mirror/postgresql
2
0
Fork 0
mirror of https://git.postgresql.org/git/postgresql.git synced 2024-12-21 08:29:39 +08:00
Code Issues Packages Projects Releases Wiki Activity

Allow "-C variable" and "--describe-config" even to root users.

Browse Source 
There's no really compelling reason to refuse to do these read-only,
non-server-starting options as root, and there's at least one good
reason to allow -C: pg_ctl uses -C to find out the true data directory
location when pointed at a config-only directory.  On Windows, this is
done before dropping administrator privileges, which means that pg_ctl
fails for administrators if and only if a config-only layout is used.

Since the root-privilege check is done so early in startup, it's a bit
awkward to check for these switches.  Make the somewhat arbitrary
decision that we'll only skip the root check if -C is the first switch.
This is not just to make the code a bit simpler: it also guarantees that
we can't misinterpret a --boot mode switch.  (While AuxiliaryProcessMain
doesn't currently recognize any such switch, it might have one in the
future.)  This is no particular problem for pg_ctl, and since the whole
behavior is undocumented anyhow, it's not a documentation issue either.
(--describe-config only works as the first switch anyway, so this is
no restriction for that case either.)

Back-patch to 9.2 where pg_ctl first began to use -C.

MauMau, heavily edited by me
This commit is contained in:
Tom Lane 2014-04-04 22:03:35 -04:00
parent 2209c0f861
commit b203c57bb7
2 changed files with 28 additions and 6 deletions
Show Stats Download Patch File Download Diff File Expand all files Collapse all files

26
src/backend/main/main.c
View File

@ -58,6 +58,8 @@ static void check_root(const char *progname);
int
main(int argc, char *argv[])
{
bool do_check_root = true;
progname = get_progname(argv[0]);
/*
@ -151,7 +153,8 @@ main(int argc, char *argv[])
unsetenv("LC_ALL");
/*
* Catch standard options before doing much else
* Catch standard options before doing much else, in particular before we
* insist on not being root.
*/
if (argc > 1)
{
@ -165,12 +168,29 @@ main(int argc, char *argv[])
puts("postgres (PostgreSQL) " PG_VERSION);
exit(0);
}
/*
* In addition to the above, we allow "--describe-config" and "-C var"
* to be called by root. This is reasonably safe since these are
* read-only activities. The -C case is important because pg_ctl may
* try to invoke it while still holding administrator privileges on
* Windows. Note that while -C can normally be in any argv position,
* if you wanna bypass the root check you gotta put it first. This
* reduces the risk that we might misinterpret some other mode's -C
* switch as being the postmaster/postgres one.
*/
if (strcmp(argv[1], "--describe-config") == 0)
do_check_root = false;
else if (argc > 2 && strcmp(argv[1], "-C") == 0)
do_check_root = false;
}
/*
* Make sure we are not running as root.
* Make sure we are not running as root, unless it's safe for the selected
* option.
*/
check_root(progname);
if (do_check_root)
check_root(progname);
/*
* Dispatch to one of various subprograms depending on first argument.

8
src/bin/pg_ctl/pg_ctl.c
View File

@ -2034,9 +2034,11 @@ adjust_data_dir(void)
else
my_exec_path = pg_strdup(exec_path);
snprintf(cmd, MAXPGPATH, SYSTEMQUOTE "\"%s\" %s%s -C data_directory" SYSTEMQUOTE,
my_exec_path, pgdata_opt ? pgdata_opt : "", post_opts ?
post_opts : "");
/* it's important for -C to be the first option, see main.c */
snprintf(cmd, MAXPGPATH, SYSTEMQUOTE "\"%s\" -C data_directory %s%s" SYSTEMQUOTE,
my_exec_path,
pgdata_opt ? pgdata_opt : "",
post_opts ? post_opts : "");
fd = popen(cmd, "r");
if (fd == NULL || fgets(filename, sizeof(filename), fd) == NULL)