src/mod_userdir.c

   1 #include "first.h"
   2
   3 #include "base.h"
   4 #include "log.h"
   5 #include "buffer.h"
   6
   7 #include "response.h"
   8
   9 #include "plugin.h"
  10
  11 #include <sys/types.h>
  12
  13 #include <stdlib.h>
  14 #include <string.h>
  15
  16 #ifdef HAVE_PWD_H
  17 # include <pwd.h>
  18 #endif
  19
  20 /* plugin config for all request/connections */
  21 typedef struct {
  22         array *exclude_user;
  23         array *include_user;
  24         buffer *path;
  25         buffer *basepath;
  26         unsigned short letterhomes;
  27         unsigned short active;
  28 } plugin_config;
  29
  30 typedef struct {
  31         PLUGIN_DATA;
  32
  33         buffer *username;
  34         buffer *temp_path;
  35
  36         plugin_config **config_storage;
  37
  38         plugin_config conf;
  39 } plugin_data;
  40
  41 /* init the plugin data */
  42 INIT_FUNC(mod_userdir_init) {
  43         plugin_data *p;
  44
  45         p = calloc(1, sizeof(*p));
  46
  47         p->username = buffer_init();
  48         p->temp_path = buffer_init();
  49
  50         return p;
  51 }
  52
  53 /* detroy the plugin data */
  54 FREE_FUNC(mod_userdir_free) {
  55         plugin_data *p = p_d;
  56
  57         if (!p) return HANDLER_GO_ON;
  58
  59         if (p->config_storage) {
  60                 size_t i;
  61
  62                 for (i = 0; i < srv->config_context->used; i++) {
  63                         plugin_config *s = p->config_storage[i];
  64
  65                         if (NULL == s) continue;
  66
  67                         array_free(s->include_user);
  68                         array_free(s->exclude_user);
  69                         buffer_free(s->path);
  70                         buffer_free(s->basepath);
  71
  72                         free(s);
  73                 }
  74                 free(p->config_storage);
  75         }
  76
  77         buffer_free(p->username);
  78         buffer_free(p->temp_path);
  79
  80         free(p);
  81
  82         return HANDLER_GO_ON;
  83 }
  84
  85 /* handle plugin config and check values */
  86
  87 SETDEFAULTS_FUNC(mod_userdir_set_defaults) {
  88         plugin_data *p = p_d;
  89         size_t i;
  90
  91         config_values_t cv[] = {
  92                 { "userdir.path",               NULL, T_CONFIG_STRING, T_CONFIG_SCOPE_CONNECTION },       /* 0 */
  93                 { "userdir.exclude-user",       NULL, T_CONFIG_ARRAY,  T_CONFIG_SCOPE_CONNECTION },       /* 1 */
  94                 { "userdir.include-user",       NULL, T_CONFIG_ARRAY,  T_CONFIG_SCOPE_CONNECTION },       /* 2 */
  95                 { "userdir.basepath",           NULL, T_CONFIG_STRING, T_CONFIG_SCOPE_CONNECTION },       /* 3 */
  96                 { "userdir.letterhomes",        NULL, T_CONFIG_BOOLEAN,T_CONFIG_SCOPE_CONNECTION },       /* 4 */
  97                 { "userdir.active",             NULL, T_CONFIG_BOOLEAN,T_CONFIG_SCOPE_CONNECTION },       /* 5 */
  98                 { NULL,                         NULL, T_CONFIG_UNSET,  T_CONFIG_SCOPE_UNSET }
  99         };
 100
 101         if (!p) return HANDLER_ERROR;
 102
 103         p->config_storage = calloc(1, srv->config_context->used * sizeof(plugin_config *));
 104
 105         for (i = 0; i < srv->config_context->used; i++) {
 106                 data_config const* config = (data_config const*)srv->config_context->data[i];
 107                 plugin_config *s;
 108
 109                 s = calloc(1, sizeof(plugin_config));
 110                 s->exclude_user = array_init();
 111                 s->include_user = array_init();
 112                 s->path = buffer_init();
 113                 s->basepath = buffer_init();
 114                 s->letterhomes = 0;
 115                 /* enabled by default for backward compatibility; if userdir.path isn't set userdir is disabled too,
 116                  * but you can't disable it by setting it to an empty string. */
 117                 s->active = 1;
 118
 119                 cv[0].destination = s->path;
 120                 cv[1].destination = s->exclude_user;
 121                 cv[2].destination = s->include_user;
 122                 cv[3].destination = s->basepath;
 123                 cv[4].destination = &(s->letterhomes);
 124                 cv[5].destination = &(s->active);
 125
 126                 p->config_storage[i] = s;
 127
 128                 if (0 != config_insert_values_global(srv, config->value, cv, i == 0 ? T_CONFIG_SCOPE_SERVER : T_CONFIG_SCOPE_CONNECTION)) {
 129                         return HANDLER_ERROR;
 130                 }
 131
 132                 if (!array_is_vlist(s->exclude_user)) {
 133                         log_error_write(srv, __FILE__, __LINE__, "s",
 134                                         "unexpected value for userdir.exclude-user; expected list of \"suffix\"");
 135                         return HANDLER_ERROR;
 136                 }
 137
 138                 if (!array_is_vlist(s->include_user)) {
 139                         log_error_write(srv, __FILE__, __LINE__, "s",
 140                                         "unexpected value for userdir.include-user; expected list of \"suffix\"");
 141                         return HANDLER_ERROR;
 142                 }
 143         }
 144
 145         return HANDLER_GO_ON;
 146 }
 147
 148 #define PATCH(x) \
 149         p->conf.x = s->x;
 150 static int mod_userdir_patch_connection(server *srv, connection *con, plugin_data *p) {
 151         size_t i, j;
 152         plugin_config *s = p->config_storage[0];
 153
 154         PATCH(path);
 155         PATCH(exclude_user);
 156         PATCH(include_user);
 157         PATCH(basepath);
 158         PATCH(letterhomes);
 159         PATCH(active);
 160
 161         /* skip the first, the global context */
 162         for (i = 1; i < srv->config_context->used; i++) {
 163                 data_config *dc = (data_config *)srv->config_context->data[i];
 164                 s = p->config_storage[i];
 165
 166                 /* condition didn't match */
 167                 if (!config_check_cond(srv, con, dc)) continue;
 168
 169                 /* merge config */
 170                 for (j = 0; j < dc->value->used; j++) {
 171                         data_unset *du = dc->value->data[j];
 172
 173                         if (buffer_is_equal_string(du->key, CONST_STR_LEN("userdir.path"))) {
 174                                 PATCH(path);
 175                         } else if (buffer_is_equal_string(du->key, CONST_STR_LEN("userdir.exclude-user"))) {
 176                                 PATCH(exclude_user);
 177                         } else if (buffer_is_equal_string(du->key, CONST_STR_LEN("userdir.include-user"))) {
 178                                 PATCH(include_user);
 179                         } else if (buffer_is_equal_string(du->key, CONST_STR_LEN("userdir.basepath"))) {
 180                                 PATCH(basepath);
 181                         } else if (buffer_is_equal_string(du->key, CONST_STR_LEN("userdir.letterhomes"))) {
 182                                 PATCH(letterhomes);
 183                         } else if (buffer_is_equal_string(du->key, CONST_STR_LEN("userdir.active"))) {
 184                                 PATCH(active);
 185                         }
 186                 }
 187         }
 188
 189         return 0;
 190 }
 191 #undef PATCH
 192
 193 URIHANDLER_FUNC(mod_userdir_docroot_handler) {
 194         plugin_data *p = p_d;
 195         size_t k;
 196         char *rel_url;
 197 #ifdef HAVE_PWD_H
 198         struct passwd *pwd = NULL;
 199 #endif
 200
 201         if (buffer_is_empty(con->uri.path)) return HANDLER_GO_ON;
 202
 203         mod_userdir_patch_connection(srv, con, p);
 204
 205         /* enforce the userdir.path to be set in the config, ugly fix for #1587;
 206          * should be replaced with a clean .enabled option in 1.5
 207          */
 208         if (!p->conf.active || buffer_is_empty(p->conf.path)) return HANDLER_GO_ON;
 209
 210         /* /~user/foo.html -> /home/user/public_html/foo.html */
 211
 212         if (con->uri.path->ptr[0] != '/' ||
 213             con->uri.path->ptr[1] != '~') return HANDLER_GO_ON;
 214
 215         if (NULL == (rel_url = strchr(con->uri.path->ptr + 2, '/'))) {
 216                 /* / is missing -> redirect to .../ as we are a user - DIRECTORY ! :) */
 217                 http_response_redirect_to_directory(srv, con);
 218
 219                 return HANDLER_FINISHED;
 220         }
 221
 222         /* /~/ is a empty username, catch it directly */
 223         if (0 == rel_url - (con->uri.path->ptr + 2)) {
 224                 return HANDLER_GO_ON;
 225         }
 226
 227         buffer_copy_string_len(p->username, con->uri.path->ptr + 2, rel_url - (con->uri.path->ptr + 2));
 228
 229         if (buffer_string_is_empty(p->conf.basepath)
 230 #ifdef HAVE_PWD_H
 231             && NULL == (pwd = getpwnam(p->username->ptr))
 232 #endif
 233             ) {
 234                 /* user not found */
 235                 return HANDLER_GO_ON;
 236         }
 237
 238
 239         for (k = 0; k < p->conf.exclude_user->used; k++) {
 240                 data_string *ds = (data_string *)p->conf.exclude_user->data[k];
 241
 242                 if (buffer_is_equal(ds->value, p->username)) {
 243                         /* user in exclude list */
 244                         return HANDLER_GO_ON;
 245                 }
 246         }
 247
 248         if (p->conf.include_user->used) {
 249                 int found_user = 0;
 250                 for (k = 0; k < p->conf.include_user->used; k++) {
 251                         data_string *ds = (data_string *)p->conf.include_user->data[k];
 252
 253                         if (buffer_is_equal(ds->value, p->username)) {
 254                                 /* user in include list */
 255                                 found_user = 1;
 256                                 break;
 257                         }
 258                 }
 259
 260                 if (!found_user) return HANDLER_GO_ON;
 261         }
 262
 263         /* we build the physical path */
 264
 265         if (buffer_string_is_empty(p->conf.basepath)) {
 266 #ifdef HAVE_PWD_H
 267                 buffer_copy_string(p->temp_path, pwd->pw_dir);
 268 #endif
 269         } else {
 270                 char *cp;
 271                 /* check if the username is valid
 272                  * a request for /~../ should lead to a directory traversal
 273                  * limiting to [-_a-z0-9.] should fix it */
 274
 275                 for (cp = p->username->ptr; *cp; cp++) {
 276                         char c = *cp;
 277
 278                         if (!(c == '-' ||
 279                               c == '_' ||
 280                               c == '.' ||
 281                               (c >= 'a' && c <= 'z') ||
 282                               (c >= 'A' && c <= 'Z') ||
 283                               (c >= '0' && c <= '9'))) {
 284
 285                                 return HANDLER_GO_ON;
 286                         }
 287                 }
 288                 if (con->conf.force_lowercase_filenames) {
 289                         buffer_to_lower(p->username);
 290                 }
 291
 292                 buffer_copy_buffer(p->temp_path, p->conf.basepath);
 293                 buffer_append_slash(p->temp_path);
 294                 if (p->conf.letterhomes) {
 295                         buffer_append_string_len(p->temp_path, p->username->ptr, 1);
 296                         buffer_append_slash(p->temp_path);
 297                 }
 298                 buffer_append_string_buffer(p->temp_path, p->username);
 299         }
 300         buffer_append_slash(p->temp_path);
 301         buffer_append_string_buffer(p->temp_path, p->conf.path);
 302
 303         if (buffer_string_is_empty(p->conf.basepath)) {
 304                 struct stat st;
 305                 int ret;
 306
 307                 ret = stat(p->temp_path->ptr, &st);
 308                 if (ret < 0 || S_ISDIR(st.st_mode) != 1) {
 309                         return HANDLER_GO_ON;
 310                 }
 311         }
 312
 313         buffer_copy_buffer(con->physical.basedir, p->temp_path);
 314
 315         /* the physical rel_path is basically the same as uri.path;
 316          * but it is converted to lowercase in case of force_lowercase_filenames and some special handling
 317          * for trailing '.', ' ' and '/' on windows
 318          * we assume that no docroot/physical handler changed this
 319          * (docroot should only set the docroot/server name, phyiscal should only change the phyiscal.path;
 320          *  the exception mod_secdownload doesn't work with userdir anyway)
 321          */
 322         buffer_append_slash(p->temp_path);
 323         /* if no second '/' is found, we assume that it was stripped from the uri.path for the special handling
 324          * on windows.
 325          * we do not care about the trailing slash here on windows, as we already ensured it is a directory
 326          *
 327          * TODO: what to do with trailing dots in usernames on windows? they may result in the same directory
 328          *       as a username without them.
 329          */
 330         if (NULL != (rel_url = strchr(con->physical.rel_path->ptr + 2, '/'))) {
 331                 buffer_append_string(p->temp_path, rel_url + 1); /* skip the / */
 332         }
 333         buffer_copy_buffer(con->physical.path, p->temp_path);
 334
 335         buffer_reset(p->temp_path);
 336
 337         return HANDLER_GO_ON;
 338 }
 339
 340 /* this function is called at dlopen() time and inits the callbacks */
 341
 342 int mod_userdir_plugin_init(plugin *p);
 343 int mod_userdir_plugin_init(plugin *p) {
 344         p->version     = LIGHTTPD_VERSION_ID;
 345         p->name        = buffer_init_string("userdir");
 346
 347         p->init           = mod_userdir_init;
 348         p->handle_physical = mod_userdir_docroot_handler;
 349         p->set_defaults   = mod_userdir_set_defaults;
 350         p->cleanup        = mod_userdir_free;
 351
 352         p->data        = NULL;
 353
 354         return 0;
 355 }