--- libaitio/src/bpf.c 2013/06/24 11:09:55 1.1.2.2 +++ libaitio/src/bpf.c 2013/06/25 08:53:22 1.1.2.8 @@ -26,24 +26,76 @@ io_get1stiface(char *szIface, int iflen) * 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) +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) +io_etherOpen(const char *csIface, int flags, int whdr, u_int *buflen, void **zcbuf) { int n = 1, eth = -1; register int i; @@ -67,24 +119,160 @@ io_etherOpen(const char *csIface, int flags) close(eth); return -1; } - n = USHRT_MAX + 1; - if (ioctl(eth, BIOCSBLEN, &n) == -1) { + if (whdr && ioctl(eth, BIOCSHDRCMPLT, &n) == -1) { LOGERR; close(eth); return -1; } + if (buflen && *buflen) { + if (!zcbuf) { + if (ioctl(eth, BIOCSBLEN, buflen) == -1) { + LOGERR; + close(eth); + return -1; + } + } 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 + *buflen = MIN(n, *buflen); + if (!(*zcbuf = allocZCbuf(*buflen))) { + close(eth); + return -1; + } + if (ioctl(eth, BIOCSETZBUF, (struct bpf_zbuf*) *zcbuf) == -1) { + LOGERR; + io_etherClose(eth, zcbuf); + return -1; + } +#endif + } + } if (csIface) strlcpy(szStr, csIface, sizeof szStr); else if (io_get1stiface(szStr, sizeof szStr) == -1) { - close(eth); + io_etherClose(eth, zcbuf); return -1; } strlcpy(ifr.ifr_name, szStr, sizeof ifr.ifr_name); if (ioctl(eth, BIOCSETIF, &ifr) == -1) { LOGERR; - close(eth); + 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 * __restrict bzh) +{ + atomic_store_rel_int(&bzh->bzh_user_gen, bzh->bzh_kernel_gen); +} + +static inline int +chkZCbuf(struct bpf_zbuf_header * __restrict bzh) +{ + /* return true if userspace owns buffer, and false otherwise. */ + return (bzh->bzh_user_gen != atomic_load_acq_int(&bzh->bzh_kernel_gen)); +} + +static inline ssize_t +nextZCbuf(void ** __restrict zcache, struct bpf_zbuf * __restrict zbuf, + const void * __restrict buf) +{ + ssize_t rlen = -1; + struct bpf_zbuf_header *bzh; + + if (!*zcache || *zcache == zbuf->bz_bufb) { + bzh = (struct bpf_zbuf_header *) zbuf->bz_bufa; + if (chkZCbuf(bzh)) { + rlen = atomic_load_acq_int(&bzh->bzh_kernel_len); + *zcache = zbuf->bz_bufa; + if (buf) + buf = ((caddr_t) *zcache) + sizeof(struct bpf_zbuf_header); + ackZCbuf(bzh); + } + } else if (*zcache == zbuf->bz_bufa) { + bzh = (struct bpf_zbuf_header *) zbuf->bz_bufb; + if (chkZCbuf(bzh)) { + rlen = atomic_load_acq_int(&bzh->bzh_kernel_len); + *zcache = zbuf->bz_bufb; + if (buf) + buf = ((caddr_t) *zcache) + sizeof(struct bpf_zbuf_header); + ackZCbuf(bzh); + } + } + + 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); +#else + io_SetErr(ENOTSUP, "bpf zero copy buffer mode is not supported"); +#endif + } + + return rlen; }