From 869f3d0ef1513dd0258ad7190c9914df16dcc4a4 Mon Sep 17 00:00:00 2001
From: Michael Grunder <michael.grunder@gmail.com>
Date: Fri, 18 Aug 2023 21:07:25 -0700
Subject: [PATCH] Make redisEnableKeepAlive a no-op on AF_UNIX connections.
 (#1215)

Fixes #1185
---
 .gitignore |  1 +
 net.c      |  4 ++++
 test.c     | 19 +++++++++++++++++++
 3 files changed, 24 insertions(+)

diff --git a/.gitignore b/.gitignore
index 056959ffe..c223f299a 100644
--- a/.gitignore
+++ b/.gitignore
@@ -7,3 +7,4 @@
 /*.pc
 *.dSYM
 tags
+compile_commands.json
diff --git a/net.c b/net.c
index c7d827139..8b7831e35 100644
--- a/net.c
+++ b/net.c
@@ -173,6 +173,10 @@ int redisKeepAlive(redisContext *c, int interval) {
     int val = 1;
     redisFD fd = c->fd;
 
+    /* TCP_KEEPALIVE makes no sense with AF_UNIX connections */
+    if (c->connection_type == REDIS_CONN_UNIX)
+        return REDIS_ERR;
+
 #ifndef _WIN32
     if (setsockopt(fd, SOL_SOCKET, SO_KEEPALIVE, &val, sizeof(val)) == -1){
         __redisSetError(c,REDIS_ERR_OTHER,strerror(errno));
diff --git a/test.c b/test.c
index 45914af42..897daf8fe 100644
--- a/test.c
+++ b/test.c
@@ -431,6 +431,24 @@ static void test_tcp_options(struct config cfg) {
     redisFree(c);
 }
 
+static void test_unix_keepalive(struct config cfg) {
+    redisContext *c;
+    redisReply *r;
+
+    c = do_connect(cfg);
+
+    test("Setting TCP_KEEPALIVE on a unix socket returns an error: ");
+    test_cond(redisEnableKeepAlive(c) == REDIS_ERR && c->err == 0);
+
+    test("Setting TCP_KEEPALIVE on a unix socket doesn't break the connection: ");
+    r = redisCommand(c, "PING");
+    test_cond(r != NULL && r->type == REDIS_REPLY_STATUS && r->len == 4 &&
+              !memcmp(r->str, "PONG", 4));
+    freeReplyObject(r);
+
+    redisFree(c);
+}
+
 static void test_reply_reader(void) {
     redisReader *reader;
     void *reply, *root;
@@ -2363,6 +2381,7 @@ int main(int argc, char **argv) {
         test_blocking_connection_timeouts(cfg);
         test_blocking_io_errors(cfg);
         test_invalid_timeout_errors(cfg);
+        test_unix_keepalive(cfg);
         if (throughput) test_throughput(cfg);
     } else {
         test_skipped();