ctdb/common/system_common.c

   1 /*
   2    ctdb system specific code to manage raw sockets on linux
   3
   4    Copyright (C) Ronnie Sahlberg  2007
   5    Copyright (C) Andrew Tridgell  2007
   6
   7    This program is free software; you can redistribute it and/or modify
   8    it under the terms of the GNU General Public License as published by
   9    the Free Software Foundation; either version 3 of the License, or
  10    (at your option) any later version.
  11
  12    This program is distributed in the hope that it will be useful,
  13    but WITHOUT ANY WARRANTY; without even the implied warranty of
  14    MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
  15    GNU General Public License for more details.
  16
  17    You should have received a copy of the GNU General Public License
  18    along with this program; if not, see <http://www.gnu.org/licenses/>.
  19 */
  20
  21 #include "includes.h"
  22 #include "system/network.h"
  23
  24 #include "ctdb_private.h"
  25
  26 /*
  27   uint16 checksum for n bytes
  28  */
  29 uint32_t uint16_checksum(uint16_t *data, size_t n)
  30 {
  31         uint32_t sum=0;
  32         while (n>=2) {
  33                 sum += (uint32_t)ntohs(*data);
  34                 data++;
  35                 n -= 2;
  36         }
  37         if (n == 1) {
  38                 sum += (uint32_t)ntohs(*(uint8_t *)data);
  39         }
  40         return sum;
  41 }
  42
  43 /*
  44   see if we currently have an interface with the given IP
  45
  46   we try to bind to it, and if that fails then we don't have that IP
  47   on an interface
  48  */
  49 bool ctdb_sys_have_ip(ctdb_sock_addr *_addr)
  50 {
  51         int s;
  52         int ret;
  53         ctdb_sock_addr __addr = *_addr;
  54         ctdb_sock_addr *addr = &__addr;
  55         socklen_t addrlen = 0;
  56
  57         switch (addr->sa.sa_family) {
  58         case AF_INET:
  59                 addr->ip.sin_port = 0;
  60                 addrlen = sizeof(struct sockaddr_in);
  61                 break;
  62         case AF_INET6:
  63                 addr->ip6.sin6_port = 0;
  64                 addrlen = sizeof(struct sockaddr_in6);
  65                 break;
  66         }
  67
  68         s = socket(addr->sa.sa_family, SOCK_STREAM, IPPROTO_TCP);
  69         if (s == -1) {
  70                 return false;
  71         }
  72
  73         ret = bind(s, (struct sockaddr *)addr, addrlen);
  74
  75         close(s);
  76         return ret == 0;
  77 }
  78
  79
  80 /* find which interface an ip address is currently assigned to */
  81 char *ctdb_sys_find_ifname(ctdb_sock_addr *addr)
  82 {
  83         int s;
  84         int size;
  85         struct ifconf ifc;
  86         char *ptr;
  87
  88         s = socket(AF_INET, SOCK_RAW, htons(IPPROTO_RAW));
  89         if (s == -1) {
  90                 DEBUG(DEBUG_CRIT,(__location__ " failed to open raw socket (%s)\n",
  91                          strerror(errno)));
  92                 return NULL;
  93         }
  94
  95
  96         size = sizeof(struct ifreq);
  97         ifc.ifc_buf = NULL;
  98         ifc.ifc_len = size;
  99
 100         while(ifc.ifc_len > (size - sizeof(struct ifreq))) {
 101                 size *= 2;
 102
 103                 free(ifc.ifc_buf);
 104                 ifc.ifc_len = size;
 105                 ifc.ifc_buf = malloc(size);
 106                 memset(ifc.ifc_buf, 0, size);
 107                 if (ioctl(s, SIOCGIFCONF, (caddr_t)&ifc) < 0) {
 108                         DEBUG(DEBUG_CRIT,("Failed to read ifc buffer from socket\n"));
 109                         free(ifc.ifc_buf);
 110                         close(s);
 111                         return NULL;
 112                 }
 113         }
 114
 115         for (ptr =(char *)ifc.ifc_buf; ptr < ((char *)ifc.ifc_buf) + ifc.ifc_len; ) {
 116                 char *ifname;
 117                 struct ifreq *ifr;
 118
 119                 ifr = (struct ifreq *)ptr;
 120
 121 #ifdef HAVE_SOCKADDR_LEN
 122                 if (ifr->ifr_addr.sa_len > sizeof(struct sockaddr)) {
 123                         ptr += sizeof(ifr->ifr_name) + ifr->ifr_addr.sa_len;
 124                 } else {
 125                         ptr += sizeof(ifr->ifr_name) + sizeof(struct sockaddr);
 126                 }
 127 #else
 128                 ptr += sizeof(struct ifreq);
 129 #endif
 130
 131                 if (ifr->ifr_addr.sa_family != addr->sa.sa_family) {
 132                         continue;
 133                 }
 134
 135                 switch (addr->sa.sa_family) {
 136                 case AF_INET:
 137
 138
 139                         if (memcmp(&addr->ip.sin_addr, &((struct sockaddr_in *)&ifr->ifr_addr)->sin_addr, sizeof(addr->ip.sin_addr))) {
 140                                 continue;
 141                         }
 142                         break;
 143                 case AF_INET6:
 144                         if (memcmp(&addr->ip6.sin6_addr, &((struct sockaddr_in6 *)&ifr->ifr_addr)->sin6_addr, sizeof(addr->ip6.sin6_addr))) {
 145                                 continue;
 146                         }
 147                         break;
 148                 }
 149
 150                 ifname = strdup(ifr->ifr_name);
 151                 free(ifc.ifc_buf);
 152                 close(s);
 153                 return ifname;
 154         }
 155
 156
 157         free(ifc.ifc_buf);
 158         close(s);
 159
 160         return NULL;
 161 }