diff options
| -rw-r--r-- | include/linux/tcp.h | 4 | ||||
| -rw-r--r-- | include/net/tcp.h | 2 | ||||
| -rw-r--r-- | net/ipv4/tcp.c | 1 | ||||
| -rw-r--r-- | net/ipv4/tcp_input.c | 26 | ||||
| -rw-r--r-- | net/ipv4/tcp_output.c | 6 |
5 files changed, 30 insertions, 9 deletions
diff --git a/include/linux/tcp.h b/include/linux/tcp.h index 711361af9ce0..9a478a0cd3a2 100644 --- a/include/linux/tcp.h +++ b/include/linux/tcp.h @@ -484,4 +484,8 @@ static inline u16 tcp_mss_clamp(const struct tcp_sock *tp, u16 mss) return (user_mss && user_mss < mss) ? user_mss : mss; } + +int tcp_skb_shift(struct sk_buff *to, struct sk_buff *from, int pcount, + int shiftlen); + #endif /* _LINUX_TCP_H */ diff --git a/include/net/tcp.h b/include/net/tcp.h index ac2f53fbfa6b..582c0caa9811 100644 --- a/include/net/tcp.h +++ b/include/net/tcp.h @@ -51,6 +51,8 @@ void tcp_time_wait(struct sock *sk, int state, int timeo); #define MAX_TCP_HEADER (128 + MAX_HEADER) #define MAX_TCP_OPTION_SPACE 40 +#define TCP_MIN_SND_MSS 48 +#define TCP_MIN_GSO_SIZE (TCP_MIN_SND_MSS - MAX_TCP_OPTION_SPACE) /* * Never offer a window over 32767 without using window scaling. Some diff --git a/net/ipv4/tcp.c b/net/ipv4/tcp.c index f12d500ec85c..79666ef8c2e2 100644 --- a/net/ipv4/tcp.c +++ b/net/ipv4/tcp.c @@ -3868,6 +3868,7 @@ void __init tcp_init(void) unsigned long limit; unsigned int i; + BUILD_BUG_ON(TCP_MIN_SND_MSS <= MAX_TCP_OPTION_SPACE); BUILD_BUG_ON(sizeof(struct tcp_skb_cb) > FIELD_SIZEOF(struct sk_buff, cb)); diff --git a/net/ipv4/tcp_input.c b/net/ipv4/tcp_input.c index 38dfc308c0fb..d95ee40df6c2 100644 --- a/net/ipv4/tcp_input.c +++ b/net/ipv4/tcp_input.c @@ -1302,7 +1302,7 @@ static bool tcp_shifted_skb(struct sock *sk, struct sk_buff *prev, TCP_SKB_CB(skb)->seq += shifted; tcp_skb_pcount_add(prev, pcount); - BUG_ON(tcp_skb_pcount(skb) < pcount); + WARN_ON_ONCE(tcp_skb_pcount(skb) < pcount); tcp_skb_pcount_add(skb, -pcount); /* When we're adding to gso_segs == 1, gso_size will be zero, @@ -1368,6 +1368,21 @@ static int skb_can_shift(const struct sk_buff *skb) return !skb_headlen(skb) && skb_is_nonlinear(skb); } +int tcp_skb_shift(struct sk_buff *to, struct sk_buff *from, + int pcount, int shiftlen) +{ + /* TCP min gso_size is 8 bytes (TCP_MIN_GSO_SIZE) + * Since TCP_SKB_CB(skb)->tcp_gso_segs is 16 bits, we need + * to make sure not storing more than 65535 * 8 bytes per skb, + * even if current MSS is bigger. + */ + if (unlikely(to->len + shiftlen >= 65535 * TCP_MIN_GSO_SIZE)) + return 0; + if (unlikely(tcp_skb_pcount(to) + pcount > 65535)) + return 0; + return skb_shift(to, from, shiftlen); +} + /* Try collapsing SACK blocks spanning across multiple skbs to a single * skb. */ @@ -1473,7 +1488,7 @@ static struct sk_buff *tcp_shift_skb_data(struct sock *sk, struct sk_buff *skb, if (!after(TCP_SKB_CB(skb)->seq + len, tp->snd_una)) goto fallback; - if (!skb_shift(prev, skb, len)) + if (!tcp_skb_shift(prev, skb, pcount, len)) goto fallback; if (!tcp_shifted_skb(sk, prev, skb, state, pcount, len, mss, dup_sack)) goto out; @@ -1491,11 +1506,10 @@ static struct sk_buff *tcp_shift_skb_data(struct sock *sk, struct sk_buff *skb, goto out; len = skb->len; - if (skb_shift(prev, skb, len)) { - pcount += tcp_skb_pcount(skb); - tcp_shifted_skb(sk, prev, skb, state, tcp_skb_pcount(skb), + pcount = tcp_skb_pcount(skb); + if (tcp_skb_shift(prev, skb, pcount, len)) + tcp_shifted_skb(sk, prev, skb, state, pcount, len, mss, 0); - } out: return prev; diff --git a/net/ipv4/tcp_output.c b/net/ipv4/tcp_output.c index f429e856e263..b8e3bbb85211 100644 --- a/net/ipv4/tcp_output.c +++ b/net/ipv4/tcp_output.c @@ -1454,8 +1454,8 @@ static inline int __tcp_mtu_to_mss(struct sock *sk, int pmtu) mss_now -= icsk->icsk_ext_hdr_len; /* Then reserve room for full set of TCP options and 8 bytes of data */ - if (mss_now < 48) - mss_now = 48; + if (mss_now < TCP_MIN_SND_MSS) + mss_now = TCP_MIN_SND_MSS; return mss_now; } @@ -2747,7 +2747,7 @@ static bool tcp_collapse_retrans(struct sock *sk, struct sk_buff *skb) if (next_skb_size <= skb_availroom(skb)) skb_copy_bits(next_skb, 0, skb_put(skb, next_skb_size), next_skb_size); - else if (!skb_shift(skb, next_skb, next_skb_size)) + else if (!tcp_skb_shift(skb, next_skb, 1, next_skb_size)) return false; } tcp_highest_sack_replace(sk, next_skb, skb); |