bool receive_meta(connection_t *c) {
int oldlen, i, result;
int lenin, lenout, reqlen;
bool decrypted = false;
char inbuf[MAXBUFSIZE];
/* Strategy:
- Read as much as possible from the TCP socket in one go.
- Decrypt it.
- Check if a full request is in the input buffer.
- If yes, process request and remove it from the buffer,
then check again.
- If not, keep stuff in buffer and exit.
*/
lenin = recv(c->socket, c->buffer + c->buflen, MAXBUFSIZE - c->buflen, 0);
if(lenin <= 0) {
if(!lenin || !errno) {
ifdebug(CONNECTIONS) logger(LOG_NOTICE, "Connection closed by %s (%s)",
c->name, c->hostname);
} else if(sockwouldblock(sockerrno))
return true;
else
logger(LOG_ERR, "Metadata socket read error for %s (%s): %s",
c->name, c->hostname, sockstrerror(sockerrno));
return false;
}
oldlen = c->buflen;
c->buflen += lenin;
while(lenin > 0) {
/* Decrypt */
if(c->status.decryptin && !decrypted) {
result = EVP_DecryptUpdate(c->inctx, (unsigned char *)inbuf, &lenout, (unsigned char *)c->buffer + oldlen, lenin);
if(!result || lenout != lenin) {
logger(LOG_ERR, "Error while decrypting metadata from %s (%s): %s",
c->name, c->hostname, ERR_error_string(ERR_get_error(), NULL));
return false;
}
memcpy(c->buffer + oldlen, inbuf, lenin);
decrypted = true;
}
/* Are we receiving a TCPpacket? */
if(c->tcplen) {
if(c->tcplen <= c->buflen) {
if(!c->node) {
if(c->outgoing && proxytype == PROXY_SOCKS4 && c->allow_request == ID) {
if(c->buffer[0] == 0 && c->buffer[1] == 0x5a) {
ifdebug(CONNECTIONS) logger(LOG_DEBUG, "Proxy request granted");
} else {
logger(LOG_ERR, "Proxy request rejected");
return false;
}
} else if(c->outgoing && proxytype == PROXY_SOCKS5 && c->allow_request == ID) {
if(c->buffer[0] != 5) {
logger(LOG_ERR, "Invalid response from proxy server");
return false;
}
if(c->buffer[1] == (char)0xff) {
logger(LOG_ERR, "Proxy request rejected: unsuitable authentication method");
return false;
}
if(c->buffer[2] != 5) {
logger(LOG_ERR, "Invalid response from proxy server");
return false;
}
if(c->buffer[3] == 0) {
ifdebug(CONNECTIONS) logger(LOG_DEBUG, "Proxy request granted");
} else {
logger(LOG_ERR, "Proxy request rejected");
return false;
}
} else {
logger(LOG_ERR, "c->tcplen set but c->node is NULL!");
abort();
}
} else {
if(c->allow_request == ALL) {
receive_tcppacket(c, c->buffer, c->tcplen);
} else {
logger(LOG_ERR, "Got unauthorized TCP packet from %s (%s)", c->name, c->hostname);
return false;
}
}
c->buflen -= c->tcplen;
lenin -= c->tcplen - oldlen;
memmove(c->buffer, c->buffer + c->tcplen, c->buflen);
oldlen = 0;
c->tcplen = 0;
continue;
} else {
break;
}
}
/* Otherwise we are waiting for a request */
reqlen = 0;
for(i = oldlen; i < c->buflen; i++) {
if(c->buffer[i] == '\n') {
c->buffer[i] = '\0'; /* replace end-of-line by end-of-string so we can use sscanf */
reqlen = i + 1;
break;
}
}
if(reqlen) {
c->reqlen = reqlen;
if(!receive_request(c))
return false;
c->buflen -= reqlen;
lenin -= reqlen - oldlen;
memmove(c->buffer, c->buffer + reqlen, c->buflen);
oldlen = 0;
continue;
} else {
break;
}
}
if(c->buflen >= MAXBUFSIZE) {
logger(LOG_ERR, "Metadata read buffer overflow for %s (%s)",
c->name, c->hostname);
return false;
}
return true;
}
bool receive_meta(connection_t *c) {
int oldlen, i, result;
int lenin, lenout, reqlen;
bool decrypted = false;
char inbuf[MAXBUFSIZE];
/* Strategy:
- Read as much as possible from the TCP socket in one go.
- Decrypt it.
- Check if a full request is in the input buffer.
- If yes, process request and remove it from the buffer,
then check again.
- If not, keep stuff in buffer and exit.
*/
lenin = recv(c->socket, c->buffer + c->buflen, MAXBUFSIZE - c->buflen, 0);
if(lenin <= 0) {
if(!lenin || !errno) {
ifdebug(CONNECTIONS) logger(LOG_NOTICE, "Connection closed by %s (%s)",
c->name, c->hostname);
} else if(sockwouldblock(sockerrno))
return true;
else
logger(LOG_ERR, "Metadata socket read error for %s (%s): %s",
c->name, c->hostname, sockstrerror(sockerrno));
return false;
}
oldlen = c->buflen;
c->buflen += lenin;
while(lenin > 0) {
/* Decrypt */
if(c->status.decryptin && !decrypted) {
result = EVP_DecryptUpdate(c->inctx, (unsigned char *)inbuf, &lenout, (unsigned char *)c->buffer + oldlen, lenin);
if(!result || lenout != lenin) {
logger(LOG_ERR, "Error while decrypting metadata from %s (%s): %s",
c->name, c->hostname, ERR_error_string(ERR_get_error(), NULL));
return false;
}
memcpy(c->buffer + oldlen, inbuf, lenin);
decrypted = true;
}
/* Are we receiving a TCPpacket? */
if(c->tcplen) {
if(c->tcplen <= c->buflen) {
receive_tcppacket(c, c->buffer, c->tcplen);
c->buflen -= c->tcplen;
lenin -= c->tcplen - oldlen;
memmove(c->buffer, c->buffer + c->tcplen, c->buflen);
oldlen = 0;
c->tcplen = 0;
continue;
} else {
break;
}
}
/* Otherwise we are waiting for a request */
reqlen = 0;
for(i = oldlen; i < c->buflen; i++) {
if(c->buffer[i] == '\n') {
c->buffer[i] = '\0'; /* replace end-of-line by end-of-string so we can use sscanf */
reqlen = i + 1;
break;
}
}
if(reqlen) {
c->reqlen = reqlen;
if(!receive_request(c))
return false;
c->buflen -= reqlen;
lenin -= reqlen - oldlen;
memmove(c->buffer, c->buffer + reqlen, c->buflen);
oldlen = 0;
continue;
} else {
break;
}
}
if(c->buflen >= MAXBUFSIZE) {
logger(LOG_ERR, "Metadata read buffer overflow for %s (%s)",
c->name, c->hostname);
return false;
}
return true;
}
