1 /*
2  * Copyright (C) 2011 matt mooney <mfm@muteddisk.com>
3  *               2005-2007 Takahiro Hirofuchi
4  *
5  * This program is free software: you can redistribute it and/or modify
6  * it under the terms of the GNU General Public License as published by
7  * the Free Software Foundation, either version 2 of the License, or
8  * (at your option) any later version.
9  *
10  * This program is distributed in the hope that it will be useful,
11  * but WITHOUT ANY WARRANTY; without even the implied warranty of
12  * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the
13  * GNU General Public License for more details.
14  *
15  * You should have received a copy of the GNU General Public License
16  * along with this program. If not, see <http://www.gnu.org/licenses/>.
17  */
18 
19 #include <sysfs/libsysfs.h>
20 
21 #include <errno.h>
22 #include <stdio.h>
23 #include <string.h>
24 
25 #include "usbip_common.h"
26 #include "utils.h"
27 
modify_match_busid(char * busid,int add)28 int modify_match_busid(char *busid, int add)
29 {
30 	char bus_type[] = "usb";
31 	char attr_name[] = "match_busid";
32 	char buff[SYSFS_BUS_ID_SIZE + 4];
33 	char sysfs_mntpath[SYSFS_PATH_MAX];
34 	char match_busid_attr_path[SYSFS_PATH_MAX];
35 	struct sysfs_attribute *match_busid_attr;
36 	int rc, ret = 0;
37 
38 	if (strnlen(busid, SYSFS_BUS_ID_SIZE) > SYSFS_BUS_ID_SIZE - 1) {
39 		dbg("busid is too long");
40 		return -1;
41 	}
42 
43 	rc = sysfs_get_mnt_path(sysfs_mntpath, SYSFS_PATH_MAX);
44 	if (rc < 0) {
45 		err("sysfs must be mounted: %s", strerror(errno));
46 		return -1;
47 	}
48 
49 	snprintf(match_busid_attr_path, sizeof(match_busid_attr_path),
50 		 "%s/%s/%s/%s/%s/%s", sysfs_mntpath, SYSFS_BUS_NAME, bus_type,
51 		 SYSFS_DRIVERS_NAME, USBIP_HOST_DRV_NAME, attr_name);
52 
53 	match_busid_attr = sysfs_open_attribute(match_busid_attr_path);
54 	if (!match_busid_attr) {
55 		dbg("problem getting match_busid attribute: %s",
56 		    strerror(errno));
57 		return -1;
58 	}
59 
60 	if (add)
61 		snprintf(buff, SYSFS_BUS_ID_SIZE + 4, "add %s", busid);
62 	else
63 		snprintf(buff, SYSFS_BUS_ID_SIZE + 4, "del %s", busid);
64 
65 	dbg("write \"%s\" to %s", buff, match_busid_attr->path);
66 
67 	rc = sysfs_write_attribute(match_busid_attr, buff, sizeof(buff));
68 	if (rc < 0) {
69 		dbg("failed to write match_busid: %s", strerror(errno));
70 		ret = -1;
71 	}
72 
73 	sysfs_close_attribute(match_busid_attr);
74 
75 	return ret;
76 }
77