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  * @cpu: copy statistic per cpu
 144  * @b: basic statistics
 145  *
 146  * Appends the basic statistics to the top level TLV created by
 147  * gnet_stats_start_copy().
 148  *
 149  * Returns 0 on success or -1 with the statistic lock released
 150  * if the room in the socket buffer was not sufficient.
 151  */
 152 int
 153 gnet_stats_copy_basic(struct gnet_dump *d,
 154                       struct gnet_stats_basic_cpu __percpu *cpu,
 155                       struct gnet_stats_basic_packed *b)
 156 {
 157         struct gnet_stats_basic_packed bstats = {0};
 158
 159         __gnet_stats_copy_basic(&bstats, cpu, b);
 160
 161         if (d->compat_tc_stats) {
 162                 d->tc_stats.bytes = bstats.bytes;
 163                 d->tc_stats.packets = bstats.packets;
 164         }
 165
 166         if (d->tail) {
 167                 struct gnet_stats_basic sb;
 168
 169                 memset(&sb, 0, sizeof(sb));
 170                 sb.bytes = bstats.bytes;
 171                 sb.packets = bstats.packets;
 172                 return gnet_stats_copy(d, TCA_STATS_BASIC, &sb, sizeof(sb));
 173         }
 174         return 0;
 175 }
 176 EXPORT_SYMBOL(gnet_stats_copy_basic);
 177
 178 /**
 179  * gnet_stats_copy_rate_est - copy rate estimator statistics into statistics TLV
 180  * @d: dumping handle
 181  * @b: basic statistics
 182  * @r: rate estimator statistics
 183  *
 184  * Appends the rate estimator statistics to the top level TLV created by
 185  * gnet_stats_start_copy().
 186  *
 187  * Returns 0 on success or -1 with the statistic lock released
 188  * if the room in the socket buffer was not sufficient.
 189  */
 190 int
 191 gnet_stats_copy_rate_est(struct gnet_dump *d,
 192                          const struct gnet_stats_basic_packed *b,
 193                          struct gnet_stats_rate_est64 *r)
 194 {
 195         struct gnet_stats_rate_est est;
 196         int res;
 197
 198         if (b && !gen_estimator_active(b, r))
 199                 return 0;
 200
 201         est.bps = min_t(u64, UINT_MAX, r->bps);
 202         /* we have some time before reaching 2^32 packets per second */
 203         est.pps = r->pps;
 204
 205         if (d->compat_tc_stats) {
 206                 d->tc_stats.bps = est.bps;
 207                 d->tc_stats.pps = est.pps;
 208         }
 209
 210         if (d->tail) {
 211                 res = gnet_stats_copy(d, TCA_STATS_RATE_EST, &est, sizeof(est));
 212                 if (res < 0 || est.bps == r->bps)
 213                         return res;
 214                 /* emit 64bit stats only if needed */
 215                 return gnet_stats_copy(d, TCA_STATS_RATE_EST64, r, sizeof(*r));
 216         }
 217
 218         return 0;
 219 }
 220 EXPORT_SYMBOL(gnet_stats_copy_rate_est);
 221
 222 static void
 223 __gnet_stats_copy_queue_cpu(struct gnet_stats_queue *qstats,
 224                             const struct gnet_stats_queue __percpu *q)
 225 {
 226         int i;
 227
 228         for_each_possible_cpu(i) {
 229                 const struct gnet_stats_queue *qcpu = per_cpu_ptr(q, i);
 230
 231                 qstats->qlen = 0;
 232                 qstats->backlog += qcpu->backlog;
 233                 qstats->drops += qcpu->drops;
 234                 qstats->requeues += qcpu->requeues;
 235                 qstats->overlimits += qcpu->overlimits;
 236         }
 237 }
 238
 239 static void __gnet_stats_copy_queue(struct gnet_stats_queue *qstats,
 240                                     const struct gnet_stats_queue __percpu *cpu,
 241                                     const struct gnet_stats_queue *q,
 242                                     __u32 qlen)
 243 {
 244         if (cpu) {
 245                 __gnet_stats_copy_queue_cpu(qstats, cpu);
 246         } else {
 247                 qstats->qlen = q->qlen;
 248                 qstats->backlog = q->backlog;
 249                 qstats->drops = q->drops;
 250                 qstats->requeues = q->requeues;
 251                 qstats->overlimits = q->overlimits;
 252         }
 253
 254         qstats->qlen = qlen;
 255 }
 256
 257 /**
 258  * gnet_stats_copy_queue - copy queue statistics into statistics TLV
 259  * @d: dumping handle
 260  * @cpu_q: per cpu queue statistics
 261  * @q: queue statistics
 262  * @qlen: queue length statistics
 263  *
 264  * Appends the queue statistics to the top level TLV created by
 265  * gnet_stats_start_copy(). Using per cpu queue statistics if
 266  * they are available.
 267  *
 268  * Returns 0 on success or -1 with the statistic lock released
 269  * if the room in the socket buffer was not sufficient.
 270  */
 271 int
 272 gnet_stats_copy_queue(struct gnet_dump *d,
 273                       struct gnet_stats_queue __percpu *cpu_q,
 274                       struct gnet_stats_queue *q, __u32 qlen)
 275 {
 276         struct gnet_stats_queue qstats = {0};
 277
 278         __gnet_stats_copy_queue(&qstats, cpu_q, q, qlen);
 279
 280         if (d->compat_tc_stats) {
 281                 d->tc_stats.drops = qstats.drops;
 282                 d->tc_stats.qlen = qstats.qlen;
 283                 d->tc_stats.backlog = qstats.backlog;
 284                 d->tc_stats.overlimits = qstats.overlimits;
 285         }
 286
 287         if (d->tail)
 288                 return gnet_stats_copy(d, TCA_STATS_QUEUE,
 289                                        &qstats, sizeof(qstats));
 290
 291         return 0;
 292 }
 293 EXPORT_SYMBOL(gnet_stats_copy_queue);
 294
 295 /**
 296  * gnet_stats_copy_app - copy application specific statistics into statistics TLV
 297  * @d: dumping handle
 298  * @st: application specific statistics data
 299  * @len: length of data
 300  *
 301  * Appends the application specific statistics to the top level TLV created by
 302  * gnet_stats_start_copy() and remembers the data for XSTATS if the dumping
 303  * handle is in backward compatibility mode.
 304  *
 305  * Returns 0 on success or -1 with the statistic lock released
 306  * if the room in the socket buffer was not sufficient.
 307  */
 308 int
 309 gnet_stats_copy_app(struct gnet_dump *d, void *st, int len)
 310 {
 311         if (d->compat_xstats) {
 312                 d->xstats = kmemdup(st, len, GFP_ATOMIC);
 313                 if (!d->xstats)
 314                         goto err_out;
 315                 d->xstats_len = len;
 316         }
 317
 318         if (d->tail)
 319                 return gnet_stats_copy(d, TCA_STATS_APP, st, len);
 320
 321         return 0;
 322
 323 err_out:
 324         d->xstats_len = 0;
 325         spin_unlock_bh(d->lock);
 326         return -1;
 327 }
 328 EXPORT_SYMBOL(gnet_stats_copy_app);
 329
 330 /**
 331  * gnet_stats_finish_copy - finish dumping procedure
 332  * @d: dumping handle
 333  *
 334  * Corrects the length of the top level TLV to include all TLVs added
 335  * by gnet_stats_copy_XXX() calls. Adds the backward compatibility TLVs
 336  * if gnet_stats_start_copy_compat() was used and releases the statistics
 337  * lock.
 338  *
 339  * Returns 0 on success or -1 with the statistic lock released
 340  * if the room in the socket buffer was not sufficient.
 341  */
 342 int
 343 gnet_stats_finish_copy(struct gnet_dump *d)
 344 {
 345         if (d->tail)
 346                 d->tail->nla_len = skb_tail_pointer(d->skb) - (u8 *)d->tail;
 347
 348         if (d->compat_tc_stats)
 349                 if (gnet_stats_copy(d, d->compat_tc_stats, &d->tc_stats,
 350                         sizeof(d->tc_stats)) < 0)
 351                         return -1;
 352
 353         if (d->compat_xstats && d->xstats) {
 354                 if (gnet_stats_copy(d, d->compat_xstats, d->xstats,
 355                         d->xstats_len) < 0)
 356                         return -1;
 357         }
 358
 359         kfree(d->xstats);
 360         d->xstats = NULL;
 361         d->xstats_len = 0;
 362         spin_unlock_bh(d->lock);
 363         return 0;
 364 }
 365 EXPORT_SYMBOL(gnet_stats_finish_copy);