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[tipc-discussion] [net-next 3/6] tipc: refactor function tipc_link_tnl_prepare()
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From: Jon M. <jon...@er...> - 2019-12-22 02:26:29
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In the coming commits we need a more generic tunneling prepare function.
As a preparation for this, we refactor it in a separate commit.
Signed-off-by: Jon Maloy <jon...@er...>
---
net/tipc/link.c | 148 +++++++++++++++++++-------------------------------------
net/tipc/msg.c | 50 +++++++++++++++++++
net/tipc/msg.h | 4 +-
3 files changed, 104 insertions(+), 98 deletions(-)
diff --git a/net/tipc/link.c b/net/tipc/link.c
index 2531f94..f16219c 100644
--- a/net/tipc/link.c
+++ b/net/tipc/link.c
@@ -1801,132 +1801,86 @@ void tipc_link_create_dummy_tnl_msg(struct tipc_link *l,
void tipc_link_tnl_prepare(struct tipc_link *l, struct tipc_link *tnl,
int mtyp, struct sk_buff_head *xmitq)
{
+ bool enhanced = tnl->peer_caps & TIPC_TUNNEL_ENHANCED;
struct sk_buff_head *fdefq = &tnl->failover_deferdq;
- struct sk_buff *skb, *tnlskb;
- struct tipc_msg *hdr, tnlhdr;
- struct sk_buff_head *queue = &l->transmq;
- struct sk_buff_head tmpxq, tnlq, frags;
- u16 pktlen, pktcnt, seqno = l->snd_nxt;
- bool pktcnt_need_update = false;
- u16 syncpt;
- int rc;
+ u32 self = tipc_own_addr(l->net);
+ struct sk_buff_head tnlq, tmpxq;
+ struct tipc_msg hdr, *_hdr;
+ u16 inner_seqno, syncpt;
+ struct sk_buff *skb;
+ int pktcnt, rc;
+ int inner_len;
if (!tnl)
return;
+ skb_queue_head_init(&tnlq);
+ skb_queue_head_init(&tmpxq);
- __skb_queue_head_init(&tnlq);
- /* Link Synching:
- * From now on, send only one single ("dummy") SYNCH message
- * to peer. The SYNCH message does not contain any data, just
- * a header conveying the synch point to the peer.
+ /* When TUNNEL_ENHANCED is supported, it is sufficient to send a
+ * single empty SYNCH message to peer, conveying the synch point
*/
- if (mtyp == SYNCH_MSG && (tnl->peer_caps & TIPC_TUNNEL_ENHANCED)) {
- tnlskb = tipc_msg_create(TUNNEL_PROTOCOL, SYNCH_MSG,
- INT_H_SIZE, 0, l->addr,
- tipc_own_addr(l->net),
- 0, 0, 0);
- if (!tnlskb) {
- pr_warn("%sunable to create dummy SYNCH_MSG\n",
- link_co_err);
+ if (mtyp == SYNCH_MSG && enhanced) {
+
+ skb = tipc_msg_create(TUNNEL_PROTOCOL, SYNCH_MSG, INT_H_SIZE, 0,
+ l->addr, tipc_own_addr(l->net), 0, 0, 0);
+ if (!skb) {
+ pr_warn("%sfailed to create SYNCH_MSG\n", link_co_err);
return;
}
-
- hdr = buf_msg(tnlskb);
+ _hdr = buf_msg(skb);
syncpt = l->snd_nxt + skb_queue_len(&l->backlogq) - 1;
- msg_set_syncpt(hdr, syncpt);
- msg_set_bearer_id(hdr, l->peer_bearer_id);
- __skb_queue_tail(&tnlq, tnlskb);
+ msg_set_syncpt(_hdr, syncpt);
+ msg_set_bearer_id(_hdr, l->peer_bearer_id);
+ __skb_queue_tail(&tnlq, skb);
tipc_link_xmit(tnl, &tnlq, xmitq);
return;
}
-
- __skb_queue_head_init(&tmpxq);
- __skb_queue_head_init(&frags);
- /* At least one packet required for safe algorithm => add dummy */
- skb = tipc_msg_create(TIPC_LOW_IMPORTANCE, TIPC_DIRECT_MSG,
- BASIC_H_SIZE, 0, l->addr, tipc_own_addr(l->net),
- 0, 0, TIPC_ERR_NO_PORT);
+ /* At least one packet is required for safe algorithm => add dummy */
+ skb = tipc_msg_create(TIPC_LOW_IMPORTANCE, TIPC_CONN_MSG, BASIC_H_SIZE,
+ 0, l->addr, self, 0, 0, TIPC_ERR_NO_PORT);
if (!skb) {
pr_warn("%sunable to create tunnel packet\n", link_co_err);
return;
}
- __skb_queue_tail(&tnlq, skb);
+ skb_queue_tail(&tnlq, skb);
tipc_link_xmit(l, &tnlq, &tmpxq);
__skb_queue_purge(&tmpxq);
- /* Initialize reusable tunnel packet header */
- tipc_msg_init(tipc_own_addr(l->net), &tnlhdr, TUNNEL_PROTOCOL,
- mtyp, INT_H_SIZE, l->addr);
+ /* Number of packets to report depends on if transmitq is linear */
if (mtyp == SYNCH_MSG)
pktcnt = l->snd_nxt - buf_seqno(skb_peek(&l->transmq));
else
pktcnt = skb_queue_len(&l->transmq);
pktcnt += skb_queue_len(&l->backlogq);
- msg_set_msgcnt(&tnlhdr, pktcnt);
- msg_set_bearer_id(&tnlhdr, l->peer_bearer_id);
-tnl:
- /* Wrap each packet into a tunnel packet */
- skb_queue_walk(queue, skb) {
- hdr = buf_msg(skb);
- if (queue == &l->backlogq)
- msg_set_seqno(hdr, seqno++);
- pktlen = msg_size(hdr);
-
- /* Tunnel link MTU is not large enough? This could be
- * due to:
- * 1) Link MTU has just changed or set differently;
- * 2) Or FAILOVER on the top of a SYNCH message
- *
- * The 2nd case should not happen if peer supports
- * TIPC_TUNNEL_ENHANCED
- */
- if (pktlen > tnl->mtu - INT_H_SIZE) {
- if (mtyp == FAILOVER_MSG &&
- (tnl->peer_caps & TIPC_TUNNEL_ENHANCED)) {
- rc = tipc_msg_fragment(skb, &tnlhdr, tnl->mtu,
- &frags);
- if (rc) {
- pr_warn("%sunable to frag msg: rc %d\n",
- link_co_err, rc);
- return;
- }
- pktcnt += skb_queue_len(&frags) - 1;
- pktcnt_need_update = true;
- skb_queue_splice_tail_init(&frags, &tnlq);
- continue;
- }
- /* Unluckily, peer doesn't have TIPC_TUNNEL_ENHANCED
- * => Just warn it and return!
- */
- pr_warn_ratelimited("%stoo large msg <%d, %d>: %d!\n",
- link_co_err, msg_user(hdr),
- msg_type(hdr), msg_size(hdr));
- return;
- }
- msg_set_size(&tnlhdr, pktlen + INT_H_SIZE);
- tnlskb = tipc_buf_acquire(pktlen + INT_H_SIZE, GFP_ATOMIC);
- if (!tnlskb) {
- pr_warn("%sunable to send packet\n", link_co_err);
- return;
- }
- skb_copy_to_linear_data(tnlskb, &tnlhdr, INT_H_SIZE);
- skb_copy_to_linear_data_offset(tnlskb, INT_H_SIZE, hdr, pktlen);
- __skb_queue_tail(&tnlq, tnlskb);
+ /* Copy all buffers into a temporary queue */
+ inner_seqno = l->snd_nxt;
+ skb_queue_walk(&l->backlogq, skb) {
+ msg_set_seqno(buf_msg(skb), inner_seqno++);
+ }
+ tipc_skb_queue_copy(&l->transmq, &tnlq);
+ tipc_skb_queue_copy(&l->backlogq, &tnlq);
+
+ /* Fragment the buffers if applicable */
+ rc = tipc_skb_queue_fragment(&tnlq, tnl->mtu, &pktcnt, enhanced, mtyp);
+ if (rc) {
+ pr_warn("%sunable to frag msg: rc %d\n", link_co_err, rc);
+ __skb_queue_purge(&tnlq);
+ return;
}
- if (queue != &l->backlogq) {
- queue = &l->backlogq;
- goto tnl;
+ /* Create reusable tunnel header and prepend to packets */
+ tipc_msg_init(self, &hdr, TUNNEL_PROTOCOL, mtyp, INT_H_SIZE, l->addr);
+ msg_set_msgcnt(&hdr, pktcnt);
+ msg_set_bearer_id(&hdr, l->peer_bearer_id);
+ skb_queue_walk(&tnlq, skb) {
+ inner_len = msg_size(buf_msg(skb));
+ skb_push(skb, INT_H_SIZE);
+ msg_set_size(&hdr, inner_len + INT_H_SIZE);
+ skb_copy_to_linear_data(skb, &hdr, INT_H_SIZE);
}
-
- if (pktcnt_need_update)
- skb_queue_walk(&tnlq, skb) {
- hdr = buf_msg(skb);
- msg_set_msgcnt(hdr, pktcnt);
- }
-
tipc_link_xmit(tnl, &tnlq, xmitq);
+ /* Prepare for receiving failover packets, if any */
if (mtyp == FAILOVER_MSG) {
tnl->drop_point = l->rcv_nxt;
tnl->failover_reasm_skb = l->reasm_buf;
diff --git a/net/tipc/msg.c b/net/tipc/msg.c
index 0d515d2..812334d 100644
--- a/net/tipc/msg.c
+++ b/net/tipc/msg.c
@@ -860,3 +860,53 @@ void tipc_skb_reject(struct net *net, int err, struct sk_buff *skb,
if (tipc_msg_reverse(tipc_own_addr(net), &skb, err))
__skb_queue_tail(xmitq, skb);
}
+
+void tipc_skb_queue_copy(struct sk_buff_head *from,
+ struct sk_buff_head *to)
+{
+ struct sk_buff *skb, *__skb;
+
+ skb_queue_walk(from, skb) {
+ __skb = pskb_copy(skb, GFP_ATOMIC);
+ if (!__skb)
+ break;
+ __skb_queue_tail(to, __skb);
+ }
+}
+
+/* tipc_skb_queue_fragment(): Fragment tunnel packets if applicable
+ * Two cases:
+ * 1) Tunnel link MTU has just changed or is set differently
+ * 2) FAILOVER on top of a SYNCH message.
+ */
+int tipc_skb_queue_fragment(struct sk_buff_head *skbq, int pktmax,
+ int *pktcnt, bool frag_supp, int mtyp)
+{
+ struct sk_buff_head frags, tmpq;
+ struct tipc_msg *hdr;
+ struct sk_buff *skb;
+ int rc = 0;
+
+ __skb_queue_head_init(&frags);
+ __skb_queue_head_init(&tmpq);
+ skb_queue_splice_tail_init(skbq, &tmpq);
+
+ skb_queue_walk(&tmpq, skb) {
+ hdr = buf_msg(skb);
+ if (msg_size(hdr) <= pktmax - INT_H_SIZE)
+ continue;
+ if (mtyp == FAILOVER_MSG && !frag_supp) {
+ rc = -1;
+ goto exit;
+ }
+ rc = tipc_msg_fragment(skb, hdr, pktmax, &frags);
+ if (rc)
+ goto exit;
+ *pktcnt += skb_queue_len(&frags) - 1;
+ skb_queue_splice_tail_init(&frags, &tmpq);
+ }
+exit:
+ __skb_queue_purge(&frags);
+ skb_queue_splice_tail_init(&tmpq, skbq);
+ return rc;
+}
diff --git a/net/tipc/msg.h b/net/tipc/msg.h
index e4c13f2..2197f64 100644
--- a/net/tipc/msg.h
+++ b/net/tipc/msg.h
@@ -1125,7 +1125,9 @@ bool tipc_msg_pskb_copy(u32 dst, struct sk_buff_head *msg,
void __tipc_skb_queue_sorted(struct sk_buff_head *list, u16 seqno,
struct sk_buff *skb);
bool tipc_msg_skb_clone(struct sk_buff_head *msg, struct sk_buff_head *cpy);
-
+void tipc_skb_queue_copy(struct sk_buff_head *from, struct sk_buff_head *to);
+int tipc_skb_queue_fragment(struct sk_buff_head *skbq, int pktmax,
+ int *pktcnt, bool frag_supp, int mtyp);
static inline u16 buf_seqno(struct sk_buff *skb)
{
return msg_seqno(buf_msg(skb));
--
2.1.4
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