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.rst
  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, packets;
 127
 128                 do {
 129                         start = u64_stats_fetch_begin_irq(&bcpu->syncp);
 130                         bytes = bcpu->bstats.bytes;
 131                         packets = bcpu->bstats.packets;
 132                 } while (u64_stats_fetch_retry_irq(&bcpu->syncp, start));
 133
 134                 bstats->bytes += bytes;
 135                 bstats->packets += packets;
 136         }
 137 }
 138
 139 void
 140 __gnet_stats_copy_basic(const seqcount_t *running,
 141                         struct gnet_stats_basic_packed *bstats,
 142                         struct gnet_stats_basic_cpu __percpu *cpu,
 143                         struct gnet_stats_basic_packed *b)
 144 {
 145         unsigned int seq;
 146
 147         if (cpu) {
 148                 __gnet_stats_copy_basic_cpu(bstats, cpu);
 149                 return;
 150         }
 151         do {
 152                 if (running)
 153                         seq = read_seqcount_begin(running);
 154                 bstats->bytes = b->bytes;
 155                 bstats->packets = b->packets;
 156         } while (running && read_seqcount_retry(running, seq));
 157 }
 158 EXPORT_SYMBOL(__gnet_stats_copy_basic);
 159
 160 static int
 161 ___gnet_stats_copy_basic(const seqcount_t *running,
 162                          struct gnet_dump *d,
 163                          struct gnet_stats_basic_cpu __percpu *cpu,
 164                          struct gnet_stats_basic_packed *b,
 165                          int type)
 166 {
 167         struct gnet_stats_basic_packed bstats = {0};
 168
 169         __gnet_stats_copy_basic(running, &bstats, cpu, b);
 170
 171         if (d->compat_tc_stats && type == TCA_STATS_BASIC) {
 172                 d->tc_stats.bytes = bstats.bytes;
 173                 d->tc_stats.packets = bstats.packets;
 174         }
 175
 176         if (d->tail) {
 177                 struct gnet_stats_basic sb;
 178                 int res;
 179
 180                 memset(&sb, 0, sizeof(sb));
 181                 sb.bytes = bstats.bytes;
 182                 sb.packets = bstats.packets;
 183                 res = gnet_stats_copy(d, type, &sb, sizeof(sb), TCA_STATS_PAD);
 184                 if (res < 0 || sb.packets == bstats.packets)
 185                         return res;
 186                 /* emit 64bit stats only if needed */
 187                 return gnet_stats_copy(d, TCA_STATS_PKT64, &bstats.packets,
 188                                        sizeof(bstats.packets), TCA_STATS_PAD);
 189         }
 190         return 0;
 191 }
 192
 193 /**
 194  * gnet_stats_copy_basic - copy basic statistics into statistic TLV
 195  * @running: seqcount_t pointer
 196  * @d: dumping handle
 197  * @cpu: copy statistic per cpu
 198  * @b: basic statistics
 199  *
 200  * Appends the basic statistics to the top level TLV created by
 201  * gnet_stats_start_copy().
 202  *
 203  * Returns 0 on success or -1 with the statistic lock released
 204  * if the room in the socket buffer was not sufficient.
 205  */
 206 int
 207 gnet_stats_copy_basic(const seqcount_t *running,
 208                       struct gnet_dump *d,
 209                       struct gnet_stats_basic_cpu __percpu *cpu,
 210                       struct gnet_stats_basic_packed *b)
 211 {
 212         return ___gnet_stats_copy_basic(running, d, cpu, b,
 213                                         TCA_STATS_BASIC);
 214 }
 215 EXPORT_SYMBOL(gnet_stats_copy_basic);
 216
 217 /**
 218  * gnet_stats_copy_basic_hw - copy basic hw statistics into statistic TLV
 219  * @running: seqcount_t pointer
 220  * @d: dumping handle
 221  * @cpu: copy statistic per cpu
 222  * @b: basic statistics
 223  *
 224  * Appends the basic statistics to the top level TLV created by
 225  * gnet_stats_start_copy().
 226  *
 227  * Returns 0 on success or -1 with the statistic lock released
 228  * if the room in the socket buffer was not sufficient.
 229  */
 230 int
 231 gnet_stats_copy_basic_hw(const seqcount_t *running,
 232                          struct gnet_dump *d,
 233                          struct gnet_stats_basic_cpu __percpu *cpu,
 234                          struct gnet_stats_basic_packed *b)
 235 {
 236         return ___gnet_stats_copy_basic(running, d, cpu, b,
 237                                         TCA_STATS_BASIC_HW);
 238 }
 239 EXPORT_SYMBOL(gnet_stats_copy_basic_hw);
 240
 241 /**
 242  * gnet_stats_copy_rate_est - copy rate estimator statistics into statistics TLV
 243  * @d: dumping handle
 244  * @rate_est: rate estimator
 245  *
 246  * Appends the rate estimator statistics to the top level TLV created by
 247  * gnet_stats_start_copy().
 248  *
 249  * Returns 0 on success or -1 with the statistic lock released
 250  * if the room in the socket buffer was not sufficient.
 251  */
 252 int
 253 gnet_stats_copy_rate_est(struct gnet_dump *d,
 254                          struct net_rate_estimator __rcu **rate_est)
 255 {
 256         struct gnet_stats_rate_est64 sample;
 257         struct gnet_stats_rate_est est;
 258         int res;
 259
 260         if (!gen_estimator_read(rate_est, &sample))
 261                 return 0;
 262         est.bps = min_t(u64, UINT_MAX, sample.bps);
 263         /* we have some time before reaching 2^32 packets per second */
 264         est.pps = sample.pps;
 265
 266         if (d->compat_tc_stats) {
 267                 d->tc_stats.bps = est.bps;
 268                 d->tc_stats.pps = est.pps;
 269         }
 270
 271         if (d->tail) {
 272                 res = gnet_stats_copy(d, TCA_STATS_RATE_EST, &est, sizeof(est),
 273                                       TCA_STATS_PAD);
 274                 if (res < 0 || est.bps == sample.bps)
 275                         return res;
 276                 /* emit 64bit stats only if needed */
 277                 return gnet_stats_copy(d, TCA_STATS_RATE_EST64, &sample,
 278                                        sizeof(sample), TCA_STATS_PAD);
 279         }
 280
 281         return 0;
 282 }
 283 EXPORT_SYMBOL(gnet_stats_copy_rate_est);
 284
 285 static void
 286 __gnet_stats_copy_queue_cpu(struct gnet_stats_queue *qstats,
 287                             const struct gnet_stats_queue __percpu *q)
 288 {
 289         int i;
 290
 291         for_each_possible_cpu(i) {
 292                 const struct gnet_stats_queue *qcpu = per_cpu_ptr(q, i);
 293
 294                 qstats->qlen = 0;
 295                 qstats->backlog += qcpu->backlog;
 296                 qstats->drops += qcpu->drops;
 297                 qstats->requeues += qcpu->requeues;
 298                 qstats->overlimits += qcpu->overlimits;
 299         }
 300 }
 301
 302 void __gnet_stats_copy_queue(struct gnet_stats_queue *qstats,
 303                              const struct gnet_stats_queue __percpu *cpu,
 304                              const struct gnet_stats_queue *q,
 305                              __u32 qlen)
 306 {
 307         if (cpu) {
 308                 __gnet_stats_copy_queue_cpu(qstats, cpu);
 309         } else {
 310                 qstats->qlen = q->qlen;
 311                 qstats->backlog = q->backlog;
 312                 qstats->drops = q->drops;
 313                 qstats->requeues = q->requeues;
 314                 qstats->overlimits = q->overlimits;
 315         }
 316
 317         qstats->qlen = qlen;
 318 }
 319 EXPORT_SYMBOL(__gnet_stats_copy_queue);
 320
 321 /**
 322  * gnet_stats_copy_queue - copy queue statistics into statistics TLV
 323  * @d: dumping handle
 324  * @cpu_q: per cpu queue statistics
 325  * @q: queue statistics
 326  * @qlen: queue length statistics
 327  *
 328  * Appends the queue statistics to the top level TLV created by
 329  * gnet_stats_start_copy(). Using per cpu queue statistics if
 330  * they are available.
 331  *
 332  * Returns 0 on success or -1 with the statistic lock released
 333  * if the room in the socket buffer was not sufficient.
 334  */
 335 int
 336 gnet_stats_copy_queue(struct gnet_dump *d,
 337                       struct gnet_stats_queue __percpu *cpu_q,
 338                       struct gnet_stats_queue *q, __u32 qlen)
 339 {
 340         struct gnet_stats_queue qstats = {0};
 341
 342         __gnet_stats_copy_queue(&qstats, cpu_q, q, qlen);
 343
 344         if (d->compat_tc_stats) {
 345                 d->tc_stats.drops = qstats.drops;
 346                 d->tc_stats.qlen = qstats.qlen;
 347                 d->tc_stats.backlog = qstats.backlog;
 348                 d->tc_stats.overlimits = qstats.overlimits;
 349         }
 350
 351         if (d->tail)
 352                 return gnet_stats_copy(d, TCA_STATS_QUEUE,
 353                                        &qstats, sizeof(qstats),
 354                                        TCA_STATS_PAD);
 355
 356         return 0;
 357 }
 358 EXPORT_SYMBOL(gnet_stats_copy_queue);
 359
 360 /**
 361  * gnet_stats_copy_app - copy application specific statistics into statistics TLV
 362  * @d: dumping handle
 363  * @st: application specific statistics data
 364  * @len: length of data
 365  *
 366  * Appends the application specific statistics to the top level TLV created by
 367  * gnet_stats_start_copy() and remembers the data for XSTATS if the dumping
 368  * handle is in backward compatibility mode.
 369  *
 370  * Returns 0 on success or -1 with the statistic lock released
 371  * if the room in the socket buffer was not sufficient.
 372  */
 373 int
 374 gnet_stats_copy_app(struct gnet_dump *d, void *st, int len)
 375 {
 376         if (d->compat_xstats) {
 377                 d->xstats = kmemdup(st, len, GFP_ATOMIC);
 378                 if (!d->xstats)
 379                         goto err_out;
 380                 d->xstats_len = len;
 381         }
 382
 383         if (d->tail)
 384                 return gnet_stats_copy(d, TCA_STATS_APP, st, len,
 385                                        TCA_STATS_PAD);
 386
 387         return 0;
 388
 389 err_out:
 390         if (d->lock)
 391                 spin_unlock_bh(d->lock);
 392         d->xstats_len = 0;
 393         return -1;
 394 }
 395 EXPORT_SYMBOL(gnet_stats_copy_app);
 396
 397 /**
 398  * gnet_stats_finish_copy - finish dumping procedure
 399  * @d: dumping handle
 400  *
 401  * Corrects the length of the top level TLV to include all TLVs added
 402  * by gnet_stats_copy_XXX() calls. Adds the backward compatibility TLVs
 403  * if gnet_stats_start_copy_compat() was used and releases the statistics
 404  * lock.
 405  *
 406  * Returns 0 on success or -1 with the statistic lock released
 407  * if the room in the socket buffer was not sufficient.
 408  */
 409 int
 410 gnet_stats_finish_copy(struct gnet_dump *d)
 411 {
 412         if (d->tail)
 413                 d->tail->nla_len = skb_tail_pointer(d->skb) - (u8 *)d->tail;
 414
 415         if (d->compat_tc_stats)
 416                 if (gnet_stats_copy(d, d->compat_tc_stats, &d->tc_stats,
 417                                     sizeof(d->tc_stats), d->padattr) < 0)
 418                         return -1;
 419
 420         if (d->compat_xstats && d->xstats) {
 421                 if (gnet_stats_copy(d, d->compat_xstats, d->xstats,
 422                                     d->xstats_len, d->padattr) < 0)
 423                         return -1;
 424         }
 425
 426         if (d->lock)
 427                 spin_unlock_bh(d->lock);
 428         kfree(d->xstats);
 429         d->xstats = NULL;
 430         d->xstats_len = 0;
 431         return 0;
 432 }
 433 EXPORT_SYMBOL(gnet_stats_finish_copy);