Changeset 0093ab6 in mainline for uspace/srv/net/tl/tcp/conn.c

Timestamp:

2011-09-21T19:56:41Z (13 years ago)

Author:

Jiri Svoboda <jiri@…>

Branches:

lfn, master, serial, ticket/834-toolchain-update, topic/msim-upgrade, topic/simplify-dev-export

Children:

032bbe7

Parents:

4c55a64

Message:

Parts of data reception. Trimming segment to receive window.

File:

• uspace/srv/net/tl/tcp/conn.c (modified) (10 diffs)

uspace/srv/net/tl/tcp/conn.c

@@ -38 +38 @@
 #include <errno.h>
 #include <io/log.h>
+#include <macros.h>
 #include <stdlib.h>
 #include "conn.h"
@@ -46 +47 @@
 #include "tqueue.h"
 
+#define RCV_BUF_SIZE 4096
+
 LIST_INITIALIZE(conn_list);
 
@@ -54 +57 @@
         tcp_conn_t *conn;
 
+        /* Allocate connection structure */
         conn = calloc(1, sizeof(tcp_conn_t));
         if (conn == NULL)
                 return NULL;
 
+        /* Allocate receive buffer */
+        conn->rcv_buf_size = RCV_BUF_SIZE;
+        conn->rcv_buf_used = 0;
+        conn->rcv_buf = calloc(1, conn->rcv_buf_size);
+        if (conn->rcv_buf == NULL) {
+                free(conn);
+                return NULL;
+        }
+
+        /* Set up receive window. */
+        conn->rcv_wnd = conn->rcv_buf_size;
+
+        /* Initialize incoming segment queue */
         tcp_iqueue_init(&conn->incoming, conn);
 
@@ -175 +192 @@
 
         tcp_tqueue_ctrl_seg(conn, CTL_SYN | CTL_ACK /* XXX */);
+
+        tcp_segment_delete(seg);
 }
 
@@ -225 +244 @@
                 tcp_tqueue_ctrl_seg(conn, CTL_SYN | CTL_ACK /* XXX */);
         }
+
+        tcp_segment_delete(seg);
 }
 
@@ -288 +309 @@
 static cproc_t tcp_conn_seg_proc_ack_est(tcp_conn_t *conn, tcp_segment_t *seg)
 {
+        log_msg(LVL_DEBUG, "tcp_conn_seg_proc_ack_est(%p, %p)", conn, seg);
+
+        log_msg(LVL_DEBUG, "SEG.ACK=%u, SND.UNA=%u, SND.NXT=%u",
+            (unsigned)seg->ack, (unsigned)conn->snd_una,
+            (unsigned)conn->snd_nxt);
+
         if (!seq_no_ack_acceptable(conn, seg->ack)) {
+                log_msg(LVL_DEBUG, "ACK not acceptable.");
                 if (!seq_no_ack_duplicate(conn, seg->ack)) {
+                        log_msg(LVL_WARN, "Not acceptable, not duplicate. "
+                            "Send ACK and drop.");
                         /* Not acceptable, not duplicate. Send ACK and drop. */
                         tcp_tqueue_ctrl_seg(conn, CTL_ACK);
                         tcp_segment_delete(seg);
                         return cp_done;
+                } else {
+                        log_msg(LVL_DEBUG, "Ignoring duplicate ACK.");
                 }
         } else {
@@ -401 +433 @@
 }
 
+/** Process segment text. */
 static cproc_t tcp_conn_seg_proc_text(tcp_conn_t *conn, tcp_segment_t *seg)
 {
+        size_t text_size;
+        size_t xfer_size;
+
+        log_msg(LVL_DEBUG, "tcp_conn_seg_proc_text(%p, %p)", conn, seg);
+
         switch (conn->cstate) {
         case st_established:
@@ -422 +460 @@
         }
 
-        /* TODO Process segment text */
+        /*
+         * Process segment text
+         */
+        assert(seq_no_segment_ready(conn, seg));
+
+        /* Trim anything outside our receive window */
+        tcp_conn_trim_seg_to_wnd(conn, seg);
+
+        /* Determine how many bytes to copy */
+        text_size = tcp_segment_text_size(seg);
+        xfer_size = min(text_size, conn->rcv_buf_size - conn->rcv_buf_used);
+
+        /* Copy data to receive buffer */
+        tcp_segment_text_copy(seg, conn->rcv_buf, xfer_size);
+
+        /* Advance RCV.NXT */
+        conn->rcv_nxt += xfer_size;
+
+        /* Update receive window. XXX Not an efficient strategy. */
+        conn->rcv_wnd -= xfer_size;
+
+        /* XXX Signal user that some data arrived. */
+
+        /* Send ACK */
+        if (xfer_size > 0)
+                tcp_tqueue_ctrl_seg(conn, CTL_ACK);
+
+        /* Anything left in the segment? (text, FIN) */
+        if (xfer_size < seg->len) {
+                /*
+                 * Some text or control remains. Insert remainder back
+                 * into the incoming queue.
+                 */
+                tcp_conn_trim_seg_to_wnd(conn, seg);
+                tcp_iqueue_insert_seg(&conn->incoming, seg);
+
+                return cp_done;
+        }
+
         return cp_continue;
 }
@@ -472 +548 @@
         if (tcp_conn_seg_proc_fin(conn, seg) == cp_done)
                 return;
+
+        tcp_segment_delete(seg);
 }
 
@@ -498 +576 @@
 }
 
+void tcp_conn_trim_seg_to_wnd(tcp_conn_t *conn, tcp_segment_t *seg)
+{
+        uint32_t left, right;
+
+        seq_no_seg_trim_calc(conn, seg, &left, &right);
+        tcp_segment_trim(seg, left, right);
+}
+
 void tcp_unexpected_segment(tcp_sockpair_t *sp, tcp_segment_t *seg)
 {