source/smbd/connection.c

   1 /*
   2    Unix SMB/Netbios implementation.
   3    Version 1.9.
   4    connection claim routines
   5    Copyright (C) Andrew Tridgell 1998
   6
   7    This program is free software; you can redistribute it and/or modify
   8    it under the terms of the GNU General Public License as published by
   9    the Free Software Foundation; either version 2 of the License, or
  10    (at your option) any later version.
  11
  12    This program is distributed in the hope that it will be useful,
  13    but WITHOUT ANY WARRANTY; without even the implied warranty of
  14    MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
  15    GNU General Public License for more details.
  16
  17    You should have received a copy of the GNU General Public License
  18    along with this program; if not, write to the Free Software
  19    Foundation, Inc., 675 Mass Ave, Cambridge, MA 02139, USA.
  20 */
  21
  22 #include "includes.h"
  23
  24
  25 extern fstring remote_machine;
  26 static TDB_CONTEXT *tdb;
  27
  28 extern int DEBUGLEVEL;
  29
  30 #ifdef WITH_UTMP
  31 static void utmp_yield(pid_t pid, const connection_struct *conn);
  32 static void utmp_claim(const struct connections_data *crec, const connection_struct *conn);
  33 #endif
  34
  35 /****************************************************************************
  36 delete a connection record
  37 ****************************************************************************/
  38 BOOL yield_connection(connection_struct *conn,char *name,int max_connections)
  39 {
  40         struct connections_key key;
  41         TDB_DATA kbuf;
  42
  43         if (!tdb) return False;
  44
  45         DEBUG(3,("Yielding connection to %s\n",name));
  46
  47         ZERO_STRUCT(key);
  48         key.pid = getpid();
  49         if (conn) key.cnum = conn->cnum;
  50         fstrcpy(key.name, name);
  51
  52         kbuf.dptr = (char *)&key;
  53         kbuf.dsize = sizeof(key);
  54
  55         tdb_delete(tdb, kbuf);
  56
  57 #ifdef WITH_UTMP
  58         if(conn)
  59                 utmp_yield(key.pid, conn);
  60 #endif
  61
  62         return(True);
  63 }
  64
  65
  66 /****************************************************************************
  67 claim an entry in the connections database
  68 ****************************************************************************/
  69 BOOL claim_connection(connection_struct *conn,char *name,int max_connections,BOOL Clear)
  70 {
  71         struct connections_key key;
  72         struct connections_data crec;
  73         TDB_DATA kbuf, dbuf;
  74
  75         if (max_connections <= 0)
  76                 return(True);
  77
  78         if (!tdb) {
  79                 tdb = tdb_open(lock_path("connections.tdb"), 0, TDB_CLEAR_IF_FIRST,
  80                                O_RDWR | O_CREAT, 0644);
  81         }
  82         if (!tdb) return False;
  83
  84         DEBUG(5,("claiming %s %d\n",name,max_connections));
  85
  86         ZERO_STRUCT(key);
  87         key.pid = getpid();
  88         key.cnum = conn?conn->cnum:-1;
  89         fstrcpy(key.name, name);
  90
  91         kbuf.dptr = (char *)&key;
  92         kbuf.dsize = sizeof(key);
  93
  94         /* fill in the crec */
  95         ZERO_STRUCT(crec);
  96         crec.magic = 0x280267;
  97         crec.pid = getpid();
  98         crec.cnum = conn?conn->cnum:-1;
  99         if (conn) {
 100                 crec.uid = conn->uid;
 101                 crec.gid = conn->gid;
 102                 StrnCpy(crec.name,
 103                         lp_servicename(SNUM(conn)),sizeof(crec.name)-1);
 104         }
 105         crec.start = time(NULL);
 106
 107         StrnCpy(crec.machine,remote_machine,sizeof(crec.machine)-1);
 108         StrnCpy(crec.addr,conn?conn->client_address:client_addr(),sizeof(crec.addr)-1);
 109
 110         dbuf.dptr = (char *)&crec;
 111         dbuf.dsize = sizeof(crec);
 112
 113         if (tdb_store(tdb, kbuf, dbuf, TDB_REPLACE) != 0) return False;
 114
 115 #ifdef WITH_UTMP
 116         if (conn)
 117             utmp_claim(&crec, conn);
 118 #endif
 119
 120         return True;
 121 }
 122
 123 #ifdef WITH_UTMP
 124
 125 /****************************************************************************
 126 Reflect connection status in utmp/wtmp files.
 127         T.D.Lee@durham.ac.uk  September 1999
 128
 129 Hints for porting:
 130         o Always attempt to use programmatic interface (pututline() etc.)
 131         o The "x" (utmpx/wtmpx; HAVE_UTMPX_H) seems preferable.
 132
 133 OS status:
 134         Solaris 2.x:  Tested on 2.6 and 2.7; should be OK on other flavours.
 135                 T.D.Lee@durham.ac.uk
 136         HPUX 9.x:  Not tested.  Appears not to have "x".
 137         IRIX 6.5:  Not tested.  Appears to have "x".
 138
 139 Notes:
 140         The 4 byte 'ut_id' component is vital to distinguish connections,
 141         of which there could be several hundered or even thousand.
 142         Entries seem to be printable characters, with optional NULL pads.
 143
 144         We need to be distinct from other entries in utmp/wtmp.
 145
 146         Observed things: therefore avoid them.  Add to this list please.
 147         From Solaris 2.x (because that's what I have):
 148                 'sN'    : run-levels; N: [0-9]
 149                 'co'    : console
 150                 'CC'    : arbitrary things;  C: [a-z]
 151                 'rXNN'  : rlogin;  N: [0-9]; X: [0-9a-z]
 152                 'tXNN'  : rlogin;  N: [0-9]; X: [0-9a-z]
 153                 '/NNN'  : Solaris CDE
 154                 'ftpZ'  : ftp (Z is the number 255, aka 0377, aka 0xff)
 155         Mostly a record uses the same 'ut_id' in both "utmp" and "wtmp",
 156         but differences have been seen.
 157
 158         Arbitrarily I have chosen to use a distinctive 'SM' for the
 159         first two bytes.
 160
 161         The remaining two encode the connection number used in samba locking
 162         functions "claim_connection() and "yield_connection()".  This seems
 163         to be a "nicely behaved" number: starting from 0 then working up
 164         looking for an available slot.
 165
 166 ****************************************************************************/
 167
 168 #include <utmp.h>
 169
 170 #ifdef HAVE_UTMPX_H
 171 #include <utmpx.h>
 172 #endif
 173
 174 static const char *ut_id_encstr =
 175         "0123456789abcdefghijklmnopqrstuvwxyzABCDEFGHIJKLMNOPQRSTUVWXYZ";
 176
 177 static
 178 int
 179 ut_id_encode(int i, char *fourbyte)
 180 {
 181         int nbase;
 182
 183         fourbyte[0] = 'S';
 184         fourbyte[1] = 'M';
 185
 186 /*
 187  * Encode remaining 2 bytes from 'i'.
 188  * 'ut_id_encstr' is the character set on which modulo arithmetic is done.
 189  * Example: digits would produce the base-10 numbers from '001'.
 190  */
 191         nbase = strlen(ut_id_encstr);
 192
 193         fourbyte[3] = ut_id_encstr[i % nbase];
 194         i /= nbase;
 195         fourbyte[2] = ut_id_encstr[i % nbase];
 196         i /= nbase;
 197
 198         return(i);      /* 0: good; else overflow */
 199 }
 200
 201 static int utmp_fill(struct utmp *u, const connection_struct *conn, pid_t pid, int i)
 202 {
 203         struct timeval timeval;
 204         int rc;
 205
 206         pstrcpy(u->ut_user, conn->user);
 207         rc = ut_id_encode(i, u->ut_id);
 208         slprintf(u->ut_line, 12, "smb/%d", i);
 209
 210         u->ut_pid = pid;
 211
 212         gettimeofday(&timeval, NULL);
 213         u->ut_time = timeval.tv_sec;
 214
 215         return(rc);
 216 }
 217
 218 /* Default path (if possible) */
 219 #ifdef  HAVE_UTMPX_H
 220
 221 # ifdef UTMPX_FILE
 222 static char *ut_pathname = UTMPX_FILE;
 223 # else
 224 static char *ut_pathname = "";
 225 # endif
 226 # ifdef WTMPX_FILE
 227 static char *wt_pathname = WTMPX_FILE;
 228 # else
 229 static char *wt_pathname = "";
 230 # endif
 231
 232 #else   /* HAVE_UTMPX_H */
 233
 234 # ifdef UTMP_FILE
 235 static char *ut_pathname = UTMP_FILE;
 236 # else
 237 static char *ut_pathname = "";
 238 # endif
 239 # ifdef WTMP_FILE
 240 static char *wt_pathname = WTMP_FILE;
 241 # else
 242 static char *wt_pathname = "";
 243 # endif
 244
 245 #endif  /* HAVE_UTMPX_H */
 246
 247 static void uw_pathname(pstring fname, const char *uw_name)
 248 {
 249         pstring dirname;
 250
 251         pstrcpy(dirname,lp_utmpdir());
 252         trim_string(dirname,"","/");
 253
 254         /* Given directory: use it */
 255         if (dirname != 0 && strlen(dirname) != 0) {
 256                 pstrcpy(fname, dirname);
 257                 pstrcat(fname, "/");
 258                 pstrcat(fname, uw_name);
 259                 return;
 260         }
 261
 262         /* No given directory: attempt to use default paths */
 263         if (uw_name[0] == 'u') {
 264                 pstrcpy(fname, ut_pathname);
 265                 return;
 266         }
 267
 268         if (uw_name[0] == 'w') {
 269                 pstrcpy(fname, wt_pathname);
 270                 return;
 271         }
 272
 273         pstrcpy(fname, "");
 274 }
 275
 276 static void utmp_update(const struct utmp *u, const char *host)
 277 {
 278         pstring fname;
 279
 280 #ifdef HAVE_UTMPX_H
 281         struct utmpx ux, *uxrc;
 282
 283         getutmpx(u, &ux);
 284         if (host) {
 285 #if defined(HAVE_UX_UT_SYSLEN)
 286                 ux.ut_syslen = strlen(host);
 287 #endif /* defined(HAVE_UX_UT_SYSLEN) */
 288                 pstrcpy(ux.ut_host, host);
 289         }
 290
 291         uw_pathname(fname, "utmpx");
 292         DEBUG(2,("utmp_update: fname:%s\n", fname));
 293         if (strlen(fname) != 0) {
 294                 utmpxname(fname);
 295         }
 296         uxrc = pututxline(&ux);
 297         if (uxrc == NULL) {
 298                 DEBUG(2,("utmp_update: pututxline() failed\n"));
 299                 return;
 300         }
 301
 302         uw_pathname(fname, "wtmpx");
 303         DEBUG(2,("utmp_update: fname:%s\n", fname));
 304         if (strlen(fname) != 0) {
 305                 updwtmpx(fname, &ux);
 306         }
 307 #else
 308         uw_pathname(fname, "utmp");
 309         DEBUG(2,("utmp_update: fname:%s\n", fname));
 310         if (strlen(fname) != 0) {
 311                 utmpname(fname);
 312         }
 313         pututline(u);
 314
 315         uw_pathname(fname, "wtmp");
 316
 317         /* *** Hmmm.  Appending wtmp (as distinct from overwriting utmp) has
 318         me baffled.  How is it to be done? *** */
 319 #endif
 320 }
 321
 322 static void utmp_yield(pid_t pid, const connection_struct *conn)
 323 {
 324         struct utmp u;
 325
 326         if (! lp_utmp(SNUM(conn))) {
 327                 DEBUG(2,("utmp_yield: lp_utmp() NULL\n"));
 328                 return;
 329         }
 330
 331         DEBUG(2,("utmp_yield: conn: user:%s cnum:%d\n",
 332                  conn->user, conn->cnum));
 333
 334         memset((char *)&u, '\0', sizeof(struct utmp));
 335         u.ut_type = DEAD_PROCESS;
 336         u.ut_exit.e_termination = 0;
 337         u.ut_exit.e_exit = 0;
 338         if (utmp_fill(&u, conn, pid, conn->cnum) == 0) {
 339                 utmp_update(&u, NULL);
 340         }
 341 }
 342
 343 static void utmp_claim(const struct connect_record *crec, const connection_struct *conn)
 344 {
 345         struct utmp u;
 346
 347         if (conn == NULL) {
 348                 DEBUG(2,("utmp_claim: conn NULL\n"));
 349                 return;
 350         }
 351
 352         if (! lp_utmp(SNUM(conn))) {
 353                 DEBUG(2,("utmp_claim: lp_utmp() NULL\n"));
 354                 return;
 355         }
 356
 357         DEBUG(2,("utmp_claim: conn: user:%s cnum:%d i:%d\n",
 358           conn->user, conn->cnum, i));
 359         DEBUG(2,("utmp_claim: crec: pid:%d, cnum:%d name:%s addr:%s mach:%s DNS:%s\n",
 360           crec->pid, crec->cnum, crec->name, crec->addr, crec->machine, client_name()));
 361
 362
 363         memset((char *)&u, '\0', sizeof(struct utmp));
 364         u.ut_type = USER_PROCESS;
 365         if (utmp_fill(&u, conn, crec->pid, conn->cnum) == 0) {
 366                 utmp_update(&u, crec->machine);
 367         }
 368 }
 369
 370 #endif