3 * Copyright 2008,2009 Free Software Foundation, Inc.
5 * This file is part of GNU Radio
7 * GNU Radio is free software; you can redistribute it and/or modify
8 * it under the terms of the GNU General Public License as published by
9 * the Free Software Foundation; either version 3, or (at your option)
12 * GNU Radio is distributed in the hope that it will be useful,
13 * but WITHOUT ANY WARRANTY; without even the implied warranty of
14 * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the
15 * GNU General Public License for more details.
17 * You should have received a copy of the GNU General Public License along
18 * with this program; if not, write to the Free Software Foundation, Inc.,
19 * 51 Franklin Street, Fifth Floor, Boston, MA 02110-1301 USA.
26 #include "eth_buffer.h"
28 #include <usrp2/data_handler.h>
29 #include <linux/if_packet.h>
30 #include <sys/socket.h>
41 #define ETH_BUFFER_DEBUG 0 // define to 0 or 1
43 #define DEBUG_LOG(x) ::write(2, (x), 1)
48 #define DEFAULT_MEM_SIZE 25e6 // ~0.25s @ 100 MB/s
49 #define MAX_MEM_SIZE 1000e6 // ~10.00s @ 100 MB/s.
50 #define MAX_SLAB_SIZE 131072 // 128 KB (FIXME fish out of /proc/slabinfo)
51 #define MAX_PKT_SIZE 1512 // we don't do jumbo frames
55 eth_buffer::eth_buffer(size_t rx_bufsize)
56 : d_fd(0), d_using_tpring(false), d_buflen(0), d_buf(0), d_frame_nr(0),
57 d_frame_size(0), d_head(0), d_ring(0), d_ethernet(new ethernet())
60 d_buflen = (size_t)DEFAULT_MEM_SIZE;
62 d_buflen = std::min((size_t)MAX_MEM_SIZE, rx_bufsize);
64 memset(d_mac, 0, sizeof(d_mac));
67 eth_buffer::~eth_buffer()
73 eth_buffer::open(const std::string &ifname, int protocol)
75 if (!d_ethernet->open(ifname, protocol)) {
76 std::cerr << "eth_buffer: unable to open interface "
77 << ifname << std::endl;
81 d_fd = d_ethernet->fd();
82 memcpy(d_mac, d_ethernet->mac(), sizeof(d_mac));
84 struct tpacket_req req;
85 size_t page_size = getpagesize();
87 // Calculate minimum power-of-two aligned size for frames
89 (unsigned int)rint(pow(2, ceil(log2(TPACKET_ALIGN(TPACKET_HDRLEN)+TPACKET_ALIGN(MAX_PKT_SIZE)))));
90 d_frame_size = req.tp_frame_size;
92 // Calculate minimum contiguous pages needed to enclose a frame
93 int npages = (page_size > req.tp_frame_size) ? 1 : ((req.tp_frame_size+page_size-1)/page_size);
94 req.tp_block_size = page_size << (int)ceil(log2(npages));
96 // Calculate number of blocks
97 req.tp_block_nr = (int)(d_buflen/req.tp_block_size);
100 // Recalculate buffer length
101 d_buflen = req.tp_block_nr*req.tp_block_size;
103 // Finally, calculate total number of frames. Since frames, blocks,
104 // and pages are all power-of-two aligned, frames are contiguous
105 req.tp_frame_nr = d_buflen/req.tp_frame_size;
106 d_frame_nr = req.tp_frame_nr;
109 if (ETH_BUFFER_DEBUG)
110 std::cerr << "eth_buffer:"
111 << " frame_size=" << req.tp_frame_size
112 << " block_size=" << req.tp_block_size
113 << " block_nr=" << req.tp_block_nr
114 << " frame_nr=" << req.tp_frame_nr
115 << " buflen=" << d_buflen
119 // Try to get kernel shared memory buffer
120 if (setsockopt(d_fd, SOL_PACKET, PACKET_RX_RING, (void *)&req, sizeof(req))) {
121 perror("eth_buffer: setsockopt");
122 d_using_tpring = false;
123 if (!(d_buf = (uint8_t *)malloc(d_buflen))) {
124 std::cerr << "eth_buffer: failed to allocate packet memory" << std::endl;
128 std::cerr << "eth_buffer: using malloc'd memory for buffer" << std::endl;
131 d_using_tpring = true;
132 void *p = mmap(0, d_buflen, PROT_READ|PROT_WRITE, MAP_SHARED, d_fd, 0);
133 if (p == MAP_FAILED){
134 perror("eth_buffer: mmap");
137 d_buf = (uint8_t *) p;
139 if (ETH_BUFFER_DEBUG)
140 std::cerr << "eth_buffer: using kernel shared mem for buffer" << std::endl;
143 // Initialize our pointers into the packet ring
144 d_ring = std::vector<uint8_t *>(req.tp_frame_nr);
145 for (unsigned int i=0; i < req.tp_frame_nr; i++) {
146 d_ring[i] = (uint8_t *)(d_buf+i*req.tp_frame_size);
149 // If not using kernel ring, instantiate select/read thread here
157 // if we have background thread, stop it here
159 if (!d_using_tpring && d_buf)
162 return d_ethernet->close();
166 eth_buffer::attach_pktfilter(pktfilter *pf)
168 return d_ethernet->attach_pktfilter(pf);
172 eth_buffer::frame_available()
174 return (((tpacket_hdr *)d_ring[d_head])->tp_status != TP_STATUS_KERNEL);
178 eth_buffer::rx_frames(data_handler *f, int timeout_in_ms)
182 while (!frame_available()) {
183 if (timeout_in_ms == 0) {
185 return EB_WOULD_BLOCK;
195 int pres = poll(&pfd, 1, timeout_in_ms);
207 // Iterate through available packets
208 while (frame_available()) {
209 // Get start of ethernet frame and length
210 tpacket_hdr *hdr = (tpacket_hdr *)d_ring[d_head];
211 void *base = (uint8_t *)hdr+hdr->tp_mac;
212 size_t len = hdr->tp_len;
214 // FYI, (base % 4 == 2) Not what we want given the current FPGA
215 // code. This means that our uint32_t samples are not 4-byte
216 // aligned. We'll have to deal with it downstream.
219 fprintf(stderr, "eth_buffer: base = %p tp_mac = %3d tp_net = %3d\n",
220 base, hdr->tp_mac, hdr->tp_net);
222 // Invoke data handler
223 data_handler::result r = (*f)(base, len);
224 if (!(r & data_handler::KEEP))
225 hdr->tp_status = TP_STATUS_KERNEL; // mark it free
229 if (r & data_handler::DONE)
238 eth_buffer::tx_frame(const void *base, size_t len, int flags)
242 if (flags & EF_DONTWAIT) // FIXME: implement flags
243 throw std::runtime_error("tx_frame: EF_DONTWAIT not implemented");
245 int res = d_ethernet->write_packet(base, len);
246 if (res < 0 || (unsigned int)res != len)
253 eth_buffer::tx_framev(const eth_iovec *iov, int iovcnt, int flags)
257 if (flags & EF_DONTWAIT) // FIXME: implement flags
258 throw std::runtime_error("tx_frame: EF_DONTWAIT not implemented");
260 int res = d_ethernet->write_packetv(iov, iovcnt);
268 eth_buffer::release_frame(void *base)
270 // Get d_frame_size aligned header
271 tpacket_hdr *hdr = (tpacket_hdr *)((intptr_t)base & ~(d_frame_size-1));
272 hdr->tp_status = TP_STATUS_KERNEL; // mark it free