net/sunrpc/sysctl.c

   1 // SPDX-License-Identifier: GPL-2.0-only
   2 /*
   3  * linux/net/sunrpc/sysctl.c
   4  *
   5  * Sysctl interface to sunrpc module.
   6  *
   7  * I would prefer to register the sunrpc table below sys/net, but that's
   8  * impossible at the moment.
   9  */
  10
  11 #include <linux/types.h>
  12 #include <linux/linkage.h>
  13 #include <linux/ctype.h>
  14 #include <linux/fs.h>
  15 #include <linux/sysctl.h>
  16 #include <linux/module.h>
  17
  18 #include <linux/uaccess.h>
  19 #include <linux/sunrpc/types.h>
  20 #include <linux/sunrpc/sched.h>
  21 #include <linux/sunrpc/stats.h>
  22 #include <linux/sunrpc/svc_xprt.h>
  23
  24 #include "netns.h"
  25
  26 /*
  27  * Declare the debug flags here
  28  */
  29 unsigned int    rpc_debug;
  30 EXPORT_SYMBOL_GPL(rpc_debug);
  31
  32 unsigned int    nfs_debug;
  33 EXPORT_SYMBOL_GPL(nfs_debug);
  34
  35 unsigned int    nfsd_debug;
  36 EXPORT_SYMBOL_GPL(nfsd_debug);
  37
  38 unsigned int    nlm_debug;
  39 EXPORT_SYMBOL_GPL(nlm_debug);
  40
  41 #if IS_ENABLED(CONFIG_SUNRPC_DEBUG)
  42
  43 static struct ctl_table_header *sunrpc_table_header;
  44 static struct ctl_table sunrpc_table[];
  45
  46 void
  47 rpc_register_sysctl(void)
  48 {
  49         if (!sunrpc_table_header)
  50                 sunrpc_table_header = register_sysctl_table(sunrpc_table);
  51 }
  52
  53 void
  54 rpc_unregister_sysctl(void)
  55 {
  56         if (sunrpc_table_header) {
  57                 unregister_sysctl_table(sunrpc_table_header);
  58                 sunrpc_table_header = NULL;
  59         }
  60 }
  61
  62 static int proc_do_xprt(struct ctl_table *table, int write,
  63                         void *buffer, size_t *lenp, loff_t *ppos)
  64 {
  65         char tmpbuf[256];
  66         size_t len;
  67
  68         if ((*ppos && !write) || !*lenp) {
  69                 *lenp = 0;
  70                 return 0;
  71         }
  72         len = svc_print_xprts(tmpbuf, sizeof(tmpbuf));
  73         return memory_read_from_buffer(buffer, *lenp, ppos, tmpbuf, len);
  74 }
  75
  76 static int
  77 proc_dodebug(struct ctl_table *table, int write, void *buffer, size_t *lenp,
  78              loff_t *ppos)
  79 {
  80         char            tmpbuf[20], *s = NULL;
  81         char *p;
  82         unsigned int    value;
  83         size_t          left, len;
  84
  85         if ((*ppos && !write) || !*lenp) {
  86                 *lenp = 0;
  87                 return 0;
  88         }
  89
  90         left = *lenp;
  91
  92         if (write) {
  93                 p = buffer;
  94                 while (left && isspace(*p)) {
  95                         left--;
  96                         p++;
  97                 }
  98                 if (!left)
  99                         goto done;
 100
 101                 if (left > sizeof(tmpbuf) - 1)
 102                         return -EINVAL;
 103                 memcpy(tmpbuf, p, left);
 104                 tmpbuf[left] = '\0';
 105
 106                 value = simple_strtol(tmpbuf, &s, 0);
 107                 if (s) {
 108                         left -= (s - tmpbuf);
 109                         if (left && !isspace(*s))
 110                                 return -EINVAL;
 111                         while (left && isspace(*s)) {
 112                                 left--;
 113                                 s++;
 114                         }
 115                 } else
 116                         left = 0;
 117                 *(unsigned int *) table->data = value;
 118                 /* Display the RPC tasks on writing to rpc_debug */
 119                 if (strcmp(table->procname, "rpc_debug") == 0)
 120                         rpc_show_tasks(&init_net);
 121         } else {
 122                 len = sprintf(tmpbuf, "0x%04x", *(unsigned int *) table->data);
 123                 if (len > left)
 124                         len = left;
 125                 memcpy(buffer, tmpbuf, len);
 126                 if ((left -= len) > 0) {
 127                         *((char *)buffer + len) = '\n';
 128                         left--;
 129                 }
 130         }
 131
 132 done:
 133         *lenp -= left;
 134         *ppos += *lenp;
 135         return 0;
 136 }
 137
 138
 139 static struct ctl_table debug_table[] = {
 140         {
 141                 .procname       = "rpc_debug",
 142                 .data           = &rpc_debug,
 143                 .maxlen         = sizeof(int),
 144                 .mode           = 0644,
 145                 .proc_handler   = proc_dodebug
 146         },
 147         {
 148                 .procname       = "nfs_debug",
 149                 .data           = &nfs_debug,
 150                 .maxlen         = sizeof(int),
 151                 .mode           = 0644,
 152                 .proc_handler   = proc_dodebug
 153         },
 154         {
 155                 .procname       = "nfsd_debug",
 156                 .data           = &nfsd_debug,
 157                 .maxlen         = sizeof(int),
 158                 .mode           = 0644,
 159                 .proc_handler   = proc_dodebug
 160         },
 161         {
 162                 .procname       = "nlm_debug",
 163                 .data           = &nlm_debug,
 164                 .maxlen         = sizeof(int),
 165                 .mode           = 0644,
 166                 .proc_handler   = proc_dodebug
 167         },
 168         {
 169                 .procname       = "transports",
 170                 .maxlen         = 256,
 171                 .mode           = 0444,
 172                 .proc_handler   = proc_do_xprt,
 173         },
 174         { }
 175 };
 176
 177 static struct ctl_table sunrpc_table[] = {
 178         {
 179                 .procname       = "sunrpc",
 180                 .mode           = 0555,
 181                 .child          = debug_table
 182         },
 183         { }
 184 };
 185
 186 #endif