mono/metadata/mono-route.c

   1 /**
   2  * \file
   3  * Read the network routing tables using sysctl(3) calls
   4  * Required for Unix-like systems that don't have Linux's /proc/net/route
   5  *
   6  * Author:
   7  *   Ben Woods (woodsb02@gmail.com)
   8  */
   9
  10 #include <config.h>
  11
  12 #include <mono/metadata/object.h>
  13 #include <mono/metadata/mono-route.h>
  14
  15 #if defined(HOST_DARWIN) || defined(HOST_BSD)
  16 #include <sys/socket.h>
  17 #include <net/if.h>
  18 #include <net/if_dl.h>
  19 #include <netinet/in.h>
  20 #include <sys/param.h>
  21 #include <sys/sysctl.h>
  22 #include <stdlib.h>
  23 #include <string.h>
  24
  25 extern MonoBoolean ves_icall_System_Net_NetworkInformation_MacOsIPInterfaceProperties_ParseRouteInfo_internal(MonoString *iface, MonoArray **gw_addr_list)
  26 {
  27         ERROR_DECL (error);
  28         size_t needed;
  29         in_addr_t in;
  30         int mib[6];
  31         int num_gws=0, gwnum=0;
  32         unsigned int ifindex = 0;
  33         char *buf, *next, *lim, *ifacename;
  34         struct rt_msghdr *rtm;
  35
  36         MonoDomain *domain = mono_domain_get ();
  37
  38         ifacename = mono_string_to_utf8_checked_internal (iface, error);
  39         if (mono_error_set_pending_exception (error))
  40                 return FALSE;
  41
  42         if ((ifindex = if_nametoindex(ifacename)) == 0)
  43                 return FALSE;
  44         g_free(ifacename);
  45
  46         // MIB array defining data to read from sysctl
  47         mib[0] = CTL_NET;       // Networking
  48         mib[1] = PF_ROUTE;      // Routing messages
  49         mib[2] = 0;             // Protocol number (always zero)
  50         mib[3] = AF_INET;       // Address family (IPv4)
  51         mib[4] = NET_RT_DUMP;   // Dump routing table
  52         mib[5] = 0;             //
  53
  54         // First sysctl call with oldp set to NULL to determine size of available data
  55         if (sysctl(mib, G_N_ELEMENTS(mib), NULL, &needed, NULL, 0) < 0)
  56                 return FALSE;
  57
  58         // Allocate suffcient memory for available data based on the previous sysctl call
  59         if ((buf = g_malloc (needed)) == NULL)
  60                 return FALSE;
  61
  62         // Second sysctl call to retrieve data into appropriately sized buffer
  63         if (sysctl(mib, G_N_ELEMENTS(mib), buf, &needed, NULL, 0) < 0) {
  64                 g_free (buf);
  65                 return FALSE;
  66         }
  67
  68         lim = buf + needed;
  69         for (next = buf; next < lim; next += rtm->rtm_msglen) {
  70                 rtm = (struct rt_msghdr *)next;
  71                 if (rtm->rtm_version != RTM_VERSION)
  72                         continue;
  73                 if (rtm->rtm_index != ifindex)
  74                         continue;
  75                 if((in = gateway_from_rtm(rtm)) == 0)
  76                         continue;
  77                 num_gws++;
  78         }
  79
  80         *gw_addr_list = mono_array_new_checked (domain, mono_get_string_class (), num_gws, error);
  81         goto_if_nok (error, leave);
  82
  83         for (next = buf; next < lim; next += rtm->rtm_msglen) {
  84                 rtm = (struct rt_msghdr *)next;
  85                 if (rtm->rtm_version != RTM_VERSION)
  86                         continue;
  87                 if (rtm->rtm_index != ifindex)
  88                         continue;
  89                 if ((in = gateway_from_rtm(rtm)) == 0)
  90                         continue;
  91
  92                 MonoString *addr_string;
  93                 char addr [16], *ptr;
  94                 int len;
  95
  96                 ptr = (char *) &in;
  97                 len = snprintf(addr, sizeof(addr), "%u.%u.%u.%u",
  98                         (unsigned char) ptr [0],
  99                         (unsigned char) ptr [1],
 100                         (unsigned char) ptr [2],
 101                         (unsigned char) ptr [3]);
 102
 103                 if ((len >= sizeof(addr)) || (len < 0))
 104                         // snprintf output truncated
 105                         continue;
 106
 107                 addr_string = mono_string_new_checked (domain, addr, error);
 108                 goto_if_nok (error, leave);
 109                 mono_array_setref_internal (*gw_addr_list, gwnum, addr_string);
 110                 gwnum++;
 111         }
 112 leave:
 113         g_free (buf);
 114         return is_ok (error);
 115 }
 116
 117 in_addr_t gateway_from_rtm(struct rt_msghdr *rtm)
 118 {
 119         struct sockaddr *gw;
 120         unsigned int l;
 121
 122         struct sockaddr *addr = (struct sockaddr *)(rtm + 1);
 123         l = roundup(addr->sa_len, sizeof(long)); \
 124         gw = (struct sockaddr *)((char *) addr + l); \
 125
 126         if (rtm->rtm_addrs & RTA_GATEWAY) {
 127                 if(gw->sa_family == AF_INET) {
 128                         struct sockaddr_in *sockin = (struct sockaddr_in *)gw;
 129                         return(sockin->sin_addr.s_addr);
 130                 }
 131         }
 132
 133         return 0;
 134 }
 135
 136 #else
 137
 138 MonoBoolean
 139 ves_icall_System_Net_NetworkInformation_MacOsIPInterfaceProperties_ParseRouteInfo_internal(MonoString *iface, MonoArray **gw_addr_list)
 140 {
 141         g_assert_not_reached ();
 142         return FALSE;
 143 }
 144
 145 #endif /* #if defined(HOST_DARWIN) || defined(HOST_BSD) */