babeld/kernel.c

   1 /*
   2 Copyright 2007, 2008 by Grégoire Henry, Julien Cristau and Juliusz Chroboczek
   3 Copyright 2011, 2012 by Matthieu Boutier and Juliusz Chroboczek
   4
   5 Permission is hereby granted, free of charge, to any person obtaining a copy
   6 of this software and associated documentation files (the "Software"), to deal
   7 in the Software without restriction, including without limitation the rights
   8 to use, copy, modify, merge, publish, distribute, sublicense, and/or sell
   9 copies of the Software, and to permit persons to whom the Software is
  10 furnished to do so, subject to the following conditions:
  11
  12 The above copyright notice and this permission notice shall be included in
  13 all copies or substantial portions of the Software.
  14
  15 THE SOFTWARE IS PROVIDED "AS IS", WITHOUT WARRANTY OF ANY KIND, EXPRESS OR
  16 IMPLIED, INCLUDING BUT NOT LIMITED TO THE WARRANTIES OF MERCHANTABILITY,
  17 FITNESS FOR A PARTICULAR PURPOSE AND NONINFRINGEMENT.  IN NO EVENT SHALL THE
  18 AUTHORS OR COPYRIGHT HOLDERS BE LIABLE FOR ANY CLAIM, DAMAGES OR OTHER
  19 LIABILITY, WHETHER IN AN ACTION OF CONTRACT, TORT OR OTHERWISE, ARISING FROM,
  20 OUT OF OR IN CONNECTION WITH THE SOFTWARE OR THE USE OR OTHER DEALINGS IN
  21 THE SOFTWARE.
  22 */
  23
  24 #include <sys/time.h>
  25 #include <sys/param.h>
  26 #include <time.h>
  27
  28 #include "babeld.h"
  29
  30
  31 #include <sys/types.h>
  32 #include <sys/socket.h>
  33 #include <netinet/in.h>
  34 #include <netdb.h>
  35 #include <arpa/inet.h>
  36
  37 #include <zebra.h>
  38 #include "prefix.h"
  39 #include "zclient.h"
  40 #include "kernel.h"
  41 #include "privs.h"
  42 #include "command.h"
  43 #include "vty.h"
  44 #include "memory.h"
  45 #include "thread.h"
  46
  47 #include "util.h"
  48 #include "babel_interface.h"
  49 #include "babel_zebra.h"
  50
  51
  52 static int
  53 kernel_route_v4(int add, const unsigned char *pref, unsigned short plen,
  54                 const unsigned char *gate, int ifindex,
  55                 unsigned int metric);
  56 static int
  57 kernel_route_v6(int add, const unsigned char *pref, unsigned short plen,
  58                 const unsigned char *gate, int ifindex,
  59                 unsigned int metric);
  60
  61 int
  62 kernel_interface_operational(struct interface *interface)
  63 {
  64     return if_is_operative(interface);
  65 }
  66
  67 int
  68 kernel_interface_mtu(struct interface *interface)
  69 {
  70     return MIN(interface->mtu, interface->mtu6);
  71 }
  72
  73 int
  74 kernel_interface_wireless(struct interface *interface)
  75 {
  76     return 0;
  77 }
  78
  79 int
  80 kernel_route(int operation, const unsigned char *pref, unsigned short plen,
  81              const unsigned char *gate, int ifindex, unsigned int metric,
  82              const unsigned char *newgate, int newifindex,
  83              unsigned int newmetric)
  84 {
  85     int rc;
  86     int ipv4;
  87
  88     /* Check that the protocol family is consistent. */
  89     if(plen >= 96 && v4mapped(pref)) {
  90         if(!v4mapped(gate)) {
  91             errno = EINVAL;
  92             return -1;
  93         }
  94         ipv4 = 1;
  95     } else {
  96         if(v4mapped(gate)) {
  97             errno = EINVAL;
  98             return -1;
  99         }
 100         ipv4 = 0;
 101     }
 102
 103     switch (operation) {
 104         case ROUTE_ADD:
 105             return ipv4 ?
 106                    kernel_route_v4(1, pref, plen, gate, ifindex, metric):
 107                    kernel_route_v6(1, pref, plen, gate, ifindex, metric);
 108             break;
 109         case ROUTE_FLUSH:
 110             return ipv4 ?
 111                    kernel_route_v4(0, pref, plen, gate, ifindex, metric):
 112                    kernel_route_v6(0, pref, plen, gate, ifindex, metric);
 113             break;
 114         case ROUTE_MODIFY:
 115             if(newmetric == metric && memcmp(newgate, gate, 16) == 0 &&
 116                newifindex == ifindex)
 117                 return 0;
 118             debugf(BABEL_DEBUG_ROUTE, "Modify route: delete old; add new.");
 119             rc = ipv4 ?
 120                 kernel_route_v4(0, pref, plen, gate, ifindex, metric):
 121                 kernel_route_v6(0, pref, plen, gate, ifindex, metric);
 122
 123             if (rc < 0)
 124                 return -1;
 125
 126             rc = ipv4 ?
 127                 kernel_route_v4(1, pref, plen, newgate, newifindex, newmetric):
 128                 kernel_route_v6(1, pref, plen, newgate, newifindex, newmetric);
 129
 130             return rc;
 131             break;
 132         default:
 133             zlog_err("this should never appens (false value - kernel_route)");
 134             assert(0);
 135             exit(1);
 136             break;
 137     }
 138 }
 139
 140 static int
 141 kernel_route_v4(int add,
 142                 const unsigned char *pref, unsigned short plen,
 143                 const unsigned char *gate, int ifindex, unsigned int metric)
 144 {
 145     struct zapi_ipv4 api;               /* quagga's communication system */
 146     struct prefix_ipv4 quagga_prefix;   /* quagga's prefix */
 147     struct in_addr babel_prefix_addr;   /* babeld's prefix addr */
 148     struct in_addr nexthop;             /* next router to go */
 149     struct in_addr *nexthop_pointer = &nexthop; /* it's an array! */
 150
 151     /* convert to be understandable by quagga */
 152     /* convert given addresses */
 153     uchar_to_inaddr(&babel_prefix_addr, pref);
 154     uchar_to_inaddr(&nexthop, gate);
 155
 156     /* make prefix structure */
 157     memset (&quagga_prefix, 0, sizeof(quagga_prefix));
 158     quagga_prefix.family = AF_INET;
 159     IPV4_ADDR_COPY (&quagga_prefix.prefix, &babel_prefix_addr);
 160     quagga_prefix.prefixlen = plen - 96; /* our plen is for v4mapped's addr */
 161     apply_mask_ipv4(&quagga_prefix);
 162
 163     api.type  = ZEBRA_ROUTE_BABEL;
 164     api.flags = 0;
 165     api.message = 0;
 166     api.safi = SAFI_UNICAST;
 167
 168     /* Unlike the native Linux and BSD interfaces, Quagga doesn't like
 169        there to be both and IPv4 nexthop and an ifindex.  Omit the
 170        ifindex, and assume that the connected prefixes be set up
 171        correctly. */
 172
 173     SET_FLAG(api.message, ZAPI_MESSAGE_NEXTHOP);
 174     api.ifindex_num = 0;
 175     if(metric >= KERNEL_INFINITY) {
 176         api.flags = ZEBRA_FLAG_REJECT;
 177         api.nexthop_num = 0;
 178     } else {
 179         api.nexthop_num = 1;
 180         api.nexthop = &nexthop_pointer;
 181         SET_FLAG(api.message, ZAPI_MESSAGE_METRIC);
 182         api.metric = metric;
 183     }
 184
 185     debugf(BABEL_DEBUG_ROUTE, "%s route (ipv4) to zebra",
 186            add ? "adding" : "removing" );
 187     return zapi_ipv4_route (add ? ZEBRA_IPV4_ROUTE_ADD :
 188                                   ZEBRA_IPV4_ROUTE_DELETE,
 189                             zclient, &quagga_prefix, &api);
 190 }
 191
 192 static int
 193 kernel_route_v6(int add, const unsigned char *pref, unsigned short plen,
 194                 const unsigned char *gate, int ifindex, unsigned int metric)
 195 {
 196     ifindex_t tmp_ifindex = ifindex;    /* (for typing) */
 197     struct zapi_ipv6 api;               /* quagga's communication system */
 198     struct prefix_ipv6 quagga_prefix;   /* quagga's prefix */
 199     struct in6_addr babel_prefix_addr;  /* babeld's prefix addr */
 200     struct in6_addr nexthop;            /* next router to go */
 201     struct in6_addr *nexthop_pointer = &nexthop;
 202
 203     /* convert to be understandable by quagga */
 204     /* convert given addresses */
 205     uchar_to_in6addr(&babel_prefix_addr, pref);
 206     uchar_to_in6addr(&nexthop, gate);
 207
 208     /* make prefix structure */
 209     memset (&quagga_prefix, 0, sizeof(quagga_prefix));
 210     quagga_prefix.family = AF_INET6;
 211     IPV6_ADDR_COPY (&quagga_prefix.prefix, &babel_prefix_addr);
 212     quagga_prefix.prefixlen = plen;
 213     apply_mask_ipv6(&quagga_prefix);
 214
 215     api.type  = ZEBRA_ROUTE_BABEL;
 216     api.flags = 0;
 217     api.message = 0;
 218     api.safi = SAFI_UNICAST;
 219     if(metric >= KERNEL_INFINITY) {
 220         api.flags = ZEBRA_FLAG_REJECT;
 221         api.nexthop_num = 0;
 222         api.ifindex_num = 0;
 223     } else {
 224         SET_FLAG(api.message, ZAPI_MESSAGE_NEXTHOP);
 225         api.nexthop_num = 1;
 226         api.nexthop = &nexthop_pointer;
 227         SET_FLAG(api.message, ZAPI_MESSAGE_IFINDEX);
 228         api.ifindex_num = 1;
 229         api.ifindex = &tmp_ifindex;
 230         SET_FLAG(api.message, ZAPI_MESSAGE_METRIC);
 231         api.metric = metric;
 232     }
 233
 234     debugf(BABEL_DEBUG_ROUTE, "%s route (ipv6) to zebra",
 235            add ? "adding" : "removing" );
 236     return zapi_ipv6_route (add ? ZEBRA_IPV6_ROUTE_ADD :
 237                             ZEBRA_IPV6_ROUTE_DELETE,
 238                             zclient, &quagga_prefix, NULL, &api);
 239 }
 240
 241 int
 242 if_eui64(char *ifname, int ifindex, unsigned char *eui)
 243 {
 244     struct interface *ifp = if_lookup_by_index(ifindex, VRF_DEFAULT);
 245     if (ifp == NULL) {
 246         return -1;
 247     }
 248 #ifdef HAVE_STRUCT_SOCKADDR_DL
 249     u_char len = ifp->sdl.sdl_alen;
 250     char *tmp = ifp->sdl.sdl_data + ifp->sdl.sdl_nlen;
 251 #else
 252     u_char len = (u_char) ifp->hw_addr_len;
 253     char *tmp = (void*) ifp->hw_addr;
 254 #endif
 255     if (len == 8) {
 256         memcpy(eui, tmp, 8);
 257         eui[0] ^= 2;
 258     } else if (len == 6) {
 259         memcpy(eui,   tmp,   3);
 260         eui[3] = 0xFF;
 261         eui[4] = 0xFE;
 262         memcpy(eui+5, tmp+3, 3);
 263     } else {
 264         return -1;
 265     }
 266     return 0;
 267 }
 268
 269 /* Like gettimeofday, but returns monotonic time.  If POSIX clocks are not
 270    available, falls back to gettimeofday but enforces monotonicity. */
 271 int
 272 gettime(struct timeval *tv)
 273 {
 274     return monotime(tv);
 275 }
 276
 277 /* If /dev/urandom doesn't exist, this will fail with ENOENT, which the
 278    caller will deal with gracefully. */
 279
 280 int
 281 read_random_bytes(void *buf, size_t len)
 282 {
 283     int fd;
 284     int rc;
 285
 286     fd = open("/dev/urandom", O_RDONLY);
 287     if(fd < 0) {
 288         rc = -1;
 289     } else {
 290         rc = read(fd, buf, len);
 291         if(rc < 0 || (unsigned) rc < len)
 292             rc = -1;
 293         close(fd);
 294     }
 295     return rc;
 296 }