_ABS, 23), - BPF_JUMP (BPF_JMP + BPF_JEQ + BPF_K, IPPROTO_UDP, 0, 6), - - /* Make sure this isn't a fragment... */ - BPF_STMT(BPF_LD + BPF_H + BPF_ABS, 20), - BPF_JUMP(BPF_JMP + BPF_JSET + BPF_K, 0x1fff, 4, 0), - - /* Get the IP header length... */ - BPF_STMT (BPF_LDX + BPF_B + BPF_MSH, 14), - - /* Make sure it's to the right port... */ - BPF_STMT (BPF_LD + BPF_H + BPF_IND, 16), - BPF_JUMP (BPF_JMP + BPF_JEQ + BPF_K, 67, 0, 1), /* patch */ - - /* If we passed all the tests, ask for the whole packet. */ - BPF_STMT(BPF_RET+BPF_K, (u_int)-1), - - /* Otherwise, drop it. */ - BPF_STMT(BPF_RET+BPF_K, 0), -}; - -void if_register_receive (info) - struct interface_info *info; -{ - int flag = 1; - struct bpf_version v; - u_int32_t addr; - struct bpf_program p; - u_int32_t bits; - - /* Open a BPF device and hang it on this interface... */ - info -> rfdesc = if_register_bpf (info); - - /* Make sure the BPF version is in range... */ - if (ioctl (info -> rfdesc, BIOCVERSION, &v) < 0) - error ("Can't get BPF version: %m"); - - if (v.bv_major != BPF_MAJOR_VERSION || - v.bv_minor < BPF_MINOR_VERSION) - error ("Kernel BPF version out of range - recompile dhcpd!"); - - /* Set immediate mode so that reads return as soon as a packet - comes in, rather than waiting for the input buffer to fill with - packets. */ - if (ioctl (info -> rfdesc, BIOCIMMEDIATE, &flag) < 0) - error ("Can't set immediate mode on bpf device: %m"); - -#ifdef NEED_OSF_PFILT_HACKS - /* 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... */ - bits = 0; - if (ioctl (info -> rfdesc, EIOCMBIS, &bits) < 0) - error ("Can't clear pfilt bits: %m"); - - /* Set the ENBATCH, ENCOPYALL, ENBPFHDR bits... */ - bits = ENBATCH | ENCOPYALL | ENBPFHDR; - if (ioctl (info -> rfdesc, EIOCMBIS, &bits) < 0) - error ("Can't set ENBATCH|ENCOPYALL|ENBPFHDR: %m"); -#endif - /* Get the required BPF buffer length from the kernel. */ - if (ioctl (info -> rfdesc, BIOCGBLEN, &info -> rbuf_max) < 0) - error ("Can't get bpf buffer length: %m"); - info -> rbuf = malloc (info -> rbuf_max); - if (!info -> rbuf) - error ("Can't allocate %d bytes for bpf input buffer."); - info -> rbuf_offset = 0; - info -> rbuf_len = 0; - - /* Set up the bpf filter program structure. */ - p.bf_len = sizeof filter / sizeof (struct bpf_insn); - p.bf_insns = filter; - - /* Patch the server port into the BPF program... - XXX changes to filter program may require changes - to the insn number(s) used below! XXX */ - filter [8].k = ntohs (local_port); - - if (ioctl (info -> rfdesc, BIOCSETF, &p) < 0) - error ("Can't install packet filter program: %m"); - note ("Listening on BPF/%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_BPF_RECEIVE */ - -#ifdef USE_BPF_SEND -size_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_BPF_SEND */ - -#ifdef USE_BPF_RECEIVE -size_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 length = 0; - int offset = 0; - struct bpf_hdr hdr; - - /* All this complexity is because BPF doesn't guarantee - that only one packet will be returned at a time. We're - getting what we deserve, though - this is a terrible abuse - of the BPF interface. Sigh. */ - - /* Process packets until we get one we can return or until we've - done a read and gotten nothing we can return... */ - - do { - /* If the buffer is empty, fill it. */ - if (interface -> rbuf_offset == interface -> rbuf_len) { - length = read (interface -> rfdesc, - interface -> rbuf, - interface -> rbuf_max); - if (length <= 0) - return length; - interface -> rbuf_offset = 0; - interface -> rbuf_len = length; - } - - /* If there isn't room for a whole bpf header, something went - wrong, but we'll ignore it and hope it goes away... XXX */ - if (interface -> rbuf_len - - interface -> rbuf_offset < sizeof hdr) { - interface -> rbuf_offset = interface -> rbuf_len; - continue; - } - - /* Copy out a bpf header... */ - memcpy (&hdr, &interface -> rbuf [interface -> rbuf_offset], - sizeof hdr); - - /* If the bpf header plus data doesn't fit in what's left - of the buffer, stick head in sand yet again... */ - if (interface -> rbuf_offset + - hdr.bh_hdrlen + hdr.bh_caplen > interface -> rbuf_len) { - interface -> rbuf_offset = interface -> rbuf_len; - continue; - } - - /* If the captured data wasn't the whole packet, or if - the packet won't fit in the input buffer, all we - can do is drop it. */ - if (hdr.bh_caplen != hdr.bh_datalen) { - interface -> rbuf_offset += - hdr.bh_hdrlen = hdr.bh_caplen; - continue; - } - - /* Skip over the BPF header... */ - interface -> rbuf_offset += hdr.bh_hdrlen; - - /* Decode the physical header... */ - offset = decode_hw_header (interface, - interface -> rbuf, - interface -> rbuf_offset, - hfrom); - - /* If a physical layer checksum failed (dunno of any - physical layer that supports this, but WTH), skip this - packet. */ - if (offset < 0) { - interface -> rbuf_offset += hdr.bh_caplen; - continue; - } - interface -> rbuf_offset += offset; - hdr.bh_caplen -= offset; - - /* Decode the IP and UDP headers... */ - offset = decode_udp_ip_header (interface, - interface -> rbuf, - interface -> rbuf_offset, - from, - (unsigned char *)0, - hdr.bh_caplen); - - /* If the IP or UDP checksum was bad, skip the packet... */ - if (offset < 0) { - interface -> rbuf_offset += hdr.bh_caplen; - continue; - } - interface -> rbuf_offset += offset; - hdr.bh_caplen -= offset; - - /* If there's not enough room to stash the packet data, - we have to skip it (this shouldn't happen in real - life, though). */ - if (hdr.bh_caplen > len) { - interface -> rbuf_offset += hdr.bh_caplen; - continue; - } - - /* Copy out the data in the packet... */ - memcpy (buf, interface -> rbuf + interface -> rbuf_offset, - hdr.bh_caplen); - interface -> rbuf_offset += hdr.bh_caplen; - return hdr.bh_caplen; - } while (!length); - return 0; -} -#endif |