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         *lenp = memory_read_from_buffer(buffer, *lenp, ppos, tmpbuf, len);
  74
  75         if (*lenp < 0) {
  76                 *lenp = 0;
  77                 return -EINVAL;
  78         }
  79         return 0;
  80 }
  81
  82 static int
  83 proc_dodebug(struct ctl_table *table, int write, void *buffer, size_t *lenp,
  84              loff_t *ppos)
  85 {
  86         char            tmpbuf[20], *s = NULL;
  87         char *p;
  88         unsigned int    value;
  89         size_t          left, len;
  90
  91         if ((*ppos && !write) || !*lenp) {
  92                 *lenp = 0;
  93                 return 0;
  94         }
  95
  96         left = *lenp;
  97
  98         if (write) {
  99                 p = buffer;
 100                 while (left && isspace(*p)) {
 101                         left--;
 102                         p++;
 103                 }
 104                 if (!left)
 105                         goto done;
 106
 107                 if (left > sizeof(tmpbuf) - 1)
 108                         return -EINVAL;
 109                 memcpy(tmpbuf, p, left);
 110                 tmpbuf[left] = '\0';
 111
 112                 value = simple_strtol(tmpbuf, &s, 0);
 113                 if (s) {
 114                         left -= (s - tmpbuf);
 115                         if (left && !isspace(*s))
 116                                 return -EINVAL;
 117                         while (left && isspace(*s)) {
 118                                 left--;
 119                                 s++;
 120                         }
 121                 } else
 122                         left = 0;
 123                 *(unsigned int *) table->data = value;
 124                 /* Display the RPC tasks on writing to rpc_debug */
 125                 if (strcmp(table->procname, "rpc_debug") == 0)
 126                         rpc_show_tasks(&init_net);
 127         } else {
 128                 len = sprintf(tmpbuf, "0x%04x", *(unsigned int *) table->data);
 129                 if (len > left)
 130                         len = left;
 131                 memcpy(buffer, tmpbuf, len);
 132                 if ((left -= len) > 0) {
 133                         *((char *)buffer + len) = '\n';
 134                         left--;
 135                 }
 136         }
 137
 138 done:
 139         *lenp -= left;
 140         *ppos += *lenp;
 141         return 0;
 142 }
 143
 144
 145 static struct ctl_table debug_table[] = {
 146         {
 147                 .procname       = "rpc_debug",
 148                 .data           = &rpc_debug,
 149                 .maxlen         = sizeof(int),
 150                 .mode           = 0644,
 151                 .proc_handler   = proc_dodebug
 152         },
 153         {
 154                 .procname       = "nfs_debug",
 155                 .data           = &nfs_debug,
 156                 .maxlen         = sizeof(int),
 157                 .mode           = 0644,
 158                 .proc_handler   = proc_dodebug
 159         },
 160         {
 161                 .procname       = "nfsd_debug",
 162                 .data           = &nfsd_debug,
 163                 .maxlen         = sizeof(int),
 164                 .mode           = 0644,
 165                 .proc_handler   = proc_dodebug
 166         },
 167         {
 168                 .procname       = "nlm_debug",
 169                 .data           = &nlm_debug,
 170                 .maxlen         = sizeof(int),
 171                 .mode           = 0644,
 172                 .proc_handler   = proc_dodebug
 173         },
 174         {
 175                 .procname       = "transports",
 176                 .maxlen         = 256,
 177                 .mode           = 0444,
 178                 .proc_handler   = proc_do_xprt,
 179         },
 180         { }
 181 };
 182
 183 static struct ctl_table sunrpc_table[] = {
 184         {
 185                 .procname       = "sunrpc",
 186                 .mode           = 0555,
 187                 .child          = debug_table
 188         },
 189         { }
 190 };
 191
 192 #endif