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* Copyright 2008 Free Software Foundation, Inc.
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* This file is part of GNU Radio
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* GNU Radio is free software; you can redistribute it and/or modify
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* it under the terms of the GNU General Public License as published by
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* the Free Software Foundation; either version 3, or (at your option)
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* GNU Radio is distributed in the hope that it will be useful,
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* but WITHOUT ANY WARRANTY; without even the implied warranty of
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* MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the
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* GNU General Public License for more details.
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* You should have received a copy of the GNU General Public License along
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* with this program; if not, write to the Free Software Foundation, Inc.,
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* 51 Franklin Street, Fifth Floor, Boston, MA 02110-1301 USA.
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#ifndef INCLUDED_USRP2_ETH_BUFFER_H
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#define INCLUDED_USRP2_ETH_BUFFER_H
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#include "pktfilter.h"
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#include <eth_common.h>
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#include <boost/utility.hpp>
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* \brief high-performance interface to send and receive raw
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* ethernet frames with out-of-order retirement of received frames.
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* On many systems it should be possible to implement this on top of libpcap
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class eth_buffer : boost::noncopyable
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int d_fd; // socket file descriptor
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uint8_t d_mac[6]; // our mac address
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bool d_using_tpring; // using kernel mapped packet ring
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size_t d_buflen; // length of our buffer
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uint8_t *d_buf; // packet ring
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unsigned int d_frame_nr; // max frames on ring
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size_t d_frame_size; // frame storage size
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unsigned int d_head; // pointer to next frame
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std::vector<uint8_t *> d_ring; // pointers into buffer
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std::auto_ptr<ethernet> d_ethernet; // our underlying interface
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bool frame_available();
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if (d_head + 1 >= d_frame_nr)
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EB_OK, //< everything's fine
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EB_ERROR, //< A non-recoverable error occurred
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EB_WOULD_BLOCK, //< A timeout of 0 was specified and nothing was ready
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EB_TIMED_OUT, //< The timeout expired before anything was ready
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static const unsigned int MAX_PKTLEN = 1512;
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static const unsigned int MIN_PKTLEN = 64;
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* \param rx_bufsize is a hint as to the number of bytes of memory
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* to allocate for received ethernet frames (0 -> reasonable default)
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eth_buffer(size_t rx_bufsize = 0);
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* \brief open the specified interface
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* \param ifname ethernet interface name, e.g., "eth0"
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* \param protocol is the ethertype protocol number in network order.
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* Use 0 to receive all protocols.
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bool open(const std::string &ifname, int protocol);
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* \brief close the interface
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* \brief attach packet filter to socket to restrict which packets read sees.
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* \param pf the packet filter
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bool attach_pktfilter(pktfilter *pf);
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* \brief return 6 byte string containing our MAC address
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const uint8_t *mac() const { return d_mac; }
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* \brief Call \p f for each frame in the receive buffer.
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* \param f is the frame data handler
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* \param timeout (in ms) controls behavior when there are no frames to read
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* If \p timeout is 0, rx_frames will not wait for frames if none are
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* available, and f will not be invoked. If \p timeout is -1 (the
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* default), rx_frames will block indefinitely until frames are
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* available. If \p timeout is positive, it indicates the number of
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* milliseconds to wait for a frame to become available. Once the
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* timeout has expired, rx_frames will return, f never having been
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* \p f will be called on each ethernet frame that is available.
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* \p f returns a bit mask with one of the following set or cleared:
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* data_handler::KEEP - hold onto the frame and present it again during
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* the next call to rx_frames, otherwise discard it
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* data_handler::DONE - return from rx_frames now even though more frames
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* might be available; otherwise continue if more
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* The idea of holding onto a frame for the next iteration allows
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* the caller to scan the received packet stream for particular
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* classes of frames (such as command replies) leaving the rest
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* intact. On the next call all kept frames, followed by any new
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* frames received, will be presented in order to \p f.
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* See usrp2.cc for an example of the pattern.
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* \returns EB_OK if at least one frame was received
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* \returns EB_WOULD_BLOCK if \p timeout is 0 and the call would have blocked
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* \returns EB_TIMED_OUT if timeout occurred
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* \returns EB_ERROR if there was an unrecoverable error.
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result rx_frames(data_handler *f, int timeout=-1);
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* \brief Release frame from buffer
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* Call to release a frame previously held by a data_handler::KEEP.
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* The pointer may be offset from the base of the frame up to its length.
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void release_frame(void *p);
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* \brief Write an ethernet frame to the interface.
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* \param base points to the beginning of the frame (the 14-byte ethernet header).
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* \param len is the length of the frame in bytes.
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* \param flags is 0 or the bitwise-or of values from eth_flags
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* The frame must begin with a 14-byte ethernet header.
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* \returns EB_OK if the frame was successfully enqueued.
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* \returns EB_WOULD_BLOCK if flags contains EF_DONT_WAIT and the call would have blocked.
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* \returns EB_ERROR if there was an unrecoverable error.
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result tx_frame(const void *base, size_t len, int flags=0);
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* \brief Write an ethernet frame to the interface using scatter/gather.
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* \param iov points to an array of iovec structs
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* \param iovcnt is the number of entries
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* \param flags is 0 or the bitwise-or of values from eth_flags
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* The frame must begin with a 14-byte ethernet header.
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* \returns EB_OK if the frame was successfully enqueued.
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* \returns EB_WOULD_BLOCK if flags contains EF_DONT_WAIT and the call would have blocked.
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* \returns EB_ERROR if there was an unrecoverable error.
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result tx_framev(const eth_iovec *iov, int iovcnt, int flags=0);
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* \brief Returns maximum possible number of frames in buffer
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unsigned int max_frames() const { return d_frame_nr; }
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}; // namespace usrp2
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#endif /* INCLUDED_USRP2_ETH_BUFFER_H */