1 files changed, 12 insertions, 4 deletions

diff --git a/server.c b/server.c
index a77d7d2..3f7eb04 100644
--- a/server.c
+++ b/server.c
@@ -5,6 +5,7 @@
 #include <poll.h>
 #include <unistd.h>
 #include <errno.h>
+#include <limits.h>
 #include <stdbool.h>
 #include <stddef.h>
 #include <stdio.h>
@@ -299,10 +300,13 @@ end:
 }
 
 struct server *server_init(const unsigned short port,
-    unsigned short *const outport)
+    unsigned short *const outport, const unsigned ubacklog)
 {
     struct server *const s = malloc(sizeof *s);
     int fds[2] = {-1, -1}, fd = -1;
+    /* Ensure default value if not set. */
+    enum {QUEUE_LEN = 10};
+    const unsigned backlog = ubacklog ? ubacklog : QUEUE_LEN;
 
     if (!s)
     {
@@ -326,14 +330,18 @@ struct server *server_init(const unsigned short port,
         .sin_port = htons(port)
     };
 
-    enum {QUEUE_LEN = 10};
-
     if (bind(fd, (const struct sockaddr *)&addr, sizeof addr))
     {
         fprintf(stderr, "%s: bind(2): %s\n", __func__, strerror(errno));
         goto failure;
     }
-    else if (listen(fd, QUEUE_LEN))
+    else if (backlog > INT_MAX)
+    {
+        fprintf(stderr, "%s: backlog (%u) exceeds maximum (%d)\n",
+            __func__, backlog, INT_MAX);
+        goto failure;
+    }
+    else if (listen(fd, backlog))
     {
         fprintf(stderr, "%s: listen(2): %s\n", __func__, strerror(errno));
         goto failure;