net/core/gen_stats.c

   1 // SPDX-License-Identifier: GPL-2.0-or-later
   2 /*
   3  * net/core/gen_stats.c
   4  *
   5  * Authors:  Thomas Graf <tgraf@suug.ch>
   6  *           Jamal Hadi Salim
   7  *           Alexey Kuznetsov, <kuznet@ms2.inr.ac.ru>
   8  *
   9  * See Documentation/networking/gen_stats.txt
  10  */
  11
  12 #include <linux/types.h>
  13 #include <linux/kernel.h>
  14 #include <linux/module.h>
  15 #include <linux/interrupt.h>
  16 #include <linux/socket.h>
  17 #include <linux/rtnetlink.h>
  18 #include <linux/gen_stats.h>
  19 #include <net/netlink.h>
  20 #include <net/gen_stats.h>
  21
  22
  23 static inline int
  24 gnet_stats_copy(struct gnet_dump *d, int type, void *buf, int size, int padattr)
  25 {
  26         if (nla_put_64bit(d->skb, type, size, buf, padattr))
  27                 goto nla_put_failure;
  28         return 0;
  29
  30 nla_put_failure:
  31         if (d->lock)
  32                 spin_unlock_bh(d->lock);
  33         kfree(d->xstats);
  34         d->xstats = NULL;
  35         d->xstats_len = 0;
  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  * @padattr: padding attribute
  48  *
  49  * Initializes the dumping handle, grabs the statistic lock and appends
  50  * an empty TLV header to the socket buffer for use a container for all
  51  * other statistic TLVS.
  52  *
  53  * The dumping handle is marked to be in backward compatibility mode telling
  54  * all gnet_stats_copy_XXX() functions to fill a local copy of struct tc_stats.
  55  *
  56  * Returns 0 on success or -1 if the room in the socket buffer was not sufficient.
  57  */
  58 int
  59 gnet_stats_start_copy_compat(struct sk_buff *skb, int type, int tc_stats_type,
  60                              int xstats_type, spinlock_t *lock,
  61                              struct gnet_dump *d, int padattr)
  62         __acquires(lock)
  63 {
  64         memset(d, 0, sizeof(*d));
  65
  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         d->padattr = padattr;
  72         if (lock) {
  73                 d->lock = lock;
  74                 spin_lock_bh(lock);
  75         }
  76         if (d->tail) {
  77                 int ret = gnet_stats_copy(d, type, NULL, 0, padattr);
  78
  79                 /* The initial attribute added in gnet_stats_copy() may be
  80                  * preceded by a padding attribute, in which case d->tail will
  81                  * end up pointing at the padding instead of the real attribute.
  82                  * Fix this so gnet_stats_finish_copy() adjusts the length of
  83                  * the right attribute.
  84                  */
  85                 if (ret == 0 && d->tail->nla_type == padattr)
  86                         d->tail = (struct nlattr *)((char *)d->tail +
  87                                                     NLA_ALIGN(d->tail->nla_len));
  88                 return ret;
  89         }
  90
  91         return 0;
  92 }
  93 EXPORT_SYMBOL(gnet_stats_start_copy_compat);
  94
  95 /**
  96  * gnet_stats_start_copy - start dumping procedure in compatibility mode
  97  * @skb: socket buffer to put statistics TLVs into
  98  * @type: TLV type for top level statistic TLV
  99  * @lock: statistics lock
 100  * @d: dumping handle
 101  * @padattr: padding attribute
 102  *
 103  * Initializes the dumping handle, grabs the statistic lock and appends
 104  * an empty TLV header to the socket buffer for use a container for all
 105  * other statistic TLVS.
 106  *
 107  * Returns 0 on success or -1 if the room in the socket buffer was not sufficient.
 108  */
 109 int
 110 gnet_stats_start_copy(struct sk_buff *skb, int type, spinlock_t *lock,
 111                       struct gnet_dump *d, int padattr)
 112 {
 113         return gnet_stats_start_copy_compat(skb, type, 0, 0, lock, d, padattr);
 114 }
 115 EXPORT_SYMBOL(gnet_stats_start_copy);
 116
 117 static void
 118 __gnet_stats_copy_basic_cpu(struct gnet_stats_basic_packed *bstats,
 119                             struct gnet_stats_basic_cpu __percpu *cpu)
 120 {
 121         int i;
 122
 123         for_each_possible_cpu(i) {
 124                 struct gnet_stats_basic_cpu *bcpu = per_cpu_ptr(cpu, i);
 125                 unsigned int start;
 126                 u64 bytes;
 127                 u32 packets;
 128
 129                 do {
 130                         start = u64_stats_fetch_begin_irq(&bcpu->syncp);
 131                         bytes = bcpu->bstats.bytes;
 132                         packets = bcpu->bstats.packets;
 133                 } while (u64_stats_fetch_retry_irq(&bcpu->syncp, start));
 134
 135                 bstats->bytes += bytes;
 136                 bstats->packets += packets;
 137         }
 138 }
 139
 140 void
 141 __gnet_stats_copy_basic(const seqcount_t *running,
 142                         struct gnet_stats_basic_packed *bstats,
 143                         struct gnet_stats_basic_cpu __percpu *cpu,
 144                         struct gnet_stats_basic_packed *b)
 145 {
 146         unsigned int seq;
 147
 148         if (cpu) {
 149                 __gnet_stats_copy_basic_cpu(bstats, cpu);
 150                 return;
 151         }
 152         do {
 153                 if (running)
 154                         seq = read_seqcount_begin(running);
 155                 bstats->bytes = b->bytes;
 156                 bstats->packets = b->packets;
 157         } while (running && read_seqcount_retry(running, seq));
 158 }
 159 EXPORT_SYMBOL(__gnet_stats_copy_basic);
 160
 161 static int
 162 ___gnet_stats_copy_basic(const seqcount_t *running,
 163                          struct gnet_dump *d,
 164                          struct gnet_stats_basic_cpu __percpu *cpu,
 165                          struct gnet_stats_basic_packed *b,
 166                          int type)
 167 {
 168         struct gnet_stats_basic_packed bstats = {0};
 169
 170         __gnet_stats_copy_basic(running, &bstats, cpu, b);
 171
 172         if (d->compat_tc_stats && type == TCA_STATS_BASIC) {
 173                 d->tc_stats.bytes = bstats.bytes;
 174                 d->tc_stats.packets = bstats.packets;
 175         }
 176
 177         if (d->tail) {
 178                 struct gnet_stats_basic sb;
 179
 180                 memset(&sb, 0, sizeof(sb));
 181                 sb.bytes = bstats.bytes;
 182                 sb.packets = bstats.packets;
 183                 return gnet_stats_copy(d, type, &sb, sizeof(sb),
 184                                        TCA_STATS_PAD);
 185         }
 186         return 0;
 187 }
 188
 189 /**
 190  * gnet_stats_copy_basic - copy basic statistics into statistic TLV
 191  * @running: seqcount_t pointer
 192  * @d: dumping handle
 193  * @cpu: copy statistic per cpu
 194  * @b: basic statistics
 195  *
 196  * Appends the basic statistics to the top level TLV created by
 197  * gnet_stats_start_copy().
 198  *
 199  * Returns 0 on success or -1 with the statistic lock released
 200  * if the room in the socket buffer was not sufficient.
 201  */
 202 int
 203 gnet_stats_copy_basic(const seqcount_t *running,
 204                       struct gnet_dump *d,
 205                       struct gnet_stats_basic_cpu __percpu *cpu,
 206                       struct gnet_stats_basic_packed *b)
 207 {
 208         return ___gnet_stats_copy_basic(running, d, cpu, b,
 209                                         TCA_STATS_BASIC);
 210 }
 211 EXPORT_SYMBOL(gnet_stats_copy_basic);
 212
 213 /**
 214  * gnet_stats_copy_basic_hw - copy basic hw statistics into statistic TLV
 215  * @running: seqcount_t pointer
 216  * @d: dumping handle
 217  * @cpu: copy statistic per cpu
 218  * @b: basic statistics
 219  *
 220  * Appends the basic statistics to the top level TLV created by
 221  * gnet_stats_start_copy().
 222  *
 223  * Returns 0 on success or -1 with the statistic lock released
 224  * if the room in the socket buffer was not sufficient.
 225  */
 226 int
 227 gnet_stats_copy_basic_hw(const seqcount_t *running,
 228                          struct gnet_dump *d,
 229                          struct gnet_stats_basic_cpu __percpu *cpu,
 230                          struct gnet_stats_basic_packed *b)
 231 {
 232         return ___gnet_stats_copy_basic(running, d, cpu, b,
 233                                         TCA_STATS_BASIC_HW);
 234 }
 235 EXPORT_SYMBOL(gnet_stats_copy_basic_hw);
 236
 237 /**
 238  * gnet_stats_copy_rate_est - copy rate estimator statistics into statistics TLV
 239  * @d: dumping handle
 240  * @rate_est: rate estimator
 241  *
 242  * Appends the rate estimator statistics to the top level TLV created by
 243  * gnet_stats_start_copy().
 244  *
 245  * Returns 0 on success or -1 with the statistic lock released
 246  * if the room in the socket buffer was not sufficient.
 247  */
 248 int
 249 gnet_stats_copy_rate_est(struct gnet_dump *d,
 250                          struct net_rate_estimator __rcu **rate_est)
 251 {
 252         struct gnet_stats_rate_est64 sample;
 253         struct gnet_stats_rate_est est;
 254         int res;
 255
 256         if (!gen_estimator_read(rate_est, &sample))
 257                 return 0;
 258         est.bps = min_t(u64, UINT_MAX, sample.bps);
 259         /* we have some time before reaching 2^32 packets per second */
 260         est.pps = sample.pps;
 261
 262         if (d->compat_tc_stats) {
 263                 d->tc_stats.bps = est.bps;
 264                 d->tc_stats.pps = est.pps;
 265         }
 266
 267         if (d->tail) {
 268                 res = gnet_stats_copy(d, TCA_STATS_RATE_EST, &est, sizeof(est),
 269                                       TCA_STATS_PAD);
 270                 if (res < 0 || est.bps == sample.bps)
 271                         return res;
 272                 /* emit 64bit stats only if needed */
 273                 return gnet_stats_copy(d, TCA_STATS_RATE_EST64, &sample,
 274                                        sizeof(sample), TCA_STATS_PAD);
 275         }
 276
 277         return 0;
 278 }
 279 EXPORT_SYMBOL(gnet_stats_copy_rate_est);
 280
 281 static void
 282 __gnet_stats_copy_queue_cpu(struct gnet_stats_queue *qstats,
 283                             const struct gnet_stats_queue __percpu *q)
 284 {
 285         int i;
 286
 287         for_each_possible_cpu(i) {
 288                 const struct gnet_stats_queue *qcpu = per_cpu_ptr(q, i);
 289
 290                 qstats->qlen = 0;
 291                 qstats->backlog += qcpu->backlog;
 292                 qstats->drops += qcpu->drops;
 293                 qstats->requeues += qcpu->requeues;
 294                 qstats->overlimits += qcpu->overlimits;
 295         }
 296 }
 297
 298 void __gnet_stats_copy_queue(struct gnet_stats_queue *qstats,
 299                              const struct gnet_stats_queue __percpu *cpu,
 300                              const struct gnet_stats_queue *q,
 301                              __u32 qlen)
 302 {
 303         if (cpu) {
 304                 __gnet_stats_copy_queue_cpu(qstats, cpu);
 305         } else {
 306                 qstats->qlen = q->qlen;
 307                 qstats->backlog = q->backlog;
 308                 qstats->drops = q->drops;
 309                 qstats->requeues = q->requeues;
 310                 qstats->overlimits = q->overlimits;
 311         }
 312
 313         qstats->qlen = qlen;
 314 }
 315 EXPORT_SYMBOL(__gnet_stats_copy_queue);
 316
 317 /**
 318  * gnet_stats_copy_queue - copy queue statistics into statistics TLV
 319  * @d: dumping handle
 320  * @cpu_q: per cpu queue statistics
 321  * @q: queue statistics
 322  * @qlen: queue length statistics
 323  *
 324  * Appends the queue statistics to the top level TLV created by
 325  * gnet_stats_start_copy(). Using per cpu queue statistics if
 326  * they are available.
 327  *
 328  * Returns 0 on success or -1 with the statistic lock released
 329  * if the room in the socket buffer was not sufficient.
 330  */
 331 int
 332 gnet_stats_copy_queue(struct gnet_dump *d,
 333                       struct gnet_stats_queue __percpu *cpu_q,
 334                       struct gnet_stats_queue *q, __u32 qlen)
 335 {
 336         struct gnet_stats_queue qstats = {0};
 337
 338         __gnet_stats_copy_queue(&qstats, cpu_q, q, qlen);
 339
 340         if (d->compat_tc_stats) {
 341                 d->tc_stats.drops = qstats.drops;
 342                 d->tc_stats.qlen = qstats.qlen;
 343                 d->tc_stats.backlog = qstats.backlog;
 344                 d->tc_stats.overlimits = qstats.overlimits;
 345         }
 346
 347         if (d->tail)
 348                 return gnet_stats_copy(d, TCA_STATS_QUEUE,
 349                                        &qstats, sizeof(qstats),
 350                                        TCA_STATS_PAD);
 351
 352         return 0;
 353 }
 354 EXPORT_SYMBOL(gnet_stats_copy_queue);
 355
 356 /**
 357  * gnet_stats_copy_app - copy application specific statistics into statistics TLV
 358  * @d: dumping handle
 359  * @st: application specific statistics data
 360  * @len: length of data
 361  *
 362  * Appends the application specific statistics to the top level TLV created by
 363  * gnet_stats_start_copy() and remembers the data for XSTATS if the dumping
 364  * handle is in backward compatibility mode.
 365  *
 366  * Returns 0 on success or -1 with the statistic lock released
 367  * if the room in the socket buffer was not sufficient.
 368  */
 369 int
 370 gnet_stats_copy_app(struct gnet_dump *d, void *st, int len)
 371 {
 372         if (d->compat_xstats) {
 373                 d->xstats = kmemdup(st, len, GFP_ATOMIC);
 374                 if (!d->xstats)
 375                         goto err_out;
 376                 d->xstats_len = len;
 377         }
 378
 379         if (d->tail)
 380                 return gnet_stats_copy(d, TCA_STATS_APP, st, len,
 381                                        TCA_STATS_PAD);
 382
 383         return 0;
 384
 385 err_out:
 386         if (d->lock)
 387                 spin_unlock_bh(d->lock);
 388         d->xstats_len = 0;
 389         return -1;
 390 }
 391 EXPORT_SYMBOL(gnet_stats_copy_app);
 392
 393 /**
 394  * gnet_stats_finish_copy - finish dumping procedure
 395  * @d: dumping handle
 396  *
 397  * Corrects the length of the top level TLV to include all TLVs added
 398  * by gnet_stats_copy_XXX() calls. Adds the backward compatibility TLVs
 399  * if gnet_stats_start_copy_compat() was used and releases the statistics
 400  * lock.
 401  *
 402  * Returns 0 on success or -1 with the statistic lock released
 403  * if the room in the socket buffer was not sufficient.
 404  */
 405 int
 406 gnet_stats_finish_copy(struct gnet_dump *d)
 407 {
 408         if (d->tail)
 409                 d->tail->nla_len = skb_tail_pointer(d->skb) - (u8 *)d->tail;
 410
 411         if (d->compat_tc_stats)
 412                 if (gnet_stats_copy(d, d->compat_tc_stats, &d->tc_stats,
 413                                     sizeof(d->tc_stats), d->padattr) < 0)
 414                         return -1;
 415
 416         if (d->compat_xstats && d->xstats) {
 417                 if (gnet_stats_copy(d, d->compat_xstats, d->xstats,
 418                                     d->xstats_len, d->padattr) < 0)
 419                         return -1;
 420         }
 421
 422         if (d->lock)
 423                 spin_unlock_bh(d->lock);
 424         kfree(d->xstats);
 425         d->xstats = NULL;
 426         d->xstats_len = 0;
 427         return 0;
 428 }
 429 EXPORT_SYMBOL(gnet_stats_finish_copy);