/*
3APA3A simpliest proxy server
(c) 2002-2006 by ZARAZA <3APA3A@security.nnov.ru>
please read License Agreement
$Id: ftppr.c,v 1.21 2006/03/10 19:25:48 vlad Exp $
*/
#include "proxy.h"
#define RETURN(xxx) { param->res = xxx; goto CLEANRET; }
#define BUFSIZE 2048
void * ftpprchild(void * data) {
#define param ((struct clientparam*)data)
int i=0, res;
unsigned char buf[BUFSIZE];
unsigned char *se;
int status = 0;
int inbuf;
int pasv = 0;
SOCKET sc = INVALID_SOCKET, ss = INVALID_SOCKET, clidatasock = INVALID_SOCKET;
SASIZETYPE sasize;
char * req = NULL;
struct linger lg;
struct pollfd fds;
param->ctrlsock = param->clisock;
param->operation = CONNECT;
lg.l_onoff = 1;
lg.l_linger = conf.timeouts[STRING_L];;
if(socksend(param->clisock, (unsigned char *)"220 Ready\r\n", 11, conf.timeouts[STRING_S])!=11) {RETURN (801);}
for(;;){
i = sockgetlinebuf(param, CLIENT, buf, BUFSIZE - 10, '\n', conf.timeouts[CONNECTION_S]);
if(!i) {
RETURN(0);
}
if(i<4) {RETURN(802);}
buf[i] = 0;
if ((se=(unsigned char *)strchr((char *)buf, '\r'))) *se = 0;
if (req) myfree (req);
req = NULL;
if (!strncasecmp((char *)buf, "OPEN ", 5)){
if(parsehostname((char *)buf+5, param, 21)){RETURN(803);}
if(param->remsock != INVALID_SOCKET) {
shutdown(param->remsock, SHUT_RDWR);
closesocket(param->remsock);
param->remsock = INVALID_SOCKET;
}
if((res = (*param->authfunc)(param))) {RETURN(res);}
if(socksend(param->ctrlsock, (unsigned char *)"220 Ready\r\n", 11, conf.timeouts[STRING_S])!=11) {RETURN (801);}
status = 1;
}
else if (!strncasecmp((char *)buf, "USER ", 5)){
if(!param->hostname && param->remsock == INVALID_SOCKET) {
if(parseconnusername((char *)buf +5, param, 0, 21)){RETURN(804);}
}
else if(parseusername((char *)buf + 5, param, 0)) {RETURN(805);}
if(!status){
if((res = (*param->authfunc)(param))) {RETURN(res);}
}
if(socksend(param->ctrlsock, (unsigned char *)"331 ok\r\n", 8, conf.timeouts[STRING_S])!=8) {RETURN (807);}
status = 2;
}
else if (!strncasecmp((char *)buf, "PASS ", 5)){
param->extpassword = (unsigned char *)mystrdup((char *)buf+5);
inbuf = BUFSIZE;
res = ftplogin(param, (char *)buf, &inbuf);
param->res = res;
if(inbuf && inbuf != BUFSIZE && socksend(param->ctrlsock, buf, inbuf, conf.timeouts[STRING_S])!=inbuf) {RETURN (807);}
if(!res) status = 3;
sprintf((char *)buf, "%.64s@%.128s%c%hu", param->extusername, param->hostname, (ntohs(param->sins.sin_port)==21)?0:':', ntohs(param->sins.sin_port));
req = mystrdup((char *)buf);
}
else if (status >= 3 && (
(!strncasecmp((char *)buf, "PASV", 4) && (pasv = 1)) ||
(!strncasecmp((char *)buf, "PORT ", 5) && !(pasv = 0))
)){
if(sc != INVALID_SOCKET) {
shutdown(sc, SHUT_RDWR);
closesocket(sc);
sc = INVALID_SOCKET;
}
if(ss != INVALID_SOCKET) {
shutdown(ss, SHUT_RDWR);
closesocket(ss);
ss = INVALID_SOCKET;
}
if ((clidatasock=socket(AF_INET, SOCK_STREAM, IPPROTO_TCP)) == INVALID_SOCKET) {RETURN(821);}
sasize = sizeof(struct sockaddr_in);
if (pasv) {
if(getsockname(param->clisock, (struct sockaddr *)¶m->sinc, &sasize)){RETURN(824);}
param->sinc.sin_port = 0;
if(bind(clidatasock, (struct sockaddr *)¶m->sinc, sasize)){RETURN(822);}
if(listen(clidatasock, 1)) {RETURN(823);}
if(getsockname(clidatasock, (struct sockaddr *)¶m->sinc, &sasize)){RETURN(824);}
sprintf((char *)buf, "227 OK (%u,%u,%u,%u,%u,%u)\r\n",
(unsigned)(((unsigned char *)(¶m->sinc.sin_addr.s_addr))[0]),
(unsigned)(((unsigned char *)(¶m->sinc.sin_addr.s_addr))[1]),
(unsigned)(((unsigned char *)(¶m->sinc.sin_addr.s_addr))[2]),
(unsigned)(((unsigned char *)(¶m->sinc.sin_addr.s_addr))[3]),
(unsigned)(((unsigned char *)(¶m->sinc.sin_port))[0]),
(unsigned)(((unsigned char *)(¶m->sinc.sin_port))[1])
);
if(socksend(param->clisock, buf, (int)strlen((char *)buf), conf.timeouts[STRING_S])!=(int)strlen((char *)buf)) {RETURN (825);}
}
else {
unsigned long b1, b2, b3, b4;
unsigned short b5, b6;
if(sscanf((char *)buf+5, "%lu,%lu,%lu,%lu,%hu,%hu", &b1, &b2, &b3, &b4, &b5, &b6)!=6) {RETURN(828);}
param->sinc.sin_family = AF_INET;
param->sinc.sin_port = htons((unsigned short)((b5<<8)^b6));
param->sinc.sin_addr.s_addr = htonl((b1<<24)^(b2<<16)^(b3<<8)^b4);
if(connect(clidatasock, (struct sockaddr *)¶m->sinc, sasize)) {
closesocket(clidatasock);
clidatasock = INVALID_SOCKET;
RETURN(826);
}
if(socksend(param->clisock, (unsigned char *)"200 OK\r\n", 8, conf.timeouts[STRING_S]) != 8) {RETURN (827);}
}
status = 4;
}
else if (status == 4 && (
!strncasecmp((char *)buf, "RETR ", 5) ||
!strncasecmp((char *)buf, "LIST", 4) ||
!strncasecmp((char *)buf, "STOR ", 5)
)){
int arg = (buf[4] && buf[5])? 1:0;
if(pasv){
fds.fd = clidatasock;
fds.events = POLLIN;
res = poll (&fds, 1, conf.timeouts[STRING_L]*1000);
if(res != 1) {RETURN(826);}
sasize = sizeof(struct sockaddr_in);
ss = accept(clidatasock, (struct sockaddr *)¶m->sinc, &sasize);
shutdown(clidatasock, SHUT_RDWR);
closesocket(clidatasock);
clidatasock = ss;
ss = INVALID_SOCKET;
}
if(clidatasock == INVALID_SOCKET){RETURN(828);}
req = mystrdup((char *)buf);
buf[4] = 0;
status = 3;
ss = ftpcommand(param, buf, arg? buf+5 : NULL);
if (ss == INVALID_SOCKET) {
if(socksend(param->ctrlsock, (unsigned char *)"425 err\r\n", 9, conf.timeouts[STRING_S])!=9) {RETURN (831);}
continue;
}
sc = param->remsock;
param->remsock = ss;
setsockopt(param->remsock, SOL_SOCKET, SO_LINGER, (unsigned char *)&lg, sizeof(lg));
setsockopt(clidatasock, SOL_SOCKET, SO_LINGER, (unsigned char *)&lg, sizeof(lg));
if(socksend(param->clisock, (unsigned char *)"125 data\r\n", 10, conf.timeouts[STRING_S]) != 10) {
param->remsock = INVALID_SOCKET;
RETURN (832);
}
param->clisock = clidatasock;
res = sockmap(param, conf.timeouts[CONNECTION_S]);
param->clisock = param->ctrlsock;
if(param->remsock != INVALID_SOCKET) {
shutdown (param->remsock, SHUT_RDWR);
closesocket(param->remsock);
}
param->remsock = sc;
sc = INVALID_SOCKET;
ss = INVALID_SOCKET;
if(clidatasock != INVALID_SOCKET){
shutdown (clidatasock, SHUT_RDWR);
closesocket(clidatasock);
clidatasock = INVALID_SOCKET;
}
while((i = sockgetlinebuf(param, SERVER, buf, BUFSIZE, '\n', conf.timeouts[STRING_L])) > 3){
param->statssrv += i;
if(socksend(param->clisock, buf, i, conf.timeouts[STRING_S])!=i) {RETURN(833);}
if(isnumber(*buf) && buf[3] != '-') break;
}
if(i < 3) {RETURN(834);}
}
else {
if(status < 3) {
if(socksend(param->remsock, (unsigned char *)"530 login\r\n", 11, conf.timeouts[STRING_S])!=1) {RETURN (810);}
continue;
}
if(!strncasecmp((char *)buf, "QUIT", 4)) status = 5;
if(!strncasecmp((char *)buf, "CWD ", 4)) req = mystrdup((char *)buf);
i = strlen((char *)buf);
buf[i++] = '\r';
buf[i++] = '\n';
if(socksend(param->remsock, buf, i, conf.timeouts[STRING_S])!=i) {RETURN (811);}
param->statscli += i;
while((i = sockgetlinebuf(param, SERVER, buf, BUFSIZE, '\n', conf.timeouts[STRING_L])) > 0){
param->statssrv += i;
if(socksend(param->clisock, buf, i, conf.timeouts[STRING_S])!=i) {RETURN (812);}
if(i > 4 && isnumber(*buf) && buf[3] != '-') break;
}
if(status == 5) {RETURN (0);}
if(i < 3) {RETURN (813);}
}
sasize = sizeof(struct sockaddr_in);
if(getpeername(param->ctrlsock, (struct sockaddr *)¶m->sinc, &sasize)){RETURN(819);}
if(req && (param->statscli || param->statssrv)){
(*param->logfunc)(param, (unsigned char *)req);
}
}
CLEANRET:
if(sc != INVALID_SOCKET) {
shutdown(sc, SHUT_RDWR);
closesocket(sc);
}
if(ss != INVALID_SOCKET) {
shutdown(ss, SHUT_RDWR);
closesocket(ss);
}
if(clidatasock != INVALID_SOCKET) {
shutdown(clidatasock, SHUT_RDWR);
closesocket(clidatasock);
}
sasize = sizeof(struct sockaddr_in);
getpeername(param->ctrlsock, (struct sockaddr *)¶m->sinc, &sasize);
if(param->res != 0 || param->statscli || param->statssrv ){
(*param->logfunc)(param, (unsigned char *)((req && (param->res > 802))? req:NULL));
}
if(req) myfree(req);
freeparam(param);
return (NULL);
}
#ifdef WITHMAIN
struct proxydef childdef = {
ftpprchild,
21,
0,
S_FTPPR,
""
};
#include "proxymain.c"
#endif
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