contrib/bind-9.5.2/lib/isc/unix/ifiter_getifaddrs.c

   1 /*
   2  * Copyright (C) 2004, 2005, 2007  Internet Systems Consortium, Inc. ("ISC")
   3  * Copyright (C) 2003  Internet Software Consortium.
   4  *
   5  * Permission to use, copy, modify, and/or distribute this software for any
   6  * purpose with or without fee is hereby granted, provided that the above
   7  * copyright notice and this permission notice appear in all copies.
   8  *
   9  * THE SOFTWARE IS PROVIDED "AS IS" AND ISC DISCLAIMS ALL WARRANTIES WITH
  10  * REGARD TO THIS SOFTWARE INCLUDING ALL IMPLIED WARRANTIES OF MERCHANTABILITY
  11  * AND FITNESS.  IN NO EVENT SHALL ISC BE LIABLE FOR ANY SPECIAL, DIRECT,
  12  * INDIRECT, OR CONSEQUENTIAL DAMAGES OR ANY DAMAGES WHATSOEVER RESULTING FROM
  13  * LOSS OF USE, DATA OR PROFITS, WHETHER IN AN ACTION OF CONTRACT, NEGLIGENCE
  14  * OR OTHER TORTIOUS ACTION, ARISING OUT OF OR IN CONNECTION WITH THE USE OR
  15  * PERFORMANCE OF THIS SOFTWARE.
  16  */
  17
  18 /* $Id: ifiter_getifaddrs.c,v 1.9 2007/06/18 23:47:48 tbox Exp $ */
  19
  20 /*! \file
  21  * \brief
  22  * Obtain the list of network interfaces using the getifaddrs(3) library.
  23  */
  24
  25 #include <ifaddrs.h>
  26
  27 /*% Iterator Magic */
  28 #define IFITER_MAGIC            ISC_MAGIC('I', 'F', 'I', 'G')
  29 /*% Valid Iterator */
  30 #define VALID_IFITER(t)         ISC_MAGIC_VALID(t, IFITER_MAGIC)
  31
  32 /*% Iterator structure */
  33 struct isc_interfaceiter {
  34         unsigned int            magic;          /*%< Magic number. */
  35         isc_mem_t               *mctx;
  36         void                    *buf;           /*%< (unused) */
  37         unsigned int            bufsize;        /*%< (always 0) */
  38         struct ifaddrs          *ifaddrs;       /*%< List of ifaddrs */
  39         struct ifaddrs          *pos;           /*%< Ptr to current ifaddr */
  40         isc_interface_t         current;        /*%< Current interface data. */
  41         isc_result_t            result;         /*%< Last result code. */
  42 };
  43
  44
  45 isc_result_t
  46 isc_interfaceiter_create(isc_mem_t *mctx, isc_interfaceiter_t **iterp) {
  47         isc_interfaceiter_t *iter;
  48         isc_result_t result;
  49         char strbuf[ISC_STRERRORSIZE];
  50
  51         REQUIRE(mctx != NULL);
  52         REQUIRE(iterp != NULL);
  53         REQUIRE(*iterp == NULL);
  54
  55         iter = isc_mem_get(mctx, sizeof(*iter));
  56         if (iter == NULL)
  57                 return (ISC_R_NOMEMORY);
  58
  59         iter->mctx = mctx;
  60         iter->buf = NULL;
  61         iter->bufsize = 0;
  62         iter->ifaddrs = NULL;
  63
  64         if (getifaddrs(&iter->ifaddrs) < 0) {
  65                 isc__strerror(errno, strbuf, sizeof(strbuf));
  66                 UNEXPECTED_ERROR(__FILE__, __LINE__,
  67                                  isc_msgcat_get(isc_msgcat,
  68                                                 ISC_MSGSET_IFITERGETIFADDRS,
  69                                                 ISC_MSG_GETIFADDRS,
  70                                                 "getting interface "
  71                                                 "addresses: getifaddrs: %s"),
  72                                  strbuf);
  73                 result = ISC_R_UNEXPECTED;
  74                 goto failure;
  75         }
  76
  77         /*
  78          * A newly created iterator has an undefined position
  79          * until isc_interfaceiter_first() is called.
  80          */
  81         iter->pos = NULL;
  82         iter->result = ISC_R_FAILURE;
  83
  84         iter->magic = IFITER_MAGIC;
  85         *iterp = iter;
  86         return (ISC_R_SUCCESS);
  87
  88  failure:
  89         if (iter->ifaddrs != NULL) /* just in case */
  90                 freeifaddrs(iter->ifaddrs);
  91         isc_mem_put(mctx, iter, sizeof(*iter));
  92         return (result);
  93 }
  94
  95 /*
  96  * Get information about the current interface to iter->current.
  97  * If successful, return ISC_R_SUCCESS.
  98  * If the interface has an unsupported address family,
  99  * return ISC_R_IGNORE.
 100  */
 101
 102 static isc_result_t
 103 internal_current(isc_interfaceiter_t *iter) {
 104         struct ifaddrs *ifa;
 105         int family;
 106         unsigned int namelen;
 107
 108         REQUIRE(VALID_IFITER(iter));
 109
 110         ifa = iter->pos;
 111
 112         INSIST(ifa != NULL);
 113         INSIST(ifa->ifa_name != NULL);
 114
 115         if (ifa->ifa_addr == NULL)
 116                 return (ISC_R_IGNORE);
 117
 118         family = ifa->ifa_addr->sa_family;
 119         if (family != AF_INET && family != AF_INET6)
 120                 return (ISC_R_IGNORE);
 121
 122         memset(&iter->current, 0, sizeof(iter->current));
 123
 124         namelen = strlen(ifa->ifa_name);
 125         if (namelen > sizeof(iter->current.name) - 1)
 126                 namelen = sizeof(iter->current.name) - 1;
 127
 128         memset(iter->current.name, 0, sizeof(iter->current.name));
 129         memcpy(iter->current.name, ifa->ifa_name, namelen);
 130
 131         iter->current.flags = 0;
 132
 133         if ((ifa->ifa_flags & IFF_UP) != 0)
 134                 iter->current.flags |= INTERFACE_F_UP;
 135
 136         if ((ifa->ifa_flags & IFF_POINTOPOINT) != 0)
 137                 iter->current.flags |= INTERFACE_F_POINTTOPOINT;
 138
 139         if ((ifa->ifa_flags & IFF_LOOPBACK) != 0)
 140                 iter->current.flags |= INTERFACE_F_LOOPBACK;
 141
 142         iter->current.af = family;
 143
 144         get_addr(family, &iter->current.address, ifa->ifa_addr, ifa->ifa_name);
 145
 146         if (ifa->ifa_netmask != NULL)
 147                 get_addr(family, &iter->current.netmask, ifa->ifa_netmask,
 148                          ifa->ifa_name);
 149
 150         if (ifa->ifa_dstaddr != NULL &&
 151             (iter->current.flags & IFF_POINTOPOINT) != 0)
 152                 get_addr(family, &iter->current.dstaddress, ifa->ifa_dstaddr,
 153                          ifa->ifa_name);
 154
 155         return (ISC_R_SUCCESS);
 156 }
 157
 158 /*
 159  * Step the iterator to the next interface.  Unlike
 160  * isc_interfaceiter_next(), this may leave the iterator
 161  * positioned on an interface that will ultimately
 162  * be ignored.  Return ISC_R_NOMORE if there are no more
 163  * interfaces, otherwise ISC_R_SUCCESS.
 164  */
 165 static isc_result_t
 166 internal_next(isc_interfaceiter_t *iter) {
 167         iter->pos = iter->pos->ifa_next;
 168
 169         if (iter->pos == NULL)
 170                 return (ISC_R_NOMORE);
 171
 172         return (ISC_R_SUCCESS);
 173 }
 174
 175 static void
 176 internal_destroy(isc_interfaceiter_t *iter) {
 177         if (iter->ifaddrs)
 178                 freeifaddrs(iter->ifaddrs);
 179         iter->ifaddrs = NULL;
 180 }
 181
 182 static
 183 void internal_first(isc_interfaceiter_t *iter) {
 184         iter->pos = iter->ifaddrs;
 185 }