--- libaitio/src/bpf.c 2013/06/24 09:22:41 1.1 +++ libaitio/src/bpf.c 2013/06/26 22:48:53 1.2 @@ -0,0 +1,346 @@ +/************************************************************************* +* (C) 2013 AITNET ltd - Sofia/Bulgaria - +* by Michael Pounov +* +* $Author: misho $ +* $Id: bpf.c,v 1.2 2013/06/26 22:48:53 misho Exp $ +* +************************************************************************** +The ELWIX and AITNET software is distributed under the following +terms: + +All of the documentation and software included in the ELWIX and AITNET +Releases is copyrighted by ELWIX - Sofia/Bulgaria + +Copyright 2004, 2005, 2006, 2007, 2008, 2009, 2010, 2011, 2012, 2013 + by Michael Pounov . All rights reserved. + +Redistribution and use in source and binary forms, with or without +modification, are permitted provided that the following conditions +are met: +1. Redistributions of source code must retain the above copyright + notice, this list of conditions and the following disclaimer. +2. Redistributions in binary form must reproduce the above copyright + notice, this list of conditions and the following disclaimer in the + documentation and/or other materials provided with the distribution. +3. All advertising materials mentioning features or use of this software + must display the following acknowledgement: +This product includes software developed by Michael Pounov +ELWIX - Embedded LightWeight unIX and its contributors. +4. Neither the name of AITNET nor the names of its contributors + may be used to endorse or promote products derived from this software + without specific prior written permission. + +THIS SOFTWARE IS PROVIDED BY AITNET AND CONTRIBUTORS ``AS IS'' AND +ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE +IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE +ARE DISCLAIMED. IN NO EVENT SHALL THE REGENTS OR CONTRIBUTORS BE LIABLE +FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL +DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS +OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION) +HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT +LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY +OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF +SUCH DAMAGE. +*/ +#include "global.h" + + +/* + * io_get1stiface() - Get first interface of host + * + * @szIface = interface string buffer + * @iflen = size of interface buffer + * return: -1 error or 0 ok + */ +int +io_get1stiface(char *szIface, int iflen) +{ + struct ifaddrs *ifa; + + if (!szIface || !iflen) + return -1; + + getifaddrs(&ifa); + strlcpy(szIface, ifa->ifa_name, iflen); + freeifaddrs(ifa); + return 0; +} + +/* + * io_etherClose() - Close BPF interface + * + * @eth = bpf handle + * @zcbuf = zero copy buffer, if BPF supports it and isn't NULL + * return: none + */ +void +io_etherClose(int eth, void **zcbuf) +{ +#ifdef __FreeBSD__ + struct bpf_zbuf *zbuf = NULL; +#endif + + if (eth > STDERR_FILENO) + close(eth); + + if (zcbuf && *zcbuf) { +#ifdef __FreeBSD__ + zbuf = *zcbuf; + munmap(zbuf->bz_bufb, zbuf->bz_buflen); + munmap(zbuf->bz_bufa, zbuf->bz_buflen); + e_free(*zcbuf); + *zcbuf = NULL; +#endif + } +} + +#ifdef __FreeBSD__ +static inline struct bpf_zbuf * +allocZCbuf(u_int len) +{ + struct bpf_zbuf *zbuf = NULL; + + zbuf = e_malloc(sizeof(struct bpf_zbuf)); + if (!zbuf) { + io_SetErr(elwix_GetErrno(), "%s", elwix_GetError()); + return NULL; + } else + memset(zbuf, 0, sizeof(struct bpf_zbuf)); + + zbuf->bz_buflen = roundup(len, getpagesize()); + zbuf->bz_bufa = mmap(NULL, zbuf->bz_buflen, PROT_READ | PROT_WRITE, MAP_ANON, -1, 0); + if (zbuf->bz_bufa == MAP_FAILED) { + LOGERR; + e_free(zbuf); + return NULL; + } else + memset(zbuf->bz_bufa, 0, zbuf->bz_buflen); + zbuf->bz_bufb = mmap(NULL, zbuf->bz_buflen, PROT_READ | PROT_WRITE, MAP_ANON, -1, 0); + if (zbuf->bz_bufb == MAP_FAILED) { + LOGERR; + munmap(zbuf->bz_bufa, zbuf->bz_buflen); + e_free(zbuf); + return NULL; + } else + memset(zbuf->bz_bufb, 0, zbuf->bz_buflen); + + return zbuf; +} +#endif + +/* + * io_etherOpen() - Open BPF interface to device + * + * @csIface = interface name + * @flags = open flags + * @whdr = with complete headers + * @buflen = buffer length + * @zcbuf = zero copy buffer, if BPF supports it and isn't NULL + * return: -1 error or >-1 bpf handle + */ +int +io_etherOpen(const char *csIface, int flags, int whdr, u_int *buflen, void **zcbuf) +{ + int eth = -1; + register int i; + char szStr[STRSIZ]; + struct ifreq ifr; + u_int n = 1; + +#ifndef __FreeBSD__ + if (zcbuf) { + io_SetErr(ENOTSUP, "bpf zero copy buffer mode is not supported"); + return -1; + } +#endif + + for (i = 0; i < BPF_DEV_MAX; i++) { + memset(szStr, 0, sizeof szStr); + snprintf(szStr, sizeof szStr, "/dev/bpf%d", i); + eth = open(szStr, flags); + if (eth > STDERR_FILENO) + break; + } + if (eth < 3) { + LOGERR; + return -1; + } + + if (!zcbuf) { + if (ioctl(eth, BIOCGBLEN, &n) == -1) { + LOGERR; + close(eth); + return -1; + } else + n = (buflen && *buflen) ? *buflen : n; + if (ioctl(eth, BIOCSBLEN, &n) == -1) { + LOGERR; + close(eth); + return -1; + } + if (buflen && *buflen) + *buflen = n; + } else { +#ifdef __FreeBSD__ + n = BPF_BUFMODE_ZBUF; + if (ioctl(eth, BIOCSETBUFMODE, &n) == -1) { + LOGERR; + close(eth); + return -1; + } + if (ioctl(eth, BIOCGETZMAX, &n) == -1) { + LOGERR; + close(eth); + return -1; + } else + n = (buflen && *buflen) ? *buflen : n; + if (!(*zcbuf = allocZCbuf(n))) { + close(eth); + return -1; + } + if (ioctl(eth, BIOCSETZBUF, *zcbuf) == -1) { + LOGERR; + io_etherClose(eth, zcbuf); + return -1; + } + if (buflen && *buflen) + *buflen = n; +#endif + } + + if (csIface) + strlcpy(szStr, csIface, sizeof szStr); + else if (io_get1stiface(szStr, sizeof szStr) == -1) { + io_etherClose(eth, zcbuf); + return -1; + } + memset(&ifr, 0, sizeof ifr); + strlcpy(ifr.ifr_name, szStr, sizeof ifr.ifr_name); + if (ioctl(eth, BIOCSETIF, &ifr) == -1) { + LOGERR; + io_etherClose(eth, zcbuf); + return -1; + } + + n = 1; + if (whdr && ioctl(eth, BIOCSHDRCMPLT, &n) == -1) { + LOGERR; + io_etherClose(eth, zcbuf); + return -1; + } + if (ioctl(eth, BIOCIMMEDIATE, &n) == -1) { + LOGERR; + io_etherClose(eth, zcbuf); + return -1; + } + + return eth; +} + +/* + * io_etherSend() - Send packet to bpf + * + * @eth = bpf handle + * @buf = buffer + * @buflen = buffer length + * return: -1 error or !=-1 written bytes + */ +ssize_t +io_etherSend(int eth, const void *buf, size_t buflen) +{ + ssize_t wlen = 0; + + if (!buf || !buflen) { + io_SetErr(EINVAL, "invalid arguments"); + return -1; + } + + wlen = write(eth, buf, buflen); + if (wlen == -1) + LOGERR; + return wlen; +} + +#ifdef __FreeBSD__ +static inline void +ackZCbuf(struct bpf_zbuf_header *bzh) +{ + atomic_store_rel_int(&bzh->bzh_user_gen, bzh->bzh_kernel_gen); +} + +static inline int +chkZCbuf(struct bpf_zbuf_header *bzh) +{ + /* return true if userspace owns buffer, and false otherwise. */ + return (bzh->bzh_user_gen != atomic_load_acq_int(&bzh->bzh_kernel_gen)); +} + +static ssize_t +nextZCbuf(int eth, struct bpf_zbuf * __restrict zbuf, void * __restrict buf, size_t buflen) +{ + ssize_t rlen = 0; + struct bpf_zbuf bz; + struct bpf_zbuf_header *bzh; + off_t pos = 0; + + bzh = (struct bpf_zbuf_header *) zbuf->bz_bufa; + if (chkZCbuf(bzh)) { + rlen = MIN(atomic_load_acq_int(&bzh->bzh_kernel_len), buflen); + memcpy(buf + pos, zbuf->bz_bufa + sizeof(struct bpf_zbuf_header), rlen); + ackZCbuf(bzh); + pos += rlen; + } + bzh = (struct bpf_zbuf_header *) zbuf->bz_bufb; + if (chkZCbuf(bzh)) { + rlen = MIN(atomic_load_acq_int(&bzh->bzh_kernel_len), buflen); + memcpy(buf + pos, zbuf->bz_bufb + sizeof(struct bpf_zbuf_header), rlen); + ackZCbuf(bzh); + pos += rlen; + } + + if (!pos) { + if ((rlen = ioctl(eth, BIOCROTZBUF, &bz)) == -1) + LOGERR; + } else + rlen = pos; + return rlen; +} +#endif + +/* + * io_etherRecv() - Receive packet from bpf + * + * @eth = bpf handle + * @buf = buffer + * @buflen = buffer length + * @zcbuf = zero copy buffer, if BPF supports it and isn't NULL + * return: -1 error or !=-1 readed bytes + */ +ssize_t +io_etherRecv(int eth, void * __restrict buf, size_t buflen, void * __restrict zcbuf) +{ + ssize_t rlen = 0; + + if (!buf || !buflen) { + io_SetErr(EINVAL, "invalid arguments"); + return -1; + } + + if (!zcbuf) { + rlen = read(eth, buf, buflen); + if (rlen == -1) + LOGERR; + } else { +#ifdef __FreeBSD__ + rlen = nextZCbuf(eth, (struct bpf_zbuf*) zcbuf, buf, buflen); + if (!rlen) + rlen = nextZCbuf(eth, (struct bpf_zbuf*) zcbuf, buf, buflen); +#else + rlen = -1; + io_SetErr(ENOTSUP, "bpf zero copy buffer mode is not supported"); +#endif + } + + return rlen; +}