126
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1
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2 /*
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3 * Copyright (C) Igor Sysoev
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4 */
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5
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6
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7 #include <ngx_config.h>
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8 #include <ngx_core.h>
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9 #include <ngx_http.h>
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10
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11
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144
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12 #define NGX_HTTP_REFERER_NO_URI_PART ((void *) 4)
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13
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326
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14 #if (NGX_PCRE)
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15
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16 typedef struct {
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17 ngx_regex_t *regex;
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18 ngx_str_t name;
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19 } ngx_http_referer_regex_t;
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20
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21 #else
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22
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23 #define ngx_regex_t void
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24
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25 #endif
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26
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27
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126
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28 typedef struct {
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312
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29 ngx_hash_combined_t hash;
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126
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30
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326
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31 #if (NGX_PCRE)
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32 ngx_array_t *regex;
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33 #endif
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34
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142
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35 ngx_flag_t no_referer;
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36 ngx_flag_t blocked_referer;
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126
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37
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142
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38 ngx_hash_keys_arrays_t *keys;
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126
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39 } ngx_http_referer_conf_t;
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40
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41
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42 static void * ngx_http_referer_create_conf(ngx_conf_t *cf);
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43 static char * ngx_http_referer_merge_conf(ngx_conf_t *cf, void *parent,
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44 void *child);
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45 static char *ngx_http_valid_referers(ngx_conf_t *cf, ngx_command_t *cmd,
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46 void *conf);
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142
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47 static char *ngx_http_add_referer(ngx_conf_t *cf, ngx_hash_keys_arrays_t *keys,
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144
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48 ngx_str_t *value, ngx_str_t *uri);
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326
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49 static char *ngx_http_add_regex_referer(ngx_conf_t *cf,
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50 ngx_http_referer_conf_t *rlcf, ngx_str_t *name, ngx_regex_t *regex);
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142
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51 static int ngx_libc_cdecl ngx_http_cmp_referer_wildcards(const void *one,
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52 const void *two);
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126
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53
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54
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55 static ngx_command_t ngx_http_referer_commands[] = {
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56
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57 { ngx_string("valid_referers"),
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58 NGX_HTTP_SRV_CONF|NGX_HTTP_LOC_CONF|NGX_CONF_1MORE,
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59 ngx_http_valid_referers,
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60 NGX_HTTP_LOC_CONF_OFFSET,
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61 0,
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62 NULL },
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63
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64 ngx_null_command
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65 };
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66
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67
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68 static ngx_http_module_t ngx_http_referer_module_ctx = {
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69 NULL, /* preconfiguration */
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70 NULL, /* postconfiguration */
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71
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72 NULL, /* create main configuration */
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73 NULL, /* init main configuration */
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74
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75 NULL, /* create server configuration */
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76 NULL, /* merge server configuration */
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77
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78 ngx_http_referer_create_conf, /* create location configuration */
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79 ngx_http_referer_merge_conf /* merge location configuration */
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80 };
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81
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82
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83 ngx_module_t ngx_http_referer_module = {
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84 NGX_MODULE_V1,
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85 &ngx_http_referer_module_ctx, /* module context */
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86 ngx_http_referer_commands, /* module directives */
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87 NGX_HTTP_MODULE, /* module type */
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88 NULL, /* init master */
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89 NULL, /* init module */
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90 NULL, /* init process */
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91 NULL, /* init thread */
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92 NULL, /* exit thread */
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93 NULL, /* exit process */
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94 NULL, /* exit master */
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95 NGX_MODULE_V1_PADDING
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96 };
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97
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98
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99 static ngx_int_t
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100 ngx_http_referer_variable(ngx_http_request_t *r, ngx_http_variable_value_t *v,
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101 uintptr_t data)
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102 {
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326
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103 u_char *p, *ref, *last;
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104 size_t len;
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105 ngx_str_t *uri;
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106 ngx_uint_t i, key;
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107 ngx_http_referer_conf_t *rlcf;
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108 u_char buf[256];
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109 #if (NGX_PCRE)
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110 ngx_int_t n;
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111 ngx_str_t referer;
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112 ngx_http_referer_regex_t *regex;
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113 #endif
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126
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114
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142
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115 rlcf = ngx_http_get_module_loc_conf(r, ngx_http_referer_module);
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126
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116
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312
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117 if (rlcf->hash.hash.buckets == NULL
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118 && rlcf->hash.wc_head == NULL
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326
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119 && rlcf->hash.wc_tail == NULL
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120 #if (NGX_PCRE)
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121 && rlcf->regex == NULL
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122 #endif
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123 )
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312
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124 {
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144
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125 goto valid;
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126
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126 }
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127
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128 if (r->headers_in.referer == NULL) {
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142
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129 if (rlcf->no_referer) {
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144
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130 goto valid;
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131 }
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126
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132
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144
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133 goto invalid;
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126
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134 }
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135
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136 len = r->headers_in.referer->value.len;
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137 ref = r->headers_in.referer->value.data;
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138
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139 if (len < sizeof("http://i.ru") - 1
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286
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140 || (ngx_strncasecmp(ref, (u_char *) "http://", 7) != 0))
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126
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141 {
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142
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142 if (rlcf->blocked_referer) {
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144
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143 goto valid;
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144 }
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126
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145
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144
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146 goto invalid;
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126
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147 }
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148
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144
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149 last = ref + len;
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126
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150 ref += 7;
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144
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151 i = 0;
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152 key = 0;
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126
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153
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144
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154 for (p = ref; p < last; p++) {
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142
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155 if (*p == '/' || *p == ':') {
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156 break;
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126
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157 }
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144
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158
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159 buf[i] = ngx_tolower(*p);
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160 key = ngx_hash(key, buf[i++]);
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161
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162 if (i == 256) {
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163 goto invalid;
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164 }
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142
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165 }
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126
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166
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326
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167 uri = ngx_hash_find_combined(&rlcf->hash, key, buf, p - ref);
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126
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168
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312
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169 if (uri) {
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170 goto uri;
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126
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171 }
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172
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326
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173 #if (NGX_PCRE)
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174
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175 if (rlcf->regex) {
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176
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177 referer.len = len - 7;
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178 referer.data = ref;
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179
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180 regex = rlcf->regex->elts;
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181
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182 for (i = 0; i < rlcf->regex->nelts; i++) {
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183 n = ngx_regex_exec(regex[i].regex, &referer, NULL, 0);
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184
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185 if (n == NGX_REGEX_NO_MATCHED) {
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186 continue;
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187 }
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188
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189 if (n < 0) {
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190 ngx_log_error(NGX_LOG_ALERT, r->connection->log, 0,
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191 ngx_regex_exec_n
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192 " failed: %d on \"%V\" using \"%V\"",
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193 n, &referer, ®ex[i].name);
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194 return NGX_ERROR;
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195 }
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196
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197 /* match */
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198
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199 goto valid;
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200 }
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201 }
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202
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203 #endif
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204
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144
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205 invalid:
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206
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126
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207 *v = ngx_http_variable_true_value;
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208
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209 return NGX_OK;
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144
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210
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211 uri:
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212
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213 for ( /* void */ ; p < last; p++) {
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214 if (*p == '/') {
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215 break;
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216 }
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217 }
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218
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219 len = last - p;
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220
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221 if (uri == NGX_HTTP_REFERER_NO_URI_PART) {
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222 goto valid;
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223 }
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224
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225 if (len < uri->len || ngx_strncmp(uri->data, p, uri->len) != 0) {
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226 goto invalid;
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227 }
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228
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229 valid:
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230
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231 *v = ngx_http_variable_null_value;
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232
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233 return NGX_OK;
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126
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234 }
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235
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236
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237 static void *
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238 ngx_http_referer_create_conf(ngx_conf_t *cf)
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239 {
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240 ngx_http_referer_conf_t *conf;
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241
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142
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242 conf = ngx_pcalloc(cf->pool, sizeof(ngx_http_referer_conf_t));
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126
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243 if (conf == NULL) {
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244 return NGX_CONF_ERROR;
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245 }
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246
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247 conf->no_referer = NGX_CONF_UNSET;
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248 conf->blocked_referer = NGX_CONF_UNSET;
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249
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250 return conf;
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251 }
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252
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253
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254 static char *
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255 ngx_http_referer_merge_conf(ngx_conf_t *cf, void *parent, void *child)
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256 {
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257 ngx_http_referer_conf_t *prev = parent;
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258 ngx_http_referer_conf_t *conf = child;
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259
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142
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260 ngx_hash_init_t hash;
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261
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262 if (conf->keys == NULL) {
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263 conf->hash = prev->hash;
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264
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126
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265 ngx_conf_merge_value(conf->no_referer, prev->no_referer, 0);
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266 ngx_conf_merge_value(conf->blocked_referer, prev->blocked_referer, 0);
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142
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267
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268 return NGX_CONF_OK;
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269 }
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270
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152
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271 if ((conf->no_referer == 1 || conf->blocked_referer == 1)
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312
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272 && conf->keys->keys.nelts == 0
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273 && conf->keys->dns_wc_head.nelts == 0
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274 && conf->keys->dns_wc_tail.nelts == 0)
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152
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275 {
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276 ngx_log_error(NGX_LOG_EMERG, cf->log, 0,
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277 "the \"none\" or \"blocked\" referers are specified "
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278 "in the \"valid_referers\" directive "
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279 "without any valid referer");
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280 return NGX_CONF_ERROR;
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281 }
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282
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142
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283 hash.key = ngx_hash_key_lc;
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284 hash.max_size = 2048; /* TODO: referer_hash_max_size; */
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285 hash.bucket_size = 64; /* TODO: referer_hash_bucket_size; */
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286 hash.name = "referers_hash";
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287 hash.pool = cf->pool;
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288
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289 if (conf->keys->keys.nelts) {
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312
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290 hash.hash = &conf->hash.hash;
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142
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291 hash.temp_pool = NULL;
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292
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293 if (ngx_hash_init(&hash, conf->keys->keys.elts, conf->keys->keys.nelts)
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294 != NGX_OK)
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295 {
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296 return NGX_CONF_ERROR;
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297 }
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298 }
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299
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312
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300 if (conf->keys->dns_wc_head.nelts) {
|
142
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301
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312
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302 ngx_qsort(conf->keys->dns_wc_head.elts,
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303 (size_t) conf->keys->dns_wc_head.nelts,
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142
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304 sizeof(ngx_hash_key_t),
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305 ngx_http_cmp_referer_wildcards);
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306
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307 hash.hash = NULL;
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308 hash.temp_pool = cf->temp_pool;
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309
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312
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310 if (ngx_hash_wildcard_init(&hash, conf->keys->dns_wc_head.elts,
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311 conf->keys->dns_wc_head.nelts)
|
142
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312 != NGX_OK)
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313 {
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314 return NGX_CONF_ERROR;
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315 }
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316
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312
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317 conf->hash.wc_head = (ngx_hash_wildcard_t *) hash.hash;
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318 }
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319
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320 if (conf->keys->dns_wc_tail.nelts) {
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321
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322 ngx_qsort(conf->keys->dns_wc_tail.elts,
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323 (size_t) conf->keys->dns_wc_tail.nelts,
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324 sizeof(ngx_hash_key_t),
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325 ngx_http_cmp_referer_wildcards);
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326
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327 hash.hash = NULL;
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328 hash.temp_pool = cf->temp_pool;
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329
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330 if (ngx_hash_wildcard_init(&hash, conf->keys->dns_wc_tail.elts,
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331 conf->keys->dns_wc_tail.nelts)
|
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332 != NGX_OK)
|
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333 {
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334 return NGX_CONF_ERROR;
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335 }
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336
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337 conf->hash.wc_tail = (ngx_hash_wildcard_t *) hash.hash;
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126
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338 }
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339
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340 if (conf->no_referer == NGX_CONF_UNSET) {
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341 conf->no_referer = 0;
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342 }
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343
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344 if (conf->blocked_referer == NGX_CONF_UNSET) {
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345 conf->blocked_referer = 0;
|
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346 }
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347
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160
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348 conf->keys = NULL;
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349
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126
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350 return NGX_CONF_OK;
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351 }
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352
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353
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354 static char *
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355 ngx_http_valid_referers(ngx_conf_t *cf, ngx_command_t *cmd, void *conf)
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356 {
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142
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357 ngx_http_referer_conf_t *rlcf = conf;
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126
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358
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142
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359 u_char *p;
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144
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360 ngx_str_t *value, uri, name;
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142
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361 ngx_uint_t i, n;
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126
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362 ngx_http_variable_t *var;
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363 ngx_http_server_name_t *sn;
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364 ngx_http_core_srv_conf_t *cscf;
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365
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366 name.len = sizeof("invalid_referer") - 1;
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367 name.data = (u_char *) "invalid_referer";
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368
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132
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369 var = ngx_http_add_variable(cf, &name,
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340
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370 NGX_HTTP_VAR_CHANGEABLE|NGX_HTTP_VAR_NOHASH);
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126
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371 if (var == NULL) {
|
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372 return NGX_CONF_ERROR;
|
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373 }
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374
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186
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375 var->get_handler = ngx_http_referer_variable;
|
126
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376
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142
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377 if (rlcf->keys == NULL) {
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378 rlcf->keys = ngx_pcalloc(cf->temp_pool, sizeof(ngx_hash_keys_arrays_t));
|
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379 if (rlcf->keys == NULL) {
|
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380 return NGX_CONF_ERROR;
|
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381 }
|
126
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382
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142
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383 rlcf->keys->pool = cf->pool;
|
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384 rlcf->keys->temp_pool = cf->pool;
|
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385
|
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386 if (ngx_hash_keys_array_init(rlcf->keys, NGX_HASH_SMALL) != NGX_OK) {
|
126
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387 return NGX_CONF_ERROR;
|
|
388 }
|
|
389 }
|
|
390
|
|
391 value = cf->args->elts;
|
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392
|
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393 for (i = 1; i < cf->args->nelts; i++) {
|
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394 if (value[i].len == 0) {
|
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395 ngx_conf_log_error(NGX_LOG_EMERG, cf, 0,
|
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396 "invalid referer \"%V\"", &value[i]);
|
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397 return NGX_CONF_ERROR;
|
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398 }
|
|
399
|
|
400 if (ngx_strcmp(value[i].data, "none") == 0) {
|
142
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401 rlcf->no_referer = 1;
|
126
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402 continue;
|
|
403 }
|
|
404
|
|
405 if (ngx_strcmp(value[i].data, "blocked") == 0) {
|
142
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406 rlcf->blocked_referer = 1;
|
126
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407 continue;
|
|
408 }
|
|
409
|
144
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410 uri.len = 0;
|
162
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411 uri.data = NULL;
|
144
|
412
|
126
|
413 if (ngx_strcmp(value[i].data, "server_names") == 0) {
|
142
|
414
|
|
415 cscf = ngx_http_conf_get_module_srv_conf(cf, ngx_http_core_module);
|
126
|
416
|
142
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417 sn = cscf->server_names.elts;
|
|
418 for (n = 0; n < cscf->server_names.nelts; n++) {
|
326
|
419
|
|
420 #if (NGX_PCRE)
|
|
421 if (sn[n].regex) {
|
|
422
|
|
423 if (ngx_http_add_regex_referer(cf, rlcf, &sn[n].name,
|
|
424 sn[n].regex)
|
|
425 != NGX_OK)
|
|
426 {
|
|
427 return NGX_CONF_ERROR;
|
|
428 }
|
|
429
|
|
430 continue;
|
|
431 }
|
|
432 #endif
|
|
433
|
144
|
434 if (ngx_http_add_referer(cf, rlcf->keys, &sn[n].name, &uri)
|
|
435 != NGX_OK)
|
|
436 {
|
142
|
437 return NGX_CONF_ERROR;
|
|
438 }
|
|
439 }
|
126
|
440
|
|
441 continue;
|
|
442 }
|
|
443
|
326
|
444 if (value[i].data[0] == '~') {
|
|
445 if (ngx_http_add_regex_referer(cf, rlcf, &value[i], NULL) != NGX_OK)
|
|
446 {
|
|
447 return NGX_CONF_ERROR;
|
|
448 }
|
|
449
|
|
450 continue;
|
|
451 }
|
|
452
|
310
|
453 p = (u_char *) ngx_strchr(value[i].data, '/');
|
126
|
454
|
142
|
455 if (p) {
|
144
|
456 uri.len = (value[i].data + value[i].len) - p;
|
|
457 uri.data = p;
|
142
|
458 value[i].len = p - value[i].data;
|
126
|
459 }
|
|
460
|
144
|
461 if (ngx_http_add_referer(cf, rlcf->keys, &value[i], &uri) != NGX_OK) {
|
126
|
462 return NGX_CONF_ERROR;
|
|
463 }
|
|
464 }
|
|
465
|
|
466 return NGX_CONF_OK;
|
|
467 }
|
142
|
468
|
|
469
|
|
470 static char *
|
|
471 ngx_http_add_referer(ngx_conf_t *cf, ngx_hash_keys_arrays_t *keys,
|
144
|
472 ngx_str_t *value, ngx_str_t *uri)
|
142
|
473 {
|
312
|
474 ngx_int_t rc;
|
|
475 ngx_str_t *u;
|
142
|
476
|
144
|
477 if (uri->len == 0) {
|
|
478 u = NGX_HTTP_REFERER_NO_URI_PART;
|
|
479
|
|
480 } else {
|
|
481 u = ngx_palloc(cf->pool, sizeof(ngx_str_t));
|
|
482 if (u == NULL) {
|
|
483 return NGX_CONF_ERROR;
|
|
484 }
|
|
485
|
|
486 *u = *uri;
|
|
487 }
|
|
488
|
312
|
489 rc = ngx_hash_add_key(keys, value, u, NGX_HASH_WILDCARD_KEY);
|
142
|
490
|
|
491 if (rc == NGX_OK) {
|
|
492 return NGX_CONF_OK;
|
|
493 }
|
|
494
|
312
|
495 if (rc == NGX_DECLINED) {
|
|
496 ngx_conf_log_error(NGX_LOG_EMERG, cf, 0,
|
|
497 "invalid hostname or wildcard \"%V\"", value);
|
|
498 }
|
|
499
|
142
|
500 if (rc == NGX_BUSY) {
|
|
501 ngx_conf_log_error(NGX_LOG_EMERG, cf, 0,
|
|
502 "conflicting parameter \"%V\"", value);
|
|
503 }
|
|
504
|
|
505 return NGX_CONF_ERROR;
|
|
506 }
|
|
507
|
|
508
|
326
|
509 static char *
|
|
510 ngx_http_add_regex_referer(ngx_conf_t *cf, ngx_http_referer_conf_t *rlcf,
|
|
511 ngx_str_t *name, ngx_regex_t *regex)
|
|
512 {
|
|
513 #if (NGX_PCRE)
|
|
514 ngx_str_t err;
|
|
515 ngx_http_referer_regex_t *rr;
|
|
516 u_char errstr[NGX_MAX_CONF_ERRSTR];
|
|
517
|
|
518 if (rlcf->regex == NULL) {
|
|
519 rlcf->regex = ngx_array_create(cf->pool, 2,
|
|
520 sizeof(ngx_http_referer_regex_t));
|
|
521 if (rlcf->regex == NULL) {
|
|
522 return NGX_CONF_ERROR;
|
|
523 }
|
|
524 }
|
|
525
|
|
526 rr = ngx_array_push(rlcf->regex);
|
|
527 if (rr == NULL) {
|
|
528 return NGX_CONF_ERROR;
|
|
529 }
|
|
530
|
|
531 if (regex) {
|
|
532 rr->regex = regex;
|
|
533 rr->name = *name;
|
|
534
|
|
535 return NGX_CONF_OK;
|
|
536 }
|
|
537
|
|
538 err.len = NGX_MAX_CONF_ERRSTR;
|
|
539 err.data = errstr;
|
|
540
|
|
541 name->len--;
|
|
542 name->data++;
|
|
543
|
|
544 rr->regex = ngx_regex_compile(name, NGX_REGEX_CASELESS, cf->pool, &err);
|
|
545
|
|
546 if (rr->regex == NULL) {
|
|
547 ngx_conf_log_error(NGX_LOG_EMERG, cf, 0, "%s", err.data);
|
|
548 return NGX_CONF_ERROR;
|
|
549 }
|
|
550
|
|
551 rr->name = *name;
|
|
552
|
|
553 return NGX_CONF_OK;
|
|
554
|
|
555 #else
|
|
556
|
|
557 ngx_conf_log_error(NGX_LOG_EMERG, cf, 0,
|
|
558 "the using of the regex \"%V\" requires PCRE library",
|
|
559 name);
|
|
560
|
|
561 return NGX_CONF_ERROR;
|
|
562
|
|
563 #endif
|
|
564 }
|
|
565
|
|
566
|
142
|
567 static int ngx_libc_cdecl
|
|
568 ngx_http_cmp_referer_wildcards(const void *one, const void *two)
|
|
569 {
|
|
570 ngx_hash_key_t *first, *second;
|
|
571
|
|
572 first = (ngx_hash_key_t *) one;
|
|
573 second = (ngx_hash_key_t *) two;
|
|
574
|
|
575 return ngx_strcmp(first->key.data, second->key.data);
|
|
576 }
|