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
gnet_stats_copy(struct gnet_dump * d,int type,void * buf,int size)28 gnet_stats_copy(struct gnet_dump *d, int type, void *buf, int size)
29 {
30 	NLA_PUT(d->skb, type, size, buf);
31 	return 0;
32 
33 nla_put_failure:
34 	spin_unlock_bh(d->lock);
35 	return -1;
36 }
37 
38 /**
39  * gnet_stats_start_copy_compat - start dumping procedure in compatibility mode
40  * @skb: socket buffer to put statistics TLVs into
41  * @type: TLV type for top level statistic TLV
42  * @tc_stats_type: TLV type for backward compatibility struct tc_stats TLV
43  * @xstats_type: TLV type for backward compatibility xstats TLV
44  * @lock: statistics lock
45  * @d: dumping handle
46  *
47  * Initializes the dumping handle, grabs the statistic lock and appends
48  * an empty TLV header to the socket buffer for use a container for all
49  * other statistic TLVS.
50  *
51  * The dumping handle is marked to be in backward compatibility mode telling
52  * all gnet_stats_copy_XXX() functions to fill a local copy of struct tc_stats.
53  *
54  * Returns 0 on success or -1 if the room in the socket buffer was not sufficient.
55  */
56 int
gnet_stats_start_copy_compat(struct sk_buff * skb,int type,int tc_stats_type,int xstats_type,spinlock_t * lock,struct gnet_dump * d)57 gnet_stats_start_copy_compat(struct sk_buff *skb, int type, int tc_stats_type,
58 	int xstats_type, spinlock_t *lock, struct gnet_dump *d)
59 	__acquires(lock)
60 {
61 	memset(d, 0, sizeof(*d));
62 
63 	spin_lock_bh(lock);
64 	d->lock = lock;
65 	if (type)
66 		d->tail = (struct nlattr *)skb_tail_pointer(skb);
67 	d->skb = skb;
68 	d->compat_tc_stats = tc_stats_type;
69 	d->compat_xstats = xstats_type;
70 
71 	if (d->tail)
72 		return gnet_stats_copy(d, type, NULL, 0);
73 
74 	return 0;
75 }
76 EXPORT_SYMBOL(gnet_stats_start_copy_compat);
77 
78 /**
79  * gnet_stats_start_copy_compat - start dumping procedure in compatibility mode
80  * @skb: socket buffer to put statistics TLVs into
81  * @type: TLV type for top level statistic TLV
82  * @lock: statistics lock
83  * @d: dumping handle
84  *
85  * Initializes the dumping handle, grabs the statistic lock and appends
86  * an empty TLV header to the socket buffer for use a container for all
87  * other statistic TLVS.
88  *
89  * Returns 0 on success or -1 if the room in the socket buffer was not sufficient.
90  */
91 int
gnet_stats_start_copy(struct sk_buff * skb,int type,spinlock_t * lock,struct gnet_dump * d)92 gnet_stats_start_copy(struct sk_buff *skb, int type, spinlock_t *lock,
93 	struct gnet_dump *d)
94 {
95 	return gnet_stats_start_copy_compat(skb, type, 0, 0, lock, d);
96 }
97 EXPORT_SYMBOL(gnet_stats_start_copy);
98 
99 /**
100  * gnet_stats_copy_basic - copy basic statistics into statistic TLV
101  * @d: dumping handle
102  * @b: basic statistics
103  *
104  * Appends the basic statistics to the top level TLV created by
105  * gnet_stats_start_copy().
106  *
107  * Returns 0 on success or -1 with the statistic lock released
108  * if the room in the socket buffer was not sufficient.
109  */
110 int
gnet_stats_copy_basic(struct gnet_dump * d,struct gnet_stats_basic_packed * b)111 gnet_stats_copy_basic(struct gnet_dump *d, struct gnet_stats_basic_packed *b)
112 {
113 	if (d->compat_tc_stats) {
114 		d->tc_stats.bytes = b->bytes;
115 		d->tc_stats.packets = b->packets;
116 	}
117 
118 	if (d->tail) {
119 		struct gnet_stats_basic sb;
120 
121 		memset(&sb, 0, sizeof(sb));
122 		sb.bytes = b->bytes;
123 		sb.packets = b->packets;
124 		return gnet_stats_copy(d, TCA_STATS_BASIC, &sb, sizeof(sb));
125 	}
126 	return 0;
127 }
128 EXPORT_SYMBOL(gnet_stats_copy_basic);
129 
130 /**
131  * gnet_stats_copy_rate_est - copy rate estimator statistics into statistics TLV
132  * @d: dumping handle
133  * @b: basic statistics
134  * @r: rate estimator statistics
135  *
136  * Appends the rate estimator statistics to the top level TLV created by
137  * gnet_stats_start_copy().
138  *
139  * Returns 0 on success or -1 with the statistic lock released
140  * if the room in the socket buffer was not sufficient.
141  */
142 int
gnet_stats_copy_rate_est(struct gnet_dump * d,const struct gnet_stats_basic_packed * b,struct gnet_stats_rate_est * r)143 gnet_stats_copy_rate_est(struct gnet_dump *d,
144 			 const struct gnet_stats_basic_packed *b,
145 			 struct gnet_stats_rate_est *r)
146 {
147 	if (b && !gen_estimator_active(b, r))
148 		return 0;
149 
150 	if (d->compat_tc_stats) {
151 		d->tc_stats.bps = r->bps;
152 		d->tc_stats.pps = r->pps;
153 	}
154 
155 	if (d->tail)
156 		return gnet_stats_copy(d, TCA_STATS_RATE_EST, r, sizeof(*r));
157 
158 	return 0;
159 }
160 EXPORT_SYMBOL(gnet_stats_copy_rate_est);
161 
162 /**
163  * gnet_stats_copy_queue - copy queue statistics into statistics TLV
164  * @d: dumping handle
165  * @q: queue statistics
166  *
167  * Appends the queue statistics to the top level TLV created by
168  * gnet_stats_start_copy().
169  *
170  * Returns 0 on success or -1 with the statistic lock released
171  * if the room in the socket buffer was not sufficient.
172  */
173 int
gnet_stats_copy_queue(struct gnet_dump * d,struct gnet_stats_queue * q)174 gnet_stats_copy_queue(struct gnet_dump *d, struct gnet_stats_queue *q)
175 {
176 	if (d->compat_tc_stats) {
177 		d->tc_stats.drops = q->drops;
178 		d->tc_stats.qlen = q->qlen;
179 		d->tc_stats.backlog = q->backlog;
180 		d->tc_stats.overlimits = q->overlimits;
181 	}
182 
183 	if (d->tail)
184 		return gnet_stats_copy(d, TCA_STATS_QUEUE, q, sizeof(*q));
185 
186 	return 0;
187 }
188 EXPORT_SYMBOL(gnet_stats_copy_queue);
189 
190 /**
191  * gnet_stats_copy_app - copy application specific statistics into statistics TLV
192  * @d: dumping handle
193  * @st: application specific statistics data
194  * @len: length of data
195  *
196  * Appends the application sepecific statistics to the top level TLV created by
197  * gnet_stats_start_copy() and remembers the data for XSTATS if the dumping
198  * handle is in backward compatibility mode.
199  *
200  * Returns 0 on success or -1 with the statistic lock released
201  * if the room in the socket buffer was not sufficient.
202  */
203 int
gnet_stats_copy_app(struct gnet_dump * d,void * st,int len)204 gnet_stats_copy_app(struct gnet_dump *d, void *st, int len)
205 {
206 	if (d->compat_xstats) {
207 		d->xstats = st;
208 		d->xstats_len = len;
209 	}
210 
211 	if (d->tail)
212 		return gnet_stats_copy(d, TCA_STATS_APP, st, len);
213 
214 	return 0;
215 }
216 EXPORT_SYMBOL(gnet_stats_copy_app);
217 
218 /**
219  * gnet_stats_finish_copy - finish dumping procedure
220  * @d: dumping handle
221  *
222  * Corrects the length of the top level TLV to include all TLVs added
223  * by gnet_stats_copy_XXX() calls. Adds the backward compatibility TLVs
224  * if gnet_stats_start_copy_compat() was used and releases the statistics
225  * lock.
226  *
227  * Returns 0 on success or -1 with the statistic lock released
228  * if the room in the socket buffer was not sufficient.
229  */
230 int
gnet_stats_finish_copy(struct gnet_dump * d)231 gnet_stats_finish_copy(struct gnet_dump *d)
232 {
233 	if (d->tail)
234 		d->tail->nla_len = skb_tail_pointer(d->skb) - (u8 *)d->tail;
235 
236 	if (d->compat_tc_stats)
237 		if (gnet_stats_copy(d, d->compat_tc_stats, &d->tc_stats,
238 			sizeof(d->tc_stats)) < 0)
239 			return -1;
240 
241 	if (d->compat_xstats && d->xstats) {
242 		if (gnet_stats_copy(d, d->compat_xstats, d->xstats,
243 			d->xstats_len) < 0)
244 			return -1;
245 	}
246 
247 	spin_unlock_bh(d->lock);
248 	return 0;
249 }
250 EXPORT_SYMBOL(gnet_stats_finish_copy);
251