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         size_t needed;
  25         in_addr_t in;
  26         int mib[6];
  27         int num_gws=0, gwnum=0;
  28         unsigned int ifindex = 0;
  29         char *buf, *next, *lim, *ifacename;
  30         struct rt_msghdr *rtm;
  31
  32         MonoDomain *domain = mono_domain_get ();
  33
  34         ifacename = mono_string_to_utf8(iface);
  35         if ((ifindex = if_nametoindex(ifacename)) == 0)
  36                 return FALSE;
  37         g_free(ifacename);
  38
  39         // MIB array defining data to read from sysctl
  40         mib[0] = CTL_NET;       // Networking
  41         mib[1] = PF_ROUTE;      // Routing messages
  42         mib[2] = 0;             // Protocol number (always zero)
  43         mib[3] = AF_INET;       // Address family (IPv4)
  44         mib[4] = NET_RT_DUMP;   // Dump routing table
  45         mib[5] = 0;             //
  46
  47         // First sysctl call with oldp set to NULL to determine size of available data
  48         if (sysctl(mib, G_N_ELEMENTS(mib), NULL, &needed, NULL, 0) < 0)
  49                 return FALSE;
  50
  51         // Allocate suffcient memory for available data based on the previous sysctl call
  52         if ((buf = malloc(needed)) == NULL)
  53                 return FALSE;
  54
  55         // Second sysctl call to retrieve data into appropriately sized buffer
  56         if (sysctl(mib, G_N_ELEMENTS(mib), buf, &needed, NULL, 0) < 0)
  57                 return FALSE;
  58
  59         lim = buf + needed;
  60         for (next = buf; next < lim; next += rtm->rtm_msglen) {
  61                 rtm = (struct rt_msghdr *)next;
  62                 if (rtm->rtm_version != RTM_VERSION)
  63                         continue;
  64                 if (rtm->rtm_index != ifindex)
  65                         continue;
  66                 if((in = gateway_from_rtm(rtm)) == 0)
  67                         continue;
  68                 num_gws++;
  69         }
  70
  71         *gw_addr_list = mono_array_new(domain, mono_get_string_class (), num_gws);
  72
  73         for (next = buf; next < lim; next += rtm->rtm_msglen) {
  74                 rtm = (struct rt_msghdr *)next;
  75                 if (rtm->rtm_version != RTM_VERSION)
  76                         continue;
  77                 if (rtm->rtm_index != ifindex)
  78                         continue;
  79                 if ((in = gateway_from_rtm(rtm)) == 0)
  80                         continue;
  81
  82                 MonoString *addr_string;
  83                 char addr [16], *ptr;
  84                 int len;
  85
  86                 ptr = (char *) &in;
  87                 len = snprintf(addr, sizeof(addr), "%u.%u.%u.%u",
  88                         (unsigned char) ptr [0],
  89                         (unsigned char) ptr [1],
  90                         (unsigned char) ptr [2],
  91                         (unsigned char) ptr [3]);
  92
  93                 if ((len >= sizeof(addr)) || (len < 0))
  94                         // snprintf output truncated
  95                         continue;
  96
  97                 addr_string = mono_string_new (domain, addr);
  98                 mono_array_setref (*gw_addr_list, gwnum, addr_string);
  99                 gwnum++;
 100         }
 101         free(buf);
 102         return TRUE;
 103 }
 104
 105 in_addr_t gateway_from_rtm(struct rt_msghdr *rtm)
 106 {
 107         struct sockaddr *gw;
 108         unsigned int l;
 109
 110         struct sockaddr *addr = (struct sockaddr *)(rtm + 1);
 111         l = roundup(addr->sa_len, sizeof(long)); \
 112         gw = (struct sockaddr *)((char *) addr + l); \
 113
 114         if (rtm->rtm_addrs & RTA_GATEWAY) {
 115                 if(gw->sa_family == AF_INET) {
 116                         struct sockaddr_in *sockin = (struct sockaddr_in *)gw;
 117                         return(sockin->sin_addr.s_addr);
 118                 }
 119         }
 120
 121         return 0;
 122 }
 123
 124 #endif /* #if defined(PLATFORM_MACOSX) || defined(PLATFORM_BSD) */