libmicrohttpd2

commit b095b425d7a624f96895bdafb8eb6d134002f2d0
parent f34e82601645693ba85385d5de37ca5a34751ea7
Author: Evgeny Grin (Karlson2k) <k2k@drgrin.dev>
Date:   Sun,  8 Feb 2026 16:12:18 +0100

Better handle size of sockaddr for externally added connections

Diffstat:
M
src/mhd2/daemon_add_conn.c
 | 
51
++++++++++++++++++++++++---------------------------

1 file changed, 24 insertions(+), 27 deletions(-)
diff --git a/src/mhd2/daemon_add_conn.c b/src/mhd2/daemon_add_conn.c
@@ -699,26 +699,25 @@ MHD_daemon_add_connection (struct MHD_Daemon *MHD_RESTRICT daemon,
       && daemon->conns.block_new)
     ret = MHD_SC_LIMIT_CONNECTIONS_REACHED;
 
-  if ((MHD_SC_OK == ret) &&
-      (0 != addr_size))
+  if (NULL != addr)
   {
-    if (addr_size < (sizeof(addr->sa_family)
-                     + offsetof (struct sockaddr, sa_family)))
-    {
-      mhd_LOG_MSG (daemon, MHD_SC_CONFIGURATION_WRONG_SA_SIZE, \
-                   "MHD_add_connection() has been called with " \
-                   "incorrect 'addr_size' value.");
-      ret = MHD_SC_CONFIGURATION_WRONG_SA_SIZE;
-    }
+    bool log_bad_addlen;
+
+    log_bad_addlen = false;
+    if (0u == addr_size)
+      log_bad_addlen = true;
+    else if (addr_size < (sizeof(addr->sa_family)
+                   + offsetof (struct sockaddr, sa_family)))
+      log_bad_addlen = true;
+#ifdef HAVE_STRUCT_SOCKADDR_SA_LEN
+    else if (addr_size < (sizeof(addr->sa_len)
+                        + offsetof (struct sockaddr, sa_len)))
+      log_bad_addlen = true;
+#endif /* HAVE_STRUCT_SOCKADDR_SA_LEN */
     else if (AF_INET == addr->sa_family)
     {
       if (sizeof(struct sockaddr_in) > addr_size)
-      {
-        mhd_LOG_MSG (daemon, MHD_SC_CONFIGURATION_WRONG_SA_SIZE, \
-                     "MHD_add_connection() has been called with " \
-                     "incorrect 'addr_size' value.");
-        ret = MHD_SC_CONFIGURATION_WRONG_SA_SIZE;
-      }
+        log_bad_addlen = true;
 #ifdef HAVE_STRUCT_SOCKADDR_SA_LEN
       else if ((0 != addr->sa_len) &&
                (sizeof(struct sockaddr_in) > (size_t) addr->sa_len) )
@@ -734,13 +733,8 @@ MHD_daemon_add_connection (struct MHD_Daemon *MHD_RESTRICT daemon,
 #ifdef HAVE_INET6
     else if (AF_INET6 == addr->sa_family)
     {
-      if (sizeof(struct sockaddr_in6) > addr_size)
-      {
-        mhd_LOG_MSG (daemon, MHD_SC_CONFIGURATION_WRONG_SA_SIZE, \
-                     "MHD_add_connection() has been called with " \
-                     "incorrect 'addr_size' value.");
-        ret = MHD_SC_CONFIGURATION_WRONG_SA_SIZE;
-      }
+      if (sizeof(struct sockaddr_in6) != addr_size)
+        log_bad_addlen = true;
 #ifdef HAVE_STRUCT_SOCKADDR_SA_LEN
       else if ((0 != addr->sa_len) &&
                (sizeof(struct sockaddr_in6) > (size_t) addr->sa_len) )
@@ -753,21 +747,24 @@ MHD_daemon_add_connection (struct MHD_Daemon *MHD_RESTRICT daemon,
       }
 #endif /* HAVE_STRUCT_SOCKADDR_SA_LEN */
     }
-#ifdef HAVE_STRUCT_SOCKADDR_SA_LEN
-    else if (addr_size < (sizeof(addr->sa_len)
-                          + offsetof (struct sockaddr, sa_len)))
+#endif /* HAVE_INET6 */
+    mhd_ASSUME ((log_bad_addlen && (MHD_SC_OK == ret)) ||
+        ((MHD_SC_OK != ret) && ! log_bad_addlen) || (MHD_SC_OK == ret));
+    if (log_bad_addlen)
     {
       mhd_LOG_MSG (daemon, MHD_SC_CONFIGURATION_WRONG_SA_SIZE, \
                    "MHD_add_connection() has been called with " \
                    "incorrect 'addr_size' value.");
       ret = MHD_SC_CONFIGURATION_WRONG_SA_SIZE;
     }
+#ifdef HAVE_STRUCT_SOCKADDR_SA_LEN
     if ((0 != addr->sa_len) &&
         (addr_size > (size_t) addr->sa_len))
       addr_size = (size_t) addr->sa_len;   /* Use safest value */
 #endif /* HAVE_STRUCT_SOCKADDR_SA_LEN */
-#endif /* HAVE_INET6 */
   }
+  else
+    addr_size = 0u;
 
   if (MHD_SC_OK == ret)
   {