tcp: initial implementation

README.md

@@ -8,7 +8,7 @@ Astral is a 64 bit operating system with its own kernel written in C for the x86
 ## Features
 
 - SMP capable preemptible kernel
-- Networking (UDP, DHCP)
+- Networking (TCP, UDP, DHCP)
 - POSIX compatibility
 - Ports: X.org, fvwm3, gcc, bash, quake, vim and more
 - Filesystems: tmpfs, devfs, ext2
@@ -17,7 +17,6 @@ Astral is a 64 bit operating system with its own kernel written in C for the x86
 
 ## Current Goals
 
-- TCP
 - Fat32
 
 ## Building

kernel-src/arch/x86-64/main.c

@@ -83,6 +83,7 @@ void kernel_entry() {
 	arp_init();
 	ipv4_init();
 	udp_init();
+	tcp_init();
 
 	block_init();
 	pseudodevices_init();

kernel-src/include/kernel/sock.h

@@ -49,6 +49,7 @@ typedef struct {
 
 #define SOCKET_TYPE_UDP 0
 #define SOCKET_TYPE_LOCAL 1
+#define SOCKET_TYPE_TCP 2
 #define SOCKFS_SOCKET_FROM_NODE(nodep) (((socketnode_t *)(nodep))->socket)
 
 static inline int sock_convertaddress(sockaddr_t *sockaddr, abisockaddr_t *abisockaddr) {
@@ -72,6 +73,7 @@ static inline int sock_convertaddress(sockaddr_t *sockaddr, abisockaddr_t *abiso
 static inline int sock_addrtoabiaddr(int socktype, sockaddr_t *sockaddr, abisockaddr_t *abisockaddr) {
 	switch (socktype) {
 		case SOCKET_TYPE_UDP:
+		case SOCKET_TYPE_TCP:
 			inaddr_t *inaddr = (inaddr_t *)abisockaddr;
 			inaddr->sin_addr = cpu_to_be_d(sockaddr->ipv4addr.addr);
 			inaddr->sin_port = cpu_to_be_w(sockaddr->ipv4addr.port);
@@ -117,6 +119,7 @@ static inline void sock_freemsghdr(msghdr_t *hdr) {
 void localsock_leavebinding(vnode_t *vnode);
 socket_t *localsock_createsocket();
 socket_t *udp_createsocket();
+socket_t *tcp_createsocket();
 socket_t *socket_create(int type);
 int sockfs_newsocket(vnode_t **vnodep, socket_t *socket);
 void sockfs_init();

kernel-src/io/net/ipv4.c

@@ -127,6 +127,7 @@ void ipv4_process(netdev_t *netdev, void *buff) {
 	ipv4frame_t *frame = buff;
 
 	if (checksum(frame, sizeof(ipv4frame_t)) != 0) {
+		printf("ipv4: bad checksum\n");
 		return;
 	}
 
@@ -135,7 +136,7 @@ void ipv4_process(netdev_t *netdev, void *buff) {
 
 	uint16_t flagsfrag = be_to_cpu_w(frame->flags_fragoffset);
 	if ((GET_FLAGS(flagsfrag) & FLAG_MF) || (GET_FRAGOFFSET(flagsfrag) > 0)) {
-		printf("ipv4: reassembly not yet supported\n");
+		printf("ipv4: reassembly not yet supported!\n");
 		return;
 	}
 
@@ -151,9 +152,26 @@ void ipv4_process(netdev_t *netdev, void *buff) {
 		case IPV4_PROTO_UDP:
 			udp_process(netdev, nextbuff, srcip);
 			break;
+		case IPV4_PROTO_TCP:
+			tcp_process(netdev, nextbuff, frame);
+			break;
 	}
+}
 
-	return;
+size_t ipv4_getmtu(uint32_t ip) {
+	routingentry_t entry = getroute(ip);
+	if (entry.netdev == NULL)
+		return 0;
+
+	return entry.netdev->mtu;
+}
+
+uint32_t ipv4_getnetdevip(uint32_t ip) {
+	routingentry_t entry = getroute(ip);
+	if (entry.netdev == NULL)
+		return 0;
+
+	return entry.netdev->ip;
 }
 
 int ipv4_sendpacket(void *buffer, size_t packetsize, uint32_t ip, int proto, netdev_t *broadcastdev) {

kernel-src/io/net/socket.c

@@ -3,10 +3,10 @@
 
 static socket_t *(*createsocket[])() = {
 	udp_createsocket,
-	localsock_createsocket
+	localsock_createsocket,
+	tcp_createsocket
 };
 
-
 socket_t *socket_create(int type) {
 	__assert(type < sizeof(createsocket) / sizeof(createsocket[0]));
 	socket_t *socket = createsocket[type]();

kernel-src/sys/scheduler.c

@@ -544,6 +544,7 @@ static void yield(context_t *context, void *) {
 }
 
 int sched_yield() {
+	__assert(_cpu()->ipl == IPL_NORMAL);
 	bool sleeping = _cpu()->thread->flags & SCHED_THREAD_FLAGS_SLEEP;
 	bool old = sleeping ? _cpu()->thread->sleepintstatus : interrupt_set(false);
 	arch_context_saveandcall(yield, _cpu()->schedulerstack, NULL);