diff options
| -rw-r--r-- | tcp_buf.c | 3 | ||||
| -rw-r--r-- | tcp_conn.h | 10 |
2 files changed, 11 insertions, 2 deletions
@@ -335,6 +335,9 @@ int tcp_buf_data_from_sock(const struct ctx *c, struct tcp_tap_conn *conn, struct iovec *iov; uint32_t seq; + if (!mss) + return 0; + /* Set up buffer descriptors we'll fill completely and partially. */ fill_bufs = DIV_ROUND_UP(wnd_scaled - already_sent, mss); if (fill_bufs > TCP_FRAMES) { @@ -51,8 +51,14 @@ struct tcp_tap_conn { #define TCP_MSS_BITS 14 unsigned int tap_mss :TCP_MSS_BITS; -#define MSS_SET(conn, mss) (conn->tap_mss = (mss >> (16 - TCP_MSS_BITS))) -#define MSS_GET(conn) (conn->tap_mss << (16 - TCP_MSS_BITS)) + + /* Clamp non-zero MSS < 4 to 1 to avoid rounding to zero */ +#define MSS_SET(conn, mss) \ + (conn->tap_mss = (mss) ? MAX(1, (mss) >> (16 - TCP_MSS_BITS)) : 0) + + /* tap_mss is stored as 1 for any non-zero MSS value <= 4 */ +#define MSS_GET(conn) \ + ((conn->tap_mss == 1) ? 1 : (conn->tap_mss << (16 - TCP_MSS_BITS))) #define RTT_EXP_BITS 4 unsigned int rtt_exp :RTT_EXP_BITS; |