1 //
2 // Copyright 2019 Ettus Research, a National Instruments brand
3 //
4 // SPDX-License-Identifier: GPL-3.0-or-later
5 //
6 #pragma once
7 
8 #include <uhdlib/transport/dpdk/common.hpp>
9 #include <uhdlib/transport/dpdk/service_queue.hpp>
10 #include <uhdlib/transport/io_service.hpp>
11 #include <rte_arp.h>
12 #include <rte_hash.h>
13 #include <rte_ip.h>
14 #include <rte_mbuf.h>
15 #include <rte_udp.h>
16 #include <vector>
17 
18 namespace uhd { namespace transport {
19 
20 class dpdk_send_io;
21 class dpdk_recv_io;
22 struct dpdk_io_if;
23 
24 class dpdk_io_service : public virtual io_service,
25                         public std::enable_shared_from_this<dpdk_io_service>
26 {
27 public:
28     using sptr = std::shared_ptr<dpdk_io_service>;
29 
30     static sptr make(
31         unsigned int lcore_id, std::vector<dpdk::dpdk_port*> ports, size_t servq_depth);
32 
33     ~dpdk_io_service();
34 
35     // Add entry to RX flow table
36     // This yields a link, which is then used for attaching to a buffer
37     // We yank from the link immediately following, then process at the transport level
38     // (so two tables here, one for transports, one for links)
39     void attach_recv_link(recv_link_if::sptr link);
40 
41     // Create object to hold set of queues, to go in TX table
42     void attach_send_link(send_link_if::sptr link);
43 
44     void detach_recv_link(recv_link_if::sptr link);
45 
46     void detach_send_link(send_link_if::sptr link);
47 
48     recv_io_if::sptr make_recv_client(recv_link_if::sptr data_link,
49         size_t num_recv_frames,
50         recv_callback_t cb,
51         send_link_if::sptr fc_link,
52         size_t num_send_frames,
53         recv_io_if::fc_callback_t fc_cb);
54 
55     send_io_if::sptr make_send_client(send_link_if::sptr send_link,
56         size_t num_send_frames,
57         send_io_if::send_callback_t send_cb,
58         recv_link_if::sptr recv_link,
59         size_t num_recv_frames,
60         recv_callback_t recv_cb,
61         send_io_if::fc_callback_t fc_cb);
62 
63 
64 private:
65     friend class dpdk_recv_io;
66     friend class dpdk_send_io;
67 
68     dpdk_io_service(
69         unsigned int lcore_id, std::vector<dpdk::dpdk_port*> ports, size_t servq_depth);
70     dpdk_io_service(const dpdk_io_service&) = delete;
71 
72     /*!
73      * I/O worker function to be passed to the DPDK lcore
74      *
75      * The argument must be a pointer to  *this* dpdk_io_service
76      *
77      * \param arg a pointer to this dpdk_io_service
78      * \return 0 for normal termination, else nonzero
79      */
80     static int _io_worker(void* arg);
81 
82     /*!
83      * Helper function for I/O thread to process requests on its service queue
84      */
85     int _service_requests();
86 
87     /*!
88      * Helper function for I/O thread to service a WAIT_FLOW_OPEN request
89      *
90      * \param req The requester's wait_req object
91      */
92     void _service_flow_open(dpdk::wait_req* req);
93 
94     /*!
95      * Helper function for I/O thread to service a WAIT_FLOW_CLOSE request
96      *
97      * \param req The requester's wait_req object
98      */
99     void _service_flow_close(dpdk::wait_req* req);
100 
101     /*!
102      * Helper function for I/O thread to service a WAIT_XPORT_CONNECT request
103      *
104      * \param req The requester's wait_req object
105      */
106     void _service_xport_connect(dpdk::wait_req* req);
107 
108     /*!
109      * Helper function for I/O thread to service a WAIT_XPORT_DISCONNECT request
110      *
111      * \param req The requester's wait_req object
112      */
113     void _service_xport_disconnect(dpdk::wait_req* req);
114 
115     /*!
116      * Get Ethernet MAC address for the given IPv4 address, and wake the
117      * requester when finished.
118      * This may only be called by an I/O service, on behalf of a requester's
119      * WAIT_ARP request.
120      *
121      * \param req The requester's wait_req object
122      * \return 0 if address was written, -EAGAIN if request was queued for
123      *         later completion, -ENOMEM if ran out of memory to complete
124      *         request
125      */
126     int _service_arp_request(dpdk::wait_req* req);
127 
128     /*!
129      * Helper function for I/O thread to do a burst of packet retrieval and
130      * processing on an RX queue
131      *
132      * \param port the DPDK NIC port used for RX
133      * \param queue the DMA queue on the port to recv from
134      */
135     int _rx_burst(dpdk::dpdk_port* port, dpdk::queue_id_t queue);
136 
137     /*!
138      * Helper function for I/O thread to do a burst of packet transmission on a
139      * TX queue
140      *
141      * \param port the DPDK NIC port used for TX
142      * \return number of buffers transmitted
143      */
144     int _tx_burst(dpdk::dpdk_port* port);
145 
146     /*!
147      * Helper function for I/O thread to release a burst of buffers from an RX
148      * release queue
149      *
150      * \param port the DPDK NIC port used for RX
151      * \return number of buffers released
152      */
153     int _rx_release(dpdk::dpdk_port* port);
154 
155     /*!
156      * Helper function for I/O thread to do send an ARP request
157      *
158      * \param port the DPDK NIC port to send the ARP request through
159      * \param queue the DMA queue on the port to send to
160      * \param ip the IPv4 address for which the caller is seeking a MAC address
161      */
162     int _send_arp_request(
163         dpdk::dpdk_port* port, dpdk::queue_id_t queue, dpdk::ipv4_addr ip);
164 
165     /*!
166      * Helper function for I/O thread to process an ARP request/reply
167      *
168      * \param port the DPDK NIC port to send any ARP replies from
169      * \param queue the DMA queue on the port to send ARP replies to
170      * \param arp_frame a pointer to the ARP frame
171      */
172     int _process_arp(
173         dpdk::dpdk_port* port, dpdk::queue_id_t queue_id, struct arp_hdr* arp_frame);
174 
175     /*!
176      * Helper function for I/O thread to process an IPv4 packet
177      *
178      * \param port the DPDK NIC port to send any ARP replies from
179      * \param mbuf a pointer to the packet buffer container
180      * \param pkt a pointer to the IPv4 header of the packet
181      */
182     int _process_ipv4(dpdk::dpdk_port* port, struct rte_mbuf* mbuf, struct ipv4_hdr* pkt);
183 
184     /*!
185      * Helper function for I/O thread to process an IPv4 packet
186      *
187      * \param port the DPDK NIC port to send any ARP replies from
188      * \param mbuf a pointer to the packet buffer container
189      * \param pkt a pointer to the UDP header of the packet
190      * \param bcast whether this packet was destined for the port's broadcast
191      *              IPv4 address
192      */
193     int _process_udp(
194         dpdk::dpdk_port* port, struct rte_mbuf* mbuf, struct udp_hdr* pkt, bool bcast);
195 
196     /*!
197      * Helper function to get a unique client ID
198      *
199      * \return a unique client ID
200      */
201     uint16_t _get_unique_client_id();
202 
203     /*!
204      * Attempt to wake client
205      */
206     void _wake_client(dpdk_io_if* dpdk_io);
207 
208     //! The reference to the DPDK context
209     std::weak_ptr<dpdk::dpdk_ctx> _ctx;
210     //! The lcore running this dpdk_io_service's work routine
211     unsigned int _lcore_id;
212     //! The NIC ports served by this dpdk_io_service
213     std::vector<dpdk::dpdk_port*> _ports;
214     //! The set of TX queues associated with a given port
215     std::unordered_map<dpdk::port_id_t, std::list<dpdk_send_io*>> _tx_queues;
216     //! The list of recv_io for each port
217     std::unordered_map<dpdk::port_id_t, std::list<dpdk_recv_io*>> _recv_xport_map;
218     //! The RX table, which provides lists of dpdk_recv_io for an IPv4 tuple
219     struct rte_hash* _rx_table;
220     //! Service queue for clients to make requests
221     dpdk::service_queue _servq;
222     //! Retry list for waking clients
223     dpdk_io_if* _retry_head = NULL;
224 
225     //! Mutex to protect below data structures
226     std::mutex _mutex;
227     //! The recv links attached to this I/O service (managed client side)
228     std::list<recv_link_if::sptr> _recv_links;
229     //! The send links attached to this I/O service (managed client side)
230     std::list<send_link_if::sptr> _send_links;
231     //! Set of IDs for new clients
232     std::set<uint16_t> _client_id_set;
233     //! Next ID to try
234     uint16_t _next_client_id;
235 
236     static constexpr int MAX_PENDING_SERVICE_REQS = 32;
237     static constexpr int MAX_FLOWS                = 128;
238     static constexpr int MAX_CLIENTS              = 2048;
239     static constexpr int RX_BURST_SIZE            = 16;
240     static constexpr int TX_BURST_SIZE            = 16;
241 };
242 
243 }} // namespace uhd::transport
244