From 8db1bae30b7cd3c3abc05f467d0f7c69b33b80e9 Mon Sep 17 00:00:00 2001 From: Jon Paul Maloy Date: Wed, 25 Jun 2014 20:41:35 -0500 Subject: [PATCH] tipc: separate building and sending of rejected messages The way we build and send rejected message is currenty perceived as hard to follow, partly because we let the transmission go via deep call chains through functions such as tipc_reject_msg() and net_route_msg(). We want to remove those functions, and make the call sequences shallower and simpler. For this purpose, we separate building and sending of rejected messages. We build the reject message using the new function tipc_msg_reverse(), and let the transmission go via the newly introduced tipc_link_xmit2() function, as all transmission eventually will do. We also ensure that all calls to tipc_link_xmit2() are made outside port_lock/bh_lock_sock. Finally, we replace all calls to tipc_reject_msg() with the two new calls at all locations in the code that we want to keep. The remaining calls are made from code that we are planning to remove, along with tipc_reject_msg() itself. Signed-off-by: Jon Maloy Reviewed-by: Erik Hugne Reviewed-by: Ying Xue Signed-off-by: David S. Miller --- net/tipc/msg.c | 42 ++++++++++++++++++++++++++++++++++++++++++ net/tipc/msg.h | 2 ++ net/tipc/socket.c | 28 ++++++++++++++++++++-------- 3 files changed, 64 insertions(+), 8 deletions(-) diff --git a/net/tipc/msg.c b/net/tipc/msg.c index 4093b4c94d26..6070dd0ec634 100644 --- a/net/tipc/msg.c +++ b/net/tipc/msg.c @@ -37,6 +37,8 @@ #include "core.h" #include "msg.h" +#define MAX_FORWARD_SIZE 1024 + static unsigned int align(unsigned int i) { return (i + 3) & ~3u; @@ -328,3 +330,43 @@ bool tipc_msg_make_bundle(struct sk_buff **buf, u32 mtu, u32 dnode) *buf = bbuf; return true; } + +/** + * tipc_msg_reverse(): swap source and destination addresses and add error code + * @buf: buffer containing message to be reversed + * @dnode: return value: node where to send message after reversal + * @err: error code to be set in message + * Consumes buffer if failure + * Returns true if success, otherwise false + */ +bool tipc_msg_reverse(struct sk_buff *buf, u32 *dnode, int err) +{ + struct tipc_msg *msg = buf_msg(buf); + uint imp = msg_importance(msg); + struct tipc_msg ohdr; + uint rdsz = min_t(uint, msg_data_sz(msg), MAX_FORWARD_SIZE); + + if (skb_linearize(buf) || !msg_isdata(msg)) + goto exit; + if (msg_dest_droppable(msg) || msg_errcode(msg)) + goto exit; + + memcpy(&ohdr, msg, msg_hdr_sz(msg)); + msg_set_importance(msg, min_t(uint, ++imp, TIPC_CRITICAL_IMPORTANCE)); + msg_set_errcode(msg, err); + msg_set_origport(msg, msg_destport(&ohdr)); + msg_set_destport(msg, msg_origport(&ohdr)); + msg_set_prevnode(msg, tipc_own_addr); + if (!msg_short(msg)) { + msg_set_orignode(msg, msg_destnode(&ohdr)); + msg_set_destnode(msg, msg_orignode(&ohdr)); + } + msg_set_size(msg, msg_hdr_sz(msg) + rdsz); + skb_trim(buf, msg_size(msg)); + skb_orphan(buf); + *dnode = msg_orignode(&ohdr); + return true; +exit: + kfree_skb(buf); + return false; +} diff --git a/net/tipc/msg.h b/net/tipc/msg.h index 5e1339d60c69..38050941a504 100644 --- a/net/tipc/msg.h +++ b/net/tipc/msg.h @@ -725,6 +725,8 @@ static inline u32 msg_tot_origport(struct tipc_msg *m) return msg_origport(m); } +bool tipc_msg_reverse(struct sk_buff *buf, u32 *dnode, int err); + void tipc_msg_init(struct tipc_msg *m, u32 user, u32 type, u32 hsize, u32 destnode); diff --git a/net/tipc/socket.c b/net/tipc/socket.c index 9a95dab13b7e..5961a6335f49 100644 --- a/net/tipc/socket.c +++ b/net/tipc/socket.c @@ -39,6 +39,7 @@ #include "node.h" #include +#include "link.h" #define SS_LISTENING -1 /* socket is listening */ #define SS_READY -2 /* socket is connectionless */ @@ -123,9 +124,12 @@ static void advance_rx_queue(struct sock *sk) static void reject_rx_queue(struct sock *sk) { struct sk_buff *buf; + u32 dnode; - while ((buf = __skb_dequeue(&sk->sk_receive_queue))) - tipc_reject_msg(buf, TIPC_ERR_NO_PORT); + while ((buf = __skb_dequeue(&sk->sk_receive_queue))) { + if (tipc_msg_reverse(buf, &dnode, TIPC_ERR_NO_PORT)) + tipc_link_xmit2(buf, dnode, 0); + } } /** @@ -303,6 +307,7 @@ static int tipc_release(struct socket *sock) struct tipc_sock *tsk; struct tipc_port *port; struct sk_buff *buf; + u32 dnode; /* * Exit if socket isn't fully initialized (occurs when a failed accept() @@ -331,7 +336,8 @@ static int tipc_release(struct socket *sock) sock->state = SS_DISCONNECTING; tipc_port_disconnect(port->ref); } - tipc_reject_msg(buf, TIPC_ERR_NO_PORT); + if (tipc_msg_reverse(buf, &dnode, TIPC_ERR_NO_PORT)) + tipc_link_xmit2(buf, dnode, 0); } } @@ -1430,14 +1436,15 @@ static int filter_rcv(struct sock *sk, struct sk_buff *buf) static int tipc_backlog_rcv(struct sock *sk, struct sk_buff *buf) { int rc; + u32 onode; struct tipc_sock *tsk = tipc_sk(sk); uint truesize = buf->truesize; rc = filter_rcv(sk, buf); - if (unlikely(rc)) - tipc_reject_msg(buf, -rc); - if (atomic_read(&tsk->dupl_rcvcnt) < TIPC_CONN_OVERLOAD_LIMIT) + if (unlikely(rc && tipc_msg_reverse(buf, &onode, -rc))) + tipc_link_xmit2(buf, onode, 0); + else if (atomic_read(&tsk->dupl_rcvcnt) < TIPC_CONN_OVERLOAD_LIMIT) atomic_add(truesize, &tsk->dupl_rcvcnt); return 0; @@ -1457,6 +1464,7 @@ int tipc_sk_rcv(struct sk_buff *buf) u32 dport = msg_destport(buf_msg(buf)); int rc = TIPC_OK; uint limit; + u32 dnode; /* Forward unresolved named message */ if (unlikely(!dport)) { @@ -1493,7 +1501,9 @@ int tipc_sk_rcv(struct sk_buff *buf) if (likely(!rc)) return 0; exit: - tipc_reject_msg(buf, -rc); + if (!tipc_msg_reverse(buf, &dnode, -rc)) + return -EHOSTUNREACH; + tipc_link_xmit2(buf, dnode, 0); return -EHOSTUNREACH; } @@ -1758,6 +1768,7 @@ static int tipc_shutdown(struct socket *sock, int how) struct tipc_sock *tsk = tipc_sk(sk); struct tipc_port *port = &tsk->port; struct sk_buff *buf; + u32 peer; int res; if (how != SHUT_RDWR) @@ -1778,7 +1789,8 @@ restart: goto restart; } tipc_port_disconnect(port->ref); - tipc_reject_msg(buf, TIPC_CONN_SHUTDOWN); + if (tipc_msg_reverse(buf, &peer, TIPC_CONN_SHUTDOWN)) + tipc_link_xmit2(buf, peer, 0); } else { tipc_port_shutdown(port->ref); } -- 2.34.1