src/mod_usertrack.c

   1 #include "first.h"
   2
   3 #include "base.h"
   4 #include "log.h"
   5 #include "buffer.h"
   6 #include "rand.h"
   7 #include "http_header.h"
   8
   9 #include "plugin.h"
  10
  11 #include <stdlib.h>
  12 #include <string.h>
  13
  14 #include "md5.h"
  15
  16 /* plugin config for all request/connections */
  17
  18 typedef struct {
  19         buffer *cookie_name;
  20         buffer *cookie_attrs;
  21         buffer *cookie_domain;
  22         unsigned int cookie_max_age;
  23 } plugin_config;
  24
  25 typedef struct {
  26         PLUGIN_DATA;
  27
  28         plugin_config **config_storage;
  29
  30         plugin_config conf;
  31 } plugin_data;
  32
  33 /* init the plugin data */
  34 INIT_FUNC(mod_usertrack_init) {
  35         plugin_data *p;
  36
  37         p = calloc(1, sizeof(*p));
  38
  39         return p;
  40 }
  41
  42 /* detroy the plugin data */
  43 FREE_FUNC(mod_usertrack_free) {
  44         plugin_data *p = p_d;
  45
  46         UNUSED(srv);
  47
  48         if (!p) return HANDLER_GO_ON;
  49
  50         if (p->config_storage) {
  51                 size_t i;
  52                 for (i = 0; i < srv->config_context->used; i++) {
  53                         plugin_config *s = p->config_storage[i];
  54
  55                         if (NULL == s) continue;
  56
  57                         buffer_free(s->cookie_name);
  58                         buffer_free(s->cookie_attrs);
  59                         buffer_free(s->cookie_domain);
  60
  61                         free(s);
  62                 }
  63                 free(p->config_storage);
  64         }
  65
  66         free(p);
  67
  68         return HANDLER_GO_ON;
  69 }
  70
  71 /* handle plugin config and check values */
  72
  73 SETDEFAULTS_FUNC(mod_usertrack_set_defaults) {
  74         plugin_data *p = p_d;
  75         size_t i = 0;
  76
  77         config_values_t cv[] = {
  78                 { "usertrack.cookie-name",       NULL, T_CONFIG_STRING, T_CONFIG_SCOPE_CONNECTION },       /* 0 */
  79                 { "usertrack.cookie-max-age",    NULL, T_CONFIG_INT, T_CONFIG_SCOPE_CONNECTION },          /* 1 */
  80                 { "usertrack.cookie-domain",     NULL, T_CONFIG_STRING, T_CONFIG_SCOPE_CONNECTION },       /* 2 */
  81                 { "usertrack.cookie-attrs",      NULL, T_CONFIG_STRING, T_CONFIG_SCOPE_CONNECTION },       /* 3 */
  82
  83                 { NULL,                          NULL, T_CONFIG_UNSET, T_CONFIG_SCOPE_UNSET }
  84         };
  85
  86         if (!p) return HANDLER_ERROR;
  87
  88         p->config_storage = calloc(srv->config_context->used, sizeof(plugin_config *));
  89
  90         for (i = 0; i < srv->config_context->used; i++) {
  91                 data_config const* config = (data_config const*)srv->config_context->data[i];
  92                 plugin_config *s;
  93
  94                 s = calloc(1, sizeof(plugin_config));
  95                 s->cookie_name    = buffer_init();
  96                 s->cookie_attrs   = buffer_init();
  97                 s->cookie_domain  = buffer_init();
  98                 s->cookie_max_age = 0;
  99
 100                 cv[0].destination = s->cookie_name;
 101                 cv[1].destination = &(s->cookie_max_age);
 102                 cv[2].destination = s->cookie_domain;
 103                 cv[3].destination = s->cookie_attrs;
 104
 105                 p->config_storage[i] = s;
 106
 107                 if (0 != config_insert_values_global(srv, config->value, cv, i == 0 ? T_CONFIG_SCOPE_SERVER : T_CONFIG_SCOPE_CONNECTION)) {
 108                         return HANDLER_ERROR;
 109                 }
 110
 111                 if (buffer_string_is_empty(s->cookie_name)) {
 112                         buffer_copy_string_len(s->cookie_name, CONST_STR_LEN("TRACKID"));
 113                 } else {
 114                         size_t j, len = buffer_string_length(s->cookie_name);
 115                         for (j = 0; j < len; j++) {
 116                                 char c = s->cookie_name->ptr[j] | 32;
 117                                 if (c < 'a' || c > 'z') {
 118                                         log_error_write(srv, __FILE__, __LINE__, "sb",
 119                                                         "invalid character in usertrack.cookie-name:",
 120                                                         s->cookie_name);
 121
 122                                         return HANDLER_ERROR;
 123                                 }
 124                         }
 125                 }
 126
 127                 if (!buffer_string_is_empty(s->cookie_domain)) {
 128                         size_t j, len = buffer_string_length(s->cookie_domain);
 129                         for (j = 0; j < len; j++) {
 130                                 char c = s->cookie_domain->ptr[j];
 131                                 if (c <= 32 || c >= 127 || c == '"' || c == '\\') {
 132                                         log_error_write(srv, __FILE__, __LINE__, "sb",
 133                                                         "invalid character in usertrack.cookie-domain:",
 134                                                         s->cookie_domain);
 135
 136                                         return HANDLER_ERROR;
 137                                 }
 138                         }
 139                 }
 140         }
 141
 142         return HANDLER_GO_ON;
 143 }
 144
 145 #define PATCH(x) \
 146         p->conf.x = s->x;
 147 static int mod_usertrack_patch_connection(server *srv, connection *con, plugin_data *p) {
 148         size_t i, j;
 149         plugin_config *s = p->config_storage[0];
 150
 151         PATCH(cookie_name);
 152         PATCH(cookie_attrs);
 153         PATCH(cookie_domain);
 154         PATCH(cookie_max_age);
 155
 156         /* skip the first, the global context */
 157         for (i = 1; i < srv->config_context->used; i++) {
 158                 data_config *dc = (data_config *)srv->config_context->data[i];
 159                 s = p->config_storage[i];
 160
 161                 /* condition didn't match */
 162                 if (!config_check_cond(srv, con, dc)) continue;
 163
 164                 /* merge config */
 165                 for (j = 0; j < dc->value->used; j++) {
 166                         data_unset *du = dc->value->data[j];
 167
 168                         if (buffer_is_equal_string(du->key, CONST_STR_LEN("usertrack.cookie-name"))) {
 169                                 PATCH(cookie_name);
 170                         } else if (buffer_is_equal_string(du->key, CONST_STR_LEN("usertrack.cookie-attrs"))) {
 171                                 PATCH(cookie_attrs);
 172                         } else if (buffer_is_equal_string(du->key, CONST_STR_LEN("usertrack.cookie-max-age"))) {
 173                                 PATCH(cookie_max_age);
 174                         } else if (buffer_is_equal_string(du->key, CONST_STR_LEN("usertrack.cookie-domain"))) {
 175                                 PATCH(cookie_domain);
 176                         }
 177                 }
 178         }
 179
 180         return 0;
 181 }
 182 #undef PATCH
 183
 184 URIHANDLER_FUNC(mod_usertrack_uri_handler) {
 185         plugin_data *p = p_d;
 186         buffer *cookie;
 187         buffer *b;
 188         unsigned char h[16];
 189         li_MD5_CTX Md5Ctx;
 190         char hh[LI_ITOSTRING_LENGTH];
 191
 192         if (buffer_is_empty(con->uri.path)) return HANDLER_GO_ON;
 193
 194         mod_usertrack_patch_connection(srv, con, p);
 195
 196         if (NULL != (b = http_header_request_get(con, HTTP_HEADER_COOKIE, CONST_STR_LEN("Cookie")))) {
 197                 char *g;
 198                 /* we have a cookie, does it contain a valid name ? */
 199
 200                 /* parse the cookie
 201                  *
 202                  * check for cookiename + (WS | '=')
 203                  *
 204                  */
 205
 206                 if (NULL != (g = strstr(b->ptr, p->conf.cookie_name->ptr))) {
 207                         char *nc;
 208
 209                         /* skip WS */
 210                         for (nc = g + buffer_string_length(p->conf.cookie_name); *nc == ' ' || *nc == '\t'; nc++);
 211
 212                         if (*nc == '=') {
 213                                 /* ok, found the key of our own cookie */
 214
 215                                 if (strlen(nc) > 32) {
 216                                         /* i'm lazy */
 217                                         return HANDLER_GO_ON;
 218                                 }
 219                         }
 220                 }
 221         }
 222
 223         /* set a cookie */
 224         cookie = srv->tmp_buf;
 225         buffer_copy_buffer(cookie, p->conf.cookie_name);
 226         buffer_append_string_len(cookie, CONST_STR_LEN("="));
 227
 228
 229         /* taken from mod_auth.c */
 230
 231         /* generate shared-secret */
 232         li_MD5_Init(&Md5Ctx);
 233         li_MD5_Update(&Md5Ctx, CONST_BUF_LEN(con->uri.path));
 234         li_MD5_Update(&Md5Ctx, CONST_STR_LEN("+"));
 235
 236         li_itostrn(hh, sizeof(hh), srv->cur_ts);
 237         li_MD5_Update(&Md5Ctx, (unsigned char *)hh, strlen(hh));
 238         li_itostrn(hh, sizeof(hh), li_rand_pseudo());
 239         li_MD5_Update(&Md5Ctx, (unsigned char *)hh, strlen(hh));
 240
 241         li_MD5_Final(h, &Md5Ctx);
 242
 243         buffer_append_string_encoded_hex_lc(cookie, (char *)h, 16);
 244
 245         /* usertrack.cookie-attrs, if set, replaces all other attrs */
 246         if (!buffer_string_is_empty(p->conf.cookie_attrs)) {
 247                 buffer_append_string_buffer(cookie, p->conf.cookie_attrs);
 248                 http_header_response_insert(con, HTTP_HEADER_SET_COOKIE, CONST_STR_LEN("Set-Cookie"), CONST_BUF_LEN(cookie));
 249                 return HANDLER_GO_ON;
 250         }
 251
 252         buffer_append_string_len(cookie, CONST_STR_LEN("; Path=/"));
 253         buffer_append_string_len(cookie, CONST_STR_LEN("; Version=1"));
 254
 255         if (!buffer_string_is_empty(p->conf.cookie_domain)) {
 256                 buffer_append_string_len(cookie, CONST_STR_LEN("; Domain="));
 257                 buffer_append_string_encoded(cookie, CONST_BUF_LEN(p->conf.cookie_domain), ENCODING_REL_URI);
 258         }
 259
 260         if (p->conf.cookie_max_age) {
 261                 buffer_append_string_len(cookie, CONST_STR_LEN("; max-age="));
 262                 buffer_append_int(cookie, p->conf.cookie_max_age);
 263         }
 264
 265         http_header_response_insert(con, HTTP_HEADER_SET_COOKIE, CONST_STR_LEN("Set-Cookie"), CONST_BUF_LEN(cookie));
 266
 267         return HANDLER_GO_ON;
 268 }
 269
 270 /* this function is called at dlopen() time and inits the callbacks */
 271
 272 int mod_usertrack_plugin_init(plugin *p);
 273 int mod_usertrack_plugin_init(plugin *p) {
 274         p->version     = LIGHTTPD_VERSION_ID;
 275         p->name        = buffer_init_string("usertrack");
 276
 277         p->init        = mod_usertrack_init;
 278         p->handle_uri_clean  = mod_usertrack_uri_handler;
 279         p->set_defaults  = mod_usertrack_set_defaults;
 280         p->cleanup     = mod_usertrack_free;
 281
 282         p->data        = NULL;
 283
 284         return 0;
 285 }