WSL2-Linux-Kernel/net/tipc/discover.c

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/*
* net/tipc/discover.c
*
* Copyright (c) 2003-2006, Ericsson AB
* Copyright (c) 2005-2006, 2010-2011, Wind River Systems
* All rights reserved.
*
* Redistribution and use in source and binary forms, with or without
* modification, are permitted provided that the following conditions are met:
*
* 1. Redistributions of source code must retain the above copyright
* notice, this list of conditions and the following disclaimer.
* 2. Redistributions in binary form must reproduce the above copyright
* notice, this list of conditions and the following disclaimer in the
* documentation and/or other materials provided with the distribution.
* 3. Neither the names of the copyright holders nor the names of its
* contributors may be used to endorse or promote products derived from
* this software without specific prior written permission.
*
* Alternatively, this software may be distributed under the terms of the
* GNU General Public License ("GPL") version 2 as published by the Free
* Software Foundation.
*
* THIS SOFTWARE IS PROVIDED BY THE COPYRIGHT HOLDERS AND CONTRIBUTORS "AS IS"
* AND ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE
* IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE
* ARE DISCLAIMED. IN NO EVENT SHALL THE COPYRIGHT OWNER OR CONTRIBUTORS BE
* LIABLE FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR
* CONSEQUENTIAL DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF
* SUBSTITUTE GOODS OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS
* INTERRUPTION) HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN
* CONTRACT, STRICT LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE)
* ARISING IN ANY WAY OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE
* POSSIBILITY OF SUCH DAMAGE.
*/
#include "core.h"
#include "link.h"
#include "discover.h"
#define TIPC_LINK_REQ_INIT 125 /* min delay during bearer start up */
#define TIPC_LINK_REQ_FAST 1000 /* max delay if bearer has no links */
#define TIPC_LINK_REQ_SLOW 60000 /* max delay if bearer has links */
#define TIPC_LINK_REQ_INACTIVE 0xffffffff /* indicates no timer in use */
/**
* struct tipc_link_req - information about an ongoing link setup request
* @bearer_id: identity of bearer issuing requests
* @dest: destination address for request messages
* @domain: network domain to which links can be established
* @num_nodes: number of nodes currently discovered (i.e. with an active link)
* @lock: spinlock for controlling access to requests
* @buf: request message to be (repeatedly) sent
* @timer: timer governing period between requests
* @timer_intv: current interval between requests (in ms)
*/
struct tipc_link_req {
u32 bearer_id;
struct tipc_media_addr dest;
u32 domain;
int num_nodes;
spinlock_t lock;
struct sk_buff *buf;
struct timer_list timer;
unsigned int timer_intv;
};
/**
* tipc_disc_init_msg - initialize a link setup message
* @type: message type (request or response)
* @b_ptr: ptr to bearer issuing message
*/
static void tipc_disc_init_msg(struct sk_buff *buf, u32 type,
struct tipc_bearer *b_ptr)
{
struct tipc_msg *msg;
u32 dest_domain = b_ptr->domain;
msg = buf_msg(buf);
tipc_msg_init(msg, LINK_CONFIG, type, INT_H_SIZE, dest_domain);
msg_set_non_seq(msg, 1);
msg_set_node_sig(msg, tipc_random);
msg_set_dest_domain(msg, dest_domain);
msg_set_bc_netid(msg, tipc_net_id);
b_ptr->media->addr2msg(&b_ptr->addr, msg_media_addr(msg));
}
/**
* disc_dupl_alert - issue node address duplication alert
* @b_ptr: pointer to bearer detecting duplication
* @node_addr: duplicated node address
* @media_addr: media address advertised by duplicated node
*/
static void disc_dupl_alert(struct tipc_bearer *b_ptr, u32 node_addr,
struct tipc_media_addr *media_addr)
{
char node_addr_str[16];
char media_addr_str[64];
tipc_addr_string_fill(node_addr_str, node_addr);
tipc: phase out most of the struct print_buf usage The tipc_printf is renamed to tipc_snprintf, as the new name describes more what the function actually does. It is also changed to take a buffer and length parameter and return number of characters written to the buffer. All callers of this function that used to pass a print_buf are updated. Final removal of the struct print_buf itself will be done synchronously with the pending removal of the deprecated logging code that also was using it. Functions that build up a response message with a list of ports, nametable contents etc. are changed to return the number of characters written to the output buffer. This information was previously hidden in a field of the print_buf struct, and the number of chars written was fetched with a call to tipc_printbuf_validate. This function is removed since it is no longer referenced nor needed. A generic max size ULTRA_STRING_MAX_LEN is defined, named in keeping with the existing TIPC_TLV_ULTRA_STRING, and the various definitions in port, link and nametable code that largely duplicated this information are removed. This means that amount of link statistics that can be returned is now increased from 2k to 32k. The buffer overflow check is now done just before the reply message is passed over netlink or TIPC to a remote node and the message indicating a truncated buffer is changed to a less dramatic one (less CAPS), placed at the end of the message. Signed-off-by: Erik Hugne <erik.hugne@ericsson.com> Signed-off-by: Jon Maloy <jon.maloy@ericsson.com> Signed-off-by: Paul Gortmaker <paul.gortmaker@windriver.com>
2012-06-29 08:50:23 +04:00
tipc_media_addr_printf(media_addr_str, sizeof(media_addr_str),
media_addr);
pr_warn("Duplicate %s using %s seen on <%s>\n", node_addr_str,
media_addr_str, b_ptr->name);
}
/**
tipc: align tipc function names with common naming practice in the network Rename the following functions, which are shorter and more in line with common naming practice in the network subsystem. tipc_bclink_send_msg->tipc_bclink_xmit tipc_bclink_recv_pkt->tipc_bclink_rcv tipc_disc_recv_msg->tipc_disc_rcv tipc_link_send_proto_msg->tipc_link_proto_xmit link_recv_proto_msg->tipc_link_proto_rcv link_send_sections_long->tipc_link_iovec_long_xmit tipc_link_send_sections_fast->tipc_link_iovec_xmit_fast tipc_link_send_sync->tipc_link_sync_xmit tipc_link_recv_sync->tipc_link_sync_rcv tipc_link_send_buf->__tipc_link_xmit tipc_link_send->tipc_link_xmit tipc_link_send_names->tipc_link_names_xmit tipc_named_recv->tipc_named_rcv tipc_link_recv_bundle->tipc_link_bundle_rcv tipc_link_dup_send_queue->tipc_link_dup_queue_xmit link_send_long_buf->tipc_link_frag_xmit tipc_multicast->tipc_port_mcast_xmit tipc_port_recv_mcast->tipc_port_mcast_rcv tipc_port_reject_sections->tipc_port_iovec_reject tipc_port_recv_proto_msg->tipc_port_proto_rcv tipc_connect->tipc_port_connect __tipc_connect->__tipc_port_connect __tipc_disconnect->__tipc_port_disconnect tipc_disconnect->tipc_port_disconnect tipc_shutdown->tipc_port_shutdown tipc_port_recv_msg->tipc_port_rcv tipc_port_recv_sections->tipc_port_iovec_rcv release->tipc_release accept->tipc_accept bind->tipc_bind get_name->tipc_getname poll->tipc_poll send_msg->tipc_sendmsg send_packet->tipc_send_packet send_stream->tipc_send_stream recv_msg->tipc_recvmsg recv_stream->tipc_recv_stream connect->tipc_connect listen->tipc_listen shutdown->tipc_shutdown setsockopt->tipc_setsockopt getsockopt->tipc_getsockopt Above changes have no impact on current users of the functions. Signed-off-by: Ying Xue <ying.xue@windriver.com> Reviewed-by: Jon Maloy <jon.maloy@ericsson.com> Signed-off-by: David S. Miller <davem@davemloft.net>
2014-02-18 12:06:46 +04:00
* tipc_disc_rcv - handle incoming link setup message (request or response)
* @buf: buffer containing message
* @b_ptr: bearer that message arrived on
*/
tipc: align tipc function names with common naming practice in the network Rename the following functions, which are shorter and more in line with common naming practice in the network subsystem. tipc_bclink_send_msg->tipc_bclink_xmit tipc_bclink_recv_pkt->tipc_bclink_rcv tipc_disc_recv_msg->tipc_disc_rcv tipc_link_send_proto_msg->tipc_link_proto_xmit link_recv_proto_msg->tipc_link_proto_rcv link_send_sections_long->tipc_link_iovec_long_xmit tipc_link_send_sections_fast->tipc_link_iovec_xmit_fast tipc_link_send_sync->tipc_link_sync_xmit tipc_link_recv_sync->tipc_link_sync_rcv tipc_link_send_buf->__tipc_link_xmit tipc_link_send->tipc_link_xmit tipc_link_send_names->tipc_link_names_xmit tipc_named_recv->tipc_named_rcv tipc_link_recv_bundle->tipc_link_bundle_rcv tipc_link_dup_send_queue->tipc_link_dup_queue_xmit link_send_long_buf->tipc_link_frag_xmit tipc_multicast->tipc_port_mcast_xmit tipc_port_recv_mcast->tipc_port_mcast_rcv tipc_port_reject_sections->tipc_port_iovec_reject tipc_port_recv_proto_msg->tipc_port_proto_rcv tipc_connect->tipc_port_connect __tipc_connect->__tipc_port_connect __tipc_disconnect->__tipc_port_disconnect tipc_disconnect->tipc_port_disconnect tipc_shutdown->tipc_port_shutdown tipc_port_recv_msg->tipc_port_rcv tipc_port_recv_sections->tipc_port_iovec_rcv release->tipc_release accept->tipc_accept bind->tipc_bind get_name->tipc_getname poll->tipc_poll send_msg->tipc_sendmsg send_packet->tipc_send_packet send_stream->tipc_send_stream recv_msg->tipc_recvmsg recv_stream->tipc_recv_stream connect->tipc_connect listen->tipc_listen shutdown->tipc_shutdown setsockopt->tipc_setsockopt getsockopt->tipc_getsockopt Above changes have no impact on current users of the functions. Signed-off-by: Ying Xue <ying.xue@windriver.com> Reviewed-by: Jon Maloy <jon.maloy@ericsson.com> Signed-off-by: David S. Miller <davem@davemloft.net>
2014-02-18 12:06:46 +04:00
void tipc_disc_rcv(struct sk_buff *buf, struct tipc_bearer *b_ptr)
{
struct tipc_node *n_ptr;
struct tipc_link *link;
tipc: Detect duplicate nodes using different network interfaces Utilizes the new "node signature" field in neighbor discovery messages to ensure that all links TIPC associates with a given <Z.C.N> network address belong to the same neighboring node. (Previously, TIPC could not tell if link setup requests arriving on different interfaces were from the same node or from two different nodes that has mistakenly been assigned the same network address.) The revised algorithm for detecting a duplicate node considers both the node signature and the network interface adddress specified in a request message when deciding how to respond to a link setup request. This prevents false alarms that might otherwise arise during normal network operation under the following scenarios: a) A neighboring node reboots. (The node's signature changes, but the network interface address remains unchanged.) b) A neighboring node's network interface is replaced. (The node's signature remains unchanged, but the network interface address changes.) c) A neighboring node is completely replaced. (The node's signature and network interface address both change.) The algorithm also handles cases in which a node reboots and re-establishes its links to TIPC (or begins re-establishing those links) before TIPC detects that it is using a new node signature. In such cases of "delayed rediscovery" TIPC simply accepts the new signature without disrupting communication that is already underway over the links. Thanks to Laser [gotolaser@gmail.com] for his contributions to the development of this enhancement. Signed-off-by: Allan Stephens <allan.stephens@windriver.com> Signed-off-by: Paul Gortmaker <paul.gortmaker@windriver.com>
2011-10-29 01:30:08 +04:00
struct tipc_media_addr media_addr;
struct sk_buff *rbuf;
struct tipc_msg *msg = buf_msg(buf);
u32 dest = msg_dest_domain(msg);
u32 orig = msg_prevnode(msg);
u32 net_id = msg_bc_netid(msg);
u32 type = msg_type(msg);
u32 signature = msg_node_sig(msg);
tipc: Detect duplicate nodes using different network interfaces Utilizes the new "node signature" field in neighbor discovery messages to ensure that all links TIPC associates with a given <Z.C.N> network address belong to the same neighboring node. (Previously, TIPC could not tell if link setup requests arriving on different interfaces were from the same node or from two different nodes that has mistakenly been assigned the same network address.) The revised algorithm for detecting a duplicate node considers both the node signature and the network interface adddress specified in a request message when deciding how to respond to a link setup request. This prevents false alarms that might otherwise arise during normal network operation under the following scenarios: a) A neighboring node reboots. (The node's signature changes, but the network interface address remains unchanged.) b) A neighboring node's network interface is replaced. (The node's signature remains unchanged, but the network interface address changes.) c) A neighboring node is completely replaced. (The node's signature and network interface address both change.) The algorithm also handles cases in which a node reboots and re-establishes its links to TIPC (or begins re-establishing those links) before TIPC detects that it is using a new node signature. In such cases of "delayed rediscovery" TIPC simply accepts the new signature without disrupting communication that is already underway over the links. Thanks to Laser [gotolaser@gmail.com] for his contributions to the development of this enhancement. Signed-off-by: Allan Stephens <allan.stephens@windriver.com> Signed-off-by: Paul Gortmaker <paul.gortmaker@windriver.com>
2011-10-29 01:30:08 +04:00
int addr_mismatch;
int link_fully_up;
media_addr.broadcast = 1;
b_ptr->media->msg2addr(b_ptr, &media_addr, msg_media_addr(msg));
kfree_skb(buf);
tipc: Detect duplicate nodes using different network interfaces Utilizes the new "node signature" field in neighbor discovery messages to ensure that all links TIPC associates with a given <Z.C.N> network address belong to the same neighboring node. (Previously, TIPC could not tell if link setup requests arriving on different interfaces were from the same node or from two different nodes that has mistakenly been assigned the same network address.) The revised algorithm for detecting a duplicate node considers both the node signature and the network interface adddress specified in a request message when deciding how to respond to a link setup request. This prevents false alarms that might otherwise arise during normal network operation under the following scenarios: a) A neighboring node reboots. (The node's signature changes, but the network interface address remains unchanged.) b) A neighboring node's network interface is replaced. (The node's signature remains unchanged, but the network interface address changes.) c) A neighboring node is completely replaced. (The node's signature and network interface address both change.) The algorithm also handles cases in which a node reboots and re-establishes its links to TIPC (or begins re-establishing those links) before TIPC detects that it is using a new node signature. In such cases of "delayed rediscovery" TIPC simply accepts the new signature without disrupting communication that is already underway over the links. Thanks to Laser [gotolaser@gmail.com] for his contributions to the development of this enhancement. Signed-off-by: Allan Stephens <allan.stephens@windriver.com> Signed-off-by: Paul Gortmaker <paul.gortmaker@windriver.com>
2011-10-29 01:30:08 +04:00
/* Ensure message from node is valid and communication is permitted */
if (net_id != tipc_net_id)
return;
if (media_addr.broadcast)
return;
if (!tipc_addr_domain_valid(dest))
return;
if (!tipc_addr_node_valid(orig))
return;
if (orig == tipc_own_addr) {
if (memcmp(&media_addr, &b_ptr->addr, sizeof(media_addr)))
disc_dupl_alert(b_ptr, tipc_own_addr, &media_addr);
return;
}
if (!tipc_in_scope(dest, tipc_own_addr))
return;
if (!tipc_in_scope(b_ptr->domain, orig))
return;
/* Locate structure corresponding to requesting node */
n_ptr = tipc_node_find(orig);
if (!n_ptr) {
n_ptr = tipc_node_create(orig);
if (!n_ptr)
return;
}
tipc_node_lock(n_ptr);
tipc: Detect duplicate nodes using different network interfaces Utilizes the new "node signature" field in neighbor discovery messages to ensure that all links TIPC associates with a given <Z.C.N> network address belong to the same neighboring node. (Previously, TIPC could not tell if link setup requests arriving on different interfaces were from the same node or from two different nodes that has mistakenly been assigned the same network address.) The revised algorithm for detecting a duplicate node considers both the node signature and the network interface adddress specified in a request message when deciding how to respond to a link setup request. This prevents false alarms that might otherwise arise during normal network operation under the following scenarios: a) A neighboring node reboots. (The node's signature changes, but the network interface address remains unchanged.) b) A neighboring node's network interface is replaced. (The node's signature remains unchanged, but the network interface address changes.) c) A neighboring node is completely replaced. (The node's signature and network interface address both change.) The algorithm also handles cases in which a node reboots and re-establishes its links to TIPC (or begins re-establishing those links) before TIPC detects that it is using a new node signature. In such cases of "delayed rediscovery" TIPC simply accepts the new signature without disrupting communication that is already underway over the links. Thanks to Laser [gotolaser@gmail.com] for his contributions to the development of this enhancement. Signed-off-by: Allan Stephens <allan.stephens@windriver.com> Signed-off-by: Paul Gortmaker <paul.gortmaker@windriver.com>
2011-10-29 01:30:08 +04:00
/* Prepare to validate requesting node's signature and media address */
link = n_ptr->links[b_ptr->identity];
tipc: Detect duplicate nodes using different network interfaces Utilizes the new "node signature" field in neighbor discovery messages to ensure that all links TIPC associates with a given <Z.C.N> network address belong to the same neighboring node. (Previously, TIPC could not tell if link setup requests arriving on different interfaces were from the same node or from two different nodes that has mistakenly been assigned the same network address.) The revised algorithm for detecting a duplicate node considers both the node signature and the network interface adddress specified in a request message when deciding how to respond to a link setup request. This prevents false alarms that might otherwise arise during normal network operation under the following scenarios: a) A neighboring node reboots. (The node's signature changes, but the network interface address remains unchanged.) b) A neighboring node's network interface is replaced. (The node's signature remains unchanged, but the network interface address changes.) c) A neighboring node is completely replaced. (The node's signature and network interface address both change.) The algorithm also handles cases in which a node reboots and re-establishes its links to TIPC (or begins re-establishing those links) before TIPC detects that it is using a new node signature. In such cases of "delayed rediscovery" TIPC simply accepts the new signature without disrupting communication that is already underway over the links. Thanks to Laser [gotolaser@gmail.com] for his contributions to the development of this enhancement. Signed-off-by: Allan Stephens <allan.stephens@windriver.com> Signed-off-by: Paul Gortmaker <paul.gortmaker@windriver.com>
2011-10-29 01:30:08 +04:00
addr_mismatch = (link != NULL) &&
memcmp(&link->media_addr, &media_addr, sizeof(media_addr));
tipc: Detect duplicate nodes using different network interfaces Utilizes the new "node signature" field in neighbor discovery messages to ensure that all links TIPC associates with a given <Z.C.N> network address belong to the same neighboring node. (Previously, TIPC could not tell if link setup requests arriving on different interfaces were from the same node or from two different nodes that has mistakenly been assigned the same network address.) The revised algorithm for detecting a duplicate node considers both the node signature and the network interface adddress specified in a request message when deciding how to respond to a link setup request. This prevents false alarms that might otherwise arise during normal network operation under the following scenarios: a) A neighboring node reboots. (The node's signature changes, but the network interface address remains unchanged.) b) A neighboring node's network interface is replaced. (The node's signature remains unchanged, but the network interface address changes.) c) A neighboring node is completely replaced. (The node's signature and network interface address both change.) The algorithm also handles cases in which a node reboots and re-establishes its links to TIPC (or begins re-establishing those links) before TIPC detects that it is using a new node signature. In such cases of "delayed rediscovery" TIPC simply accepts the new signature without disrupting communication that is already underway over the links. Thanks to Laser [gotolaser@gmail.com] for his contributions to the development of this enhancement. Signed-off-by: Allan Stephens <allan.stephens@windriver.com> Signed-off-by: Paul Gortmaker <paul.gortmaker@windriver.com>
2011-10-29 01:30:08 +04:00
/*
* Ensure discovery message's signature is correct
*
* If signature is incorrect and there is no working link to the node,
* accept the new signature but invalidate all existing links to the
* node so they won't re-activate without a new discovery message.
*
* If signature is incorrect and the requested link to the node is
* working, accept the new signature. (This is an instance of delayed
* rediscovery, where a link endpoint was able to re-establish contact
* with its peer endpoint on a node that rebooted before receiving a
* discovery message from that node.)
*
* If signature is incorrect and there is a working link to the node
* that is not the requested link, reject the request (must be from
* a duplicate node).
*/
if (signature != n_ptr->signature) {
if (n_ptr->working_links == 0) {
struct tipc_link *curr_link;
int i;
for (i = 0; i < MAX_BEARERS; i++) {
curr_link = n_ptr->links[i];
if (curr_link) {
memset(&curr_link->media_addr, 0,
sizeof(media_addr));
tipc_link_reset(curr_link);
}
}
addr_mismatch = (link != NULL);
} else if (tipc_link_is_up(link) && !addr_mismatch) {
/* delayed rediscovery */
} else {
disc_dupl_alert(b_ptr, orig, &media_addr);
tipc_node_unlock(n_ptr);
return;
}
tipc: Detect duplicate nodes using different network interfaces Utilizes the new "node signature" field in neighbor discovery messages to ensure that all links TIPC associates with a given <Z.C.N> network address belong to the same neighboring node. (Previously, TIPC could not tell if link setup requests arriving on different interfaces were from the same node or from two different nodes that has mistakenly been assigned the same network address.) The revised algorithm for detecting a duplicate node considers both the node signature and the network interface adddress specified in a request message when deciding how to respond to a link setup request. This prevents false alarms that might otherwise arise during normal network operation under the following scenarios: a) A neighboring node reboots. (The node's signature changes, but the network interface address remains unchanged.) b) A neighboring node's network interface is replaced. (The node's signature remains unchanged, but the network interface address changes.) c) A neighboring node is completely replaced. (The node's signature and network interface address both change.) The algorithm also handles cases in which a node reboots and re-establishes its links to TIPC (or begins re-establishing those links) before TIPC detects that it is using a new node signature. In such cases of "delayed rediscovery" TIPC simply accepts the new signature without disrupting communication that is already underway over the links. Thanks to Laser [gotolaser@gmail.com] for his contributions to the development of this enhancement. Signed-off-by: Allan Stephens <allan.stephens@windriver.com> Signed-off-by: Paul Gortmaker <paul.gortmaker@windriver.com>
2011-10-29 01:30:08 +04:00
n_ptr->signature = signature;
}
/*
* Ensure requesting node's media address is correct
*
* If media address doesn't match and the link is working, reject the
* request (must be from a duplicate node).
*
* If media address doesn't match and the link is not working, accept
* the new media address and reset the link to ensure it starts up
* cleanly.
*/
tipc: Detect duplicate nodes using different network interfaces Utilizes the new "node signature" field in neighbor discovery messages to ensure that all links TIPC associates with a given <Z.C.N> network address belong to the same neighboring node. (Previously, TIPC could not tell if link setup requests arriving on different interfaces were from the same node or from two different nodes that has mistakenly been assigned the same network address.) The revised algorithm for detecting a duplicate node considers both the node signature and the network interface adddress specified in a request message when deciding how to respond to a link setup request. This prevents false alarms that might otherwise arise during normal network operation under the following scenarios: a) A neighboring node reboots. (The node's signature changes, but the network interface address remains unchanged.) b) A neighboring node's network interface is replaced. (The node's signature remains unchanged, but the network interface address changes.) c) A neighboring node is completely replaced. (The node's signature and network interface address both change.) The algorithm also handles cases in which a node reboots and re-establishes its links to TIPC (or begins re-establishing those links) before TIPC detects that it is using a new node signature. In such cases of "delayed rediscovery" TIPC simply accepts the new signature without disrupting communication that is already underway over the links. Thanks to Laser [gotolaser@gmail.com] for his contributions to the development of this enhancement. Signed-off-by: Allan Stephens <allan.stephens@windriver.com> Signed-off-by: Paul Gortmaker <paul.gortmaker@windriver.com>
2011-10-29 01:30:08 +04:00
if (addr_mismatch) {
if (tipc_link_is_up(link)) {
disc_dupl_alert(b_ptr, orig, &media_addr);
tipc_node_unlock(n_ptr);
return;
tipc: Detect duplicate nodes using different network interfaces Utilizes the new "node signature" field in neighbor discovery messages to ensure that all links TIPC associates with a given <Z.C.N> network address belong to the same neighboring node. (Previously, TIPC could not tell if link setup requests arriving on different interfaces were from the same node or from two different nodes that has mistakenly been assigned the same network address.) The revised algorithm for detecting a duplicate node considers both the node signature and the network interface adddress specified in a request message when deciding how to respond to a link setup request. This prevents false alarms that might otherwise arise during normal network operation under the following scenarios: a) A neighboring node reboots. (The node's signature changes, but the network interface address remains unchanged.) b) A neighboring node's network interface is replaced. (The node's signature remains unchanged, but the network interface address changes.) c) A neighboring node is completely replaced. (The node's signature and network interface address both change.) The algorithm also handles cases in which a node reboots and re-establishes its links to TIPC (or begins re-establishing those links) before TIPC detects that it is using a new node signature. In such cases of "delayed rediscovery" TIPC simply accepts the new signature without disrupting communication that is already underway over the links. Thanks to Laser [gotolaser@gmail.com] for his contributions to the development of this enhancement. Signed-off-by: Allan Stephens <allan.stephens@windriver.com> Signed-off-by: Paul Gortmaker <paul.gortmaker@windriver.com>
2011-10-29 01:30:08 +04:00
} else {
memcpy(&link->media_addr, &media_addr,
sizeof(media_addr));
tipc_link_reset(link);
}
}
/* Create a link endpoint for this bearer, if necessary */
if (!link) {
link = tipc_link_create(n_ptr, b_ptr, &media_addr);
if (!link) {
tipc_node_unlock(n_ptr);
return;
}
}
/* Accept discovery message & send response, if necessary */
link_fully_up = link_working_working(link);
tipc: remove interface state mirroring in bearer struct 'tipc_bearer' is a generic representation of the underlying media type, and exists in a one-to-one relationship to each interface TIPC is using. The struct contains a 'blocked' flag that mirrors the operational and execution state of the represented interface, and is updated through notification calls from the latter. The users of tipc_bearer are checking this flag before each attempt to send a packet via the interface. This state mirroring serves no purpose in the current code base. TIPC links will not discover a media failure any faster through this mechanism, and in reality the flag only adds overhead at packet sending and reception. Furthermore, the fact that the flag needs to be protected by a spinlock aggregated into tipc_bearer has turned out to cause a serious and completely unnecessary deadlock problem. CPU0 CPU1 ---- ---- Time 0: bearer_disable() link_timeout() Time 1: spin_lock_bh(&b_ptr->lock) tipc_link_push_queue() Time 2: tipc_link_delete() tipc_bearer_blocked(b_ptr) Time 3: k_cancel_timer(&req->timer) spin_lock_bh(&b_ptr->lock) Time 4: del_timer_sync(&req->timer) I.e., del_timer_sync() on CPU0 never returns, because the timer handler on CPU1 is waiting for the bearer lock. We eliminate the 'blocked' flag from struct tipc_bearer, along with all tests on this flag. This not only resolves the deadlock, but also simplifies and speeds up the data path execution of TIPC. It also fits well into our ongoing effort to make the locking policy simpler and more manageable. An effect of this change is that we can get rid of functions such as tipc_bearer_blocked(), tipc_continue() and tipc_block_bearer(). We replace the latter with a new function, tipc_reset_bearer(), which resets all links associated to the bearer immediately after an interface goes down. A user might notice one slight change in link behaviour after this change. When an interface goes down, (e.g. through a NETDEV_DOWN event) all attached links will be reset immediately, instead of leaving it to each link to detect the failure through a timer-driven mechanism. We consider this an improvement, and see no obvious risks with the new behavior. Signed-off-by: Erik Hugne <erik.hugne@ericsson.com> Reviewed-by: Ying Xue <ying.xue@windriver.com> Reviewed-by: Paul Gortmaker <Paul.Gortmaker@windriver.com> Signed-off-by: Jon Maloy <jon.maloy@ericsson.com> Signed-off-by: David S. Miller <davem@davemloft.net>
2013-12-06 19:08:00 +04:00
if ((type == DSC_REQ_MSG) && !link_fully_up) {
rbuf = tipc_buf_acquire(INT_H_SIZE);
if (rbuf) {
tipc_disc_init_msg(rbuf, DSC_RESP_MSG, b_ptr);
tipc_bearer_send(b_ptr->identity, rbuf, &media_addr);
kfree_skb(rbuf);
}
}
tipc_node_unlock(n_ptr);
}
/**
* disc_update - update frequency of periodic link setup requests
* @req: ptr to link request structure
*
* Reinitiates discovery process if discovery object has no associated nodes
* and is either not currently searching or is searching at a slow rate
*/
static void disc_update(struct tipc_link_req *req)
{
if (!req->num_nodes) {
if ((req->timer_intv == TIPC_LINK_REQ_INACTIVE) ||
(req->timer_intv > TIPC_LINK_REQ_FAST)) {
req->timer_intv = TIPC_LINK_REQ_INIT;
k_start_timer(&req->timer, req->timer_intv);
}
}
}
/**
* tipc_disc_add_dest - increment set of discovered nodes
* @req: ptr to link request structure
*/
void tipc_disc_add_dest(struct tipc_link_req *req)
{
spin_lock_bh(&req->lock);
req->num_nodes++;
spin_unlock_bh(&req->lock);
}
/**
* tipc_disc_remove_dest - decrement set of discovered nodes
* @req: ptr to link request structure
*/
void tipc_disc_remove_dest(struct tipc_link_req *req)
{
spin_lock_bh(&req->lock);
req->num_nodes--;
disc_update(req);
spin_unlock_bh(&req->lock);
}
/**
* disc_timeout - send a periodic link setup request
* @req: ptr to link request structure
*
* Called whenever a link setup request timer associated with a bearer expires.
*/
static void disc_timeout(struct tipc_link_req *req)
{
int max_delay;
spin_lock_bh(&req->lock);
/* Stop searching if only desired node has been found */
if (tipc_node(req->domain) && req->num_nodes) {
req->timer_intv = TIPC_LINK_REQ_INACTIVE;
goto exit;
}
/*
* Send discovery message, then update discovery timer
*
* Keep doubling time between requests until limit is reached;
* hold at fast polling rate if don't have any associated nodes,
* otherwise hold at slow polling rate
*/
tipc_bearer_send(req->bearer_id, req->buf, &req->dest);
tipc: remove interface state mirroring in bearer struct 'tipc_bearer' is a generic representation of the underlying media type, and exists in a one-to-one relationship to each interface TIPC is using. The struct contains a 'blocked' flag that mirrors the operational and execution state of the represented interface, and is updated through notification calls from the latter. The users of tipc_bearer are checking this flag before each attempt to send a packet via the interface. This state mirroring serves no purpose in the current code base. TIPC links will not discover a media failure any faster through this mechanism, and in reality the flag only adds overhead at packet sending and reception. Furthermore, the fact that the flag needs to be protected by a spinlock aggregated into tipc_bearer has turned out to cause a serious and completely unnecessary deadlock problem. CPU0 CPU1 ---- ---- Time 0: bearer_disable() link_timeout() Time 1: spin_lock_bh(&b_ptr->lock) tipc_link_push_queue() Time 2: tipc_link_delete() tipc_bearer_blocked(b_ptr) Time 3: k_cancel_timer(&req->timer) spin_lock_bh(&b_ptr->lock) Time 4: del_timer_sync(&req->timer) I.e., del_timer_sync() on CPU0 never returns, because the timer handler on CPU1 is waiting for the bearer lock. We eliminate the 'blocked' flag from struct tipc_bearer, along with all tests on this flag. This not only resolves the deadlock, but also simplifies and speeds up the data path execution of TIPC. It also fits well into our ongoing effort to make the locking policy simpler and more manageable. An effect of this change is that we can get rid of functions such as tipc_bearer_blocked(), tipc_continue() and tipc_block_bearer(). We replace the latter with a new function, tipc_reset_bearer(), which resets all links associated to the bearer immediately after an interface goes down. A user might notice one slight change in link behaviour after this change. When an interface goes down, (e.g. through a NETDEV_DOWN event) all attached links will be reset immediately, instead of leaving it to each link to detect the failure through a timer-driven mechanism. We consider this an improvement, and see no obvious risks with the new behavior. Signed-off-by: Erik Hugne <erik.hugne@ericsson.com> Reviewed-by: Ying Xue <ying.xue@windriver.com> Reviewed-by: Paul Gortmaker <Paul.Gortmaker@windriver.com> Signed-off-by: Jon Maloy <jon.maloy@ericsson.com> Signed-off-by: David S. Miller <davem@davemloft.net>
2013-12-06 19:08:00 +04:00
req->timer_intv *= 2;
if (req->num_nodes)
max_delay = TIPC_LINK_REQ_SLOW;
else
max_delay = TIPC_LINK_REQ_FAST;
if (req->timer_intv > max_delay)
req->timer_intv = max_delay;
k_start_timer(&req->timer, req->timer_intv);
exit:
spin_unlock_bh(&req->lock);
}
/**
* tipc_disc_create - create object to send periodic link setup requests
* @b_ptr: ptr to bearer issuing requests
* @dest: destination address for request messages
* @dest_domain: network domain to which links can be established
*
* Returns 0 if successful, otherwise -errno.
*/
int tipc_disc_create(struct tipc_bearer *b_ptr, struct tipc_media_addr *dest)
{
struct tipc_link_req *req;
req = kmalloc(sizeof(*req), GFP_ATOMIC);
if (!req)
return -ENOMEM;
req->buf = tipc_buf_acquire(INT_H_SIZE);
if (!req->buf) {
kfree(req);
return -ENOMEM;
}
tipc_disc_init_msg(req->buf, DSC_REQ_MSG, b_ptr);
memcpy(&req->dest, dest, sizeof(*dest));
req->bearer_id = b_ptr->identity;
req->domain = b_ptr->domain;
req->num_nodes = 0;
req->timer_intv = TIPC_LINK_REQ_INIT;
spin_lock_init(&req->lock);
k_init_timer(&req->timer, (Handler)disc_timeout, (unsigned long)req);
k_start_timer(&req->timer, req->timer_intv);
b_ptr->link_req = req;
tipc_bearer_send(req->bearer_id, req->buf, &req->dest);
return 0;
}
/**
* tipc_disc_delete - destroy object sending periodic link setup requests
* @req: ptr to link request structure
*/
void tipc_disc_delete(struct tipc_link_req *req)
{
k_cancel_timer(&req->timer);
k_term_timer(&req->timer);
kfree_skb(req->buf);
kfree(req);
}
/**
* tipc_disc_reset - reset object to send periodic link setup requests
* @b_ptr: ptr to bearer issuing requests
* @dest_domain: network domain to which links can be established
*/
void tipc_disc_reset(struct tipc_bearer *b_ptr)
{
struct tipc_link_req *req = b_ptr->link_req;
spin_lock_bh(&req->lock);
tipc_disc_init_msg(req->buf, DSC_REQ_MSG, b_ptr);
req->bearer_id = b_ptr->identity;
req->domain = b_ptr->domain;
req->num_nodes = 0;
req->timer_intv = TIPC_LINK_REQ_INIT;
k_start_timer(&req->timer, req->timer_intv);
tipc_bearer_send(req->bearer_id, req->buf, &req->dest);
spin_unlock_bh(&req->lock);
}