diff options
author | Daniel Baumann <daniel.baumann@progress-linux.org> | 2024-04-28 09:53:30 +0000 |
---|---|---|
committer | Daniel Baumann <daniel.baumann@progress-linux.org> | 2024-04-28 09:53:30 +0000 |
commit | 2c7cac91ed6e7db0f6937923d2b57f97dbdbc337 (patch) | |
tree | c05dc0f8e6aa3accc84e3e5cffc933ed94941383 /isisd/isis_pfpacket.c | |
parent | Initial commit. (diff) | |
download | frr-2c7cac91ed6e7db0f6937923d2b57f97dbdbc337.tar.xz frr-2c7cac91ed6e7db0f6937923d2b57f97dbdbc337.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_pfpacket.c')
-rw-r--r-- | isisd/isis_pfpacket.c | 426 |
1 files changed, 426 insertions, 0 deletions
diff --git a/isisd/isis_pfpacket.c b/isisd/isis_pfpacket.c new file mode 100644 index 0000000..84278f3 --- /dev/null +++ b/isisd/isis_pfpacket.c @@ -0,0 +1,426 @@ +/* + * IS-IS Rout(e)ing protocol - isis_pfpacket.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_PFPACKET +#include <net/ethernet.h> /* the L2 protocols */ +#include <netpacket/packet.h> + +#include <linux/filter.h> + +#include "log.h" +#include "network.h" +#include "stream.h" +#include "if.h" +#include "lib_errors.h" +#include "vrf.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" + +/* tcpdump -i eth0 'isis' -dd */ +static const struct sock_filter isisfilter[] = { + /* NB: we're in SOCK_DGRAM, so src/dst mac + length are stripped + * off! + * (OTOH it's a bit more lower-layer agnostic and might work + * over GRE?) */ + /* { 0x28, 0, 0, 0x0000000c - 14 }, */ + /* { 0x25, 5, 0, 0x000005dc }, */ + {0x28, 0, 0, 0x0000000e - 14}, {0x15, 0, 3, 0x0000fefe}, + {0x30, 0, 0, 0x00000011 - 14}, {0x15, 0, 1, 0x00000083}, + {0x6, 0, 0, 0x00040000}, {0x6, 0, 0, 0x00000000}, +}; + +static const struct sock_fprog bpf = { + .len = array_size(isisfilter), + .filter = (struct sock_filter *)isisfilter, +}; + +/* + * 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 const uint8_t ALL_ISS[6] = {0x09, 0x00, 0x2B, 0x00, 0x00, 0x05}; +static const uint8_t ALL_ESS[6] = {0x09, 0x00, 0x2B, 0x00, 0x00, 0x04}; + +static uint8_t discard_buff[8192]; + +/* + * if level is 0 we are joining p2p multicast + * FIXME: and the p2p multicast being ??? + */ +static int isis_multicast_join(int fd, int registerto, int if_num) +{ + struct packet_mreq mreq; + + memset(&mreq, 0, sizeof(mreq)); + mreq.mr_ifindex = if_num; + if (registerto) { + mreq.mr_type = PACKET_MR_MULTICAST; + mreq.mr_alen = ETH_ALEN; + if (registerto == 1) + memcpy(&mreq.mr_address, ALL_L1_ISS, ETH_ALEN); + else if (registerto == 2) + memcpy(&mreq.mr_address, ALL_L2_ISS, ETH_ALEN); + else if (registerto == 3) + memcpy(&mreq.mr_address, ALL_ISS, ETH_ALEN); + else + memcpy(&mreq.mr_address, ALL_ESS, ETH_ALEN); + + } else { + mreq.mr_type = PACKET_MR_ALLMULTI; + } +#ifdef EXTREME_DEBUG + if (IS_DEBUG_EVENTS) + zlog_debug( + "%s: fd=%d, reg_to=%d, if_num=%d, address = %02x:%02x:%02x:%02x:%02x:%02x", + __func__, fd, registerto, if_num, mreq.mr_address[0], + mreq.mr_address[1], mreq.mr_address[2], + mreq.mr_address[3], mreq.mr_address[4], + mreq.mr_address[5]); +#endif /* EXTREME_DEBUG */ + if (setsockopt(fd, SOL_PACKET, PACKET_ADD_MEMBERSHIP, &mreq, + sizeof(struct packet_mreq))) { + zlog_warn("%s: setsockopt(): %s", __func__, + safe_strerror(errno)); + return ISIS_WARNING; + } + + return ISIS_OK; +} + +static int open_packet_socket(struct isis_circuit *circuit) +{ + struct sockaddr_ll s_addr; + int fd, retval = ISIS_OK; + struct vrf *vrf = NULL; + + vrf = circuit->interface->vrf; + + fd = vrf_socket(PF_PACKET, SOCK_DGRAM, htons(ETH_P_ALL), vrf->vrf_id, + vrf->name); + + if (fd < 0) { + zlog_warn("%s: socket() failed %s", __func__, + safe_strerror(errno)); + return ISIS_WARNING; + } + + if (setsockopt(fd, SOL_SOCKET, SO_ATTACH_FILTER, &bpf, sizeof(bpf))) { + zlog_warn("%s: SO_ATTACH_FILTER failed: %s", __func__, + safe_strerror(errno)); + } + + /* + * Bind to the physical interface + */ + memset(&s_addr, 0, sizeof(s_addr)); + s_addr.sll_family = AF_PACKET; + s_addr.sll_protocol = htons(ETH_P_ALL); + s_addr.sll_ifindex = circuit->interface->ifindex; + + if (bind(fd, (struct sockaddr *)(&s_addr), sizeof(struct sockaddr_ll)) + < 0) { + zlog_warn("%s: bind() failed: %s", __func__, + safe_strerror(errno)); + close(fd); + return ISIS_WARNING; + } + + circuit->fd = fd; + + if (if_is_broadcast(circuit->interface)) { + /* + * Join to multicast groups + * according to + * 8.4.2 - Broadcast subnetwork IIH PDUs + * FIXME: is there a case only one will fail?? + */ + /* joining ALL_L1_ISS */ + retval |= isis_multicast_join(circuit->fd, 1, + circuit->interface->ifindex); + /* joining ALL_L2_ISS */ + retval |= isis_multicast_join(circuit->fd, 2, + circuit->interface->ifindex); + /* joining ALL_ISS (used in RFC 5309 p2p-over-lan as well) */ + retval |= isis_multicast_join(circuit->fd, 3, + circuit->interface->ifindex); + } else { + retval = isis_multicast_join(circuit->fd, 0, + circuit->interface->ifindex); + } + + return retval; +} + +/* + * 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_packet_socket(circuit); + + if (retval != ISIS_OK) { + zlog_warn("%s: could not initialize the socket", + __func__); + break; + } + + /* Assign Rx and Tx callbacks are based on real if type */ + if (if_is_broadcast(circuit->interface)) { + circuit->tx = isis_send_pdu_bcast; + circuit->rx = isis_recv_pdu_bcast; + } else if (if_is_pointopoint(circuit->interface)) { + circuit->tx = isis_send_pdu_p2p; + circuit->rx = isis_recv_pdu_p2p; + } else { + zlog_warn("%s: unknown circuit type", __func__); + retval = ISIS_WARNING; + break; + } + } + + return retval; +} + +static inline int llc_check(uint8_t *llc) +{ + if (*llc != ISO_SAP || *(llc + 1) != ISO_SAP || *(llc + 2) != 3) + return 0; + + return 1; +} + +int isis_recv_pdu_bcast(struct isis_circuit *circuit, uint8_t *ssnpa) +{ + int bytesread, addr_len; + struct sockaddr_ll s_addr; + uint8_t llc[LLC_LEN]; + + addr_len = sizeof(s_addr); + + memset(&s_addr, 0, sizeof(s_addr)); + + bytesread = + recvfrom(circuit->fd, (void *)&llc, LLC_LEN, MSG_PEEK, + (struct sockaddr *)&s_addr, (socklen_t *)&addr_len); + + if ((bytesread < 0) + || (s_addr.sll_ifindex != (int)circuit->interface->ifindex)) { + if (bytesread < 0) { + zlog_warn( + "%s: ifname %s, fd %d, bytesread %d, recvfrom(): %s", + __func__, circuit->interface->name, circuit->fd, + bytesread, safe_strerror(errno)); + } + if (s_addr.sll_ifindex != (int)circuit->interface->ifindex) { + zlog_warn( + "packet is received on multiple interfaces: socket interface %d, circuit interface %d, packet type %u", + s_addr.sll_ifindex, circuit->interface->ifindex, + s_addr.sll_pkttype); + } + + /* get rid of the packet */ + bytesread = recvfrom(circuit->fd, discard_buff, + sizeof(discard_buff), MSG_DONTWAIT, + (struct sockaddr *)&s_addr, + (socklen_t *)&addr_len); + + if (bytesread < 0) + zlog_warn("%s: recvfrom() failed", __func__); + + return ISIS_WARNING; + } + /* + * Filtering by llc field, discard packets sent by this host (other + * circuit) + */ + if (!llc_check(llc) || s_addr.sll_pkttype == PACKET_OUTGOING) { + /* Read the packet into discard buff */ + bytesread = recvfrom(circuit->fd, discard_buff, + sizeof(discard_buff), MSG_DONTWAIT, + (struct sockaddr *)&s_addr, + (socklen_t *)&addr_len); + if (bytesread < 0) + zlog_warn("%s: recvfrom() failed", __func__); + return ISIS_WARNING; + } + + /* Ensure that we have enough space for a pdu padded to fill the mtu */ + unsigned int max_size = + circuit->interface->mtu > circuit->interface->mtu6 + ? circuit->interface->mtu + : circuit->interface->mtu6; + uint8_t temp_buff[max_size]; + bytesread = + recvfrom(circuit->fd, temp_buff, max_size, MSG_DONTWAIT, + (struct sockaddr *)&s_addr, (socklen_t *)&addr_len); + if (bytesread < 0) { + zlog_warn("%s: recvfrom() failed", __func__); + return ISIS_WARNING; + } + /* then we lose the LLC */ + stream_write(circuit->rcv_stream, temp_buff + LLC_LEN, + bytesread - LLC_LEN); + memcpy(ssnpa, &s_addr.sll_addr, s_addr.sll_halen); + + return ISIS_OK; +} + +int isis_recv_pdu_p2p(struct isis_circuit *circuit, uint8_t *ssnpa) +{ + int bytesread, addr_len; + struct sockaddr_ll s_addr; + + memset(&s_addr, 0, sizeof(s_addr)); + addr_len = sizeof(s_addr); + + /* we can read directly to the stream */ + (void)stream_recvfrom( + circuit->rcv_stream, circuit->fd, circuit->interface->mtu, 0, + (struct sockaddr *)&s_addr, (socklen_t *)&addr_len); + + if (s_addr.sll_pkttype == PACKET_OUTGOING) { + /* Read the packet into discard buff */ + bytesread = recvfrom(circuit->fd, discard_buff, + sizeof(discard_buff), MSG_DONTWAIT, + (struct sockaddr *)&s_addr, + (socklen_t *)&addr_len); + if (bytesread < 0) + zlog_warn("%s: recvfrom() failed", __func__); + return ISIS_WARNING; + } + + /* If we don't have protocol type 0x00FE which is + * ISO over GRE we exit with pain :) + */ + if (ntohs(s_addr.sll_protocol) != 0x00FE) { + zlog_warn("%s: protocol mismatch(): %X", __func__, + ntohs(s_addr.sll_protocol)); + return ISIS_WARNING; + } + + memcpy(ssnpa, &s_addr.sll_addr, s_addr.sll_halen); + + return ISIS_OK; +} + +int isis_send_pdu_bcast(struct isis_circuit *circuit, int level) +{ + struct msghdr msg; + struct iovec iov[2]; + char temp_buff[LLC_LEN]; + + /* we need to do the LLC in here because of P2P circuits, which will + * not need it + */ + struct sockaddr_ll sa; + + stream_set_getp(circuit->snd_stream, 0); + memset(&sa, 0, sizeof(sa)); + sa.sll_family = AF_PACKET; + + size_t frame_size = stream_get_endp(circuit->snd_stream) + LLC_LEN; + sa.sll_protocol = htons(isis_ethertype(frame_size)); + sa.sll_ifindex = circuit->interface->ifindex; + sa.sll_halen = ETH_ALEN; + /* RFC5309 section 4.1 recommends ALL_ISS */ + if (circuit->circ_type == CIRCUIT_T_P2P) + memcpy(&sa.sll_addr, ALL_ISS, ETH_ALEN); + else if (level == 1) + memcpy(&sa.sll_addr, ALL_L1_ISS, ETH_ALEN); + else + memcpy(&sa.sll_addr, ALL_L2_ISS, ETH_ALEN); + + /* on a broadcast circuit */ + /* first we put the LLC in */ + temp_buff[0] = 0xFE; + temp_buff[1] = 0xFE; + temp_buff[2] = 0x03; + + memset(&msg, 0, sizeof(msg)); + msg.msg_name = &sa; + msg.msg_namelen = sizeof(struct sockaddr_ll); + msg.msg_iov = iov; + msg.msg_iovlen = 2; + iov[0].iov_base = temp_buff; + iov[0].iov_len = LLC_LEN; + iov[1].iov_base = circuit->snd_stream->data; + iov[1].iov_len = stream_get_endp(circuit->snd_stream); + + if (sendmsg(circuit->fd, &msg, 0) < 0) { + zlog_warn("IS-IS pfpacket: 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; +} + +int isis_send_pdu_p2p(struct isis_circuit *circuit, int level) +{ + struct sockaddr_ll sa; + ssize_t rv; + + stream_set_getp(circuit->snd_stream, 0); + memset(&sa, 0, sizeof(sa)); + sa.sll_family = AF_PACKET; + sa.sll_ifindex = circuit->interface->ifindex; + sa.sll_halen = ETH_ALEN; + if (level == 1) + memcpy(&sa.sll_addr, ALL_L1_ISS, ETH_ALEN); + else + memcpy(&sa.sll_addr, ALL_L2_ISS, ETH_ALEN); + + + /* lets try correcting the protocol */ + sa.sll_protocol = htons(0x00FE); + rv = sendto(circuit->fd, circuit->snd_stream->data, + stream_get_endp(circuit->snd_stream), 0, + (struct sockaddr *)&sa, sizeof(struct sockaddr_ll)); + if (rv < 0) { + zlog_warn("IS-IS pfpacket: 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_PFPACKET */ |