--- /dev/null
+// -*- mode:C++; tab-width:8; c-basic-offset:2; indent-tabs-mode:t -*-
+/*
+ * This file is open source software, licensed to you under the terms
+ * of the Apache License, Version 2.0 (the "License"). See the NOTICE file
+ * distributed with this work for additional information regarding copyright
+ * ownership. You may not use this file except in compliance with the License.
+ *
+ * You may obtain a copy of the License at
+ *
+ * http://www.apache.org/licenses/LICENSE-2.0
+ *
+ * Unless required by applicable law or agreed to in writing,
+ * software distributed under the License is distributed on an
+ * "AS IS" BASIS, WITHOUT WARRANTIES OR CONDITIONS OF ANY
+ * KIND, either express or implied. See the License for the
+ * specific language governing permissions and limitations
+ * under the License.
+ */
+/*
+ * Copyright (C) 2014 Cloudius Systems, Ltd.
+ */
+/*
+ * Ceph - scalable distributed file system
+ *
+ * Copyright (C) 2015 XSky <haomai@xsky.com>
+ *
+ * Author: Haomai Wang <haomaiwang@gmail.com>
+ *
+ * This is free software; you can redistribute it and/or
+ * modify it under the terms of the GNU Lesser General Public
+ * License version 2.1, as published by the Free Software
+ * Foundation. See file COPYING.
+ *
+ */
+
+
+#ifndef CEPH_MSG_PACKET_H_
+#define CEPH_MSG_PACKET_H_
+
+#include <vector>
+#include <algorithm>
+#include <iosfwd>
+
+#include "include/types.h"
+#include "common/Tub.h"
+#include "common/deleter.h"
+#include "msg/async/Event.h"
+
+#include "const.h"
+
+struct fragment {
+ char* base;
+ size_t size;
+};
+
+struct offload_info {
+ ip_protocol_num protocol = ip_protocol_num::unused;
+ bool needs_csum = false;
+ uint8_t ip_hdr_len = 20;
+ uint8_t tcp_hdr_len = 20;
+ uint8_t udp_hdr_len = 8;
+ bool needs_ip_csum = false;
+ bool reassembled = false;
+ uint16_t tso_seg_size = 0;
+ // HW stripped VLAN header (CPU order)
+ Tub<uint16_t> vlan_tci;
+};
+
+// Zero-copy friendly packet class
+//
+// For implementing zero-copy, we need a flexible destructor that can
+// destroy packet data in different ways: decrementing a reference count,
+// or calling a free()-like function.
+//
+// Moreover, we need different destructors for each set of fragments within
+// a single fragment. For example, a header and trailer might need delete[]
+// to be called, while the internal data needs a reference count to be
+// released. Matters are complicated in that fragments can be split
+// (due to virtual/physical translation).
+//
+// To implement this, we associate each packet with a single destructor,
+// but allow composing a packet from another packet plus a fragment to
+// be added, with its own destructor, causing the destructors to be chained.
+//
+// The downside is that the data needed for the destructor is duplicated,
+// if it is already available in the fragment itself.
+//
+// As an optimization, when we allocate small fragments, we allocate some
+// extra space, so prepending to the packet does not require extra
+// allocations. This is useful when adding headers.
+//
+class Packet {
+ // enough for lots of headers, not quite two cache lines:
+ static constexpr size_t internal_data_size = 128 - 16;
+ static constexpr size_t default_nr_frags = 4;
+
+ struct pseudo_vector {
+ fragment* _start;
+ fragment* _finish;
+ pseudo_vector(fragment* start, size_t nr)
+ : _start(start), _finish(_start + nr) {}
+ fragment* begin() { return _start; }
+ fragment* end() { return _finish; }
+ fragment& operator[](size_t idx) { return _start[idx]; }
+ };
+
+ struct impl {
+ // when destroyed, virtual destructor will reclaim resources
+ deleter _deleter;
+ unsigned _len = 0;
+ uint16_t _nr_frags = 0;
+ uint16_t _allocated_frags;
+ offload_info _offload_info;
+ Tub<uint32_t> rss_hash;
+ char data[internal_data_size]; // only frags[0] may use
+ unsigned headroom = internal_data_size; // in data
+ // FIXME: share data/frags space
+
+ fragment frags[];
+
+ impl(size_t nr_frags = default_nr_frags);
+ impl(const impl&) = delete;
+ impl(fragment frag, size_t nr_frags = default_nr_frags);
+
+ pseudo_vector fragments() { return { frags, _nr_frags }; }
+
+ static std::unique_ptr<impl> allocate(size_t nr_frags) {
+ nr_frags = MAX(nr_frags, default_nr_frags);
+ return std::unique_ptr<impl>(new (nr_frags) impl(nr_frags));
+ }
+
+ static std::unique_ptr<impl> copy(impl* old, size_t nr) {
+ auto n = allocate(nr);
+ n->_deleter = std::move(old->_deleter);
+ n->_len = old->_len;
+ n->_nr_frags = old->_nr_frags;
+ n->headroom = old->headroom;
+ n->_offload_info = old->_offload_info;
+ n->rss_hash.construct(old->rss_hash);
+ std::copy(old->frags, old->frags + old->_nr_frags, n->frags);
+ old->copy_internal_fragment_to(n.get());
+ return std::move(n);
+ }
+
+ static std::unique_ptr<impl> copy(impl* old) {
+ return copy(old, old->_nr_frags);
+ }
+
+ static std::unique_ptr<impl> allocate_if_needed(std::unique_ptr<impl> old, size_t extra_frags) {
+ if (old->_allocated_frags >= old->_nr_frags + extra_frags) {
+ return std::move(old);
+ }
+ return copy(old.get(), std::max<size_t>(old->_nr_frags + extra_frags, 2 * old->_nr_frags));
+ }
+ void* operator new(size_t size, size_t nr_frags = default_nr_frags) {
+ assert(nr_frags == uint16_t(nr_frags));
+ return ::operator new(size + nr_frags * sizeof(fragment));
+ }
+ // Matching the operator new above
+ void operator delete(void* ptr, size_t nr_frags) {
+ return ::operator delete(ptr);
+ }
+ // Since the above "placement delete" hides the global one, expose it
+ void operator delete(void* ptr) {
+ return ::operator delete(ptr);
+ }
+
+ bool using_internal_data() const {
+ return _nr_frags
+ && frags[0].base >= data
+ && frags[0].base < data + internal_data_size;
+ }
+
+ void unuse_internal_data() {
+ if (!using_internal_data()) {
+ return;
+ }
+ auto buf = static_cast<char*>(::malloc(frags[0].size));
+ if (!buf) {
+ throw std::bad_alloc();
+ }
+ deleter d = make_free_deleter(buf);
+ std::copy(frags[0].base, frags[0].base + frags[0].size, buf);
+ frags[0].base = buf;
+ _deleter.append(std::move(d));
+ headroom = internal_data_size;
+ }
+ void copy_internal_fragment_to(impl* to) {
+ if (!using_internal_data()) {
+ return;
+ }
+ to->frags[0].base = to->data + headroom;
+ std::copy(frags[0].base, frags[0].base + frags[0].size,
+ to->frags[0].base);
+ }
+ };
+ Packet(std::unique_ptr<impl>&& impl) : _impl(std::move(impl)) {}
+ std::unique_ptr<impl> _impl;
+public:
+ static Packet from_static_data(const char* data, size_t len) {
+ return {fragment{const_cast<char*>(data), len}, deleter()};
+ }
+
+ // build empty Packet
+ Packet();
+ // build empty Packet with nr_frags allocated
+ Packet(size_t nr_frags);
+ // move existing Packet
+ Packet(Packet&& x) noexcept;
+ // copy data into Packet
+ Packet(const char* data, size_t len);
+ // copy data into Packet
+ Packet(fragment frag);
+ // zero-copy single fragment
+ Packet(fragment frag, deleter del);
+ // zero-copy multiple fragments
+ Packet(std::vector<fragment> frag, deleter del);
+ // build Packet with iterator
+ template <typename Iterator>
+ Packet(Iterator begin, Iterator end, deleter del);
+ // append fragment (copying new fragment)
+ Packet(Packet&& x, fragment frag);
+ // prepend fragment (copying new fragment, with header optimization)
+ Packet(fragment frag, Packet&& x);
+ // prepend fragment (zero-copy)
+ Packet(fragment frag, deleter del, Packet&& x);
+ // append fragment (zero-copy)
+ Packet(Packet&& x, fragment frag, deleter d);
+ // append deleter
+ Packet(Packet&& x, deleter d);
+
+ Packet& operator=(Packet&& x) {
+ if (this != &x) {
+ this->~Packet();
+ new (this) Packet(std::move(x));
+ }
+ return *this;
+ }
+
+ unsigned len() const { return _impl->_len; }
+ unsigned memory() const { return len() + sizeof(Packet::impl); }
+
+ fragment frag(unsigned idx) const { return _impl->frags[idx]; }
+ fragment& frag(unsigned idx) { return _impl->frags[idx]; }
+
+ unsigned nr_frags() const { return _impl->_nr_frags; }
+ pseudo_vector fragments() const { return { _impl->frags, _impl->_nr_frags }; }
+ fragment* fragment_array() const { return _impl->frags; }
+
+ // share Packet data (reference counted, non COW)
+ Packet share();
+ Packet share(size_t offset, size_t len);
+
+ void append(Packet&& p);
+
+ void trim_front(size_t how_much);
+ void trim_back(size_t how_much);
+
+ // get a header pointer, linearizing if necessary
+ template <typename Header>
+ Header* get_header(size_t offset = 0);
+
+ // get a header pointer, linearizing if necessary
+ char* get_header(size_t offset, size_t size);
+
+ // prepend a header (default-initializing it)
+ template <typename Header>
+ Header* prepend_header(size_t extra_size = 0);
+
+ // prepend a header (uninitialized!)
+ char* prepend_uninitialized_header(size_t size);
+
+ Packet free_on_cpu(EventCenter *c, std::function<void()> cb = []{});
+
+ void linearize() { return linearize(0, len()); }
+
+ void reset() { _impl.reset(); }
+
+ void reserve(int n_frags) {
+ if (n_frags > _impl->_nr_frags) {
+ auto extra = n_frags - _impl->_nr_frags;
+ _impl = impl::allocate_if_needed(std::move(_impl), extra);
+ }
+ }
+ Tub<uint32_t> rss_hash() {
+ return _impl->rss_hash;
+ }
+ void set_rss_hash(uint32_t hash) {
+ _impl->rss_hash.construct(hash);
+ }
+private:
+ void linearize(size_t at_frag, size_t desired_size);
+ bool allocate_headroom(size_t size);
+public:
+ class offload_info offload_info() const { return _impl->_offload_info; }
+ class offload_info& offload_info_ref() { return _impl->_offload_info; }
+ void set_offload_info(class offload_info oi) { _impl->_offload_info = oi; }
+};
+
+std::ostream& operator<<(std::ostream& os, const Packet& p);
+
+inline Packet::Packet(Packet&& x) noexcept
+ : _impl(std::move(x._impl)) {
+}
+
+inline Packet::impl::impl(size_t nr_frags)
+ : _len(0), _allocated_frags(nr_frags) {
+}
+
+inline Packet::impl::impl(fragment frag, size_t nr_frags)
+ : _len(frag.size), _allocated_frags(nr_frags) {
+ assert(_allocated_frags > _nr_frags);
+ if (frag.size <= internal_data_size) {
+ headroom -= frag.size;
+ frags[0] = { data + headroom, frag.size };
+ } else {
+ auto buf = static_cast<char*>(::malloc(frag.size));
+ if (!buf) {
+ throw std::bad_alloc();
+ }
+ deleter d = make_free_deleter(buf);
+ frags[0] = { buf, frag.size };
+ _deleter.append(std::move(d));
+ }
+ std::copy(frag.base, frag.base + frag.size, frags[0].base);
+ ++_nr_frags;
+}
+
+inline Packet::Packet(): _impl(impl::allocate(1)) {
+}
+
+inline Packet::Packet(size_t nr_frags): _impl(impl::allocate(nr_frags)) {
+}
+
+inline Packet::Packet(fragment frag): _impl(new impl(frag)) {
+}
+
+inline Packet::Packet(const char* data, size_t size):
+ Packet(fragment{const_cast<char*>(data), size}) {
+}
+
+inline Packet::Packet(fragment frag, deleter d)
+ : _impl(impl::allocate(1)) {
+ _impl->_deleter = std::move(d);
+ _impl->frags[_impl->_nr_frags++] = frag;
+ _impl->_len = frag.size;
+}
+
+inline Packet::Packet(std::vector<fragment> frag, deleter d)
+ : _impl(impl::allocate(frag.size())) {
+ _impl->_deleter = std::move(d);
+ std::copy(frag.begin(), frag.end(), _impl->frags);
+ _impl->_nr_frags = frag.size();
+ _impl->_len = 0;
+ for (auto&& f : _impl->fragments()) {
+ _impl->_len += f.size;
+ }
+}
+
+template <typename Iterator>
+inline Packet::Packet(Iterator begin, Iterator end, deleter del) {
+ unsigned nr_frags = 0, len = 0;
+ nr_frags = std::distance(begin, end);
+ std::for_each(begin, end, [&] (fragment& frag) { len += frag.size; });
+ _impl = impl::allocate(nr_frags);
+ _impl->_deleter = std::move(del);
+ _impl->_len = len;
+ _impl->_nr_frags = nr_frags;
+ std::copy(begin, end, _impl->frags);
+}
+
+inline Packet::Packet(Packet&& x, fragment frag)
+ : _impl(impl::allocate_if_needed(std::move(x._impl), 1)) {
+ _impl->_len += frag.size;
+ char* buf = new char[frag.size];
+ std::copy(frag.base, frag.base + frag.size, buf);
+ _impl->frags[_impl->_nr_frags++] = {buf, frag.size};
+ _impl->_deleter = make_deleter(std::move(_impl->_deleter), [buf] {
+ delete[] buf;
+ });
+}
+
+inline bool Packet::allocate_headroom(size_t size) {
+ if (_impl->headroom >= size) {
+ _impl->_len += size;
+ if (!_impl->using_internal_data()) {
+ _impl = impl::allocate_if_needed(std::move(_impl), 1);
+ std::copy_backward(_impl->frags, _impl->frags + _impl->_nr_frags,
+ _impl->frags + _impl->_nr_frags + 1);
+ _impl->frags[0] = { _impl->data + internal_data_size, 0 };
+ ++_impl->_nr_frags;
+ }
+ _impl->headroom -= size;
+ _impl->frags[0].base -= size;
+ _impl->frags[0].size += size;
+ return true;
+ } else {
+ return false;
+ }
+}
+
+
+inline Packet::Packet(fragment frag, Packet&& x)
+ : _impl(std::move(x._impl)) {
+ // try to prepend into existing internal fragment
+ if (allocate_headroom(frag.size)) {
+ std::copy(frag.base, frag.base + frag.size, _impl->frags[0].base);
+ return;
+ } else {
+ // didn't work out, allocate and copy
+ _impl->unuse_internal_data();
+ _impl = impl::allocate_if_needed(std::move(_impl), 1);
+ _impl->_len += frag.size;
+ char *buf = new char[frag.size];
+ std::copy(frag.base, frag.base + frag.size, buf);
+ std::copy_backward(_impl->frags, _impl->frags + _impl->_nr_frags,
+ _impl->frags + _impl->_nr_frags + 1);
+ ++_impl->_nr_frags;
+ _impl->frags[0] = {buf, frag.size};
+ _impl->_deleter = make_deleter(
+ std::move(_impl->_deleter), [buf] { delete []buf; });
+ }
+}
+
+inline Packet::Packet(Packet&& x, fragment frag, deleter d)
+ : _impl(impl::allocate_if_needed(std::move(x._impl), 1)) {
+ _impl->_len += frag.size;
+ _impl->frags[_impl->_nr_frags++] = frag;
+ d.append(std::move(_impl->_deleter));
+ _impl->_deleter = std::move(d);
+}
+
+inline Packet::Packet(Packet&& x, deleter d): _impl(std::move(x._impl)) {
+ _impl->_deleter.append(std::move(d));
+}
+
+inline void Packet::append(Packet&& p) {
+ if (!_impl->_len) {
+ *this = std::move(p);
+ return;
+ }
+ _impl = impl::allocate_if_needed(std::move(_impl), p._impl->_nr_frags);
+ _impl->_len += p._impl->_len;
+ p._impl->unuse_internal_data();
+ std::copy(p._impl->frags, p._impl->frags + p._impl->_nr_frags,
+ _impl->frags + _impl->_nr_frags);
+ _impl->_nr_frags += p._impl->_nr_frags;
+ p._impl->_deleter.append(std::move(_impl->_deleter));
+ _impl->_deleter = std::move(p._impl->_deleter);
+}
+
+inline char* Packet::get_header(size_t offset, size_t size) {
+ if (offset + size > _impl->_len) {
+ return nullptr;
+ }
+ size_t i = 0;
+ while (i != _impl->_nr_frags && offset >= _impl->frags[i].size) {
+ offset -= _impl->frags[i++].size;
+ }
+ if (i == _impl->_nr_frags) {
+ return nullptr;
+ }
+ if (offset + size > _impl->frags[i].size) {
+ linearize(i, offset + size);
+ }
+ return _impl->frags[i].base + offset;
+}
+
+template <typename Header>
+inline Header* Packet::get_header(size_t offset) {
+ return reinterpret_cast<Header*>(get_header(offset, sizeof(Header)));
+}
+
+inline void Packet::trim_front(size_t how_much) {
+ assert(how_much <= _impl->_len);
+ _impl->_len -= how_much;
+ size_t i = 0;
+ while (how_much && how_much >= _impl->frags[i].size) {
+ how_much -= _impl->frags[i++].size;
+ }
+ std::copy(_impl->frags + i, _impl->frags + _impl->_nr_frags, _impl->frags);
+ _impl->_nr_frags -= i;
+ if (!_impl->using_internal_data()) {
+ _impl->headroom = internal_data_size;
+ }
+ if (how_much) {
+ if (_impl->using_internal_data()) {
+ _impl->headroom += how_much;
+ }
+ _impl->frags[0].base += how_much;
+ _impl->frags[0].size -= how_much;
+ }
+}
+
+inline void Packet::trim_back(size_t how_much) {
+ assert(how_much <= _impl->_len);
+ _impl->_len -= how_much;
+ size_t i = _impl->_nr_frags - 1;
+ while (how_much && how_much >= _impl->frags[i].size) {
+ how_much -= _impl->frags[i--].size;
+ }
+ _impl->_nr_frags = i + 1;
+ if (how_much) {
+ _impl->frags[i].size -= how_much;
+ if (i == 0 && _impl->using_internal_data()) {
+ _impl->headroom += how_much;
+ }
+ }
+}
+
+template <typename Header>
+Header* Packet::prepend_header(size_t extra_size) {
+ auto h = prepend_uninitialized_header(sizeof(Header) + extra_size);
+ return new (h) Header{};
+}
+
+// prepend a header (uninitialized!)
+inline char* Packet::prepend_uninitialized_header(size_t size) {
+ if (!allocate_headroom(size)) {
+ // didn't work out, allocate and copy
+ _impl->unuse_internal_data();
+ // try again, after unuse_internal_data we may have space after all
+ if (!allocate_headroom(size)) {
+ // failed
+ _impl->_len += size;
+ _impl = impl::allocate_if_needed(std::move(_impl), 1);
+ char *buf = new char[size];
+ std::copy_backward(_impl->frags, _impl->frags + _impl->_nr_frags,
+ _impl->frags + _impl->_nr_frags + 1);
+ ++_impl->_nr_frags;
+ _impl->frags[0] = {buf, size};
+ _impl->_deleter = make_deleter(std::move(_impl->_deleter),
+ [buf] { delete []buf; });
+ }
+ }
+ return _impl->frags[0].base;
+}
+
+inline Packet Packet::share() {
+ return share(0, _impl->_len);
+}
+
+inline Packet Packet::share(size_t offset, size_t len) {
+ _impl->unuse_internal_data(); // FIXME: eliminate?
+ Packet n;
+ n._impl = impl::allocate_if_needed(std::move(n._impl), _impl->_nr_frags);
+ size_t idx = 0;
+ while (offset > 0 && offset >= _impl->frags[idx].size) {
+ offset -= _impl->frags[idx++].size;
+ }
+ while (n._impl->_len < len) {
+ auto& f = _impl->frags[idx++];
+ auto fsize = std::min(len - n._impl->_len, f.size - offset);
+ n._impl->frags[n._impl->_nr_frags++] = { f.base + offset, fsize };
+ n._impl->_len += fsize;
+ offset = 0;
+ }
+ n._impl->_offload_info = _impl->_offload_info;
+ assert(!n._impl->_deleter);
+ n._impl->_deleter = _impl->_deleter.share();
+ return n;
+}
+
+#endif /* CEPH_MSG_PACKET_H_ */
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