1 /*
2 * Copyright 2013 Google Inc.
3 * Author: Willem de Bruijn <willemb@google.com>
4 * Daniel Borkmann <dborkman@redhat.com>
5 *
6 * License (GPLv2):
7 *
8 * This program is free software; you can redistribute it and/or modify it
9 * under the terms and conditions of the GNU General Public License,
10 * version 2, as published by the Free Software Foundation.
11 *
12 * This program is distributed in the hope it will be useful, but WITHOUT
13 * ANY WARRANTY; without even the implied warranty of MERCHANTABILITY or
14 * FITNESS FOR A PARTICULAR PURPOSE. * See the GNU General Public License for
15 * more details.
16 *
17 * You should have received a copy of the GNU General Public License along with
18 * this program; if not, write to the Free Software Foundation, Inc.,
19 * 51 Franklin St - Fifth Floor, Boston, MA 02110-1301 USA.
20 */
21
22 #ifndef PSOCK_LIB_H
23 #define PSOCK_LIB_H
24
25 #include <sys/types.h>
26 #include <sys/socket.h>
27 #include <string.h>
28 #include <arpa/inet.h>
29 #include <unistd.h>
30
31 #define DATA_LEN 100
32 #define DATA_CHAR 'a'
33 #define DATA_CHAR_1 'b'
34
35 #define PORT_BASE 8000
36
37 #ifndef __maybe_unused
38 # define __maybe_unused __attribute__ ((__unused__))
39 #endif
40
pair_udp_setfilter(int fd)41 static __maybe_unused void pair_udp_setfilter(int fd)
42 {
43 /* the filter below checks for all of the following conditions that
44 * are based on the contents of create_payload()
45 * ether type 0x800 and
46 * ip proto udp and
47 * skb->len == DATA_LEN and
48 * udp[38] == 'a' or udp[38] == 'b'
49 * It can be generated from the following bpf_asm input:
50 * ldh [12]
51 * jne #0x800, drop ; ETH_P_IP
52 * ldb [23]
53 * jneq #17, drop ; IPPROTO_UDP
54 * ld len ; ld skb->len
55 * jlt #100, drop ; DATA_LEN
56 * ldb [80]
57 * jeq #97, pass ; DATA_CHAR
58 * jne #98, drop ; DATA_CHAR_1
59 * pass:
60 * ret #-1
61 * drop:
62 * ret #0
63 */
64 struct sock_filter bpf_filter[] = {
65 { 0x28, 0, 0, 0x0000000c },
66 { 0x15, 0, 8, 0x00000800 },
67 { 0x30, 0, 0, 0x00000017 },
68 { 0x15, 0, 6, 0x00000011 },
69 { 0x80, 0, 0, 0000000000 },
70 { 0x35, 0, 4, 0x00000064 },
71 { 0x30, 0, 0, 0x00000050 },
72 { 0x15, 1, 0, 0x00000061 },
73 { 0x15, 0, 1, 0x00000062 },
74 { 0x06, 0, 0, 0xffffffff },
75 { 0x06, 0, 0, 0000000000 },
76 };
77 struct sock_fprog bpf_prog;
78
79 bpf_prog.filter = bpf_filter;
80 bpf_prog.len = sizeof(bpf_filter) / sizeof(struct sock_filter);
81
82 if (setsockopt(fd, SOL_SOCKET, SO_ATTACH_FILTER, &bpf_prog,
83 sizeof(bpf_prog))) {
84 perror("setsockopt SO_ATTACH_FILTER");
85 exit(1);
86 }
87 }
88
pair_udp_open(int fds[],uint16_t port)89 static __maybe_unused void pair_udp_open(int fds[], uint16_t port)
90 {
91 struct sockaddr_in saddr, daddr;
92
93 fds[0] = socket(PF_INET, SOCK_DGRAM, 0);
94 fds[1] = socket(PF_INET, SOCK_DGRAM, 0);
95 if (fds[0] == -1 || fds[1] == -1) {
96 fprintf(stderr, "ERROR: socket dgram\n");
97 exit(1);
98 }
99
100 memset(&saddr, 0, sizeof(saddr));
101 saddr.sin_family = AF_INET;
102 saddr.sin_port = htons(port);
103 saddr.sin_addr.s_addr = htonl(INADDR_LOOPBACK);
104
105 memset(&daddr, 0, sizeof(daddr));
106 daddr.sin_family = AF_INET;
107 daddr.sin_port = htons(port + 1);
108 daddr.sin_addr.s_addr = htonl(INADDR_LOOPBACK);
109
110 /* must bind both to get consistent hash result */
111 if (bind(fds[1], (void *) &daddr, sizeof(daddr))) {
112 perror("bind");
113 exit(1);
114 }
115 if (bind(fds[0], (void *) &saddr, sizeof(saddr))) {
116 perror("bind");
117 exit(1);
118 }
119 if (connect(fds[0], (void *) &daddr, sizeof(daddr))) {
120 perror("connect");
121 exit(1);
122 }
123 }
124
pair_udp_send_char(int fds[],int num,char payload)125 static __maybe_unused void pair_udp_send_char(int fds[], int num, char payload)
126 {
127 char buf[DATA_LEN], rbuf[DATA_LEN];
128
129 memset(buf, payload, sizeof(buf));
130 while (num--) {
131 /* Should really handle EINTR and EAGAIN */
132 if (write(fds[0], buf, sizeof(buf)) != sizeof(buf)) {
133 fprintf(stderr, "ERROR: send failed left=%d\n", num);
134 exit(1);
135 }
136 if (read(fds[1], rbuf, sizeof(rbuf)) != sizeof(rbuf)) {
137 fprintf(stderr, "ERROR: recv failed left=%d\n", num);
138 exit(1);
139 }
140 if (memcmp(buf, rbuf, sizeof(buf))) {
141 fprintf(stderr, "ERROR: data failed left=%d\n", num);
142 exit(1);
143 }
144 }
145 }
146
pair_udp_send(int fds[],int num)147 static __maybe_unused void pair_udp_send(int fds[], int num)
148 {
149 return pair_udp_send_char(fds, num, DATA_CHAR);
150 }
151
pair_udp_close(int fds[])152 static __maybe_unused void pair_udp_close(int fds[])
153 {
154 close(fds[0]);
155 close(fds[1]);
156 }
157
158 #endif /* PSOCK_LIB_H */
159