1 | /* |
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2 | * nonlocal-shadow.c |
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3 | * shadow database for nss_nonlocal proxy. |
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4 | * |
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5 | * Copyright © 2007–2010 Anders Kaseorg <andersk@mit.edu> |
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6 | * |
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7 | * This file is part of nss_nonlocal. |
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8 | * |
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9 | * nss_nonlocal is free software; you can redistribute it and/or |
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10 | * modify it under the terms of the GNU Lesser General Public License |
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11 | * as published by the Free Software Foundation; either version 2.1 of |
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12 | * the License, or (at your option) any later version. |
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13 | * |
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14 | * nss_nonlocal is distributed in the hope that it will be useful, but |
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15 | * WITHOUT ANY WARRANTY; without even the implied warranty of |
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16 | * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the GNU |
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17 | * Lesser General Public License for more details. |
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18 | * |
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19 | * You should have received a copy of the GNU Lesser General Public |
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20 | * License along with nss_nonlocal; if not, write to the Free Software |
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21 | * Foundation, Inc., 51 Franklin Street, Fifth Floor, Boston, MA |
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22 | * 02110-1301 USA |
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23 | */ |
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24 | |
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25 | #define _GNU_SOURCE |
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26 | |
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27 | #include <sys/types.h> |
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28 | #include <dlfcn.h> |
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29 | #include <errno.h> |
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30 | #include <nss.h> |
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31 | #include <shadow.h> |
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32 | #include <stdbool.h> |
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33 | #include <stddef.h> |
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34 | #include <stdlib.h> |
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35 | #include <string.h> |
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36 | #include <syslog.h> |
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37 | |
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38 | #include "nsswitch-internal.h" |
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39 | #include "nonlocal.h" |
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40 | |
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41 | |
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42 | static service_user *__nss_shadow_nonlocal_database; |
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43 | |
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44 | static int |
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45 | internal_function |
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46 | __nss_shadow_nonlocal_lookup(service_user **ni, const char *fct_name, |
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47 | void **fctp) |
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48 | { |
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49 | if (__nss_shadow_nonlocal_database == NULL |
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50 | && __nss_database_lookup("shadow_nonlocal", NULL, NULL, |
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51 | &__nss_shadow_nonlocal_database) < 0) |
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52 | return -1; |
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53 | |
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54 | *ni = __nss_shadow_nonlocal_database; |
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55 | |
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56 | *fctp = __nss_lookup_function(*ni, fct_name); |
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57 | return 0; |
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58 | } |
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59 | |
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60 | |
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61 | static bool spent_initialized = false; |
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62 | static service_user *spent_startp, *spent_nip; |
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63 | static void *spent_fct_start; |
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64 | static union { |
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65 | enum nss_status (*l)(struct spwd *pwd, char *buffer, size_t buflen, |
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66 | int *errnop); |
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67 | void *ptr; |
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68 | } spent_fct; |
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69 | static const char *spent_fct_name = "getspent_r"; |
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70 | |
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71 | enum nss_status |
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72 | _nss_nonlocal_setspent(int stayopen) |
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73 | { |
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74 | enum nss_status status; |
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75 | const struct walk_nss w = { |
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76 | .lookup = &__nss_shadow_nonlocal_lookup, .fct_name = "setspent", |
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77 | .status = &status |
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78 | }; |
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79 | const __typeof__(&_nss_nonlocal_setspent) self = NULL; |
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80 | #define args (stayopen) |
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81 | #include "walk_nss.h" |
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82 | #undef args |
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83 | if (status != NSS_STATUS_SUCCESS) |
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84 | return status; |
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85 | |
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86 | if (!spent_initialized) { |
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87 | __nss_shadow_nonlocal_lookup(&spent_startp, spent_fct_name, |
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88 | &spent_fct_start); |
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89 | __sync_synchronize(); |
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90 | spent_initialized = true; |
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91 | } |
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92 | spent_nip = spent_startp; |
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93 | spent_fct.ptr = spent_fct_start; |
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94 | return NSS_STATUS_SUCCESS; |
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95 | } |
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96 | |
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97 | enum nss_status |
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98 | _nss_nonlocal_endspent(void) |
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99 | { |
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100 | enum nss_status status; |
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101 | const struct walk_nss w = { |
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102 | .lookup = &__nss_shadow_nonlocal_lookup, .fct_name = "endspent", |
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103 | .status = &status |
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104 | }; |
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105 | const __typeof__(&_nss_nonlocal_endspent) self = NULL; |
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106 | |
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107 | spent_nip = NULL; |
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108 | |
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109 | #define args () |
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110 | #include "walk_nss.h" |
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111 | #undef args |
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112 | return status; |
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113 | } |
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114 | |
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115 | enum nss_status |
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116 | _nss_nonlocal_getspent_r(struct spwd *pwd, char *buffer, size_t buflen, |
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117 | int *errnop) |
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118 | { |
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119 | enum nss_status status; |
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120 | |
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121 | char *nonlocal_ignore = getenv(NONLOCAL_IGNORE_ENV); |
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122 | if (nonlocal_ignore != NULL && nonlocal_ignore[0] != '\0') |
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123 | return NSS_STATUS_UNAVAIL; |
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124 | |
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125 | if (spent_nip == NULL) { |
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126 | status = _nss_nonlocal_setspent(0); |
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127 | if (status != NSS_STATUS_SUCCESS) |
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128 | return status; |
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129 | } |
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130 | do { |
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131 | if (spent_fct.ptr == NULL) |
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132 | status = NSS_STATUS_UNAVAIL; |
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133 | else |
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134 | status = DL_CALL_FCT(spent_fct.l, (pwd, buffer, buflen, errnop)); |
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135 | if (status == NSS_STATUS_TRYAGAIN && *errnop == ERANGE) |
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136 | return status; |
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137 | |
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138 | if (status == NSS_STATUS_SUCCESS) |
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139 | return NSS_STATUS_SUCCESS; |
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140 | } while (__nss_next(&spent_nip, spent_fct_name, &spent_fct.ptr, status, 0) == 0); |
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141 | |
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142 | spent_nip = NULL; |
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143 | return NSS_STATUS_NOTFOUND; |
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144 | } |
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145 | |
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146 | |
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147 | enum nss_status |
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148 | _nss_nonlocal_getspnam_r(const char *name, struct spwd *pwd, |
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149 | char *buffer, size_t buflen, int *errnop) |
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150 | { |
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151 | enum nss_status status; |
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152 | const struct walk_nss w = { |
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153 | .lookup = __nss_shadow_nonlocal_lookup, .fct_name = "getspnam_r", |
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154 | .status = &status, .errnop = errnop |
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155 | }; |
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156 | const __typeof__(&_nss_nonlocal_getspnam_r) self = NULL; |
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157 | #define args (name, pwd, buffer, buflen, errnop) |
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158 | #include "walk_nss.h" |
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159 | #undef args |
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160 | if (status != NSS_STATUS_SUCCESS) |
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161 | return status; |
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162 | |
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163 | if (strcmp(name, pwd->sp_namp) != 0) { |
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164 | syslog(LOG_ERR, "nss_nonlocal: discarding shadow %s from lookup for shadow %s\n", pwd->sp_namp, name); |
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165 | return NSS_STATUS_NOTFOUND; |
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166 | } |
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167 | |
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168 | return NSS_STATUS_SUCCESS; |
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169 | } |
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