| lh | 9ed821d | 2023-04-07 01:36:19 -0700 | [diff] [blame] | 1 | /* Copyright (C) 1996-2015 Free Software Foundation, Inc. |
| 2 | This file is part of the GNU C Library. |
| 3 | Contributed by Ulrich Drepper <drepper@cygnus.com>, 1996. |
| 4 | |
| 5 | The GNU C Library is free software; you can redistribute it and/or |
| 6 | modify it under the terms of the GNU Lesser General Public |
| 7 | License as published by the Free Software Foundation; either |
| 8 | version 2.1 of the License, or (at your option) any later version. |
| 9 | |
| 10 | The GNU C Library 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 GNU |
| 13 | Lesser General Public License for more details. |
| 14 | |
| 15 | You should have received a copy of the GNU Lesser General Public |
| 16 | License along with the GNU C Library; if not, see |
| 17 | <http://www.gnu.org/licenses/>. */ |
| 18 | |
| 19 | #include <errno.h> |
| 20 | #include <netinet/ether.h> |
| 21 | #include <netinet/if_ether.h> |
| 22 | #include <string.h> |
| 23 | |
| 24 | #include <nss/nsswitch.h> |
| 25 | |
| 26 | |
| 27 | /* Type of the lookup function we need here. */ |
| 28 | typedef int (*lookup_function) (const struct ether_addr *, struct etherent *, |
| 29 | char *, size_t, int *); |
| 30 | |
| 31 | /* The lookup function for the first entry of this service. */ |
| 32 | extern int __nss_ethers_lookup (service_user **nip, const char *name, |
| 33 | void **fctp) internal_function; |
| 34 | |
| 35 | |
| 36 | int |
| 37 | ether_ntohost (char *hostname, const struct ether_addr *addr) |
| 38 | { |
| 39 | static service_user *startp; |
| 40 | static lookup_function start_fct; |
| 41 | service_user *nip; |
| 42 | union |
| 43 | { |
| 44 | lookup_function f; |
| 45 | void *ptr; |
| 46 | } fct; |
| 47 | int no_more; |
| 48 | enum nss_status status = NSS_STATUS_UNAVAIL; |
| 49 | struct etherent etherent; |
| 50 | |
| 51 | if (startp == NULL) |
| 52 | { |
| 53 | no_more = __nss_ethers_lookup (&nip, "getntohost_r", &fct.ptr); |
| 54 | if (no_more) |
| 55 | startp = (service_user *) -1; |
| 56 | else |
| 57 | { |
| 58 | startp = nip; |
| 59 | start_fct = fct.f; |
| 60 | } |
| 61 | } |
| 62 | else |
| 63 | { |
| 64 | fct.f = start_fct; |
| 65 | no_more = (nip = startp) == (service_user *) -1; |
| 66 | } |
| 67 | |
| 68 | while (no_more == 0) |
| 69 | { |
| 70 | char buffer[1024]; |
| 71 | |
| 72 | status = (*fct.f) (addr, ðerent, buffer, sizeof buffer, &errno); |
| 73 | |
| 74 | no_more = __nss_next2 (&nip, "getntohost_r", NULL, &fct.ptr, status, 0); |
| 75 | } |
| 76 | |
| 77 | if (status == NSS_STATUS_SUCCESS) |
| 78 | /* XXX This is a potential cause of trouble because the size of |
| 79 | the HOSTNAME buffer is not known but the interface does not |
| 80 | provide this information. */ |
| 81 | strcpy (hostname, etherent.e_name); |
| 82 | |
| 83 | return status == NSS_STATUS_SUCCESS ? 0 : -1; |
| 84 | } |