Commit 6e9feb33 authored by David S. Miller's avatar David S. Miller

Merge branch 'tipc-next'

Jon Maloy says:

====================
tipc: make connection setup more robust

In this series we make a few improvements to the connection setup and
probing mechanism, culminating in the last commit where we make it
possible for a client socket to make multiple setup attempts in case
it encounters receive buffer overflow at the listener socket.
====================
Signed-off-by: default avatarDavid S. Miller <davem@davemloft.net>
parents a337531b 67879274
......@@ -499,54 +499,56 @@ bool tipc_msg_make_bundle(struct sk_buff **skb, struct tipc_msg *msg,
/**
* tipc_msg_reverse(): swap source and destination addresses and add error code
* @own_node: originating node id for reversed message
* @skb: buffer containing message to be reversed; may be replaced.
* @skb: buffer containing message to be reversed; will be consumed
* @err: error code to be set in message, if any
* Consumes buffer at failure
* Replaces consumed buffer with new one when successful
* Returns true if success, otherwise false
*/
bool tipc_msg_reverse(u32 own_node, struct sk_buff **skb, int err)
{
struct sk_buff *_skb = *skb;
struct tipc_msg *hdr;
struct tipc_msg ohdr;
int dlen;
struct tipc_msg *_hdr, *hdr;
int hlen, dlen;
if (skb_linearize(_skb))
goto exit;
hdr = buf_msg(_skb);
dlen = min_t(uint, msg_data_sz(hdr), MAX_FORWARD_SIZE);
if (msg_dest_droppable(hdr))
_hdr = buf_msg(_skb);
dlen = min_t(uint, msg_data_sz(_hdr), MAX_FORWARD_SIZE);
hlen = msg_hdr_sz(_hdr);
if (msg_dest_droppable(_hdr))
goto exit;
if (msg_errcode(hdr))
if (msg_errcode(_hdr))
goto exit;
/* Take a copy of original header before altering message */
memcpy(&ohdr, hdr, msg_hdr_sz(hdr));
/* Never return SHORT header */
if (hlen == SHORT_H_SIZE)
hlen = BASIC_H_SIZE;
/* Don't return data along with SYN+, - sender has a clone */
if (msg_is_syn(_hdr) && err == TIPC_ERR_OVERLOAD)
dlen = 0;
/* Never return SHORT header; expand by replacing buffer if necessary */
if (msg_short(hdr)) {
*skb = tipc_buf_acquire(BASIC_H_SIZE + dlen, GFP_ATOMIC);
/* Allocate new buffer to return */
*skb = tipc_buf_acquire(hlen + dlen, GFP_ATOMIC);
if (!*skb)
goto exit;
memcpy((*skb)->data + BASIC_H_SIZE, msg_data(hdr), dlen);
kfree_skb(_skb);
_skb = *skb;
hdr = buf_msg(_skb);
memcpy(hdr, &ohdr, BASIC_H_SIZE);
msg_set_hdr_sz(hdr, BASIC_H_SIZE);
}
memcpy((*skb)->data, _skb->data, msg_hdr_sz(_hdr));
memcpy((*skb)->data + hlen, msg_data(_hdr), dlen);
/* Now reverse the concerned fields */
/* Build reverse header in new buffer */
hdr = buf_msg(*skb);
msg_set_hdr_sz(hdr, hlen);
msg_set_errcode(hdr, err);
msg_set_non_seq(hdr, 0);
msg_set_origport(hdr, msg_destport(&ohdr));
msg_set_destport(hdr, msg_origport(&ohdr));
msg_set_destnode(hdr, msg_prevnode(&ohdr));
msg_set_origport(hdr, msg_destport(_hdr));
msg_set_destport(hdr, msg_origport(_hdr));
msg_set_destnode(hdr, msg_prevnode(_hdr));
msg_set_prevnode(hdr, own_node);
msg_set_orignode(hdr, own_node);
msg_set_size(hdr, msg_hdr_sz(hdr) + dlen);
skb_trim(_skb, msg_size(hdr));
msg_set_size(hdr, hlen + dlen);
skb_orphan(_skb);
kfree_skb(_skb);
return true;
exit:
kfree_skb(_skb);
......@@ -554,6 +556,22 @@ bool tipc_msg_reverse(u32 own_node, struct sk_buff **skb, int err)
return false;
}
bool tipc_msg_skb_clone(struct sk_buff_head *msg, struct sk_buff_head *cpy)
{
struct sk_buff *skb, *_skb;
skb_queue_walk(msg, skb) {
_skb = skb_clone(skb, GFP_ATOMIC);
if (!_skb) {
__skb_queue_purge(cpy);
pr_err_ratelimited("Failed to clone buffer chain\n");
return false;
}
__skb_queue_tail(cpy, _skb);
}
return true;
}
/**
* tipc_msg_lookup_dest(): try to find new destination for named message
* @skb: the buffer containing the message.
......
......@@ -216,6 +216,16 @@ static inline void msg_set_non_seq(struct tipc_msg *m, u32 n)
msg_set_bits(m, 0, 20, 1, n);
}
static inline int msg_is_syn(struct tipc_msg *m)
{
return msg_bits(m, 0, 17, 1);
}
static inline void msg_set_syn(struct tipc_msg *m, u32 d)
{
msg_set_bits(m, 0, 17, 1, d);
}
static inline int msg_dest_droppable(struct tipc_msg *m)
{
return msg_bits(m, 0, 19, 1);
......@@ -970,6 +980,7 @@ bool tipc_msg_pskb_copy(u32 dst, struct sk_buff_head *msg,
struct sk_buff_head *cpy);
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);
static inline u16 buf_seqno(struct sk_buff *skb)
{
......
......@@ -45,6 +45,7 @@
/* Optional capabilities supported by this code version
*/
enum {
TIPC_SYN_BIT = (1),
TIPC_BCAST_SYNCH = (1 << 1),
TIPC_BCAST_STATE_NACK = (1 << 2),
TIPC_BLOCK_FLOWCTL = (1 << 3),
......@@ -53,7 +54,8 @@ enum {
TIPC_LINK_PROTO_SEQNO = (1 << 6)
};
#define TIPC_NODE_CAPABILITIES (TIPC_BCAST_SYNCH | \
#define TIPC_NODE_CAPABILITIES (TIPC_SYN_BIT | \
TIPC_BCAST_SYNCH | \
TIPC_BCAST_STATE_NACK | \
TIPC_BCAST_RCAST | \
TIPC_BLOCK_FLOWCTL | \
......
......@@ -80,7 +80,6 @@ struct sockaddr_pair {
* @publications: list of publications for port
* @blocking_link: address of the congested link we are currently sleeping on
* @pub_count: total # of publications port has made during its lifetime
* @probing_state:
* @conn_timeout: the time we can wait for an unresponded setup request
* @dupl_rcvcnt: number of bytes counted twice, in both backlog and rcv queue
* @cong_link_cnt: number of congested links
......@@ -102,8 +101,8 @@ struct tipc_sock {
struct list_head cong_links;
struct list_head publications;
u32 pub_count;
uint conn_timeout;
atomic_t dupl_rcvcnt;
u16 conn_timeout;
bool probe_unacked;
u16 cong_link_cnt;
u16 snt_unacked;
......@@ -507,6 +506,9 @@ static void __tipc_shutdown(struct socket *sock, int error)
tipc_wait_for_cond(sock, &timeout, (!tsk->cong_link_cnt &&
!tsk_conn_cong(tsk)));
/* Remove any pending SYN message */
__skb_queue_purge(&sk->sk_write_queue);
/* Reject all unreceived messages, except on an active connection
* (which disconnects locally & sends a 'FIN+' to peer).
*/
......@@ -1319,6 +1321,7 @@ static int __tipc_sendmsg(struct socket *sock, struct msghdr *m, size_t dlen)
tsk->conn_type = dest->addr.name.name.type;
tsk->conn_instance = dest->addr.name.name.instance;
}
msg_set_syn(hdr, 1);
}
seq = &dest->addr.nameseq;
......@@ -1361,6 +1364,8 @@ static int __tipc_sendmsg(struct socket *sock, struct msghdr *m, size_t dlen)
rc = tipc_msg_build(hdr, m, 0, dlen, mtu, &pkts);
if (unlikely(rc != dlen))
return rc;
if (unlikely(syn && !tipc_msg_skb_clone(&pkts, &sk->sk_write_queue)))
return -ENOMEM;
rc = tipc_node_xmit(net, &pkts, dnode, tsk->portid);
if (unlikely(rc == -ELINKCONG)) {
......@@ -1478,6 +1483,7 @@ static void tipc_sk_finish_conn(struct tipc_sock *tsk, u32 peer_port,
struct net *net = sock_net(sk);
struct tipc_msg *msg = &tsk->phdr;
msg_set_syn(msg, 0);
msg_set_destnode(msg, peer_node);
msg_set_destport(msg, peer_port);
msg_set_type(msg, TIPC_CONN_MSG);
......@@ -1489,6 +1495,7 @@ static void tipc_sk_finish_conn(struct tipc_sock *tsk, u32 peer_port,
tipc_node_add_conn(net, peer_node, tsk->portid, peer_port);
tsk->max_pkt = tipc_node_get_mtu(net, peer_node, tsk->portid);
tsk->peer_caps = tipc_node_get_capabilities(net, peer_node);
__skb_queue_purge(&sk->sk_write_queue);
if (tsk->peer_caps & TIPC_BLOCK_FLOWCTL)
return;
......@@ -1959,91 +1966,90 @@ static void tipc_sk_proto_rcv(struct sock *sk,
}
/**
* tipc_filter_connect - Handle incoming message for a connection-based socket
* tipc_sk_filter_connect - check incoming message for a connection-based socket
* @tsk: TIPC socket
* @skb: pointer to message buffer. Set to NULL if buffer is consumed
*
* Returns true if everything ok, false otherwise
* @skb: pointer to message buffer.
* Returns true if message should be added to receive queue, false otherwise
*/
static bool tipc_sk_filter_connect(struct tipc_sock *tsk, struct sk_buff *skb)
{
struct sock *sk = &tsk->sk;
struct net *net = sock_net(sk);
struct tipc_msg *hdr = buf_msg(skb);
u32 pport = msg_origport(hdr);
u32 pnode = msg_orignode(hdr);
bool con_msg = msg_connected(hdr);
u32 pport = tsk_peer_port(tsk);
u32 pnode = tsk_peer_node(tsk);
u32 oport = msg_origport(hdr);
u32 onode = msg_orignode(hdr);
int err = msg_errcode(hdr);
unsigned long delay;
if (unlikely(msg_mcast(hdr)))
return false;
switch (sk->sk_state) {
case TIPC_CONNECTING:
/* Accept only ACK or NACK message */
if (unlikely(!msg_connected(hdr))) {
if (pport != tsk_peer_port(tsk) ||
pnode != tsk_peer_node(tsk))
return false;
tipc_set_sk_state(sk, TIPC_DISCONNECTING);
sk->sk_err = ECONNREFUSED;
sk->sk_state_change(sk);
return true;
}
if (unlikely(msg_errcode(hdr))) {
tipc_set_sk_state(sk, TIPC_DISCONNECTING);
sk->sk_err = ECONNREFUSED;
sk->sk_state_change(sk);
return true;
}
if (unlikely(!msg_isdata(hdr))) {
tipc_set_sk_state(sk, TIPC_DISCONNECTING);
sk->sk_err = EINVAL;
sk->sk_state_change(sk);
return true;
}
tipc_sk_finish_conn(tsk, msg_origport(hdr), msg_orignode(hdr));
/* Setup ACK */
if (likely(con_msg)) {
if (err)
break;
tipc_sk_finish_conn(tsk, oport, onode);
msg_set_importance(&tsk->phdr, msg_importance(hdr));
/* If 'ACK+' message, add to socket receive queue */
/* ACK+ message with data is added to receive queue */
if (msg_data_sz(hdr))
return true;
/* If empty 'ACK-' message, wake up sleeping connect() */
/* Empty ACK-, - wake up sleeping connect() and drop */
sk->sk_data_ready(sk);
/* 'ACK-' message is neither accepted nor rejected: */
msg_set_dest_droppable(hdr, 1);
return false;
}
/* Ignore connectionless message if not from listening socket */
if (oport != pport || onode != pnode)
return false;
/* Rejected SYN */
if (err != TIPC_ERR_OVERLOAD)
break;
/* Prepare for new setup attempt if we have a SYN clone */
if (skb_queue_empty(&sk->sk_write_queue))
break;
get_random_bytes(&delay, 2);
delay %= (tsk->conn_timeout / 4);
delay = msecs_to_jiffies(delay + 100);
sk_reset_timer(sk, &sk->sk_timer, jiffies + delay);
return false;
case TIPC_OPEN:
case TIPC_DISCONNECTING:
break;
return false;
case TIPC_LISTEN:
/* Accept only SYN message */
if (!msg_connected(hdr) && !(msg_errcode(hdr)))
if (!msg_is_syn(hdr) &&
tipc_node_get_capabilities(net, onode) & TIPC_SYN_BIT)
return false;
if (!con_msg && !err)
return true;
break;
return false;
case TIPC_ESTABLISHED:
/* Accept only connection-based messages sent by peer */
if (unlikely(!tsk_peer_msg(tsk, hdr)))
if (likely(con_msg && !err && pport == oport && pnode == onode))
return true;
if (!tsk_peer_msg(tsk, hdr))
return false;
if (unlikely(msg_errcode(hdr))) {
if (!err)
return true;
tipc_set_sk_state(sk, TIPC_DISCONNECTING);
/* Let timer expire on it's own */
tipc_node_remove_conn(net, tsk_peer_node(tsk),
tsk->portid);
tipc_node_remove_conn(net, pnode, tsk->portid);
sk->sk_state_change(sk);
}
return true;
default:
pr_err("Unknown sk_state %u\n", sk->sk_state);
}
return false;
/* Abort connection setup attempt */
tipc_set_sk_state(sk, TIPC_DISCONNECTING);
sk->sk_err = ECONNREFUSED;
sk->sk_state_change(sk);
return true;
}
/**
......@@ -2545,43 +2551,78 @@ static int tipc_shutdown(struct socket *sock, int how)
return res;
}
static void tipc_sk_check_probing_state(struct sock *sk,
struct sk_buff_head *list)
{
struct tipc_sock *tsk = tipc_sk(sk);
u32 pnode = tsk_peer_node(tsk);
u32 pport = tsk_peer_port(tsk);
u32 self = tsk_own_node(tsk);
u32 oport = tsk->portid;
struct sk_buff *skb;
if (tsk->probe_unacked) {
tipc_set_sk_state(sk, TIPC_DISCONNECTING);
sk->sk_err = ECONNABORTED;
tipc_node_remove_conn(sock_net(sk), pnode, pport);
sk->sk_state_change(sk);
return;
}
/* Prepare new probe */
skb = tipc_msg_create(CONN_MANAGER, CONN_PROBE, INT_H_SIZE, 0,
pnode, self, pport, oport, TIPC_OK);
if (skb)
__skb_queue_tail(list, skb);
tsk->probe_unacked = true;
sk_reset_timer(sk, &sk->sk_timer, jiffies + CONN_PROBING_INTV);
}
static void tipc_sk_retry_connect(struct sock *sk, struct sk_buff_head *list)
{
struct tipc_sock *tsk = tipc_sk(sk);
/* Try again later if dest link is congested */
if (tsk->cong_link_cnt) {
sk_reset_timer(sk, &sk->sk_timer, msecs_to_jiffies(100));
return;
}
/* Prepare SYN for retransmit */
tipc_msg_skb_clone(&sk->sk_write_queue, list);
}
static void tipc_sk_timeout(struct timer_list *t)
{
struct sock *sk = from_timer(sk, t, sk_timer);
struct tipc_sock *tsk = tipc_sk(sk);
u32 peer_port = tsk_peer_port(tsk);
u32 peer_node = tsk_peer_node(tsk);
u32 own_node = tsk_own_node(tsk);
u32 own_port = tsk->portid;
struct net *net = sock_net(sk);
struct sk_buff *skb = NULL;
u32 pnode = tsk_peer_node(tsk);
struct sk_buff_head list;
int rc = 0;
skb_queue_head_init(&list);
bh_lock_sock(sk);
if (!tipc_sk_connected(sk))
goto exit;
/* Try again later if socket is busy */
if (sock_owned_by_user(sk)) {
sk_reset_timer(sk, &sk->sk_timer, jiffies + HZ / 20);
goto exit;
bh_unlock_sock(sk);
return;
}
if (tsk->probe_unacked) {
tipc_set_sk_state(sk, TIPC_DISCONNECTING);
tipc_node_remove_conn(net, peer_node, peer_port);
sk->sk_state_change(sk);
goto exit;
}
/* Send new probe */
skb = tipc_msg_create(CONN_MANAGER, CONN_PROBE, INT_H_SIZE, 0,
peer_node, own_node, peer_port, own_port,
TIPC_OK);
tsk->probe_unacked = true;
sk_reset_timer(sk, &sk->sk_timer, jiffies + CONN_PROBING_INTV);
exit:
if (sk->sk_state == TIPC_ESTABLISHED)
tipc_sk_check_probing_state(sk, &list);
else if (sk->sk_state == TIPC_CONNECTING)
tipc_sk_retry_connect(sk, &list);
bh_unlock_sock(sk);
if (skb)
tipc_node_xmit_skb(net, skb, peer_node, own_port);
if (!skb_queue_empty(&list))
rc = tipc_node_xmit(sock_net(sk), &list, pnode, tsk->portid);
/* SYN messages may cause link congestion */
if (rc == -ELINKCONG) {
tipc_dest_push(&tsk->cong_links, pnode, 0);
tsk->cong_link_cnt = 1;
}
sock_put(sk);
}
......
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