Commit 08e9e5337383 fixed proper initialization of the dns-resolve module, and made DNS resolution asynchronous.
A side effect of that change revealed a long standing logic bug which broke ovsdb-server listener configuration using DNS names. Previously this worked because the DNS resolution would block, now that DNS resolution is asynchronous the code before this change would assume the error from jsonrpc_pstream_open meant the listener was in fact a specification for an active outgoing connection, even when that was not the case. To fix this a couple of changes was made to socket-util: 1) Pass optional result of dns resolution from inet_parse_passive. When (re-)configuring listeners that use DNS names, we may need to know whether the provided connection string is invalid or if the provided DNS name has finished resolving. 2) Check dns resolution status in inet_open_passive. If the connection string is valid, and contains a DNS name, inet_open_passive will now return -ENODATA if dns resolution failed. DNS resolution failure may either mean the asynchronous resolver has not completed yet, or that the name does not resolve. Reported-at: https://bugs.launchpad.net/bugs/1998781 Fixes: 08e9e5337383 ("ovsdb: raft: Fix inability to read the database with DNS host names.") Fixes: 771680d96fb6 ("DNS: Add basic support for asynchronous DNS resolving") Signed-off-by: Frode Nordahl <frode.nord...@canonical.com> --- lib/socket-util.c | 13 ++++++++++--- lib/socket-util.h | 3 ++- ovsdb/jsonrpc-server.c | 43 ++++++++++++++++++++++++++---------------- 3 files changed, 39 insertions(+), 20 deletions(-) diff --git a/lib/socket-util.c b/lib/socket-util.c index 38705cc51..eba350ccb 100644 --- a/lib/socket-util.c +++ b/lib/socket-util.c @@ -660,7 +660,8 @@ exit: * zeros '*ss' and returns false. */ bool inet_parse_passive(const char *target_, int default_port, - struct sockaddr_storage *ss) + struct sockaddr_storage *ss, + bool resolve_host, bool *dns_failure) { char *target = xstrdup(target_); char *port, *host; @@ -672,7 +673,7 @@ inet_parse_passive(const char *target_, int default_port, ok = false; } else { ok = parse_sockaddr_components(ss, host, port, default_port, - target_, true, NULL); + target_, resolve_host, dns_failure); } if (!ok) { memset(ss, 0, sizeof *ss); @@ -710,8 +711,14 @@ inet_open_passive(int style, const char *target, int default_port, struct sockaddr_storage ss; int fd = 0, error; unsigned int yes = 1; + bool dns_failure; - if (!inet_parse_passive(target, default_port, &ss)) { + if (!inet_parse_passive(target, default_port, &ss, true, &dns_failure)) { + if (dns_failure) { + /* DNS failure means asynchronous DNS resolution is in progress, + * or that the name does currently not resolve. */ + return -ENODATA; + } return -EAFNOSUPPORT; } kernel_chooses_port = ss_get_port(&ss) == 0; diff --git a/lib/socket-util.h b/lib/socket-util.h index bf66393df..4eec627e3 100644 --- a/lib/socket-util.h +++ b/lib/socket-util.h @@ -55,7 +55,8 @@ int inet_open_active(int style, const char *target, int default_port, struct sockaddr_storage *ssp, int *fdp, uint8_t dscp); bool inet_parse_passive(const char *target, int default_port, - struct sockaddr_storage *ssp); + struct sockaddr_storage *ssp, + bool resolve_host, bool *dns_failure); int inet_open_passive(int style, const char *target, int default_port, struct sockaddr_storage *ssp, uint8_t dscp, bool kernel_print_port); diff --git a/ovsdb/jsonrpc-server.c b/ovsdb/jsonrpc-server.c index 916a1f414..b4eb17467 100644 --- a/ovsdb/jsonrpc-server.c +++ b/ovsdb/jsonrpc-server.c @@ -267,25 +267,36 @@ ovsdb_jsonrpc_server_add_remote(struct ovsdb_jsonrpc_server *svr, int error; error = jsonrpc_pstream_open(name, &listener, options->dscp); - if (error && error != EAFNOSUPPORT) { - VLOG_ERR_RL(&rl, "%s: listen failed: %s", name, ovs_strerror(error)); - return NULL; - } + switch (error) { + case 0: + case EAFNOSUPPORT: + remote = xmalloc(sizeof *remote); + remote->server = svr; + remote->listener = listener; + ovs_list_init(&remote->sessions); + remote->dscp = options->dscp; + remote->read_only = options->read_only; + remote->role = nullable_xstrdup(options->role); + shash_add(&svr->remotes, name, remote); + if (!listener) { + /* Not a listener, attempt creation of active jsonrpc sesssion. */ + ovsdb_jsonrpc_session_create(remote, + jsonrpc_session_open(name, true), + svr->read_only || remote->read_only); + } + return remote; - remote = xmalloc(sizeof *remote); - remote->server = svr; - remote->listener = listener; - ovs_list_init(&remote->sessions); - remote->dscp = options->dscp; - remote->read_only = options->read_only; - remote->role = nullable_xstrdup(options->role); - shash_add(&svr->remotes, name, remote); + case ENODATA: + VLOG_DBG_RL(&rl, "%s: listen failed: " + "DNS resolution in progress or host not found", name); + return NULL; - if (!listener) { - ovsdb_jsonrpc_session_create(remote, jsonrpc_session_open(name, true), - svr->read_only || remote->read_only); + default: + VLOG_ERR_RL(&rl, "%s: listen failed: %s", name, + ovs_strerror(error)); + return NULL; } - return remote; + OVS_NOT_REACHED(); } static void -- 2.38.1 _______________________________________________ dev mailing list d...@openvswitch.org https://mail.openvswitch.org/mailman/listinfo/ovs-dev
