1 /*
2  * Copyright (c) 2023 Benjamin Stürz <benni@stuerz.xyz>
3  *
4  * Permission to use, copy, modify, and distribute this software for any
5  * purpose with or without fee is hereby granted, provided that the above
6  * copyright notice and this permission notice appear in all copies.
7  *
8  * THE SOFTWARE IS PROVIDED "AS IS" AND THE AUTHOR DISCLAIMS ALL WARRANTIES
9  * WITH REGARD TO THIS SOFTWARE INCLUDING ALL IMPLIED WARRANTIES OF
10  * MERCHANTABILITY AND FITNESS. IN NO EVENT SHALL THE AUTHOR BE LIABLE FOR
11  * ANY SPECIAL, DIRECT, INDIRECT, OR CONSEQUENTIAL DAMAGES OR ANY DAMAGES
12  * WHATSOEVER RESULTING FROM LOSS OF USE, DATA OR PROFITS, WHETHER IN AN
13  * ACTION OF CONTRACT, NEGLIGENCE OR OTHER TORTIOUS ACTION, ARISING OUT OF
14  * OR IN CONNECTION WITH THE USE OR PERFORMANCE OF THIS SOFTWARE.
15  */
16 #define _XOPEN_SOURCE 700
17 #define _BSD_SOURCE 1
18 #define DKTYPENAMES
19 #include <stddef.h>
20 #include <sys/cdefs.h>
21 #include <sys/types.h>
22 #include <sys/disklabel.h>
23 #include <sys/sysctl.h>
24 #include <sys/ioctl.h>
25 #include <sys/mount.h>
26 #include <sys/dkio.h>
27 #include <inttypes.h>
28 #include <stdbool.h>
29 #include <string.h>
30 #include <stdarg.h>
31 #include <stdint.h>
32 #include <stdlib.h>
33 #include <unistd.h>
34 #include <stdio.h>
35 #include <fcntl.h>
36 #include <errno.h>
37 
38 static __dead void die (const char *fmt, ...)
39 {
40     va_list ap;
41 
42     va_start (ap, fmt);
43     fputs ("Error: ", stderr);
44     vfprintf (stderr, fmt, ap);
45 
46     if (errno != 0) {
47         fprintf (stderr, ": %s\n", strerror (errno));
48     } else {
49         fputc ('\n', stderr);
50     }
51 
52     exit (1);
53 }
54 
55 static int diskcount (void)
56 {
57     const int mib[2] = { CTL_HW, HW_DISKCOUNT };
58     int diskcount;
59     size_t len = sizeof diskcount;
60 
61     if (sysctl (mib, 2, &diskcount, &len, NULL, 0) == -1)
62         die ("sysctl(hw.diskcount)");
63 
64     return diskcount;
65 }
66 
67 static char *disknames (void)
68 {
69     const int num = diskcount ();
70     const int mib[2] = { CTL_HW, HW_DISKNAMES };
71     size_t len = 32 * num;
72     char *buffer = malloc (len);
73 
74     if (sysctl (mib, 2, buffer, &len, NULL, 0) == -1)
75         die ("sysctl(hw.disknames)");
76 
77     return buffer;
78 }
79 
80 static char *stripdisk (char *n)
81 {
82     const char sufx[] = " disk";
83     const size_t ln = strnlen (n, 16);
84     const size_t ls = sizeof sufx - 1;
85 
86     if (!memcmp (n + ln - ls, sufx, ls)) {
87         n[ln - ls] = '\0';
88     }
89 
90     return n;
91 }
92 
93 static void print_size (uint64_t sz)
94 {
95     struct unit {
96         char sym;
97         uint64_t factor;
98     };
99 
100     const struct unit units[] = {
101         { 'P', 1ull << 50 },
102         { 'T', 1ull << 40 },
103         { 'G', 1ull << 30 },
104         { 'M', 1ull << 20 },
105         { 'K', 1ull << 10 },
106         { '0', 0 },
107     };
108 
109     char sym = 'B';
110     uint64_t factor = 1;
111 
112     for (const struct unit *u = &units[0]; u->factor; ++u) {
113         if (sz >= (u->factor * 9 / 10)) {
114             sym = u->sym;
115             factor = u->factor;
116             break;
117         }
118     }
119 
120     const unsigned scaled10 = sz * 10 / factor;
121     const unsigned scaled = sz / factor;
122     if (scaled10 >= 1000) {
123         printf ("%u", scaled);
124     } else if (scaled10 >= 100) {
125         printf (" %u", scaled);
126     } else {
127         printf ("%u.%u", scaled, scaled10 % 10);
128     }
129 
130     putchar (sym);
131     putchar (' ');
132 }
133 
134 enum {
135     FIELD_NAME  = 0x01,
136     FIELD_SIZE  = 0x02,
137     FIELD_USED  = 0x04,
138     FIELD_FREE  = 0x08,
139     FIELD_TYPE  = 0x10,
140     FIELD_LMNT  = 0x20,
141 
142     FIELD_DEFAULT   = FIELD_NAME | FIELD_SIZE | FIELD_TYPE | FIELD_LMNT,
143 };
144 
145 struct my_partinfo {
146     char name[5];
147     uint64_t size;
148     uint64_t fssize;
149     uint64_t free;
150     const char *fstype;
151     const char *mount;
152 };
153 
154 struct my_diskinfo {
155     char type[16];
156     char label[16];
157     char name[4];
158     uint64_t size;
159     uint64_t used;
160     uint8_t num_parts;
161     struct my_partinfo parts[MAXPARTITIONS];
162 };
163 
164 static void print_header (int fields)
165 {
166     if (fields & FIELD_NAME)
167         printf ("%-6s ", "NAME");
168 
169     if (fields & FIELD_SIZE)
170         printf ("%-4s ", "SIZE");
171 
172     if (fields & FIELD_USED)
173         printf ("%-4s ", "USED");
174 
175     if (fields & FIELD_FREE)
176         printf ("%-4s ", "FREE");
177 
178     if (fields & FIELD_TYPE)
179         printf ("%-8s ", "TYPE");
180 
181     if (fields & FIELD_LMNT)
182         printf ("LABEL/MOUNT ");
183 
184     putchar ('\n');
185 }
186 
187 static void print_part (const struct my_partinfo *part, int fields)
188 {
189     if (fields & FIELD_NAME)
190         printf ("  %s ", part->name);
191 
192     if (fields & FIELD_SIZE)
193         print_size (part->size);
194 
195     if (fields & FIELD_USED) {
196         if (part->fssize) {
197             print_size (part->fssize - part->free);
198         } else {
199             printf (" N/A ");
200         }
201     }
202 
203     if (fields & FIELD_FREE) {
204         if (part->fssize) {
205             print_size (part->free);
206         } else {
207             printf (" N/A ");
208         }
209     }
210 
211     if (fields & FIELD_TYPE)
212         printf ("%-8.16s ", part->fstype);
213 
214     if (fields & FIELD_LMNT && part->mount)
215         printf ("%s ", part->mount);
216 
217     putchar ('\n');
218 }
219 
220 static void print_disk (const struct my_diskinfo *disk, int fields)
221 {
222     if (fields & FIELD_NAME)
223         printf ("%s    ", disk->name);
224 
225     if (fields & FIELD_SIZE)
226         print_size (disk->size);
227 
228     if (fields & FIELD_USED)
229         print_size (disk->used);
230 
231     if (fields & FIELD_FREE)
232         print_size (disk->size - disk->used);
233 
234     // Pad only upto 8 characters because most disk types are <=8 bytes long.
235     if (fields & FIELD_TYPE)
236         printf ("%-8.16s ", disk->type);
237 
238     if (fields & FIELD_LMNT)
239         printf ("%.16s ", disk->label);
240 
241     putchar ('\n');
242 
243     for (uint8_t i = 0; i < disk->num_parts; ++i)
244         print_part (&disk->parts[i], fields);
245 }
246 
247 static const struct statfs *find_mount (const char *dev)
248 {
249     static struct statfs *mounts = NULL;
250     static int n_mounts;
251 
252     if (!mounts) {
253         n_mounts = getmntinfo (&mounts, MNT_NOWAIT);
254         if (n_mounts == 0)
255             die ("getmntinfo()");
256     }
257 
258     for (int i = 0; i < n_mounts; ++i) {
259         if (!strcmp (dev, mounts[i].f_mntfromname))
260             return &mounts[i];
261     }
262 
263     return NULL;
264 }
265 
266 static struct my_diskinfo read_disk (const char *name)
267 {
268     struct my_diskinfo disk;
269     struct disklabel label;
270 
271     bzero (&disk, sizeof disk);
272 
273     {   // Read disklabel.
274         char path[5 + 4 + 1];
275         int fd;
276 
277         snprintf (path, sizeof path, "/dev/%.3sc", name);
278         fd = open (path, O_RDONLY);
279         if (fd < 0)
280             die ("open(%s)", path);
281         if (ioctl (fd, DIOCGDINFO, &label) < 0)
282             die ("ioctl(%s, DIOCGDINFO)", path);
283         close (fd);
284     }
285 
286     memcpy (disk.name, name, 3);
287     disk.name[3] = '\0';
288     disk.size = DL_GETDSIZE (&label) * label.d_secsize;
289     memcpy (disk.type, label.d_typename, 16);
290     stripdisk (disk.type);
291     memcpy (disk.label, label.d_packname, 16);
292     disk.num_parts = 0;
293 
294     for (uint16_t i = 0; i < label.d_npartitions; ++i) {
295         const struct partition *p = &label.d_partitions[i];
296         const struct statfs *mnt;
297         struct my_partinfo part;
298         char path[5 + 4 + 1];
299 
300         bzero (&part, sizeof part);
301 
302         part.size = DL_GETPSIZE (p) * label.d_secsize;
303 
304         if (!part.size)
305             continue;
306 
307         memcpy (part.name, disk.name, 3);
308         part.name[3] = 'a' + i;
309         part.name[4] = '\0';
310 
311         snprintf (path, sizeof path, "/dev/%s", part.name);
312         mnt = find_mount (path);
313 
314         if (mnt) {
315             const uint64_t bs = mnt->f_bsize;
316             part.mount = mnt->f_mntonname;
317             part.fssize = mnt->f_blocks * bs;
318             part.free = mnt->f_bfree * bs;
319         }
320 
321         part.fstype = fstypenames[p->p_fstype];
322         if (i != 2)
323             disk.used += part.size;
324         disk.parts[disk.num_parts++] = part;
325     }
326 
327     return disk;
328 }
329 
330 static int usage (void)
331 {
332     fputs ("Usage: lsblk [-Vanu]\n", stderr);
333     return 1;
334 }
335 
336 int main (int argc, char *argv[])
337 {
338     int option;
339     bool header = true;
340     int fields = FIELD_DEFAULT;
341 
342     if (unveil ("/dev", "r") == -1)
343         die ("unveil(/dev)");
344 
345     if (unveil (NULL, NULL) == -1)
346         die ("unveil()");
347 
348     while ((option = getopt (argc, argv, ":Vanu")) != -1) {
349         switch (option) {
350         case 'V':
351             puts ("lsblk-" VERSION);
352             return 0;
353         case 'a':
354             fields = -1;
355             break;
356         case 'n':
357             header = false;
358             break;
359         case 'u':
360             fields |= FIELD_USED | FIELD_FREE;
361             break;
362         default:
363             return usage ();
364         }
365     }
366 
367     if (argc != optind)
368         return usage ();
369 
370     struct statfs *mounts;
371     char *names = disknames ();
372 
373     if (pledge ("stdio rpath disklabel", NULL) == -1)
374         die ("pledge()");
375 
376     const int n_mounts = getmntinfo (&mounts, MNT_NOWAIT);
377     if (n_mounts == 0)
378         die ("getmntinfo()");
379 
380     size_t cap_disks = 10;
381     size_t num_disks = 0;
382     struct my_diskinfo *disks = calloc (cap_disks, sizeof (struct my_diskinfo));
383 
384     for (char *disk; (disk = strsep (&names, ",")) != NULL; ) {
385         if (num_disks == cap_disks) {
386             cap_disks = cap_disks * 13 / 8;
387             disks = reallocarray (disks, cap_disks, sizeof (struct my_diskinfo));
388         }
389         disks[num_disks++] = read_disk (disk);
390     }
391 
392     free (names);
393 
394     if (header)
395         print_header (fields);
396 
397     for (size_t i = 0; i < num_disks; ++i) {
398         print_disk (&disks[i], fields);
399     }
400     return 0;
401 }