/*  * This file is part of the UCB release of Plan 9. It is subject to the license * terms in the LICENSE file found in the top-level directory of this * distribution and at http://akaros.cs.berkeley.edu/files/Plan9License. No * part of the UCB release of Plan 9, including this file, may be copied, * modified, propagated, or distributed except according to the terms contained * in the LICENSE file. */ #include "stdinc.h" #include "9.h" typedef struct Srv Srv;struct Srv {	int	fd;	int	srvfd;	char*	service;	char*	mntpnt; 	Srv*	next;	Srv*	prev;}; static struct {	VtLock*	lock; 	Srv*	head;	Srv*	tail;} sbox; static intsrvFd(char* name, int mode, int fd, char** mntpnt){	int n, srvfd;	char *p, buf[10]; 	/*	 * Drop a file descriptor with given name and mode into /srv.	 * Create with ORCLOSE and don't close srvfd so it will be removed	 * automatically on process exit.	 */	p = smprint("/srv/%s", name);	if((srvfd = create(p, ORCLOSE|OWRITE, mode)) < 0){		vtMemFree(p);		p = smprint("#s/%s", name);		if((srvfd = create(p, ORCLOSE|OWRITE, mode)) < 0){			vtSetError("create %s: %r", p);			vtMemFree(p);			return -1;		}	} 	n = snprint(buf, sizeof(buf), "%d", fd);	if(write(srvfd, buf, n) < 0){		close(srvfd);		vtSetError("write %s: %r", p);		vtMemFree(p);		return -1;	} 	*mntpnt = p; 	return srvfd;} static voidsrvFree(Srv* srv){	if(srv->prev != nil)		srv->prev->next = srv->next;	else		sbox.head = srv->next;	if(srv->next != nil)		srv->next->prev = srv->prev;	else		sbox.tail = srv->prev; 	if(srv->srvfd != -1)		close(srv->srvfd);	vtMemFree(srv->service);	vtMemFree(srv->mntpnt);	vtMemFree(srv);} static Srv*srvAlloc(char* service, int mode, int fd){	Dir *dir;	Srv *srv;	int srvfd;	char *mntpnt; 	vtLock(sbox.lock);	for(srv = sbox.head; srv != nil; srv = srv->next){		if(strcmp(srv->service, service) != 0)			continue;		/*		 * If the service exists, but is stale,		 * free it up and let the name be reused.		 */		if((dir = dirfstat(srv->srvfd)) != nil){			free(dir);			vtSetError("srv: already serving '%s'", service);			vtUnlock(sbox.lock);			return nil;		}		srvFree(srv);		break;	} 	if((srvfd = srvFd(service, mode, fd, &mntpnt)) < 0){		vtUnlock(sbox.lock);		return nil;	}	close(fd); 	srv = vtMemAllocZ(sizeof(Srv));	srv->srvfd = srvfd;	srv->service = vtStrDup(service);	srv->mntpnt = mntpnt; 	if(sbox.tail != nil){		srv->prev = sbox.tail;		sbox.tail->next = srv;	}	else{		sbox.head = srv;		srv->prev = nil;	}	sbox.tail = srv;	vtUnlock(sbox.lock); 	return srv;} static intcmdSrv(int argc, char* argv[]){	Con *con;	Srv *srv;	char *usage = "usage: srv [-APWdp] [service]";	int conflags, dflag, fd[2], mode, pflag, r; 	dflag = 0;	pflag = 0;	conflags = 0;	mode = 0666; 	ARGBEGIN{	default:		return cliError(usage);	case 'A':		conflags |= ConNoAuthCheck;		break;	case 'I':		conflags |= ConIPCheck;		break;	case 'N':		conflags |= ConNoneAllow;		break;	case 'P':		conflags |= ConNoPermCheck;		mode = 0600;		break;	case 'W':		conflags |= ConWstatAllow;		mode = 0600;		break;	case 'd':		dflag = 1;		break;	case 'p':		pflag = 1;		mode = 0600;		break;	}ARGEND 	if(pflag && (conflags&ConNoPermCheck)){		vtSetError("srv: cannot use -P with -p");		return 0;	} 	switch(argc){	default:		return cliError(usage);	case 0:		vtRLock(sbox.lock);		for(srv = sbox.head; srv != nil; srv = srv->next)			consPrint("\t%s\t%d\n", srv->service, srv->srvfd);		vtRUnlock(sbox.lock); 		return 1;	case 1:		if(!dflag)			break; 		vtLock(sbox.lock);		for(srv = sbox.head; srv != nil; srv = srv->next){			if(strcmp(srv->service, argv[0]) != 0)				continue;			srvFree(srv);			break;		}		vtUnlock(sbox.lock); 		if(srv == nil){			vtSetError("srv: '%s' not found", argv[0]);			return 0;		} 		return 1;	} 	if(pipe(fd) < 0){		vtSetError("srv pipe: %r");		return 0;	}	if((srv = srvAlloc(argv[0], mode, fd[0])) == nil){		close(fd[0]); close(fd[1]);		return 0;	} 	if(pflag)		r = consOpen(fd[1], srv->srvfd, -1);	else{		con = conAlloc(fd[1], srv->mntpnt, conflags);		if(con == nil)			r = 0;		else			r = 1;	}	if(r == 0){		close(fd[1]);		vtLock(sbox.lock);		srvFree(srv);		vtUnlock(sbox.lock);	} 	return r;} intsrvInit(void){	sbox.lock = vtLockAlloc(); 	cliAddCmd("srv", cmdSrv); 	return 1;}