> On 21. märts 2017, at 17:15, Ian Lepore <i...@freebsd.org> wrote: > > On Tue, 2017-03-21 at 15:35 +0300, Slawa Olhovchenkov wrote: >> On Mon, Mar 20, 2017 at 10:20:17PM +0000, Toomas Soome wrote: >> >>> >>> Author: tsoome >>> Date: Mon Mar 20 22:20:17 2017 >>> New Revision: 315653 >>> URL: https://svnweb.freebsd.org/changeset/base/315653 >>> >>> Log: >>> loader: verify the value from dhcp.interface-mtu and use snprintf >>> to set mtu >>> >>> Since the uset can set dhcp.interface-mtu, we need to try to >>> validate the >>> value. So we verify if the conversion to int is successful and we >>> will not >>> allow to set value greater than max IPv4 packet size. >>> >>> + tmp > USHRT_MAX) { >>> + printf("%s: bad value: >>> \"%s\", " >>> + "ignoring\n", >>> + "dhcp.interface-mtu", >>> val); >> === >> USHRT_MAX Maximum value for an object of type unsigned short >> int >> 65535 (216-1) or greater* >> >> * the actual value depends on the particular system and library >> implementation, but shall reflect the limits of these types in the >> target platform. >> === >> >> I mean IF_MAXMTU more correct. >> > > The context here is libstand; because it is standalone by design, the > code doesn't have access to IF_MAXMTU or other kernel/userland > constants. There is also no question that a short is 16 bits or that > USHRT_MAX will be anything other than 65535 in that environment. If > some platform did appear that had a different-sized short by default, > we would add whatever flags are necessary to force it back to 16 bits > in src/share/mk/bsd.stand.mk. >
Also note the “upper” value is entirely fictional - we felt we need to pick some “sane” default, with current (common 1Gb/s) ethernet hardware you will be in trouble long before reaching that value;) rgds, toomas _______________________________________________ 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"
