Add qemu 2.4.0

Change-Id: Ic99cbad4b61f8b127b7dc74d04576c0bcbaaf4f5
Signed-off-by: Yang Zhang <yang.z.zhang@intel.com>

1 files changed, 237 insertions, 0 deletions

diff --git a/qemu/slirp/if.c b/qemu/slirp/if.c
new file mode 100644
index 000000000..fb7acf87d
--- /dev/null
+++ b/qemu/slirp/if.c
@@ -0,0 +1,237 @@
+/*
+ * Copyright (c) 1995 Danny Gasparovski.
+ *
+ * Please read the file COPYRIGHT for the
+ * terms and conditions of the copyright.
+ */
+
+#include <slirp.h>
+#include "qemu/timer.h"
+
+static void
+ifs_insque(struct mbuf *ifm, struct mbuf *ifmhead)
+{
+	ifm->ifs_next = ifmhead->ifs_next;
+	ifmhead->ifs_next = ifm;
+	ifm->ifs_prev = ifmhead;
+	ifm->ifs_next->ifs_prev = ifm;
+}
+
+static void
+ifs_remque(struct mbuf *ifm)
+{
+	ifm->ifs_prev->ifs_next = ifm->ifs_next;
+	ifm->ifs_next->ifs_prev = ifm->ifs_prev;
+}
+
+void
+if_init(Slirp *slirp)
+{
+    slirp->if_fastq.ifq_next = slirp->if_fastq.ifq_prev = &slirp->if_fastq;
+    slirp->if_batchq.ifq_next = slirp->if_batchq.ifq_prev = &slirp->if_batchq;
+    slirp->next_m = &slirp->if_batchq;
+}
+
+/*
+ * if_output: Queue packet into an output queue.
+ * There are 2 output queue's, if_fastq and if_batchq.
+ * Each output queue is a doubly linked list of double linked lists
+ * of mbufs, each list belonging to one "session" (socket).  This
+ * way, we can output packets fairly by sending one packet from each
+ * session, instead of all the packets from one session, then all packets
+ * from the next session, etc.  Packets on the if_fastq get absolute
+ * priority, but if one session hogs the link, it gets "downgraded"
+ * to the batchq until it runs out of packets, then it'll return
+ * to the fastq (eg. if the user does an ls -alR in a telnet session,
+ * it'll temporarily get downgraded to the batchq)
+ */
+void
+if_output(struct socket *so, struct mbuf *ifm)
+{
+	Slirp *slirp = ifm->slirp;
+	struct mbuf *ifq;
+	int on_fastq = 1;
+
+	DEBUG_CALL("if_output");
+	DEBUG_ARG("so = %lx", (long)so);
+	DEBUG_ARG("ifm = %lx", (long)ifm);
+
+	/*
+	 * First remove the mbuf from m_usedlist,
+	 * since we're gonna use m_next and m_prev ourselves
+	 * XXX Shouldn't need this, gotta change dtom() etc.
+	 */
+	if (ifm->m_flags & M_USEDLIST) {
+		remque(ifm);
+		ifm->m_flags &= ~M_USEDLIST;
+	}
+
+	/*
+	 * See if there's already a batchq list for this session.
+	 * This can include an interactive session, which should go on fastq,
+	 * but gets too greedy... hence it'll be downgraded from fastq to batchq.
+	 * We mustn't put this packet back on the fastq (or we'll send it out of order)
+	 * XXX add cache here?
+	 */
+	for (ifq = slirp->if_batchq.ifq_prev; ifq != &slirp->if_batchq;
+	     ifq = ifq->ifq_prev) {
+		if (so == ifq->ifq_so) {
+			/* A match! */
+			ifm->ifq_so = so;
+			ifs_insque(ifm, ifq->ifs_prev);
+			goto diddit;
+		}
+	}
+
+	/* No match, check which queue to put it on */
+	if (so && (so->so_iptos & IPTOS_LOWDELAY)) {
+		ifq = slirp->if_fastq.ifq_prev;
+		on_fastq = 1;
+		/*
+		 * Check if this packet is a part of the last
+		 * packet's session
+		 */
+		if (ifq->ifq_so == so) {
+			ifm->ifq_so = so;
+			ifs_insque(ifm, ifq->ifs_prev);
+			goto diddit;
+		}
+        } else {
+		ifq = slirp->if_batchq.ifq_prev;
+                /* Set next_m if the queue was empty so far */
+                if (slirp->next_m == &slirp->if_batchq) {
+                    slirp->next_m = ifm;
+                }
+        }
+
+	/* Create a new doubly linked list for this session */
+	ifm->ifq_so = so;
+	ifs_init(ifm);
+	insque(ifm, ifq);
+
+diddit:
+	if (so) {
+		/* Update *_queued */
+		so->so_queued++;
+		so->so_nqueued++;
+		/*
+		 * Check if the interactive session should be downgraded to
+		 * the batchq.  A session is downgraded if it has queued 6
+		 * packets without pausing, and at least 3 of those packets
+		 * have been sent over the link
+		 * (XXX These are arbitrary numbers, probably not optimal..)
+		 */
+		if (on_fastq && ((so->so_nqueued >= 6) &&
+				 (so->so_nqueued - so->so_queued) >= 3)) {
+
+			/* Remove from current queue... */
+			remque(ifm->ifs_next);
+
+			/* ...And insert in the new.  That'll teach ya! */
+			insque(ifm->ifs_next, &slirp->if_batchq);
+		}
+	}
+
+#ifndef FULL_BOLT
+	/*
+	 * This prevents us from malloc()ing too many mbufs
+	 */
+	if_start(ifm->slirp);
+#endif
+}
+
+/*
+ * Send a packet
+ * We choose a packet based on its position in the output queues;
+ * If there are packets on the fastq, they are sent FIFO, before
+ * everything else.  Otherwise we choose the first packet from the
+ * batchq and send it.  the next packet chosen will be from the session
+ * after this one, then the session after that one, and so on..  So,
+ * for example, if there are 3 ftp session's fighting for bandwidth,
+ * one packet will be sent from the first session, then one packet
+ * from the second session, then one packet from the third, then back
+ * to the first, etc. etc.
+ */
+void if_start(Slirp *slirp)
+{
+    uint64_t now = qemu_clock_get_ns(QEMU_CLOCK_REALTIME);
+    bool from_batchq, next_from_batchq;
+    struct mbuf *ifm, *ifm_next, *ifqt;
+
+    DEBUG_CALL("if_start");
+
+    if (slirp->if_start_busy) {
+        return;
+    }
+    slirp->if_start_busy = true;
+
+    if (slirp->if_fastq.ifq_next != &slirp->if_fastq) {
+        ifm_next = slirp->if_fastq.ifq_next;
+        next_from_batchq = false;
+    } else if (slirp->next_m != &slirp->if_batchq) {
+        /* Nothing on fastq, pick up from batchq via next_m */
+        ifm_next = slirp->next_m;
+        next_from_batchq = true;
+    } else {
+        ifm_next = NULL;
+    }
+
+    while (ifm_next) {
+        ifm = ifm_next;
+        from_batchq = next_from_batchq;
+
+        ifm_next = ifm->ifq_next;
+        if (ifm_next == &slirp->if_fastq) {
+            /* No more packets in fastq, switch to batchq */
+            ifm_next = slirp->next_m;
+            next_from_batchq = true;
+        }
+        if (ifm_next == &slirp->if_batchq) {
+            /* end of batchq */
+            ifm_next = NULL;
+        }
+
+        /* Try to send packet unless it already expired */
+        if (ifm->expiration_date >= now && !if_encap(slirp, ifm)) {
+            /* Packet is delayed due to pending ARP resolution */
+            continue;
+        }
+
+        if (ifm == slirp->next_m) {
+            /* Set which packet to send on next iteration */
+            slirp->next_m = ifm->ifq_next;
+        }
+
+        /* Remove it from the queue */
+        ifqt = ifm->ifq_prev;
+        remque(ifm);
+
+        /* If there are more packets for this session, re-queue them */
+        if (ifm->ifs_next != ifm) {
+            struct mbuf *next = ifm->ifs_next;
+
+            insque(next, ifqt);
+            ifs_remque(ifm);
+
+            if (!from_batchq) {
+                /* Next packet in fastq is from the same session */
+                ifm_next = next;
+                next_from_batchq = false;
+            } else if (slirp->next_m == &slirp->if_batchq) {
+                /* Set next_m and ifm_next if the session packet is now the
+                 * only one on batchq */
+                slirp->next_m = ifm_next = next;
+            }
+        }
+
+        /* Update so_queued */
+        if (ifm->ifq_so && --ifm->ifq_so->so_queued == 0) {
+            /* If there's no more queued, reset nqueued */
+            ifm->ifq_so->so_nqueued = 0;
+        }
+
+        m_free(ifm);
+    }
+
+    slirp->if_start_busy = false;
+}