winsup/cygwin/fhandler/procnet.cc

   1 /* fhandler_procnet.cc: fhandler for /proc/net virtual filesystem
   2
   3 This file is part of Cygwin.
   4
   5 This software is a copyrighted work licensed under the terms of the
   6 Cygwin license.  Please consult the file "CYGWIN_LICENSE" for
   7 details. */
   8
   9 #define  __INSIDE_CYGWIN_NET__
  10 #define USE_SYS_TYPES_FD_SET
  11 #include "winsup.h"
  12 /* 2014-04-24: Current Mingw headers define sockaddr_in6 using u_long (8 byte)
  13    because a redefinition for LP64 systems is missing.  This leads to a wrong
  14    definition and size of sockaddr_in6 when building with winsock headers. */
  15 #undef u_long
  16 #define u_long __ms_u_long
  17 #include <w32api/ws2tcpip.h>
  18 #include <w32api/iphlpapi.h>
  19 #include <asm/byteorder.h>
  20 #include <stdio.h>
  21 #include "cygerrno.h"
  22 #include "path.h"
  23 #include "fhandler.h"
  24 #include "fhandler_virtual.h"
  25 #include "dtable.h"
  26
  27 bool get_adapters_addresses (PIP_ADAPTER_ADDRESSES *pa0, ULONG family);
  28
  29 static off_t format_procnet_ifinet6 (void *, char *&);
  30
  31 static const virt_tab_t procnet_tab[] =
  32 {
  33   { _VN ("."),        FH_PROCNET, virt_directory, NULL },
  34   { _VN (".."),       FH_PROCNET, virt_directory, NULL },
  35   { _VN ("if_inet6"), FH_PROCNET, virt_file,      format_procnet_ifinet6 },
  36   { NULL, 0,          FH_NADA,    virt_none,      NULL }
  37 };
  38
  39 static const int PROCNET_LINK_COUNT =
  40   (sizeof (procnet_tab) / sizeof (virt_tab_t)) - 1;
  41
  42 virtual_ftype_t
  43 fhandler_procnet::exists ()
  44 {
  45   const char *path = get_name ();
  46   debug_printf ("exists (%s)", path);
  47   path += proc_len + 1;
  48   while (*path != 0 && !isdirsep (*path))
  49     path++;
  50   if (*path == 0)
  51     return virt_rootdir;
  52
  53   virt_tab_t *entry = virt_tab_search (path + 1, false, procnet_tab,
  54                                        PROCNET_LINK_COUNT);
  55   if (entry)
  56     {
  57       if (entry->type == virt_file && !get_adapters_addresses (NULL, AF_INET6))
  58         return virt_none;
  59       fileid = entry - procnet_tab;
  60       return entry->type;
  61     }
  62   return virt_none;
  63 }
  64
  65 fhandler_procnet::fhandler_procnet ():
  66   fhandler_proc ()
  67 {
  68 }
  69
  70 int
  71 fhandler_procnet::fstat (struct stat *buf)
  72 {
  73   fhandler_base::fstat (buf);
  74   buf->st_mode &= ~_IFMT & NO_W;
  75   int file_type = exists ();
  76   switch (file_type)
  77     {
  78     case virt_none:
  79       set_errno (ENOENT);
  80       return -1;
  81     case virt_directory:
  82     case virt_rootdir:
  83       buf->st_mode |= S_IFDIR | S_IXUSR | S_IXGRP | S_IXOTH;
  84       buf->st_nlink = 2;
  85       return 0;
  86     case virt_file:
  87     default:
  88       buf->st_mode |= S_IFREG | S_IRUSR | S_IRGRP | S_IROTH;
  89       return 0;
  90     }
  91 }
  92
  93 int
  94 fhandler_procnet::readdir (DIR *dir, dirent *de)
  95 {
  96   int res = ENMFILE;
  97   if (dir->__d_position >= PROCNET_LINK_COUNT)
  98     goto out;
  99   if (procnet_tab[dir->__d_position].type == virt_file
 100       && !get_adapters_addresses (NULL, AF_INET6))
 101     goto out;
 102   strcpy (de->d_name, procnet_tab[dir->__d_position].name);
 103   de->d_type = virt_ftype_to_dtype (procnet_tab[dir->__d_position].type);
 104   dir->__d_position++;
 105   dir->__flags |= dirent_saw_dot | dirent_saw_dot_dot;
 106   res = 0;
 107 out:
 108   syscall_printf ("%d = readdir(%p, %p) (%s)", res, dir, de, de->d_name);
 109   return res;
 110 }
 111
 112 int
 113 fhandler_procnet::open (int flags, mode_t mode)
 114 {
 115   int res = fhandler_virtual::open (flags, mode);
 116   if (!res)
 117     goto out;
 118
 119   nohandle (true);
 120
 121   const char *path;
 122   path = get_name () + proc_len + 1;
 123   while (*path != 0 && !isdirsep (*path))
 124     path++;
 125
 126   if (*path == 0)
 127     {
 128       if ((flags & (O_CREAT | O_EXCL)) == (O_CREAT | O_EXCL))
 129         {
 130           set_errno (EEXIST);
 131           res = 0;
 132           goto out;
 133         }
 134       else if (flags & O_WRONLY)
 135         {
 136           set_errno (EISDIR);
 137           res = 0;
 138           goto out;
 139         }
 140       else
 141         {
 142           diropen = true;
 143           goto success;
 144         }
 145     }
 146
 147   virt_tab_t *entry;
 148   entry = virt_tab_search (path + 1, true, procnet_tab, PROCNET_LINK_COUNT);
 149   if (!entry)
 150     {
 151       set_errno ((flags & O_CREAT) ? EROFS : ENOENT);
 152       res = 0;
 153       goto out;
 154     }
 155   if (flags & O_WRONLY)
 156     {
 157       set_errno (EROFS);
 158       res = 0;
 159       goto out;
 160     }
 161
 162   fileid = entry - procnet_tab;
 163   if (!fill_filebuf ())
 164         {
 165           res = 0;
 166           goto out;
 167         }
 168
 169   if (flags & O_APPEND)
 170     position = filesize;
 171   else
 172     position = 0;
 173
 174 success:
 175   res = 1;
 176   set_flags ((flags & ~O_TEXT) | O_BINARY);
 177   set_open_status ();
 178 out:
 179   syscall_printf ("%d = fhandler_proc::open(%y, 0%o)", res, flags, mode);
 180   return res;
 181 }
 182
 183 bool
 184 fhandler_procnet::fill_filebuf ()
 185 {
 186   if (procnet_tab[fileid].format_func)
 187     {
 188       filesize = procnet_tab[fileid].format_func (NULL, filebuf);
 189       return true;
 190     }
 191   return false;
 192 }
 193
 194 /* Return the same scope values as Linux. */
 195 static unsigned int
 196 get_scope (struct in6_addr *addr)
 197 {
 198   if (IN6_IS_ADDR_LOOPBACK (addr))
 199     return 0x10;
 200   if (IN6_IS_ADDR_LINKLOCAL (addr))
 201     return 0x20;
 202   if (IN6_IS_ADDR_SITELOCAL (addr))
 203     return 0x40;
 204   if (IN6_IS_ADDR_V4COMPAT (addr))
 205     return 0x80;
 206   return 0x0;
 207 }
 208
 209 /* Convert DAD state into Linux compatible values. */
 210 static unsigned int dad_to_flags[] =
 211 {
 212   0x02,         /* Invalid -> NODAD */
 213   0x40,         /* Tentative -> TENTATIVE */
 214   0xc0,         /* Duplicate -> PERMANENT | TENTATIVE */
 215   0x20,         /* Deprecated -> DEPRECATED */
 216   0x80          /* Preferred -> PERMANENT */
 217 };
 218
 219 static off_t
 220 format_procnet_ifinet6 (void *, char *&filebuf)
 221 {
 222   PIP_ADAPTER_ADDRESSES pa0 = NULL, pap;
 223   PIP_ADAPTER_UNICAST_ADDRESS pua;
 224   ULONG alloclen;
 225   off_t filesize = 0;
 226
 227   if (!get_adapters_addresses (&pa0, AF_INET6))
 228     goto out;
 229   alloclen = 0;
 230   for (pap = pa0; pap; pap = pap->Next)
 231     for (pua = pap->FirstUnicastAddress; pua; pua = pua->Next)
 232       alloclen += 100;
 233   if (!alloclen)
 234     goto out;
 235   filebuf = (char *) crealloc (filebuf, alloclen);
 236   if (!filebuf)
 237     goto out;
 238   for (pap = pa0; pap; pap = pap->Next)
 239     for (pua = pap->FirstUnicastAddress; pua; pua = pua->Next)
 240       {
 241         struct sockaddr_in6 *sin6 = (struct sockaddr_in6 *)
 242                                     pua->Address.lpSockaddr;
 243         for (int i = 0; i < 8; ++i)
 244           /* __small_sprintf generates upper-case hex. */
 245           filesize += sprintf (filebuf + filesize, "%04x",
 246                                ntohs (sin6->sin6_addr.s6_addr16[i]));
 247         filebuf[filesize++] = ' ';
 248         filesize += sprintf (filebuf + filesize,
 249                              "%02lx %02x %02x %02x %s\n",
 250                              (long) pap->Ipv6IfIndex,
 251                              pua->OnLinkPrefixLength,
 252                              get_scope (&((struct sockaddr_in6 *)
 253                                         pua->Address.lpSockaddr)->sin6_addr),
 254                              dad_to_flags [pua->DadState],
 255                              pap->AdapterName);
 256       }
 257
 258 out:
 259   if (pa0)
 260     free (pa0);
 261   return filesize;
 262 }