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authorDaniel Baumann <daniel.baumann@progress-linux.org>2024-04-28 09:53:30 +0000
committerDaniel Baumann <daniel.baumann@progress-linux.org>2024-04-28 09:53:30 +0000
commit2c7cac91ed6e7db0f6937923d2b57f97dbdbc337 (patch)
treec05dc0f8e6aa3accc84e3e5cffc933ed94941383 /isisd/isis_bpf.c
parentInitial commit. (diff)
downloadfrr-2536d89cfd3a79f991a2c9774117e8ccbf7cb5df.tar.xz
frr-2536d89cfd3a79f991a2c9774117e8ccbf7cb5df.zip
Adding upstream version 8.4.4.upstream/8.4.4upstream
Signed-off-by: Daniel Baumann <daniel.baumann@progress-linux.org>
Diffstat (limited to 'isisd/isis_bpf.c')
-rw-r--r--isisd/isis_bpf.c314
1 files changed, 314 insertions, 0 deletions
diff --git a/isisd/isis_bpf.c b/isisd/isis_bpf.c
new file mode 100644
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--- /dev/null
+++ b/isisd/isis_bpf.c
@@ -0,0 +1,314 @@
+/*
+ * 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; see the file COPYING; if not, write to the Free Software
+ * Foundation, Inc., 51 Franklin St, Fifth Floor, Boston, MA 02110-1301 USA
+ */
+
+#include <zebra.h>
+#if ISIS_METHOD == ISIS_METHOD_BPF
+#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 "network.h"
+#include "stream.h"
+#include "if.h"
+#include "lib_errors.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 "isisd/isis_pdu.h"
+
+#include "privs.h"
+
+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, (unsigned int)-1),
+ BPF_STMT(BPF_RET + BPF_K, 0)};
+unsigned int readblen = 0;
+uint8_t *readbuff = NULL;
+
+/*
+ * Table 9 - Architectural constants for use with ISO 8802 subnetworks
+ * ISO 10589 - 8.4.8
+ */
+
+static const uint8_t ALL_L1_ISS[6] = {0x01, 0x80, 0xC2, 0x00, 0x00, 0x14};
+static const uint8_t ALL_L2_ISS[6] = {0x01, 0x80, 0xC2, 0x00, 0x00, 0x15};
+static char sock_buff[16384];
+
+static int open_bpf_dev(struct isis_circuit *circuit)
+{
+ int i = 0, fd;
+ char bpfdev[128];
+ struct ifreq ifr;
+ unsigned int blen, immediate;
+#ifdef BIOCSSEESENT
+ unsigned int seesent;
+#endif
+ 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.
+ */
+ immediate = 1;
+ if (ioctl(fd, BIOCIMMEDIATE, (caddr_t)&immediate) < 0) {
+ zlog_warn("failed to set BPF dev to immediate mode");
+ }
+
+#ifdef BIOCSSEESENT
+ /*
+ * We want to see only incoming packets
+ */
+ seesent = 0;
+ if (ioctl(fd, BIOCSSEESENT, (caddr_t)&seesent) < 0) {
+ zlog_warn("failed to set BPF dev to incoming only mode");
+ }
+#endif
+
+ /*
+ * ...but all of them
+ */
+ if (ioctl(fd, BIOCPROMISC) < 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(bpf_prog));
+ bpf_prog.bf_len = 8;
+ bpf_prog.bf_insns = &(llcfilter[0]);
+ if (ioctl(fd, BIOCSETF, (caddr_t)&bpf_prog) < 0) {
+ zlog_warn("%s: failed to install filter: %s", __func__,
+ 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;
+
+ frr_with_privs(&isisd_privs) {
+
+ retval = open_bpf_dev(circuit);
+
+ if (retval != ISIS_OK) {
+ zlog_warn("%s: could not initialize the socket",
+ __func__);
+ break;
+ }
+
+ if (if_is_broadcast(circuit->interface)) {
+ circuit->tx = isis_send_pdu_bcast;
+ circuit->rx = isis_recv_pdu_bcast;
+ } else {
+ zlog_warn("%s: unknown circuit type", __func__);
+ retval = ISIS_WARNING;
+ break;
+ }
+ }
+
+ return retval;
+}
+
+int isis_recv_pdu_bcast(struct isis_circuit *circuit, uint8_t *ssnpa)
+{
+ int bytesread = 0, bytestoread = 0, offset, one = 1;
+ uint8_t *buff_ptr;
+ 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("%s: read() failed: %s", __func__,
+ safe_strerror(errno));
+ return ISIS_WARNING;
+ }
+
+ if (bytesread == 0)
+ return ISIS_WARNING;
+
+ buff_ptr = readbuff;
+ while (buff_ptr < readbuff + bytesread) {
+ bpf_hdr = (struct bpf_hdr *) buff_ptr;
+ 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, buff_ptr + offset,
+ bpf_hdr->bh_caplen - LLC_LEN - ETHER_HDR_LEN);
+ stream_set_getp(circuit->rcv_stream, 0);
+
+ memcpy(ssnpa, buff_ptr + bpf_hdr->bh_hdrlen + ETHER_ADDR_LEN,
+ ETHER_ADDR_LEN);
+
+ isis_handle_pdu(circuit, ssnpa);
+ stream_reset(circuit->rcv_stream);
+ buff_ptr += BPF_WORDALIGN(bpf_hdr->bh_hdrlen +
+ bpf_hdr->bh_datalen);
+ }
+
+
+ if (ioctl(circuit->fd, BIOCFLUSH, &one) < 0)
+ zlog_warn("Flushing failed: %s", safe_strerror(errno));
+
+ return ISIS_OK;
+}
+
+int isis_send_pdu_bcast(struct isis_circuit *circuit, int level)
+{
+ struct ether_header *eth;
+ ssize_t written;
+ size_t buflen;
+
+ buflen = stream_get_endp(circuit->snd_stream) + LLC_LEN + ETHER_HDR_LEN;
+ if (buflen > sizeof(sock_buff)) {
+ zlog_warn(
+ "%s: sock_buff size %zu is less than output pdu size %zu on circuit %s",
+ __func__, sizeof(sock_buff), buflen,
+ circuit->interface->name);
+ return ISIS_WARNING;
+ }
+
+ 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, ETH_ALEN);
+ else
+ memcpy(eth->ether_dhost, ALL_L2_ISS, ETH_ALEN);
+ memcpy(eth->ether_shost, circuit->u.bc.snpa, ETH_ALEN);
+ size_t frame_size = stream_get_endp(circuit->snd_stream) + LLC_LEN;
+ eth->ether_type = htons(isis_ethertype(frame_size));
+
+ /*
+ * 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, buflen);
+ if (written < 0) {
+ zlog_warn("IS-IS bpf: could not transmit packet on %s: %s",
+ circuit->interface->name, safe_strerror(errno));
+ if (ERRNO_IO_RETRY(errno))
+ return ISIS_WARNING;
+ return ISIS_ERROR;
+ }
+
+ return ISIS_OK;
+}
+
+#endif /* ISIS_METHOD == ISIS_METHOD_BPF */