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-rw-r--r--Documentation/networking/segmentation-offloads.txt11
-rw-r--r--include/linux/skbuff.h22
-rw-r--r--net/core/filter.c60
3 files changed, 73 insertions, 20 deletions
diff --git a/Documentation/networking/segmentation-offloads.txt b/Documentation/networking/segmentation-offloads.txt
index d47480b61ac6..23a8dd91a9ec 100644
--- a/Documentation/networking/segmentation-offloads.txt
+++ b/Documentation/networking/segmentation-offloads.txt
@@ -153,8 +153,15 @@ To signal this, gso_size is set to the special value GSO_BY_FRAGS.
Therefore, any code in the core networking stack must be aware of the
possibility that gso_size will be GSO_BY_FRAGS and handle that case
-appropriately. (For size checks, the skb_gso_validate_*_len family of
-helpers do this automatically.)
+appropriately.
+
+There are a couple of helpers to make this easier:
+
+ - For size checks, the skb_gso_validate_*_len family of helpers correctly
+ considers GSO_BY_FRAGS.
+
+ - For manipulating packets, skb_increase_gso_size and skb_decrease_gso_size
+ will check for GSO_BY_FRAGS and WARN if asked to manipulate these skbs.
This also affects drivers with the NETIF_F_FRAGLIST & NETIF_F_GSO_SCTP bits
set. Note also that NETIF_F_GSO_SCTP is included in NETIF_F_GSO_SOFTWARE.
diff --git a/include/linux/skbuff.h b/include/linux/skbuff.h
index c1e66bdcf583..8c67c33f40c9 100644
--- a/include/linux/skbuff.h
+++ b/include/linux/skbuff.h
@@ -4038,6 +4038,12 @@ static inline bool skb_is_gso_v6(const struct sk_buff *skb)
return skb_shinfo(skb)->gso_type & SKB_GSO_TCPV6;
}
+/* Note: Should be called only if skb_is_gso(skb) is true */
+static inline bool skb_is_gso_sctp(const struct sk_buff *skb)
+{
+ return skb_shinfo(skb)->gso_type & SKB_GSO_SCTP;
+}
+
static inline void skb_gso_reset(struct sk_buff *skb)
{
skb_shinfo(skb)->gso_size = 0;
@@ -4045,6 +4051,22 @@ static inline void skb_gso_reset(struct sk_buff *skb)
skb_shinfo(skb)->gso_type = 0;
}
+static inline void skb_increase_gso_size(struct skb_shared_info *shinfo,
+ u16 increment)
+{
+ if (WARN_ON_ONCE(shinfo->gso_size == GSO_BY_FRAGS))
+ return;
+ shinfo->gso_size += increment;
+}
+
+static inline void skb_decrease_gso_size(struct skb_shared_info *shinfo,
+ u16 decrement)
+{
+ if (WARN_ON_ONCE(shinfo->gso_size == GSO_BY_FRAGS))
+ return;
+ shinfo->gso_size -= decrement;
+}
+
void __skb_warn_lro_forwarding(const struct sk_buff *skb);
static inline bool skb_warn_if_lro(const struct sk_buff *skb)
diff --git a/net/core/filter.c b/net/core/filter.c
index 0c121adbdbaa..48aa7c7320db 100644
--- a/net/core/filter.c
+++ b/net/core/filter.c
@@ -2087,6 +2087,10 @@ static int bpf_skb_proto_4_to_6(struct sk_buff *skb)
u32 off = skb_mac_header_len(skb);
int ret;
+ /* SCTP uses GSO_BY_FRAGS, thus cannot adjust it. */
+ if (skb_is_gso(skb) && unlikely(skb_is_gso_sctp(skb)))
+ return -ENOTSUPP;
+
ret = skb_cow(skb, len_diff);
if (unlikely(ret < 0))
return ret;
@@ -2096,19 +2100,21 @@ static int bpf_skb_proto_4_to_6(struct sk_buff *skb)
return ret;
if (skb_is_gso(skb)) {
+ struct skb_shared_info *shinfo = skb_shinfo(skb);
+
/* SKB_GSO_TCPV4 needs to be changed into
* SKB_GSO_TCPV6.
*/
- if (skb_shinfo(skb)->gso_type & SKB_GSO_TCPV4) {
- skb_shinfo(skb)->gso_type &= ~SKB_GSO_TCPV4;
- skb_shinfo(skb)->gso_type |= SKB_GSO_TCPV6;
+ if (shinfo->gso_type & SKB_GSO_TCPV4) {
+ shinfo->gso_type &= ~SKB_GSO_TCPV4;
+ shinfo->gso_type |= SKB_GSO_TCPV6;
}
/* Due to IPv6 header, MSS needs to be downgraded. */
- skb_shinfo(skb)->gso_size -= len_diff;
+ skb_decrease_gso_size(shinfo, len_diff);
/* Header must be checked, and gso_segs recomputed. */
- skb_shinfo(skb)->gso_type |= SKB_GSO_DODGY;
- skb_shinfo(skb)->gso_segs = 0;
+ shinfo->gso_type |= SKB_GSO_DODGY;
+ shinfo->gso_segs = 0;
}
skb->protocol = htons(ETH_P_IPV6);
@@ -2123,6 +2129,10 @@ static int bpf_skb_proto_6_to_4(struct sk_buff *skb)
u32 off = skb_mac_header_len(skb);
int ret;
+ /* SCTP uses GSO_BY_FRAGS, thus cannot adjust it. */
+ if (skb_is_gso(skb) && unlikely(skb_is_gso_sctp(skb)))
+ return -ENOTSUPP;
+
ret = skb_unclone(skb, GFP_ATOMIC);
if (unlikely(ret < 0))
return ret;
@@ -2132,19 +2142,21 @@ static int bpf_skb_proto_6_to_4(struct sk_buff *skb)
return ret;
if (skb_is_gso(skb)) {
+ struct skb_shared_info *shinfo = skb_shinfo(skb);
+
/* SKB_GSO_TCPV6 needs to be changed into
* SKB_GSO_TCPV4.
*/
- if (skb_shinfo(skb)->gso_type & SKB_GSO_TCPV6) {
- skb_shinfo(skb)->gso_type &= ~SKB_GSO_TCPV6;
- skb_shinfo(skb)->gso_type |= SKB_GSO_TCPV4;
+ if (shinfo->gso_type & SKB_GSO_TCPV6) {
+ shinfo->gso_type &= ~SKB_GSO_TCPV6;
+ shinfo->gso_type |= SKB_GSO_TCPV4;
}
/* Due to IPv4 header, MSS can be upgraded. */
- skb_shinfo(skb)->gso_size += len_diff;
+ skb_increase_gso_size(shinfo, len_diff);
/* Header must be checked, and gso_segs recomputed. */
- skb_shinfo(skb)->gso_type |= SKB_GSO_DODGY;
- skb_shinfo(skb)->gso_segs = 0;
+ shinfo->gso_type |= SKB_GSO_DODGY;
+ shinfo->gso_segs = 0;
}
skb->protocol = htons(ETH_P_IP);
@@ -2243,6 +2255,10 @@ static int bpf_skb_net_grow(struct sk_buff *skb, u32 len_diff)
u32 off = skb_mac_header_len(skb) + bpf_skb_net_base_len(skb);
int ret;
+ /* SCTP uses GSO_BY_FRAGS, thus cannot adjust it. */
+ if (skb_is_gso(skb) && unlikely(skb_is_gso_sctp(skb)))
+ return -ENOTSUPP;
+
ret = skb_cow(skb, len_diff);
if (unlikely(ret < 0))
return ret;
@@ -2252,11 +2268,13 @@ static int bpf_skb_net_grow(struct sk_buff *skb, u32 len_diff)
return ret;
if (skb_is_gso(skb)) {
+ struct skb_shared_info *shinfo = skb_shinfo(skb);
+
/* Due to header grow, MSS needs to be downgraded. */
- skb_shinfo(skb)->gso_size -= len_diff;
+ skb_decrease_gso_size(shinfo, len_diff);
/* Header must be checked, and gso_segs recomputed. */
- skb_shinfo(skb)->gso_type |= SKB_GSO_DODGY;
- skb_shinfo(skb)->gso_segs = 0;
+ shinfo->gso_type |= SKB_GSO_DODGY;
+ shinfo->gso_segs = 0;
}
return 0;
@@ -2267,6 +2285,10 @@ static int bpf_skb_net_shrink(struct sk_buff *skb, u32 len_diff)
u32 off = skb_mac_header_len(skb) + bpf_skb_net_base_len(skb);
int ret;
+ /* SCTP uses GSO_BY_FRAGS, thus cannot adjust it. */
+ if (skb_is_gso(skb) && unlikely(skb_is_gso_sctp(skb)))
+ return -ENOTSUPP;
+
ret = skb_unclone(skb, GFP_ATOMIC);
if (unlikely(ret < 0))
return ret;
@@ -2276,11 +2298,13 @@ static int bpf_skb_net_shrink(struct sk_buff *skb, u32 len_diff)
return ret;
if (skb_is_gso(skb)) {
+ struct skb_shared_info *shinfo = skb_shinfo(skb);
+
/* Due to header shrink, MSS can be upgraded. */
- skb_shinfo(skb)->gso_size += len_diff;
+ skb_increase_gso_size(shinfo, len_diff);
/* Header must be checked, and gso_segs recomputed. */
- skb_shinfo(skb)->gso_type |= SKB_GSO_DODGY;
- skb_shinfo(skb)->gso_segs = 0;
+ shinfo->gso_type |= SKB_GSO_DODGY;
+ shinfo->gso_segs = 0;
}
return 0;
generated by cgit v1.2.3 (git 2.39.1) at 2024-10-16 22:38:46 +0000