mqueues: Add support for _SC_MQ_OPEN_MAX in sysconf(3).

P1B_SYSCTL() / p31b_setcfg() as found in kern/kern_posix4_mib.c
don't fit well for writeable sysctls.

diff --git a/lib/libc/gen/sysconf.c b/lib/libc/gen/sysconf.c
index aa73f45..2025bfc 100644 (file)
--- a/lib/libc/gen/sysconf.c
+++ b/lib/libc/gen/sysconf.c
@@ -279,10 +279,6 @@ do_NAME_MAX:
                mib[0] = CTL_P1003_1B;
                mib[1] = CTL_P1003_1B_DELAYTIMER_MAX;
                goto yesno;
-       case _SC_MQ_OPEN_MAX:
-               mib[0] = CTL_P1003_1B;
-               mib[1] = CTL_P1003_1B_MQ_OPEN_MAX;
-               goto yesno;
        case _SC_PAGESIZE:
                defaultresult = getpagesize();
                mib[0] = CTL_P1003_1B;
@@ -381,6 +377,13 @@ yesno:
 #else
                return (_POSIX_MONOTONIC_CLOCK);
 #endif
+       case _SC_MQ_OPEN_MAX:
+               len = sizeof(lvalue);
+               if (sysctlbyname("kern.mqueue.mq_open_max", &lvalue, &len,
+                       NULL, 0) == -1)
+                       return (-1);
+               return (lvalue);        
+               
        case _SC_MQ_PRIO_MAX:
                len = sizeof(lvalue);
                if (sysctlbyname("kern.mqueue.mq_prio_max", &lvalue, &len,