| /* |
| * 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 link_req - information about an ongoing link setup request |
| * @bearer: 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) |
| * @buf: request message to be (repeatedly) sent |
| * @timer: timer governing period between requests |
| * @timer_intv: current interval between requests (in ms) |
| */ |
| struct link_req { |
| struct tipc_bearer *bearer; |
| struct tipc_media_addr dest; |
| u32 domain; |
| int num_nodes; |
| 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) |
| * @dest_domain: network domain of node(s) which should respond to message |
| * @b_ptr: ptr to bearer issuing message |
| */ |
| |
| static struct sk_buff *tipc_disc_init_msg(u32 type, |
| u32 dest_domain, |
| struct tipc_bearer *b_ptr) |
| { |
| struct sk_buff *buf = tipc_buf_acquire(INT_H_SIZE); |
| struct tipc_msg *msg; |
| |
| if (buf) { |
| msg = buf_msg(buf); |
| tipc_msg_init(msg, LINK_CONFIG, type, INT_H_SIZE, dest_domain); |
| msg_set_non_seq(msg, 1); |
| msg_set_dest_domain(msg, dest_domain); |
| msg_set_bc_netid(msg, tipc_net_id); |
| msg_set_media_addr(msg, &b_ptr->addr); |
| } |
| return buf; |
| } |
| |
| /** |
| * 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]; |
| struct print_buf pb; |
| |
| tipc_addr_string_fill(node_addr_str, node_addr); |
| tipc_printbuf_init(&pb, media_addr_str, sizeof(media_addr_str)); |
| tipc_media_addr_printf(&pb, media_addr); |
| tipc_printbuf_validate(&pb); |
| warn("Duplicate %s using %s seen on <%s>\n", |
| node_addr_str, media_addr_str, b_ptr->name); |
| } |
| |
| /** |
| * tipc_disc_recv_msg - handle incoming link setup message (request or response) |
| * @buf: buffer containing message |
| * @b_ptr: bearer that message arrived on |
| */ |
| |
| void tipc_disc_recv_msg(struct sk_buff *buf, struct tipc_bearer *b_ptr) |
| { |
| struct tipc_node *n_ptr; |
| struct link *link; |
| struct tipc_media_addr media_addr, *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); |
| int link_fully_up; |
| |
| msg_get_media_addr(msg, &media_addr); |
| buf_discard(buf); |
| |
| /* Validate discovery message from requesting node */ |
| if (net_id != tipc_net_id) |
| 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->link_req->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); |
| |
| /* Don't talk to neighbor during cleanup after last session */ |
| if (n_ptr->cleanup_required) { |
| tipc_node_unlock(n_ptr); |
| return; |
| } |
| |
| link = n_ptr->links[b_ptr->identity]; |
| |
| /* 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; |
| } |
| } |
| |
| /* |
| * 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. |
| */ |
| addr = &link->media_addr; |
| if (memcmp(addr, &media_addr, sizeof(*addr))) { |
| if (tipc_link_is_up(link) || (!link->started)) { |
| disc_dupl_alert(b_ptr, orig, &media_addr); |
| tipc_node_unlock(n_ptr); |
| return; |
| } |
| warn("Resetting link <%s>, peer interface address changed\n", |
| link->name); |
| memcpy(addr, &media_addr, sizeof(*addr)); |
| tipc_link_reset(link); |
| } |
| |
| /* Accept discovery message & send response, if necessary */ |
| link_fully_up = link_working_working(link); |
| |
| if ((type == DSC_REQ_MSG) && !link_fully_up && !b_ptr->blocked) { |
| rbuf = tipc_disc_init_msg(DSC_RESP_MSG, orig, b_ptr); |
| if (rbuf) { |
| b_ptr->media->send_msg(rbuf, b_ptr, &media_addr); |
| buf_discard(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 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 link_req *req) |
| { |
| req->num_nodes++; |
| } |
| |
| /** |
| * tipc_disc_remove_dest - decrement set of discovered nodes |
| * @req: ptr to link request structure |
| */ |
| |
| void tipc_disc_remove_dest(struct link_req *req) |
| { |
| req->num_nodes--; |
| disc_update(req); |
| } |
| |
| /** |
| * disc_send_msg - send link setup request message |
| * @req: ptr to link request structure |
| */ |
| |
| static void disc_send_msg(struct link_req *req) |
| { |
| if (!req->bearer->blocked) |
| tipc_bearer_send(req->bearer, req->buf, &req->dest); |
| } |
| |
| /** |
| * 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 link_req *req) |
| { |
| int max_delay; |
| |
| spin_lock_bh(&req->bearer->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 |
| */ |
| |
| disc_send_msg(req); |
| |
| 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->bearer->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, u32 dest_domain) |
| { |
| struct link_req *req; |
| |
| req = kmalloc(sizeof(*req), GFP_ATOMIC); |
| if (!req) |
| return -ENOMEM; |
| |
| req->buf = tipc_disc_init_msg(DSC_REQ_MSG, dest_domain, b_ptr); |
| if (!req->buf) { |
| kfree(req); |
| return -ENOMSG; |
| } |
| |
| memcpy(&req->dest, dest, sizeof(*dest)); |
| req->bearer = b_ptr; |
| req->domain = dest_domain; |
| req->num_nodes = 0; |
| req->timer_intv = TIPC_LINK_REQ_INIT; |
| k_init_timer(&req->timer, (Handler)disc_timeout, (unsigned long)req); |
| k_start_timer(&req->timer, req->timer_intv); |
| b_ptr->link_req = req; |
| disc_send_msg(req); |
| return 0; |
| } |
| |
| /** |
| * tipc_disc_delete - destroy object sending periodic link setup requests |
| * @req: ptr to link request structure |
| */ |
| |
| void tipc_disc_delete(struct link_req *req) |
| { |
| k_cancel_timer(&req->timer); |
| k_term_timer(&req->timer); |
| buf_discard(req->buf); |
| kfree(req); |
| } |
| |