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         kfree(d->xstats);
  36         d->xstats = NULL;
  37         d->xstats_len = 0;
  38         spin_unlock_bh(d->lock);
  39         return -1;
  40 }
  41
  42 /**
  43  * gnet_stats_start_copy_compat - start dumping procedure in compatibility mode
  44  * @skb: socket buffer to put statistics TLVs into
  45  * @type: TLV type for top level statistic TLV
  46  * @tc_stats_type: TLV type for backward compatibility struct tc_stats TLV
  47  * @xstats_type: TLV type for backward compatibility xstats TLV
  48  * @lock: statistics lock
  49  * @d: dumping handle
  50  *
  51  * Initializes the dumping handle, grabs the statistic lock and appends
  52  * an empty TLV header to the socket buffer for use a container for all
  53  * other statistic TLVS.
  54  *
  55  * The dumping handle is marked to be in backward compatibility mode telling
  56  * all gnet_stats_copy_XXX() functions to fill a local copy of struct tc_stats.
  57  *
  58  * Returns 0 on success or -1 if the room in the socket buffer was not sufficient.
  59  */
  60 int
  61 gnet_stats_start_copy_compat(struct sk_buff *skb, int type, int tc_stats_type,
  62         int xstats_type, spinlock_t *lock, struct gnet_dump *d)
  63         __acquires(lock)
  64 {
  65         memset(d, 0, sizeof(*d));
  66
  67         spin_lock_bh(lock);
  68         d->lock = lock;
  69         if (type)
  70                 d->tail = (struct nlattr *)skb_tail_pointer(skb);
  71         d->skb = skb;
  72         d->compat_tc_stats = tc_stats_type;
  73         d->compat_xstats = xstats_type;
  74
  75         if (d->tail)
  76                 return gnet_stats_copy(d, type, NULL, 0);
  77
  78         return 0;
  79 }
  80 EXPORT_SYMBOL(gnet_stats_start_copy_compat);
  81
  82 /**
  83  * gnet_stats_start_copy_compat - start dumping procedure in compatibility mode
  84  * @skb: socket buffer to put statistics TLVs into
  85  * @type: TLV type for top level statistic TLV
  86  * @lock: statistics lock
  87  * @d: dumping handle
  88  *
  89  * Initializes the dumping handle, grabs the statistic lock and appends
  90  * an empty TLV header to the socket buffer for use a container for all
  91  * other statistic TLVS.
  92  *
  93  * Returns 0 on success or -1 if the room in the socket buffer was not sufficient.
  94  */
  95 int
  96 gnet_stats_start_copy(struct sk_buff *skb, int type, spinlock_t *lock,
  97         struct gnet_dump *d)
  98 {
  99         return gnet_stats_start_copy_compat(skb, type, 0, 0, lock, d);
 100 }
 101 EXPORT_SYMBOL(gnet_stats_start_copy);
 102
 103 /**
 104  * gnet_stats_copy_basic - copy basic statistics into statistic TLV
 105  * @d: dumping handle
 106  * @b: basic statistics
 107  *
 108  * Appends the basic statistics to the top level TLV created by
 109  * gnet_stats_start_copy().
 110  *
 111  * Returns 0 on success or -1 with the statistic lock released
 112  * if the room in the socket buffer was not sufficient.
 113  */
 114 int
 115 gnet_stats_copy_basic(struct gnet_dump *d, struct gnet_stats_basic_packed *b)
 116 {
 117         if (d->compat_tc_stats) {
 118                 d->tc_stats.bytes = b->bytes;
 119                 d->tc_stats.packets = b->packets;
 120         }
 121
 122         if (d->tail) {
 123                 struct gnet_stats_basic sb;
 124
 125                 memset(&sb, 0, sizeof(sb));
 126                 sb.bytes = b->bytes;
 127                 sb.packets = b->packets;
 128                 return gnet_stats_copy(d, TCA_STATS_BASIC, &sb, sizeof(sb));
 129         }
 130         return 0;
 131 }
 132 EXPORT_SYMBOL(gnet_stats_copy_basic);
 133
 134 /**
 135  * gnet_stats_copy_rate_est - copy rate estimator statistics into statistics TLV
 136  * @d: dumping handle
 137  * @b: basic statistics
 138  * @r: rate estimator statistics
 139  *
 140  * Appends the rate estimator statistics to the top level TLV created by
 141  * gnet_stats_start_copy().
 142  *
 143  * Returns 0 on success or -1 with the statistic lock released
 144  * if the room in the socket buffer was not sufficient.
 145  */
 146 int
 147 gnet_stats_copy_rate_est(struct gnet_dump *d,
 148                          const struct gnet_stats_basic_packed *b,
 149                          struct gnet_stats_rate_est64 *r)
 150 {
 151         struct gnet_stats_rate_est est;
 152         int res;
 153
 154         if (b && !gen_estimator_active(b, r))
 155                 return 0;
 156
 157         est.bps = min_t(u64, UINT_MAX, r->bps);
 158         /* we have some time before reaching 2^32 packets per second */
 159         est.pps = r->pps;
 160
 161         if (d->compat_tc_stats) {
 162                 d->tc_stats.bps = est.bps;
 163                 d->tc_stats.pps = est.pps;
 164         }
 165
 166         if (d->tail) {
 167                 res = gnet_stats_copy(d, TCA_STATS_RATE_EST, &est, sizeof(est));
 168                 if (res < 0 || est.bps == r->bps)
 169                         return res;
 170                 /* emit 64bit stats only if needed */
 171                 return gnet_stats_copy(d, TCA_STATS_RATE_EST64, r, sizeof(*r));
 172         }
 173
 174         return 0;
 175 }
 176 EXPORT_SYMBOL(gnet_stats_copy_rate_est);
 177
 178 /**
 179  * gnet_stats_copy_queue - copy queue statistics into statistics TLV
 180  * @d: dumping handle
 181  * @q: queue statistics
 182  *
 183  * Appends the queue statistics to the top level TLV created by
 184  * gnet_stats_start_copy().
 185  *
 186  * Returns 0 on success or -1 with the statistic lock released
 187  * if the room in the socket buffer was not sufficient.
 188  */
 189 int
 190 gnet_stats_copy_queue(struct gnet_dump *d, struct gnet_stats_queue *q)
 191 {
 192         if (d->compat_tc_stats) {
 193                 d->tc_stats.drops = q->drops;
 194                 d->tc_stats.qlen = q->qlen;
 195                 d->tc_stats.backlog = q->backlog;
 196                 d->tc_stats.overlimits = q->overlimits;
 197         }
 198
 199         if (d->tail)
 200                 return gnet_stats_copy(d, TCA_STATS_QUEUE, q, sizeof(*q));
 201
 202         return 0;
 203 }
 204 EXPORT_SYMBOL(gnet_stats_copy_queue);
 205
 206 /**
 207  * gnet_stats_copy_app - copy application specific statistics into statistics TLV
 208  * @d: dumping handle
 209  * @st: application specific statistics data
 210  * @len: length of data
 211  *
 212  * Appends the application sepecific statistics to the top level TLV created by
 213  * gnet_stats_start_copy() and remembers the data for XSTATS if the dumping
 214  * handle is in backward compatibility mode.
 215  *
 216  * Returns 0 on success or -1 with the statistic lock released
 217  * if the room in the socket buffer was not sufficient.
 218  */
 219 int
 220 gnet_stats_copy_app(struct gnet_dump *d, void *st, int len)
 221 {
 222         if (d->compat_xstats) {
 223                 d->xstats = kmemdup(st, len, GFP_ATOMIC);
 224                 if (!d->xstats)
 225                         goto err_out;
 226                 d->xstats_len = len;
 227         }
 228
 229         if (d->tail)
 230                 return gnet_stats_copy(d, TCA_STATS_APP, st, len);
 231
 232         return 0;
 233
 234 err_out:
 235         d->xstats_len = 0;
 236         spin_unlock_bh(d->lock);
 237         return -1;
 238 }
 239 EXPORT_SYMBOL(gnet_stats_copy_app);
 240
 241 /**
 242  * gnet_stats_finish_copy - finish dumping procedure
 243  * @d: dumping handle
 244  *
 245  * Corrects the length of the top level TLV to include all TLVs added
 246  * by gnet_stats_copy_XXX() calls. Adds the backward compatibility TLVs
 247  * if gnet_stats_start_copy_compat() was used and releases the statistics
 248  * lock.
 249  *
 250  * Returns 0 on success or -1 with the statistic lock released
 251  * if the room in the socket buffer was not sufficient.
 252  */
 253 int
 254 gnet_stats_finish_copy(struct gnet_dump *d)
 255 {
 256         if (d->tail)
 257                 d->tail->nla_len = skb_tail_pointer(d->skb) - (u8 *)d->tail;
 258
 259         if (d->compat_tc_stats)
 260                 if (gnet_stats_copy(d, d->compat_tc_stats, &d->tc_stats,
 261                         sizeof(d->tc_stats)) < 0)
 262                         return -1;
 263
 264         if (d->compat_xstats && d->xstats) {
 265                 if (gnet_stats_copy(d, d->compat_xstats, d->xstats,
 266                         d->xstats_len) < 0)
 267                         return -1;
 268         }
 269
 270         kfree(d->xstats);
 271         d->xstats = NULL;
 272         d->xstats_len = 0;
 273         spin_unlock_bh(d->lock);
 274         return 0;
 275 }
 276 EXPORT_SYMBOL(gnet_stats_finish_copy);