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, int padattr)
  29 {
  30         if (nla_put_64bit(d->skb, type, size, buf, padattr))
  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,
  63                              struct gnet_dump *d, int padattr)
  64         __acquires(lock)
  65 {
  66         memset(d, 0, sizeof(*d));
  67
  68         spin_lock_bh(lock);
  69         d->lock = lock;
  70         if (type)
  71                 d->tail = (struct nlattr *)skb_tail_pointer(skb);
  72         d->skb = skb;
  73         d->compat_tc_stats = tc_stats_type;
  74         d->compat_xstats = xstats_type;
  75         d->padattr = padattr;
  76
  77         if (d->tail)
  78                 return gnet_stats_copy(d, type, NULL, 0, padattr);
  79
  80         return 0;
  81 }
  82 EXPORT_SYMBOL(gnet_stats_start_copy_compat);
  83
  84 /**
  85  * gnet_stats_start_copy - start dumping procedure in compatibility mode
  86  * @skb: socket buffer to put statistics TLVs into
  87  * @type: TLV type for top level statistic TLV
  88  * @lock: statistics lock
  89  * @d: dumping handle
  90  *
  91  * Initializes the dumping handle, grabs the statistic lock and appends
  92  * an empty TLV header to the socket buffer for use a container for all
  93  * other statistic TLVS.
  94  *
  95  * Returns 0 on success or -1 if the room in the socket buffer was not sufficient.
  96  */
  97 int
  98 gnet_stats_start_copy(struct sk_buff *skb, int type, spinlock_t *lock,
  99                       struct gnet_dump *d, int padattr)
 100 {
 101         return gnet_stats_start_copy_compat(skb, type, 0, 0, lock, d, padattr);
 102 }
 103 EXPORT_SYMBOL(gnet_stats_start_copy);
 104
 105 static void
 106 __gnet_stats_copy_basic_cpu(struct gnet_stats_basic_packed *bstats,
 107                             struct gnet_stats_basic_cpu __percpu *cpu)
 108 {
 109         int i;
 110
 111         for_each_possible_cpu(i) {
 112                 struct gnet_stats_basic_cpu *bcpu = per_cpu_ptr(cpu, i);
 113                 unsigned int start;
 114                 u64 bytes;
 115                 u32 packets;
 116
 117                 do {
 118                         start = u64_stats_fetch_begin_irq(&bcpu->syncp);
 119                         bytes = bcpu->bstats.bytes;
 120                         packets = bcpu->bstats.packets;
 121                 } while (u64_stats_fetch_retry_irq(&bcpu->syncp, start));
 122
 123                 bstats->bytes += bytes;
 124                 bstats->packets += packets;
 125         }
 126 }
 127
 128 void
 129 __gnet_stats_copy_basic(struct gnet_stats_basic_packed *bstats,
 130                         struct gnet_stats_basic_cpu __percpu *cpu,
 131                         struct gnet_stats_basic_packed *b)
 132 {
 133         if (cpu) {
 134                 __gnet_stats_copy_basic_cpu(bstats, cpu);
 135         } else {
 136                 bstats->bytes = b->bytes;
 137                 bstats->packets = b->packets;
 138         }
 139 }
 140 EXPORT_SYMBOL(__gnet_stats_copy_basic);
 141
 142 /**
 143  * gnet_stats_copy_basic - copy basic statistics into statistic TLV
 144  * @d: dumping handle
 145  * @cpu: copy statistic per cpu
 146  * @b: basic statistics
 147  *
 148  * Appends the basic statistics to the top level TLV created by
 149  * gnet_stats_start_copy().
 150  *
 151  * Returns 0 on success or -1 with the statistic lock released
 152  * if the room in the socket buffer was not sufficient.
 153  */
 154 int
 155 gnet_stats_copy_basic(struct gnet_dump *d,
 156                       struct gnet_stats_basic_cpu __percpu *cpu,
 157                       struct gnet_stats_basic_packed *b)
 158 {
 159         struct gnet_stats_basic_packed bstats = {0};
 160
 161         __gnet_stats_copy_basic(&bstats, cpu, b);
 162
 163         if (d->compat_tc_stats) {
 164                 d->tc_stats.bytes = bstats.bytes;
 165                 d->tc_stats.packets = bstats.packets;
 166         }
 167
 168         if (d->tail) {
 169                 struct gnet_stats_basic sb;
 170
 171                 memset(&sb, 0, sizeof(sb));
 172                 sb.bytes = bstats.bytes;
 173                 sb.packets = bstats.packets;
 174                 return gnet_stats_copy(d, TCA_STATS_BASIC, &sb, sizeof(sb),
 175                                        TCA_STATS_PAD);
 176         }
 177         return 0;
 178 }
 179 EXPORT_SYMBOL(gnet_stats_copy_basic);
 180
 181 /**
 182  * gnet_stats_copy_rate_est - copy rate estimator statistics into statistics TLV
 183  * @d: dumping handle
 184  * @b: basic statistics
 185  * @r: rate estimator statistics
 186  *
 187  * Appends the rate estimator statistics to the top level TLV created by
 188  * gnet_stats_start_copy().
 189  *
 190  * Returns 0 on success or -1 with the statistic lock released
 191  * if the room in the socket buffer was not sufficient.
 192  */
 193 int
 194 gnet_stats_copy_rate_est(struct gnet_dump *d,
 195                          const struct gnet_stats_basic_packed *b,
 196                          struct gnet_stats_rate_est64 *r)
 197 {
 198         struct gnet_stats_rate_est est;
 199         int res;
 200
 201         if (b && !gen_estimator_active(b, r))
 202                 return 0;
 203
 204         est.bps = min_t(u64, UINT_MAX, r->bps);
 205         /* we have some time before reaching 2^32 packets per second */
 206         est.pps = r->pps;
 207
 208         if (d->compat_tc_stats) {
 209                 d->tc_stats.bps = est.bps;
 210                 d->tc_stats.pps = est.pps;
 211         }
 212
 213         if (d->tail) {
 214                 res = gnet_stats_copy(d, TCA_STATS_RATE_EST, &est, sizeof(est),
 215                                       TCA_STATS_PAD);
 216                 if (res < 0 || est.bps == r->bps)
 217                         return res;
 218                 /* emit 64bit stats only if needed */
 219                 return gnet_stats_copy(d, TCA_STATS_RATE_EST64, r, sizeof(*r),
 220                                        TCA_STATS_PAD);
 221         }
 222
 223         return 0;
 224 }
 225 EXPORT_SYMBOL(gnet_stats_copy_rate_est);
 226
 227 static void
 228 __gnet_stats_copy_queue_cpu(struct gnet_stats_queue *qstats,
 229                             const struct gnet_stats_queue __percpu *q)
 230 {
 231         int i;
 232
 233         for_each_possible_cpu(i) {
 234                 const struct gnet_stats_queue *qcpu = per_cpu_ptr(q, i);
 235
 236                 qstats->qlen = 0;
 237                 qstats->backlog += qcpu->backlog;
 238                 qstats->drops += qcpu->drops;
 239                 qstats->requeues += qcpu->requeues;
 240                 qstats->overlimits += qcpu->overlimits;
 241         }
 242 }
 243
 244 static void __gnet_stats_copy_queue(struct gnet_stats_queue *qstats,
 245                                     const struct gnet_stats_queue __percpu *cpu,
 246                                     const struct gnet_stats_queue *q,
 247                                     __u32 qlen)
 248 {
 249         if (cpu) {
 250                 __gnet_stats_copy_queue_cpu(qstats, cpu);
 251         } else {
 252                 qstats->qlen = q->qlen;
 253                 qstats->backlog = q->backlog;
 254                 qstats->drops = q->drops;
 255                 qstats->requeues = q->requeues;
 256                 qstats->overlimits = q->overlimits;
 257         }
 258
 259         qstats->qlen = qlen;
 260 }
 261
 262 /**
 263  * gnet_stats_copy_queue - copy queue statistics into statistics TLV
 264  * @d: dumping handle
 265  * @cpu_q: per cpu queue statistics
 266  * @q: queue statistics
 267  * @qlen: queue length statistics
 268  *
 269  * Appends the queue statistics to the top level TLV created by
 270  * gnet_stats_start_copy(). Using per cpu queue statistics if
 271  * they are available.
 272  *
 273  * Returns 0 on success or -1 with the statistic lock released
 274  * if the room in the socket buffer was not sufficient.
 275  */
 276 int
 277 gnet_stats_copy_queue(struct gnet_dump *d,
 278                       struct gnet_stats_queue __percpu *cpu_q,
 279                       struct gnet_stats_queue *q, __u32 qlen)
 280 {
 281         struct gnet_stats_queue qstats = {0};
 282
 283         __gnet_stats_copy_queue(&qstats, cpu_q, q, qlen);
 284
 285         if (d->compat_tc_stats) {
 286                 d->tc_stats.drops = qstats.drops;
 287                 d->tc_stats.qlen = qstats.qlen;
 288                 d->tc_stats.backlog = qstats.backlog;
 289                 d->tc_stats.overlimits = qstats.overlimits;
 290         }
 291
 292         if (d->tail)
 293                 return gnet_stats_copy(d, TCA_STATS_QUEUE,
 294                                        &qstats, sizeof(qstats),
 295                                        TCA_STATS_PAD);
 296
 297         return 0;
 298 }
 299 EXPORT_SYMBOL(gnet_stats_copy_queue);
 300
 301 /**
 302  * gnet_stats_copy_app - copy application specific statistics into statistics TLV
 303  * @d: dumping handle
 304  * @st: application specific statistics data
 305  * @len: length of data
 306  *
 307  * Appends the application specific statistics to the top level TLV created by
 308  * gnet_stats_start_copy() and remembers the data for XSTATS if the dumping
 309  * handle is in backward compatibility mode.
 310  *
 311  * Returns 0 on success or -1 with the statistic lock released
 312  * if the room in the socket buffer was not sufficient.
 313  */
 314 int
 315 gnet_stats_copy_app(struct gnet_dump *d, void *st, int len)
 316 {
 317         if (d->compat_xstats) {
 318                 d->xstats = kmemdup(st, len, GFP_ATOMIC);
 319                 if (!d->xstats)
 320                         goto err_out;
 321                 d->xstats_len = len;
 322         }
 323
 324         if (d->tail)
 325                 return gnet_stats_copy(d, TCA_STATS_APP, st, len,
 326                                        TCA_STATS_PAD);
 327
 328         return 0;
 329
 330 err_out:
 331         d->xstats_len = 0;
 332         spin_unlock_bh(d->lock);
 333         return -1;
 334 }
 335 EXPORT_SYMBOL(gnet_stats_copy_app);
 336
 337 /**
 338  * gnet_stats_finish_copy - finish dumping procedure
 339  * @d: dumping handle
 340  *
 341  * Corrects the length of the top level TLV to include all TLVs added
 342  * by gnet_stats_copy_XXX() calls. Adds the backward compatibility TLVs
 343  * if gnet_stats_start_copy_compat() was used and releases the statistics
 344  * lock.
 345  *
 346  * Returns 0 on success or -1 with the statistic lock released
 347  * if the room in the socket buffer was not sufficient.
 348  */
 349 int
 350 gnet_stats_finish_copy(struct gnet_dump *d)
 351 {
 352         if (d->tail)
 353                 d->tail->nla_len = skb_tail_pointer(d->skb) - (u8 *)d->tail;
 354
 355         if (d->compat_tc_stats)
 356                 if (gnet_stats_copy(d, d->compat_tc_stats, &d->tc_stats,
 357                                     sizeof(d->tc_stats), d->padattr) < 0)
 358                         return -1;
 359
 360         if (d->compat_xstats && d->xstats) {
 361                 if (gnet_stats_copy(d, d->compat_xstats, d->xstats,
 362                                     d->xstats_len, d->padattr) < 0)
 363                         return -1;
 364         }
 365
 366         kfree(d->xstats);
 367         d->xstats = NULL;
 368         d->xstats_len = 0;
 369         spin_unlock_bh(d->lock);
 370         return 0;
 371 }
 372 EXPORT_SYMBOL(gnet_stats_finish_copy);