17c478bd9Sstevel@tonic-gate /* 2*e9af4bc0SJohn Beck * Copyright (c) 2000-2001, 2005, 2008 Sendmail, Inc. and its suppliers. 37c478bd9Sstevel@tonic-gate * All rights reserved. 47c478bd9Sstevel@tonic-gate * 57c478bd9Sstevel@tonic-gate * By using this file, you agree to the terms and conditions set 67c478bd9Sstevel@tonic-gate * forth in the LICENSE file which can be found at the top level of 77c478bd9Sstevel@tonic-gate * the sendmail distribution. 87c478bd9Sstevel@tonic-gate */ 97c478bd9Sstevel@tonic-gate 107c478bd9Sstevel@tonic-gate #include <sm/gen.h> 11*e9af4bc0SJohn Beck SM_RCSID("@(#)$Id: sem.c,v 1.14 2008/05/30 16:26:38 ca Exp $") 127c478bd9Sstevel@tonic-gate 137c478bd9Sstevel@tonic-gate #if SM_CONF_SEM 147c478bd9Sstevel@tonic-gate # include <stdlib.h> 157c478bd9Sstevel@tonic-gate # include <unistd.h> 16*e9af4bc0SJohn Beck # include <sm/string.h> 177c478bd9Sstevel@tonic-gate # include <sm/sem.h> 187c478bd9Sstevel@tonic-gate # include <sm/heap.h> 1949218d4fSjbeck # include <errno.h> 207c478bd9Sstevel@tonic-gate 217c478bd9Sstevel@tonic-gate /* 227c478bd9Sstevel@tonic-gate ** SM_SEM_START -- initialize semaphores 237c478bd9Sstevel@tonic-gate ** 247c478bd9Sstevel@tonic-gate ** Parameters: 257c478bd9Sstevel@tonic-gate ** key -- key for semaphores. 267c478bd9Sstevel@tonic-gate ** nsem -- number of semaphores. 277c478bd9Sstevel@tonic-gate ** semflg -- flag for semget(), if 0, use a default. 287c478bd9Sstevel@tonic-gate ** owner -- create semaphores. 297c478bd9Sstevel@tonic-gate ** 307c478bd9Sstevel@tonic-gate ** Returns: 317c478bd9Sstevel@tonic-gate ** id for semaphores. 327c478bd9Sstevel@tonic-gate ** < 0 on failure. 337c478bd9Sstevel@tonic-gate */ 347c478bd9Sstevel@tonic-gate 357c478bd9Sstevel@tonic-gate int 367c478bd9Sstevel@tonic-gate sm_sem_start(key, nsem, semflg, owner) 377c478bd9Sstevel@tonic-gate key_t key; 387c478bd9Sstevel@tonic-gate int nsem; 397c478bd9Sstevel@tonic-gate int semflg; 407c478bd9Sstevel@tonic-gate bool owner; 417c478bd9Sstevel@tonic-gate { 4249218d4fSjbeck int semid, i, err; 437c478bd9Sstevel@tonic-gate unsigned short *semvals; 447c478bd9Sstevel@tonic-gate 457c478bd9Sstevel@tonic-gate semvals = NULL; 467c478bd9Sstevel@tonic-gate if (semflg == 0) 477c478bd9Sstevel@tonic-gate semflg = (SEM_A|SEM_R)|((SEM_A|SEM_R) >> 3); 487c478bd9Sstevel@tonic-gate if (owner) 497c478bd9Sstevel@tonic-gate semflg |= IPC_CREAT|IPC_EXCL; 507c478bd9Sstevel@tonic-gate semid = semget(key, nsem, semflg); 517c478bd9Sstevel@tonic-gate if (semid < 0) 527c478bd9Sstevel@tonic-gate goto error; 537c478bd9Sstevel@tonic-gate 547c478bd9Sstevel@tonic-gate if (owner) 557c478bd9Sstevel@tonic-gate { 567c478bd9Sstevel@tonic-gate union semun semarg; 577c478bd9Sstevel@tonic-gate 587c478bd9Sstevel@tonic-gate semvals = (unsigned short *) sm_malloc(nsem * sizeof semvals); 597c478bd9Sstevel@tonic-gate if (semvals == NULL) 607c478bd9Sstevel@tonic-gate goto error; 617c478bd9Sstevel@tonic-gate semarg.array = semvals; 627c478bd9Sstevel@tonic-gate 637c478bd9Sstevel@tonic-gate /* initialize semaphore values to be available */ 647c478bd9Sstevel@tonic-gate for (i = 0; i < nsem; i++) 657c478bd9Sstevel@tonic-gate semvals[i] = 1; 667c478bd9Sstevel@tonic-gate if (semctl(semid, 0, SETALL, semarg) < 0) 677c478bd9Sstevel@tonic-gate goto error; 687c478bd9Sstevel@tonic-gate } 697c478bd9Sstevel@tonic-gate return semid; 707c478bd9Sstevel@tonic-gate 717c478bd9Sstevel@tonic-gate error: 7249218d4fSjbeck err = errno; 737c478bd9Sstevel@tonic-gate if (semvals != NULL) 747c478bd9Sstevel@tonic-gate sm_free(semvals); 757c478bd9Sstevel@tonic-gate if (semid >= 0) 767c478bd9Sstevel@tonic-gate sm_sem_stop(semid); 7749218d4fSjbeck return (err > 0) ? (0 - err) : -1; 787c478bd9Sstevel@tonic-gate } 797c478bd9Sstevel@tonic-gate 807c478bd9Sstevel@tonic-gate /* 817c478bd9Sstevel@tonic-gate ** SM_SEM_STOP -- stop using semaphores. 827c478bd9Sstevel@tonic-gate ** 837c478bd9Sstevel@tonic-gate ** Parameters: 847c478bd9Sstevel@tonic-gate ** semid -- id for semaphores. 857c478bd9Sstevel@tonic-gate ** 867c478bd9Sstevel@tonic-gate ** Returns: 877c478bd9Sstevel@tonic-gate ** 0 on success. 887c478bd9Sstevel@tonic-gate ** < 0 on failure. 897c478bd9Sstevel@tonic-gate */ 907c478bd9Sstevel@tonic-gate 917c478bd9Sstevel@tonic-gate int 927c478bd9Sstevel@tonic-gate sm_sem_stop(semid) 937c478bd9Sstevel@tonic-gate int semid; 947c478bd9Sstevel@tonic-gate { 957c478bd9Sstevel@tonic-gate return semctl(semid, 0, IPC_RMID, NULL); 967c478bd9Sstevel@tonic-gate } 977c478bd9Sstevel@tonic-gate 987c478bd9Sstevel@tonic-gate /* 997c478bd9Sstevel@tonic-gate ** SM_SEM_ACQ -- acquire semaphore. 1007c478bd9Sstevel@tonic-gate ** 1017c478bd9Sstevel@tonic-gate ** Parameters: 1027c478bd9Sstevel@tonic-gate ** semid -- id for semaphores. 1037c478bd9Sstevel@tonic-gate ** semnum -- number of semaphore. 1047c478bd9Sstevel@tonic-gate ** timeout -- how long to wait for operation to succeed. 1057c478bd9Sstevel@tonic-gate ** 1067c478bd9Sstevel@tonic-gate ** Returns: 1077c478bd9Sstevel@tonic-gate ** 0 on success. 1087c478bd9Sstevel@tonic-gate ** < 0 on failure. 1097c478bd9Sstevel@tonic-gate */ 1107c478bd9Sstevel@tonic-gate 1117c478bd9Sstevel@tonic-gate int 1127c478bd9Sstevel@tonic-gate sm_sem_acq(semid, semnum, timeout) 1137c478bd9Sstevel@tonic-gate int semid; 1147c478bd9Sstevel@tonic-gate int semnum; 1157c478bd9Sstevel@tonic-gate int timeout; 1167c478bd9Sstevel@tonic-gate { 1177c478bd9Sstevel@tonic-gate int r; 1187c478bd9Sstevel@tonic-gate struct sembuf semops[1]; 1197c478bd9Sstevel@tonic-gate 1207c478bd9Sstevel@tonic-gate semops[0].sem_num = semnum; 1217c478bd9Sstevel@tonic-gate semops[0].sem_op = -1; 1227c478bd9Sstevel@tonic-gate semops[0].sem_flg = SEM_UNDO | 1237c478bd9Sstevel@tonic-gate (timeout != SM_TIME_FOREVER ? 0 : IPC_NOWAIT); 1247c478bd9Sstevel@tonic-gate if (timeout == SM_TIME_IMMEDIATE || timeout == SM_TIME_FOREVER) 1257c478bd9Sstevel@tonic-gate return semop(semid, semops, 1); 1267c478bd9Sstevel@tonic-gate do 1277c478bd9Sstevel@tonic-gate { 1287c478bd9Sstevel@tonic-gate r = semop(semid, semops, 1); 1297c478bd9Sstevel@tonic-gate if (r == 0) 1307c478bd9Sstevel@tonic-gate return r; 1317c478bd9Sstevel@tonic-gate sleep(1); 1327c478bd9Sstevel@tonic-gate --timeout; 1337c478bd9Sstevel@tonic-gate } while (timeout > 0); 1347c478bd9Sstevel@tonic-gate return r; 1357c478bd9Sstevel@tonic-gate } 1367c478bd9Sstevel@tonic-gate 1377c478bd9Sstevel@tonic-gate /* 1387c478bd9Sstevel@tonic-gate ** SM_SEM_REL -- release semaphore. 1397c478bd9Sstevel@tonic-gate ** 1407c478bd9Sstevel@tonic-gate ** Parameters: 1417c478bd9Sstevel@tonic-gate ** semid -- id for semaphores. 1427c478bd9Sstevel@tonic-gate ** semnum -- number of semaphore. 1437c478bd9Sstevel@tonic-gate ** timeout -- how long to wait for operation to succeed. 1447c478bd9Sstevel@tonic-gate ** 1457c478bd9Sstevel@tonic-gate ** Returns: 1467c478bd9Sstevel@tonic-gate ** 0 on success. 1477c478bd9Sstevel@tonic-gate ** < 0 on failure. 1487c478bd9Sstevel@tonic-gate */ 1497c478bd9Sstevel@tonic-gate 1507c478bd9Sstevel@tonic-gate int 1517c478bd9Sstevel@tonic-gate sm_sem_rel(semid, semnum, timeout) 1527c478bd9Sstevel@tonic-gate int semid; 1537c478bd9Sstevel@tonic-gate int semnum; 1547c478bd9Sstevel@tonic-gate int timeout; 1557c478bd9Sstevel@tonic-gate { 1567c478bd9Sstevel@tonic-gate int r; 1577c478bd9Sstevel@tonic-gate struct sembuf semops[1]; 1587c478bd9Sstevel@tonic-gate 1597c478bd9Sstevel@tonic-gate #if PARANOID 1607c478bd9Sstevel@tonic-gate /* XXX should we check whether the value is already 0 ? */ 1617c478bd9Sstevel@tonic-gate SM_REQUIRE(sm_get_sem(semid, semnum) > 0); 1627c478bd9Sstevel@tonic-gate #endif /* PARANOID */ 1637c478bd9Sstevel@tonic-gate 1647c478bd9Sstevel@tonic-gate semops[0].sem_num = semnum; 1657c478bd9Sstevel@tonic-gate semops[0].sem_op = 1; 1667c478bd9Sstevel@tonic-gate semops[0].sem_flg = SEM_UNDO | 1677c478bd9Sstevel@tonic-gate (timeout != SM_TIME_FOREVER ? 0 : IPC_NOWAIT); 1687c478bd9Sstevel@tonic-gate if (timeout == SM_TIME_IMMEDIATE || timeout == SM_TIME_FOREVER) 1697c478bd9Sstevel@tonic-gate return semop(semid, semops, 1); 1707c478bd9Sstevel@tonic-gate do 1717c478bd9Sstevel@tonic-gate { 1727c478bd9Sstevel@tonic-gate r = semop(semid, semops, 1); 1737c478bd9Sstevel@tonic-gate if (r == 0) 1747c478bd9Sstevel@tonic-gate return r; 1757c478bd9Sstevel@tonic-gate sleep(1); 1767c478bd9Sstevel@tonic-gate --timeout; 1777c478bd9Sstevel@tonic-gate } while (timeout > 0); 1787c478bd9Sstevel@tonic-gate return r; 1797c478bd9Sstevel@tonic-gate } 1807c478bd9Sstevel@tonic-gate 1817c478bd9Sstevel@tonic-gate /* 1827c478bd9Sstevel@tonic-gate ** SM_SEM_GET -- get semaphore value. 1837c478bd9Sstevel@tonic-gate ** 1847c478bd9Sstevel@tonic-gate ** Parameters: 1857c478bd9Sstevel@tonic-gate ** semid -- id for semaphores. 1867c478bd9Sstevel@tonic-gate ** semnum -- number of semaphore. 1877c478bd9Sstevel@tonic-gate ** 1887c478bd9Sstevel@tonic-gate ** Returns: 1897c478bd9Sstevel@tonic-gate ** value of semaphore on success. 1907c478bd9Sstevel@tonic-gate ** < 0 on failure. 1917c478bd9Sstevel@tonic-gate */ 1927c478bd9Sstevel@tonic-gate 1937c478bd9Sstevel@tonic-gate int 1947c478bd9Sstevel@tonic-gate sm_sem_get(semid, semnum) 1957c478bd9Sstevel@tonic-gate int semid; 1967c478bd9Sstevel@tonic-gate int semnum; 1977c478bd9Sstevel@tonic-gate { 1987c478bd9Sstevel@tonic-gate int semval; 1997c478bd9Sstevel@tonic-gate 2007c478bd9Sstevel@tonic-gate if ((semval = semctl(semid, semnum, GETVAL, NULL)) < 0) 2017c478bd9Sstevel@tonic-gate return -1; 2027c478bd9Sstevel@tonic-gate return semval; 2037c478bd9Sstevel@tonic-gate } 204*e9af4bc0SJohn Beck 205*e9af4bc0SJohn Beck /* 206*e9af4bc0SJohn Beck ** SM_SEMSETOWNER -- set owner/group/mode of semaphores. 207*e9af4bc0SJohn Beck ** 208*e9af4bc0SJohn Beck ** Parameters: 209*e9af4bc0SJohn Beck ** semid -- id for semaphores. 210*e9af4bc0SJohn Beck ** uid -- uid to use 211*e9af4bc0SJohn Beck ** gid -- gid to use 212*e9af4bc0SJohn Beck ** mode -- mode to use 213*e9af4bc0SJohn Beck ** 214*e9af4bc0SJohn Beck ** Returns: 215*e9af4bc0SJohn Beck ** 0 on success. 216*e9af4bc0SJohn Beck ** < 0 on failure. 217*e9af4bc0SJohn Beck */ 218*e9af4bc0SJohn Beck 219*e9af4bc0SJohn Beck int 220*e9af4bc0SJohn Beck sm_semsetowner(semid, uid, gid, mode) 221*e9af4bc0SJohn Beck int semid; 222*e9af4bc0SJohn Beck uid_t uid; 223*e9af4bc0SJohn Beck gid_t gid; 224*e9af4bc0SJohn Beck mode_t mode; 225*e9af4bc0SJohn Beck { 226*e9af4bc0SJohn Beck int r; 227*e9af4bc0SJohn Beck struct semid_ds semidds; 228*e9af4bc0SJohn Beck union semun { 229*e9af4bc0SJohn Beck int val; 230*e9af4bc0SJohn Beck struct semid_ds *buf; 231*e9af4bc0SJohn Beck ushort *array; 232*e9af4bc0SJohn Beck } arg; 233*e9af4bc0SJohn Beck 234*e9af4bc0SJohn Beck memset(&semidds, 0, sizeof(semidds)); 235*e9af4bc0SJohn Beck arg.buf = &semidds; 236*e9af4bc0SJohn Beck if ((r = semctl(semid, 1, IPC_STAT, arg)) < 0) 237*e9af4bc0SJohn Beck return r; 238*e9af4bc0SJohn Beck semidds.sem_perm.uid = uid; 239*e9af4bc0SJohn Beck semidds.sem_perm.gid = gid; 240*e9af4bc0SJohn Beck semidds.sem_perm.mode = mode; 241*e9af4bc0SJohn Beck if ((r = semctl(semid, 1, IPC_SET, arg)) < 0) 242*e9af4bc0SJohn Beck return r; 243*e9af4bc0SJohn Beck return 0; 244*e9af4bc0SJohn Beck } 2457c478bd9Sstevel@tonic-gate #endif /* SM_CONF_SEM */ 246