Rename OpenVPNPacketFlow to OpenVPNPacketFlowBridge

2026-04-24 00:00:05 +08:00 · 2017-10-28 13:12:25 +03:00
parent a4d2004128
commit f7678976c5
4 changed files with 25 additions and 25 deletions
@@ -0,0 +1,176 @@
+//
+//  OpenVPNPacketFlowBridge.mm
+//  OpenVPN Adapter
+//
+//  Created by Jonathan Downing on 12/10/2017.
+//
+
+#import <NetworkExtension/NetworkExtension.h>
+#import <openvpn/ip/ip.hpp>
+#import "OpenVPNPacketFlowBridge.h"
+
+@interface OpenVPNPacketFlowBridge () {
+    CFSocketRef _openVPNClientSocket;
+    CFSocketRef _packetFlowSocket;
+}
+
+@property (nonatomic) NEPacketTunnelFlow *packetFlow;
+
+@end
+
+@implementation OpenVPNPacketFlowBridge
+
+- (CFSocketNativeHandle)socketHandle {
+    return CFSocketGetNative(_openVPNClientSocket);
+}
+
+- (instancetype)initWithPacketFlow:(NEPacketTunnelFlow *)packetFlow {
+    if ((self = [super init])) {
+        self.packetFlow = packetFlow;
+        
+        if (![self configureSockets]) {
+            return nil;
+        }
+        
+        [self readPacketFlowPackets];
+    }
+    return self;
+}
+
+static inline void PacketFlowSocketCallback(CFSocketRef socket, CFSocketCallBackType type, CFDataRef address, const void *data, void *adapter) {
+    [(__bridge OpenVPNPacketFlowBridge *)adapter writeDataToPacketFlow:(__bridge NSData *)data];
+}
+
+- (BOOL)configureSockets {
+    int sockets[2];
+    if (socketpair(PF_LOCAL, SOCK_DGRAM, IPPROTO_IP, sockets) == -1) {
+        NSLog(@"Failed to create a pair of connected sockets: %@", [NSString stringWithUTF8String:strerror(errno)]);
+        return NO;
+    }
+    
+    CFSocketContext socketCtxt = {0, (__bridge void *)self, NULL, NULL, NULL};
+    
+    _packetFlowSocket = CFSocketCreateWithNative(kCFAllocatorDefault, sockets[0], kCFSocketDataCallBack, PacketFlowSocketCallback, &socketCtxt);
+    _openVPNClientSocket = CFSocketCreateWithNative(kCFAllocatorDefault, sockets[1], kCFSocketNoCallBack, NULL, NULL);
+    
+    if (!(_packetFlowSocket && _openVPNClientSocket)) {
+        NSLog(@"Failed to create core foundation sockets from native sockets");
+        return NO;
+    }
+    
+    if (!([self configureOptionsForSocket:_packetFlowSocket] && [self configureOptionsForSocket:_openVPNClientSocket])) {
+        NSLog(@"Failed to configure buffer size of the sockets");
+        return NO;
+    }
+    
+    CFRunLoopSourceRef packetFlowSocketSource = CFSocketCreateRunLoopSource(kCFAllocatorDefault, _packetFlowSocket, 0);
+    CFRunLoopAddSource(CFRunLoopGetMain(), packetFlowSocketSource, kCFRunLoopDefaultMode);
+    CFRelease(packetFlowSocketSource);
+    
+    return YES;
+}
+
+- (BOOL)configureOptionsForSocket:(CFSocketRef)socket {
+    CFSocketNativeHandle socketHandle = CFSocketGetNative(socket);
+    
+    int buf_value = 65536;
+    socklen_t buf_len = sizeof(buf_value);
+    
+    if (setsockopt(socketHandle, SOL_SOCKET, SO_RCVBUF, &buf_value, buf_len) == -1) {
+        NSLog(@"Failed to setup buffer size for input: %@", [NSString stringWithUTF8String:strerror(errno)]);
+        return NO;
+    }
+    
+    if (setsockopt(socketHandle, SOL_SOCKET, SO_SNDBUF, &buf_value, buf_len) == -1) {
+        NSLog(@"Failed to setup buffer size for output: %@", [NSString stringWithUTF8String:strerror(errno)]);
+        return NO;
+    }
+    
+    return YES;
+}
+
+- (void)readPacketFlowPackets {
+    __weak typeof(self) weakSelf = self;
+    [self.packetFlow readPacketObjectsWithCompletionHandler:^(NSArray<NEPacket *> * _Nonnull packets) {
+        __strong typeof(self) self = weakSelf;
+
+        [self writeVPNPacketObjects:packets];
+        [self readPacketFlowPackets];
+    }];
+}
+
+- (void)writeVPNPacketObjects:(NSArray<NEPacket *> *)packets {
+    for (NEPacket *packet in packets) {
+        CFSocketSendData(_packetFlowSocket, NULL, (CFDataRef)[self dataFromPacket:packet], 0.05);
+    }
+}
+
+- (NSData *)dataFromPacket:(NEPacket *)packet {
+#if TARGET_OS_IPHONE
+    // Prepend data with network protocol. It should be done because OpenVPN on iOS uses uint32_t prefixes containing network protocol.
+    uint32_t prefix = CFSwapInt32HostToBig((uint32_t)packet.protocolFamily);
+    NSMutableData *data = [[NSMutableData alloc] initWithCapacity:sizeof(prefix) + packet.data.length];
+    [data appendBytes:&prefix length:sizeof(prefix)];
+    [data appendData:packet.data];
+    return data;
+#else
+    return packet.data;
+#endif
+}
+
+- (NEPacket *)packetFromData:(NSData *)data {
+#if TARGET_OS_IPHONE
+    // Get network protocol from prefix
+    NSUInteger prefixSize = sizeof(uint32_t);
+    
+    if (data.length < prefixSize) {
+        return nil;
+    }
+    
+    uint32_t protocol = PF_UNSPEC;
+    [data getBytes:&protocol length:prefixSize];
+    protocol = CFSwapInt32BigToHost(protocol);
+    
+    NSRange range = NSMakeRange(prefixSize, data.length - prefixSize);
+    NSData *packetData = [data subdataWithRange:range];
+#else
+    // Get network protocol from header
+    uint8_t header = 0;
+    [data getBytes:&header length:1];
+    
+    uint32_t version = openvpn::IPHeader::version(header);
+    sa_family_t protocol = [self protocolFamilyForVersion:version];
+    
+    NSData *packetData = data;
+#endif
+    
+    return [[NEPacket alloc] initWithData:packetData protocolFamily:protocol];
+}
+
+- (void)writeDataToPacketFlow:(NSData *)data {
+    NEPacket *packet = [self packetFromData:data];
+    
+    if (!packet) {
+        return;
+    }
+    
+    [self.packetFlow writePacketObjects:@[packet]];
+}
+
+- (sa_family_t)protocolFamilyForVersion:(uint32_t)version {
+    switch (version) {
+        case 4: return PF_INET;
+        case 6: return PF_INET6;
+        default: return PF_UNSPEC;
+    }
+}
+
+- (void)dealloc {
+    CFSocketInvalidate(_openVPNClientSocket);
+    CFRelease(_openVPNClientSocket);
+    
+    CFSocketInvalidate(_packetFlowSocket);
+    CFRelease(_packetFlowSocket);
+}
+
+@end