diff --git a/kernel-src/include/kernel/jobctl.h b/kernel-src/include/kernel/jobctl.h
index 6e9f34d3..be9eb935 100644
--- a/kernel-src/include/kernel/jobctl.h
+++ b/kernel-src/include/kernel/jobctl.h
@@ -14,5 +14,7 @@ pid_t jobctl_getsid(proc_t *proc);
 void jobctl_setctty(proc_t *proc, void *ctty);
 void *jobctl_getctty(proc_t *proc);
 int jobctl_signal(proc_t *proc, int signal);
+proc_t *jobctl_getforeground(proc_t *proc);
+int jobctl_setforeground(proc_t *session, proc_t *pgrp);
 
 #endif
diff --git a/kernel-src/include/kernel/tty.h b/kernel-src/include/kernel/tty.h
index 8a69e40d..370a96ec 100644
--- a/kernel-src/include/kernel/tty.h
+++ b/kernel-src/include/kernel/tty.h
@@ -28,6 +28,8 @@ typedef struct {
 	int minor;
 	winsize_t winsize;
 	vnode_t *mastervnode;
+	spinlock_t sessionlock;
+	struct proc_t *session;
 } tty_t;
 
 void tty_init();
diff --git a/kernel-src/io/net/tcp.c b/kernel-src/io/net/tcp.c
new file mode 100644
index 00000000..1e1f613d
--- /dev/null
+++ b/kernel-src/io/net/tcp.c
@@ -0,0 +1,127 @@
+#include <kernel/net.h>
+#include <kernel/sock.h>
+#include <ringbuffer.h>
+
+#define WORKER_COUNT 8
+#define WORKER_BUFFER_SIZE (64 * 1024)
+#define WORKER_INTERNAL_BUFFER_SIZE 2048
+// MSS will be min(MSS_LIMIT, mtu - sizeof(ipv4header_t) - sizeof(tcpheader_t))
+#define MSS_LIMIT = (WORKER_INTERNAL_BUFFER_SIZE - sizeof(tcpheader_t))
+
+typedef struct {
+	spinlock_t lock;
+	semaphore_t semaphore;
+	// format:
+	// ipv4 pseudo header
+	// tcp packet
+	ringbuffer_t ringbuffer;
+} tcpworker_t;
+
+static tcpworker_t worker[WORKER_COUNT];
+static uint64_t currentworker;
+
+typedef struct {
+	uint32_t peer;
+	uint16_t peerport;
+	uint16_t localport;
+} connkey_t;
+
+typedef struct {
+	uint16_t srcport;
+	uint16_t dstport;
+	uint32_t seq;
+	uint32_t ack;
+	uint8_t dataoffset;
+	uint8_t control;
+	uint16_t window;
+	uint16_t checksum;
+	uint16_t urgentptr;
+} __attribute__((packed)) tcpheader_t;
+
+typedef struct {
+	uint32_t source;
+	uint32_t dest;
+	uint8_t zero;
+	uint8_t protocol;
+	uint16_t length;
+} __attribute__((packed)) ipv4pseudoheader_t;
+
+#define TCP_STATE_LISTEN 0 // listening for connections
+#define TCP_STATE_SYNSENT 1 // sent a connection request
+#define TCP_STATE_SYNRECEIVED 2 // received a connection request, waiting for ACK
+#define TCP_STATE_ESTABILISHED 3 // got connection ACK, connection is oppen
+#define TCP_STATE_FINWAIT1 4 // waiting for connection termination from peer or an ack for the already sent FIN
+#define TCP_STATE_FINWAIT2 5 // waiting for connection termination from peer
+#define TCP_STATE_CLOSEWAIT 7 // waiting for a termination request from local user
+#define TCP_STATE_CLOSING 8 // waiting for termination ack
+
+typedef struct {
+	spinlock_t lock;
+	int state;
+	ringbuffer_t ringbuffer;
+
+	uint32_t snduna;
+	uint32_t sndnext;
+	uint32_t sndwindow;
+	uint32_t sndurgent;
+	uint32_t sndseqwl;
+	uint32_t sndackwl;
+	uint32_t iss;
+
+	uint32_t rcvnext;
+	uint32_t rcvwindow;
+	uint32_t rcvurgent;
+	uint32_t irs;
+} tcb_t;
+
+// TODO dpc:
+// construct ipv4header
+// calculate checksum
+// check against WORKER_INTERNAL_BUFFER_SIZE
+
+// ran in DPC context
+void tcp_process(netdev_t *netdev, void *buffer, ipv4frame_t *ipv4frame) {
+	
+}
+
+__attribute__((noreturn)) static void tcp_worker() {
+	tcpworker_t *self = _cpu()->thread->kernelarg;
+	ipv4pseudoheader_t ipv4;
+	uint8_t buffer[WORKER_INTERNAL_BUFFER_SIZE];
+
+	for (;;) {
+		// wait for a task
+		semaphore_wait(&self->semaphore, false);
+
+		interrupt_set(false);
+		spinlock_acquire(&self->lock);
+
+		// read pseudo ipv4 header constructed by tcp_process
+		// the checksum has already been calculated by it
+		__assert(ringbuffer_read(&self->ringbuffer, &ipv4, sizeof(ipv4pseudoheader_t)) == sizeof(ipv4pseudoheader_t));
+
+		// and then the actual tcp packet
+		__assert(ringbuffer_read(&self->ringbuffer, buffer, ipv4.length) == ipv4.length);
+
+		spinlock_release(&self->lock);
+		interrupt_set(true);
+
+		tcpheader_t *tcpheader = buffer;
+
+		// TODO get tcb of connection (if any)
+	}
+}
+
+void tcp_init() {
+	for (int i = 0; i < WORKER_COUNT; ++i) {
+		// initialize worker threads
+
+		SPINLOCK_INIT(worker[i].lock);
+		SEMAPHORE_INIT(&worker[i].semaphore, 0);
+		__assert(ringbuffer_init(&worker[i].ringbuffer, WORKER_BUFFER_SIZE) == 0);
+		thread_t *thread = sched_newthread(tcp_worker, PAGE_SIZE * 3, 0, NULL, NULL);
+		__assert(thread);
+		thread->kernelarg = &worker[i];
+		sched_queue(thread);
+	}
+}
diff --git a/kernel-src/io/pty.c b/kernel-src/io/pty.c
index ec8b529c..d67b5452 100644
--- a/kernel-src/io/pty.c
+++ b/kernel-src/io/pty.c
@@ -96,7 +96,6 @@ static int close(int minor, int flags) {
 	if (pty == NULL)
 		return ENODEV;
 
-	// TODO do tty cleanup stuff like sending sighup
 	bool intstatus = interrupt_set(false);
 	spinlock_acquire(&pty->lock);
 	pty->hangup = true;
diff --git a/kernel-src/io/tty.c b/kernel-src/io/tty.c
index b6185493..fb8f6a9a 100644
--- a/kernel-src/io/tty.c
+++ b/kernel-src/io/tty.c
@@ -376,6 +376,7 @@ tty_t *tty_create(char *name, ttydevicewritefn_t writefn, ttyinactivefn_t inacti
 	strcpy(tty->name, name);
 	MUTEX_INIT(&tty->readmutex);
 	MUTEX_INIT(&tty->writemutex);
+	SPINLOCK_INIT(tty->sessionlock);
 
 	tty->termios.c_iflag = ICRNL;
 	tty->termios.c_oflag = ONLCR;
@@ -412,6 +413,22 @@ tty_t *tty_create(char *name, ttydevicewritefn_t writefn, ttyinactivefn_t inacti
 
 void tty_unregister(tty_t *tty) {
 	devfs_remove(tty->name, DEV_MAJOR_TTY, tty->minor);
+	bool intstatus = interrupt_set(false);
+	spinlock_acquire(&tty->sessionlock);
+	proc_t *session = tty->session;
+	if (session) {
+		PROC_HOLD(session);
+	}
+	spinlock_release(&tty->sessionlock);
+	interrupt_set(intstatus);
+
+	if (session) {
+		proc_t *foreground = jobctl_getforeground(session);
+		jobctl_signal(foreground, SIGHUP);
+
+		PROC_RELEASE(session);
+		PROC_RELEASE(foreground);
+	}
 }
 
 
diff --git a/kernel-src/sys/jobctl.c b/kernel-src/sys/jobctl.c
index 7291e1d8..5b1fe52a 100644
--- a/kernel-src/sys/jobctl.c
+++ b/kernel-src/sys/jobctl.c
@@ -49,11 +49,19 @@ void jobctl_setctty(proc_t *proc, void *_ctty) {
 	if (tty == NULL && proc->session.controllingtty) {
 		unholdtty = proc->session.controllingtty;
 		proc->session.controllingtty = NULL;
+		spinlock_acquire(&unholdtty->sessionlock);
+		unholdtty->session = NULL;
+		spinlock_release(&unholdtty->sessionlock);
 	}
 
 	if (tty && proc->session.controllingtty == NULL) {
-		VOP_HOLD(tty->mastervnode);
-		proc->session.controllingtty = tty;
+		spinlock_acquire(&tty->sessionlock);
+		if (tty->session == NULL) {
+			VOP_HOLD(tty->mastervnode);
+			proc->session.controllingtty = tty;
+			tty->session = proc;
+		}
+		spinlock_release(&tty->sessionlock);
 	}
 
 	leave:
@@ -226,6 +234,8 @@ void jobctl_detach(proc_t *proc) {
 	// called on process exit (when the last userland thread is exiting)
 	proc_t *unholdpgrp = NULL;
 	proc_t *unholdsession = NULL;
+	proc_t *foreground = NULL;
+
 	bool intstatus = interrupt_set(false);
 	spinlock_acquire(&proc->jobctllock);
 
@@ -238,6 +248,10 @@ void jobctl_detach(proc_t *proc) {
 	if (proc->session.leader) {
 		unholdsession = proc->session.leader;
 		proc->session.leader = NULL;
+	} else {
+		// send sighup and sigcont to all processes in the foreground group
+		foreground = proc->session.foreground ? proc->session.foreground : proc;
+		PROC_HOLD(foreground);
 	}
 
 	spinlock_release(&proc->jobctllock);
@@ -249,6 +263,11 @@ void jobctl_detach(proc_t *proc) {
 
 	if (unholdsession) {
 		PROC_RELEASE(unholdsession);
+	} else {
+		jobctl_setctty(proc, NULL);
+		jobctl_signal(foreground, SIGHUP);
+		jobctl_signal(foreground, SIGCONT);
+		PROC_RELEASE(foreground);
 	}
 }
 
@@ -272,6 +291,63 @@ void jobctl_addproc(proc_t *parent, proc_t *proc) {
 	interrupt_set(intstatus);
 }
 
+proc_t *jobctl_getforeground(proc_t *proc) {
+	proc_t *foreground = NULL;
+
+	bool intstatus = interrupt_set(false);
+	spinlock_acquire(&proc->jobctllock);
+
+	if (proc->session.leader)
+		goto leave;
+
+	foreground = proc->session.foreground ? proc->session.foreground : proc;
+	PROC_HOLD(foreground);
+
+	leave:
+	spinlock_release(&proc->jobctllock);
+	interrupt_set(intstatus);
+
+	return foreground;
+}
+int jobctl_setforeground(proc_t *session, proc_t *pgrp) {
+	proc_t *unhold = NULL;
+	int error = 0;
+
+	bool intstatus = interrupt_set(false);
+	spinlock_acquire(&session->jobctllock);
+	if (session->session.leader) {
+		error = EINVAL;
+		goto leave;
+	}
+
+	if (session != pgrp) {
+		spinlock_acquire(&pgrp->jobctllock);
+		if (pgrp->pgrp.leader || pgrp->session.leader != session) {
+			error = EPERM;
+			goto leave;
+		}
+	}
+
+	if (session->session.foreground)
+		unhold = session->session.foreground;
+
+	session->session.foreground = pgrp;
+	PROC_HOLD(pgrp);
+
+	leave:
+	if (session != pgrp)
+		spinlock_release(&pgrp->jobctllock);
+
+	spinlock_release(&session->jobctllock);
+	interrupt_set(intstatus);
+
+	if (unhold) {
+		PROC_RELEASE(unhold);
+	}
+
+	return error;
+}
+
 void jobctl_procremove(proc_t *proc) {
 	// called after all refcounts to a proc are released
 	// cleans up session stuff