net: sockets: Fix sendmsg() user mode param checks

[jukkar]

If we are calling sendmsg() for a connected socket, then msg_namelen
is 0 and msg_name is NULL. Check these allowed values properly.

Also modify unit tests so that we test this scenario.

Fixes #25925

Signed-off-by: Jukka Rissanen jukka.rissanen@linux.intel.com

[ABOSTM]

What about msg_control filed ? is it also optional ?
If not optional then tests/net/socket/socketpair/ should be updated to set this field, otherwise test will still be failed.
If optional the same behaviour than msg_name should be applied to msg_control .

[jukkar]

What about msg_control filed ? is it also optional ?

Yes, it is optional, just forgot to add the checks.

[zephyrbot]

All checks passed.

checkpatch (informational only, not a failure)

-:120: WARNING:LONG_LINE: line over 80 characters
#120: FILE: tests/net/socket/udp/src/main.c:972:
+			 ztest_user_unit_test(test_v4_sendmsg_recvfrom_no_aux_data),

- total: 0 errors, 1 warnings, 110 lines checked

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[ABOSTM]

LGTM