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freebsd/sbin/mdmfs/mdmfs.c
Ian Dowse 2dc4ac06ce Enable bug-for-bug compatibility with mount_mfs when the program
name is "mount_mfs" or "mfs". Previously, the condition was that
the program name must start with "mount_", but this both missed
the case where mount(8) invokes mdmfs with argv[0] = "mfs", and it
included cases such as "mount_md" where compatibility is not
required.

Reviewed by:	dd
2001-09-30 15:14:16 +00:00

691 lines
17 KiB
C

/*
* Copyright (c) 2001 Dima Dorfman.
* All rights reserved.
*
* Redistribution and use in source and binary forms, with or without
* modification, are permitted provided that the following conditions
* are met:
* 1. Redistributions of source code must retain the above copyright
* notice, this list of conditions and the following disclaimer.
* 2. Redistributions in binary form must reproduce the above copyright
* notice, this list of conditions and the following disclaimer in the
* documentation and/or other materials provided with the distribution.
*
* THIS SOFTWARE IS PROVIDED BY THE AUTHOR AND CONTRIBUTORS ``AS IS'' AND
* ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE
* IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE
* ARE DISCLAIMED. IN NO EVENT SHALL THE AUTHOR OR CONTRIBUTORS BE LIABLE
* FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL
* DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS
* OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION)
* HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT
* LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY
* OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF
* SUCH DAMAGE.
*/
/*
* mdmfs (md/MFS) is a wrapper around mdconfig(8), disklabel(8),
* newfs(8), and mount(8) that mimics the command line option set of
* the deprecated mount_mfs(8).
*/
#ifndef lint
static const char rcsid[] =
"$FreeBSD$";
#endif /* not lint */
#include <sys/param.h>
#include <sys/mdioctl.h>
#include <sys/stat.h>
#include <sys/wait.h>
#include <assert.h>
#include <err.h>
#include <fcntl.h>
#include <grp.h>
#include <paths.h>
#include <pwd.h>
#include <stdarg.h>
#include <stdio.h>
#include <stdlib.h>
#include <string.h>
#include <unistd.h>
#include "pathnames.h"
typedef enum { false, true } bool;
struct mtpt_info {
uid_t mi_uid;
bool mi_have_uid;
gid_t mi_gid;
bool mi_have_gid;
mode_t mi_mode;
bool mi_have_mode;
};
static bool compat; /* Full compatibility with mount_mfs? */
static bool debug; /* Emit debugging information? */
static bool loudsubs; /* Suppress output from helper programs? */
static bool norun; /* Actually run the helper programs? */
static int unit; /* The unit we're working with. */
static const char *mdname; /* Name of memory disk device (e.g., "md"). */
static size_t mdnamelen; /* Length of mdname. */
static void argappend(char **, const char *, ...) __printflike(2, 3);
static void debugprintf(const char *, ...) __printflike(1, 2);
static void do_disklabel(void);
static void do_mdconfig_attach(const char *, const enum md_types);
static void do_mdconfig_attach_au(const char *, const enum md_types);
static void do_mdconfig_detach(void);
static void do_mount(const char *, const char *);
static void do_mtptsetup(const char *, struct mtpt_info *);
static void do_newfs(const char *);
static void extract_ugid(const char *, struct mtpt_info *);
static int run(int *, const char *, ...) __printflike(2, 3);
static void usage(void);
int
main(int argc, char **argv)
{
struct mtpt_info mi; /* Mountpoint info. */
char *mdconfig_arg, *newfs_arg, /* Args to helper programs. */
*mount_arg;
enum md_types mdtype; /* The type of our memory disk. */
bool have_mdtype;
bool detach, softdep, autounit;
char *mtpoint, *unitstr;
char ch, *p;
/* Misc. initialization. */
(void)memset(&mi, '\0', sizeof(mi));
detach = true;
softdep = true;
autounit = false;
have_mdtype = false;
mdname = MD_NAME;
mdnamelen = strlen(mdname);
/*
* Can't set these to NULL. They may be passed to the
* respective programs without modification. I.e., we may not
* receive any command-line options which will caused them to
* be modified.
*/
mdconfig_arg = strdup("");
newfs_arg = strdup("");
mount_arg = strdup("");
/* If we were started as mount_mfs or mfs, imply -C. */
if (strcmp(getprogname(), "mount_mfs") == 0 ||
strcmp(getprogname(), "mfs") == 0)
compat = true;
while ((ch = getopt(argc, argv,
"a:b:Cc:Dd:e:F:f:hi:LMm:Nn:O:o:p:Ss:t:Uw:X")) != -1)
switch (ch) {
case 'a':
argappend(&newfs_arg, "-a %s", optarg);
break;
case 'b':
argappend(&newfs_arg, "-b %s", optarg);
break;
case 'C':
if (compat)
usage();
compat = true;
break;
case 'c':
argappend(&newfs_arg, "-c %s", optarg);
break;
case 'D':
if (compat)
usage();
detach = false;
break;
case 'd':
argappend(&newfs_arg, "-d %s", optarg);
break;
case 'e':
argappend(&newfs_arg, "-e %s", optarg);
break;
case 'F':
if (have_mdtype)
usage();
mdtype = MD_VNODE;
have_mdtype = true;
argappend(&mdconfig_arg, "-f %s", optarg);
break;
case 'f':
argappend(&newfs_arg, "-f %s", optarg);
break;
case 'h':
usage();
break;
case 'i':
argappend(&newfs_arg, "-i %s", optarg);
break;
case 'L':
if (compat)
usage();
loudsubs = true;
break;
case 'M':
if (have_mdtype)
usage();
mdtype = MD_MALLOC;
have_mdtype = true;
break;
case 'm':
argappend(&newfs_arg, "-m %s", optarg);
break;
case 'N':
if (compat)
usage();
norun = true;
break;
case 'n':
argappend(&newfs_arg, "-n %s", optarg);
break;
case 'O':
argappend(&newfs_arg, "-o %s", optarg);
break;
case 'o':
argappend(&mount_arg, "-o %s", optarg);
break;
case 'p':
if (compat)
usage();
if (*optarg >= '0' && *optarg <= '7')
mi.mi_mode = strtol(optarg, NULL, 8);
if ((mi.mi_mode & ~07777) != 0)
usage();
mi.mi_have_mode = true;
break;
case 'S':
if (compat)
usage();
softdep = false;
break;
case 's':
argappend(&mdconfig_arg, "-s %s", optarg);
break;
case 'U':
softdep = true;
break;
case 'w':
if (compat)
usage();
extract_ugid(optarg, &mi);
break;
case 'X':
if (compat)
usage();
debug = true;
break;
default:
usage();
}
argc -= optind;
argv += optind;
if (argc < 2)
usage();
/* Make compatibility assumptions. */
if (compat) {
mi.mi_mode = 01777;
mi.mi_have_mode = true;
}
/* Derive 'unit' (global). */
unitstr = argv[0];
if (strncmp(unitstr, "/dev/", 5) == 0)
unitstr += 5;
if (strncmp(unitstr, mdname, mdnamelen) == 0)
unitstr += mdnamelen;
if (*unitstr == '\0') {
autounit = true;
unit = -1;
} else {
unit = strtoul(unitstr, &p, 10);
if ((unsigned)unit == ULONG_MAX || *p != '\0')
errx(1, "bad device unit: %s", unitstr);
}
mtpoint = argv[1];
if (!have_mdtype)
mdtype = MD_SWAP;
if (softdep)
argappend(&newfs_arg, "-U");
/* Do the work. */
if (detach && !autounit)
do_mdconfig_detach();
if (autounit)
do_mdconfig_attach_au(mdconfig_arg, mdtype);
else
do_mdconfig_attach(mdconfig_arg, mdtype);
do_disklabel();
do_newfs(newfs_arg);
do_mount(mount_arg, mtpoint);
do_mtptsetup(mtpoint, &mi);
return (0);
}
/*
* Append the expansion of 'fmt' to the buffer pointed to by '*dstp';
* reallocate as required.
*/
static void
argappend(char **dstp, const char *fmt, ...)
{
char *old, *new;
va_list ap;
old = *dstp;
assert(old != NULL);
va_start(ap, fmt);
if (vasprintf(&new, fmt,ap) == -1)
errx(1, "vasprintf");
va_end(ap);
*dstp = new;
if (asprintf(&new, "%s %s", old, new) == -1)
errx(1, "asprintf");
free(*dstp);
free(old);
*dstp = new;
}
/*
* If run-time debugging is enabled, print the expansion of 'fmt'.
* Otherwise, do nothing.
*/
static void
debugprintf(const char *fmt, ...)
{
va_list ap;
if (!debug)
return;
fprintf(stderr, "DEBUG: ");
va_start(ap, fmt);
vfprintf(stderr, fmt, ap);
va_end(ap);
fprintf(stderr, "\n");
fflush(stderr);
}
/*
* Label the memory disk.
*/
static void
do_disklabel(void)
{
int rv;
rv = run(NULL, "%s -r -w %s%d auto", PATH_DISKLABEL, mdname, unit);
if (rv)
errx(1, "disklabel exited with error code %d", rv);
}
/*
* Attach a memory disk with a known unit.
*/
static void
do_mdconfig_attach(const char *args, const enum md_types mdtype)
{
int rv;
const char *ta; /* Type arg. */
switch (mdtype) {
case MD_SWAP:
ta = "-t swap";
break;
case MD_VNODE:
ta = "-t vnode";
break;
case MD_MALLOC:
ta = "-t malloc";
break;
default:
abort();
}
rv = run(NULL, "%s -a %s%s -u %s%d", PATH_MDCONFIG, ta, args,
mdname, unit);
if (rv)
errx(1, "mdconfig (attach) exited with error code %d", rv);
}
/*
* Attach a memory disk with an unknown unit; use autounit.
*/
static void
do_mdconfig_attach_au(const char *args, const enum md_types mdtype)
{
const char *ta; /* Type arg. */
char *linep, *linebuf; /* Line pointer, line buffer. */
int fd; /* Standard output of mdconfig invocation. */
FILE *sfd;
int rv;
char *p;
size_t linelen;
switch (mdtype) {
case MD_SWAP:
ta = "-t swap";
break;
case MD_VNODE:
ta = "-t vnode";
break;
case MD_MALLOC:
ta = "-t malloc";
break;
default:
abort();
}
rv = run(&fd, "%s -a %s%s", PATH_MDCONFIG, ta, args);
if (rv)
errx(1, "mdconfig (attach) exited with error code %d", rv);
/* Receive the unit number. */
if (norun) { /* Since we didn't run, we can't read. Fake it. */
unit = -1;
return;
}
sfd = fdopen(fd, "r");
if (sfd == NULL)
err(1, "fdopen");
linep = fgetln(sfd, &linelen);
if (linep == NULL && linelen < mdnamelen + 1)
errx(1, "unexpected output from mdconfig (attach)");
/* If the output format changes, we want to know about it. */
assert(strncmp(linep, mdname, mdnamelen) == 0);
linebuf = malloc(linelen - mdnamelen + 1);
assert(linebuf != NULL);
/* Can't use strlcpy because linep is not NULL-terminated. */
strncpy(linebuf, linep + mdnamelen, linelen);
linebuf[linelen] = '\0';
unit = strtoul(linebuf, &p, 10);
if ((unsigned)unit == ULONG_MAX || *p != '\n')
errx(1, "unexpected output from mdconfig (attach)");
fclose(sfd);
close(fd);
}
/*
* Detach a memory disk.
*/
static void
do_mdconfig_detach(void)
{
int rv;
rv = run(NULL, "%s -d -u %s%d", PATH_MDCONFIG, mdname, unit);
if (rv && debug) /* This is allowed to fail. */
warnx("mdconfig (detach) exited with error code %d (ignored)",
rv);
}
/*
* Mount the configured memory disk.
*/
static void
do_mount(const char *args, const char *mtpoint)
{
int rv;
rv = run(NULL, "%s%s /dev/%s%dc %s", PATH_MOUNT, args,
mdname, unit, mtpoint);
if (rv)
errx(1, "mount exited with error code %d", rv);
}
/*
* Various configuration of the mountpoint. Mostly, enact 'mip'.
*/
static void
do_mtptsetup(const char *mtpoint, struct mtpt_info *mip)
{
if (mip->mi_have_mode) {
debugprintf("changing mode of %s to %o.", mtpoint,
mip->mi_mode);
if (!norun)
if (chmod(mtpoint, mip->mi_mode) == -1)
err(1, "chmod: %s", mtpoint);
}
/*
* We have to do these separately because the user may have
* only specified one of them.
*/
if (mip->mi_have_uid) {
debugprintf("changing owner (user) or %s to %u.", mtpoint,
mip->mi_uid);
if (!norun)
if (chown(mtpoint, mip->mi_uid, -1) == -1)
err(1, "chown %s to %u (user)", mtpoint,
mip->mi_uid);
}
if (mip->mi_have_gid) {
debugprintf("changing owner (group) or %s to %u.", mtpoint,
mip->mi_gid);
if (!norun)
if (chown(mtpoint, -1, mip->mi_gid) == -1)
err(1, "chown %s to %u (group)", mtpoint,
mip->mi_gid);
}
}
/*
* Put a filesystem on the memory disk.
*/
static void
do_newfs(const char *args)
{
int rv;
rv = run(NULL, "%s%s /dev/%s%dc", PATH_NEWFS, args, mdname, unit);
if (rv)
errx(1, "newfs exited with error code %d", rv);
}
/*
* 'str' should be a user and group name similar to the last argument
* to chown(1); i.e., a user, followed by a colon, followed by a
* group. The user and group in 'str' may be either a [ug]id or a
* name. Upon return, the uid and gid fields in 'mip' will contain
* the uid and gid of the user and group name in 'str', respectively.
*
* In other words, this derives a user and group id from a string
* formatted like the last argument to chown(1).
*/
static void
extract_ugid(const char *str, struct mtpt_info *mip)
{
char *ug; /* Writable 'str'. */
char *user, *group; /* Result of extracton. */
struct passwd *pw;
struct group *gr;
char *p;
uid_t *uid;
gid_t *gid;
uid = &mip->mi_uid;
gid = &mip->mi_gid;
mip->mi_have_uid = mip->mi_have_gid = false;
/* Extract the user and group from 'str'. Format above. */
ug = strdup(str);
assert(ug != NULL);
group = ug;
user = strsep(&group, ":");
if (user == NULL || group == NULL || *user == '\0' || *group == '\0')
usage();
/* Derive uid. */
*uid = strtoul(user, &p, 10);
if ((unsigned)*uid == ULONG_MAX)
usage();
if (*p != '\0') {
pw = getpwnam(user);
if (pw == NULL)
errx(1, "invalid user: %s", user);
*uid = pw->pw_uid;
mip->mi_have_uid = true;
}
/* Derive gid. */
*gid = strtoul(group, &p, 10);
if ((unsigned)*gid == ULONG_MAX)
usage();
if (*p != '\0') {
gr = getgrnam(group);
if (gr == NULL)
errx(1, "invalid group: %s", group);
*gid = gr->gr_gid;
mip->mi_have_gid = true;
}
free(ug);
/*
* At this point we don't support only a username or only a
* group name. do_mtptsetup already does, so when this
* feature is desired, this is the only routine that needs to
* be changed.
*/
assert(mip->mi_have_uid);
assert(mip->mi_have_gid);
}
/*
* Run a process with command name and arguments pointed to by the
* formatted string 'cmdline'. Since system(3) is not used, the first
* space-delimited token of 'cmdline' must be the full pathname of the
* program to run. The return value is the return code of the process
* spawned. If 'ofd' is non-NULL, it is set to the standard output of
* the program spawned (i.e., you can read from ofd and get the output
* of the program).
*/
static int
run(int *ofd, const char *cmdline, ...)
{
char **argv, **argvp; /* Result of splitting 'cmd'. */
int argc;
char *cmd; /* Expansion of 'cmdline'. */
int pid, status; /* Child info. */
int pfd[2]; /* Pipe to the child. */
int nfd; /* Null (/dev/null) file descriptor. */
bool dup2dn; /* Dup /dev/null to stdout? */
va_list ap;
char *p;
int rv, i;
dup2dn = true;
va_start(ap, cmdline);
rv = vasprintf(&cmd, cmdline, ap);
if (rv == -1)
err(1, "vasprintf");
va_end(ap);
/* Split up 'cmd' into 'argv' for use with execve. */
for (argc = 1, p = cmd; (p = strchr(p, ' ')) != NULL; p++)
argc++; /* 'argc' generation loop. */
argv = (char **)malloc(sizeof(*argv) * (argc + 1));
assert(argv != NULL);
for (p = cmd, argvp = argv; (*argvp = strsep(&p, " ")) != NULL;)
if (**argv != '\0')
if (++argvp >= &argv[argc]) {
*argvp = NULL;
break;
}
assert(*argv);
/* Make sure the above loop works as expected. */
if (debug) {
/*
* We can't, but should, use debugprintf here. First,
* it appends a trailing newline to the output, and
* second it prepends "DEBUG: " to the output. The
* former is a problem for this would-be first call,
* and the latter for the would-be call inside the
* loop.
*/
(void)fprintf(stderr, "DEBUG: running:");
/* Should be equivilent to 'cmd' (before strsep, of course). */
for (i = 0; argv[i] != NULL; i++)
(void)fprintf(stderr, " %s", argv[i]);
(void)fprintf(stderr, "\n");
}
/* Create a pipe if necessary and fork the helper program. */
if (ofd != NULL) {
if (pipe(&pfd[0]) == -1)
err(1, "pipe");
*ofd = pfd[0];
dup2dn = false;
}
pid = fork();
switch (pid) {
case 0:
/* XXX can we call err() in here? */
if (norun)
_exit(0);
if (ofd != NULL)
if (dup2(pfd[1], STDOUT_FILENO) < 0)
err(1, "dup2");
if (!loudsubs) {
nfd = open(_PATH_DEVNULL, O_RDWR);
if (nfd == -1)
err(1, "open: %s", _PATH_DEVNULL);
if (dup2(nfd, STDIN_FILENO) < 0)
err(1, "dup2");
if (dup2dn)
if (dup2(nfd, STDOUT_FILENO) < 0)
err(1, "dup2");
if (dup2(nfd, STDERR_FILENO) < 0)
err(1, "dup2");
}
(void)execv(argv[0], argv);
warn("exec: %s", argv[0]);
_exit(-1);
case -1:
err(1, "fork");
}
free(cmd);
free(argv);
while (waitpid(pid, &status, 0) != pid)
;
return (WEXITSTATUS(status));
}
static void
usage(void)
{
const char *name;
if (compat)
name = getprogname();
else
name = "mdmfs";
if (!compat)
fprintf(stderr,
"Usage: %s [-DLMNSUX] [-a maxcontig [-b block-size] [-c cylinders]\n"
"\t[-d rotdelay] [-e maxbpg] [-F file] [-f frag-size] [-i bytes]\n"
"\t[-m percent-free] [-n rotational-positions] [-O optimization]\n"
"\t[-o mount-options] [-p permissions] [-s size] [-w user:group]\n"
"\tmd-device mount-point\n", name);
fprintf(stderr,
"Usage: %s -C [-NU] [-a maxcontig] [-b block-size] [-c cylinders]\n"
"\t[-d rotdelay] [-e maxbpg] [-F file] [-f frag-size] [-i bytes]\n"
"\t[-m percent-free] [-n rotational-positions] [-O optimization]\n"
"\t[-o mount-options] [-s size] md-device mount-point\n", name);
exit(1);
}