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freebsd-nq/sbin/mdmfs/mdmfs.c
Yaroslav Tykhiy 3cb8dc7cd5 Fix a typo: argv -> argvp 
Rationale:
We are interested in the current (last) element of the argv array
there, not in its first element.  The if construct is there because
we want to avoid adding empty (zero-length) arguments to argv, so
we just don't advance argvp if the current argument is empty, and
it gets overwritten at the next iteration.  Note that strsep(3)
doesn't treat consecutive delim characters as a single separator,
it returns empty fields between such characters, and it's up to the
caller to handle them this or that way.

Also add a comment that the argv array ends up null-terminated in
any case (it's due to the design of the for loop) as an answer to
a possible question why the whole argv isn't zero-filled.

Submitted by:	yongari
Tested by:	yongari
MFC after:	3 days
2007-04-30 13:21:43 +00:00

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/*
* 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),
* newfs(8), and mount(8) that mimics the command line option set of
* the deprecated mount_mfs(8).
*/
#include <sys/cdefs.h>
__FBSDID("$FreeBSD$");
#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 <ctype.h>
#include <unistd.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 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 const char *mdsuffix; /* Suffix of memory disk device (e.g., ".uzip"). */
static size_t mdnamelen; /* Length of mdname. */
static const char *path_mdconfig =_PATH_MDCONFIG;
static void argappend(char **, const char *, ...) __printflike(2, 3);
static void debugprintf(const char *, ...) __printflike(1, 2);
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, newfs;
char *mtpoint, *unitstr;
char *p;
int ch;
void *set;
unsigned long ul;
/* Misc. initialization. */
(void)memset(&mi, '\0', sizeof(mi));
detach = true;
softdep = true;
autounit = false;
newfs = true;
have_mdtype = false;
mdtype = MD_SWAP;
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) {
/* Make compatibility assumptions. */
mi.mi_mode = 01777;
mi.mi_have_mode = true;
}
while ((ch = getopt(argc, argv,
"a:b:Cc:Dd:E:e:F:f:hi:LlMm:Nn:O:o:Pp:Ss:t:Uv:w:X")) != -1)
switch (ch) {
case 'a':
argappend(&newfs_arg, "-a %s", optarg);
break;
case 'b':
argappend(&newfs_arg, "-b %s", optarg);
break;
case 'C':
/* Ignored for compatibility. */
break;
case 'c':
argappend(&newfs_arg, "-c %s", optarg);
break;
case 'D':
detach = false;
break;
case 'd':
argappend(&newfs_arg, "-d %s", optarg);
break;
case 'E':
path_mdconfig = 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':
loudsubs = true;
break;
case 'l':
argappend(&newfs_arg, "-l");
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':
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':
newfs = false;
break;
case 'p':
if ((set = setmode(optarg)) == NULL)
usage();
mi.mi_mode = getmode(set, S_IRWXU | S_IRWXG | S_IRWXO);
mi.mi_have_mode = true;
free(set);
break;
case 'S':
softdep = false;
break;
case 's':
argappend(&mdconfig_arg, "-s %s", optarg);
break;
case 'U':
softdep = true;
break;
case 'v':
argappend(&newfs_arg, "-O %s", optarg);
break;
case 'w':
extract_ugid(optarg, &mi);
break;
case 'X':
debug = true;
break;
default:
usage();
}
argc -= optind;
argv += optind;
if (argc < 2)
usage();
/* Derive 'unit' (global). */
unitstr = argv[0];
if (strncmp(unitstr, "/dev/", 5) == 0)
unitstr += 5;
if (strncmp(unitstr, mdname, mdnamelen) == 0)
unitstr += mdnamelen;
if (!isdigit(*unitstr)) {
autounit = true;
unit = -1;
mdsuffix = unitstr;
} else {
ul = strtoul(unitstr, &p, 10);
if (ul == ULONG_MAX)
errx(1, "bad device unit: %s", unitstr);
unit = ul;
mdsuffix = p; /* can be empty */
}
mtpoint = argv[1];
if (!have_mdtype)
mdtype = MD_SWAP;
if (softdep)
argappend(&newfs_arg, "-U");
if (mdtype != MD_VNODE && !newfs)
errx(1, "-P requires a vnode-backed disk");
/* 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);
if (newfs)
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);
}
/*
* 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;
unsigned long ul;
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 = 0;
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';
ul = strtoul(linebuf, &p, 10);
if (ul == ULONG_MAX || *p != '\n')
errx(1, "unexpected output from mdconfig (attach)");
unit = ul;
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%d%s %s", _PATH_MOUNT, args,
mdname, unit, mdsuffix, 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 file system on the memory disk.
*/
static void
do_newfs(const char *args)
{
int rv;
rv = run(NULL, "%s%s /dev/%s%d", _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).
*
* Notice: 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.
*/
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 (*uid == (uid_t)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 (*gid == (gid_t)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);
}
/*
* 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 (**argvp != '\0')
if (++argvp >= &argv[argc]) {
*argvp = NULL;
break;
}
assert(*argv);
/* The argv array ends up NULL-terminated here. */
/* 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)
{
fprintf(stderr,
"usage: %s [-DLlMNPSUX] [-a maxcontig] [-b block-size]\n"
"\t[-c blocks-per-cylinder-group][-d max-extent-size] [-E path-mdconfig]\n"
"\t[-e maxbpg] [-F file] [-f frag-size] [-i bytes] [-m percent-free]\n"
"\t[-n rotational-positions] [-O optimization] [-o mount-options]\n"
"\t[-p permissions] [-s size] [-v version] [-w user:group]\n"
"\tmd-device mount-point\n", getprogname());
exit(1);
}
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