fs/proc/net.c

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 1 /*
 2  * linux/fs/proc/net.c
 3  *
 4  * Copyright (C) 1991, 1992 Linus Torvalds
 5  *
 6  * gjh 3/'93 heim@peanuts.informatik.uni-tuebingen.de (Gerald J. Heim)
 7  * most of this file is stolen from base.c
 8  * it works, but you shouldn't use it as a guideline
 9  * for new proc-fs entries. once i'll make it better.
 10  * fvk 3/'93 waltje@uwalt.nl.mugnet.org (Fred N. van Kempen)
 11  * cleaned up the whole thing, moved "net" specific code to
 12  * the NET kernel layer (where it belonged in the first place).
 13  * Michael K. Johnson (johnsonm@stolaf.edu) 3/93
 14  * Added support from my previous inet.c. Cleaned things up
 15  * quite a bit, modularized the code.
 16  * fvk 4/'93 waltje@uwalt.nl.mugnet.org (Fred N. van Kempen)
 17  * Renamed "route_get_info()" to "rt_get_info()" for consistency.
 18  * Alan Cox (gw4pts@gw4pts.ampr.org) 4/94
 19  * Dusted off the code and added IPX. Fixed the 4K limit.
 20  * Erik Schoenfelder (schoenfr@ibr.cs.tu-bs.de)
 21  * /proc/net/snmp.
 22  * Alan Cox (gw4pts@gw4pts.ampr.org) 1/95
 23  * Added Appletalk slots
 24  *
 25  * proc net directory handling functions
 26  */
 27 #include <linux/autoconf.h>
 28
 29 #include <asm/segment.h>
 30
 31 #include <linux/errno.h>
 32 #include <linux/sched.h>
 33 #include <linux/proc_fs.h>
 34 #include <linux/stat.h>
 35 #include <linux/fcntl.h>
 36 #include <linux/config.h>
 37 #include <linux/mm.h>
 38
 39 /* forward references */
 40 static intproc_readnet(struct inode * inode,struct file * file,
 41 char* buf,int count);
 42 static intproc_readnetdir(struct inode *,struct file *,
 43 void*, filldir_t filldir);
 44 static intproc_lookupnet(struct inode *,const char*,int,struct inode **);
 45
 46 static struct file_operations proc_net_operations = {
 47  NULL,/* lseek - default */
 48  proc_readnet,/* read - bad */
 49  NULL,/* write - bad */
 50  proc_readnetdir,/* readdir */
 51  NULL,/* select - default */
 52  NULL,/* ioctl - default */
 53  NULL,/* mmap */
 54  NULL,/* no special open code */
 55  NULL,/* no special release code */
 56  NULL /* can't fsync */
 57 };
 58
 59 /*
 60  * proc directories can do almost nothing..
 61  */
 62 struct inode_operations proc_net_inode_operations = {
 63 &proc_net_operations,/* default net directory file-ops */
 64  NULL,/* create */
 65  proc_lookupnet,/* lookup */
 66  NULL,/* link */
 67  NULL,/* unlink */
 68  NULL,/* symlink */
 69  NULL,/* mkdir */
 70  NULL,/* rmdir */
 71  NULL,/* mknod */
 72  NULL,/* rename */
 73  NULL,/* readlink */
 74  NULL,/* follow_link */
 75  NULL,/* bmap */
 76  NULL,/* truncate */
 77  NULL /* permission */
 78 };
 79
 80 #define NR_MAX_PROC_NET_DIR 100
 81 static struct proc_dir_entry *net_dir[NR_MAX_PROC_NET_DIR] = {
 82  NULL,
 83 };
 84
 85 static int nr_net_direntry =0;
 86
 87 intproc_net_register(struct proc_dir_entry *dp)
 88 {
 89 int i;
 90
 91 for(i =0; net_dir[i] != NULL; ++i ) ;
 92
 93 if(i >= NR_MAX_PROC_NET_DIR)
 94 return-ENOMEM;
 95
 96  net_dir[i] = dp;
 97  net_dir[i+1] = NULL;/* Just make sure.. */
 98 ++nr_net_direntry;
 99 return i;
 100 }
 101
 102 intproc_net_unregister(int ino)
 103 {
 104 int i;
 105 for(i =0; net_dir[i] != NULL && i < nr_net_direntry; ++i)
 106 if(net_dir[i]->low_ino == ino) {
 107 for( ; net_dir[i] != NULL; ++i )
 108  net_dir[i] = net_dir[i+1];
 109 --nr_net_direntry;
 110 return0;
 111 }
 112 return-ENOENT;
 113 }
 114
 115 static intdir_get_info(char* a,char** b, off_t d,int e,int f)
 116 {
 117 return-EISDIR;
 118 }
 119
 120 voidproc_net_init(void)
 121 {
 122 static struct proc_dir_entry
 123  nd_thisdir = { PROC_NET, dir_get_info,1,"."},
 124  nd_rootdir = { PROC_ROOT_INO, dir_get_info,1,".."};
 125 static int already =0;
 126
 127 if(already)return;
 128  already =1;
 129
 130 proc_net_register(&nd_thisdir);
 131 proc_net_register(&nd_rootdir);
 132 }
 133
 134
 135 static intproc_lookupnet(struct inode * dir,const char* name,int len,
 136 struct inode ** result)
 137 {
 138 struct proc_dir_entry **de;
 139
 140 *result = NULL;
 141 if(!dir)
 142 return-ENOENT;
 143 if(!S_ISDIR(dir->i_mode)) {
 144 iput(dir);
 145 return-ENOENT;
 146 }
 147 for(de = net_dir ; (*de)->name ; de++) {
 148 if(!proc_match(len, name, *de))
 149 continue;
 150 *result =iget(dir->i_sb, (*de)->low_ino);
 151 iput(dir);
 152 if(!*result)
 153 return-ENOENT;
 154 return0;
 155 }
 156 iput(dir);
 157 return-ENOENT;
 158 }
 159
 160 static intproc_readnetdir(struct inode * inode,struct file * filp,
 161 void* dirent, filldir_t filldir)
 162 {
 163 struct proc_dir_entry * de;
 164 unsigned int ino;
 165
 166 if(!inode || !S_ISDIR(inode->i_mode))
 167 return-EBADF;
 168  ino = inode->i_ino;
 169 while(((unsigned) filp->f_pos) < nr_net_direntry) {
 170  de = net_dir[filp->f_pos];
 171 if(filldir(dirent, de->name, de->namelen, filp->f_pos, de->low_ino) <0)
 172 break;
 173  filp->f_pos++;
 174 }
 175 return0;
 176 }
 177
 178
 179 #define PROC_BLOCK_SIZE (3*1024)/* 4K page size but our output routines use some slack for overruns */
 180
 181 static intproc_readnet(struct inode * inode,struct file * file,
 182 char* buf,int count)
 183 {
 184 char* page;
 185 unsigned int ino;
 186 int bytes=count;
 187 int i;
 188 int copied=0;
 189 char*start;
 190 struct proc_dir_entry * dp;
 191
 192 if(count <0)
 193 return-EINVAL;
 194  ino = inode->i_ino;
 195 for(i =0; ;i++) {
 196 if(i >= NR_MAX_PROC_NET_DIR || (dp = net_dir[i]) == NULL)
 197 return-EBADF;
 198 if(dp->low_ino == ino)
 199 break;
 200 }
 201 if(!(page = (char*)__get_free_page(GFP_KERNEL)))
 202 return-ENOMEM;
 203
 204 while(bytes>0)
 205 {
 206 int length, thistime=bytes;
 207 if(bytes > PROC_BLOCK_SIZE)
 208  thistime=PROC_BLOCK_SIZE;
 209
 210  length = dp->get_info(page, &start,
 211  file->f_pos,
 212  thistime,
 213 (file->f_flags & O_ACCMODE) == O_RDWR);
 214
 215 /*
 216  * We have been given a non page aligned block of
 217  * the data we asked for + a bit. We have been given
 218  * the start pointer and we know the length..
 219  */
 220
 221 if(length <=0)
 222 break;
 223 /*
 224  * Copy the bytes
 225  */
 226 memcpy_tofs(buf+copied, start, length);
 227  file->f_pos += length;/* Move down the file */
 228  bytes -= length;
 229  copied += length;
 230 if(length<thistime)
 231 break;/* End of file */
 232 }
 233 free_page((unsigned long) page);
 234 return copied;
 235 }