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     {
  52       fileid () = 0;
  53       return virt_rootdir;
  54     }
  55
  56   virt_tab_t *entry = virt_tab_search (path + 1, false, procnet_tab,
  57                                        PROCNET_LINK_COUNT);
  58   if (entry)
  59     {
  60       if (entry->type == virt_file && !get_adapters_addresses (NULL, AF_INET6))
  61         return virt_none;
  62       fileid () = entry - procnet_tab;
  63       return entry->type;
  64     }
  65   fileid () = -1;
  66   return virt_none;
  67 }
  68
  69 fhandler_procnet::fhandler_procnet ():
  70   fhandler_proc ()
  71 {
  72 }
  73
  74 int
  75 fhandler_procnet::fstat (struct stat *buf)
  76 {
  77   fhandler_base::fstat (buf);
  78   buf->st_mode &= ~_IFMT & NO_W;
  79   int file_type = exists ();
  80   switch (file_type)
  81     {
  82     case virt_none:
  83       set_errno (ENOENT);
  84       return -1;
  85     case virt_directory:
  86     case virt_rootdir:
  87       buf->st_mode |= S_IFDIR | S_IXUSR | S_IXGRP | S_IXOTH;
  88       buf->st_nlink = 2;
  89       return 0;
  90     case virt_file:
  91     default:
  92       buf->st_mode |= S_IFREG | S_IRUSR | S_IRGRP | S_IROTH;
  93       return 0;
  94     }
  95 }
  96
  97 int
  98 fhandler_procnet::readdir (DIR *dir, dirent *de)
  99 {
 100   int res = ENMFILE;
 101   if (dir->__d_position >= PROCNET_LINK_COUNT)
 102     goto out;
 103   if (procnet_tab[dir->__d_position].type == virt_file
 104       && !get_adapters_addresses (NULL, AF_INET6))
 105     goto out;
 106   strcpy (de->d_name, procnet_tab[dir->__d_position].name);
 107   de->d_type = virt_ftype_to_dtype (procnet_tab[dir->__d_position].type);
 108   dir->__d_position++;
 109   dir->__flags |= dirent_saw_dot | dirent_saw_dot_dot;
 110   res = 0;
 111 out:
 112   syscall_printf ("%d = readdir(%p, %p) (%s)", res, dir, de, de->d_name);
 113   return res;
 114 }
 115
 116 int
 117 fhandler_procnet::open (int flags, mode_t mode)
 118 {
 119   int res = fhandler_virtual::open (flags, mode);
 120   if (!res)
 121     goto out;
 122
 123   nohandle (true);
 124
 125   const char *path;
 126   path = get_name () + proc_len + 1;
 127   while (*path != 0 && !isdirsep (*path))
 128     path++;
 129
 130   if (*path == 0)
 131     {
 132       if ((flags & (O_CREAT | O_EXCL)) == (O_CREAT | O_EXCL))
 133         {
 134           set_errno (EEXIST);
 135           res = 0;
 136           goto out;
 137         }
 138       else if (flags & O_WRONLY)
 139         {
 140           set_errno (EISDIR);
 141           res = 0;
 142           goto out;
 143         }
 144       else
 145         {
 146           diropen = true;
 147           goto success;
 148         }
 149     }
 150
 151   virt_tab_t *entry;
 152   entry = virt_tab_search (path + 1, true, procnet_tab, PROCNET_LINK_COUNT);
 153   if (!entry)
 154     {
 155       set_errno ((flags & O_CREAT) ? EROFS : ENOENT);
 156       res = 0;
 157       goto out;
 158     }
 159   if (flags & O_WRONLY)
 160     {
 161       set_errno (EROFS);
 162       res = 0;
 163       goto out;
 164     }
 165
 166   fileid () = entry - procnet_tab;
 167   if (!fill_filebuf ())
 168         {
 169           res = 0;
 170           goto out;
 171         }
 172
 173   if (flags & O_APPEND)
 174     position = filesize;
 175   else
 176     position = 0;
 177
 178 success:
 179   res = 1;
 180   set_flags ((flags & ~O_TEXT) | O_BINARY);
 181   set_open_status ();
 182 out:
 183   syscall_printf ("%d = fhandler_proc::open(%y, 0%o)", res, flags, mode);
 184   return res;
 185 }
 186
 187 bool
 188 fhandler_procnet::fill_filebuf ()
 189 {
 190   if (procnet_tab[fileid ()].format_func)
 191     {
 192       filesize = procnet_tab[fileid ()].format_func (NULL, filebuf);
 193       return true;
 194     }
 195   return false;
 196 }
 197
 198 /* Return the same scope values as Linux. */
 199 static unsigned int
 200 get_scope (struct in6_addr *addr)
 201 {
 202   if (IN6_IS_ADDR_LOOPBACK (addr))
 203     return 0x10;
 204   if (IN6_IS_ADDR_LINKLOCAL (addr))
 205     return 0x20;
 206   if (IN6_IS_ADDR_SITELOCAL (addr))
 207     return 0x40;
 208   if (IN6_IS_ADDR_V4COMPAT (addr))
 209     return 0x80;
 210   return 0x0;
 211 }
 212
 213 /* Convert DAD state into Linux compatible values. */
 214 static unsigned int dad_to_flags[] =
 215 {
 216   0x02,         /* Invalid -> NODAD */
 217   0x40,         /* Tentative -> TENTATIVE */
 218   0xc0,         /* Duplicate -> PERMANENT | TENTATIVE */
 219   0x20,         /* Deprecated -> DEPRECATED */
 220   0x80          /* Preferred -> PERMANENT */
 221 };
 222
 223 static off_t
 224 format_procnet_ifinet6 (void *, char *&filebuf)
 225 {
 226   PIP_ADAPTER_ADDRESSES pa0 = NULL, pap;
 227   PIP_ADAPTER_UNICAST_ADDRESS pua;
 228   ULONG alloclen;
 229   off_t filesize = 0;
 230
 231   if (!get_adapters_addresses (&pa0, AF_INET6))
 232     goto out;
 233   alloclen = 0;
 234   for (pap = pa0; pap; pap = pap->Next)
 235     for (pua = pap->FirstUnicastAddress; pua; pua = pua->Next)
 236       alloclen += 100;
 237   if (!alloclen)
 238     goto out;
 239   filebuf = (char *) crealloc (filebuf, alloclen);
 240   if (!filebuf)
 241     goto out;
 242   for (pap = pa0; pap; pap = pap->Next)
 243     for (pua = pap->FirstUnicastAddress; pua; pua = pua->Next)
 244       {
 245         struct sockaddr_in6 *sin6 = (struct sockaddr_in6 *)
 246                                     pua->Address.lpSockaddr;
 247         for (int i = 0; i < 8; ++i)
 248           /* __small_sprintf generates upper-case hex. */
 249           filesize += sprintf (filebuf + filesize, "%04x",
 250                                ntohs (sin6->sin6_addr.s6_addr16[i]));
 251         filebuf[filesize++] = ' ';
 252         filesize += sprintf (filebuf + filesize,
 253                              "%02lx %02x %02x %02x %s\n",
 254                              (long) pap->Ipv6IfIndex,
 255                              pua->OnLinkPrefixLength,
 256                              get_scope (&((struct sockaddr_in6 *)
 257                                         pua->Address.lpSockaddr)->sin6_addr),
 258                              dad_to_flags [pua->DadState],
 259                              pap->AdapterName);
 260       }
 261
 262 out:
 263   if (pa0)
 264     free (pa0);
 265   return filesize;
 266 }