ngtcp2: introduce qlog support

If the QLOGDIR environment variable is set, enable qlogging.

... and create Curl_qlogdir() in the new generic vquic/vquic.c file for
QUIC functions that are backend independent.

Closes #5353

1 files changed, 85 insertions, 0 deletions

diff --git a/lib/vquic/vquic.c b/lib/vquic/vquic.c
new file mode 100644
index 000000000..aae8e0951
--- /dev/null
+++ b/lib/vquic/vquic.c
@@ -0,0 +1,85 @@
+/***************************************************************************
+ *                                  _   _ ____  _
+ *  Project                     ___| | | |  _ \| |
+ *                             / __| | | | |_) | |
+ *                            | (__| |_| |  _ <| |___
+ *                             \___|\___/|_| \_\_____|
+ *
+ * Copyright (C) 1998 - 2020, Daniel Stenberg, <daniel@haxx.se>, et al.
+ *
+ * This software is licensed as described in the file COPYING, which
+ * you should have received as part of this distribution. The terms
+ * are also available at https://curl.haxx.se/docs/copyright.html.
+ *
+ * You may opt to use, copy, modify, merge, publish, distribute and/or sell
+ * copies of the Software, and permit persons to whom the Software is
+ * furnished to do so, under the terms of the COPYING file.
+ *
+ * This software is distributed on an "AS IS" basis, WITHOUT WARRANTY OF ANY
+ * KIND, either express or implied.
+ *
+ ***************************************************************************/
+
+#include "curl_setup.h"
+
+#ifdef ENABLE_QUIC
+
+#ifdef HAVE_FCNTL_H
+#include <fcntl.h>
+#endif
+#include "urldata.h"
+#include "dynbuf.h"
+#include "curl_printf.h"
+#include "vquic.h"
+
+#ifdef O_BINARY
+#define QLOGMODE O_WRONLY|O_CREAT|O_BINARY
+#else
+#define QLOGMODE O_WRONLY|O_CREAT
+#endif
+
+/*
+ * If the QLOGDIR environment variable is set, open and return a file
+ * descriptor to write the log to.
+ *
+ * This function returns error if something failed outside of failing to
+ * create the file. Open file success is deemed by seeing if the returned fd
+ * is != -1.
+ */
+CURLcode Curl_qlogdir(struct Curl_easy *data,
+                      unsigned char *scid,
+                      size_t scidlen,
+                      int *qlogfdp)
+{
+  const char *qlog_dir = getenv("QLOGDIR");
+  *qlogfdp = -1;
+  if(qlog_dir) {
+    struct dynbuf fname;
+    CURLcode result;
+    unsigned int i;
+    Curl_dyn_init(&fname, DYN_QLOG_NAME);
+    result = Curl_dyn_add(&fname, qlog_dir);
+    if(!result)
+      result = Curl_dyn_add(&fname, "/");
+    for(i = 0; (i < scidlen) && !result; i++) {
+      char hex[3];
+      msnprintf(hex, 3, "%02x", scid[i]);
+      result = Curl_dyn_add(&fname, hex);
+    }
+    if(!result)
+      result = Curl_dyn_add(&fname, ".qlog");
+
+    if(!result) {
+      int qlogfd = open(Curl_dyn_ptr(&fname), QLOGMODE,
+                        data->set.new_file_perms);
+      if(qlogfd != -1)
+        *qlogfdp = qlogfd;
+    }
+    Curl_dyn_free(&fname);
+    if(result)
+      return result;
+  }
+
+  return CURLE_OK;
+}
+#endif