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author | Zbigniew Jędrzejewski-Szmek <zbyszek@in.waw.pl> | 2023-03-25 11:34:47 +0100 |
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committer | Lennart Poettering <lennart@poettering.net> | 2023-04-03 12:32:56 +0200 |
commit | a78413baae0e999384b535d327203ebf417b1e24 (patch) | |
tree | 25a291248447fe7b56b91fa5140a33065ae362bc | |
parent | dc2b3f94690bc02c2c1b6bdeca0d362f3639d7f0 (diff) | |
download | systemd-a78413baae0e999384b535d327203ebf417b1e24.tar.gz |
user-sessions: do not remove /etc/nologin
pam_nologin looks for /etc/nologin and /run/nologin.
user-sessions creates (and removes) /run/nologin, but also removes
/etc/nologin. (This behaviour is unchanged since the introduction
of the binary in e92787416c691c3f34f47349e5eae3fa68eae856.)
By not removing pam_nologin we fully drop compatibility with PAM < 1.1.
This has the advantage that now /etc/nologin can be used by administrator to
disable user logins, e.g. for extended maintanance. We already specified
PAM >= 1.1.2 as dependency, so this was already covered.
The makes the code match the man page.
Fixes #26965.
-rw-r--r-- | src/shared/fileio-label.c | 12 | ||||
-rw-r--r-- | src/user-sessions/user-sessions.c | 13 |
2 files changed, 14 insertions, 11 deletions
diff --git a/src/shared/fileio-label.c b/src/shared/fileio-label.c index d03b0548ec..572b8f62ad 100644 --- a/src/shared/fileio-label.c +++ b/src/shared/fileio-label.c @@ -23,9 +23,15 @@ int write_string_file_atomic_label_ts(const char *fn, const char *line, struct t int create_shutdown_run_nologin_or_warn(void) { int r; - /* This is used twice: once in systemd-user-sessions.service, in order to block logins when we actually go - * down, and once in systemd-logind.service when shutdowns are scheduled, and logins are to be turned off a bit - * in advance. We use the same wording of the message in both cases. */ + /* This is used twice: once in systemd-user-sessions.service, in order to block logins when we + * actually go down, and once in systemd-logind.service when shutdowns are scheduled, and logins are + * to be turned off a bit in advance. We use the same wording of the message in both cases. + * + * Traditionally, there was only /etc/nologin, and we managed that. Then, in PAM 1.1 + * support for /run/nologin was added as alternative + * (https://github.com/linux-pam/linux-pam/commit/e9e593f6ddeaf975b7fe8446d184e6bc387d450b). + * 13 years later we stopped managing /etc/nologin, leaving it for the administrator to manage. + */ r = write_string_file_atomic_label("/run/nologin", "System is going down. Unprivileged users are not permitted to log in anymore. " diff --git a/src/user-sessions/user-sessions.c b/src/user-sessions/user-sessions.c index 6b7493fd88..37867ee3ed 100644 --- a/src/user-sessions/user-sessions.c +++ b/src/user-sessions/user-sessions.c @@ -15,7 +15,7 @@ #include "string-util.h" static int run(int argc, char *argv[]) { - int r, k; + int r; if (argc != 2) return log_error_errno(SYNTHETIC_ERRNO(EINVAL), @@ -29,14 +29,11 @@ static int run(int argc, char *argv[]) { if (r < 0) return r; - if (streq(argv[1], "start")) { - r = unlink_or_warn("/run/nologin"); - k = unlink_or_warn("/etc/nologin"); - if (r < 0) - return r; - return k; + /* We only touch /run/nologin. See create_shutdown_run_nologin_or_warn() for details. */ - } else if (streq(argv[1], "stop")) + if (streq(argv[1], "start")) + return unlink_or_warn("/run/nologin"); + if (streq(argv[1], "stop")) return create_shutdown_run_nologin_or_warn(); return log_error_errno(SYNTHETIC_ERRNO(EINVAL), "Unknown verb '%s'.", argv[1]); |