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MtProtoKit: fix pre-auth handshake reads could hang forever #181

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MtProtoKit: fix pre-auth handshake reads could hang forever #181

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46 changes: 34 additions & 12 deletions submodules/MtProtoKit/Sources/MTTcpConnection.m
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Original file line number Diff line number Diff line change
Expand Up @@ -781,8 +781,30 @@ - (void)socketDidDisconnect:(GCDAsyncSocket *)socket withError:(NSError *)error
}
}

// MARK: Swiftgram
// Upstream extends read timeouts indefinitely (-1.0) here. That's fine once regular
// API requests are flowing, since MTRequestMessageService's request-level watchdog can
// force a transport reset if one stalls. But this only covers the explicit SOCKS5
// pre-auth handshake reads below - nothing else. A stalled proxy that accepts
// the TCP connection but never answers those hangs forever with zero protection.
// Bound only that handshake phase here, everything past it stays unbounded like upstream.
- (NSTimeInterval)socket:(GCDAsyncSocket *)sock shouldTimeoutReadWithTag:(long)tag elapsed:(NSTimeInterval)elapsed bytesDone:(NSUInteger)length {
return -1.0;
switch (tag) {
case MTTcpSocksLogin:
case MTTcpSocksRequest:
case MTTcpSocksReceiveBindAddr4:
case MTTcpSocksReceiveBindAddr6:
case MTTcpSocksReceiveBindAddrDomainNameLength:
case MTTcpSocksReceiveBindAddrDomainName:
case MTTcpSocksReceiveBindAddrPort:
case MTTcpSocksReceiveAuthResponse:
case MTTcpSocksReceiveHelloResponse:
case MTTcpSocksReceiveHelloResponse1:
case MTTcpSocksReceiveHelloResponse2:
return 0.0;
default:
return -1.0;
}
}

@end
Expand Down Expand Up @@ -1109,7 +1131,7 @@ - (void)start
memcpy(((uint8_t *)helloData.mutableBytes) + 11, cHMAC, CC_SHA256_DIGEST_LENGTH);

[strongSelf->_socket writeData:helloData];
[strongSelf->_socket readDataToLength:5 withTimeout:-1 tag:MTTcpSocksReceiveHelloResponse];
[strongSelf->_socket readDataToLength:5 withTimeout:15.0 tag:MTTcpSocksReceiveHelloResponse];
} else {
strongSelf->_readyToSendData = true;
[strongSelf sendDataIfNeeded];
Expand All @@ -1130,7 +1152,7 @@ - (void)start
req.Methods[1] = 0x02;
}
[strongSelf->_socket writeData:[NSData dataWithBytes:&req length:2 + req.NumberOfMethods]];
[strongSelf->_socket readDataToLength:sizeof(struct socks5_ident_resp) withTimeout:-1 tag:MTTcpSocksLogin];
[strongSelf->_socket readDataToLength:sizeof(struct socks5_ident_resp) withTimeout:15.0 tag:MTTcpSocksLogin];
}
}];
} file:__FILE_NAME__ line:__LINE__]];
Expand Down Expand Up @@ -1479,7 +1501,7 @@ - (void)requestSocksConnection {
[reqData appendBytes:&port length:2];

[_socket writeData:reqData];
[_socket readDataToLength:4 withTimeout:-1 tag:MTTcpSocksRequest];
[_socket readDataToLength:4 withTimeout:15.0 tag:MTTcpSocksRequest];
}

- (void)connectionInterfaceDidReadData:(NSData *)rawData withTag:(long)tag networkType:(int32_t)networkType
Expand Down Expand Up @@ -1535,7 +1557,7 @@ - (void)connectionInterfaceDidReadData:(NSData *)rawData withTag:(long)tag netwo
[reqData appendData:passwordData];

[_socket writeData:reqData];
[_socket readDataToLength:2 withTimeout:-1 tag:MTTcpSocksReceiveAuthResponse];
[_socket readDataToLength:2 withTimeout:15.0 tag:MTTcpSocksReceiveAuthResponse];
} else {
[self requestSocksConnection];
}
Expand All @@ -1562,15 +1584,15 @@ - (void)connectionInterfaceDidReadData:(NSData *)rawData withTag:(long)tag netwo

switch (resp.AddrType) {
case 1: {
[_socket readDataToLength:sizeof(struct in_addr) withTimeout:-1 tag:MTTcpSocksReceiveBindAddr4];
[_socket readDataToLength:sizeof(struct in_addr) withTimeout:15.0 tag:MTTcpSocksReceiveBindAddr4];
break;
}
case 3: {
[_socket readDataToLength:1 withTimeout:-1 tag:MTTcpSocksReceiveBindAddrDomainNameLength];
[_socket readDataToLength:1 withTimeout:15.0 tag:MTTcpSocksReceiveBindAddrDomainNameLength];
break;
}
case 4: {
[_socket readDataToLength:sizeof(struct in6_addr) withTimeout:-1 tag:MTTcpSocksReceiveBindAddr6];
[_socket readDataToLength:sizeof(struct in6_addr) withTimeout:15.0 tag:MTTcpSocksReceiveBindAddr6];
break;
}
default: {
Expand All @@ -1595,11 +1617,11 @@ - (void)connectionInterfaceDidReadData:(NSData *)rawData withTag:(long)tag netwo
uint8_t length = 0;
[rawData getBytes:&length length:1];

[_socket readDataToLength:(int)length withTimeout:-1 tag:MTTcpSocksReceiveBindAddrDomainName];
[_socket readDataToLength:(int)length withTimeout:15.0 tag:MTTcpSocksReceiveBindAddrDomainName];

return;
} else if (tag == MTTcpSocksReceiveBindAddrDomainName || tag == MTTcpSocksReceiveBindAddr4 || tag == MTTcpSocksReceiveBindAddr6) {
[_socket readDataToLength:2 withTimeout:-1 tag:MTTcpSocksReceiveBindAddrPort];
[_socket readDataToLength:2 withTimeout:15.0 tag:MTTcpSocksReceiveBindAddrPort];

return;
} else if (tag == MTTcpSocksReceiveBindAddrPort) {
Expand Down Expand Up @@ -1668,7 +1690,7 @@ - (void)connectionInterfaceDidReadData:(NSData *)rawData withTag:(long)tag netwo

_currentHelloResponse = [NSData dataWithData:rawData];

[_socket readDataToLength:((int)nextLength) + 9 + 2 withTimeout:-1 tag:MTTcpSocksReceiveHelloResponse1];
[_socket readDataToLength:((int)nextLength) + 9 + 2 withTimeout:15.0 tag:MTTcpSocksReceiveHelloResponse1];

return;
} else if (tag == MTTcpSocksReceiveHelloResponse1) {
Expand Down Expand Up @@ -1698,7 +1720,7 @@ - (void)connectionInterfaceDidReadData:(NSData *)rawData withTag:(long)tag netwo
[currentHelloResponse appendData:rawData];
_currentHelloResponse = currentHelloResponse;

[_socket readDataToLength:((int)nextLength) withTimeout:-1 tag:MTTcpSocksReceiveHelloResponse2];
[_socket readDataToLength:((int)nextLength) withTimeout:15.0 tag:MTTcpSocksReceiveHelloResponse2];
return;
} else if (tag == MTTcpSocksReceiveHelloResponse2) {
NSMutableData *currentHelloResponse = [[NSMutableData alloc] init];
Expand Down