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 #define _GNU_SOURCE
33 #include <config.h>
34
35 #include <stdio.h>
36 #include <stdlib.h>
37 #include <unistd.h>
38 #include <sys/types.h>
39 #include <sys/stat.h>
40 #include <fcntl.h>
41 #include <string.h>
42 #include <sys/sysctl.h>
43
44 #include "ibverbs.h"
45
46 static const char *sysfs_path;
47
ibv_get_sysfs_path(void)48 const char *ibv_get_sysfs_path(void)
49 {
50 const char *env = NULL;
51
52 if (sysfs_path)
53 return sysfs_path;
54
55 /*
56 * Only follow use path passed in through the calling user's
57 * environment if we're not running SUID.
58 */
59 if (getuid() == geteuid())
60 env = getenv("SYSFS_PATH");
61
62 if (env) {
63 int len;
64 char *dup;
65
66 sysfs_path = dup = strndup(env, IBV_SYSFS_PATH_MAX);
67 len = strlen(dup);
68 while (len > 0 && dup[len - 1] == '/') {
69 --len;
70 dup[len] = '\0';
71 }
72 } else
73 sysfs_path = "/sys";
74
75 return sysfs_path;
76 }
77
ibv_read_sysfs_file(const char * dir,const char * file,char * buf,size_t size)78 int ibv_read_sysfs_file(const char *dir, const char *file,
79 char *buf, size_t size)
80 {
81 char *path, *s;
82 int ret;
83 size_t len;
84
85 if (asprintf(&path, "%s/%s", dir, file) < 0)
86 return -1;
87
88 for (s = &path[0]; *s != '\0'; s++)
89 if (*s == '/')
90 *s = '.';
91
92 len = size;
93 ret = sysctlbyname(&path[1], buf, &len, NULL, 0);
94 free(path);
95
96 if (ret == -1)
97 return -1;
98
99 if (len > 0 && buf[len - 1] == '\n')
100 buf[--len] = '\0';
101
102 return len;
103 }
104