xiaomi-sm8450/android_kernel_xiaomi_sm8450
1
0
Fork 0
Code Issues Pull Requests Actions Packages Projects Releases Wiki Activity

rxrpc: Use info in skbuff instead of reparsing a jumbo packet

Browse Source 
Use the information now cached in the skbuff private data to avoid the need
to reparse a jumbo packet.  We can find all the subpackets by dead
reckoning, so it's only necessary to note how many there are, whether the
last one is flagged as LAST_PACKET and whether any have the REQUEST_ACK
flag set.

This is necessary as once recvmsg() can see the packet, it can start
modifying it, such as doing in-place decryption.

Fixes: 248f219cb8 ("rxrpc: Rewrite the data and ack handling code")
Signed-off-by: David Howells <dhowells@redhat.com>
This commit is contained in:
David Howells
2019-08-27 09:51:30 +01:00
parent c3c9e3df49
commit e2de6c4048
3 changed files with 138 additions and 135 deletions
Download Patch File Download Diff File Expand all files Collapse all files

41
net/rxrpc/recvmsg.c
View File

@@ -177,7 +177,8 @@ static void rxrpc_rotate_rx_window(struct rxrpc_call *call)
struct sk_buff *skb;
rxrpc_serial_t serial;
rxrpc_seq_t hard_ack, top;
u8 flags;
bool last = false;
u8 subpacket;
int ix;
_enter("%d", call->debug_id);
@@ -191,10 +192,13 @@ static void rxrpc_rotate_rx_window(struct rxrpc_call *call)
skb = call->rxtx_buffer[ix];
rxrpc_see_skb(skb, rxrpc_skb_rx_rotated);
sp = rxrpc_skb(skb);
flags = sp->hdr.flags;
serial = sp->hdr.serial;
if (call->rxtx_annotations[ix] & RXRPC_RX_ANNO_JUMBO)
serial += (call->rxtx_annotations[ix] & RXRPC_RX_ANNO_JUMBO) - 1;
subpacket = call->rxtx_annotations[ix] & RXRPC_RX_ANNO_SUBPACKET;
serial = sp->hdr.serial + subpacket;
if (subpacket == sp->nr_subpackets - 1 &&
sp->rx_flags & RXRPC_SKB_INCL_LAST)
last = true;
call->rxtx_buffer[ix] = NULL;
call->rxtx_annotations[ix] = 0;
@@ -203,9 +207,8 @@ static void rxrpc_rotate_rx_window(struct rxrpc_call *call)
rxrpc_free_skb(skb, rxrpc_skb_rx_freed);
_debug("%u,%u,%02x", hard_ack, top, flags);
trace_rxrpc_receive(call, rxrpc_receive_rotate, serial, hard_ack);
if (flags & RXRPC_LAST_PACKET) {
if (last) {
rxrpc_end_rx_phase(call, serial);
} else {
/* Check to see if there's an ACK that needs sending. */
@@ -233,18 +236,19 @@ static int rxrpc_verify_packet(struct rxrpc_call *call, struct sk_buff *skb,
struct rxrpc_skb_priv *sp = rxrpc_skb(skb);
rxrpc_seq_t seq = sp->hdr.seq;
u16 cksum = sp->hdr.cksum;
u8 subpacket = annotation & RXRPC_RX_ANNO_SUBPACKET;
_enter("");
/* For all but the head jumbo subpacket, the security checksum is in a
* jumbo header immediately prior to the data.
*/
if ((annotation & RXRPC_RX_ANNO_JUMBO) > 1) {
if (subpacket > 0) {
__be16 tmp;
if (skb_copy_bits(skb, offset - 2, &tmp, 2) < 0)
BUG();
cksum = ntohs(tmp);
seq += (annotation & RXRPC_RX_ANNO_JUMBO) - 1;
seq += subpacket;
}
return call->conn->security->verify_packet(call, skb, offset, len,
@@ -265,19 +269,18 @@ static int rxrpc_locate_data(struct rxrpc_call *call, struct sk_buff *skb,
u8 *_annotation,
unsigned int *_offset, unsigned int *_len)
{
struct rxrpc_skb_priv *sp = rxrpc_skb(skb);
unsigned int offset = sizeof(struct rxrpc_wire_header);
unsigned int len;
int ret;
u8 annotation = *_annotation;
u8 subpacket = annotation & RXRPC_RX_ANNO_SUBPACKET;
/* Locate the subpacket */
offset += subpacket * RXRPC_JUMBO_SUBPKTLEN;
len = skb->len - offset;
if ((annotation & RXRPC_RX_ANNO_JUMBO) > 0) {
offset += (((annotation & RXRPC_RX_ANNO_JUMBO) - 1) *
RXRPC_JUMBO_SUBPKTLEN);
len = (annotation & RXRPC_RX_ANNO_JLAST) ?
skb->len - offset : RXRPC_JUMBO_SUBPKTLEN;
}
if (subpacket < sp->nr_subpackets - 1)
len = RXRPC_JUMBO_DATALEN;
if (!(annotation & RXRPC_RX_ANNO_VERIFIED)) {
ret = rxrpc_verify_packet(call, skb, annotation, offset, len);
@@ -303,6 +306,7 @@ static int rxrpc_recvmsg_data(struct socket *sock, struct rxrpc_call *call,
{
struct rxrpc_skb_priv *sp;
struct sk_buff *skb;
rxrpc_serial_t serial;
rxrpc_seq_t hard_ack, top, seq;
size_t remain;
bool last;
@@ -339,9 +343,12 @@ static int rxrpc_recvmsg_data(struct socket *sock, struct rxrpc_call *call,
rxrpc_see_skb(skb, rxrpc_skb_rx_seen);
sp = rxrpc_skb(skb);
if (!(flags & MSG_PEEK))
if (!(flags & MSG_PEEK)) {
serial = sp->hdr.serial;
serial += call->rxtx_annotations[ix] & RXRPC_RX_ANNO_SUBPACKET;
trace_rxrpc_receive(call, rxrpc_receive_front,
sp->hdr.serial, seq);
serial, seq);
}
if (msg)
sock_recv_timestamp(msg, sock->sk, skb);