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2 * IS-IS Rout(e)ing protocol - isis_bpf.c
4 * Copyright (C) 2001,2002 Sampo Saaristo
5 * Tampere University of Technology
6 * Institute of Communications Engineering
8 * This program is free software; you can redistribute it and/or modify it
9 * under the terms of the GNU General Public Licenseas published by the Free
10 * Software Foundation; either version 2 of the License, or (at your option)
13 * This program is distributed in the hope that it will be useful,but WITHOUT
14 * ANY WARRANTY; without even the implied warranty of MERCHANTABILITY or
15 * FITNESS FOR A PARTICULAR PURPOSE. See the GNU General Public License for
18 * You should have received a copy of the GNU General Public License along
19 * with this program; see the file COPYING; if not, write to the Free Software
20 * Foundation, Inc., 51 Franklin St, Fifth Floor, Boston, MA 02110-1301 USA
24 #if ISIS_METHOD == ISIS_METHOD_BPF
26 #include <netinet/if_ether.h>
28 #include <sys/ioctl.h>
35 #include "lib_errors.h"
37 #include "isisd/isis_constants.h"
38 #include "isisd/isis_common.h"
39 #include "isisd/isis_circuit.h"
40 #include "isisd/isis_flags.h"
41 #include "isisd/isisd.h"
42 #include "isisd/isis_constants.h"
43 #include "isisd/isis_circuit.h"
44 #include "isisd/isis_network.h"
45 #include "isisd/isis_pdu.h"
49 struct bpf_insn llcfilter
[] = {
50 BPF_STMT(BPF_LD
+ BPF_B
+ BPF_ABS
,
51 ETHER_HDR_LEN
), /* check first byte */
52 BPF_JUMP(BPF_JMP
+ BPF_JEQ
+ BPF_K
, ISO_SAP
, 0, 5),
53 BPF_STMT(BPF_LD
+ BPF_B
+ BPF_ABS
, ETHER_HDR_LEN
+ 1),
54 BPF_JUMP(BPF_JMP
+ BPF_JEQ
+ BPF_K
, ISO_SAP
, 0,
55 3), /* check second byte */
56 BPF_STMT(BPF_LD
+ BPF_B
+ BPF_ABS
, ETHER_HDR_LEN
+ 2),
57 BPF_JUMP(BPF_JMP
+ BPF_JEQ
+ BPF_K
, 0x03, 0, 1), /* check third byte */
58 BPF_STMT(BPF_RET
+ BPF_K
, (unsigned int)-1),
59 BPF_STMT(BPF_RET
+ BPF_K
, 0)};
60 unsigned int readblen
= 0;
61 uint8_t *readbuff
= NULL
;
64 * Table 9 - Architectural constants for use with ISO 8802 subnetworks
68 static const uint8_t ALL_L1_ISS
[6] = {0x01, 0x80, 0xC2, 0x00, 0x00, 0x14};
69 static const uint8_t ALL_L2_ISS
[6] = {0x01, 0x80, 0xC2, 0x00, 0x00, 0x15};
70 static char sock_buff
[16384];
72 static int open_bpf_dev(struct isis_circuit
*circuit
)
77 unsigned int blen
, immediate
;
81 struct timeval timeout
;
82 struct bpf_program bpf_prog
;
85 (void)snprintf(bpfdev
, sizeof(bpfdev
), "/dev/bpf%d", i
++);
86 fd
= open(bpfdev
, O_RDWR
);
87 } while (fd
< 0 && errno
== EBUSY
);
90 zlog_warn("open_bpf_dev(): failed to create bpf socket: %s",
91 safe_strerror(errno
));
95 zlog_debug("Opened BPF device %s", bpfdev
);
97 memcpy(ifr
.ifr_name
, circuit
->interface
->name
, sizeof(ifr
.ifr_name
));
98 if (ioctl(fd
, BIOCSETIF
, (caddr_t
)&ifr
) < 0) {
99 zlog_warn("open_bpf_dev(): failed to bind to interface: %s",
100 safe_strerror(errno
));
104 if (ioctl(fd
, BIOCGBLEN
, (caddr_t
)&blen
) < 0) {
105 zlog_warn("failed to get BPF buffer len");
106 blen
= circuit
->interface
->mtu
;
111 if (readbuff
== NULL
)
112 readbuff
= malloc(blen
);
114 zlog_debug("BPF buffer len = %u", blen
);
116 /* BPF(4): reads return immediately upon packet reception.
117 * Otherwise, a read will block until either the kernel
118 * buffer becomes full or a timeout occurs.
121 if (ioctl(fd
, BIOCIMMEDIATE
, (caddr_t
)&immediate
) < 0) {
122 zlog_warn("failed to set BPF dev to immediate mode");
127 * We want to see only incoming packets
130 if (ioctl(fd
, BIOCSSEESENT
, (caddr_t
)&seesent
) < 0) {
131 zlog_warn("failed to set BPF dev to incoming only mode");
138 if (ioctl(fd
, BIOCPROMISC
) < 0) {
139 zlog_warn("failed to set BPF dev to promiscuous mode");
143 * If the buffer length is smaller than our mtu, lets try to increase it
145 if (blen
< circuit
->interface
->mtu
) {
146 if (ioctl(fd
, BIOCSBLEN
, &circuit
->interface
->mtu
) < 0) {
147 zlog_warn("failed to set BPF buffer len (%u to %u)",
148 blen
, circuit
->interface
->mtu
);
153 * Set a timeout parameter - hope this helps select()
155 timeout
.tv_sec
= 600;
157 if (ioctl(fd
, BIOCSRTIMEOUT
, (caddr_t
)&timeout
) < 0) {
158 zlog_warn("failed to set BPF device timeout");
164 memset(&bpf_prog
, 0, sizeof(struct bpf_program
));
166 bpf_prog
.bf_insns
= &(llcfilter
[0]);
167 if (ioctl(fd
, BIOCSETF
, (caddr_t
)&bpf_prog
) < 0) {
168 zlog_warn("open_bpf_dev(): failed to install filter: %s",
169 safe_strerror(errno
));
181 * Create the socket and set the tx/rx funcs
183 int isis_sock_init(struct isis_circuit
*circuit
)
185 int retval
= ISIS_OK
;
187 frr_with_privs(&isisd_privs
) {
189 retval
= open_bpf_dev(circuit
);
191 if (retval
!= ISIS_OK
) {
192 zlog_warn("%s: could not initialize the socket",
197 if (if_is_broadcast(circuit
->interface
)) {
198 circuit
->tx
= isis_send_pdu_bcast
;
199 circuit
->rx
= isis_recv_pdu_bcast
;
201 zlog_warn("isis_sock_init(): unknown circuit type");
202 retval
= ISIS_WARNING
;
210 int isis_recv_pdu_bcast(struct isis_circuit
*circuit
, uint8_t *ssnpa
)
212 int bytesread
= 0, bytestoread
= 0, offset
, one
= 1;
214 struct bpf_hdr
*bpf_hdr
;
216 assert(circuit
->fd
> 0);
218 if (ioctl(circuit
->fd
, FIONREAD
, (caddr_t
)&bytestoread
) < 0) {
219 zlog_warn("ioctl() FIONREAD failed: %s", safe_strerror(errno
));
223 bytesread
= read(circuit
->fd
, readbuff
, readblen
);
226 zlog_warn("isis_recv_pdu_bcast(): read() failed: %s",
227 safe_strerror(errno
));
235 while (buff_ptr
< readbuff
+ bytesread
) {
236 bpf_hdr
= (struct bpf_hdr
*) buff_ptr
;
237 assert(bpf_hdr
->bh_caplen
== bpf_hdr
->bh_datalen
);
238 offset
= bpf_hdr
->bh_hdrlen
+ LLC_LEN
+ ETHER_HDR_LEN
;
240 /* then we lose the BPF, LLC and ethernet headers */
241 stream_write(circuit
->rcv_stream
, buff_ptr
+ offset
,
242 bpf_hdr
->bh_caplen
- LLC_LEN
- ETHER_HDR_LEN
);
243 stream_set_getp(circuit
->rcv_stream
, 0);
245 memcpy(ssnpa
, buff_ptr
+ bpf_hdr
->bh_hdrlen
+ ETHER_ADDR_LEN
,
248 isis_handle_pdu(circuit
, ssnpa
);
249 stream_reset(circuit
->rcv_stream
);
250 buff_ptr
+= BPF_WORDALIGN(bpf_hdr
->bh_hdrlen
+
251 bpf_hdr
->bh_datalen
);
255 if (ioctl(circuit
->fd
, BIOCFLUSH
, &one
) < 0)
256 zlog_warn("Flushing failed: %s", safe_strerror(errno
));
261 int isis_send_pdu_bcast(struct isis_circuit
*circuit
, int level
)
263 struct ether_header
*eth
;
267 buflen
= stream_get_endp(circuit
->snd_stream
) + LLC_LEN
+ ETHER_HDR_LEN
;
268 if (buflen
> sizeof(sock_buff
)) {
270 "isis_send_pdu_bcast: sock_buff size %zu is less than output pdu size %zu on circuit %s",
271 sizeof(sock_buff
), buflen
, circuit
->interface
->name
);
275 stream_set_getp(circuit
->snd_stream
, 0);
278 * First the eth header
280 eth
= (struct ether_header
*)sock_buff
;
282 memcpy(eth
->ether_dhost
, ALL_L1_ISS
, ETH_ALEN
);
284 memcpy(eth
->ether_dhost
, ALL_L2_ISS
, ETH_ALEN
);
285 memcpy(eth
->ether_shost
, circuit
->u
.bc
.snpa
, ETH_ALEN
);
286 size_t frame_size
= stream_get_endp(circuit
->snd_stream
) + LLC_LEN
;
287 eth
->ether_type
= htons(isis_ethertype(frame_size
));
292 sock_buff
[ETHER_HDR_LEN
] = ISO_SAP
;
293 sock_buff
[ETHER_HDR_LEN
+ 1] = ISO_SAP
;
294 sock_buff
[ETHER_HDR_LEN
+ 2] = 0x03;
296 /* then we copy the data */
297 memcpy(sock_buff
+ (LLC_LEN
+ ETHER_HDR_LEN
), circuit
->snd_stream
->data
,
298 stream_get_endp(circuit
->snd_stream
));
300 /* now we can send this */
301 written
= write(circuit
->fd
, sock_buff
, buflen
);
303 zlog_warn("IS-IS bpf: could not transmit packet on %s: %s",
304 circuit
->interface
->name
, safe_strerror(errno
));
305 if (ERRNO_IO_RETRY(errno
))
313 #endif /* ISIS_METHOD == ISIS_METHOD_BPF */