xref: /openbmc/obmc-console/console-dbus.c (revision bd4af900)
1 /**
2  * Copyright © 2023 IBM Corporation
3  *
4  * Licensed under the Apache License, Version 2.0 (the "License");
5  * you may not use this file except in compliance with the License.
6  * You may obtain a copy of the License at
7  *
8  *     http://www.apache.org/licenses/LICENSE-2.0
9  *
10  * Unless required by applicable law or agreed to in writing, software
11  * distributed under the License is distributed on an "AS IS" BASIS,
12  * WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
13  * See the License for the specific language governing permissions and
14  * limitations under the License.
15  */
16 
17 #include <assert.h>
18 #include <errno.h>
19 #include <err.h>
20 #include <string.h>
21 #include <sys/socket.h>
22 
23 #include "console-server.h"
24 
25 /* size of the dbus object path length */
26 const size_t dbus_obj_path_len = 1024;
27 
28 #define DBUS_ERR    "org.openbmc.error"
29 #define DBUS_NAME   "xyz.openbmc_project.Console.%s"
30 #define OBJ_NAME    "/xyz/openbmc_project/console/%s"
31 #define UART_INTF   "xyz.openbmc_project.Console.UART"
32 #define ACCESS_INTF "xyz.openbmc_project.Console.Access"
33 
34 static void tty_change_baudrate(struct console *console)
35 {
36 	struct handler *handler;
37 	int i;
38 	int rc;
39 
40 	tty_init_termios(console);
41 
42 	for (i = 0; i < console->n_handlers; i++) {
43 		handler = console->handlers[i];
44 		if (!handler->baudrate) {
45 			continue;
46 		}
47 
48 		rc = handler->baudrate(handler, console->tty.uart.baud);
49 		if (rc) {
50 			warnx("Can't set terminal baudrate for handler %s",
51 			      handler->name);
52 		}
53 	}
54 }
55 
56 static int set_baud_handler(sd_bus *bus, const char *path,
57 			    const char *interface, const char *property,
58 			    sd_bus_message *msg, void *userdata,
59 			    sd_bus_error *err __attribute__((unused)))
60 {
61 	struct console *console = userdata;
62 	uint64_t baudrate;
63 	speed_t speed;
64 	int r;
65 
66 	if (!console) {
67 		return -ENOENT;
68 	}
69 
70 	r = sd_bus_message_read(msg, "t", &baudrate);
71 	if (r < 0 || baudrate > UINT32_MAX) {
72 		return -EINVAL;
73 	}
74 
75 	speed = parse_int_to_baud((uint32_t)baudrate);
76 	if (!speed) {
77 		warnx("Invalid baud rate: '%" PRIu64 "'", baudrate);
78 		return -EINVAL;
79 	}
80 
81 	assert(console->tty.type == TTY_DEVICE_UART);
82 	console->tty.uart.baud = speed;
83 	tty_change_baudrate(console);
84 
85 	sd_bus_emit_properties_changed(bus, path, interface, property, NULL);
86 
87 	return 1;
88 }
89 
90 static int get_baud_handler(sd_bus *bus __attribute__((unused)),
91 			    const char *path __attribute__((unused)),
92 			    const char *interface __attribute__((unused)),
93 			    const char *property __attribute__((unused)),
94 			    sd_bus_message *reply, void *userdata,
95 			    sd_bus_error *error __attribute__((unused)))
96 {
97 	struct console *console = userdata;
98 	uint64_t baudrate;
99 	int r;
100 
101 	assert(console->tty.type == TTY_DEVICE_UART);
102 	baudrate = parse_baud_to_int(console->tty.uart.baud);
103 	if (!baudrate) {
104 		warnx("Invalid baud rate: '%d'", console->tty.uart.baud);
105 	}
106 
107 	r = sd_bus_message_append(reply, "t", baudrate);
108 
109 	return r;
110 }
111 
112 static int method_connect(sd_bus_message *msg, void *userdata,
113 			  sd_bus_error *err)
114 {
115 	struct console *console = userdata;
116 	int rc;
117 	int socket_fd = -1;
118 
119 	if (!console) {
120 		warnx("Internal error: Console pointer is null");
121 		sd_bus_error_set_const(err, DBUS_ERR, "Internal error");
122 		return sd_bus_reply_method_error(msg, err);
123 	}
124 
125 	/* Register the consumer. */
126 	socket_fd = dbus_create_socket_consumer(console);
127 	if (socket_fd < 0) {
128 		rc = socket_fd;
129 		warnx("Failed to create socket consumer: %s", strerror(rc));
130 		sd_bus_error_set_const(err, DBUS_ERR,
131 				       "Failed to create socket consumer");
132 		return sd_bus_reply_method_error(msg, err);
133 	}
134 
135 	rc = sd_bus_reply_method_return(msg, "h", socket_fd);
136 
137 	/* Close the our end */
138 	close(socket_fd);
139 
140 	return rc;
141 }
142 
143 static const sd_bus_vtable console_uart_vtable[] = {
144 	SD_BUS_VTABLE_START(0),
145 	SD_BUS_WRITABLE_PROPERTY("Baud", "t", get_baud_handler,
146 				 set_baud_handler, 0,
147 				 SD_BUS_VTABLE_UNPRIVILEGED |
148 					 SD_BUS_VTABLE_PROPERTY_EMITS_CHANGE),
149 	SD_BUS_VTABLE_END,
150 };
151 
152 static const sd_bus_vtable console_access_vtable[] = {
153 	SD_BUS_VTABLE_START(0),
154 	SD_BUS_METHOD("Connect", SD_BUS_NO_ARGS, "h", method_connect,
155 		      SD_BUS_VTABLE_UNPRIVILEGED),
156 	SD_BUS_VTABLE_END,
157 };
158 
159 void dbus_init(struct console *console,
160 	       struct config *config __attribute__((unused)))
161 {
162 	char obj_name[dbus_obj_path_len];
163 	char dbus_name[dbus_obj_path_len];
164 	int dbus_poller = 0;
165 	int fd;
166 	int r;
167 	size_t bytes;
168 
169 	if (!console) {
170 		warnx("Couldn't get valid console");
171 		return;
172 	}
173 
174 	r = sd_bus_default_system(&console->bus);
175 	if (r < 0) {
176 		warnx("Failed to connect to system bus: %s", strerror(-r));
177 		return;
178 	}
179 
180 	/* Register support console interface */
181 	bytes = snprintf(obj_name, dbus_obj_path_len, OBJ_NAME,
182 			 console->console_id);
183 	if (bytes >= dbus_obj_path_len) {
184 		warnx("Console id '%s' is too long. There is no enough space in the buffer.",
185 		      console->console_id);
186 		return;
187 	}
188 
189 	if (console->tty.type == TTY_DEVICE_UART) {
190 		/* Register UART interface */
191 		r = sd_bus_add_object_vtable(console->bus, NULL, obj_name,
192 					     UART_INTF, console_uart_vtable,
193 					     console);
194 		if (r < 0) {
195 			warnx("Failed to register UART interface: %s",
196 			      strerror(-r));
197 			return;
198 		}
199 	}
200 
201 	/* Register access interface */
202 	r = sd_bus_add_object_vtable(console->bus, NULL, obj_name, ACCESS_INTF,
203 				     console_access_vtable, console);
204 	if (r < 0) {
205 		warnx("Failed to issue method call: %s", strerror(-r));
206 		return;
207 	}
208 
209 	bytes = snprintf(dbus_name, dbus_obj_path_len, DBUS_NAME,
210 			 console->console_id);
211 	if (bytes >= dbus_obj_path_len) {
212 		warnx("Console id '%s' is too long. There is no enough space in the buffer.",
213 		      console->console_id);
214 		return;
215 	}
216 
217 	/* Finally register the bus name */
218 	r = sd_bus_request_name(console->bus, dbus_name,
219 				SD_BUS_NAME_ALLOW_REPLACEMENT |
220 					SD_BUS_NAME_REPLACE_EXISTING);
221 	if (r < 0) {
222 		warnx("Failed to acquire service name: %s", strerror(-r));
223 		return;
224 	}
225 
226 	fd = sd_bus_get_fd(console->bus);
227 	if (fd < 0) {
228 		warnx("Couldn't get the bus file descriptor");
229 		return;
230 	}
231 
232 	dbus_poller = POLLFD_DBUS;
233 
234 	console->pollfds[dbus_poller].fd = fd;
235 	console->pollfds[dbus_poller].events = POLLIN;
236 }
237