--- libaitio/src/bpf.c 2013/06/24 14:48:04 1.1.2.5 +++ libaitio/src/bpf.c 2013/06/25 08:18:57 1.1.2.6 @@ -172,3 +172,88 @@ io_etherOpen(const char *csIface, int flags, int whdr, 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 ssize_t +nextZCbuf(void ** __restrict zcache, struct bpf_zbuf * __restrict zbuf) +{ + ssize_t rlen = -1; + struct bpf_zbuf_header *bzh; + + if (!*zcache || *zcache == zbuf->bz_bufb) { + bzh = (struct bpf_zbuf_header *) zbuf->bz_bufa; + if (bzh->bzh_user_gen != atomic_load_acq_int(&bzh->bzh_kernel_gen)) { + rlen = atomic_load_acq_int(&bzh->bzh_kernel_len); + *zcache = zbuf->bz_bufa; + } + } else if (*zcache == zbuf->bz_bufa) { + bzh = (struct bpf_zbuf_header *) zbuf->bz_bufb; + if (bzh->bzh_user_gen != atomic_load_acq_int(&bzh->bzh_kernel_gen)) { + rlen = atomic_load_acq_int(&bzh->bzh_kernel_len); + *zcache = zbuf->bz_bufb; + } + } + + 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; + void **zcache = NULL; + + 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(zcache, (struct bpf_zbuf*) zcbuf); + buf = *zcache; +#else + io_SetErr(ENOTSUP, "bpf zero copy buffer mode is not supported"); +#endif + } + + return rlen; +}