From aa62596afcc9143aa663bf834d305441cdd4cc70 Mon Sep 17 00:00:00 2001

From: "Richard W.M. Jones" <rjones@redhat.com>

Date: Tue, 19 May 2020 11:15:07 +0100

Subject: [PATCH 17/19] curl: Case insensitive check for accept-ranges

 (RHBZ#1837337).

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When accessing an HTTP/2 server we read lowercase headers so the

existing test for byte range support did not work.  You would see an

error like this:

  nbdkit: curl[1]: error: server does not support 'range' (byte range) requests

This commit copies the bug fix which was recently added to qemu’s

block/curl.c.

qemu commits:

  commit 69032253c33ae1774233c63cedf36d32242a85fc

  Author: David Edmondson <david.edmondson@oracle.com>

  Date:   Mon Feb 24 10:13:10 2020 +0000

    block/curl: HTTP header field names are case insensitive

  commit 7788a319399f17476ff1dd43164c869e320820a2

  Author: David Edmondson <david.edmondson@oracle.com>

  Date:   Mon Feb 24 10:13:09 2020 +0000

    block/curl: HTTP header fields allow whitespace around values

Thanks: David Edmondson, Pino Toscano, Zi Liu

(cherry picked from commit c1260ec1f6538831e10f164567b53054a2ec0c2a)

---

 plugins/curl/Makefile.am |  1 +

 plugins/curl/curl.c      | 29 ++++++++++++++++++++++++-----

 tests/web-server.c       |  2 +-

 3 files changed, 26 insertions(+), 6 deletions(-)

diff --git a/plugins/curl/Makefile.am b/plugins/curl/Makefile.am

index 024ddb6d..3dbe3ca8 100644

--- a/plugins/curl/Makefile.am

+++ b/plugins/curl/Makefile.am

@@ -44,6 +44,7 @@ nbdkit_curl_plugin_la_SOURCES = \

 nbdkit_curl_plugin_la_CPPFLAGS = \

 	-I$(top_srcdir)/include \

+	-I$(top_srcdir)/common/include \

 	-I$(top_srcdir)/common/utils \

 	$(NULL)

 nbdkit_curl_plugin_la_CFLAGS = \

diff --git a/plugins/curl/curl.c b/plugins/curl/curl.c

index b1693dc0..ac30cbdd 100644

--- a/plugins/curl/curl.c

+++ b/plugins/curl/curl.c

@@ -57,6 +57,7 @@

 #include <nbdkit-plugin.h>

 #include "cleanup.h"

+#include "ascii-ctype.h"

 static const char *url = NULL;

 static const char *user = NULL;

@@ -497,12 +498,30 @@ header_cb (void *ptr, size_t size, size_t nmemb, void *opaque)

 {

   struct curl_handle *h = opaque;

   size_t realsize = size * nmemb;

-  const char *accept_line = "Accept-Ranges: bytes";

-  const char *line = ptr;

+  const char *header = ptr;

+  const char *end = header + realsize;

+  const char *accept_ranges = "accept-ranges:";

+  const char *bytes = "bytes";

-  if (realsize >= strlen (accept_line) &&

-      strncmp (line, accept_line, strlen (accept_line)) == 0)

-    h->accept_range = true;

+  if (realsize >= strlen (accept_ranges) &&

+      strncasecmp (header, accept_ranges, strlen (accept_ranges)) == 0) {

+    const char *p = strchr (header, ':') + 1;

+

+    /* Skip whitespace between the header name and value. */

+    while (p < end && *p && ascii_isspace (*p))

+      p++;

+

+    if (end - p >= strlen (bytes)

+        && strncmp (p, bytes, strlen (bytes)) == 0) {

+      /* Check that there is nothing but whitespace after the value. */

+      p += strlen (bytes);

+      while (p < end && *p && ascii_isspace (*p))

+        p++;

+

+      if (p == end || !*p)

+        h->accept_range = true;

+    }

+  }

   return realsize;

 }

diff --git a/tests/web-server.c b/tests/web-server.c

index f27ee70d..f9f10917 100644

--- a/tests/web-server.c

+++ b/tests/web-server.c

@@ -235,7 +235,7 @@ handle_request (int s, bool headers_only)

   const char response1_ok[] = "HTTP/1.1 200 OK\r\n";

   const char response1_partial[] = "HTTP/1.1 206 Partial Content\r\n";

   const char response2[] =

-    "Accept-Ranges: bytes\r\n"

+    "Accept-rANGES:     bytes\r\n" /* See RHBZ#1837337 */

     "Connection: keep-alive\r\n"

     "Content-Type: application/octet-stream\r\n";

   char response3[64];

-- 

2.18.2