reorganization: first steps

1 files changed, 0 insertions, 268 deletions

diff --git a/src/user/app/netstack/tcp.c b/src/user/app/netstack/tcp.c
deleted file mode 100644
index d1adeab..0000000
--- a/src/user/app/netstack/tcp.c
+++ /dev/null
@@ -1,268 +0,0 @@
-/* Welcome to spaghetti land.
- * This is anything but production quality. It's throwaway code, meant
- * only to see how networking could fit into the architecture of the
- * system. */
-#include "proto.h"
-#include "util.h"
-#include <assert.h>
-#include <shared/ring.h>
-
-enum {
-	SrcPort = 0,
-	DstPort = 2,
-	Seq     = 4,
-	AckNum  = 8, /* last processed seq + 1 */
-	Flags   = 12,
-		FlagSize = 0xF000, /* size of header / 4 bytes */
-		/* 3 bits: 0, still unused
-		 * 3 bits: modern stuff not in the original RFC */
-		FlagURG = 0x0020, /* urgent */
-		FlagACK = 0x0010,
-		FlagPSH = 0x0008, /* force buffer flush */
-		FlagRST = 0x0004, /* reset connection */
-		FlagSYN = 0x0002, /* first packet; sync sequence numbers */
-		FlagFIN = 0x0001, /* last packet */
-		FlagAll = 0x003F,
-	WinSize  = 14, /* amount of data we're willing to receive */
-	Checksum = 16,
-	Urgent   = 18,
-	MinHdr   = 20,
-};
-
-enum tcp_state {
-	LISTEN,
-	SYN_SENT,
-	SYN_RCVD,
-	ESTABILISHED,
-	LAST_ACK,
-	CLOSED,
-};
-
-struct tcp_conn {
-	uint32_t lip, rip;
-	mac_t rmac;
-	uint16_t lport, rport;
-	struct tcp_conn *next, **link;
-
-	enum tcp_state state;
-	uint32_t lack, rack;
-	uint32_t lseq;
-	bool uclosed; /* did the user close? */
-
-	void (*on_conn)(struct tcp_conn *, void *carg);
-	void (*on_recv)(void *carg);
-	void (*on_close)(void *carg);
-	void *carg;
-
-	ring_t rx;
-};
-static struct tcp_conn *conns;
-static void conns_append(struct tcp_conn *c) {
-	c->next = conns;
-	if (c->next)
-		c->next->link = &c->next;
-	c->link = &conns;
-	*c->link = c;
-}
-static void tcpc_sendraw(struct tcp_conn *c, uint16_t flags, const void *buf, size_t len) {
-	uint8_t *pkt = malloc(MinHdr + len);
-	memset(pkt, 0, MinHdr);
-
-	nput16(pkt + SrcPort, c->lport);
-	nput16(pkt + DstPort, c->rport);
-	nput32(pkt + Seq, c->lseq);
-	c->lseq += len;
-	nput32(pkt + AckNum, c->lack);
-	flags |= (MinHdr / 4) << 12;
-	nput16(pkt + Flags, flags);
-	nput16(pkt + WinSize, ring_avail(&c->rx));
-	memcpy(pkt + MinHdr, buf, len);
-	nput16(pkt + Checksum, ip_checksumphdr(pkt, MinHdr + len, c->lip, c->rip, 6));
-
-	ipv4_send(pkt, MinHdr + len, (struct ipv4){
-		.proto = 6,
-		.src = c->lip,
-		.dst = c->rip,
-		.e.dst = &c->rmac,
-	});
-	free(pkt);
-}
-void tcp_listen(
-	uint16_t port,
-	void (*on_conn)(struct tcp_conn *, void *carg),
-	void (*on_recv)(void *carg),
-	void (*on_close)(void *carg),
-	void *carg)
-{
-	struct tcp_conn *c = malloc(sizeof *c);
-	memset(c, 0, sizeof *c);
-	c->lport = port;
-	c->lip = state.ip;
-	c->state = LISTEN;
-	c->on_conn = on_conn;
-	c->on_recv = on_recv;
-	c->on_close = on_close;
-	c->carg = carg;
-	// TODO setting the ring size super low loses every nth byte. probably a bug with ring_t itself!
-	c->rx = (ring_t){malloc(4096), 4096, 0, 0};
-	conns_append(c);
-}
-struct tcp_conn *tcpc_new(
-	struct tcp t,
-	void (*on_recv)(void *carg),
-	void (*on_close)(void *carg),
-	void *carg)
-{
-	struct tcp_conn *c = malloc(sizeof *c);
-	memset(c, 0, sizeof *c);
-	c->lip = t.ip.src ? t.ip.src : state.ip;
-	c->rip = t.ip.dst;
-	c->lport = t.src ? t.src : 50002; // TODO randomize source ports
-	c->rport = t.dst;
-	if (arpcache_get(c->rip, &c->rmac) < 0) {
-		// TODO wait for ARP reply
-		arp_request(c->rip);
-		if (arpcache_get(state.gateway, &c->rmac) < 0) {
-			eprintf("neither target nor gateway not in ARP cache, dropping");
-			free(c);
-			return NULL;
-		}
-	}
-
-	c->state = SYN_SENT;
-	c->on_recv = on_recv;
-	c->on_close = on_close;
-	c->carg = carg;
-	c->rx = (ring_t){malloc(4096), 4096, 0, 0};
-	conns_append(c);
-
-	tcpc_sendraw(c, FlagSYN, NULL, 0);
-	c->lseq++;
-	return c;
-}
-size_t tcpc_tryread(struct tcp_conn *c, void *buf, size_t len) {
-	if (!buf) return ring_used(&c->rx);
-	return ring_get(&c->rx, buf, len);
-}
-void tcpc_send(struct tcp_conn *c, const void *buf, size_t len) {
-	tcpc_sendraw(c, FlagACK | FlagPSH, buf, len);
-}
-static void tcpc_tryfree(struct tcp_conn *c) {
-	if (c->state == CLOSED && c->uclosed) {
-		if (c->next) c->next->link = c->link;
-		*c->link = c->next;
-		free(c->rx.buf);
-		free(c);
-	}
-}
-void tcpc_close(struct tcp_conn *c) {
-	/* ONLY FOR USE BY THE USER, drops their reference */
-	assert(!c->uclosed);
-	c->uclosed = true;
-	if (c->state != CLOSED && c->state != LAST_ACK && c->state != LISTEN) {
-		tcpc_sendraw(c, FlagFIN | FlagACK, NULL, 0);
-		c->state = LAST_ACK;
-		c->on_conn = NULL;
-		c->on_close = NULL;
-	}
-	tcpc_tryfree(c);
-}
-
-void tcp_parse(const uint8_t *buf, size_t len, struct ipv4 ip) {
-	if (len < 20) return;
-	uint16_t srcport = nget16(buf + SrcPort);
-	uint16_t dstport = nget16(buf + DstPort);
-	uint32_t seq     = nget32(buf + Seq);
-	uint32_t acknum  = nget32(buf + AckNum);
-	uint16_t flags   = nget16(buf + Flags);
-	// uint16_t winsize = nget16(buf + WinSize);
-	// uint16_t chksum  = nget16(buf + Checksum);
-	uint16_t hdrlen = ((flags & FlagSize) >> 12) * 4;
-	if (hdrlen > len) return;
-	uint16_t payloadlen = len - hdrlen;
-
-	for (struct tcp_conn *iter = conns; iter; iter = iter->next) {
-		if (iter->state == CLOSED) continue;
-		if (iter->lport != dstport) continue;
-
-		if (iter->state == LISTEN && (flags & FlagAll) == FlagSYN) {
-			iter->state = SYN_RCVD;
-			iter->rip = ip.src;
-			iter->rport = srcport;
-			iter->lack = seq + 1;
-			memcpy(&iter->rmac, ip.e.src, sizeof(mac_t));
-			tcpc_sendraw(iter, FlagSYN | FlagACK, NULL, 0);
-			iter->lseq++;
-			if (iter->on_conn) iter->on_conn(iter, iter->carg);
-			return;
-		}
-
-		if (iter->rip == ip.src && iter->rport == srcport) {
-			// TODO doesn't handle seq/ack overflows
-			if (iter->state == SYN_SENT) {
-				if (flags & FlagSYN) {
-					iter->state = ESTABILISHED;
-					iter->lack = seq + 1;
-					tcpc_sendraw(iter, FlagACK, NULL, 0);
-					return;
-				} else {
-					// TODO resend syn?
-					return;
-				}
-			}
-			if (flags & FlagACK) {
-				if (iter->rack < acknum)
-					iter->rack = acknum;
-				if (iter->state == LAST_ACK) {
-					// TODO check if ack has correct number
-					iter->state = CLOSED;
-					tcpc_tryfree(iter);
-					// TODO free (also after a timeout)
-					return;
-				}
-			}
-			if (iter->lack != seq && iter->lack - 1 != seq) {
-				eprintf("remote seq jumped by %d", seq - iter->lack);
-				tcpc_sendraw(iter, FlagACK, NULL, 0);
-				return;
-			}
-			// TODO check if overflows window size
-			if (payloadlen) {
-				iter->lack = seq + payloadlen;
-				ring_put(&iter->rx, buf + hdrlen, payloadlen);
-				if (iter->on_recv) iter->on_recv(iter->carg);
-				tcpc_sendraw(iter, FlagACK, NULL, 0);
-			}
-			if (flags & FlagFIN) {
-				// TODO should resend the packet until an ACK is received
-				// TODO duplicated in tcpc_close
-				tcpc_sendraw(iter, FlagFIN | FlagACK, NULL, 0);
-				iter->state = LAST_ACK;
-				if (iter->on_close) iter->on_close(iter->carg);
-				return;
-			}
-			return;
-		}
-	}
-
-	if ((flags & FlagRST) == 0) {
-		uint8_t *pkt = malloc(MinHdr);
-		memset(pkt, 0, MinHdr);
-		nput16(pkt + SrcPort, dstport);
-		nput16(pkt + DstPort, srcport);
-		nput32(pkt + Seq, acknum);
-		nput32(pkt + AckNum, seq + 1);
-		uint16_t pktflags = FlagRST | FlagACK;
-		pktflags |= (MinHdr / 4) << 12;
-		nput16(pkt + Flags, pktflags);
-		nput16(pkt + Checksum, ip_checksumphdr(pkt, MinHdr, ip.src, ip.dst, 6));
-
-		ipv4_send(pkt, MinHdr, (struct ipv4){
-			.proto = 6,
-			.src = ip.dst,
-			.dst = ip.src,
-			.e.dst = ip.e.src,
-		});
-		free(pkt);
-	}
-}