net/sctp/objcnt.c

   1 /* SCTP kernel implementation
   2  * (C) Copyright IBM Corp. 2001, 2004
   3  *
   4  * This file is part of the SCTP kernel implementation
   5  *
   6  * Support for memory object debugging.  This allows one to monitor the
   7  * object allocations/deallocations for types instrumented for this
   8  * via the proc fs.
   9  *
  10  * This SCTP implementation is free software;
  11  * you can redistribute it and/or modify it under the terms of
  12  * the GNU General Public License as published by
  13  * the Free Software Foundation; either version 2, or (at your option)
  14  * any later version.
  15  *
  16  * This SCTP implementation is distributed in the hope that it
  17  * will be useful, but WITHOUT ANY WARRANTY; without even the implied
  18  *                 ************************
  19  * warranty of MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.
  20  * See the GNU General Public License for more details.
  21  *
  22  * You should have received a copy of the GNU General Public License
  23  * along with GNU CC; see the file COPYING.  If not, see
  24  * <http://www.gnu.org/licenses/>.
  25  *
  26  * Please send any bug reports or fixes you make to the
  27  * email address(es):
  28  *    lksctp developers <linux-sctp@vger.kernel.org>
  29  *
  30  * Written or modified by:
  31  *    Jon Grimm             <jgrimm@us.ibm.com>
  32  */
  33
  34 #define pr_fmt(fmt) KBUILD_MODNAME ": " fmt
  35
  36 #include <linux/kernel.h>
  37 #include <net/sctp/sctp.h>
  38
  39 /*
  40  * Global counters to count raw object allocation counts.
  41  * To add new counters, choose a unique suffix for the variable
  42  * name as the helper macros key off this suffix to make
  43  * life easier for the programmer.
  44  */
  45
  46 SCTP_DBG_OBJCNT(sock);
  47 SCTP_DBG_OBJCNT(ep);
  48 SCTP_DBG_OBJCNT(transport);
  49 SCTP_DBG_OBJCNT(assoc);
  50 SCTP_DBG_OBJCNT(bind_addr);
  51 SCTP_DBG_OBJCNT(bind_bucket);
  52 SCTP_DBG_OBJCNT(chunk);
  53 SCTP_DBG_OBJCNT(addr);
  54 SCTP_DBG_OBJCNT(datamsg);
  55 SCTP_DBG_OBJCNT(keys);
  56
  57 /* An array to make it easy to pretty print the debug information
  58  * to the proc fs.
  59  */
  60 static struct sctp_dbg_objcnt_entry sctp_dbg_objcnt[] = {
  61         SCTP_DBG_OBJCNT_ENTRY(sock),
  62         SCTP_DBG_OBJCNT_ENTRY(ep),
  63         SCTP_DBG_OBJCNT_ENTRY(assoc),
  64         SCTP_DBG_OBJCNT_ENTRY(transport),
  65         SCTP_DBG_OBJCNT_ENTRY(chunk),
  66         SCTP_DBG_OBJCNT_ENTRY(bind_addr),
  67         SCTP_DBG_OBJCNT_ENTRY(bind_bucket),
  68         SCTP_DBG_OBJCNT_ENTRY(addr),
  69         SCTP_DBG_OBJCNT_ENTRY(datamsg),
  70         SCTP_DBG_OBJCNT_ENTRY(keys),
  71 };
  72
  73 /* Callback from procfs to read out objcount information.
  74  * Walk through the entries in the sctp_dbg_objcnt array, dumping
  75  * the raw object counts for each monitored type.
  76  */
  77 static int sctp_objcnt_seq_show(struct seq_file *seq, void *v)
  78 {
  79         int i;
  80
  81         i = (int)*(loff_t *)v;
  82         seq_setwidth(seq, 127);
  83         seq_printf(seq, "%s: %d", sctp_dbg_objcnt[i].label,
  84                                 atomic_read(sctp_dbg_objcnt[i].counter));
  85         seq_pad(seq, '\n');
  86         return 0;
  87 }
  88
  89 static void *sctp_objcnt_seq_start(struct seq_file *seq, loff_t *pos)
  90 {
  91         return (*pos >= ARRAY_SIZE(sctp_dbg_objcnt)) ? NULL : (void *)pos;
  92 }
  93
  94 static void sctp_objcnt_seq_stop(struct seq_file *seq, void *v)
  95 {
  96 }
  97
  98 static void *sctp_objcnt_seq_next(struct seq_file *seq, void *v, loff_t *pos)
  99 {
 100         ++*pos;
 101         return (*pos >= ARRAY_SIZE(sctp_dbg_objcnt)) ? NULL : (void *)pos;
 102 }
 103
 104 static const struct seq_operations sctp_objcnt_seq_ops = {
 105         .start = sctp_objcnt_seq_start,
 106         .next  = sctp_objcnt_seq_next,
 107         .stop  = sctp_objcnt_seq_stop,
 108         .show  = sctp_objcnt_seq_show,
 109 };
 110
 111 static int sctp_objcnt_seq_open(struct inode *inode, struct file *file)
 112 {
 113         return seq_open(file, &sctp_objcnt_seq_ops);
 114 }
 115
 116 static const struct file_operations sctp_objcnt_ops = {
 117         .open    = sctp_objcnt_seq_open,
 118         .read    = seq_read,
 119         .llseek  = seq_lseek,
 120         .release = seq_release,
 121 };
 122
 123 /* Initialize the objcount in the proc filesystem.  */
 124 void sctp_dbg_objcnt_init(struct net *net)
 125 {
 126         struct proc_dir_entry *ent;
 127
 128         ent = proc_create("sctp_dbg_objcnt", 0,
 129                           net->sctp.proc_net_sctp, &sctp_objcnt_ops);
 130         if (!ent)
 131                 pr_warn("sctp_dbg_objcnt: Unable to create /proc entry.\n");
 132 }
 133
 134 /* Cleanup the objcount entry in the proc filesystem.  */
 135 void sctp_dbg_objcnt_exit(struct net *net)
 136 {
 137         remove_proc_entry("sctp_dbg_objcnt", net->sctp.proc_net_sctp);
 138 }
 139
 140