ubase/mount.c
2016-02-11 14:36:54 +00:00

326 lines
7.1 KiB
C

/* See LICENSE file for copyright and license details. */
#include <sys/mount.h>
#include <sys/stat.h>
#include <sys/types.h>
#include <sys/wait.h>
#include <errno.h>
#include <limits.h>
#include <mntent.h>
#include <stdio.h>
#include <stdlib.h>
#include <string.h>
#include <unistd.h>
#include "text.h"
#include "util.h"
#define FSOPTS_MAXLEN 512
struct {
const char *opt;
const char *notopt;
unsigned long v;
} optnames[] = {
{ "defaults", NULL, 0 },
{ "remount", NULL, MS_REMOUNT },
{ "ro", "rw", MS_RDONLY },
{ "sync", "async", MS_SYNCHRONOUS },
{ "dirsync", NULL, MS_DIRSYNC },
{ "nodev", "dev", MS_NODEV },
{ "noatime", "atime", MS_NOATIME },
{ "nodiratime", "diratime", MS_NODIRATIME },
{ "noexec", "exec", MS_NOEXEC },
{ "nosuid", "suid", MS_NOSUID },
{ "mand", "nomand", MS_MANDLOCK },
{ "relatime", "norelatime", MS_RELATIME },
{ "bind", NULL, MS_BIND },
{ NULL, NULL, 0 }
};
static unsigned long argflags = 0;
static char fsopts[FSOPTS_MAXLEN] = "";
static char *
findtype(const char *types, const char *t)
{
const char *p;
size_t len;
for (len = strlen(t); (p = strstr(types, t)); types = p + len) {
if (!strncmp(p, t, len) && (p[len] == '\0' || p[len] == ','))
return (char *)p;
}
return NULL;
}
static void
parseopts(const char *popts, unsigned long *flags, char *data, size_t datasiz)
{
unsigned int i, validopt;
size_t optlen, dlen = 0;
const char *name, *e;
name = popts;
data[0] = '\0';
do {
if ((e = strstr(name, ",")))
optlen = e - name;
else
optlen = strlen(name);
validopt = 0;
for (i = 0; optnames[i].opt; i++) {
if (optnames[i].opt &&
!strncmp(name, optnames[i].opt, optlen)) {
*flags |= optnames[i].v;
validopt = 1;
break;
}
if (optnames[i].notopt &&
!strncmp(name, optnames[i].notopt, optlen)) {
*flags &= ~optnames[i].v;
validopt = 1;
break;
}
}
if (!validopt && optlen > 0) {
/* unknown option, pass as data option to mount() */
if (dlen + optlen + 2 >= datasiz)
return; /* prevent overflow */
if (dlen)
data[dlen++] = ',';
memcpy(&data[dlen], name, optlen);
dlen += optlen;
data[dlen] = '\0';
}
name = e + 1;
} while (e);
}
static int
mounthelper(const char *fsname, const char *dir, const char *fstype)
{
pid_t pid;
char eprog[PATH_MAX];
char const *eargv[10];
int status, i;
pid = fork();
switch(pid) {
case -1:
break;
case 0:
snprintf(eprog, sizeof(eprog), "mount.%s", fstype);
i = 0;
eargv[i++] = eprog;
if (argflags & MS_BIND)
eargv[i++] = "-B";
if (argflags & MS_MOVE)
eargv[i++] = "-M";
if (argflags & MS_REC)
eargv[i++] = "-R";
if (fsopts[0]) {
eargv[i++] = "-o";
eargv[i++] = fsopts;
}
eargv[i++] = fsname;
eargv[i++] = dir;
eargv[i] = NULL;
execvp(eprog, (char * const *)eargv);
if (errno == ENOENT)
_exit(1);
weprintf("execvp:");
_exit(1);
break;
default:
if (waitpid(pid, &status, 0) < 0) {
weprintf("waitpid:");
return -1;
}
if (WIFEXITED(status))
return WEXITSTATUS(status);
else if (WIFSIGNALED(status))
return 1;
break;
}
return 0;
}
static int
mounted(const char *dir)
{
FILE *fp;
struct mntent *me, mebuf;
struct stat st1, st2;
char linebuf[256];
if (stat(dir, &st1) < 0) {
weprintf("stat %s:", dir);
return 0;
}
if (!(fp = setmntent("/proc/mounts", "r")))
eprintf("setmntent %s:", "/proc/mounts");
while ((me = getmntent_r(fp, &mebuf, linebuf, sizeof(linebuf)))) {
if (stat(me->mnt_dir, &st2) < 0) {
weprintf("stat %s:", me->mnt_dir);
continue;
}
if (st1.st_dev == st2.st_dev &&
st1.st_ino == st2.st_ino)
return 1;
}
endmntent(fp);
return 0;
}
static void
usage(void)
{
eprintf("usage: %s [-BMRan] [-t fstype] [-o options] [source] [target]\n",
argv0);
}
int
main(int argc, char *argv[])
{
char *types = NULL, data[FSOPTS_MAXLEN] = "", *resolvpath = NULL;
char *files[] = { "/proc/mounts", "/etc/fstab", NULL };
const char *source, *target;
struct mntent *me = NULL;
int aflag = 0, status = 0, i, r;
unsigned long flags = 0;
FILE *fp;
ARGBEGIN {
case 'B':
argflags |= MS_BIND;
break;
case 'M':
argflags |= MS_MOVE;
break;
case 'R':
argflags |= MS_REC;
break;
case 'a':
aflag = 1;
break;
case 'o':
estrlcat(fsopts, EARGF(usage()), sizeof(fsopts));
parseopts(fsopts, &flags, data, sizeof(data));
break;
case 't':
types = EARGF(usage());
break;
case 'n':
break;
default:
usage();
} ARGEND;
if (argc < 1 && aflag == 0) {
if (!(fp = fopen(files[0], "r")))
eprintf("fopen %s:", files[0]);
concat(fp, files[0], stdout, "<stdout>");
fclose(fp);
return 0;
}
if (aflag == 1)
goto mountall;
source = argv[0];
target = argv[1];
if (!target) {
target = argv[0];
source = NULL;
if (!(resolvpath = realpath(target, NULL)))
eprintf("realpath %s:", target);
target = resolvpath;
}
for (i = 0; files[i]; i++) {
if (!(fp = setmntent(files[i], "r"))) {
if (strcmp(files[i], "/proc/mounts") != 0)
weprintf("setmntent %s:", files[i]);
continue;
}
while ((me = getmntent(fp))) {
if (strcmp(me->mnt_dir, target) == 0 ||
strcmp(me->mnt_fsname, target) == 0 ||
(source && strcmp(me->mnt_dir, source) == 0) ||
(source && strcmp(me->mnt_fsname, source) == 0)) {
if (!source) {
target = me->mnt_dir;
source = me->mnt_fsname;
}
if (!fsopts[0])
estrlcat(fsopts, me->mnt_opts, sizeof(fsopts));
parseopts(fsopts, &flags, data, sizeof(data));
if (!types)
types = me->mnt_type;
goto mountsingle;
}
}
endmntent(fp);
fp = NULL;
}
if (!source)
eprintf("can't find %s in /etc/fstab\n", target);
mountsingle:
r = mounthelper(source, target, types);
if (r == -1)
status = 1;
if (r > 0 && mount(source, target, types, argflags | flags, data) < 0) {
weprintf("mount: %s:", source);
status = 1;
}
if (fp)
endmntent(fp);
free(resolvpath);
return status;
mountall:
if (!(fp = setmntent("/etc/fstab", "r")))
eprintf("setmntent %s:", "/etc/fstab");
while ((me = getmntent(fp))) {
/* has "noauto" option or already mounted: skip */
if (hasmntopt(me, MNTOPT_NOAUTO) || mounted(me->mnt_dir))
continue;
flags = 0;
fsopts[0] = '\0';
if (strlcat(fsopts, me->mnt_opts, sizeof(fsopts)) >= sizeof(fsopts)) {
weprintf("%s: option string too long\n", me->mnt_dir);
status = 1;
continue;
}
parseopts(fsopts, &flags, data, sizeof(data));
/* if -t types specified:
* if non-match, skip
* if match and prefixed with "no", skip */
if (types &&
((types[0] == 'n' && types[1] == 'o' &&
findtype(types + 2, me->mnt_type)) ||
(!findtype(types, me->mnt_type))))
continue;
r = mounthelper(me->mnt_fsname, me->mnt_dir, me->mnt_type);
if (r > 0 && mount(me->mnt_fsname, me->mnt_dir, me->mnt_type,
argflags | flags, data) < 0) {
weprintf("mount: %s:", me->mnt_fsname);
status = 1;
}
}
endmntent(fp);
return status;
}