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                 int ret = gnet_stats_copy(d, type, NULL, 0, padattr);
  82
  83                 /* The initial attribute added in gnet_stats_copy() may be
  84                  * preceded by a padding attribute, in which case d->tail will
  85                  * end up pointing at the padding instead of the real attribute.
  86                  * Fix this so gnet_stats_finish_copy() adjusts the length of
  87                  * the right attribute.
  88                  */
  89                 if (ret == 0 && d->tail->nla_type == padattr)
  90                         d->tail = (struct nlattr *)((char *)d->tail +
  91                                                     NLA_ALIGN(d->tail->nla_len));
  92                 return ret;
  93         }
  94
  95         return 0;
  96 }
  97 EXPORT_SYMBOL(gnet_stats_start_copy_compat);
  98
  99 /**
 100  * gnet_stats_start_copy - start dumping procedure in compatibility mode
 101  * @skb: socket buffer to put statistics TLVs into
 102  * @type: TLV type for top level statistic TLV
 103  * @lock: statistics lock
 104  * @d: dumping handle
 105  * @padattr: padding attribute
 106  *
 107  * Initializes the dumping handle, grabs the statistic lock and appends
 108  * an empty TLV header to the socket buffer for use a container for all
 109  * other statistic TLVS.
 110  *
 111  * Returns 0 on success or -1 if the room in the socket buffer was not sufficient.
 112  */
 113 int
 114 gnet_stats_start_copy(struct sk_buff *skb, int type, spinlock_t *lock,
 115                       struct gnet_dump *d, int padattr)
 116 {
 117         return gnet_stats_start_copy_compat(skb, type, 0, 0, lock, d, padattr);
 118 }
 119 EXPORT_SYMBOL(gnet_stats_start_copy);
 120
 121 static void
 122 __gnet_stats_copy_basic_cpu(struct gnet_stats_basic_packed *bstats,
 123                             struct gnet_stats_basic_cpu __percpu *cpu)
 124 {
 125         int i;
 126
 127         for_each_possible_cpu(i) {
 128                 struct gnet_stats_basic_cpu *bcpu = per_cpu_ptr(cpu, i);
 129                 unsigned int start;
 130                 u64 bytes;
 131                 u32 packets;
 132
 133                 do {
 134                         start = u64_stats_fetch_begin_irq(&bcpu->syncp);
 135                         bytes = bcpu->bstats.bytes;
 136                         packets = bcpu->bstats.packets;
 137                 } while (u64_stats_fetch_retry_irq(&bcpu->syncp, start));
 138
 139                 bstats->bytes += bytes;
 140                 bstats->packets += packets;
 141         }
 142 }
 143
 144 void
 145 __gnet_stats_copy_basic(const seqcount_t *running,
 146                         struct gnet_stats_basic_packed *bstats,
 147                         struct gnet_stats_basic_cpu __percpu *cpu,
 148                         struct gnet_stats_basic_packed *b)
 149 {
 150         unsigned int seq;
 151
 152         if (cpu) {
 153                 __gnet_stats_copy_basic_cpu(bstats, cpu);
 154                 return;
 155         }
 156         do {
 157                 if (running)
 158                         seq = read_seqcount_begin(running);
 159                 bstats->bytes = b->bytes;
 160                 bstats->packets = b->packets;
 161         } while (running && read_seqcount_retry(running, seq));
 162 }
 163 EXPORT_SYMBOL(__gnet_stats_copy_basic);
 164
 165 /**
 166  * gnet_stats_copy_basic - copy basic statistics into statistic TLV
 167  * @running: seqcount_t pointer
 168  * @d: dumping handle
 169  * @cpu: copy statistic per cpu
 170  * @b: basic statistics
 171  *
 172  * Appends the basic statistics to the top level TLV created by
 173  * gnet_stats_start_copy().
 174  *
 175  * Returns 0 on success or -1 with the statistic lock released
 176  * if the room in the socket buffer was not sufficient.
 177  */
 178 int
 179 gnet_stats_copy_basic(const seqcount_t *running,
 180                       struct gnet_dump *d,
 181                       struct gnet_stats_basic_cpu __percpu *cpu,
 182                       struct gnet_stats_basic_packed *b)
 183 {
 184         struct gnet_stats_basic_packed bstats = {0};
 185
 186         __gnet_stats_copy_basic(running, &bstats, cpu, b);
 187
 188         if (d->compat_tc_stats) {
 189                 d->tc_stats.bytes = bstats.bytes;
 190                 d->tc_stats.packets = bstats.packets;
 191         }
 192
 193         if (d->tail) {
 194                 struct gnet_stats_basic sb;
 195
 196                 memset(&sb, 0, sizeof(sb));
 197                 sb.bytes = bstats.bytes;
 198                 sb.packets = bstats.packets;
 199                 return gnet_stats_copy(d, TCA_STATS_BASIC, &sb, sizeof(sb),
 200                                        TCA_STATS_PAD);
 201         }
 202         return 0;
 203 }
 204 EXPORT_SYMBOL(gnet_stats_copy_basic);
 205
 206 /**
 207  * gnet_stats_copy_rate_est - copy rate estimator statistics into statistics TLV
 208  * @d: dumping handle
 209  * @rate_est: rate estimator
 210  *
 211  * Appends the rate estimator statistics to the top level TLV created by
 212  * gnet_stats_start_copy().
 213  *
 214  * Returns 0 on success or -1 with the statistic lock released
 215  * if the room in the socket buffer was not sufficient.
 216  */
 217 int
 218 gnet_stats_copy_rate_est(struct gnet_dump *d,
 219                          struct net_rate_estimator __rcu **rate_est)
 220 {
 221         struct gnet_stats_rate_est64 sample;
 222         struct gnet_stats_rate_est est;
 223         int res;
 224
 225         if (!gen_estimator_read(rate_est, &sample))
 226                 return 0;
 227         est.bps = min_t(u64, UINT_MAX, sample.bps);
 228         /* we have some time before reaching 2^32 packets per second */
 229         est.pps = sample.pps;
 230
 231         if (d->compat_tc_stats) {
 232                 d->tc_stats.bps = est.bps;
 233                 d->tc_stats.pps = est.pps;
 234         }
 235
 236         if (d->tail) {
 237                 res = gnet_stats_copy(d, TCA_STATS_RATE_EST, &est, sizeof(est),
 238                                       TCA_STATS_PAD);
 239                 if (res < 0 || est.bps == sample.bps)
 240                         return res;
 241                 /* emit 64bit stats only if needed */
 242                 return gnet_stats_copy(d, TCA_STATS_RATE_EST64, &sample,
 243                                        sizeof(sample), TCA_STATS_PAD);
 244         }
 245
 246         return 0;
 247 }
 248 EXPORT_SYMBOL(gnet_stats_copy_rate_est);
 249
 250 static void
 251 __gnet_stats_copy_queue_cpu(struct gnet_stats_queue *qstats,
 252                             const struct gnet_stats_queue __percpu *q)
 253 {
 254         int i;
 255
 256         for_each_possible_cpu(i) {
 257                 const struct gnet_stats_queue *qcpu = per_cpu_ptr(q, i);
 258
 259                 qstats->backlog += qcpu->backlog;
 260                 qstats->drops += qcpu->drops;
 261                 qstats->requeues += qcpu->requeues;
 262                 qstats->overlimits += qcpu->overlimits;
 263         }
 264 }
 265
 266 void __gnet_stats_copy_queue(struct gnet_stats_queue *qstats,
 267                              const struct gnet_stats_queue __percpu *cpu,
 268                              const struct gnet_stats_queue *q,
 269                              __u32 qlen)
 270 {
 271         if (cpu) {
 272                 __gnet_stats_copy_queue_cpu(qstats, cpu);
 273         } else {
 274                 qstats->backlog = q->backlog;
 275                 qstats->drops = q->drops;
 276                 qstats->requeues = q->requeues;
 277                 qstats->overlimits = q->overlimits;
 278         }
 279
 280         qstats->qlen = qlen;
 281 }
 282 EXPORT_SYMBOL(__gnet_stats_copy_queue);
 283
 284 /**
 285  * gnet_stats_copy_queue - copy queue statistics into statistics TLV
 286  * @d: dumping handle
 287  * @cpu_q: per cpu queue statistics
 288  * @q: queue statistics
 289  * @qlen: queue length statistics
 290  *
 291  * Appends the queue statistics to the top level TLV created by
 292  * gnet_stats_start_copy(). Using per cpu queue statistics if
 293  * they are available.
 294  *
 295  * Returns 0 on success or -1 with the statistic lock released
 296  * if the room in the socket buffer was not sufficient.
 297  */
 298 int
 299 gnet_stats_copy_queue(struct gnet_dump *d,
 300                       struct gnet_stats_queue __percpu *cpu_q,
 301                       struct gnet_stats_queue *q, __u32 qlen)
 302 {
 303         struct gnet_stats_queue qstats = {0};
 304
 305         __gnet_stats_copy_queue(&qstats, cpu_q, q, qlen);
 306
 307         if (d->compat_tc_stats) {
 308                 d->tc_stats.drops = qstats.drops;
 309                 d->tc_stats.qlen = qstats.qlen;
 310                 d->tc_stats.backlog = qstats.backlog;
 311                 d->tc_stats.overlimits = qstats.overlimits;
 312         }
 313
 314         if (d->tail)
 315                 return gnet_stats_copy(d, TCA_STATS_QUEUE,
 316                                        &qstats, sizeof(qstats),
 317                                        TCA_STATS_PAD);
 318
 319         return 0;
 320 }
 321 EXPORT_SYMBOL(gnet_stats_copy_queue);
 322
 323 /**
 324  * gnet_stats_copy_app - copy application specific statistics into statistics TLV
 325  * @d: dumping handle
 326  * @st: application specific statistics data
 327  * @len: length of data
 328  *
 329  * Appends the application specific statistics to the top level TLV created by
 330  * gnet_stats_start_copy() and remembers the data for XSTATS if the dumping
 331  * handle is in backward compatibility mode.
 332  *
 333  * Returns 0 on success or -1 with the statistic lock released
 334  * if the room in the socket buffer was not sufficient.
 335  */
 336 int
 337 gnet_stats_copy_app(struct gnet_dump *d, void *st, int len)
 338 {
 339         if (d->compat_xstats) {
 340                 d->xstats = kmemdup(st, len, GFP_ATOMIC);
 341                 if (!d->xstats)
 342                         goto err_out;
 343                 d->xstats_len = len;
 344         }
 345
 346         if (d->tail)
 347                 return gnet_stats_copy(d, TCA_STATS_APP, st, len,
 348                                        TCA_STATS_PAD);
 349
 350         return 0;
 351
 352 err_out:
 353         if (d->lock)
 354                 spin_unlock_bh(d->lock);
 355         d->xstats_len = 0;
 356         return -1;
 357 }
 358 EXPORT_SYMBOL(gnet_stats_copy_app);
 359
 360 /**
 361  * gnet_stats_finish_copy - finish dumping procedure
 362  * @d: dumping handle
 363  *
 364  * Corrects the length of the top level TLV to include all TLVs added
 365  * by gnet_stats_copy_XXX() calls. Adds the backward compatibility TLVs
 366  * if gnet_stats_start_copy_compat() was used and releases the statistics
 367  * lock.
 368  *
 369  * Returns 0 on success or -1 with the statistic lock released
 370  * if the room in the socket buffer was not sufficient.
 371  */
 372 int
 373 gnet_stats_finish_copy(struct gnet_dump *d)
 374 {
 375         if (d->tail)
 376                 d->tail->nla_len = skb_tail_pointer(d->skb) - (u8 *)d->tail;
 377
 378         if (d->compat_tc_stats)
 379                 if (gnet_stats_copy(d, d->compat_tc_stats, &d->tc_stats,
 380                                     sizeof(d->tc_stats), d->padattr) < 0)
 381                         return -1;
 382
 383         if (d->compat_xstats && d->xstats) {
 384                 if (gnet_stats_copy(d, d->compat_xstats, d->xstats,
 385                                     d->xstats_len, d->padattr) < 0)
 386                         return -1;
 387         }
 388
 389         if (d->lock)
 390                 spin_unlock_bh(d->lock);
 391         kfree(d->xstats);
 392         d->xstats = NULL;
 393         d->xstats_len = 0;
 394         return 0;
 395 }
 396 EXPORT_SYMBOL(gnet_stats_finish_copy);