1 /* SPDX-License-Identifier: GPL-2.0-only */
2 /*
3  * Copyright 2013 Google Inc.
4  * Author: Willem de Bruijn <willemb@google.com>
5  *         Daniel Borkmann <dborkman@redhat.com>
6  */
7 
8 #ifndef PSOCK_LIB_H
9 #define PSOCK_LIB_H
10 
11 #include <sys/types.h>
12 #include <sys/socket.h>
13 #include <string.h>
14 #include <arpa/inet.h>
15 #include <unistd.h>
16 
17 #define DATA_LEN			100
18 #define DATA_CHAR			'a'
19 #define DATA_CHAR_1			'b'
20 
21 #define PORT_BASE			8000
22 
23 #ifndef __maybe_unused
24 # define __maybe_unused		__attribute__ ((__unused__))
25 #endif
26 
27 static __maybe_unused void pair_udp_setfilter(int fd)
28 {
29 	/* the filter below checks for all of the following conditions that
30 	 * are based on the contents of create_payload()
31 	 *  ether type 0x800 and
32 	 *  ip proto udp     and
33 	 *  skb->len == DATA_LEN and
34 	 *  udp[38] == 'a' or udp[38] == 'b'
35 	 * It can be generated from the following bpf_asm input:
36 	 *	ldh [12]
37 	 *	jne #0x800, drop	; ETH_P_IP
38 	 *	ldb [23]
39 	 *	jneq #17, drop		; IPPROTO_UDP
40 	 *	ld len			; ld skb->len
41 	 *	jlt #100, drop		; DATA_LEN
42 	 *	ldb [80]
43 	 *	jeq #97, pass		; DATA_CHAR
44 	 *	jne #98, drop		; DATA_CHAR_1
45 	 *	pass:
46 	 *	  ret #-1
47 	 *	drop:
48 	 *	  ret #0
49 	 */
50 	struct sock_filter bpf_filter[] = {
51 		{ 0x28,  0,  0, 0x0000000c },
52 		{ 0x15,  0,  8, 0x00000800 },
53 		{ 0x30,  0,  0, 0x00000017 },
54 		{ 0x15,  0,  6, 0x00000011 },
55 		{ 0x80,  0,  0, 0000000000 },
56 		{ 0x35,  0,  4, 0x00000064 },
57 		{ 0x30,  0,  0, 0x00000050 },
58 		{ 0x15,  1,  0, 0x00000061 },
59 		{ 0x15,  0,  1, 0x00000062 },
60 		{ 0x06,  0,  0, 0xffffffff },
61 		{ 0x06,  0,  0, 0000000000 },
62 	};
63 	struct sock_fprog bpf_prog;
64 
65 	bpf_prog.filter = bpf_filter;
66 	bpf_prog.len = sizeof(bpf_filter) / sizeof(struct sock_filter);
67 
68 	if (setsockopt(fd, SOL_SOCKET, SO_ATTACH_FILTER, &bpf_prog,
69 		       sizeof(bpf_prog))) {
70 		perror("setsockopt SO_ATTACH_FILTER");
71 		exit(1);
72 	}
73 }
74 
75 static __maybe_unused void pair_udp_open(int fds[], uint16_t port)
76 {
77 	struct sockaddr_in saddr, daddr;
78 
79 	fds[0] = socket(PF_INET, SOCK_DGRAM, 0);
80 	fds[1] = socket(PF_INET, SOCK_DGRAM, 0);
81 	if (fds[0] == -1 || fds[1] == -1) {
82 		fprintf(stderr, "ERROR: socket dgram\n");
83 		exit(1);
84 	}
85 
86 	memset(&saddr, 0, sizeof(saddr));
87 	saddr.sin_family = AF_INET;
88 	saddr.sin_port = htons(port);
89 	saddr.sin_addr.s_addr = htonl(INADDR_LOOPBACK);
90 
91 	memset(&daddr, 0, sizeof(daddr));
92 	daddr.sin_family = AF_INET;
93 	daddr.sin_port = htons(port + 1);
94 	daddr.sin_addr.s_addr = htonl(INADDR_LOOPBACK);
95 
96 	/* must bind both to get consistent hash result */
97 	if (bind(fds[1], (void *) &daddr, sizeof(daddr))) {
98 		perror("bind");
99 		exit(1);
100 	}
101 	if (bind(fds[0], (void *) &saddr, sizeof(saddr))) {
102 		perror("bind");
103 		exit(1);
104 	}
105 	if (connect(fds[0], (void *) &daddr, sizeof(daddr))) {
106 		perror("connect");
107 		exit(1);
108 	}
109 }
110 
111 static __maybe_unused void pair_udp_send_char(int fds[], int num, char payload)
112 {
113 	char buf[DATA_LEN], rbuf[DATA_LEN];
114 
115 	memset(buf, payload, sizeof(buf));
116 	while (num--) {
117 		/* Should really handle EINTR and EAGAIN */
118 		if (write(fds[0], buf, sizeof(buf)) != sizeof(buf)) {
119 			fprintf(stderr, "ERROR: send failed left=%d\n", num);
120 			exit(1);
121 		}
122 		if (read(fds[1], rbuf, sizeof(rbuf)) != sizeof(rbuf)) {
123 			fprintf(stderr, "ERROR: recv failed left=%d\n", num);
124 			exit(1);
125 		}
126 		if (memcmp(buf, rbuf, sizeof(buf))) {
127 			fprintf(stderr, "ERROR: data failed left=%d\n", num);
128 			exit(1);
129 		}
130 	}
131 }
132 
133 static __maybe_unused void pair_udp_send(int fds[], int num)
134 {
135 	return pair_udp_send_char(fds, num, DATA_CHAR);
136 }
137 
138 static __maybe_unused void pair_udp_close(int fds[])
139 {
140 	close(fds[0]);
141 	close(fds[1]);
142 }
143 
144 #endif /* PSOCK_LIB_H */
145