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