X-Git-Url: http://git.meshlink.io/?a=blobdiff_plain;f=utcp.c;h=e6f6cf9ede28360df84fad0161b0a993e01a3c0f;hb=ea89f59bebc6529e3270eebcc86825ee1eb7055e;hp=f062319fa33a1daa665faaa96f3c567eb488f245;hpb=2ccd5cc7da5f6157beca8cfe9dbf115e95a99776;p=utcp

diff --git a/utcp.c b/utcp.c
index f062319..e6f6cf9 100644
--- a/utcp.c
+++ b/utcp.c
@@ -130,16 +130,30 @@ static int32_t seqdiff(uint32_t a, uint32_t b) {
 // TODO: convert to ringbuffers to avoid memmove() operations.
 
 // Store data into the buffer
-static ssize_t buffer_put(struct buffer *buf, const void *data, size_t len) {
+static ssize_t buffer_put_at(struct buffer *buf, size_t offset, const void *data, size_t len) {
 	if(buf->maxsize <= buf->used)
 		return 0;
-	if(len > buf->maxsize - buf->used)
-		len = buf->maxsize - buf->used;
-	if(len > buf->size - buf->used) {
+
+	debug("buffer_put_at %zu %zu %zu\n", buf->used, offset, len);
+
+	size_t required = offset + len;
+	if(required > buf->maxsize) {
+		if(offset >= buf->maxsize)
+			return 0;
+		abort();
+		len = buf->maxsize - offset;
+		required = buf->maxsize;
+	}
+
+	if(required > buf->size) {
 		size_t newsize = buf->size;
-		do {
-			newsize *= 2;
-		} while(newsize < buf->used + len);
+		if(!newsize) {
+			newsize = required;
+		} else {
+			do {
+				newsize *= 2;
+			} while(newsize < buf->used + len);
+		}
 		if(newsize > buf->maxsize)
 			newsize = buf->maxsize;
 		char *newdata = realloc(buf->data, newsize);
@@ -148,11 +162,17 @@ static ssize_t buffer_put(struct buffer *buf, const void *data, size_t len) {
 		buf->data = newdata;
 		buf->size = newsize;
 	}
-	memcpy(buf->data + buf->used, data, len);
-	buf->used += len;
+
+	memcpy(buf->data + offset, data, len);
+	if(required > buf->used)
+		buf->used = required;
 	return len;
 }
 
+static ssize_t buffer_put(struct buffer *buf, const void *data, size_t len) {
+	return buffer_put_at(buf, buf->used, data, len);
+}
+
 // Get data from the buffer. data can be NULL.
 static ssize_t buffer_get(struct buffer *buf, void *data, size_t len) {
 	if(len > buf->used)
@@ -282,7 +302,12 @@ static struct utcp_connection *allocate_connection(struct utcp *utcp, uint16_t s
 
 	c->src = src;
 	c->dst = dst;
+#ifdef UTCP_DEBUG
+#warning debugging
+	c->snd.iss = 0;
+#else
 	c->snd.iss = rand();
+#endif
 	c->snd.una = c->snd.iss;
 	c->snd.nxt = c->snd.iss + 1;
 	c->rcv.wnd = utcp->mtu;
@@ -360,7 +385,7 @@ static void ack(struct utcp_connection *c, bool sendatleastone) {
 	} *pkt;
 
 	pkt = malloc(sizeof pkt->hdr + c->utcp->mtu);
-	if(!pkt->data)
+	if(!pkt)
 		return;
 
 	pkt->hdr.src = c->src;
@@ -465,11 +490,8 @@ static void retransmit(struct utcp_connection *c) {
 	pkt->hdr.dst = c->dst;
 
 	switch(c->state) {
-		case LISTEN:
-			// TODO: this should not happen
-			break;
-
 		case SYN_SENT:
+			// Send our SYN again
 			pkt->hdr.seq = c->snd.iss;
 			pkt->hdr.ack = 0;
 			pkt->hdr.wnd = c->rcv.wnd;
@@ -479,6 +501,7 @@ static void retransmit(struct utcp_connection *c) {
 			break;
 
 		case SYN_RECEIVED:
+			// Send SYNACK again
 			pkt->hdr.seq = c->snd.nxt;
 			pkt->hdr.ack = c->rcv.nxt;
 			pkt->hdr.ctl = SYN | ACK;
@@ -488,28 +511,35 @@ static void retransmit(struct utcp_connection *c) {
 
 		case ESTABLISHED:
 		case FIN_WAIT_1:
+		case CLOSE_WAIT:
+		case CLOSING:
+		case LAST_ACK:
+			// Send unacked data again.
 			pkt->hdr.seq = c->snd.una;
 			pkt->hdr.ack = c->rcv.nxt;
 			pkt->hdr.ctl = ACK;
-			uint32_t len = seqdiff(c->snd.nxt, c->snd.una);
-			if(c->state == FIN_WAIT_1)
-				len--;
+			uint32_t len = seqdiff(c->snd.last, c->snd.una);
 			if(len > utcp->mtu)
 				len = utcp->mtu;
-			else {
-				if(c->state == FIN_WAIT_1)
-					pkt->hdr.ctl |= FIN;
+			if(fin_wanted(c, c->snd.una + len)) {
+				len--;
+				pkt->hdr.ctl |= FIN;
 			}
+			c->snd.nxt = c->snd.una + len;
 			buffer_copy(&c->sndbuf, pkt->data, 0, len);
 			print_packet(c->utcp, "rtrx", pkt, sizeof pkt->hdr + len);
 			utcp->send(utcp, pkt, sizeof pkt->hdr + len);
 			break;
 
-		default:
-			// TODO: implement
+		case CLOSED:
+		case LISTEN:
+		case TIME_WAIT:
+		case FIN_WAIT_2:
+			// We shouldn't need to retransmit anything in this state.
 #ifdef UTCP_DEBUG
 			abort();
 #endif
+			timerclear(&c->rtrx_timeout);
 			break;
 	}
 
@@ -984,7 +1014,7 @@ reset:
 }
 
 int utcp_shutdown(struct utcp_connection *c, int dir) {
-	debug("%p shutdown %d at %u\n", c ? c->utcp : NULL, dir, c->snd.last);
+	debug("%p shutdown %d at %u\n", c ? c->utcp : NULL, dir, c ? c->snd.last : 0);
 	if(!c) {
 		errno = EFAULT;
 		return -1;
@@ -996,13 +1026,26 @@ int utcp_shutdown(struct utcp_connection *c, int dir) {
 		return -1;
 	}
 
-	// TODO: handle dir
-	// TODO: check that repeated calls with the same parameters should have no effect
+	if(!(dir == UTCP_SHUT_RD || dir == UTCP_SHUT_WR || dir == UTCP_SHUT_RDWR)) {
+		errno = EINVAL;
+		return -1;
+	}
+
+	// TCP does not have a provision for stopping incoming packets.
+	// The best we can do is to just ignore them.
+	if(dir == UTCP_SHUT_RD || dir == UTCP_SHUT_RDWR)
+		c->recv = NULL;
+
+	// The rest of the code deals with shutting down writes.
+	if(dir == UTCP_SHUT_RD)
+		return 0;
 
 	switch(c->state) {
 	case CLOSED:
-		return 0;
 	case LISTEN:
+		errno = ENOTCONN;
+		return -1;
+
 	case SYN_SENT:
 		set_state(c, CLOSED);
 		return 0;
@@ -1150,6 +1193,17 @@ struct timeval utcp_timeout(struct utcp *utcp) {
 	return diff;
 }
 
+bool utcp_is_active(struct utcp *utcp) {
+	if(!utcp)
+		return false;
+
+	for(int i = 0; i < utcp->nconnections; i++)
+		if(utcp->connections[i]->state != CLOSED && utcp->connections[i]->state != TIME_WAIT)
+			return true;
+
+	return false;
+}
+
 struct utcp *utcp_init(utcp_accept_t accept, utcp_pre_accept_t pre_accept, utcp_send_t send, void *priv) {
 	struct utcp *utcp = calloc(1, sizeof *utcp);
 	if(!utcp)
@@ -1252,3 +1306,10 @@ void utcp_set_poll_cb(struct utcp_connection *c, utcp_poll_t poll) {
 	if(c)
 		c->poll = poll;
 }
+
+void utcp_set_accept_cb(struct utcp *utcp, utcp_accept_t accept, utcp_pre_accept_t pre_accept) {
+	if(utcp) {
+		utcp->accept = accept;
+		utcp->pre_accept = pre_accept;
+	}
+}