Date: Tue, 16 Mar 2004 10:03:01 -0800 From: Wes Peters <wes@softweyr.com> To: current@freebsd.org Subject: ramdisks revisited Message-ID: <200403161003.01889.wes@opensail.org>
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The guy who originally asked for the ability to control ownership and
permissions of his ramdisks discovered one critical flaw in my lovely
rc.d script: chown isn't in /sbin (or /rescue) on a vanilla 5.x system.
As an alternative to moving binaries into the root filesystem, I propose
the following patch to mdconfig to add options to specify the ownership
and permissions of the newly attached md device. Options added are
-m mode, -g group, and -O owner (because -o and -u were both already used.)
I will, of course, update the man page before committing. Any objections?
Index: mdconfig.c
===================================================================
RCS file: /big/ncvs/src/sbin/mdconfig/mdconfig.c,v
retrieving revision 1.31
diff -u -w -r1.31 mdconfig.c
--- mdconfig.c 10 Mar 2004 20:41:09 -0000 1.31
+++ mdconfig.c 16 Mar 2004 17:52:38 -0000
@@ -13,6 +13,8 @@
#include <stdio.h>
#include <stdlib.h>
#include <fcntl.h>
+#include <grp.h>
+#include <pwd.h>
#include <unistd.h>
#include <string.h>
#include <err.h>
@@ -21,6 +23,7 @@
#include <sys/module.h>
#include <sys/linker.h>
#include <sys/mdioctl.h>
+#include <sys/stat.h>
#include <sys/sysctl.h>
#include <sys/queue.h>
@@ -28,6 +31,9 @@
void mdmaybeload(void);
int query(const int, const int);
void usage(void);
+gid_t getgroup(char *);
+uid_t getuser(char *);
+mode_t getperms(char *);
struct md_ioctl mdio;
@@ -39,7 +45,9 @@
usage()
{
fprintf(stderr, "usage:\n");
- fprintf(stderr, "\tmdconfig -a -t type [-n] [-o [no]option]... [ -f file]
[-s size] [-S sectorsize] [-u unit]\n");
+ fprintf(stderr, "\tmdconfig -a -t type [-n] [-o [no]option]... [-f
file]\n");
+ fprintf(stderr, "\t [-s size] [-S sectorsize] [-u unit]\n");
+ fprintf(stderr, "\t [-O owner] [-g group] [-m mode]\n");
fprintf(stderr, "\tmdconfig -d -u unit\n");
fprintf(stderr, "\tmdconfig -l [-n] [-u unit]\n");
fprintf(stderr, "\t\ttype = {malloc, preload, vnode, swap}\n");
@@ -54,9 +62,12 @@
int ch, fd, i;
char *p;
int cmdline = 0;
+ gid_t group = 0;
+ uid_t owner = 0;
+ mode_t perms = 0;
for (;;) {
- ch = getopt(argc, argv, "ab:df:lno:s:S:t:u:x:y:");
+ ch = getopt(argc, argv, "ab:df:g:lm:nO:o:s:S:t:u:x:y:");
if (ch == -1)
break;
switch (ch) {
@@ -182,6 +193,15 @@
usage();
mdio.md_fwheads = strtoul(optarg, &p, 0);
break;
+ case 'g':
+ group = getgroup(optarg);
+ break;
+ case 'm':
+ perms = getperms(optarg);
+ break;
+ case 'O':
+ owner = getuser(optarg);
+ break;
default:
usage();
}
@@ -205,6 +225,8 @@
else
query(fd, mdio.md_unit);
} else if (action == ATTACH) {
+ char devname[40];
+
if (cmdline < 2)
usage();
i = ioctl(fd, MDIOCATTACH, &mdio);
@@ -212,6 +234,12 @@
err(1, "ioctl(/dev/%s)", MDCTL_NAME);
if (mdio.md_options & MD_AUTOUNIT)
printf("%s%d\n", nflag ? "" : MD_NAME, mdio.md_unit);
+
+ snprintf(devname, 40, "/dev/%s%d", MD_NAME, mdio.md_unit);
+ if (owner || group)
+ chown(devname, (uid_t)owner, (gid_t)group);
+ if (perms)
+ chmod(devname, perms);
} else if (action == DETACH) {
if (mdio.md_options & MD_AUTOUNIT)
usage();
@@ -312,3 +340,35 @@
kldload(name);
}
+
+gid_t
+getgroup(char *name)
+{
+ struct group *gr;
+
+ if ((gr = getgrnam(name)) != NULL) {
+ endgrent();
+ return gr->gr_gid;
+ }
+ return ((gid_t)strtol(name, (char **)NULL, 10));
+}
+
+
+uid_t
+getuser(char *name)
+{
+ struct passwd *pw;
+
+ if ((pw = getpwnam(name)) != NULL) {
+ endpwent();
+ return pw->pw_uid;
+ }
+ return ((uid_t)strtol(name, (char **)NULL, 10));
+}
+
+
+mode_t
+getperms(char *string)
+{
+ return ((mode_t)strtol(string, (char **)NULL, 8));
+}
--
"Where am I, and what am I doing in this handbasket?"
Wes Peters wes@OpenSail.ORG
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