xref: /linux/net/core/gen_stats.c (revision c4ee0af3fa0dc65f690fc908f02b8355f9576ea0)
1 /*
2  * net/core/gen_stats.c
3  *
4  *             This program is free software; you can redistribute it and/or
5  *             modify it under the terms of the GNU General Public License
6  *             as published by the Free Software Foundation; either version
7  *             2 of the License, or (at your option) any later version.
8  *
9  * Authors:  Thomas Graf <tgraf@suug.ch>
10  *           Jamal Hadi Salim
11  *           Alexey Kuznetsov, <kuznet@ms2.inr.ac.ru>
12  *
13  * See Documentation/networking/gen_stats.txt
14  */
15 
16 #include <linux/types.h>
17 #include <linux/kernel.h>
18 #include <linux/module.h>
19 #include <linux/interrupt.h>
20 #include <linux/socket.h>
21 #include <linux/rtnetlink.h>
22 #include <linux/gen_stats.h>
23 #include <net/netlink.h>
24 #include <net/gen_stats.h>
25 
26 
27 static inline int
28 gnet_stats_copy(struct gnet_dump *d, int type, void *buf, int size)
29 {
30 	if (nla_put(d->skb, type, size, buf))
31 		goto nla_put_failure;
32 	return 0;
33 
34 nla_put_failure:
35 	spin_unlock_bh(d->lock);
36 	return -1;
37 }
38 
39 /**
40  * gnet_stats_start_copy_compat - start dumping procedure in compatibility mode
41  * @skb: socket buffer to put statistics TLVs into
42  * @type: TLV type for top level statistic TLV
43  * @tc_stats_type: TLV type for backward compatibility struct tc_stats TLV
44  * @xstats_type: TLV type for backward compatibility xstats TLV
45  * @lock: statistics lock
46  * @d: dumping handle
47  *
48  * Initializes the dumping handle, grabs the statistic lock and appends
49  * an empty TLV header to the socket buffer for use a container for all
50  * other statistic TLVS.
51  *
52  * The dumping handle is marked to be in backward compatibility mode telling
53  * all gnet_stats_copy_XXX() functions to fill a local copy of struct tc_stats.
54  *
55  * Returns 0 on success or -1 if the room in the socket buffer was not sufficient.
56  */
57 int
58 gnet_stats_start_copy_compat(struct sk_buff *skb, int type, int tc_stats_type,
59 	int xstats_type, spinlock_t *lock, struct gnet_dump *d)
60 	__acquires(lock)
61 {
62 	memset(d, 0, sizeof(*d));
63 
64 	spin_lock_bh(lock);
65 	d->lock = lock;
66 	if (type)
67 		d->tail = (struct nlattr *)skb_tail_pointer(skb);
68 	d->skb = skb;
69 	d->compat_tc_stats = tc_stats_type;
70 	d->compat_xstats = xstats_type;
71 
72 	if (d->tail)
73 		return gnet_stats_copy(d, type, NULL, 0);
74 
75 	return 0;
76 }
77 EXPORT_SYMBOL(gnet_stats_start_copy_compat);
78 
79 /**
80  * gnet_stats_start_copy_compat - start dumping procedure in compatibility mode
81  * @skb: socket buffer to put statistics TLVs into
82  * @type: TLV type for top level statistic TLV
83  * @lock: statistics lock
84  * @d: dumping handle
85  *
86  * Initializes the dumping handle, grabs the statistic lock and appends
87  * an empty TLV header to the socket buffer for use a container for all
88  * other statistic TLVS.
89  *
90  * Returns 0 on success or -1 if the room in the socket buffer was not sufficient.
91  */
92 int
93 gnet_stats_start_copy(struct sk_buff *skb, int type, spinlock_t *lock,
94 	struct gnet_dump *d)
95 {
96 	return gnet_stats_start_copy_compat(skb, type, 0, 0, lock, d);
97 }
98 EXPORT_SYMBOL(gnet_stats_start_copy);
99 
100 /**
101  * gnet_stats_copy_basic - copy basic statistics into statistic TLV
102  * @d: dumping handle
103  * @b: basic statistics
104  *
105  * Appends the basic statistics to the top level TLV created by
106  * gnet_stats_start_copy().
107  *
108  * Returns 0 on success or -1 with the statistic lock released
109  * if the room in the socket buffer was not sufficient.
110  */
111 int
112 gnet_stats_copy_basic(struct gnet_dump *d, struct gnet_stats_basic_packed *b)
113 {
114 	if (d->compat_tc_stats) {
115 		d->tc_stats.bytes = b->bytes;
116 		d->tc_stats.packets = b->packets;
117 	}
118 
119 	if (d->tail) {
120 		struct gnet_stats_basic sb;
121 
122 		memset(&sb, 0, sizeof(sb));
123 		sb.bytes = b->bytes;
124 		sb.packets = b->packets;
125 		return gnet_stats_copy(d, TCA_STATS_BASIC, &sb, sizeof(sb));
126 	}
127 	return 0;
128 }
129 EXPORT_SYMBOL(gnet_stats_copy_basic);
130 
131 /**
132  * gnet_stats_copy_rate_est - copy rate estimator statistics into statistics TLV
133  * @d: dumping handle
134  * @b: basic statistics
135  * @r: rate estimator statistics
136  *
137  * Appends the rate estimator statistics to the top level TLV created by
138  * gnet_stats_start_copy().
139  *
140  * Returns 0 on success or -1 with the statistic lock released
141  * if the room in the socket buffer was not sufficient.
142  */
143 int
144 gnet_stats_copy_rate_est(struct gnet_dump *d,
145 			 const struct gnet_stats_basic_packed *b,
146 			 struct gnet_stats_rate_est64 *r)
147 {
148 	struct gnet_stats_rate_est est;
149 	int res;
150 
151 	if (b && !gen_estimator_active(b, r))
152 		return 0;
153 
154 	est.bps = min_t(u64, UINT_MAX, r->bps);
155 	/* we have some time before reaching 2^32 packets per second */
156 	est.pps = r->pps;
157 
158 	if (d->compat_tc_stats) {
159 		d->tc_stats.bps = est.bps;
160 		d->tc_stats.pps = est.pps;
161 	}
162 
163 	if (d->tail) {
164 		res = gnet_stats_copy(d, TCA_STATS_RATE_EST, &est, sizeof(est));
165 		if (res < 0 || est.bps == r->bps)
166 			return res;
167 		/* emit 64bit stats only if needed */
168 		return gnet_stats_copy(d, TCA_STATS_RATE_EST64, r, sizeof(*r));
169 	}
170 
171 	return 0;
172 }
173 EXPORT_SYMBOL(gnet_stats_copy_rate_est);
174 
175 /**
176  * gnet_stats_copy_queue - copy queue statistics into statistics TLV
177  * @d: dumping handle
178  * @q: queue statistics
179  *
180  * Appends the queue statistics to the top level TLV created by
181  * gnet_stats_start_copy().
182  *
183  * Returns 0 on success or -1 with the statistic lock released
184  * if the room in the socket buffer was not sufficient.
185  */
186 int
187 gnet_stats_copy_queue(struct gnet_dump *d, struct gnet_stats_queue *q)
188 {
189 	if (d->compat_tc_stats) {
190 		d->tc_stats.drops = q->drops;
191 		d->tc_stats.qlen = q->qlen;
192 		d->tc_stats.backlog = q->backlog;
193 		d->tc_stats.overlimits = q->overlimits;
194 	}
195 
196 	if (d->tail)
197 		return gnet_stats_copy(d, TCA_STATS_QUEUE, q, sizeof(*q));
198 
199 	return 0;
200 }
201 EXPORT_SYMBOL(gnet_stats_copy_queue);
202 
203 /**
204  * gnet_stats_copy_app - copy application specific statistics into statistics TLV
205  * @d: dumping handle
206  * @st: application specific statistics data
207  * @len: length of data
208  *
209  * Appends the application sepecific statistics to the top level TLV created by
210  * gnet_stats_start_copy() and remembers the data for XSTATS if the dumping
211  * handle is in backward compatibility mode.
212  *
213  * Returns 0 on success or -1 with the statistic lock released
214  * if the room in the socket buffer was not sufficient.
215  */
216 int
217 gnet_stats_copy_app(struct gnet_dump *d, void *st, int len)
218 {
219 	if (d->compat_xstats) {
220 		d->xstats = st;
221 		d->xstats_len = len;
222 	}
223 
224 	if (d->tail)
225 		return gnet_stats_copy(d, TCA_STATS_APP, st, len);
226 
227 	return 0;
228 }
229 EXPORT_SYMBOL(gnet_stats_copy_app);
230 
231 /**
232  * gnet_stats_finish_copy - finish dumping procedure
233  * @d: dumping handle
234  *
235  * Corrects the length of the top level TLV to include all TLVs added
236  * by gnet_stats_copy_XXX() calls. Adds the backward compatibility TLVs
237  * if gnet_stats_start_copy_compat() was used and releases the statistics
238  * lock.
239  *
240  * Returns 0 on success or -1 with the statistic lock released
241  * if the room in the socket buffer was not sufficient.
242  */
243 int
244 gnet_stats_finish_copy(struct gnet_dump *d)
245 {
246 	if (d->tail)
247 		d->tail->nla_len = skb_tail_pointer(d->skb) - (u8 *)d->tail;
248 
249 	if (d->compat_tc_stats)
250 		if (gnet_stats_copy(d, d->compat_tc_stats, &d->tc_stats,
251 			sizeof(d->tc_stats)) < 0)
252 			return -1;
253 
254 	if (d->compat_xstats && d->xstats) {
255 		if (gnet_stats_copy(d, d->compat_xstats, d->xstats,
256 			d->xstats_len) < 0)
257 			return -1;
258 	}
259 
260 	spin_unlock_bh(d->lock);
261 	return 0;
262 }
263 EXPORT_SYMBOL(gnet_stats_finish_copy);
264