net/core/gen_stats.c

   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);