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         if (d->lock)
  36                 spin_unlock_bh(d->lock);
  37         kfree(d->xstats);
  38         d->xstats = NULL;
  39         d->xstats_len = 0;
  40         return -1;
  41 }
  42
  43 /**
  44  * gnet_stats_start_copy_compat - start dumping procedure in compatibility mode
  45  * @skb: socket buffer to put statistics TLVs into
  46  * @type: TLV type for top level statistic TLV
  47  * @tc_stats_type: TLV type for backward compatibility struct tc_stats TLV
  48  * @xstats_type: TLV type for backward compatibility xstats TLV
  49  * @lock: statistics lock
  50  * @d: dumping handle
  51  * @padattr: padding attribute
  52  *
  53  * Initializes the dumping handle, grabs the statistic lock and appends
  54  * an empty TLV header to the socket buffer for use a container for all
  55  * other statistic TLVS.
  56  *
  57  * The dumping handle is marked to be in backward compatibility mode telling
  58  * all gnet_stats_copy_XXX() functions to fill a local copy of struct tc_stats.
  59  *
  60  * Returns 0 on success or -1 if the room in the socket buffer was not sufficient.
  61  */
  62 int
  63 gnet_stats_start_copy_compat(struct sk_buff *skb, int type, int tc_stats_type,
  64                              int xstats_type, spinlock_t *lock,
  65                              struct gnet_dump *d, int padattr)
  66         __acquires(lock)
  67 {
  68         memset(d, 0, sizeof(*d));
  69
  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         if (lock) {
  77                 d->lock = lock;
  78                 spin_lock_bh(lock);
  79         }
  80         if (d->tail)
  81                 return gnet_stats_copy(d, type, NULL, 0, padattr);
  82
  83         return 0;
  84 }
  85 EXPORT_SYMBOL(gnet_stats_start_copy_compat);
  86
  87 /**
  88  * gnet_stats_start_copy - start dumping procedure in compatibility mode
  89  * @skb: socket buffer to put statistics TLVs into
  90  * @type: TLV type for top level statistic TLV
  91  * @lock: statistics lock
  92  * @d: dumping handle
  93  * @padattr: padding attribute
  94  *
  95  * Initializes the dumping handle, grabs the statistic lock and appends
  96  * an empty TLV header to the socket buffer for use a container for all
  97  * other statistic TLVS.
  98  *
  99  * Returns 0 on success or -1 if the room in the socket buffer was not sufficient.
 100  */
 101 int
 102 gnet_stats_start_copy(struct sk_buff *skb, int type, spinlock_t *lock,
 103                       struct gnet_dump *d, int padattr)
 104 {
 105         return gnet_stats_start_copy_compat(skb, type, 0, 0, lock, d, padattr);
 106 }
 107 EXPORT_SYMBOL(gnet_stats_start_copy);
 108
 109 static void
 110 __gnet_stats_copy_basic_cpu(struct gnet_stats_basic_packed *bstats,
 111                             struct gnet_stats_basic_cpu __percpu *cpu)
 112 {
 113         int i;
 114
 115         for_each_possible_cpu(i) {
 116                 struct gnet_stats_basic_cpu *bcpu = per_cpu_ptr(cpu, i);
 117                 unsigned int start;
 118                 u64 bytes;
 119                 u32 packets;
 120
 121                 do {
 122                         start = u64_stats_fetch_begin_irq(&bcpu->syncp);
 123                         bytes = bcpu->bstats.bytes;
 124                         packets = bcpu->bstats.packets;
 125                 } while (u64_stats_fetch_retry_irq(&bcpu->syncp, start));
 126
 127                 bstats->bytes += bytes;
 128                 bstats->packets += packets;
 129         }
 130 }
 131
 132 void
 133 __gnet_stats_copy_basic(const seqcount_t *running,
 134                         struct gnet_stats_basic_packed *bstats,
 135                         struct gnet_stats_basic_cpu __percpu *cpu,
 136                         struct gnet_stats_basic_packed *b)
 137 {
 138         unsigned int seq;
 139
 140         if (cpu) {
 141                 __gnet_stats_copy_basic_cpu(bstats, cpu);
 142                 return;
 143         }
 144         do {
 145                 if (running)
 146                         seq = read_seqcount_begin(running);
 147                 bstats->bytes = b->bytes;
 148                 bstats->packets = b->packets;
 149         } while (running && read_seqcount_retry(running, seq));
 150 }
 151 EXPORT_SYMBOL(__gnet_stats_copy_basic);
 152
 153 /**
 154  * gnet_stats_copy_basic - copy basic statistics into statistic TLV
 155  * @running: seqcount_t pointer
 156  * @d: dumping handle
 157  * @cpu: copy statistic per cpu
 158  * @b: basic statistics
 159  *
 160  * Appends the basic statistics to the top level TLV created by
 161  * gnet_stats_start_copy().
 162  *
 163  * Returns 0 on success or -1 with the statistic lock released
 164  * if the room in the socket buffer was not sufficient.
 165  */
 166 int
 167 gnet_stats_copy_basic(const seqcount_t *running,
 168                       struct gnet_dump *d,
 169                       struct gnet_stats_basic_cpu __percpu *cpu,
 170                       struct gnet_stats_basic_packed *b)
 171 {
 172         struct gnet_stats_basic_packed bstats = {0};
 173
 174         __gnet_stats_copy_basic(running, &bstats, cpu, b);
 175
 176         if (d->compat_tc_stats) {
 177                 d->tc_stats.bytes = bstats.bytes;
 178                 d->tc_stats.packets = bstats.packets;
 179         }
 180
 181         if (d->tail) {
 182                 struct gnet_stats_basic sb;
 183
 184                 memset(&sb, 0, sizeof(sb));
 185                 sb.bytes = bstats.bytes;
 186                 sb.packets = bstats.packets;
 187                 return gnet_stats_copy(d, TCA_STATS_BASIC, &sb, sizeof(sb),
 188                                        TCA_STATS_PAD);
 189         }
 190         return 0;
 191 }
 192 EXPORT_SYMBOL(gnet_stats_copy_basic);
 193
 194 /**
 195  * gnet_stats_copy_rate_est - copy rate estimator statistics into statistics TLV
 196  * @d: dumping handle
 197  * @rate_est: rate estimator
 198  *
 199  * Appends the rate estimator statistics to the top level TLV created by
 200  * gnet_stats_start_copy().
 201  *
 202  * Returns 0 on success or -1 with the statistic lock released
 203  * if the room in the socket buffer was not sufficient.
 204  */
 205 int
 206 gnet_stats_copy_rate_est(struct gnet_dump *d,
 207                          struct net_rate_estimator __rcu **rate_est)
 208 {
 209         struct gnet_stats_rate_est64 sample;
 210         struct gnet_stats_rate_est est;
 211         int res;
 212
 213         if (!gen_estimator_read(rate_est, &sample))
 214                 return 0;
 215         est.bps = min_t(u64, UINT_MAX, sample.bps);
 216         /* we have some time before reaching 2^32 packets per second */
 217         est.pps = sample.pps;
 218
 219         if (d->compat_tc_stats) {
 220                 d->tc_stats.bps = est.bps;
 221                 d->tc_stats.pps = est.pps;
 222         }
 223
 224         if (d->tail) {
 225                 res = gnet_stats_copy(d, TCA_STATS_RATE_EST, &est, sizeof(est),
 226                                       TCA_STATS_PAD);
 227                 if (res < 0 || est.bps == sample.bps)
 228                         return res;
 229                 /* emit 64bit stats only if needed */
 230                 return gnet_stats_copy(d, TCA_STATS_RATE_EST64, &sample,
 231                                        sizeof(sample), TCA_STATS_PAD);
 232         }
 233
 234         return 0;
 235 }
 236 EXPORT_SYMBOL(gnet_stats_copy_rate_est);
 237
 238 static void
 239 __gnet_stats_copy_queue_cpu(struct gnet_stats_queue *qstats,
 240                             const struct gnet_stats_queue __percpu *q)
 241 {
 242         int i;
 243
 244         for_each_possible_cpu(i) {
 245                 const struct gnet_stats_queue *qcpu = per_cpu_ptr(q, i);
 246
 247                 qstats->qlen = 0;
 248                 qstats->backlog += qcpu->backlog;
 249                 qstats->drops += qcpu->drops;
 250                 qstats->requeues += qcpu->requeues;
 251                 qstats->overlimits += qcpu->overlimits;
 252         }
 253 }
 254
 255 static void __gnet_stats_copy_queue(struct gnet_stats_queue *qstats,
 256                                     const struct gnet_stats_queue __percpu *cpu,
 257                                     const struct gnet_stats_queue *q,
 258                                     __u32 qlen)
 259 {
 260         if (cpu) {
 261                 __gnet_stats_copy_queue_cpu(qstats, cpu);
 262         } else {
 263                 qstats->qlen = q->qlen;
 264                 qstats->backlog = q->backlog;
 265                 qstats->drops = q->drops;
 266                 qstats->requeues = q->requeues;
 267                 qstats->overlimits = q->overlimits;
 268         }
 269
 270         qstats->qlen = qlen;
 271 }
 272
 273 /**
 274  * gnet_stats_copy_queue - copy queue statistics into statistics TLV
 275  * @d: dumping handle
 276  * @cpu_q: per cpu queue statistics
 277  * @q: queue statistics
 278  * @qlen: queue length statistics
 279  *
 280  * Appends the queue statistics to the top level TLV created by
 281  * gnet_stats_start_copy(). Using per cpu queue statistics if
 282  * they are available.
 283  *
 284  * Returns 0 on success or -1 with the statistic lock released
 285  * if the room in the socket buffer was not sufficient.
 286  */
 287 int
 288 gnet_stats_copy_queue(struct gnet_dump *d,
 289                       struct gnet_stats_queue __percpu *cpu_q,
 290                       struct gnet_stats_queue *q, __u32 qlen)
 291 {
 292         struct gnet_stats_queue qstats = {0};
 293
 294         __gnet_stats_copy_queue(&qstats, cpu_q, q, qlen);
 295
 296         if (d->compat_tc_stats) {
 297                 d->tc_stats.drops = qstats.drops;
 298                 d->tc_stats.qlen = qstats.qlen;
 299                 d->tc_stats.backlog = qstats.backlog;
 300                 d->tc_stats.overlimits = qstats.overlimits;
 301         }
 302
 303         if (d->tail)
 304                 return gnet_stats_copy(d, TCA_STATS_QUEUE,
 305                                        &qstats, sizeof(qstats),
 306                                        TCA_STATS_PAD);
 307
 308         return 0;
 309 }
 310 EXPORT_SYMBOL(gnet_stats_copy_queue);
 311
 312 /**
 313  * gnet_stats_copy_app - copy application specific statistics into statistics TLV
 314  * @d: dumping handle
 315  * @st: application specific statistics data
 316  * @len: length of data
 317  *
 318  * Appends the application specific statistics to the top level TLV created by
 319  * gnet_stats_start_copy() and remembers the data for XSTATS if the dumping
 320  * handle is in backward compatibility mode.
 321  *
 322  * Returns 0 on success or -1 with the statistic lock released
 323  * if the room in the socket buffer was not sufficient.
 324  */
 325 int
 326 gnet_stats_copy_app(struct gnet_dump *d, void *st, int len)
 327 {
 328         if (d->compat_xstats) {
 329                 d->xstats = kmemdup(st, len, GFP_ATOMIC);
 330                 if (!d->xstats)
 331                         goto err_out;
 332                 d->xstats_len = len;
 333         }
 334
 335         if (d->tail)
 336                 return gnet_stats_copy(d, TCA_STATS_APP, st, len,
 337                                        TCA_STATS_PAD);
 338
 339         return 0;
 340
 341 err_out:
 342         if (d->lock)
 343                 spin_unlock_bh(d->lock);
 344         d->xstats_len = 0;
 345         return -1;
 346 }
 347 EXPORT_SYMBOL(gnet_stats_copy_app);
 348
 349 /**
 350  * gnet_stats_finish_copy - finish dumping procedure
 351  * @d: dumping handle
 352  *
 353  * Corrects the length of the top level TLV to include all TLVs added
 354  * by gnet_stats_copy_XXX() calls. Adds the backward compatibility TLVs
 355  * if gnet_stats_start_copy_compat() was used and releases the statistics
 356  * lock.
 357  *
 358  * Returns 0 on success or -1 with the statistic lock released
 359  * if the room in the socket buffer was not sufficient.
 360  */
 361 int
 362 gnet_stats_finish_copy(struct gnet_dump *d)
 363 {
 364         if (d->tail)
 365                 d->tail->nla_len = skb_tail_pointer(d->skb) - (u8 *)d->tail;
 366
 367         if (d->compat_tc_stats)
 368                 if (gnet_stats_copy(d, d->compat_tc_stats, &d->tc_stats,
 369                                     sizeof(d->tc_stats), d->padattr) < 0)
 370                         return -1;
 371
 372         if (d->compat_xstats && d->xstats) {
 373                 if (gnet_stats_copy(d, d->compat_xstats, d->xstats,
 374                                     d->xstats_len, d->padattr) < 0)
 375                         return -1;
 376         }
 377
 378         if (d->lock)
 379                 spin_unlock_bh(d->lock);
 380         kfree(d->xstats);
 381         d->xstats = NULL;
 382         d->xstats_len = 0;
 383         return 0;
 384 }
 385 EXPORT_SYMBOL(gnet_stats_finish_copy);