Move low-level functions out into sshcommon.c.

These are essentially data-structure maintenance, and it seems silly
to have them be part of the same file that manages the topmost
structure of the SSH connection.

sshcommon.c

@@ -0,0 +1,161 @@
+/*
+ * Supporting routines used in common by all the various components of
+ * the SSH system.
+ */
+
+#include <assert.h>
+
+#include "ssh.h"
+#include "sshchan.h"
+
+/* ----------------------------------------------------------------------
+ * Implementation of PacketQueue.
+ */
+
+void pq_base_push(PacketQueueBase *pqb, PacketQueueNode *node)
+{
+    assert(!node->next);
+    assert(!node->prev);
+    node->next = &pqb->end;
+    node->prev = pqb->end.prev;
+    node->next->prev = node;
+    node->prev->next = node;
+}
+
+void pq_base_push_front(PacketQueueBase *pqb, PacketQueueNode *node)
+{
+    assert(!node->next);
+    assert(!node->prev);
+    node->prev = &pqb->end;
+    node->next = pqb->end.next;
+    node->next->prev = node;
+    node->prev->next = node;
+}
+
+static PktIn *pq_in_get(PacketQueueBase *pqb, int pop)
+{
+    PacketQueueNode *node = pqb->end.next;
+    if (node == &pqb->end)
+        return NULL;
+
+    if (pop) {
+        node->next->prev = node->prev;
+        node->prev->next = node->next;
+        node->prev = node->next = NULL;
+    }
+
+    return FROMFIELD(node, PktIn, qnode);
+}
+
+static PktOut *pq_out_get(PacketQueueBase *pqb, int pop)
+{
+    PacketQueueNode *node = pqb->end.next;
+    if (node == &pqb->end)
+        return NULL;
+
+    if (pop) {
+        node->next->prev = node->prev;
+        node->prev->next = node->next;
+        node->prev = node->next = NULL;
+    }
+
+    return FROMFIELD(node, PktOut, qnode);
+}
+
+void pq_in_init(PktInQueue *pq)
+{
+    pq->pqb.end.next = pq->pqb.end.prev = &pq->pqb.end;
+    pq->get = pq_in_get;
+}
+
+void pq_out_init(PktOutQueue *pq)
+{
+    pq->pqb.end.next = pq->pqb.end.prev = &pq->pqb.end;
+    pq->get = pq_out_get;
+}
+
+void pq_in_clear(PktInQueue *pq)
+{
+    PktIn *pkt;
+    while ((pkt = pq_pop(pq)) != NULL)
+        ssh_unref_packet(pkt);
+}
+
+void pq_out_clear(PktOutQueue *pq)
+{
+    PktOut *pkt;
+    while ((pkt = pq_pop(pq)) != NULL)
+        ssh_free_pktout(pkt);
+}
+
+int pq_base_empty_on_to_front_of(PacketQueueBase *src, PacketQueueBase *dest)
+{
+    struct PacketQueueNode *srcfirst, *srclast;
+
+    if (src->end.next == &src->end)
+        return FALSE;
+
+    srcfirst = src->end.next;
+    srclast = src->end.prev;
+    srcfirst->prev = &dest->end;
+    srclast->next = dest->end.next;
+    srcfirst->prev->next = srcfirst;
+    srclast->next->prev = srclast;
+    src->end.next = src->end.prev = &src->end;
+
+    return TRUE;
+}
+
+/* ----------------------------------------------------------------------
+ * Low-level functions for the packet structures themselves.
+ */
+
+static void ssh_pkt_BinarySink_write(BinarySink *bs,
+                                     const void *data, size_t len);
+PktOut *ssh_new_packet(void)
+{
+    PktOut *pkt = snew(PktOut);
+
+    BinarySink_INIT(pkt, ssh_pkt_BinarySink_write);
+    pkt->data = NULL;
+    pkt->length = 0;
+    pkt->maxlen = 0;
+    pkt->downstream_id = 0;
+    pkt->additional_log_text = NULL;
+    pkt->qnode.next = pkt->qnode.prev = NULL;
+
+    return pkt;
+}
+
+static void ssh_pkt_ensure(PktOut *pkt, int length)
+{
+    if (pkt->maxlen < length) {
+        pkt->maxlen = length + 256;
+        pkt->data = sresize(pkt->data, pkt->maxlen, unsigned char);
+    }
+}
+static void ssh_pkt_adddata(PktOut *pkt, const void *data, int len)
+{
+    pkt->length += len;
+    ssh_pkt_ensure(pkt, pkt->length);
+    memcpy(pkt->data + pkt->length - len, data, len);
+}
+
+static void ssh_pkt_BinarySink_write(BinarySink *bs,
+                                     const void *data, size_t len)
+{
+    PktOut *pkt = BinarySink_DOWNCAST(bs, PktOut);
+    ssh_pkt_adddata(pkt, data, len);
+}
+
+void ssh_unref_packet(PktIn *pkt)
+{
+    if (--pkt->refcount <= 0)
+        sfree(pkt);
+}
+
+void ssh_free_pktout(PktOut *pkt)
+{
+    sfree(pkt->data);
+    sfree(pkt);
+}