From 02da215c10422d28fbe8646f5dca07448c12d7e1 Mon Sep 17 00:00:00 2001 From: Zhu Shangzhong Date: Tue, 12 Mar 2019 20:49:48 +0800 Subject: ctdb: Initialize addr struct to zero before reparsing as IPV4 Failed to kill the tcp connection that using IPv4-mapped IPv6 address (e.g. ctdb_killtcp eth0 ::ffff:192.168.200.44:2049 ::ffff:192.168.200.45:863). When the ctdb_killtcp is used to kill the tcp connection, the IPs and ports in the connection will be parsed to conn.client and conn.server (call stack: main->ctdb_sock_addr_from_string->ip_from_string). In the ip_from_string, as we are using IPv4-mapped IPv6 addresses, the ipv6_from_string will be used to parse ip to addr.ip6 first. The next step the ipv4_from_string will be used to reparse ip to addr.ip. As a result, the data that dump from conn.server is "2 0 8 1 192 168 200 44 0 0 0 0 0 0 0 0 0 0 255 255 192 168 200 44 0 0 0 0", the data from conn.client is "2 0 3 95 192 168 200 45 0 0 0 0 0 0 0 0 0 0 255 255 192 168 200 45 0 0 0 0". The connection will be add to conn_list by ctdb_connection_list_add. Then the reset_connections_send uses conn_list as parameter to start to reset connections in the conn_list. In the reset_connections_send, the database "connections" will be created. The connections from conn_list will be written to the database(call db_hash_add), and use the data that dump from conn_client and conn_server as key. In the reset_connections_capture_tcp_handler, the ctdb_sys_read_tcp_packet will receive data on the raw socket. And extract the IPs and ports from the tcp packet. when extracting IP and port, the tcp4_extract OR tcp6_extract will be used. Then we got the new conn.client and conn.server. the data that dump from the conn.server is "2 0 8 1 192 168 200 44 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0", the data from conn.client is "2 0 3 95 192 168 200 45 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0". Finally, we use the data as key to check if this connection is one being reset(call db_hash_delete). The db_hash_delete will return ENOENT. Because the two key that being used by db_hash_delete and db_hash_add are different. So, the TCP RST will be NOT sent for the connection forever. We should initialize addr struct to zero before reparsing as IPV4 in the ip_from_string. BUG: https://bugzilla.samba.org/show_bug.cgi?id=13839 Signed-off-by: Zhu Shangzhong Reviewed-by: Martin Schwenke Reviewed-by: Amitay Isaacs (cherry picked from commit 539b5ff32b32b7c75dfaaa119e41f5af6ff1e6fc) --- ctdb/protocol/protocol_util.c | 3 +++ 1 file changed, 3 insertions(+) diff --git a/ctdb/protocol/protocol_util.c b/ctdb/protocol/protocol_util.c index 77e79867443..a46cde9f46f 100644 --- a/ctdb/protocol/protocol_util.c +++ b/ctdb/protocol/protocol_util.c @@ -251,6 +251,9 @@ static int ip_from_string(const char *str, ctdb_sock_addr *addr) if (memcmp(&addr->ip6.sin6_addr.s6_addr[0], ipv4_mapped_prefix, sizeof(ipv4_mapped_prefix)) == 0) { + /* Initialize addr struct to zero before reparsing as IPV4 */ + ZERO_STRUCTP(addr); + /* Reparse as IPv4 */ ret = ipv4_from_string(p+1, &addr->ip); } -- cgit v1.2.1