1 /*
2 3APA3A simpliest proxy server
3 (c) 2002-2016 by Vladimir Dubrovin <3proxy@3proxy.ru>
4
5 please read License Agreement
6
7 */
8
9 #include "proxy.h"
10
11 #define RETURN(xxx) { param->res = xxx; goto CLEANRET; }
12 #define BUFSIZE 2048
13
ftpprchild(struct clientparam * param)14 void * ftpprchild(struct clientparam* param) {
15 int i=0, res;
16 unsigned char *buf;
17 unsigned char *se;
18 int status = 0;
19 int inbuf;
20 int pasv = 0;
21 SOCKET sc = INVALID_SOCKET, ss = INVALID_SOCKET, clidatasock = INVALID_SOCKET;
22 SASIZETYPE sasize;
23 char * req = NULL;
24 struct linger lg;
25 struct pollfd fds;
26
27 if(!(buf = myalloc(BUFSIZE))) RETURN(876);
28 param->ctrlsock = param->clisock;
29 param->operation = CONNECT;
30 lg.l_onoff = 1;
31 lg.l_linger = conf.timeouts[STRING_L];;
32 if(socksend(param->ctrlsock, (unsigned char *)"220 Ready\r\n", 11, conf.timeouts[STRING_S])!=11) {RETURN (801);}
33 for(;;){
34 i = sockgetlinebuf(param, CLIENT, buf, BUFSIZE - 10, '\n', conf.timeouts[CONNECTION_S]);
35 if(!i) {
36 RETURN(0);
37 }
38 if(i<4) {RETURN(802);}
39 buf[i] = 0;
40 if ((se=(unsigned char *)strchr((char *)buf, '\r'))) *se = 0;
41 if (req) myfree (req);
42 req = NULL;
43
44 if (!strncasecmp((char *)buf, "OPEN ", 5)){
45 if(parsehostname((char *)buf+5, param, 21)){RETURN(803);}
46 if(param->remsock != INVALID_SOCKET) {
47 so._shutdown(param->remsock, SHUT_RDWR);
48 so._closesocket(param->remsock);
49 param->remsock = INVALID_SOCKET;
50 }
51 if((res = (*param->srv->authfunc)(param))) {RETURN(res);}
52 param->ctrlsocksrv = param->remsock;
53 if(socksend(param->ctrlsock, (unsigned char *)"220 Ready\r\n", 11, conf.timeouts[STRING_S])!=11) {RETURN (801);}
54 status = 1;
55 }
56 else if (!strncasecmp((char *)buf, "USER ", 5)){
57 if(parseconnusername((char *)buf +5, param, 0, 21)){RETURN(804);}
58 if(!status){
59 if((res = (*param->srv->authfunc)(param))) {RETURN(res);}
60 param->ctrlsocksrv = param->remsock;
61 }
62 if(socksend(param->ctrlsock, (unsigned char *)"331 ok\r\n", 8, conf.timeouts[STRING_S])!=8) {RETURN (807);}
63 status = 2;
64
65 }
66 else if (!strncasecmp((char *)buf, "PASS ", 5)){
67 param->extpassword = (unsigned char *)mystrdup((char *)buf+5);
68 inbuf = BUFSIZE;
69 res = ftplogin(param, (char *)buf, &inbuf);
70 param->res = res;
71 if(inbuf && inbuf != BUFSIZE && socksend(param->ctrlsock, buf, inbuf, conf.timeouts[STRING_S])!=inbuf) {RETURN (807);}
72 if(!res) status = 3;
73 sprintf((char *)buf, "%.128s@%.128s%c%hu", param->extusername, param->hostname, (ntohs(*SAPORT(¶m->sinsr))==21)?0:':', ntohs(*SAPORT(¶m->sinsr)));
74 req = mystrdup((char *)buf);
75 #ifndef WITHMAIN
76 {
77 int action, reqbufsize, reqsize;
78 reqbufsize = BUFSIZE;
79 reqsize = (int)strlen((char *)buf) + 1;
80
81 action = handlereqfilters(param, &buf, &reqbufsize, 0, &reqsize);
82 if(action == HANDLED){
83 RETURN(0);
84 }
85 if(action != PASS) RETURN(877);
86 }
87 #endif
88 }
89 else if (status >= 3 && (
90 (!strncasecmp((char *)buf, "PASV", 4) && (pasv = 1)) ||
91 (!strncasecmp((char *)buf, "EPSV", 4) && (pasv = 2)) ||
92 (!strncasecmp((char *)buf, "PORT ", 5) && !(pasv = 0))
93 )){
94 #ifndef WITHMAIN
95 {
96 int action, reqbufsize, reqsize;
97 reqbufsize = BUFSIZE;
98 reqsize = (int)strlen((char *)buf) + 1;
99
100 action = handlehdrfilterscli(param, &buf, &reqbufsize, 0, &reqsize);
101 if(action == HANDLED){
102 RETURN(0);
103 }
104 if(action != PASS) RETURN(878);
105 }
106 #endif
107 if(sc != INVALID_SOCKET) {
108 so._shutdown(sc, SHUT_RDWR);
109 so._closesocket(sc);
110 sc = INVALID_SOCKET;
111 }
112 if(ss != INVALID_SOCKET) {
113 so._shutdown(ss, SHUT_RDWR);
114 so._closesocket(ss);
115 ss = INVALID_SOCKET;
116 }
117 if(clidatasock != INVALID_SOCKET) {
118 so._shutdown(clidatasock, SHUT_RDWR);
119 so._closesocket(clidatasock);
120 clidatasock = INVALID_SOCKET;
121 }
122 if ((clidatasock=socket(SASOCK(¶m->sincl), SOCK_STREAM, IPPROTO_TCP)) == INVALID_SOCKET) {RETURN(821);}
123 *SAPORT(¶m->sincl) = 0;
124 if(so._bind(clidatasock, (struct sockaddr *)¶m->sincl, SASIZE(¶m->sincl))){RETURN(822);}
125 if (pasv) {
126 if(so._listen(clidatasock, 1)) {RETURN(823);}
127 sasize = sizeof(param->sincl);
128 if(so._getsockname(clidatasock, (struct sockaddr *)¶m->sincl, &sasize)){RETURN(824);}
129 if(pasv == 1){
130 if(*SAFAMILY(¶m->sincl) == AF_INET)
131 sprintf((char *)buf, "227 OK (%u,%u,%u,%u,%u,%u)\r\n",
132 (unsigned)(((unsigned char *)(SAADDR(¶m->sincl)))[0]),
133 (unsigned)(((unsigned char *)(SAADDR(¶m->sincl)))[1]),
134 (unsigned)(((unsigned char *)(SAADDR(¶m->sincl)))[2]),
135 (unsigned)(((unsigned char *)(SAADDR(¶m->sincl)))[3]),
136 (unsigned)(((unsigned char *)(SAPORT(¶m->sincl)))[0]),
137 (unsigned)(((unsigned char *)(SAPORT(¶m->sincl)))[1])
138 );
139 else sprintf((char *)buf, "227 OK (127,0,0,1,%u,%u)\r\n",
140 (unsigned)(((unsigned char *)(SAPORT(¶m->sincl)))[0]),
141 (unsigned)(((unsigned char *)(SAPORT(¶m->sincl)))[1])
142 );
143 }
144 else {
145 sprintf((char *)buf, "229 OK (|||%u|)\r\n",
146 (unsigned)ntohs(*SAPORT(¶m->sincl))
147 );
148 }
149 }
150 else {
151 unsigned long b1, b2, b3, b4;
152 unsigned short b5, b6;
153
154 if(sscanf((char *)buf+5, "%lu,%lu,%lu,%lu,%hu,%hu", &b1, &b2, &b3, &b4, &b5, &b6)!=6) {RETURN(828);}
155 *SAPORT(¶m->sincr) = htons((unsigned short)((b5<<8)^b6));
156 if(connectwithpoll(clidatasock, (struct sockaddr *)¶m->sincr, SASIZE(¶m->sincr),CONNECT_TO)) {
157 so._closesocket(clidatasock);
158 clidatasock = INVALID_SOCKET;
159 RETURN(826);
160 }
161 sprintf((char *)buf, "200 OK\r\n");
162 }
163 #ifndef WITHMAIN
164 {
165 int action, reqbufsize, reqsize;
166 reqbufsize = BUFSIZE;
167 reqsize = (int)strlen((char *)buf) + 1;
168
169 action = handlehdrfilterssrv(param, &buf, &reqbufsize, 0, &reqsize);
170 if(action == HANDLED){
171 RETURN(0);
172 }
173 if(action != PASS) RETURN(879);
174 }
175 #endif
176 if(socksend(param->ctrlsock, buf, (int)strlen((char *)buf), conf.timeouts[STRING_S])!=(int)strlen((char *)buf)) {RETURN (825);}
177 status = 4;
178 }
179 else if (status == 4 && (
180 !(strncasecmp((char *)buf, "RETR ", 5) && (param->operation = FTP_GET)) ||
181 !(strncasecmp((char *)buf, "LIST", 4) && (param->operation = FTP_LIST))||
182 !(strncasecmp((char *)buf, "NLST ", 5) && (param->operation = FTP_LIST)) ||
183 !(strncasecmp((char *)buf, "MLSD", 4) && (param->operation = FTP_LIST)) ||
184 !(strncasecmp((char *)buf, "APPE ", 5) && (param->operation = FTP_PUT)) ||
185 !(strncasecmp((char *)buf, "STOR ", 5) && (param->operation = FTP_PUT))
186 )){
187 int arg = (buf[4] && buf[5])? 1:0;
188 int ressent = 0;
189
190
191 #ifndef WITHMAIN
192 {
193 int action, reqbufsize, reqsize;
194 reqbufsize = BUFSIZE;
195 reqsize = (int)strlen((char *)buf) + 1;
196
197 action = handlehdrfilterscli(param, &buf, &reqbufsize, 0, &reqsize);
198 if(action == HANDLED){
199 RETURN(0);
200 }
201 if(action != PASS) RETURN(880);
202 }
203 #endif
204 if(clidatasock == INVALID_SOCKET) { RETURN (829);}
205 if(pasv){
206
207 memset(&fds, 0, sizeof(fds));
208 fds.fd = clidatasock;
209 fds.events = POLLIN;
210
211 res = so._poll (&fds, 1, conf.timeouts[STRING_L]*1000);
212 if(res != 1) {
213 RETURN(857);
214 }
215 sasize = sizeof(param->sincr);
216 ss = so._accept(clidatasock, (struct sockaddr *)¶m->sincr, &sasize);
217 if (ss == INVALID_SOCKET) { RETURN (858);}
218 so._shutdown(clidatasock, SHUT_RDWR);
219 so._closesocket(clidatasock);
220 clidatasock = ss;
221 ss = INVALID_SOCKET;
222 }
223 if(clidatasock == INVALID_SOCKET){RETURN(828);}
224 req = mystrdup((char *)buf);
225 buf[4] = 0;
226 status = 3;
227 ss = ftpcommand(param, buf, arg? buf+5 : NULL);
228 if (ss == INVALID_SOCKET) {
229 so._shutdown(clidatasock, SHUT_RDWR);
230 so._closesocket(clidatasock);
231 clidatasock = INVALID_SOCKET;
232
233 if(socksend(param->ctrlsock, (unsigned char *)"550 err\r\n", 9, conf.timeouts[STRING_S])!=9) {RETURN (831);}
234 continue;
235 }
236
237 if(socksend(param->ctrlsock, (unsigned char *)"125 data\r\n", 10, conf.timeouts[STRING_S]) != 10) {
238 param->remsock = INVALID_SOCKET;
239 RETURN (832);
240 }
241 if(param->srvoffset < param->srvinbuf)while((i = sockgetlinebuf(param, SERVER, buf, BUFSIZE, '\n', 0)) > 3){
242 if(socksend(param->ctrlsock, buf, i, conf.timeouts[STRING_S])!=i) {RETURN(833);}
243 if(isnumber(*buf) && buf[3] != '-') {
244 ressent = 1;
245 break;
246 }
247 }
248 sc = param->remsock;
249 param->remsock = ss;
250 so._setsockopt(param->remsock, SOL_SOCKET, SO_LINGER, (char *)&lg, sizeof(lg));
251 so._setsockopt(clidatasock, SOL_SOCKET, SO_LINGER, (char *)&lg, sizeof(lg));
252 param->clisock = clidatasock;
253 res = mapsocket(param, conf.timeouts[CONNECTION_S]);
254 if(param->remsock != INVALID_SOCKET) {
255 so._shutdown (param->remsock, SHUT_RDWR);
256 so._closesocket(param->remsock);
257 }
258 if(param->clisock != INVALID_SOCKET) {
259 so._shutdown (param->clisock, SHUT_RDWR);
260 so._closesocket(param->clisock);
261 }
262 param->clisock = param->ctrlsock;
263 param->remsock = sc;
264 sc = INVALID_SOCKET;
265 ss = INVALID_SOCKET;
266 clidatasock = INVALID_SOCKET;
267 if(!ressent){
268 while((i = sockgetlinebuf(param, SERVER, buf, BUFSIZE, '\n', conf.timeouts[STRING_L])) > 3){
269 if(socksend(param->ctrlsock, buf, i, conf.timeouts[STRING_S])!=i) {RETURN(833);}
270 if(isnumber(*buf) && buf[3] != '-') break;
271 }
272 if(i < 3) {RETURN(834);}
273 }
274 }
275 else {
276 if(status < 3) {
277 if(socksend(param->remsock, (unsigned char *)"530 login\r\n", 11, conf.timeouts[STRING_S])!=1) {RETURN (810);}
278 continue;
279 }
280 if(!strncasecmp((char *)buf, "QUIT", 4)) status = 5;
281 if(!strncasecmp((char *)buf, "CWD ", 4)) req = mystrdup((char *)buf);
282 i = (int)strlen((char *)buf);
283 buf[i++] = '\r';
284 buf[i++] = '\n';
285 if(socksend(param->remsock, buf, i, conf.timeouts[STRING_S])!=i) {RETURN (811);}
286 param->statscli64+=(i);
287 param->nwrites++;
288 while((i = sockgetlinebuf(param, SERVER, buf, BUFSIZE, '\n', conf.timeouts[STRING_L])) > 0){
289 if(socksend(param->ctrlsock, buf, i, conf.timeouts[STRING_S])!=i) {RETURN (812);}
290 if(i > 4 && isnumber(*buf) && buf[3] != '-') break;
291 }
292 if(status == 5) {RETURN (0);}
293 if(i < 3) {RETURN (813);}
294 }
295 sasize = sizeof(param->sincr);
296 if(so._getpeername(param->ctrlsock, (struct sockaddr *)¶m->sincr, &sasize)){RETURN(819);}
297 if(req && (param->statscli64 || param->statssrv64)){
298 dolog(param, (unsigned char *)req);
299 }
300 }
301
302 CLEANRET:
303
304 if(sc != INVALID_SOCKET) {
305 so._shutdown(sc, SHUT_RDWR);
306 so._closesocket(sc);
307 }
308 if(ss != INVALID_SOCKET) {
309 so._shutdown(ss, SHUT_RDWR);
310 so._closesocket(ss);
311 }
312 if(clidatasock != INVALID_SOCKET) {
313 so._shutdown(clidatasock, SHUT_RDWR);
314 so._closesocket(clidatasock);
315 }
316 sasize = sizeof(param->sincr);
317 so._getpeername(param->ctrlsock, (struct sockaddr *)¶m->sincr, &sasize);
318 if(param->res != 0 || param->statscli64 || param->statssrv64 ){
319 dolog(param, (unsigned char *)((req && (param->res > 802))? req:NULL));
320 }
321 if(req) myfree(req);
322 if(buf) myfree(buf);
323 freeparam(param);
324 return (NULL);
325 }
326
327 #ifdef WITHMAIN
328 struct proxydef childdef = {
329 ftpprchild,
330 21,
331 0,
332 S_FTPPR,
333 " -hdefault_host[:port] - use this host and port as default if no host specified\n"
334 };
335 #include "proxymain.c"
336 #endif
337