diff options
Diffstat (limited to 'src')
| -rw-r--r-- | src/net/tcp.c | 33 |
1 files changed, 25 insertions, 8 deletions
diff --git a/src/net/tcp.c b/src/net/tcp.c index 1c48769..987cb63 100644 --- a/src/net/tcp.c +++ b/src/net/tcp.c @@ -16,6 +16,7 @@ #include <ipxe/uri.h> #include <ipxe/netdevice.h> #include <ipxe/profile.h> +#include <ipxe/process.h> #include <ipxe/tcpip.h> #include <ipxe/tcp.h> @@ -107,6 +108,8 @@ struct tcp_connection { struct list_head tx_queue; /** Receive queue */ struct list_head rx_queue; + /** Transmission process */ + struct process process; /** Retransmission timer */ struct retry_timer timer; /** Shutdown (TIME_WAIT) timer */ @@ -166,6 +169,7 @@ static struct profiler tcp_rx_profiler __profiler = { .name = "tcp.rx" }; static struct profiler tcp_xfer_profiler __profiler = { .name = "tcp.xfer" }; /* Forward declarations */ +static struct process_descriptor tcp_process_desc; static struct interface_descriptor tcp_xfer_desc; static void tcp_expired ( struct retry_timer *timer, int over ); static void tcp_wait_expired ( struct retry_timer *timer, int over ); @@ -273,6 +277,7 @@ static int tcp_open ( struct interface *xfer, struct sockaddr *peer, DBGC ( tcp, "TCP %p allocated\n", tcp ); ref_init ( &tcp->refcnt, NULL ); intf_init ( &tcp->xfer, &tcp_xfer_desc, &tcp->refcnt ); + process_init_stopped ( &tcp->process, &tcp_process_desc, &tcp->refcnt ); timer_init ( &tcp->timer, tcp_expired, &tcp->refcnt ); timer_init ( &tcp->wait, tcp_wait_expired, &tcp->refcnt ); tcp->prev_tcp_state = TCP_CLOSED; @@ -369,6 +374,7 @@ static void tcp_close ( struct tcp_connection *tcp, int rc ) { pending_put ( &tcp->pending_flags ); /* Remove from list and drop reference */ + process_del ( &tcp->process ); stop_timer ( &tcp->timer ); stop_timer ( &tcp->wait ); list_del ( &tcp->list ); @@ -497,7 +503,7 @@ static size_t tcp_process_tx_queue ( struct tcp_connection *tcp, size_t max_len, * will have been started if necessary, and so the stack will * eventually attempt to retransmit the failed packet. */ -static int tcp_xmit ( struct tcp_connection *tcp ) { +static void tcp_xmit ( struct tcp_connection *tcp ) { struct io_buffer *iobuf; struct tcp_header *tcphdr; struct tcp_mss_option *mssopt; @@ -517,7 +523,7 @@ static int tcp_xmit ( struct tcp_connection *tcp ) { /* If retransmission timer is already running, do nothing */ if ( timer_running ( &tcp->timer ) ) - return 0; + return; /* Calculate both the actual (payload) and sequence space * lengths that we wish to transmit. @@ -537,7 +543,7 @@ static int tcp_xmit ( struct tcp_connection *tcp ) { /* If we have nothing to transmit, stop now */ if ( ( seq_len == 0 ) && ! ( tcp->flags & TCP_ACK_PENDING ) ) - return 0; + return; /* If we are transmitting anything that requires * acknowledgement (i.e. consumes sequence space), start the @@ -553,7 +559,7 @@ static int tcp_xmit ( struct tcp_connection *tcp ) { DBGC ( tcp, "TCP %p could not allocate iobuf for %08x..%08x " "%08x\n", tcp, tcp->snd_seq, ( tcp->snd_seq + seq_len ), tcp->rcv_ack ); - return -ENOMEM; + return; } iob_reserve ( iobuf, TCP_MAX_HEADER_LEN ); @@ -620,16 +626,19 @@ static int tcp_xmit ( struct tcp_connection *tcp ) { DBGC ( tcp, "TCP %p could not transmit %08x..%08x %08x: %s\n", tcp, tcp->snd_seq, ( tcp->snd_seq + tcp->snd_sent ), tcp->rcv_ack, strerror ( rc ) ); - return rc; + return; } /* Clear ACK-pending flag */ tcp->flags &= ~TCP_ACK_PENDING; profile_stop ( &tcp_tx_profiler ); - return 0; } +/** TCP process descriptor */ +static struct process_descriptor tcp_process_desc = + PROC_DESC_ONCE ( struct tcp_connection, process, tcp_xmit ); + /** * Retransmission timer expired * @@ -1272,8 +1281,16 @@ static int tcp_rx ( struct io_buffer *iobuf, /* Dump out any state change as a result of the received packet */ tcp_dump_state ( tcp ); - /* Send out any pending data */ - tcp_xmit ( tcp ); + /* Schedule transmission of ACK (and any pending data). If we + * have received any out-of-order packets (i.e. if the receive + * queue remains non-empty after processing) then send the ACK + * immediately in order to trigger Fast Retransmission. + */ + if ( list_empty ( &tcp->rx_queue ) ) { + process_add ( &tcp->process ); + } else { + tcp_xmit ( tcp ); + } /* If this packet was the last we expect to receive, set up * timer to expire and cause the connection to be freed. |