posix: add networking apis

[cfriedt]

Add implementations (some fully supported, some stubs) for the remaining POSIX networking API calls

endhostent
endnetent
endprotoent
endservent
gethostent
getnetbyaddr
getnetbyname
getnetent
getprotobyname
getprotobynumber
getprotoent
getservbyname
getservbyport
getservent
if_freenameindex
if_indextoname
if_nameindex
if_nametoindex
inet_addr
inet_ntoa
sethostent
setnetent
setprotoent
setservent
sockatmark

With this, and with existing network subsystem API, we have mostly complete support for the POSIX_NETWORKING Option Group, as described in Section E.1 of IEEE 1003.1-2017.

The POSIX_NETWORKING Option Group is required by PSE53 and PSE54 Application Environment Profiles.

[jukkar]

Thanks Chris, looks very good 🙇‍♂️

[cfriedt]

Had to add a cast to int in calls to isdigit() and isspace() for newlib to avoid these warnings being promoted to errors.

/__w/zephyr/zephyr/lib/posix/options/net.c: In function 'inet_addr':
/__w/zephyr/zephyr/lib/posix/options/net.c:41:38: error: array subscript has type 'char' [-Werror=char-subscripts]
   41 |                 } else if (isdigit(cp[i])) {
      |                                    ~~^~~
/__w/zephyr/zephyr/lib/posix/options/net.c:45:38: error: array subscript has type 'char' [-Werror=char-subscripts]
   45 |                 } else if (isspace(cp[i])) {
      |                                    ~~^~~
cc1: all warnings being treated as errors

[cfriedt]

This is running fine locally with net-setup.sh from net-tools first and then west build -p auto -b qemu_x86 -t run tests/posix/net. Twister runs fine locally too with twister -i -p qemu_x86 -T tests/posix/net/

Am I missing something obvious for CI to pass?

*** Booting Zephyr OS build v3.6.0-1560-g064b91cf8792 ***
Running TESTSUITE net
===================================================================
START - test_if_freenameindex
 PASS - test_if_freenameindex in 0.001 seconds
===================================================================
START - test_if_indextoname
1 interfaces
interface 1: eth0
 PASS - test_if_indextoname in 0.001 seconds
===================================================================
START - test_if_nameindex
1 interfaces
interface 1: eth0
 PASS - test_if_nameindex in 0.001 seconds
===================================================================
START - test_if_nametoindex
1 interfaces
interface 1: eth0
 PASS - test_if_nametoindex in 0.001 seconds
===================================================================
START - test_inet_addr
 PASS - test_inet_addr in 0.001 seconds
===================================================================
START - test_inet_ntoa
 PASS - test_inet_ntoa in 0.001 seconds
===================================================================
TESTSUITE net succeeded

------ TESTSUITE SUMMARY START ------

SUITE PASS - 100.00% [net]: pass = 6, fail = 0, skip = 0, total = 6 duration = 0.006 seconds
 - PASS - [net.test_if_freenameindex] duration = 0.001 seconds
 - PASS - [net.test_if_indextoname] duration = 0.001 seconds
 - PASS - [net.test_if_nameindex] duration = 0.001 seconds
 - PASS - [net.test_if_nametoindex] duration = 0.001 seconds
 - PASS - [net.test_inet_addr] duration = 0.001 seconds
 - PASS - [net.test_inet_ntoa] duration = 0.001 seconds

------ TESTSUITE SUMMARY END ------

===================================================================
PROJECT EXECUTION SUCCESSFUL