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jarodwilsondavem330
jarodwilson
authored and
davem330
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net: use core MTU range checking in core net infra
geneve: - Merge __geneve_change_mtu back into geneve_change_mtu, set max_mtu - This one isn't quite as straight-forward as others, could use some closer inspection and testing macvlan: - set min/max_mtu tun: - set min/max_mtu, remove tun_net_change_mtu vxlan: - Merge __vxlan_change_mtu back into vxlan_change_mtu - Set max_mtu to IP_MAX_MTU and retain dynamic MTU range checks in change_mtu function - This one is also not as straight-forward and could use closer inspection and testing from vxlan folks bridge: - set max_mtu of IP_MAX_MTU and retain dynamic MTU range checks in change_mtu function openvswitch: - set min/max_mtu, remove internal_dev_change_mtu - note: max_mtu wasn't checked previously, it's been set to 65535, which is the largest possible size supported sch_teql: - set min/max_mtu (note: max_mtu previously unchecked, used max of 65535) macsec: - min_mtu = 0, max_mtu = 65535 macvlan: - min_mtu = 0, max_mtu = 65535 ntb_netdev: - min_mtu = 0, max_mtu = 65535 veth: - min_mtu = 68, max_mtu = 65535 8021q: - min_mtu = 0, max_mtu = 65535 CC: [email protected] CC: Nicolas Dichtel <[email protected]> CC: Hannes Frederic Sowa <[email protected]> CC: Tom Herbert <[email protected]> CC: Daniel Borkmann <[email protected]> CC: Alexander Duyck <[email protected]> CC: Paolo Abeni <[email protected]> CC: Jiri Benc <[email protected]> CC: WANG Cong <[email protected]> CC: Roopa Prabhu <[email protected]> CC: Pravin B Shelar <[email protected]> CC: Sabrina Dubroca <[email protected]> CC: Patrick McHardy <[email protected]> CC: Stephen Hemminger <[email protected]> CC: Pravin Shelar <[email protected]> CC: Maxim Krasnyansky <[email protected]> Signed-off-by: Jarod Wilson <[email protected]> Signed-off-by: David S. Miller <[email protected]>
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11 files changed

+81
-102
lines changed

11 files changed

+81
-102
lines changed

‎drivers/net/geneve.c

Lines changed: 19 additions & 29 deletions
Original file line numberDiff line numberDiff line change
@@ -1034,39 +1034,18 @@ static netdev_tx_t geneve_xmit(struct sk_buff *skb, struct net_device *dev)
10341034
return geneve_xmit_skb(skb, dev, info);
10351035
}
10361036

1037-
static int __geneve_change_mtu(struct net_device *dev, int new_mtu, bool strict)
1037+
static int geneve_change_mtu(struct net_device *dev, int new_mtu)
10381038
{
1039-
struct geneve_dev *geneve = netdev_priv(dev);
1040-
/* The max_mtu calculation does not take account of GENEVE
1041-
* options, to avoid excluding potentially valid
1042-
* configurations.
1039+
/* Only possible if called internally, ndo_change_mtu path's new_mtu
1040+
* is guaranteed to be between dev->min_mtu and dev->max_mtu.
10431041
*/
1044-
int max_mtu = IP_MAX_MTU - GENEVE_BASE_HLEN - dev->hard_header_len;
1045-
1046-
if (geneve->remote.sa.sa_family == AF_INET6)
1047-
max_mtu -= sizeof(struct ipv6hdr);
1048-
else
1049-
max_mtu -= sizeof(struct iphdr);
1050-
1051-
if (new_mtu < 68)
1052-
return -EINVAL;
1053-
1054-
if (new_mtu > max_mtu) {
1055-
if (strict)
1056-
return -EINVAL;
1057-
1058-
new_mtu = max_mtu;
1059-
}
1042+
if (new_mtu > dev->max_mtu)
1043+
new_mtu = dev->max_mtu;
10601044

10611045
dev->mtu = new_mtu;
10621046
return 0;
10631047
}
10641048

1065-
static int geneve_change_mtu(struct net_device *dev, int new_mtu)
1066-
{
1067-
return __geneve_change_mtu(dev, new_mtu, true);
1068-
}
1069-
10701049
static int geneve_fill_metadata_dst(struct net_device *dev, struct sk_buff *skb)
10711050
{
10721051
struct ip_tunnel_info *info = skb_tunnel_info(skb);
@@ -1170,6 +1149,14 @@ static void geneve_setup(struct net_device *dev)
11701149
dev->hw_features |= NETIF_F_SG | NETIF_F_HW_CSUM | NETIF_F_RXCSUM;
11711150
dev->hw_features |= NETIF_F_GSO_SOFTWARE;
11721151

1152+
/* MTU range: 68 - (something less than 65535) */
1153+
dev->min_mtu = ETH_MIN_MTU;
1154+
/* The max_mtu calculation does not take account of GENEVE
1155+
* options, to avoid excluding potentially valid
1156+
* configurations. This will be further reduced by IPvX hdr size.
1157+
*/
1158+
dev->max_mtu = IP_MAX_MTU - GENEVE_BASE_HLEN - dev->hard_header_len;
1159+
11731160
netif_keep_dst(dev);
11741161
dev->priv_flags &= ~IFF_TX_SKB_SHARING;
11751162
dev->priv_flags |= IFF_LIVE_ADDR_CHANGE | IFF_NO_QUEUE;
@@ -1285,10 +1272,13 @@ static int geneve_configure(struct net *net, struct net_device *dev,
12851272

12861273
/* make enough headroom for basic scenario */
12871274
encap_len = GENEVE_BASE_HLEN + ETH_HLEN;
1288-
if (remote->sa.sa_family == AF_INET)
1275+
if (remote->sa.sa_family == AF_INET) {
12891276
encap_len += sizeof(struct iphdr);
1290-
else
1277+
dev->max_mtu -= sizeof(struct iphdr);
1278+
} else {
12911279
encap_len += sizeof(struct ipv6hdr);
1280+
dev->max_mtu -= sizeof(struct ipv6hdr);
1281+
}
12921282
dev->needed_headroom = encap_len + ETH_HLEN;
12931283

12941284
if (metadata) {
@@ -1488,7 +1478,7 @@ struct net_device *geneve_dev_create_fb(struct net *net, const char *name,
14881478
/* openvswitch users expect packet sizes to be unrestricted,
14891479
* so set the largest MTU we can.
14901480
*/
1491-
err = __geneve_change_mtu(dev, IP_MAX_MTU, false);
1481+
err = geneve_change_mtu(dev, IP_MAX_MTU);
14921482
if (err)
14931483
goto err;
14941484

‎drivers/net/macsec.c

Lines changed: 2 additions & 0 deletions
Original file line numberDiff line numberDiff line change
@@ -2970,6 +2970,8 @@ static void macsec_free_netdev(struct net_device *dev)
29702970
static void macsec_setup(struct net_device *dev)
29712971
{
29722972
ether_setup(dev);
2973+
dev->min_mtu = 0;
2974+
dev->max_mtu = ETH_MAX_MTU;
29732975
dev->priv_flags |= IFF_NO_QUEUE;
29742976
dev->netdev_ops = &macsec_netdev_ops;
29752977
dev->destructor = macsec_free_netdev;

‎drivers/net/macvlan.c

Lines changed: 7 additions & 1 deletion
Original file line numberDiff line numberDiff line change
@@ -777,7 +777,7 @@ static int macvlan_change_mtu(struct net_device *dev, int new_mtu)
777777
{
778778
struct macvlan_dev *vlan = netdev_priv(dev);
779779

780-
if (new_mtu < 68 || vlan->lowerdev->mtu < new_mtu)
780+
if (vlan->lowerdev->mtu < new_mtu)
781781
return -EINVAL;
782782
dev->mtu = new_mtu;
783783
return 0;
@@ -1085,6 +1085,8 @@ void macvlan_common_setup(struct net_device *dev)
10851085
{
10861086
ether_setup(dev);
10871087

1088+
dev->min_mtu = 0;
1089+
dev->max_mtu = ETH_MAX_MTU;
10881090
dev->priv_flags &= ~IFF_TX_SKB_SHARING;
10891091
netif_keep_dst(dev);
10901092
dev->priv_flags |= IFF_UNICAST_FLT;
@@ -1297,6 +1299,10 @@ int macvlan_common_newlink(struct net *src_net, struct net_device *dev,
12971299
else if (dev->mtu > lowerdev->mtu)
12981300
return -EINVAL;
12991301

1302+
/* MTU range: 68 - lowerdev->max_mtu */
1303+
dev->min_mtu = ETH_MIN_MTU;
1304+
dev->max_mtu = lowerdev->max_mtu;
1305+
13001306
if (!tb[IFLA_ADDRESS])
13011307
eth_hw_addr_random(dev);
13021308

‎drivers/net/ntb_netdev.c

Lines changed: 3 additions & 0 deletions
Original file line numberDiff line numberDiff line change
@@ -433,6 +433,9 @@ static int ntb_netdev_probe(struct device *client_dev)
433433
ndev->netdev_ops = &ntb_netdev_ops;
434434
ndev->ethtool_ops = &ntb_ethtool_ops;
435435

436+
ndev->min_mtu = 0;
437+
ndev->max_mtu = ETH_MAX_MTU;
438+
436439
dev->qp = ntb_transport_create_queue(ndev, client_dev,
437440
&ntb_netdev_handlers);
438441
if (!dev->qp) {

‎drivers/net/tun.c

Lines changed: 6 additions & 14 deletions
Original file line numberDiff line numberDiff line change
@@ -925,18 +925,6 @@ static void tun_net_mclist(struct net_device *dev)
925925
*/
926926
}
927927

928-
#define MIN_MTU 68
929-
#define MAX_MTU 65535
930-
931-
static int
932-
tun_net_change_mtu(struct net_device *dev, int new_mtu)
933-
{
934-
if (new_mtu < MIN_MTU || new_mtu + dev->hard_header_len > MAX_MTU)
935-
return -EINVAL;
936-
dev->mtu = new_mtu;
937-
return 0;
938-
}
939-
940928
static netdev_features_t tun_net_fix_features(struct net_device *dev,
941929
netdev_features_t features)
942930
{
@@ -1014,7 +1002,6 @@ static const struct net_device_ops tun_netdev_ops = {
10141002
.ndo_open = tun_net_open,
10151003
.ndo_stop = tun_net_close,
10161004
.ndo_start_xmit = tun_net_xmit,
1017-
.ndo_change_mtu = tun_net_change_mtu,
10181005
.ndo_fix_features = tun_net_fix_features,
10191006
.ndo_select_queue = tun_select_queue,
10201007
#ifdef CONFIG_NET_POLL_CONTROLLER
@@ -1029,7 +1016,6 @@ static const struct net_device_ops tap_netdev_ops = {
10291016
.ndo_open = tun_net_open,
10301017
.ndo_stop = tun_net_close,
10311018
.ndo_start_xmit = tun_net_xmit,
1032-
.ndo_change_mtu = tun_net_change_mtu,
10331019
.ndo_fix_features = tun_net_fix_features,
10341020
.ndo_set_rx_mode = tun_net_mclist,
10351021
.ndo_set_mac_address = eth_mac_addr,
@@ -1062,6 +1048,9 @@ static void tun_flow_uninit(struct tun_struct *tun)
10621048
tun_flow_flush(tun);
10631049
}
10641050

1051+
#define MIN_MTU 68
1052+
#define MAX_MTU 65535
1053+
10651054
/* Initialize net device. */
10661055
static void tun_net_init(struct net_device *dev)
10671056
{
@@ -1092,6 +1081,9 @@ static void tun_net_init(struct net_device *dev)
10921081

10931082
break;
10941083
}
1084+
1085+
dev->min_mtu = MIN_MTU;
1086+
dev->max_mtu = MAX_MTU - dev->hard_header_len;
10951087
}
10961088

10971089
/* Character device part */

‎drivers/net/veth.c

Lines changed: 3 additions & 14 deletions
Original file line numberDiff line numberDiff line change
@@ -23,9 +23,6 @@
2323
#define DRV_NAME "veth"
2424
#define DRV_VERSION "1.0"
2525

26-
#define MIN_MTU 68 /* Min L3 MTU */
27-
#define MAX_MTU 65535 /* Max L3 MTU (arbitrary) */
28-
2926
struct pcpu_vstats {
3027
u64 packets;
3128
u64 bytes;
@@ -216,17 +213,9 @@ static int veth_close(struct net_device *dev)
216213
return 0;
217214
}
218215

219-
static int is_valid_veth_mtu(int new_mtu)
216+
static int is_valid_veth_mtu(int mtu)
220217
{
221-
return new_mtu >= MIN_MTU && new_mtu <= MAX_MTU;
222-
}
223-
224-
static int veth_change_mtu(struct net_device *dev, int new_mtu)
225-
{
226-
if (!is_valid_veth_mtu(new_mtu))
227-
return -EINVAL;
228-
dev->mtu = new_mtu;
229-
return 0;
218+
return mtu >= ETH_MIN_MTU && mtu <= ETH_MAX_MTU;
230219
}
231220

232221
static int veth_dev_init(struct net_device *dev)
@@ -300,7 +289,6 @@ static const struct net_device_ops veth_netdev_ops = {
300289
.ndo_open = veth_open,
301290
.ndo_stop = veth_close,
302291
.ndo_start_xmit = veth_xmit,
303-
.ndo_change_mtu = veth_change_mtu,
304292
.ndo_get_stats64 = veth_get_stats64,
305293
.ndo_set_rx_mode = veth_set_multicast_list,
306294
.ndo_set_mac_address = eth_mac_addr,
@@ -337,6 +325,7 @@ static void veth_setup(struct net_device *dev)
337325
NETIF_F_HW_VLAN_CTAG_RX |
338326
NETIF_F_HW_VLAN_STAG_RX);
339327
dev->destructor = veth_dev_free;
328+
dev->max_mtu = ETH_MAX_MTU;
340329

341330
dev->hw_features = VETH_FEATURES;
342331
dev->hw_enc_features = VETH_FEATURES;

‎drivers/net/vxlan.c

Lines changed: 34 additions & 30 deletions
Original file line numberDiff line numberDiff line change
@@ -2367,43 +2367,31 @@ static void vxlan_set_multicast_list(struct net_device *dev)
23672367
{
23682368
}
23692369

2370-
static int __vxlan_change_mtu(struct net_device *dev,
2371-
struct net_device *lowerdev,
2372-
struct vxlan_rdst *dst, int new_mtu, bool strict)
2370+
static int vxlan_change_mtu(struct net_device *dev, int new_mtu)
23732371
{
2374-
int max_mtu = IP_MAX_MTU;
2375-
2376-
if (lowerdev)
2377-
max_mtu = lowerdev->mtu;
2372+
struct vxlan_dev *vxlan = netdev_priv(dev);
2373+
struct vxlan_rdst *dst = &vxlan->default_dst;
2374+
struct net_device *lowerdev = __dev_get_by_index(vxlan->net,
2375+
dst->remote_ifindex);
2376+
bool use_ipv6 = false;
23782377

23792378
if (dst->remote_ip.sa.sa_family == AF_INET6)
2380-
max_mtu -= VXLAN6_HEADROOM;
2381-
else
2382-
max_mtu -= VXLAN_HEADROOM;
2383-
2384-
if (new_mtu < 68)
2385-
return -EINVAL;
2379+
use_ipv6 = true;
23862380

2387-
if (new_mtu > max_mtu) {
2388-
if (strict)
2381+
/* This check is different than dev->max_mtu, because it looks at
2382+
* the lowerdev->mtu, rather than the static dev->max_mtu
2383+
*/
2384+
if (lowerdev) {
2385+
int max_mtu = lowerdev->mtu -
2386+
(use_ipv6 ? VXLAN6_HEADROOM : VXLAN_HEADROOM);
2387+
if (new_mtu > max_mtu)
23892388
return -EINVAL;
2390-
2391-
new_mtu = max_mtu;
23922389
}
23932390

23942391
dev->mtu = new_mtu;
23952392
return 0;
23962393
}
23972394

2398-
static int vxlan_change_mtu(struct net_device *dev, int new_mtu)
2399-
{
2400-
struct vxlan_dev *vxlan = netdev_priv(dev);
2401-
struct vxlan_rdst *dst = &vxlan->default_dst;
2402-
struct net_device *lowerdev = __dev_get_by_index(vxlan->net,
2403-
dst->remote_ifindex);
2404-
return __vxlan_change_mtu(dev, lowerdev, dst, new_mtu, true);
2405-
}
2406-
24072395
static int vxlan_fill_metadata_dst(struct net_device *dev, struct sk_buff *skb)
24082396
{
24092397
struct vxlan_dev *vxlan = netdev_priv(dev);
@@ -2795,6 +2783,10 @@ static int vxlan_dev_configure(struct net *src_net, struct net_device *dev,
27952783
vxlan_ether_setup(dev);
27962784
}
27972785

2786+
/* MTU range: 68 - 65535 */
2787+
dev->min_mtu = ETH_MIN_MTU;
2788+
dev->max_mtu = ETH_MAX_MTU;
2789+
27982790
vxlan->net = src_net;
27992791

28002792
dst->remote_vni = conf->vni;
@@ -2838,7 +2830,8 @@ static int vxlan_dev_configure(struct net *src_net, struct net_device *dev,
28382830
#endif
28392831

28402832
if (!conf->mtu)
2841-
dev->mtu = lowerdev->mtu - (use_ipv6 ? VXLAN6_HEADROOM : VXLAN_HEADROOM);
2833+
dev->mtu = lowerdev->mtu -
2834+
(use_ipv6 ? VXLAN6_HEADROOM : VXLAN_HEADROOM);
28422835

28432836
needed_headroom = lowerdev->hard_header_len;
28442837
} else if (vxlan_addr_multicast(&dst->remote_ip)) {
@@ -2847,9 +2840,20 @@ static int vxlan_dev_configure(struct net *src_net, struct net_device *dev,
28472840
}
28482841

28492842
if (conf->mtu) {
2850-
err = __vxlan_change_mtu(dev, lowerdev, dst, conf->mtu, false);
2851-
if (err)
2852-
return err;
2843+
int max_mtu = ETH_MAX_MTU;
2844+
2845+
if (lowerdev)
2846+
max_mtu = lowerdev->mtu;
2847+
2848+
max_mtu -= (use_ipv6 ? VXLAN6_HEADROOM : VXLAN_HEADROOM);
2849+
2850+
if (conf->mtu < dev->min_mtu || conf->mtu > dev->max_mtu)
2851+
return -EINVAL;
2852+
2853+
dev->mtu = conf->mtu;
2854+
2855+
if (conf->mtu > max_mtu)
2856+
dev->mtu = max_mtu;
28532857
}
28542858

28552859
if (use_ipv6 || conf->flags & VXLAN_F_COLLECT_METADATA)

‎net/8021q/vlan_dev.c

Lines changed: 3 additions & 0 deletions
Original file line numberDiff line numberDiff line change
@@ -826,5 +826,8 @@ void vlan_setup(struct net_device *dev)
826826
dev->destructor = vlan_dev_free;
827827
dev->ethtool_ops = &vlan_ethtool_ops;
828828

829+
dev->min_mtu = 0;
830+
dev->max_mtu = ETH_MAX_MTU;
831+
829832
eth_zero_addr(dev->broadcast);
830833
}

‎net/bridge/br_device.c

Lines changed: 2 additions & 1 deletion
Original file line numberDiff line numberDiff line change
@@ -185,7 +185,7 @@ static struct rtnl_link_stats64 *br_get_stats64(struct net_device *dev,
185185
static int br_change_mtu(struct net_device *dev, int new_mtu)
186186
{
187187
struct net_bridge *br = netdev_priv(dev);
188-
if (new_mtu < 68 || new_mtu > br_min_mtu(br))
188+
if (new_mtu > br_min_mtu(br))
189189
return -EINVAL;
190190

191191
dev->mtu = new_mtu;
@@ -410,6 +410,7 @@ void br_dev_setup(struct net_device *dev)
410410
br->bridge_hello_time = br->hello_time = 2 * HZ;
411411
br->bridge_forward_delay = br->forward_delay = 15 * HZ;
412412
br->ageing_time = BR_DEFAULT_AGEING_TIME;
413+
dev->max_mtu = ETH_MAX_MTU;
413414

414415
br_netfilter_rtable_init(br);
415416
br_stp_timer_init(br);

‎net/openvswitch/vport-internal_dev.c

Lines changed: 0 additions & 10 deletions
Original file line numberDiff line numberDiff line change
@@ -89,15 +89,6 @@ static const struct ethtool_ops internal_dev_ethtool_ops = {
8989
.get_link = ethtool_op_get_link,
9090
};
9191

92-
static int internal_dev_change_mtu(struct net_device *netdev, int new_mtu)
93-
{
94-
if (new_mtu < 68)
95-
return -EINVAL;
96-
97-
netdev->mtu = new_mtu;
98-
return 0;
99-
}
100-
10192
static void internal_dev_destructor(struct net_device *dev)
10293
{
10394
struct vport *vport = ovs_internal_dev_get_vport(dev);
@@ -148,7 +139,6 @@ static const struct net_device_ops internal_dev_netdev_ops = {
148139
.ndo_stop = internal_dev_stop,
149140
.ndo_start_xmit = internal_dev_xmit,
150141
.ndo_set_mac_address = eth_mac_addr,
151-
.ndo_change_mtu = internal_dev_change_mtu,
152142
.ndo_get_stats64 = internal_get_stats,
153143
.ndo_set_rx_headroom = internal_set_rx_headroom,
154144
};

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