initial user mode network support

git-svn-id: svn://svn.savannah.nongnu.org/qemu/trunk@733 c046a42c-6fe2-441c-8c8c-71466251a162

1 files changed, 320 insertions, 0 deletions

diff --git a/slirp/if.c b/slirp/if.c
new file mode 100644
index 0000000000..282b674c5e
--- /dev/null
+++ b/slirp/if.c
@@ -0,0 +1,320 @@
+/*
+ * Copyright (c) 1995 Danny Gasparovski.
+ *
+ * Please read the file COPYRIGHT for the
+ * terms and conditions of the copyright.
+ */
+
+#include <slirp.h>
+
+int if_mtu, if_mru;
+int if_comp;
+int if_maxlinkhdr;
+int     if_queued = 0;                  /* Number of packets queued so far */
+int     if_thresh = 10;                 /* Number of packets queued before we start sending
+					 * (to prevent allocing too many mbufs) */
+
+struct  mbuf if_fastq;                  /* fast queue (for interactive data) */
+struct  mbuf if_batchq;                 /* queue for non-interactive data */
+struct	mbuf *next_m;			/* Pointer to next mbuf to output */
+
+#define ifs_init(ifm) ((ifm)->ifs_next = (ifm)->ifs_prev = (ifm))
+
+void
+ifs_insque(ifm, ifmhead)
+	struct mbuf *ifm, *ifmhead;
+{
+	ifm->ifs_next = ifmhead->ifs_next;
+	ifmhead->ifs_next = ifm;
+	ifm->ifs_prev = ifmhead;
+	ifm->ifs_next->ifs_prev = ifm;
+}
+
+void
+ifs_remque(ifm)
+	struct mbuf *ifm;
+{
+	ifm->ifs_prev->ifs_next = ifm->ifs_next;
+	ifm->ifs_next->ifs_prev = ifm->ifs_prev;
+}
+
+void
+if_init()
+{
+#if 0
+	/*
+	 * Set if_maxlinkhdr to 48 because it's 40 bytes for TCP/IP,
+	 * and 8 bytes for PPP, but need to have it on an 8byte boundary
+	 */
+#ifdef USE_PPP
+	if_maxlinkhdr = 48;
+#else
+	if_maxlinkhdr = 40;
+#endif
+#else
+        /* 14 for ethernet + 40 */
+        if_maxlinkhdr = 14 + 40;
+#endif
+	if_mtu = 1500;
+	if_mru = 1500;
+	if_comp = IF_AUTOCOMP;
+	if_fastq.ifq_next = if_fastq.ifq_prev = &if_fastq;
+	if_batchq.ifq_next = if_batchq.ifq_prev = &if_batchq;
+        //	sl_compress_init(&comp_s);
+	next_m = &if_batchq;
+}
+
+#if 0
+/*
+ * This shouldn't be needed since the modem is blocking and
+ * we don't expect any signals, but what the hell..
+ */
+inline int
+writen(fd, bptr, n)
+	int fd;
+	char *bptr;
+	int n;
+{
+	int ret;
+	int total;
+	
+	/* This should succeed most of the time */
+	ret = write(fd, bptr, n);
+	if (ret == n || ret <= 0)
+	   return ret;
+	
+	/* Didn't write everything, go into the loop */
+	total = ret;
+	while (n > total) {
+		ret = write(fd, bptr+total, n-total);
+		if (ret <= 0)
+		   return ret;
+		total += ret;
+	}
+	return total;
+}
+
+/*
+ * if_input - read() the tty, do "top level" processing (ie: check for any escapes),
+ * and pass onto (*ttyp->if_input)
+ * 
+ * XXXXX Any zeros arriving by themselves are NOT placed into the arriving packet.
+ */
+#define INBUFF_SIZE 2048 /* XXX */
+void
+if_input(ttyp)
+	struct ttys *ttyp;
+{
+	u_char if_inbuff[INBUFF_SIZE];
+	int if_n;
+	
+	DEBUG_CALL("if_input");
+	DEBUG_ARG("ttyp = %lx", (long)ttyp);
+	
+	if_n = read(ttyp->fd, (char *)if_inbuff, INBUFF_SIZE);
+	
+	DEBUG_MISC((dfd, " read %d bytes\n", if_n));
+	
+	if (if_n <= 0) {
+		if (if_n == 0 || (errno != EINTR && errno != EAGAIN)) {
+			if (ttyp->up)
+			   link_up--;
+			tty_detached(ttyp, 0);
+		}
+		return;
+	}
+	if (if_n == 1) {
+		if (*if_inbuff == '0') {
+			ttyp->ones = 0;
+			if (++ttyp->zeros >= 5)
+			   slirp_exit(0);
+			return;
+		}
+		if (*if_inbuff == '1') {
+			ttyp->zeros = 0;
+			if (++ttyp->ones >= 5)
+			   tty_detached(ttyp, 0);
+			return;
+		}
+	}
+	ttyp->ones = ttyp->zeros = 0;
+	
+	(*ttyp->if_input)(ttyp, if_inbuff, if_n);
+}
+#endif	
+	
+/*
+ * 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(so, ifm)
+	struct socket *so;
+	struct mbuf *ifm;
+{
+	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 = if_batchq.ifq_prev; ifq != &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 = 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 = if_batchq.ifq_prev;
+	
+	/* Create a new doubly linked list for this session */
+	ifm->ifq_so = so;
+	ifs_init(ifm);
+	insque(ifm, ifq);
+	
+diddit:
+	++if_queued;
+	
+	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, &if_batchq);
+		}
+	}
+
+#ifndef FULL_BOLT
+	/*
+	 * This prevents us from malloc()ing too many mbufs
+	 */
+	if (link_up) {
+		/* if_start will check towrite */
+		if_start();
+	}
+#endif
+}
+
+/*
+ * Send a packet
+ * We choose a packet based on it's 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(void)
+{
+	struct mbuf *ifm, *ifqt;
+	
+	DEBUG_CALL("if_start");
+	
+	if (if_queued == 0)
+	   return; /* Nothing to do */
+	
+ again:
+        /* check if we can really output */
+        if (!slirp_can_output())
+            return;
+
+	/*
+	 * See which queue to get next packet from
+	 * If there's something in the fastq, select it immediately
+	 */
+	if (if_fastq.ifq_next != &if_fastq) {
+		ifm = if_fastq.ifq_next;
+	} else {
+		/* Nothing on fastq, see if next_m is valid */
+		if (next_m != &if_batchq)
+		   ifm = next_m;
+		else
+		   ifm = if_batchq.ifq_next;
+		
+		/* Set which packet to send on next iteration */
+		next_m = ifm->ifq_next;
+	}
+	/* Remove it from the queue */
+	ifqt = ifm->ifq_prev;
+	remque(ifm);
+	--if_queued;
+	
+	/* If there are more packets for this session, re-queue them */
+	if (ifm->ifs_next != /* ifm->ifs_prev != */ ifm) {
+		insque(ifm->ifs_next, ifqt);
+		ifs_remque(ifm);
+	}
+	
+	/* Update so_queued */
+	if (ifm->ifq_so) {
+		if (--ifm->ifq_so->so_queued == 0)
+		   /* If there's no more queued, reset nqueued */
+		   ifm->ifq_so->so_nqueued = 0;
+	}
+	
+	/* Encapsulate the packet for sending */
+        if_encap(ifm->m_data, ifm->m_len);
+
+	if (if_queued)
+	   goto again;
+}