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 4b241872 2007-03-26 devnull 		 * 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 4b241872 2007-03-26 devnull 		 * (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 f08fdedc 2003-11-23 devnull 	int c;
116 f08fdedc 2003-11-23 devnull 	char *s, *ewd=&wd[8192], *stop;
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 f08fdedc 2003-11-23 devnull 	stop = ifs->val?ifs->val->word:"";
123 f08fdedc 2003-11-23 devnull 	if(pipe(pfd)<0){
124 f08fdedc 2003-11-23 devnull 		Xerror("can't make pipe");
125 f08fdedc 2003-11-23 devnull 		return;
126 f08fdedc 2003-11-23 devnull 	}
127 f08fdedc 2003-11-23 devnull 	switch(pid = fork()){
128 f08fdedc 2003-11-23 devnull 	case -1:
129 f08fdedc 2003-11-23 devnull 		Xerror("try again");
130 f08fdedc 2003-11-23 devnull 		close(pfd[PRD]);
131 f08fdedc 2003-11-23 devnull 		close(pfd[PWR]);
132 f08fdedc 2003-11-23 devnull 		return;
133 f08fdedc 2003-11-23 devnull 	case 0:
134 4b241872 2007-03-26 devnull 		clearwaitpids();
135 f08fdedc 2003-11-23 devnull 		close(pfd[PRD]);
136 f08fdedc 2003-11-23 devnull 		start(runq->code, runq->pc+1, runq->local);
137 f08fdedc 2003-11-23 devnull 		pushredir(ROPEN, pfd[PWR], 1);
138 f08fdedc 2003-11-23 devnull 		return;
139 f08fdedc 2003-11-23 devnull 	default:
140 4b241872 2007-03-26 devnull 		addwaitpid(pid);
141 f08fdedc 2003-11-23 devnull 		close(pfd[PWR]);
142 f08fdedc 2003-11-23 devnull 		f = openfd(pfd[PRD]);
143 f08fdedc 2003-11-23 devnull 		s = wd;
144 f08fdedc 2003-11-23 devnull 		v = 0;
145 f08fdedc 2003-11-23 devnull 		while((c = rchr(f))!=EOF){
146 f08fdedc 2003-11-23 devnull 			if(strchr(stop, c) || s==ewd){
147 f08fdedc 2003-11-23 devnull 				if(s!=wd){
148 f08fdedc 2003-11-23 devnull 					*s='\0';
149 f08fdedc 2003-11-23 devnull 					v = newword(wd, v);
150 f08fdedc 2003-11-23 devnull 					s = wd;
151 f08fdedc 2003-11-23 devnull 				}
152 f08fdedc 2003-11-23 devnull 			}
153 f08fdedc 2003-11-23 devnull 			else *s++=c;
154 f08fdedc 2003-11-23 devnull 		}
155 f08fdedc 2003-11-23 devnull 		if(s!=wd){
156 f08fdedc 2003-11-23 devnull 			*s='\0';
157 f08fdedc 2003-11-23 devnull 			v = newword(wd, v);
158 f08fdedc 2003-11-23 devnull 		}
159 f08fdedc 2003-11-23 devnull 		closeio(f);
160 f08fdedc 2003-11-23 devnull 		Waitfor(pid, 0);
161 f08fdedc 2003-11-23 devnull 		/* v points to reversed arglist -- reverse it onto argv */
162 f08fdedc 2003-11-23 devnull 		while(v){
163 f08fdedc 2003-11-23 devnull 			nextv = v->next;
164 f08fdedc 2003-11-23 devnull 			v->next = runq->argv->words;
165 f08fdedc 2003-11-23 devnull 			runq->argv->words = v;
166 f08fdedc 2003-11-23 devnull 			v = nextv;
167 f08fdedc 2003-11-23 devnull 		}
168 74be4603 2009-08-08 mt4swm 		p->pc = p->code[p->pc].i;
169 f08fdedc 2003-11-23 devnull 		return;
170 f08fdedc 2003-11-23 devnull 	}
171 f08fdedc 2003-11-23 devnull }
172 f08fdedc 2003-11-23 devnull 
173 f08fdedc 2003-11-23 devnull void
174 f08fdedc 2003-11-23 devnull Xpipefd(void)
175 f08fdedc 2003-11-23 devnull {
176 f08fdedc 2003-11-23 devnull 	struct thread *p = runq;
177 4b241872 2007-03-26 devnull 	int pc = p->pc, pid;
178 f08fdedc 2003-11-23 devnull 	char name[40];
179 f08fdedc 2003-11-23 devnull 	int pfd[2];
180 38b62735 2009-09-13 mt4swm 	struct { int sidefd, mainfd; } fd[2], *r, *w;
181 38b62735 2009-09-13 mt4swm 
182 38b62735 2009-09-13 mt4swm 	r = &fd[0];
183 38b62735 2009-09-13 mt4swm 	w = &fd[1];
184 38b62735 2009-09-13 mt4swm 	switch(p->code[pc].i){
185 38b62735 2009-09-13 mt4swm 	case READ:
186 38b62735 2009-09-13 mt4swm 		w = nil;
187 38b62735 2009-09-13 mt4swm 		break;
188 38b62735 2009-09-13 mt4swm 	case WRITE:
189 38b62735 2009-09-13 mt4swm 		r = nil;
190 f08fdedc 2003-11-23 devnull 	}
191 38b62735 2009-09-13 mt4swm 
192 38b62735 2009-09-13 mt4swm 	if(r){
193 38b62735 2009-09-13 mt4swm 		if(pipe(pfd)<0){
194 38b62735 2009-09-13 mt4swm 			Xerror("can't get pipe");
195 38b62735 2009-09-13 mt4swm 			return;
196 38b62735 2009-09-13 mt4swm 		}
197 38b62735 2009-09-13 mt4swm  		r->sidefd = pfd[PWR];
198 38b62735 2009-09-13 mt4swm  		r->mainfd = pfd[PRD];
199 f08fdedc 2003-11-23 devnull 	}
200 38b62735 2009-09-13 mt4swm 	if(w){
201 38b62735 2009-09-13 mt4swm 		if(pipe(pfd)<0){
202 38b62735 2009-09-13 mt4swm 			Xerror("can't get pipe");
203 38b62735 2009-09-13 mt4swm 			return;
204 38b62735 2009-09-13 mt4swm 		}
205 38b62735 2009-09-13 mt4swm  		w->sidefd = pfd[PRD];
206 38b62735 2009-09-13 mt4swm  		w->mainfd = pfd[PWR];
207 f08fdedc 2003-11-23 devnull 	}
208 4b241872 2007-03-26 devnull 	switch(pid = fork()){
209 f08fdedc 2003-11-23 devnull 	case -1:
210 f08fdedc 2003-11-23 devnull 		Xerror("try again");
211 f08fdedc 2003-11-23 devnull 		break;
212 f08fdedc 2003-11-23 devnull 	case 0:
213 4b241872 2007-03-26 devnull 		clearwaitpids();
214 f08fdedc 2003-11-23 devnull 		start(p->code, pc+2, runq->local);
215 38b62735 2009-09-13 mt4swm 		if(r){
216 38b62735 2009-09-13 mt4swm 			close(r->mainfd);
217 38b62735 2009-09-13 mt4swm 			pushredir(ROPEN, r->sidefd, 1);
218 38b62735 2009-09-13 mt4swm 		}
219 38b62735 2009-09-13 mt4swm 		if(w){
220 38b62735 2009-09-13 mt4swm 			close(w->mainfd);
221 38b62735 2009-09-13 mt4swm 			pushredir(ROPEN, w->sidefd, 0);
222 38b62735 2009-09-13 mt4swm 		}
223 f08fdedc 2003-11-23 devnull 		runq->ret = 0;
224 f08fdedc 2003-11-23 devnull 		break;
225 f08fdedc 2003-11-23 devnull 	default:
226 4b241872 2007-03-26 devnull 		addwaitpid(pid);
227 38b62735 2009-09-13 mt4swm 		if(w){
228 38b62735 2009-09-13 mt4swm 			close(w->sidefd);
229 38b62735 2009-09-13 mt4swm 			pushredir(ROPEN, w->mainfd, w->mainfd);	/* so that Xpopredir can close it later */
230 38b62735 2009-09-13 mt4swm 			strcpy(name, Fdprefix);
231 38b62735 2009-09-13 mt4swm 			inttoascii(name+strlen(name), w->mainfd);
232 38b62735 2009-09-13 mt4swm 			pushword(name);
233 38b62735 2009-09-13 mt4swm 		}
234 38b62735 2009-09-13 mt4swm 		if(r){
235 38b62735 2009-09-13 mt4swm 			close(r->sidefd);
236 38b62735 2009-09-13 mt4swm 			pushredir(ROPEN, r->mainfd, r->mainfd);
237 38b62735 2009-09-13 mt4swm 			strcpy(name, Fdprefix);
238 38b62735 2009-09-13 mt4swm 			inttoascii(name+strlen(name), r->mainfd);
239 38b62735 2009-09-13 mt4swm 			pushword(name);
240 38b62735 2009-09-13 mt4swm 		}
241 f08fdedc 2003-11-23 devnull 		p->pc = p->code[pc+1].i;
242 f08fdedc 2003-11-23 devnull 		break;
243 f08fdedc 2003-11-23 devnull 	}
244 f08fdedc 2003-11-23 devnull }
245 f08fdedc 2003-11-23 devnull 
246 f08fdedc 2003-11-23 devnull void
247 f08fdedc 2003-11-23 devnull Xsubshell(void)
248 f08fdedc 2003-11-23 devnull {
249 f08fdedc 2003-11-23 devnull 	int pid;
250 f08fdedc 2003-11-23 devnull 	switch(pid = fork()){
251 f08fdedc 2003-11-23 devnull 	case -1:
252 f08fdedc 2003-11-23 devnull 		Xerror("try again");
253 f08fdedc 2003-11-23 devnull 		break;
254 f08fdedc 2003-11-23 devnull 	case 0:
255 4b241872 2007-03-26 devnull 		clearwaitpids();
256 f08fdedc 2003-11-23 devnull 		start(runq->code, runq->pc+1, runq->local);
257 f08fdedc 2003-11-23 devnull 		runq->ret = 0;
258 f08fdedc 2003-11-23 devnull 		break;
259 f08fdedc 2003-11-23 devnull 	default:
260 4b241872 2007-03-26 devnull 		addwaitpid(pid);
261 f08fdedc 2003-11-23 devnull 		Waitfor(pid, 1);
262 f08fdedc 2003-11-23 devnull 		runq->pc = runq->code[runq->pc].i;
263 f08fdedc 2003-11-23 devnull 		break;
264 f08fdedc 2003-11-23 devnull 	}
265 f08fdedc 2003-11-23 devnull }
266 f08fdedc 2003-11-23 devnull 
267 f08fdedc 2003-11-23 devnull int
268 f08fdedc 2003-11-23 devnull execforkexec(void)
269 f08fdedc 2003-11-23 devnull {
270 f08fdedc 2003-11-23 devnull 	int pid;
271 f08fdedc 2003-11-23 devnull 	int n;
272 f08fdedc 2003-11-23 devnull 	char buf[ERRMAX];
273 f08fdedc 2003-11-23 devnull 
274 f08fdedc 2003-11-23 devnull 	switch(pid = fork()){
275 f08fdedc 2003-11-23 devnull 	case -1:
276 f08fdedc 2003-11-23 devnull 		return -1;
277 f08fdedc 2003-11-23 devnull 	case 0:
278 4b241872 2007-03-26 devnull 		clearwaitpids();
279 f08fdedc 2003-11-23 devnull 		pushword("exec");
280 f08fdedc 2003-11-23 devnull 		execexec();
281 f08fdedc 2003-11-23 devnull 		strcpy(buf, "can't exec: ");
282 f08fdedc 2003-11-23 devnull 		n = strlen(buf);
283 f08fdedc 2003-11-23 devnull 		errstr(buf+n, ERRMAX-n);
284 f08fdedc 2003-11-23 devnull 		Exit(buf);
285 f08fdedc 2003-11-23 devnull 	}
286 4b241872 2007-03-26 devnull 	addwaitpid(pid);
287 f08fdedc 2003-11-23 devnull 	return pid;
288 f08fdedc 2003-11-23 devnull }