*/
static void tcp_init_nondata_skb(struct sk_buff *skb, u32 seq, u8 flags)
{
+ struct skb_shared_info *shinfo = skb_shinfo(skb);
+
skb->ip_summed = CHECKSUM_PARTIAL;
skb->csum = 0;
TCP_SKB_CB(skb)->tcp_flags = flags;
TCP_SKB_CB(skb)->sacked = 0;
- skb_shinfo(skb)->gso_segs = 1;
- skb_shinfo(skb)->gso_size = 0;
- skb_shinfo(skb)->gso_type = 0;
+ shinfo->gso_segs = 1;
+ shinfo->gso_size = 0;
+ shinfo->gso_type = 0;
TCP_SKB_CB(skb)->seq = seq;
if (flags & (TCPHDR_SYN | TCPHDR_FIN))
* Beware: Something in the Internet is very sensitive to the ordering of
* TCP options, we learned this through the hard way, so be careful here.
* Luckily we can at least blame others for their non-compliance but from
- * inter-operatibility perspective it seems that we're somewhat stuck with
+ * inter-operability perspective it seems that we're somewhat stuck with
* the ordering which we have been using if we want to keep working with
* those broken things (not that it currently hurts anybody as there isn't
* particular reason why the ordering would need to be changed).
*
* Its important tcp_wfree() can be replaced by sock_wfree() in the event skb
* needs to be reallocated in a driver.
- * The invariant being skb->truesize substracted from sk->sk_wmem_alloc
+ * The invariant being skb->truesize subtracted from sk->sk_wmem_alloc
*
* Since transmit from skb destructor is forbidden, we use a tasklet
* to process all sockets that eventually need to send more skbs.
tcp_write_xmit(sk, tcp_current_mss(sk), 0, 0, GFP_ATOMIC);
}
/*
- * One tasklest per cpu tries to send more skbs.
+ * One tasklet per cpu tries to send more skbs.
* We run in tasklet context but need to disable irqs when
- * transfering tsq->head because tcp_wfree() might
+ * transferring tsq->head because tcp_wfree() might
* interrupt us (non NAPI drivers)
*/
static void tcp_tasklet_func(unsigned long data)
/*
* Write buffer destructor automatically called from kfree_skb.
- * We cant xmit new skbs from this context, as we might already
+ * We can't xmit new skbs from this context, as we might already
* hold qdisc lock.
*/
void tcp_wfree(struct sk_buff *skb)
static void tcp_set_skb_tso_segs(const struct sock *sk, struct sk_buff *skb,
unsigned int mss_now)
{
+ struct skb_shared_info *shinfo = skb_shinfo(skb);
+
/* Make sure we own this skb before messing gso_size/gso_segs */
WARN_ON_ONCE(skb_cloned(skb));
/* Avoid the costly divide in the normal
* non-TSO case.
*/
- skb_shinfo(skb)->gso_segs = 1;
- skb_shinfo(skb)->gso_size = 0;
- skb_shinfo(skb)->gso_type = 0;
+ shinfo->gso_segs = 1;
+ shinfo->gso_size = 0;
+ shinfo->gso_type = 0;
} else {
- skb_shinfo(skb)->gso_segs = DIV_ROUND_UP(skb->len, mss_now);
- skb_shinfo(skb)->gso_size = mss_now;
- skb_shinfo(skb)->gso_type = sk->sk_gso_type;
+ shinfo->gso_segs = DIV_ROUND_UP(skb->len, mss_now);
+ shinfo->gso_size = mss_now;
+ shinfo->gso_type = sk->sk_gso_type;
}
}
*/
static void __pskb_trim_head(struct sk_buff *skb, int len)
{
+ struct skb_shared_info *shinfo;
int i, k, eat;
eat = min_t(int, len, skb_headlen(skb));
}
eat = len;
k = 0;
- for (i = 0; i < skb_shinfo(skb)->nr_frags; i++) {
- int size = skb_frag_size(&skb_shinfo(skb)->frags[i]);
+ shinfo = skb_shinfo(skb);
+ for (i = 0; i < shinfo->nr_frags; i++) {
+ int size = skb_frag_size(&shinfo->frags[i]);
if (size <= eat) {
skb_frag_unref(skb, i);
eat -= size;
} else {
- skb_shinfo(skb)->frags[k] = skb_shinfo(skb)->frags[i];
+ shinfo->frags[k] = shinfo->frags[i];
if (eat) {
- skb_shinfo(skb)->frags[k].page_offset += eat;
- skb_frag_size_sub(&skb_shinfo(skb)->frags[k], eat);
+ shinfo->frags[k].page_offset += eat;
+ skb_frag_size_sub(&shinfo->frags[k], eat);
eat = 0;
}
k++;
}
}
- skb_shinfo(skb)->nr_frags = k;
+ shinfo->nr_frags = k;
skb_reset_tail_pointer(skb);
skb->data_len -= len;
}
}
-/* Returns the portion of skb which can be sent right away without
- * introducing MSS oddities to segment boundaries. In rare cases where
- * mss_now != mss_cache, we will request caller to create a small skb
- * per input skb which could be mostly avoided here (if desired).
- *
- * We explicitly want to create a request for splitting write queue tail
- * to a small skb for Nagle purposes while avoiding unnecessary modulos,
- * thus all the complexity (cwnd_len is always MSS multiple which we
- * return whenever allowed by the other factors). Basically we need the
- * modulo only when the receiver window alone is the limiting factor or
- * when we would be allowed to send the split-due-to-Nagle skb fully.
+/* Minshall's variant of the Nagle send check. */
+static bool tcp_minshall_check(const struct tcp_sock *tp)
+{
+ return after(tp->snd_sml, tp->snd_una) &&
+ !after(tp->snd_sml, tp->snd_nxt);
+}
+
+/* Update snd_sml if this skb is under mss
+ * Note that a TSO packet might end with a sub-mss segment
+ * The test is really :
+ * if ((skb->len % mss) != 0)
+ * tp->snd_sml = TCP_SKB_CB(skb)->end_seq;
+ * But we can avoid doing the divide again given we already have
+ * skb_pcount = skb->len / mss_now
+ */
+static void tcp_minshall_update(struct tcp_sock *tp, unsigned int mss_now,
+ const struct sk_buff *skb)
+{
+ if (skb->len < tcp_skb_pcount(skb) * mss_now)
+ tp->snd_sml = TCP_SKB_CB(skb)->end_seq;
+}
+
+/* Return false, if packet can be sent now without violation Nagle's rules:
+ * 1. It is full sized. (provided by caller in %partial bool)
+ * 2. Or it contains FIN. (already checked by caller)
+ * 3. Or TCP_CORK is not set, and TCP_NODELAY is set.
+ * 4. Or TCP_CORK is not set, and all sent packets are ACKed.
+ * With Minshall's modification: all sent small packets are ACKed.
*/
-static unsigned int tcp_mss_split_point(const struct sock *sk, const struct sk_buff *skb,
- unsigned int mss_now, unsigned int max_segs)
+static bool tcp_nagle_check(bool partial, const struct tcp_sock *tp,
+ unsigned int mss_now, int nonagle)
+{
+ return partial &&
+ ((nonagle & TCP_NAGLE_CORK) ||
+ (!nonagle && tp->packets_out && tcp_minshall_check(tp)));
+}
+/* Returns the portion of skb which can be sent right away */
+static unsigned int tcp_mss_split_point(const struct sock *sk,
+ const struct sk_buff *skb,
+ unsigned int mss_now,
+ unsigned int max_segs,
+ int nonagle)
{
const struct tcp_sock *tp = tcp_sk(sk);
- u32 needed, window, max_len;
+ u32 partial, needed, window, max_len;
window = tcp_wnd_end(tp) - TCP_SKB_CB(skb)->seq;
max_len = mss_now * max_segs;
if (max_len <= needed)
return max_len;
- return needed - needed % mss_now;
+ partial = needed % mss_now;
+ /* If last segment is not a full MSS, check if Nagle rules allow us
+ * to include this last segment in this skb.
+ * Otherwise, we'll split the skb at last MSS boundary
+ */
+ if (tcp_nagle_check(partial != 0, tp, mss_now, nonagle))
+ return needed - partial;
+
+ return needed;
}
/* Can at least one segment of SKB be sent right now, according to the
return tso_segs;
}
-/* Minshall's variant of the Nagle send check. */
-static inline bool tcp_minshall_check(const struct tcp_sock *tp)
-{
- return after(tp->snd_sml, tp->snd_una) &&
- !after(tp->snd_sml, tp->snd_nxt);
-}
-
-/* Return false, if packet can be sent now without violation Nagle's rules:
- * 1. It is full sized.
- * 2. Or it contains FIN. (already checked by caller)
- * 3. Or TCP_CORK is not set, and TCP_NODELAY is set.
- * 4. Or TCP_CORK is not set, and all sent packets are ACKed.
- * With Minshall's modification: all sent small packets are ACKed.
- */
-static inline bool tcp_nagle_check(const struct tcp_sock *tp,
- const struct sk_buff *skb,
- unsigned int mss_now, int nonagle)
-{
- return skb->len < mss_now &&
- ((nonagle & TCP_NAGLE_CORK) ||
- (!nonagle && tp->packets_out && tcp_minshall_check(tp)));
-}
/* Return true if the Nagle test allows this packet to be
* sent now.
if (tcp_urg_mode(tp) || (TCP_SKB_CB(skb)->tcp_flags & TCPHDR_FIN))
return true;
- if (!tcp_nagle_check(tp, skb, cur_mss, nonagle))
+ if (!tcp_nagle_check(skb->len < cur_mss, tp, cur_mss, nonagle))
return true;
return false;
limit = tcp_mss_split_point(sk, skb, mss_now,
min_t(unsigned int,
cwnd_quota,
- sk->sk_gso_max_segs));
+ sk->sk_gso_max_segs),
+ nonagle);
if (skb->len > limit &&
unlikely(tso_fragment(sk, skb, limit, mss_now, gfp)))
EXPORT_SYMBOL(tcp_make_synack);
/* Do all connect socket setups that can be done AF independent. */
-void tcp_connect_init(struct sock *sk)
+static void tcp_connect_init(struct sock *sk)
{
const struct dst_entry *dst = __sk_dst_get(sk);
struct tcp_sock *tp = tcp_sk(sk);
projects / firefly-linux-kernel-4.4.55.git / blobdiff