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 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 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 } 124 125 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 } 146 147 static __maybe_unused void pair_udp_send(int fds[], int num) 148 { 149 return pair_udp_send_char(fds, num, DATA_CHAR); 150 } 151 152 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