diff --git a/include/linux/skbuff.h b/include/linux/skbuff.h index ac89a93b7c83..5ebc0f869720 100644 --- a/include/linux/skbuff.h +++ b/include/linux/skbuff.h @@ -3287,6 +3287,7 @@ int skb_shift(struct sk_buff *tgt, struct sk_buff *skb, int shiftlen); void skb_scrub_packet(struct sk_buff *skb, bool xnet); unsigned int skb_gso_transport_seglen(const struct sk_buff *skb); bool skb_gso_validate_mtu(const struct sk_buff *skb, unsigned int mtu); +bool skb_gso_validate_mac_len(const struct sk_buff *skb, unsigned int len); struct sk_buff *skb_segment(struct sk_buff *skb, netdev_features_t features); struct sk_buff *skb_vlan_untag(struct sk_buff *skb); int skb_ensure_writable(struct sk_buff *skb, int write_len); @@ -4120,6 +4121,21 @@ static inline unsigned int skb_gso_network_seglen(const struct sk_buff *skb) return hdr_len + skb_gso_transport_seglen(skb); } +/** + * skb_gso_mac_seglen - Return length of individual segments of a gso packet + * + * @skb: GSO skb + * + * skb_gso_mac_seglen is used to determine the real size of the + * individual segments, including MAC/L2, Layer3 (IP, IPv6) and L4 + * headers (TCP/UDP). + */ +static inline unsigned int skb_gso_mac_seglen(const struct sk_buff *skb) +{ + unsigned int hdr_len = skb_transport_header(skb) - skb_mac_header(skb); + return hdr_len + skb_gso_transport_seglen(skb); +} + /* Local Checksum Offload. * Compute outer checksum based on the assumption that the * inner checksum will be offloaded later. diff --git a/net/core/skbuff.c b/net/core/skbuff.c index 01e8285aea73..8c61c27c1b28 100644 --- a/net/core/skbuff.c +++ b/net/core/skbuff.c @@ -4913,6 +4913,45 @@ unsigned int skb_gso_transport_seglen(const struct sk_buff *skb) } EXPORT_SYMBOL_GPL(skb_gso_transport_seglen); +/** + * skb_gso_size_check - check the skb size, considering GSO_BY_FRAGS + * + * There are a couple of instances where we have a GSO skb, and we + * want to determine what size it would be after it is segmented. + * + * We might want to check: + * - L3+L4+payload size (e.g. IP forwarding) + * - L2+L3+L4+payload size (e.g. sanity check before passing to driver) + * + * This is a helper to do that correctly considering GSO_BY_FRAGS. + * + * @seg_len: The segmented length (from skb_gso_*_seglen). In the + * GSO_BY_FRAGS case this will be [header sizes + GSO_BY_FRAGS]. + * + * @max_len: The maximum permissible length. + * + * Returns true if the segmented length <= max length. + */ +static inline bool skb_gso_size_check(const struct sk_buff *skb, + unsigned int seg_len, + unsigned int max_len) { + const struct skb_shared_info *shinfo = skb_shinfo(skb); + const struct sk_buff *iter; + + if (shinfo->gso_size != GSO_BY_FRAGS) + return seg_len <= max_len; + + /* Undo this so we can re-use header sizes */ + seg_len -= GSO_BY_FRAGS; + + skb_walk_frags(skb, iter) { + if (seg_len + skb_headlen(iter) > max_len) + return false; + } + + return true; +} + /** * skb_gso_validate_mtu - Return in case such skb fits a given MTU * @@ -4924,27 +4963,25 @@ EXPORT_SYMBOL_GPL(skb_gso_transport_seglen); */ bool skb_gso_validate_mtu(const struct sk_buff *skb, unsigned int mtu) { - const struct skb_shared_info *shinfo = skb_shinfo(skb); - const struct sk_buff *iter; - unsigned int hlen; - - hlen = skb_gso_network_seglen(skb); - - if (shinfo->gso_size != GSO_BY_FRAGS) - return hlen <= mtu; - - /* Undo this so we can re-use header sizes */ - hlen -= GSO_BY_FRAGS; - - skb_walk_frags(skb, iter) { - if (hlen + skb_headlen(iter) > mtu) - return false; - } - - return true; + return skb_gso_size_check(skb, skb_gso_network_seglen(skb), mtu); } EXPORT_SYMBOL_GPL(skb_gso_validate_mtu); +/** + * skb_gso_validate_mac_len - Will a split GSO skb fit in a given length? + * + * @skb: GSO skb + * @len: length to validate against + * + * skb_gso_validate_mac_len validates if a given skb will fit a wanted + * length once split, including L2, L3 and L4 headers and the payload. + */ +bool skb_gso_validate_mac_len(const struct sk_buff *skb, unsigned int len) +{ + return skb_gso_size_check(skb, skb_gso_mac_seglen(skb), len); +} +EXPORT_SYMBOL_GPL(skb_gso_validate_mac_len); + static struct sk_buff *skb_reorder_vlan_header(struct sk_buff *skb) { if (skb_cow(skb, skb_headroom(skb)) < 0) { diff --git a/net/sched/sch_tbf.c b/net/sched/sch_tbf.c index 83e76d046993..229172d509cc 100644 --- a/net/sched/sch_tbf.c +++ b/net/sched/sch_tbf.c @@ -142,16 +142,6 @@ static u64 psched_ns_t2l(const struct psched_ratecfg *r, return len; } -/* - * Return length of individual segments of a gso packet, - * including all headers (MAC, IP, TCP/UDP) - */ -static unsigned int skb_gso_mac_seglen(const struct sk_buff *skb) -{ - unsigned int hdr_len = skb_transport_header(skb) - skb_mac_header(skb); - return hdr_len + skb_gso_transport_seglen(skb); -} - /* GSO packet is too big, segment it so that tbf can transmit * each segment in time */