rxrpc: Don't store the rxrpc header in the Tx queue sk_buffs
Don't store the rxrpc protocol header in sk_buffs on the transmit queue,
but rather generate it on the fly and pass it to kernel_sendmsg() as a
separate iov. This reduces the amount of storage required.
Note that the security header is still stored in the sk_buff as it may get
encrypted along with the data (and doesn't change with each transmission).
Signed-off-by: David Howells <dhowells@redhat.com>
diff --git a/net/rxrpc/output.c b/net/rxrpc/output.c
index 16e18a9..817fb0e 100644
--- a/net/rxrpc/output.c
+++ b/net/rxrpc/output.c
@@ -208,19 +208,42 @@
/*
* send a packet through the transport endpoint
*/
-int rxrpc_send_data_packet(struct rxrpc_connection *conn, struct sk_buff *skb)
+int rxrpc_send_data_packet(struct rxrpc_call *call, struct sk_buff *skb)
{
- struct kvec iov[1];
+ struct rxrpc_connection *conn = call->conn;
+ struct rxrpc_wire_header whdr;
+ struct rxrpc_skb_priv *sp = rxrpc_skb(skb);
struct msghdr msg;
+ struct kvec iov[2];
+ rxrpc_serial_t serial;
+ size_t len;
int ret, opt;
_enter(",{%d}", skb->len);
- iov[0].iov_base = skb->head;
- iov[0].iov_len = skb->len;
+ /* Each transmission of a Tx packet needs a new serial number */
+ serial = atomic_inc_return(&conn->serial);
- msg.msg_name = &conn->params.peer->srx.transport;
- msg.msg_namelen = conn->params.peer->srx.transport_len;
+ whdr.epoch = htonl(conn->proto.epoch);
+ whdr.cid = htonl(call->cid);
+ whdr.callNumber = htonl(call->call_id);
+ whdr.seq = htonl(sp->hdr.seq);
+ whdr.serial = htonl(serial);
+ whdr.type = RXRPC_PACKET_TYPE_DATA;
+ whdr.flags = sp->hdr.flags;
+ whdr.userStatus = 0;
+ whdr.securityIndex = call->security_ix;
+ whdr._rsvd = htons(sp->hdr._rsvd);
+ whdr.serviceId = htons(call->service_id);
+
+ iov[0].iov_base = &whdr;
+ iov[0].iov_len = sizeof(whdr);
+ iov[1].iov_base = skb->head;
+ iov[1].iov_len = skb->len;
+ len = iov[0].iov_len + iov[1].iov_len;
+
+ msg.msg_name = &call->peer->srx.transport;
+ msg.msg_namelen = call->peer->srx.transport_len;
msg.msg_control = NULL;
msg.msg_controllen = 0;
msg.msg_flags = 0;
@@ -234,26 +257,33 @@
}
}
+ _proto("Tx DATA %%%u { #%u }", serial, sp->hdr.seq);
+
/* send the packet with the don't fragment bit set if we currently
* think it's small enough */
- if (skb->len - sizeof(struct rxrpc_wire_header) < conn->params.peer->maxdata) {
- down_read(&conn->params.local->defrag_sem);
- /* send the packet by UDP
- * - returns -EMSGSIZE if UDP would have to fragment the packet
- * to go out of the interface
- * - in which case, we'll have processed the ICMP error
- * message and update the peer record
- */
- ret = kernel_sendmsg(conn->params.local->socket, &msg, iov, 1,
- iov[0].iov_len);
+ if (iov[1].iov_len >= call->peer->maxdata)
+ goto send_fragmentable;
- up_read(&conn->params.local->defrag_sem);
- if (ret == -EMSGSIZE)
- goto send_fragmentable;
+ down_read(&conn->params.local->defrag_sem);
+ /* send the packet by UDP
+ * - returns -EMSGSIZE if UDP would have to fragment the packet
+ * to go out of the interface
+ * - in which case, we'll have processed the ICMP error
+ * message and update the peer record
+ */
+ ret = kernel_sendmsg(conn->params.local->socket, &msg, iov, 2, len);
- _leave(" = %d [%u]", ret, conn->params.peer->maxdata);
- return ret;
+ up_read(&conn->params.local->defrag_sem);
+ if (ret == -EMSGSIZE)
+ goto send_fragmentable;
+
+done:
+ if (ret == 0) {
+ sp->resend_at = jiffies + rxrpc_resend_timeout;
+ sp->hdr.serial = serial;
}
+ _leave(" = %d [%u]", ret, call->peer->maxdata);
+ return ret;
send_fragmentable:
/* attempt to send this message with fragmentation enabled */
@@ -268,8 +298,8 @@
SOL_IP, IP_MTU_DISCOVER,
(char *)&opt, sizeof(opt));
if (ret == 0) {
- ret = kernel_sendmsg(conn->params.local->socket, &msg, iov, 1,
- iov[0].iov_len);
+ ret = kernel_sendmsg(conn->params.local->socket, &msg,
+ iov, 2, len);
opt = IP_PMTUDISC_DO;
kernel_setsockopt(conn->params.local->socket, SOL_IP,
@@ -298,8 +328,7 @@
}
up_write(&conn->params.local->defrag_sem);
- _leave(" = %d [frag %u]", ret, conn->params.peer->maxdata);
- return ret;
+ goto done;
}
/*