diff options
Diffstat (limited to 'net')
| -rw-r--r-- | net/ipv4/tcp.c | 1 | ||||
| -rw-r--r-- | net/ipv4/tcp_input.c | 28 | ||||
| -rw-r--r-- | net/ipv4/tcp_output.c | 4 |
3 files changed, 25 insertions, 8 deletions
diff --git a/net/ipv4/tcp.c b/net/ipv4/tcp.c index e0f421f9b..81d126477 100644 --- a/net/ipv4/tcp.c +++ b/net/ipv4/tcp.c @@ -3456,6 +3456,7 @@ void __init tcp_init(void) int max_rshare, max_wshare, cnt; unsigned int i; + BUILD_BUG_ON(TCP_MIN_SND_MSS <= MAX_TCP_OPTION_SPACE); BUILD_BUG_ON(sizeof(struct tcp_skb_cb) > sizeof(skb->cb)); percpu_counter_init(&tcp_sockets_allocated, 0); diff --git a/net/ipv4/tcp_input.c b/net/ipv4/tcp_input.c index 8c17fb27c..3222e5f89 100644 --- a/net/ipv4/tcp_input.c +++ b/net/ipv4/tcp_input.c @@ -1256,7 +1256,7 @@ static bool tcp_shifted_skb(struct sock *sk, struct sk_buff *skb, TCP_SKB_CB(skb)->seq += shifted; skb_shinfo(prev)->gso_segs += pcount; - BUG_ON(skb_shinfo(skb)->gso_segs < pcount); + WARN_ON_ONCE(tcp_skb_pcount(skb) < pcount); skb_shinfo(skb)->gso_segs -= pcount; /* When we're adding to gso_segs == 1, gso_size will be zero, @@ -1324,6 +1324,21 @@ 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. */ @@ -1335,6 +1350,7 @@ static struct sk_buff *tcp_shift_skb_data(struct sock *sk, struct sk_buff *skb, struct tcp_sock *tp = tcp_sk(sk); struct sk_buff *prev; int mss; + int next_pcount; int pcount = 0; int len; int in_sack; @@ -1429,7 +1445,7 @@ 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, skb, state, pcount, len, mss, dup_sack)) goto out; @@ -1448,11 +1464,11 @@ 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, skb, state, tcp_skb_pcount(skb), len, mss, 0); + next_pcount = tcp_skb_pcount(skb); + if (tcp_skb_shift(prev, skb, next_pcount, len)) { + pcount += next_pcount; + tcp_shifted_skb(sk, skb, state, next_pcount, len, mss, 0); } - out: state->fack_count += pcount; return prev; diff --git a/net/ipv4/tcp_output.c b/net/ipv4/tcp_output.c index 814a35e39..1267347f7 100644 --- a/net/ipv4/tcp_output.c +++ b/net/ipv4/tcp_output.c @@ -1239,8 +1239,8 @@ 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; } |