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 int proc_do_xprt(const struct ctl_table *table, int write,
  44                         void *buffer, size_t *lenp, loff_t *ppos)
  45 {
  46         char tmpbuf[256];
  47         ssize_t len;
  48
  49         if (write || *ppos) {
  50                 *lenp = 0;
  51                 return 0;
  52         }
  53         len = svc_print_xprts(tmpbuf, sizeof(tmpbuf));
  54         len = memory_read_from_buffer(buffer, *lenp, ppos, tmpbuf, len);
  55
  56         if (len < 0) {
  57                 *lenp = 0;
  58                 return -EINVAL;
  59         }
  60         *lenp = len;
  61         return 0;
  62 }
  63
  64 static int
  65 proc_dodebug(const struct ctl_table *table, int write, void *buffer, size_t *lenp,
  66              loff_t *ppos)
  67 {
  68         char            tmpbuf[20], *s = NULL;
  69         char *p;
  70         unsigned int    value;
  71         size_t          left, len;
  72
  73         if ((*ppos && !write) || !*lenp) {
  74                 *lenp = 0;
  75                 return 0;
  76         }
  77
  78         left = *lenp;
  79
  80         if (write) {
  81                 p = buffer;
  82                 while (left && isspace(*p)) {
  83                         left--;
  84                         p++;
  85                 }
  86                 if (!left)
  87                         goto done;
  88
  89                 if (left > sizeof(tmpbuf) - 1)
  90                         return -EINVAL;
  91                 memcpy(tmpbuf, p, left);
  92                 tmpbuf[left] = '\0';
  93
  94                 value = simple_strtol(tmpbuf, &s, 0);
  95                 if (s) {
  96                         left -= (s - tmpbuf);
  97                         if (left && !isspace(*s))
  98                                 return -EINVAL;
  99                         while (left && isspace(*s)) {
 100                                 left--;
 101                                 s++;
 102                         }
 103                 } else
 104                         left = 0;
 105                 *(unsigned int *) table->data = value;
 106                 /* Display the RPC tasks on writing to rpc_debug */
 107                 if (strcmp(table->procname, "rpc_debug") == 0)
 108                         rpc_show_tasks(&init_net);
 109         } else {
 110                 len = sprintf(tmpbuf, "0x%04x", *(unsigned int *) table->data);
 111                 if (len > left)
 112                         len = left;
 113                 memcpy(buffer, tmpbuf, len);
 114                 if ((left -= len) > 0) {
 115                         *((char *)buffer + len) = '\n';
 116                         left--;
 117                 }
 118         }
 119
 120 done:
 121         *lenp -= left;
 122         *ppos += *lenp;
 123         return 0;
 124 }
 125
 126 static struct ctl_table_header *sunrpc_table_header;
 127
 128 static struct ctl_table debug_table[] = {
 129         {
 130                 .procname       = "rpc_debug",
 131                 .data           = &rpc_debug,
 132                 .maxlen         = sizeof(int),
 133                 .mode           = 0644,
 134                 .proc_handler   = proc_dodebug
 135         },
 136         {
 137                 .procname       = "nfs_debug",
 138                 .data           = &nfs_debug,
 139                 .maxlen         = sizeof(int),
 140                 .mode           = 0644,
 141                 .proc_handler   = proc_dodebug
 142         },
 143         {
 144                 .procname       = "nfsd_debug",
 145                 .data           = &nfsd_debug,
 146                 .maxlen         = sizeof(int),
 147                 .mode           = 0644,
 148                 .proc_handler   = proc_dodebug
 149         },
 150         {
 151                 .procname       = "nlm_debug",
 152                 .data           = &nlm_debug,
 153                 .maxlen         = sizeof(int),
 154                 .mode           = 0644,
 155                 .proc_handler   = proc_dodebug
 156         },
 157         {
 158                 .procname       = "transports",
 159                 .maxlen         = 256,
 160                 .mode           = 0444,
 161                 .proc_handler   = proc_do_xprt,
 162         },
 163 };
 164
 165 void
 166 rpc_register_sysctl(void)
 167 {
 168         if (!sunrpc_table_header)
 169                 sunrpc_table_header = register_sysctl("sunrpc", debug_table);
 170 }
 171
 172 void
 173 rpc_unregister_sysctl(void)
 174 {
 175         if (sunrpc_table_header) {
 176                 unregister_sysctl_table(sunrpc_table_header);
 177                 sunrpc_table_header = NULL;
 178         }
 179 }
 180 #endif