mir/ovs
2
0
Fork 0
mirror of https://github.com/openvswitch/ovs synced 2025-09-05 16:55:42 +00:00
Code Issues Releases Wiki Activity

ovsdb: raft: Fix inability to read the database with DNS host names.

Browse Source 
Clustered OVSDB allows to use DNS names as addresses of raft members.
However, if DNS resolution fails during the initial database read,
this causes a fatal failure and exit of the ovsdb-server process.

Also, if DNS name of a joining server is not resolvable for one of the
followers, this follower will reject append requests for a new server
to join until the name is successfully resolved.  This makes a follower
effectively non-functional while DNS is unavailable.

To fix the problem relax the address verification.  Allowing validation
to pass if only name resolution failed and the address is valid
otherwise.  This will allow addresses to be added to the database, so
connections could be established later when the DNS is available.

Additionally fixing missed initialization of the dns-resolve module.
Without it, DNS requests are blocking.  This causes unexpected delays
in runtime.

Fixes: 771680d96f ("DNS: Add basic support for asynchronous DNS resolving")
Reported-at: https://bugzilla.redhat.com/2055097
Acked-by: Dumitru Ceara <dceara@redhat.com>
Signed-off-by: Ilya Maximets <i.maximets@ovn.org>
This commit is contained in:
Ilya Maximets
2022-03-10 23:33:17 +01:00
parent d96d14b147
commit 08e9e53373
7 changed files with 39 additions and 18 deletions
Download Patch File Download Diff File Expand all files Collapse all files

39
lib/socket-util.c
View File

@@ -62,7 +62,8 @@ static bool parse_sockaddr_components(struct sockaddr_storage *ss,
const char *port_s,
uint16_t default_port,
const char *s,
bool resolve_host);
bool resolve_host,
bool *dns_failure);
/* Sets 'fd' to non-blocking mode. Returns 0 if successful, otherwise a
* positive errno value. */
@@ -438,7 +439,7 @@ parse_sockaddr_components_dns(struct sockaddr_storage *ss OVS_UNUSED,
dns_resolve(host_s, &tmp_host_s);
if (tmp_host_s != NULL) {
parse_sockaddr_components(ss, tmp_host_s, port_s,
default_port, s, false);
default_port, s, false, NULL);
free(tmp_host_s);
return true;
}
@@ -450,11 +451,15 @@ parse_sockaddr_components(struct sockaddr_storage *ss,
char *host_s,
const char *port_s, uint16_t default_port,
const char *s,
bool resolve_host)
bool resolve_host, bool *dns_failure)
{
struct sockaddr_in *sin = sin_cast(sa_cast(ss));
int port;
if (dns_failure) {
*dns_failure = false;
}
if (port_s && port_s[0]) {
if (!str_to_int(port_s, 10, &port) || port < 0 || port > 65535) {
VLOG_ERR("%s: bad port number \"%s\"", s, port_s);
@@ -501,10 +506,15 @@ parse_sockaddr_components(struct sockaddr_storage *ss,
return true;
resolve:
if (resolve_host && parse_sockaddr_components_dns(ss, host_s, port_s,
default_port, s)) {
return true;
} else if (!resolve_host) {
if (resolve_host) {
if (parse_sockaddr_components_dns(ss, host_s, port_s,
default_port, s)) {
return true;
}
if (dns_failure) {
*dns_failure = true;
}
} else {
VLOG_ERR("%s: bad IP address \"%s\"", s, host_s);
}
exit:
@@ -521,10 +531,12 @@ exit:
* It resolves the host if 'resolve_host' is true.
*
* On success, returns true and stores the parsed remote address into '*ss'.
* On failure, logs an error, stores zeros into '*ss', and returns false. */
* On failure, logs an error, stores zeros into '*ss', and returns false,
* '*dns_failure' indicates if the host resolution failed. */
bool
inet_parse_active(const char *target_, int default_port,
struct sockaddr_storage *ss, bool resolve_host)
struct sockaddr_storage *ss,
bool resolve_host, bool *dns_failure)
{
char *target = xstrdup(target_);
char *port, *host;
@@ -539,7 +551,7 @@ inet_parse_active(const char *target_, int default_port,
ok = false;
} else {
ok = parse_sockaddr_components(ss, host, port, default_port,
target_, resolve_host);
target_, resolve_host, dns_failure);
}
if (!ok) {
memset(ss, 0, sizeof *ss);
@@ -576,7 +588,7 @@ inet_open_active(int style, const char *target, int default_port,
int error;
/* Parse. */
if (!inet_parse_active(target, default_port, &ss, true)) {
if (!inet_parse_active(target, default_port, &ss, true, NULL)) {
error = EAFNOSUPPORT;
goto exit;
}
@@ -660,7 +672,7 @@ inet_parse_passive(const char *target_, int default_port,
ok = false;
} else {
ok = parse_sockaddr_components(ss, host, port, default_port,
target_, true);
target_, true, NULL);
}
if (!ok) {
memset(ss, 0, sizeof *ss);
@@ -783,7 +795,8 @@ inet_parse_address(const char *target_, struct sockaddr_storage *ss)
{
char *target = xstrdup(target_);
char *host = unbracket(target);
bool ok = parse_sockaddr_components(ss, host, NULL, 0, target_, false);
bool ok = parse_sockaddr_components(ss, host, NULL, 0,
target_, false, NULL);
if (!ok) {
memset(ss, 0, sizeof *ss);
}