diff --git a/drivers/net/tap.c b/drivers/net/tap.c index 832439b8a898..2f19fb07bb2d 100644 --- a/drivers/net/tap.c +++ b/drivers/net/tap.c @@ -278,9 +278,10 @@ rx_handler_result_t tap_handle_frame(struct sk_buff **pskb) if (q->flags & IFF_VNET_HDR) features |= tap->tap_features; if (netif_needs_gso(skb, features)) { - struct sk_buff *segs = __skb_gso_segment(skb, features, false); + struct sk_buff *segs; struct sk_buff *next; + segs = __skb_gso_segment(skb, features, false, 0); if (IS_ERR(segs)) { drop_reason = SKB_DROP_REASON_SKB_GSO_SEG; goto drop; diff --git a/include/net/gso.h b/include/net/gso.h index 0749230d414e..fe3260b381d4 100644 --- a/include/net/gso.h +++ b/include/net/gso.h @@ -21,6 +21,8 @@ struct skb_gso_cb { __u16 csum_start; /* Number of IPv4/IPv6 GSO handler entries for this packet. */ u8 recursion_counter; + /* Max MSS segs per output skb, 0 = no limit */ + u8 max_segs; }; #define SKB_GSO_CB_OFFSET 32 #define SKB_GSO_CB(skb) ((struct skb_gso_cb *)((skb)->cb + SKB_GSO_CB_OFFSET)) @@ -83,12 +85,13 @@ static inline __sum16 gso_make_checksum(struct sk_buff *skb, __wsum res) } struct sk_buff *__skb_gso_segment(struct sk_buff *skb, - netdev_features_t features, bool tx_path); + netdev_features_t features, bool tx_path, + unsigned int max_segs); static inline struct sk_buff *skb_gso_segment(struct sk_buff *skb, netdev_features_t features) { - return __skb_gso_segment(skb, features, true); + return __skb_gso_segment(skb, features, true, 0); } struct sk_buff *skb_eth_gso_segment(struct sk_buff *skb, diff --git a/include/net/udp.h b/include/net/udp.h index 1fee17274745..5bc25dcf25fb 100644 --- a/include/net/udp.h +++ b/include/net/udp.h @@ -613,7 +613,7 @@ static inline struct sk_buff *udp_rcv_segment(struct sock *sk, /* the GSO CB lays after the UDP one, no need to save and restore any * CB fragment */ - segs = __skb_gso_segment(skb, features, false); + segs = __skb_gso_segment(skb, features, false, 0); if (IS_ERR_OR_NULL(segs)) { drop_count = skb_shinfo(skb)->gso_segs; goto drop; diff --git a/net/core/gso.c b/net/core/gso.c index e96ef6350064..b5bd269e56e4 100644 --- a/net/core/gso.c +++ b/net/core/gso.c @@ -77,6 +77,8 @@ static bool skb_needs_check(const struct sk_buff *skb, bool tx_path) * @skb: buffer to segment * @features: features for the output path (see dev->features) * @tx_path: whether it is called in TX path + * @max_segs: maximum MSS segments per output GSO skb, 0 means no limit; + * set only for an unencapsulated TCP skb without a frag_list * * This function segments the given skb and returns a list of segments. * @@ -86,7 +88,8 @@ static bool skb_needs_check(const struct sk_buff *skb, bool tx_path) * Segmentation preserves SKB_GSO_CB_OFFSET bytes of previous skb cb. */ struct sk_buff *__skb_gso_segment(struct sk_buff *skb, - netdev_features_t features, bool tx_path) + netdev_features_t features, bool tx_path, + unsigned int max_segs) { struct sk_buff *segs; @@ -118,6 +121,7 @@ struct sk_buff *__skb_gso_segment(struct sk_buff *skb, SKB_GSO_CB(skb)->mac_offset = skb_headroom(skb); SKB_GSO_CB(skb)->encap_level = 0; SKB_GSO_CB(skb)->recursion_counter = 0; + SKB_GSO_CB(skb)->max_segs = min(max_segs, U8_MAX); skb_reset_mac_header(skb); skb_reset_mac_len(skb); diff --git a/net/core/skbuff.c b/net/core/skbuff.c index d56f4f0102f7..c53de400127f 100644 --- a/net/core/skbuff.c +++ b/net/core/skbuff.c @@ -4797,6 +4797,7 @@ struct sk_buff *skb_segment(struct sk_buff *head_skb, struct sk_buff *segs = NULL; struct sk_buff *tail = NULL; struct sk_buff *list_skb = skb_shinfo(head_skb)->frag_list; + unsigned int max_segs = SKB_GSO_CB(head_skb)->max_segs; unsigned int mss = skb_shinfo(head_skb)->gso_size; bool gso_by_frags = mss == GSO_BY_FRAGS; unsigned int doffset = head_skb->data - skb_mac_header(head_skb); @@ -4843,7 +4844,7 @@ struct sk_buff *skb_segment(struct sk_buff *head_skb, csum = !!can_checksum_protocol(features, proto); if (sg && csum && !gso_by_frags) { - if (!(features & NETIF_F_GSO_PARTIAL)) { + if (!max_segs && !(features & NETIF_F_GSO_PARTIAL)) { struct sk_buff *iter; unsigned int frag_len; @@ -4877,8 +4878,11 @@ struct sk_buff *skb_segment(struct sk_buff *head_skb, * doesn't fit into an MSS sized block, so take care of that * now. */ - DEBUG_NET_WARN_ON_ONCE(len / mss > GSO_MAX_SEGS); - partial_segs = min(len / mss, GSO_MAX_SEGS); + DEBUG_NET_WARN_ON_ONCE(!max_segs && len / mss > GSO_MAX_SEGS); + if (max_segs) + partial_segs = min(len / mss, max_segs); + else + partial_segs = min(len / mss, GSO_MAX_SEGS); if (partial_segs > 1) mss *= partial_segs; else diff --git a/net/openvswitch/datapath.c b/net/openvswitch/datapath.c index 42835694f35c..b2a0b09fd4a5 100644 --- a/net/openvswitch/datapath.c +++ b/net/openvswitch/datapath.c @@ -375,7 +375,7 @@ static int queue_gso_packets(struct datapath *dp, struct sk_buff *skb, int err; BUILD_BUG_ON(sizeof(*OVS_CB(skb)) > SKB_GSO_CB_OFFSET); - segs = __skb_gso_segment(skb, NETIF_F_SG, false); + segs = __skb_gso_segment(skb, NETIF_F_SG, false, 0); if (IS_ERR(segs)) return PTR_ERR(segs); if (segs == NULL)