Author: se Date: Sat Oct 31 23:48:41 2020 New Revision: 367243 URL: https://svnweb.freebsd.org/changeset/base/367243
Log: Make sysctl user.local a tunable that can be written at run-time This sysctl value had been provided as a read-only variable that is compiled into the C library based on the value of _PATH_LOCALBASE in paths.h. After this change, the value is compiled into the kernel as an empty string, which is translated to _PATH_LOCALBASE by the C library. This empty string can be overridden at boot time or by a privileged user at run time and will then be returned by sysctl. When set to an empty string, the value returned by sysctl reverts to _PATH_LOCALBASE. This update does not change the behavior on any system that does not modify the default value of user.localbase. I consider this change as experimental and would prefer if the run-time write permission was reconsidered and the sysctl variable defined with CLFLAG_RDTUN instead to restrict it to be set at boot time. MFC after: 1 month Modified: head/lib/libc/gen/sysctl.c head/sys/kern/kern_mib.c Modified: head/lib/libc/gen/sysctl.c ============================================================================== --- head/lib/libc/gen/sysctl.c Sat Oct 31 23:19:59 2020 (r367242) +++ head/lib/libc/gen/sysctl.c Sat Oct 31 23:48:41 2020 (r367243) @@ -68,14 +68,14 @@ sysctl(const int *name, u_int namelen, void *oldp, siz if (retval || name[0] != CTL_USER) return (retval); - if (newp != NULL) { - errno = EPERM; - return (-1); - } if (namelen != 2) { errno = EINVAL; return (-1); } + if (newp != NULL && name[1] != USER_LOCALBASE) { + errno = EPERM; + return (-1); + } switch (name[1]) { case USER_CS_PATH: @@ -88,13 +88,21 @@ sysctl(const int *name, u_int namelen, void *oldp, siz memmove(oldp, _PATH_STDPATH, sizeof(_PATH_STDPATH)); return (0); case USER_LOCALBASE: - if (oldp != NULL && orig_oldlen < sizeof(_PATH_LOCALBASE)) { - errno = ENOMEM; - return (-1); + if (oldlenp != NULL) { + if (oldp == NULL) { + if (*oldlenp == 1) + *oldlenp = sizeof(_PATH_LOCALBASE); + } else { + if (*oldlenp != 1) + return (retval); + if (orig_oldlen < sizeof(_PATH_LOCALBASE)) { + errno = ENOMEM; + return (-1); + } + *oldlenp = sizeof(_PATH_LOCALBASE); + memmove(oldp, _PATH_LOCALBASE, sizeof(_PATH_LOCALBASE)); + } } - *oldlenp = sizeof(_PATH_LOCALBASE); - if (oldp != NULL) - memmove(oldp, _PATH_LOCALBASE, sizeof(_PATH_LOCALBASE)); return (0); } Modified: head/sys/kern/kern_mib.c ============================================================================== --- head/sys/kern/kern_mib.c Sat Oct 31 23:19:59 2020 (r367242) +++ head/sys/kern/kern_mib.c Sat Oct 31 23:48:41 2020 (r367243) @@ -652,8 +652,11 @@ SYSCTL_INT(_user, USER_STREAM_MAX, stream_max, CTLFLAG SYSCTL_NULL_INT_PTR, 0, "Min Maximum number of streams a process may have open at one time"); SYSCTL_INT(_user, USER_TZNAME_MAX, tzname_max, CTLFLAG_RD, SYSCTL_NULL_INT_PTR, 0, "Min Maximum number of types supported for timezone names"); -SYSCTL_STRING(_user, USER_LOCALBASE, localbase, CTLFLAG_RD, - "", 0, "Prefix used to install and locate add-on packages"); + +static char localbase[MAXPATHLEN] = ""; + +SYSCTL_STRING(_user, USER_LOCALBASE, localbase, CTLFLAG_RWTUN, + localbase, sizeof(localbase), "Prefix used to install and locate add-on packages"); #include <sys/vnode.h> SYSCTL_INT(_debug_sizeof, OID_AUTO, vnode, CTLFLAG_RD, _______________________________________________ svn-src-head@freebsd.org mailing list https://lists.freebsd.org/mailman/listinfo/svn-src-head To unsubscribe, send any mail to "svn-src-head-unsubscr...@freebsd.org"