1
2
3
4
5
6
7
8
9
10
11
12
13
14
15
16
17
18
19
20
21
22
23
24
25
26
27
28
29
30
31
32
33
34
35
36
37
38
39
40
41
42
43
44
45
46
47
48
49
50
51
52
53
54
55
56
57
58
59
60
61
62
63
64
65
66
67
68
69
70
71
72
73
74
75
76
77
78
79
80
81
82
83
84
85
86
87
88
89
90
91
92
93
94
95
96
97
98
99
100
101
102
103
104
105
106
107
108
109
110
111
112
113
114
115
116
117
118
119
120
121
122
123
124
125
126
127
128
129
130
131
132
133
134
135
136
137
138
139
140
141
142
143
144
145
146
147
148
149
150
151
152
153
154
155
156
157
158
159
160
161
162
163
164
165
166
167
168
169
170
171
172
173
174
175
176
177
178
179
180
181
182
183
184
185
186
187
188
189
190
191
192
193
194
195
196
197
198
199
|
/* Copyright (C) 2023 CZ.NIC, z.s.p.o. <knot-dns@labs.nic.cz>
This program is free software: you can redistribute it and/or modify
it under the terms of the GNU General Public License as published by
the Free Software Foundation, either version 3 of the License, or
(at your option) any later version.
This program is distributed in the hope that it will be useful,
but WITHOUT ANY WARRANTY; without even the implied warranty of
MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the
GNU General Public License for more details.
You should have received a copy of the GNU General Public License
along with this program. If not, see <https://www.gnu.org/licenses/>.
*/
/*!
* \file
*
* \brief XDP IO interface.
*
* \addtogroup xdp
* @{
*/
#pragma once
#include <stdbool.h>
#include <stdint.h>
#include <stdio.h>
#include <netinet/in.h>
#include "libknot/xdp/bpf-consts.h"
#include "libknot/xdp/msg.h"
/*!
* \brief Styles of loading BPF program.
*
* \note In *all* the cases loading can only succeed if at the end
* a compatible BPF program is loaded on the interface.
*/
typedef enum {
KNOT_XDP_LOAD_BPF_NEVER, /*!< Do not load; error out if not loaded already. */
KNOT_XDP_LOAD_BPF_ALWAYS, /*!< Always load a program (overwrite it). */
KNOT_XDP_LOAD_BPF_ALWAYS_UNLOAD, /*!< KNOT_XDP_LOAD_BPF_ALWAYS + unload previous. */
KNOT_XDP_LOAD_BPF_MAYBE, /*!< Try with present program or load if none. */
/* Implementation caveat: when re-using program in _MAYBE case, we get a message:
* libbpf: Kernel error message: XDP program already attached */
} knot_xdp_load_bpf_t;
/*! \brief Context structure for one XDP socket. */
typedef struct knot_xdp_socket knot_xdp_socket_t;
/*! \brief Configuration of XDP socket. */
struct knot_xdp_config {
bool force_generic; /*!< Use generic XDP mode (avoid driver/hadrware implementation). */
bool force_copy; /*!< Force copying packet data between kernel and user-space (avoid zero-copy). */
bool extra_frames; /*!< Extra FQ frames. */
};
/*! \brief Configuration of XDP socket. */
typedef struct knot_xdp_config knot_xdp_config_t;
/*!
* \brief Initialize XDP socket.
*
* \param socket XDP socket.
* \param if_name Name of the net iface (e.g. eth0).
* \param if_queue Network card queue to be used (normally 1 socket per each queue).
* \param flags XDP filter configuration flags.
* \param udp_port UDP and/or TCP port to listen on if enabled via \a opts.
* \param quic_port QUIC/UDP port to listen on if enabled via \a opts.
* \param load_bpf Insert BPF program into packet processing.
* \param xdp_config Optional XDP socket configuration.
*
* \return KNOT_E* or -errno
*/
int knot_xdp_init(knot_xdp_socket_t **socket, const char *if_name, int if_queue,
knot_xdp_filter_flag_t flags, uint16_t udp_port, uint16_t quic_port,
knot_xdp_load_bpf_t load_bpf, const knot_xdp_config_t *xdp_config);
/*!
* \brief De-init XDP socket.
*
* \param socket XDP socket.
*/
void knot_xdp_deinit(knot_xdp_socket_t *socket);
/*!
* \brief Return a file descriptor to be polled on for incoming packets.
*
* \param socket XDP socket.
*
* \return KNOT_E*
*/
int knot_xdp_socket_fd(knot_xdp_socket_t *socket);
/*!
* \brief Collect completed TX buffers, so they can be used by knot_xdp_send_alloc().
*
* \param socket XDP socket.
*/
void knot_xdp_send_prepare(knot_xdp_socket_t *socket);
/*!
* \brief Allocate one buffer for an outgoing packet.
*
* \param socket XDP socket.
* \param flags Flags for new message.
* \param out Out: the allocated packet buffer.
*
* \return KNOT_E*
*/
int knot_xdp_send_alloc(knot_xdp_socket_t *socket, knot_xdp_msg_flag_t flags,
knot_xdp_msg_t *out);
/*!
* \brief Allocate one buffer for a reply packet.
*
* \param socket XDP socket.
* \param query The packet to be replied to.
* \param out Out: the allocated packet buffer.
*
* \return KNOT_E*
*/
int knot_xdp_reply_alloc(knot_xdp_socket_t *socket, const knot_xdp_msg_t *query,
knot_xdp_msg_t *out);
/*!
* \brief Send multiple packets thru XDP.
*
* \note The packets all must have been allocated by knot_xdp_send_alloc()!
* \note Do not free the packet payloads afterwards.
* \note Packets with zero length will be skipped.
*
* \param socket XDP socket.
* \param msgs Packets to be sent.
* \param count Number of packets.
* \param sent Out: number of packet successfully sent.
*
* \return KNOT_E*
*/
int knot_xdp_send(knot_xdp_socket_t *socket, const knot_xdp_msg_t msgs[],
uint32_t count, uint32_t *sent);
/*!
* \brief Cleanup messages that have not been knot_xdp_send().
*
* ...possibly due to some error.
*
* \param socket XDP socket.
* \param msgs Messages to be freed.
* \param count Number of messages.
*/
void knot_xdp_send_free(knot_xdp_socket_t *socket, const knot_xdp_msg_t msgs[],
uint32_t count);
/*!
* \brief Syscall to kernel to wake up the network card driver after knot_xdp_send().
*
* \param socket XDP socket.
*
* \return KNOT_E* or -errno
*/
int knot_xdp_send_finish(knot_xdp_socket_t *socket);
/*!
* \brief Receive multiple packets thru XDP.
*
* \param socket XDP socket.
* \param msgs Out: buffers to be filled in with incoming packets.
* \param max_count Limit for number of packets received at once.
* \param count Out: real number of received packets.
* \param wire_size Out: (optional) total wire size of received packets.
*
* \return KNOT_E*
*/
int knot_xdp_recv(knot_xdp_socket_t *socket, knot_xdp_msg_t msgs[],
uint32_t max_count, uint32_t *count, size_t *wire_size);
/*!
* \brief Free buffers with received packets.
*
* \param socket XDP socket.
* \param msgs Buffers with received packets.
* \param count Number of received packets to free.
*/
void knot_xdp_recv_finish(knot_xdp_socket_t *socket, const knot_xdp_msg_t msgs[],
uint32_t count);
/*!
* \brief Print some info about the XDP socket.
*
* \param socket XDP socket.
* \param file Output file.
*/
void knot_xdp_socket_info(const knot_xdp_socket_t *socket, FILE *file);
/*! @} */
|
