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
 133         return HANDLER_GO_ON;
 134 }
 135
 136 #define PATCH(x) \
 137         p->conf.x = s->x;
 138 static int mod_userdir_patch_connection(server *srv, connection *con, plugin_data *p) {
 139         size_t i, j;
 140         plugin_config *s = p->config_storage[0];
 141
 142         PATCH(path);
 143         PATCH(exclude_user);
 144         PATCH(include_user);
 145         PATCH(basepath);
 146         PATCH(letterhomes);
 147         PATCH(active);
 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("userdir.path"))) {
 162                                 PATCH(path);
 163                         } else if (buffer_is_equal_string(du->key, CONST_STR_LEN("userdir.exclude-user"))) {
 164                                 PATCH(exclude_user);
 165                         } else if (buffer_is_equal_string(du->key, CONST_STR_LEN("userdir.include-user"))) {
 166                                 PATCH(include_user);
 167                         } else if (buffer_is_equal_string(du->key, CONST_STR_LEN("userdir.basepath"))) {
 168                                 PATCH(basepath);
 169                         } else if (buffer_is_equal_string(du->key, CONST_STR_LEN("userdir.letterhomes"))) {
 170                                 PATCH(letterhomes);
 171                         } else if (buffer_is_equal_string(du->key, CONST_STR_LEN("userdir.active"))) {
 172                                 PATCH(active);
 173                         }
 174                 }
 175         }
 176
 177         return 0;
 178 }
 179 #undef PATCH
 180
 181 URIHANDLER_FUNC(mod_userdir_docroot_handler) {
 182         plugin_data *p = p_d;
 183         size_t k;
 184         char *rel_url;
 185 #ifdef HAVE_PWD_H
 186         struct passwd *pwd = NULL;
 187 #endif
 188
 189         if (buffer_is_empty(con->uri.path)) return HANDLER_GO_ON;
 190
 191         mod_userdir_patch_connection(srv, con, p);
 192
 193         /* enforce the userdir.path to be set in the config, ugly fix for #1587;
 194          * should be replaced with a clean .enabled option in 1.5
 195          */
 196         if (!p->conf.active || buffer_is_empty(p->conf.path)) return HANDLER_GO_ON;
 197
 198         /* /~user/foo.html -> /home/user/public_html/foo.html */
 199
 200         if (con->uri.path->ptr[0] != '/' ||
 201             con->uri.path->ptr[1] != '~') return HANDLER_GO_ON;
 202
 203         if (NULL == (rel_url = strchr(con->uri.path->ptr + 2, '/'))) {
 204                 /* / is missing -> redirect to .../ as we are a user - DIRECTORY ! :) */
 205                 http_response_redirect_to_directory(srv, con);
 206
 207                 return HANDLER_FINISHED;
 208         }
 209
 210         /* /~/ is a empty username, catch it directly */
 211         if (0 == rel_url - (con->uri.path->ptr + 2)) {
 212                 return HANDLER_GO_ON;
 213         }
 214
 215         buffer_copy_string_len(p->username, con->uri.path->ptr + 2, rel_url - (con->uri.path->ptr + 2));
 216
 217         if (buffer_string_is_empty(p->conf.basepath)
 218 #ifdef HAVE_PWD_H
 219             && NULL == (pwd = getpwnam(p->username->ptr))
 220 #endif
 221             ) {
 222                 /* user not found */
 223                 return HANDLER_GO_ON;
 224         }
 225
 226
 227         for (k = 0; k < p->conf.exclude_user->used; k++) {
 228                 data_string *ds = (data_string *)p->conf.exclude_user->data[k];
 229
 230                 if (buffer_is_equal(ds->value, p->username)) {
 231                         /* user in exclude list */
 232                         return HANDLER_GO_ON;
 233                 }
 234         }
 235
 236         if (p->conf.include_user->used) {
 237                 int found_user = 0;
 238                 for (k = 0; k < p->conf.include_user->used; k++) {
 239                         data_string *ds = (data_string *)p->conf.include_user->data[k];
 240
 241                         if (buffer_is_equal(ds->value, p->username)) {
 242                                 /* user in include list */
 243                                 found_user = 1;
 244                                 break;
 245                         }
 246                 }
 247
 248                 if (!found_user) return HANDLER_GO_ON;
 249         }
 250
 251         /* we build the physical path */
 252
 253         if (buffer_string_is_empty(p->conf.basepath)) {
 254 #ifdef HAVE_PWD_H
 255                 buffer_copy_string(p->temp_path, pwd->pw_dir);
 256 #endif
 257         } else {
 258                 char *cp;
 259                 /* check if the username is valid
 260                  * a request for /~../ should lead to a directory traversal
 261                  * limiting to [-_a-z0-9.] should fix it */
 262
 263                 for (cp = p->username->ptr; *cp; cp++) {
 264                         char c = *cp;
 265
 266                         if (!(c == '-' ||
 267                               c == '_' ||
 268                               c == '.' ||
 269                               (c >= 'a' && c <= 'z') ||
 270                               (c >= 'A' && c <= 'Z') ||
 271                               (c >= '0' && c <= '9'))) {
 272
 273                                 return HANDLER_GO_ON;
 274                         }
 275                 }
 276                 if (con->conf.force_lowercase_filenames) {
 277                         buffer_to_lower(p->username);
 278                 }
 279
 280                 buffer_copy_buffer(p->temp_path, p->conf.basepath);
 281                 buffer_append_slash(p->temp_path);
 282                 if (p->conf.letterhomes) {
 283                         buffer_append_string_len(p->temp_path, p->username->ptr, 1);
 284                         buffer_append_slash(p->temp_path);
 285                 }
 286                 buffer_append_string_buffer(p->temp_path, p->username);
 287         }
 288         buffer_append_slash(p->temp_path);
 289         buffer_append_string_buffer(p->temp_path, p->conf.path);
 290
 291         if (buffer_string_is_empty(p->conf.basepath)) {
 292                 struct stat st;
 293                 int ret;
 294
 295                 ret = stat(p->temp_path->ptr, &st);
 296                 if (ret < 0 || S_ISDIR(st.st_mode) != 1) {
 297                         return HANDLER_GO_ON;
 298                 }
 299         }
 300
 301         buffer_copy_buffer(con->physical.basedir, p->temp_path);
 302
 303         /* the physical rel_path is basically the same as uri.path;
 304          * but it is converted to lowercase in case of force_lowercase_filenames and some special handling
 305          * for trailing '.', ' ' and '/' on windows
 306          * we assume that no docroot/physical handler changed this
 307          * (docroot should only set the docroot/server name, phyiscal should only change the phyiscal.path;
 308          *  the exception mod_secdownload doesn't work with userdir anyway)
 309          */
 310         buffer_append_slash(p->temp_path);
 311         /* if no second '/' is found, we assume that it was stripped from the uri.path for the special handling
 312          * on windows.
 313          * we do not care about the trailing slash here on windows, as we already ensured it is a directory
 314          *
 315          * TODO: what to do with trailing dots in usernames on windows? they may result in the same directory
 316          *       as a username without them.
 317          */
 318         if (NULL != (rel_url = strchr(con->physical.rel_path->ptr + 2, '/'))) {
 319                 buffer_append_string(p->temp_path, rel_url + 1); /* skip the / */
 320         }
 321         buffer_copy_buffer(con->physical.path, p->temp_path);
 322
 323         buffer_reset(p->temp_path);
 324
 325         return HANDLER_GO_ON;
 326 }
 327
 328 /* this function is called at dlopen() time and inits the callbacks */
 329
 330 int mod_userdir_plugin_init(plugin *p);
 331 int mod_userdir_plugin_init(plugin *p) {
 332         p->version     = LIGHTTPD_VERSION_ID;
 333         p->name        = buffer_init_string("userdir");
 334
 335         p->init           = mod_userdir_init;
 336         p->handle_physical = mod_userdir_docroot_handler;
 337         p->set_defaults   = mod_userdir_set_defaults;
 338         p->cleanup        = mod_userdir_free;
 339
 340         p->data        = NULL;
 341
 342         return 0;
 343 }