commit 873e239a4c3d8ec235c27439c1bdc5bbf8aa1818
Author: Florian Weimer <fweimer@redhat.com>
Date: Wed Oct 14 10:54:39 2020 +0200
support: Provide a way to reorder responses within the DNS test server
diff --git a/support/Makefile b/support/Makefile
index 3c940aa6a7bdfc99..37d5dcc92a5c6dee 100644
--- a/support/Makefile
+++ b/support/Makefile
@@ -35,6 +35,8 @@ libsupport-routines = \
ignore_stderr \
next_to_fault \
oom_error \
+ resolv_response_context_duplicate \
+ resolv_response_context_free \
resolv_test \
set_fortify_handler \
support-xfstat \
diff --git a/support/resolv_response_context_duplicate.c b/support/resolv_response_context_duplicate.c
new file mode 100644
index 0000000000000000..f9c5c3462ad053ec
--- /dev/null
+++ b/support/resolv_response_context_duplicate.c
@@ -0,0 +1,37 @@
+/* Duplicate a response context used in DNS resolver tests.
+ Copyright (C) 2020 Free Software Foundation, Inc.
+ This file is part of the GNU C Library.
+
+ The GNU C Library is free software; you can redistribute it and/or
+ modify it under the terms of the GNU Lesser General Public
+ License as published by the Free Software Foundation; either
+ version 2.1 of the License, or (at your option) any later version.
+
+ The GNU C Library is distributed in the hope that it will be useful,
+ but WITHOUT ANY WARRANTY; without even the implied warranty of
+ MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the GNU
+ Lesser General Public License for more details.
+
+ You should have received a copy of the GNU Lesser General Public
+ License along with the GNU C Library; if not, see
+ <https://www.gnu.org/licenses/>. */
+
+#include <string.h>
+#include <support/resolv_test.h>
+#include <support/support.h>
+
+struct resolv_response_context *
+resolv_response_context_duplicate (const struct resolv_response_context *ctx)
+{
+ struct resolv_response_context *result = xmalloc (sizeof (*result));
+ memcpy (result, ctx, sizeof (*result));
+ if (result->client_address != NULL)
+ {
+ result->client_address = xmalloc (result->client_address_length);
+ memcpy (result->client_address, ctx->client_address,
+ result->client_address_length);
+ }
+ result->query_buffer = xmalloc (result->query_length);
+ memcpy (result->query_buffer, ctx->query_buffer, result->query_length);
+ return result;
+}
diff --git a/support/resolv_response_context_free.c b/support/resolv_response_context_free.c
new file mode 100644
index 0000000000000000..b88c05ffd4acfdd4
--- /dev/null
+++ b/support/resolv_response_context_free.c
@@ -0,0 +1,28 @@
+/* Free a response context used in DNS resolver tests.
+ Copyright (C) 2020 Free Software Foundation, Inc.
+ This file is part of the GNU C Library.
+
+ The GNU C Library is free software; you can redistribute it and/or
+ modify it under the terms of the GNU Lesser General Public
+ License as published by the Free Software Foundation; either
+ version 2.1 of the License, or (at your option) any later version.
+
+ The GNU C Library is distributed in the hope that it will be useful,
+ but WITHOUT ANY WARRANTY; without even the implied warranty of
+ MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the GNU
+ Lesser General Public License for more details.
+
+ You should have received a copy of the GNU Lesser General Public
+ License along with the GNU C Library; if not, see
+ <https://www.gnu.org/licenses/>. */
+
+#include <stdlib.h>
+#include <support/resolv_test.h>
+
+void
+resolv_response_context_free (struct resolv_response_context *ctx)
+{
+ free (ctx->query_buffer);
+ free (ctx->client_address);
+ free (ctx);
+}
diff --git a/support/resolv_test.c b/support/resolv_test.c
index 28af227cb5ed901c..8cca4e6cf723de28 100644
--- a/support/resolv_test.c
+++ b/support/resolv_test.c
@@ -434,9 +434,9 @@ resolv_response_buffer (const struct resolv_response_builder *b)
return result;
}
-static struct resolv_response_builder *
-response_builder_allocate
- (const unsigned char *query_buffer, size_t query_length)
+struct resolv_response_builder *
+resolv_response_builder_allocate (const unsigned char *query_buffer,
+ size_t query_length)
{
struct resolv_response_builder *b = xmalloc (sizeof (*b));
memset (b, 0, offsetof (struct resolv_response_builder, buffer));
@@ -445,8 +445,8 @@ response_builder_allocate
return b;
}
-static void
-response_builder_free (struct resolv_response_builder *b)
+void
+resolv_response_builder_free (struct resolv_response_builder *b)
{
tdestroy (b->compression_offsets, free);
free (b);
@@ -661,13 +661,17 @@ server_thread_udp_process_one (struct resolv_test *obj, int server_index)
struct resolv_response_context ctx =
{
+ .test = obj,
+ .client_address = &peer,
+ .client_address_length = peerlen,
.query_buffer = query,
.query_length = length,
.server_index = server_index,
.tcp = false,
.edns = qinfo.edns,
};
- struct resolv_response_builder *b = response_builder_allocate (query, length);
+ struct resolv_response_builder *b
+ = resolv_response_builder_allocate (query, length);
obj->config.response_callback
(&ctx, b, qinfo.qname, qinfo.qclass, qinfo.qtype);
@@ -684,7 +688,7 @@ server_thread_udp_process_one (struct resolv_test *obj, int server_index)
if (b->offset >= 12)
printf ("info: UDP server %d: sending response:"
" %zu bytes, RCODE %d (for %s/%u/%u)\n",
- server_index, b->offset, b->buffer[3] & 0x0f,
+ ctx.server_index, b->offset, b->buffer[3] & 0x0f,
qinfo.qname, qinfo.qclass, qinfo.qtype);
else
printf ("info: UDP server %d: sending response: %zu bytes"
@@ -694,23 +698,31 @@ server_thread_udp_process_one (struct resolv_test *obj, int server_index)
if (b->truncate_bytes > 0)
printf ("info: truncated by %u bytes\n", b->truncate_bytes);
}
- size_t to_send = b->offset;
- if (to_send < b->truncate_bytes)
- to_send = 0;
- else
- to_send -= b->truncate_bytes;
-
- /* Ignore most errors here because the other end may have closed
- the socket. */
- if (sendto (obj->servers[server_index].socket_udp,
- b->buffer, to_send, 0,
- (struct sockaddr *) &peer, peerlen) < 0)
- TEST_VERIFY_EXIT (errno != EBADF);
+ resolv_response_send_udp (&ctx, b);
}
- response_builder_free (b);
+ resolv_response_builder_free (b);
return true;
}
+void
+resolv_response_send_udp (const struct resolv_response_context *ctx,
+ struct resolv_response_builder *b)
+{
+ TEST_VERIFY_EXIT (!ctx->tcp);
+ size_t to_send = b->offset;
+ if (to_send < b->truncate_bytes)
+ to_send = 0;
+ else
+ to_send -= b->truncate_bytes;
+
+ /* Ignore most errors here because the other end may have closed
+ the socket. */
+ if (sendto (ctx->test->servers[ctx->server_index].socket_udp,
+ b->buffer, to_send, 0,
+ ctx->client_address, ctx->client_address_length) < 0)
+ TEST_VERIFY_EXIT (errno != EBADF);
+}
+
/* UDP thread_callback function. Variant for one thread per
server. */
static void
@@ -897,14 +909,15 @@ server_thread_tcp_client (void *arg)
struct resolv_response_context ctx =
{
+ .test = closure->obj,
.query_buffer = query_buffer,
.query_length = query_length,
.server_index = closure->server_index,
.tcp = true,
.edns = qinfo.edns,
};
- struct resolv_response_builder *b = response_builder_allocate
- (query_buffer, query_length);
+ struct resolv_response_builder *b
+ = resolv_response_builder_allocate (query_buffer, query_length);
closure->obj->config.response_callback
(&ctx, b, qinfo.qname, qinfo.qclass, qinfo.qtype);
@@ -936,7 +949,7 @@ server_thread_tcp_client (void *arg)
writev_fully (closure->client_socket, buffers, 2);
}
bool close_flag = b->close;
- response_builder_free (b);
+ resolv_response_builder_free (b);
free (query_buffer);
if (close_flag)
break;
diff --git a/support/resolv_test.h b/support/resolv_test.h
index be736aead40cd0cc..ff5571dace92c936 100644
--- a/support/resolv_test.h
+++ b/support/resolv_test.h
@@ -35,25 +35,36 @@ struct resolv_edns_info
uint16_t payload_size;
};
+/* This opaque struct collects information about the resolver testing
+ currently in progress. */
+struct resolv_test;
+
/* This struct provides context information when the response callback
specified in struct resolv_redirect_config is invoked. */
struct resolv_response_context
{
- const unsigned char *query_buffer;
+ struct resolv_test *test;
+ void *client_address;
+ size_t client_address_length;
+ unsigned char *query_buffer;
size_t query_length;
int server_index;
bool tcp;
struct resolv_edns_info edns;
};
+/* Produces a deep copy of the context. */
+struct resolv_response_context *
+ resolv_response_context_duplicate (const struct resolv_response_context *);
+
+/* Frees the copy. For the context passed to the response function,
+ this happens implicitly. */
+void resolv_response_context_free (struct resolv_response_context *);
+
/* This opaque struct is used to construct responses from within the
response callback function. */
struct resolv_response_builder;
-/* This opaque struct collects information about the resolver testing
- currently in progress. */
-struct resolv_test;
-
enum
{
/* Maximum number of test servers supported by the framework. */
@@ -188,6 +199,22 @@ void resolv_response_close (struct resolv_response_builder *);
/* The size of the response packet built so far. */
size_t resolv_response_length (const struct resolv_response_builder *);
+/* Allocates a response builder tied to a specific query packet,
+ starting at QUERY_BUFFER, containing QUERY_LENGTH bytes. */
+struct resolv_response_builder *
+ resolv_response_builder_allocate (const unsigned char *query_buffer,
+ size_t query_length);
+
+/* Deallocates a response buffer. */
+void resolv_response_builder_free (struct resolv_response_builder *);
+
+/* Sends a UDP response using a specific context. This can be used to
+ reorder or duplicate responses, along with
+ resolv_response_context_duplicate and
+ response_builder_allocate. */
+void resolv_response_send_udp (const struct resolv_response_context *,
+ struct resolv_response_builder *);
+
__END_DECLS
#endif /* SUPPORT_RESOLV_TEST_H */