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-rw-r--r--lib/dns/tcpmsg.c239
1 files changed, 239 insertions, 0 deletions
diff --git a/lib/dns/tcpmsg.c b/lib/dns/tcpmsg.c
new file mode 100644
index 0000000..bb2a5d9
--- /dev/null
+++ b/lib/dns/tcpmsg.c
@@ -0,0 +1,239 @@
+/*
+ * Copyright (C) Internet Systems Consortium, Inc. ("ISC")
+ *
+ * This Source Code Form is subject to the terms of the Mozilla Public
+ * License, v. 2.0. If a copy of the MPL was not distributed with this
+ * file, You can obtain one at http://mozilla.org/MPL/2.0/.
+ *
+ * See the COPYRIGHT file distributed with this work for additional
+ * information regarding copyright ownership.
+ */
+
+
+/*! \file */
+
+#include <config.h>
+
+#include <inttypes.h>
+
+#include <isc/mem.h>
+#include <isc/print.h>
+#include <isc/task.h>
+#include <isc/util.h>
+
+#include <dns/events.h>
+#include <dns/result.h>
+#include <dns/tcpmsg.h>
+
+#ifdef TCPMSG_DEBUG
+#include <stdio.h> /* Required for printf. */
+#define XDEBUG(x) printf x
+#else
+#define XDEBUG(x)
+#endif
+
+#define TCPMSG_MAGIC ISC_MAGIC('T', 'C', 'P', 'm')
+#define VALID_TCPMSG(foo) ISC_MAGIC_VALID(foo, TCPMSG_MAGIC)
+
+static void recv_length(isc_task_t *, isc_event_t *);
+static void recv_message(isc_task_t *, isc_event_t *);
+
+
+static void
+recv_length(isc_task_t *task, isc_event_t *ev_in) {
+ isc_socketevent_t *ev = (isc_socketevent_t *)ev_in;
+ isc_event_t *dev;
+ dns_tcpmsg_t *tcpmsg = ev_in->ev_arg;
+ isc_region_t region;
+ isc_result_t result;
+
+ INSIST(VALID_TCPMSG(tcpmsg));
+
+ dev = &tcpmsg->event;
+ tcpmsg->address = ev->address;
+
+ if (ev->result != ISC_R_SUCCESS) {
+ tcpmsg->result = ev->result;
+ goto send_and_free;
+ }
+
+ /*
+ * Success.
+ */
+ tcpmsg->size = ntohs(tcpmsg->size);
+ if (tcpmsg->size == 0) {
+ tcpmsg->result = ISC_R_UNEXPECTEDEND;
+ goto send_and_free;
+ }
+ if (tcpmsg->size > tcpmsg->maxsize) {
+ tcpmsg->result = ISC_R_RANGE;
+ goto send_and_free;
+ }
+
+ region.base = isc_mem_get(tcpmsg->mctx, tcpmsg->size);
+ region.length = tcpmsg->size;
+ if (region.base == NULL) {
+ tcpmsg->result = ISC_R_NOMEMORY;
+ goto send_and_free;
+ }
+ XDEBUG(("Allocated %d bytes\n", tcpmsg->size));
+
+ isc_buffer_init(&tcpmsg->buffer, region.base, region.length);
+ result = isc_socket_recv(tcpmsg->sock, &region, 0,
+ task, recv_message, tcpmsg);
+ if (result != ISC_R_SUCCESS) {
+ tcpmsg->result = result;
+ goto send_and_free;
+ }
+
+ isc_event_free(&ev_in);
+ return;
+
+ send_and_free:
+ isc_task_send(tcpmsg->task, &dev);
+ tcpmsg->task = NULL;
+ isc_event_free(&ev_in);
+ return;
+}
+
+static void
+recv_message(isc_task_t *task, isc_event_t *ev_in) {
+ isc_socketevent_t *ev = (isc_socketevent_t *)ev_in;
+ isc_event_t *dev;
+ dns_tcpmsg_t *tcpmsg = ev_in->ev_arg;
+
+ (void)task;
+
+ INSIST(VALID_TCPMSG(tcpmsg));
+
+ dev = &tcpmsg->event;
+ tcpmsg->address = ev->address;
+
+ if (ev->result != ISC_R_SUCCESS) {
+ tcpmsg->result = ev->result;
+ goto send_and_free;
+ }
+
+ tcpmsg->result = ISC_R_SUCCESS;
+ isc_buffer_add(&tcpmsg->buffer, ev->n);
+
+ XDEBUG(("Received %u bytes (of %d)\n", ev->n, tcpmsg->size));
+
+ send_and_free:
+ isc_task_send(tcpmsg->task, &dev);
+ tcpmsg->task = NULL;
+ isc_event_free(&ev_in);
+}
+
+void
+dns_tcpmsg_init(isc_mem_t *mctx, isc_socket_t *sock, dns_tcpmsg_t *tcpmsg) {
+ REQUIRE(mctx != NULL);
+ REQUIRE(sock != NULL);
+ REQUIRE(tcpmsg != NULL);
+
+ tcpmsg->magic = TCPMSG_MAGIC;
+ tcpmsg->size = 0;
+ tcpmsg->buffer.base = NULL;
+ tcpmsg->buffer.length = 0;
+ tcpmsg->maxsize = 65535; /* Largest message possible. */
+ tcpmsg->mctx = mctx;
+ tcpmsg->sock = sock;
+ tcpmsg->task = NULL; /* None yet. */
+ tcpmsg->result = ISC_R_UNEXPECTED; /* None yet. */
+ /*
+ * Should probably initialize the event here, but it can wait.
+ */
+}
+
+
+void
+dns_tcpmsg_setmaxsize(dns_tcpmsg_t *tcpmsg, unsigned int maxsize) {
+ REQUIRE(VALID_TCPMSG(tcpmsg));
+ REQUIRE(maxsize < 65536);
+
+ tcpmsg->maxsize = maxsize;
+}
+
+
+isc_result_t
+dns_tcpmsg_readmessage(dns_tcpmsg_t *tcpmsg,
+ isc_task_t *task, isc_taskaction_t action, void *arg)
+{
+ isc_result_t result;
+ isc_region_t region;
+
+ REQUIRE(VALID_TCPMSG(tcpmsg));
+ REQUIRE(task != NULL);
+ REQUIRE(tcpmsg->task == NULL); /* not currently in use */
+
+ if (tcpmsg->buffer.base != NULL) {
+ isc_mem_put(tcpmsg->mctx, tcpmsg->buffer.base,
+ tcpmsg->buffer.length);
+ tcpmsg->buffer.base = NULL;
+ tcpmsg->buffer.length = 0;
+ }
+
+ tcpmsg->task = task;
+ tcpmsg->action = action;
+ tcpmsg->arg = arg;
+ tcpmsg->result = ISC_R_UNEXPECTED; /* unknown right now */
+
+ ISC_EVENT_INIT(&tcpmsg->event, sizeof(isc_event_t), 0, 0,
+ DNS_EVENT_TCPMSG, action, arg, tcpmsg,
+ NULL, NULL);
+
+ region.base = (unsigned char *)&tcpmsg->size;
+ region.length = 2; /* uint16_t */
+ result = isc_socket_recv(tcpmsg->sock, &region, 0,
+ tcpmsg->task, recv_length, tcpmsg);
+
+ if (result != ISC_R_SUCCESS)
+ tcpmsg->task = NULL;
+
+ return (result);
+}
+
+void
+dns_tcpmsg_cancelread(dns_tcpmsg_t *tcpmsg) {
+ REQUIRE(VALID_TCPMSG(tcpmsg));
+
+ isc_socket_cancel(tcpmsg->sock, NULL, ISC_SOCKCANCEL_RECV);
+}
+
+void
+dns_tcpmsg_keepbuffer(dns_tcpmsg_t *tcpmsg, isc_buffer_t *buffer) {
+ REQUIRE(VALID_TCPMSG(tcpmsg));
+ REQUIRE(buffer != NULL);
+
+ *buffer = tcpmsg->buffer;
+ tcpmsg->buffer.base = NULL;
+ tcpmsg->buffer.length = 0;
+}
+
+#if 0
+void
+dns_tcpmsg_freebuffer(dns_tcpmsg_t *tcpmsg) {
+ REQUIRE(VALID_TCPMSG(tcpmsg));
+
+ if (tcpmsg->buffer.base == NULL)
+ return;
+
+ isc_mem_put(tcpmsg->mctx, tcpmsg->buffer.base, tcpmsg->buffer.length);
+ tcpmsg->buffer.base = NULL;
+ tcpmsg->buffer.length = 0;
+}
+#endif
+
+void
+dns_tcpmsg_invalidate(dns_tcpmsg_t *tcpmsg) {
+ REQUIRE(VALID_TCPMSG(tcpmsg));
+
+ tcpmsg->magic = 0;
+
+ if (tcpmsg->buffer.base != NULL) {
+ isc_mem_put(tcpmsg->mctx, tcpmsg->buffer.base,
+ tcpmsg->buffer.length);
+ tcpmsg->buffer.base = NULL;
+ tcpmsg->buffer.length = 0;
+ }
+}