/* $OpenBSD: sem.c,v 1.15 2003/06/11 21:09:50 deraadt Exp $ */ /* $NetBSD: sem.c,v 1.9 1995/09/27 00:38:50 jtc Exp $ */ /*- * Copyright (c) 1980, 1991, 1993 * The Regents of the University of California. All rights reserved. * * Redistribution and use in source and binary forms, with or without * modification, are permitted provided that the following conditions * are met: * 1. Redistributions of source code must retain the above copyright * notice, this list of conditions and the following disclaimer. * 2. Redistributions in binary form must reproduce the above copyright * notice, this list of conditions and the following disclaimer in the * documentation and/or other materials provided with the distribution. * 3. Neither the name of the University nor the names of its contributors * may be used to endorse or promote products derived from this software * without specific prior written permission. * * THIS SOFTWARE IS PROVIDED BY THE REGENTS AND CONTRIBUTORS ``AS IS'' AND * ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE * IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE * ARE DISCLAIMED. IN NO EVENT SHALL THE REGENTS OR CONTRIBUTORS BE LIABLE * FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL * DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS * OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION) * HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT * LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY * OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF * SUCH DAMAGE. */ #ifndef lint #if 0 static char sccsid[] = "@(#)sem.c 8.1 (Berkeley) 5/31/93"; #else static char rcsid[] = "$OpenBSD: sem.c,v 1.15 2003/06/11 21:09:50 deraadt Exp $"; #endif #endif /* not lint */ #include #include #include #include #include #include #include #include #include #include "csh.h" #include "proc.h" #include "extern.h" static void vffree(int); static Char *splicepipe(struct command *t, Char *); static void doio(struct command *t, int *, int *); static void chkclob(char *); void execute(struct command *t, int wanttty, int *pipein, int *pipeout) { bool forked = 0; struct biltins *bifunc; int pid = 0; int pv[2]; sigset_t sigset; static sigset_t csigset; static sigset_t ocsigset; static int onosigchld = 0; static int nosigchld = 0; UNREGISTER(forked); UNREGISTER(bifunc); UNREGISTER(wanttty); if (t == 0) return; if (t->t_dflg & F_AMPERSAND) wanttty = 0; switch (t->t_dtyp) { case NODE_COMMAND: if ((t->t_dcom[0][0] & (QUOTE | TRIM)) == QUOTE) (void) memmove(t->t_dcom[0], t->t_dcom[0] + 1, (Strlen(t->t_dcom[0] + 1) + 1) * sizeof(Char)); if ((t->t_dflg & F_REPEAT) == 0) Dfix(t); /* $ " ' \ */ if (t->t_dcom[0] == 0) return; /* fall into... */ case NODE_PAREN: if (t->t_dflg & F_PIPEOUT) mypipe(pipeout); /* * Must do << early so parent will know where input pointer should be. * If noexec then this is all we do. */ if (t->t_dflg & F_READ) { (void) close(0); heredoc(t->t_dlef); if (noexec) (void) close(0); } set(STRstatus, Strsave(STR0)); /* * This mess is the necessary kludge to handle the prefix builtins: * nice, nohup, time. These commands can also be used by themselves, * and this is not handled here. This will also work when loops are * parsed. */ while (t->t_dtyp == NODE_COMMAND) if (eq(t->t_dcom[0], STRnice)) if (t->t_dcom[1]) if (strchr("+-", t->t_dcom[1][0])) if (t->t_dcom[2]) { setname("nice"); t->t_nice = getn(t->t_dcom[1]); lshift(t->t_dcom, 2); t->t_dflg |= F_NICE; } else break; else { t->t_nice = 4; lshift(t->t_dcom, 1); t->t_dflg |= F_NICE; } else break; else if (eq(t->t_dcom[0], STRnohup)) if (t->t_dcom[1]) { t->t_dflg |= F_NOHUP; lshift(t->t_dcom, 1); } else break; else if (eq(t->t_dcom[0], STRtime)) if (t->t_dcom[1]) { t->t_dflg |= F_TIME; lshift(t->t_dcom, 1); } else break; else break; /* is it a command */ if (t->t_dtyp == NODE_COMMAND) { /* * Check if we have a builtin function and remember which one. */ bifunc = isbfunc(t); if (noexec) { /* * Continue for builtins that are part of the scripting language */ if (bifunc && bifunc->bfunct != dobreak && bifunc->bfunct != docontin && bifunc->bfunct != doelse && bifunc->bfunct != doend && bifunc->bfunct != doforeach && bifunc->bfunct != dogoto && bifunc->bfunct != doif && bifunc->bfunct != dorepeat && bifunc->bfunct != doswbrk && bifunc->bfunct != doswitch && bifunc->bfunct != dowhile && bifunc->bfunct != dozip) break; } } else { /* not a command */ bifunc = NULL; if (noexec) break; } /* * We fork only if we are timed, or are not the end of a parenthesized * list and not a simple builtin function. Simple meaning one that is * not pipedout, niced, nohupped, or &'d. It would be nice(?) to not * fork in some of these cases. */ /* * Prevent forking cd, pushd, popd, chdir cause this will cause the * shell not to change dir! */ if (bifunc && (bifunc->bfunct == dochngd || bifunc->bfunct == dopushd || bifunc->bfunct == dopopd)) t->t_dflg &= ~(F_NICE); if (((t->t_dflg & F_TIME) || ((t->t_dflg & F_NOFORK) == 0 && (!bifunc || t->t_dflg & (F_PIPEOUT | F_AMPERSAND | F_NICE | F_NOHUP)))) || /* * We have to fork for eval too. */ (bifunc && (t->t_dflg & (F_PIPEIN | F_PIPEOUT)) != 0 && bifunc->bfunct == doeval)) { if (t->t_dtyp == NODE_PAREN || t->t_dflg & (F_REPEAT | F_AMPERSAND) || bifunc) { forked++; /* * We need to block SIGCHLD here, so that if the process does * not die before we can set the process group */ if (wanttty >= 0 && !nosigchld) { sigemptyset(&sigset); sigaddset(&sigset, SIGCHLD); sigprocmask(SIG_BLOCK, &sigset, &csigset); nosigchld = 1; } pid = pfork(t, wanttty); if (pid == 0 && nosigchld) { sigprocmask(SIG_SETMASK, &csigset, NULL); nosigchld = 0; } else if (pid != 0 && (t->t_dflg & F_AMPERSAND)) backpid = pid; } else { int ochild, osetintr, ohaderr, odidfds; int oSHIN, oSHOUT, oSHERR, oOLDSTD, otpgrp; sigset_t osigset; /* * Prepare for the vfork by saving everything that the child * corrupts before it exec's. Note that in some signal * implementations which keep the signal info in user space * (e.g. Sun's) it will also be necessary to save and restore * the current sigaction's for the signals the child touches * before it exec's. */ if (wanttty >= 0 && !nosigchld && !noexec) { sigemptyset(&sigset); sigaddset(&sigset, SIGCHLD); sigprocmask(SIG_BLOCK, &sigset, &csigset); nosigchld = 1; } sigemptyset(&sigset); sigaddset(&sigset, SIGCHLD); sigaddset(&sigset, SIGINT); sigprocmask(SIG_BLOCK, &sigset, &osigset); ochild = child; osetintr = setintr; ohaderr = haderr; odidfds = didfds; oSHIN = SHIN; oSHOUT = SHOUT; oSHERR = SHERR; oOLDSTD = OLDSTD; otpgrp = tpgrp; ocsigset = csigset; onosigchld = nosigchld; Vsav = Vdp = 0; Vexpath = 0; Vt = 0; pid = vfork(); if (pid < 0) { sigprocmask(SIG_SETMASK, &osigset, NULL); stderror(ERR_NOPROC); } forked++; if (pid) { /* parent */ child = ochild; setintr = osetintr; haderr = ohaderr; didfds = odidfds; SHIN = oSHIN; SHOUT = oSHOUT; SHERR = oSHERR; OLDSTD = oOLDSTD; tpgrp = otpgrp; csigset = ocsigset; nosigchld = onosigchld; xfree((ptr_t) Vsav); Vsav = 0; xfree((ptr_t) Vdp); Vdp = 0; xfree((ptr_t) Vexpath); Vexpath = 0; blkfree((Char **) Vt); Vt = 0; /* this is from pfork() */ palloc(pid, t); sigprocmask(SIG_SETMASK, &osigset, NULL); } else { /* child */ /* this is from pfork() */ int pgrp; bool ignint = 0; if (nosigchld) { sigprocmask(SIG_SETMASK, &csigset, NULL); nosigchld = 0; } if (setintr) ignint = (tpgrp == -1 && (t->t_dflg & F_NOINTERRUPT)) || (gointr && eq(gointr, STRminus)); pgrp = pcurrjob ? pcurrjob->p_jobid : getpid(); child++; if (setintr) { setintr = 0; if (ignint) { (void) signal(SIGINT, SIG_IGN); (void) signal(SIGQUIT, SIG_IGN); } else { (void) signal(SIGINT, vffree); (void) signal(SIGQUIT, SIG_DFL); } if (wanttty >= 0) { (void) signal(SIGTSTP, SIG_DFL); (void) signal(SIGTTIN, SIG_DFL); (void) signal(SIGTTOU, SIG_DFL); } (void) signal(SIGTERM, parterm); } else if (tpgrp == -1 && (t->t_dflg & F_NOINTERRUPT)) { (void) signal(SIGINT, SIG_IGN); (void) signal(SIGQUIT, SIG_IGN); } pgetty(wanttty, pgrp); if (t->t_dflg & F_NOHUP) (void) signal(SIGHUP, SIG_IGN); if (t->t_dflg & F_NICE) (void) setpriority(PRIO_PROCESS, 0, t->t_nice); } } } if (pid != 0) { /* * It would be better if we could wait for the whole job when we * knew the last process had been started. Pwait, in fact, does * wait for the whole job anyway, but this test doesn't really * express our intentions. */ if (didfds == 0 && t->t_dflg & F_PIPEIN) { (void) close(pipein[0]); (void) close(pipein[1]); } if ((t->t_dflg & F_PIPEOUT) == 0) { if (nosigchld) { sigprocmask(SIG_SETMASK, &csigset, NULL); nosigchld = 0; } if ((t->t_dflg & F_AMPERSAND) == 0) pwait(); } break; } doio(t, pipein, pipeout); if (t->t_dflg & F_PIPEOUT) { (void) close(pipeout[0]); (void) close(pipeout[1]); } /* * Perform a builtin function. If we are not forked, arrange for * possible stopping */ if (bifunc) { func(t, bifunc); if (forked) exitstat(); break; } if (t->t_dtyp != NODE_PAREN) { doexec(NULL, t); /* NOTREACHED */ } /* * For () commands must put new 0,1,2 in FSH* and recurse */ OLDSTD = dcopy(0, FOLDSTD); SHOUT = dcopy(1, FSHOUT); SHERR = dcopy(2, FSHERR); (void) close(SHIN); SHIN = -1; didfds = 0; wanttty = -1; t->t_dspr->t_dflg |= t->t_dflg & F_NOINTERRUPT; execute(t->t_dspr, wanttty, NULL, NULL); exitstat(); case NODE_PIPE: t->t_dcar->t_dflg |= F_PIPEOUT | (t->t_dflg & (F_PIPEIN | F_AMPERSAND | F_STDERR | F_NOINTERRUPT)); execute(t->t_dcar, wanttty, pipein, pv); t->t_dcdr->t_dflg |= F_PIPEIN | (t->t_dflg & (F_PIPEOUT | F_AMPERSAND | F_NOFORK | F_NOINTERRUPT)); if (wanttty > 0) wanttty = 0; /* got tty already */ execute(t->t_dcdr, wanttty, pv, pipeout); break; case NODE_LIST: if (t->t_dcar) { t->t_dcar->t_dflg |= t->t_dflg & F_NOINTERRUPT; execute(t->t_dcar, wanttty, NULL, NULL); /* * In strange case of A&B make a new job after A */ if (t->t_dcar->t_dflg & F_AMPERSAND && t->t_dcdr && (t->t_dcdr->t_dflg & F_AMPERSAND) == 0) pendjob(); } if (t->t_dcdr) { t->t_dcdr->t_dflg |= t->t_dflg & (F_NOFORK | F_NOINTERRUPT); execute(t->t_dcdr, wanttty, NULL, NULL); } break; case NODE_OR: case NODE_AND: if (t->t_dcar) { t->t_dcar->t_dflg |= t->t_dflg & F_NOINTERRUPT; execute(t->t_dcar, wanttty, NULL, NULL); if ((getn(value(STRstatus)) == 0) != (t->t_dtyp == NODE_AND)) return; } if (t->t_dcdr) { t->t_dcdr->t_dflg |= t->t_dflg & (F_NOFORK | F_NOINTERRUPT); execute(t->t_dcdr, wanttty, NULL, NULL); } break; } /* * Fall through for all breaks from switch * * If there will be no more executions of this command, flush all file * descriptors. Places that turn on the F_REPEAT bit are responsible for * doing donefds after the last re-execution */ if (didfds && !(t->t_dflg & F_REPEAT)) donefds(); } static void vffree(int i) { _exit(i); } /* * Expand and glob the words after an i/o redirection. * If more than one word is generated, then update the command vector. * * This is done differently in all the shells: * 1. in the bourne shell and ksh globbing is not performed * 2. Bash/csh say ambiguous * 3. zsh does i/o to/from all the files * 4. itcsh concatenates the words. * * I don't know what is best to do. I think that Ambiguous is better * than restructuring the command vector, because the user can get * unexpected results. In any case, the command vector restructuring * code is present and the user can choose it by setting noambiguous */ static Char * splicepipe(struct command *t, Char *cp) /* word after < or > */ { Char *blk[2]; if (adrof(STRnoambiguous)) { Char **pv; blk[0] = Dfix1(cp); /* expand $ */ blk[1] = NULL; gflag = 0, tglob(blk); if (gflag) { pv = globall(blk); if (pv == NULL) { setname(vis_str(blk[0])); xfree((ptr_t) blk[0]); stderror(ERR_NAME | ERR_NOMATCH); } gargv = NULL; if (pv[1] != NULL) { /* we need to fix the command vector */ Char **av = blkspl(t->t_dcom, &pv[1]); xfree((ptr_t) t->t_dcom); t->t_dcom = av; } xfree((ptr_t) blk[0]); blk[0] = pv[0]; xfree((ptr_t) pv); } } else { blk[0] = globone(blk[1] = Dfix1(cp), G_ERROR); xfree((ptr_t) blk[1]); } return(blk[0]); } /* * Perform io redirection. * We may or maynot be forked here. */ static void doio(struct command *t, int *pipein, int *pipeout) { int fd; Char *cp; int flags = t->t_dflg; if (didfds || (flags & F_REPEAT)) return; if ((flags & F_READ) == 0) {/* F_READ already done */ if (t->t_dlef) { char tmp[MAXPATHLEN]; /* * so < /dev/std{in,out,err} work */ (void) dcopy(SHIN, 0); (void) dcopy(SHOUT, 1); (void) dcopy(SHERR, 2); cp = splicepipe(t, t->t_dlef); strlcpy(tmp, short2str(cp), sizeof tmp); xfree((ptr_t) cp); if ((fd = open(tmp, O_RDONLY)) < 0) stderror(ERR_SYSTEM, tmp, strerror(errno)); (void) dmove(fd, 0); } else if (flags & F_PIPEIN) { (void) close(0); (void) dup(pipein[0]); (void) close(pipein[0]); (void) close(pipein[1]); } else if ((flags & F_NOINTERRUPT) && tpgrp == -1) { (void) close(0); (void) open(_PATH_DEVNULL, O_RDONLY); } else { (void) close(0); (void) dup(OLDSTD); (void) ioctl(0, FIONCLEX, NULL); } } if (t->t_drit) { char tmp[MAXPATHLEN]; cp = splicepipe(t, t->t_drit); strlcpy(tmp, short2str(cp), sizeof tmp); xfree((ptr_t) cp); /* * so > /dev/std{out,err} work */ (void) dcopy(SHOUT, 1); (void) dcopy(SHERR, 2); if ((flags & F_APPEND) && #ifdef O_APPEND (fd = open(tmp, O_WRONLY | O_APPEND)) >= 0); #else (fd = open(tmp, O_WRONLY)) >= 0) (void) lseek(1, (off_t) 0, SEEK_END); #endif else { if (!(flags & F_OVERWRITE) && adrof(STRnoclobber)) { if (flags & F_APPEND) stderror(ERR_SYSTEM, tmp, strerror(errno)); chkclob(tmp); } if ((fd = open(tmp, O_WRONLY | O_CREAT | O_TRUNC, 0666)) < 0) stderror(ERR_SYSTEM, tmp, strerror(errno)); } (void) dmove(fd, 1); } else if (flags & F_PIPEOUT) { (void) close(1); (void) dup(pipeout[1]); } else { (void) close(1); (void) dup(SHOUT); (void) ioctl(1, FIONCLEX, NULL); } (void) close(2); if (flags & F_STDERR) { (void) dup(1); } else { (void) dup(SHERR); (void) ioctl(2, FIONCLEX, NULL); } didfds = 1; } void mypipe(int *pv) { if (pipe(pv) < 0) goto oops; pv[0] = dmove(pv[0], -1); pv[1] = dmove(pv[1], -1); if (pv[0] >= 0 && pv[1] >= 0) return; oops: stderror(ERR_PIPE); } static void chkclob(char *cp) { struct stat stb; if (stat(cp, &stb) < 0) return; if (S_ISCHR(stb.st_mode)) return; stderror(ERR_EXISTS, cp); }