1// SPDX-License-Identifier: GPL-2.0
  2
  3#include <linux/mutex.h>
  4#include <linux/netdevice.h>
  5#include <linux/xarray.h>
  6#include <net/net_debug.h>
  7#include <net/page_pool/types.h>
  8#include <net/page_pool/helpers.h>
  9#include <net/sock.h>
 10
 11#include "page_pool_priv.h"
 12#include "netdev-genl-gen.h"
 13
 14static DEFINE_XARRAY_FLAGS(page_pools, XA_FLAGS_ALLOC1);
 15/* Protects: page_pools, netdevice->page_pools, pool->slow.netdev, pool->user.
 16 * Ordering: inside rtnl_lock
 17 */
 18static DEFINE_MUTEX(page_pools_lock);
 19
 20/* Page pools are only reachable from user space (via netlink) if they are
 21 * linked to a netdev at creation time. Following page pool "visibility"
 22 * states are possible:
 23 *  - normal
 24 *    - user.list: linked to real netdev, netdev: real netdev
 25 *  - orphaned - real netdev has disappeared
 26 *    - user.list: linked to lo, netdev: lo
 27 *  - invisible - either (a) created without netdev linking, (b) unlisted due
 28 *      to error, or (c) the entire namespace which owned this pool disappeared
 29 *    - user.list: unhashed, netdev: unknown
 30 */
 31
 32typedef int (*pp_nl_fill_cb)(struct sk_buff *rsp, const struct page_pool *pool,
 33			     const struct genl_info *info);
 34
 35static int
 36netdev_nl_page_pool_get_do(struct genl_info *info, u32 id, pp_nl_fill_cb fill)
 37{
 38	struct page_pool *pool;
 39	struct sk_buff *rsp;
 40	int err;
 41
 42	mutex_lock(&page_pools_lock);
 43	pool = xa_load(&page_pools, id);
 44	if (!pool || hlist_unhashed(&pool->user.list) ||
 45	    !net_eq(dev_net(pool->slow.netdev), genl_info_net(info))) {
 46		err = -ENOENT;
 47		goto err_unlock;
 48	}
 49
 50	rsp = genlmsg_new(GENLMSG_DEFAULT_SIZE, GFP_KERNEL);
 51	if (!rsp) {
 52		err = -ENOMEM;
 53		goto err_unlock;
 54	}
 55
 56	err = fill(rsp, pool, info);
 57	if (err)
 58		goto err_free_msg;
 59
 60	mutex_unlock(&page_pools_lock);
 61
 62	return genlmsg_reply(rsp, info);
 63
 64err_free_msg:
 65	nlmsg_free(rsp);
 66err_unlock:
 67	mutex_unlock(&page_pools_lock);
 68	return err;
 69}
 70
 71struct page_pool_dump_cb {
 72	unsigned long ifindex;
 73	u32 pp_id;
 74};
 75
 76static int
 77netdev_nl_page_pool_get_dump(struct sk_buff *skb, struct netlink_callback *cb,
 78			     pp_nl_fill_cb fill)
 79{
 80	struct page_pool_dump_cb *state = (void *)cb->ctx;
 81	const struct genl_info *info = genl_info_dump(cb);
 82	struct net *net = sock_net(skb->sk);
 83	struct net_device *netdev;
 84	struct page_pool *pool;
 85	int err = 0;
 86
 87	rtnl_lock();
 88	mutex_lock(&page_pools_lock);
 89	for_each_netdev_dump(net, netdev, state->ifindex) {
 90		hlist_for_each_entry(pool, &netdev->page_pools, user.list) {
 91			if (state->pp_id && state->pp_id < pool->user.id)
 92				continue;
 93
 94			state->pp_id = pool->user.id;
 95			err = fill(skb, pool, info);
 96			if (err)
 97				goto out;
 98		}
 99
100		state->pp_id = 0;
101	}
102out:
103	mutex_unlock(&page_pools_lock);
104	rtnl_unlock();
105
106	return err;
107}
108
109static int
110page_pool_nl_stats_fill(struct sk_buff *rsp, const struct page_pool *pool,
111			const struct genl_info *info)
112{
113#ifdef CONFIG_PAGE_POOL_STATS
114	struct page_pool_stats stats = {};
115	struct nlattr *nest;
116	void *hdr;
117
118	if (!page_pool_get_stats(pool, &stats))
119		return 0;
120
121	hdr = genlmsg_iput(rsp, info);
122	if (!hdr)
123		return -EMSGSIZE;
124
125	nest = nla_nest_start(rsp, NETDEV_A_PAGE_POOL_STATS_INFO);
126
127	if (nla_put_uint(rsp, NETDEV_A_PAGE_POOL_ID, pool->user.id) ||
128	    (pool->slow.netdev->ifindex != LOOPBACK_IFINDEX &&
129	     nla_put_u32(rsp, NETDEV_A_PAGE_POOL_IFINDEX,
130			 pool->slow.netdev->ifindex)))
131		goto err_cancel_nest;
132
133	nla_nest_end(rsp, nest);
134
135	if (nla_put_uint(rsp, NETDEV_A_PAGE_POOL_STATS_ALLOC_FAST,
136			 stats.alloc_stats.fast) ||
137	    nla_put_uint(rsp, NETDEV_A_PAGE_POOL_STATS_ALLOC_SLOW,
138			 stats.alloc_stats.slow) ||
139	    nla_put_uint(rsp, NETDEV_A_PAGE_POOL_STATS_ALLOC_SLOW_HIGH_ORDER,
140			 stats.alloc_stats.slow_high_order) ||
141	    nla_put_uint(rsp, NETDEV_A_PAGE_POOL_STATS_ALLOC_EMPTY,
142			 stats.alloc_stats.empty) ||
143	    nla_put_uint(rsp, NETDEV_A_PAGE_POOL_STATS_ALLOC_REFILL,
144			 stats.alloc_stats.refill) ||
145	    nla_put_uint(rsp, NETDEV_A_PAGE_POOL_STATS_ALLOC_WAIVE,
146			 stats.alloc_stats.waive) ||
147	    nla_put_uint(rsp, NETDEV_A_PAGE_POOL_STATS_RECYCLE_CACHED,
148			 stats.recycle_stats.cached) ||
149	    nla_put_uint(rsp, NETDEV_A_PAGE_POOL_STATS_RECYCLE_CACHE_FULL,
150			 stats.recycle_stats.cache_full) ||
151	    nla_put_uint(rsp, NETDEV_A_PAGE_POOL_STATS_RECYCLE_RING,
152			 stats.recycle_stats.ring) ||
153	    nla_put_uint(rsp, NETDEV_A_PAGE_POOL_STATS_RECYCLE_RING_FULL,
154			 stats.recycle_stats.ring_full) ||
155	    nla_put_uint(rsp, NETDEV_A_PAGE_POOL_STATS_RECYCLE_RELEASED_REFCNT,
156			 stats.recycle_stats.released_refcnt))
157		goto err_cancel_msg;
158
159	genlmsg_end(rsp, hdr);
160
161	return 0;
162err_cancel_nest:
163	nla_nest_cancel(rsp, nest);
164err_cancel_msg:
165	genlmsg_cancel(rsp, hdr);
166	return -EMSGSIZE;
167#else
168	GENL_SET_ERR_MSG(info, "kernel built without CONFIG_PAGE_POOL_STATS");
169	return -EOPNOTSUPP;
170#endif
171}
172
173int netdev_nl_page_pool_stats_get_doit(struct sk_buff *skb,
174				       struct genl_info *info)
175{
176	struct nlattr *tb[ARRAY_SIZE(netdev_page_pool_info_nl_policy)];
177	struct nlattr *nest;
178	int err;
179	u32 id;
180
181	if (GENL_REQ_ATTR_CHECK(info, NETDEV_A_PAGE_POOL_STATS_INFO))
182		return -EINVAL;
183
184	nest = info->attrs[NETDEV_A_PAGE_POOL_STATS_INFO];
185	err = nla_parse_nested(tb, ARRAY_SIZE(tb) - 1, nest,
186			       netdev_page_pool_info_nl_policy,
187			       info->extack);
188	if (err)
189		return err;
190
191	if (NL_REQ_ATTR_CHECK(info->extack, nest, tb, NETDEV_A_PAGE_POOL_ID))
192		return -EINVAL;
193	if (tb[NETDEV_A_PAGE_POOL_IFINDEX]) {
194		NL_SET_ERR_MSG_ATTR(info->extack,
195				    tb[NETDEV_A_PAGE_POOL_IFINDEX],
196				    "selecting by ifindex not supported");
197		return -EINVAL;
198	}
199
200	id = nla_get_uint(tb[NETDEV_A_PAGE_POOL_ID]);
201
202	return netdev_nl_page_pool_get_do(info, id, page_pool_nl_stats_fill);
203}
204
205int netdev_nl_page_pool_stats_get_dumpit(struct sk_buff *skb,
206					 struct netlink_callback *cb)
207{
208	return netdev_nl_page_pool_get_dump(skb, cb, page_pool_nl_stats_fill);
209}
210
211static int
212page_pool_nl_fill(struct sk_buff *rsp, const struct page_pool *pool,
213		  const struct genl_info *info)
214{
215	size_t inflight, refsz;
216	void *hdr;
217
218	hdr = genlmsg_iput(rsp, info);
219	if (!hdr)
220		return -EMSGSIZE;
221
222	if (nla_put_uint(rsp, NETDEV_A_PAGE_POOL_ID, pool->user.id))
223		goto err_cancel;
224
225	if (pool->slow.netdev->ifindex != LOOPBACK_IFINDEX &&
226	    nla_put_u32(rsp, NETDEV_A_PAGE_POOL_IFINDEX,
227			pool->slow.netdev->ifindex))
228		goto err_cancel;
229	if (pool->user.napi_id &&
230	    nla_put_uint(rsp, NETDEV_A_PAGE_POOL_NAPI_ID, pool->user.napi_id))
231		goto err_cancel;
232
233	inflight = page_pool_inflight(pool, false);
234	refsz =	PAGE_SIZE << pool->p.order;
235	if (nla_put_uint(rsp, NETDEV_A_PAGE_POOL_INFLIGHT, inflight) ||
236	    nla_put_uint(rsp, NETDEV_A_PAGE_POOL_INFLIGHT_MEM,
237			 inflight * refsz))
238		goto err_cancel;
239	if (pool->user.detach_time &&
240	    nla_put_uint(rsp, NETDEV_A_PAGE_POOL_DETACH_TIME,
241			 pool->user.detach_time))
242		goto err_cancel;
243
244	genlmsg_end(rsp, hdr);
245
246	return 0;
247err_cancel:
248	genlmsg_cancel(rsp, hdr);
249	return -EMSGSIZE;
250}
251
252static void netdev_nl_page_pool_event(const struct page_pool *pool, u32 cmd)
253{
254	struct genl_info info;
255	struct sk_buff *ntf;
256	struct net *net;
257
258	lockdep_assert_held(&page_pools_lock);
259
260	/* 'invisible' page pools don't matter */
261	if (hlist_unhashed(&pool->user.list))
262		return;
263	net = dev_net(pool->slow.netdev);
264
265	if (!genl_has_listeners(&netdev_nl_family, net, NETDEV_NLGRP_PAGE_POOL))
266		return;
267
268	genl_info_init_ntf(&info, &netdev_nl_family, cmd);
269
270	ntf = genlmsg_new(GENLMSG_DEFAULT_SIZE, GFP_KERNEL);
271	if (!ntf)
272		return;
273
274	if (page_pool_nl_fill(ntf, pool, &info)) {
275		nlmsg_free(ntf);
276		return;
277	}
278
279	genlmsg_multicast_netns(&netdev_nl_family, net, ntf,
280				0, NETDEV_NLGRP_PAGE_POOL, GFP_KERNEL);
281}
282
283int netdev_nl_page_pool_get_doit(struct sk_buff *skb, struct genl_info *info)
284{
285	u32 id;
286
287	if (GENL_REQ_ATTR_CHECK(info, NETDEV_A_PAGE_POOL_ID))
288		return -EINVAL;
289
290	id = nla_get_uint(info->attrs[NETDEV_A_PAGE_POOL_ID]);
291
292	return netdev_nl_page_pool_get_do(info, id, page_pool_nl_fill);
293}
294
295int netdev_nl_page_pool_get_dumpit(struct sk_buff *skb,
296				   struct netlink_callback *cb)
297{
298	return netdev_nl_page_pool_get_dump(skb, cb, page_pool_nl_fill);
299}
300
301int page_pool_list(struct page_pool *pool)
302{
303	static u32 id_alloc_next;
304	int err;
305
306	mutex_lock(&page_pools_lock);
307	err = xa_alloc_cyclic(&page_pools, &pool->user.id, pool, xa_limit_32b,
308			      &id_alloc_next, GFP_KERNEL);
309	if (err < 0)
310		goto err_unlock;
311
312	INIT_HLIST_NODE(&pool->user.list);
313	if (pool->slow.netdev) {
314		hlist_add_head(&pool->user.list,
315			       &pool->slow.netdev->page_pools);
316		pool->user.napi_id = pool->p.napi ? pool->p.napi->napi_id : 0;
317
318		netdev_nl_page_pool_event(pool, NETDEV_CMD_PAGE_POOL_ADD_NTF);
319	}
320
321	mutex_unlock(&page_pools_lock);
322	return 0;
323
324err_unlock:
325	mutex_unlock(&page_pools_lock);
326	return err;
327}
328
329void page_pool_detached(struct page_pool *pool)
330{
331	mutex_lock(&page_pools_lock);
332	pool->user.detach_time = ktime_get_boottime_seconds();
333	netdev_nl_page_pool_event(pool, NETDEV_CMD_PAGE_POOL_CHANGE_NTF);
334	mutex_unlock(&page_pools_lock);
335}
336
337void page_pool_unlist(struct page_pool *pool)
338{
339	mutex_lock(&page_pools_lock);
340	netdev_nl_page_pool_event(pool, NETDEV_CMD_PAGE_POOL_DEL_NTF);
341	xa_erase(&page_pools, pool->user.id);
342	if (!hlist_unhashed(&pool->user.list))
343		hlist_del(&pool->user.list);
344	mutex_unlock(&page_pools_lock);
345}
346
347static void page_pool_unreg_netdev_wipe(struct net_device *netdev)
348{
349	struct page_pool *pool;
350	struct hlist_node *n;
351
352	mutex_lock(&page_pools_lock);
353	hlist_for_each_entry_safe(pool, n, &netdev->page_pools, user.list) {
354		hlist_del_init(&pool->user.list);
355		pool->slow.netdev = NET_PTR_POISON;
356	}
357	mutex_unlock(&page_pools_lock);
358}
359
360static void page_pool_unreg_netdev(struct net_device *netdev)
361{
362	struct page_pool *pool, *last;
363	struct net_device *lo;
364
365	lo = dev_net(netdev)->loopback_dev;
366
367	mutex_lock(&page_pools_lock);
368	last = NULL;
369	hlist_for_each_entry(pool, &netdev->page_pools, user.list) {
370		pool->slow.netdev = lo;
371		netdev_nl_page_pool_event(pool,
372					  NETDEV_CMD_PAGE_POOL_CHANGE_NTF);
373		last = pool;
374	}
375	if (last)
376		hlist_splice_init(&netdev->page_pools, &last->user.list,
377				  &lo->page_pools);
378	mutex_unlock(&page_pools_lock);
379}
380
381static int
382page_pool_netdevice_event(struct notifier_block *nb,
383			  unsigned long event, void *ptr)
384{
385	struct net_device *netdev = netdev_notifier_info_to_dev(ptr);
386
387	if (event != NETDEV_UNREGISTER)
388		return NOTIFY_DONE;
389
390	if (hlist_empty(&netdev->page_pools))
391		return NOTIFY_OK;
392
393	if (netdev->ifindex != LOOPBACK_IFINDEX)
394		page_pool_unreg_netdev(netdev);
395	else
396		page_pool_unreg_netdev_wipe(netdev);
397	return NOTIFY_OK;
398}
399
400static struct notifier_block page_pool_netdevice_nb = {
401	.notifier_call = page_pool_netdevice_event,
402};
403
404static int __init page_pool_user_init(void)
405{
406	return register_netdevice_notifier(&page_pool_netdevice_nb);
407}
408
409subsys_initcall(page_pool_user_init);