Subversion Repositories planix.SVN

Rev

Rev 2 | Details | Compare with Previous | Last modification | View Log | RSS feed

Rev Author Line No. Line
2 - 1 
#include <u.h>
2 
#include <libc.h>
3 
#include <bio.h>
4 
#include <ndb.h>
5 
#include <fcall.h>
6 
 
7 
enum
8 
{
9 
	Maxpath=	128,
10 
};
11 
 
12 
typedef struct Endpoints Endpoints;
13 
struct Endpoints
14 
{
15 
	char 	*net;
16 
	char	*lsys;
17 
	char	*lserv;
18 
	char	*rsys;
19 
	char	*rserv;
20 
};
21 
 
22 
void		xfer(int, int);
23 
void		xfer9p(int, int);
24 
Endpoints*	getendpoints(char*);
25 
void		freeendpoints(Endpoints*);
26 
char*		iptomac(char*, char*);
27 
int		macok(char*);
28 
 
29 
void
30 
usage(void)
31 
{
32 
	fprint(2, "usage: trampoline [-9] [-a addr] [-m netdir] addr\n");
33 
	exits("usage");
34 
}
35 
 
36 
void
37 
main(int argc, char **argv)
38 
{
39 
	char *altaddr, *checkmac, *mac;
40 
	int fd, fd0, fd1;
41 
	void (*x)(int, int);
42 
	Endpoints *ep;
43 
 
44 
	checkmac = nil;
45 
	altaddr = nil;
46 
	x = xfer;
47 
	ARGBEGIN{
48 
	case '9':
49 
		x = xfer9p;
50 
		break;
51 
	case 'a':
52 
		altaddr = EARGF(usage());
53 
		break;
54 
	case 'm':
55 
		checkmac = EARGF(usage());
56 
		break;
57 
	default:
58 
		usage();
59 
	}ARGEND;
60 
 
61 
	if(argc != 1)
62 
		usage();
63 
 
64 
	if(checkmac){
65 
		ep = getendpoints(checkmac);
66 
		mac = iptomac(ep->rsys, ep->net);
67 
		if(!macok(mac)){
68 
			syslog(0, "trampoline", "badmac %s from %s!%s for %s!%s on %s",
69 
				mac, ep->rsys, ep->rserv, ep->lsys, ep->lserv, ep->net);
70 
			exits("bad mac");
71 
		}
72 
	}
73 
 
74 
	fd0 = 0;
75 
	fd1 = 1;
76 
	if(altaddr){
77 
		fd0 = dial(altaddr, 0, 0, 0);
78 
		if(fd0 < 0)
79 
			sysfatal("dial %s: %r", altaddr);
80 
		fd1 = fd0;
81 
	}
82 
	fd = dial(argv[0], 0, 0, 0);
83 
	if(fd < 0)
84 
		sysfatal("dial %s: %r", argv[0]);
85 
 
86 
	rfork(RFNOTEG);
87 
	switch(fork()){
88 
	case -1:
89 
		fprint(2, "%s: fork: %r\n", argv0);
90 
		exits("dial");
91 
	case 0:
92 
		(*x)(fd0, fd);
93 
		break;
94 
	default:
95 
		(*x)(fd, fd1);
96 
		break;
97 
	}
98 
	postnote(PNGROUP, getpid(), "die yankee pig dog");
99 
	exits(0);
100 
}
101 
 
102 
void
103 
xfer(int from, int to)
104 
{
105 
	char buf[12*1024];
106 
	int n;
107 
 
108 
	while((n = read(from, buf, sizeof buf)) > 0)
109 
		if(write(to, buf, n) < 0)
110 
			break;
111 
}
112 
 
113 
void
114 
xfer9p(int from, int to)
115 
{
116 
	uchar *buf;
117 
	uint nbuf;
118 
	int n;
119 
 
120 
	nbuf = 256;
121 
	buf = malloc(nbuf);
122 
	if(buf == nil)
123 
		sysfatal("xfer: malloc %ud: %r", nbuf);
124 
 
125 
	for(;;){
126 
		if(readn(from, buf, 4) != 4)
127 
			break;
128 
		n = GBIT32(buf);
129 
		if(n > nbuf){
130 
			nbuf = n+8192;
131 
			buf = realloc(buf, nbuf);
132 
			if(buf == nil)
133 
				sysfatal("xfer: realloc %ud: %r", nbuf);
134 
		}
135 
		if(readn(from, buf+4, n-4) != n-4)
136 
			break;
137 
		if(write(to, buf, n) != n){
138 
			sysfatal("oops: %r");
139 
			break;
140 
		}
141 
	}
142 
}
143 
 
144 
void
145 
getendpoint(char *dir, char *file, char **sysp, char **servp)
146 
{
147 
	int fd, n;
148 
	char buf[Maxpath];
149 
	char *sys, *serv;
150 
 
151 
	sys = serv = 0;
152 
 
153 
	snprint(buf, sizeof buf, "%s/%s", dir, file);
154 
	fd = open(buf, OREAD);
155 
	if(fd >= 0){
156 
		n = read(fd, buf, sizeof(buf)-1);
157 
		if(n>0){
158 
			buf[n-1] = 0;
159 
			serv = strchr(buf, '!');
160 
			if(serv){
161 
				*serv++ = 0;
162 
				serv = strdup(serv);
163 
			}
164 
			sys = strdup(buf);
165 
		}
166 
		close(fd);
167 
	}
168 
	if(serv == 0)
169 
		serv = strdup("unknown");
170 
	if(sys == 0)
171 
		sys = strdup("unknown");
172 
	*servp = serv;
173 
	*sysp = sys;
174 
}
175 
 
176 
Endpoints *
177 
getendpoints(char *dir)
178 
{
179 
	Endpoints *ep;
180 
	char *p;
181 
 
182 
	ep = malloc(sizeof(*ep));
183 
	ep->net = strdup(dir);
184 
	p = strchr(ep->net+1, '/');
185 
	if(p == nil){
186 
		free(ep->net);
187 
		ep->net = "/net";
188 
	} else
189 
		*p = 0;
190 
	getendpoint(dir, "local", &ep->lsys, &ep->lserv);
191 
	getendpoint(dir, "remote", &ep->rsys, &ep->rserv);
192 
	return ep;
193 
}
194 
 
195 
void
196 
freeendpoints(Endpoints *ep)
197 
{
198 
	free(ep->lsys);
199 
	free(ep->rsys);
200 
	free(ep->lserv);
201 
	free(ep->rserv);
202 
	free(ep);
203 
}
204 
 
205 
char*
206 
iptomac(char *ip, char *net)
207 
{
208 
	char file[Maxpath];
209 
	Biobuf *b;
210 
	char *p;
211 
	char *f[5];
212 
 
213 
	snprint(file, sizeof(file), "%s/arp", net);
214 
	b = Bopen(file, OREAD);
215 
	if(b == nil)
216 
		return nil;
217 
	while((p = Brdline(b, '\n')) != nil){
218 
		p[Blinelen(b)-1] = 0;
219 
		if(tokenize(p, f, nelem(f)) < 4)
220 
			continue;
221 
		if(strcmp(f[1], "OK") == 0
222 
		&& strcmp(f[2], ip) == 0){
223 
			p = strdup(f[3]);
224 
			Bterm(b);
225 
			return p;
226 
		}
227 
	}
228 
	Bterm(b);
229 
	return nil;
230 
}
231 
 
232 
int
233 
macok(char *mac)
234 
{
235 
	char *p;
236 
 
237 
	if(mac == nil)
238 
		return 0;
239 
	free(p = csgetvalue("/net", "ether", mac, "trampok", nil));
240 
	return !(p == nil);
241 
}