1
2
3
4#include <errno.h>
5#include <getopt.h>
6#include <libgen.h>
7#include <net/if.h>
8#include <stdio.h>
9#include <stdlib.h>
10#include <sys/socket.h>
11#include <sys/un.h>
12#include <unistd.h>
13
14#include <bpf/bpf.h>
15#include <bpf/xsk.h>
16#include "xdpsock.h"
17
18static const char *opt_if = "";
19
20static struct option long_options[] = {
21 {"interface", required_argument, 0, 'i'},
22 {0, 0, 0, 0}
23};
24
25static void usage(const char *prog)
26{
27 const char *str =
28 " Usage: %s [OPTIONS]\n"
29 " Options:\n"
30 " -i, --interface=n Run on interface n\n"
31 "\n";
32 fprintf(stderr, "%s\n", str);
33
34 exit(0);
35}
36
37static void parse_command_line(int argc, char **argv)
38{
39 int option_index, c;
40
41 opterr = 0;
42
43 for (;;) {
44 c = getopt_long(argc, argv, "i:",
45 long_options, &option_index);
46 if (c == -1)
47 break;
48
49 switch (c) {
50 case 'i':
51 opt_if = optarg;
52 break;
53 default:
54 usage(basename(argv[0]));
55 }
56 }
57}
58
59static int send_xsks_map_fd(int sock, int fd)
60{
61 char cmsgbuf[CMSG_SPACE(sizeof(int))];
62 struct msghdr msg;
63 struct iovec iov;
64 int value = 0;
65
66 if (fd == -1) {
67 fprintf(stderr, "Incorrect fd = %d\n", fd);
68 return -1;
69 }
70 iov.iov_base = &value;
71 iov.iov_len = sizeof(int);
72
73 msg.msg_name = NULL;
74 msg.msg_namelen = 0;
75 msg.msg_iov = &iov;
76 msg.msg_iovlen = 1;
77 msg.msg_flags = 0;
78 msg.msg_control = cmsgbuf;
79 msg.msg_controllen = CMSG_LEN(sizeof(int));
80
81 struct cmsghdr *cmsg = CMSG_FIRSTHDR(&msg);
82
83 cmsg->cmsg_level = SOL_SOCKET;
84 cmsg->cmsg_type = SCM_RIGHTS;
85 cmsg->cmsg_len = CMSG_LEN(sizeof(int));
86
87 *(int *)CMSG_DATA(cmsg) = fd;
88 int ret = sendmsg(sock, &msg, 0);
89
90 if (ret == -1) {
91 fprintf(stderr, "Sendmsg failed with %s", strerror(errno));
92 return -errno;
93 }
94
95 return ret;
96}
97
98int
99main(int argc, char **argv)
100{
101 struct sockaddr_un server;
102 int listening = 1;
103 int rval, msgsock;
104 int ifindex = 0;
105 int flag = 1;
106 int cmd = 0;
107 int sock;
108 int err;
109 int xsks_map_fd;
110
111 parse_command_line(argc, argv);
112
113 ifindex = if_nametoindex(opt_if);
114 if (ifindex == 0) {
115 fprintf(stderr, "Unable to get ifindex for Interface %s. Reason:%s",
116 opt_if, strerror(errno));
117 return -errno;
118 }
119
120 sock = socket(AF_UNIX, SOCK_STREAM, 0);
121 if (sock < 0) {
122 fprintf(stderr, "Opening socket stream failed: %s", strerror(errno));
123 return -errno;
124 }
125
126 server.sun_family = AF_UNIX;
127 strcpy(server.sun_path, SOCKET_NAME);
128
129 setsockopt(sock, SOL_SOCKET, SO_REUSEADDR, &flag, sizeof(int));
130
131 if (bind(sock, (struct sockaddr *)&server, sizeof(struct sockaddr_un))) {
132 fprintf(stderr, "Binding to socket stream failed: %s", strerror(errno));
133 return -errno;
134 }
135
136 listen(sock, MAX_NUM_OF_CLIENTS);
137
138 err = xsk_setup_xdp_prog(ifindex, &xsks_map_fd);
139 if (err) {
140 fprintf(stderr, "Setup of xdp program failed\n");
141 goto close_sock;
142 }
143
144 while (listening) {
145 msgsock = accept(sock, 0, 0);
146 if (msgsock == -1) {
147 fprintf(stderr, "Error accepting connection: %s", strerror(errno));
148 err = -errno;
149 goto close_sock;
150 }
151 err = send_xsks_map_fd(msgsock, xsks_map_fd);
152 if (err <= 0) {
153 fprintf(stderr, "Error %d sending xsks_map_fd\n", err);
154 goto cleanup;
155 }
156 do {
157 rval = read(msgsock, &cmd, sizeof(int));
158 if (rval < 0) {
159 fprintf(stderr, "Error reading stream message");
160 } else {
161 if (cmd != CLOSE_CONN)
162 fprintf(stderr, "Recv unknown cmd = %d\n", cmd);
163 listening = 0;
164 break;
165 }
166 } while (rval > 0);
167 }
168 close(msgsock);
169 close(sock);
170 unlink(SOCKET_NAME);
171
172
173 err = bpf_set_link_xdp_fd(ifindex, -1, 0);
174 if (err) {
175 fprintf(stderr, "Error when unsetting bpf prog_fd for ifindex(%d)\n", ifindex);
176 return err;
177 }
178
179 return 0;
180
181cleanup:
182 close(msgsock);
183close_sock:
184 close(sock);
185 unlink(SOCKET_NAME);
186 return err;
187}
188
