From ce79811bce54fea22848c2a3769b32d4852d20dc Mon Sep 17 00:00:00 2001
From: goldsimon <goldsimon@gmx.de>
Date: Wed, 24 Jan 2018 14:35:17 +0100
Subject: [PATCH] sockets: add hooks to implement additional socket options

LWIP_HOOK_SOCKETS_SETSOCKOPT() and LWIP_HOOK_SOCKETS_GETSOCKOPT()
are introduced to implement additional socket options. The hooks
are always called first and report back if they handled the option
or not.

Signed-off-by: goldsimon <goldsimon@gmx.de>
---
 src/api/sockets.c      | 16 +++++++++++++++
 src/include/lwip/opt.h | 44 ++++++++++++++++++++++++++++++++++++++++++
 2 files changed, 60 insertions(+)

diff --git a/src/api/sockets.c b/src/api/sockets.c
index da0d6c23..fcc4b970 100644
--- a/src/api/sockets.c
+++ b/src/api/sockets.c
@@ -64,6 +64,10 @@
 
 #include <string.h>
 
+#ifdef LWIP_HOOK_FILENAME
+#include LWIP_HOOK_FILENAME
+#endif
+
 /* If the netconn API is not required publicly, then we include the necessary
    files here to get the implementation */
 #if !LWIP_NETCONN
@@ -2835,6 +2839,12 @@ lwip_getsockopt_impl(int s, int level, int optname, void *optval, socklen_t *opt
     return EBADF;
   }
 
+#ifdef LWIP_HOOK_SOCKETS_GETSOCKOPT
+  if (LWIP_HOOK_SOCKETS_GETSOCKOPT(s, sock, level, optname, optval, optlen, &err)) {
+    return err;
+  }
+#endif
+
   switch (level) {
 
     /* Level: SOL_SOCKET */
@@ -3250,6 +3260,12 @@ lwip_setsockopt_impl(int s, int level, int optname, const void *optval, socklen_
     return EBADF;
   }
 
+#ifdef LWIP_HOOK_SOCKETS_SETSOCKOPT
+  if (LWIP_HOOK_SOCKETS_SETSOCKOPT(s, sock, level, optname, optval, optlen, &err)) {
+    return err;
+  }
+#endif
+
   switch (level) {
 
     /* Level: SOL_SOCKET */
diff --git a/src/include/lwip/opt.h b/src/include/lwip/opt.h
index 930253c1..15127c61 100644
--- a/src/include/lwip/opt.h
+++ b/src/include/lwip/opt.h
@@ -2935,6 +2935,50 @@
 #define LWIP_HOOK_DHCP_PARSE_OPTION(netif, dhcp, state, msg, msg_type, option, len, pbuf, offset)
 #endif
 
+/**
+ * LWIP_HOOK_SOCKETS_SETSOCKOPT(s, sock, level, optname, optval, optlen, err)
+ * Called from socket API to implement setsockopt() for options not provided by lwIP.
+ * Core lock is held when this hook is called.
+ * Signature:
+ *   int my_hook(int s, struct lwip_sock *sock, int level, int optname, const void *optval, socklen_t optlen, int *err)
+ * Arguments:
+ * - s: socket file descriptor
+ * - sock: internal socket descriptor (see lwip/priv/sockets_priv.h)
+ * - level: protocol level at which the option resides
+ * - optname: option to set
+ * - optval: value to set
+ * - optlen: size of optval
+ * - err: output error
+ * Return values:
+ * - 0: Hook has not consumed the option, code continues as normal (to internal options)
+ * - != 0: Hook has consumed the option, 'err' is returned
+ */
+#ifdef __DOXYGEN__
+#define LWIP_HOOK_SOCKETS_SETSOCKOPT(s, sock, level, optname, optval, optlen, err)
+#endif
+
+/**
+ * LWIP_HOOK_SOCKETS_GETSOCKOPT(s, sock, level, optname, optval, optlen, err)
+ * Called from socket API to implement getsockopt() for options not provided by lwIP.
+ * Core lock is held when this hook is called.
+ * Signature:
+ *   int my_hook(int s, struct lwip_sock *sock, int level, int optname, void *optval, socklen_t *optlen, int *err)
+ * Arguments:
+ * - s: socket file descriptor
+ * - sock: internal socket descriptor (see lwip/priv/sockets_priv.h)
+ * - level: protocol level at which the option resides
+ * - optname: option to get
+ * - optval: value to get
+ * - optlen: size of optval
+ * - err: output error
+ * Return values:
+ * - 0: Hook has not consumed the option, code continues as normal (to internal options)
+ * - != 0: Hook has consumed the option, 'err' is returned
+ */
+#ifdef __DOXYGEN__
+#define LWIP_HOOK_SOCKETS_GETSOCKOPT(s, sock, level, optname, optval, optlen, err)
+#endif
+
 /**
  * LWIP_HOOK_NETCONN_EXTERNAL_RESOLVE(name, addr, addrtype, err)
  * Called from netconn APIs (not usable with callback apps) allowing an