From c909085bb319c97b7eccbce4dcbd47a32016e0f7 Mon Sep 17 00:00:00 2001 From: Mikulas Patocka Date: Thu, 11 Mar 2021 13:27:29 -0500 Subject: [PATCH] dm ioctl: filter the returned values according to name or uuid prefix If we set non-empty param->name or param->uuid on the DM_LIST_DEVICES_CMD ioctl, the set values are considered filter prefixes. The ioctl will only return entries with matching name or uuid prefix. Signed-off-by: Mikulas Patocka Signed-off-by: Mike Snitzer --- drivers/md/dm-ioctl.c | 28 ++++++++++++++++++++++++++++ 1 file changed, 28 insertions(+) diff --git a/drivers/md/dm-ioctl.c b/drivers/md/dm-ioctl.c index 0812ac6e9d70..2209cbcd84db 100644 --- a/drivers/md/dm-ioctl.c +++ b/drivers/md/dm-ioctl.c @@ -540,6 +540,30 @@ static void *get_result_buffer(struct dm_ioctl *param, size_t param_size, return ((void *) param) + param->data_start; } +static bool filter_device(struct hash_cell *hc, const char *pfx_name, const char *pfx_uuid) +{ + const char *val; + size_t val_len, pfx_len; + + val = hc->name; + val_len = strlen(val); + pfx_len = strnlen(pfx_name, DM_NAME_LEN); + if (pfx_len > val_len) + return false; + if (memcmp(val, pfx_name, pfx_len)) + return false; + + val = hc->uuid ? hc->uuid : ""; + val_len = strlen(val); + pfx_len = strnlen(pfx_uuid, DM_UUID_LEN); + if (pfx_len > val_len) + return false; + if (memcmp(val, pfx_uuid, pfx_len)) + return false; + + return true; +} + static int list_devices(struct file *filp, struct dm_ioctl *param, size_t param_size) { struct rb_node *n; @@ -557,6 +581,8 @@ static int list_devices(struct file *filp, struct dm_ioctl *param, size_t param_ */ for (n = rb_first(&name_rb_tree); n; n = rb_next(n)) { hc = container_of(n, struct hash_cell, name_node); + if (!filter_device(hc, param->name, param->uuid)) + continue; needed += align_val(offsetof(struct dm_name_list, name) + strlen(hc->name) + 1); needed += align_val(sizeof(uint32_t) * 2); if (param->flags & DM_UUID_FLAG && hc->uuid) @@ -581,6 +607,8 @@ static int list_devices(struct file *filp, struct dm_ioctl *param, size_t param_ for (n = rb_first(&name_rb_tree); n; n = rb_next(n)) { void *uuid_ptr; hc = container_of(n, struct hash_cell, name_node); + if (!filter_device(hc, param->name, param->uuid)) + continue; if (old_nl) old_nl->next = (uint32_t) ((void *) nl - (void *) old_nl); -- 2.20.1