1 /*
2 * Copyright (c) 2006 Cisco Systems, Inc. All rights reserved.
3 *
4 * This software is available to you under a choice of one of two
5 * licenses. You may choose to be licensed under the terms of the GNU
6 * General Public License (GPL) Version 2, available from the file
7 * COPYING in the main directory of this source tree, or the
8 * OpenIB.org BSD license below:
9 *
10 * Redistribution and use in source and binary forms, with or
11 * without modification, are permitted provided that the following
12 * conditions are met:
13 *
14 * - Redistributions of source code must retain the above
15 * copyright notice, this list of conditions and the following
16 * disclaimer.
17 *
18 * - Redistributions in binary form must reproduce the above
19 * copyright notice, this list of conditions and the following
20 * disclaimer in the documentation and/or other materials
21 * provided with the distribution.
22 *
23 * THE SOFTWARE IS PROVIDED "AS IS", WITHOUT WARRANTY OF ANY KIND,
24 * EXPRESS OR IMPLIED, INCLUDING BUT NOT LIMITED TO THE WARRANTIES OF
25 * MERCHANTABILITY, FITNESS FOR A PARTICULAR PURPOSE AND
26 * NONINFRINGEMENT. IN NO EVENT SHALL THE AUTHORS OR COPYRIGHT HOLDERS
27 * BE LIABLE FOR ANY CLAIM, DAMAGES OR OTHER LIABILITY, WHETHER IN AN
28 * ACTION OF CONTRACT, TORT OR OTHERWISE, ARISING FROM, OUT OF OR IN
29 * CONNECTION WITH THE SOFTWARE OR THE USE OR OTHER DEALINGS IN THE
30 * SOFTWARE.
31 */
32
33 #if HAVE_CONFIG_H
34 # include <config.h>
35 #endif /* HAVE_CONFIG_H */
36
37 #include <stdio.h>
38 #include <stdlib.h>
39 #include <unistd.h>
40 #include <sys/types.h>
41 #include <sys/stat.h>
42 #include <fcntl.h>
43 #include <string.h>
44
45 #include <sys/sysctl.h>
46
47 #include "ibverbs.h"
48
49 static char *sysfs_path;
50
ibv_get_sysfs_path(void)51 const char *ibv_get_sysfs_path(void)
52 {
53 char *env = NULL;
54
55 if (sysfs_path)
56 return sysfs_path;
57
58 /*
59 * Only follow use path passed in through the calling user's
60 * environment if we're not running SUID.
61 */
62 if (getuid() == geteuid())
63 env = getenv("SYSFS_PATH");
64
65 if (env) {
66 int len;
67
68 sysfs_path = strndup(env, IBV_SYSFS_PATH_MAX);
69 len = strlen(sysfs_path);
70 while (len > 0 && sysfs_path[len - 1] == '/') {
71 --len;
72 sysfs_path[len] = '\0';
73 }
74 } else
75 sysfs_path = "/sys";
76
77 return sysfs_path;
78 }
79
ibv_read_sysfs_file(const char * dir,const char * file,char * buf,size_t size)80 int ibv_read_sysfs_file(const char *dir, const char *file,
81 char *buf, size_t size)
82 {
83 char *path, *s;
84 int fd;
85 size_t len;
86
87 if (asprintf(&path, "%s/%s", dir, file) < 0)
88 return -1;
89
90 for (s = &path[0]; *s != '\0'; s++)
91 if (*s == '/')
92 *s = '.';
93
94 len = size;
95 if (sysctlbyname(&path[1], buf, &len, NULL, 0) == -1)
96 return -1;
97
98 free(path);
99
100 if (len > 0 && buf[len - 1] == '\n')
101 buf[--len] = '\0';
102
103 return len;
104 }
105