xref: /illumos-gate/usr/src/lib/sun_sas/common/devlink_disco.c (revision 9c3024a3457d2d1269be18124a1ac69e33000da7)
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  * Copyright 2019 Joyent, Inc.
28  */
29 
30 #include <sun_sas.h>
31 #include <sys/types.h>
32 #include <sys/stat.h>
33 #include <fcntl.h>
34 #include <unistd.h>
35 #include <dirent.h>
36 #include <libdevinfo.h>
37 
38 /*
39  * structure for di_devlink_walk
40  */
41 typedef struct walk_devlink {
42 	char *path;
43 	size_t len;
44 	char **linkpp;
45 } walk_devlink_t;
46 
47 /*
48  * callback funtion for di_devlink_walk
49  * Find matching /dev link for the given path argument.
50  * devlink element and callback function argument.
51  * The input path is expected to not have "/devices".
52  */
53 static int
54 get_devlink(di_devlink_t devlink, void *arg)
55 {
56 	const char ROUTINE[] = "get_devlink";
57 	walk_devlink_t *warg = (walk_devlink_t *)arg;
58 
59 	/*
60 	 * When path is specified, it doesn't have minor
61 	 * name. Therefore, the ../.. prefixes needs to be stripped.
62 	 */
63 	if (warg->path) {
64 		char *content = (char *)di_devlink_content(devlink);
65 		char *start = strstr(content, "/devices");
66 
67 		if (start == NULL ||
68 		    strncmp(start, warg->path, warg->len) != 0 ||
69 		    /* make it sure the device path has minor name */
70 		    start[warg->len] != ':') {
71 			return (DI_WALK_CONTINUE);
72 		}
73 	}
74 
75 	*(warg->linkpp) = strdup(di_devlink_path(devlink));
76 	log(LOG_DEBUG, ROUTINE, "Walk terminate");
77 	return (DI_WALK_TERMINATE);
78 }
79 
80 /*
81  * Convert /devices paths to /dev sym-link paths.
82  * The mapping buffer OSDeviceName paths will be
83  * converted to short names.
84  * mappings The target mappings data to convert to short names
85  *
86  * If no link is found, the long path is left as is.
87  * Note: The NumberOfEntries field MUST not be greater than the size
88  * of the array passed in.
89  */
90 void
91 convertDevpathToDevlink(PSMHBA_TARGETMAPPING mappings)
92 {
93 	const char ROUTINE[] = "convertDevpathToLink";
94 	di_devlink_handle_t hdl;
95 	walk_devlink_t	    warg;
96 	int		    j;
97 	char		    *minor_path, *devlinkp;
98 
99 	if ((hdl = di_devlink_init(NULL, 0)) == NULL) {
100 		log(LOG_DEBUG, ROUTINE, "di_devlink failed: errno:%d",
101 		    strerror(errno));
102 		return;
103 	}
104 
105 	for (j = 0; j < mappings->NumberOfEntries; j++) {
106 		if (strchr(mappings->entry[j].ScsiId.OSDeviceName, ':')) {
107 			/* search link for minor node */
108 			minor_path = mappings->entry[j].ScsiId.OSDeviceName;
109 			if (strstr(minor_path, "/devices") != NULL) {
110 				minor_path = mappings->entry[j].ScsiId.
111 				    OSDeviceName + strlen("/devices");
112 			}
113 			warg.path = NULL;
114 		} else {
115 			minor_path = NULL;
116 			if (strstr(mappings->entry[j].ScsiId.OSDeviceName,
117 			    "/devices") != NULL) {
118 				warg.len = strlen(mappings->entry[j].ScsiId.
119 				    OSDeviceName) - strlen("/devices");
120 				warg.path = mappings->entry[j].
121 				    ScsiId.OSDeviceName + strlen("/devices");
122 			} else {
123 				warg.len = strlen(mappings->entry[j].ScsiId.
124 				    OSDeviceName);
125 				warg.path = mappings->entry[j].ScsiId.
126 				    OSDeviceName;
127 			}
128 		}
129 
130 		devlinkp = NULL;
131 		warg.linkpp = &devlinkp;
132 		(void) di_devlink_walk(hdl, NULL, minor_path, DI_PRIMARY_LINK,
133 		    (void *)&warg, get_devlink);
134 
135 		if (devlinkp != NULL) {
136 			(void) snprintf(mappings->entry[j].ScsiId.OSDeviceName,
137 			    sizeof (mappings->entry[j].ScsiId.OSDeviceName),
138 			    "%s", devlinkp);
139 			free(devlinkp);
140 		}
141 
142 	}
143 
144 	(void) di_devlink_fini(&hdl);
145 }
146 
147 /*
148  * Finds controller path for a give device path.
149  *
150  * Return value: /dev link for dir and minor name.
151  */
152 static HBA_STATUS
153 lookupLink(char *path, char *link, const char *dir, const char *mname)
154 {
155 	const char ROUTINE[] = "lookupLink";
156 	DIR    *dp;
157 	char    buf[MAXPATHLEN];
158 	char    node[MAXPATHLEN];
159 	char	*charptr;
160 	struct dirent *newdirp, *dirp;
161 	ssize_t	count;
162 	int	dirplen;
163 	char	*subpath;
164 	char	tmpPath[MAXPATHLEN];
165 
166 	if ((dp = opendir(dir)) == NULL) {
167 		log(LOG_DEBUG, ROUTINE,
168 		"Unable to open %s to find controller number.", dir);
169 		return (HBA_STATUS_ERROR);
170 	}
171 
172 	if (link == NULL) {
173 		log(LOG_DEBUG, ROUTINE,
174 		    "Invalid argument for storing the link.");
175 		return (HBA_STATUS_ERROR);
176 	}
177 
178 	/*
179 	 * dirplen is large enough to fit the largest path-
180 	 * struct dirent includes one byte (the terminator)
181 	 * so we don't add 1 to the calculation here.
182 	 */
183 	dirplen = pathconf(dir, _PC_NAME_MAX);
184 	dirplen = ((dirplen <= 0) ? MAXNAMELEN : dirplen) +
185 	    sizeof (struct dirent);
186 	dirp = (struct dirent *)malloc(dirplen);
187 	if (dirp == NULL) {
188 		OUT_OF_MEMORY(ROUTINE);
189 		return (HBA_STATUS_ERROR);
190 	}
191 
192 	while ((readdir_r(dp, dirp, &newdirp)) == 0 && newdirp != NULL) {
193 		if (strcmp(dirp->d_name, ".") == 0 ||
194 		    strcmp(dirp->d_name, "..") == 0) {
195 			continue;
196 		}
197 		/*
198 		 * set to another pointer since dirp->d_name length is 1
199 		 * that will store only the first char 'c' from the name.
200 		 */
201 		charptr = dirp->d_name;
202 		(void) snprintf(node, strlen(charptr) + strlen(dir) + 2,
203 		    "%s/%s", dir, charptr);
204 		if ((count = readlink(node, buf, sizeof (buf))) > 0) {
205 			subpath = NULL;
206 			subpath = strstr(buf, path);
207 			buf[count] = '\0';
208 			if (subpath != NULL) {
209 				(void) strlcpy(tmpPath, path, MAXPATHLEN);
210 				(void) strlcat(tmpPath, mname, MAXPATHLEN);
211 				/*
212 				 * if device path has substring of path
213 				 * and exactally matching with :scsi suffix
214 				 */
215 				if (strcmp(subpath, tmpPath) == 0) {
216 					(void) strlcpy(link, node, MAXPATHLEN);
217 					(void) closedir(dp);
218 					S_FREE(dirp);
219 					return (HBA_STATUS_OK);
220 				}
221 			}
222 		}
223 	}
224 
225 	(void) closedir(dp);
226 	S_FREE(dirp);
227 	return (HBA_STATUS_ERROR);
228 }
229 
230 /*
231  * Finds controller path for a give device path.
232  *
233  * Return vale:i smp devlink.
234  */
235 HBA_STATUS
236 lookupControllerLink(char *path, char *link)
237 {
238 	const char dir[] = "/dev/cfg";
239 	const char mname[] = ":scsi";
240 	return (lookupLink(path, link, dir, mname));
241 }
242 
243 /*
244  * Finds smp devlink  for a give smp path.
245  *
246  * Return vale: smp devlink.
247  */
248 HBA_STATUS
249 lookupSMPLink(char *path, char *link)
250 {
251 	const char dir[] = "/dev/smp";
252 	const char mname[] = ":smp";
253 	return (lookupLink(path, link, dir, mname));
254 }
255