Although we have an abstraction for the "slow path" (DHCP, NDP) guest bound packets, the TCP and UDP forwarding paths write directly to the tap fd. However, it turns out how they send frames to the tap device is more similar than it originally appears. This series unifies the low-level tap send functions for TCP and UDP, and makes some clean ups along the way. This is based on my earlier outstanding series. Changes since v2: * Rebase on the latest version of the UDP tap/splice socket unification * Rework pcap_frame() to return an error rather than printing itself, restoring less verbose behaviour for one error in a group of frames. * Assorted typo fixes in comments and commit messages Changes since v1: * Abstract tap header construction as well as frame send (a number of new patches) * Remove unneeded flags buf_bytes globals as well * Fix bug where we weren't correctly setting iov_len after the move to giving variable sized iovecs to send_frames(). David Gibson (18): pcap: Introduce pcap_frame() helper pcap: Replace pcapm() with pcap_multiple() tcp: Combine two parts of passt tap send path together tcp: Don't compute total bytes in a message until we need it tcp: Improve interface to tcp_l2_buf_flush() tcp: Combine two parts of pasta tap send path together tap, tcp: Move tap send path to tap.c util: Introduce hton*_constant() in place of #ifdefs tcp, udp: Use named field initializers in iov_init functions util: Parameterize ethernet header initializer macro tcp: Remove redundant and incorrect initialization from *_iov_init() tcp: Consolidate calculation of total frame size tap: Add "tap headers" abstraction tcp: Use abstracted tap header tap: Use different io vector bases depending on tap type udp: Use abstracted tap header tap: Improve handling of partial frame sends udp: Use tap_send_frames() dhcpv6.c | 50 +++-------- pcap.c | 86 ++++++------------- pcap.h | 3 +- tap.c | 121 ++++++++++++++++++++++++++ tap.h | 54 ++++++++++++ tcp.c | 254 +++++++++++++------------------------------------------ udp.c | 213 ++++++---------------------------------------- udp.h | 2 +- util.h | 47 ++-------- 9 files changed, 310 insertions(+), 520 deletions(-) -- 2.39.0