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         ssize_t len;
  67
  68         if (write || *ppos) {
  69                 *lenp = 0;
  70                 return 0;
  71         }
  72         len = svc_print_xprts(tmpbuf, sizeof(tmpbuf));
  73         len = memory_read_from_buffer(buffer, *lenp, ppos, tmpbuf, len);
  74
  75         if (len < 0) {
  76                 *lenp = 0;
  77                 return -EINVAL;
  78         }
  79         *lenp = len;
  80         return 0;
  81 }
  82
  83 static int
  84 proc_dodebug(struct ctl_table *table, int write, void *buffer, size_t *lenp,
  85              loff_t *ppos)
  86 {
  87         char            tmpbuf[20], *s = NULL;
  88         char *p;
  89         unsigned int    value;
  90         size_t          left, len;
  91
  92         if ((*ppos && !write) || !*lenp) {
  93                 *lenp = 0;
  94                 return 0;
  95         }
  96
  97         left = *lenp;
  98
  99         if (write) {
 100                 p = buffer;
 101                 while (left && isspace(*p)) {
 102                         left--;
 103                         p++;
 104                 }
 105                 if (!left)
 106                         goto done;
 107
 108                 if (left > sizeof(tmpbuf) - 1)
 109                         return -EINVAL;
 110                 memcpy(tmpbuf, p, left);
 111                 tmpbuf[left] = '\0';
 112
 113                 value = simple_strtol(tmpbuf, &s, 0);
 114                 if (s) {
 115                         left -= (s - tmpbuf);
 116                         if (left && !isspace(*s))
 117                                 return -EINVAL;
 118                         while (left && isspace(*s)) {
 119                                 left--;
 120                                 s++;
 121                         }
 122                 } else
 123                         left = 0;
 124                 *(unsigned int *) table->data = value;
 125                 /* Display the RPC tasks on writing to rpc_debug */
 126                 if (strcmp(table->procname, "rpc_debug") == 0)
 127                         rpc_show_tasks(&init_net);
 128         } else {
 129                 len = sprintf(tmpbuf, "0x%04x", *(unsigned int *) table->data);
 130                 if (len > left)
 131                         len = left;
 132                 memcpy(buffer, tmpbuf, len);
 133                 if ((left -= len) > 0) {
 134                         *((char *)buffer + len) = '\n';
 135                         left--;
 136                 }
 137         }
 138
 139 done:
 140         *lenp -= left;
 141         *ppos += *lenp;
 142         return 0;
 143 }
 144
 145
 146 static struct ctl_table debug_table[] = {
 147         {
 148                 .procname       = "rpc_debug",
 149                 .data           = &rpc_debug,
 150                 .maxlen         = sizeof(int),
 151                 .mode           = 0644,
 152                 .proc_handler   = proc_dodebug
 153         },
 154         {
 155                 .procname       = "nfs_debug",
 156                 .data           = &nfs_debug,
 157                 .maxlen         = sizeof(int),
 158                 .mode           = 0644,
 159                 .proc_handler   = proc_dodebug
 160         },
 161         {
 162                 .procname       = "nfsd_debug",
 163                 .data           = &nfsd_debug,
 164                 .maxlen         = sizeof(int),
 165                 .mode           = 0644,
 166                 .proc_handler   = proc_dodebug
 167         },
 168         {
 169                 .procname       = "nlm_debug",
 170                 .data           = &nlm_debug,
 171                 .maxlen         = sizeof(int),
 172                 .mode           = 0644,
 173                 .proc_handler   = proc_dodebug
 174         },
 175         {
 176                 .procname       = "transports",
 177                 .maxlen         = 256,
 178                 .mode           = 0444,
 179                 .proc_handler   = proc_do_xprt,
 180         },
 181         { }
 182 };
 183
 184 static struct ctl_table sunrpc_table[] = {
 185         {
 186                 .procname       = "sunrpc",
 187                 .mode           = 0555,
 188                 .child          = debug_table
 189         },
 190         { }
 191 };
 192
 193 #endif