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comparison tcpfwd-remote.c @ 9:7f77962de998

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- Reworked non-channel fd handling to listener.c - More channel cleaning up
author Matt Johnston <matt@ucc.asn.au>
date Thu, 03 Jun 2004 16:45:53 +0000
parents
children f76c9389e9e0
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7:425ed5c20157 9:7f77962de998
1 #include "includes.h"
2 #include "ssh.h"
3 #include "tcpfwd-remote.h"
4 #include "dbutil.h"
5 #include "session.h"
6 #include "buffer.h"
7 #include "packet.h"
8 #include "listener.h"
9
10 #ifndef DISABLE_REMOTETCPFWD
11
12 struct RemoteTCP {
13
14 unsigned char* addr;
15 unsigned int port;
16
17 };
18
19 static void send_msg_request_success();
20 static void send_msg_request_failure();
21 static int cancelremotetcp();
22 static int remotetcpreq();
23 static int listen_tcpfwd(unsigned char* bindaddr, unsigned int port);
24 static void acceptremote(struct Listener *listener);
25
26 /* At the moment this is completely used for tcp code (with the name reflecting
27 * that). If new request types are added, this should be replaced with code
28 * similar to the request-switching in chansession.c */
29 void recv_msg_global_request_remotetcp() {
30
31 unsigned char* reqname = NULL;
32 unsigned int namelen;
33 unsigned int wantreply = 0;
34 int ret = DROPBEAR_FAILURE;
35
36 TRACE(("enter recv_msg_global_request_remotetcp"));
37
38 if (ses.opts->noremotetcp) {
39 TRACE(("leave recv_msg_global_request_remotetcp: remote tcp forwarding disabled"));
40 goto out;
41 }
42
43 reqname = buf_getstring(ses.payload, &namelen);
44 wantreply = buf_getbyte(ses.payload);
45
46 if (namelen > MAXNAMLEN) {
47 TRACE(("name len is wrong: %d", namelen));
48 goto out;
49 }
50
51 if (strcmp("tcpip-forward", reqname) == 0) {
52 ret = remotetcpreq();
53 } else if (strcmp("cancel-tcpip-forward", reqname) == 0) {
54 ret = cancelremotetcp();
55 } else {
56 TRACE(("reqname isn't tcpip-forward: '%s'", reqname));
57 }
58
59 out:
60 if (wantreply) {
61 if (ret == DROPBEAR_SUCCESS) {
62 send_msg_request_success();
63 } else {
64 send_msg_request_failure();
65 }
66 }
67
68 m_free(reqname);
69
70 TRACE(("leave recv_msg_global_request"));
71 }
72
73 static const struct ChanType chan_tcpremote = {
74 0, /* sepfds */
75 "forwarded-tcpip",
76 NULL,
77 NULL,
78 NULL,
79 NULL
80 };
81
82
83 static void acceptremote(struct Listener *listener) {
84
85 int fd;
86 struct sockaddr addr;
87 int len;
88 char ipstring[NI_MAXHOST], portstring[NI_MAXSERV];
89 struct RemoteTCP *tcpinfo = (struct RemoteTCP*)(listener->typedata);
90
91 len = sizeof(addr);
92
93 fd = accept(listener->sock, &addr, &len);
94 if (fd < 0) {
95 return;
96 }
97
98 if (getnameinfo(&addr, len, ipstring, sizeof(ipstring), portstring,
99 sizeof(portstring), NI_NUMERICHOST | NI_NUMERICSERV) != 0) {
100 return;
101 }
102
103 if (send_msg_channel_open_init(fd, &chan_tcpremote) == DROPBEAR_SUCCESS) {
104
105 buf_putstring(ses.writepayload, tcpinfo->addr,
106 strlen(tcpinfo->addr));
107 buf_putint(ses.writepayload, tcpinfo->port);
108 buf_putstring(ses.writepayload, ipstring, strlen(ipstring));
109 buf_putint(ses.writepayload, atol(portstring));
110 encrypt_packet();
111
112 } else {
113 /* XXX debug? */
114 close(fd);
115 }
116 }
117
118 static void cleanupremote(struct Listener *listener) {
119
120 struct RemoteTCP *tcpinfo = (struct RemoteTCP*)(listener->typedata);
121
122 m_free(tcpinfo->addr);
123 m_free(tcpinfo);
124 }
125
126 static void send_msg_request_success() {
127
128 CHECKCLEARTOWRITE();
129 buf_putbyte(ses.writepayload, SSH_MSG_REQUEST_SUCCESS);
130 encrypt_packet();
131
132 }
133
134 static void send_msg_request_failure() {
135
136 CHECKCLEARTOWRITE();
137 buf_putbyte(ses.writepayload, SSH_MSG_REQUEST_FAILURE);
138 encrypt_packet();
139
140 }
141
142 static int matchtcp(void* typedata1, void* typedata2) {
143
144 const struct RemoteTCP *info1 = (struct RemoteTCP*)typedata1;
145 const struct RemoteTCP *info2 = (struct RemoteTCP*)typedata2;
146
147 return info1->port == info2->port
148 && (strcmp(info1->addr, info2->addr) == 0);
149 }
150
151 static int cancelremotetcp() {
152
153 int ret = DROPBEAR_FAILURE;
154 unsigned char * bindaddr = NULL;
155 unsigned int addrlen;
156 unsigned int port;
157 struct Listener * listener = NULL;
158 struct RemoteTCP tcpinfo;
159
160 TRACE(("enter cancelremotetcp"));
161
162 bindaddr = buf_getstring(ses.payload, &addrlen);
163 if (addrlen > MAX_IP_LEN) {
164 TRACE(("addr len too long: %d", addrlen));
165 goto out;
166 }
167
168 port = buf_getint(ses.payload);
169
170 tcpinfo.addr = bindaddr;
171 tcpinfo.port = port;
172 listener = get_listener(CHANNEL_ID_TCPFORWARDED, &tcpinfo, matchtcp);
173 if (listener) {
174 remove_listener( listener );
175 ret = DROPBEAR_SUCCESS;
176 }
177
178 out:
179 m_free(bindaddr);
180 TRACE(("leave cancelremotetcp"));
181 return ret;
182 }
183
184 static int remotetcpreq() {
185
186 int ret = DROPBEAR_FAILURE;
187 unsigned char * bindaddr = NULL;
188 unsigned int addrlen;
189 unsigned int port;
190
191 TRACE(("enter remotetcpreq"));
192
193 bindaddr = buf_getstring(ses.payload, &addrlen);
194 if (addrlen > MAX_IP_LEN) {
195 TRACE(("addr len too long: %d", addrlen));
196 goto out;
197 }
198
199 port = buf_getint(ses.payload);
200
201 if (port == 0) {
202 dropbear_log(LOG_INFO, "Server chosen tcpfwd ports are unsupported");
203 goto out;
204 }
205
206 if (port < 1 || port > 65535) {
207 TRACE(("invalid port: %d", port));
208 goto out;
209 }
210
211 /* XXX matt - server change
212 if (ses.authstate.pw->pw_uid != 0
213 && port < IPPORT_RESERVED) {
214 TRACE(("can't assign port < 1024 for non-root"));
215 goto out;
216 }
217 */
218
219 ret = listen_tcpfwd(bindaddr, port);
220
221 out:
222 if (ret == DROPBEAR_FAILURE) {
223 /* we only free it if a listener wasn't created, since the listener
224 * has to remember it if it's to be cancelled */
225 m_free(bindaddr);
226 }
227 TRACE(("leave remotetcpreq"));
228 return ret;
229 }
230
231 static int listen_tcpfwd(unsigned char* bindaddr, unsigned int port) {
232
233 struct RemoteTCP * tcpinfo = NULL;
234 char portstring[6]; /* "65535\0" */
235 struct addrinfo *res = NULL, *ai = NULL;
236 struct addrinfo hints;
237 int sock = -1;
238 struct Listener *listener = NULL;
239
240 TRACE(("enter listen_tcpfwd"));
241
242 /* first we try to bind, so don't need to do so much cleanup on failure */
243 snprintf(portstring, sizeof(portstring), "%d", port);
244 memset(&hints, 0x0, sizeof(hints));
245 hints.ai_socktype = SOCK_STREAM;
246 hints.ai_family = PF_INET;
247 hints.ai_flags = AI_PASSIVE | AI_NUMERICHOST;
248
249 if (getaddrinfo(bindaddr, portstring, &hints, &res) < 0) {
250 TRACE(("leave listen_tcpfwd: getaddrinfo failed: %s",
251 strerror(errno)));
252 goto done;
253 }
254
255 /* find the first one which works */
256 for (ai = res; ai != NULL; ai = ai->ai_next) {
257 if (ai->ai_family != PF_INET && ai->ai_family != PF_INET6) {
258 continue;
259 }
260
261 sock = socket(ai->ai_family, SOCK_STREAM, 0);
262 if (sock < 0) {
263 TRACE(("socket failed: %s", strerror(errno)));
264 goto fail;
265 }
266
267 if (bind(sock, ai->ai_addr, ai->ai_addrlen) < 0) {
268 TRACE(("bind failed: %s", strerror(errno)));
269 goto fail;
270 }
271
272 if (listen(sock, 20) < 0) {
273 TRACE(("listen failed: %s", strerror(errno)));
274 goto fail;
275 }
276
277 if (fcntl(sock, F_SETFL, O_NONBLOCK) < 0) {
278 TRACE(("fcntl nonblocking failed: %s", strerror(errno)));
279 goto fail;
280 }
281
282 /* success */
283 break;
284
285 fail:
286 close(sock);
287 }
288
289
290 if (ai == NULL) {
291 TRACE(("no successful sockets"));
292 goto done;
293 }
294
295 tcpinfo = (struct RemoteTCP*)m_malloc(sizeof(struct RemoteTCP));
296 tcpinfo->addr = bindaddr;
297 tcpinfo->port = port;
298
299 listener = new_listener(sock, CHANNEL_ID_TCPFORWARDED, tcpinfo,
300 acceptremote, cleanupremote);
301
302 if (listener == NULL) {
303 m_free(tcpinfo);
304 }
305
306 done:
307 if (res) {
308 freeaddrinfo(res);
309 }
310
311 TRACE(("leave listen_tcpfwd"));
312 if (listener == NULL) {
313 return DROPBEAR_FAILURE;
314 } else {
315 return DROPBEAR_SUCCESS;
316 }
317 }
318
319 #endif /* DISABLE_REMOTETCPFWD */