Annotation of libaitio/src/bpf.c, revision 1.5.4.4
1.2 misho 1: /*************************************************************************
2: * (C) 2013 AITNET ltd - Sofia/Bulgaria - <misho@aitnet.org>
3: * by Michael Pounov <misho@elwix.org>
4: *
5: * $Author: misho $
1.5.4.4 ! misho 6: * $Id: bpf.c,v 1.5.4.3 2014/02/08 18:58:12 misho Exp $
1.2 misho 7: *
8: **************************************************************************
9: The ELWIX and AITNET software is distributed under the following
10: terms:
11:
12: All of the documentation and software included in the ELWIX and AITNET
13: Releases is copyrighted by ELWIX - Sofia/Bulgaria <info@elwix.org>
14:
1.5.4.2 misho 15: Copyright 2004 - 2014
1.2 misho 16: by Michael Pounov <misho@elwix.org>. All rights reserved.
17:
18: Redistribution and use in source and binary forms, with or without
19: modification, are permitted provided that the following conditions
20: are met:
21: 1. Redistributions of source code must retain the above copyright
22: notice, this list of conditions and the following disclaimer.
23: 2. Redistributions in binary form must reproduce the above copyright
24: notice, this list of conditions and the following disclaimer in the
25: documentation and/or other materials provided with the distribution.
26: 3. All advertising materials mentioning features or use of this software
27: must display the following acknowledgement:
28: This product includes software developed by Michael Pounov <misho@elwix.org>
29: ELWIX - Embedded LightWeight unIX and its contributors.
30: 4. Neither the name of AITNET nor the names of its contributors
31: may be used to endorse or promote products derived from this software
32: without specific prior written permission.
33:
34: THIS SOFTWARE IS PROVIDED BY AITNET AND CONTRIBUTORS ``AS IS'' AND
35: ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE
36: IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE
37: ARE DISCLAIMED. IN NO EVENT SHALL THE REGENTS OR CONTRIBUTORS BE LIABLE
38: FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL
39: DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS
40: OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION)
41: HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT
42: LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY
43: OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF
44: SUCH DAMAGE.
45: */
46: #include "global.h"
47:
48:
49: /*
50: * io_get1stiface() - Get first interface of host
51: *
52: * @szIface = interface string buffer
53: * @iflen = size of interface buffer
54: * return: -1 error or 0 ok
55: */
56: int
57: io_get1stiface(char *szIface, int iflen)
58: {
59: struct ifaddrs *ifa;
60:
61: if (!szIface || !iflen)
62: return -1;
63:
64: getifaddrs(&ifa);
65: strlcpy(szIface, ifa->ifa_name, iflen);
66: freeifaddrs(ifa);
67: return 0;
68: }
69:
70: /*
1.5 misho 71: * io_getmaciface() - Get MAC address from interface name
72: *
73: * @csIface = interface name
74: * @ea = ethernet address
75: * return: -1 error, 0 ok or 1 not found
76: */
77: int
78: io_getmaciface(const char *csIface, ether_addr_t * __restrict ea)
79: {
80: struct ifaddrs *ifa, *ifp;
81: struct sockaddr_dl *dl;
82: int ret = 1;
83:
84: if (!csIface || !ea)
85: return -1;
86: else
87: memset(ea, 0, sizeof(ether_addr_t));
88:
89: getifaddrs(&ifa);
90: for (ifp = ifa; ifp; ifp = ifp->ifa_next)
91: if (!strcmp(csIface, ifp->ifa_name) && ifp->ifa_addr &&
92: ifp->ifa_addr->sa_family == AF_LINK) {
93: dl = (struct sockaddr_dl*) ifp->ifa_addr;
94: if ((dl->sdl_type == IFT_ETHER || dl->sdl_type == IFT_L2VLAN ||
95: dl->sdl_type == IFT_BRIDGE) &&
96: dl->sdl_alen == ETHER_ADDR_LEN) {
97: memcpy(ea, LLADDR(dl), sizeof(ether_addr_t));
98: ret = 0;
99: break;
100: }
101: }
102: freeifaddrs(ifa);
103:
104: return ret;
105: }
106:
107: /*
1.2 misho 108: * io_etherClose() - Close BPF interface
109: *
110: * @eth = bpf handle
111: * @zcbuf = zero copy buffer, if BPF supports it and isn't NULL
112: * return: none
113: */
114: void
115: io_etherClose(int eth, void **zcbuf)
116: {
1.5.4.1 misho 117: #if defined(__FreeBSD__) && defined(ZCBUF_ENABLE)
1.2 misho 118: struct bpf_zbuf *zbuf = NULL;
119: #endif
120:
121: if (eth > STDERR_FILENO)
122: close(eth);
123:
124: if (zcbuf && *zcbuf) {
1.5.4.1 misho 125: #if defined(__FreeBSD__) && defined(ZCBUF_ENABLE)
1.2 misho 126: zbuf = *zcbuf;
127: munmap(zbuf->bz_bufb, zbuf->bz_buflen);
128: munmap(zbuf->bz_bufa, zbuf->bz_buflen);
129: e_free(*zcbuf);
130: *zcbuf = NULL;
131: #endif
132: }
133: }
134:
1.5.4.1 misho 135: #if defined(__FreeBSD__) && defined(ZCBUF_ENABLE)
1.2 misho 136: static inline struct bpf_zbuf *
137: allocZCbuf(u_int len)
138: {
139: struct bpf_zbuf *zbuf = NULL;
140:
141: zbuf = e_malloc(sizeof(struct bpf_zbuf));
142: if (!zbuf) {
143: io_SetErr(elwix_GetErrno(), "%s", elwix_GetError());
144: return NULL;
145: } else
146: memset(zbuf, 0, sizeof(struct bpf_zbuf));
147:
148: zbuf->bz_buflen = roundup(len, getpagesize());
149: zbuf->bz_bufa = mmap(NULL, zbuf->bz_buflen, PROT_READ | PROT_WRITE, MAP_ANON, -1, 0);
150: if (zbuf->bz_bufa == MAP_FAILED) {
151: LOGERR;
152: e_free(zbuf);
153: return NULL;
154: } else
155: memset(zbuf->bz_bufa, 0, zbuf->bz_buflen);
156: zbuf->bz_bufb = mmap(NULL, zbuf->bz_buflen, PROT_READ | PROT_WRITE, MAP_ANON, -1, 0);
157: if (zbuf->bz_bufb == MAP_FAILED) {
158: LOGERR;
159: munmap(zbuf->bz_bufa, zbuf->bz_buflen);
160: e_free(zbuf);
161: return NULL;
162: } else
163: memset(zbuf->bz_bufb, 0, zbuf->bz_buflen);
164:
165: return zbuf;
166: }
167: #endif
168:
169: /*
170: * io_etherOpen() - Open BPF interface to device
171: *
172: * @csIface = interface name
173: * @flags = open flags
174: * @whdr = with complete headers
1.3 misho 175: * @wdlt = with data link type
1.2 misho 176: * @buflen = buffer length
177: * @zcbuf = zero copy buffer, if BPF supports it and isn't NULL
178: * return: -1 error or >-1 bpf handle
179: */
180: int
1.5.4.2 misho 181: io_etherOpen(const char *csIface, int flags, u_int whdr, u_int wdlt,
1.3 misho 182: u_int *buflen, void **zcbuf)
1.2 misho 183: {
184: int eth = -1;
185: register int i;
186: char szStr[STRSIZ];
187: struct ifreq ifr;
188: u_int n = 1;
189:
1.5.4.1 misho 190: #if !defined(__FreeBSD__) || !defined(ZCBUF_ENABLE)
1.2 misho 191: if (zcbuf) {
192: io_SetErr(ENOTSUP, "bpf zero copy buffer mode is not supported");
193: return -1;
194: }
195: #endif
196:
197: for (i = 0; i < BPF_DEV_MAX; i++) {
198: memset(szStr, 0, sizeof szStr);
199: snprintf(szStr, sizeof szStr, "/dev/bpf%d", i);
200: eth = open(szStr, flags);
201: if (eth > STDERR_FILENO)
202: break;
203: }
204: if (eth < 3) {
205: LOGERR;
206: return -1;
207: }
208:
1.4 misho 209: if (csIface)
210: strlcpy(szStr, csIface, sizeof szStr);
211: else if (io_get1stiface(szStr, sizeof szStr) == -1) {
212: close(eth);
213: return -1;
214: }
215:
1.5.4.4 ! misho 216: n = wdlt;
! 217: if (wdlt && ioctl(eth, BIOCSDLT, &n) == -1) {
1.4 misho 218: LOGERR;
219: close(eth);
220: return -1;
221: }
1.5.4.4 ! misho 222: n = 1;
1.5.4.2 misho 223: if (whdr && ioctl(eth, BIOCSHDRCMPLT, &n) == -1) {
1.4 misho 224: LOGERR;
225: close(eth);
226: return -1;
227: }
1.5.4.4 ! misho 228: if (ioctl(eth, BIOCIMMEDIATE, &n) == -1) {
1.4 misho 229: LOGERR;
230: close(eth);
231: return -1;
232: }
233:
1.2 misho 234: if (!zcbuf) {
235: if (ioctl(eth, BIOCGBLEN, &n) == -1) {
236: LOGERR;
237: close(eth);
238: return -1;
239: } else
1.4 misho 240: n = (buflen && *buflen) ? *buflen : getpagesize();
241:
1.2 misho 242: if (ioctl(eth, BIOCSBLEN, &n) == -1) {
243: LOGERR;
244: close(eth);
245: return -1;
246: }
1.4 misho 247: if (buflen)
1.2 misho 248: *buflen = n;
249: } else {
1.5.4.1 misho 250: #if defined(__FreeBSD__) && defined(ZCBUF_ENABLE)
1.2 misho 251: n = BPF_BUFMODE_ZBUF;
252: if (ioctl(eth, BIOCSETBUFMODE, &n) == -1) {
253: LOGERR;
254: close(eth);
255: return -1;
256: }
257: if (ioctl(eth, BIOCGETZMAX, &n) == -1) {
258: LOGERR;
259: close(eth);
260: return -1;
261: } else
262: n = (buflen && *buflen) ? *buflen : n;
263: if (!(*zcbuf = allocZCbuf(n))) {
264: close(eth);
265: return -1;
266: }
267: if (ioctl(eth, BIOCSETZBUF, *zcbuf) == -1) {
268: LOGERR;
269: io_etherClose(eth, zcbuf);
270: return -1;
271: }
272: if (buflen && *buflen)
273: *buflen = n;
274: #endif
275: }
276:
277: memset(&ifr, 0, sizeof ifr);
278: strlcpy(ifr.ifr_name, szStr, sizeof ifr.ifr_name);
279: if (ioctl(eth, BIOCSETIF, &ifr) == -1) {
280: LOGERR;
281: io_etherClose(eth, zcbuf);
282: return -1;
283: }
284:
285: return eth;
286: }
287:
288: /*
289: * io_etherSend() - Send packet to bpf
290: *
291: * @eth = bpf handle
292: * @buf = buffer
293: * @buflen = buffer length
294: * return: -1 error or !=-1 written bytes
295: */
296: ssize_t
297: io_etherSend(int eth, const void *buf, size_t buflen)
298: {
299: ssize_t wlen = 0;
300:
301: if (!buf || !buflen) {
302: io_SetErr(EINVAL, "invalid arguments");
303: return -1;
304: }
305:
306: wlen = write(eth, buf, buflen);
307: if (wlen == -1)
308: LOGERR;
309: return wlen;
310: }
311:
1.5.4.1 misho 312: #if defined(__FreeBSD__) && defined(ZCBUF_ENABLE)
1.2 misho 313: static inline void
314: ackZCbuf(struct bpf_zbuf_header *bzh)
315: {
316: atomic_store_rel_int(&bzh->bzh_user_gen, bzh->bzh_kernel_gen);
317: }
318:
319: static inline int
320: chkZCbuf(struct bpf_zbuf_header *bzh)
321: {
322: /* return true if userspace owns buffer, and false otherwise. */
323: return (bzh->bzh_user_gen != atomic_load_acq_int(&bzh->bzh_kernel_gen));
324: }
325:
326: static ssize_t
327: nextZCbuf(int eth, struct bpf_zbuf * __restrict zbuf, void * __restrict buf, size_t buflen)
328: {
329: ssize_t rlen = 0;
330: struct bpf_zbuf bz;
331: struct bpf_zbuf_header *bzh;
332: off_t pos = 0;
333:
334: bzh = (struct bpf_zbuf_header *) zbuf->bz_bufa;
335: if (chkZCbuf(bzh)) {
336: rlen = MIN(atomic_load_acq_int(&bzh->bzh_kernel_len), buflen);
337: memcpy(buf + pos, zbuf->bz_bufa + sizeof(struct bpf_zbuf_header), rlen);
338: ackZCbuf(bzh);
339: pos += rlen;
340: }
341: bzh = (struct bpf_zbuf_header *) zbuf->bz_bufb;
342: if (chkZCbuf(bzh)) {
343: rlen = MIN(atomic_load_acq_int(&bzh->bzh_kernel_len), buflen);
344: memcpy(buf + pos, zbuf->bz_bufb + sizeof(struct bpf_zbuf_header), rlen);
345: ackZCbuf(bzh);
346: pos += rlen;
347: }
348:
349: if (!pos) {
350: if ((rlen = ioctl(eth, BIOCROTZBUF, &bz)) == -1)
351: LOGERR;
352: } else
353: rlen = pos;
354: return rlen;
355: }
356: #endif
357:
358: /*
359: * io_etherRecv() - Receive packet from bpf
360: *
361: * @eth = bpf handle
362: * @buf = buffer
363: * @buflen = buffer length
364: * @zcbuf = zero copy buffer, if BPF supports it and isn't NULL
365: * return: -1 error or !=-1 readed bytes
366: */
367: ssize_t
368: io_etherRecv(int eth, void * __restrict buf, size_t buflen, void * __restrict zcbuf)
369: {
370: ssize_t rlen = 0;
1.3 misho 371: struct bpf_hdr *h;
1.2 misho 372:
373: if (!buf || !buflen) {
374: io_SetErr(EINVAL, "invalid arguments");
375: return -1;
376: }
377:
378: if (!zcbuf) {
379: rlen = read(eth, buf, buflen);
1.4 misho 380: if (rlen == -1) {
1.2 misho 381: LOGERR;
1.4 misho 382: return -1;
383: }
1.2 misho 384: } else {
1.5.4.1 misho 385: #if defined(__FreeBSD__) && defined(ZCBUF_ENABLE)
1.2 misho 386: rlen = nextZCbuf(eth, (struct bpf_zbuf*) zcbuf, buf, buflen);
387: if (!rlen)
388: rlen = nextZCbuf(eth, (struct bpf_zbuf*) zcbuf, buf, buflen);
389: #else
390: rlen = -1;
391: io_SetErr(ENOTSUP, "bpf zero copy buffer mode is not supported");
392: #endif
393: }
394:
1.3 misho 395: h = (struct bpf_hdr*) buf;
396: rlen -= h->bh_hdrlen;
397:
398: if (h->bh_caplen != rlen) {
399: if (h->bh_caplen < rlen)
400: rlen = h->bh_caplen;
401: else {
402: io_SetErr(EIO, "Captured %d bytes should be at most %d bytes",
403: h->bh_caplen, rlen);
404: return -1;
405: }
406: }
407:
408: memmove(buf, buf + h->bh_hdrlen, rlen);
1.2 misho 409: return rlen;
410: }
1.4 misho 411:
412: /*
413: * io_etherFilter() - BPF filter routine
414: *
415: * @eth = bpf handle
416: * @io = filter direction
417: * (IO_ETHER_FILTER_PROMISC|IO_ETHER_FILTER_NOTREAD|IO_ETHER_FILTER_READ|IO_ETHER_FILTER_WRITE)
418: * @insn = BPF filter instruction array
419: * @insnlen = Length of BPF filter instruction array
420: * return: -1 error or 0 ok
421: */
422: int
423: io_etherFilter(int eth, int io, struct bpf_insn * __restrict insn, size_t insnlen)
424: {
425: int ret = 0;
426: struct bpf_program fcode = { 0 };
427:
428: if (io != IO_ETHER_FILTER_PROMISC && (!insn || !insnlen)) {
429: io_SetErr(EINVAL, "invalid arguments");
430: return -1;
431: }
432:
433: switch (io) {
434: case IO_ETHER_FILTER_PROMISC: /* promiscuous mode */
435: ret = ioctl(eth, BIOCPROMISC, NULL);
436: break;
437: case IO_ETHER_FILTER_NOTREAD: /* read not filter */
438: fcode.bf_len = insnlen / sizeof(struct bpf_insn);
439: fcode.bf_insns = insn;
440: ret = ioctl(eth, BIOCSETFNR, &fcode);
441: break;
442: case IO_ETHER_FILTER_READ: /* read filter */
443: fcode.bf_len = insnlen / sizeof(struct bpf_insn);
444: fcode.bf_insns = insn;
445: ret = ioctl(eth, BIOCSETF, &fcode);
446: break;
447: case IO_ETHER_FILTER_WRITE: /* write filter */
448: fcode.bf_len = insnlen / sizeof(struct bpf_insn);
449: fcode.bf_insns = insn;
450: ret = ioctl(eth, BIOCSETWF, &fcode);
451: break;
452: }
453:
454: if (ret == -1)
455: LOGERR;
456: return ret;
457: }
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