xref: /titanic_44/usr/src/lib/sun_sas/common/devlink_disco.c (revision 9e86db79b7d1bbc5f2f04e99954cbd5eae0e22bb)
1 /*
2  * CDDL HEADER START
3  *
4  * The contents of this file are subject to the terms of the
5  * Common Development and Distribution License (the "License").
6  * You may not use this file except in compliance with the License.
7  *
8  * You can obtain a copy of the license at usr/src/OPENSOLARIS.LICENSE
9  * or http://www.opensolaris.org/os/licensing.
10  * See the License for the specific language governing permissions
11  * and limitations under the License.
12  *
13  * When distributing Covered Code, include this CDDL HEADER in each
14  * file and include the License file at usr/src/OPENSOLARIS.LICENSE.
15  * If applicable, add the following below this CDDL HEADER, with the
16  * fields enclosed by brackets "[]" replaced with your own identifying
17  * information: Portions Copyright [yyyy] [name of copyright owner]
18  *
19  * CDDL HEADER END
20  */
21 
22 /*
23  * Copyright 2009 Sun Microsystems, Inc.  All rights reserved.
24  * Use is subject to license terms.
25  */
26 
27 #include <sun_sas.h>
28 #include <sys/types.h>
29 #include <sys/stat.h>
30 #include <fcntl.h>
31 #include <unistd.h>
32 #include <dirent.h>
33 #include <libdevinfo.h>
34 
35 /*
36  * structure for di_devlink_walk
37  */
38 typedef struct walk_devlink {
39 	char *path;
40 	size_t len;
41 	char **linkpp;
42 } walk_devlink_t;
43 
44 /*
45  * callback funtion for di_devlink_walk
46  * Find matching /dev link for the given path argument.
47  * devlink element and callback function argument.
48  * The input path is expected to not have "/devices".
49  */
50 static int
get_devlink(di_devlink_t devlink,void * arg)51 get_devlink(di_devlink_t devlink, void *arg)
52 {
53 	const char ROUTINE[] = "get_devlink";
54 	walk_devlink_t *warg = (walk_devlink_t *)arg;
55 
56 	/*
57 	 * When path is specified, it doesn't have minor
58 	 * name. Therefore, the ../.. prefixes needs to be stripped.
59 	 */
60 	if (warg->path) {
61 		char *content = (char *)di_devlink_content(devlink);
62 		char *start = strstr(content, "/devices");
63 
64 		if (start == NULL ||
65 		    strncmp(start, warg->path, warg->len) != 0 ||
66 		    /* make it sure the device path has minor name */
67 		    start[warg->len] != ':') {
68 			return (DI_WALK_CONTINUE);
69 		}
70 	}
71 
72 	*(warg->linkpp) = strdup(di_devlink_path(devlink));
73 	log(LOG_DEBUG, ROUTINE, "Walk terminate");
74 	return (DI_WALK_TERMINATE);
75 }
76 
77 /*
78  * Convert /devices paths to /dev sym-link paths.
79  * The mapping buffer OSDeviceName paths will be
80  * converted to short names.
81  * mappings The target mappings data to convert to short names
82  *
83  * If no link is found, the long path is left as is.
84  * Note: The NumberOfEntries field MUST not be greater than the size
85  * of the array passed in.
86  */
87 void
convertDevpathToDevlink(PSMHBA_TARGETMAPPING mappings)88 convertDevpathToDevlink(PSMHBA_TARGETMAPPING mappings)
89 {
90 	const char ROUTINE[] = "convertDevpathToLink";
91 	di_devlink_handle_t hdl;
92 	walk_devlink_t	    warg;
93 	int		    j;
94 	char		    *minor_path, *devlinkp;
95 
96 	if ((hdl = di_devlink_init(NULL, 0)) == NULL) {
97 		log(LOG_DEBUG, ROUTINE, "di_devlink failed: errno:%d",
98 		    strerror(errno));
99 		return;
100 	}
101 
102 	for (j = 0; j < mappings->NumberOfEntries; j++) {
103 		if (strchr(mappings->entry[j].ScsiId.OSDeviceName, ':')) {
104 			/* search link for minor node */
105 			minor_path = mappings->entry[j].ScsiId.OSDeviceName;
106 			if (strstr(minor_path, "/devices") != NULL) {
107 				minor_path = mappings->entry[j].ScsiId.
108 				    OSDeviceName + strlen("/devices");
109 			}
110 			warg.path = NULL;
111 		} else {
112 			minor_path = NULL;
113 			if (strstr(mappings->entry[j].ScsiId.OSDeviceName,
114 			    "/devices") != NULL) {
115 				warg.len = strlen(mappings->entry[j].ScsiId.
116 				    OSDeviceName) - strlen("/devices");
117 				warg.path = mappings->entry[j].
118 				    ScsiId.OSDeviceName + strlen("/devices");
119 			} else {
120 				warg.len = strlen(mappings->entry[j].ScsiId.
121 				    OSDeviceName);
122 				warg.path = mappings->entry[j].ScsiId.
123 				    OSDeviceName;
124 			}
125 		}
126 
127 		devlinkp = NULL;
128 		warg.linkpp = &devlinkp;
129 		(void) di_devlink_walk(hdl, NULL, minor_path, DI_PRIMARY_LINK,
130 		    (void *)&warg, get_devlink);
131 
132 		if (devlinkp != NULL) {
133 			(void) snprintf(mappings->entry[j].ScsiId.OSDeviceName,
134 			    sizeof (mappings->entry[j].ScsiId.OSDeviceName),
135 			    "%s", devlinkp);
136 			free(devlinkp);
137 		}
138 
139 	}
140 
141 	(void) di_devlink_fini(&hdl);
142 }
143 
144 /*
145  * Finds controller path for a give device path.
146  *
147  * Return value: /dev link for dir and minor name.
148  */
149 static HBA_STATUS
lookupLink(char * path,char * link,const char * dir,const char * mname)150 lookupLink(char *path, char *link, const char *dir, const char *mname)
151 {
152 	const char ROUTINE[] = "lookupLink";
153 	DIR    *dp;
154 	char    buf[MAXPATHLEN];
155 	char    node[MAXPATHLEN];
156 	char	*charptr;
157 	struct dirent *newdirp, *dirp;
158 	ssize_t	count;
159 	int	dirplen;
160 	char	*subpath;
161 	char	tmpPath[MAXPATHLEN];
162 
163 	if ((dp = opendir(dir)) == NULL) {
164 		log(LOG_DEBUG, ROUTINE,
165 		"Unable to open %s to find controller number.", dir);
166 		return (HBA_STATUS_ERROR);
167 	}
168 
169 	if (link == NULL) {
170 		log(LOG_DEBUG, ROUTINE,
171 		    "Invalid argument for storing the link.");
172 		return (HBA_STATUS_ERROR);
173 	}
174 
175 	/*
176 	 * dirplen is large enough to fit the largest path-
177 	 * struct dirent includes one byte (the terminator)
178 	 * so we don't add 1 to the calculation here.
179 	 */
180 	dirplen = pathconf(dir, _PC_NAME_MAX);
181 	dirplen = ((dirplen <= 0) ? MAXNAMELEN : dirplen) +
182 	    sizeof (struct dirent);
183 	dirp = (struct dirent *)malloc(dirplen);
184 	if (dirp == NULL) {
185 		OUT_OF_MEMORY(ROUTINE);
186 		return (HBA_STATUS_ERROR);
187 	}
188 
189 	while ((readdir_r(dp, dirp, &newdirp)) == 0 && newdirp != NULL) {
190 		if (strcmp(dirp->d_name, ".") == 0 ||
191 		    strcmp(dirp->d_name, "..") == 0) {
192 			continue;
193 		}
194 		/*
195 		 * set to another pointer since dirp->d_name length is 1
196 		 * that will store only the first char 'c' from the name.
197 		 */
198 		charptr = dirp->d_name;
199 		(void) snprintf(node, strlen(charptr) + strlen(dir) + 2,
200 		    "%s/%s", dir, charptr);
201 		if (count = readlink(node, buf, sizeof (buf))) {
202 			subpath = NULL;
203 			subpath = strstr(buf, path);
204 			buf[count] = '\0';
205 			if (subpath != NULL) {
206 				(void) strlcpy(tmpPath, path, MAXPATHLEN);
207 				(void) strlcat(tmpPath, mname, MAXPATHLEN);
208 				/*
209 				 * if device path has substring of path
210 				 * and exactally matching with :scsi suffix
211 				 */
212 				if (strcmp(subpath, tmpPath) == 0) {
213 					(void) strlcpy(link, node, MAXPATHLEN);
214 					(void) closedir(dp);
215 					S_FREE(dirp);
216 					return (HBA_STATUS_OK);
217 				}
218 			}
219 		}
220 	}
221 
222 	(void) closedir(dp);
223 	S_FREE(dirp);
224 	return (HBA_STATUS_ERROR);
225 }
226 
227 /*
228  * Finds controller path for a give device path.
229  *
230  * Return vale:i smp devlink.
231  */
232 HBA_STATUS
lookupControllerLink(char * path,char * link)233 lookupControllerLink(char *path, char *link)
234 {
235 	const char dir[] = "/dev/cfg";
236 	const char mname[] = ":scsi";
237 	return (lookupLink(path, link, dir, mname));
238 }
239 
240 /*
241  * Finds smp devlink  for a give smp path.
242  *
243  * Return vale: smp devlink.
244  */
245 HBA_STATUS
lookupSMPLink(char * path,char * link)246 lookupSMPLink(char *path, char *link)
247 {
248 	const char dir[] = "/dev/smp";
249 	const char mname[] = ":smp";
250 	return (lookupLink(path, link, dir, mname));
251 }
252