psock_lib.h

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