For stream-based protocols (TCP), adding less data than requested
("short write") is generally not a problem - the rest of data can
be sent in the next packet. So, make net_pkt_append() return length
of written data instead of just bool flag, which makes it closer
to the behavior of POSIX send()/write() calls.
There're many users of older net_pkt_append() in the codebase
however, so net_pkt_append_all() convenience function is added which
keeps returning a boolean flag. All current users were converted to
this function, except for two:
samples/net/http_server/src/ssl_utils.c
samples/net/mbedtls_sslclient/src/tcp.c
Both are related to TLS and implement mbedTLS "tx callback", which
follows POSIX short-write semantics. Both cases also had a code to
workaround previous boolean-only behavior of net_pkt_append() - after
calling it, they measured length of the actual data added (but only
in case of successful return of net_pkt_append(), so that didn't
really help). So, these 2 cases are already improved.
Jira: ZEP-1984
Change-Id: Ibaf7c029b15e91b516d73dab3612eed190ee982b
Signed-off-by: Paul Sokolovsky <paul.sokolovsky@linaro.org>
25307d5331