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, write to
  24  * the Free Software Foundation, 59 Temple Place - Suite 330,
  25  * Boston, MA 02111-1307, USA.
  26  *
  27  * Please send any bug reports or fixes you make to the
  28  * email address(es):
  29  *    lksctp developers <linux-sctp@vger.kernel.org>
  30  *
  31  * Written or modified by:
  32  *    Jon Grimm             <jgrimm@us.ibm.com>
  33  */
  34
  35 #define pr_fmt(fmt) KBUILD_MODNAME ": " fmt
  36
  37 #include <linux/kernel.h>
  38 #include <net/sctp/sctp.h>
  39
  40 /*
  41  * Global counters to count raw object allocation counts.
  42  * To add new counters, choose a unique suffix for the variable
  43  * name as the helper macros key off this suffix to make
  44  * life easier for the programmer.
  45  */
  46
  47 SCTP_DBG_OBJCNT(sock);
  48 SCTP_DBG_OBJCNT(ep);
  49 SCTP_DBG_OBJCNT(transport);
  50 SCTP_DBG_OBJCNT(assoc);
  51 SCTP_DBG_OBJCNT(bind_addr);
  52 SCTP_DBG_OBJCNT(bind_bucket);
  53 SCTP_DBG_OBJCNT(chunk);
  54 SCTP_DBG_OBJCNT(addr);
  55 SCTP_DBG_OBJCNT(ssnmap);
  56 SCTP_DBG_OBJCNT(datamsg);
  57 SCTP_DBG_OBJCNT(keys);
  58
  59 /* An array to make it easy to pretty print the debug information
  60  * to the proc fs.
  61  */
  62 static sctp_dbg_objcnt_entry_t sctp_dbg_objcnt[] = {
  63         SCTP_DBG_OBJCNT_ENTRY(sock),
  64         SCTP_DBG_OBJCNT_ENTRY(ep),
  65         SCTP_DBG_OBJCNT_ENTRY(assoc),
  66         SCTP_DBG_OBJCNT_ENTRY(transport),
  67         SCTP_DBG_OBJCNT_ENTRY(chunk),
  68         SCTP_DBG_OBJCNT_ENTRY(bind_addr),
  69         SCTP_DBG_OBJCNT_ENTRY(bind_bucket),
  70         SCTP_DBG_OBJCNT_ENTRY(addr),
  71         SCTP_DBG_OBJCNT_ENTRY(ssnmap),
  72         SCTP_DBG_OBJCNT_ENTRY(datamsg),
  73         SCTP_DBG_OBJCNT_ENTRY(keys),
  74 };
  75
  76 /* Callback from procfs to read out objcount information.
  77  * Walk through the entries in the sctp_dbg_objcnt array, dumping
  78  * the raw object counts for each monitored type.
  79  */
  80 static int sctp_objcnt_seq_show(struct seq_file *seq, void *v)
  81 {
  82         int i;
  83
  84         i = (int)*(loff_t *)v;
  85         seq_setwidth(seq, 127);
  86         seq_printf(seq, "%s: %d", sctp_dbg_objcnt[i].label,
  87                                 atomic_read(sctp_dbg_objcnt[i].counter));
  88         seq_pad(seq, '\n');
  89         return 0;
  90 }
  91
  92 static void *sctp_objcnt_seq_start(struct seq_file *seq, loff_t *pos)
  93 {
  94         return (*pos >= ARRAY_SIZE(sctp_dbg_objcnt)) ? NULL : (void *)pos;
  95 }
  96
  97 static void sctp_objcnt_seq_stop(struct seq_file *seq, void *v)
  98 {
  99 }
 100
 101 static void * sctp_objcnt_seq_next(struct seq_file *seq, void *v, loff_t *pos)
 102 {
 103         ++*pos;
 104         return (*pos >= ARRAY_SIZE(sctp_dbg_objcnt)) ? NULL : (void *)pos;
 105 }
 106
 107 static const struct seq_operations sctp_objcnt_seq_ops = {
 108         .start = sctp_objcnt_seq_start,
 109         .next  = sctp_objcnt_seq_next,
 110         .stop  = sctp_objcnt_seq_stop,
 111         .show  = sctp_objcnt_seq_show,
 112 };
 113
 114 static int sctp_objcnt_seq_open(struct inode *inode, struct file *file)
 115 {
 116         return seq_open(file, &sctp_objcnt_seq_ops);
 117 }
 118
 119 static const struct file_operations sctp_objcnt_ops = {
 120         .open    = sctp_objcnt_seq_open,
 121         .read    = seq_read,
 122         .llseek  = seq_lseek,
 123         .release = seq_release,
 124 };
 125
 126 /* Initialize the objcount in the proc filesystem.  */
 127 void sctp_dbg_objcnt_init(struct net *net)
 128 {
 129         struct proc_dir_entry *ent;
 130
 131         ent = proc_create("sctp_dbg_objcnt", 0,
 132                           net->sctp.proc_net_sctp, &sctp_objcnt_ops);
 133         if (!ent)
 134                 pr_warn("sctp_dbg_objcnt: Unable to create /proc entry.\n");
 135 }
 136
 137 /* Cleanup the objcount entry in the proc filesystem.  */
 138 void sctp_dbg_objcnt_exit(struct net *net)
 139 {
 140         remove_proc_entry("sctp_dbg_objcnt", net->sctp.proc_net_sctp);
 141 }
 142
 143