src/mod_usertrack.c

   1 #include "first.h"
   2
   3 #include "base.h"
   4 #include "log.h"
   5 #include "buffer.h"
   6
   7 #include "plugin.h"
   8
   9 #include <ctype.h>
  10 #include <stdlib.h>
  11 #include <string.h>
  12
  13 #include "md5.h"
  14
  15 /* plugin config for all request/connections */
  16
  17 typedef struct {
  18         buffer *cookie_name;
  19         buffer *cookie_domain;
  20         unsigned int cookie_max_age;
  21 } plugin_config;
  22
  23 typedef struct {
  24         PLUGIN_DATA;
  25
  26         plugin_config **config_storage;
  27
  28         plugin_config conf;
  29 } plugin_data;
  30
  31 /* init the plugin data */
  32 INIT_FUNC(mod_usertrack_init) {
  33         plugin_data *p;
  34
  35         p = calloc(1, sizeof(*p));
  36
  37         return p;
  38 }
  39
  40 /* detroy the plugin data */
  41 FREE_FUNC(mod_usertrack_free) {
  42         plugin_data *p = p_d;
  43
  44         UNUSED(srv);
  45
  46         if (!p) return HANDLER_GO_ON;
  47
  48         if (p->config_storage) {
  49                 size_t i;
  50                 for (i = 0; i < srv->config_context->used; i++) {
  51                         plugin_config *s = p->config_storage[i];
  52
  53                         if (NULL == s) continue;
  54
  55                         buffer_free(s->cookie_name);
  56                         buffer_free(s->cookie_domain);
  57
  58                         free(s);
  59                 }
  60                 free(p->config_storage);
  61         }
  62
  63         free(p);
  64
  65         return HANDLER_GO_ON;
  66 }
  67
  68 /* handle plugin config and check values */
  69
  70 SETDEFAULTS_FUNC(mod_usertrack_set_defaults) {
  71         plugin_data *p = p_d;
  72         size_t i = 0;
  73
  74         config_values_t cv[] = {
  75                 { "usertrack.cookie-name",       NULL, T_CONFIG_STRING, T_CONFIG_SCOPE_CONNECTION },       /* 0 */
  76                 { "usertrack.cookie-max-age",    NULL, T_CONFIG_INT, T_CONFIG_SCOPE_CONNECTION },          /* 1 */
  77                 { "usertrack.cookie-domain",     NULL, T_CONFIG_STRING, T_CONFIG_SCOPE_CONNECTION },       /* 2 */
  78
  79                 { NULL,                          NULL, T_CONFIG_UNSET, T_CONFIG_SCOPE_UNSET }
  80         };
  81
  82         if (!p) return HANDLER_ERROR;
  83
  84         p->config_storage = calloc(1, srv->config_context->used * sizeof(plugin_config *));
  85
  86         for (i = 0; i < srv->config_context->used; i++) {
  87                 data_config const* config = (data_config const*)srv->config_context->data[i];
  88                 plugin_config *s;
  89
  90                 s = calloc(1, sizeof(plugin_config));
  91                 s->cookie_name    = buffer_init();
  92                 s->cookie_domain  = buffer_init();
  93                 s->cookie_max_age = 0;
  94
  95                 cv[0].destination = s->cookie_name;
  96                 cv[1].destination = &(s->cookie_max_age);
  97                 cv[2].destination = s->cookie_domain;
  98
  99                 p->config_storage[i] = s;
 100
 101                 if (0 != config_insert_values_global(srv, config->value, cv, i == 0 ? T_CONFIG_SCOPE_SERVER : T_CONFIG_SCOPE_CONNECTION)) {
 102                         return HANDLER_ERROR;
 103                 }
 104
 105                 if (buffer_string_is_empty(s->cookie_name)) {
 106                         buffer_copy_string_len(s->cookie_name, CONST_STR_LEN("TRACKID"));
 107                 } else {
 108                         size_t j, len = buffer_string_length(s->cookie_name);
 109                         for (j = 0; j < len; j++) {
 110                                 char c = s->cookie_name->ptr[j] | 32;
 111                                 if (c < 'a' || c > 'z') {
 112                                         log_error_write(srv, __FILE__, __LINE__, "sb",
 113                                                         "invalid character in usertrack.cookie-name:",
 114                                                         s->cookie_name);
 115
 116                                         return HANDLER_ERROR;
 117                                 }
 118                         }
 119                 }
 120
 121                 if (!buffer_string_is_empty(s->cookie_domain)) {
 122                         size_t j, len = buffer_string_length(s->cookie_domain);
 123                         for (j = 0; j < len; j++) {
 124                                 char c = s->cookie_domain->ptr[j];
 125                                 if (c <= 32 || c >= 127 || c == '"' || c == '\\') {
 126                                         log_error_write(srv, __FILE__, __LINE__, "sb",
 127                                                         "invalid character in usertrack.cookie-domain:",
 128                                                         s->cookie_domain);
 129
 130                                         return HANDLER_ERROR;
 131                                 }
 132                         }
 133                 }
 134         }
 135
 136         return HANDLER_GO_ON;
 137 }
 138
 139 #define PATCH(x) \
 140         p->conf.x = s->x;
 141 static int mod_usertrack_patch_connection(server *srv, connection *con, plugin_data *p) {
 142         size_t i, j;
 143         plugin_config *s = p->config_storage[0];
 144
 145         PATCH(cookie_name);
 146         PATCH(cookie_domain);
 147         PATCH(cookie_max_age);
 148
 149         /* skip the first, the global context */
 150         for (i = 1; i < srv->config_context->used; i++) {
 151                 data_config *dc = (data_config *)srv->config_context->data[i];
 152                 s = p->config_storage[i];
 153
 154                 /* condition didn't match */
 155                 if (!config_check_cond(srv, con, dc)) continue;
 156
 157                 /* merge config */
 158                 for (j = 0; j < dc->value->used; j++) {
 159                         data_unset *du = dc->value->data[j];
 160
 161                         if (buffer_is_equal_string(du->key, CONST_STR_LEN("usertrack.cookie-name"))) {
 162                                 PATCH(cookie_name);
 163                         } else if (buffer_is_equal_string(du->key, CONST_STR_LEN("usertrack.cookie-max-age"))) {
 164                                 PATCH(cookie_max_age);
 165                         } else if (buffer_is_equal_string(du->key, CONST_STR_LEN("usertrack.cookie-domain"))) {
 166                                 PATCH(cookie_domain);
 167                         }
 168                 }
 169         }
 170
 171         return 0;
 172 }
 173 #undef PATCH
 174
 175 URIHANDLER_FUNC(mod_usertrack_uri_handler) {
 176         plugin_data *p = p_d;
 177         data_string *ds;
 178         unsigned char h[16];
 179         li_MD5_CTX Md5Ctx;
 180         char hh[LI_ITOSTRING_LENGTH];
 181
 182         if (buffer_is_empty(con->uri.path)) return HANDLER_GO_ON;
 183
 184         mod_usertrack_patch_connection(srv, con, p);
 185
 186         if (NULL != (ds = (data_string *)array_get_element(con->request.headers, "Cookie"))) {
 187                 char *g;
 188                 /* we have a cookie, does it contain a valid name ? */
 189
 190                 /* parse the cookie
 191                  *
 192                  * check for cookiename + (WS | '=')
 193                  *
 194                  */
 195
 196                 if (NULL != (g = strstr(ds->value->ptr, p->conf.cookie_name->ptr))) {
 197                         char *nc;
 198
 199                         /* skip WS */
 200                         for (nc = g + buffer_string_length(p->conf.cookie_name); *nc == ' ' || *nc == '\t'; nc++);
 201
 202                         if (*nc == '=') {
 203                                 /* ok, found the key of our own cookie */
 204
 205                                 if (strlen(nc) > 32) {
 206                                         /* i'm lazy */
 207                                         return HANDLER_GO_ON;
 208                                 }
 209                         }
 210                 }
 211         }
 212
 213         /* set a cookie */
 214         if (NULL == (ds = (data_string *)array_get_unused_element(con->response.headers, TYPE_STRING))) {
 215                 ds = data_response_init();
 216         }
 217         buffer_copy_string_len(ds->key, CONST_STR_LEN("Set-Cookie"));
 218         buffer_copy_buffer(ds->value, p->conf.cookie_name);
 219         buffer_append_string_len(ds->value, CONST_STR_LEN("="));
 220
 221
 222         /* taken from mod_auth.c */
 223
 224         /* generate shared-secret */
 225         li_MD5_Init(&Md5Ctx);
 226         li_MD5_Update(&Md5Ctx, CONST_BUF_LEN(con->uri.path));
 227         li_MD5_Update(&Md5Ctx, CONST_STR_LEN("+"));
 228
 229         /* we assume sizeof(time_t) == 4 here, but if not it ain't a problem at all */
 230         li_itostrn(hh, sizeof(hh), srv->cur_ts);
 231         li_MD5_Update(&Md5Ctx, (unsigned char *)hh, strlen(hh));
 232         li_MD5_Update(&Md5Ctx, (unsigned char *)srv->entropy, sizeof(srv->entropy));
 233         li_itostrn(hh, sizeof(hh), rand());
 234         li_MD5_Update(&Md5Ctx, (unsigned char *)hh, strlen(hh));
 235
 236         li_MD5_Final(h, &Md5Ctx);
 237
 238         buffer_append_string_encoded(ds->value, (char *)h, 16, ENCODING_HEX);
 239         buffer_append_string_len(ds->value, CONST_STR_LEN("; Path=/"));
 240         buffer_append_string_len(ds->value, CONST_STR_LEN("; Version=1"));
 241
 242         if (!buffer_string_is_empty(p->conf.cookie_domain)) {
 243                 buffer_append_string_len(ds->value, CONST_STR_LEN("; Domain="));
 244                 buffer_append_string_encoded(ds->value, CONST_BUF_LEN(p->conf.cookie_domain), ENCODING_REL_URI);
 245         }
 246
 247         if (p->conf.cookie_max_age) {
 248                 buffer_append_string_len(ds->value, CONST_STR_LEN("; max-age="));
 249                 buffer_append_int(ds->value, p->conf.cookie_max_age);
 250         }
 251
 252         array_insert_unique(con->response.headers, (data_unset *)ds);
 253
 254         return HANDLER_GO_ON;
 255 }
 256
 257 /* this function is called at dlopen() time and inits the callbacks */
 258
 259 int mod_usertrack_plugin_init(plugin *p);
 260 int mod_usertrack_plugin_init(plugin *p) {
 261         p->version     = LIGHTTPD_VERSION_ID;
 262         p->name        = buffer_init_string("usertrack");
 263
 264         p->init        = mod_usertrack_init;
 265         p->handle_uri_clean  = mod_usertrack_uri_handler;
 266         p->set_defaults  = mod_usertrack_set_defaults;
 267         p->cleanup     = mod_usertrack_free;
 268
 269         p->data        = NULL;
 270
 271         return 0;
 272 }