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 f08fdedc 2003-11-23 devnull 	char wd[8193];
114 f08fdedc 2003-11-23 devnull 	int c;
115 f08fdedc 2003-11-23 devnull 	char *s, *ewd=&wd[8192], *stop;
116 f08fdedc 2003-11-23 devnull 	struct io *f;
117 f08fdedc 2003-11-23 devnull 	var *ifs = vlook("ifs");
118 f08fdedc 2003-11-23 devnull 	word *v, *nextv;
119 f08fdedc 2003-11-23 devnull 	int pfd[2];
120 f08fdedc 2003-11-23 devnull 	int pid;
121 f08fdedc 2003-11-23 devnull 	stop = ifs->val?ifs->val->word:"";
122 f08fdedc 2003-11-23 devnull 	if(pipe(pfd)<0){
123 f08fdedc 2003-11-23 devnull 		Xerror("can't make pipe");
124 f08fdedc 2003-11-23 devnull 		return;
125 f08fdedc 2003-11-23 devnull 	}
126 f08fdedc 2003-11-23 devnull 	switch(pid = fork()){
127 f08fdedc 2003-11-23 devnull 	case -1:
128 f08fdedc 2003-11-23 devnull 		Xerror("try again");
129 f08fdedc 2003-11-23 devnull 		close(pfd[PRD]);
130 f08fdedc 2003-11-23 devnull 		close(pfd[PWR]);
131 f08fdedc 2003-11-23 devnull 		return;
132 f08fdedc 2003-11-23 devnull 	case 0:
133 4b241872 2007-03-26 devnull 		clearwaitpids();
134 f08fdedc 2003-11-23 devnull 		close(pfd[PRD]);
135 f08fdedc 2003-11-23 devnull 		start(runq->code, runq->pc+1, runq->local);
136 f08fdedc 2003-11-23 devnull 		pushredir(ROPEN, pfd[PWR], 1);
137 f08fdedc 2003-11-23 devnull 		return;
138 f08fdedc 2003-11-23 devnull 	default:
139 4b241872 2007-03-26 devnull 		addwaitpid(pid);
140 f08fdedc 2003-11-23 devnull 		close(pfd[PWR]);
141 f08fdedc 2003-11-23 devnull 		f = openfd(pfd[PRD]);
142 f08fdedc 2003-11-23 devnull 		s = wd;
143 f08fdedc 2003-11-23 devnull 		v = 0;
144 f08fdedc 2003-11-23 devnull 		while((c = rchr(f))!=EOF){
145 f08fdedc 2003-11-23 devnull 			if(strchr(stop, c) || s==ewd){
146 f08fdedc 2003-11-23 devnull 				if(s!=wd){
147 f08fdedc 2003-11-23 devnull 					*s='\0';
148 f08fdedc 2003-11-23 devnull 					v = newword(wd, v);
149 f08fdedc 2003-11-23 devnull 					s = wd;
150 f08fdedc 2003-11-23 devnull 				}
151 f08fdedc 2003-11-23 devnull 			}
152 f08fdedc 2003-11-23 devnull 			else *s++=c;
153 f08fdedc 2003-11-23 devnull 		}
154 f08fdedc 2003-11-23 devnull 		if(s!=wd){
155 f08fdedc 2003-11-23 devnull 			*s='\0';
156 f08fdedc 2003-11-23 devnull 			v = newword(wd, v);
157 f08fdedc 2003-11-23 devnull 		}
158 f08fdedc 2003-11-23 devnull 		closeio(f);
159 f08fdedc 2003-11-23 devnull 		Waitfor(pid, 0);
160 f08fdedc 2003-11-23 devnull 		/* v points to reversed arglist -- reverse it onto argv */
161 f08fdedc 2003-11-23 devnull 		while(v){
162 f08fdedc 2003-11-23 devnull 			nextv = v->next;
163 f08fdedc 2003-11-23 devnull 			v->next = runq->argv->words;
164 f08fdedc 2003-11-23 devnull 			runq->argv->words = v;
165 f08fdedc 2003-11-23 devnull 			v = nextv;
166 f08fdedc 2003-11-23 devnull 		}
167 f08fdedc 2003-11-23 devnull 		runq->pc = runq->code[runq->pc].i;
168 f08fdedc 2003-11-23 devnull 		return;
169 f08fdedc 2003-11-23 devnull 	}
170 f08fdedc 2003-11-23 devnull }
171 f08fdedc 2003-11-23 devnull 
172 f08fdedc 2003-11-23 devnull void
173 f08fdedc 2003-11-23 devnull Xpipefd(void)
174 f08fdedc 2003-11-23 devnull {
175 f08fdedc 2003-11-23 devnull 	struct thread *p = runq;
176 4b241872 2007-03-26 devnull 	int pc = p->pc, pid;
177 f08fdedc 2003-11-23 devnull 	char name[40];
178 f08fdedc 2003-11-23 devnull 	int pfd[2];
179 f08fdedc 2003-11-23 devnull 	int sidefd, mainfd;
180 f08fdedc 2003-11-23 devnull 	if(pipe(pfd)<0){
181 f08fdedc 2003-11-23 devnull 		Xerror("can't get pipe");
182 f08fdedc 2003-11-23 devnull 		return;
183 f08fdedc 2003-11-23 devnull 	}
184 f08fdedc 2003-11-23 devnull 	if(p->code[pc].i==READ){
185 f08fdedc 2003-11-23 devnull 		sidefd = pfd[PWR];
186 f08fdedc 2003-11-23 devnull 		mainfd = pfd[PRD];
187 f08fdedc 2003-11-23 devnull 	}
188 f08fdedc 2003-11-23 devnull 	else{
189 f08fdedc 2003-11-23 devnull 		sidefd = pfd[PRD];
190 f08fdedc 2003-11-23 devnull 		mainfd = pfd[PWR];
191 f08fdedc 2003-11-23 devnull 	}
192 4b241872 2007-03-26 devnull 	switch(pid = fork()){
193 f08fdedc 2003-11-23 devnull 	case -1:
194 f08fdedc 2003-11-23 devnull 		Xerror("try again");
195 f08fdedc 2003-11-23 devnull 		break;
196 f08fdedc 2003-11-23 devnull 	case 0:
197 4b241872 2007-03-26 devnull 		clearwaitpids();
198 f08fdedc 2003-11-23 devnull 		start(p->code, pc+2, runq->local);
199 f08fdedc 2003-11-23 devnull 		close(mainfd);
200 f08fdedc 2003-11-23 devnull 		pushredir(ROPEN, sidefd, p->code[pc].i==READ?1:0);
201 f08fdedc 2003-11-23 devnull 		runq->ret = 0;
202 f08fdedc 2003-11-23 devnull 		break;
203 f08fdedc 2003-11-23 devnull 	default:
204 4b241872 2007-03-26 devnull 		addwaitpid(pid);
205 f08fdedc 2003-11-23 devnull 		close(sidefd);
206 f08fdedc 2003-11-23 devnull 		pushredir(ROPEN, mainfd, mainfd);	/* isn't this a noop? */
207 f08fdedc 2003-11-23 devnull 		strcpy(name, Fdprefix);
208 f08fdedc 2003-11-23 devnull 		inttoascii(name+strlen(name), mainfd);
209 f08fdedc 2003-11-23 devnull 		pushword(name);
210 f08fdedc 2003-11-23 devnull 		p->pc = p->code[pc+1].i;
211 f08fdedc 2003-11-23 devnull 		break;
212 f08fdedc 2003-11-23 devnull 	}
213 f08fdedc 2003-11-23 devnull }
214 f08fdedc 2003-11-23 devnull 
215 f08fdedc 2003-11-23 devnull void
216 f08fdedc 2003-11-23 devnull Xsubshell(void)
217 f08fdedc 2003-11-23 devnull {
218 f08fdedc 2003-11-23 devnull 	int pid;
219 f08fdedc 2003-11-23 devnull 	switch(pid = fork()){
220 f08fdedc 2003-11-23 devnull 	case -1:
221 f08fdedc 2003-11-23 devnull 		Xerror("try again");
222 f08fdedc 2003-11-23 devnull 		break;
223 f08fdedc 2003-11-23 devnull 	case 0:
224 4b241872 2007-03-26 devnull 		clearwaitpids();
225 f08fdedc 2003-11-23 devnull 		start(runq->code, runq->pc+1, runq->local);
226 f08fdedc 2003-11-23 devnull 		runq->ret = 0;
227 f08fdedc 2003-11-23 devnull 		break;
228 f08fdedc 2003-11-23 devnull 	default:
229 4b241872 2007-03-26 devnull 		addwaitpid(pid);
230 f08fdedc 2003-11-23 devnull 		Waitfor(pid, 1);
231 f08fdedc 2003-11-23 devnull 		runq->pc = runq->code[runq->pc].i;
232 f08fdedc 2003-11-23 devnull 		break;
233 f08fdedc 2003-11-23 devnull 	}
234 f08fdedc 2003-11-23 devnull }
235 f08fdedc 2003-11-23 devnull 
236 f08fdedc 2003-11-23 devnull int
237 f08fdedc 2003-11-23 devnull execforkexec(void)
238 f08fdedc 2003-11-23 devnull {
239 f08fdedc 2003-11-23 devnull 	int pid;
240 f08fdedc 2003-11-23 devnull 	int n;
241 f08fdedc 2003-11-23 devnull 	char buf[ERRMAX];
242 f08fdedc 2003-11-23 devnull 
243 f08fdedc 2003-11-23 devnull 	switch(pid = fork()){
244 f08fdedc 2003-11-23 devnull 	case -1:
245 f08fdedc 2003-11-23 devnull 		return -1;
246 f08fdedc 2003-11-23 devnull 	case 0:
247 4b241872 2007-03-26 devnull 		clearwaitpids();
248 f08fdedc 2003-11-23 devnull 		pushword("exec");
249 f08fdedc 2003-11-23 devnull 		execexec();
250 f08fdedc 2003-11-23 devnull 		strcpy(buf, "can't exec: ");
251 f08fdedc 2003-11-23 devnull 		n = strlen(buf);
252 f08fdedc 2003-11-23 devnull 		errstr(buf+n, ERRMAX-n);
253 f08fdedc 2003-11-23 devnull 		Exit(buf);
254 f08fdedc 2003-11-23 devnull 	}
255 4b241872 2007-03-26 devnull 	addwaitpid(pid);
256 f08fdedc 2003-11-23 devnull 	return pid;
257 f08fdedc 2003-11-23 devnull }