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Diffstat (limited to 'src/core/dynamic-user.c')
-rw-r--r--src/core/dynamic-user.c177
1 files changed, 103 insertions, 74 deletions
diff --git a/src/core/dynamic-user.c b/src/core/dynamic-user.c
index f1b5ee7ecb..3da31bf870 100644
--- a/src/core/dynamic-user.c
+++ b/src/core/dynamic-user.c
@@ -1,3 +1,4 @@
+/* SPDX-License-Identifier: LGPL-2.1+ */
/***
This file is part of systemd.
@@ -82,7 +83,7 @@ static int dynamic_user_add(Manager *m, const char *name, int storage_socket[2],
return 0;
}
-int dynamic_user_acquire(Manager *m, const char *name, DynamicUser** ret) {
+static int dynamic_user_acquire(Manager *m, const char *name, DynamicUser** ret) {
_cleanup_close_pair_ int storage_socket[2] = { -1, -1 };
DynamicUser *d;
int r;
@@ -146,7 +147,7 @@ int dynamic_user_acquire(Manager *m, const char *name, DynamicUser** ret) {
static int make_uid_symlinks(uid_t uid, const char *name, bool b) {
- char path1[strlen("/run/systemd/dynamic-uid/direct:") + DECIMAL_STR_MAX(uid_t) + 1];
+ char path1[STRLEN("/run/systemd/dynamic-uid/direct:") + DECIMAL_STR_MAX(uid_t) + 1];
const char *path2;
int r = 0, k;
@@ -174,7 +175,7 @@ static int make_uid_symlinks(uid_t uid, const char *name, bool b) {
r = k;
}
- if (b && symlink(path1 + strlen("/run/systemd/dynamic-uid/direct:"), path2) < 0) {
+ if (b && symlink(path1 + STRLEN("/run/systemd/dynamic-uid/direct:"), path2) < 0) {
k = log_warning_errno(errno, "Failed to symlink \"%s\": %m", path2);
if (r == 0)
r = k;
@@ -217,7 +218,7 @@ static int pick_uid(char **suggested_paths, const char *name, uid_t *ret_uid) {
(void) mkdir("/run/systemd/dynamic-uid", 0755);
for (;;) {
- char lock_path[strlen("/run/systemd/dynamic-uid/") + DECIMAL_STR_MAX(uid_t) + 1];
+ char lock_path[STRLEN("/run/systemd/dynamic-uid/") + DECIMAL_STR_MAX(uid_t) + 1];
_cleanup_close_ int lock_fd = -1;
uid_t candidate;
ssize_t l;
@@ -410,7 +411,7 @@ static int dynamic_user_push(DynamicUser *d, uid_t uid, int lock_fd) {
}
static void unlink_uid_lock(int lock_fd, uid_t uid, const char *name) {
- char lock_path[strlen("/run/systemd/dynamic-uid/") + DECIMAL_STR_MAX(uid_t) + 1];
+ char lock_path[STRLEN("/run/systemd/dynamic-uid/") + DECIMAL_STR_MAX(uid_t) + 1];
if (lock_fd < 0)
return;
@@ -421,31 +422,55 @@ static void unlink_uid_lock(int lock_fd, uid_t uid, const char *name) {
(void) make_uid_symlinks(uid, name, false); /* remove direct lookup symlinks */
}
-int dynamic_user_realize(DynamicUser *d, char **suggested_dirs, uid_t *ret) {
+static int lockfp(int fd, int *fd_lock) {
+ if (lockf(fd, F_LOCK, 0) < 0)
+ return -errno;
+ *fd_lock = fd;
+ return 0;
+}
- _cleanup_close_ int etc_passwd_lock_fd = -1, uid_lock_fd = -1;
- uid_t uid = UID_INVALID;
+static void unlockfp(int *fd_lock) {
+ if (*fd_lock < 0)
+ return;
+ lockf(*fd_lock, F_ULOCK, 0);
+ *fd_lock = -1;
+}
+
+static int dynamic_user_realize(
+ DynamicUser *d,
+ char **suggested_dirs,
+ uid_t *ret_uid, gid_t *ret_gid,
+ bool is_user) {
+
+ _cleanup_(unlockfp) int storage_socket0_lock = -1;
+ _cleanup_close_ int uid_lock_fd = -1;
+ _cleanup_close_ int etc_passwd_lock_fd = -1;
+ uid_t num = UID_INVALID; /* a uid if is_user, and a gid otherwise */
+ gid_t gid = GID_INVALID; /* a gid if is_user, ignored otherwise */
int r;
assert(d);
+ assert(is_user == !!ret_uid);
+ assert(ret_gid);
/* Acquire a UID for the user name. This will allocate a UID for the user name if the user doesn't exist
* yet. If it already exists its existing UID/GID will be reused. */
- if (lockf(d->storage_socket[0], F_LOCK, 0) < 0)
- return -errno;
+ r = lockfp(d->storage_socket[0], &storage_socket0_lock);
+ if (r < 0)
+ return r;
- r = dynamic_user_pop(d, &uid, &uid_lock_fd);
+ r = dynamic_user_pop(d, &num, &uid_lock_fd);
if (r < 0) {
int new_uid_lock_fd;
uid_t new_uid;
if (r != -EAGAIN)
- goto finish;
+ return r;
/* OK, nothing stored yet, let's try to find something useful. While we are working on this release the
* lock however, so that nobody else blocks on our NSS lookups. */
- (void) lockf(d->storage_socket[0], F_ULOCK, 0);
+ unlockfp(&storage_socket0_lock);
/* Let's see if a proper, static user or group by this name exists. Try to take the lock on
* /etc/passwd, if that fails with EROFS then /etc is read-only. In that case it's fine if we don't
@@ -455,47 +480,58 @@ int dynamic_user_realize(DynamicUser *d, char **suggested_dirs, uid_t *ret) {
return etc_passwd_lock_fd;
/* First, let's parse this as numeric UID */
- r = parse_uid(d->name, &uid);
+ r = parse_uid(d->name, &num);
if (r < 0) {
struct passwd *p;
struct group *g;
- /* OK, this is not a numeric UID. Let's see if there's a user by this name */
- p = getpwnam(d->name);
- if (p)
- uid = p->pw_uid;
-
- /* Let's see if there's a group by this name */
- g = getgrnam(d->name);
- if (g) {
- /* If the UID/GID of the user/group of the same don't match, refuse operation */
- if (uid != UID_INVALID && uid != (uid_t) g->gr_gid)
- return -EILSEQ;
-
- uid = (uid_t) g->gr_gid;
+ if (is_user) {
+ /* OK, this is not a numeric UID. Let's see if there's a user by this name */
+ p = getpwnam(d->name);
+ if (p) {
+ num = p->pw_uid;
+ gid = p->pw_gid;
+ } else {
+ /* if the user does not exist but the group with the same name exists, refuse operation */
+ g = getgrnam(d->name);
+ if (g)
+ return -EILSEQ;
+ }
+ } else {
+ /* Let's see if there's a group by this name */
+ g = getgrnam(d->name);
+ if (g)
+ num = (uid_t) g->gr_gid;
+ else {
+ /* if the group does not exist but the user with the same name exists, refuse operation */
+ p = getpwnam(d->name);
+ if (p)
+ return -EILSEQ;
+ }
}
}
- if (uid == UID_INVALID) {
+ if (num == UID_INVALID) {
/* No static UID assigned yet, excellent. Let's pick a new dynamic one, and lock it. */
- uid_lock_fd = pick_uid(suggested_dirs, d->name, &uid);
+ uid_lock_fd = pick_uid(suggested_dirs, d->name, &num);
if (uid_lock_fd < 0)
return uid_lock_fd;
}
/* So, we found a working UID/lock combination. Let's see if we actually still need it. */
- if (lockf(d->storage_socket[0], F_LOCK, 0) < 0) {
- unlink_uid_lock(uid_lock_fd, uid, d->name);
- return -errno;
+ r = lockfp(d->storage_socket[0], &storage_socket0_lock);
+ if (r < 0) {
+ unlink_uid_lock(uid_lock_fd, num, d->name);
+ return r;
}
r = dynamic_user_pop(d, &new_uid, &new_uid_lock_fd);
if (r < 0) {
if (r != -EAGAIN) {
/* OK, something bad happened, let's get rid of the bits we acquired. */
- unlink_uid_lock(uid_lock_fd, uid, d->name);
- goto finish;
+ unlink_uid_lock(uid_lock_fd, num, d->name);
+ return r;
}
/* Great! Nothing is stored here, still. Store our newly acquired data. */
@@ -503,10 +539,10 @@ int dynamic_user_realize(DynamicUser *d, char **suggested_dirs, uid_t *ret) {
/* Hmm, so as it appears there's now something stored in the storage socket. Throw away what we
* acquired, and use what's stored now. */
- unlink_uid_lock(uid_lock_fd, uid, d->name);
+ unlink_uid_lock(uid_lock_fd, num, d->name);
safe_close(uid_lock_fd);
- uid = new_uid;
+ num = new_uid;
uid_lock_fd = new_uid_lock_fd;
}
}
@@ -514,19 +550,21 @@ int dynamic_user_realize(DynamicUser *d, char **suggested_dirs, uid_t *ret) {
/* If the UID/GID was already allocated dynamically, push the data we popped out back in. If it was already
* allocated statically, push the UID back too, but do not push the lock fd in. If we allocated the UID
* dynamically right here, push that in along with the lock fd for it. */
- r = dynamic_user_push(d, uid, uid_lock_fd);
+ r = dynamic_user_push(d, num, uid_lock_fd);
if (r < 0)
- goto finish;
+ return r;
- *ret = uid;
- r = 0;
+ if (is_user) {
+ *ret_uid = num;
+ *ret_gid = gid != GID_INVALID ? gid : num;
+ } else
+ *ret_gid = num;
-finish:
- (void) lockf(d->storage_socket[0], F_ULOCK, 0);
- return r;
+ return 0;
}
-int dynamic_user_current(DynamicUser *d, uid_t *ret) {
+static int dynamic_user_current(DynamicUser *d, uid_t *ret) {
+ _cleanup_(unlockfp) int storage_socket0_lock = -1;
_cleanup_close_ int lock_fd = -1;
uid_t uid;
int r;
@@ -536,26 +574,23 @@ int dynamic_user_current(DynamicUser *d, uid_t *ret) {
/* Get the currently assigned UID for the user, if there's any. This simply pops the data from the storage socket, and pushes it back in right-away. */
- if (lockf(d->storage_socket[0], F_LOCK, 0) < 0)
- return -errno;
+ r = lockfp(d->storage_socket[0], &storage_socket0_lock);
+ if (r < 0)
+ return r;
r = dynamic_user_pop(d, &uid, &lock_fd);
if (r < 0)
- goto finish;
+ return r;
r = dynamic_user_push(d, uid, lock_fd);
if (r < 0)
- goto finish;
+ return r;
*ret = uid;
- r = 0;
-
-finish:
- (void) lockf(d->storage_socket[0], F_ULOCK, 0);
- return r;
+ return 0;
}
-DynamicUser* dynamic_user_ref(DynamicUser *d) {
+static DynamicUser* dynamic_user_ref(DynamicUser *d) {
if (!d)
return NULL;
@@ -565,7 +600,7 @@ DynamicUser* dynamic_user_ref(DynamicUser *d) {
return d;
}
-DynamicUser* dynamic_user_unref(DynamicUser *d) {
+static DynamicUser* dynamic_user_unref(DynamicUser *d) {
if (!d)
return NULL;
@@ -580,6 +615,7 @@ DynamicUser* dynamic_user_unref(DynamicUser *d) {
}
static int dynamic_user_close(DynamicUser *d) {
+ _cleanup_(unlockfp) int storage_socket0_lock = -1;
_cleanup_close_ int lock_fd = -1;
uid_t uid;
int r;
@@ -587,28 +623,23 @@ static int dynamic_user_close(DynamicUser *d) {
/* Release the user ID, by releasing the lock on it, and emptying the storage socket. After this the user is
* unrealized again, much like it was after it the DynamicUser object was first allocated. */
- if (lockf(d->storage_socket[0], F_LOCK, 0) < 0)
- return -errno;
+ r = lockfp(d->storage_socket[0], &storage_socket0_lock);
+ if (r < 0)
+ return r;
r = dynamic_user_pop(d, &uid, &lock_fd);
- if (r == -EAGAIN) {
+ if (r == -EAGAIN)
/* User wasn't realized yet, nothing to do. */
- r = 0;
- goto finish;
- }
+ return 0;
if (r < 0)
- goto finish;
+ return r;
/* This dynamic user was realized and dynamically allocated. In this case, let's remove the lock file. */
unlink_uid_lock(lock_fd, uid, d->name);
- r = 1;
-
-finish:
- (void) lockf(d->storage_socket[0], F_ULOCK, 0);
- return r;
+ return 1;
}
-DynamicUser* dynamic_user_destroy(DynamicUser *d) {
+static DynamicUser* dynamic_user_destroy(DynamicUser *d) {
if (!d)
return NULL;
@@ -713,7 +744,7 @@ void dynamic_user_vacuum(Manager *m, bool close_user) {
}
int dynamic_user_lookup_uid(Manager *m, uid_t uid, char **ret) {
- char lock_path[strlen("/run/systemd/dynamic-uid/") + DECIMAL_STR_MAX(uid_t) + 1];
+ char lock_path[STRLEN("/run/systemd/dynamic-uid/") + DECIMAL_STR_MAX(uid_t) + 1];
_cleanup_free_ char *user = NULL;
uid_t check_uid;
int r;
@@ -814,21 +845,19 @@ int dynamic_creds_realize(DynamicCreds *creds, char **suggested_paths, uid_t *ui
/* Realize both the referenced user and group */
if (creds->user) {
- r = dynamic_user_realize(creds->user, suggested_paths, &u);
+ r = dynamic_user_realize(creds->user, suggested_paths, &u, &g, true);
if (r < 0)
return r;
}
if (creds->group && creds->group != creds->user) {
- r = dynamic_user_realize(creds->group, suggested_paths, &g);
+ r = dynamic_user_realize(creds->group, suggested_paths, NULL, &g, false);
if (r < 0)
return r;
- } else
- g = u;
+ }
*uid = u;
*gid = g;
-
return 0;
}
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