openrc/src/mountinfo.c

/*
   mountinfo.c
   Obtains information about mounted filesystems.

   Copyright 2007 Gentoo Foundation
   */

#define APPLET "mountinfo"

#include <sys/types.h>

#if defined(__DragonFly__) || defined(__FreeBSD__) || \
	defined(__NetBSD__) || defined(__OpenBSD__)
#define BSD
#include <sys/param.h>
#include <sys/ucred.h>
#include <sys/mount.h>
#elif defined (__linux__)
#include <mntent.h>
#endif

#include <errno.h>
#include <getopt.h>
#include <limits.h>
#include <stdio.h>
#include <stdlib.h>
#include <string.h>
#include <regex.h>

#include "builtins.h"
#include "einfo.h"
#include "rc.h"
#include "rc-misc.h"
#include "strlist.h"

typedef enum {
	mount_from,
	mount_to,
	mount_fstype,
	mount_options
} mount_type;

typedef enum {
	net_ignore,
	net_yes,
	net_no
} net_opts;

struct args {
	regex_t *node_regex;
	regex_t *skip_node_regex;
	regex_t *fstype_regex;
	regex_t *skip_fstype_regex;
	regex_t *options_regex;
	regex_t *skip_options_regex;
	char **mounts;
	mount_type mount_type;
	net_opts netdev;
};

static int process_mount (char ***list, struct args *args,
						  char *from, char *to, char *fstype, char *options,
						  int netdev)
{
	char *p;

	errno = ENOENT;

#ifdef __linux__
	/* Skip the really silly rootfs */
	if (strcmp (fstype, "rootfs") == 0)
		return (-1);
#endif

	if (args->netdev == net_yes && (netdev != -1 || args->mounts)) {
		if (netdev != 0)
			return (1);
	} else if (args->netdev == net_no && (netdev != -1 || args->mounts)) {
		if (netdev != 1)
			return (1);
	} else {
		if (args->node_regex &&
			regexec (args->node_regex, from, 0, NULL, 0) != 0)
			return (1);
		if (args->skip_node_regex &&
			regexec (args->skip_node_regex, from, 0, NULL, 0) == 0)
			return (1);

		if (args->fstype_regex &&
			regexec (args->fstype_regex, fstype, 0, NULL, 0) != 0)
			return (-1);
		if (args->skip_fstype_regex &&
			regexec (args->skip_fstype_regex, fstype, 0, NULL, 0) == 0)
			return (-1);

		if (args->options_regex &&
			regexec (args->options_regex, options, 0, NULL, 0) != 0)
			return (-1);
		if (args->skip_options_regex &&
			regexec (args->skip_options_regex, options, 0, NULL, 0) == 0)
			return (-1);
	}

	if (args->mounts) {
		bool found = false;
		int j;
		char *mnt;
		STRLIST_FOREACH (args->mounts, mnt, j)
			if (strcmp (mnt, to) == 0) {
				found = true;
				break;
			}
		if (! found)
			return (-1);
	}

	switch (args->mount_type) {
		case mount_from:
			p = from;
			break;
		case mount_to:
			p = to;
			break;
		case mount_fstype:
			p = fstype;
			break;
		case mount_options:
			p = options;
			break;
		default:
			p = NULL;
			errno = EINVAL;
			break;
	}

	if (p) {
		errno = 0;
		rc_strlist_addsortc (list, p);
		return (0);
	}

	return (-1);
}

#ifdef BSD 

/* Translate the mounted options to english
 * This is taken directly from FreeBSD mount.c */
static struct opt {
	int o_opt;
	const char *o_name;
} optnames[] = {
	{ MNT_ASYNC,        "asynchronous" },
	{ MNT_EXPORTED,     "NFS exported" },
	{ MNT_LOCAL,        "local" },
	{ MNT_NOATIME,      "noatime" },
	{ MNT_NOEXEC,       "noexec" },
	{ MNT_NOSUID,       "nosuid" },
	{ MNT_NOSYMFOLLOW,  "nosymfollow" },
	{ MNT_QUOTA,        "with quotas" },
	{ MNT_RDONLY,       "read-only" },
	{ MNT_SYNCHRONOUS,  "synchronous" },
	{ MNT_UNION,        "union" },
	{ MNT_NOCLUSTERR,   "noclusterr" },
	{ MNT_NOCLUSTERW,   "noclusterw" },
	{ MNT_SUIDDIR,      "suiddir" },
	{ MNT_SOFTDEP,      "soft-updates" },
	{ MNT_MULTILABEL,   "multilabel" },
	{ MNT_ACLS,         "acls" },
#ifdef MNT_GJOURNAL
	{ MNT_GJOURNAL,     "gjournal" },
#endif
	{ 0, NULL }
};

static char **find_mounts (struct args *args)
{
	struct statfs *mnts;
	int nmnts;
	int i;
	char **list = NULL;
	char *options = NULL;
	int flags;
	struct opt *o;

	if ((nmnts = getmntinfo (&mnts, MNT_NOWAIT)) == 0)
		eerrorx ("getmntinfo: %s", strerror (errno));

	for (i = 0; i < nmnts; i++) {
		int netdev = 0;
		flags = mnts[i].f_flags & MNT_VISFLAGMASK;
		for (o = optnames; flags && o->o_opt; o++) {
			if (flags & o->o_opt) {
				if (o->o_opt == MNT_LOCAL)
					netdev = 1;
				if (! options)
					options = xstrdup (o->o_name);
				else {
					char *tmp = NULL;
					int l = strlen (options) + strlen (o->o_name) + 2;
					tmp = xmalloc (sizeof (char) * l);
					snprintf (tmp, l, "%s,%s", options, o->o_name);
					free (options);
					options = tmp;
				}
			}
			flags &= ~o->o_opt;
		}

		process_mount (&list, args,
					   mnts[i].f_mntfromname,
					   mnts[i].f_mntonname,
					   mnts[i].f_fstypename,
					   options,
					   netdev);

		free (options);
		options = NULL;
	}

	return (list);
}

#elif defined (__linux__)
static struct mntent *getmntfile (const char *file)
{
	struct mntent *ent = NULL;
	FILE *fp;

	fp = setmntent ("/etc/fstab", "r");
	while ((ent = getmntent (fp)))
		if (strcmp (file, ent->mnt_dir) == 0)
			break;
	endmntent (fp);
	
	return (ent);
}

static char **find_mounts (struct args *args)
{
	FILE *fp;
	char *buffer;
	char *p;
	char *from;
	char *to;
	char *fst;
	char *opts;
	char **list = NULL;
	struct mntent *ent;
	int netdev;

	if ((fp = fopen ("/proc/mounts", "r")) == NULL)
		eerrorx ("getmntinfo: %s", strerror (errno));

	buffer = xmalloc (sizeof (char) * PATH_MAX * 3);
	while (fgets (buffer, PATH_MAX * 3, fp)) {
		netdev = -1;
		p = buffer;
		from = strsep (&p, " ");
		to = strsep (&p, " ");
		fst = strsep (&p, " ");
		opts = strsep (&p, " ");

		if ((ent = getmntfile (to))) {
			if (strstr (ent->mnt_opts, "_netdev"))
				netdev = 0;
		}

		process_mount (&list, args, from, to, fst, opts, netdev);
	}
	free (buffer);
	fclose (fp);

	return (list);
}

#else
#  error "Operating system not supported!"
#endif

static regex_t *get_regex (const char *string)
{
	regex_t *reg = xmalloc (sizeof (regex_t));
	int result;
	char buffer[256];

	if ((result = regcomp (reg, string, REG_EXTENDED | REG_NOSUB)) != 0)
	{
		regerror (result, reg, buffer, sizeof (buffer));
		eerrorx ("%s: invalid regex `%s'", APPLET, buffer);
	}

	return (reg);
}

#include "_usage.h"
#define extraopts "[mount1] [mount2] ..."
#define getoptstring "f:F:n:N:o:O:p:P:ist" getoptstring_COMMON
static struct option longopts[] = {
	{ "fstype-regex",        1, NULL, 'f'},
	{ "skip-fstype-regex",   1, NULL, 'F'},
	{ "node-regex",          1, NULL, 'n'},
	{ "skip-node-regex",     1, NULL, 'N'},
	{ "options-regex",       1, NULL, 'o'},
	{ "skip-options-regex",  1, NULL, 'O'},
	{ "point-regex",         1, NULL, 'p'},
	{ "skip-point-regex",    1, NULL, 'P'},
	{ "options",             0, NULL, 'i'},
	{ "fstype",              0, NULL, 's'},
	{ "node",                0, NULL, 't'},
	{ "netdev",				 0, NULL, 'e'},
	{ "nonetdev",            0, NULL, 'E'},
	longopts_COMMON
};
static const char * const longopts_help[] = {
	"fstype regex to find",
	"fstype regex to skip",
	"node regex to find",
	"node regex to skip",
	"options regex to find",
	"options regex to skip",
	"point regex to find",
	"point regex to skip",
	"print options",
	"print fstype",
	"print node",
	"is it a network device",
	"is it not a network device",
	longopts_help_COMMON
};
#include "_usage.c"

int mountinfo (int argc, char **argv)
{
	int i;
	struct args args;
	regex_t *point_regex = NULL;
	regex_t *skip_point_regex = NULL;
	char **nodes = NULL;
	char *n;
	int opt;
	int result;

#define DO_REG(_var) \
	if (_var) free (_var); \
	_var = get_regex (optarg);
#define REG_FREE(_var) \
	if (_var) { regfree (_var); free (_var); }

	memset (&args, 0, sizeof (struct args));
	args.mount_type = mount_to;
	args.netdev = net_ignore;

	while ((opt = getopt_long (argc, argv, getoptstring,
							   longopts, (int *) 0)) != -1)
	{
		switch (opt) {
			case 'e':
				args.netdev = net_yes;
				break;
			case 'E':
				args.netdev = net_no;
				break;
			case 'f':
				DO_REG (args.fstype_regex);
				break;
			case 'F':
				DO_REG (args.skip_fstype_regex);
				break;
			case 'n':
				DO_REG (args.node_regex);
				break;
			case 'N':
				DO_REG (args.skip_node_regex);
				break;
			case 'o':
				DO_REG (args.options_regex);
				break;
			case 'O':
				DO_REG (args.skip_options_regex);
				break;
			case 'p':
				DO_REG (point_regex);
				break;
			case 'P':
				DO_REG (skip_point_regex);
				break;
			case 'i':
				args.mount_type = mount_options;
				break;
			case 's':
				args.mount_type = mount_fstype;
				break;
			case 't':
				args.mount_type = mount_from;
				break;

				case_RC_COMMON_GETOPT
		}
	}

	while (optind < argc) {
		if (argv[optind][0] != '/')
			eerrorx ("%s: `%s' is not a mount point", argv[0], argv[optind]);
		rc_strlist_add (&args.mounts, argv[optind++]);
	}

	nodes = find_mounts (&args);

	REG_FREE (args.fstype_regex);
	REG_FREE (args.skip_fstype_regex);
	REG_FREE (args.node_regex);
	REG_FREE (args.skip_node_regex);
	REG_FREE (args.options_regex);
	REG_FREE (args.skip_options_regex);
	
	rc_strlist_reverse (nodes);

	result = EXIT_FAILURE;
	STRLIST_FOREACH (nodes, n, i) {
		if (point_regex && regexec (point_regex, n, 0, NULL, 0) != 0)
			continue;
		if (skip_point_regex && regexec (skip_point_regex, n, 0, NULL, 0) == 0)
			continue;
		if (! rc_env_bool ("RC_QUIET"))
			printf ("%s\n", n);
		result = EXIT_SUCCESS;
	}
	rc_strlist_free (nodes);

	REG_FREE (point_regex);
	REG_FREE (skip_point_regex);

	exit (result);
}