1/*
2 * Copyright � 2007 Alistair Crooks.  All rights reserved.
3 *
4 * Redistribution and use in source and binary forms, with or without
5 * modification, are permitted provided that the following conditions
6 * are met:
7 * 1. Redistributions of source code must retain the above copyright
8 *    notice, this list of conditions and the following disclaimer.
9 * 2. Redistributions in binary form must reproduce the above copyright
10 *    notice, this list of conditions and the following disclaimer in the
11 *    documentation and/or other materials provided with the distribution.
12 * 3. The name of the author may not be used to endorse or promote
13 *    products derived from this software without specific prior written
14 *    permission.
15 *
16 * THIS SOFTWARE IS PROVIDED BY THE AUTHOR ``AS IS'' AND ANY EXPRESS
17 * OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE IMPLIED
18 * WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE
19 * ARE DISCLAIMED.  IN NO EVENT SHALL THE AUTHOR BE LIABLE FOR ANY
20 * DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL
21 * DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE
22 * GOODS OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS
23 * INTERRUPTION) HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY,
24 * WHETHER IN CONTRACT, STRICT LIABILITY, OR TORT (INCLUDING
25 * NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY OUT OF THE USE OF THIS
26 * SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF SUCH DAMAGE.
27 */
28#include <sys/types.h>
29
30#include <err.h>
31#include <errno.h>
32#include <fcntl.h>
33#include <fuse.h>
34#include <regex.h>
35#include <stdio.h>
36#include <stdlib.h>
37#include <string.h>
38#include <unistd.h>
39
40#include "virtdir.h"
41#include "defs.h"
42
43static int		 verbose; /* how chatty are we? */
44
45static virtdir_t	 pci;
46
47/* a device node describes the device that is printed in the dmesg */
48typedef struct devicenode_t {
49	char	*dev;		/* device name */
50	int	 devlen;	/* length of name */
51	char	*parent;	/* its parent device name */
52	int	 parentlen;	/* length of parent name */
53	char	*descr;		/* description of the device itself */
54	int	 descrlen;	/* length of description */
55	int	 p;		/* device node subscript of parent */
56	int	 dir;		/* nonzero if this is a directory */
57} devicenode_t;
58
59DEFINE_ARRAY(devices_t, devicenode_t);
60
61static devices_t	devices;
62
63
64/* perform the stat operation */
65/* if this is the root, then just synthesise the data */
66static int
67dmesgfs_getattr(const char *path, struct stat *st)
68{
69	virt_dirent_t	*ep;
70
71	if (strcmp(path, "/") == 0) {
72		(void) memset(st, 0x0, sizeof(*st));
73		st->st_mode = (S_IFDIR | 0755);
74		st->st_nlink = 2;
75		return 0;
76	}
77	if ((ep = virtdir_find(&pci, path, strlen(path))) == NULL) {
78		return -ENOENT;
79	}
80	switch(ep->type) {
81	case 'f':
82		(void) memcpy(st, &pci.file, sizeof(*st));
83		st->st_size = ep->tgtlen;
84		st->st_mode = S_IFREG | 0644;
85		break;
86	case 'd':
87		(void) memcpy(st, &pci.dir, sizeof(*st));
88		break;
89	case 'l':
90		(void) memcpy(st, &pci.lnk, sizeof(*st));
91		st->st_size = ep->tgtlen;
92		st->st_mode = S_IFLNK | 0755;
93		break;
94	}
95	st->st_ino = virtdir_offset(&pci, ep) + 10;
96	return 0;
97}
98
99/* readdir operation */
100static int
101dmesgfs_readdir(const char *path, void *buf, fuse_fill_dir_t filler,
102	      off_t offset, struct fuse_file_info * fi)
103{
104	static VIRTDIR	*dirp;
105	virt_dirent_t	*dp;
106
107	if (offset == 0) {
108		if ((dirp = openvirtdir(&pci, path)) == NULL) {
109			return 0;
110		}
111		filler(buf, ".", NULL, 0);
112		filler(buf, "..", NULL, 0);
113	}
114	while ((dp = readvirtdir(dirp)) != NULL) {
115		if (filler(buf, dp->d_name, NULL, 0) != 0) {
116			return 0;
117		}
118	}
119	closevirtdir(dirp);
120	dirp = NULL;
121	return 0;
122}
123
124/* open the file in the file system */
125static int
126dmesgfs_open(const char *path, struct fuse_file_info * fi)
127{
128	return 0;
129}
130
131/* read the file's contents in the file system */
132static int
133dmesgfs_read(const char *path, char *buf, size_t size, off_t offset,
134	   struct fuse_file_info * fi)
135{
136	virt_dirent_t	*ep;
137
138	if ((ep = virtdir_find(&pci, path, strlen(path))) == NULL) {
139		return -ENOENT;
140	}
141	if (ep->tgt == NULL) {
142		return -ENOENT;
143	}
144	(void) memcpy(buf, &ep->tgt[offset], size);
145	return ep->tgtlen;
146}
147
148/* fill in the statvfs struct */
149static int
150dmesgfs_statfs(const char *path, struct statvfs *st)
151{
152	(void) memset(st, 0x0, sizeof(*st));
153	return 0;
154}
155
156/* read the symbolic link */
157static int
158dmesgfs_readlink(const char *path, char *buf, size_t size)
159{
160	virt_dirent_t	*ep;
161
162	if ((ep = virtdir_find(&pci, path, strlen(path))) == NULL) {
163		return -ENOENT;
164	}
165	if (ep->tgt == NULL) {
166		return -ENOENT;
167	}
168	(void) strlcpy(buf, ep->tgt, size);
169	return 0;
170}
171
172/* operations struct */
173static struct fuse_operations dmesgfs_oper = {
174	.getattr = dmesgfs_getattr,
175	.readlink = dmesgfs_readlink,
176	.readdir = dmesgfs_readdir,
177	.open = dmesgfs_open,
178	.read = dmesgfs_read,
179	.statfs = dmesgfs_statfs
180};
181
182/* save `n' chars of `s' in malloc'd memory */
183static char *
184strnsave(const char *s, int n)
185{
186	char	*cp;
187
188	if (n < 0) {
189		n = strlen(s);
190	}
191	NEWARRAY(char, cp, n + 1, "strnsave", exit(EXIT_FAILURE));
192	(void) memcpy(cp, s, n);
193	cp[n] = 0x0;
194	return cp;
195}
196
197/* find a device in the device node tree */
198static int
199finddev(const char *s, int len, int updir)
200{
201	int	i;
202
203	for (i = 0 ; i < devices.c ; i++) {
204		if (strncmp(devices.v[i].dev, s, len) == 0 &&
205		    devices.v[i].devlen == len) {
206			if (updir) {
207				devices.v[i].dir = 1;
208			}
209			return i;
210		}
211	}
212	return -1;
213}
214
215/* add a device to the device node tree */
216static void
217add_dev(const char *dev, int len, const char *parent, int parentlen, const char *descr, int descrlen)
218{
219	int	d;
220
221	if ((d = finddev(dev, len, 0)) < 0) {
222		ALLOC(devicenode_t, devices.v, devices.size, devices.c, 10, 10, "add_dev", exit(EXIT_FAILURE));
223		devices.v[devices.c].dev = strnsave(dev, len);
224		devices.v[devices.c].devlen = len;
225		devices.v[devices.c].parent = strnsave(parent, parentlen);
226		devices.v[devices.c].parentlen = parentlen;
227		devices.v[devices.c].descr = strnsave(descr, descrlen);
228		devices.v[devices.c].descrlen = descrlen;
229		devices.c += 1;
230	}
231}
232
233/* print the parent device pathname */
234static int
235pparent(int d, char *buf, size_t size)
236{
237	int	cc;
238
239	if (d != 0) {
240		cc = pparent(devices.v[d].p, buf, size);
241		size -= cc;
242	}
243	(void) strlcat(buf, "/", size);
244	(void) strlcat(buf, devices.v[d].dev, size - 1);
245	return devices.v[d].devlen + 1;
246}
247
248#define NEXUS_DESCRIPTION	"Nexus - the root of everything"
249
250/* build up a fuse_tree from the information in the database */
251static int
252build_tree(virtdir_t *tp, const char *nexus, char type)
253{
254	struct stat	 dir;
255	struct stat	 f;
256	regmatch_t	 matchv[10];
257	regex_t		 r;
258	FILE		*pp;
259	char		 buf[BUFSIZ];
260	int		 i;
261	int		 p;
262
263	(void) stat(".", &dir);
264	(void) memcpy(&f, &dir, sizeof(f));
265	f.st_mode = S_IFREG | 0644;
266	if (regcomp(&r, "^([a-z0-9]+) at ([a-z0-9]+)(.*)", REG_EXTENDED) != 0) {
267		warn("can't compile regular expression\n");
268		return 0;
269	}
270	if ((pp = popen("dmesg", "r")) == NULL) {
271		return 0;
272	}
273	add_dev(nexus, strlen(nexus), nexus, strlen(nexus), NEXUS_DESCRIPTION,
274		strlen(NEXUS_DESCRIPTION));
275	while (fgets(buf, sizeof(buf), pp) != NULL) {
276		if (type == 'l') {
277			buf[strlen(buf) - 1] = 0x0;
278		}
279		if (regexec(&r, buf, 10, matchv, 0) == 0) {
280			add_dev(&buf[matchv[1].rm_so],
281				matchv[1].rm_eo - matchv[1].rm_so,
282				&buf[matchv[2].rm_so],
283				matchv[2].rm_eo - matchv[2].rm_so,
284				buf,
285				matchv[0].rm_eo - matchv[0].rm_so);
286		}
287	}
288	printf("%d devices\n", devices.c);
289	(void) pclose(pp);
290	for (i = 0 ; i < devices.c ; i++) {
291		if ((p = finddev(devices.v[i].parent, devices.v[i].parentlen, 1)) < 0) {
292			warn("No parent device for %s\n", devices.v[i].dev);
293		}
294		devices.v[i].p = p;
295	}
296	for (i = 0 ; i < devices.c ; i++) {
297		pparent(i, buf, sizeof(buf));
298		virtdir_add(tp, buf, strlen(buf),
299			(devices.v[i].dir) ? 'd' : type,
300			devices.v[i].descr, devices.v[i].descrlen);
301		if (devices.v[i].dir) {
302			(void) strlcat(buf, "/", sizeof(buf));
303			(void) strlcat(buf, "Description", sizeof(buf));
304			virtdir_add(tp, buf, strlen(buf), type,
305				devices.v[i].descr, devices.v[i].descrlen);
306		}
307		if (verbose) {
308			printf("dmesgfs: adding %s `%s' -> `%s'\n",
309				(type == 'l') ? "symbolic link" : "file",
310				buf, devices.v[i].descr);
311		}
312		buf[0] = 0x0;
313	}
314	return 1;
315}
316
317int
318main(int argc, char **argv)
319{
320	char	*nexus;
321	char	 type;
322	int	 i;
323
324	nexus = NULL;
325	type = 'l';
326	while ((i = getopt(argc, argv, "fln:v")) != -1) {
327		switch(i) {
328		case 'f':
329			type = 'f';
330			break;
331		case 'l':
332			type = 'l';
333			break;
334		case 'n':
335			nexus = optarg;
336			break;
337		case 'v':
338			verbose += 1;
339			break;
340		}
341	}
342	if (!build_tree(&pci, (nexus) ? nexus : "mainbus0", type)) {
343		exit(EXIT_FAILURE);
344	}
345	return fuse_main(argc, argv, &dmesgfs_oper, NULL);
346}
347