1/*-
2 * SPDX-License-Identifier: BSD-2-Clause
3 *
4 * Copyright (c) 2020 Netflix, Inc.
5 *
6 * Redistribution and use in source and binary forms, with or without
7 * modification, are permitted provided that the following conditions
8 * are met:
9 * 1. Redistributions of source code must retain the above copyright
10 *    notice, this list of conditions and the following disclaimer.
11 * 2. Redistributions in binary form must reproduce the above copyright
12 *    notice, this list of conditions and the following disclaimer in the
13 *    documentation and/or other materials provided with the distribution.
14 *
15 * THIS SOFTWARE IS PROVIDED BY THE AUTHOR AND CONTRIBUTORS ``AS IS'' AND
16 * ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE
17 * IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE
18 * ARE DISCLAIMED.  IN NO EVENT SHALL THE AUTHOR OR CONTRIBUTORS BE LIABLE
19 * FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL
20 * DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS
21 * OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION)
22 * HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT
23 * LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY
24 * OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF
25 * SUCH DAMAGE.
26 */
27
28#include <sys/types.h>
29#include <sys/socket.h>
30#include <sys/sysctl.h>
31#include <sys/uio.h>
32
33#include <netinet/in.h>
34
35#include <err.h>
36#include <errno.h>
37#include <fcntl.h>
38#include <pthread.h>
39#include <stdbool.h>
40#include <stdio.h>
41#include <stdlib.h>
42#include <string.h>
43#include <unistd.h>
44
45static char buf[1024*1024];
46ssize_t readlen;
47static volatile bool read_done = false;
48
49static int
50tcp_socketpair(int *sv)
51{
52	struct sockaddr_in sin = {
53		.sin_len = sizeof(struct sockaddr_in),
54		.sin_family = AF_INET,
55		.sin_addr.s_addr = htonl(INADDR_LOOPBACK),
56	};
57	int flags;
58	int ls;
59
60	ls = socket(PF_INET, SOCK_STREAM, 0);
61	if (ls < 0)
62		err(1, "socket ls");
63
64	if (setsockopt(ls, SOL_SOCKET, SO_REUSEADDR, &(socklen_t){1},
65	    sizeof(int)) < 0)
66		err(1, "SO_REUSEADDR");
67
68	if (bind(ls, (struct sockaddr *)&sin, sizeof(sin)) < 0)
69		err(1, "bind ls");
70
71	if (getsockname(ls, (struct sockaddr *)&sin,
72	    &(socklen_t){ sizeof(sin) }) < 0)
73		err(1, "getsockname");
74
75	if (listen(ls, 5) < 0)
76		err(1, "listen ls");
77
78	sv[0] = socket(PF_INET, SOCK_STREAM, 0);
79	if (sv[0] < 0)
80		err(1, "socket cs");
81
82	flags = fcntl(sv[0], F_GETFL);
83	flags |= O_NONBLOCK;
84	if (fcntl(sv[0], F_SETFL, flags) == -1)
85		err(1, "fcntl +O_NONBLOCK");
86
87	if (connect(sv[0], (void *)&sin, sizeof(sin)) != -1 ||
88	    errno != EINPROGRESS)
89		err(1, "connect cs");
90
91	sv[1] = accept(ls, NULL, 0);
92	if (sv[1] < 0)
93		err(1, "accept ls");
94
95	flags &= ~O_NONBLOCK;
96	if (fcntl(sv[0], F_SETFL, flags) == -1)
97		err(1, "fcntl -O_NONBLOCK");
98
99	close(ls);
100
101	return (0);
102}
103
104static void *
105receiver(void *arg)
106{
107	int s = *(int *)arg;
108	ssize_t rv;
109
110	do {
111		rv = read(s, buf, sizeof(buf));
112		if (rv == -1)
113			err(2, "read receiver");
114		if (rv == 0)
115			break;
116		readlen -= rv;
117	} while (readlen != 0);
118
119	read_done = true;
120
121	return NULL;
122}
123
124static void
125usage(void)
126{
127	errx(1, "usage: %s [-u] <file> <start> <len> <flags>", getprogname());
128}
129
130int
131main(int argc, char **argv)
132{
133	pthread_t pt;
134	off_t start;
135	int ch, fd, ss[2], flags, error;
136	bool pf_unix = false;
137
138	while ((ch = getopt(argc, argv, "u")) != -1)
139		switch (ch) {
140		case 'u':
141			pf_unix = true;
142			break;
143		default:
144			usage();
145		}
146	argc -= optind;
147	argv += optind;
148
149	if (argc != 4)
150		usage();
151
152	start = strtoull(argv[1], NULL, 0);
153	readlen = strtoull(argv[2], NULL, 0);
154	flags = strtoul(argv[3], NULL, 0);
155
156	fd = open(argv[0], O_RDONLY);
157	if (fd < 0)
158		err(1, "open");
159
160	if (pf_unix) {
161		if (socketpair(PF_LOCAL, SOCK_STREAM, 0, ss) != 0)
162			err(1, "socketpair");
163	} else
164		tcp_socketpair(ss);
165
166	error = pthread_create(&pt, NULL, receiver, &ss[1]);
167	if (error)
168		errc(1, error, "pthread_create");
169
170	if (sendfile(fd, ss[0], start, readlen, NULL, NULL, flags) < 0)
171		err(3, "sendfile");
172
173	while (!read_done)
174		usleep(1000);
175
176	exit(0);
177}
178