1 | /* Copyright (C) 1996, 1997, 1999, 2001, 2002 Free Software Foundation, Inc. |
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2 | This file is part of the GNU C Library. |
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3 | Contributed by Ulrich Drepper <drepper@cygnus.com>, 1996. |
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4 | |
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5 | The GNU C Library is free software; you can redistribute it and/or |
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6 | modify it under the terms of the GNU Lesser General Public |
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7 | License as published by the Free Software Foundation; either |
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8 | version 2.1 of the License, or (at your option) any later version. |
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9 | |
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10 | The GNU C Library is distributed in the hope that it will be useful, |
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11 | but WITHOUT ANY WARRANTY; without even the implied warranty of |
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12 | MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the GNU |
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13 | Lesser General Public License for more details. |
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14 | |
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15 | You should have received a copy of the GNU Lesser General Public |
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16 | License along with the GNU C Library; if not, write to the Free |
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17 | Software Foundation, Inc., 59 Temple Place, Suite 330, Boston, MA |
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18 | 02111-1307 USA. */ |
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19 | |
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20 | #include <errno.h> |
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21 | #include <netinet/ether.h> |
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22 | #include <netinet/if_ether.h> |
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23 | #include <string.h> |
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24 | #include "etherent.h" |
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25 | |
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26 | #include "nsswitch.h" |
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27 | |
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28 | |
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29 | /* Type of the lookup function we need here. */ |
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30 | typedef int (*lookup_function) (const struct ether_addr *, struct etherent *, |
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31 | char *, size_t, int *); |
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32 | |
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33 | /* The lookup function for the first entry of this service. */ |
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34 | extern int __nss_ethers_lookup (service_user **nip, const char *name, |
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35 | void **fctp) internal_function; |
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36 | |
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37 | |
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38 | int |
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39 | ether_ntohost (char *hostname, const struct ether_addr *addr) |
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40 | { |
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41 | static service_user *startp; |
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42 | static lookup_function start_fct; |
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43 | service_user *nip; |
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44 | union |
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45 | { |
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46 | lookup_function f; |
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47 | void *ptr; |
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48 | } fct; |
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49 | int no_more; |
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50 | enum nss_status status = NSS_STATUS_UNAVAIL; |
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51 | struct etherent etherent; |
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52 | |
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53 | if (startp == NULL) |
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54 | { |
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55 | no_more = __nss_ethers_lookup (&nip, "getntohost_r", &fct.ptr); |
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56 | if (no_more) |
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57 | startp = (service_user *) -1; |
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58 | else |
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59 | { |
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60 | startp = nip; |
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61 | start_fct = fct.f; |
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62 | } |
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63 | } |
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64 | else |
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65 | { |
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66 | fct.f = start_fct; |
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67 | no_more = (nip = startp) == (service_user *) -1; |
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68 | } |
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69 | |
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70 | while (no_more == 0) |
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71 | { |
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72 | char buffer[1024]; |
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73 | |
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74 | status = (*fct.f) (addr, ðerent, buffer, sizeof buffer, &errno); |
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75 | |
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76 | no_more = __nss_next (&nip, "getntohost_r", &fct.ptr, status, 0); |
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77 | } |
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78 | |
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79 | if (status == NSS_STATUS_SUCCESS) |
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80 | /* XXX This is a potential cause of trouble because the size of |
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81 | the HOSTNAME buffer is not known but the interface does not |
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82 | provide this information. */ |
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83 | strcpy (hostname, etherent.e_name); |
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84 | |
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85 | return status == NSS_STATUS_SUCCESS ? 0 : -1; |
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86 | } |
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