[CC += Fredrik, John, David S., Steven, Oliver, Urs] Hi, On 3/17/21 3:12 PM, Erik Flodin wrote: > Hi, > > The documentation for SIOCGIFFLAGS/SIOCSIFFLAGS in netdevice.7 lists > IFF_LOWER_UP, IFF_DORMANT and IFF_ECHO, but those can't be set in > ifr_flags as it is only a short and the flags start at 1<<16. > > See also https://git.kernel.org/pub/scm/linux/kernel/git/torvalds/linux.git/commit/?id=746e6ad23cd6fec2edce056e014a0eabeffa838c > I don't know what's the history of that. I researched a bit, and while the struct member is indeed a 'short' [1], the flags were added to the kernel for some reason. I added a few people to the thread that may know better what to do.Let's see if they can comment. Links to relevant commits: <https://git.kernel.org/pub/scm/linux/kernel/git/torvalds/linux.git/commit/?id=746e6ad23cd6fec2edce056e014a0eabeffa838c> <https://git.kernel.org/pub/scm/linux/kernel/git/torvalds/linux.git/commit/?id=b00055aacdb172c05067612278ba27265fcd05ce> <https://git.kernel.org/pub/scm/linux/kernel/git/torvalds/linux.git/commit/?id=cd05acfe65ed2cf2db683fa9a6adb8d35635263b> <https://git.kernel.org/pub/scm/docs/man-pages/man-pages.git/commit/?id=6ecda4d14604d250d385346f4fe9de707f281759> Thanks, Alex [1]: .../linux$ sed -n '/struct ifreq {/,/};/p' include/uapi/linux/if.h struct ifreq { #define IFHWADDRLEN 6 union { char ifrn_name[IFNAMSIZ]; /* if name, e.g. "en0" */ } ifr_ifrn; union { struct sockaddr ifru_addr; struct sockaddr ifru_dstaddr; struct sockaddr ifru_broadaddr; struct sockaddr ifru_netmask; struct sockaddr ifru_hwaddr; short ifru_flags; int ifru_ivalue; int ifru_mtu; struct ifmap ifru_map; char ifru_slave[IFNAMSIZ]; /* Just fits the size */ char ifru_newname[IFNAMSIZ]; void __user * ifru_data; struct if_settings ifru_settings; } ifr_ifru; }; .../linux$ grep 'define\sifr_flags' include/uapi/linux/if.h #define ifr_flags ifr_ifru.ifru_flags /* flags */ .../linux$ -- Alejandro Colomar Linux man-pages comaintainer; https://www.kernel.org/doc/man-pages/ http://www.alejandro-colomar.es/
