libmicrohttpd2

commit db299f58f31bce5a6e19ab4e6effe5287cf41175
parent 75f0be5f084c39e6596c4f1ead827d30509ab60f
Author: Evgeny Grin (Karlson2k) <k2k@drgrin.dev>
Date:   Sat, 27 Jun 2026 20:38:27 +0200

Response header building: simplified and re-used some code

Diffstat:
M
src/mhd2/stream_process_reply.c
 | 
66
+++++++++++++++++++++++++++++++++++++++++-------------------------

1 file changed, 41 insertions(+), 25 deletions(-)
diff --git a/src/mhd2/stream_process_reply.c b/src/mhd2/stream_process_reply.c
@@ -531,6 +531,32 @@ buffer_append (char *buf,
 
 
 /**
+ * Append CRLF to the buffer if enough space is available,
+ * update position.
+ * @param[out] buf the buffer to append data to
+ * @param[in,out] ppos the pointer to position in the @a buffer
+ * @param buf_size the size of the @a buffer
+ * @return true if CRLF has been added and position has been updated,
+ *         false if not enough space is available
+ */
+mhd_static_inline MHD_FN_PAR_NONNULL_ALL_ bool
+buffer_append_crlf (char *restrict buf,
+                    size_t *restrict ppos,
+                    size_t buf_size)
+{
+  mhd_assert (NULL != buf); /* Mute static analyzer */
+  if (mhd_COND_HARDLY_EVER (*ppos + 2 < 2)) /* Check for overflow */
+    return false;
+  if (mhd_COND_ALMOST_NEVER (buf_size < *ppos + 2))
+    return false;
+  buf[*ppos] = '\r';
+  buf[*ppos + 1] = '\n';
+  *ppos += 2;
+  return true;
+}
+
+
+/**
  * Add user-defined headers from response object to
  * the text buffer.
  *
@@ -816,12 +842,10 @@ build_header_response_inn (struct MHD_Connection *restrict c)
       return false;
   }
   /* The linefeed */
-  if (mhd_COND_HARDLY_EVER (pos + 2 < 2)) /* Check for overflow */
+  if (! buffer_append_crlf (buf,
+                            &pos,
+                            buf_size))
     return false;
-  if (buf_size < pos + 2)
-    return false;
-  buf[pos++] = '\r';
-  buf[pos++] = '\n';
 
   /* * The headers * */
 
@@ -829,18 +853,14 @@ build_header_response_inn (struct MHD_Connection *restrict c)
   if (0 != r->special_resp.spec_hdr_len)
   {
     mhd_assert (r->cfg.int_err_resp);
-    if (mhd_COND_HARDLY_EVER (r->special_resp.spec_hdr_len + 2 < 2)) /* Check for overflow */
-      return false;
-    if (mhd_COND_HARDLY_EVER (pos + r->special_resp.spec_hdr_len + 2 < pos)) /* Check for overflow */
+    if (! buffer_append (buf, &pos, buf_size,
+                         r->special_resp.spec_hdr,
+                         r->special_resp.spec_hdr_len))
       return false;
-    if (buf_size < pos + r->special_resp.spec_hdr_len + 2)
+    if (! buffer_append_crlf (buf,
+                              &pos,
+                              buf_size))
       return false;
-    memcpy (buf + pos,
-            r->special_resp.spec_hdr,
-            r->special_resp.spec_hdr_len);
-    pos += r->special_resp.spec_hdr_len;
-    buf[pos++] = '\r';
-    buf[pos++] = '\n';
   }
 
   /* Main automatic headers */
@@ -949,12 +969,10 @@ build_header_response_inn (struct MHD_Connection *restrict c)
             return false;
           pos += el_size;
 
-          if (pos + 2 < 2) /* Check for overflow */
+          if (! buffer_append_crlf (buf,
+                                    &pos,
+                                    buf_size))
             return false;
-          if (buf_size < pos + 2)
-            return false;
-          buf[pos++] = '\r';
-          buf[pos++] = '\n';
         }
       }
       else
@@ -967,12 +985,10 @@ build_header_response_inn (struct MHD_Connection *restrict c)
   }
 
   /* * Header termination * */
-  if (mhd_COND_HARDLY_EVER (pos + 2 < 2)) /* Check for overflow */
-    return false;
-  if (buf_size < pos + 2)
+  if (! buffer_append_crlf (buf,
+                            &pos,
+                            buf_size))
     return false;
-  buf[pos++] = '\r';
-  buf[pos++] = '\n';
 
   c->write_buffer_append_offset = pos;
   return true;