mono/metadata/mono-route.c

   1 /*
   2  * mono-route.c: Read the network routing tables using sysctl(3) calls
   3  *               Required for Unix-like systems that don't have Linux's /proc/net/route
   4  *
   5  * Author:
   6  *   Ben Woods (woodsb02@gmail.com)
   7  */
   8
   9 #if defined(PLATFORM_MACOSX) || defined(PLATFORM_BSD)
  10
  11 #include <sys/socket.h>
  12 #include <net/if.h>
  13 #include <net/if_dl.h>
  14 #include <netinet/in.h>
  15 #include <sys/param.h>
  16 #include <sys/sysctl.h>
  17 #include <stdlib.h>
  18 #include <string.h>
  19 #include <mono/metadata/object.h>
  20 #include <mono/metadata/mono-route.h>
  21
  22 extern MonoBoolean ves_icall_System_Net_NetworkInformation_MacOsIPInterfaceProperties_ParseRouteInfo_internal(MonoString *iface, MonoArray **gw_addr_list)
  23 {
  24         MonoError error;
  25         size_t needed;
  26         in_addr_t in;
  27         int mib[6];
  28         int num_gws=0, gwnum=0;
  29         unsigned int ifindex = 0;
  30         char *buf, *next, *lim, *ifacename;
  31         struct rt_msghdr *rtm;
  32
  33         MonoDomain *domain = mono_domain_get ();
  34
  35         ifacename = mono_string_to_utf8_checked(iface, &error);
  36         if (mono_error_set_pending_exception (&error))
  37                 return FALSE;
  38
  39         if ((ifindex = if_nametoindex(ifacename)) == 0)
  40                 return FALSE;
  41         g_free(ifacename);
  42
  43         // MIB array defining data to read from sysctl
  44         mib[0] = CTL_NET;       // Networking
  45         mib[1] = PF_ROUTE;      // Routing messages
  46         mib[2] = 0;             // Protocol number (always zero)
  47         mib[3] = AF_INET;       // Address family (IPv4)
  48         mib[4] = NET_RT_DUMP;   // Dump routing table
  49         mib[5] = 0;             //
  50
  51         // First sysctl call with oldp set to NULL to determine size of available data
  52         if (sysctl(mib, G_N_ELEMENTS(mib), NULL, &needed, NULL, 0) < 0)
  53                 return FALSE;
  54
  55         // Allocate suffcient memory for available data based on the previous sysctl call
  56         if ((buf = g_malloc (needed)) == NULL)
  57                 return FALSE;
  58
  59         // Second sysctl call to retrieve data into appropriately sized buffer
  60         if (sysctl(mib, G_N_ELEMENTS(mib), buf, &needed, NULL, 0) < 0)
  61                 return FALSE;
  62
  63         lim = buf + needed;
  64         for (next = buf; next < lim; next += rtm->rtm_msglen) {
  65                 rtm = (struct rt_msghdr *)next;
  66                 if (rtm->rtm_version != RTM_VERSION)
  67                         continue;
  68                 if (rtm->rtm_index != ifindex)
  69                         continue;
  70                 if((in = gateway_from_rtm(rtm)) == 0)
  71                         continue;
  72                 num_gws++;
  73         }
  74
  75         *gw_addr_list = mono_array_new(domain, mono_get_string_class (), num_gws);
  76
  77         for (next = buf; next < lim; next += rtm->rtm_msglen) {
  78                 rtm = (struct rt_msghdr *)next;
  79                 if (rtm->rtm_version != RTM_VERSION)
  80                         continue;
  81                 if (rtm->rtm_index != ifindex)
  82                         continue;
  83                 if ((in = gateway_from_rtm(rtm)) == 0)
  84                         continue;
  85
  86                 MonoString *addr_string;
  87                 char addr [16], *ptr;
  88                 int len;
  89
  90                 ptr = (char *) &in;
  91                 len = snprintf(addr, sizeof(addr), "%u.%u.%u.%u",
  92                         (unsigned char) ptr [0],
  93                         (unsigned char) ptr [1],
  94                         (unsigned char) ptr [2],
  95                         (unsigned char) ptr [3]);
  96
  97                 if ((len >= sizeof(addr)) || (len < 0))
  98                         // snprintf output truncated
  99                         continue;
 100
 101                 addr_string = mono_string_new (domain, addr);
 102                 mono_array_setref (*gw_addr_list, gwnum, addr_string);
 103                 gwnum++;
 104         }
 105         g_free (buf);
 106         return TRUE;
 107 }
 108
 109 in_addr_t gateway_from_rtm(struct rt_msghdr *rtm)
 110 {
 111         struct sockaddr *gw;
 112         unsigned int l;
 113
 114         struct sockaddr *addr = (struct sockaddr *)(rtm + 1);
 115         l = roundup(addr->sa_len, sizeof(long)); \
 116         gw = (struct sockaddr *)((char *) addr + l); \
 117
 118         if (rtm->rtm_addrs & RTA_GATEWAY) {
 119                 if(gw->sa_family == AF_INET) {
 120                         struct sockaddr_in *sockin = (struct sockaddr_in *)gw;
 121                         return(sockin->sin_addr.s_addr);
 122                 }
 123         }
 124
 125         return 0;
 126 }
 127
 128 #endif /* #if defined(PLATFORM_MACOSX) || defined(PLATFORM_BSD) */