1 4b241872 2007-03-26 devnull #include <u.h>
  2 4b241872 2007-03-26 devnull #include <signal.h>
  3 4b241872 2007-03-26 devnull #if defined(PLAN9PORT) && defined(__sun__)
  4 4b241872 2007-03-26 devnull #	define BSD_COMP	/* sigh.  for TIOCNOTTY */
  5 4b241872 2007-03-26 devnull #endif
  6 4b241872 2007-03-26 devnull #include <sys/ioctl.h>
  7 f08fdedc 2003-11-23 devnull #include "rc.h"
  8 f08fdedc 2003-11-23 devnull #include "getflags.h"
  9 f08fdedc 2003-11-23 devnull #include "exec.h"
 10 f08fdedc 2003-11-23 devnull #include "io.h"
 11 f08fdedc 2003-11-23 devnull #include "fns.h"
 12 f08fdedc 2003-11-23 devnull 
 13 f08fdedc 2003-11-23 devnull int havefork = 1;
 14 f08fdedc 2003-11-23 devnull 
 15 f08fdedc 2003-11-23 devnull void
 16 f08fdedc 2003-11-23 devnull Xasync(void)
 17 f08fdedc 2003-11-23 devnull {
 18 f08fdedc 2003-11-23 devnull 	int null = open("/dev/null", 0);
 19 4b241872 2007-03-26 devnull 	int tty;
 20 f08fdedc 2003-11-23 devnull 	int pid;
 21 f08fdedc 2003-11-23 devnull 	char npid[10];
 22 f08fdedc 2003-11-23 devnull 	if(null<0){
 23 f08fdedc 2003-11-23 devnull 		Xerror("Can't open /dev/null\n");
 24 f08fdedc 2003-11-23 devnull 		return;
 25 f08fdedc 2003-11-23 devnull 	}
 26 f08fdedc 2003-11-23 devnull 	switch(pid = rfork(RFFDG|RFPROC|RFNOTEG)){
 27 f08fdedc 2003-11-23 devnull 	case -1:
 28 f08fdedc 2003-11-23 devnull 		close(null);
 29 f08fdedc 2003-11-23 devnull 		Xerror("try again");
 30 f08fdedc 2003-11-23 devnull 		break;
 31 f08fdedc 2003-11-23 devnull 	case 0:
 32 4b241872 2007-03-26 devnull 		clearwaitpids();
 33 4b241872 2007-03-26 devnull 		/*
 34 4b241872 2007-03-26 devnull 		 * I don't know what the right thing to do here is,
 35 4b241872 2007-03-26 devnull 		 * so this is all experimentally determined.
 36 4b241872 2007-03-26 devnull 		 * If we just dup /dev/null onto 0, then running
 37 4b241872 2007-03-26 devnull 		 * ssh foo & will reopen /dev/tty, try to read a password,
 38 4b241872 2007-03-26 devnull 		 * get a signal, and repeat, in a tight loop, forever.
 39 4b241872 2007-03-26 devnull 		 * Arguably this is a bug in ssh (it behaves the same
 40 fa325e9b 2020-01-10 cross 		 * way under bash as under rc) but I'm fixing it here
 41 4b241872 2007-03-26 devnull 		 * anyway.  If we dissociate the process from the tty,
 42 4b241872 2007-03-26 devnull 		 * then it won't be able to open /dev/tty ever again.
 43 4b241872 2007-03-26 devnull 		 * The SIG_IGN on SIGTTOU makes writing the tty
 44 fa325e9b 2020-01-10 cross 		 * (via fd 1 or 2, for example) succeed even though
 45 4b241872 2007-03-26 devnull 		 * our pgrp is not the terminal's controlling pgrp.
 46 4b241872 2007-03-26 devnull 		 */
 47 4b241872 2007-03-26 devnull 		if((tty = open("/dev/tty", OREAD)) >= 0){
 48 4b241872 2007-03-26 devnull 			/*
 49 4b241872 2007-03-26 devnull 			 * Should make reads of tty fail, writes succeed.
 50 4b241872 2007-03-26 devnull 			 */
 51 4b241872 2007-03-26 devnull 			signal(SIGTTIN, SIG_IGN);
 52 4b241872 2007-03-26 devnull 			signal(SIGTTOU, SIG_IGN);
 53 4b241872 2007-03-26 devnull 			ioctl(tty, TIOCNOTTY);
 54 4b241872 2007-03-26 devnull 			close(tty);
 55 4b241872 2007-03-26 devnull 		}
 56 4b241872 2007-03-26 devnull 		if(isatty(0))
 57 4b241872 2007-03-26 devnull 			pushredir(ROPEN, null, 0);
 58 4b241872 2007-03-26 devnull 		else
 59 4b241872 2007-03-26 devnull 			close(null);
 60 f08fdedc 2003-11-23 devnull 		start(runq->code, runq->pc+1, runq->local);
 61 f08fdedc 2003-11-23 devnull 		runq->ret = 0;
 62 f08fdedc 2003-11-23 devnull 		break;
 63 f08fdedc 2003-11-23 devnull 	default:
 64 4b241872 2007-03-26 devnull 		addwaitpid(pid);
 65 f08fdedc 2003-11-23 devnull 		close(null);
 66 f08fdedc 2003-11-23 devnull 		runq->pc = runq->code[runq->pc].i;
 67 f08fdedc 2003-11-23 devnull 		inttoascii(npid, pid);
 68 f08fdedc 2003-11-23 devnull 		setvar("apid", newword(npid, (word *)0));
 69 f08fdedc 2003-11-23 devnull 		break;
 70 f08fdedc 2003-11-23 devnull 	}
 71 f08fdedc 2003-11-23 devnull }
 72 f08fdedc 2003-11-23 devnull 
 73 f08fdedc 2003-11-23 devnull void
 74 f08fdedc 2003-11-23 devnull Xpipe(void)
 75 f08fdedc 2003-11-23 devnull {
 76 f08fdedc 2003-11-23 devnull 	struct thread *p = runq;
 77 f08fdedc 2003-11-23 devnull 	int pc = p->pc, forkid;
 78 f08fdedc 2003-11-23 devnull 	int lfd = p->code[pc++].i;
 79 f08fdedc 2003-11-23 devnull 	int rfd = p->code[pc++].i;
 80 f08fdedc 2003-11-23 devnull 	int pfd[2];
 81 f08fdedc 2003-11-23 devnull 	if(pipe(pfd)<0){
 82 f08fdedc 2003-11-23 devnull 		Xerror("can't get pipe");
 83 f08fdedc 2003-11-23 devnull 		return;
 84 f08fdedc 2003-11-23 devnull 	}
 85 f08fdedc 2003-11-23 devnull 	switch(forkid = fork()){
 86 f08fdedc 2003-11-23 devnull 	case -1:
 87 f08fdedc 2003-11-23 devnull 		Xerror("try again");
 88 f08fdedc 2003-11-23 devnull 		break;
 89 f08fdedc 2003-11-23 devnull 	case 0:
 90 4b241872 2007-03-26 devnull 		clearwaitpids();
 91 f08fdedc 2003-11-23 devnull 		start(p->code, pc+2, runq->local);
 92 f08fdedc 2003-11-23 devnull 		runq->ret = 0;
 93 f08fdedc 2003-11-23 devnull 		close(pfd[PRD]);
 94 f08fdedc 2003-11-23 devnull 		pushredir(ROPEN, pfd[PWR], lfd);
 95 f08fdedc 2003-11-23 devnull 		break;
 96 f08fdedc 2003-11-23 devnull 	default:
 97 4b241872 2007-03-26 devnull 		addwaitpid(forkid);
 98 f08fdedc 2003-11-23 devnull 		start(p->code, p->code[pc].i, runq->local);
 99 f08fdedc 2003-11-23 devnull 		close(pfd[PWR]);
100 f08fdedc 2003-11-23 devnull 		pushredir(ROPEN, pfd[PRD], rfd);
101 f08fdedc 2003-11-23 devnull 		p->pc = p->code[pc+1].i;
102 f08fdedc 2003-11-23 devnull 		p->pid = forkid;
103 f08fdedc 2003-11-23 devnull 		break;
104 f08fdedc 2003-11-23 devnull 	}
105 f08fdedc 2003-11-23 devnull }
106 f08fdedc 2003-11-23 devnull 
107 f08fdedc 2003-11-23 devnull /*
108 f08fdedc 2003-11-23 devnull  * Who should wait for the exit from the fork?
109 f08fdedc 2003-11-23 devnull  */
110 f08fdedc 2003-11-23 devnull void
111 f08fdedc 2003-11-23 devnull Xbackq(void)
112 f08fdedc 2003-11-23 devnull {
113 74be4603 2009-08-08 mt4swm 	struct thread *p = runq;
114 f08fdedc 2003-11-23 devnull 	char wd[8193];
115 72f66c2d 2011-01-02 rsc 	int c, n;
116 72f66c2d 2011-01-02 rsc 	char *s, *ewd=&wd[8192], *stop, *q;
117 f08fdedc 2003-11-23 devnull 	struct io *f;
118 f08fdedc 2003-11-23 devnull 	var *ifs = vlook("ifs");
119 f08fdedc 2003-11-23 devnull 	word *v, *nextv;
120 f08fdedc 2003-11-23 devnull 	int pfd[2];
121 f08fdedc 2003-11-23 devnull 	int pid;
122 72f66c2d 2011-01-02 rsc 	Rune r;
123 f08fdedc 2003-11-23 devnull 	stop = ifs->val?ifs->val->word:"";
124 f08fdedc 2003-11-23 devnull 	if(pipe(pfd)<0){
125 f08fdedc 2003-11-23 devnull 		Xerror("can't make pipe");
126 f08fdedc 2003-11-23 devnull 		return;
127 f08fdedc 2003-11-23 devnull 	}
128 f08fdedc 2003-11-23 devnull 	switch(pid = fork()){
129 f08fdedc 2003-11-23 devnull 	case -1:
130 f08fdedc 2003-11-23 devnull 		Xerror("try again");
131 f08fdedc 2003-11-23 devnull 		close(pfd[PRD]);
132 f08fdedc 2003-11-23 devnull 		close(pfd[PWR]);
133 f08fdedc 2003-11-23 devnull 		return;
134 f08fdedc 2003-11-23 devnull 	case 0:
135 4b241872 2007-03-26 devnull 		clearwaitpids();
136 f08fdedc 2003-11-23 devnull 		close(pfd[PRD]);
137 f08fdedc 2003-11-23 devnull 		start(runq->code, runq->pc+1, runq->local);
138 f08fdedc 2003-11-23 devnull 		pushredir(ROPEN, pfd[PWR], 1);
139 f08fdedc 2003-11-23 devnull 		return;
140 f08fdedc 2003-11-23 devnull 	default:
141 4b241872 2007-03-26 devnull 		addwaitpid(pid);
142 f08fdedc 2003-11-23 devnull 		close(pfd[PWR]);
143 f08fdedc 2003-11-23 devnull 		f = openfd(pfd[PRD]);
144 f08fdedc 2003-11-23 devnull 		s = wd;
145 f08fdedc 2003-11-23 devnull 		v = 0;
146 f08fdedc 2003-11-23 devnull 		while((c = rchr(f))!=EOF){
147 72f66c2d 2011-01-02 rsc 			if(s != ewd) {
148 72f66c2d 2011-01-02 rsc 				*s++ = c;
149 72f66c2d 2011-01-02 rsc 				for(q=stop; *q; q+=n) {
150 72f66c2d 2011-01-02 rsc 					n = chartorune(&r, q);
151 72f66c2d 2011-01-02 rsc 					if(s-wd >= n && memcmp(s-n, q, n) == 0) {
152 72f66c2d 2011-01-02 rsc 						s -= n;
153 72f66c2d 2011-01-02 rsc 						goto stop;
154 72f66c2d 2011-01-02 rsc 					}
155 f08fdedc 2003-11-23 devnull 				}
156 72f66c2d 2011-01-02 rsc 				continue;
157 f08fdedc 2003-11-23 devnull 			}
158 72f66c2d 2011-01-02 rsc 		stop:
159 6886b3cd 2011-02-16 rsc 			if(s != wd) {
160 6886b3cd 2011-02-16 rsc 				*s = '\0';
161 6886b3cd 2011-02-16 rsc 				v = newword(wd, v);
162 6886b3cd 2011-02-16 rsc 			}
163 72f66c2d 2011-01-02 rsc 			s = wd;
164 f08fdedc 2003-11-23 devnull 		}
165 f08fdedc 2003-11-23 devnull 		if(s!=wd){
166 f08fdedc 2003-11-23 devnull 			*s='\0';
167 f08fdedc 2003-11-23 devnull 			v = newword(wd, v);
168 f08fdedc 2003-11-23 devnull 		}
169 f08fdedc 2003-11-23 devnull 		closeio(f);
170 f08fdedc 2003-11-23 devnull 		Waitfor(pid, 0);
171 f08fdedc 2003-11-23 devnull 		/* v points to reversed arglist -- reverse it onto argv */
172 f08fdedc 2003-11-23 devnull 		while(v){
173 f08fdedc 2003-11-23 devnull 			nextv = v->next;
174 f08fdedc 2003-11-23 devnull 			v->next = runq->argv->words;
175 f08fdedc 2003-11-23 devnull 			runq->argv->words = v;
176 f08fdedc 2003-11-23 devnull 			v = nextv;
177 f08fdedc 2003-11-23 devnull 		}
178 74be4603 2009-08-08 mt4swm 		p->pc = p->code[p->pc].i;
179 f08fdedc 2003-11-23 devnull 		return;
180 f08fdedc 2003-11-23 devnull 	}
181 f08fdedc 2003-11-23 devnull }
182 f08fdedc 2003-11-23 devnull 
183 f08fdedc 2003-11-23 devnull void
184 f08fdedc 2003-11-23 devnull Xpipefd(void)
185 f08fdedc 2003-11-23 devnull {
186 f08fdedc 2003-11-23 devnull 	struct thread *p = runq;
187 4b241872 2007-03-26 devnull 	int pc = p->pc, pid;
188 f08fdedc 2003-11-23 devnull 	char name[40];
189 f08fdedc 2003-11-23 devnull 	int pfd[2];
190 38b62735 2009-09-13 mt4swm 	struct { int sidefd, mainfd; } fd[2], *r, *w;
191 38b62735 2009-09-13 mt4swm 
192 38b62735 2009-09-13 mt4swm 	r = &fd[0];
193 38b62735 2009-09-13 mt4swm 	w = &fd[1];
194 38b62735 2009-09-13 mt4swm 	switch(p->code[pc].i){
195 38b62735 2009-09-13 mt4swm 	case READ:
196 38b62735 2009-09-13 mt4swm 		w = nil;
197 38b62735 2009-09-13 mt4swm 		break;
198 38b62735 2009-09-13 mt4swm 	case WRITE:
199 38b62735 2009-09-13 mt4swm 		r = nil;
200 f08fdedc 2003-11-23 devnull 	}
201 38b62735 2009-09-13 mt4swm 
202 38b62735 2009-09-13 mt4swm 	if(r){
203 38b62735 2009-09-13 mt4swm 		if(pipe(pfd)<0){
204 38b62735 2009-09-13 mt4swm 			Xerror("can't get pipe");
205 38b62735 2009-09-13 mt4swm 			return;
206 38b62735 2009-09-13 mt4swm 		}
207 38b62735 2009-09-13 mt4swm  		r->sidefd = pfd[PWR];
208 38b62735 2009-09-13 mt4swm  		r->mainfd = pfd[PRD];
209 f08fdedc 2003-11-23 devnull 	}
210 38b62735 2009-09-13 mt4swm 	if(w){
211 38b62735 2009-09-13 mt4swm 		if(pipe(pfd)<0){
212 38b62735 2009-09-13 mt4swm 			Xerror("can't get pipe");
213 38b62735 2009-09-13 mt4swm 			return;
214 38b62735 2009-09-13 mt4swm 		}
215 38b62735 2009-09-13 mt4swm  		w->sidefd = pfd[PRD];
216 38b62735 2009-09-13 mt4swm  		w->mainfd = pfd[PWR];
217 f08fdedc 2003-11-23 devnull 	}
218 4b241872 2007-03-26 devnull 	switch(pid = fork()){
219 f08fdedc 2003-11-23 devnull 	case -1:
220 f08fdedc 2003-11-23 devnull 		Xerror("try again");
221 f08fdedc 2003-11-23 devnull 		break;
222 f08fdedc 2003-11-23 devnull 	case 0:
223 4b241872 2007-03-26 devnull 		clearwaitpids();
224 f08fdedc 2003-11-23 devnull 		start(p->code, pc+2, runq->local);
225 38b62735 2009-09-13 mt4swm 		if(r){
226 38b62735 2009-09-13 mt4swm 			close(r->mainfd);
227 38b62735 2009-09-13 mt4swm 			pushredir(ROPEN, r->sidefd, 1);
228 38b62735 2009-09-13 mt4swm 		}
229 38b62735 2009-09-13 mt4swm 		if(w){
230 38b62735 2009-09-13 mt4swm 			close(w->mainfd);
231 38b62735 2009-09-13 mt4swm 			pushredir(ROPEN, w->sidefd, 0);
232 38b62735 2009-09-13 mt4swm 		}
233 f08fdedc 2003-11-23 devnull 		runq->ret = 0;
234 f08fdedc 2003-11-23 devnull 		break;
235 f08fdedc 2003-11-23 devnull 	default:
236 4b241872 2007-03-26 devnull 		addwaitpid(pid);
237 38b62735 2009-09-13 mt4swm 		if(w){
238 38b62735 2009-09-13 mt4swm 			close(w->sidefd);
239 38b62735 2009-09-13 mt4swm 			pushredir(ROPEN, w->mainfd, w->mainfd);	/* so that Xpopredir can close it later */
240 38b62735 2009-09-13 mt4swm 			strcpy(name, Fdprefix);
241 38b62735 2009-09-13 mt4swm 			inttoascii(name+strlen(name), w->mainfd);
242 38b62735 2009-09-13 mt4swm 			pushword(name);
243 38b62735 2009-09-13 mt4swm 		}
244 38b62735 2009-09-13 mt4swm 		if(r){
245 38b62735 2009-09-13 mt4swm 			close(r->sidefd);
246 38b62735 2009-09-13 mt4swm 			pushredir(ROPEN, r->mainfd, r->mainfd);
247 38b62735 2009-09-13 mt4swm 			strcpy(name, Fdprefix);
248 38b62735 2009-09-13 mt4swm 			inttoascii(name+strlen(name), r->mainfd);
249 38b62735 2009-09-13 mt4swm 			pushword(name);
250 38b62735 2009-09-13 mt4swm 		}
251 f08fdedc 2003-11-23 devnull 		p->pc = p->code[pc+1].i;
252 f08fdedc 2003-11-23 devnull 		break;
253 f08fdedc 2003-11-23 devnull 	}
254 f08fdedc 2003-11-23 devnull }
255 f08fdedc 2003-11-23 devnull 
256 f08fdedc 2003-11-23 devnull void
257 f08fdedc 2003-11-23 devnull Xsubshell(void)
258 f08fdedc 2003-11-23 devnull {
259 f08fdedc 2003-11-23 devnull 	int pid;
260 f08fdedc 2003-11-23 devnull 	switch(pid = fork()){
261 f08fdedc 2003-11-23 devnull 	case -1:
262 f08fdedc 2003-11-23 devnull 		Xerror("try again");
263 f08fdedc 2003-11-23 devnull 		break;
264 f08fdedc 2003-11-23 devnull 	case 0:
265 4b241872 2007-03-26 devnull 		clearwaitpids();
266 f08fdedc 2003-11-23 devnull 		start(runq->code, runq->pc+1, runq->local);
267 f08fdedc 2003-11-23 devnull 		runq->ret = 0;
268 f08fdedc 2003-11-23 devnull 		break;
269 f08fdedc 2003-11-23 devnull 	default:
270 4b241872 2007-03-26 devnull 		addwaitpid(pid);
271 f08fdedc 2003-11-23 devnull 		Waitfor(pid, 1);
272 f08fdedc 2003-11-23 devnull 		runq->pc = runq->code[runq->pc].i;
273 f08fdedc 2003-11-23 devnull 		break;
274 f08fdedc 2003-11-23 devnull 	}
275 f08fdedc 2003-11-23 devnull }
276 f08fdedc 2003-11-23 devnull 
277 f08fdedc 2003-11-23 devnull int
278 f08fdedc 2003-11-23 devnull execforkexec(void)
279 f08fdedc 2003-11-23 devnull {
280 f08fdedc 2003-11-23 devnull 	int pid;
281 f08fdedc 2003-11-23 devnull 	int n;
282 f08fdedc 2003-11-23 devnull 	char buf[ERRMAX];
283 f08fdedc 2003-11-23 devnull 
284 f08fdedc 2003-11-23 devnull 	switch(pid = fork()){
285 f08fdedc 2003-11-23 devnull 	case -1:
286 f08fdedc 2003-11-23 devnull 		return -1;
287 f08fdedc 2003-11-23 devnull 	case 0:
288 4b241872 2007-03-26 devnull 		clearwaitpids();
289 f08fdedc 2003-11-23 devnull 		pushword("exec");
290 f08fdedc 2003-11-23 devnull 		execexec();
291 f08fdedc 2003-11-23 devnull 		strcpy(buf, "can't exec: ");
292 f08fdedc 2003-11-23 devnull 		n = strlen(buf);
293 f08fdedc 2003-11-23 devnull 		errstr(buf+n, ERRMAX-n);
294 f08fdedc 2003-11-23 devnull 		Exit(buf);
295 f08fdedc 2003-11-23 devnull 	}
296 4b241872 2007-03-26 devnull 	addwaitpid(pid);
297 f08fdedc 2003-11-23 devnull 	return pid;
298 f08fdedc 2003-11-23 devnull }