Allow custom backlog connections

libweb calls listen(2) when setting up the HTTP server, and its backlog
argument was hardcoded to 10. While probably not an issue for some
applications, it can be too limiting for some others.

Therefore, it is desirable to allow library users to set up their own
limits. Otherwise, 10 is still chosen as a sane default.

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;