{182782396} Look up peer's short hostname

Signed-off-by: Rivers Zhang <hzhang320@bloomberg.net>

Author: riverszhang89

bdb/bdb_net.c

@@ -41,6 +41,7 @@
 #include "printformats.h"
 #include "crc32c.h"
 #include <timer_util.h>
+#include <hostname_support.h>
 
 #undef UDP_DEBUG
 #undef UDP_TRACE
@@ -200,33 +201,23 @@ void comdb2_early_ack(DB_ENV *dbenv, DB_LSN permlsn, uint32_t commit_gen, uint32
 char *print_addr(struct sockaddr_in *addr, char *buf)
 {
     buf[0] = '\0';
+    short port = ntohs(addr->sin_port);
     if (addr == NULL) {
         return buf;
     }
     if(addr->sin_addr.s_addr == htonl(INADDR_ANY)) {
-        sprintf(buf, "[0.0.0.0 0.0.0.0:%d ]", ntohs(addr->sin_port));
+        sprintf(buf, "[0.0.0.0 0.0.0.0:%d ]", port);
         return buf;
     }
     char ip[32] = {0};
-    char name[256] = {0};
-    char service[256] = {0};
+    const char *name;
     char errbuf[256] = {0};
-    socklen_t len;
 
-    len = sizeof(*addr);
-    int rc = getnameinfo((struct sockaddr *)addr, len, name, sizeof(name),
-                         service, sizeof(service), 0);
-    if (rc) {
-#pragma GCC diagnostic push
-#pragma GCC diagnostic ignored "-Wunused-result"
-        strerror_r(errno, errbuf, sizeof(errbuf));
-#pragma GCC diagnostic pop
-        sprintf(buf, "%s:getnameinfo errbuf=%s", __func__, errbuf);
+    if ((name = get_cached_hostname_by_addr(addr)) == NULL)
         return buf;
-    }
 
     if (inet_ntop(addr->sin_family, &addr->sin_addr.s_addr, ip, sizeof(ip))) {
-        sprintf(buf, "[%s %s:%s] ", name, ip, service);
+        sprintf(buf, "[%s %s:%hd] ", name, ip, port);
     } else {
 #pragma GCC diagnostic push
 #pragma GCC diagnostic ignored "-Wunused-result"

db/config.c

@@ -460,7 +460,8 @@ static char *legacy_options[] = {
     "disable_sql_table_replacement 1",
     "endianize_locklist 0",
     "track_db_open 0",
-    "clear_ufid_on_db_close 0"
+    "clear_ufid_on_db_close 0",
+    "get_peer_fqdn 0"
 };
 // clang-format on
 

db/db_tunables.c

@@ -626,6 +626,7 @@ extern int gbl_new_connection_grace_ms;
 extern int gbl_accept_headroom;
 extern int gbl_db_track_open;
 extern int gbl_clear_ufid_on_db_close;
+extern int gbl_get_peer_fqdn;
 
 int parse_int64(const char *value, int64_t *num);
 

db/db_tunables.h

@@ -2614,4 +2614,6 @@ REGISTER_TUNABLE("track_db_open", "Track berkdb open DB handles", TUNABLE_INTEGE
                  NULL, NULL, NULL);
 REGISTER_TUNABLE("clear_ufid_on_db_close", "Clear ufid hash on db->close", TUNABLE_INTEGER, &gbl_clear_ufid_on_db_close,
                  INTERNAL, NULL, NULL, NULL, NULL);
+REGISTER_TUNABLE("get_peer_fqdn", "When set, use peer's FQDN", TUNABLE_BOOLEAN, &gbl_get_peer_fqdn, INTERNAL, NULL,
+                 NULL, NULL, NULL);
 #endif /* _DB_TUNABLES_H */

net/net.c

@@ -73,6 +73,7 @@
 #include "thread_util.h"
 #include <timer_util.h>
 #include <comdb2_atomic.h>
+#include <hostname_support.h>
 
 #ifdef UDP_DEBUG
 static int curr_udp_cnt = 0;
@@ -2524,23 +2525,19 @@ static int get_subnet_incomming_syn(host_node_type *host_node_ptr)
         return 0;
     }
 
-    char host[NI_MAXHOST], service[NI_MAXSERV];
     /* get our host name for local _into_ address of connection */
-    int s = getnameinfo((struct sockaddr *)&lcl_addr_inet, lcl_len, host,
-                        NI_MAXHOST, service, NI_MAXSERV, 0);
-
-    if (s != 0) {
-        logmsg(LOGMSG_WARN, "Incoming connection into unknown (%s:%u): %s\n",
-               inet_ntoa(lcl_addr_inet.sin_addr),
-               (unsigned)ntohs(lcl_addr_inet.sin_port), gai_strerror(s));
+    const char *host = get_cached_hostname_by_addr(&lcl_addr_inet);
+    if (host == NULL) {
+        logmsg(LOGMSG_WARN, "Incoming connection into unknown (%s:%u)\n", inet_ntoa(lcl_addr_inet.sin_addr),
+               (unsigned)ntohs(lcl_addr_inet.sin_port));
         return 0;
     }
 
     /* extract the suffix of subnet ex. '_n3' in name node1_n3 */
     int myh_len = strlen(host_node_ptr->netinfo_ptr->myhostname);
     if (strncmp(host_node_ptr->netinfo_ptr->myhostname, host, myh_len) == 0) {
         assert(myh_len <= sizeof(host));
-        char *subnet = &host[myh_len];
+        const char *subnet = &host[myh_len];
         if (subnet[0])
             strncpy0(host_node_ptr->subnet, subnet, HOSTNAME_LEN);
     }

util/hostname_support.c

@@ -15,6 +15,7 @@
  */
 
 #include <arpa/inet.h>
+#include <errno.h>
 #include <netdb.h>
 #include <stdio.h>
 #include <stdlib.h>
@@ -23,19 +24,23 @@
 #include <sys/types.h>
 
 #include <hostname_support.h>
-#include <errno.h>
+#include <logmsg.h>
 
 #ifdef CDB2API_TEST
 #include <cdb2api_ssl_test.h>
 #endif
 
+int gbl_get_peer_fqdn = 1;
 static int get_hostname_by_addr(struct sockaddr_in *addr, char *host, socklen_t hostlen)
 {
+    int rc;
+    int flags = gbl_get_peer_fqdn ? 0 : NI_NOFQDN;
     socklen_t addrlen = sizeof(*addr);
-    if (getnameinfo((struct sockaddr *)addr, addrlen, host, hostlen, NULL, 0, 0)) {
-        if (!inet_ntop(addr->sin_family, &addr->sin_addr, host, hostlen)) {
-            return -1;
-        }
+    if ((rc = getnameinfo((struct sockaddr *)addr, addrlen, host, hostlen, NULL, 0, flags)) != 0) {
+#ifndef DISABLE_HOSTADDR_CACHE
+        logmsg(LOGMSG_WARN, "getnameinfo: %s\n", gai_strerror(rc));
+#endif
+        return -1;
     }
     return 0;
 }