2 * uxproxy.c: Unix implementation of platform_new_connection(),
3 * supporting an OpenSSH-like proxy command.
12 #define DEFINE_PLUG_METHOD_MACROS
18 typedef struct Socket_localproxy_tag * Local_Proxy_Socket;
20 struct Socket_localproxy_tag {
21 const struct socket_function_table *fn;
22 /* the above variable absolutely *must* be the first in this structure */
24 int to_cmd, from_cmd; /* fds */
30 bufchain pending_output_data;
31 bufchain pending_input_data;
36 static int localproxy_select_result(int fd, int event);
39 * Trees to look up the pipe fds in.
41 static tree234 *localproxy_by_fromfd, *localproxy_by_tofd;
42 static int localproxy_fromfd_cmp(void *av, void *bv)
44 Local_Proxy_Socket a = (Local_Proxy_Socket)av;
45 Local_Proxy_Socket b = (Local_Proxy_Socket)bv;
46 if (a->from_cmd < b->from_cmd)
48 if (a->from_cmd > b->from_cmd)
52 static int localproxy_fromfd_find(void *av, void *bv)
55 Local_Proxy_Socket b = (Local_Proxy_Socket)bv;
62 static int localproxy_tofd_cmp(void *av, void *bv)
64 Local_Proxy_Socket a = (Local_Proxy_Socket)av;
65 Local_Proxy_Socket b = (Local_Proxy_Socket)bv;
66 if (a->to_cmd < b->to_cmd)
68 if (a->to_cmd > b->to_cmd)
72 static int localproxy_tofd_find(void *av, void *bv)
75 Local_Proxy_Socket b = (Local_Proxy_Socket)bv;
83 /* basic proxy socket functions */
85 static Plug sk_localproxy_plug (Socket s, Plug p)
87 Local_Proxy_Socket ps = (Local_Proxy_Socket) s;
94 static void sk_localproxy_close (Socket s)
96 Local_Proxy_Socket ps = (Local_Proxy_Socket) s;
98 del234(localproxy_by_fromfd, ps);
99 del234(localproxy_by_tofd, ps);
107 static int localproxy_try_send(Local_Proxy_Socket ps)
111 while (bufchain_size(&ps->pending_output_data) > 0) {
115 bufchain_prefix(&ps->pending_output_data, &data, &len);
116 ret = write(ps->to_cmd, data, len);
117 if (ret < 0 && errno != EWOULDBLOCK) {
118 /* We're inside the Unix frontend here, so we know
119 * that the frontend handle is unnecessary. */
120 logevent(NULL, strerror(errno));
121 fatalbox("%s", strerror(errno));
122 } else if (ret <= 0) {
125 bufchain_consume(&ps->pending_output_data, ret);
130 if (bufchain_size(&ps->pending_output_data) == 0)
131 uxsel_del(ps->to_cmd);
133 uxsel_set(ps->to_cmd, 2, localproxy_select_result);
138 static int sk_localproxy_write (Socket s, const char *data, int len)
140 Local_Proxy_Socket ps = (Local_Proxy_Socket) s;
142 bufchain_add(&ps->pending_output_data, data, len);
144 localproxy_try_send(ps);
146 return bufchain_size(&ps->pending_output_data);
149 static int sk_localproxy_write_oob (Socket s, const char *data, int len)
152 * oob data is treated as inband; nasty, but nothing really
155 return sk_localproxy_write(s, data, len);
158 static void sk_localproxy_flush (Socket s)
160 /* Local_Proxy_Socket ps = (Local_Proxy_Socket) s; */
164 static void sk_localproxy_set_private_ptr (Socket s, void *ptr)
166 Local_Proxy_Socket ps = (Local_Proxy_Socket) s;
170 static void * sk_localproxy_get_private_ptr (Socket s)
172 Local_Proxy_Socket ps = (Local_Proxy_Socket) s;
176 static void sk_localproxy_set_frozen (Socket s, int is_frozen)
178 Local_Proxy_Socket ps = (Local_Proxy_Socket) s;
181 uxsel_del(ps->from_cmd);
183 uxsel_set(ps->from_cmd, 1, localproxy_select_result);
186 static const char * sk_localproxy_socket_error (Socket s)
188 Local_Proxy_Socket ps = (Local_Proxy_Socket) s;
192 static int localproxy_select_result(int fd, int event)
194 Local_Proxy_Socket s;
198 if (!(s = find234(localproxy_by_fromfd, &fd, localproxy_fromfd_find)) &&
199 !(s = find234(localproxy_by_tofd, &fd, localproxy_tofd_find)) )
200 return 1; /* boggle */
203 assert(fd == s->from_cmd);
204 ret = read(fd, buf, sizeof(buf));
206 return plug_closing(s->plug, strerror(errno), errno, 0);
207 } else if (ret == 0) {
208 return plug_closing(s->plug, NULL, 0, 0);
210 return plug_receive(s->plug, 1, buf, ret);
212 } else if (event == 2) {
213 assert(fd == s->to_cmd);
214 if (localproxy_try_send(s))
215 plug_sent(s->plug, bufchain_size(&s->pending_output_data));
222 Socket platform_new_connection(SockAddr addr, char *hostname,
223 int port, int privport,
224 int oobinline, int nodelay, Plug plug,
229 static const struct socket_function_table socket_fn_table = {
233 sk_localproxy_write_oob,
235 sk_localproxy_set_private_ptr,
236 sk_localproxy_get_private_ptr,
237 sk_localproxy_set_frozen,
238 sk_localproxy_socket_error
241 Local_Proxy_Socket ret;
242 int to_cmd_pipe[2], from_cmd_pipe[2], pid;
244 if (cfg->proxy_type != PROXY_CMD)
247 cmd = format_telnet_command(addr, port, cfg);
249 ret = snew(struct Socket_localproxy_tag);
250 ret->fn = &socket_fn_table;
254 bufchain_init(&ret->pending_input_data);
255 bufchain_init(&ret->pending_output_data);
258 * Create the pipes to the proxy command, and spawn the proxy
261 if (pipe(to_cmd_pipe) < 0 ||
262 pipe(from_cmd_pipe) < 0) {
263 ret->error = dupprintf("pipe: %s", strerror(errno));
270 ret->error = dupprintf("fork: %s", strerror(errno));
272 } else if (pid == 0) {
276 dup2(to_cmd_pipe[0], 0);
277 dup2(from_cmd_pipe[1], 1);
278 for (i = 3; i < 127; i++)
280 fcntl(0, F_SETFD, 0);
281 fcntl(1, F_SETFD, 0);
282 execl("/bin/sh", "sh", "-c", cmd, NULL);
286 close(to_cmd_pipe[0]);
287 close(from_cmd_pipe[1]);
289 ret->to_cmd = to_cmd_pipe[1];
290 ret->from_cmd = from_cmd_pipe[0];
292 if (!localproxy_by_fromfd)
293 localproxy_by_fromfd = newtree234(localproxy_fromfd_cmp);
294 if (!localproxy_by_tofd)
295 localproxy_by_tofd = newtree234(localproxy_tofd_cmp);
297 add234(localproxy_by_fromfd, ret);
298 add234(localproxy_by_tofd, ret);
300 uxsel_set(ret->from_cmd, 1, localproxy_select_result);
302 /* We are responsible for this and don't need it any more */