1 #include <u.h>
2 #include <libc.h>
3 #include <regexp.h>
4 #include <thread.h>
5 #include <fcall.h>
6 
7 int debug;
8 int dfd;
9 int srvfd;
10 int netfd;
11 int srv_to_net[2];
12 int net_to_srv[2];
13 char *srv;
14 char	*addr;
15 char *ns;
16 
17 void	shuffle(void *arg);
18 int	post(char *srv);
19 void	remoteside(char *ns, char *srv);
20 int	call(char *rsys, char *ns, char *srv);
21 void*	emalloc(int size);
22 void	runproc(void *arg);
23 
24 char *REXEXEC = "ssh";
25 char *prog = "import";
26 
27 enum
28 {
29 	Stack= 32*1024,
30 };
31 
32 void
33 usage(void)
34 {
35 	fprint(2, "usage: %s [-df] [-s service] [-n remote-ns] [-p remote-prog] remote-system\n", argv0);
36 	threadexitsall("usage");
37 }
38 
39 void
40 fatal(char *fmt, ...)
41 {
42 	char buf[256];
43 	va_list arg;
44 
45 	va_start(arg, fmt);
46 	vseprint(buf, buf+sizeof buf, fmt, arg);
47 	va_end(arg);
48 
49 	fprint(2, "%s: %s\n", argv0 ? argv0 : "<prog>", buf);
50 	threadexitsall("fatal");
51 }
52 
53 void
54 threadmain(int argc, char *argv[])
55 {
56 	int dofork;
57 	int rem;
58 
59 	dofork = 1;
60 	rem = 0;
61 	ns = nil;
62 	srv = "plumb";
63 
64 	ARGBEGIN{
65 	case 'd':
66 		debug = 1;
67 		break;
68 	case 'f':
69 		dofork = 0;
70 		break;
71 	case 'n':	// name of remote namespace
72 		ns = EARGF(usage());
73 		break;
74 	case 'p':
75 		prog = EARGF(usage());
76 		break;
77 	case 's':	// name of service
78 		srv = EARGF(usage());
79 		break;
80 	case 'R':
81 		rem = 1;
82 		break;
83 	}ARGEND
84 
85 	if(debug){
86 		char *dbgfile;
87 
88 		if(rem)
89 			dbgfile = smprint("/tmp/%s.export.debug", getuser());
90 		else
91 			dbgfile = smprint("/tmp/%s.import.debug", getuser());
92 		dfd = create(dbgfile, OWRITE, 0664);
93 		free(dbgfile);
94 		fmtinstall('F', fcallfmt);
95 	}
96 
97 	// is this the remote side?
98 	if(rem){
99 		if(srv == nil)
100 			fatal("-R requires -s");
101 		remoteside(ns, srv);
102 		threadexitsall(0);
103 	}
104 
105 	if(argc != 1)
106 		usage();
107 
108 	addr = argv[0];
109 	
110 	if(dofork)
111 		proccreate(runproc, nil, Stack);
112 	else
113 		runproc(nil);
114 }
115 
116 void
117 runproc(void *arg)
118 {
119 	USED(arg);
120 
121 	// start a loal service and connect to remote service
122 	srvfd = post(srv);
123 	netfd = call(addr, ns, srv);
124 
125 	// threads to shuffle messages each way
126 	srv_to_net[0] = srvfd;
127 	srv_to_net[1] = netfd;
128 	proccreate(shuffle, srv_to_net, Stack);
129 	net_to_srv[0] = netfd;
130 	net_to_srv[1] = srvfd;
131 	shuffle(net_to_srv);
132 }
133 
134 /* post a local service */
135 int
136 post(char *srv)
137 {
138 	int p[2];
139 
140 	if(pipe(p) < 0)
141 		fatal("can't create pipe: %r");
142 
143 	/* 0 will be server end, 1 will be client end */
144 	if(post9pservice(p[1], "plumb") < 0)
145 		fatal("post9pservice plumb: %r");
146 	close(p[1]);
147 
148 	return p[0];
149 }
150 
151 /* start a stub on the remote server */
152 int
153 call(char *rsys, char *ns, char *srv)
154 {
155 	int p[2];
156 	int ac;
157 	char *av[12];
158 	char buf[2];
159 
160 	if(pipe(p) < 0)
161 		fatal("can't create pipe: %r");
162 	ac = 0;
163 	av[ac++] = REXEXEC;
164 	av[ac++] = rsys;
165 	av[ac++] = prog;
166 	if(debug)
167 		av[ac++] = "-d";
168 	av[ac++] = "-R";
169 	if(ns != nil){
170 		av[ac++] = "-n";
171 		av[ac++] = ns;
172 	}
173 	av[ac++] = "-s";
174 	av[ac++] = srv;
175 	av[ac] = 0;
176 
177 	if(debug){
178 		fprint(dfd, "execing ");
179 		for(ac = 0; av[ac]; ac++)
180 			fprint(dfd, " %s", av[ac]);
181 		fprint(dfd, "\n");
182 	}
183 
184 	switch(fork()){
185 	case -1:
186 		fatal("%r");
187 	case 0:
188 		dup(p[1], 0);
189 		dup(p[1], 1);
190 		close(p[0]);
191 		close(p[1]);
192 		execvp(REXEXEC, av);
193 		fatal("can't exec %s", REXEXEC);
194 	default:
195 		break;
196 	}
197 	close(p[1]);
198 
199 	// ignore crap that might come out of the .profile
200 	// keep reading till we have an "OK"
201 	if(read(p[0], &buf[0], 1) != 1)
202 		fatal("EOF");
203 	for(;;){
204 		if(read(p[0], &buf[1], 1) != 1)
205 			fatal("EOF");
206 		if(strncmp(buf, "OK", 2) == 0)
207 			break;
208 		buf[0] = buf[1];
209 	}
210 	if(debug)
211 		fprint(dfd, "got OK\n");
212 
213 	return p[0];
214 }
215 
216 enum
217 {
218 	BLEN=16*1024
219 };
220 
221 void
222 shuffle(void *arg)
223 {
224 	int *fd;
225 	char *buf, *tbuf;
226 	int n;
227 	Fcall *t;
228 
229 	fd = (int*)arg;
230 	buf = emalloc(BLEN+1);
231 	t = nil;
232 	tbuf = nil;
233 	for(;;){
234 		n = read9pmsg(fd[0], buf, BLEN);
235 		if(n <= 0){
236 			if(debug)
237 				fprint(dfd, "%d->%d read returns %d: %r\n", fd[0], fd[1], n);
238 			break;
239 		}
240 		if(debug){
241 			if(t == nil)
242 				t = emalloc(sizeof(Fcall));
243 			if(tbuf == nil)
244 				tbuf = emalloc(BLEN+1);
245 			memmove(tbuf, buf, n);	// because convM2S is destructive
246 			if(convM2S((uchar*)tbuf, n, t) != n)
247 				fprint(dfd, "%d->%d convert error in convM2S", fd[0], fd[1]);
248 			else
249 				fprint(dfd, "%d->%d %F\n", fd[0], fd[1], t);
250 		}
251 		if(write(fd[1], buf, n) != n)
252 			break;
253 	}
254 }
255 
256 void
257 remoteside(char *ns, char *srv)
258 {
259 	int srv_to_net[2];
260 	int net_to_srv[2];
261 	char *addr;
262 	int srvfd;
263 
264 	if(ns == nil)
265 		ns = getns();
266 
267 	addr = smprint("unix!%s/%s", ns, srv);
268 	if(addr == nil)
269 		fatal("%r");
270 	if(debug)
271 		fprint(dfd, "remoteside starting %s\n", addr);
272 
273 	srvfd = dial(addr, 0, 0, 0);
274 	if(srvfd < 0)
275 		fatal("dial %s: %r", addr);
276 	if(debug)
277 		fprint(dfd, "remoteside dial %s succeeded\n", addr);
278 	fcntl(srvfd, F_SETFL, FD_CLOEXEC);
279 
280 	write(1, "OK", 2);
281 
282 	/* threads to shuffle messages each way */
283 	srv_to_net[0] = srvfd;
284 	srv_to_net[1] = 1;
285 	proccreate(shuffle, srv_to_net, Stack);
286 	net_to_srv[0] = 0;
287 	net_to_srv[1] = srvfd;
288 	shuffle(net_to_srv);
289 
290 	threadexitsall(0);
291 }
292 
293 void*
294 emalloc(int size)
295 {
296 	void *x;
297 
298 	x = malloc(size);
299 	if(x == nil)
300 		fatal("allocation fails: %r");
301 	return x;
302 }