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auth/box: -s, -. flags

Browse source 
-. decides where we chdir to before execing, we can't
sit where we are because our directory may not exist.
If not specified we go to '/'.

-s is used to source a rc script instead of execing cmd.
This is primarily to enable:
	'#!/bin/auth/box -s'
Shebang line size is a bit tight(32), so we have this shorthand
to use rc along with setting up the required namespace components.
This commit is contained in:
Jacob Moody 2022-07-10 13:13:03 +00:00
parent 34dab15f40
commit cd64b7129c
2 changed files with 60 additions and 25 deletions
Show stats Download patch file Download diff file Expand all files Collapse all files

6
sys/man/8/auth
View file

@ -296,7 +296,11 @@ removes access to all kernel drivers from
the child namespace; the
.B -e
flag specifies a string of driver
characters to keep.
characters to keep. The
.B -s
flag gives a base set of namespace
components, ones expected by rc, then passes
the first argument as a script file to rc.
.PP
.I As
executes

79
sys/src/cmd/auth/box.c
View file

@ -10,11 +10,11 @@ binderr(char *new, char *old, int flag)
char dash[4] = { '-' };
if(debug){
if(flag & MCREATE){
if(flag & MCREATE)
dash[2] = 'c';
flag &= ~MCREATE;
}
switch(flag){
case MCREATE|MREPL:
case MREPL:
dash[0] = ' ';
if(dash[2] == 'c')
@ -133,26 +133,40 @@ skelfs(void)
sysfatal("/mnt/d mount setup: %r");
}
static char *parts[256];
static int mflags[nelem(parts)];
static int nparts;
static char *rc[] = { "/bin/rc", nil , nil};
static void
push(char *path, int flag)
{
if(nparts == nelem(parts))
sysfatal("component overflow");
parts[nparts] = path;
mflags[nparts++] = flag;
}
void
usage(void)
{
fprint(2, "usage %s: [ -d ] [ -r file ] [ -c dir ] [ -e devs ] cmd args...\n", argv0);
fprint(2, "usage %s: [ -d ] [ -r file ] [ -c dir ] [ -e devs ] [ -. path ] cmd args...\n", argv0);
exits("usage");
}
void
main(int argc, char **argv)
{
char *b;
Dir *d;
char devs[1024];
int dfd;
char *parts[256];
int mflags[256];
int nparts;
char *path;
char *a;
int sflag;
nparts = 0;
path = "/";
memset(devs, 0, sizeof devs);
sflag = 0;
ARGBEGIN{
case 'D':
debug++;
@ -160,35 +174,48 @@ main(int argc, char **argv)
debug++;
break;
case 'r':
parts[nparts] = EARGF(usage());
mflags[nparts++] = MREPL;
a = EARGF(usage());
push(a, MREPL);
break;
case 'c':
parts[nparts] = EARGF(usage());
mflags[nparts++] = MCREATE|MREPL;
a = EARGF(usage());
push(a, MREPL|MCREATE);
break;
case 'e':
snprint(devs, sizeof devs, "%s%s", devs, EARGF(usage()));
break;
case '.':
path = EARGF(usage());
break;
case 's':
sflag = 1;
break;
default:
usage();
break;
}ARGEND
if(argc == 0)
usage();
b = argv[0];
d = dirstat(b);
if(d == nil){
b = smprint("/bin/%s", b);
d = dirstat(b);
if(d == nil)
sysfatal("could not stat %s %r", argv[0]);
if(sflag){
snprint(devs, sizeof devs, "%s%s", devs, "|d");
push("/srv", MREPL|MCREATE);
push("/env", MREPL|MCREATE);
push("/rc", MREPL);
push("/bin", MREPL);
push(argv[0], MREPL);
rc[1] = argv[0];
argv = rc;
} else {
if(access(argv[0], AEXIST) == -1){
if((argv[0] = smprint("/bin/%s", argv[0])) == nil)
sysfatal("smprint: %r");
if(access(argv[0], AEXIST) == -1)
sysfatal("could not stat %s %r", argv[0]);
}
push(argv[0], MREPL);
}
free(d);
parts[nparts] = b;
mflags[nparts++] = MREPL;
argv[0] = b;
rfork(RFNAMEG|RFFDG);
skelfs();
@ -210,5 +237,9 @@ main(int argc, char **argv)
sysfatal("could not write chdev: %r");
}
close(dfd);
if(chdir(path) < 0)
sysfatal("can not cd to %s", path);
exec(argv[0], argv);
sysfatal("exec: %r");
}