1/* TODO merge/factor in debugfs.c here */
  2
  3#include <errno.h>
  4#include <stdbool.h>
  5#include <stdio.h>
  6#include <string.h>
  7#include <sys/vfs.h>
  8
  9#include "debugfs.h"
 10#include "fs.h"
 11
 12static const char * const sysfs__fs_known_mountpoints[] = {
 13	"/sys",
 14	0,
 15};
 16
 17static const char * const procfs__known_mountpoints[] = {
 18	"/proc",
 19	0,
 20};
 21
 22struct fs {
 23	const char		*name;
 24	const char * const	*mounts;
 25	char			 path[PATH_MAX + 1];
 26	bool			 found;
 27	long			 magic;
 28};
 29
 30enum {
 31	FS__SYSFS  = 0,
 32	FS__PROCFS = 1,
 33};
 34
 35static struct fs fs__entries[] = {
 36	[FS__SYSFS] = {
 37		.name	= "sysfs",
 38		.mounts	= sysfs__fs_known_mountpoints,
 39		.magic	= SYSFS_MAGIC,
 40	},
 41	[FS__PROCFS] = {
 42		.name	= "proc",
 43		.mounts	= procfs__known_mountpoints,
 44		.magic	= PROC_SUPER_MAGIC,
 45	},
 46};
 47
 48static bool fs__read_mounts(struct fs *fs)
 49{
 50	bool found = false;
 51	char type[100];
 52	FILE *fp;
 53
 54	fp = fopen("/proc/mounts", "r");
 55	if (fp == NULL)
 56		return NULL;
 57
 58	while (!found &&
 59	       fscanf(fp, "%*s %" STR(PATH_MAX) "s %99s %*s %*d %*d\n",
 60		      fs->path, type) == 2) {
 61
 62		if (strcmp(type, fs->name) == 0)
 63			found = true;
 64	}
 65
 66	fclose(fp);
 67	return fs->found = found;
 68}
 69
 70static int fs__valid_mount(const char *fs, long magic)
 71{
 72	struct statfs st_fs;
 73
 74	if (statfs(fs, &st_fs) < 0)
 75		return -ENOENT;
 76	else if (st_fs.f_type != magic)
 77		return -ENOENT;
 78
 79	return 0;
 80}
 81
 82static bool fs__check_mounts(struct fs *fs)
 83{
 84	const char * const *ptr;
 85
 86	ptr = fs->mounts;
 87	while (*ptr) {
 88		if (fs__valid_mount(*ptr, fs->magic) == 0) {
 89			fs->found = true;
 90			strcpy(fs->path, *ptr);
 91			return true;
 92		}
 93		ptr++;
 94	}
 95
 96	return false;
 97}
 98
 99static const char *fs__get_mountpoint(struct fs *fs)
100{
101	if (fs__check_mounts(fs))
102		return fs->path;
103
104	return fs__read_mounts(fs) ? fs->path : NULL;
105}
106
107static const char *fs__mountpoint(int idx)
108{
109	struct fs *fs = &fs__entries[idx];
110
111	if (fs->found)
112		return (const char *)fs->path;
113
114	return fs__get_mountpoint(fs);
115}
116
117#define FS__MOUNTPOINT(name, idx)	\
118const char *name##__mountpoint(void)	\
119{					\
120	return fs__mountpoint(idx);	\
121}
122
123FS__MOUNTPOINT(sysfs,  FS__SYSFS);
124FS__MOUNTPOINT(procfs, FS__PROCFS);