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(ssnmap);
  55 SCTP_DBG_OBJCNT(datamsg);
  56 SCTP_DBG_OBJCNT(keys);
  57
  58 /* An array to make it easy to pretty print the debug information
  59  * to the proc fs.
  60  */
  61 static sctp_dbg_objcnt_entry_t sctp_dbg_objcnt[] = {
  62         SCTP_DBG_OBJCNT_ENTRY(sock),
  63         SCTP_DBG_OBJCNT_ENTRY(ep),
  64         SCTP_DBG_OBJCNT_ENTRY(assoc),
  65         SCTP_DBG_OBJCNT_ENTRY(transport),
  66         SCTP_DBG_OBJCNT_ENTRY(chunk),
  67         SCTP_DBG_OBJCNT_ENTRY(bind_addr),
  68         SCTP_DBG_OBJCNT_ENTRY(bind_bucket),
  69         SCTP_DBG_OBJCNT_ENTRY(addr),
  70         SCTP_DBG_OBJCNT_ENTRY(ssnmap),
  71         SCTP_DBG_OBJCNT_ENTRY(datamsg),
  72         SCTP_DBG_OBJCNT_ENTRY(keys),
  73 };
  74
  75 /* Callback from procfs to read out objcount information.
  76  * Walk through the entries in the sctp_dbg_objcnt array, dumping
  77  * the raw object counts for each monitored type.
  78  */
  79 static int sctp_objcnt_seq_show(struct seq_file *seq, void *v)
  80 {
  81         int i;
  82
  83         i = (int)*(loff_t *)v;
  84         seq_setwidth(seq, 127);
  85         seq_printf(seq, "%s: %d", sctp_dbg_objcnt[i].label,
  86                                 atomic_read(sctp_dbg_objcnt[i].counter));
  87         seq_pad(seq, '\n');
  88         return 0;
  89 }
  90
  91 static void *sctp_objcnt_seq_start(struct seq_file *seq, loff_t *pos)
  92 {
  93         return (*pos >= ARRAY_SIZE(sctp_dbg_objcnt)) ? NULL : (void *)pos;
  94 }
  95
  96 static void sctp_objcnt_seq_stop(struct seq_file *seq, void *v)
  97 {
  98 }
  99
 100 static void *sctp_objcnt_seq_next(struct seq_file *seq, void *v, loff_t *pos)
 101 {
 102         ++*pos;
 103         return (*pos >= ARRAY_SIZE(sctp_dbg_objcnt)) ? NULL : (void *)pos;
 104 }
 105
 106 static const struct seq_operations sctp_objcnt_seq_ops = {
 107         .start = sctp_objcnt_seq_start,
 108         .next  = sctp_objcnt_seq_next,
 109         .stop  = sctp_objcnt_seq_stop,
 110         .show  = sctp_objcnt_seq_show,
 111 };
 112
 113 static int sctp_objcnt_seq_open(struct inode *inode, struct file *file)
 114 {
 115         return seq_open(file, &sctp_objcnt_seq_ops);
 116 }
 117
 118 static const struct file_operations sctp_objcnt_ops = {
 119         .open    = sctp_objcnt_seq_open,
 120         .read    = seq_read,
 121         .llseek  = seq_lseek,
 122         .release = seq_release,
 123 };
 124
 125 /* Initialize the objcount in the proc filesystem.  */
 126 void sctp_dbg_objcnt_init(struct net *net)
 127 {
 128         struct proc_dir_entry *ent;
 129
 130         ent = proc_create("sctp_dbg_objcnt", 0,
 131                           net->sctp.proc_net_sctp, &sctp_objcnt_ops);
 132         if (!ent)
 133                 pr_warn("sctp_dbg_objcnt: Unable to create /proc entry.\n");
 134 }
 135
 136 /* Cleanup the objcount entry in the proc filesystem.  */
 137 void sctp_dbg_objcnt_exit(struct net *net)
 138 {
 139         remove_proc_entry("sctp_dbg_objcnt", net->sctp.proc_net_sctp);
 140 }
 141
 142