From 5f45b9e996ac305f55c96bda3f667e5376fad2fc Mon Sep 17 00:00:00 2001
From: Michael Sauer <michael.sauer@qconnex.com>
Date: Fri, 11 Sep 2026 23:51:11 +0200
Subject: [PATCH] =?UTF-8?q?fix:=20Gesamt-Timeout=20f=C3=BCr=20HTTP-Anfrage?=
 =?UTF-8?q?n?=
MIME-Version: 1.0
Content-Type: text/plain; charset=UTF-8
Content-Transfer-Encoding: 8bit

I2: SO_RCVTIMEO=5s war ein Timeout pro recv(), nicht für die gesamte
Anfrage. Ein Client, der 1 Byte alle 4,9 s schickt, konnte den einzigen
HTTP-Server-Task damit stundenlang belegen (Spec §7.2 will 5 s pro Header).

serve() rechnet jetzt eine absolute Deadline (nl_app_now_ms() + 5000 ms)
und setzt SO_RCVTIMEO vor jedem recv() auf die verbleibende Zeit (mindestens
1 ms); ist die Deadline überschritten, wird die Verbindung sofort verworfen.

Nicht host-testbar (nl_http_server.c bindet SDK-Sockets ein); über den
Firmware-Build verifiziert.
---
 src/net/nl_http_server.c | 20 ++++++++++++++++++--
 1 file changed, 18 insertions(+), 2 deletions(-)

diff --git a/src/net/nl_http_server.c b/src/net/nl_http_server.c
index 2fbc0ca..0e89f45 100644
--- a/src/net/nl_http_server.c
+++ b/src/net/nl_http_server.c
@@ -33,19 +33,35 @@ static void simple_error(int status, const char *msg)
     strcpy(s_resp.body, msg);
 }
 
+#define NL_HTTP_REQUEST_TIMEOUT_MS 5000u
+
 static void serve(int fd)
 {
     struct timeval tv;
     nl_http_request_t req;
     nl_http_parse_t pr = NL_HTTP_INCOMPLETE;
     size_t len = 0, out;
+    uint32_t deadline = nl_app_now_ms() + NL_HTTP_REQUEST_TIMEOUT_MS;
 
     tv.tv_sec = 5;
     tv.tv_usec = 0;
-    setsockopt(fd, SOL_SOCKET, SO_RCVTIMEO, &tv, sizeof tv);
     setsockopt(fd, SOL_SOCKET, SO_SNDTIMEO, &tv, sizeof tv);
+    /* I2: 5 s is a deadline for the whole header+body read, not a per-recv() timeout -
+     * otherwise a client trickling in 1 byte per <5 s occupies the single server task forever. */
     while (pr == NL_HTTP_INCOMPLETE && len < sizeof s_buf) {
-        int n = recv(fd, s_buf + len, sizeof s_buf - len, 0);
+        uint32_t now = nl_app_now_ms();
+        uint32_t remaining_ms;
+        int n;
+
+        if ((int32_t)(deadline - now) <= 0)
+            return; /* overall deadline passed: drop silently */
+        remaining_ms = deadline - now;
+        tv.tv_sec = remaining_ms / 1000u;
+        tv.tv_usec = (remaining_ms % 1000u) * 1000u;
+        if (tv.tv_sec == 0 && tv.tv_usec == 0)
+            tv.tv_usec = 1000; /* at least 1 ms */
+        setsockopt(fd, SOL_SOCKET, SO_RCVTIMEO, &tv, sizeof tv);
+        n = recv(fd, s_buf + len, sizeof s_buf - len, 0);
         if (n <= 0)
             return; /* timeout or closed: drop silently */
         len += (size_t)n;