altcp is an abstraction layer that prevents applications linking against the
tcp.h functions but provides the same functionality. It is used to e.g. add
SSL/TLS or proxy-connect support to an application written for the tcp callback
API without that application knowing the protocol details.
Applications written against the altcp API are directly linked against the
tcp callback API for LWIP_ALTCP==0, but then cannot use layered protocols.
User should not use ppp_connect or ppp_listen return value to retry
later, it must wait for the callback to be called. This is primarily
done this way to have a consistent behavior with and without the
holdoff feature.
Remove returned error value from PPP link level API connect and listen
callbacks because we are not using them anymore, then make ppp_connect
or ppp_listen to always return ERR_OK, thus we are not breaking the PPP
user API.
We don't need the return code here, all PPP link level drivers can't
fail at all (e.g. PPPoS) or retry if necessary (PPPoE and PPPoL2TP).
This commit adds support to the netconn write APIs to take an input of
vectors instead of a single data pointer
This allows vectors sent on a TCP connection via sendmsg to be treated
atomically. The set of vectors is segmented into as much data as can
fit into the send buffer and then the TCP output function is called
Previously, each vector was passed to netconn_write_partly and tcp_write
segmented it into its own packet, which was then it was sent via
tcp_output (if not Nagleing)
This commit adds vector support to lwip_netconn_do_writemore() which
is the meat of the TCP write functionality from netconn/sockets layer.
A new netconn API netconn_write_vectors_partly() takes a set of vectors
as input and hooks up to do_writemore()
This commit also defines IOV_MAX because we are limited to only
supporting 65535 vectors due to choice of u16_t for the vector count
Create new function dhcp_release_and_stop() that stops DHCP statemachine and sends release message if needed. Also stops AUTOIP if in coop mode.
Old dhcp_release() and dhcp_stop() function internally call dhcp_release_and_stop() now.
lwIP aims to support zero-copy TX, and thus, must internally handle
all cases that pbufs are referenced rather than copied upon low-level
output. However, in the current situation, the arp/ndp packet queuing
routines conservatively copy entire packets, even when unnecessary in
cases where lwIP is used in a zero-copy compliant manner. This patch
moves the decision whether to copy into a centralized macro, allowing
zero-copy compliant applications to override the macro to avoid the
unnecessary copies. The macro defaults to the safe behavior, though.
This commit makes a couple of cleanups discussed in patch #8882:
1) msg.w.offset should not be set to 0 in the error case. It is
only valid when err == ERR_OK
2) Remove out-of-date comment which indicated the entire write had
completed (not true for non-blocking write)
This also updates the documentation on offset to include that offset
is only valid when err == ERR_OK
