| /* Get source filter. Linux version. |
| Copyright (C) 2004-2014 Free Software Foundation, Inc. |
| This file is part of the GNU C Library. |
| Contributed by Ulrich Drepper <drepper@redhat.com>, 2004. |
| |
| The GNU C Library is free software; you can redistribute it and/or |
| modify it under the terms of the GNU Lesser General Public |
| License as published by the Free Software Foundation; either |
| version 2.1 of the License, or (at your option) any later version. |
| |
| The GNU C Library is distributed in the hope that it will be useful, |
| but WITHOUT ANY WARRANTY; without even the implied warranty of |
| MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the GNU |
| Lesser General Public License for more details. |
| |
| You should have received a copy of the GNU Lesser General Public |
| License along with the GNU C Library; if not, see |
| <http://www.gnu.org/licenses/>. */ |
| |
| #include <alloca.h> |
| #include <assert.h> |
| #include <errno.h> |
| #include <stdlib.h> |
| #include <string.h> |
| #include <stdint.h> |
| #include <netatalk/at.h> |
| #include <netax25/ax25.h> |
| #include <netinet/in.h> |
| #include <netipx/ipx.h> |
| #include <netpacket/packet.h> |
| #include <netrose/rose.h> |
| #include <sys/param.h> |
| #include <sys/socket.h> |
| |
| |
| static const struct |
| { |
| int sol; |
| int af; |
| socklen_t size; |
| } sol_map[] = |
| { |
| /* Sort the array according to importance of the protocols. Add |
| more protocols when they become available. */ |
| { SOL_IP, AF_INET, sizeof (struct sockaddr_in) }, |
| { SOL_IPV6, AF_INET6, sizeof (struct sockaddr_in6) }, |
| { SOL_AX25, AF_AX25, sizeof (struct sockaddr_ax25) }, |
| { SOL_IPX, AF_IPX, sizeof (struct sockaddr_ipx) }, |
| { SOL_ATALK, AF_APPLETALK, sizeof (struct sockaddr_at) }, |
| { SOL_ROSE, AF_ROSE, sizeof (struct sockaddr_rose) }, |
| { SOL_PACKET, AF_PACKET, sizeof (struct sockaddr_ll) } |
| }; |
| #define NSOL_MAP (sizeof (sol_map) / sizeof (sol_map[0])) |
| |
| |
| /* Try to determine the socket level value. Ideally both side and |
| family are set. But sometimes only the size is correct and the |
| family value might be bogus. Loop over the array entries and look |
| for a perfect match or the first match based on size. */ |
| int |
| __get_sol (int af, socklen_t len) |
| { |
| int first_size_sol = -1; |
| |
| for (size_t cnt = 0; cnt < NSOL_MAP; ++cnt) |
| { |
| /* Just a test so that we make sure the special value used to |
| signal the "we have so far no socket level value" is OK. */ |
| assert (sol_map[cnt].sol != -1); |
| |
| if (len == sol_map[cnt].size) |
| { |
| /* The size matches, which is a requirement. If the family |
| matches, too, we have a winner. Otherwise we remember the |
| socket level value for this protocol if it is the first |
| match. */ |
| if (af == sol_map[cnt].af) |
| /* Bingo! */ |
| return sol_map[cnt].sol; |
| |
| if (first_size_sol == -1) |
| first_size_sol = sol_map[cnt].sol; |
| } |
| } |
| |
| return first_size_sol; |
| } |
| |
| |
| int |
| getsourcefilter (int s, uint32_t interface, const struct sockaddr *group, |
| socklen_t grouplen, uint32_t *fmode, uint32_t *numsrc, |
| struct sockaddr_storage *slist) |
| { |
| /* We have to create an struct ip_msfilter object which we can pass |
| to the kernel. */ |
| socklen_t needed = GROUP_FILTER_SIZE (*numsrc); |
| int use_alloca = __libc_use_alloca (needed); |
| |
| struct group_filter *gf; |
| if (use_alloca) |
| gf = (struct group_filter *) alloca (needed); |
| else |
| { |
| gf = (struct group_filter *) malloc (needed); |
| if (gf == NULL) |
| return -1; |
| } |
| |
| gf->gf_interface = interface; |
| memcpy (&gf->gf_group, group, grouplen); |
| gf->gf_numsrc = *numsrc; |
| |
| /* We need to provide the appropriate socket level value. */ |
| int result; |
| int sol = __get_sol (group->sa_family, grouplen); |
| if (sol == -1) |
| { |
| __set_errno (EINVAL); |
| result = -1; |
| } |
| else |
| { |
| result = __getsockopt (s, sol, MCAST_MSFILTER, gf, &needed); |
| |
| /* If successful, copy the results to the places the caller wants |
| them in. */ |
| if (result == 0) |
| { |
| *fmode = gf->gf_fmode; |
| memcpy (slist, gf->gf_slist, |
| MIN (*numsrc, gf->gf_numsrc) |
| * sizeof (struct sockaddr_storage)); |
| *numsrc = gf->gf_numsrc; |
| } |
| } |
| |
| if (! use_alloca) |
| { |
| int save_errno = errno; |
| free (gf); |
| __set_errno (save_errno); |
| } |
| |
| return result; |
| } |