1*0Sstevel@tonic-gate /* 2*0Sstevel@tonic-gate * CDDL HEADER START 3*0Sstevel@tonic-gate * 4*0Sstevel@tonic-gate * The contents of this file are subject to the terms of the 5*0Sstevel@tonic-gate * Common Development and Distribution License, Version 1.0 only 6*0Sstevel@tonic-gate * (the "License"). You may not use this file except in compliance 7*0Sstevel@tonic-gate * with the License. 8*0Sstevel@tonic-gate * 9*0Sstevel@tonic-gate * You can obtain a copy of the license at usr/src/OPENSOLARIS.LICENSE 10*0Sstevel@tonic-gate * or http://www.opensolaris.org/os/licensing. 11*0Sstevel@tonic-gate * See the License for the specific language governing permissions 12*0Sstevel@tonic-gate * and limitations under the License. 13*0Sstevel@tonic-gate * 14*0Sstevel@tonic-gate * When distributing Covered Code, include this CDDL HEADER in each 15*0Sstevel@tonic-gate * file and include the License file at usr/src/OPENSOLARIS.LICENSE. 16*0Sstevel@tonic-gate * If applicable, add the following below this CDDL HEADER, with the 17*0Sstevel@tonic-gate * fields enclosed by brackets "[]" replaced with your own identifying 18*0Sstevel@tonic-gate * information: Portions Copyright [yyyy] [name of copyright owner] 19*0Sstevel@tonic-gate * 20*0Sstevel@tonic-gate * CDDL HEADER END 21*0Sstevel@tonic-gate */ 22*0Sstevel@tonic-gate /* Copyright (c) 1984, 1986, 1987, 1988, 1989 AT&T */ 23*0Sstevel@tonic-gate /* All Rights Reserved */ 24*0Sstevel@tonic-gate 25*0Sstevel@tonic-gate 26*0Sstevel@tonic-gate /* 27*0Sstevel@tonic-gate * University Copyright- Copyright (c) 1982, 1986, 1988 28*0Sstevel@tonic-gate * The Regents of the University of California 29*0Sstevel@tonic-gate * All Rights Reserved 30*0Sstevel@tonic-gate * 31*0Sstevel@tonic-gate * University Acknowledgment- Portions of this document are derived from 32*0Sstevel@tonic-gate * software developed by the University of California, Berkeley, and its 33*0Sstevel@tonic-gate * contributors. 34*0Sstevel@tonic-gate */ 35*0Sstevel@tonic-gate 36*0Sstevel@tonic-gate #pragma ident "%Z%%M% %I% %E% SMI" 37*0Sstevel@tonic-gate 38*0Sstevel@tonic-gate /* 39*0Sstevel@tonic-gate * mailx -- a modified version of a University of California at Berkeley 40*0Sstevel@tonic-gate * mail program 41*0Sstevel@tonic-gate */ 42*0Sstevel@tonic-gate 43*0Sstevel@tonic-gate /* 44*0Sstevel@tonic-gate * This code is only compiled in if SIG_HOLD is not defined! 45*0Sstevel@tonic-gate * 46*0Sstevel@tonic-gate * Retrofit new signal interface to old signal primitives. 47*0Sstevel@tonic-gate * Supported routines: 48*0Sstevel@tonic-gate * sigsys(sig, func) 49*0Sstevel@tonic-gate * sigset(sig, func) 50*0Sstevel@tonic-gate * sighold(sig) 51*0Sstevel@tonic-gate * sigrelse(sig) 52*0Sstevel@tonic-gate * sigignore(sig) 53*0Sstevel@tonic-gate * sigpause(sig) 54*0Sstevel@tonic-gate * Also, 55*0Sstevel@tonic-gate * sigchild() 56*0Sstevel@tonic-gate * to set all held signals to ignored signals in the 57*0Sstevel@tonic-gate * child process after fork(2) 58*0Sstevel@tonic-gate */ 59*0Sstevel@tonic-gate #include <signal.h> 60*0Sstevel@tonic-gate 61*0Sstevel@tonic-gate #ifndef SIG_HOLD 62*0Sstevel@tonic-gate # include <errno.h> 63*0Sstevel@tonic-gate # include <setjmp.h> 64*0Sstevel@tonic-gate # include <stdio.h> 65*0Sstevel@tonic-gate 66*0Sstevel@tonic-gate extern int errno; 67*0Sstevel@tonic-gate 68*0Sstevel@tonic-gate typedef void (*sigtype)(); 69*0Sstevel@tonic-gate 70*0Sstevel@tonic-gate #define SIG_HOLD ((sigtype) 2) 71*0Sstevel@tonic-gate #ifndef SIG_ERR 72*0Sstevel@tonic-gate # define SIG_ERR ((sigtype) -1) 73*0Sstevel@tonic-gate #endif 74*0Sstevel@tonic-gate 75*0Sstevel@tonic-gate sigtype sigdisp(), sighold(), sigignore(); 76*0Sstevel@tonic-gate void _Sigtramp(); 77*0Sstevel@tonic-gate 78*0Sstevel@tonic-gate /* 79*0Sstevel@tonic-gate * The following helps us keep the extended signal semantics together. 80*0Sstevel@tonic-gate * We remember for each signal the address of the function we're 81*0Sstevel@tonic-gate * supposed to call. s_func is SIG_DFL / SIG_IGN if appropriate. 82*0Sstevel@tonic-gate */ 83*0Sstevel@tonic-gate static struct sigtable { 84*0Sstevel@tonic-gate sigtype s_func; /* What to call */ 85*0Sstevel@tonic-gate int s_flag; /* Signal flags; see below */ 86*0Sstevel@tonic-gate } sigtable[NSIG + 1]; 87*0Sstevel@tonic-gate 88*0Sstevel@tonic-gate /* 89*0Sstevel@tonic-gate * Signal flag values. 90*0Sstevel@tonic-gate */ 91*0Sstevel@tonic-gate #define SHELD 1 /* Signal is being held */ 92*0Sstevel@tonic-gate #define SDEFER 2 /* Signal occured while held */ 93*0Sstevel@tonic-gate #define SSET 4 /* s_func is believable */ 94*0Sstevel@tonic-gate #define SPAUSE 8 /* are pausing, waiting for sig */ 95*0Sstevel@tonic-gate 96*0Sstevel@tonic-gate jmp_buf _pause; /* For doing sigpause() */ 97*0Sstevel@tonic-gate 98*0Sstevel@tonic-gate /* 99*0Sstevel@tonic-gate * Approximate sigsys() system call 100*0Sstevel@tonic-gate * This is almost useless since one only calls sigsys() 101*0Sstevel@tonic-gate * in the child of a vfork(). If you have vfork(), you have new signals 102*0Sstevel@tonic-gate * anyway. The real sigsys() does all the stuff needed to support 103*0Sstevel@tonic-gate * the real sigset() library. We don't bother here, assuming that 104*0Sstevel@tonic-gate * you are either ignoring or defaulting a signal in the child. 105*0Sstevel@tonic-gate */ 106*0Sstevel@tonic-gate sigtype 107*0Sstevel@tonic-gate sigsys(int sig, sigtype func) 108*0Sstevel@tonic-gate { 109*0Sstevel@tonic-gate sigtype old; 110*0Sstevel@tonic-gate 111*0Sstevel@tonic-gate old = sigdisp(sig); 112*0Sstevel@tonic-gate signal(sig, func); 113*0Sstevel@tonic-gate return(old); 114*0Sstevel@tonic-gate } 115*0Sstevel@tonic-gate 116*0Sstevel@tonic-gate 117*0Sstevel@tonic-gate /* 118*0Sstevel@tonic-gate * Set the (permanent) disposition of a signal. 119*0Sstevel@tonic-gate * If the signal is subsequently (or even now) held, 120*0Sstevel@tonic-gate * the action you set here can be enabled using sigrelse(). 121*0Sstevel@tonic-gate */ 122*0Sstevel@tonic-gate sigtype 123*0Sstevel@tonic-gate sigset(int sig, sigtype func) 124*0Sstevel@tonic-gate { 125*0Sstevel@tonic-gate sigtype old; 126*0Sstevel@tonic-gate 127*0Sstevel@tonic-gate if (sig < 1 || sig > NSIG) { 128*0Sstevel@tonic-gate errno = EINVAL; 129*0Sstevel@tonic-gate return(SIG_ERR); 130*0Sstevel@tonic-gate } 131*0Sstevel@tonic-gate old = sigdisp(sig); 132*0Sstevel@tonic-gate /* 133*0Sstevel@tonic-gate * Does anyone actually call sigset with SIG_HOLD!? 134*0Sstevel@tonic-gate */ 135*0Sstevel@tonic-gate if (func == SIG_HOLD) { 136*0Sstevel@tonic-gate sighold(sig); 137*0Sstevel@tonic-gate return(old); 138*0Sstevel@tonic-gate } 139*0Sstevel@tonic-gate sigtable[sig].s_flag |= SSET; 140*0Sstevel@tonic-gate sigtable[sig].s_func = func; 141*0Sstevel@tonic-gate if (func == SIG_DFL) { 142*0Sstevel@tonic-gate /* 143*0Sstevel@tonic-gate * If signal has been held, must retain 144*0Sstevel@tonic-gate * the catch so that we can note occurrance 145*0Sstevel@tonic-gate * of signal. 146*0Sstevel@tonic-gate */ 147*0Sstevel@tonic-gate if ((sigtable[sig].s_flag & SHELD) == 0) 148*0Sstevel@tonic-gate signal(sig, SIG_DFL); 149*0Sstevel@tonic-gate else 150*0Sstevel@tonic-gate signal(sig, _Sigtramp); 151*0Sstevel@tonic-gate return(old); 152*0Sstevel@tonic-gate } 153*0Sstevel@tonic-gate if (func == SIG_IGN) { 154*0Sstevel@tonic-gate /* 155*0Sstevel@tonic-gate * Clear pending signal 156*0Sstevel@tonic-gate */ 157*0Sstevel@tonic-gate signal(sig, SIG_IGN); 158*0Sstevel@tonic-gate sigtable[sig].s_flag &= ~SDEFER; 159*0Sstevel@tonic-gate return(old); 160*0Sstevel@tonic-gate } 161*0Sstevel@tonic-gate signal(sig, _Sigtramp); 162*0Sstevel@tonic-gate return(old); 163*0Sstevel@tonic-gate } 164*0Sstevel@tonic-gate 165*0Sstevel@tonic-gate /* 166*0Sstevel@tonic-gate * Hold a signal. 167*0Sstevel@tonic-gate * This CAN be tricky if the signal's disposition is SIG_DFL. 168*0Sstevel@tonic-gate * In that case, we still catch the signal so we can note it 169*0Sstevel@tonic-gate */ 170*0Sstevel@tonic-gate sigtype 171*0Sstevel@tonic-gate sighold(int sig) 172*0Sstevel@tonic-gate { 173*0Sstevel@tonic-gate sigtype old; 174*0Sstevel@tonic-gate 175*0Sstevel@tonic-gate if (sig < 1 || sig > NSIG) { 176*0Sstevel@tonic-gate errno = EINVAL; 177*0Sstevel@tonic-gate return(SIG_ERR); 178*0Sstevel@tonic-gate } 179*0Sstevel@tonic-gate old = sigdisp(sig); 180*0Sstevel@tonic-gate if (sigtable[sig].s_flag & SHELD) 181*0Sstevel@tonic-gate return(old); 182*0Sstevel@tonic-gate /* 183*0Sstevel@tonic-gate * When the default action is required, we have to 184*0Sstevel@tonic-gate * set up to catch the signal to note signal's occurrance. 185*0Sstevel@tonic-gate */ 186*0Sstevel@tonic-gate if (old == SIG_DFL) { 187*0Sstevel@tonic-gate sigtable[sig].s_flag |= SSET; 188*0Sstevel@tonic-gate signal(sig, _Sigtramp); 189*0Sstevel@tonic-gate } 190*0Sstevel@tonic-gate sigtable[sig].s_flag |= SHELD; 191*0Sstevel@tonic-gate return(old); 192*0Sstevel@tonic-gate } 193*0Sstevel@tonic-gate 194*0Sstevel@tonic-gate /* 195*0Sstevel@tonic-gate * Release a signal 196*0Sstevel@tonic-gate * If the signal occurred while we had it held, cause the signal. 197*0Sstevel@tonic-gate */ 198*0Sstevel@tonic-gate sigtype 199*0Sstevel@tonic-gate sigrelse(int sig) 200*0Sstevel@tonic-gate { 201*0Sstevel@tonic-gate sigtype old; 202*0Sstevel@tonic-gate 203*0Sstevel@tonic-gate if (sig < 1 || sig > NSIG) { 204*0Sstevel@tonic-gate errno = EINVAL; 205*0Sstevel@tonic-gate return(SIG_ERR); 206*0Sstevel@tonic-gate } 207*0Sstevel@tonic-gate old = sigdisp(sig); 208*0Sstevel@tonic-gate if ((sigtable[sig].s_flag & SHELD) == 0) 209*0Sstevel@tonic-gate return(old); 210*0Sstevel@tonic-gate sigtable[sig].s_flag &= ~SHELD; 211*0Sstevel@tonic-gate if (sigtable[sig].s_flag & SDEFER) 212*0Sstevel@tonic-gate _Sigtramp(sig); 213*0Sstevel@tonic-gate /* 214*0Sstevel@tonic-gate * If disposition was the default, then we can unset the 215*0Sstevel@tonic-gate * catch to _Sigtramp() and let the system do the work. 216*0Sstevel@tonic-gate */ 217*0Sstevel@tonic-gate if (sigtable[sig].s_func == SIG_DFL) 218*0Sstevel@tonic-gate signal(sig, SIG_DFL); 219*0Sstevel@tonic-gate return(old); 220*0Sstevel@tonic-gate } 221*0Sstevel@tonic-gate 222*0Sstevel@tonic-gate /* 223*0Sstevel@tonic-gate * Ignore a signal. 224*0Sstevel@tonic-gate */ 225*0Sstevel@tonic-gate sigtype 226*0Sstevel@tonic-gate sigignore(int sig) 227*0Sstevel@tonic-gate { 228*0Sstevel@tonic-gate return(sigset(sig, SIG_IGN)); 229*0Sstevel@tonic-gate } 230*0Sstevel@tonic-gate 231*0Sstevel@tonic-gate /* 232*0Sstevel@tonic-gate * Pause, waiting for sig to occur. 233*0Sstevel@tonic-gate * We assume LUSER called us with the signal held. 234*0Sstevel@tonic-gate * When we got the signal, mark the signal as having 235*0Sstevel@tonic-gate * occurred. It will actually cause something when 236*0Sstevel@tonic-gate * the signal is released. 237*0Sstevel@tonic-gate */ 238*0Sstevel@tonic-gate int 239*0Sstevel@tonic-gate sigpause(int sig) 240*0Sstevel@tonic-gate { 241*0Sstevel@tonic-gate if (sig < 1 || sig > NSIG) { 242*0Sstevel@tonic-gate errno = EINVAL; 243*0Sstevel@tonic-gate return; 244*0Sstevel@tonic-gate } 245*0Sstevel@tonic-gate sigtable[sig].s_flag |= SHELD|SPAUSE; 246*0Sstevel@tonic-gate if (setjmp(_pause) == 0) 247*0Sstevel@tonic-gate pause(); 248*0Sstevel@tonic-gate sigtable[sig].s_flag &= ~SPAUSE; 249*0Sstevel@tonic-gate sigtable[sig].s_flag |= SDEFER; 250*0Sstevel@tonic-gate } 251*0Sstevel@tonic-gate 252*0Sstevel@tonic-gate /* 253*0Sstevel@tonic-gate * In the child process after fork(2), set the disposition of all held 254*0Sstevel@tonic-gate * signals to SIG_IGN. This is a new procedure not in the real sigset() 255*0Sstevel@tonic-gate * package, provided for retrofitting purposes. 256*0Sstevel@tonic-gate */ 257*0Sstevel@tonic-gate int 258*0Sstevel@tonic-gate sigchild(void) 259*0Sstevel@tonic-gate { 260*0Sstevel@tonic-gate register int i; 261*0Sstevel@tonic-gate 262*0Sstevel@tonic-gate for (i = 1; i <= NSIG; i++) 263*0Sstevel@tonic-gate if (sigtable[i].s_flag & SHELD) 264*0Sstevel@tonic-gate signal(i, SIG_IGN); 265*0Sstevel@tonic-gate } 266*0Sstevel@tonic-gate 267*0Sstevel@tonic-gate 268*0Sstevel@tonic-gate /* 269*0Sstevel@tonic-gate * Return the current disposition of a signal 270*0Sstevel@tonic-gate * If we have not set this signal before, we have to 271*0Sstevel@tonic-gate * ask the system 272*0Sstevel@tonic-gate */ 273*0Sstevel@tonic-gate sigtype 274*0Sstevel@tonic-gate sigdisp(int sig) 275*0Sstevel@tonic-gate { 276*0Sstevel@tonic-gate sigtype old; 277*0Sstevel@tonic-gate 278*0Sstevel@tonic-gate if (sig < 1 || sig > NSIG) { 279*0Sstevel@tonic-gate errno = EINVAL; 280*0Sstevel@tonic-gate return(SIG_ERR); 281*0Sstevel@tonic-gate } 282*0Sstevel@tonic-gate /* 283*0Sstevel@tonic-gate * If we have no knowledge of this signal, 284*0Sstevel@tonic-gate * ask the system, then save the result for later. 285*0Sstevel@tonic-gate */ 286*0Sstevel@tonic-gate if ((sigtable[sig].s_flag & SSET) == 0) { 287*0Sstevel@tonic-gate old = signal(sig, SIG_IGN); 288*0Sstevel@tonic-gate sigtable[sig].s_func = old; 289*0Sstevel@tonic-gate sigtable[sig].s_flag |= SSET; 290*0Sstevel@tonic-gate signal(sig, old); 291*0Sstevel@tonic-gate return(old); 292*0Sstevel@tonic-gate } 293*0Sstevel@tonic-gate /* 294*0Sstevel@tonic-gate * If we have set this signal before, then sigset() 295*0Sstevel@tonic-gate * will have been careful to leave something meaningful 296*0Sstevel@tonic-gate * in s_func. 297*0Sstevel@tonic-gate */ 298*0Sstevel@tonic-gate return(sigtable[sig].s_func); 299*0Sstevel@tonic-gate } 300*0Sstevel@tonic-gate 301*0Sstevel@tonic-gate /* 302*0Sstevel@tonic-gate * The following routine gets called for any signal 303*0Sstevel@tonic-gate * that is to be trapped to a user function. 304*0Sstevel@tonic-gate */ 305*0Sstevel@tonic-gate void 306*0Sstevel@tonic-gate _Sigtramp(int sig) 307*0Sstevel@tonic-gate { 308*0Sstevel@tonic-gate sigtype old; 309*0Sstevel@tonic-gate 310*0Sstevel@tonic-gate if (sig < 1 || sig > NSIG) { 311*0Sstevel@tonic-gate errno = EINVAL; 312*0Sstevel@tonic-gate return; 313*0Sstevel@tonic-gate } 314*0Sstevel@tonic-gate 315*0Sstevel@tonic-gate top: 316*0Sstevel@tonic-gate old = signal(sig, SIG_IGN); 317*0Sstevel@tonic-gate /* 318*0Sstevel@tonic-gate * If signal being paused on, wakeup sigpause() 319*0Sstevel@tonic-gate */ 320*0Sstevel@tonic-gate if (sigtable[sig].s_flag & SPAUSE) 321*0Sstevel@tonic-gate longjmp(_pause, 1); 322*0Sstevel@tonic-gate /* 323*0Sstevel@tonic-gate * If signal is being held, mark its table entry 324*0Sstevel@tonic-gate * so we can trigger it when signal is released. 325*0Sstevel@tonic-gate * Then just return. 326*0Sstevel@tonic-gate */ 327*0Sstevel@tonic-gate if (sigtable[sig].s_flag & SHELD) { 328*0Sstevel@tonic-gate sigtable[sig].s_flag |= SDEFER; 329*0Sstevel@tonic-gate signal(sig, _Sigtramp); 330*0Sstevel@tonic-gate return; 331*0Sstevel@tonic-gate } 332*0Sstevel@tonic-gate /* 333*0Sstevel@tonic-gate * If the signal is being ignored, just return. 334*0Sstevel@tonic-gate * This would make SIGCONT more normal, but of course 335*0Sstevel@tonic-gate * any system with SIGCONT also has the new signal pkg, so... 336*0Sstevel@tonic-gate */ 337*0Sstevel@tonic-gate if (sigtable[sig].s_func == SIG_IGN) 338*0Sstevel@tonic-gate return; 339*0Sstevel@tonic-gate /* 340*0Sstevel@tonic-gate * If the signal is SIG_DFL, then we probably got here 341*0Sstevel@tonic-gate * by holding the signal, having it happen, then releasing 342*0Sstevel@tonic-gate * the signal. 343*0Sstevel@tonic-gate */ 344*0Sstevel@tonic-gate if (sigtable[sig].s_func == SIG_DFL) { 345*0Sstevel@tonic-gate signal(sig, SIG_DFL); 346*0Sstevel@tonic-gate kill(getpid(), sig); 347*0Sstevel@tonic-gate /* Will we get back here? */ 348*0Sstevel@tonic-gate return; 349*0Sstevel@tonic-gate } 350*0Sstevel@tonic-gate /* 351*0Sstevel@tonic-gate * Looks like we should just cause the signal... 352*0Sstevel@tonic-gate * We hold the signal for the duration of the user's 353*0Sstevel@tonic-gate * code with the signal re-enabled. If the signal 354*0Sstevel@tonic-gate * happens again while in user code, we will recursively 355*0Sstevel@tonic-gate * trap here and mark that we had another occurance 356*0Sstevel@tonic-gate * and return to the user's trap code. When we return 357*0Sstevel@tonic-gate * from there, we can cause the signal again. 358*0Sstevel@tonic-gate */ 359*0Sstevel@tonic-gate sigtable[sig].s_flag &= ~SDEFER; 360*0Sstevel@tonic-gate sigtable[sig].s_flag |= SHELD; 361*0Sstevel@tonic-gate signal(sig, _Sigtramp); 362*0Sstevel@tonic-gate (*sigtable[sig].s_func)(sig); 363*0Sstevel@tonic-gate /* 364*0Sstevel@tonic-gate * If the signal re-occurred while in the user's routine, 365*0Sstevel@tonic-gate * just go try it again... 366*0Sstevel@tonic-gate */ 367*0Sstevel@tonic-gate sigtable[sig].s_flag &= ~SHELD; 368*0Sstevel@tonic-gate if (sigtable[sig].s_flag & SDEFER) 369*0Sstevel@tonic-gate goto top; 370*0Sstevel@tonic-gate } 371*0Sstevel@tonic-gate #endif 372