From 14bdf57a99026aed21002d0dda78572dcdc264c2 Mon Sep 17 00:00:00 2001 From: cragw Date: Mon, 23 Nov 2020 01:32:34 +0800 Subject: [PATCH] pam_zfs_key: accommodate different dataset naming scheme MIME-Version: 1.0 Content-Type: text/plain; charset=UTF-8 Content-Transfer-Encoding: 8bit Name of dataset for user home directory may vary from the expected $homes_prefix/$username, if different naming scheme is being used. We can use property mountpoint to specify the dataset for $username as long as its value is identical to passwd's pw_dir. For example: NAME PROPERTY VALUE rpool/home/myuser_123456 mountpoint /home/myuser Reviewed-by: Felix Dörre Reviewed-by: Brian Behlendorf Signed-off-by: Crag Wang Closes #11165 --- contrib/pam_zfs_key/pam_zfs_key.c | 54 +++++++++++++++++++++++++++++++ 1 file changed, 54 insertions(+) diff --git a/contrib/pam_zfs_key/pam_zfs_key.c b/contrib/pam_zfs_key/pam_zfs_key.c index 0a96f19a3..4cafc37b9 100644 --- a/contrib/pam_zfs_key/pam_zfs_key.c +++ b/contrib/pam_zfs_key/pam_zfs_key.c @@ -386,6 +386,8 @@ unmount_unload(pam_handle_t *pamh, const char *ds_name) typedef struct { char *homes_prefix; char *runstatedir; + char *homedir; + char *dsname; uid_t uid; const char *username; int unmount_and_unload; @@ -423,6 +425,8 @@ zfs_key_config_load(pam_handle_t *pamh, zfs_key_config_t *config, config->uid = entry->pw_uid; config->username = name; config->unmount_and_unload = 1; + config->dsname = NULL; + config->homedir = NULL; for (int c = 0; c < argc; c++) { if (strncmp(argv[c], "homes=", 6) == 0) { free(config->homes_prefix); @@ -432,6 +436,8 @@ zfs_key_config_load(pam_handle_t *pamh, zfs_key_config_t *config, config->runstatedir = strdup(argv[c] + 12); } else if (strcmp(argv[c], "nounmount") == 0) { config->unmount_and_unload = 0; + } else if (strcmp(argv[c], "prop_mountpoint") == 0) { + config->homedir = strdup(entry->pw_dir); } } return (0); @@ -441,11 +447,59 @@ static void zfs_key_config_free(zfs_key_config_t *config) { free(config->homes_prefix); + free(config->runstatedir); + free(config->homedir); + free(config->dsname); +} + +static int +find_dsname_by_prop_value(zfs_handle_t *zhp, void *data) +{ + zfs_type_t type = zfs_get_type(zhp); + zfs_key_config_t *target = data; + char mountpoint[ZFS_MAXPROPLEN]; + + /* Skip any datasets whose type does not match */ + if ((type & ZFS_TYPE_FILESYSTEM) == 0) { + zfs_close(zhp); + return (0); + } + + /* Skip any datasets whose mountpoint does not match */ + (void) zfs_prop_get(zhp, ZFS_PROP_MOUNTPOINT, mountpoint, + sizeof (mountpoint), NULL, NULL, 0, B_FALSE); + if (strcmp(target->homedir, mountpoint) != 0) { + zfs_close(zhp); + return (0); + } + + target->dsname = strdup(zfs_get_name(zhp)); + zfs_close(zhp); + return (1); } static char * zfs_key_config_get_dataset(zfs_key_config_t *config) { + if (config->homedir != NULL && + config->homes_prefix != NULL) { + zfs_handle_t *zhp = zfs_open(g_zfs, config->homes_prefix, + ZFS_TYPE_FILESYSTEM); + if (zhp == NULL) { + pam_syslog(NULL, LOG_ERR, "dataset %s not found", + config->homes_prefix); + zfs_close(zhp); + return (NULL); + } + + (void) zfs_iter_filesystems(zhp, find_dsname_by_prop_value, + config); + zfs_close(zhp); + char *dsname = config->dsname; + config->dsname = NULL; + return (dsname); + } + size_t len = ZFS_MAX_DATASET_NAME_LEN; size_t total_len = strlen(config->homes_prefix) + 1 + strlen(config->username);