1 // SPDX-License-Identifier: GPL-2.0
2 #include <errno.h>
3 #include <stdio.h>
4 #include <stdlib.h>
5 #include <string.h>
6 #include <unistd.h>
7 #include <sys/mman.h>
8 #include <sys/socket.h>
9 #include <linux/if_xdp.h>
10 #include <linux/if_link.h>
11 #include <net/if.h>
12 #include <inttypes.h>
13
14 #define UMEM_SZ (1U << 16)
15 #define NUM_DESC (UMEM_SZ / 2048)
16
17 /* Move this to a common header when reused! */
ksft_ready(void)18 static void ksft_ready(void)
19 {
20 const char msg[7] = "ready\n";
21 char *env_str;
22 int fd;
23
24 env_str = getenv("KSFT_READY_FD");
25 if (env_str) {
26 fd = atoi(env_str);
27 if (!fd) {
28 fprintf(stderr, "invalid KSFT_READY_FD = '%s'\n",
29 env_str);
30 return;
31 }
32 } else {
33 fd = STDOUT_FILENO;
34 }
35
36 write(fd, msg, sizeof(msg));
37 if (fd != STDOUT_FILENO)
38 close(fd);
39 }
40
ksft_wait(void)41 static void ksft_wait(void)
42 {
43 char *env_str;
44 char byte;
45 int fd;
46
47 env_str = getenv("KSFT_WAIT_FD");
48 if (env_str) {
49 fd = atoi(env_str);
50 if (!fd) {
51 fprintf(stderr, "invalid KSFT_WAIT_FD = '%s'\n",
52 env_str);
53 return;
54 }
55 } else {
56 /* Not running in KSFT env, wait for input from STDIN instead */
57 fd = STDIN_FILENO;
58 }
59
60 read(fd, &byte, sizeof(byte));
61 if (fd != STDIN_FILENO)
62 close(fd);
63 }
64
65 /* this is a simple helper program that creates an XDP socket and does the
66 * minimum necessary to get bind() to succeed.
67 *
68 * this test program is not intended to actually process packets, but could be
69 * extended in the future if that is actually needed.
70 *
71 * it is used by queues.py to ensure the xsk netlinux attribute is set
72 * correctly.
73 */
main(int argc,char ** argv)74 int main(int argc, char **argv)
75 {
76 struct xdp_umem_reg umem_reg = { 0 };
77 struct sockaddr_xdp sxdp = { 0 };
78 int num_desc = NUM_DESC;
79 void *umem_area;
80 int ifindex;
81 int sock_fd;
82 int queue;
83
84 if (argc != 3) {
85 fprintf(stderr, "Usage: %s ifindex queue_id\n", argv[0]);
86 return 1;
87 }
88
89 sock_fd = socket(AF_XDP, SOCK_RAW, 0);
90 if (sock_fd < 0) {
91 perror("socket creation failed");
92 /* if the kernel doesn't support AF_XDP, let the test program
93 * know with -1. All other error paths return 1.
94 */
95 if (errno == EAFNOSUPPORT)
96 return -1;
97 return 1;
98 }
99
100 /* "Probing mode", just checking if AF_XDP sockets are supported */
101 if (!strcmp(argv[1], "-") && !strcmp(argv[2], "-")) {
102 printf("AF_XDP support detected\n");
103 close(sock_fd);
104 return 0;
105 }
106
107 ifindex = atoi(argv[1]);
108 queue = atoi(argv[2]);
109
110 umem_area = mmap(NULL, UMEM_SZ, PROT_READ | PROT_WRITE, MAP_PRIVATE |
111 MAP_ANONYMOUS, -1, 0);
112 if (umem_area == MAP_FAILED) {
113 perror("mmap failed");
114 return 1;
115 }
116
117 umem_reg.addr = (uintptr_t)umem_area;
118 umem_reg.len = UMEM_SZ;
119 umem_reg.chunk_size = 2048;
120 umem_reg.headroom = 0;
121
122 setsockopt(sock_fd, SOL_XDP, XDP_UMEM_REG, &umem_reg,
123 sizeof(umem_reg));
124 setsockopt(sock_fd, SOL_XDP, XDP_UMEM_FILL_RING, &num_desc,
125 sizeof(num_desc));
126 setsockopt(sock_fd, SOL_XDP, XDP_UMEM_COMPLETION_RING, &num_desc,
127 sizeof(num_desc));
128 setsockopt(sock_fd, SOL_XDP, XDP_RX_RING, &num_desc, sizeof(num_desc));
129
130 sxdp.sxdp_family = AF_XDP;
131 sxdp.sxdp_ifindex = ifindex;
132 sxdp.sxdp_queue_id = queue;
133 sxdp.sxdp_flags = 0;
134
135 if (bind(sock_fd, (struct sockaddr *)&sxdp, sizeof(sxdp)) != 0) {
136 munmap(umem_area, UMEM_SZ);
137 perror("bind failed");
138 close(sock_fd);
139 return 1;
140 }
141
142 ksft_ready();
143 ksft_wait();
144
145 /* parent program will write a byte to stdin when its ready for this
146 * helper to exit
147 */
148
149 close(sock_fd);
150 return 0;
151 }
152