Corrected bugs in the TCP logic. There might be a few more which need to be taken care of.
This commit is contained in:
Nikhil Chandru Rao
parent
72cd29f13c
commit
8bf38fb400
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@ -326,8 +326,6 @@ void tcp_trans ( struct tcp_connection *conn, int nxt_state ) {
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conn->tcp_lstate = conn->tcp_state;
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conn->tcp_state = nxt_state;
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printf ( "Transition from %s to %s\n", tcp_states[conn->tcp_lstate], tcp_states[conn->tcp_state] );
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/* TODO: Check if this check is required */
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if ( conn->tcp_lstate == conn->tcp_state ||
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conn->tcp_state == TCP_INVALID ) {
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@ -343,20 +341,8 @@ void tcp_trans ( struct tcp_connection *conn, int nxt_state ) {
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* @v tcphdr TCP header
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*/
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void tcp_dump ( struct tcp_header *tcphdr ) {
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/*
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DBG ( "TCP header at %p+%d\n", tcphdr, sizeof ( *tcphdr ) );
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DBG ( "\tSource port = %d, Destination port = %d\n",
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ntohs ( tcphdr->src ), ntohs ( tcphdr->dest ) );
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DBG ( "\tSequence Number = %ld, Acknowledgement Number = %ld\n",
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ntohl ( tcphdr->seq ), ntohl ( tcphdr->ack ) );
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DBG ( "\tHeader length (/4) = %hd, Flags [..RAPUSF]= %#x\n",
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( ( tcphdr->hlen & TCP_MASK_HLEN ) / 16 ),
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( tcphdr->flags & TCP_MASK_FLAGS ) );
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DBG ( "\tAdvertised window = %ld, Checksum = %x, Urgent Pointer = %d\n",
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ntohs ( tcphdr->win ), tcphdr->csum, ntohs ( tcphdr->urg ) );
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*/
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DBG ( "TCP %p at %p src:%d dest:%d seq:%lld ack:%lld hlen:%hd flags:%#hx\n",
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&tcp_protocol, tcphdr, ntohs ( tcphdr->src ), ntohs ( tcphdr->dest ), ntohl ( tcphdr->seq ),
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DBG ( "TCP %p src:%d dest:%d seq:%lld ack:%lld hlen:%hd flags:%#hx\n",
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tcphdr, ntohs ( tcphdr->src ), ntohs ( tcphdr->dest ), ntohl ( tcphdr->seq ),
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ntohl ( tcphdr->ack ), ( ( tcphdr->hlen & TCP_MASK_HLEN ) / 16 ), ( tcphdr->flags & TCP_MASK_FLAGS ) );
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}
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@ -437,7 +423,7 @@ void tcp_expired ( struct retry_timer *timer, int over ) {
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return;
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send_tcp_nomsg:
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// free_pkb ( conn->tx_pkb );
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free_pkb ( conn->tx_pkb );
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conn->tx_pkb = alloc_pkb ( MIN_PKB_LEN );
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pkb_reserve ( conn->tx_pkb, MAX_HDR_LEN );
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tcp_set_flags ( conn );
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@ -657,7 +643,6 @@ int tcp_send ( struct tcp_connection *conn, const void *data, size_t len ) {
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tcphdr->csum = tcpip_chksum ( pkb->data, pkb_len ( pkb ) );
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/* Dump the TCP header */
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tcp_dump ( tcphdr );
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/* Start the timer */
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if ( ( conn->tcp_state == TCP_ESTABLISHED && conn->tcp_lstate == TCP_SYN_SENT ) ||
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@ -685,7 +670,7 @@ static int tcp_rx ( struct pk_buff *pkb,
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struct tcp_header *tcphdr;
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uint32_t acked, toack;
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int hlen;
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int add = 0;
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int add = 4;
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/* Sanity check */
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if ( pkb_len ( pkb ) < sizeof ( *tcphdr ) ) {
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@ -709,7 +694,8 @@ static int tcp_rx ( struct pk_buff *pkb,
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return -EINVAL;
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}
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}
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/* TODO: Verify checksum */
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/* Demux TCP connection */
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@ -768,13 +754,14 @@ static int tcp_rx ( struct pk_buff *pkb,
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*/
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conn->snd_una = ntohl ( tcphdr->ack );
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conn->tcp_op->connected ( conn );
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out_flags |= TCP_ACK;
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tcp_senddata ( conn );
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return;
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} else {
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tcp_trans ( conn, TCP_SYN_RCVD );
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out_flags |= TCP_SYN;
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goto send_tcp_nomsg;
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}
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/* Send SYN,ACK or ACK packet */
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goto send_tcp_nomsg;
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}
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/* Unexpected packet */
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goto unexpected;
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@ -792,12 +779,12 @@ static int tcp_rx ( struct pk_buff *pkb,
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*/
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conn->snd_una = tcphdr->ack - 1;
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conn->tcp_op->connected ( conn );
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tcp_senddata ( conn );
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return 0;
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}
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/* Unexpected packet */
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goto unexpected;
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case TCP_ESTABLISHED:
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#if 0
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if ( tcphdr->flags & TCP_FIN ) {
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tcp_trans ( conn, TCP_CLOSE_WAIT );
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/* FIN consumes one byte */
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@ -806,6 +793,7 @@ static int tcp_rx ( struct pk_buff *pkb,
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/* Send an acknowledgement */
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goto send_tcp_nomsg;
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}
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#endif
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/* Packet might contain data */
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break;
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case TCP_FIN_WAIT_1:
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@ -874,6 +862,9 @@ static int tcp_rx ( struct pk_buff *pkb,
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if ( conn->rcv_nxt == ntohl ( tcphdr->seq ) ) {
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conn->rcv_nxt += toack;
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conn->tcp_op->newdata ( conn, pkb->data + sizeof ( *tcphdr ) + add, toack );
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} else {
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printf ( "Unexpected sequence number %ld\n",
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ntohl ( tcphdr->seq ) );
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}
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/* Acknowledge new data */
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@ -892,13 +883,24 @@ static int tcp_rx ( struct pk_buff *pkb,
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}
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/* Advance snd stream */
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conn->snd_una += acked;
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/* Set the ACK flag */
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conn->tcp_flags |= TCP_ACK;
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/* Invoke the acked() callback function */
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conn->tcp_op->acked ( conn, acked );
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/* Invoke the senddata() callback function */
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tcp_senddata ( conn );
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}
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/* If the connection is in ESTABLISHED and it receives a FIN */
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if ( conn->tcp_state == ESTABLISHED && ( tcphdr->flags & TCP_FIN ) ) {
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tcp_trans ( conn, TCP_CLOSE_WAIT );
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conn->tcp_op->closed ( conn, CONN_SNDCLOSE );
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conn->rcv_nxt++;
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if ( ! ( tcphdr->flags & TCP_ACK ) ) {
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out_flags |= TCP_ACK;
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/* Send an acknowledgement */
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goto send_tcp_nomsg;
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}
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/* Otherwise, the packet has been ACKed already */
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}
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return 0;
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send_tcp_nomsg:
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