1/*-
2 * SPDX-License-Identifier: BSD-2-Clause-FreeBSD
3 *
4 * Copyright (c) 2011 NetApp, Inc.
5 * All rights reserved.
6 *
7 * Redistribution and use in source and binary forms, with or without
8 * modification, are permitted provided that the following conditions
9 * are met:
10 * 1. Redistributions of source code must retain the above copyright
11 *    notice, this list of conditions and the following disclaimer.
12 * 2. Redistributions in binary form must reproduce the above copyright
13 *    notice, this list of conditions and the following disclaimer in the
14 *    documentation and/or other materials provided with the distribution.
15 *
16 * THIS SOFTWARE IS PROVIDED BY NETAPP, INC ``AS IS'' AND
17 * ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE
18 * IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE
19 * ARE DISCLAIMED.  IN NO EVENT SHALL NETAPP, INC OR CONTRIBUTORS BE LIABLE
20 * FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL
21 * DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS
22 * OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION)
23 * HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT
24 * LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY
25 * OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF
26 * SUCH DAMAGE.
27 *
28 * $FreeBSD$
29 */
30
31#include <sys/cdefs.h>
32__FBSDID("$FreeBSD$");
33
34#include <sys/types.h>
35#ifndef WITHOUT_CAPSICUM
36#include <sys/capsicum.h>
37#endif
38#include <sys/socket.h>
39#include <netinet/in.h>
40#include <netinet/tcp.h>
41#include <sys/uio.h>
42
43#ifndef WITHOUT_CAPSICUM
44#include <capsicum_helpers.h>
45#endif
46#include <err.h>
47#include <stdio.h>
48#include <stdlib.h>
49#include <sysexits.h>
50#include <fcntl.h>
51#include <unistd.h>
52#include <errno.h>
53
54#include "inout.h"
55#include "dbgport.h"
56#include "pci_lpc.h"
57
58#define	BVM_DBG_PORT	0x224
59#define	BVM_DBG_SIG	('B' << 8 | 'V')
60
61static int listen_fd, conn_fd;
62
63static struct sockaddr_in sin;
64
65static int
66dbg_handler(struct vmctx *ctx, int vcpu, int in, int port, int bytes,
67	    uint32_t *eax, void *arg)
68{
69	int nwritten, nread, printonce;
70	int on = 1;
71	char ch;
72
73	if (bytes == 2 && in) {
74		*eax = BVM_DBG_SIG;
75		return (0);
76	}
77
78	if (bytes != 4)
79		return (-1);
80
81again:
82	printonce = 0;
83	while (conn_fd < 0) {
84		if (!printonce) {
85			printf("Waiting for connection from gdb\r\n");
86			printonce = 1;
87		}
88		conn_fd = accept4(listen_fd, NULL, NULL, SOCK_NONBLOCK);
89		if (conn_fd >= 0) {
90			/* Avoid EPIPE after the client drops off. */
91			(void)setsockopt(conn_fd, SOL_SOCKET, SO_NOSIGPIPE,
92			    &on, sizeof(on));
93			/* Improve latency for one byte at a time tranfers. */
94			(void)setsockopt(conn_fd, IPPROTO_TCP, TCP_NODELAY,
95			    &on, sizeof(on));
96		} else if (errno != EINTR) {
97			perror("accept");
98		}
99	}
100
101	if (in) {
102		nread = read(conn_fd, &ch, 1);
103		if (nread == -1 && errno == EAGAIN)
104			*eax = -1;
105		else if (nread == 1)
106			*eax = ch;
107		else {
108			close(conn_fd);
109			conn_fd = -1;
110			goto again;
111		}
112	} else {
113		ch = *eax;
114		nwritten = write(conn_fd, &ch, 1);
115		if (nwritten != 1) {
116			close(conn_fd);
117			conn_fd = -1;
118			goto again;
119		}
120	}
121	return (0);
122}
123
124static struct inout_port dbgport = {
125	"bvmdbg",
126	BVM_DBG_PORT,
127	1,
128	IOPORT_F_INOUT,
129	dbg_handler
130};
131
132SYSRES_IO(BVM_DBG_PORT, 4);
133
134void
135init_dbgport(int sport)
136{
137	int reuse;
138#ifndef WITHOUT_CAPSICUM
139	cap_rights_t rights;
140#endif
141
142	conn_fd = -1;
143
144	if ((listen_fd = socket(AF_INET, SOCK_STREAM, 0)) < 0) {
145		perror("cannot create socket");
146		exit(4);
147	}
148
149	sin.sin_len = sizeof(sin);
150	sin.sin_family = AF_INET;
151	sin.sin_addr.s_addr = htonl(INADDR_ANY);
152	sin.sin_port = htons(sport);
153
154	reuse = 1;
155	if (setsockopt(listen_fd, SOL_SOCKET, SO_REUSEADDR, &reuse,
156	    sizeof(reuse)) < 0) {
157		perror("cannot set socket options");
158		exit(4);
159	}
160
161	if (bind(listen_fd, (struct sockaddr *)&sin, sizeof(sin)) < 0) {
162		perror("cannot bind socket");
163		exit(4);
164	}
165
166	if (listen(listen_fd, 1) < 0) {
167		perror("cannot listen socket");
168		exit(4);
169	}
170
171#ifndef WITHOUT_CAPSICUM
172	cap_rights_init(&rights, CAP_ACCEPT, CAP_READ, CAP_WRITE);
173	if (caph_rights_limit(listen_fd, &rights) == -1)
174		errx(EX_OSERR, "Unable to apply rights for sandbox");
175#endif
176
177	register_inout(&dbgport);
178}
179