authd/providers/ident.c

   1 /* authd/providers/ident.c - ident lookup provider for authd
   2  * Copyright (c) 2016 Elizabeth Myers <elizabeth@interlinked.me>
   3  *
   4  * Permission to use, copy, modify, and/or distribute this software for any
   5  * purpose with or without fee is hereby granted, provided that the above
   6  * copyright notice and this permission notice is present in all copies.
   7  *
   8  * THIS SOFTWARE IS PROVIDED BY THE AUTHOR ``AS IS'' AND ANY EXPRESS OR
   9  * IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE IMPLIED
  10  * WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE ARE
  11  * DISCLAIMED. IN NO EVENT SHALL THE AUTHOR BE LIABLE FOR ANY DIRECT,
  12  * INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL DAMAGES
  13  * (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS OR
  14  * SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION)
  15  * HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT,
  16  * STRICT LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING
  17  * IN ANY WAY OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE
  18  * POSSIBILITY OF SUCH DAMAGE.
  19  */
  20
  21 /* Largely adapted from old s_auth.c, but reworked for authd. rDNS code
  22  * moved to its own provider.
  23  *
  24  * --Elizafox 13 March 2016
  25  */
  26
  27 #include "stdinc.h"
  28 #include "match.h"
  29 #include "authd.h"
  30 #include "notice.h"
  31 #include "provider.h"
  32 #include "res.h"
  33
  34 #define IDENT_BUFSIZE 128
  35
  36 struct ident_query
  37 {
  38         time_t timeout;                         /* Timeout interval */
  39         rb_fde_t *F;                            /* Our FD */
  40 };
  41
  42 /* Goinked from old s_auth.c --Elizafox */
  43 static const char *messages[] =
  44 {
  45         "*** Checking Ident",
  46         "*** Got Ident response",
  47         "*** No Ident response",
  48 };
  49
  50 typedef enum
  51 {
  52         REPORT_LOOKUP,
  53         REPORT_FOUND,
  54         REPORT_FAIL,
  55 } ident_message;
  56
  57 static EVH timeout_ident_queries_event;
  58 static CNCB ident_connected;
  59 static PF read_ident_reply;
  60
  61 static void client_fail(struct auth_client *auth, ident_message message);
  62 static void client_success(struct auth_client *auth);
  63 static char * get_valid_ident(char *buf);
  64
  65 static struct ev_entry *timeout_ev;
  66 static int ident_timeout = 5;
  67
  68
  69 /* Timeout outstanding queries */
  70 static void
  71 timeout_ident_queries_event(void *notused)
  72 {
  73         struct auth_client *auth;
  74         rb_dictionary_iter iter;
  75
  76         RB_DICTIONARY_FOREACH(auth, &iter, auth_clients)
  77         {
  78                 struct ident_query *query = auth->data[PROVIDER_IDENT];
  79
  80                 if(query != NULL && query->timeout < rb_current_time())
  81                         client_fail(auth, REPORT_FAIL);
  82         }
  83 }
  84
  85 /*
  86  * ident_connected() - deal with the result of rb_connect_tcp()
  87  *
  88  * If the connection failed, we simply close the auth fd and report
  89  * a failure. If the connection suceeded send the ident server a query
  90  * giving "theirport , ourport". The write is only attempted *once* so
  91  * it is deemed to be a fail if the entire write doesn't write all the
  92  * data given.  This shouldnt be a problem since the socket should have
  93  * a write buffer far greater than this message to store it in should
  94  * problems arise. -avalon
  95  */
  96 static void
  97 ident_connected(rb_fde_t *F, int error, void *data)
  98 {
  99         struct auth_client *auth = data;
 100         struct ident_query *query = auth->data[PROVIDER_IDENT];
 101         char authbuf[32];
 102         int authlen;
 103
 104         if(query == NULL)
 105                 return;
 106
 107         /* Check the error */
 108         if(error != RB_OK)
 109         {
 110                 /* We had an error during connection :( */
 111                 client_fail(auth, REPORT_FAIL);
 112                 return;
 113         }
 114
 115         snprintf(authbuf, sizeof(authbuf), "%u , %u\r\n",
 116                         auth->c_port, auth->l_port);
 117         authlen = strlen(authbuf);
 118
 119         if(rb_write(query->F, authbuf, authlen) != authlen)
 120         {
 121                 client_fail(auth, REPORT_FAIL);
 122                 return;
 123         }
 124
 125         read_ident_reply(query->F, auth);
 126 }
 127
 128 static void
 129 read_ident_reply(rb_fde_t *F, void *data)
 130 {
 131         struct auth_client *auth = data;
 132         struct ident_query *query = auth->data[PROVIDER_IDENT];
 133         char *s = NULL;
 134         char *t = NULL;
 135         int len;
 136         int count;
 137         char buf[IDENT_BUFSIZE + 1];    /* buffer to read auth reply into */
 138
 139         if(query == NULL)
 140                 return;
 141
 142         len = rb_read(F, buf, IDENT_BUFSIZE);
 143         if(len < 0 && rb_ignore_errno(errno))
 144         {
 145                 rb_setselect(F, RB_SELECT_READ, read_ident_reply, query);
 146                 return;
 147         }
 148
 149         if(len > 0)
 150         {
 151                 buf[len] = '\0';
 152
 153                 if((s = get_valid_ident(buf)))
 154                 {
 155                         t = auth->username;
 156
 157                         while (*s == '~' || *s == '^')
 158                                 s++;
 159
 160                         for (count = USERLEN; *s && count; s++)
 161                         {
 162                                 if(*s == '@')
 163                                 {
 164                                         break;
 165                                 }
 166                                 if(*s != ' ' && *s != ':' && *s != '[')
 167                                 {
 168                                         *t++ = *s;
 169                                         count--;
 170                                 }
 171                         }
 172                         *t = '\0';
 173                 }
 174         }
 175
 176         if(s == NULL)
 177                 client_fail(auth, REPORT_FAIL);
 178         else
 179                 client_success(auth);
 180 }
 181
 182 static void
 183 client_fail(struct auth_client *auth, ident_message report)
 184 {
 185         struct ident_query *query = auth->data[PROVIDER_IDENT];
 186
 187         if(query == NULL)
 188                 return;
 189
 190         rb_strlcpy(auth->username, "*", sizeof(auth->username));
 191
 192         if(query->F != NULL)
 193                 rb_close(query->F);
 194
 195         rb_free(query);
 196         auth->data[PROVIDER_IDENT] = NULL;
 197
 198         notice_client(auth->cid, messages[report]);
 199         provider_done(auth, PROVIDER_IDENT);
 200 }
 201
 202 static void
 203 client_success(struct auth_client *auth)
 204 {
 205         struct ident_query *query = auth->data[PROVIDER_IDENT];
 206
 207         if(query == NULL)
 208                 return;
 209
 210         if(query->F != NULL)
 211                 rb_close(query->F);
 212
 213         rb_free(query);
 214         auth->data[PROVIDER_IDENT] = NULL;
 215
 216         notice_client(auth->cid, messages[REPORT_FOUND]);
 217         provider_done(auth, PROVIDER_IDENT);
 218 }
 219
 220 /* get_valid_ident
 221  * parse ident query reply from identd server
 222  *
 223  * Taken from old s_auth.c --Elizafox
 224  *
 225  * Inputs       - pointer to ident buf
 226  * Outputs      - NULL if no valid ident found, otherwise pointer to name
 227  * Side effects - None
 228  */
 229 static char *
 230 get_valid_ident(char *buf)
 231 {
 232         int remp = 0;
 233         int locp = 0;
 234         char *colon1Ptr;
 235         char *colon2Ptr;
 236         char *colon3Ptr;
 237         char *commaPtr;
 238         char *remotePortString;
 239
 240         /* All this to get rid of a sscanf() fun. */
 241         remotePortString = buf;
 242
 243         colon1Ptr = strchr(remotePortString, ':');
 244         if(!colon1Ptr)
 245                 return 0;
 246
 247         *colon1Ptr = '\0';
 248         colon1Ptr++;
 249         colon2Ptr = strchr(colon1Ptr, ':');
 250         if(!colon2Ptr)
 251                 return 0;
 252
 253         *colon2Ptr = '\0';
 254         colon2Ptr++;
 255         commaPtr = strchr(remotePortString, ',');
 256
 257         if(!commaPtr)
 258                 return 0;
 259
 260         *commaPtr = '\0';
 261         commaPtr++;
 262
 263         remp = atoi(remotePortString);
 264         if(!remp)
 265                 return 0;
 266
 267         locp = atoi(commaPtr);
 268         if(!locp)
 269                 return 0;
 270
 271         /* look for USERID bordered by first pair of colons */
 272         if(!strstr(colon1Ptr, "USERID"))
 273                 return 0;
 274
 275         colon3Ptr = strchr(colon2Ptr, ':');
 276         if(!colon3Ptr)
 277                 return 0;
 278
 279         *colon3Ptr = '\0';
 280         colon3Ptr++;
 281         return (colon3Ptr);
 282 }
 283
 284 static bool
 285 ident_init(void)
 286 {
 287         timeout_ev = rb_event_addish("timeout_ident_queries_event", timeout_ident_queries_event, NULL, 1);
 288         return (timeout_ev != NULL);
 289 }
 290
 291 static void
 292 ident_destroy(void)
 293 {
 294         struct auth_client *auth;
 295         rb_dictionary_iter iter;
 296
 297         /* Nuke all ident queries */
 298         RB_DICTIONARY_FOREACH(auth, &iter, auth_clients)
 299         {
 300                 if(auth->data[PROVIDER_IDENT] != NULL)
 301                         client_fail(auth, REPORT_FAIL);
 302         }
 303 }
 304
 305 static bool ident_start(struct auth_client *auth)
 306 {
 307         struct ident_query *query = rb_malloc(sizeof(struct ident_query));
 308         struct rb_sockaddr_storage l_addr, c_addr;
 309         int family = GET_SS_FAMILY(&auth->c_addr);
 310
 311         notice_client(auth->cid, messages[REPORT_LOOKUP]);
 312
 313         auth->data[PROVIDER_IDENT] = query;
 314         query->timeout = rb_current_time() + ident_timeout;
 315
 316         if((query->F = rb_socket(family, SOCK_STREAM, 0, "ident")) == NULL)
 317         {
 318                 warn_opers(L_DEBUG, "Could not create ident socket: %s", strerror(errno));
 319                 client_fail(auth, REPORT_FAIL);
 320                 return true;    /* Not a fatal error */
 321         }
 322
 323         /* Build sockaddr_storages for rb_connect_tcp below */
 324         memcpy(&l_addr, &auth->l_addr, sizeof(l_addr));
 325         memcpy(&c_addr, &auth->c_addr, sizeof(c_addr));
 326
 327         /* Set the ports correctly */
 328 #ifdef RB_IPV6
 329         if(GET_SS_FAMILY(&l_addr) == AF_INET6)
 330                 ((struct sockaddr_in6 *)&l_addr)->sin6_port = 0;
 331         else
 332 #endif
 333                 ((struct sockaddr_in *)&l_addr)->sin_port = 0;
 334
 335 #ifdef RB_IPV6
 336         if(GET_SS_FAMILY(&c_addr) == AF_INET6)
 337                 ((struct sockaddr_in6 *)&c_addr)->sin6_port = htons(113);
 338         else
 339 #endif
 340                 ((struct sockaddr_in *)&c_addr)->sin_port = htons(113);
 341
 342         rb_connect_tcp(query->F, (struct sockaddr *)&c_addr,
 343                         (struct sockaddr *)&l_addr,
 344                         GET_SS_LEN(&l_addr), ident_connected,
 345                         query, ident_timeout);
 346
 347         set_provider_on(auth, PROVIDER_IDENT);
 348
 349         return true;
 350 }
 351
 352 static void
 353 ident_cancel(struct auth_client *auth)
 354 {
 355         struct ident_query *query = auth->data[PROVIDER_IDENT];
 356
 357         if(query != NULL)
 358                 client_fail(auth, REPORT_FAIL);
 359 }
 360
 361 static void
 362 add_conf_ident_timeout(const char *key, int parc, const char **parv)
 363 {
 364         int timeout = atoi(parv[0]);
 365
 366         if(timeout < 0)
 367         {
 368                 warn_opers(L_CRIT, "BUG: ident timeout < 0 (value: %d)", timeout);
 369                 return;
 370         }
 371
 372         ident_timeout = timeout;
 373 }
 374
 375 struct auth_opts_handler ident_options[] =
 376 {
 377         { "ident_timeout", 1, add_conf_ident_timeout },
 378         { NULL, 0, NULL },
 379 };
 380
 381
 382 struct auth_provider ident_provider =
 383 {
 384         .id = PROVIDER_IDENT,
 385         .init = ident_init,
 386         .destroy = ident_destroy,
 387         .start = ident_start,
 388         .cancel = ident_cancel,
 389         .completed = NULL,
 390         .opt_handlers = ident_options,
 391 };