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author | Daniel Baumann <daniel.baumann@progress-linux.org> | 2024-04-28 09:53:30 +0000 |
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committer | Daniel Baumann <daniel.baumann@progress-linux.org> | 2024-04-28 09:53:30 +0000 |
commit | 2c7cac91ed6e7db0f6937923d2b57f97dbdbc337 (patch) | |
tree | c05dc0f8e6aa3accc84e3e5cffc933ed94941383 /isisd/isis_bpf.c | |
parent | Initial commit. (diff) | |
download | frr-upstream.tar.xz frr-upstream.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.c | 314 |
1 files changed, 314 insertions, 0 deletions
diff --git a/isisd/isis_bpf.c b/isisd/isis_bpf.c new file mode 100644 index 0000000..11f4327 --- /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 */ |