Message ID | 20130724161325.38404ed3@nehalam.linuxnetplumber.net |
---|---|
State | Changes Requested, archived |
Delegated to: | David Miller |
Headers | show |
On Wed, 2013-07-24 at 16:13 -0700, Stephen Hemminger wrote: > This patch adds new ioctl to allow setting the ethtool information > returned by the TUN device. This is useful when using tun device as a surrogate > for hardware or other software emulation. I don't like this idea. Which tools are you trying to fool? How does this work when you don't implement any driver-specific behaviour (e.g. SIOCDEVPRIVATE) they expect? > If the application does not override the ethtool settings, the > original hard coded values are used. > > Signed-off-by: Stephen Hemminger <stephen@networkplumber.org> [...] > --- a/include/uapi/linux/if_tun.h 2013-07-24 11:24:55.543040360 -0700 > +++ b/include/uapi/linux/if_tun.h 2013-07-24 11:35:54.620898504 -0700 > @@ -56,6 +56,7 @@ > #define TUNGETVNETHDRSZ _IOR('T', 215, int) > #define TUNSETVNETHDRSZ _IOW('T', 216, int) > #define TUNSETQUEUE _IOW('T', 217, int) > +#define TUNSETINFO _IOW('T', 219, struct tun_info) > > /* TUNSETIFF ifr flags */ > #define IFF_TUN 0x0001 > @@ -103,4 +104,11 @@ struct tun_filter { > __u8 addr[0][ETH_ALEN]; > }; > > +/* Subset of ethtool_info */ > +struct tun_info { > + char driver[32]; > + char bus[32]; > + char version[32]; > +}; > + > #endif /* _UAPI__IF_TUN_H */ What about fw_version? Ben.
On Thu, 25 Jul 2013 00:48:07 +0100 Ben Hutchings <bhutchings@solarflare.com> wrote: > On Wed, 2013-07-24 at 16:13 -0700, Stephen Hemminger wrote: > > This patch adds new ioctl to allow setting the ethtool information > > returned by the TUN device. This is useful when using tun device as a surrogate > > for hardware or other software emulation. > > I don't like this idea. Which tools are you trying to fool? How does > this work when you don't implement any driver-specific behaviour (e.g. > SIOCDEVPRIVATE) they expect? We use surrogate interfaces in user mode application and want to display different information for these than the normal TUN device. -- To unsubscribe from this list: send the line "unsubscribe netdev" in the body of a message to majordomo@vger.kernel.org More majordomo info at http://vger.kernel.org/majordomo-info.html
On Wed, 2013-07-24 at 17:16 -0700, Stephen Hemminger wrote: > On Thu, 25 Jul 2013 00:48:07 +0100 > Ben Hutchings <bhutchings@solarflare.com> wrote: > > > On Wed, 2013-07-24 at 16:13 -0700, Stephen Hemminger wrote: > > > This patch adds new ioctl to allow setting the ethtool information > > > returned by the TUN device. This is useful when using tun device as a surrogate > > > for hardware or other software emulation. > > > > I don't like this idea. Which tools are you trying to fool? How does > > this work when you don't implement any driver-specific behaviour (e.g. > > SIOCDEVPRIVATE) they expect? > > We use surrogate interfaces in user mode application and want to > display different information for these than the normal TUN device. What is the problem that can't be solved purely in userland? Ben.
On Thu, 25 Jul 2013 22:19:17 +0100 Ben Hutchings <bhutchings@solarflare.com> wrote: > On Wed, 2013-07-24 at 17:16 -0700, Stephen Hemminger wrote: > > On Thu, 25 Jul 2013 00:48:07 +0100 > > Ben Hutchings <bhutchings@solarflare.com> wrote: > > > > > On Wed, 2013-07-24 at 16:13 -0700, Stephen Hemminger wrote: > > > > This patch adds new ioctl to allow setting the ethtool information > > > > returned by the TUN device. This is useful when using tun device as a surrogate > > > > for hardware or other software emulation. > > > > > > I don't like this idea. Which tools are you trying to fool? How does > > > this work when you don't implement any driver-specific behaviour (e.g. > > > SIOCDEVPRIVATE) they expect? > > > > We use surrogate interfaces in user mode application and want to > > display different information for these than the normal TUN device. > > What is the problem that can't be solved purely in userland? > > Ben. > There applications (like SNMP) that use ethtool info. -- To unsubscribe from this list: send the line "unsubscribe netdev" in the body of a message to majordomo@vger.kernel.org More majordomo info at http://vger.kernel.org/majordomo-info.html
On Thu, 2013-07-25 at 14:32 -0700, Stephen Hemminger wrote: > On Thu, 25 Jul 2013 22:19:17 +0100 > Ben Hutchings <bhutchings@solarflare.com> wrote: > > > On Wed, 2013-07-24 at 17:16 -0700, Stephen Hemminger wrote: > > > On Thu, 25 Jul 2013 00:48:07 +0100 > > > Ben Hutchings <bhutchings@solarflare.com> wrote: > > > > > > > On Wed, 2013-07-24 at 16:13 -0700, Stephen Hemminger wrote: > > > > > This patch adds new ioctl to allow setting the ethtool information > > > > > returned by the TUN device. This is useful when using tun device as a surrogate > > > > > for hardware or other software emulation. > > > > > > > > I don't like this idea. Which tools are you trying to fool? How does > > > > this work when you don't implement any driver-specific behaviour (e.g. > > > > SIOCDEVPRIVATE) they expect? > > > > > > We use surrogate interfaces in user mode application and want to > > > display different information for these than the normal TUN device. > > > > What is the problem that can't be solved purely in userland? > > > > Ben. > > > > There applications (like SNMP) that use ethtool info. Huh, I never expected they would record the driver and version. So you want them to report the userland software name and version? I can sort of see how this might be useful as part of a test harness, but I would hate to see this get used in production. Users ought to be able to trust that 'ethtool -i' shows them the kernel driver information. Ben.
On Thu, 25 Jul 2013 22:36:22 +0100 Ben Hutchings <bhutchings@solarflare.com> wrote: > On Thu, 2013-07-25 at 14:32 -0700, Stephen Hemminger wrote: > > On Thu, 25 Jul 2013 22:19:17 +0100 > > Ben Hutchings <bhutchings@solarflare.com> wrote: > > > > > On Wed, 2013-07-24 at 17:16 -0700, Stephen Hemminger wrote: > > > > On Thu, 25 Jul 2013 00:48:07 +0100 > > > > Ben Hutchings <bhutchings@solarflare.com> wrote: > > > > > > > > > On Wed, 2013-07-24 at 16:13 -0700, Stephen Hemminger wrote: > > > > > > This patch adds new ioctl to allow setting the ethtool information > > > > > > returned by the TUN device. This is useful when using tun device as a surrogate > > > > > > for hardware or other software emulation. > > > > > > > > > > I don't like this idea. Which tools are you trying to fool? How does > > > > > this work when you don't implement any driver-specific behaviour (e.g. > > > > > SIOCDEVPRIVATE) they expect? > > > > > > > > We use surrogate interfaces in user mode application and want to > > > > display different information for these than the normal TUN device. > > > > > > What is the problem that can't be solved purely in userland? > > > > > > Ben. > > > > > > > There applications (like SNMP) that use ethtool info. > > Huh, I never expected they would record the driver and version. So you > want them to report the userland software name and version? I can sort > of see how this might be useful as part of a test harness, but I would > hate to see this get used in production. Users ought to be able to > trust that 'ethtool -i' shows them the kernel driver information. > > Ben. > It is more the bus info. The user mode driver knows the PCI address of the device it is controlling. -- To unsubscribe from this list: send the line "unsubscribe netdev" in the body of a message to majordomo@vger.kernel.org More majordomo info at http://vger.kernel.org/majordomo-info.html
--- a/drivers/net/tun.c 2013-07-24 11:33:06.759433743 -0700 +++ b/drivers/net/tun.c 2013-07-24 11:39:56.233298852 -0700 @@ -189,6 +189,7 @@ struct tun_struct { u32 flow_count; u32 speed; u8 duplex; + struct tun_info info; }; static inline u32 tun_hashfn(u32 rxhash) @@ -872,9 +873,13 @@ static void tun_net_init(struct net_devi { struct tun_struct *tun = netdev_priv(dev); + strlcpy(tun->info.driver, DRV_NAME, sizeof(tun->info.driver)); + strlcpy(tun->info.version, DRV_VERSION, sizeof(tun->info.version)); + switch (tun->flags & TUN_TYPE_MASK) { case TUN_TUN_DEV: dev->netdev_ops = &tun_netdev_ops; + strlcpy(tun->info.bus, "tun", sizeof(tun->info.bus)); /* Point-to-Point TUN Device */ dev->hard_header_len = 0; @@ -889,6 +894,8 @@ static void tun_net_init(struct net_devi case TUN_TAP_DEV: dev->netdev_ops = &tap_netdev_ops; + strlcpy(tun->info.bus, "tap", sizeof(tun->info.bus)); + /* Ethernet TAP Device */ ether_setup(dev); dev->priv_flags &= ~IFF_TX_SKB_SHARING; @@ -2092,6 +2099,15 @@ static long __tun_chr_ioctl(struct file tun_detach_filter(tun, tun->numqueues); break; + case TUNSETINFO: { + struct tun_info info; + + if (copy_from_user(&info, argp, sizeof(info))) + return -EFAULT; + + tun->info = info; + break; + } default: ret = -EINVAL; break; @@ -2120,6 +2136,7 @@ static long tun_chr_compat_ioctl(struct case TUNSETTXFILTER: case TUNGETSNDBUF: case TUNSETSNDBUF: + case TUNSETINFO: case SIOCGIFHWADDR: case SIOCSIFHWADDR: arg = (unsigned long)compat_ptr(arg); @@ -2267,17 +2284,9 @@ static void tun_get_drvinfo(struct net_d { struct tun_struct *tun = netdev_priv(dev); - strlcpy(info->driver, DRV_NAME, sizeof(info->driver)); - strlcpy(info->version, DRV_VERSION, sizeof(info->version)); - - switch (tun->flags & TUN_TYPE_MASK) { - case TUN_TUN_DEV: - strlcpy(info->bus_info, "tun", sizeof(info->bus_info)); - break; - case TUN_TAP_DEV: - strlcpy(info->bus_info, "tap", sizeof(info->bus_info)); - break; - } + strlcpy(info->driver, tun->info.driver, sizeof(info->driver)); + strlcpy(info->version, tun->info.version, sizeof(info->version)); + strlcpy(info->bus_info, tun->info.bus, sizeof(info->bus_info)); } static u32 tun_get_msglevel(struct net_device *dev) --- a/include/uapi/linux/if_tun.h 2013-07-24 11:24:55.543040360 -0700 +++ b/include/uapi/linux/if_tun.h 2013-07-24 11:35:54.620898504 -0700 @@ -56,6 +56,7 @@ #define TUNGETVNETHDRSZ _IOR('T', 215, int) #define TUNSETVNETHDRSZ _IOW('T', 216, int) #define TUNSETQUEUE _IOW('T', 217, int) +#define TUNSETINFO _IOW('T', 219, struct tun_info) /* TUNSETIFF ifr flags */ #define IFF_TUN 0x0001 @@ -103,4 +104,11 @@ struct tun_filter { __u8 addr[0][ETH_ALEN]; }; +/* Subset of ethtool_info */ +struct tun_info { + char driver[32]; + char bus[32]; + char version[32]; +}; + #endif /* _UAPI__IF_TUN_H */
This patch adds new ioctl to allow setting the ethtool information returned by the TUN device. This is useful when using tun device as a surrogate for hardware or other software emulation. If the application does not override the ethtool settings, the original hard coded values are used. Signed-off-by: Stephen Hemminger <stephen@networkplumber.org> --- drivers/net/tun.c | 56 +++++++++++++++++++++++++++++++++----------- include/uapi/linux/if_tun.h | 15 +++++++++++ 2 files changed, 58 insertions(+), 13 deletions(-) -- To unsubscribe from this list: send the line "unsubscribe netdev" in the body of a message to majordomo@vger.kernel.org More majordomo info at http://vger.kernel.org/majordomo-info.html