xref: /openbmc/obmc-console/console-socket.c (revision 533f9702)
1 /**
2  * Copyright © 2016 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 "console-server.h"
18 
19 #include <errno.h>
20 #include <limits.h>
21 #include <stdio.h>
22 #include <stdlib.h>
23 #include <sys/socket.h>
24 #include <sys/un.h>
25 #include <sys/types.h>
26 #include <unistd.h>
27 
28 #define CONSOLE_SOCKET_PREFIX "obmc-console"
29 
30 ssize_t console_socket_path(struct sockaddr_un *addr, const char *id)
31 {
32 	char *sun_path;
33 	ssize_t rc;
34 
35 	sun_path = (char *)addr + sizeof(*addr) - sizeof(addr->sun_path);
36 
37 	if (id) {
38 		rc = snprintf(sun_path + 1, sizeof(addr->sun_path) - 1,
39 			      CONSOLE_SOCKET_PREFIX ".%s", id);
40 	} else {
41 		rc = snprintf(sun_path + 1, sizeof(addr->sun_path) - 1,
42 			      CONSOLE_SOCKET_PREFIX);
43 	}
44 
45 	if (rc < 0) {
46 		return rc;
47 	}
48 
49 	if ((size_t)rc > (sizeof(addr->sun_path) - 1)) {
50 		errno = 0;
51 		return -1;
52 	}
53 
54 	sun_path[0] = '\0';
55 
56 	return rc + 1 /* Capture NUL prefix */;
57 }
58 
59 ssize_t console_socket_path_readable(const struct sockaddr_un *addr,
60 				     size_t addrlen, socket_path_t path)
61 {
62 	const char *src = (const char *)addr;
63 	size_t len;
64 
65 	if (addrlen > SSIZE_MAX) {
66 		return -EINVAL;
67 	}
68 
69 	len = addrlen - sizeof(addr->sun_family) - 1;
70 	memcpy(path, src + sizeof(addr->sun_family) + 1, len);
71 	path[len] = '\0';
72 
73 	return (ssize_t)len; /* strlen() style */
74 }
75