libknot: error: unknown type name 'sa_endpoints_t' (support earlier OS?)

[barracuda156]

I have seen that the port is currently restricted to Darwin 15+, so setting priority to low. But maybe this can be fixed? It fails here:

gcc-4.2:

contrib/net.c: In function 'tfo_connect':
contrib/net.c:254: error: 'sa_endpoints_t' undeclared (first use in this function)
contrib/net.c:254: error: (Each undeclared identifier is reported only once
contrib/net.c:254: error: for each function it appears in.)
contrib/net.c:254: error: expected ';' before 'ep'
contrib/net.c:258: error: 'CONNECT_DATA_IDEMPOTENT' undeclared (first use in this function)
contrib/net.c:258: error: 'CONNECT_RESUME_ON_READ_WRITE' undeclared (first use in this function)
contrib/net.c:260: warning: implicit declaration of function 'connectx'
contrib/net.c:260: error: 'ep' undeclared (first use in this function)
contrib/net.c:260: error: 'SAE_ASSOCID_ANY' undeclared (first use in this function)
contrib/semaphore.c:24: warning: ignoring #pragma clang diagnostic
make[3]: *** [contrib/libcontrib_la-net.lo] Error 1

gcc-13:

contrib/net.c: In function 'tfo_connect':
contrib/net.c:254:9: error: unknown type name 'sa_endpoints_t'
  254 |         sa_endpoints_t ep = {
      |         ^~~~~~~~~~~~~~
contrib/net.c:255:17: error: field name not in record or union initializer
  255 |                 .sae_dstaddr = (const struct sockaddr *)addr,
      |                 ^
contrib/net.c:255:17: note: (near initialization for 'ep')
contrib/net.c:255:32: warning: initialization of 'int' from 'const struct sockaddr *' makes integer from pointer without a cast [-Wint-conversion]
  255 |                 .sae_dstaddr = (const struct sockaddr *)addr,
      |                                ^
contrib/net.c:255:32: note: (near initialization for 'ep')
contrib/net.c:256:17: error: field name not in record or union initializer
  256 |                 .sae_dstaddrlen = sockaddr_len(addr)
      |                 ^
contrib/net.c:256:17: note: (near initialization for 'ep')
contrib/net.c:256:35: warning: excess elements in scalar initializer
  256 |                 .sae_dstaddrlen = sockaddr_len(addr)
      |                                   ^~~~~~~~~~~~
contrib/net.c:256:35: note: (near initialization for 'ep')
contrib/net.c:258:22: error: 'CONNECT_DATA_IDEMPOTENT' undeclared (first use in this function)
  258 |         int flags =  CONNECT_DATA_IDEMPOTENT | CONNECT_RESUME_ON_READ_WRITE;
      |                      ^~~~~~~~~~~~~~~~~~~~~~~
contrib/net.c:258:22: note: each undeclared identifier is reported only once for each function it appears in
contrib/net.c:258:48: error: 'CONNECT_RESUME_ON_READ_WRITE' undeclared (first use in this function)
  258 |         int flags =  CONNECT_DATA_IDEMPOTENT | CONNECT_RESUME_ON_READ_WRITE;
      |                                                ^~~~~~~~~~~~~~~~~~~~~~~~~~~~
contrib/net.c:260:19: error: implicit declaration of function 'connectx'; did you mean 'connect'? [-Werror=implicit-function-declaration]
  260 |         int ret = connectx(sock, &ep, SAE_ASSOCID_ANY, flags, NULL, 0, NULL, NULL);
      |                   ^~~~~~~~
      |                   connect
contrib/net.c:260:39: error: 'SAE_ASSOCID_ANY' undeclared (first use in this function)
  260 |         int ret = connectx(sock, &ep, SAE_ASSOCID_ANY, flags, NULL, 0, NULL, NULL);
      |                                       ^~~~~~~~~~~~~~~
cc1: some warnings being treated as errors

[catap (Kirill A. Korinsky)]

Base on ​https://developer.apple.com/documentation/kernel/sa_endpoints_t it is clear that required structure were introduced since 10.11 :)

You may try to add condition to this ifdef that brokes TCP Fast Open feature. Probably it might work after all.