From ac104706433523524c5f013d5f01de28fc2c1b22 Mon Sep 17 00:00:00 2001
From: fbernon <fbernon>
Date: Wed, 5 Dec 2007 23:00:02 +0000
Subject: [PATCH] netdb.c: add a LWIP_DNS_API_HOSTENT_STORAGE option to decide
 to use a static set of variables (=0) or a local one (=1). In this last case,
 your port should provide a function "struct hostent* sys_thread_hostent(
 struct hostent* h)" which have to do a copy of "h" and return a pointer ont
 the "per-thread" copy.

---
 CHANGELOG       |  6 ++++++
 src/api/netdb.c | 28 +++++++++++++++++++++++-----
 2 files changed, 29 insertions(+), 5 deletions(-)

diff --git a/CHANGELOG b/CHANGELOG
index 1eb48747..edd76510 100644
--- a/CHANGELOG
+++ b/CHANGELOG
@@ -19,6 +19,12 @@ HISTORY
 
   ++ New features:
 
+  2007-12-05 Frédéric Bernon
+  * netdb.c: add a LWIP_DNS_API_HOSTENT_STORAGE option to decide to use a static
+    set of variables (=0) or a local one (=1). In this last case, your port should
+    provide a function "struct hostent* sys_thread_hostent( struct hostent* h)"
+    which have to do a copy of "h" and return a pointer ont the "per-thread" copy.
+
   2007-12-03 Simon Goldschmidt
   * ip.c: ip_input: check if a packet is for inp first before checking all other
     netifs on netif_list (speeds up packet receiving in most cases)
diff --git a/src/api/netdb.c b/src/api/netdb.c
index fa3aadc4..ea891a62 100644
--- a/src/api/netdb.c
+++ b/src/api/netdb.c
@@ -54,11 +54,18 @@ struct gethostbyname_r_helper {
 int h_errno;
 #endif /* LWIP_DNS_API_DECLARE_H_ERRNO */
 
-/* static buffer variables for lwip_gethostbyname() */
-static struct hostent s_hostent;
-static char *s_aliases;
-static struct ip_addr s_hostent_addr;
-static struct ip_addr *s_phostent_addr;
+/** define "hostent" variables storage: 0 if we use a static (but unprotected)
+ * set of variables for lwip_gethostbyname, 1 if we use a local storage */
+#ifndef LWIP_DNS_API_HOSTENT_STORAGE
+#define LWIP_DNS_API_HOSTENT_STORAGE 0
+#endif
+
+/** define "hostent" variables storage */
+#if LWIP_DNS_API_HOSTENT_STORAGE
+#define HOSTENT_STORAGE
+#else
+#define HOSTENT_STORAGE static
+#endif /* LWIP_DNS_API_STATIC_HOSTENT */
 
 /**
  * Returns an entry containing addresses of address family AF_INET
@@ -75,6 +82,12 @@ lwip_gethostbyname(const char *name)
   err_t err;
   struct ip_addr addr;
 
+  /* buffer variables for lwip_gethostbyname() */
+  HOSTENT_STORAGE struct hostent s_hostent;
+  HOSTENT_STORAGE char *s_aliases;
+  HOSTENT_STORAGE struct ip_addr s_hostent_addr;
+  HOSTENT_STORAGE struct ip_addr *s_phostent_addr;
+
   /* query host IP address */
   err = netconn_gethostbyname(name, &addr);
   if (err != ERR_OK) {
@@ -115,7 +128,12 @@ lwip_gethostbyname(const char *name)
   }
 #endif /* DNS_DEBUG */
 
+#if LWIP_DNS_API_HOSTENT_STORAGE
+  /* this function should return the "per-thread" hostent after copy from s_hostent */
+  return sys_thread_hostent(&s_hostent);
+#else
   return &s_hostent;
+#endif /* LWIP_DNS_API_HOSTENT_STORAGE */
 }
 
 /**