]>
Commit | Line | Data |
---|---|---|
8bc98059 PJ |
1 | /* |
2 | * IS-IS Rout(e)ing protocol - isis_bpf.c | |
3 | * | |
4 | * Copyright (C) 2001,2002 Sampo Saaristo | |
d62a17ae | 5 | * Tampere University of Technology |
8bc98059 PJ |
6 | * Institute of Communications Engineering |
7 | * | |
d62a17ae | 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) | |
8bc98059 PJ |
11 | * any later version. |
12 | * | |
d62a17ae | 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 | |
8bc98059 | 16 | * more details. |
896014f4 DL |
17 | * |
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 | |
8bc98059 PJ |
21 | */ |
22 | ||
23 | #include <zebra.h> | |
745bf05f | 24 | #if ISIS_METHOD == ISIS_METHOD_BPF |
8bc98059 PJ |
25 | #include <net/if.h> |
26 | #include <netinet/if_ether.h> | |
27 | #include <sys/time.h> | |
28 | #include <sys/ioctl.h> | |
29 | #include <net/bpf.h> | |
30 | ||
31 | #include "log.h" | |
cfd1f27b | 32 | #include "network.h" |
8bc98059 PJ |
33 | #include "stream.h" |
34 | #include "if.h" | |
38937bd5 | 35 | #include "lib_errors.h" |
8bc98059 | 36 | |
8bc98059 PJ |
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" | |
344b4a29 | 45 | #include "isisd/isis_pdu.h" |
8bc98059 PJ |
46 | |
47 | #include "privs.h" | |
48 | ||
8bc98059 | 49 | struct bpf_insn llcfilter[] = { |
12386e86 RZ |
50 | BPF_STMT(BPF_LD + BPF_B + BPF_ABS, |
51 | ETHER_HDR_LEN), /* check first byte */ | |
d62a17ae | 52 | BPF_JUMP(BPF_JMP + BPF_JEQ + BPF_K, ISO_SAP, 0, 5), |
12386e86 RZ |
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 */ | |
d7c0a89a | 58 | BPF_STMT(BPF_RET + BPF_K, (unsigned int)-1), |
d62a17ae | 59 | BPF_STMT(BPF_RET + BPF_K, 0)}; |
d7c0a89a QY |
60 | unsigned int readblen = 0; |
61 | uint8_t *readbuff = NULL; | |
8bc98059 PJ |
62 | |
63 | /* | |
64 | * Table 9 - Architectural constants for use with ISO 8802 subnetworks | |
65 | * ISO 10589 - 8.4.8 | |
66 | */ | |
67 | ||
d7c0a89a QY |
68 | uint8_t ALL_L1_ISS[6] = {0x01, 0x80, 0xC2, 0x00, 0x00, 0x14}; |
69 | uint8_t ALL_L2_ISS[6] = {0x01, 0x80, 0xC2, 0x00, 0x00, 0x15}; | |
70 | uint8_t ALL_ISS[6] = {0x09, 0x00, 0x2B, 0x00, 0x00, 0x05}; | |
71 | uint8_t ALL_ESS[6] = {0x09, 0x00, 0x2B, 0x00, 0x00, 0x04}; | |
8bc98059 PJ |
72 | |
73 | static char sock_buff[8192]; | |
74 | ||
d62a17ae | 75 | static int open_bpf_dev(struct isis_circuit *circuit) |
8bc98059 | 76 | { |
d62a17ae | 77 | int i = 0, fd; |
78 | char bpfdev[128]; | |
79 | struct ifreq ifr; | |
d7c0a89a | 80 | unsigned int blen, immediate; |
f94d4e70 | 81 | #ifdef BIOCSSEESENT |
d7c0a89a | 82 | unsigned int seesent; |
f94d4e70 | 83 | #endif |
d62a17ae | 84 | struct timeval timeout; |
85 | struct bpf_program bpf_prog; | |
86 | ||
87 | do { | |
88 | (void)snprintf(bpfdev, sizeof(bpfdev), "/dev/bpf%d", i++); | |
89 | fd = open(bpfdev, O_RDWR); | |
90 | } while (fd < 0 && errno == EBUSY); | |
91 | ||
92 | if (fd < 0) { | |
93 | zlog_warn("open_bpf_dev(): failed to create bpf socket: %s", | |
94 | safe_strerror(errno)); | |
95 | return ISIS_WARNING; | |
96 | } | |
97 | ||
98 | zlog_debug("Opened BPF device %s", bpfdev); | |
99 | ||
100 | memcpy(ifr.ifr_name, circuit->interface->name, sizeof(ifr.ifr_name)); | |
101 | if (ioctl(fd, BIOCSETIF, (caddr_t)&ifr) < 0) { | |
102 | zlog_warn("open_bpf_dev(): failed to bind to interface: %s", | |
103 | safe_strerror(errno)); | |
104 | return ISIS_WARNING; | |
105 | } | |
106 | ||
107 | if (ioctl(fd, BIOCGBLEN, (caddr_t)&blen) < 0) { | |
108 | zlog_warn("failed to get BPF buffer len"); | |
109 | blen = circuit->interface->mtu; | |
110 | } | |
111 | ||
112 | readblen = blen; | |
113 | ||
114 | if (readbuff == NULL) | |
115 | readbuff = malloc(blen); | |
116 | ||
117 | zlog_debug("BPF buffer len = %u", blen); | |
118 | ||
119 | /* BPF(4): reads return immediately upon packet reception. | |
120 | * Otherwise, a read will block until either the kernel | |
121 | * buffer becomes full or a timeout occurs. | |
122 | */ | |
123 | immediate = 1; | |
124 | if (ioctl(fd, BIOCIMMEDIATE, (caddr_t)&immediate) < 0) { | |
125 | zlog_warn("failed to set BPF dev to immediate mode"); | |
126 | } | |
8bc98059 PJ |
127 | |
128 | #ifdef BIOCSSEESENT | |
d62a17ae | 129 | /* |
130 | * We want to see only incoming packets | |
131 | */ | |
132 | seesent = 0; | |
133 | if (ioctl(fd, BIOCSSEESENT, (caddr_t)&seesent) < 0) { | |
134 | zlog_warn("failed to set BPF dev to incoming only mode"); | |
135 | } | |
8bc98059 PJ |
136 | #endif |
137 | ||
d62a17ae | 138 | /* |
139 | * ...but all of them | |
140 | */ | |
141 | if (ioctl(fd, BIOCPROMISC) < 0) { | |
142 | zlog_warn("failed to set BPF dev to promiscuous mode"); | |
143 | } | |
144 | ||
145 | /* | |
146 | * If the buffer length is smaller than our mtu, lets try to increase it | |
147 | */ | |
148 | if (blen < circuit->interface->mtu) { | |
149 | if (ioctl(fd, BIOCSBLEN, &circuit->interface->mtu) < 0) { | |
150 | zlog_warn("failed to set BPF buffer len (%u to %u)", | |
151 | blen, circuit->interface->mtu); | |
152 | } | |
153 | } | |
154 | ||
155 | /* | |
156 | * Set a timeout parameter - hope this helps select() | |
157 | */ | |
158 | timeout.tv_sec = 600; | |
159 | timeout.tv_usec = 0; | |
160 | if (ioctl(fd, BIOCSRTIMEOUT, (caddr_t)&timeout) < 0) { | |
161 | zlog_warn("failed to set BPF device timeout"); | |
162 | } | |
163 | ||
164 | /* | |
165 | * And set the filter | |
166 | */ | |
167 | memset(&bpf_prog, 0, sizeof(struct bpf_program)); | |
168 | bpf_prog.bf_len = 8; | |
169 | bpf_prog.bf_insns = &(llcfilter[0]); | |
170 | if (ioctl(fd, BIOCSETF, (caddr_t)&bpf_prog) < 0) { | |
171 | zlog_warn("open_bpf_dev(): failed to install filter: %s", | |
172 | safe_strerror(errno)); | |
173 | return ISIS_WARNING; | |
8bc98059 | 174 | } |
d62a17ae | 175 | |
176 | assert(fd > 0); | |
177 | ||
178 | circuit->fd = fd; | |
179 | ||
180 | return ISIS_OK; | |
8bc98059 PJ |
181 | } |
182 | ||
183 | /* | |
184 | * Create the socket and set the tx/rx funcs | |
185 | */ | |
d62a17ae | 186 | int isis_sock_init(struct isis_circuit *circuit) |
8bc98059 | 187 | { |
d62a17ae | 188 | int retval = ISIS_OK; |
189 | ||
0cf6db21 | 190 | frr_with_privs(&isisd_privs) { |
d62a17ae | 191 | |
01b9e3fd | 192 | retval = open_bpf_dev(circuit); |
d62a17ae | 193 | |
01b9e3fd | 194 | if (retval != ISIS_OK) { |
633fc9b1 DL |
195 | zlog_warn("%s: could not initialize the socket", |
196 | __func__); | |
01b9e3fd DL |
197 | break; |
198 | } | |
d62a17ae | 199 | |
01b9e3fd DL |
200 | if (if_is_broadcast(circuit->interface)) { |
201 | circuit->tx = isis_send_pdu_bcast; | |
202 | circuit->rx = isis_recv_pdu_bcast; | |
203 | } else { | |
204 | zlog_warn("isis_sock_init(): unknown circuit type"); | |
205 | retval = ISIS_WARNING; | |
206 | break; | |
207 | } | |
633fc9b1 | 208 | } |
8bc98059 | 209 | |
d62a17ae | 210 | return retval; |
8bc98059 PJ |
211 | } |
212 | ||
d7c0a89a | 213 | int isis_recv_pdu_bcast(struct isis_circuit *circuit, uint8_t *ssnpa) |
8bc98059 | 214 | { |
3009394b | 215 | int bytesread = 0, bytestoread, offset, one = 1; |
d7c0a89a | 216 | uint8_t *buff_ptr; |
d62a17ae | 217 | struct bpf_hdr *bpf_hdr; |
8bc98059 | 218 | |
d62a17ae | 219 | assert(circuit->fd > 0); |
8bc98059 | 220 | |
d62a17ae | 221 | if (ioctl(circuit->fd, FIONREAD, (caddr_t)&bytestoread) < 0) { |
222 | zlog_warn("ioctl() FIONREAD failed: %s", safe_strerror(errno)); | |
223 | } | |
8bc98059 | 224 | |
d62a17ae | 225 | if (bytestoread) { |
226 | bytesread = read(circuit->fd, readbuff, readblen); | |
227 | } | |
228 | if (bytesread < 0) { | |
229 | zlog_warn("isis_recv_pdu_bcast(): read() failed: %s", | |
b9347997 | 230 | safe_strerror(errno)); |
d62a17ae | 231 | return ISIS_WARNING; |
232 | } | |
8bc98059 | 233 | |
d62a17ae | 234 | if (bytesread == 0) |
235 | return ISIS_WARNING; | |
8bc98059 | 236 | |
b9347997 | 237 | buff_ptr = readbuff; |
238 | while (buff_ptr < readbuff + bytesread) { | |
239 | bpf_hdr = (struct bpf_hdr *) buff_ptr; | |
240 | assert(bpf_hdr->bh_caplen == bpf_hdr->bh_datalen); | |
241 | offset = bpf_hdr->bh_hdrlen + LLC_LEN + ETHER_HDR_LEN; | |
8bc98059 | 242 | |
b9347997 | 243 | /* then we lose the BPF, LLC and ethernet headers */ |
244 | stream_write(circuit->rcv_stream, buff_ptr + offset, | |
245 | bpf_hdr->bh_caplen - LLC_LEN - ETHER_HDR_LEN); | |
246 | stream_set_getp(circuit->rcv_stream, 0); | |
8bc98059 | 247 | |
b9347997 | 248 | memcpy(ssnpa, buff_ptr + bpf_hdr->bh_hdrlen + ETHER_ADDR_LEN, |
249 | ETHER_ADDR_LEN); | |
8bc98059 | 250 | |
3009394b | 251 | isis_handle_pdu(circuit, ssnpa); |
b9347997 | 252 | stream_reset(circuit->rcv_stream); |
253 | buff_ptr += BPF_WORDALIGN(bpf_hdr->bh_hdrlen + | |
254 | bpf_hdr->bh_datalen); | |
255 | } | |
8bc98059 | 256 | |
8bc98059 | 257 | |
d62a17ae | 258 | if (ioctl(circuit->fd, BIOCFLUSH, &one) < 0) |
259 | zlog_warn("Flushing failed: %s", safe_strerror(errno)); | |
8bc98059 | 260 | |
d62a17ae | 261 | return ISIS_OK; |
8bc98059 PJ |
262 | } |
263 | ||
d62a17ae | 264 | int isis_send_pdu_bcast(struct isis_circuit *circuit, int level) |
8bc98059 | 265 | { |
d62a17ae | 266 | struct ether_header *eth; |
267 | ssize_t written; | |
268 | size_t buflen; | |
269 | ||
12386e86 | 270 | buflen = stream_get_endp(circuit->snd_stream) + LLC_LEN + ETHER_HDR_LEN; |
d62a17ae | 271 | if (buflen > sizeof(sock_buff)) { |
272 | zlog_warn( | |
273 | "isis_send_pdu_bcast: sock_buff size %zu is less than " | |
274 | "output pdu size %zu on circuit %s", | |
275 | sizeof(sock_buff), buflen, circuit->interface->name); | |
276 | return ISIS_WARNING; | |
277 | } | |
278 | ||
279 | stream_set_getp(circuit->snd_stream, 0); | |
280 | ||
281 | /* | |
282 | * First the eth header | |
283 | */ | |
284 | eth = (struct ether_header *)sock_buff; | |
285 | if (level == 1) | |
d1be6968 | 286 | memcpy(eth->ether_dhost, ALL_L1_ISS, ETH_ALEN); |
d62a17ae | 287 | else |
d1be6968 DS |
288 | memcpy(eth->ether_dhost, ALL_L2_ISS, ETH_ALEN); |
289 | memcpy(eth->ether_shost, circuit->u.bc.snpa, ETH_ALEN); | |
d62a17ae | 290 | size_t frame_size = stream_get_endp(circuit->snd_stream) + LLC_LEN; |
291 | eth->ether_type = htons(isis_ethertype(frame_size)); | |
292 | ||
293 | /* | |
294 | * Then the LLC | |
295 | */ | |
12386e86 RZ |
296 | sock_buff[ETHER_HDR_LEN] = ISO_SAP; |
297 | sock_buff[ETHER_HDR_LEN + 1] = ISO_SAP; | |
298 | sock_buff[ETHER_HDR_LEN + 2] = 0x03; | |
d62a17ae | 299 | |
300 | /* then we copy the data */ | |
12386e86 | 301 | memcpy(sock_buff + (LLC_LEN + ETHER_HDR_LEN), circuit->snd_stream->data, |
d62a17ae | 302 | stream_get_endp(circuit->snd_stream)); |
303 | ||
304 | /* now we can send this */ | |
305 | written = write(circuit->fd, sock_buff, buflen); | |
306 | if (written < 0) { | |
307 | zlog_warn("IS-IS bpf: could not transmit packet on %s: %s", | |
308 | circuit->interface->name, safe_strerror(errno)); | |
309 | if (ERRNO_IO_RETRY(errno)) | |
310 | return ISIS_WARNING; | |
311 | return ISIS_ERROR; | |
312 | } | |
313 | ||
314 | return ISIS_OK; | |
8bc98059 PJ |
315 | } |
316 | ||
745bf05f | 317 | #endif /* ISIS_METHOD == ISIS_METHOD_BPF */ |