vde-2/src/vde_vxlan/vxlan.c

   1 /*
   2  * VDE - vde_vxlan Network emulator for vde
   3  * Copyright (C) 2014 Renzo Davoli, Alessandro Ghedini VirtualSquare
   4  *
   5  * This program is free software; you can redistribute it and/or modify
   6  * it under the terms of the GNU General Public License as published by
   7  * the Free Software Foundation; either version 2 of the License, or
   8  * (at your option) any later version.
   9  *
  10  * This program is distributed in the hope that it will be useful,
  11  * but WITHOUT ANY WARRANTY; without even the implied warranty of
  12  * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
  13  * GNU General Public License for more details.
  14  *
  15  * You should have received a copy of the GNU General Public License
  16  * along with this program; if not, write to the Free Software
  17  * Foundation, Inc., 51 Franklin St, Fifth Floor, Boston, MA  02110-1301, USA.
  18  */
  19
  20 #include <stdlib.h>
  21 #include <stddef.h>
  22 #include <unistd.h>
  23 #include <poll.h>
  24
  25 #include <netinet/in.h>
  26 #include <sys/un.h>
  27
  28 #include "vxlan_hash.h"
  29 #include "log.h"
  30 #include "vxlan.h"
  31 #include "plug.h"
  32
  33 #define ntoh24(p) (((p)[0] << 16) | ((p)[1] << 8) | ((p)[2]))
  34 #define hton24(p, v) { \
  35         p[0] = (((v) >> 16) & 0xFF); \
  36         p[1] = (((v) >> 8) & 0xFF); \
  37         p[2] = ((v) & 0xFF); \
  38 }
  39
  40 int       vxlan_id   = -1;
  41 in_addr_t vxlan_addr = INADDR_NONE;
  42 int       vxlan_port = 4879;
  43 int       vxlan_mttl = 1;
  44
  45 static int    vxlan_fd = -1;
  46
  47 void vxlan_open(struct pollfd *pfd) {
  48         int sock;
  49         int loop = 0;
  50
  51         struct ip_mreq mc_req;
  52         struct sockaddr_in addr_in;
  53
  54         if ((sock = socket(AF_INET, SOCK_DGRAM, IPPROTO_UDP)) < 0) {
  55                 printlog(LOG_ERR, "socket(): %s", strerror(errno));
  56                 exit(1);
  57         }
  58
  59         if ((setsockopt(sock, IPPROTO_IP, IP_MULTICAST_TTL,
  60                                         &vxlan_mttl, sizeof(vxlan_mttl))) < 0) {
  61                 printlog(LOG_ERR, "setsockopt(TTL): %s", strerror(errno));
  62                 exit(1);
  63         }
  64
  65         if ((setsockopt(sock, IPPROTO_IP, IP_MULTICAST_LOOP,
  66                                         &loop, sizeof(loop))) < 0) {
  67                 printlog(LOG_ERR, "setsockopt(LOOP): %s", strerror(errno));
  68                 exit(1);
  69         }
  70
  71         memset(&addr_in, 0, sizeof(addr_in));
  72         addr_in.sin_family      = AF_INET;
  73         addr_in.sin_addr.s_addr = htonl(INADDR_ANY);
  74         addr_in.sin_port        = htons(vxlan_port);
  75
  76         if ((bind(sock, (struct sockaddr *) &addr_in, sizeof(addr_in))) < 0) {
  77                 printlog(LOG_ERR, "bind(): %s", strerror(errno));
  78                 exit(1);
  79         }
  80
  81         /* send an IGMP join request */
  82         mc_req.imr_multiaddr.s_addr = vxlan_addr;
  83         mc_req.imr_interface.s_addr = htonl(INADDR_ANY);
  84
  85         if ((setsockopt(sock, IPPROTO_IP, IP_ADD_MEMBERSHIP,
  86                                         &mc_req, sizeof(mc_req))) < 0) {
  87                 printlog(LOG_ERR, "setsockopt(ADD): %s", strerror(errno));
  88                 exit(1);
  89         }
  90
  91         vxlan_fd = sock;
  92
  93         pfd[2].fd = sock;
  94         pfd[2].events = POLLIN | POLLHUP;
  95 }
  96
  97 void vxlan_process() {
  98         struct vxlan_pkt pkt;
  99
 100         struct sockaddr_in src_addr;
 101         socklen_t src_addr_len=sizeof(src_addr);
 102
 103         in_addr_t dest_addr;
 104
 105         size_t len = recvfrom(vxlan_fd, &pkt, sizeof(pkt), 0,
 106                         (struct sockaddr *) &src_addr, &src_addr_len);
 107
 108         if (len < 0)
 109                 printlog(LOG_ERR, "recvfrom(): %s", strerror(errno));
 110
 111         printlog(LOG_DEBUG, "VXLAN packet from %s",inet_ntoa(src_addr.sin_addr));
 112
 113         if (pkt.flags != (1<<3)) {
 114                 printlog(LOG_ERR, "Invalid flags");
 115                 return;
 116         }
 117
 118         if (ntoh24(pkt.id) != vxlan_id) {
 119                 printlog(LOG_DEBUG, "Invalid VNI");
 120                 return;
 121         }
 122
 123         find_in_hash_update(pkt.pkt.header.src, vxlan_id,
 124                         src_addr.sin_addr.s_addr, NULL);
 125
 126         if ((pkt.pkt.header.dest[0] == 0xff) &&
 127             (pkt.pkt.header.dest[1] == 0xff) &&
 128             (pkt.pkt.header.dest[2] == 0xff) &&
 129             (pkt.pkt.header.dest[3] == 0xff) &&
 130             (pkt.pkt.header.dest[4] == 0xff) &&
 131             (pkt.pkt.header.dest[5] == 0xff)) {
 132                 printlog(LOG_DEBUG, "Broadcast send");
 133
 134                 plug_send(&pkt.pkt, len-offsetof(struct vxlan_pkt,pkt));
 135                 return;
 136         }
 137
 138         find_in_hash(pkt.pkt.header.dest, vxlan_id, &dest_addr);
 139
 140         switch (dest_addr) {
 141                 case 0:
 142                         printlog(LOG_DEBUG, "Not found");
 143                 case 1:
 144                         plug_send(&pkt.pkt,len-offsetof(struct vxlan_pkt,pkt));
 145                         printlog(LOG_DEBUG, "Send to VDE");
 146                         break;
 147
 148                 default:
 149                         printlog(LOG_DEBUG, "Drop");
 150                         break;
 151         }
 152 }
 153
 154 void vxlan_send(in_addr_t addr_s, struct vxlan_pkt *pkt, size_t len) {
 155         struct sockaddr_in addr;
 156
 157         addr.sin_family      = AF_INET;
 158         addr.sin_addr.s_addr = addr_s ? addr_s : vxlan_addr;
 159         addr.sin_port        = htons(vxlan_port);
 160
 161         memset(pkt, 0, offsetof(struct vxlan_pkt,pkt));
 162         pkt->flags = (1 << 3);
 163
 164         hton24(pkt->id, vxlan_id);
 165
 166         if (sendto(vxlan_fd, pkt, len+offsetof(struct vxlan_pkt,pkt), 0,
 167                    (struct sockaddr *) &addr, sizeof(addr)) < 0)
 168                 printlog(LOG_ERR, "sendto(): %s", strerror(errno));
 169 }
 170
 171 void vxlan_close() {
 172         if (vxlan_fd == -1)
 173                 return;
 174
 175         struct ip_mreq mc_req;
 176
 177         mc_req.imr_multiaddr.s_addr = vxlan_addr;
 178         mc_req.imr_interface.s_addr = htonl(INADDR_ANY);
 179
 180         if ((setsockopt(vxlan_fd, IPPROTO_IP, IP_DROP_MEMBERSHIP,
 181                         (void *) &mc_req, sizeof(mc_req))) < 0) {
 182                 printlog(LOG_ERR, "setsockopt(DROP): %s", strerror(errno));
 183                 exit(1);
 184         }
 185
 186         close(vxlan_fd);
 187 }