Second try at fixing tcp_keepalives_idle option on Solaris.

Buildfarm evidence shows that TCP_KEEPALIVE_THRESHOLD doesn't exist
after all on Solaris < 11.  This means we need to take positive action to
prevent the TCP_KEEPALIVE code path from being taken on that platform.
I've chosen to limit it with "&& defined(__darwin__)", since it's unclear
that anyone else would follow Apple's precedent of spelling the symbol
that way.

Also, follow a suggestion from Michael Paquier of eliminating code
duplication by defining a couple of intermediate symbols for the
socket option.

In passing, make some effort to reduce the number of translatable messages
by replacing "setsockopt(foo) failed" with "setsockopt(%s) failed", etc,
throughout the affected files.  And update relevant documentation so
that it doesn't claim to provide an exhaustive list of the possible
socket option names.

Like the previous commit (f0256c774), back-patch to all supported branches.

Discussion: https://postgr.es/m/20170627163757.25161.528@wrigleys.postgresql.org

1 files changed, 29 insertions, 31 deletions

diff --git a/src/interfaces/libpq/fe-connect.c b/src/interfaces/libpq/fe-connect.c
index 443b4fb3e2b..e61ed7dc28c 100644
--- a/src/interfaces/libpq/fe-connect.c
+++ b/src/interfaces/libpq/fe-connect.c
@@ -100,6 +100,25 @@ static int ldapServiceLookup(const char *purl, PQconninfoOption *options,
 #define ERRCODE_CANNOT_CONNECT_NOW "57P03"
 
 /*
+ * Cope with the various platform-specific ways to spell TCP keepalive socket
+ * options.  This doesn't cover Windows, which as usual does its own thing.
+ */
+#if defined(TCP_KEEPIDLE)
+/* TCP_KEEPIDLE is the name of this option on Linux and *BSD */
+#define PG_TCP_KEEPALIVE_IDLE TCP_KEEPIDLE
+#define PG_TCP_KEEPALIVE_IDLE_STR "TCP_KEEPIDLE"
+#elif defined(TCP_KEEPALIVE_THRESHOLD)
+/* TCP_KEEPALIVE_THRESHOLD is the name of this option on Solaris >= 11 */
+#define PG_TCP_KEEPALIVE_IDLE TCP_KEEPALIVE_THRESHOLD
+#define PG_TCP_KEEPALIVE_IDLE_STR "TCP_KEEPALIVE_THRESHOLD"
+#elif defined(TCP_KEEPALIVE) && defined(__darwin__)
+/* TCP_KEEPALIVE is the name of this option on macOS */
+/* Caution: Solaris has this symbol but it means something different */
+#define PG_TCP_KEEPALIVE_IDLE TCP_KEEPALIVE
+#define PG_TCP_KEEPALIVE_IDLE_STR "TCP_KEEPALIVE"
+#endif
+
+/*
  * fall back options if they are not specified by arguments or defined
  * by environment variables
  */
@@ -1280,39 +1299,15 @@ setKeepalivesIdle(PGconn *conn)
 	if (idle < 0)
 		idle = 0;
 
-#if defined(TCP_KEEPIDLE)
-	/* TCP_KEEPIDLE is the name of this option on Linux and *BSD */
-	if (setsockopt(conn->sock, IPPROTO_TCP, TCP_KEEPIDLE,
-				   (char *) &idle, sizeof(idle)) < 0)
-	{
-		char		sebuf[256];
-
-		appendPQExpBuffer(&conn->errorMessage,
-					  libpq_gettext("setsockopt(TCP_KEEPIDLE) failed: %s\n"),
-						  SOCK_STRERROR(SOCK_ERRNO, sebuf, sizeof(sebuf)));
-		return 0;
-	}
-#elif defined(TCP_KEEPALIVE_THRESHOLD)
-	/* TCP_KEEPALIVE_THRESHOLD is the name of this option on Solaris */
-	if (setsockopt(conn->sock, IPPROTO_TCP, TCP_KEEPALIVE_THRESHOLD,
-				   (char *) &idle, sizeof(idle)) < 0)
-	{
-		char		sebuf[256];
-
-		appendPQExpBuffer(&conn->errorMessage,
-						  libpq_gettext("setsockopt(TCP_KEEPALIVE_THRESHOLD) failed: %s\n"),
-						  SOCK_STRERROR(SOCK_ERRNO, sebuf, sizeof(sebuf)));
-		return 0;
-	}
-#elif defined(TCP_KEEPALIVE)
-	/* TCP_KEEPALIVE is the name of this option on macOS */
-	if (setsockopt(conn->sock, IPPROTO_TCP, TCP_KEEPALIVE,
+#ifdef PG_TCP_KEEPALIVE_IDLE
+	if (setsockopt(conn->sock, IPPROTO_TCP, PG_TCP_KEEPALIVE_IDLE,
 				   (char *) &idle, sizeof(idle)) < 0)
 	{
 		char		sebuf[256];
 
 		appendPQExpBuffer(&conn->errorMessage,
-					 libpq_gettext("setsockopt(TCP_KEEPALIVE) failed: %s\n"),
+						  libpq_gettext("setsockopt(%s) failed: %s\n"),
+						  PG_TCP_KEEPALIVE_IDLE_STR,
 						  SOCK_STRERROR(SOCK_ERRNO, sebuf, sizeof(sebuf)));
 		return 0;
 	}
@@ -1343,7 +1338,8 @@ setKeepalivesInterval(PGconn *conn)
 		char		sebuf[256];
 
 		appendPQExpBuffer(&conn->errorMessage,
-					 libpq_gettext("setsockopt(TCP_KEEPINTVL) failed: %s\n"),
+						  libpq_gettext("setsockopt(%s) failed: %s\n"),
+						  "TCP_KEEPINTVL",
 						  SOCK_STRERROR(SOCK_ERRNO, sebuf, sizeof(sebuf)));
 		return 0;
 	}
@@ -1375,7 +1371,8 @@ setKeepalivesCount(PGconn *conn)
 		char		sebuf[256];
 
 		appendPQExpBuffer(&conn->errorMessage,
-					   libpq_gettext("setsockopt(TCP_KEEPCNT) failed: %s\n"),
+						  libpq_gettext("setsockopt(%s) failed: %s\n"),
+						  "TCP_KEEPCNT",
 						  SOCK_STRERROR(SOCK_ERRNO, sebuf, sizeof(sebuf)));
 		return 0;
 	}
@@ -1841,7 +1838,8 @@ keep_going:						/* We will come back to here until there is
 											(char *) &on, sizeof(on)) < 0)
 						{
 							appendPQExpBuffer(&conn->errorMessage,
-											  libpq_gettext("setsockopt(SO_KEEPALIVE) failed: %s\n"),
+											  libpq_gettext("setsockopt(%s) failed: %s\n"),
+											  "SO_KEEPALIVE",
 							SOCK_STRERROR(SOCK_ERRNO, sebuf, sizeof(sebuf)));
 							err = 1;
 						}