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-rw-r--r--isisd/isis_bpf.c340
1 files changed, 340 insertions, 0 deletions
diff --git a/isisd/isis_bpf.c b/isisd/isis_bpf.c
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--- /dev/null
+++ b/isisd/isis_bpf.c
@@ -0,0 +1,340 @@
+/*
+ * IS-IS Rout(e)ing protocol - isis_bpf.c
+ *
+ * Copyright (C) 2001,2002 Sampo Saaristo
+ * Tampere University of Technology
+ * Institute of Communications Engineering
+ *
+ * This program is free software; you can redistribute it and/or modify it
+ * under the terms of the GNU General Public Licenseas published by the Free
+ * Software Foundation; either version 2 of the License, or (at your option)
+ * any later version.
+ *
+ * This program is distributed in the hope that it will be useful,but WITHOUT
+ * ANY WARRANTY; without even the implied warranty of MERCHANTABILITY or
+ * FITNESS FOR A PARTICULAR PURPOSE. See the GNU General Public License for
+ * more details.
+
+ * You should have received a copy of the GNU General Public License along
+ * with this program; if not, write to the Free Software Foundation, Inc.,
+ * 59 Temple Place - Suite 330, Boston, MA 02111-1307, USA.
+ */
+
+#include <zebra.h>
+#include <net/if.h>
+#include <netinet/if_ether.h>
+#include <sys/time.h>
+#include <sys/ioctl.h>
+#include <net/bpf.h>
+
+#include "log.h"
+#include "stream.h"
+#include "if.h"
+
+#include "isisd/dict.h"
+#include "isisd/include-netbsd/iso.h"
+#include "isisd/isis_constants.h"
+#include "isisd/isis_common.h"
+#include "isisd/isis_circuit.h"
+#include "isisd/isis_flags.h"
+#include "isisd/isisd.h"
+#include "isisd/isis_constants.h"
+#include "isisd/isis_circuit.h"
+#include "isisd/isis_network.h"
+
+#include "privs.h"
+
+extern struct zebra_privs_t isisd_privs;
+
+struct bpf_insn llcfilter[] = {
+ BPF_STMT (BPF_LD + BPF_B + BPF_ABS, ETHER_HDR_LEN), /* check first byte */
+ BPF_JUMP (BPF_JMP + BPF_JEQ + BPF_K, ISO_SAP, 0, 5),
+ BPF_STMT (BPF_LD + BPF_B + BPF_ABS, ETHER_HDR_LEN + 1),
+ BPF_JUMP (BPF_JMP + BPF_JEQ + BPF_K, ISO_SAP, 0, 3), /* check second byte */
+ BPF_STMT (BPF_LD + BPF_B + BPF_ABS, ETHER_HDR_LEN + 2),
+ BPF_JUMP (BPF_JMP + BPF_JEQ + BPF_K, 0x03, 0, 1), /* check third byte */
+ BPF_STMT (BPF_RET + BPF_K, (u_int) - 1),
+ BPF_STMT (BPF_RET + BPF_K, 0)
+};
+int readblen = 0;
+u_char *readbuff = NULL;
+
+/*
+ * Table 9 - Architectural constants for use with ISO 8802 subnetworks
+ * ISO 10589 - 8.4.8
+ */
+
+u_char ALL_L1_ISS[6] = { 0x01, 0x80, 0xC2, 0x00, 0x00, 0x14 };
+u_char ALL_L2_ISS[6] = { 0x01, 0x80, 0xC2, 0x00, 0x00, 0x15 };
+u_char ALL_ISS[6] = { 0x09, 0x00, 0x2B, 0x00, 0x00, 0x05 };
+u_char ALL_ESS[6] = { 0x09, 0x00, 0x2B, 0x00, 0x00, 0x04 };
+
+static char sock_buff[8192];
+
+static int
+open_bpf_dev (struct isis_circuit *circuit)
+{
+ int i = 0, fd;
+ char bpfdev[128];
+ struct ifreq ifr;
+ u_int16_t blen;
+ int true = 1, false = 0;
+ struct timeval timeout;
+ struct bpf_program bpf_prog;
+
+ do
+ {
+ (void) snprintf (bpfdev, sizeof (bpfdev), "/dev/bpf%d", i++);
+ fd = open (bpfdev, O_RDWR);
+ }
+ while (fd < 0 && errno == EBUSY);
+
+ if (fd < 0)
+ {
+ zlog_warn ("open_bpf_dev(): failed to create bpf socket: %s",
+ safe_strerror (errno));
+ return ISIS_WARNING;
+ }
+
+ zlog_debug ("Opened BPF device %s", bpfdev);
+
+ memcpy (ifr.ifr_name, circuit->interface->name, sizeof (ifr.ifr_name));
+ if (ioctl (fd, BIOCSETIF, (caddr_t) & ifr) < 0)
+ {
+ zlog_warn ("open_bpf_dev(): failed to bind to interface: %s",
+ safe_strerror (errno));
+ return ISIS_WARNING;
+ }
+
+ if (ioctl (fd, BIOCGBLEN, (caddr_t) & blen) < 0)
+ {
+ zlog_warn ("failed to get BPF buffer len");
+ blen = circuit->interface->mtu;
+ }
+
+ readblen = blen;
+
+ if (readbuff == NULL)
+ readbuff = malloc (blen);
+
+ zlog_debug ("BPF buffer len = %u", blen);
+
+ /* BPF(4): reads return immediately upon packet reception.
+ * Otherwise, a read will block until either the kernel
+ * buffer becomes full or a timeout occurs.
+ */
+ if (ioctl (fd, BIOCIMMEDIATE, (caddr_t) & true) < 0)
+ {
+ zlog_warn ("failed to set BPF dev to immediate mode");
+ }
+
+#ifdef BIOCSSEESENT
+ /*
+ * We want to see only incoming packets
+ */
+ if (ioctl (fd, BIOCSSEESENT, (caddr_t) & false) < 0)
+ {
+ zlog_warn ("failed to set BPF dev to incoming only mode");
+ }
+#endif
+
+ /*
+ * ...but all of them
+ */
+ if (ioctl (fd, BIOCPROMISC, (caddr_t) & true) < 0)
+ {
+ zlog_warn ("failed to set BPF dev to promiscuous mode");
+ }
+
+ /*
+ * If the buffer length is smaller than our mtu, lets try to increase it
+ */
+ if (blen < circuit->interface->mtu)
+ {
+ if (ioctl (fd, BIOCSBLEN, &circuit->interface->mtu) < 0)
+ {
+ zlog_warn ("failed to set BPF buffer len (%u to %u)", blen,
+ circuit->interface->mtu);
+ }
+ }
+
+ /*
+ * Set a timeout parameter - hope this helps select()
+ */
+ timeout.tv_sec = 600;
+ timeout.tv_usec = 0;
+ if (ioctl (fd, BIOCSRTIMEOUT, (caddr_t) & timeout) < 0)
+ {
+ zlog_warn ("failed to set BPF device timeout");
+ }
+
+ /*
+ * And set the filter
+ */
+ memset (&bpf_prog, 0, sizeof (struct bpf_program));
+ bpf_prog.bf_len = 8;
+ bpf_prog.bf_insns = &(llcfilter[0]);
+ if (ioctl (fd, BIOCSETF, (caddr_t) & bpf_prog) < 0)
+ {
+ zlog_warn ("open_bpf_dev(): failed to install filter: %s",
+ safe_strerror (errno));
+ return ISIS_WARNING;
+ }
+
+ assert (fd > 0);
+
+ circuit->fd = fd;
+
+ return ISIS_OK;
+}
+
+/*
+ * Create the socket and set the tx/rx funcs
+ */
+int
+isis_sock_init (struct isis_circuit *circuit)
+{
+ int retval = ISIS_OK;
+
+ if (isisd_privs.change (ZPRIVS_RAISE))
+ zlog_err ("%s: could not raise privs, %s", __func__, safe_strerror (errno));
+
+ retval = open_bpf_dev (circuit);
+
+ if (retval != ISIS_OK)
+ {
+ zlog_warn ("%s: could not initialize the socket", __func__);
+ goto end;
+ }
+
+ if (circuit->circ_type == CIRCUIT_T_BROADCAST)
+ {
+ circuit->tx = isis_send_pdu_bcast;
+ circuit->rx = isis_recv_pdu_bcast;
+ }
+ else if (circuit->circ_type == CIRCUIT_T_P2P)
+ {
+ circuit->tx = isis_send_pdu_p2p;
+ circuit->rx = isis_recv_pdu_p2p;
+ }
+ else
+ {
+ zlog_warn ("isis_sock_init(): unknown circuit type");
+ retval = ISIS_WARNING;
+ goto end;
+ }
+
+end:
+ if (isisd_privs.change (ZPRIVS_LOWER))
+ zlog_err ("%s: could not lower privs, %s", __func__, safe_strerror (errno));
+
+ return retval;
+}
+
+int
+isis_recv_pdu_bcast (struct isis_circuit *circuit, u_char * ssnpa)
+{
+ int bytesread = 0, bytestoread, offset, one = 1;
+ struct bpf_hdr *bpf_hdr;
+
+ assert (circuit->fd > 0);
+
+ if (ioctl (circuit->fd, FIONREAD, (caddr_t) & bytestoread) < 0)
+ {
+ zlog_warn ("ioctl() FIONREAD failed: %s", safe_strerror (errno));
+ }
+
+ if (bytestoread)
+ {
+ bytesread = read (circuit->fd, readbuff, readblen);
+ }
+ if (bytesread < 0)
+ {
+ zlog_warn ("isis_recv_pdu_bcast(): read() failed: %s",
+ safe_strerror (errno));
+ return ISIS_WARNING;
+ }
+
+ if (bytesread == 0)
+ return ISIS_WARNING;
+
+ bpf_hdr = (struct bpf_hdr *) readbuff;
+
+ assert (bpf_hdr->bh_caplen == bpf_hdr->bh_datalen);
+
+ offset = bpf_hdr->bh_hdrlen + LLC_LEN + ETHER_HDR_LEN;
+
+ /* then we lose the BPF, LLC and ethernet headers */
+ stream_write (circuit->rcv_stream, readbuff + offset,
+ bpf_hdr->bh_caplen - LLC_LEN - ETHER_HDR_LEN);
+ stream_set_getp (circuit->rcv_stream, 0);
+
+ memcpy (ssnpa, readbuff + bpf_hdr->bh_hdrlen + ETHER_ADDR_LEN,
+ ETHER_ADDR_LEN);
+
+ if (ioctl (circuit->fd, BIOCFLUSH, &one) < 0)
+ zlog_warn ("Flushing failed: %s", safe_strerror (errno));
+
+ return ISIS_OK;
+}
+
+int
+isis_recv_pdu_p2p (struct isis_circuit *circuit, u_char * ssnpa)
+{
+ int bytesread;
+
+ bytesread = stream_read (circuit->rcv_stream, circuit->fd,
+ circuit->interface->mtu);
+
+ if (bytesread < 0)
+ {
+ zlog_warn ("isis_recv_pdu_p2p(): read () failed: %s", safe_strerror (errno));
+ return ISIS_WARNING;
+ }
+
+ return ISIS_OK;
+}
+
+int
+isis_send_pdu_bcast (struct isis_circuit *circuit, int level)
+{
+ struct ether_header *eth;
+ int written;
+
+ stream_set_getp (circuit->snd_stream, 0);
+
+ /*
+ * First the eth header
+ */
+ eth = (struct ether_header *) sock_buff;
+ if (level == 1)
+ memcpy (eth->ether_dhost, ALL_L1_ISS, ETHER_ADDR_LEN);
+ else
+ memcpy (eth->ether_dhost, ALL_L2_ISS, ETHER_ADDR_LEN);
+ memcpy (eth->ether_shost, circuit->u.bc.snpa, ETHER_ADDR_LEN);
+ eth->ether_type = htons (stream_get_endp (circuit->snd_stream) + LLC_LEN);
+
+ /*
+ * Then the LLC
+ */
+ sock_buff[ETHER_HDR_LEN] = ISO_SAP;
+ sock_buff[ETHER_HDR_LEN + 1] = ISO_SAP;
+ sock_buff[ETHER_HDR_LEN + 2] = 0x03;
+
+ /* then we copy the data */
+ memcpy (sock_buff + (LLC_LEN + ETHER_HDR_LEN), circuit->snd_stream->data,
+ stream_get_endp (circuit->snd_stream));
+
+ /* now we can send this */
+ written = write (circuit->fd, sock_buff,
+ stream_get_endp (circuit->snd_stream)
+ + LLC_LEN + ETHER_HDR_LEN);
+
+ return ISIS_OK;
+}
+
+int
+isis_send_pdu_p2p (struct isis_circuit *circuit, int level)
+{
+ return ISIS_OK;
+}
generated by cgit v1.2.1 (git 2.18.0) at 2024-11-16 22:12:24 +0000